BACKGROUND Laparoscopic surgery has reduced morbidity and mortality rates,shorter post-operative recovery periods and lower complication rates than open surgery.It is routine practice in high-income countries and is b...BACKGROUND Laparoscopic surgery has reduced morbidity and mortality rates,shorter post-operative recovery periods and lower complication rates than open surgery.It is routine practice in high-income countries and is becoming increasingly common in countries with limited resources.However,introducing laparoscopic surgery in low-and-middle-income countries(LMIC)can be expensive and requires resour-ces,equipment,and trainers.AIM To report the challenges and benefits of introducing laparoscopic surgery in LMIC as well as to identify solutions to these challenges for countries with limited finances and resources.METHODS MEDLINE,EMBASE and Cochrane databases were searched for studies reporting first experience in laparoscopic surgery in LMIC.Included studies were published between 1996 and 2022 with full text available in English.Exclusion criteria were studies considering only open surgery,ear,nose,and throat,endoscopy,arthro-scopy,hysteroscopy,cystoscopy,transplant,or bariatric surgery.RESULTS Ten studies out of 3409 screened papers,from eight LMIC were eligible for inclusion in the final analysis,totaling 2497 patients.Most reported challenges were related to costs of equipment and training programmes,equipment pro-blems such as faulty equipment,and access to surgical kits.Training-related challenges were reliance on foreign trainers and lack of locally trained surgeons and theatre staff.The benefits of introducing laparoscopic surgery were economic and clinical,including a reduction in hospital stay,complications,and morbidi-ty/mortality.The introduction of laparoscopic surgery also provided training opportunities for junior doctors.CONCLUSION Despite financial and technical challenges,many studies emphasise the overall benefit of introducing laparoscopic surgery in LMICs such as reduced hospital stay and the related lower cost for patients.While many of the clinical centres in LMICs have proposed practical solutions to the challenges reported,more support is critically required,in particular regarding training.展开更多
BACKGROUND Undernutrition is a crucial cause of morbidity and mortality among children in low-or middle-income countries(LMICs).A better understanding of maternal general healthy nutrition knowledge,as well as misbeli...BACKGROUND Undernutrition is a crucial cause of morbidity and mortality among children in low-or middle-income countries(LMICs).A better understanding of maternal general healthy nutrition knowledge,as well as misbeliefs,is highly essential,especially in such settings.In the current era of infodemics,it is very strenuous for mothers to select not only the right source for maternal nutrition information but the correct information as well.AIM To assess maternal healthy nutritional knowledge and nutrition-related misbeliefs and misinformation in an LMIC,and to determine the sources of such information and their assessment methods.METHODS This cross-sectional analytical observational study enrolled 5148 randomly selected Egyptian mothers who had one or more children less than 15 years old.The data were collected through online questionnaire forms:One was for the general nutrition knowledge assessment,and the other was for the nutritional myth score.Sources of information and ways of evaluating internet sources using the Currency,Relevance,Authority,Accuracy,and Purpose test were additionally analyzed.RESULTS The mean general nutrition knowledge score was 29±9,with a percent score of 70.8%±12.1%(total score:41).The median myth score was 9(interquartile range:6,12;total score:18).The primary sources of nutrition knowledge for the enrolled mothers were social media platforms(55%).Half of the mothers managed information for currency and authority,except for considering the author's contact information.More than 60%regularly checked information for accuracy and purpose.The mothers with significant nutrition knowledge checked periodically for the author's contact information(P=0.012).The nutrition myth score was significantly lower among mothers who periodically checked the evidence of the information(P=0.016).Mothers dependent on their healthcare providers as the primary source of their general nutritional knowledge were less likely to hold myths by 13%(P=0.044).However,using social media increased the likelihood of having myths among mothers by approximately 1.2(P=0.001).CONCLUSION Social media platforms were found to be the primary source of maternal nutrition information in the current era of infodemics.However,healthcare providers were the only source for decreasing the incidence of maternal myths among the surveyed mothers.展开更多
Using the daily data of temperature from China Meteorological Administration and the NCEP/NCAR reanalysis from 1960 to 2005, we have analyzed the relationships between the summertime high/low temperature events in the...Using the daily data of temperature from China Meteorological Administration and the NCEP/NCAR reanalysis from 1960 to 2005, we have analyzed the relationships between the summertime high/low temperature events in the middle and lower reaches of the Yangtze River (MLRYR) and the related circulation anomalies in the Eastern Hemisphere. Our results have demonstrated that a significantly increasing trend is observed in daily minimum temperature in the past 50 years. And in some regions in the Northern Hemisphere, the opposite scenarios are observed in circulation anomalies in lower and upper parts of the troposphere in the years when the temperatures are higher than normal, as compared to those in the years when the temperatures are lower than normal in the middle and lower reaches of the Yangtze River (MLRYR). Additionally, the anomalous circulation structure in vertical direction in both the high and lower temperature years are barotropic. It is found that the emergence and maintenance of the aforementioned anomalous circulations are related to three kinds of wave train teleconnection patterns. Further more, influences of the long wave surface radiation on the air temperature are stronger in the nighttime than that in the daytime. While both the maximum and minimum temperatures have negative relationships with the sensible heat flux but positive relationships with the latent heat flux. To some extent, the anomalous dynamic heating (cooling) caused by the vertical thermal advection as well as the diabatic heating (cooling) caused by diabatic processes can explain the formation of the high (low) temperature events in the middle and lower reaches of the Yangtze River (MLRYR) in boreal summer.展开更多
Using the monthly geopotential heights and winds for 700 and 200 hPa for India during July and August, and the weekly M-100 Soviet rocketsonde temperature and wind data for Thumba (8.5 ° N, 76.9 ° E) during ...Using the monthly geopotential heights and winds for 700 and 200 hPa for India during July and August, and the weekly M-100 Soviet rocketsonde temperature and wind data for Thumba (8.5 ° N, 76.9 ° E) during the last week of June and the first week of September for the two contrasting summer monsoon years 1975 (a very strong monsoon year) and 1979 (a very weak monsoon year), a study has been made to examine the mean circulation features of the troposphere over India, and the structures of the temperatures and the winds of the middle atmosphere over Thumba. The study suggested that the axis of the monsoon trough (AMT) at 700 hPa shifted southward in 1975 and northward towards the foothills of the Himalayas in 1979, from its normal position. Superimposed on the low-pressure area (AMT) at 700 hPa, a well-defined divergence was noticed at 200 hPa over the northern India in 1975.The mean temperatures at 25,50 and 60 km (middle atmosphere) over Thumba were cooler in 1975 than in 1979. While a cooling trend in 1975 and warming trend in 1979 were observed at 25 and 50 km, a reversed picture was noticed at 60 km. There was a weak easterly / westerly (weak westerly phase) zonal wind in 1975 and a strong easterly zonal wind in 1979. A phase reversal of the zonal wind was observed at 50 km. A tentative physical mechanism was offered, in terms of upward propagation of the two equatorially trapped planetary waves i.e. the Kelvin and the mixed Rossby-gravity waves, to explain the occurrence of the two spells of strong warmings in the mesosphere in 1975.展开更多
