Interest in the dynamics of soil respiration(R_(S))in subalpine forest ecosystems is increasing due to their high soil carbon density and potential sensitivity to environmental changes.However,as a principal silvicult...Interest in the dynamics of soil respiration(R_(S))in subalpine forest ecosystems is increasing due to their high soil carbon density and potential sensitivity to environmental changes.However,as a principal silvicultural practice,the long-term impacts of thinning on R_(S) and its heterotrophic and autotrophic respiration components(R_(h) and Ra,respectively)in subalpine plantations are poorly understood,espe-cially in winter.A 3-year field observation was carried out with consideration of winter CO_(2) efflux in middle-aged sub-alpine spruce plantations in northwestern China.A trench-ing method was used to explore the long-term impacts of thinning on Rs,Rn and R_(a).Seventeen years after thinning,mean annual Rs,Rn and R_(a) increased,while the contribu-tion of R_(h) to R_(s) decreased with thinning intensity.Thinning significantly decreased winter R,because of the reduction in R_(n) but had no significant effect on Ra.The temperature sensitivity(Q_(10))of R_(h) and R_(a) also increased with thinning intensity,with lower Q_(10) values for R_(h)(2.1-2.6)than for Ra(2.4-2.8).The results revealed the explanatory variables and pathways related to R_(n) and R_(a) dynamics.Thinning increased soil moisture and nitrate nitrogen(NO_(3)^(-)-N),and the enhanced nitrogen and water availability promoted R_(h) and R_(a) by improving fine root biomass and microbial activity.Our results highlight the positive roles of NO_(3)^(-)-N in stimulating R_(s) components following long-term thinning.Therefore,applications of nitrogen fertilizer are not recommended while thinning subalpine spruce plantations from the perspective of reducing soil CO_(2) emissions.The increased Q_(10) values of R_(s) components indicate that a large increase in soil CO_(2) emissions would be expected following thinning because of more pronounced climate warming in alpineregions.展开更多
The function of exogenous alanine(Ala)in regulating biomass accumulation,lipid production,photosynthesis,and respiration in Chlorella pyrenoidosa was studied.Result shows that the supplementation of Ala increased C.py...The function of exogenous alanine(Ala)in regulating biomass accumulation,lipid production,photosynthesis,and respiration in Chlorella pyrenoidosa was studied.Result shows that the supplementation of Ala increased C.pyrenoidosa biomass and lipid production in an 8-d batch culture.The concentration of 10 mmol/L of Ala was optimum and increased the microalgal cell biomass and lipid content by 39.3%and 21.4%,respectively,compared with that in the control(0-mmol/L Ala).Ala supplementation reduced photosynthetic activity while boosting respiratory activity and pyruvate levels,indicating that C.pyrenoidosa used exogenous Ala for biomass accumulation through the respiratory metabolic process.The accelerated respiratory metabolism due to Ala supplementation elevated the substrate pool and improved the lipogenic gene expression,promoting lipid production at last.This study provided a novel method for increasing biomass accumulation and lipid production and elucidated the role of Ala in regulating lipid production.展开更多
Rhizobium tropici-derived extracellular polymeric substances (EPS) have been used in soils to enhance soil structures and mitigate soil erosions. However, information on their use to improve soil health and fertility ...Rhizobium tropici-derived extracellular polymeric substances (EPS) have been used in soils to enhance soil structures and mitigate soil erosions. However, information on their use to improve soil health and fertility indicators, and plant growth is limited. In a greenhouse study, we investigated their effects on some soil health, soil fertility indices, and the growth of black-eyed peas (Vigna unguiculate). Results showed that soils incubated with EPS significantly increased basal soil respiration, soil microbial biomass, permanganate oxidizable carbon (POC), and potentially mineralizable nitrogen (PMN). The EPS shifted microbial populations from bacteria to fungi and Gram (−ve) to Gram ( ve) bacteria. However, it had little or no effects on soil pH, soil organic matter (SOM), and cation exchange capacity (CEC). The EPS decreased soil moisture loss, increased soil aggregate stability, but delayed blacked-eyed peas germinations in the soils. At 0.1% (w/w) concentrations in soils, there was increase in plant root nodulations and vegetative growth. This study was carried out within 40 days of incubating soils with EPS or growing the black-eyed peas in a greenhouse study. The plant growth parameters were taken before flowering and fruiting. Further studies of the effects of incubating soils with the extracellular polymeric substances on plant growth. Soil microbial biomass, microbial diversities, and other soil fertility indices are deemed necessary.展开更多
Moso bamboo(Phyllostachys Pubescens)expansion into adjacent forests has been widely reported to affect plant diversity and its association with mycorrhizal fungi in subtropical China,which will likely have significant...Moso bamboo(Phyllostachys Pubescens)expansion into adjacent forests has been widely reported to affect plant diversity and its association with mycorrhizal fungi in subtropical China,which will likely have significant impacts on soil respiration.However,there is still limited information on how Moso bamboo expansion changes soil respiration components and their linkage with microbial community composition and activity.Based on a mesh exclusion method,soil respirations derived from roots,arbuscular mycorrhizal(AM)mycelium,and free-living microbes were investigated in a pure Moso bamboo forest(expanded),an adjacent broadleaved forest(nonexpanded),and a mixed bamboo-broadleaved forest(expanding).Our results showed that bamboo expansion decreased the cumulative CO_(2)effluxes from total soil respiration,root respiration and soil heterotrophic respiration(by 19.01%,30.34%,and 29.92%on average),whereas increased those from AM mycelium(by 78.67%in comparison with the broadleaved forests).Bamboo expansion significantly decreased soil organic carbon(C)content,bacterial and fungal abundances,and enzyme activities involved in C,N and P cycling whereas enhanced the interactive relationships among bacterial communities.In contrast,the ingrowth of AM mycelium increased the activities ofβ-glucosidase and N-acetyl-β-glucosaminidase and decreased the interactive relationships among bacterial communities.Changes in soil heterotrophic respiration and AM mycelium respiration had positive correlations with soil enzyme activities and fungal abundances.In summary,our findings suggest that bamboo expansion decreased soil heterotrophic respiration by decreasing soil microbial activity but increased the contribution of AM mycelial respiration to soil C efflux,which may potentially increase soil C loss from AM mycelial pathway.展开更多
Chinese hickory(Carya cathayensis Sarg.)is a popular nut tree in China,but there is little information about the influences of fertilization on soil CO_(2) efflux and soil microbial biomass.This study evaluated the sh...Chinese hickory(Carya cathayensis Sarg.)is a popular nut tree in China,but there is little information about the influences of fertilization on soil CO_(2) efflux and soil microbial biomass.This study evaluated the short-term effects of different fertilizer applications on soil CO_(2) efflux and soil microbial biomass in Chinese hickory stands.Four fertilizer treatments were established:control(CK,no fertilizer),inorganic fertilizer(IF),organic fertilizer(OF),and equal parts organic and inorganic N fertilizers(OIF).A field experiment was conducted to measure soil CO_(2) effluxes using closed chamber and gas chromatography techniques.Regardless of the fertilization practices,soil CO_(2) effluxes of all the treatments showed a similar temporal pattern,with the highest value in summer and the lowest in winter.The mean annual soil CO_(2) efflux in the IF treatment was significantly higher than that in the CK,OIF,and OF treatments.There was no significant difference in soil CO_(2) efflux between the OIF,OF,and CK treatments.Soil CO_(2) effluxes were significantly affected by soil temperature.Soil dissolved organic carbon(DOC)was positively correlated with soil CO_(2) efflux only in the CK treatment.Regression analysis,including soil temperature,moisture,and DOC,showed that soil temperature was the primary factor influencing soil CO_(2) effluxes.Both OF and OIF treatments increased concentrations of soil microbial biomass carbon(MBC)and microbial biomass nitrogen(MBN),but decreased the ratio of MBC:MBN.These results reveal that applying organic fertilizer,either alone or combined with inorganic fertilizer,may be the optimal strategy for mitigating soil CO_(2) emission and improving soil quality in Chinese hickory stands.展开更多
