More tree growth reduction due to consecutive drought and its legacy effect for a semiarid larch plantation in Northwest China

Extreme climate has increasingly led to negative impacts on forest ecosystems globally,especially in semiarid areas where forest ecosystems are more vulnerable.However,it is poorly understood how tree growth is affected by different drought events.In 2006–2009,the larch plantations in the semiarid areas of Northwest China were negatively affected by four consecutive dry years,which was a very rare phenomenon that may occur frequently under future climate warming.In this study,we analyzed the effect of these consecutive dry years on tree growth based on the data of the tree rings in the dominant layer of the forest canopy on a larch plantation.We found that the tree-ring width index(RWI)in dry years was lower than that in normal years,and it experienced a rapidly decreasing trend from 2006 to 2009(slope=-0.139 year^(-1),r=-0.94)due to water supply deficits in those dry years.Drought induced legacy effects of tree growth reduction,and consecutive dry years corresponded with greater growth reductions and legacy effects.Growth reductions and legacy effects were significantly stronger in the third and fourth consecutive dry years than that of single dry year(p<0.05),which might have been due to the cumulative stress caused by consecutive dry years.Our results showed that larch trees experienced greater tree growth reduction due to consecutive dry years and their legacy effect,and the trees had lower recovery rates after consecutive dry years.Our results highlight that consecutive dry years pose a new threat to plantations under climate warming,and thus,the effect of climate extremes on tree growth should be considered in growth models in semiarid areas.

Variations in stem radii of Larix principis-rupprechtii to environmental factors at two slope locations in the Liupan Mountains,northwest China

Relationships between stem growth and climatic and edaphic factors,notably air temperatures and soil moisture for different slopes,are not completely understood.Stem radial variations were monitored at the bottom and top slope positions in a Larix principis-rupprechtii plantation during the 2017 and 2018 growing seasons.Total precipitation during the growing season in 2017 and 2018 was 566 mm and 728 mm,respectively.Stem contractions typically occurred after mid-morning followed by swelling in the late afternoon in both plots,reflecting the diurnal cycle of water uptake and loss.Trees at the two locations showed the same growth initiation(mid-May)because of the small differences in air and soil temperatures.There were no significant differences in cumulative stem radial growth between the bottom plot(1.57±0.34 mm)and the top plot(1.55±0.26 mm)in 2018.However,in 2017,the main growth period of the bottom plot ceased 17 days earlier than in the top plot,while cumulative seasonal growth of the bottom plot(1.08±0.25 mm)was significantly less than the top plot(1.54±0.43 mm).Maximum daily stem shrinkage was positively correlated with air and soil temperatures,solar radiation,vapor pressure deficits,and negatively correlated with volumetric soil moisture content.The maximum daily shrinkage reflected transpiration rates as affected by environmental factors.Daily radial stem increment was correlated with precipitation and volumetric soil moisture in both years,but with air temperatures only in 2017.The seasonal growth of L.principis-rupprechtii Mayr thus shows interannual dynamics,while precipitation constitutes a key driving factor.

ILF2 cooperates with E2F1 to maintain mitochondrial homeostasis and promote small cell lung cancer progression

Objective:Mitochondria play multifunctional roles in carcinogenesis.Deciphering uncertainties of molecular interactions within mitochondria will promote further understanding of cancer.Interleukin enhancer binding factor 2(ILF2)is upregulated in several malignancies,however,much remains unknown regarding ILF2 in small cell lung cancer(SCLC).In the current study,we explored ILF2's role in SCLC and demonstrated its importance in mitochondria quality control.Methods:Colony formation,cell proliferation,cell viability and xenograft studies were performed to examine ILF2's role on SCLC progression.Glucose uptake,lactate production,cellular oxygen consumption rate and extracellular acidification rate were measured to examine the effect of ILF2 on glucose metabolism.RNA-sequencing was utilized to explore genes regulated by ILF2.E2 F1 transcriptional activity was determined by dual luciferase reporter assay.Mitochondria quantification and mitochondrial membrane potential assays were performed to examine mitochondrial quality.Gene expression was determined by RT-qPCR,Western blot and IHC assay.Results:ILF2 promotes SCLC tumor growth in vitro and in vivo.ILF2 elevates oxidative phosphorylation expression and declines glucose intake and lactate production.Genome-wide analysis of ILF2 targets identified a cohort of genes regulated by E2 F1.In consistent with this,we found ILF2 interacts with E2 F1 in SCLC cells.Further studies demonstrated that suppression of E2 F1 expression could reverse ILF2-induced tumor growth and enhanced mitochondria function.Significantly,expression of ILF2 is progressively increased during SCLC progression and high ILF2 expression is correlated with higher histologic grades,which indicates ILF2's oncogenic role in SCLC.Conclusions:Our results demonstrate that ILF2 interacts with E2 F1 to maintain mitochondria quality and confers SCLC cells growth advantage in tumorigenesis.