CO oxidation is probably the most studied reaction in heterogeneous catalysis.This reaction has become a hot topic with the discovery of nanogold catalysts,which are active at low temperatures(at or below room temper...CO oxidation is probably the most studied reaction in heterogeneous catalysis.This reaction has become a hot topic with the discovery of nanogold catalysts,which are active at low temperatures(at or below room temperature).Au catalysts are the benchmark for judging the activities of other metals in CO oxidation.Pt-group metals(PGMs) that give comparable performances are of particular interest.In this mini-review,we summarize the advances in various PGM(Pt,Pd,Ir,Rh,Ru)catalysts that have high catalytic activities in low-temperature CO oxidation arising from reducible supports or the presence of OH species.The effects of the size of the metal species and the importance of the interface between the metal and the reducible support are covered and discussed in terms of their promotional role in CO oxidation at low temperatures.展开更多
Low-temperature deposition of diamond thin films in the range of 280 ̄445℃ has been successfully carried out by microwave plasma-assisted CVD method.At lower deposition temperatures (280 ̄445℃),the large increase in...Low-temperature deposition of diamond thin films in the range of 280 ̄445℃ has been successfully carried out by microwave plasma-assisted CVD method.At lower deposition temperatures (280 ̄445℃),the large increase in the nucleation density and great improvement in the average surfae roughness of the diamond were observed. Results of low temperature deposition and characterization of diamond thin films obtained are presented.展开更多
Developing efficient supported Pd catalysts and understanding their catalytic mechanism in CO oxidation are challenging research topics in recent years.This paper describes the synthesis of Pd nanoparticles supported ...Developing efficient supported Pd catalysts and understanding their catalytic mechanism in CO oxidation are challenging research topics in recent years.This paper describes the synthesis of Pd nanoparticles supported on CeO2 nanotubes via an alcohol reduction method.The effect of the support morphology on the catalytic reaction was explored.Subsequently,the performance of the prepared catalysts was investigated toward CO oxidation reaction and characterized by Nitrogen sorption,X-ray diffraction,X-ray photoelectron spectroscopy,transmission electron microscopy,and CO-temperature-programmed desorption techniques.The results indicated that the catalyst of Pd on CeO2 nanotubes exhibits excellent activity in CO oxidation at low temperatures,due to its large surface area,the high dispersion of Pd species,the mesoporous and tubular structure of the CeO2-nanotube support,the abundant Ce3+,formation of Pd–O–Ce bonding,and enhanced metal–support interaction on the catalyst surface.展开更多
The impact of alkyl dimethyl betaine (ADB) on the collection capacity of sodium oleate (NaOl) at low temperatures was evaluated using flotation tests at various scales. The low-temperature synergistic mechanism of ADB...The impact of alkyl dimethyl betaine (ADB) on the collection capacity of sodium oleate (NaOl) at low temperatures was evaluated using flotation tests at various scales. The low-temperature synergistic mechanism of ADB and NaOl was explored by infrared spectroscopy, X-ray photoelectron spectroscopy, surface tension measurement, foam performance test, and flotation reagent size measurement.The flotation tests revealed that the collector mixed with octadecyl dimethyl betaine (ODB) and NaOl in a mass ratio of 4:96 exhibited the highest collection capacity. The combined collector could increase the scheelite recovery by 3.48% at low temperatures of 8–12℃. This is particularly relevant in the Luanchuan area, which has the largest scheelite concentrate output in China. The results confirmed that ODB enhanced the collection capability of NaOl by improving the dispersion and foaming performance. Betaine can be introduced as an additive to NaOl to improve the recovery of scheelite at low temperatures.展开更多
Electrolyte design holds the greatest opportunity for the development of batteries that are capable of sub-zero temperature operation.To get the most energy storage out of the battery at low temperatures,improvements ...Electrolyte design holds the greatest opportunity for the development of batteries that are capable of sub-zero temperature operation.To get the most energy storage out of the battery at low temperatures,improvements in electrolyte chemistry need to be coupled with optimized electrode materials and tailored electrolyte/electrode interphases.Herein,this review critically outlines electrolytes’limiting factors,including reduced ionic conductivity,large de-solvation energy,sluggish charge transfer,and slow Li-ion transportation across the electrolyte/electrode interphases,which affect the low-temperature performance of Li-metal batteries.Detailed theoretical derivations that explain the explicit influence of temperature on battery performance are presented to deepen understanding.Emerging improvement strategies from the aspects of electrolyte design and electrolyte/electrode interphase engineering are summarized and rigorously compared.Perspectives on future research are proposed to guide the ongoing exploration for better low-temperature Li-metal batteries.展开更多
Fast-charging and low temperature operation are of vital importance for the further development of lithium-ion batteries(LIBs),which is hindered by the utilization of conventional carbonate-based electrolytes due to t...Fast-charging and low temperature operation are of vital importance for the further development of lithium-ion batteries(LIBs),which is hindered by the utilization of conventional carbonate-based electrolytes due to their slow kinetics,narrow operating temperature and voltage range.Herein,an acetonitrile(AN)-based localized high-concentration electrolyte(LHCE)is proposed to retain liquid state and high ionic conductivity at ultra-low temperatures while possessing high oxidation stability.We originally reveal the excellent thermal shielding effect of non-solvating diluent to prevent the aggregation of Li^(+) solvates as temperature drops,maintaining the merits of fast Li transport and facile desolvation as at room temperature,which bestows the graphite electrode with remarkable low temperature performance(264 mA h g^(-1) at-20 C).Remarkably,an extremely high capacity retention of 97%is achieved for high-voltage high-energy graphite||NCM batteries after 250 cycles at-20 C,and a high capacity of 110 mA h g^(-1)(71%of its room-temperature capacity)is retained at-30°C.The study unveils the key role of the non-solvating diluents and provides instructive guidance in designing electrolytes towards fast-charging and low temperature LIBs.展开更多
