期刊文献+
共找到2,745篇文章
< 1 2 138 >
每页显示 20 50 100
Characterization of six tumorsuppressor genes and microsatellite instability in hepatocellular carcinomain southern African blacks 被引量:21
1
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
下载PDF
Trends of Cardiovascular Mortality in Blacks Africans from Central African City: Hospital Based Study, Brazzaville (Congo)
2
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
下载PDF
Fibroadenoma in Blacks
3
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
下载PDF
HNA-1 a and HNA-1 b gene frequencies in the Tunisian Blacks
4
《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
下载PDF
The Tragedy of Jeff and the Rising of American Blacks Today
5
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
下载PDF
Hepatocellular carcinoma in African Blacks: Recent progress in etiology and pathogenesis 被引量:5
6
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
下载PDF
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
7
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
下载PDF
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
8
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
下载PDF
Polyphenol components in black chokeberry(Aronia melanocarpa)as clinically proven diseases control factors——an overview
9
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
下载PDF
Covalently Bonded Ni Sites in Black Phosphorene with Electron Redistribution for Efficient Metal‑Lightweighted Water Electrolysis
10
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
下载PDF
Straw mulching alters the composition and loss of dissolved organic matter in farmland surface runoff by inhibiting the fragmentation of soil small macroaggregates
11
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
下载PDF
Ash removal from inferior coal via ammonium fluoride roasting and simultaneous yield of white carbon black
12
作者 Xuqin Duan Shuaiyu Lu +3 位作者 Yuxiao Fu Jiazhe Zhang Tong Liu Jian Ma 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2024年第2期261-279,共19页
The quality upgrading and deashing of inferior coal by chemical method still faces great challenges.The dangers of strong acid,strong alkali,waste water and exhaust gas as well as high cost limit its industrial produc... The quality upgrading and deashing of inferior coal by chemical method still faces great challenges.The dangers of strong acid,strong alkali,waste water and exhaust gas as well as high cost limit its industrial production.This paper systematically investigates the ash reduction and desilicification of two typical inferior coal utilizing ammonium fluoride roasting method.Under the optimal conditions,for fat coal and gas coal,the deashing rates are 69.02%and 54.13%,and the desilicification rates are 92.64%and 90.27%,respectively.The molar dosage of ammonium fluoride remains consistent for both coals;however,the gas coal,characterized by a lower ash and silica content(less than half that of the fat coal),achieves optimum deashing effect at a reduced time and temperature.The majority of silicon in coal transforms into gaseous ammonium fluorosilicate,subsequently preparing nanoscale amorphous silica with a purity of 99.90%through ammonia precipitation.Most of the fluorine in deashed coal are assigned in inorganic minerals,suggesting the possibility of further fluorine and ash removal via flotation.This research provides a green and facile route to deash inferior coal and produce nano-scale white carbon black simultaneously. 展开更多
关键词 Inferior coal Deashing treatment Silicon recycling Ammonium fluoride roasting White carbon black
下载PDF
Thermodynamics in a quantum corrected Reissner-Nordstr?m-AdS black hole and its GUP-corrections
13
作者 宋建君 刘成周 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第4期345-353,共9页
We calculate the thermodynamic quantities in the quantum corrected Reissner-Nordstr?m-AdS(RN-AdS)black hole,and examine their quantum corrections.By analyzing the mass and heat capacity,we give the critical state and ... We calculate the thermodynamic quantities in the quantum corrected Reissner-Nordstr?m-AdS(RN-AdS)black hole,and examine their quantum corrections.By analyzing the mass and heat capacity,we give the critical state and the remnant state,respectively,and discuss their consistency.Then,we investigate the quantum tunneling from the event horizon of massless scalar particle by using the null geodesic method,and charged massive boson W^(±)and fermions by using the Hamilton-Jacob method.It is shown that the same Hawking temperature can be obtained from these tunneling processes of different particles and methods.Next,by using the generalized uncertainty principle(GUP),we study the quantum corrections to the tunneling and the temperature.Then the logarithmic correction to the black hole entropy is obtained. 展开更多