Environmental and canopy conditions regulate the forest floor evapotranspiration of larch plantations

Background:Integrated forest-water management focusing on forest-water coordination is an important way to alleviate water use conflicts among forests and other sectors in vast dryland regions.Forest floor evapotranspiration(FE),which is an important component of forest evapotranspiration,accounts for a large proportion of the water consumed in arid forests.Elucidating how environmental and canopy conditions impact FE has important significance for guiding integrated forest-water management in a changing environment.Methods:The microlysimeter(ML)-measured evapotranspiration(FE_(ML)),reference evapotranspiration(ET_(o)),volumetric soil moisture(VSM),and canopy leaf area index(LAI)were monitored in a Larix principis-rupprechtii plantation located in the semi-humid Liupan Mountains of Northwest China in 2019(June–September)and 2021(May–September).The response functions of the FE coefficient(the ratio of daily FEML to ET_(o))to the individual factors of VSM and LAI were determined using upper boundary lines of scatter diagrams of measured data.The framework of the daily FE(FE_(ML))model was established by multiplying the response functions to individual factors and then calibrated and validated using measured data to assess the FE response to environmental and canopy conditions.Results:(1)The FE coefficient increased first rapidly and then slowly with rising VSM but decreased slowly with rising LAI.(2)The simple daily FE(FE_(ML))model developed by coupling the impacts of ET_(o),LAI,and VSM in this study performed well for predicting FE.(3)The impacts of ET_(o),LAI,and VSM were quantified using the FE(FE_(ML))model,e.g.,at a given VSM,the impact of ETo on FE increased obviously with decreasing LAI;at a given ET_(o),the impact of LAI on FE increased with rising VSM.(4)In the two study years,when directly using the microlysimeter measurement,the real FE on the forest floor was overestimated when the VSM in microlysimeters was above 0.215 but underestimated below 0.215 due to the difference in VSM from the forest floor.Thus,the VSM on the forest floor should be input into the FE model for estimating the real FE on the forest floor.Conclusions:The daily FE of larch plantation is controlled by three main factors of environmental(ET_(o) and VSM)and canopy conditions(LAI).The variation in daily FE on the forest floor can be well estimated using the simple FE model coupling the effects of the three main factors and by inputting the VSM on the forest floor into the model to avoid the errors when directly using the microlysimeter measurement with different VSMs from the forest floor.The developed FE model and suggested prediction approach are helpful to estimate the FE response to changing conditions,and to guide forest management practices when saving water by thinning is required.

Characteristics of canopy interception and its simulation with a revised Gash model for a larch plantation in the Liupan Mountains, China

