期刊文献+
共找到221篇文章
< 1 2 12 >
每页显示 20 50 100
Myelin histology:a key tool in nervous system research
1
作者 Óscar Darío García-García Víctor Carriel Jesús Chato-Astrain 《Neural Regeneration Research》 SCIE CAS CSCD 2024年第2期277-281,共5页
The myelin sheath is a lipoprotein-rich,multilayered structure capable of increasing conduction velocity in central and peripheral myelinated nerve fibers.Due to the complex structure and composition of myelin,various... The myelin sheath is a lipoprotein-rich,multilayered structure capable of increasing conduction velocity in central and peripheral myelinated nerve fibers.Due to the complex structure and composition of myelin,various histological techniques have been developed over the centuries to evaluate myelin under normal,pathological or experimental conditions.Today,methods to assess myelin integrity or content are key tools in both clinical diagnosis and neuroscience research.In this review,we provide an updated summary of the composition and structure of the myelin sheath and discuss some histological procedures,from tissue fixation and processing techniques to the most used and practical myelin histological staining methods.Considering the lipoprotein nature of myelin,the main features and technical details of the different available methods that can be used to evaluate the lipid or protein components of myelin are described,as well as the precise ultrastructural techniques. 展开更多
关键词 fluorescence microscopy HISTOLOGY light microscopy lipid histochemistry metallographic techniques myelin histochemistry myelin immunohistochemistry myelin structure&composition myelin ultrastructural evaluation tissue fixation&processing
下载PDF
The Effect of the Paleo Diet on People Suffering from Osteoporosis (Review Paper)
2
作者 Sanabhi Gupta 《Food and Nutrition Sciences》 CAS 2024年第9期899-904,共6页
Osteoporosis is a disease that decreases bone mass and increases bone porosity, weakening bones. The Paleo diet is an eating plan that imitates the dietary patterns of the Stone Age. It excludes grains, dairy, and pro... Osteoporosis is a disease that decreases bone mass and increases bone porosity, weakening bones. The Paleo diet is an eating plan that imitates the dietary patterns of the Stone Age. It excludes grains, dairy, and processed foods and emphasizes feeding on lean meats, fruits, vegetables, and nuts. Consumption of the Paleo diet has many positive sides, such as high protein intake and weight loss. Still, excluding dairy products risks calcium and vitamin D deficiencies, which are crucial for bone health. Statistics and simulations that have explored the relationship between the Paleo diet and bone health (especially for people suffering from low bone density) show mixed outcomes on bone health.). While the consumer does get lots of benefits from fruit and vegetable intake in a large sum due to them containing nutrients like magnesium, potassium, and vitamin K (which are also necessary for bone health), the lack of dairy products (gives the maximum amount of calcium and vitamin D) raises concerns about maintaining adequate bone mineral density (BMD). More information on this topic shows the negative impact of this diet on people suffering from osteoporosis due to a lack of nutrient intake that nourishes the bone. Although the Paleo diet can enhance overall health through nutrient-dense foods and reduced processed intake, it can’t be said the same for people suffering from osteoporosis. 展开更多
关键词 OSTEOPOROSIS Paleo Diet Bone Density Calcium and Vitamin D Deficiency Bone Health Nutrient Deficiency Dietary Patterns Bone Mineral Density (BMD) Nutritional Imbalance
下载PDF
Small but big leaps towards neuroglycomics:exploring N-glycome in the brain to advance the understanding of brain development and function
3
作者 Boyoung Lee Hyun Joo An 《Neural Regeneration Research》 SCIE CAS CSCD 2024年第3期489-490,共2页
Glycosylation is a process that involves the addition of sugar moieties or glycans to different types of molecules,including proteins,lipids,and nucleic acids.Among these,protein glycosylation is one of the most preva... Glycosylation is a process that involves the addition of sugar moieties or glycans to different types of molecules,including proteins,lipids,and nucleic acids.Among these,protein glycosylation is one of the most prevalent forms of post-translational modification,playing a crucial role in biological complexity.With more than ten monosaccharides identified within mammalian brain cells and more than 1×1012 possible combinations,the heterogeneity of glycosylation is extensive(Conroy et al.,2021).The diversity of glycans and the complexity of their structures allow for a wide range of protein functions.N-glycans are one of