关键词 black hole thermodynamics quantum corrections quantum tunneling generalized uncertainty principle
下载PDF
Metal-free two-dimensional phosphorene-based electrocatalyst with covalent P-N heterointerfacial reconstruction for electrolyte-lean lithium-sulfur batteries
14
作者 Jiangqi Zhou Chengyong Shu +7 位作者 Jiawu Cui Chengxin Peng Yong Liu Weibo Hua Laura Simonelli Yuping Wu Shi Xue Dou Wei Tang 《Carbon Energy》 SCIE EI CAS CSCD 2024年第5期175-185,共11页
The use of lithium-sulfur batteries under high sulfur loading and low electrolyte concentrations is severely restricted by the detrimental shuttling behavior of polysulfides and the sluggish kinetics in redox processe... The use of lithium-sulfur batteries under high sulfur loading and low electrolyte concentrations is severely restricted by the detrimental shuttling behavior of polysulfides and the sluggish kinetics in redox processes.Two-dimensional(2D)few layered black phosphorus with fully exposed atoms and high sulfur affinity can be potential lithium-sulfur battery electrocatalysts,which,however,have limitations of restricted catalytic activity and poor electrochemical/chemical stability.To resolve these issues,we developed a multifunctional metal-free catalyst by covalently bonding few layered black phosphorus nanosheets with nitrogen-doped carbon-coated multiwalled carbon nanotubes(denoted c-FBP-NC).The experimental characterizations and theoretical calculations show that the formed polarized P-N covalent bonds in c-FBP-NC can efficiently regulate electron transfer from NC to FBP and significantly promote the capture and catalysis of lithium polysulfides,thus alleviating the shuttle effect.Meanwhile,the robust 1D-2D interwoven structure with large surface area and high porosity allows strong physical confinement and fast mass transfer.Impressively,with c-FBP-NC as the sulfur host,the battery shows a high areal capacity of 7.69 mAh cm^(−2) under high sulfur loading of 8.74 mg cm^(−2) and a low electrolyte/sulfur ratio of 5.7μL mg^(−1).Moreover,the assembled pouch cell with sulfur loading of 4 mg cm^(−2) and an electrolyte/sulfur ratio of 3.5μL mg^(−1) shows good rate capability and outstanding cyclability.This work proposes an interfacial and electronic structure engineering strategy for fast and durable sulfur electrochemistry,demonstrating great potential in lithium-sulfur batteries. 展开更多
关键词 black phosphorus electronic structure high sulfur loading interfacial covalent bonds lean electrolyte
下载PDF
View of thermodynamic phase transition of the charged Gauss-Bonnet AdS black hole via the shadow
15
作者 何柯腱 郭森 +1 位作者 罗智 李国平 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第4期355-362,共8页
We examine thermodynamic phase transition(PT)of the charged Gauss-Bonnet Ad S black hole(BH)by utilizing the shadow radius.In this system,we rescale the corresponding Gauss-Bonnet coefficientαby a factor of 1/(D-4),a... We examine thermodynamic phase transition(PT)of the charged Gauss-Bonnet Ad S black hole(BH)by utilizing the shadow radius.In this system,we rescale the corresponding Gauss-Bonnet coefficientαby a factor of 1/(D-4),and ensure thatαis positive to avoid any singularity problems.The equation derived for the shadow radius indicates that it increases as the event horizon radius increases,making it an independent variable for determining BH temperature.By investigating the PT curve in relation to shadows,we can observe that the shadow radius can be used as an alternative to the event horizon radius in explaining the phenomenon of BH PT.Furthermore,the results indicate that an increase in the parameterαcorresponds to a decrease in the temperature of the BH.By utilizing the relationship between the temperature and the shadow radius,it is possible to obtain the thermal profile of the Gauss-Bonnet AdS BH.It is evident that there is an N-type variation in temperature for pressures P<P_(c).Additionally,as the parameterαincreases,the region covered by shadow expands while the temperature decreases.The utilization of BH shadows as a probe holds immense significance in gaining a deeper understanding of BH thermodynamic behavior. 展开更多
关键词 Gauss-Bonnet AdS black hole thermodynamic SHADOW
下载PDF
Triple points and phase transitions of D-dimensional dyonic Ad S black holes with quasitopological electromagnetism in Einstein–Gauss–Bonnet gravity
16
作者 牟平辉 蒋青权 +1 位作者 何柯腱 李国平 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第6期272-287,共16页