Changes in precipitation and nitrogen(N)addition may significantly affect the processes of soil carbon(C)cycle in terrestrial ecosystems,such as soil respiration.However,relatively few studies have investigated the ef...Changes in precipitation and nitrogen(N)addition may significantly affect the processes of soil carbon(C)cycle in terrestrial ecosystems,such as soil respiration.However,relatively few studies have investigated the effects of changes in precipitation and N addition on soil respiration in the upper soil layer in desert steppes.In this study,we conducted a control experiment that involved a field simulation from July 2020 to December 2021 in a desert steppe in Yanchi County,China.Specifically,we measured soil parameters including soil temperature,soil moisture,total nitrogen(TN),soil organic carbon(SOC),soil microbial biomass carbon(SMBC),soil microbial biomass nitrogen(SMBN),and contents of soil microorganisms including bacteria,fungi,actinomyces,and protozoa,and determined the components of soil respiration including soil respiration with litter(RS+L),soil respiration without litter(RS),and litter respiration(RL)under short-term changes in precipitation(control,increased precipitation by 30%,and decreased precipitation by 30%)and N addition(0.0 and 10.0 g/(m^(2)·a))treatments.Our results indicated that short-term changes in precipitation and N addition had substantial positive effects on the contents of TN,SOC,and SMBC,as well as the contents of soil actinomyces and protozoa.In addition,N addition significantly enhanced the rates of RS+L and RS by 4.8%and 8.0%(P<0.05),respectively.The increase in precipitation markedly increased the rates of RS+L and RS by 2.3%(P<0.05)and 5.7%(P<0.001),respectively.The decrease in precipitation significantly increased the rates of RS+L and RS by 12.9%(P<0.05)and 23.4%(P<0.001),respectively.In contrast,short-term changes in precipitation and N addition had no significant effects on RL rate(P>0.05).The mean RL/RS+L value observed under all treatments was 27.63%,which suggested that RL is an important component of soil respiration in the desert steppe ecosystems.The results also showed that short-term changes in precipitation and N addition had significant interactive effects on the rates of RS+L,RS,and RL(P<0.001).In addition,soil temperature was the most important abiotic factor that affected the rates of RS+L,RS,and RL.Results of the correlation analysis demonstrated that the rates of RS+L,RS,and RL were closely related to soil temperature,soil moisture,TN,SOC,and the contents of soil microorganisms,and the structural equation model revealed that SOC and SMBC are the key factors influencing the rates of RS+L,RS,and RL.This study provides further insights into the characteristics of soil C emissions in desert steppe ecosystems in the context of climate change,which can be used as a reference for future related studies.展开更多
Sea cucumber(Apostichopus japonicus)is an excellent model for investigating effects of bottom-dwellers on carbon mig-ration and transformation.However,the molecular mechanism of respiratory metabolism process variatio...Sea cucumber(Apostichopus japonicus)is an excellent model for investigating effects of bottom-dwellers on carbon mig-ration and transformation.However,the molecular mechanism of respiratory metabolism process variation caused by feeding rations is poorly understood.In this study,treatment groups set as 1%(about 0.63g),3%,and 7%of total body weight(named F1,F3 and F7 groups respectively).The potential molecular mechanisms behind the functions of respiratory tree and body wall were investigated by RNA-Seq.A total of 52411 expressed genes were identified from 89342 expressed transcripts.The results showed 759,254 and 334 genes were up-regulated,and 334,445 and 992 genes were down-regulated in respiratory tree of F1 vs.F3,F1 vs.F7 and F3 vs.F7,respectively.Meanwhile,2070,1601 and 896 genes were up-regulated,and 1303,1337 and 1144 genes were down-regulated in body wall between F1 vs.F3,F1 vs.F7 and F3 vs.F7,respectively.Differentially expressed genes were enriched in salivary secretion and ECM-receptor interaction pathways in respiratory tree,and in various types of N-glycan biosynthesis,ribosome and sphingolipid metabolism pathways in body wall.These results suggested respiratory tree and body wall were involved in activation of respiratory metabolisms in response to different feeding rations.Our research provided valuable knowledge for physiological differences in res-piratory metabolism.展开更多
Identifying and selecting high-quality seeds is crucial for improving crop yield.The purpose of this study was to improve the selection of crop seeds based on separating vital seeds from dead seeds,by predicting the p...Identifying and selecting high-quality seeds is crucial for improving crop yield.The purpose of this study was to improve the selection of crop seeds based on separating vital seeds from dead seeds,by predicting the potential germination ability of each seed,and thus improving seed quality.The methods of oxygen consumption (Q) of seeds and the headspace-gas chromatography-ion mobility spectrometry(HS-GC-IMS) were evaluated for identifying the viability of individual seeds.Firstly,the oxygen consumption technique showed clear differences among the values related to respiratory characteristics for seeds that were either vital or not,and the discrimination ability of final oxygen consumption(Q_(120)) was achieved not only in sweet corn seeds but also in pepper and wheat seeds.Besides,Qtwas established as a new variable to shorten the measuring process in the Q2 (oxygen sensor) procedure,which was significantly related to the viability of individual seeds.To minimize seed damage during measurement,the timing for viability evaluation was pinpointed at the 12,6 and 9 h for pepper,sweet corn,and wheat seeds based on the new variables concerning oxygen consumption (i.e.,Q_(12),Q_(6)and Q_(9),respectively).The accuracies of viability prediction were 91.9,97.7 and 96.2%,respectively.Dead seeds were identified and hence discarded,leading to an enhancement in the quality of the seed lot as indicated by an increase in germination percentage,from 86.6,90.9,and 53.8%to all at 100%.We then used the HS-GC-IMS to determine the viability of individual sweet corn seeds,noting that corn seed has a heavier weight so the volatile gas components are more likely to be detected.A total of 48 chromatographic peaks were identified,among which 38 target compounds were characterized,including alcohols,aldehydes,acids and esters.However,there were no significant differences between the vital and dead seeds,due to the trace amount volatile composition differences among the individual seeds.Furthermore,a PCA based on the signal intensities of the target volatile compounds obtained was found to lose its effectiveness,as it was unable to distinguish those two types of sweet corn seeds.These strategies can provide a reference for the rapid detection of single seed viability.展开更多
Cumulative inhalation of respirable coal mine dust(RCMD)can lead to severe lung diseases,including coal worker's pneu-moconiosis(CWP),silicosis,mixed dust pneumoconiosis,dust-related diffuse fibrosis(DDF),and prog...Cumulative inhalation of respirable coal mine dust(RCMD)can lead to severe lung diseases,including coal worker's pneu-moconiosis(CWP),silicosis,mixed dust pneumoconiosis,dust-related diffuse fibrosis(DDF),and progressive massive fibrosis(PMF).Statistics from the number of reported cases showed a significant decrease in the progression of respiratory diseases in the 1990s.However,an unexpected increase in the number of CWP cases was reported in the late 1990s.To date,there has been no comprehensive systematic review to assess all contributing factors to the resurgence of CWP cases.This study aims to investigate the effects of various mining parameters on the prevalence of CWP in coal mines.A systematic review using the preferred reporting items for systematic reviews and meta-analysis(PRISMA)method was conducted to investigate the health effects of RCMD exposure and identify the factors that may contribute to the recent resurgence of CWP cases.The systematic review yielded a total of 401 papers,which were added to the database.The total number of 148 and 208 papers were excluded from the database in the process of screening and eligibility,respectively.Then,18 papers were considered for data selection and full-text assessment.The review revealed that factors including geographic location,mine size,mining operation type,coal-seam thickness,coal rank,changes in mining practices,technology advancement,and engi-neering dust control practices are contributing to the recent resurgence of CWP among coal workers.However,the evidence for root causes is limited owing to the methodological constraints of the studies;therefore,further detailed studies are needed.展开更多