A rice low temperature-induced albino variant was determined by the recessive ltia1 and ltia2 genes.LTIA1 and LTIA2 encode highly conserved mini-ribonucleasesⅢlocated in chloroplasts and expressed in aerial parts of ...A rice low temperature-induced albino variant was determined by the recessive ltia1 and ltia2 genes.LTIA1 and LTIA2 encode highly conserved mini-ribonucleasesⅢlocated in chloroplasts and expressed in aerial parts of the plant.At low temperature,LTIA1 and LTIA2 redundantly affect chlorophyll levels,non-photochemical quenching,photosynthetic quantum yield of PSⅡand seedling growth.LTIA1 and LTIA2 proteins are involved in splicing of atp F and the biogenesis of 16S and 23S rRNA in chloroplasts.Presence/absence variation of LTIA1,the ancestral copy,was found only in japonica but that of LTIA2 in all rice subgroups.Accessions with LTIA2 presence tended to be distributed more remote from the equator compared to those with LTIA2 absence.LTIA2 duplicated from LTIA1 at the early stage of divergence of the AA genome Oryza species but deleted againin O.nivara.In cultivated rice,absence of LTIA2 is derived from O.nivara.LTIA1 absence occurred more recently in japonica.展开更多
Low-temperature,ambient processing of high-quality CsPbBr_(3)films is demanded for scalable production of efficient,low-cost carbon-electrode perovskite solar cells(PSCs).Herein,we demonstrate a crystal orientation en...Low-temperature,ambient processing of high-quality CsPbBr_(3)films is demanded for scalable production of efficient,low-cost carbon-electrode perovskite solar cells(PSCs).Herein,we demonstrate a crystal orientation engineering strategy of PbBr_(2)precursor film to accelerate its reaction with CsBr precursor during two-step sequential deposition of CsPbBr_(3)films.Such a novel strategy is proceeded by adding CsBr species into PbBr_(2)precursor,which can tailor the preferred crystal orientation of PbBr_(2)film from[020]into[031],with CsBr additive staying in the film as CsPb_(2)Br_(5)phase.Theoretical calculations show that the reaction energy barrier of(031)planes of PbBr_(2)with CsBr is lower about 2.28 eV than that of(O2O)planes.Therefore,CsPbBr_(3)films with full coverage,high purity,high crystallinity,micro-sized grains can be obtained at a low temperature of 150℃.Carbon-electrode PSCs with these desired CsPbBr_(3)films yield the record-high efficiency of 10.27%coupled with excellent operation stability.Meanwhile,the 1 cm^(2)area one with the superior efficiency of 8.00%as well as the flexible one with the champion efficiency of 8.27%and excellent mechanical bending characteristics are also achieved.展开更多
Grapes,one of the oldest tree species globally,are rich in vitamins.However,environmental conditions such as low temperature and soil salinization significantly affect grape yield and quality.The glutamate receptor(GLR...Grapes,one of the oldest tree species globally,are rich in vitamins.However,environmental conditions such as low temperature and soil salinization significantly affect grape yield and quality.The glutamate receptor(GLR)family,comprising highly conserved ligand-gated ion channels,regulates plant growth and development in response to stress.In this study,11 members of the VvGLR gene family in grapes were identified using whole-genome sequence analysis.Bioinformatic methods were employed to analyze the basic physical and chemical properties,phylogenetic trees,conserved domains,motifs,expression patterns,and evolutionary relationships.Phylogenetic and collinear analyses revealed that the VvGLRs were divided into three subgroups,showing the high conservation of the grape GLR family.These members exhibited 2 glutamate receptor binding regions(GABAb and GluR)and 3-4 transmembrane regions(M1,M2,M3,and M4).Real-time quantitative PCR analysis demonstrated the sensitivity of all VvGLRs to low temperature and salt stress.Subsequent localization studies in Nicotiana tabacum verified that VvGLR3.1 and VvGLR3.2 proteins were located on the cell membrane and cell nucleus.Additionally,yeast transformation experiments confirmed the functionality of VvGLR3.1 and VvGLR3.2 in response to low temperature and salt stress.Thesefindings highlight the significant role of the GLR family,a highly conserved group of ion channels,in enhancing grape stress resistance.This study offers new insights into the grape GLR gene family,providing fundamental knowledge for further functional analysis and breeding of stress-resistant grapevines.展开更多
The microbial consortium GF-20(GF-20) can efficiently decompose corn stover at low temperatures. The present study explored the key microbes of GF-20 and evaluated different culture conditions on its composition stabi...The microbial consortium GF-20(GF-20) can efficiently decompose corn stover at low temperatures. The present study explored the key microbes of GF-20 and evaluated different culture conditions on its composition stability to promote the utilization of corn stover decomposing microbes in low temperature regions. GF-20 was subcultured to the 15 th generation under different temperatures, pHs, carbon, and nitrogen sources. Then, the dynamics of fermenting pH, cellulose enzyme activities, carbohydrate concentration, and oxidation reduction potential were determined to estimate the degradation efficiency of corn stover with GF-20. Furthermore, the structural stability and functional microbes of GF-20 were identified on the basis of PCR-denaturing gradient gel electrophoresis(DGGE) profiling and principal component analysis. The results showed that the offspring of GF-20 subcultured under different temperatures(4–30°C) and pH(6.0–9.0) conditions maintained stable growth, decomposition function, and composition structure. Furthermore, consortia GF-20 had a stable composition structure, which induced GF-20 to secrete cellulose and promote substrate decomposition as corn stover and ammonium were used as sources of carbon and nitrogen, respectively. According to the PCR-DGGE profiles, the key strains of GF-20 were determined to be Bacillus licheniformis, Cellvibrio mixtus subsp. mixtus, Bacillus tequilensis, Clostridium populeti, and Clostridium xylanolyticum.展开更多
Rechargeable aqueous Zn-ion batteries (ZIBs) have attracted great attention due to their costeffectiveness,high safety,and environmental friendliness.However,some issues associated with poor structural instability of ...Rechargeable aqueous Zn-ion batteries (ZIBs) have attracted great attention due to their costeffectiveness,high safety,and environmental friendliness.However,some issues associated with poor structural instability of cathode materials and fast self-discharge hinder the further development of ZIBs.Herein,a new configuration is introduced by placing a reduced graphene oxide film as a block layer between the separator and the V2O5·nH2O cathode.This layer prevents the free diffusion of dissolved active materials to the anode and facilitates the transport of Zn ion and electrons,largely improving the cyclic stability and alleviating the self-discharge.Accordingly,the optimized battery delivers a remarkable capacity of 191 mAh g^-1 after 500 cycles at 2 A g^-1.Moreover,a high capacity of 106 mAh g^-1 is achieved after 100 cycles at-20℃.The strategy proposed is expected to be applicable to other electrode systems,thus offering a new approach to circumvent the critical challenges facing aqueous batteries.展开更多