By considering the negative cosmological constant Λ as a thermodynamic pressure, we study the thermodynamics and phase transitions of the D-dimensional dyonic Ad S black holes(BHs) with quasitopological electromagnet... By considering the negative cosmological constant Λ as a thermodynamic pressure, we study the thermodynamics and phase transitions of the D-dimensional dyonic Ad S black holes(BHs) with quasitopological electromagnetism in Einstein–Gauss–Bonnet(EGB) gravity. The results indicate that the small/large BH phase transition that is similar to the van der Waals(vdW) liquid/gas phase transition always exists for any spacetime dimensions. Interestingly, we then find that this BH system exhibits a more complex phase structure in 6-dimensional case that is missed in other dimensions.Specifically, it shows for D = 6 that we observed the small/intermediate/large BH phase transitions in a specific parameter region with the triple point naturally appeared. Moreover, when the magnetic charge turned off, we still observed the small/intermediate/large BH phase transitions and triple point only in 6-dimensional spacetime, which is consistent with the previous results. However, for the dyonic Ad S BHs with quasitopological electromagnetism in Einstein–Born–Infeld(EBI) gravity, the novel phase structure composed of two separate coexistence curves observed by Li et al. [Phys. Rev. D105 104048(2022)] disappeared in EGB gravity. This implies that this novel phase structure is closely related to gravity theories, and seems to have nothing to do with the effect of quasitopological electromagnetism. In addition, it is also true that the critical exponents calculated near the critical points possess identical values as mean field theory. Finally, we conclude that these findings shall provide some deep insights into the intriguing thermodynamic properties of the dyonic Ad S BHs with quasitopological electromagnetism in EGB gravity. 展开更多
关键词 AdS black hole phase transition triple point
下载PDF
Analysis of flavor and widely metabolomics differences in black sesame before and after processing
17
作者 Yini Yang Linhai Wang +3 位作者 Yunhai Wang Yuting An Qi Zhou Xia Xiang 《Oil Crop Science》 CSCD 2024年第1期38-45,共8页
The objective of this study was to determine the differences of aroma and taste in three black sesame originsbefore and after processing via flavor and widely metabolomics.By analyzing the sensory characteristics and ... The objective of this study was to determine the differences of aroma and taste in three black sesame originsbefore and after processing via flavor and widely metabolomics.By analyzing the sensory characteristics and metabolites of raw and treated black sesame from China,Vietnam,and Myanmar,treated Chinese sesame have the most significant change in hardness after thermal processing,low viscosity and was easy to chew.The electronic nose could distinguish between raw and treated sesame due to the aroma distribution.The reason of treated sesame from China was“fragrant”is due to the highest content(2545.50μg/kg)of total pyrazines including 2,5-dimethylpyrazine,2-ethyl-5-methylpyrazine,2,3,5-trimethylpyrazine,3-ethyl-2,5-dimethylpyrazine.933 metabolites were detected via a wide targeted metabolomics in the taste of raw and treated sesame.Based on the analysis of metabolites related to bitterness,145 substances were selected.The main bitter contributors may be amino acids,dipeptides and organic acids. 展开更多
关键词 Flavoromics Metabolomics Black sesame AROMA TASTE Distribution
下载PDF
Genome-Wide Characterization of the Hyaluronidase Gene Family and Their Potential Roles in Viviparous Black Rockfish(Sebastes schlegeli)
18
作者 LIU Zhiying NIU Jingning +4 位作者 ZHAO Xi LIU Huaxiang LI Zibin HE Yan QI Jie 《Journal of Ocean University of China》 CAS CSCD 2024年第2期487-498,共12页
Black rockfish(Sebastes schlegelii)has evolved viviparous reproduction mode.Different from the oviparous fishes,the spermatozoa of black rockfish are stored on the surface of ovarian follicle for over four months unti... Black rockfish(Sebastes schlegelii)has evolved viviparous reproduction mode.Different from the oviparous fishes,the spermatozoa of black rockfish are stored on the surface of ovarian follicle for over four months until the egg mature in ovary,while the adaptive evolution of fertilization-related genes remains to be studied.In the present study,based on the genome and transcriptome information of black rockfish,a total of 10 hyaluronidase genes were identified by phylogenetic and sequence analyses,including hyal1,hyal2,hyal3,hyal4,hyal6 and spam1a,spam1b,spam1c and spam1d.The spam1 subfamilies,including spam1a,spam1b,spam1c and spam1d,were significantly expanded compared to other species.The adaptive evolution of hyaluronidase was further