Background:The survival of pancreatic cancer cells,particularly cancer stem cells which are responsible for tumor relapse,depends on mitochondrial function.Mitochondrial transcription factor A(TFAM)is critical for the...Background:The survival of pancreatic cancer cells,particularly cancer stem cells which are responsible for tumor relapse,depends on mitochondrial function.Mitochondrial transcription factor A(TFAM)is critical for the regulation of mitochondrial DNA and thus mitochondrial function.However,the possible involvement of TFAM in pancreatic cancer is unknown.Methods:Human samples were obtained from pancreatic cancers and their adjacent tissues;human pancreatic cell lines were cultured in RPMI1640 medium.TFAM expressions in pancreatic tissues and cultured cells were determined using immunohistochemistry,ELISA,and reverse transcription polymerase chain reaction(RT-PCR).The effect of TFAM on cell growth,migration,colony formation and apoptosis were evaluated.Mitochondrial biogenesis in pancreatic cancer and normal cells were examined.Results:The majority of pancreatic cancer tissues exhibited higher TFAM expression compared to the adjacent counterparts.Consistently,TFAM mRNA and protein levels were higher in pancreatic cancer cell lines than in immortalized normal pancreatic epithelial cells.There was no difference on TFAM level between gemcitabine-sensitive and resistant pancreatic cancer cells.Functional analysis demonstrated that TFAM overexpression activated pancreatic normal and tumor cells whereas TFAM inhibition effectively inhibited the growth of pancreatic cancer cells.TFAM inhibition enhanced gemcitabine’s cytotoxicity and suppressed growth,anchorage-independent colony formation and survival of gemcitabine-resistant pancreatic cancer cells.Mechanistic studies showed that TFAM inhibition resulted in remarkable mitochondrial dysfunction and energy crisis followed by oxidative stress.The basal mitochondrial biogenesis level correlated well with TFAM level in pancreatic cancer cells.Conclusions:TFAM played essential roles in pancreatic cancer via regulating mitochondrial functions which highlighted the therapeutic value of inhibiting TFAM to overcome gemcitabine resistance.展开更多
Background A simple measurement of central venous pressure(CVP)-mean by the digital monitor display has become increasingly popular.However,the agreement between CVP-mean and CVP-end(a standard method of CVP measureme...Background A simple measurement of central venous pressure(CVP)-mean by the digital monitor display has become increasingly popular.However,the agreement between CVP-mean and CVP-end(a standard method of CVP measurement by analyzing the waveform at end-expiration)is not well determined.This study was designed to identify the relationship between CVP-mean and CVP-end in critically ill patients and to introduce a new parameter of CVP amplitude(ΔCVP=CVPmax-CVPmin)during the respiratory period to identify the agreement/disagreement between CVP-mean and CVP-end.Methods In total,291 patients were included in the study.CVP-mean and CVP-end were obtained simultaneously from each patient.CVP measurement difference(|CVP-mean-CVP-end|)was defined as the difference between CVP-mean and CVP-end.TheΔCVP was calculated as the difference between the peak(CVPmax)and the nadir value(CVPmin)during the respiratory cycle,which was automatically recorded on the monitor screen.Subjects with|CVP-mean-CVP-end|≥2 mm Hg were divided into the inconsistent group,while subjects with|CVP-mean-CVP-end|2 mm Hg were divided into the consistent group.ResultsΔCVP was significantly higher in the inconsistent group[7.17(2.77)vs.5.24(2.18),P0.001]than that in the consistent group.There was a significantly positive relationship betweenΔCVP and|CVP-mean-CVP-end|(r=0.283,P 0.0001).Bland-Altman plot showed the bias was-0.61 mm Hg with a wide 95%limit of agreement(-3.34,2.10)of CVP-end and CVP-mean.The area under the receiver operating characteristic curves(AUC)ofΔCVP for predicting|CVP-mean-CVP-end|≥2 mm Hg was 0.709.With a high diagnostic specificity,usingΔCVP3 to detect|CVP-mean-CVP-end|lower than 2mm Hg(consistent measurement)resulted in a sensitivity of 22.37%and a specificity of 93.06%.UsingΔCVP8 to detect|CVP-mean-CVPend|8 mm Hg(inconsistent measurement)resulted in a sensitivity of 31.94%and a specificity of 91.32%.Conclusions CVP-end and CVP-mean have statistical discrepancies in specific clinical scenarios.ΔCVP during the respiratory period is related to the variation of the two CVP methods.A highΔCVP indicates a poor agreement between these two methods,whereas a lowΔCVP indicates a good agreement between these two methods.展开更多
The short term(hourly scale)variability of heterotrophic prokaryote(HP)vertical distribution and respiratory activity,was investigated in the north-western(NW)Mediterranean Sea.HP vertical distribution was determined ...The short term(hourly scale)variability of heterotrophic prokaryote(HP)vertical distribution and respiratory activity,was investigated in the north-western(NW)Mediterranean Sea.HP vertical distribution was determined on board by flow cytometry analysis of seawater samples collected by series of CTD casts.Cell counts and viability were determined for all samples.HP respiratory rates were determined later in the laboratory from filtered seawater samples(23 dm^(3))from 300-1150-m depth.The average cell viability was 94.8%±2.2%(n=240).There was no accumulation of dead cells,due to quick decay of damaged cells.In the epipelagic layer,three HP groups were distinguished,two(HNA1,HNA2)who se cells exhibited a high nucleic acid content and one(LNA)with low nucleic acid content cells.HNA2 was most populated at 50 m but not detected at 90 m and below,presumably aerobic anoxygenic photoheterotrophic bacteria(AAPs).The variability in HP abundance was mainly confined in the upper 80 m.A few secondary peaks of HP abundance were observed(80-150 m)in connection with abundance troughs in the surface layer.HP cells were continuously present in a wide layer around 500 m(mean 191×10^(3)cells/cm^(3)).Below this layer,HP abundance randomly exhibited peaks,coupled to respiratory rate peaks.The HP abundance and variability in the water column was suppressed during a strong wind event.The observed sporadic variability was tentatively interpreted through a pulsed carbon-export mechanism induced by the microorganism production of dissolved poly saccharide s,followed by flocculation and rapid sinking.This mechanism would thus contribute to(ⅰ)preventing organic matter accumulation in the epipelagic layer,(ⅱ)seeding the water column with live HP cells,and(ⅲ)supplying the aphotic water column with fre sh and labile organic matter.This important vertical flux mechanism needs further observations and modelling.展开更多
Objective:To investigate the effect of the first prone position on arterial blood gas analysis and respiratory parameters of acute respiratory distress syndrome(ARDS)patients with and without COVID.Methods:This study ...Objective:To investigate the effect of the first prone position on arterial blood gas analysis and respiratory parameters of acute respiratory distress syndrome(ARDS)patients with and without COVID.Methods:This study was conducted retrospectively with 22 COVID-ARDS and 22 non-COVID ARDS patients,who were placed in a prone position for at least 16 hours on the first day at the intensive care unit admission,and arterial blood gas analysis was taken in the pre-prone,prone and post-prone periods.Results:PaO2 were significantly increased in the pre-prone vs.prone comparison in both groups,but the increase in the PaO2/FiO2 ratio was not significant.In comparing the pre-prone vs.post-prone PaO2/FiO2 ratios,there was a significant difference only in the non-COVID ARDS group.Conclusions:The improved oxygenation provided by prone positioning is more permanent with the“post-prone effect”in non-COVID ARDS patients.This can be attributed to the differences in the pathogenesis of the two ARDS types.展开更多
Owing to the recent trends in remote health monitoring,real-time appli-cations for measuring Heartbeat Rate and Respiration Rate(HARR)from video signals are growing rapidly.Photo Plethysmo Graphy(PPG)is a method that ...Owing to the recent trends in remote health monitoring,real-time appli-cations for measuring Heartbeat Rate and Respiration Rate(HARR)from video signals are growing rapidly.Photo Plethysmo Graphy(PPG)is a method that is operated by estimating the infinitesimal change in color of the human face,rigid motion of facial skin and head parts,etc.Ballisto Cardiography(BCG)is a non-surgical tool for obtaining a graphical depiction of the human body’s heartbeat by inducing repetitive movements found in the heart pulses.The resilience against motion artifacts induced by luminancefluctuation and the patient’s mobility var-iation is the major difficulty faced while processing the real-time video signals.In this research,a video-based HARR measuring framework is proposed based on combined PPG and BCG.Here,the noise from the input video signals is removed by using an Adaptive Kalmanfilter(AKF).Three different algorithms are used for estimating the HARR from the noise-free input signals.Initially,the noise-free sig-nals are subjected to Modified Adaptive Fourier Decomposition(MAFD)and then to Enhanced Hilbert vibration Decomposition(EHVD)andfinally to Improved Var-iation mode Decomposition(IVMD)for attaining three various results of HARR.The obtained values are compared with each other and found that the EHVD is showing better results when compared with all the other methods.展开更多
