Importance:While laparoscopic pancreaticoduodenectomy(LPD)is being adopted with increasing enthusiasm worldwide,it is still challenging for both technical and anatomical reasons.Currently,there is no consensus on the ...Importance:While laparoscopic pancreaticoduodenectomy(LPD)is being adopted with increasing enthusiasm worldwide,it is still challenging for both technical and anatomical reasons.Currently,there is no consensus on the technical standards for LPD.Objective:The aim of this consensus statement is to guide the continued safe progression and adoption of LPD.Evidence Review:An international panel of experts was selected based on their clinical and scientific expertise in laparoscopic and open pancreaticoduodenectomy.Statements were produced upon reviewing the literature and assessed by the members of the expert panel.The literature search and its critical appraisal were limited to articles published in English during the period from 1994 to 2019.The Web of Science,Medline,and Cochrane Library and Clinical Trials databases were searched,The search strategy included,but was not limited to,the terms'laparoscopic','pancreaticoduodenectomy,'pancreatoduodenectomy','Whipple's operation',and'minimally invasive surgery'.Reference lists from the included articles were manually checked for any additional studies,which were included when appropriate.Delphi method was used to establish expert consensus and the AGREE II-GRS Instrument was applied to assess the methodological quality and externally validate the final statements.The statements were further discussed during a one-day face-to-face meeting at the 1st Summit on Minimally Invasive Pancreatico-Biliary Surgery in Wuhan,China.Findings:Twenty-eight international experts from 8 countries constructed the expert panel.Sixteen statements were produced by the members of the expert panel.At least 80%of responders agreed with the majority(80%)of statements.Other than three randomized controlled trials published to date,most evidences were based on level 3 or 4 studies according to the AGREE II-GRS Instrument.Conclusions and Relevance:The Wuhan international expert consensus meeting on LPD has produced a set of clinical practice statements for the safe development and progression of LP展开更多
This study investigated the drivers and physical processes for the abrupt decadal summer surface warming and increases in hot temperature extremes that occurred over Northeast Asia in the mid-1990s. Observations indic...This study investigated the drivers and physical processes for the abrupt decadal summer surface warming and increases in hot temperature extremes that occurred over Northeast Asia in the mid-1990s. Observations indicate an abrupt increase in summer mean surface air temperature （SAT） over Northeast Asia since the mid-1990s. Accompanying this abrupt surface wanning, significant changes in some temperature extremes, characterized by increases in summer mean daily maximum temperature （Tmax）, daily minimum temperature （Train）, annual hottest day temperature （TXx）, and annual warmest night temperature （TNx） were observed. There were also increases in the frequency of summer days （SU） and tropical nights （TR）. Atmospheric general circulation model experiments forced by changes in sea surface temperature （SST）/sea ice extent （SIE）, anthropogenic greenhouse gas （GHG） concentrations, and anthropogenic aerosol （AA） forcing, relative to the period 1964- 93, reproduced the general patterns of observed summer mean SAT changes and associated changes in temperature extremes, although the abrupt decrease in precipitation since the mid-1990s was not simulated. Additional model experiments with different forcings indicated that changes in SST/SIE explained 76% of the area-averaged summer mean surface warming signal over Northeast Asia, while the direct impact of changes in GHG and AA explained the remaining 24% of the surface warming signal. Analysis of physical processes indicated that the direct impact of the changes in AA （through aerosol- radiation and aerosol-cloud interactions）, mainly related to the reduction of AA precursor emissions over Europe, played a dominant role in the increase in TXx and a similarly important role as SST/SIE changes in the increase in the frequency of SU over Northeast Asia via AA-induced coupled atmosphere-land surface and cloud feedbacks, rather than through a direct impact of AA changes on cloud condensation nuclei. The modelling results also imply展开更多
Objective: Gastrointestinal (GI) discomfort is experienced by millions of people every day. This study aimed to evaluate the effect of PhenActiv<sup>TM</sup>, a novel green kiwifruit extract, on gastrointe...Objective: Gastrointestinal (GI) discomfort is experienced by millions of people every day. This study aimed to evaluate the effect of PhenActiv<sup>TM</sup>, a novel green kiwifruit extract, on gastrointestinal tract (GIT) function in otherwise healthy adults. Methods: 41 healthy adults with mild GI discomfort were enrolled in this double-blind, randomized, placebo-controlled study. Participants were randomized to either take 3.0 g/day of PhenActiv<sup>TM</sup> or a placebo for 6 weeks. Interviews were conducted at baseline, week 3 and week 6, with participants completing questionnaires regarding GI symptoms. Frequency of bowel movements was self-recorded daily. Results: There were no differences in daily and weekly defecation frequency and stool characteristics in either group. The active and placebo groups significantly improve GSRS scores (p , only the active group had a significant improvement in the IBSSS and PAC-QOL scores (p < 0.05) from baseline. Neither group had changes in sleep quality, quality of life and fatigue, plasma zonulin concentrations or macular pigment optical density scores. The product was well tolerated with no GI disturbances or adverse events being reported. Conclusion: Supplementation of 3.0 g/day of PhenActiv<sup>TM</sup> for 6 weeks did not improve defecation frequency or stool composition in healthy adults, but did improve perceived symptoms of GIT function, including symptoms of functional GIT disorders, IBS and constipation. The product was well tolerated and future trials investigating higher doses with more participants and/or a different population would be beneficial.展开更多
