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Characterization of six tumorsuppressor genes and microsatellite instability in hepatocellular carcinomain southern African blacks 被引量:21
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作者 Martins C Kedda MA Kew MC 《World Journal of Gastroenterology》 SCIE CAS CSCD 1999年第6期470-476,共7页
AIM To analyse cumulative loss of heterozygosity (LOH) of chromosomal regions and tumor suppressor genes in hepatocellular carcinomas (HCCs) from 20 southern African blacks. METHODS p53, RB1, BRCA1, BRCA2, WT1 and E c... AIM To analyse cumulative loss of heterozygosity (LOH) of chromosomal regions and tumor suppressor genes in hepatocellular carcinomas (HCCs) from 20 southern African blacks. METHODS p53, RB1, BRCA1, BRCA2, WT1 and E cadherin genes were analysed for LOH, and p53 gene was also analysed for the codon 249 mutation, in tumor and adjacent non tumorous liver tissues using molecular techniques and 10 polymorphic microsatellite markers. RESULTS p53 codon 249 mutation was found in 25% of the subjects, as was expected, because many patients were from Mozambique, a country with high aflatoxin B 1 exposure. LOH was found at the RB1, BRCA2 and WT1 loci in 20%(4/*!20) of the HCCs, supporting a possible role of these genes in HCC. No LOH was evident in any of the remaining genes. Reports of mutations of p53 and RB1 genes in combination, described in other populations, were not confirmed in this study. Change in microsatellite repeat number was noted at 9/*!10 microsatellite loci in different HCCs, and changes at two or more loci were detected in 15%(3/*!20) of subjects. CONCLUSION We propose that microsatellite/genomic instability may play a role in the pathogenesis of a subset of HCCs in black Africans. 展开更多
关键词 carcinoma hepatocellular southern African blacks CUMULATIVE LOH TUMOR SUPPRESSOR genes MICROSATELLITE genomic instability liver neoplasms
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Trends of Cardiovascular Mortality in Blacks Africans from Central African City: Hospital Based Study, Brazzaville (Congo)
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作者 Bertrand F. Ellenga-Mbolla Aude Loko-Lemba +5 位作者 Solange F. Mongo-Ngamami Christian M. Kouala-Landa Igor Ondze-Kafata Stephane M. Ikama Thierry R. Gombet Gisèle Kimbally-Kaky 《World Journal of Cardiovascular Diseases》 2019年第9期698-705,共8页
Background: To determine mortality causes and the associated factors. Patients and Method: This cross-sectional study was conducted from June 2014 to May 2015 (1 year) in the department of cardiology at University and... Background: To determine mortality causes and the associated factors. Patients and Method: This cross-sectional study was conducted from June 2014 to May 2015 (1 year) in the department of cardiology at University and teaching Hospital of Brazzaville. Patients admitted for cardiovascular diseases were included. Patients admitted for cardiovascular disease in other departments of the hospital, or without cardiovascular diseases were not included. Results: In total, 1035 patients, 605 women (5804%) were included. Mean age was 57.1 ± 7 years (range: 18 - 85 years). The patients were: elderly (n = 498, 48.1%), educated (n = 809, 78.1%), low-income (n = 253, 24.2%). The medical history of patients was: hypertension (n = 440, 42.5%), diabetes (n = 316, 30.5%), reduced physical activity (n = 154, 14.9%), excessive alcohol intake (n = 56, 5.4%). Heart failure was reported in 386 cases (37.3%). The mortality rate was 8% (n = 83);the mean age of deceased was 61.9 ± 7.3 years (p s in death were dilated cardiomyopathy (n = 37, 44.6%, OR 5, 95%CI 3.1 - 8, p -3.3, p = 0.002), atrial fibrillation (n = 24, 29%, OR 3.6, 95%CI 2.2 - 6, p - 9.8, p = 0.005). The associated death comorbidities were: acute respiratory infection (n = 44, 53%, OR 10.1, 95%CI 6.2 - 16, p - 10 p - 6.8, p Conclusion: Hypertension, heart failure and cardiomyopathies are the leading causes of mortality in the department of cardiology. Prevention and patient education in a low-income environment are essential elements to reduce this morbidity. 展开更多
关键词 Mortality CARDIOVASCULAR Disease blacks AFRICANS Sub-Saharan AFRICA
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Fibroadenoma in Blacks
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作者 Raphael Odobueze Egejuru Ikechukwu Godfrey Nnadi Okechukwu Nwabugo Duru 《Health》 2017年第11期1475-1481,共7页