Ulmus crassifolia Nutt. (Cedar elm, Ulmaceae) is a tree found in central and east Texas, northern Mexico, east to Florida, and north to southern Missouri and Oklahoma. Ungnadia speciosa Endl. (Mexican-buckeye, Sapinda...Ulmus crassifolia Nutt. (Cedar elm, Ulmaceae) is a tree found in central and east Texas, northern Mexico, east to Florida, and north to southern Missouri and Oklahoma. Ungnadia speciosa Endl. (Mexican-buckeye, Sapindaceae) is a shrub or small tree found in woodlands and savannas of central and western Texas, southern New Mexico and northern Mexico. In central Texas, both species are found in Juniperus ashei/Quercus virginiana woodlands or savannas or also at low density in inter-canopy grassland gaps or patches. Environmental conditions in this area are stressful because of shallow soils, high summer temperatures, and inconsistent low rainfall. Currently, both species have a low density in these areas, and Ulmus crassifolia is usually a tree, while Ungnadia speciosa is a woody understory shrub. This study suggests U. crassifolia and U. speciosa are tolerant or intermediate species, with juveniles starting in shade. Maximum photosynthetic rate (A<sub>max</sub>), dark respiration (R<sub>d</sub>), intercellular CO<sub>2</sub>, light saturation (L<sub>sp</sub>) and water use efficiency significantly increased when light levels and CO<sub>2</sub> concentrations were elevated for both species, but not when temperatures were elevated. Stomatal conductance decreased when the CO<sub>2</sub> concentration doubled, but there were few effects from elevated temperature. These findings suggest that U. speciosa and U. crassifolia should be more common and imply that they will have a higher density in a future high CO<sub>2</sub> environment.展开更多
Based on the photosynthesis-respiration reversible reaction and the available statistics, we attempted to quantify the planetary seasonal exchanges of CO<sub>2</sub> between air and water from 1970 and com...Based on the photosynthesis-respiration reversible reaction and the available statistics, we attempted to quantify the planetary seasonal exchanges of CO<sub>2</sub> between air and water from 1970 and compared them to the glacial ACC cycles as reported from ice cores archives. In 2020, the overall continental absorption (AW) was 8.0 giga tonnes of carbon per year (GtC/y). Emissions into the atmosphere (EW) resulting from mineral degradation by respiration and combustion of biomass and fossil hydrocarbons were 14.7 GtC/y, an increase of 2.4% per year since 1970. The continental surplus balance (-AW+EW) of 6.7 GtC/y was shared between the atmosphere, which received 5.1 GtC/y (GATM), and the ocean which absorbed 1.6 GtC/y. This ocean contribution (OC) corresponded to 17% of the 9.2 GtC/y emissions by combustion of fossil hydrocarbons (EFOS). Analysis of the ACC oscillations during 2020 in the northern hemisphere showed that the ocean absorbed 11.1 GtC during the warm season and outgassed 9.5 GtC during the cold season. Assuming proportionality to world population, the ACC, 414 parts per million (ppm) in 2021, would reach 584 ppm in 2080, still growing at a rate of 0.6% per year. The gain of atmospheric CO<sub>2</sub> (GATM) and its absorption by the ocean (OC) were expected to peak at 7.0 and 2.2 GtC/y, respectively, in 2080. This increase in the availability of atmospheric CO<sub>2</sub> resulted in improved yields of agriculture which more than compensated for the reduction by half of food-producing areas per capita from 1970.展开更多
The key for dust control of coal mine is to clarify the dust concentration distribution and sedimentation in different areas. Both similarity experiment and numerical simulation method have certain restrictions and ar...The key for dust control of coal mine is to clarify the dust concentration distribution and sedimentation in different areas. Both similarity experiment and numerical simulation method have certain restrictions and are quite different from the actual situation on site. In order to study the dust sedimentation regularity of coal mine in large mining height, “filter membrane method” is adopted in this paper, i.e., to dry and weigh the filter membrane before and after sampling, collect the dust of respirable zone on mining face and calculate the dust concentration based on a main airway of 100 m. The result shows that: A large amount of dust will be produced during coal mining, wherein the maximum dust concentration from 6 m upstream to 100 m downstream of coal cutter is 121 mg/m3</sup>, while the minimum dust concentration is 61 mg/m3</sup>;The dust concentration in return airway is reduced with the distance increases, while the dust concentration at the entrance is 91 mg/m3</sup>;A large amount of dust may fall from roof during section advancing and improves the dust concentration of hydraulic support in walking area obviously;The dust granularity of mining face and return airway is 0 - 100 μm, but the amount of respirable dust is higher than 80%, the larger the dust particle size, the higher the dust concentration. Besides, dust in small particle size can be suspended in air flow for longer, but that in large particle size may subside under the action of gravity;To reduce dust exposure, the mining position shall be located in the windward direction of advancing or coal cutter. This research can provide guidance for taking dust prevention measures of working face in large mining height.展开更多
The diurnal and seasonal dynamics of soil respiration in the A. ordosica shrubland on Ordos Plateau were investigated in the growing season (May-October) of 2006 and their environmental driving factors were also ana...The diurnal and seasonal dynamics of soil respiration in the A. ordosica shrubland on Ordos Plateau were investigated in the growing season (May-October) of 2006 and their environmental driving factors were also analyzed, Results indicated that diurnal dynamics of soil respiration rate and its temperature dependence showed some discrepancy in two different growth stages (the vegetative growth stage and the reproductive growth stage). During the vegetative growth stage, the diurnal variation of soil respiration was slight and not correlated with the daily temperature change, but during the reproductive growth stage, the daily respiration variation was relatively large and significantly correlated with the diurnal variation of air and soil temperature. In the growing season, the peak value of soil respiration occurred at July and August because of the better soil water-heat conditions and their optimal deployment in this period. In the shrubland ecosystem, precipitation was the switch of soil respiration pulses and can greatly increase soil respiration rates after soil rewetting. Moreover, the soil respiration rates in the growing season and the air temperature and soil surface water content were closely correlated (p〈0.05) each other. The stepwise regression model indicated that the variation of soil surface moisture accounted for 41.9% of the variation in soil respiration (p〈0.05).展开更多
AIM:To present and integrate findings of studies investigating the effects of laparoscopic cholecystectomy on various aspects of lung function.METHODS:We extensively reviewed literature of the past 24 years concerning...AIM:To present and integrate findings of studies investigating the effects of laparoscopic cholecystectomy on various aspects of lung function.METHODS:We extensively reviewed literature of the past 24 years concerning the effects of laparoscopic cholecystectomy in comparison to the open procedure on many aspects of lung function including spirometricvalues,arterial blood gases,respiratory muscle performance and aspects of breathing control,by critically analyzing physiopathologic interpretations and clinically important conclusions.A total of thirty-four articles were used to extract information for the meta-analysis concerning the impact of the laparoscopic procedure on lung function and respiratory physiopathology.The quality of the literature reviewed was evaluated by the number of their citations and the total impact factor of the corresponding journals.A fixed and random effect meta-analysis was used to estimate the pooled standardized mean difference of studied parameters for laparoscopic(LC)and open(OC)procedures.A crude comparison of the two methods using all available information was performed testing the postoperative values expressed as percentages of the preoperative ones using the Mann-Whitney two-sample test.RESULTS:Most of the relevant studies have investigated and compared changes in spirometric parameters.The median percentage and interquartile range(IQR)of preoperative values in forced vital capacity(FVC),forced expiratory volume in 1 s and forced expiratory flow(FEF)at 25%-75%of FVC(FEF25%-75%)expressed as percentage of their preoperative values 24 h after LC and OC were respectively as follows:[77.6(73.0,80.0)L vs 55.4(50.0,64.0)L,P<0.001;76.0(72.3,81.0)L vs 52.5(50.0,56.7)L,P<0.001;and 78.8(68.8,80.9)L/s vs 60.0(36.1,66.1)L/s,P=0.005].Concerning arterial blood gases,partial pressure of oxygen[Pa O2(k Pa)]at 24 or 48 h after surgical treatment showed reductions that were significantly greater in OC compared with LC[LC median 1.0,IQR(0.6,1.3);OC median 2.4,IQR(1.2,2.6),P=0.019].Fewer studies have investigated the effect of LC on respiratory muscle performance showing less impact of this surgical method on maximal respiratory pressures(P<0.01);and changes in the control of breathing after LC evidenced by increase in mean inspiratory impedance(P<0.001)and minimal reduction of duty cycle(P=0.01)compared with preoperative data.CONCLUSION:Laparoscopic cholecystectomy seems to be associated with less postoperative derangement of lung function compared to the open procedure.展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos.41701296 and 42277481)the Natural Science Foundation of Gansu Province (GrantNo.22JR5RA058)the Youth Science and Technology Fund Program of Gansu Province (Grant No.22JR5RA087).