Evaluating whether hybrid zones are stable or mobile can provide novelinsights for evolution and conservation biology. Butterflies exhibit high sensitivity to envi-ronmental changes and represent an important model sy...Evaluating whether hybrid zones are stable or mobile can provide novelinsights for evolution and conservation biology. Butterflies exhibit high sensitivity to envi-ronmental changes and represent an important model system for the study of hybrid zoneorigins and maintenance. Here, we review the literature exploring butterfly hybrid zones,with a special focus on their spatiotemporal dynamics and the potential mechanisms thatcould lead to their movement or stability. We then compare different lines of evidenceused to investigate hybrid zone dynamics and discuss the strengths and weaknesses ofeach approach. Our goal with this review is to reveal general conditions associated withthe stability or mobility of butterfly hybrid zones by synthesizing evidence obtained us-ing different types of data sampled across multiple regions and spatial scales. Finally, wediscuss spatiotemporal dynamics in the context of a speciation/divergence continuum, therelevance of hybrid zones for conservation biology, and recommend key topics for futureinvestigation.展开更多
Using reclaimed wastewater for crop irrigation is a practical alternative to discharge wastewater treatment plant effluents into surface waters.However,biofouling has been identified as a major contributor to emitter ...Using reclaimed wastewater for crop irrigation is a practical alternative to discharge wastewater treatment plant effluents into surface waters.However,biofouling has been identified as a major contributor to emitter clogging in drip irrigation systems distributing reclaimed wastewater.Little is known about the biofilm structure and its influence on clogging in the drip emitter flow path.This study was first to investigate the microbial characteristics of mature biofilms present in the emitters and the effect of flow path structures on the biofilm microbial communities.The analysis of biofilm matrix structure using a scanning electron microscopy（SEM） revealed that particles in the matrix of the biofilm coupled extracellular polysaccharides（EPS） and formed sediment in the emitter flow path.Analysis of biofilm mass including protein,polysaccharide,and phospholipid fatty acids（PLFAs） showed that emitter flow path style influenced biofilm community structure and diversity.The correlations of biofilm biomass and discharge reduction after 360 h irrigation were computed and suggest that PFLAs provide the best correlation coeffcient.Comparatively,the emitter with the unsymmetrical dentate structure and shorter flow path（Emitter C） had the best anti-clogging capability.By optimizing the dentate structure,the internal flow pattern within the flow path could be enhanced as an important method to control the biofilm within emitter flow path.This study established electron microscope techniques and biochemical microbial analysis methods that may provide a framework for future emitter biofilm studies.展开更多
Pancreatic neuroendocrine neoplasms are a rare and complex group of neoplastic lesions that develop from pancreatic islet cells.Their incidence has dramatically increased during the last two decades.Due to its complex...Pancreatic neuroendocrine neoplasms are a rare and complex group of neoplastic lesions that develop from pancreatic islet cells.Their incidence has dramatically increased during the last two decades.Due to its complex nature and pathophysiological behaviour,surgical management continues to evolve.Surgery remains the cornerstone of treatment for most non-functional and functional pancreatic neuroendocrine tumours,while lymphadenectomy remains a controversial subject.Different techniques,such as pancreas-preserving and minimally invasive approaches,continue to evolve and offer the same overall outcomes as open surgery.This comprehensive review describes in detail the current and most up-todate classification and staging of pancreatic neuroendocrine tumours,explores the rationale for nonsurgical and surgical management,and focuses on surgical treatment and more specifically,on minimally invasive approaches.展开更多
Wildlife trafficking is a global phenomenon posing many negative impacts on socio-environmental systems.Scientific exploration of wildlife trafficking trends and the impact of interventions is significantly encumbered...Wildlife trafficking is a global phenomenon posing many negative impacts on socio-environmental systems.Scientific exploration of wildlife trafficking trends and the impact of interventions is significantly encumbered by a suite of data reuse challenges.We describe a novel,open-access data directory on wildlife trafficking and a corresponding visualization tool that can be used to identify data for multiple purposes,such as exploring wildlife trafficking hotspots and convergence points with other crime,discovering key drivers or deterrents of wildlife trafficking,and uncovering structural patterns.Keyword searches,expert elicitation,and peer-reviewed publications were used to search for extant sources used by industry and non-profit organizations,as well as those leveraged to publish academic research articles.The open-access data directory is designed to be a living document and searchable according to multiple measures.The directory can be instrumental in the data-driven analysis of unsustainable illegal wildlife trade,supply chain structure via link prediction models,the value of demand and supply reduction initiatives via multi-item knapsack problems,or trafficking behavior and transportation choices via network interdiction problems.展开更多
From the beginning of the COVID-19 pandemic,universities have experienced unique challenges due to their dual nature as a place of education and residence.Current research has explored non-pharmaceutical approaches to...From the beginning of the COVID-19 pandemic,universities have experienced unique challenges due to their dual nature as a place of education and residence.Current research has explored non-pharmaceutical approaches to combating COVID-19,including representing in models different categories such as age groups.One key area not currently well represented in models is the effect of pharmaceutical preventative measures,specifically vaccinations,on COVID-19 spread on college campuses.There remain key questions on the sensitivity of COVID-19 infection rates on college campuses to potentially time-varying vaccine immunity.Here we introduce a compartment model that decomposes a campus population into constituent subpopulations and implements vaccinations with timevarying efficacy.We use this model to represent a campus population with both vaccinated and unvaccinated individuals,and we analyze this model using two metrics of interest:maximum isolation population and symptomatic infection.We demonstrate a decrease in symptomatic infections occurs for vaccinated individuals when the frequency of testing for unvaccinated individuals is increased.We find that the number of symptomatic infections is insensitive to the frequency of testing of the unvaccinated subpopulation once about 80%or more of the population is vaccinated.Through a Sobol’global sensitivity analysis,we characterize the sensitivity of modeled infection rates to these uncertain parameters.We find that in order to manage symptomatic infections and the maximum isolation population campuses must minimize contact between infected and uninfected individuals,promote high vaccine protection at the beginning of the semester,and minimize the number of individuals developing symptoms.展开更多