The effect of a modified ester collector named as BL on the flotation of chalcopyrite at low temperatures was investigated by micro-flotation tests,contact angle measurements,adsorption experiments,laser particle size...The effect of a modified ester collector named as BL on the flotation of chalcopyrite at low temperatures was investigated by micro-flotation tests,contact angle measurements,adsorption experiments,laser particle size analysis,cryogenic transmission electron microscopy(Cryo-TEM)and Fourier transform infrared(FTIR)analyses.Micro-flotation tests proved that the collecting ability of BL for chalcopyrite was significantly better than that of N,N-diethyl dithiocarbamate propiononitrile ester(ester-105)at low temperatures.Combined with laser particle size,Cryo-TEM and FTIR analyses,it was found that the particle size of BL in water was smaller than that of ester-105,and the distributed density of BL was higher than that of ester-105 at low temperatures,indicating that BL dispersed well at low temperatures.Therefore,BL was more easily adsorbed on the chalcopyrite surface and improved the surface hydrophobic degree of chalcopyrite,which were also confirmed by the contact angle measurements and adsorption experiments.展开更多
This paper reviews recent developments in complete oxidation of methane atlow temperatures over noble metal catalysts in the past 20 years. The Pd/Al_2O_3 catalyst system isfully discussed. The review mainly focuses o...This paper reviews recent developments in complete oxidation of methane atlow temperatures over noble metal catalysts in the past 20 years. The Pd/Al_2O_3 catalyst system isfully discussed. The review mainly focuses on the kinetic aspects of methane oxidation over thiscatalyst, and methane activation behavior over Pd and PdO phases (the form of PdO on the surface,transient behavior, the nature of the active sites, the influence of metal particle size and theirstructure sensitivities, and so on). Some Pd catalysts supported on other oxides besides the Al_2O_3support are briefly discussed. Possible routes of non-noble metal catalysts as substitutes for thePd catalyst are also proposed.展开更多
Activated carbon preparation from sugarcane leaves and rice straw by carbonization(250℃–400℃)and activation at 500℃were studied.The effects of pre-oxidation,hydrolysis of derived charcoals by boiled KMnO4 aqueous ...Activated carbon preparation from sugarcane leaves and rice straw by carbonization(250℃–400℃)and activation at 500℃were studied.The effects of pre-oxidation,hydrolysis of derived charcoals by boiled KMnO4 aqueous solution were evaluated.The derived charcoals products were pretreated using oxidation-hydrolysis with 1–5 wt.%KMnO4 at 100℃and then activated at 500℃.The derived charcoal and activated carbon products were characterized by FTIR,XRD,SEM-EDS and BET.Iodine number and methylene blue number of derived products were also used for the analysis of the products.It was found that fabricated charcoal materials made at 350℃–400℃possess good characteristics with low content of surface functional groups and high carbon content.After pre-oxidation-hydrolysis and activation at 500℃,the resulting derived activated carbon materials from charcoals with 400℃carbonization temperature have high content of oxygen containing surface functional groups such as Mn-O,Si-O,Si-O-Si,C-O,or O-H.In addition,MnO_(2) accumulated on the surface of the derived activated carbon products.The surface area and pore volume of the activated carbon products have also increased with increasing of KMnO_(4) concentration from 1 to 3 wt.%and then decreased with 5 wt.%used during activation.Therefore,activated carbon products made by pre-oxidation-hydrolysis with 3 wt.%KMnO_(4) were used for Fe(Ⅲ)adsorption experiments.It was found that Fe(Ⅲ)adsorption on the activated carbon materials can be fitted with both the Freundlich and the Langmuir models.The calculated maximum Fe(Ⅲ)adsorption capacities of sugarcane leaves derived activated carbon and rice straw derived activated carbon products were 50.00 and 39.37 mg/g,respectively.It was shown that the effect of pre-oxidation-hydrolysis by KMnO_(4) and activation at 500℃are beneficial for activated carbon preparation with environmentally friendly and low-cost simplified operation.展开更多
Low temperatures during germination inhibit seed growth,lead to small and weak seedlings,and significantly reduce the wheat yield.Alleviating the adverse effects of low temperature on wheat seed germination is highly ...Low temperatures during germination inhibit seed growth,lead to small and weak seedlings,and significantly reduce the wheat yield.Alleviating the adverse effects of low temperature on wheat seed germination is highly important for achieving high and stable wheat yields.In this study,Tongmai 6(insensitive)and Zhengmai 113(sensitive),which have different low-temperature sensitivities during germination were treated with low temperature during germination.The transcriptome,metabolome and physiological data revealed that low temperature decreased the germination rate,downregulated the expression of a large number of genes involved in regulating glycometabolism,and inhibited carbon,nitrogen(especially amino acids)and energy metabolism in the seeds.Arginine content increased at low temperature,and its increase in the low-temperature-tolerant variety was significantly greater than that in the sensitive variety.Arginine priming experiment showed that treatment with an appropriate concentration of arginine improved the seed germination rate.The conversion of starch to soluble sugar significantly increased under exogenous arginine conditions,the content of key metabolites in energy metabolism increased,and the utilization of ATP in the seeds increased.Taken together,arginine priming increased seed germination at low temperature by relieving inhibition of seed carbon and nitrogen metabolism and improving seed energy metabolism.展开更多
文摘BACKGROUND Laparoscopic surgery has reduced morbidity and mortality rates,shorter post-operative recovery periods and lower complication rates than open surgery.It is routine practice in high-income countries and is becoming increasingly common in countries with limited resources.However,introducing laparoscopic surgery in low-and-middle-income countries(LMIC)can be expensive and requires resour-ces,equipment,and trainers.AIM To report the challenges and benefits of introducing laparoscopic surgery in LMIC as well as to identify solutions to these challenges for countries with limited finances and resources.METHODS MEDLINE,EMBASE and Cochrane databases were searched for studies reporting first experience in laparoscopic surgery in LMIC.Included studies were published between 1996 and 2022 with full text available in English.Exclusion criteria were studies considering only open surgery,ear,nose,and throat,endoscopy,arthro-scopy,hysteroscopy,cystoscopy,transplant,or bariatric surgery.RESULTS Ten studies out of 3409 screened papers,from eight LMIC were eligible for inclusion in the final analysis,totaling 2497 patients.Most reported challenges were related to costs of equipment and training programmes,equipment pro-blems such as faulty equipment,and access to surgical kits.Training-related challenges were reliance on foreign trainers and lack of locally trained surgeons and theatre staff.The benefits of introducing laparoscopic surgery were economic and clinical,including a reduction in hospital stay,complications,and morbidi-ty/mortality.The introduction of laparoscopic surgery also provided training opportunities for junior doctors.CONCLUSION Despite financial and technical challenges,many studies emphasise the overall benefit of introducing laparoscopic surgery in LMICs such as reduced hospital stay and the related lower cost for patients.While many of the clinical centres in LMICs have proposed practical solutions to the challenges reported,more support is critically required,in particular regarding training.