文摘Interest in the dynamics of soil respiration(R_(S))in subalpine forest ecosystems is increasing due to their high soil carbon density and potential sensitivity to environmental changes.However,as a principal silvicultural practice,the long-term impacts of thinning on R_(S) and its heterotrophic and autotrophic respiration components(R_(h) and Ra,respectively)in subalpine plantations are poorly understood,espe-cially in winter.A 3-year field observation was carried out with consideration of winter CO_(2) efflux in middle-aged sub-alpine spruce plantations in northwestern China.A trench-ing method was used to explore the long-term impacts of thinning on Rs,Rn and R_(a).Seventeen years after thinning,mean annual Rs,Rn and R_(a) increased,while the contribu-tion of R_(h) to R_(s) decreased with thinning intensity.Thinning significantly decreased winter R,because of the reduction in R_(n) but had no significant effect on Ra.The temperature sensitivity(Q_(10))of R_(h) and R_(a) also increased with thinning intensity,with lower Q_(10) values for R_(h)(2.1-2.6)than for Ra(2.4-2.8).The results revealed the explanatory variables and pathways related to R_(n) and R_(a) dynamics.Thinning increased soil moisture and nitrate nitrogen(NO_(3)^(-)-N),and the enhanced nitrogen and water availability promoted R_(h) and R_(a) by improving fine root biomass and microbial activity.Our results highlight the positive roles of NO_(3)^(-)-N in stimulating R_(s) components following long-term thinning.Therefore,applications of nitrogen fertilizer are not recommended while thinning subalpine spruce plantations from the perspective of reducing soil CO_(2) emissions.The increased Q_(10) values of R_(s) components indicate that a large increase in soil CO_(2) emissions would be expected following thinning because of more pronounced climate warming in alpineregions.
基金Supported by the National Natural Science Foundation of China(Nos.32002411,42276189)the Innovation and Entrepreneurship Project for College Students of Hohai University(No.2022102941027)the Jiangsu Innovation Center for Marine Bioresources(No.822153216)。
文摘The function of exogenous alanine(Ala)in regulating biomass accumulation,lipid production,photosynthesis,and respiration in Chlorella pyrenoidosa was studied.Result shows that the supplementation of Ala increased C.pyrenoidosa biomass and lipid production in an 8-d batch culture.The concentration of 10 mmol/L of Ala was optimum and increased the microalgal cell biomass and lipid content by 39.3%and 21.4%,respectively,compared with that in the control(0-mmol/L Ala).Ala supplementation reduced photosynthetic activity while boosting respiratory activity and pyruvate levels,indicating that C.pyrenoidosa used exogenous Ala for biomass accumulation through the respiratory metabolic process.The accelerated respiratory metabolism due to Ala supplementation elevated the substrate pool and improved the lipogenic gene expression,promoting lipid production at last.This study provided a novel method for increasing biomass accumulation and lipid production and elucidated the role of Ala in regulating lipid production.
文摘Rhizobium tropici-derived extracellular polymeric substances (EPS) have been used in soils to enhance soil structures and mitigate soil erosions. However, information on their use to improve soil health and fertility indicators, and plant growth is limited. In a greenhouse study, we investigated their effects on some soil health, soil fertility indices, and the growth of black-eyed peas (Vigna unguiculate). Results showed that soils incubated with EPS significantly increased basal soil respiration, soil microbial biomass, permanganate oxidizable carbon (POC), and potentially mineralizable nitrogen (PMN). The EPS shifted microbial populations from bacteria to fungi and Gram (−ve) to Gram ( ve) bacteria. However, it had little or no effects on soil pH, soil organic matter (SOM), and cation exchange capacity (CEC). The EPS decreased soil moisture loss, increased soil aggregate stability, but delayed blacked-eyed peas germinations in the soils. At 0.1% (w/w) concentrations in soils, there was increase in plant root nodulations and vegetative growth. This study was carried out within 40 days of incubating soils with EPS or growing the black-eyed peas in a greenhouse study. The plant growth parameters were taken before flowering and fruiting. Further studies of the effects of incubating soils with the extracellular polymeric substances on plant growth. Soil microbial biomass, microbial diversities, and other soil fertility indices are deemed necessary.
基金funded by the National Natural Science Foundation of China(Nos.31971631,32271850)Natural Science Foundation of Zhejiang Province under grant number LZ22C160001.
文摘Moso bamboo(Phyllostachys Pubescens)expansion into adjacent forests has been widely reported to affect plant diversity and its association with mycorrhizal fungi in subtropical China,which will likely have significant impacts on soil respiration.However,there is still limited information on how Moso bamboo expansion changes soil respiration components and their linkage with microbial community composition and activity.Based on a mesh exclusion method,soil respirations derived from roots,arbuscular mycorrhizal(AM)mycelium,and free-living microbes were investigated in a pure Moso bamboo forest(expanded),an adjacent broadleaved forest(nonexpanded),and a mixed bamboo-broadleaved forest(expanding).Our results showed that bamboo expansion decreased the cumulative CO_(2)effluxes from total soil respiration,root respiration and soil heterotrophic respiration(by 19.01%,30.34%,and 29.92%on average),whereas increased those from AM mycelium(by 78.67%in comparison with the broadleaved forests).Bamboo expansion significantly decreased soil organic carbon(C)content,bacterial and fungal abundances,and enzyme activities involved in C,N and P cycling whereas enhanced the interactive relationships among bacterial communities.In contrast,the ingrowth of AM mycelium increased the activities ofβ-glucosidase and N-acetyl-β-glucosaminidase and decreased the interactive relationships among bacterial communities.Changes in soil heterotrophic respiration and AM mycelium respiration had positive correlations with soil enzyme activities and fungal abundances.In summary,our findings suggest that bamboo expansion decreased soil heterotrophic respiration by decreasing soil microbial activity but increased the contribution of AM mycelial respiration to soil C efflux,which may potentially increase soil C loss from AM mycelial pathway.
基金funded by the Key Research and Development Plan of Zhejiang Province(No.2019C02008-03)the State Key Laboratory of Soil and Sustainable Agriculture,Institute of Soil Science,Chinese Academy of Sciences(No.0812000056).
文摘Chinese hickory(Carya cathayensis Sarg.)is a popular nut tree in China,but there is little information about the influences of fertilization on soil CO_(2) efflux and soil microbial biomass.This study evaluated the short-term effects of different fertilizer applications on soil CO_(2) efflux and soil microbial biomass in Chinese hickory stands.Four fertilizer treatments were established:control(CK,no fertilizer),inorganic fertilizer(IF),organic fertilizer(OF),and equal parts organic and inorganic N fertilizers(OIF).A field experiment was conducted to measure soil CO_(2) effluxes using closed chamber and gas chromatography techniques.Regardless of the fertilization practices,soil CO_(2) effluxes of all the treatments showed a similar temporal pattern,with the highest value in summer and the lowest in winter.The mean annual soil CO_(2) efflux in the IF treatment was significantly higher than that in the CK,OIF,and OF treatments.There was no significant difference in soil CO_(2) efflux between the OIF,OF,and CK treatments.Soil CO_(2) effluxes were significantly affected by soil temperature.Soil dissolved organic carbon(DOC)was positively correlated with soil CO_(2) efflux only in the CK treatment.Regression analysis,including soil temperature,moisture,and DOC,showed that soil temperature was the primary factor influencing soil CO_(2) effluxes.Both OF and OIF treatments increased concentrations of soil microbial biomass carbon(MBC)and microbial biomass nitrogen(MBN),but decreased the ratio of MBC:MBN.These results reveal that applying organic fertilizer,either alone or combined with inorganic fertilizer,may be the optimal strategy for mitigating soil CO_(2) emission and improving soil quality in Chinese hickory stands.