Thermosensitive polymers show an entropy-driven transition from a well-solvated to a poorly solvated polymer chain, resulting in a more compact globular conformation. The transition at the lower critical solution temp...Thermosensitive polymers show an entropy-driven transition from a well-solvated to a poorly solvated polymer chain, resulting in a more compact globular conformation. The transition at the lower critical solution temperature（LCST） is often sharp, which allows for a wide range of smart material applications.At the LCST, oligo（ethylene glycol）-substituted polyisocyanides（PICs） form soft hydrogels, composed of polymer bundles similar to biological gels, such as actin, fibrin and intermediate filaments. Here, we show that the LCST of PICs strongly depends linearly on the length of the ethylene glycol（EG） tails; every EG group increases the LCSTand thus the gelation temperature by nearly 30 ℃. Using a copolymerisation approach, we demonstrate that we can precisely tailor the gelation temperature between 10 ℃ and 60 ℃and, consequently, tune the mechanical properties of the PIC gels.展开更多
Background:The evidence concerning which physical exercise characteristics are most effective for older adults is fragmented.We aimed to characterize the extent of this diversity and inconsistency and identify future ...Background:The evidence concerning which physical exercise characteristics are most effective for older adults is fragmented.We aimed to characterize the extent of this diversity and inconsistency and identify future directions for research by undertaking a systematic review of metaanalyses of exercise interventions in older adults.Methods:We searched the Cochrane Database of Systematic Reviews,PsycInfo,MEDLINE,Embase,CINAHL,AMED,SPORTDiscus,and Web of Science for articles that met the following criteria:(1)meta-analyses that synthesized measures of improvement(e.g.,effect sizes)on any outcome identified in studies of exercise interventions;(2)participants in the studies meta-analyzed were adults aged 65+or had a mean age of 70+;(3)meta-analyses that included studies of any type of exercise,including its duration,frequency,intensity,and mode of delivery;(4)interventions that included multiple components(e.g.,exercise and cognitive stimulation),with effect sizes that were computed separately for the exercise component;and(5)meta-analyses that were published in any year or language.The characteristics of the reviews,of the interventions,and of the parameters improved through exercise were reported through narrative synthesis.Identification of the interventions linked to the largest improvements was carried out by identifying the highest values for improvement recorded across the reviews.The study included 56 meta-analyses that were heterogeneous in relation to population,sample size,settings,outcomes,and intervention characteristics.Results:The largest effect sizes for improvement were found for resistance training,meditative movement interventions,and exercise-based active videogames.Conclusion:The review identified important gaps in research,including a lack of studies investigating the benefits of group interventions,the characteristics of professionals delivering the interventions associated with better outcomes,and the impact of motivational strategies and of significant others(e.g.,carers)on intervention deli展开更多
Objective: To investigate the clinical features of the multiple cutaneous and uterine leiomyomatosis (MCUL) syndrome, including the hereditary leiomyomatosis and renal cell cancer syndrome. Design: A case series of pa...Objective: To investigate the clinical features of the multiple cutaneous and uterine leiomyomatosis (MCUL) syndrome, including the hereditary leiomyomatosis and renal cell cancer syndrome. Design: A case series of patients with multiple skin leiomyomas solicited via a circular letter to dermatologists. Setting: Research institute. Patients: A total of 108 affected individuals, including 46 probands and 62 affected relatives. Main Outcome Measures: The proportion of probands with underlying fumarate hydratase (FH) mutations, the penetrance of FH mutations, and clinicopathologic features of MCUL. Results: Forty-one (89% ) of 46 probands with multiple skin leiomyomas had evidence of germline FH mutations, which were highly penetrant. All 26 male mutation carriers had skin leiomyomas. Of 67 women with FH mutations, 46 (69% ) had both skin and uterine leiomyomas; 10 (15% ) had only skin leiomyomas;5(7% )had only uterine leiomyomas;and 6(9% )were clinically unaffected. Patients presented with skin leiomyomas at a mean age of 24 years and had a mean of 25 lesions. Forty-one individuals (89% ) reported painful lesions, particularly in response to cold or trauma. Fibroids were histologically unremarkable, highly symptomatic, and associated with a high risk of early hysterectomy. One individual had a very aggressive collecting duct renal cancer. The G354R FH mutation predisposed patients to uterine fibroids without skin leiomyomas (P=.03). Many patients with skin leiomyomas had not previously presented for medical attention. Fibroids were rarely recognized as cases of MCUL. Conclusions: Highly penetrant FH mutations underlie MCUL. Increased clinical awareness is important because of the associated risk of severe uterine fibroids and, in some cases, aggressive renal cancer.展开更多
Highly efficient nonlinear optical（NLO） materials with well-defined architectures in the wavelength and subwavelength length scales are of particular importance for next generation of integrated photonic circuits. F...Highly efficient nonlinear optical（NLO） materials with well-defined architectures in the wavelength and subwavelength length scales are of particular importance for next generation of integrated photonic circuits. Fluorenone analogues have been demonstrated to be promising candidates as building blocks for assembly of organic NLO materials thanks to their synergistic supramolecular interactions and brilliant optical properties. Here we have studied the polymorphs of a phenylethynyl functionalized fluorenone derivative, and their controlled self-assembly for microstructures with different morphologies. These polymorphic microcrystals exhibit very distinctive NLO properties, highly related to their supramolecular and electronic structures.展开更多
