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Performance assessment of meta-heuristic MPPT strategies for solar panels under complex partial shading conditions and load variation
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作者 Abdulbari Talib Naser Nur Fadilah Ab Aziz +2 位作者 Karam Khairullah Mohammed Karmila binti Kamil Saad Mekhilef 《Global Energy Interconnection》 2025年第4期554-571,共18页
Weather variations present a major challenge for photovoltaic(PV)systems in obtaining the optimal output during maximum power point tracking(MPPT),particularly under partial shadowing conditions(PSCs).Bypass diodes ar... Weather variations present a major challenge for photovoltaic(PV)systems in obtaining the optimal output during maximum power point tracking(MPPT),particularly under partial shadowing conditions(PSCs).Bypass diodes are typically installed across the series-connected PV modules to avoid the occurrence of the hotspots.Consequently,the power curve exhibits several local peaks(LPs)and one global peak(GP).The conventional MPPTs typically become stuck in one of these LPs,presenting a significant decrease in both the power output and overall efficiency of the PV system.A major constraint of several optimization techniques is their inability to differ-entiate between the irradiancefluctuations and load alterations.In this study,we analyze seven different methods for MPPT.These include:the team game algorithm(TGA),social ki driver algorithm(SSD),differential evolution(DE),grey wolf optimization(GWO),particle swarm optimization(PSO),cuckoo search(CS),and the perturb and observe(P&O)method.These algorithms were applied in practice,and their effectiveness was experimentally demonstrated under different amounts of solar irradiation while maintain-ing a constant temperature.The results indicate that the CS and TGA approaches can accurately track the MPPT across various posi-tions on the P-V curve.These methods achieve average efficiencies of 99.59%and 99.54%,respectively.Additionally,the TGA achieves superior performance with the shortest average tracking time of 0.92 s,outperforming the existing MPPT algorithms. 展开更多
关键词 Maximum power point tracking(MPPT) Partial shading conditions(PSCs) Photovoltaic system(PV) Particle swarm optimization(PSO)
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Paleoseismological analysis of the Palu Segment within the East Anatolian fault system:Implications for seismic hazard assessment
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作者 Fikret KOÇBULUT Elif AKGÜN +2 位作者 Mustafa SOFTA Sinan KOŞAROĞLU Orhan TATAR 《Journal of Mountain Science》 2025年第7期2332-2355,共24页
The Palu segment,situated in the northeastern part of the East Anatolian Fault System(EAFS),is a crucial structural feature with notable seismic potential.This study examines the paleoseismic activity of the Palu segm... The Palu segment,situated in the northeastern part of the East Anatolian Fault System(EAFS),is a crucial structural feature with notable seismic potential.This study examines the paleoseismic activity of the Palu segment through trench excavations and geochronological analyses utilizing Optically Stimulated Luminescence(OSL)and radiocarbon(14C)dating methods.Two trenches,located near Karşıbahçeler,exposed evidence of multiple surface-rupturing seismic events spanning the Holocene and Pleistocene epochs.Chronological analyses identified five distinct seismic events in trench 1(P1),dated between 94.09±6.07 ka and 0.84±0.45 ka,and three events in trench 2(P2),dated between 28.83±1.61 ka and 351±21 BP.Bayesian analysis using Oxcal distribution suggested event timings between 90.52±25.99 ka and 1.25±0.55 ka.Comparative analysis with historical earthquake records correlates the most recent event with the 1789 or 1874 AD earthquakes,while the penultimate event matches the 995 AD earthquake.Earlier events reflect prehistoric tectonic activity.The recurrence intervals for these events range from 710 to 5,370 years during the Holocene,with evidence of seismic activity extending into the Pleistocene.Stress inversion analyses and geodetic data indicate a predominantly strike-slip stress regime,consistent with geometry of the fault.These findings provide critical insights into the long-term seismic behavior and recurrence patterns of the Palu segment,enhancing seismic hazard assessments for the region. 展开更多
关键词 Palu segment East Anatolian fault system PALEOSEISMOLOGY Kinematic analysis Recurrences Interval
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Epstein-Barr virus:Silent companion or causative agent of chronic liver disease? 被引量:10
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作者 Mihaela Petrova Victor Kamburov 《World Journal of Gastroenterology》 SCIE CAS CSCD 2010年第33期4130-4134,共5页