Background: Fibroadenoma is the commonest benign tumour of the breast affecting the majority of young females below the age of thirty in our environment. It is a source of concern and psychological problems in females... Background: Fibroadenoma is the commonest benign tumour of the breast affecting the majority of young females below the age of thirty in our environment. It is a source of concern and psychological problems in females requiring medical attention in our hospitals. Aim: This study describes the clinicopathologic characteristics of fibroadenoma in Eastern Nigerian Igbo females. Methodology: The archives of the Department of Pathology Federal Medical Centre, Owerri was used for the data collection and analyzed using simple statistics. Results: 504 fibroadenomas were analyzed. The average size was 1.99 cm with a range of 0.5 cm to 18 cm. The average age of the patients was 22.6 ± 6.7 years with a range of 9 to 60 years. The peak age of incidence was in the 11 - 20 (44.64%) age group followed closely by the 21 - 30 (43.45%) age group. The ratio of involvement of the left to the right breast was 1:1.2. Fibroadenoma was 18% multiple and 10.7% bilateral. 5.3% (27), 0.6% (3), and 0.2% (1) of the cases were giant, complex fibroadenoma and malignant breast disease in fibroadenoma respectively. Conclusion: This study has provided insights into the clinicopathologic characteristics of fibroadenoma among Nigerian Igbos and calls for more research in this area in other parts Nigeria and elsewhere. 展开更多
关键词 FIBROADENOMA blacks Owerri
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“Not Now!”1—On the Contemporary Relevance of Faulkner's Exploration of the Blacks
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作者 BAO Zhong-ming XIN Cai-na 《Journal of Literature and Art Studies》 2015年第5期346-354,共9页
The accession of an African-American Obama to the U.S. Presidency in 2008 is an epoch-making event. The thesis focuses on the current situation of the blacks in U.S. to highlight the prophetic nature of Faulkner, the ... The accession of an African-American Obama to the U.S. Presidency in 2008 is an epoch-making event. The thesis focuses on the current situation of the blacks in U.S. to highlight the prophetic nature of Faulkner, the Nobel Prize winning American novelist's exploration of the blacks throughout his career, namely, the miserable living states of the blacks, racial segregation against the blacks in the sphere of education and religion, racial discrimination against the blacks with regard to civil rights, racial persecution against the blacks in legal cases, and the dependency upon the black leadership to salvage the multi-ethnic nation and so on. The paper comes up with the conclusion that Faulkner is accurate in his prophecy that the savior of the nation, the blacks shall suffer and lead. 展开更多
关键词 William Faulkner Barrack Obama race the blacks human rights
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HNA-1 a and HNA-1 b gene frequencies in the Tunisian Blacks
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《中国输血杂志》 CAS CSCD 2001年第S1期366-,共1页
关键词 HNA-1 a and HNA-1 b gene frequencies in the Tunisian blacks GENE
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The Tragedy of Jeff and the Rising of American Blacks Today
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作者 Xia Xiaobin 《福建江夏学院学报》 1995年第2期42-44,共3页
"Nigger Jeff"is a short story,It was written by Theodore Dreiser,a famous American novel-ist in the twentieth century. It was no accident that such a work snould appear during the era of racial discrimanatio... "Nigger Jeff"is a short story,It was written by Theodore Dreiser,a famous American novel-ist in the twentieth century. It was no accident that such a work snould appear during the era of racial discrimanation.The setting of the story is the South. The balcks were slaves before the Civil War there. They re-mained the second class citizens after. Southern whites often used lynching without trial to pur-nish imdividuals and intimeidate the balcks in general. In this story,Jeff,a typical of all the 展开更多
关键词 In The Tragedy of Jeff and the Rising of American blacks Today
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Hepatocellular carcinoma in African Blacks: Recent progress in etiology and pathogenesis 被引量:5
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作者 Michael C Kew 《World Journal of Hepatology》 2010年第2期65-73,共9页