Canopy interception is a significant proportion of incident rainfall and evapotranspiration of forest ecosystems. Hence, identifying its magnitude is vital for studies of eco-hydrological processes and hydrological impact evaluation. In this study, throughfall, stemflow and interception were measured in a pure Larix principis-rupprechtii Mayr.（larch） plantation in the Liupan Mountains of northwestern China during the growing season（May–October） of 2015, and simulated using a revised Gash model. During the study period, the total precipitation was 499.0 mm; corresponding total throughfall, stemflow and canopy interception were 410.3, 2.0 and 86.7 mm,accounting for 82.2, 0.4 and 17.4% of the total precipitation, respectively. With increasing rainfall, the canopy interception ratio of individual rainfall events decreased initially and then tended to stabilize. Within the study period, the simulated total canopy interception, throughfall and stemflow were 2.2 mm lower, 2.5 mm higher and 0.3 mm lower than their measured values, with a relative error of 2.5, 0.6 and 15.0%, respectively. As quantified by the model, canopy interception loss（79%） mainly consisted of interception caused by canopy adsorption, while the proportions of additional interception and trunk interception were small. The revised Gash model was highly sensitive to the parameter of canopy storage capacity,followed by the parameters of canopy density and mean rainfall intensity, but less sensitive to the parameters of mean evaporation rate, trunk storage capacity, and stemflow ratio. The revised Gash model satisfactorily simulated the total canopy interception of the larch plantation within the growing season but was less accurate for some individual rainfall events, indicating that some flaws exist in the model structure. Further measures to improve the model’s ability in simulating the interception of individual rainfall events were suggested.

One-pot green mass production of hierarchically porous carbon via a recyclable salt-templating strategy

Porous carbon materials have exhibited a series of promising applications in supercapacitors and other research fields,yet still confronting the complicated synthetic procedures and massive usage of toxic reagents.Herein,we propose a green and one-pot method to produce heteroatomdoped hierarchical porous carbon materials in large-scale without any toxic reagents employed.Eventually,the as-prepared nitrogen-doped porous carbon(NPC)displays a high specific surface area of 2018 m^(2)g^(-1)together with abundant heteroatom dopants(14.8 wt%O and 1.03 wt%N).The potassium carbonate template can be recycled via a simple rinsing and re-precipitation process.Furthermore,the as-prepared nitrogen-doped porous carbon delivers a high specific capacitance of 361 F g^(-1)at 0.5 A g^(-1)and excellent rate capability of 240 F g^(-1)at 20 A g^(-1)(66.5%capacitance retention).Finally,considering the low-price raw materials and facile green synthesis procedure,the present approach can be easily scalable to prepare biomass-derived heteroatoms doped porous carbon,which is not only applicable for supercapacitor but also for other research fields.

Investigation of NO removal using a pulseassisted RF discharge

In this paper,removal of nitrogen oxide（NO） is investigated in capacitive atmospheric pressure discharges driven by both radio-frequency（RF） and trapezoidal pulsed power with a onedimensional self-consistent fluid model.The results show that the number density of NO could be reduced significantly once a short pulse of low duty ratio is additionally applied to the RF power.It is found that the process of NO removal by the pulse-modulated RF discharge could be divided into three stages：the quick reaction stage,the NO removal stage,and the sustaining stage.Furthermore,the temporal evolution of particle densities is analyzed,and the key reactions in each stage are discovered.Finally,the influence on the removal efficiency of the voltage amplitude of the pulse and the RF voltage amplitude is investigated.

Modelling the response of larch growth to age,density,and elevation and the implications for multifunctional management in northwest China

Plantations of Rupprecht's larch(Larix principis-rupprechtii)have been widely established in the drylands of northwest and north China under traditional fastgrowing plantation management strategies.These strategies and the long-term logging ban have led to over-populated stands with lower structural and functional stability,less economic benefit and higher water consumption.To guide the sustainable management of larch plantations,field surveys and historical data compilation were undertaken in the Liupan Mountains of northwest China.The main influencing factors(stand structure and site condition)and their effects on mean tree height,mean DBH and timber volumes were determined based on up-boundary line analysis.Tree growth models coupling the effects of tree age,stand density,and elevation were established.Both height and DBH markedly increased initially and then slowly with tree age,decreased with stand density,and showed unimodal change with elevation.The coupled growth models accounted for72-78%of the variations in tree height,DBH and timber growth.Recommendations for future plantation management are:(1)prolong the rotation to at least 60 years to produce large-diameter,high-quality timber and maintain greater carbon stocks;(2)zone the target functions of stands by elevation;and,(3)reduce stand density for balanced supply of multiple ecosystem services.The growth models developed can predict growth response of larch plantations to density alteration under given ages and elevations,and assist the transformation from traditional management for maximum timber production to site-specific and multifunctional management with longer rotations and moderate tree density.