文摘BACKGROUND Undernutrition is a crucial cause of morbidity and mortality among children in low-or middle-income countries(LMICs).A better understanding of maternal general healthy nutrition knowledge,as well as misbeliefs,is highly essential,especially in such settings.In the current era of infodemics,it is very strenuous for mothers to select not only the right source for maternal nutrition information but the correct information as well.AIM To assess maternal healthy nutritional knowledge and nutrition-related misbeliefs and misinformation in an LMIC,and to determine the sources of such information and their assessment methods.METHODS This cross-sectional analytical observational study enrolled 5148 randomly selected Egyptian mothers who had one or more children less than 15 years old.The data were collected through online questionnaire forms:One was for the general nutrition knowledge assessment,and the other was for the nutritional myth score.Sources of information and ways of evaluating internet sources using the Currency,Relevance,Authority,Accuracy,and Purpose test were additionally analyzed.RESULTS The mean general nutrition knowledge score was 29±9,with a percent score of 70.8%±12.1%(total score:41).The median myth score was 9(interquartile range:6,12;total score:18).The primary sources of nutrition knowledge for the enrolled mothers were social media platforms(55%).Half of the mothers managed information for currency and authority,except for considering the author's contact information.More than 60%regularly checked information for accuracy and purpose.The mothers with significant nutrition knowledge checked periodically for the author's contact information(P=0.012).The nutrition myth score was significantly lower among mothers who periodically checked the evidence of the information(P=0.016).Mothers dependent on their healthcare providers as the primary source of their general nutritional knowledge were less likely to hold myths by 13%(P=0.044).However,using social media increased the likelihood of having myths among mothers by approximately 1.2(P=0.001).CONCLUSION Social media platforms were found to be the primary source of maternal nutrition information in the current era of infodemics.However,healthcare providers were the only source for decreasing the incidence of maternal myths among the surveyed mothers.
基金The key technology R&D program of China, No.2007BAC29B02Project of Jiangsu Key Laboratory of Meteorological Disaster, No.KLME060101
文摘Using the daily data of temperature from China Meteorological Administration and the NCEP/NCAR reanalysis from 1960 to 2005, we have analyzed the relationships between the summertime high/low temperature events in the middle and lower reaches of the Yangtze River (MLRYR) and the related circulation anomalies in the Eastern Hemisphere. Our results have demonstrated that a significantly increasing trend is observed in daily minimum temperature in the past 50 years. And in some regions in the Northern Hemisphere, the opposite scenarios are observed in circulation anomalies in lower and upper parts of the troposphere in the years when the temperatures are higher than normal, as compared to those in the years when the temperatures are lower than normal in the middle and lower reaches of the Yangtze River (MLRYR). Additionally, the anomalous circulation structure in vertical direction in both the high and lower temperature years are barotropic. It is found that the emergence and maintenance of the aforementioned anomalous circulations are related to three kinds of wave train teleconnection patterns. Further more, influences of the long wave surface radiation on the air temperature are stronger in the nighttime than that in the daytime. While both the maximum and minimum temperatures have negative relationships with the sensible heat flux but positive relationships with the latent heat flux. To some extent, the anomalous dynamic heating (cooling) caused by the vertical thermal advection as well as the diabatic heating (cooling) caused by diabatic processes can explain the formation of the high (low) temperature events in the middle and lower reaches of the Yangtze River (MLRYR) in boreal summer.
文摘Using the monthly geopotential heights and winds for 700 and 200 hPa for India during July and August, and the weekly M-100 Soviet rocketsonde temperature and wind data for Thumba (8.5 ° N, 76.9 ° E) during the last week of June and the first week of September for the two contrasting summer monsoon years 1975 (a very strong monsoon year) and 1979 (a very weak monsoon year), a study has been made to examine the mean circulation features of the troposphere over India, and the structures of the temperatures and the winds of the middle atmosphere over Thumba. The study suggested that the axis of the monsoon trough (AMT) at 700 hPa shifted southward in 1975 and northward towards the foothills of the Himalayas in 1979, from its normal position. Superimposed on the low-pressure area (AMT) at 700 hPa, a well-defined divergence was noticed at 200 hPa over the northern India in 1975.The mean temperatures at 25,50 and 60 km (middle atmosphere) over Thumba were cooler in 1975 than in 1979. While a cooling trend in 1975 and warming trend in 1979 were observed at 25 and 50 km, a reversed picture was noticed at 60 km. There was a weak easterly / westerly (weak westerly phase) zonal wind in 1975 and a strong easterly zonal wind in 1979. A phase reversal of the zonal wind was observed at 50 km. A tentative physical mechanism was offered, in terms of upward propagation of the two equatorially trapped planetary waves i.e. the Kelvin and the mixed Rossby-gravity waves, to explain the occurrence of the two spells of strong warmings in the mesosphere in 1975.