Androgen deprivation therapy （ADT） has been an essential treatment option for treating prostate cancer （PCa）. The role for hormonal treatment initially was restricted to men with metastatic and inoperable, locally...Androgen deprivation therapy （ADT） has been an essential treatment option for treating prostate cancer （PCa）. The role for hormonal treatment initially was restricted to men with metastatic and inoperable, locally advanced disease. Now it has been extended to neoadjuvant or adjuvant therapy for surgery and radiotherapy, for biochemical relapse after surgery or radiation, and even as primary therapy for non-metastatic disease. Fifty percent of PCa patients treated will receive ADT at some point. There is growing concern about the adverse effects and costs associated with more widespread ADT use. The adverse effects on quality of life （QoL）, including physical, social and psychological well-being when men are androgen-deprived, may be considerable. This review examines the QoL issues in the following areas： body feminisation, sexual changes, relationship changes, cognitive and affective symptoms, fatigue, sleep disturbance, depression and physical effects. Further suggestions for therapeutic approaches to reduce these alterations are suFuzested.展开更多
AIM To determine if a standardized asthma severity scoring system(PASS) was associated with the time spent on continuous albuterol and length of stay in the pediatric intensive care unit(PICU).METHODS This is a single...AIM To determine if a standardized asthma severity scoring system(PASS) was associated with the time spent on continuous albuterol and length of stay in the pediatric intensive care unit(PICU).METHODS This is a single center,retrospective chart review study at a major children's hospital in an urban location.To qualify for this study,participants must have been admitted to the PICU with a diagnosis of status asthmaticus.There were a total of 188 participants between the ages of two and nineteen,excluding patients receiving antibiotics for pneumonia.PASS was calculated upon PICU admission.Subjects were put into one of three categories based on PASS: ≤ 7(mild),8-11(moderate),and ≥ 12(severe).The groups were compared based on different variables,including length of continuous albuterol and PICU stay.RESULTS The age distribution across all groups was similar.The median length of continuous albuterol was longest in the severe group with a duration of 21.5 h(11.5-27.5),compared to 15(7.75-23.75) and 10(5-15) in the moderate and mild groups,respectively(P = 0.001).Thelength of stay was longest in the severe group,with a stay of 35.6 h(22-49) compared to 26.5(17-30) and 17.6(12-29) in the moderate and mild groups,respectively(P = 0.001).CONCLUSION A higher PASS is associated with a longer time on continuous albuterol,an increased likelihood to require noninvasive ventilation,and a longer stay in the ICU.This may help safely distribute asthmatics to lower and higher levels of care in the future.展开更多
Based on AMS 14 C dating data,carbon and nitrogen isotope analyses were conducted on mammal bone collagen of deer,cattle and pigs from the Zhongba site in the Three Gorges Reservoir region of the Yangtze River.These a...Based on AMS 14 C dating data,carbon and nitrogen isotope analyses were conducted on mammal bone collagen of deer,cattle and pigs from the Zhongba site in the Three Gorges Reservoir region of the Yangtze River.These analyses were conducted to reconstruct palaeodiets of mammals,palaeoecology,palaeoenviroment and previous human activities in the study area.Results show that the collagen loss of bone did not change the in vivo isotopic composition of carbon and nitrogen stable isotopes,and most of the bone fossils were well preserved.The bone collagen of samples from deer had a mean δ 13 C of-23.1‰ and a mean δ 15 N of 4.7‰,suggesting that deer subsisted in a closed habitat and fed on branches and leaves.The bone collagen of cattle had a mean δ 13 C of-19.6‰ and a mean δ 15 N of 5.2‰,which indicates that cattle subsisted in an open habitat and fed on grasses and stems.The δ 13 C values show that both deer and cattle fed on C 3 plants and lived in the same ecosystem,but the t-test results show that deer δ 13 C and δ 15 N values were both more negative than those of cattle,indicating that they inhabited different niches.The δ 13 C and δ 15 N values of cattle partially overlapped those of deer,suggesting some competition in diets between them.The t-tests show that the δ 13 C and δ 15 N values of pigs were more positive than those of cattle and deer,which signifies that pigs occupied a higher trophic level compared to cattle and deer.The wide range of pig δ 13 C values demonstrates that pig trading had been taking place from early Neolithic Age to late Bronze Age.There were no significant differences in deer δ 13 C and δ 15 N values among different archaeological periods,making it clear that climatic,ecological and environmental conditions were kept relatively stable from 2200 to 4200 a BP.This stability may have been responsible for the extensive and complete cultural layers at the Zhongba site.The minimum number of samples required to estimate the mean δ 13 C values of deer,pigs and cattle are 8展开更多
Charge exchange recombination spectroscopy （CXRS） based on a diagnostic neutral beam （DNB） installed in the HT-7 tokamak is introduced. DNB can provide a 6 A extracted current at 50 kV for 0.1 s in hydrogen. It ca...Charge exchange recombination spectroscopy （CXRS） based on a diagnostic neutral beam （DNB） installed in the HT-7 tokamak is introduced. DNB can provide a 6 A extracted current at 50 kV for 0.1 s in hydrogen. It can penetrate into the core plasma in HT-7. The CXRS system is designed to observe charge exchange （CX） transitions in the visible spectrum. CX light from the beam is focused onto 10 optical fibers, which view the plasma from -5 cm to 20 cm. The CXRS system can measure the ion temperature as low as 0.1 keV. With CXRS, the local ion temperature profile in HT-7 was obtained for the first time.展开更多
基金This study was supported by grants from The National Natural Science Foundation of China(81772950)Tongji Hospital Clinical Research Flagship Program(2019CR203)to RQ.