Occult hepatitis B virus (HBV) infection was shown to be present in 75% of Black Africans with hepatocellular carcinoma (HCC) in whom the tumor was hitherto not thought to be caused by chronic HBV infection. The assoc... Occult hepatitis B virus (HBV) infection was shown to be present in 75% of Black Africans with hepatocellular carcinoma (HCC) in whom the tumor was hitherto not thought to be caused by chronic HBV infection. The association between chronic HBV infection and the development of the tumor is thus even closer than was originally thought. HBV viral load was found to be significantly higher in patients with HCC than in Black African controls. As in other populations, HBV e antigen-positive patients with hepatocellular carcinoma had significantly higher viral loads than patients negative for this antigen. The significance of this finding is discussed. The risk for HCC development with genotype A of HBV, the predominant genotype in African isolates, has not been investigated. Genotype A was shown to be 4.5 times more likely than other genotypes to cause HCC in Black Africans, and tumours occurred at a significantly younger age. Increasing numbers of patients with human immunodeficiency virus (HIV) and HBV co-infection are being reported to develop HCC. A preliminary case/control comparison supports the belief that HIV co-infection enhances the hepatocarcinogenic potential of HBV. A study from The Gambia provides the first evidence that dietary exposure to afltoxin B1 may cause cirrhosis and thatthis may play a contributory role in the pathogenesis of aflatoxin-induced HCC. An animal model has provided experimental support for the clinical evidence that dietary iron overload in the African is directly hepatocarcinogenic, in addition to causing the tumor indirectly through the development of cirrhosis. 展开更多
关键词 Hepatocellular carcinoma Black Africans Occult hepatitis B Virus infection Hepatitis B viral loads Hepatitis B virus genotype A AFLATOXIN Dietary iron overload
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Relationship between Obesity, Serum Uric Acid, Serum Potassium and Glomerular Filtration Rate with Electric Left Ventricular Hypertrophy in Blacks Central Africans with High Blood Pressure 被引量:1
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作者 Bertrand Fikahem Ellenga Mbolla Paul Macaire Ossou Nguiet +6 位作者 Richard Loumingou Meo Stéphane Ikama Narcisse Ngangoue Thierry Raoul Gombet Henri Germain Monabeka Benjamn Longo Mbenza Gisèle Kimbally Kaky 《World Journal of Cardiovascular Diseases》 2018年第4期248-255,共8页
The authors conducted a retrospective study over a period of 6 months in a hypertensive population in order to determine the correlation between serum uric acid on glomerular filtration rate (GFR) and estimated serum ... The authors conducted a retrospective study over a period of 6 months in a hypertensive population in order to determine the correlation between serum uric acid on glomerular filtration rate (GFR) and estimated serum potassium with left ventricular hypertrophy (LVH) and obesity. This study enrolled 122 patients including 63 women (51.6%). The mean age was 55.9 ± 10.6 years (range 30 to 74 years). Obesity weight was found in 38 cases (31.1%) of which 20?were men (33.9%) and 18 women (28.6%). Abdominal obesity was found in 104 cases (85.2%). The average serum uric acid in patients with obesity weight was 63.3 ± 18.9 mg/L vs 62.4 ± 14.2 mg/L for no-obese patients (p?= 0.63). The average serum potassium in obese patients was 4.06 ± 0.42 mEq/L vs 4.02 ± 0.46 mEq/L for no-obese (p?= 0.65). The average GFR was 73.4 ± 21.4 ml/L in obese patients vs 66.6 ± 22.6 ml/min in no-obese (p?= 0.03). The LVH was found in 81 cases (66.4%). The LVH was found in 65 (62.5%) obese patients vs?16 (88%) non-obese patients (OR = 4.8, 95% 1.04?-?22?p?= 0.02). Only abdominal?obesity has been correlated with left ventricular hypertrophy after multivariate analysis. Emphasis must be focused on public health actions for effective and appropriate measures against obesity and hypertension, whose prevalence is increasing in our region. 展开更多
关键词 OBESITY High Blood Pressure Glomerular FILTRATION Rate Uric Acid SERUM POTASSIUM Black AFRICAN
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A progress review of black carbon deposition on Arctic snow and ice and its impact on climate change 被引量:1
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作者 ZHANG Zilu ZHOU Libo ZHANG Meigen 《Advances in Polar Science》 CSCD 2024年第2期178-191,共14页