the most abundant forms of glycans and are involved in various cellular functions.N-glycans can be added to proteins at specific sequons,Asn-X-Ser/Thr,and are classified into three main types in mature glycoproteins:high mannose,complex,and hybrid.High mannose N-glycans consist of 5-9 mannose residues linked to a chitobiose core and undergo processing into complex or hybrid forms in the Golgi apparatus(Varki et al.,2017).Complex N-glycans are more diverse and contain various branched structures such as antennae with fucose,galactose,and sialic acid residues.Hybrid N-glycans contain one or more complex branches in conjunction with an oligomannose branch(Fisher and Ungar,2016).Understanding the specific functions of these different types of N-glycans in protein regulation,folding,and function is an active area of research in the life sciences,including glycobiology. 展开更多
关键词 functions FUNCTION apparatus
下载PDF
Basic Research on the Burden of Dropping off and Picking up Children: Differences by Employment Type and Gender in the Tokyo Metropolitan Area
4
作者 Jun Morio Koshi Isono +1 位作者 Masahiko Kikuchi Tetsuo Morita 《Journal of Transportation Technologies》 2024年第3期445-461,共17页
There is a need to reduce the burden of child drop-off and pick-up for child-rearing generations, but most studies on the actual situation in Japan are based on survey results. In this study, we analyzed differences i... There is a need to reduce the burden of child drop-off and pick-up for child-rearing generations, but most studies on the actual situation in Japan are based on survey results. In this study, we analyzed differences in child drop-off and pick-up by employment type and gender, utilizing the “Metropolitan Area Person Trip Survey,” which is a statistical data set. The study targeted households in which both spouses were between 30 and 49 years old, had children under the age of 6, and included the following three groups. 1) Dual-income Group 1 (both spouses employed/on contract/temporary);2) Dual-income Group 2 (husband employed/on contract/temporary, wife part-time);3) Full-time housewife group (husband employed, wife unemployed). The analysis revealed that a) wives are almost always responsible for dropping off and picking up their children;b) husbands drop off and pick up their children less frequently in dual-income households;and c) households with children raising within 10 to 30 km of Tokyo Station have longer commuting times and need to reduce the burden of dropping off and picking up their children. 展开更多
关键词 Drop-Off and Pick-Up Employment Type GENDER Dual-Income Households Tokyo Metropolitan Area
下载PDF
Physical activity and amyloid beta in middle-aged and older adults:A systematic review and meta-analysis
5
作者 María Rodriguez-Ayllon Patricio Solis-Urra +7 位作者 Cristina Arroyo-ávila Miriam álvarez-Ortega Pablo Molina-García Cristina Molina-Hidalgo Manuel Gómez-Río Belinda Brown Kirk I.Erickson Irene Esteban-Cornejo 《Journal of Sport and Health Science》 SCIE CAS CSCD 2024年第2期133-144,共12页
Background:One of the pathological hallmarks distinguishing Alzheimer’s disease from other dementias is the accumulation of amyloid beta(Aβ).Higher physical activity is associated with decreased dementia risk,and on... Background:One of the pathological hallmarks distinguishing Alzheimer’s disease from other dementias is the accumulation of amyloid beta(Aβ).Higher physical activity is associated with decreased dementia risk,and one potential path could be through Aβlevels modulation.We aimed to explore the relationship between physical activity and Aβin middle-aged and older adults.Methods:A systematic search of PubMed,Web of Science,PsycINFO,Cochrane Central Register of Controlled Trials,and SPORTDiscus was performed from inception to April 28,2022.Studies were eligible if they included physical activity and Aβdata in adults aged 45 years or older.Multi-level metaanalyses of intervention and observational studies were performed to examine the role of physical activity in modulating Aβlevels.Results:In total,37 articles were included(8 randomized controlled trials,3 non-randomized controlled trials,4 prospective longitudinal studies,and 22 cross-sectional studies).The overall effect size of physical activity interventions on changes in blood Aβwas medium(pooled standardized mean difference=-0.69,95%confidence interval(95%CI):-1.41 to 0.03;I^(2)=74.6%).However,these results were not statistically significant,and there were not enough studies to explore the effects of physical activity on cerebrospinal fluid(CSF)and brain Aβ.Data from observational studies were examined based on measurements of Aβin the brain using positron emission tomography scans,CSF,and blood.Higher physical activity was positively associated with Aβonly in the CSF(Estimate r=0.12;95%CI:0.05-0.18;I^(2)=38.00%).Conclusion:Physical activity might moderately reduce blood Aβin middle-aged and older adults.However,results were only near statistical significance and might be interpreted with caution given the methodological limitations observed in some of the included studies.In observational studies,higher levels of physical activity were positively associated with Aβonly in CSF.Therefore,further research is needed to understand the modulating role of physical activity in the brain,CSF,and blood Aβ,as well as its implication for cognitive health. 展开更多