Impacts of environmental and canopy conditions on the nighttime sap flow of larch plantations in the Liupan Mountains,China

Nighttime sap flow(Q_(n))is an important physiological activity under which trees manage drought stress.An in-depth understanding of the characteristics of Q_(n)and its response to environmental and canopy conditions are of significance for arid area forest and water management.This study measured daily sap flow(Q_(s))of a Larix principis-rupprechtii plantation in the Liupan Mountains,northwest China during the 2017-2019 growing seasons,and separated Q_(s)into daytime sap flow(Qd)and Q_(n).Meteorological conditions(reference evapotranspiration,ETref),canopy structure(leaf area index,LAI),and soil moisture(relative soil water content,RSWC)were considered as the main biophysical factors affecting Q_(n).The structural equation model and upper boundary line method determined the effects of compound and single factors on Q_(n)The daily mean Q_(n)values during the growing seasons in 2017,2018,and 2019 were 0.024,0.026,and 0.030 mm d-1,accounting for 6.2,11.2,and 10.1%of Q_(s),respectively.Q_(n)at different canopy development phases(leaf expanding,LG;leaf expanded,LD;and defoliation,DF)over three years was LD>LG>DF.Q_(n)increased with increasing ETref,whereas the ratio of Q_(n)to Q_(s)decreased.Q_(n)did not show regular variation in the three-year growing seasons under different soil moisture conditions.ETrefand LAI mainly controlled Q_(n)by affecting Qd,whereas RSWC had no significant effect on Q_(n).Q_(n)had a positive and linear relationship with LAI and a quadratic relationship with ETref.Both explained 40%of variation in Q_(n)Meteorological and canopy conditions are important factors affecting Q_(n)on the semi-humid study site.The application of the Q_(n)model coupled with the impact of ETrefand LAI furthers understanding of the impacts of climate and forest structure change on Q_(n).

Importance Analysis of Urban Rail Transit Network Station Based on Passenger

Current urban rail transit has become a major mode of transportation, and passenger is an important factor of urban rail transport, so this article is based on passenger and the degree of the road network structure, calculating the point intensity of stations of urban rail transit, and then reaching a station importance by integrating many point intensities in a survey cycle time, and getting the station importance of urban rail transit network through concrete examples.

The mitochondrial genomes of Macrocheraia grandis grandis and Myrmoplasta mira(Hemiptera:Heteroptera:Pentatomomorpha) and the unique mitogenome rearrangement in Pyrrhocoroidea

Sequencing technology has developed rapidly in recent years. Complete or nearly complete mitochondrial genomes(mitogenomes) of 155 species from 47 families in Heteroptera have been sequenced. However, the amounts of mitogenomes between those families are unbalanced, which makes it difficult to correctly discern the patterns of mitogenome rearrangement in Heteroptera. Among 21 species from ten families, ten variations in mitogenome rearrangement had been previously reported, among which the translocation between tRNA-Thr and tRNA-Pro was considered as a synapomorphy of Pyrrhocoroidea based on two mitogenomes. As only one mitogenome in each of Largidae and Pyrrhocoridae had been sequenced to conclude the synapomorphy, more mitogenomes of Pyrrhocoroidea need to be explored. In this study, additional two mitogenomes of Pyrrhocoroidea(Macrocheraia grandis grandis(Gray, 1832) and Myrmoplasta mira Gerst-cker, 1892) were sequenced. Both of them also possess the same translocation between tRNA-Thr and tRNA-Pro, which reaffirms that this kind of rearrangement is a molecular synapomorphy of Pyrrhocoroidea. Moreover, we discovered a more complex rearrangement in Myrmoplasta mira, in which six nearly identical duplications of tRNA-Thr were found located downstream of tRNA-Pro. Considering the high biodiversity of Heteroptera, more mitogenomic studies are needed to improve our knowledge about mitogenome rearrangements and the potential synapomorphies.