The rapid warming of the Arctic,accompanied by glacier and sea ice melt,has significant consequences for the Earth’s climate,ecosystems,and economy.Black carbon(BC)deposition on snow and ice can trigger a significant... The rapid warming of the Arctic,accompanied by glacier and sea ice melt,has significant consequences for the Earth’s climate,ecosystems,and economy.Black carbon(BC)deposition on snow and ice can trigger a significant reduction in snow albedo and accelerate melting of snow and ice in the Arctic.By reviewing the published literatures over the past decades,this work provides an overview of the progress in both the measurement and modeling of BC deposition and its impact on Arctic climate change.In summary,the maximum value of BC deposition appears in the western Russian Arctic(26 ng·g^(–1)),and the minimum value appears in Greenland(3 ng·g^(–1)).BC records in the Arctic ice core already peaked in 1920s and 1970s,and shows a regional difference between Greenland and Canadian Arctic.The different temporal variations of Arctic BC ice core records in different regions are closely related to the large variability of BC emissions and transportation processes across the Arctic region.Model simulations usually underestimate the concentration of BC in snow and ice by 2–3 times,and cannot accurately reflect the seasonal and regional changes in BC deposition.Wet deposition is the main removal mechanism of BC in the Arctic,and observations show different seasonal variations in BC wet deposition in Ny-Ålesund and Barrow.This discrepancy may result from varying contributions of anthropogenic and biomass burning(BB)emissions,given the strong influence by BC from BB emissions at Barrow.Arctic BC deposition significantly influences regional climate change in the Arctic,increasing fire activities in the Arctic have made BB source of Arctic BC more crucial.On average,BC in Arctic snow and ice causes an increase of+0.17 W·m^(–2)in radiative forcing and 8 Gt·a^(–1)in runoff in Greenland.As stressed in the latest Arctic Monitoring and Assessment Programme report,reliable source information and long-term and high-resolution observations on Arctic BC deposition will be crucial for a more comprehensive understanding and a better mitigation strategy of Arctic BC.In the future,it is necessary to collect more observations on BC deposition and the corresponding physical processes(e.g.,snow/ice melting,surface energy balance)in the Arctic to provide reliable data for understanding and clarifying the mechanism of the climatic impacts of BC deposition on Arctic snow and ice. 展开更多
关键词 Arctic climate black carbon ALBEDO SNOW DEPOSITION
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Performance improvement in stepped solar still modified by sponge layer
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作者 Mahtab TARAHOMI Saman RASHIDI +1 位作者 Faramarz HORMOZI Shahabeddin ASHTIANI 《Journal of Central South University》 SCIE EI CAS CSCD 2024年第6期1973-1982,共10页
In this paper,the experimental investigation on the performance improvement of conventional stepped solar still is conducted.The steps are covered by the porous material to improve the performance of the conventional ... In this paper,the experimental investigation on the performance improvement of conventional stepped solar still is conducted.The steps are covered by the porous material to improve the performance of the conventional device and increase the evaporation rate.All the parameters,including the temperature on the glass surface,the water temperature inside the evaporation zone,and the amount of water produced in both conventional and modified stepped solar stills are measured and compared.The efficiency of two devices and their exergy efficiency have been calculated.Finally,the economic analysis of both devices has been done to check the economic feasibility of the modified device.The amount of freshwater generated during one day was 2244.4 and 3076.2 mL/m^(2),respectively for the conventional and modified stepped solar stills.As a result,the amount of water produced in one day by modified stepped solar still is 35.5% more than the conventional one.Also,the costs for the conventional and modified stepped solar stills have been calculated as 0.0359 and 0.029$/(L·m^(-2)),respectively. 展开更多
关键词 stepped solar still black sponge EFFICIENCY EXERGY economic analysis
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Cloning of sft-4 and its influence on vitality and virulence of pine wood nematode,Bursaphelenchus xylophilus
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作者 Shuisong Liu Linsong Wang +5 位作者 Ronggui Li Mengyu Chen Wenjun Deng Chao Wang Guicai Du Qunqun Guo 《Journal of Forestry Research》 SCIE EI CAS CSCD 2024年第5期191-200,共10页