文摘Importance:While laparoscopic pancreaticoduodenectomy(LPD)is being adopted with increasing enthusiasm worldwide,it is still challenging for both technical and anatomical reasons.Currently,there is no consensus on the technical standards for LPD.Objective:The aim of this consensus statement is to guide the continued safe progression and adoption of LPD.Evidence Review:An international panel of experts was selected based on their clinical and scientific expertise in laparoscopic and open pancreaticoduodenectomy.Statements were produced upon reviewing the literature and assessed by the members of the expert panel.The literature search and its critical appraisal were limited to articles published in English during the period from 1994 to 2019.The Web of Science,Medline,and Cochrane Library and Clinical Trials databases were searched,The search strategy included,but was not limited to,the terms'laparoscopic','pancreaticoduodenectomy,'pancreatoduodenectomy','Whipple's operation',and'minimally invasive surgery'.Reference lists from the included articles were manually checked for any additional studies,which were included when appropriate.Delphi method was used to establish expert consensus and the AGREE II-GRS Instrument was applied to assess the methodological quality and externally validate the final statements.The statements were further discussed during a one-day face-to-face meeting at the 1st Summit on Minimally Invasive Pancreatico-Biliary Surgery in Wuhan,China.Findings:Twenty-eight international experts from 8 countries constructed the expert panel.Sixteen statements were produced by the members of the expert panel.At least 80%of responders agreed with the majority(80%)of statements.Other than three randomized controlled trials published to date,most evidences were based on level 3 or 4 studies according to the AGREE II-GRS Instrument.Conclusions and Relevance:The Wuhan international expert consensus meeting on LPD has produced a set of clinical practice statements for the safe development and progression of LP
基金supported by the UK– China Research & Innovation Partnership Fund through the Met Office Climate Science for Service Partnership (CSSP) of China, as part of the Newton Fundsupported by the UK National Centre for Atmospheric Science–Climate (NCAS– Climate) at the University of Reading
文摘This study investigated the drivers and physical processes for the abrupt decadal summer surface warming and increases in hot temperature extremes that occurred over Northeast Asia in the mid-1990s. Observations indicate an abrupt increase in summer mean surface air temperature （SAT） over Northeast Asia since the mid-1990s. Accompanying this abrupt surface wanning, significant changes in some temperature extremes, characterized by increases in summer mean daily maximum temperature （Tmax）, daily minimum temperature （Train）, annual hottest day temperature （TXx）, and annual warmest night temperature （TNx） were observed. There were also increases in the frequency of summer days （SU） and tropical nights （TR）. Atmospheric general circulation model experiments forced by changes in sea surface temperature （SST）/sea ice extent （SIE）, anthropogenic greenhouse gas （GHG） concentrations, and anthropogenic aerosol （AA） forcing, relative to the period 1964- 93, reproduced the general patterns of observed summer mean SAT changes and associated changes in temperature extremes, although the abrupt decrease in precipitation since the mid-1990s was not simulated. Additional model experiments with different forcings indicated that changes in SST/SIE explained 76% of the area-averaged summer mean surface warming signal over Northeast Asia, while the direct impact of changes in GHG and AA explained the remaining 24% of the surface warming signal. Analysis of physical processes indicated that the direct impact of the changes in AA （through aerosol- radiation and aerosol-cloud interactions）, mainly related to the reduction of AA precursor emissions over Europe, played a dominant role in the increase in TXx and a similarly important role as SST/SIE changes in the increase in the frequency of SU over Northeast Asia via AA-induced coupled atmosphere-land surface and cloud feedbacks, rather than through a direct impact of AA changes on cloud condensation nuclei. The modelling results also imply
文摘Objective: Gastrointestinal (GI) discomfort is experienced by millions of people every day. This study aimed to evaluate the effect of PhenActiv<sup>TM</sup>, a novel green kiwifruit extract, on gastrointestinal tract (GIT) function in otherwise healthy adults. Methods: 41 healthy adults with mild GI discomfort were enrolled in this double-blind, randomized, placebo-controlled study. Participants were randomized to either take 3.0 g/day of PhenActiv<sup>TM</sup> or a placebo for 6 weeks. Interviews were conducted at baseline, week 3 and week 6, with participants completing questionnaires regarding GI symptoms. Frequency of bowel movements was self-recorded daily. Results: There were no differences in daily and weekly defecation frequency and stool characteristics in either group. The active and placebo groups significantly improve GSRS scores (p , only the active group had a significant improvement in the IBSSS and PAC-QOL scores (p < 0.05) from baseline. Neither group had changes in sleep quality, quality of life and fatigue, plasma zonulin concentrations or macular pigment optical density scores. The product was well tolerated with no GI disturbances or adverse events being reported. Conclusion: Supplementation of 3.0 g/day of PhenActiv<sup>TM</sup> for 6 weeks did not improve defecation frequency or stool composition in healthy adults, but did improve perceived symptoms of GIT function, including symptoms of functional GIT disorders, IBS and constipation. The product was well tolerated and future trials investigating higher doses with more participants and/or a different population would be beneficial.