基金supported by the National Natural Science Foundation of China(21076211,21203181,21576251,21676269)the "Strategic Priority Research Program" of the Chinese Academy of Sciences(XDB17020100)+1 种基金the National Key projects for Fundamental Research and Development of China(2016YFA0202801)Department of Science and Technology of Liaoning Province under contract of 2015020086-101~~
文摘CO oxidation is probably the most studied reaction in heterogeneous catalysis.This reaction has become a hot topic with the discovery of nanogold catalysts,which are active at low temperatures(at or below room temperature).Au catalysts are the benchmark for judging the activities of other metals in CO oxidation.Pt-group metals(PGMs) that give comparable performances are of particular interest.In this mini-review,we summarize the advances in various PGM(Pt,Pd,Ir,Rh,Ru)catalysts that have high catalytic activities in low-temperature CO oxidation arising from reducible supports or the presence of OH species.The effects of the size of the metal species and the importance of the interface between the metal and the reducible support are covered and discussed in terms of their promotional role in CO oxidation at low temperatures.
文摘Low-temperature deposition of diamond thin films in the range of 280 ̄445℃ has been successfully carried out by microwave plasma-assisted CVD method.At lower deposition temperatures (280 ̄445℃),the large increase in the nucleation density and great improvement in the average surfae roughness of the diamond were observed. Results of low temperature deposition and characterization of diamond thin films obtained are presented.
基金supported by the National Natural Science Foundation of China(21376209,21376169)Zhejiang Provincial Natural Science Foundation(LZ13B060004)+1 种基金Program for Zhejiang Leading Team of S&T Innovation(2013TD07)Program of Introducing Talents of Discipline to Universities(B06006)~~
文摘Developing efficient supported Pd catalysts and understanding their catalytic mechanism in CO oxidation are challenging research topics in recent years.This paper describes the synthesis of Pd nanoparticles supported on CeO2 nanotubes via an alcohol reduction method.The effect of the support morphology on the catalytic reaction was explored.Subsequently,the performance of the prepared catalysts was investigated toward CO oxidation reaction and characterized by Nitrogen sorption,X-ray diffraction,X-ray photoelectron spectroscopy,transmission electron microscopy,and CO-temperature-programmed desorption techniques.The results indicated that the catalyst of Pd on CeO2 nanotubes exhibits excellent activity in CO oxidation at low temperatures,due to its large surface area,the high dispersion of Pd species,the mesoporous and tubular structure of the CeO2-nanotube support,the abundant Ce3+,formation of Pd–O–Ce bonding,and enhanced metal–support interaction on the catalyst surface.
基金financially supported by the National Natural Science Foundation of China (Nos.51904339 and No.51974364)the Key Laboratory of Hunan Province for Clean and Efficient Utilization of Strategic Calcium-containing Mineral Resources,China (No.2018TP1002)the Co-Innovation Centre for Clean and Efficient Utilization of Strategic Metal Mineral Resources,and the Postgraduate Independent Exploration and Innovation Project of Central South University,China (No.2018zzts224)。
文摘The impact of alkyl dimethyl betaine (ADB) on the collection capacity of sodium oleate (NaOl) at low temperatures was evaluated using flotation tests at various scales. The low-temperature synergistic mechanism of ADB and NaOl was explored by infrared spectroscopy, X-ray photoelectron spectroscopy, surface tension measurement, foam performance test, and flotation reagent size measurement.The flotation tests revealed that the collector mixed with octadecyl dimethyl betaine (ODB) and NaOl in a mass ratio of 4:96 exhibited the highest collection capacity. The combined collector could increase the scheelite recovery by 3.48% at low temperatures of 8–12℃. This is particularly relevant in the Luanchuan area, which has the largest scheelite concentrate output in China. The results confirmed that ODB enhanced the collection capability of NaOl by improving the dispersion and foaming performance. Betaine can be introduced as an additive to NaOl to improve the recovery of scheelite at low temperatures.
基金The work described in this paper was fully supported by a Grant from the City University of Hong Kong(Project No.9610641).
文摘Electrolyte design holds the greatest opportunity for the development of batteries that are capable of sub-zero temperature operation.To get the most energy storage out of the battery at low temperatures,improvements in electrolyte chemistry need to be coupled with optimized electrode materials and tailored electrolyte/electrode interphases.Herein,this review critically outlines electrolytes’limiting factors,including reduced ionic conductivity,large de-solvation energy,sluggish charge transfer,and slow Li-ion transportation across the electrolyte/electrode interphases,which affect the low-temperature performance of Li-metal batteries.Detailed theoretical derivations that explain the explicit influence of temperature on battery performance are presented to deepen understanding.Emerging improvement strategies from the aspects of electrolyte design and electrolyte/electrode interphase engineering are summarized and rigorously compared.Perspectives on future research are proposed to guide the ongoing exploration for better low-temperature Li-metal batteries.
基金supported by the National Natural Science Foundation of China (No.92372123)the Natural Science Foundation of Guangdong Province (No.2022B1515020005)the Department of Science and Technology of Guangdong Province (No.2020B0101030005)
文摘Fast-charging and low temperature operation are of vital importance for the further development of lithium-ion batteries(LIBs),which is hindered by the utilization of conventional carbonate-based electrolytes due to their slow kinetics,narrow operating temperature and voltage range.Herein,an acetonitrile(AN)-based localized high-concentration electrolyte(LHCE)is proposed to retain liquid state and high ionic conductivity at ultra-low temperatures while possessing high oxidation stability.We originally reveal the excellent thermal shielding effect of non-solvating diluent to prevent the aggregation of Li^(+) solvates as temperature drops,maintaining the merits of fast Li transport and facile desolvation as at room temperature,which bestows the graphite electrode with remarkable low temperature performance(264 mA h g^(-1) at-20 C).Remarkably,an extremely high capacity retention of 97%is achieved for high-voltage high-energy graphite||NCM batteries after 250 cycles at-20 C,and a high capacity of 110 mA h g^(-1)(71%of its room-temperature capacity)is retained at-30°C.The study unveils the key role of the non-solvating diluents and provides instructive guidance in designing electrolytes towards fast-charging and low temperature LIBs.