In our previous screening of the transcriptome of the causal agent of the devastating pine wilt disease,pine wood nematode(PWN,Bursaphelenchus xylophilus),after treatment with the nematicide fomepizole,Surfeit locus g... In our previous screening of the transcriptome of the causal agent of the devastating pine wilt disease,pine wood nematode(PWN,Bursaphelenchus xylophilus),after treatment with the nematicide fomepizole,Surfeit locus gene sft-4,which encodes a regulatory factor,was found to be downregulated.In situ hybridization results showed that the sft-4 was continuously expressed from egg to adult and was especially high in the reproductive system.Here in a study of the effect of RNA interference(RNAi)of sft-4 and recombinant SFT-4 on PWN activity,treatment with sft-4 dsRNA inhibited feeding,reproduction,oviposition and egg hatching of PWN with the greatest inhibition on reproduction and oviposition,whereas recombinant SFT-4 had the opposite effect.In addition,RNAi of sft-4 changed the female–male ratio and lifespan of PWN.In bioassays of PWNs,with RNAi of sft-4 on seedlings and 2-year-old Pinus thunbergii trees,none of the treated plants developed symp-toms during the monitoring period,indicating that virulence of PWNs was either significantly weakened.These results indicate that the influence of sft-4 on PWN pathogenicity may be mainly through regulating reproductive function of PWN and its lifespan. 展开更多
关键词 Black pine PINACEAE Bursaphelenchus xylophilus Sft-4 In situ hybridization RNAI PATHOGENICITY
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Sedimentary Environment and Mineralization of the Black Shale Polymetallic Layer in the Early Cambrian,SW China:Constraints from in situ LA-ICP-MS Analysis of Pyrite
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作者 YANG Zhen FU Yong +2 位作者 LI Chao CAI Xi GUO Chuan 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2024年第2期416-429,共14页
A polymetallic layer is usually developed at the bottom of the early Cambrian black shale in Guizhou Province.The mineral that makes up the polymetallic layer is related to the sedimentary facies.To analyze the differ... A polymetallic layer is usually developed at the bottom of the early Cambrian black shale in Guizhou Province.The mineral that makes up the polymetallic layer is related to the sedimentary facies.To analyze the differentiation mechanism between polymetallic deposits(Ni-Mo and V),the Zhijin Gezhongwu profile located in the outer shelf and the Sansui Haishan V deposit located in the lower slope are selected to study the in situ sulfur isotopes and trace elements of pyrite.The results show that δ^(34)S values of pyrite vary widely from−7.8‰to 28‰in the Gezhongwu profile,while the δ^(34)S values are relatively uniform(from 27.8‰to 38.4‰)in the Haishan profile.The isotopic S composition is consistent with the transition that occurs in the sedimentary phase from the shelf to the deep sea on the transgressive Yangtze platform;this indicates that the δ^(34)SO_(4)^(2−)values in seawater must be differently distributed in depositional environments.The sulfur in the Ni-Mo layer is produced after the mixing of seawater and hydrothermal fluid,while the V layer mainly originates from seawater.Overall,the Ni-Mo and V deposits have been differentiated primarily on the basis of the combined effect of continental weathering and hydrothermal fluid. 展开更多
关键词 sedimentary environment black shale polymetallic layer PYRITE early Cambrian
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Mitigation of black carbon emissions could immediately reduce 6.3% of glacier melting in the Qilian Mountains
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作者 Ji-Zu CHEN Wen-Tao DU +6 位作者 Shi-Chang KANG Xiang QIN Wei-Jun SUN Li-Hui LUO Yang LI Jun-Hua YANG You-Yan JIANG 《Advances in Climate Change Research》 SCIE CSCD 2024年第4期725-736,共12页
Global warming in tandem with surface albedo reduction caused by black carbon(BC)deposition on glaciers accelerated glacier melting;however,their respective contributions remain unclear.Glaciers in the Qilian Mountain... Global warming in tandem with surface albedo reduction caused by black carbon(BC)deposition on glaciers accelerated glacier melting;however,their respective contributions remain unclear.Glaciers in the Qilian Mountains are crucial for the development of oases in the Hexi Corridor;however,their area has decreased by more than 20%over the past half-century.Thus,this study developed a dynamic deposition model for light-absorbing particles(LAPs),coupled with a surface energy and mass balance model.We comprehensively assessed the effects of BC and warming on the melting of a typical glacier in the Qilian Mountains based on the coupled model.BC on the glacier surface caused 13.1%of annual glacier-wide melting,of which directly deposited atmospheric BC reduced the surface albedo by 0.02 and accounted for 9.1%of glacier melting.The air temperature during 2000-2010 has increased by 1.5°C relative to that during the 1950s,accounting for 51.9%of current glacier melting.Meanwhile,BC emission have increased by 4.6 times compared to those of the early Industrial Revolution recorded in an ice core,accounting conservatively for 6.3%of current glacier melting.Mitigating BC emissions has a limited influence on current glacier melting;however,in the long-term,mitigation should exert a noteworthy impact on glacier melting through the self-purification of glaciers. 展开更多