Numerical study of atmospheric-pressure argon plasma jet propagating into ambient nitrogen

A 2D axial symmetry fluid model is applied to study the features of an atmospheric-pressure argon(Ar) plasma jet propagating into ambient nitrogen(N_(2)) driven by a pulsed voltage,emphasizing the influence of gas velocity on the dynamic characteristics of the jet. The results show that the Ar jet exhibits a cylindrical-shaped channel and the jet channel gradually shrinks with the increase in propagation length. The jet propagation velocity varies with time. Inside the dielectric tube, the plasma jet accelerates propagation and reaches its maximum value near the nozzle. Exiting the tube, its velocity quickly decreases and when approaching the metal plane,the decrease in jet velocity slows down. The increase in gas speed results in the variation of jet spatial distribution. The electron density presents a solid structure at lower gas flow speeds,whereas an annular structure can be observed under the higher gas flow velocity in the ionization head. The jet length increases with the flow velocity. However, when the flow velocity exceeds a critical value, the increase in the rate of the plasma jet length slows down. In addition, the gas velocity effect on the generation and transport of the reactive particles is also studied and discussed.

M^(2)LC-Net: A Multi-Modal Multi-Disease Long-Tailed Classification Network for Real Clinical Scenes

Leveraging deep learning-based techniques to classify diseases has attracted extensive research interest in recent years.Nevertheless,most of the current studies only consider single-modal medical images,and the number of ophthalmic diseases that can be classified is relatively small.Moreover,imbalanced data distribution of different ophthalmic diseases is not taken into consideration,which limits the application of deep learning techniques in realistic clinical scenes.In this paper,we propose a Multimodal Multi-disease Long-tailed Classification Network(M^(2)LC-Net)in response to the challenges mentioned above.M^(2)LC-Net leverages ResNet18-CBAM to extract features from fundus images and Optical Coherence Tomography(OCT)images,respectively,and conduct feature fusion to classify 11 common ophthalmic diseases.Moreover,Class Activation Mapping(CAM)is employed to visualize each mode to improve interpretability of M^(2)LC-Net.We conduct comprehensive experiments on realistic dataset collected from a Grade III Level A ophthalmology hospital in China,including 34,396 images of 11 disease labels.Experimental results demonstrate effectiveness of our proposed model M^(2)LC-Net.Compared with the stateof-the-art,various performance metrics have been improved significantly.Specifically,Cohen’s kappa coefficient κ has been improved by 3.21%,which is a remarkable improvement.

Optimization of Extraction Conditions for Total Flavonoids from Fructus Aurantii Immaturus and Its Anti-UVB Radiation Activity

[Objectives]Optimum extraction conditions of total flavonoids from Fructus Aurantii Immaturus(TFFAI)and its resistance activity to ultraviolet radiation were investigated in present research.[Methods]The optimal extraction conditions of TFFAI were determined by single factor and orthogonal experiments,and the survival rate of TFFAI on HaCaT cells irradiated with UVB rays was investigated.It s antioxidant capacity was determined by ABTS.[Results]The results showed that the highest yield of TFFAI was obtained with 70%ethanol at a solid-to-liquid ratio of 1:50(w/v)and 40℃for 1.5 h by single-factor and orthogonal experiments.Total flavonoids(0.25-1.00 mg/ml)could significantly improve the survival rate of HaCaT cell line.Meanwhile,the maximum absorption peak of TFFAI was found at 283 nm,and in-vitro antioxidant experiment identified that TFFAI had a good clearance rate to ABTS.It suggestes that TFFAI could protect the cells from UVB damage by absorption of UVB rays and anti-oxidation.[Conclusions]TFFAI played a protective role on UVB irradiated cells through UVB ultraviolet absorption and antioxidant pathways.