文摘Evaluating whether hybrid zones are stable or mobile can provide novelinsights for evolution and conservation biology. Butterflies exhibit high sensitivity to envi-ronmental changes and represent an important model system for the study of hybrid zoneorigins and maintenance. Here, we review the literature exploring butterfly hybrid zones,with a special focus on their spatiotemporal dynamics and the potential mechanisms thatcould lead to their movement or stability. We then compare different lines of evidenceused to investigate hybrid zone dynamics and discuss the strengths and weaknesses ofeach approach. Our goal with this review is to reveal general conditions associated withthe stability or mobility of butterfly hybrid zones by synthesizing evidence obtained us-ing different types of data sampled across multiple regions and spatial scales. Finally, wediscuss spatiotemporal dynamics in the context of a speciation/divergence continuum, therelevance of hybrid zones for conservation biology, and recommend key topics for futureinvestigation.
基金supported by the National Natural Science Foundation of China (No.50379053,50609029,50779068)
文摘Using reclaimed wastewater for crop irrigation is a practical alternative to discharge wastewater treatment plant effluents into surface waters.However,biofouling has been identified as a major contributor to emitter clogging in drip irrigation systems distributing reclaimed wastewater.Little is known about the biofilm structure and its influence on clogging in the drip emitter flow path.This study was first to investigate the microbial characteristics of mature biofilms present in the emitters and the effect of flow path structures on the biofilm microbial communities.The analysis of biofilm matrix structure using a scanning electron microscopy（SEM） revealed that particles in the matrix of the biofilm coupled extracellular polysaccharides（EPS） and formed sediment in the emitter flow path.Analysis of biofilm mass including protein,polysaccharide,and phospholipid fatty acids（PLFAs） showed that emitter flow path style influenced biofilm community structure and diversity.The correlations of biofilm biomass and discharge reduction after 360 h irrigation were computed and suggest that PFLAs provide the best correlation coeffcient.Comparatively,the emitter with the unsymmetrical dentate structure and shorter flow path（Emitter C） had the best anti-clogging capability.By optimizing the dentate structure,the internal flow pattern within the flow path could be enhanced as an important method to control the biofilm within emitter flow path.This study established electron microscope techniques and biochemical microbial analysis methods that may provide a framework for future emitter biofilm studies.
文摘Pancreatic neuroendocrine neoplasms are a rare and complex group of neoplastic lesions that develop from pancreatic islet cells.Their incidence has dramatically increased during the last two decades.Due to its complex nature and pathophysiological behaviour,surgical management continues to evolve.Surgery remains the cornerstone of treatment for most non-functional and functional pancreatic neuroendocrine tumours,while lymphadenectomy remains a controversial subject.Different techniques,such as pancreas-preserving and minimally invasive approaches,continue to evolve and offer the same overall outcomes as open surgery.This comprehensive review describes in detail the current and most up-todate classification and staging of pancreatic neuroendocrine tumours,explores the rationale for nonsurgical and surgical management,and focuses on surgical treatment and more specifically,on minimally invasive approaches.
基金the National Science Foundation[CMMI-1935451]and National Science Foundation[ISS-2039951]。
文摘Wildlife trafficking is a global phenomenon posing many negative impacts on socio-environmental systems.Scientific exploration of wildlife trafficking trends and the impact of interventions is significantly encumbered by a suite of data reuse challenges.We describe a novel,open-access data directory on wildlife trafficking and a corresponding visualization tool that can be used to identify data for multiple purposes,such as exploring wildlife trafficking hotspots and convergence points with other crime,discovering key drivers or deterrents of wildlife trafficking,and uncovering structural patterns.Keyword searches,expert elicitation,and peer-reviewed publications were used to search for extant sources used by industry and non-profit organizations,as well as those leveraged to publish academic research articles.The open-access data directory is designed to be a living document and searchable according to multiple measures.The directory can be instrumental in the data-driven analysis of unsustainable illegal wildlife trade,supply chain structure via link prediction models,the value of demand and supply reduction initiatives via multi-item knapsack problems,or trafficking behavior and transportation choices via network interdiction problems.
文摘From the beginning of the COVID-19 pandemic,universities have experienced unique challenges due to their dual nature as a place of education and residence.Current research has explored non-pharmaceutical approaches to combating COVID-19,including representing in models different categories such as age groups.One key area not currently well represented in models is the effect of pharmaceutical preventative measures,specifically vaccinations,on COVID-19 spread on college campuses.There remain key questions on the sensitivity of COVID-19 infection rates on college campuses to potentially time-varying vaccine immunity.Here we introduce a compartment model that decomposes a campus population into constituent subpopulations and implements vaccinations with timevarying efficacy.We use this model to represent a campus population with both vaccinated and unvaccinated individuals,and we analyze this model using two metrics of interest:maximum isolation population and symptomatic infection.We demonstrate a decrease in symptomatic infections occurs for vaccinated individuals when the frequency of testing for unvaccinated individuals is increased.We find that the number of symptomatic infections is insensitive to the frequency of testing of the unvaccinated subpopulation once about 80%or more of the population is vaccinated.Through a Sobol’global sensitivity analysis,we characterize the sensitivity of modeled infection rates to these uncertain parameters.We find that in order to manage symptomatic infections and the maximum isolation population campuses must minimize contact between infected and uninfected individuals,promote high vaccine protection at the beginning of the semester,and minimize the number of individuals developing symptoms.