The Epstein-Barr virus(EBV)has an important and multifaceted role in liver pathology.As a member of the herpes virus family,EBV establishes a persistent infection in more than 90%of adults.Besides acute hepatitis duri... The Epstein-Barr virus(EBV)has an important and multifaceted role in liver pathology.As a member of the herpes virus family,EBV establishes a persistent infection in more than 90%of adults.Besides acute hepatitis during primary infection,many clinical syndromes of interest for the hepatologist are associated with EBV infection.The role of EBV in the evolution of chronic hepatitis from hepatotropic viruses is considered.Chronic EBVassociated hepatitis is suspected in immunocompetent adults with compatible serology,suggestive histology and detection of the viral genome in the liver and/or increase of specific circulating cytotoxic T-lymphocytes.EBV is the main cause of post-transplant lymphoproliferative disorders which occur in up to 30%of cases.EBV-driven lymphoproliferative diseases are also recognized in non-immunocompromised patients and liver is involved in up to a third of the cases.Directly implicated in the pathogenesis of different tumors,EBV has a disputable role in hepatocellular carcinoma carcinogenesis.Further research is required in order to establish or reject the role of EBV in human liver cancer.This paper attempts to discuss the range of EBV-associated chronic liver diseases in immunocompetent patients,from mild,self-limiting mononuclear hepatitis to liver cancer. 展开更多
关键词 Epstein-Barr virus Chronic hepatitis Liver disease Chronic active Epstein-Barr virus Post-transplant lymphoproliferative disorder Infectious mononucleosis
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Effect of acid etching on marginal adaptation of mineral trioxide aggregate to apical dentin:microcomputed tomography and scanning electron microscopy analysis 被引量:3
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作者 Khalid Al-Fouzan Ziad Al-Garawi +3 位作者 Khalid Al-Hezaimi Fawad Javed Thakib Al-Shalan Ilan Rotstein 《International Journal of Oral Science》 SCIE CAS CSCD 2012年第4期202-207,共6页
The present investigation assessed the effect of acid etching on marginal adaptation of white- and gray-colored mineral trioxide aggregate (MTA) to apical dentin using microcomputed tomography (micro-CT) and scann... The present investigation assessed the effect of acid etching on marginal adaptation of white- and gray-colored mineral trioxide aggregate (MTA) to apical dentin using microcomputed tomography (micro-CT) and scanning electron microscopy (SEM). Sixty-four extracted single-rooted human maxillary teeth were used. Following root-end resection and apical preparation, the teeth were equally divided into four groups according to the following root end filling materials: (i) white-colored MTA (WMTA), (ii) etched WMTA (EWMTA), (iii) gray-colored MTA (GMTA) and (iv) etched GMTA (EGMTA). After 48 h, the interface between root-end filling materials and the dentinal walls was assessed using micro-CT and SEM. Data were statistically analyzed using the KruskaI-Wallis and Dunn tests. Micro-CT analysis revealed gap volumes between the apical cavity dentin walls and EGMTA, GMTA, EWMTA and WMTA of (0.007 1±0.004) mm3, (0.053±0.002) mm3, (0.003 6±0.001) mm3 and (0.005 9±0.002) mm3 respectively. SEM analysis revealed gap sizes for EGMTA, WMTA, EWMTA and GMTA to be (492.3±13.8) μm, (594.5±17.12)μm, (543.1±15.33) μm and (910.7±26.2)μm respectively. A significant difference in gap size between root end preparations filled with GMTA and EGMTA was found (P〈O.05). No significance difference in gap size between WMTA and EWMTA were found in either SEM or micro-CT analysis. In conclusion, pre-etching of apical dentin can provide a better seal for GMTA but not for WMTA. 展开更多
关键词 acid etching BIOCOMPATIBILITY mineral trioxide aggregate root end filling
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Design, Synthesis of Analgesics and Anticancer of Some New Derivatives of Benzimidazole 被引量:2
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作者 Helmy M. Sakr Rezk R. Ayyad +2 位作者 Kazem Mahmoud Ahmed M. Mansour Ahmed. G Ahmed 《International Journal of Organic Chemistry》 CAS 2021年第3期144-169,共26页