Target Resistance of Eleusine indica to Glyphosate

[Objectives]This study was conducted to detect the evolution of resistance to glyphosate in Eleusine indica.[Methods]In the previous study,glyphosate-resistant population T2-4 was screened out from E.indica populations in sugarcane fields in Guangxi.In this study,we determined the resistance index of T2-4 by whole plant bioactivity assay and further explored the molecular biological mechanism of resistance.[Results]The resistance index of T2-4 was 112,and it is thus a highly resistant population.Amino acid mutations were found at positions 102,106 and 381 in the EPSPS sequence of T2-4,containing at least a triple mutation allele in Thr-102-Ile,Pro-106-Ser and Pro-381-Leu and a double mutation allele in Pro-106-Ser and Pro-381-Leu.qPCR was used to determine the EPSPS gene copy number and expression in resistant plants of T2-4.EPSPS gene copy number and expression both increased,with 8.3-fold higher copy number and 2.7-fold higher expression than the sensitive population.Therefore,the resistance of T2-4 to glyphosate was mainly caused by multiple target mechanisms including mutation of EPSPS gene,copy number increase and expression increase,and the resistance of E.indica to glyphosate needs our high attention.[Conclusions]At present,the level of resistance to glyphosate is very high in the sugarcane fields of Guangxi,and it is necessary to take a variety of weed control measures to solve the problem of glyphosate resistance.

Studies on the Distribution Characteristics of the Cloud-to-Ground Lightning and Its Disasters Prevention in Xinjiang, China in 2017

Xinjiang, China is affected by geographical terrain and other factors, and is prone to lightning disasters. In order to effectively carry out lightning protection and disaster reduction work and improve defense capabilities, based on the data of lightning location monitoring in Xinjiang in 2017 and the statistics reports of the lightning disasters from 2015 to 2017, the characteristics of the cloud-to-ground (CG) lightning activities and disasters in Xinjiang were statistically analyzed. The results show that the CG lightning in Xinjiang is mainly the negative one, accounting for 79.7% of the total lightning. In 2017, the distribution of positive, negative and total the CG lightning months mainly focuses on June to August, and the main occurrence period is from 14 to 23 hours. The intensity of total the CG lightning and negative the CG lightning mainly distributes from 20 to 40 kA, and the peak value appears in 30 kA. The CG lightning intensity is mainly distributed in 30 - 70 kA. The distribution of the CG lightning density in Xinjiang is larger in the north than in the south and larger in the west than in the east. Lightning disasters mainly occur from May to August, accounting for 93.2 percent of the total, with the largest number in June. From 2005 to 2017, 44.6% of lightning accidents occurred in farming and pastoral areas, followed by civil electronic equipment damage. In addition, electrical equipment, buildings and factory equipment are damaged by lightning strikes to varying degrees.

Severe pseudo-stenosis of intracranial segment of verte-bral artery:a case report

Objective:To describe the clinical fea-tures of a case of ischemic stroke caused by pseudo severe stenosis of vertebral artery(VA).Methods:The clinical history and image data of a 52-year-old man with ischemic stroke were collected.Results:Computerized tomography angiography(CTA)revealed stenosis of V1 and V4 of the left VA.DSA confirmed that the anterior blood flow recov-ered after stent implantation,and the V4 segment of the left VA was normal without stenosis.Conclusions:It is spec-ulated that the upper stenosis is due to local hemodynamic changes rather than real stenosis.This case suggests that the interpretation of stenosis on CTA should consider cere-bral vascular anatomy and hemodynamic changes.

Mixing state and evolutionary mechanism of oxalic acid homologs in Liaocheng,East China:Insights from seasonal and hourly observations

Oxalic acid(C_(2))is a significant tracer of secondary organic aerosols(SOA),yet its precursors,evolutionary processes,and formation mechanisms are not fully understood.This knowledge gap leads to uncertainties in evaluating the climate effect and global budget of SOA.Here we compared the size distribution,mixing fraction,and evolutionary mechanism of C_(2)-containing particles between summer and winter.In summer,the number of C_(2) particles and their homologs decreased compared to winter.However,the proportion of C_(2) relative to the total number of determined particles increased,indicating that the summertime particles are more aged.Higher relative aerosol acidity(Rra)and lower in-situ pH(pHis)in summer suggest that particles are more acidic during this season.Correlation analysis and temporal variation characteristics suggest that from 9:00 to 15:00 in summer,C_(2) particles mostly originate from the photochemical decomposition of larger dicarboxylic aids,driven by O3 concentration.Conversely,from 16:00 to 20:00,C_(2) particles are predominantly formed through aqueous-phase oxidation,influenced by higher relative humidity(RH),aerosol liquid water content(ALWC),and acidity.Additionally,heavy metal particles were the predominant type of C_(2) particles,and C_(2) particles exhibited an opposite diurnal variation to Fe in summer,suggesting that the photolysis of iron oxalate complexes is an important sink of C_(2) particles during this period.In winter,biomass burning(BB)particles were the most abundant,and a robust correlation between levoglucosan and C_(2) particles indicated a substantial influence of BB on C_(2) particles.The aqueous generation of C_(2) particles fromα-dicarbonyls driven by acidity was most effective when RH varied from 40%to 60%in the wintertime state of particles.These findings highlight the hourly and seasonal variations in the sources and evolutionary processes of SOA.Such variations must be considered in developing control measures and simulating the climate effect of SOA.