基金the Netherlands Organisation for Scientific Research (NWO)for providing and supporting beam time at the DutchBelgium beamline(DUBBLE) for SAXS experiments(No. BM26-02773)financial support from NWO (VENI grant No. 680-47-437)+2 种基金the Euopean Union's 2020 ResearchInnovation Programme under Grant Agreement No. 642687project Biogel
文摘Thermosensitive polymers show an entropy-driven transition from a well-solvated to a poorly solvated polymer chain, resulting in a more compact globular conformation. The transition at the lower critical solution temperature（LCST） is often sharp, which allows for a wide range of smart material applications.At the LCST, oligo（ethylene glycol）-substituted polyisocyanides（PICs） form soft hydrogels, composed of polymer bundles similar to biological gels, such as actin, fibrin and intermediate filaments. Here, we show that the LCST of PICs strongly depends linearly on the length of the ethylene glycol（EG） tails; every EG group increases the LCSTand thus the gelation temperature by nearly 30 ℃. Using a copolymerisation approach, we demonstrate that we can precisely tailor the gelation temperature between 10 ℃ and 60 ℃and, consequently, tune the mechanical properties of the PIC gels.
基金funded by the National Institute for Health Research(NIHR)under its Programme Grants for Applied Research Programme(Reference Number RP-PG-0614-20007)。
文摘Background:The evidence concerning which physical exercise characteristics are most effective for older adults is fragmented.We aimed to characterize the extent of this diversity and inconsistency and identify future directions for research by undertaking a systematic review of metaanalyses of exercise interventions in older adults.Methods:We searched the Cochrane Database of Systematic Reviews,PsycInfo,MEDLINE,Embase,CINAHL,AMED,SPORTDiscus,and Web of Science for articles that met the following criteria:(1)meta-analyses that synthesized measures of improvement(e.g.,effect sizes)on any outcome identified in studies of exercise interventions;(2)participants in the studies meta-analyzed were adults aged 65+or had a mean age of 70+;(3)meta-analyses that included studies of any type of exercise,including its duration,frequency,intensity,and mode of delivery;(4)interventions that included multiple components(e.g.,exercise and cognitive stimulation),with effect sizes that were computed separately for the exercise component;and(5)meta-analyses that were published in any year or language.The characteristics of the reviews,of the interventions,and of the parameters improved through exercise were reported through narrative synthesis.Identification of the interventions linked to the largest improvements was carried out by identifying the highest values for improvement recorded across the reviews.The study included 56 meta-analyses that were heterogeneous in relation to population,sample size,settings,outcomes,and intervention characteristics.Results:The largest effect sizes for improvement were found for resistance training,meditative movement interventions,and exercise-based active videogames.Conclusion:The review identified important gaps in research,including a lack of studies investigating the benefits of group interventions,the characteristics of professionals delivering the interventions associated with better outcomes,and the impact of motivational strategies and of significant others(e.g.,carers)on intervention deli
文摘Objective: To investigate the clinical features of the multiple cutaneous and uterine leiomyomatosis (MCUL) syndrome, including the hereditary leiomyomatosis and renal cell cancer syndrome. Design: A case series of patients with multiple skin leiomyomas solicited via a circular letter to dermatologists. Setting: Research institute. Patients: A total of 108 affected individuals, including 46 probands and 62 affected relatives. Main Outcome Measures: The proportion of probands with underlying fumarate hydratase (FH) mutations, the penetrance of FH mutations, and clinicopathologic features of MCUL. Results: Forty-one (89% ) of 46 probands with multiple skin leiomyomas had evidence of germline FH mutations, which were highly penetrant. All 26 male mutation carriers had skin leiomyomas. Of 67 women with FH mutations, 46 (69% ) had both skin and uterine leiomyomas; 10 (15% ) had only skin leiomyomas;5(7% )had only uterine leiomyomas;and 6(9% )were clinically unaffected. Patients presented with skin leiomyomas at a mean age of 24 years and had a mean of 25 lesions. Forty-one individuals (89% ) reported painful lesions, particularly in response to cold or trauma. Fibroids were histologically unremarkable, highly symptomatic, and associated with a high risk of early hysterectomy. One individual had a very aggressive collecting duct renal cancer. The G354R FH mutation predisposed patients to uterine fibroids without skin leiomyomas (P=.03). Many patients with skin leiomyomas had not previously presented for medical attention. Fibroids were rarely recognized as cases of MCUL. Conclusions: Highly penetrant FH mutations underlie MCUL. Increased clinical awareness is important because of the associated risk of severe uterine fibroids and, in some cases, aggressive renal cancer.
基金the financial supports from the National Natural Science Foundation of China(NSFC) (Nos.21773168, 51503143 and 21761132007)the Tianjin Natural Science Foundation(No. 16JCQNJC05000)+5 种基金the Innovation Foundation of Tianjin University (No. 2016XRX-0017)the China International Science and Technology Projects(No. S2016G3413)The Netherlands Organization for Scientific Research (NWO) with the Veni Grant (No. 680-47-437)The Royal Netherlands Academy of Arts and Sciences(KNAW) with the China-Exchange Program (No. 530-4CDPO2)the Tianjin 1000 Youth Talents Planthe Chinese Scholarship Council (CSC)
文摘Highly efficient nonlinear optical（NLO） materials with well-defined architectures in the wavelength and subwavelength length scales are of particular importance for next generation of integrated photonic circuits. Fluorenone analogues have been demonstrated to be promising candidates as building blocks for assembly of organic NLO materials thanks to their synergistic supramolecular interactions and brilliant optical properties. Here we have studied the polymorphs of a phenylethynyl functionalized fluorenone derivative, and their controlled self-assembly for microstructures with different morphologies. These polymorphic microcrystals exhibit very distinctive NLO properties, highly related to their supramolecular and electronic structures.