基金supported by the National Natural Science Foundation of China(31960359)the Ningxia Hui Autonomous Region Key Research and Development Project(2021BEG02005,2023BEG02049)the Natural Science Foundation of Ningxia Hui Autonomous Region,China(2020AAC03102,2023AAC03061)。
文摘Changes in precipitation and nitrogen(N)addition may significantly affect the processes of soil carbon(C)cycle in terrestrial ecosystems,such as soil respiration.However,relatively few studies have investigated the effects of changes in precipitation and N addition on soil respiration in the upper soil layer in desert steppes.In this study,we conducted a control experiment that involved a field simulation from July 2020 to December 2021 in a desert steppe in Yanchi County,China.Specifically,we measured soil parameters including soil temperature,soil moisture,total nitrogen(TN),soil organic carbon(SOC),soil microbial biomass carbon(SMBC),soil microbial biomass nitrogen(SMBN),and contents of soil microorganisms including bacteria,fungi,actinomyces,and protozoa,and determined the components of soil respiration including soil respiration with litter(RS+L),soil respiration without litter(RS),and litter respiration(RL)under short-term changes in precipitation(control,increased precipitation by 30%,and decreased precipitation by 30%)and N addition(0.0 and 10.0 g/(m^(2)·a))treatments.Our results indicated that short-term changes in precipitation and N addition had substantial positive effects on the contents of TN,SOC,and SMBC,as well as the contents of soil actinomyces and protozoa.In addition,N addition significantly enhanced the rates of RS+L and RS by 4.8%and 8.0%(P<0.05),respectively.The increase in precipitation markedly increased the rates of RS+L and RS by 2.3%(P<0.05)and 5.7%(P<0.001),respectively.The decrease in precipitation significantly increased the rates of RS+L and RS by 12.9%(P<0.05)and 23.4%(P<0.001),respectively.In contrast,short-term changes in precipitation and N addition had no significant effects on RL rate(P>0.05).The mean RL/RS+L value observed under all treatments was 27.63%,which suggested that RL is an important component of soil respiration in the desert steppe ecosystems.The results also showed that short-term changes in precipitation and N addition had significant interactive effects on the rates of RS+L,RS,and RL(P<0.001).In addition,soil temperature was the most important abiotic factor that affected the rates of RS+L,RS,and RL.Results of the correlation analysis demonstrated that the rates of RS+L,RS,and RL were closely related to soil temperature,soil moisture,TN,SOC,and the contents of soil microorganisms,and the structural equation model revealed that SOC and SMBC are the key factors influencing the rates of RS+L,RS,and RL.This study provides further insights into the characteristics of soil C emissions in desert steppe ecosystems in the context of climate change,which can be used as a reference for future related studies.
基金supported by the National Natural Science Foundation of China(No.31672657).
文摘Sea cucumber(Apostichopus japonicus)is an excellent model for investigating effects of bottom-dwellers on carbon mig-ration and transformation.However,the molecular mechanism of respiratory metabolism process variation caused by feeding rations is poorly understood.In this study,treatment groups set as 1%(about 0.63g),3%,and 7%of total body weight(named F1,F3 and F7 groups respectively).The potential molecular mechanisms behind the functions of respiratory tree and body wall were investigated by RNA-Seq.A total of 52411 expressed genes were identified from 89342 expressed transcripts.The results showed 759,254 and 334 genes were up-regulated,and 334,445 and 992 genes were down-regulated in respiratory tree of F1 vs.F3,F1 vs.F7 and F3 vs.F7,respectively.Meanwhile,2070,1601 and 896 genes were up-regulated,and 1303,1337 and 1144 genes were down-regulated in body wall between F1 vs.F3,F1 vs.F7 and F3 vs.F7,respectively.Differentially expressed genes were enriched in salivary secretion and ECM-receptor interaction pathways in respiratory tree,and in various types of N-glycan biosynthesis,ribosome and sphingolipid metabolism pathways in body wall.These results suggested respiratory tree and body wall were involved in activation of respiratory metabolisms in response to different feeding rations.Our research provided valuable knowledge for physiological differences in res-piratory metabolism.
基金supported by the National Key Research and Development Program of China(2018YFD0100903)。
文摘Identifying and selecting high-quality seeds is crucial for improving crop yield.The purpose of this study was to improve the selection of crop seeds based on separating vital seeds from dead seeds,by predicting the potential germination ability of each seed,and thus improving seed quality.The methods of oxygen consumption (Q) of seeds and the headspace-gas chromatography-ion mobility spectrometry(HS-GC-IMS) were evaluated for identifying the viability of individual seeds.Firstly,the oxygen consumption technique showed clear differences among the values related to respiratory characteristics for seeds that were either vital or not,and the discrimination ability of final oxygen consumption(Q_(120)) was achieved not only in sweet corn seeds but also in pepper and wheat seeds.Besides,Qtwas established as a new variable to shorten the measuring process in the Q2 (oxygen sensor) procedure,which was significantly related to the viability of individual seeds.To minimize seed damage during measurement,the timing for viability evaluation was pinpointed at the 12,6 and 9 h for pepper,sweet corn,and wheat seeds based on the new variables concerning oxygen consumption (i.e.,Q_(12),Q_(6)and Q_(9),respectively).The accuracies of viability prediction were 91.9,97.7 and 96.2%,respectively.Dead seeds were identified and hence discarded,leading to an enhancement in the quality of the seed lot as indicated by an increase in germination percentage,from 86.6,90.9,and 53.8%to all at 100%.We then used the HS-GC-IMS to determine the viability of individual sweet corn seeds,noting that corn seed has a heavier weight so the volatile gas components are more likely to be detected.A total of 48 chromatographic peaks were identified,among which 38 target compounds were characterized,including alcohols,aldehydes,acids and esters.However,there were no significant differences between the vital and dead seeds,due to the trace amount volatile composition differences among the individual seeds.Furthermore,a PCA based on the signal intensities of the target volatile compounds obtained was found to lose its effectiveness,as it was unable to distinguish those two types of sweet corn seeds.These strategies can provide a reference for the rapid detection of single seed viability.
基金funded by the National Institute for Occupational Safety and Health (NIOSH) (75D30119C06390).
文摘Cumulative inhalation of respirable coal mine dust(RCMD)can lead to severe lung diseases,including coal worker's pneu-moconiosis(CWP),silicosis,mixed dust pneumoconiosis,dust-related diffuse fibrosis(DDF),and progressive massive fibrosis(PMF).Statistics from the number of reported cases showed a significant decrease in the progression of respiratory diseases in the 1990s.However,an unexpected increase in the number of CWP cases was reported in the late 1990s.To date,there has been no comprehensive systematic review to assess all contributing factors to the resurgence of CWP cases.This study aims to investigate the effects of various mining parameters on the prevalence of CWP in coal mines.A systematic review using the preferred reporting items for systematic reviews and meta-analysis(PRISMA)method was conducted to investigate the health effects of RCMD exposure and identify the factors that may contribute to the recent resurgence of CWP cases.The systematic review yielded a total of 401 papers,which were added to the database.The total number of 148 and 208 papers were excluded from the database in the process of screening and eligibility,respectively.Then,18 papers were considered for data selection and full-text assessment.The review revealed that factors including geographic location,mine size,mining operation type,coal-seam thickness,coal rank,changes in mining practices,technology advancement,and engi-neering dust control practices are contributing to the recent resurgence of CWP among coal workers.However,the evidence for root causes is limited owing to the methodological constraints of the studies;therefore,further detailed studies are needed.
基金This work was supported by the grant from Science and Technology Project of Hubei Provincial Department of Education(B2020139).