关键词 AGING Cognitive impairment DEMENTIA EXERCISE PET
下载PDF
Metastatic pancreatic and lung cancer patient in complete remission following immunotherapy: A case report and review of literature
6
作者 Joaquina Martínez-Galán Cristina Jiménez-Luna +5 位作者 Isabel Rodriguez Elisabeth Maza Carlos García-Collado Antonio Rodríguez-Fernández Javier Luis López-Hidalgo Octavio Caba 《World Journal of Gastrointestinal Oncology》 SCIE 2024年第5期2233-2240,共8页
BACKGROUND Metastatic pancreatic ductal adenocarcinoma(PDAC)is a lethal malignancy with dispiriting survival data.Immunotherapy is a promising approach to many cancer types,but achieves poor outcomes in advanced PDAC ... BACKGROUND Metastatic pancreatic ductal adenocarcinoma(PDAC)is a lethal malignancy with dispiriting survival data.Immunotherapy is a promising approach to many cancer types,but achieves poor outcomes in advanced PDAC due to its immunosuppressive tumor microenvironment.We describe a case of metastatic PDAC effectively treated with pembrolizumab.CASE SUMMARY We report the case of a 67-year-old woman with unresectable locally advanced PDAC,treated with gemcitabine plus nab-paclitaxel followed by radiotherapy plus capecitabine.At nine months,pancreatic tumor progression was observed at the level of the hepatic hilum with the appearance of a new pulmonary nodule suggestive of a second primary,confirmed by left lung biopsy.Systemic immunotherapy was then initiated with pembrolizumab,an immune checkpoint inhibitor targeting programmed cell death protein-1 that covers the two tumor types.The patient showed a complete metabolic response that was maintained throughout the treatment.The patient continues to be disease-free at 5.6 years since the start of immunotherapy.CONCLUSION These results suggest that the administration of pembrolizumab after chemoradiotherapy has a beneficial effect in patients with metastatic PDAC.To our knowledge,this is the first reported case of a patient with metastatic PDAC and metastatic lung cancer showing such a long-lasting complete response after pembrolizumab treatment without curative surgery.Further studies are required to determine biomarkers that identify PDAC patients most likely to benefit from this immunotherapy. 展开更多
关键词 Pancreatic ductal adenocarcinoma Lung cancer IMMUNOTHERAPY Pembrolizumab Programmed cell death protein-1 Case report
下载PDF
Recent Advances in Patterning Strategies for Full‑Color Perovskite Light‑Emitting Diodes
7
作者 Gwang Heon Lee Kiwook Kim +2 位作者 Yunho Kim Jiwoong Yang Moon Kee Choi 《Nano-Micro Letters》 SCIE EI CSCD 2024年第3期99-137,共39页
Metal halide perovskites have emerged as promising light-emitting materials for next-generation displays owing to their remarkable material characteristics including broad color tunability,pure color emission with rem... Metal halide perovskites have emerged as promising light-emitting materials for next-generation displays owing to their remarkable material characteristics including broad color tunability,pure color emission with remarkably narrow bandwidths,high quantum yield,and solution processability.Despite recent advances have pushed the luminance efficiency of monochromic perovskite light-emitting diodes(PeLEDs)to their theoretical limits,their current fabrication using the spincoating process poses limitations for fabrication of full-color displays.To integrate PeLEDs into full-color display panels,it is crucial to pattern red–green–blue(RGB)perovskite pixels,while mitigating issues such as cross-contamination and reductions in luminous efficiency.Herein,we present state-of-the-art patterning technologies for the development of full-color PeLEDs.First,we highlight recent advances in the development of efficient PeLEDs.Second,we discuss various patterning techniques of MPHs(i.e.,photolithography,inkjet printing,electron beam lithography and laserassisted lithography,electrohydrodynamic jet printing,thermal evaporation,and transfer printing)for fabrication of RGB pixelated displays.These patterning techniques can be classified into two distinct approaches:in situ crystallization patterning using perovskite precursors and patterning of colloidal perovskite nanocrystals.This review highlights advancements and limitations in patterning techniques for PeLEDs,paving the way for integrating PeLEDs into full-color panels. 展开更多