investigated by selection pressure analysis of branch model and branch site model.The results showed that only spam1 subfamily was positively selected with a large number of positive selection sites,and the evolution rate was significantly higher thanthose of other teleosts.Two positively selected sites,LYS-171 and GLY-164,were located in the neutral hyaluronidase activity domain,which was pivotal for SPAM1 to participate in enzymatic hydrolysis of the extracellular hyaluronic acid matrix and mediate acrosome reaction in mammals.Furthermore,spam1 was mainly expressed in spermatocytes,secondary spermatocytes,and spermatids of testis,whereas it was not found in metamorphic sperm and mature sperm based on the spatiotemporal expression analysis.All results indicated that spam1 might originate from the testis and might be an adaptation of viviparous trait in black rockfish. 展开更多
关键词 adaptation of viviparous black rockfish(Sebastes schlegelii) HYALURONIDASE selective pressure analysis
下载PDF
Giant and controllable Goos—Hänchen shift of a reflective beam off a hyperbolic metasurface of polar crystals
19
作者 薛天 李宇博 +5 位作者 宋浩元 王相光 张强 付淑芳 周胜 王选章 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第1期428-435,共8页
We conduct a theoretical analysis of the massive and tunable Goos–Hänchen(GH) shift on a polar crystal covered with periodical black phosphorus(BP)-patches in the THz range. The surface plasmon phonon polaritons... We conduct a theoretical analysis of the massive and tunable Goos–Hänchen(GH) shift on a polar crystal covered with periodical black phosphorus(BP)-patches in the THz range. The surface plasmon phonon polaritons(SPPPs), which are coupled by the surface phonon polaritons(SPh Ps) and surface plasmon polaritons(SPPs), can greatly increase GH shifts.Based on the in-plane anisotropy of BP, two typical metasurface models are designed and investigated. An enormous GH shift of about-7565.58 λ_(0) is achieved by adjusting the physical parameters of the BP-patches. In the designed metasurface structure, the maximum sensitivity accompanying large GH shifts can reach about 6.43 × 10^(8) λ_(0)/RIU, which is extremely sensitive to the size, carrier density, and layer number of BP. Compared with a traditional surface plasmon resonance sensor, the sensitivity is increased by at least two orders of magnitude. We believe that investigating metasurface-based SPPPs sensors could lead to high-sensitivity biochemical detection applications. 展开更多
关键词 Goos–H?nchen shift black phosphorus surface plasmon phonon polaritons sensitivity metasurfaces
下载PDF
Secure and Reliable Routing in the Internet of Vehicles Network:AODV-RL with BHA Attack Defense
20
作者 Nadeem Ahmed Khalid Mohammadani +3 位作者 Ali Kashif Bashir Marwan Omar Angel Jones Fayaz Hassan 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第4期633-659,共27页
Wireless technology is transforming the future of transportation through the development of the Internet of Vehicles(IoV).However,intricate security challenges are intertwinedwith technological progress:Vehicular ad h... Wireless technology is transforming the future of transportation through the development of the Internet of Vehicles(IoV).However,intricate security challenges are intertwinedwith technological progress:Vehicular ad hoc Networks(VANETs),a core component of IoV,face security issues,particularly the Black Hole Attack(BHA).This malicious attack disrupts the seamless flow of data and threatens the network’s overall reliability;also,BHA strategically disrupts communication pathways by dropping data packets from legitimate nodes altogether.Recognizing the importance of this challenge,we have introduced a new solution called ad hoc On-Demand Distance Vector-Reputation-based mechanism Local Outlier Factor(AODV-RL).The significance of AODVRL lies in its unique approach:it verifies and confirms the trustworthiness of network components,providing robust protection against BHA.An additional safety layer is established by implementing the Local Outlier Factor(LOF),which detects and addresses abnormal network behaviors.Rigorous testing of our solution has revealed its remarkable ability to enhance communication in VANETs.Specifically,Our experimental results achieve message delivery ratios of up to 94.25%andminimal packet loss ratios of just 0.297%.Based on our experimental results,the proposedmechanismsignificantly improves VANET communication reliability and security.These results promise a more secure and dependable future for IoV,capable of transforming transportation safety and efficiency. 展开更多
关键词 Black hole attack IoV vehicular ad hoc network AODV routing protocol
下载PDF
上一页 1 2 138 下一页 到第
使用帮助 返回顶部