基金supported by Zhejiang Provincial Natural Science Foundation of China (LD24C130002)Scientific Research Foundation of China Jiliang University。
文摘A rice low temperature-induced albino variant was determined by the recessive ltia1 and ltia2 genes.LTIA1 and LTIA2 encode highly conserved mini-ribonucleasesⅢlocated in chloroplasts and expressed in aerial parts of the plant.At low temperature,LTIA1 and LTIA2 redundantly affect chlorophyll levels,non-photochemical quenching,photosynthetic quantum yield of PSⅡand seedling growth.LTIA1 and LTIA2 proteins are involved in splicing of atp F and the biogenesis of 16S and 23S rRNA in chloroplasts.Presence/absence variation of LTIA1,the ancestral copy,was found only in japonica but that of LTIA2 in all rice subgroups.Accessions with LTIA2 presence tended to be distributed more remote from the equator compared to those with LTIA2 absence.LTIA2 duplicated from LTIA1 at the early stage of divergence of the AA genome Oryza species but deleted againin O.nivara.In cultivated rice,absence of LTIA2 is derived from O.nivara.LTIA1 absence occurred more recently in japonica.
基金the financial support from the National Key R&D program of China(2021YFF0500501 and 2021YFF0500504)the Fundamental Research Funds for the Central Universities(YJS2213 and JB211408)+1 种基金the National Natural Science Foundation of China(61874083)the Joint Research Funds of Department of Science&Technology of Shaanxi Province and Northwestern Polytechnical University(No.2020GXLH-Z-014)
文摘Low-temperature,ambient processing of high-quality CsPbBr_(3)films is demanded for scalable production of efficient,low-cost carbon-electrode perovskite solar cells(PSCs).Herein,we demonstrate a crystal orientation engineering strategy of PbBr_(2)precursor film to accelerate its reaction with CsBr precursor during two-step sequential deposition of CsPbBr_(3)films.Such a novel strategy is proceeded by adding CsBr species into PbBr_(2)precursor,which can tailor the preferred crystal orientation of PbBr_(2)film from[020]into[031],with CsBr additive staying in the film as CsPb_(2)Br_(5)phase.Theoretical calculations show that the reaction energy barrier of(031)planes of PbBr_(2)with CsBr is lower about 2.28 eV than that of(O2O)planes.Therefore,CsPbBr_(3)films with full coverage,high purity,high crystallinity,micro-sized grains can be obtained at a low temperature of 150℃.Carbon-electrode PSCs with these desired CsPbBr_(3)films yield the record-high efficiency of 10.27%coupled with excellent operation stability.Meanwhile,the 1 cm^(2)area one with the superior efficiency of 8.00%as well as the flexible one with the champion efficiency of 8.27%and excellent mechanical bending characteristics are also achieved.
基金This research was funded by the Natural Science Foundation of Shandong Province of China(ZR2022MC144).
文摘Grapes,one of the oldest tree species globally,are rich in vitamins.However,environmental conditions such as low temperature and soil salinization significantly affect grape yield and quality.The glutamate receptor(GLR)family,comprising highly conserved ligand-gated ion channels,regulates plant growth and development in response to stress.In this study,11 members of the VvGLR gene family in grapes were identified using whole-genome sequence analysis.Bioinformatic methods were employed to analyze the basic physical and chemical properties,phylogenetic trees,conserved domains,motifs,expression patterns,and evolutionary relationships.Phylogenetic and collinear analyses revealed that the VvGLRs were divided into three subgroups,showing the high conservation of the grape GLR family.These members exhibited 2 glutamate receptor binding regions(GABAb and GluR)and 3-4 transmembrane regions(M1,M2,M3,and M4).Real-time quantitative PCR analysis demonstrated the sensitivity of all VvGLRs to low temperature and salt stress.Subsequent localization studies in Nicotiana tabacum verified that VvGLR3.1 and VvGLR3.2 proteins were located on the cell membrane and cell nucleus.Additionally,yeast transformation experiments confirmed the functionality of VvGLR3.1 and VvGLR3.2 in response to low temperature and salt stress.Thesefindings highlight the significant role of the GLR family,a highly conserved group of ion channels,in enhancing grape stress resistance.This study offers new insights into the grape GLR gene family,providing fundamental knowledge for further functional analysis and breeding of stress-resistant grapevines.
基金supported by the National Natural Science Foundation of China (31760353 and 31560360)the National Key R&D Program of China (2017YFD0300804 and 2016YFD0300103)+2 种基金the earmarked fund for China Agriculture Research System (CARS-02-63)the Crop Science Observation & Experiment Station in Loess Plateau of North China, Ministry of Agriculture, China (25204120)the Advanced Talented Scholars of Inner Mongolia Agricultural University, China (NDYB2016-15)
文摘The microbial consortium GF-20(GF-20) can efficiently decompose corn stover at low temperatures. The present study explored the key microbes of GF-20 and evaluated different culture conditions on its composition stability to promote the utilization of corn stover decomposing microbes in low temperature regions. GF-20 was subcultured to the 15 th generation under different temperatures, pHs, carbon, and nitrogen sources. Then, the dynamics of fermenting pH, cellulose enzyme activities, carbohydrate concentration, and oxidation reduction potential were determined to estimate the degradation efficiency of corn stover with GF-20. Furthermore, the structural stability and functional microbes of GF-20 were identified on the basis of PCR-denaturing gradient gel electrophoresis(DGGE) profiling and principal component analysis. The results showed that the offspring of GF-20 subcultured under different temperatures(4–30°C) and pH(6.0–9.0) conditions maintained stable growth, decomposition function, and composition structure. Furthermore, consortia GF-20 had a stable composition structure, which induced GF-20 to secrete cellulose and promote substrate decomposition as corn stover and ammonium were used as sources of carbon and nitrogen, respectively. According to the PCR-DGGE profiles, the key strains of GF-20 were determined to be Bacillus licheniformis, Cellvibrio mixtus subsp. mixtus, Bacillus tequilensis, Clostridium populeti, and Clostridium xylanolyticum.