关键词 PEROVSKITE Light-emitting diode Full-color display High-resolution patterning ELECTROLUMINESCENCE
下载PDF
Association between lifestyle factors and thyroid function in young euthyroid adults
8
作者 Elisa Merchan-Ramirez Guillermo Sanchez-Delgado +4 位作者 Lucas Jurado-Fasoli Francisco M Acosta Manuel Munoz-Torres Jose M.Llamas-Elvira Jonatan R Ruiz 《Food Science and Human Wellness》 SCIE CSCD 2024年第1期265-275,共11页
Purpose:The present work examines the associations of dietary habits,sedentarism,physical activity(PA)levels and sleep habits,with thyroid function in young euthyroid adults.Methods:A total of 105 young euthyroid adul... Purpose:The present work examines the associations of dietary habits,sedentarism,physical activity(PA)levels and sleep habits,with thyroid function in young euthyroid adults.Methods:A total of 105 young euthyroid adults participated in this cross-sectional study.Thyroid function was determined in fasting conditions(>6 h).Dietary habits were measured by a food frequency questionnaire and three non-consecutive 24 h recalls,and different dietary intake and patterns were then estimated.The time spent in sedentary,PA levels and sleep habits were objectively measured using a wrist-worn accelerometer.Results:Energy and carbohydrate intake were positively associated with thyroid stimulating hormone(TSH)(β=0.222;R^(2)=0.102;P=0.022 andβ=0.425;R^(2)=0.129;P=0.007,respectively)whereas fat intake was negatively associated with TSH(β=-0.428;R^(2)=0.137;P=0.004).Energy intake was also positively associated with free triiodothyronine(β=0.277;R^(2)=0.137;P=0.004).Further,adherence to the Mediterranean diet was negatively related to TSH and free thyroxine(FT4)(β=-0.221;R^(2)=0.113;P=0.020 andβ=-0.268;R^(2)=0.071;P=0.007,respectively).Vigorous-intensity and overall PA were negatively associated with FT4(β=-0.227;R^(2)=0.052;P=0.022 andβ=-0.204;R^(2)=0.042;P=0.041,respectively).In contrast,no associations were found between sleep parameters and thyroid function.Conclusions:Lifestyle factors such as dietary intake and PA levels seems to be related to thyroid function even in young euthyroid adults. 展开更多
关键词 Thyroid hormones Dietary intake SLEEP Physical activity Euthyroid
下载PDF
Muscle strength deficits are associated with low bone mineral density in young pediatric cancer survivors:The iBoneFIT project
9
作者 Andres Marmol-Perez Jose J.Gil-Cosano +6 位作者 Esther Ubago-Guisado Francisco J.Llorente-Cantarero Juan Francisco Pascual-Gázquez Kirsten K.Ness Vicente Martinez-Vizcaino Jonatan R.Ruiz Luis Gracia-Marco 《Journal of Sport and Health Science》 SCIE CAS CSCD 2024年第3期419-427,共9页
Background Pediatric cancer survivors are at increased risk of muscle weakness and low areal bone mineral density(aBMD).However,the prevalence of muscle strength deficits is not well documented,and the associations of... Background Pediatric cancer survivors are at increased risk of muscle weakness and low areal bone mineral density(aBMD).However,the prevalence of muscle strength deficits is not well documented,and the associations of muscle strength with aBMD are unknown in this population.Therefore,this study aimed to investigate the prevalence of upper-and lower-body muscle strength deficits and to examine the associations of upper-and lower-body muscle strength with age-,sex,and race-specific aBMD Z-scores at the total body,total hip,femoral neck,and lumbar spine.Methods This cross-sectional study included 116 pediatric cancer survivors(12.1±3.3 years old,mean±SD;42.2%female).Upper-and lower-body muscle strength were assessed by handgrip and standing long jump test,respectively.Dual‑energy X‑ray absorptiometry was used to measure aBMD(g/cm2).Associations between muscle strength and aBMD were evaluated in multivariable linear regression models.Logistic regression was used to evaluate the contribution of muscle strength(1-decile lower)to the odds of having low aBMD(Z-score≤1.0).All analyses were adjusted for time from treatment completion,radiotherapy exposure,and body mass index.Results More than one-half of survivors were within the 2 lowest deciles for upper-(56.9%)and lower-body muscle strength(60.0%)in comparison to age-and sex-specific reference values.Muscle strength deficits were associated with lower aBMD Z-scores at all sites(B=0.133–0.258,p=0.001–0.032).Each 1-decile lower in upper-body muscle strength was associated with 30%–95%higher odds of having low aBMD Z-scores at all sites.Each 1-decile lower in lower-body muscle strength was associated with 35%–70%higher odds of having low aBMD Z-scores at total body,total hip,and femoral neck.Conclusion Muscle strength deficits are prevalent in young pediatric cancer survivors,and such deficits are associated with lower aBMD Z-scores at all sites.These results suggest that interventions designed to improve muscle strength in this vulnerable population may have the added benefit of improving aBMD. 展开更多