T<span style="font-family:Verdana;">his work, contain<span style="font-family:Verdana;">s<span style="font-family:Verdana;"> some new compounds from benzimidazole deriva... T<span style="font-family:Verdana;">his work, contain<span style="font-family:Verdana;">s<span style="font-family:Verdana;"> some new compounds from benzimidazole derivatives, which <span style="font-family:Verdana;">are <span style="font-family:Verdana;">synthesized by condensation of Orthophenylene diamine and Carbon disulfide resulting <span style="font-family:Verdana;">in <span style="font-family:Verdana;">2-Mercapto-benzimidazole which <span style="font-family:Verdana;">is <span style="font-family:Verdana;">treated by alcoholic potassium hydroxide forming potassium salt of 2-mercaptobenzimidazole which reacts with different substances (alkyl chlo<span style="font-family:Verdana;">roacetates, chloroacetic chloride, alkyl halides) also the ethoxy carbonyl methyl thiobenzimidazole reacts with different amines. In addition to chloromethyl benzimidazole which resulted from the reaction between orthophenylene diamine and chloroacetic acid, which reacted with different amines. The synthesized compound tested as analgesics and anticancer activity the new derivatives revealed moderate, strong and very strong analgesics and moderate and strong anticancer activity<span style="font-family:Verdana;">. 展开更多
关键词 BENZIMIDAZOLE Analgesics and Anticancer
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Energy Analyses of Thermoelectric Renewable Energy Sources 被引量:1
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作者 Jarman T. Jarman Essam E. Khalil Elsayed Khalaf 《Open Journal of Energy Efficiency》 2013年第4期143-153,共11页
The recent energy crisis and environmental burden are becoming increasingly urgent and drawing enormous attention to solar-energy utilization. Direct solar thermal power generation technologies, such as, thermoelectri... The recent energy crisis and environmental burden are becoming increasingly urgent and drawing enormous attention to solar-energy utilization. Direct solar thermal power generation technologies, such as, thermoelectric, thermionic, magneto hydrodynamic, and alkali-metal thermoelectric methods, are among the most attractive ways to provide electric energy from solar heat. Direct solar thermal power generation has been an attractive electricity generation technology using a concentrator to gather solar radiation on a heat collector and then directly converting heat to electricity through a thermal electric conversion element. Compared with the traditional indirect solar thermal power technology utilizing a steam-turbine generator, the direct conversion technology can realize the thermal to electricity conversion without the conventional intermediate mechanical conversion process. The power system is, thus, easy to extend, stable to operate, reliable, and silent, making the method especially suitable for some small-scale distributed energy supply areas. Also, at some occasions that have high requirements on system stability, long service life, and noiselessness demand, such as military and deep-space exploration areas, direct solar thermal power generation has very attractive merit in practice. At present, the realistic conversion efficiency of direct solar thermal power technology is still not very high, mainly due to material restriction and inconvenient design. However, from the energy conversion aspect, there is no conventional intermediate mechanical conversion process in direct thermal power conversion, which therefore guarantees the enormous potential of thermal power efficiency when compared with traditional indirect solar thermal power technology [1]. 展开更多
关键词 Solar ENERGY Two STAGE CONCENTRATOR MATHEMATICAL Modeling Thermal Analysis THERMOELECTRIC Power Generation
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Impact of stopping smoking on metabolic parameters in diabetes mellitus:A scoping review 被引量:1
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作者 Magdalena Walicka Cristina Russo +3 位作者 Michael Baxter Isaac John Grazia Caci Riccardo Polosa 《World Journal of Diabetes》 SCIE 2022年第6期422-433,共12页
The purpose of this scoping review is to create a single narrative that describes the impact of smoking cessation on metabolic parameters in people with diabetes.It is generally well accepted that smoking enhances the... The purpose of this scoping review is to create a single narrative that describes the impact of smoking cessation on metabolic parameters in people with diabetes.It is generally well accepted that smoking enhances the harmful effects of elevated blood glucose levels,accelerating the vascular damage seen in patients with diabetes.Smoking cessation has clear benefits in terms of reducing cardiovascular morbidity and mortality.However,there is less evidence for the impact of smoking cessation on other diabetes-related complications.Studies in people with diabetes have shown improvement as well as temporary deterioration in glycemic control after ceasing smoking.Only a few studies have described the effect of quitting smoking on insulin resistance and lipid parameters,however,their results have been inconclusive.In this situation,healthcare professionals should not assume that cessation of smoking will improve metabolic parameters in patients with diabetes.It seems they should, first of all, emphasize the prevention of weight gain that may be associatedwith quitting smoking. The lack of data regarding the metabolic effects of smoking and smokingcessation in diabetes is very disappointing and this area needs to be addressed. 展开更多