基金financially supported by the Hong Kong Polytechnic University(Grant 1-ZE83,Area of Excellence Project 1ZE30)。
文摘Rechargeable aqueous Zn-ion batteries (ZIBs) have attracted great attention due to their costeffectiveness,high safety,and environmental friendliness.However,some issues associated with poor structural instability of cathode materials and fast self-discharge hinder the further development of ZIBs.Herein,a new configuration is introduced by placing a reduced graphene oxide film as a block layer between the separator and the V2O5·nH2O cathode.This layer prevents the free diffusion of dissolved active materials to the anode and facilitates the transport of Zn ion and electrons,largely improving the cyclic stability and alleviating the self-discharge.Accordingly,the optimized battery delivers a remarkable capacity of 191 mAh g^-1 after 500 cycles at 2 A g^-1.Moreover,a high capacity of 106 mAh g^-1 is achieved after 100 cycles at-20℃.The strategy proposed is expected to be applicable to other electrode systems,thus offering a new approach to circumvent the critical challenges facing aqueous batteries.
基金financial supports from the National Natural Science Foundation of China(No.52074206)the Talent Science and Technology Fund of Xi’an University of Architecture and Technology,China(No.ZR19062)+4 种基金the Open Foundation of State Key Laboratory of Mineral Processing,China(No.BGRIMM-KJSKL-2021-19)the Natural Science Basic Research Plan in Shaanxi Province of China(No.2021JQ-507)the Special Research Project of Shaanxi Education Department,China(No.21JK0731)the Key Program for International S&T Cooperation Projects of Shaanxi Province,China(No.2021KWZ-16)the Natural Science Foundation of Qinghai Province,China(No.2021-ZJ-975Q)。
文摘The effect of a modified ester collector named as BL on the flotation of chalcopyrite at low temperatures was investigated by micro-flotation tests,contact angle measurements,adsorption experiments,laser particle size analysis,cryogenic transmission electron microscopy(Cryo-TEM)and Fourier transform infrared(FTIR)analyses.Micro-flotation tests proved that the collecting ability of BL for chalcopyrite was significantly better than that of N,N-diethyl dithiocarbamate propiononitrile ester(ester-105)at low temperatures.Combined with laser particle size,Cryo-TEM and FTIR analyses,it was found that the particle size of BL in water was smaller than that of ester-105,and the distributed density of BL was higher than that of ester-105 at low temperatures,indicating that BL dispersed well at low temperatures.Therefore,BL was more easily adsorbed on the chalcopyrite surface and improved the surface hydrophobic degree of chalcopyrite,which were also confirmed by the contact angle measurements and adsorption experiments.
基金Supported by the Visiting Scholar Foundation of Key Labs. in Universities.
文摘This paper reviews recent developments in complete oxidation of methane atlow temperatures over noble metal catalysts in the past 20 years. The Pd/Al_2O_3 catalyst system isfully discussed. The review mainly focuses on the kinetic aspects of methane oxidation over thiscatalyst, and methane activation behavior over Pd and PdO phases (the form of PdO on the surface,transient behavior, the nature of the active sites, the influence of metal particle size and theirstructure sensitivities, and so on). Some Pd catalysts supported on other oxides besides the Al_2O_3support are briefly discussed. Possible routes of non-noble metal catalysts as substitutes for thePd catalyst are also proposed.
文摘Activated carbon preparation from sugarcane leaves and rice straw by carbonization(250℃–400℃)and activation at 500℃were studied.The effects of pre-oxidation,hydrolysis of derived charcoals by boiled KMnO4 aqueous solution were evaluated.The derived charcoals products were pretreated using oxidation-hydrolysis with 1–5 wt.%KMnO4 at 100℃and then activated at 500℃.The derived charcoal and activated carbon products were characterized by FTIR,XRD,SEM-EDS and BET.Iodine number and methylene blue number of derived products were also used for the analysis of the products.It was found that fabricated charcoal materials made at 350℃–400℃possess good characteristics with low content of surface functional groups and high carbon content.After pre-oxidation-hydrolysis and activation at 500℃,the resulting derived activated carbon materials from charcoals with 400℃carbonization temperature have high content of oxygen containing surface functional groups such as Mn-O,Si-O,Si-O-Si,C-O,or O-H.In addition,MnO_(2) accumulated on the surface of the derived activated carbon products.The surface area and pore volume of the activated carbon products have also increased with increasing of KMnO_(4) concentration from 1 to 3 wt.%and then decreased with 5 wt.%used during activation.Therefore,activated carbon products made by pre-oxidation-hydrolysis with 3 wt.%KMnO_(4) were used for Fe(Ⅲ)adsorption experiments.It was found that Fe(Ⅲ)adsorption on the activated carbon materials can be fitted with both the Freundlich and the Langmuir models.The calculated maximum Fe(Ⅲ)adsorption capacities of sugarcane leaves derived activated carbon and rice straw derived activated carbon products were 50.00 and 39.37 mg/g,respectively.It was shown that the effect of pre-oxidation-hydrolysis by KMnO_(4) and activation at 500℃are beneficial for activated carbon preparation with environmentally friendly and low-cost simplified operation.
基金supported by the Key Research and Development Program of Shaanxi(2021NY-083)the National Natural Science Foundation of China(31871567).
文摘Low temperatures during germination inhibit seed growth,lead to small and weak seedlings,and significantly reduce the wheat yield.Alleviating the adverse effects of low temperature on wheat seed germination is highly important for achieving high and stable wheat yields.In this study,Tongmai 6(insensitive)and Zhengmai 113(sensitive),which have different low-temperature sensitivities during germination were treated with low temperature during germination.The transcriptome,metabolome and physiological data revealed that low temperature decreased the germination rate,downregulated the expression of a large number of genes involved in regulating glycometabolism,and inhibited carbon,nitrogen(especially amino acids)and energy metabolism in the seeds.Arginine content increased at low temperature,and its increase in the low-temperature-tolerant variety was significantly greater than that in the sensitive variety.Arginine priming experiment showed that treatment with an appropriate concentration of arginine improved the seed germination rate.The conversion of starch to soluble sugar significantly increased under exogenous arginine conditions,the content of key metabolites in energy metabolism increased,and the utilization of ATP in the seeds increased.Taken together,arginine priming increased seed germination at low temperature by relieving inhibition of seed carbon and nitrogen metabolism and improving seed energy metabolism.