关键词 Bone health Childhood cancer DXA Lean mass Resistance training
下载PDF
Serum biomarkers for the differentiation of autoimmune pancreatitis from pancreatic ductal adenocarcinoma 被引量:2
10
作者 Octavio Caba Carmelo Diéguez-Castillo +2 位作者 Joaquina Martínez-Galán Irene González-Cebrián Cristina Jiménez-Luna 《World Journal of Gastrointestinal Oncology》 SCIE 2023年第2期268-275,共8页
Autoimmune pancreatitis(AIP),a chronic inflammation caused by the immune system attacking the pancreas,usually presents imaging and clinical features that overlap with those of pancreatic ductal adenocarcinoma(PDAC).S... Autoimmune pancreatitis(AIP),a chronic inflammation caused by the immune system attacking the pancreas,usually presents imaging and clinical features that overlap with those of pancreatic ductal adenocarcinoma(PDAC).Serum biomarkers,substances that quantitatively change in sera during disease development,are a promising non-invasive tool with high utility for differentiating between these diseases.In this way,the presence of AIP is currently suspected when serum concentrations of immunoglobulin G4(IgG4)antibody are elevated.However,this approach has some drawbacks.Notably,IgG4 antibody concentrations are also elevated in sera from some patients with PDAC.This review focuses on the most recent and relevant serum biomarkers proposed to differentiate between AIP and PDAC,evaluating the usefulness of immunoglobulins,autoantibodies,chemokines,and cytokines.The proposed serum biomarkers have proven useful,although most studies had a small sample size,did not examine their presence in patients with PDAC,or did not test them in humans.In addition,current evidence suggests that a single serum biomarker is unlikely to accurately differentiate these diseases and that a set of biomarkers will be needed to achieve adequate specificity and sensitivity,either alone or in combination with clinical data and/or radiological images. 展开更多
关键词 Autoimmune pancreatitis Pancreatic ductal adenocarcinoma SERUM Biomarkers DIFFERENTIATION
下载PDF
Peripheral nerve regeneration through nerve conduits evokes differential expression of growth-associated protein-43 in the spinal cord 被引量:1
11
作者 Jesús Chato-Astrain Olga Roda +5 位作者 David Sánchez-Porras Esther Miralles Miguel Alaminos Fernando Campos Óscar Darío García-García Víctor Carriel 《Neural Regeneration Research》 SCIE CAS CSCD 2023年第8期1852-1856,共5页
Growth-associated protein 43 plays a key role in neurite outgrowth through cytoskeleton remodeling.We have previously demonstrated that structural damage of peripheral nerves induces growth-associated protein 43 upreg... Growth-associated protein 43 plays a key role in neurite outgrowth through cytoskeleton remodeling.We have previously demonstrated that structural damage of peripheral nerves induces growth-associated protein 43 upregulation to promote growth cone formation.Conversely,the limited regenerative capacity of the central nervous system due to an inhibitory environment prevents major changes in neurite outgrowth and should be presumably associated with low levels of growth-associated protein 43 expression.However,central alterations due to peripheral nerve damage have never been assessed using the growthassociated protein 43 marker.In this study,we used the tubulization technique to repair 1 cm-long nerve gaps in the rat nerve injury/repair model and detected growth-associated protein 43 expression in the peripheral and central nervous systems.First,histological analysis of the regeneration process confirmed an active regeneration process of the nerve gaps through the conduit from 10 days onwards.The growth-associated protein 43 expression profile varied across regions and follow-up times,from a localized expression to an abundant and consistent expression throughout the regeneration tissue,confirming the presence of an active nerve regeneration process.Second,spinal cord changes were also histologically assessed,and no apparent changes in the structural and cellular organization were observed using routine staining methods.Surprisingly,remarkable differences and local changes appeared in growth-associated protein 43 expression at the spinal cord level,in particular at 20 days post-repair and beyond.Growth-associated protein 43 protein was first localized in the gracile fasciculus and was homogeneously distributed in the left posterior cord.These findings differed from the growth-associated protein 43 pattern observed in the healthy control,which did not express growth-associated protein 43 at these levels.Our results revealed a differential expression in growth-associated protein 43 protein not only in the regenerating nerve tissue but also in the spinal cord after peripheral nerve transection.These findings open the possibility of using this marker to monitor changes in the central nervous system after peripheral nerve injury. 展开更多