文摘Androgen deprivation therapy （ADT） has been an essential treatment option for treating prostate cancer （PCa）. The role for hormonal treatment initially was restricted to men with metastatic and inoperable, locally advanced disease. Now it has been extended to neoadjuvant or adjuvant therapy for surgery and radiotherapy, for biochemical relapse after surgery or radiation, and even as primary therapy for non-metastatic disease. Fifty percent of PCa patients treated will receive ADT at some point. There is growing concern about the adverse effects and costs associated with more widespread ADT use. The adverse effects on quality of life （QoL）, including physical, social and psychological well-being when men are androgen-deprived, may be considerable. This review examines the QoL issues in the following areas： body feminisation, sexual changes, relationship changes, cognitive and affective symptoms, fatigue, sleep disturbance, depression and physical effects. Further suggestions for therapeutic approaches to reduce these alterations are suFuzested.
文摘AIM To determine if a standardized asthma severity scoring system(PASS) was associated with the time spent on continuous albuterol and length of stay in the pediatric intensive care unit(PICU).METHODS This is a single center,retrospective chart review study at a major children's hospital in an urban location.To qualify for this study,participants must have been admitted to the PICU with a diagnosis of status asthmaticus.There were a total of 188 participants between the ages of two and nineteen,excluding patients receiving antibiotics for pneumonia.PASS was calculated upon PICU admission.Subjects were put into one of three categories based on PASS: ≤ 7(mild),8-11(moderate),and ≥ 12(severe).The groups were compared based on different variables,including length of continuous albuterol and PICU stay.RESULTS The age distribution across all groups was similar.The median length of continuous albuterol was longest in the severe group with a duration of 21.5 h(11.5-27.5),compared to 15(7.75-23.75) and 10(5-15) in the moderate and mild groups,respectively(P = 0.001).Thelength of stay was longest in the severe group,with a stay of 35.6 h(22-49) compared to 26.5(17-30) and 17.6(12-29) in the moderate and mild groups,respectively(P = 0.001).CONCLUSION A higher PASS is associated with a longer time on continuous albuterol,an increased likelihood to require noninvasive ventilation,and a longer stay in the ICU.This may help safely distribute asthmatics to lower and higher levels of care in the future.
基金supported by the National Natural Science Foundation of China(40971115)the University Doctoral Foundation(20090091110036)+2 种基金the Open Foundation of the State Key Laboratory of Loess and Quaternary Geology from the Institute of Earth Environment,CAS (SKLLQG0817)the Test Foundation of Modern Analyses Center of Nanjing University(0209001309)the Foundation of the Ministry of Science and Technology of the People’s Republic of China(2010BAK67B02)
文摘Based on AMS 14 C dating data,carbon and nitrogen isotope analyses were conducted on mammal bone collagen of deer,cattle and pigs from the Zhongba site in the Three Gorges Reservoir region of the Yangtze River.These analyses were conducted to reconstruct palaeodiets of mammals,palaeoecology,palaeoenviroment and previous human activities in the study area.Results show that the collagen loss of bone did not change the in vivo isotopic composition of carbon and nitrogen stable isotopes,and most of the bone fossils were well preserved.The bone collagen of samples from deer had a mean δ 13 C of-23.1‰ and a mean δ 15 N of 4.7‰,suggesting that deer subsisted in a closed habitat and fed on branches and leaves.The bone collagen of cattle had a mean δ 13 C of-19.6‰ and a mean δ 15 N of 5.2‰,which indicates that cattle subsisted in an open habitat and fed on grasses and stems.The δ 13 C values show that both deer and cattle fed on C 3 plants and lived in the same ecosystem,but the t-test results show that deer δ 13 C and δ 15 N values were both more negative than those of cattle,indicating that they inhabited different niches.The δ 13 C and δ 15 N values of cattle partially overlapped those of deer,suggesting some competition in diets between them.The t-tests show that the δ 13 C and δ 15 N values of pigs were more positive than those of cattle and deer,which signifies that pigs occupied a higher trophic level compared to cattle and deer.The wide range of pig δ 13 C values demonstrates that pig trading had been taking place from early Neolithic Age to late Bronze Age.There were no significant differences in deer δ 13 C and δ 15 N values among different archaeological periods,making it clear that climatic,ecological and environmental conditions were kept relatively stable from 2200 to 4200 a BP.This stability may have been responsible for the extensive and complete cultural layers at the Zhongba site.The minimum number of samples required to estimate the mean δ 13 C values of deer,pigs and cattle are 8
基金supported by the Instruments R&D Project of the Chinese Academy of Sciences (title: Active Beam Spectra Diagnostic)partially supported by National Natural Science Foundation of China (Nos. 10725523, 10975155)the U. S. Department of Energy Under Grant No. DE-FG02-03ER54729 to the University of Texas
文摘Charge exchange recombination spectroscopy （CXRS） based on a diagnostic neutral beam （DNB） installed in the HT-7 tokamak is introduced. DNB can provide a 6 A extracted current at 50 kV for 0.1 s in hydrogen. It can penetrate into the core plasma in HT-7. The CXRS system is designed to observe charge exchange （CX） transitions in the visible spectrum. CX light from the beam is focused onto 10 optical fibers, which view the plasma from -5 cm to 20 cm. The CXRS system can measure the ion temperature as low as 0.1 keV. With CXRS, the local ion temperature profile in HT-7 was obtained for the first time.