关键词 GLACIER MELTING Black carbon Simulation Qilian Mountains
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Carbonic anhydrase 2 mediates anti-obesity effects of black tea as thermogenic activator
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作者 Peng Ma Jie Xiao +12 位作者 Biyu Hou Ping He Xinyu Yang Yisa Wang Zijing Wang Tianshu Xu Xiuying Yang Xuan Zhu Shasha Xiang Song Li Guanhua Du Jian Ying Guifen Qiang 《Food Science and Human Wellness》 SCIE CAS CSCD 2024年第5期2917-2936,共20页
Obesity is a metabolic disorder due to over-accumulation of adipose tissue and ultimately becomes a“disease”.Brown adipose tissue(BAT)thermogenesis and white adipose tissue(WAT)browning emerge as a potential strateg... Obesity is a metabolic disorder due to over-accumulation of adipose tissue and ultimately becomes a“disease”.Brown adipose tissue(BAT)thermogenesis and white adipose tissue(WAT)browning emerge as a potential strategy of anti-obesity by dissipating energy as heat.However,drugs based on adipose tissue thermogenesis have not been successfully approved yet.In current study,we found that black tea extract(BTE)obtained by patentauthorized manufacturing process prevented body weight gain as novel thermogenic activator with reduction of adiposity,improvement of adipose distribution,and glucose metabolism improvement in diet-induced obesity mice.Mechanismly,anti-obesity effect of BTE depends on promoting BAT thermogenesis and WAT browning with upregulation of uncoupling protein 1(UCP1),especially visceral adipose tissue(VAT)with browning resistance.Specifically,utilizing in silico approach of network pharmacology and molecular docking,we identified carbonic anhydrase 2(CA2)in nitrogen metabolism as anti-obesity target of BTE and further elucidated that protein kinase B(AKT)signaling pathway linked CA2 and UCP1.Meanwhile gut microbiota regulation may prompt the CA2-dependent thermogenesis activation.Our findings demonstrated anti-obesity effect of BTE as thermogenic activator through CA2-mediated BAT thermogenesis and WAT browning via CA2-AKT-UCP1 signaling pathway,which could be developed as promising anti-obesity agent with good safety and efficacy. 展开更多
关键词 OBESITY Black tea THERMOGENESIS BROWNING Adipose tissue
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Polyphenol components in black chokeberry(Aronia melanocarpa)as clinically proven diseases control factors——an overview
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作者 Ningxuan Gao Chi Shu +10 位作者 Yuehua Wang Jinlong Tian Yuxi Lang Chenyu Jin Xingyue Cui Hanqian Jiang Shi’an Liu Zhiying Li Wei Chen Hao Xu Bin Li 《Food Science and Human Wellness》 SCIE CSCD 2024年第3期1152-1167,共16页
The black chokeberry is rich in polyphenols,including flavonoids with anthocyanins,flavanols and lavonols as the main components and a variety of phenolic acids represented by chlorogenic acid.Because of these polyphe... The black chokeberry is rich in polyphenols,including flavonoids with anthocyanins,flavanols and lavonols as the main components and a variety of phenolic acids represented by chlorogenic acid.Because of these polyphenols,black chokeberry has the effect of preventing and adjuvant therapy diseases.This study summarized the current research results on the types and contents of functional components in black chokeberry,and analyzed their digestion,absorption and metabolism in human body.On this basis,the disease control functions that have been proved effective in clinical research were reviewed and analyzed.These studies showed that black chokeberry have good prevention and adjuvant therapy effects on hyperlipidemia,hypertension,diabetes and inflammation.Because there are different functional components in black chokeberry,its prevention and treatment of the same disease can come from multiple pathways,which provides a more reliable effectiveness for the disease control of different populations. 展开更多
关键词 Black chokeberry HYPERLIPIDEMIA HYPERTENSION DIABETES Inflammation
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How is a black hole created from nothing?