关键词 growth-associated protein 43(GAP-43) IMMUNOHISTOCHEMISTRY nerve guide nerve tissue regeneration peripheral nerve repair spinal cord tissue engineering
下载PDF
Chitosan conduits enriched with fibrin-collagen hydrogel with or without adipose-derived mesenchymal stem cells for the repair of 15-mm-long sciatic nerve defect 被引量:1
12
作者 Marwa El Soury óscar Darío García-García +6 位作者 Isabella Tarulli Jesús Chato-Astrain Isabelle Perroteau Stefano Geuna Stefania Raimondo Giovanna Gambarotia Víctor Carriel 《Neural Regeneration Research》 SCIE CAS CSCD 2023年第6期1378-1385,共8页
Hollow conduits of natural or synthetic origins have shown acceptable regeneration results in short nerve gap repair;however,results are still not comparable with the current gold standard technique“autografts”.Holl... Hollow conduits of natural or synthetic origins have shown acceptable regeneration results in short nerve gap repair;however,results are still not comparable with the current gold standard technique“autografts”.Hollow conduits do not provide a successful regeneration outcome when it comes to critical nerve gap repair.Enriching the lumen of conduits with different extracellular materials and cells could provide a better biomimicry of the natural nerve regenerating environment and is expected to ameliorate the conduit performance.In this study,we evaluated nerve regeneration in vivo using hollow chitosan conduits or conduits enriched with fibrin-collagen hydrogels alone or with the further addition of adipose-derived mesenchymal stem cells in a 15 mm rat sciatic nerve transection model.Unexpected changes in the hydrogel consistency and structural stability in vivo led to a failure of nerve regeneration after 15 weeks.Nevertheless,the molecular assessment in the early regeneration phase(7,14,and 28 days)has shown an upregulation of useful regenerative genes in hydrogel enriched conduits compared with the hollow ones.Hydrogels composed of fibrin-collagen were able to upregulate the expression of soluble NRG1,a growth factor that plays an important role in Schwann cell transdifferentiation.The further enrichment with adipose-derived mesenchymal stem cells has led to the upregulation of other important genes such as ErbB2,VEGF-A,BDNF,c-Jun,and ATF3. 展开更多
关键词 adipose-derived stem cells chitosan conduit fibrin and collagen hydrogel nerve regeneration nerve repair neuregulin 1 peripheral nerve sciatic nerve
下载PDF
Assessing the effects of alternative fuel treatments to reduce wildfire exposure
13
作者 Roghayeh Jahdi Liliana Del Giudice +4 位作者 Massimo Melis Raff aella Lovreglio Michele Salis Bachisio Arca Pierpaolo Duce 《Journal of Forestry Research》 SCIE CAS CSCD 2023年第2期373-386,共14页
Effective landscape-scale fuel management strategies are essential for reducing wildfire risk in Mediterranean fire-prone areas.In this study,the minimum travel time(MTT)fire-spread algorithm as implemented in FlamMap... Effective landscape-scale fuel management strategies are essential for reducing wildfire risk in Mediterranean fire-prone areas.In this study,the minimum travel time(MTT)fire-spread algorithm as implemented in FlamMap was applied to assess the potential of alternative fuel treatments for lowering wildfire losses in a 5,740-ha study area in eastern Sardinia,Italy.Twenty-seven wildfires at 10-m resolution were simulated considering three wind speeds(15,18,and 21 km h-1)to compare fuel treatments:no treatment(NT),irrigated agroforestry areas with shrub clearing(T1),prescribed fire in eucalyptus stands(T2),and irrigated grasslands(T3).The simulations replicated a recent large wildfire that occurred in the study area(Orrìwildfire,2019)and considered the weather and fuel moisture conditions associated with this event.The average wildfire exposure outputs(burned area,probability of burning,conditional flame length,potential crown fire occurrence,and surfaces withflame lengths above 2.5 m)decreased after fuel treatments,compared to no treatment.T1 was the most effective strategy in mitigating wildfire hazards and provided the most significant performance for several wildfire exposure indicators.Treating only 0.5%of the study area(~30 ha)resulted in a decrease in all wildfire exposure metrics to~10%within the study area.In addition,the total surface characterized by high flame length(average>2.5 m)was the lowest in the T1 treatment.This study can help land and fire managers optimize fuel treatment opportunities and wildfire risk mitigation strategies in Mediterranean areas. 展开更多