血浆吸附治疗老年重型新型冠状病毒感染1例

新型冠状病毒感染(coronavirus disease 2019,COVID-19)是一种新发急性感染性疾病,人群普遍易感,以发热、乏力、干咳为主要表现,重症/危重症患者在发病早期即可出现呼吸困难和(或)低氧血症,快速进展为急性呼吸窘迫综合征(acute respiratory distress syndrome,ARDS)、脓毒症休克、难以纠正的代谢性酸中毒和出凝血功能障碍及多器官功能衰竭等。高龄(>60岁)及合并基础疾病是造成重型/危重型新冠病毒感染患者高病死率的重要原因[1]。如何降低重型/危重型患者的病死率,是其救治的重点和难点。我们对1例老年重型COVID-19患者进行血浆吸附治疗,在阻止ARDS进展方面取得良好的效果,现将诊治过程和体会报道如下。

miR-495 andmiR-5688 are down-regulated in non-small cell lung cancer under hypoxia to maintain interleukin-11 expression

Background:Hypoxia is a hallmark of cancer and is associated with poor prognosis.However,the molecular mechanism by which hypoxia promotes tumor progression remains unclear.MicroRNAs dysregulation has been shown to play a critical role in the tumor and tumor microenvironment.Here,we investigated the roles ofmiR-495 and miR-5688 in human non-small cell lung cancer(NSCLC)and their underlying mechanism.Methods:The expression levels of miR-495 and miR-5688 in human NSCLC tissue specimens were measured by quantitative real-time polymerase chain reaction(qRT-PCR).Deferoxamine(DFO)was used to determine whether the regulation of miR-495 and miR-5688 under hypoxia was dependent on hypoxia-inducible factor 1-alpha(HIF-1α).Furthermore,the functions of miR-495 and miR-5688 in tumor progression were evaluated using colony formation,3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2Htetrazolium(MTS),wound healing,transwell assays,and xenograft model.Two algorithms,PicTAR and Targetscan,were used to predict the target gene of these two miRNAs,and dual-luciferase reporter assay was conducted to confirm the target.The unpaired two-tailed t test,Pearson correlation analysis,and Fisher’s exact probability test were performed for statistical analyses.Results:Two miRNAs,miR-495 and miR-5688,were found to participate in NSCLC progression under hypoxia.They were down-regulated in NSCLC tissues compared with normal tissues.We determined that hypoxia led to the down-regulation of miR-495 and miR-5688 in NSCLC cells,which was independent of HIF-1αand cellular metabolic energy.In addition,miR-495 and miR-5688 suppressed cell proliferation,migration,and invasion in vitro.The NSCLC xenograft model showed that miR-495 and miR-5688 inhibited tumor formation in vivo.Interestingly,we found that miR-495 and miR-5688 had the same target,interleukin-11(IL-11).Recombinant human IL-11 counteracted the effects of miR-495 and miR-5688 on NSCLC cells,suggesting that miR-495 and miR-5688 executed their tumor suppressive role by repressing IL-11 expression.Conclusion:We found that hypoxia down-regulated the expression levels of miR-495 and miR-5688 in NSCLCto enhance IL-11 expression and tumor progression,indicating that the miR-495/miR-5688/IL-11 axismay serve as a therapeutic target and potential biomarker for NSCLC.