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作者 Zhongchao Wu 《中国科学技术大学学报》 CAS CSCD 北大核心 2024年第7期35-38,34,I0002,共6页
Using the synchronous coordinates,the creation of a Schwarzschild black hole immersed in a de Sitter spacetime can be viewed as a coherent creation of a collection of timelike geodesics.The previously supposed conical... Using the synchronous coordinates,the creation of a Schwarzschild black hole immersed in a de Sitter spacetime can be viewed as a coherent creation of a collection of timelike geodesics.The previously supposed conical singularities do not exist at the horizons of the constrained instanton.Instead,the unavoidable irregularity is presented as a nonvanishing second fundamental form elsewhere at the quantum transition 3-surface.The same arguments can be applied to charged,topological,or higher dimensional black hole cases. 展开更多
关键词 black hole creation quantum black hole quantum cosmology
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Covalently Bonded Ni Sites in Black Phosphorene with Electron Redistribution for Efficient Metal‑Lightweighted Water Electrolysis
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作者 Wenfang Zhai Ya Chen +5 位作者 Yaoda Liu Yuanyuan Ma Paranthaman Vijayakumar Yuanbin Qin Yongquan Qu Zhengfei Dai 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第6期233-245,共13页
The metal-lightweighted electrocatalysts for water splitting are highly desired for sustainable and economic hydrogen energy deployments,but challengeable.In this work,a low-content Ni-functionalized approach triggers... The metal-lightweighted electrocatalysts for water splitting are highly desired for sustainable and economic hydrogen energy deployments,but challengeable.In this work,a low-content Ni-functionalized approach triggers the high capability of black phosphorene(BP)with hydrogen and oxygen evolution reaction(HER/OER)bifunctionality.Through a facile in situ electro-exfoliation route,the ionized Ni sites are covalently functionalized in BP nanosheets with electron redistribution and controllable metal contents.It is found that the as-fabricated Ni-BP electrocatalysts can drive the water splitting with much enhanced HER and OER activities.In 1.0 M KOH electrolyte,the optimized 1.5 wt%Nifunctionalized BP nanosheets have readily achieved low overpotentials of 136 mV for HER and 230 mV for OER at 10 mA cm^(−2).Moreover,the covalently bonding between Ni and P has also strengthened the catalytic stability of the Ni-functionalized BP electrocatalyst,stably delivering the overall water splitting for 50 h at 20 mA cm^(−2).Theoretical calculations have revealed that Ni–P covalent binding can regulate the electronic structure and optimize the reaction energy barrier to improve the catalytic activity effectively.This work confirms that Ni-functionalized BP is a suitable candidate for electrocatalytic overall water splitting,and provides effective strategies for constructing metal-lightweighted economic electrocatalysts. 展开更多
关键词 Black phosphorus Water electrolysis ELECTROCATALYST Electron redistribution Covalent functionalization
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Self‑Healing Dynamic Hydrogel Microparticles with Structural Color for Wound Management
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作者 Li Wang Xiaoya Ding +5 位作者 Lu Fan Anne M.Filppula Qinyu Li Hongbo Zhang Yuanjin Zhao Luoran Shang 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第11期177-190,共14页
Chronic diabetic wounds confront a significant medical challenge because of increasing prevalence and difficult-healing circumstances.It is vital to develop multifunctional hydrogel dressings,with well-designed morpho... Chronic diabetic wounds confront a significant medical challenge because of increasing prevalence and difficult-healing circumstances.It is vital to develop multifunctional hydrogel dressings,with well-designed morphology and structure to enhance flexibility and effectiveness in wound management.To achieve these,we propose a self-healing hydrogel dressing based on structural color microspheres for wound management.The microsphere comprised a photothermal-responsive inverse opal framework,which was constructed by hyaluronic acid methacryloyl,silk fibroin methacryloyl and black phosphorus quantum dots(BPQDs),and was further re-filled with a dynamic hydrogel.The dynamic hydrogel filler was formed by Knoevenagel condensation reaction between cyanoacetate and benzaldehyde-functionalized dextran(DEX-CA and DEX-BA).Notably,the composite microspheres can be applied arbitrarily,and they can adhere together upon near-infrared irradiation by leveraging the BPQDs-mediated photothermal effect and the thermoreversible stiffness change of dynamic hydrogel.Additionally,eumenitin and vascular endothelial growth factor were co-loaded in the microspheres and their release behavior can be regulated by the same mechanism.Moreover,effective monitoring of the drug release process can be achieved through visual color variations.The microsphere system has demonstrated desired capabilities of controllable drug release and efficient wound management.These characteristics suggest broad prospects for the proposed composite microspheres in clinical applications. 展开更多
关键词 Black phosphorus Structural color Dynamic hydrogel Inverse opal Wound management
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Straw mulching alters the composition and loss of dissolved organic matter in farmland surface runoff by inhibiting the fragmentation of soil small macroaggregates