文摘Background:The survival of pancreatic cancer cells,particularly cancer stem cells which are responsible for tumor relapse,depends on mitochondrial function.Mitochondrial transcription factor A(TFAM)is critical for the regulation of mitochondrial DNA and thus mitochondrial function.However,the possible involvement of TFAM in pancreatic cancer is unknown.Methods:Human samples were obtained from pancreatic cancers and their adjacent tissues;human pancreatic cell lines were cultured in RPMI1640 medium.TFAM expressions in pancreatic tissues and cultured cells were determined using immunohistochemistry,ELISA,and reverse transcription polymerase chain reaction(RT-PCR).The effect of TFAM on cell growth,migration,colony formation and apoptosis were evaluated.Mitochondrial biogenesis in pancreatic cancer and normal cells were examined.Results:The majority of pancreatic cancer tissues exhibited higher TFAM expression compared to the adjacent counterparts.Consistently,TFAM mRNA and protein levels were higher in pancreatic cancer cell lines than in immortalized normal pancreatic epithelial cells.There was no difference on TFAM level between gemcitabine-sensitive and resistant pancreatic cancer cells.Functional analysis demonstrated that TFAM overexpression activated pancreatic normal and tumor cells whereas TFAM inhibition effectively inhibited the growth of pancreatic cancer cells.TFAM inhibition enhanced gemcitabine’s cytotoxicity and suppressed growth,anchorage-independent colony formation and survival of gemcitabine-resistant pancreatic cancer cells.Mechanistic studies showed that TFAM inhibition resulted in remarkable mitochondrial dysfunction and energy crisis followed by oxidative stress.The basal mitochondrial biogenesis level correlated well with TFAM level in pancreatic cancer cells.Conclusions:TFAM played essential roles in pancreatic cancer via regulating mitochondrial functions which highlighted the therapeutic value of inhibiting TFAM to overcome gemcitabine resistance.
基金Supported by the National High-Level Hospital Clinical Research Funding(2022-PUMCH-B-115,2022-PUMCH-D-005).
文摘Background A simple measurement of central venous pressure(CVP)-mean by the digital monitor display has become increasingly popular.However,the agreement between CVP-mean and CVP-end(a standard method of CVP measurement by analyzing the waveform at end-expiration)is not well determined.This study was designed to identify the relationship between CVP-mean and CVP-end in critically ill patients and to introduce a new parameter of CVP amplitude(ΔCVP=CVPmax-CVPmin)during the respiratory period to identify the agreement/disagreement between CVP-mean and CVP-end.Methods In total,291 patients were included in the study.CVP-mean and CVP-end were obtained simultaneously from each patient.CVP measurement difference(|CVP-mean-CVP-end|)was defined as the difference between CVP-mean and CVP-end.TheΔCVP was calculated as the difference between the peak(CVPmax)and the nadir value(CVPmin)during the respiratory cycle,which was automatically recorded on the monitor screen.Subjects with|CVP-mean-CVP-end|≥2 mm Hg were divided into the inconsistent group,while subjects with|CVP-mean-CVP-end|2 mm Hg were divided into the consistent group.ResultsΔCVP was significantly higher in the inconsistent group[7.17(2.77)vs.5.24(2.18),P0.001]than that in the consistent group.There was a significantly positive relationship betweenΔCVP and|CVP-mean-CVP-end|(r=0.283,P 0.0001).Bland-Altman plot showed the bias was-0.61 mm Hg with a wide 95%limit of agreement(-3.34,2.10)of CVP-end and CVP-mean.The area under the receiver operating characteristic curves(AUC)ofΔCVP for predicting|CVP-mean-CVP-end|≥2 mm Hg was 0.709.With a high diagnostic specificity,usingΔCVP3 to detect|CVP-mean-CVP-end|lower than 2mm Hg(consistent measurement)resulted in a sensitivity of 22.37%and a specificity of 93.06%.UsingΔCVP8 to detect|CVP-mean-CVPend|8 mm Hg(inconsistent measurement)resulted in a sensitivity of 31.94%and a specificity of 91.32%.Conclusions CVP-end and CVP-mean have statistical discrepancies in specific clinical scenarios.ΔCVP during the respiratory period is related to the variation of the two CVP methods.A highΔCVP indicates a poor agreement between these two methods,whereas a lowΔCVP indicates a good agreement between these two methods.
基金Supported by the PROOF Grant provided by the INSU-CNRS and was part of the PECHE project“Production and exportation of carbon:control by heterotrophic organisms at small time scales”。
文摘The short term(hourly scale)variability of heterotrophic prokaryote(HP)vertical distribution and respiratory activity,was investigated in the north-western(NW)Mediterranean Sea.HP vertical distribution was determined on board by flow cytometry analysis of seawater samples collected by series of CTD casts.Cell counts and viability were determined for all samples.HP respiratory rates were determined later in the laboratory from filtered seawater samples(23 dm^(3))from 300-1150-m depth.The average cell viability was 94.8%±2.2%(n=240).There was no accumulation of dead cells,due to quick decay of damaged cells.In the epipelagic layer,three HP groups were distinguished,two(HNA1,HNA2)who se cells exhibited a high nucleic acid content and one(LNA)with low nucleic acid content cells.HNA2 was most populated at 50 m but not detected at 90 m and below,presumably aerobic anoxygenic photoheterotrophic bacteria(AAPs).The variability in HP abundance was mainly confined in the upper 80 m.A few secondary peaks of HP abundance were observed(80-150 m)in connection with abundance troughs in the surface layer.HP cells were continuously present in a wide layer around 500 m(mean 191×10^(3)cells/cm^(3)).Below this layer,HP abundance randomly exhibited peaks,coupled to respiratory rate peaks.The HP abundance and variability in the water column was suppressed during a strong wind event.The observed sporadic variability was tentatively interpreted through a pulsed carbon-export mechanism induced by the microorganism production of dissolved poly saccharide s,followed by flocculation and rapid sinking.This mechanism would thus contribute to(ⅰ)preventing organic matter accumulation in the epipelagic layer,(ⅱ)seeding the water column with live HP cells,and(ⅲ)supplying the aphotic water column with fre sh and labile organic matter.This important vertical flux mechanism needs further observations and modelling.
文摘Objective:To investigate the effect of the first prone position on arterial blood gas analysis and respiratory parameters of acute respiratory distress syndrome(ARDS)patients with and without COVID.Methods:This study was conducted retrospectively with 22 COVID-ARDS and 22 non-COVID ARDS patients,who were placed in a prone position for at least 16 hours on the first day at the intensive care unit admission,and arterial blood gas analysis was taken in the pre-prone,prone and post-prone periods.Results:PaO2 were significantly increased in the pre-prone vs.prone comparison in both groups,but the increase in the PaO2/FiO2 ratio was not significant.In comparing the pre-prone vs.post-prone PaO2/FiO2 ratios,there was a significant difference only in the non-COVID ARDS group.Conclusions:The improved oxygenation provided by prone positioning is more permanent with the“post-prone effect”in non-COVID ARDS patients.This can be attributed to the differences in the pathogenesis of the two ARDS types.
文摘Owing to the recent trends in remote health monitoring,real-time appli-cations for measuring Heartbeat Rate and Respiration Rate(HARR)from video signals are growing rapidly.Photo Plethysmo Graphy(PPG)is a method that is operated by estimating the infinitesimal change in color of the human face,rigid motion of facial skin and head parts,etc.Ballisto Cardiography(BCG)is a non-surgical tool for obtaining a graphical depiction of the human body’s heartbeat by inducing repetitive movements found in the heart pulses.The resilience against motion artifacts induced by luminancefluctuation and the patient’s mobility var-iation is the major difficulty faced while processing the real-time video signals.In this research,a video-based HARR measuring framework is proposed based on combined PPG and BCG.Here,the noise from the input video signals is removed by using an Adaptive Kalmanfilter(AKF).Three different algorithms are used for estimating the HARR from the noise-free input signals.Initially,the noise-free sig-nals are subjected to Modified Adaptive Fourier Decomposition(MAFD)and then to Enhanced Hilbert vibration Decomposition(EHVD)andfinally to Improved Var-iation mode Decomposition(IVMD)for attaining three various results of HARR.The obtained values are compared with each other and found that the EHVD is showing better results when compared with all the other methods.