关键词 Fuel treatment strategies Fire prevention Mediterranean areas Minimum travel time(MTT) Wildfi re exposure
下载PDF
2023年上半年巴西纸浆出口额增至41亿美元
14
作者 陈京环 《造纸信息》 2023年第9期57-57,共1页
巴西林木工业(Ibá)报告显示,2023年上半年,巴西纸浆出口总量为910万t,同比增长1.5%,纸浆出口总额为41亿美元,同比增长8.2%。增长动力主要来自对中国和北美(美国和加拿大)的销售,其对中国和北美的纸浆出口额同比分别增长25.4%和19.9... 巴西林木工业(Ibá)报告显示,2023年上半年,巴西纸浆出口总量为910万t,同比增长1.5%,纸浆出口总额为41亿美元,同比增长8.2%。增长动力主要来自对中国和北美(美国和加拿大)的销售,其对中国和北美的纸浆出口额同比分别增长25.4%和19.9%。中国是巴西纸浆出口的主要目的地,上半年巴西对中国纸浆出口的贸易额达到18亿美元;其次是欧洲,为10亿美元。 展开更多
关键词 纸浆 巴西 出口总量 出口额 加拿大 贸易额 出口总额 目的地
下载PDF
Exploring catalytic behaviors of CoS_(2)-ReS_(2) heterojunction by interfacial engineering
15
作者 Jianmin Yu Yongteng Qian +12 位作者 Sohyeon Seo Yang Liu Huong T.D.Bui Ngoc Quang Tran Jinsun Lee Ashwani Kumar Hongdan Wang Yongguang Luo Xiaodong Shao Yunhee Cho Xinghui Liu Min Gyu Kim Hyoyoung Lee 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2023年第10期11-18,I0002,共9页
Herein, a stable and efficient CoS_(2)-ReS_(2) electrocatalyst is successfully constructed by using the different molar ratios of CoS_(2) on ReS_(2). The size and morphology of the catalysts are significantly changed ... Herein, a stable and efficient CoS_(2)-ReS_(2) electrocatalyst is successfully constructed by using the different molar ratios of CoS_(2) on ReS_(2). The size and morphology of the catalysts are significantly changed after the CoS_(2) is grown on ReS_(2), providing regulation of the catalytic activity of ReS_(2). Particularly, the optimized CoS_(2)-ReS_(2) shows superior electrocatalytic properties with a low voltage of 1.48 V at 20 mA cm^(-2) for overall water splitting in 1.0 M KOH, which is smaller than the noble metal-based catalysts(1.77 V at 20 mA cm^(-2)). The XPS, XAS, and theoretical data confirm that the interfacial regulation of ReS_(2) by CoS_(2) can provide rich edge catalytic sites, which greatly optimizes the catalytic kinetics and drop the energy barrier for oxygen/hydrogen evolution reactions. Our results demonstrated that interfacial engineering is an efficient route for fabricating high-performance water splitting electrocatalysts. 展开更多
关键词 CoS_(2) ReS_(2) Interfacial engineering Catalytic kinetics Water splitting
下载PDF
Intrinsic Mechanisms of Morphological Engineering and Carbon Doping for Improved Photocatalysis of 2D/2D Carbon Nitride Van Der Waals Heterojunction
16
作者 Jinqiang Zhang Xiaoli Zhao +10 位作者 Lin Chen Shuli Li Haijun Chen Yuezhao Zhu Shuaijun Wang Yang Liu Huayang Zhang Xiaoguang Duan Mingbo Wu Shaobin Wang Hongqi Sun 《Energy & Environmental Materials》 SCIE EI CAS CSCD 2023年第3期96-106,共11页
Van der Waals(VDW)heterojunctions in a 2D/2D contact provide the highest area for the separation and transfer of charge carriers.In this work,a top-down strategy with a gas erosion process was employed to fabricate a ... Van der Waals(VDW)heterojunctions in a 2D/2D contact provide the highest area for the separation and transfer of charge carriers.In this work,a top-down strategy with a gas erosion process was employed to fabricate a 2D/2D carbon nitride VDW heterojunction in carbon nitride(g-C_(3)N_(4))with carbon-rich carbon nitride.The created 2D semiconducting channel in the VDW structure exhibits enhanced electric field exposure and radiation absorption,which facilitates the separation of the charge carriers and their mobility.Consequently,compared with bulk g-C_(3)N_(4)and its nanosheets,the photocatalytic performance of the fabricated carbon nitride VDW heterojunction in the water splitting reaction to hydrogen is improved by 8.6 and 3.3 times,respectively,while maintaining satisfactory photo-stability.Mechanistically,the finite element method(FEM)was employed to evaluate and clarify the contributions of the formation of VDW heterojunction to enhanced photocatalysis,in agreement quantitatively with experimental ones.This study provides a new and effective strategy for the modification and more insights to performance improvement on polymeric semiconductors in photocatalysis and energy conversion. 展开更多
关键词 carbon nitride Van der Waals heterojunctions enhanced electric field exposure improved radiation absorption photocatalytic water splitting promoted dynamics of charge carriers
下载PDF
聚丙烯改性研究进展 被引量:13
17
作者 廖小青 朱江 +1 位作者 刘香 彭琤 《重庆文理学院学报(社会科学版)》 2013年第5期22-27,共6页
文章介绍目前广泛采用的聚丙烯改性方法——弹性体增韧、刚性体增韧和β成核剂改性,同时介绍各改性方法间协同复合改性.