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作者 Shanshan Cai Lei Sun +7 位作者 Wei Wang Yan Li Jianli Ding Liang Jin Yumei Li Jiuming Zhang Jingkuan Wang Dan Wei 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2024年第5期1703-1717,共15页
Straw mulching is a widespread practice for reducing the soil carbon loss caused by erosion.However,the effects of straw mulching on dissolved organic matter(DOM)runoff loss from black soil are not well studied.How st... Straw mulching is a widespread practice for reducing the soil carbon loss caused by erosion.However,the effects of straw mulching on dissolved organic matter(DOM)runoff loss from black soil are not well studied.How straw mulching affects the composition and loss of runoff DOM by changing soil aggregates remains largely unclear.Here,a straw mulching treatment was compared to a no mulching treatment(as a control)on sloping farmland with black soil erosion in Northeast China.We divided the soil into large macroaggregates(>2 mm),small macroaggregates(0.25-2 mm),and microaggregates(<0.25 mm).After five rain events,the effects of straw mulching on the concentration(characterized by dissolved organic carbon(DoC)and composition(analyzed by fluorescence spectroscopy)of runoff and soil aggregate DOM were studied.The results showed that straw mulching reduced the runoff amount by 54.7%.Therefore,although straw mulching increased the average DOc concentration in runoff,it reduced the total runoff DOM loss by 48.3%.The composition of runoff DOM is similar to that of soil,as both contain humic-like acid and protein-like components.With straw mulching treatment,the protein-like components in small macroaggregates accumulated and the protein-like components in runoff declined with rain events.Fluorescence spectroscopy technology may help in understanding the hydrological paths of rain events by capturing the dynamic changes of runoff and soil DOM characteristics.A variation partitioning analysis(VPA)indicated that the DOM concentration and composition of microaggregates explained 68.2%of the change in runoff DOM from no mulching plots,while the change in runoff DOM from straw mulching plots was dominated by small macroaggregates at a rate of 55.1%.Taken together,our results demonstrated that straw mulching reduces the fragmentation of small macroaggregates and the loss of microaggregates,thus effecting DOM compositions in soil and reducing the DOM loss in runoff.These results provide a theoretical basis for reducing carbon loss in sloping farmland. 展开更多
关键词 dissolved organic matter black soil surface runoff AGGREGATES fluorescence spectrum
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Nitrogen isotope stratigraphy of the Early Cambrian successions in the Tarim Basin:Spatial variability of nitrogen cycling and its implication for paleo-oceanic redox conditions
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作者 Bi Zhu Xuefeng Li +1 位作者 Lu Ge Yongquan Chen 《Acta Geochimica》 EI CAS CSCD 2024年第4期785-801,共17页
The Early Cambrian represents a critical time period characterized by extraordinary biological innovations and dynamic redox conditions in seawaters.Nitrogen isotopic signatures of ancient sediments have the potential... The Early Cambrian represents a critical time period characterized by extraordinary biological innovations and dynamic redox conditions in seawaters.Nitrogen isotopic signatures of ancient sediments have the potential to elucidate the evolutionary path of marine redox states and the biogeochemical nitrogen cycle within the water column of the Early Cambrian ocean.While existing research on this topic has predominantly focused on South China,the exploration of other continental margins has been limited,leaving contradictory hypotheses untested.In this study,pairedδ^(15)N andδ^(13)C org analyses were performed on the Lower Cambrian successions from the Shiairike section(inner ramp)and Well Tadong 2(deep shelf/basin)in the northwestern and eastern Tarim Basin,respectively.Our data from the Shiairike section reveal a discernible shift in the operation of different nitrogen cycles for the black chert-shale unit,also referred to as the black rock series in Chinese literature,of the Yurtus Formation(Fortunian stage to lower Stage 3).Oscillatingδ^(15)N values for its lower part are suggestive of alternating anaerobic assimilation of NH 4+and denitrification/anammox.This is likely attributed to a shallow,unstable chemocline consistent with the upwelling and incursion of deep,anoxic waters during a major transgression.In contrast,aerobic nitrogen cycling,indicated by positiveδ^(15)N values of>2‰,dominated the upper part alongside a reduction in upwelling intensity.On the other hand,theδ^(15)N signatures of Xishanbulake and Xidashan Formations of Well Tadong 2,which encompass a time interval from the Cambrian Fortunian Age to Age 4,are indicative of N_(2)fixation by diazotrophs as the major nitrogen source.The two studied intervals,although not time-equivalent,exhibit separated states of nitrogen cycling at least during the deposition of the Yurtus black rock series.The spatially different nitrogen cycling of the studied sections is compatible with a redox-stratified ocean during the deposition of the Yurtus black rock series.The build-up of a NO_(3)−reservoir and aerobic nitrogen cycling in seawater was largely restricted to near-shore settings whereas anaerobic nitrogen cycling dominated by N_(2)fixation served as the main nitrogen uptake pathway in off-shore settings. 展开更多
关键词 Nitrogen isotopes Early Cambrian TARIM Black rock series
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