文摘Ulmus crassifolia Nutt. (Cedar elm, Ulmaceae) is a tree found in central and east Texas, northern Mexico, east to Florida, and north to southern Missouri and Oklahoma. Ungnadia speciosa Endl. (Mexican-buckeye, Sapindaceae) is a shrub or small tree found in woodlands and savannas of central and western Texas, southern New Mexico and northern Mexico. In central Texas, both species are found in Juniperus ashei/Quercus virginiana woodlands or savannas or also at low density in inter-canopy grassland gaps or patches. Environmental conditions in this area are stressful because of shallow soils, high summer temperatures, and inconsistent low rainfall. Currently, both species have a low density in these areas, and Ulmus crassifolia is usually a tree, while Ungnadia speciosa is a woody understory shrub. This study suggests U. crassifolia and U. speciosa are tolerant or intermediate species, with juveniles starting in shade. Maximum photosynthetic rate (A<sub>max</sub>), dark respiration (R<sub>d</sub>), intercellular CO<sub>2</sub>, light saturation (L<sub>sp</sub>) and water use efficiency significantly increased when light levels and CO<sub>2</sub> concentrations were elevated for both species, but not when temperatures were elevated. Stomatal conductance decreased when the CO<sub>2</sub> concentration doubled, but there were few effects from elevated temperature. These findings suggest that U. speciosa and U. crassifolia should be more common and imply that they will have a higher density in a future high CO<sub>2</sub> environment.
文摘Based on the photosynthesis-respiration reversible reaction and the available statistics, we attempted to quantify the planetary seasonal exchanges of CO<sub>2</sub> between air and water from 1970 and compared them to the glacial ACC cycles as reported from ice cores archives. In 2020, the overall continental absorption (AW) was 8.0 giga tonnes of carbon per year (GtC/y). Emissions into the atmosphere (EW) resulting from mineral degradation by respiration and combustion of biomass and fossil hydrocarbons were 14.7 GtC/y, an increase of 2.4% per year since 1970. The continental surplus balance (-AW+EW) of 6.7 GtC/y was shared between the atmosphere, which received 5.1 GtC/y (GATM), and the ocean which absorbed 1.6 GtC/y. This ocean contribution (OC) corresponded to 17% of the 9.2 GtC/y emissions by combustion of fossil hydrocarbons (EFOS). Analysis of the ACC oscillations during 2020 in the northern hemisphere showed that the ocean absorbed 11.1 GtC during the warm season and outgassed 9.5 GtC during the cold season. Assuming proportionality to world population, the ACC, 414 parts per million (ppm) in 2021, would reach 584 ppm in 2080, still growing at a rate of 0.6% per year. The gain of atmospheric CO<sub>2</sub> (GATM) and its absorption by the ocean (OC) were expected to peak at 7.0 and 2.2 GtC/y, respectively, in 2080. This increase in the availability of atmospheric CO<sub>2</sub> resulted in improved yields of agriculture which more than compensated for the reduction by half of food-producing areas per capita from 1970.
文摘The key for dust control of coal mine is to clarify the dust concentration distribution and sedimentation in different areas. Both similarity experiment and numerical simulation method have certain restrictions and are quite different from the actual situation on site. In order to study the dust sedimentation regularity of coal mine in large mining height, “filter membrane method” is adopted in this paper, i.e., to dry and weigh the filter membrane before and after sampling, collect the dust of respirable zone on mining face and calculate the dust concentration based on a main airway of 100 m. The result shows that: A large amount of dust will be produced during coal mining, wherein the maximum dust concentration from 6 m upstream to 100 m downstream of coal cutter is 121 mg/m3</sup>, while the minimum dust concentration is 61 mg/m3</sup>;The dust concentration in return airway is reduced with the distance increases, while the dust concentration at the entrance is 91 mg/m3</sup>;A large amount of dust may fall from roof during section advancing and improves the dust concentration of hydraulic support in walking area obviously;The dust granularity of mining face and return airway is 0 - 100 μm, but the amount of respirable dust is higher than 80%, the larger the dust particle size, the higher the dust concentration. Besides, dust in small particle size can be suspended in air flow for longer, but that in large particle size may subside under the action of gravity;To reduce dust exposure, the mining position shall be located in the windward direction of advancing or coal cutter. This research can provide guidance for taking dust prevention measures of working face in large mining height.
基金National Natural Sciences Foundation of China (Nos.40501072 and 40673067)the Major State Basic Research Develop-ment Program of China (No.2002CB 412503)the Knowledge Inno-vation Program of the Institute of Geographic Sciences and Natural Re-sources Research,CAS "The effect of human activities on regional envi-ronmental quality,the health risk and the environmental remediation"
文摘The diurnal and seasonal dynamics of soil respiration in the A. ordosica shrubland on Ordos Plateau were investigated in the growing season (May-October) of 2006 and their environmental driving factors were also analyzed, Results indicated that diurnal dynamics of soil respiration rate and its temperature dependence showed some discrepancy in two different growth stages (the vegetative growth stage and the reproductive growth stage). During the vegetative growth stage, the diurnal variation of soil respiration was slight and not correlated with the daily temperature change, but during the reproductive growth stage, the daily respiration variation was relatively large and significantly correlated with the diurnal variation of air and soil temperature. In the growing season, the peak value of soil respiration occurred at July and August because of the better soil water-heat conditions and their optimal deployment in this period. In the shrubland ecosystem, precipitation was the switch of soil respiration pulses and can greatly increase soil respiration rates after soil rewetting. Moreover, the soil respiration rates in the growing season and the air temperature and soil surface water content were closely correlated (p〈0.05) each other. The stepwise regression model indicated that the variation of soil surface moisture accounted for 41.9% of the variation in soil respiration (p〈0.05).
文摘AIM:To present and integrate findings of studies investigating the effects of laparoscopic cholecystectomy on various aspects of lung function.METHODS:We extensively reviewed literature of the past 24 years concerning the effects of laparoscopic cholecystectomy in comparison to the open procedure on many aspects of lung function including spirometricvalues,arterial blood gases,respiratory muscle performance and aspects of breathing control,by critically analyzing physiopathologic interpretations and clinically important conclusions.A total of thirty-four articles were used to extract information for the meta-analysis concerning the impact of the laparoscopic procedure on lung function and respiratory physiopathology.The quality of the literature reviewed was evaluated by the number of their citations and the total impact factor of the corresponding journals.A fixed and random effect meta-analysis was used to estimate the pooled standardized mean difference of studied parameters for laparoscopic(LC)and open(OC)procedures.A crude comparison of the two methods using all available information was performed testing the postoperative values expressed as percentages of the preoperative ones using the Mann-Whitney two-sample test.RESULTS:Most of the relevant studies have investigated and compared changes in spirometric parameters.The median percentage and interquartile range(IQR)of preoperative values in forced vital capacity(FVC),forced expiratory volume in 1 s and forced expiratory flow(FEF)at 25%-75%of FVC(FEF25%-75%)expressed as percentage of their preoperative values 24 h after LC and OC were respectively as follows:[77.6(73.0,80.0)L vs 55.4(50.0,64.0)L,P<0.001;76.0(72.3,81.0)L vs 52.5(50.0,56.7)L,P<0.001;and 78.8(68.8,80.9)L/s vs 60.0(36.1,66.1)L/s,P=0.005].Concerning arterial blood gases,partial pressure of oxygen[Pa O2(k Pa)]at 24 or 48 h after surgical treatment showed reductions that were significantly greater in OC compared with LC[LC median 1.0,IQR(0.6,1.3);OC median 2.4,IQR(1.2,2.6),P=0.019].Fewer studies have investigated the effect of LC on respiratory muscle performance showing less impact of this surgical method on maximal respiratory pressures(P<0.01);and changes in the control of breathing after LC evidenced by increase in mean inspiratory impedance(P<0.001)and minimal reduction of duty cycle(P=0.01)compared with preoperative data.CONCLUSION:Laparoscopic cholecystectomy seems to be associated with less postoperative derangement of lung function compared to the open procedure.