关键词 聚丙烯 弹性体 刚性体 Β成核剂 协同效应
下载PDF
西江特大桥精细有限元仿真分析 被引量:4
18
作者 徐郁峰 周雅妍 方世乐 《中外公路》 北大核心 2009年第5期111-115,共5页
随着计算机软硬件技术的快速发展,利用高性能计算机进行结构精细的仿真分析逐渐成为趋势。该文针对西江特大桥的实际情况,尝试利用高性能计算机进行全桥全块体单元模型的精细有限元仿真分析,分析中考虑该桥的施工过程及后期的收缩徐变... 随着计算机软硬件技术的快速发展,利用高性能计算机进行结构精细的仿真分析逐渐成为趋势。该文针对西江特大桥的实际情况,尝试利用高性能计算机进行全桥全块体单元模型的精细有限元仿真分析,分析中考虑该桥的施工过程及后期的收缩徐变效应。高精度的分析结果有效地指导了设计工作,说明了利用高性能计算机进行精细仿真分析已经成为现实。 展开更多
关键词 精细仿真分析 高性能计算机 块体单元 施工过程 收缩徐变
下载PDF
用羟丙基β-环糊精手性柱HPLC法拆分米那普仑对映体 被引量:1
19
作者 陈秀娟 郑振 +3 位作者 张明勇 乐嘉琰 李武宏 洪战英 《药学服务与研究》 CAS 2017年第3期210-212,共3页
目的:建立拆分米那普仑对映体的手性固定相HPLC法。方法:采用Astec CYCLOBONDTMⅠ2000RSP色谱柱(250mm×4.6mm,5μm),考察了流动相组分比例、pH值、流速以及柱温对米那普仑手性对映体拆分效果的影响。结果:确定了最佳拆分条件:流动... 目的:建立拆分米那普仑对映体的手性固定相HPLC法。方法:采用Astec CYCLOBONDTMⅠ2000RSP色谱柱(250mm×4.6mm,5μm),考察了流动相组分比例、pH值、流速以及柱温对米那普仑手性对映体拆分效果的影响。结果:确定了最佳拆分条件:流动相为乙腈∶0.1%醋酸三乙胺溶液(pH 6.0)=5∶95(V/V),流速为0.8 ml/min,检测波长为220nm,柱温为25℃,米那普仑对映体拆分的分离度为1.63,对映体能够得到良好的拆分。结论:该法操作简便,可用于米那普仑对映体的分离及质量控制。 展开更多
关键词 米那普仑 手性拆分 羟丙基β-环糊精类手性固定相 色谱法 高效液相
下载PDF
内蒙古赤峰召庙花岗岩表面的冰川壶穴、泄水槽、盐风化穴和剥离面理 被引量:1
20
作者 吕洪波 浦津 高于 《地质通报》 CAS CSCD 北大核心 2022年第4期517-532,共16页
在内蒙古赤峰市巴林左旗林东镇以南约20 km的召庙,出露一片面积约20 km^(2)的花岗岩,称为召庙花岗岩体。该岩体被至少2组垂直节理及与地面起伏一致的剥离面理切割成大小不等的弧形岩块,构成高于周围地表300~400 m的花岗岩山区。在多条... 在内蒙古赤峰市巴林左旗林东镇以南约20 km的召庙,出露一片面积约20 km^(2)的花岗岩,称为召庙花岗岩体。该岩体被至少2组垂直节理及与地面起伏一致的剥离面理切割成大小不等的弧形岩块,构成高于周围地表300~400 m的花岗岩山区。在多条花岗岩山脊上保存有大小不等的壶穴,山脊两侧则发育从上到下紧密排列的泄水槽,而泄水槽则被剥离面理横向切割,沿剥离面理的露头线发育大小不等的风化穴。通过详细的野外调查,认为花岗岩山脊上的壶穴不是风蚀和风化所致,而是晚更新世冰盖上的冰川融水下泄冲刷形成的;山脊两侧的泄水槽也是冰川融水下泄冲刷的结果;剥离面理是第四纪冰川发育导致地表之下岩石温度变化的热变应力所致,可用于恢复第四纪冰川作用时期的基岩古地貌;盐风化穴是第四纪冰川退缩后本区重要的物理风化类型,优先沿着剥离面理发育。本区3种微型地貌景观和大型的剥离面理共生组合记录了更新世以来召庙花岗岩山区的地貌演化史。 展开更多
关键词 花岗岩体 壶穴 泄水槽 盐风化 风化穴 剥离面理 更新世冰盖 内蒙古
下载PDF
上一页 1 2 12 下一页 到第
使用帮助 返回顶部