关键词 SMOKING Smoking cessation DIABETES Insulin resistance GLUCOSE LIPIDS
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Role of endoscopic ultrasound in the characterization of solid pseudopapillary neoplasm of the pancreas 被引量:1
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作者 Katarzyna M Pawlak Nadeem Tehami +18 位作者 Ben Maher Shujaath Asif Krishn Kant Rawal Daniel Vasile Balaban Mohammed Tag-Adeen Fahd Ghalim Wael A Abbas Elsayed Ghoneem Khaled Ragab Mahmoud El-Ansary Shanil Kadir Sunil Amin Keith Siau Anna Wiechowska-Kozlowska Klaus Mönkemüller Dalia Abdelfatah Abeer Abdellatef Sundeep Lakhtakia Hussein Hassan Okasha 《World Journal of Gastrointestinal Endoscopy》 2023年第4期273-284,共12页
BACKGROUND Solid pseudopapillary neoplasm(SPN)is an uncommon pathology of the pancreas with unpredictable malignant potential.Endoscopic ultrasound(EUS)assessment plays a vital role in lesion characterization and conf... BACKGROUND Solid pseudopapillary neoplasm(SPN)is an uncommon pathology of the pancreas with unpredictable malignant potential.Endoscopic ultrasound(EUS)assessment plays a vital role in lesion characterization and confirmation of the tissue diagnosis.However,there is a paucity of data regarding the imaging assessment of these lesions.AIM To determine the characteristic EUS features of SPN and define its role in preoperative assessment.METHODS This was an international,multicenter,retrospective,observational study of prospective cohorts from 7 large hepatopancreaticobiliary centers.All cases with postoperative histology of SPN were included in the study.Data collected included clinical,biochemical,histological and EUS characteristics.RESULTS One hundred and six patients with the diagnosis of SPN were included.The mean age was 26 years(range 9 to 70 years),with female predominance(89.6%).The most frequent clinical presentation was abdominal pain(80/106;75.5%).The mean diameter of the lesion was 53.7 mm(range 15 to 130 mm),with the slight predominant location in the head of the pancreas(44/106;41.5%).The majority of lesions presented with solid imaging features(59/106;55.7%)although 33.0%(35/106)had mixed solid/cystic characteristics and 11.3%(12/106)had cystic morphology.Calcification was observed in only 4(3.8%)cases.Main pancreatic duct dilation was uncommon,evident in only 2 cases(1.9%),whilst common bile duct dilation was observed in 5(11.3%)cases.One patient demonstrated a double duct sign at presentation.Elastography and Doppler evaluation demonstrated inconsistent appearances with no emergence of a predictable pattern.EUS guided biopsy was performed using three different types of needles:Fine needle aspiration(67/106;63.2%),fine needle biopsy(37/106;34.9%),and Sonar Trucut(2/106;1.9%).The diagnosis was conclusive in 103(97.2%)cases.Ninety-seven patients were treated surgically(91.5%)and the post-surgical SPN diagnosis was confirmed in all cases.During the 2-year follow-up period,no recurrence was observed.CONCLUSION SPN presented primarily as a solid lesion on endosonographic assessment.The lesion tended to be located in the head or body of the pancreas.There was no consistent characteristic pattern apparent on either elastography or Doppler assessment.Similarly SPN did not frequently cause stricture of the pancreatic duct or common bile duct.Importantly,we confirmed that EUS-guided biopsy was an efficient and safe diagnostic tool.The needle type used does not appear to have a significant impact on the diagnostic yield.Overall SPN remains a challenging diagnosis based on EUS imaging with no pathognomonic features.EUS guided biopsy remains the gold standard in establishing the diagnosis. 展开更多
关键词 Solid pseudopapillary neoplasm SPN Frantz tumor Endoscopic ultrasound features EUSguided biopsy Fine needle aspiration/biopsy
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Validation of a Value Management Approach Developed for the Saudi Public Sector
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作者 Mohammed Auda S Alalshikh 《Journal of Civil Engineering and Architecture》 2014年第2期197-206,共10页
A VM (value management) approach was developed that better suits the culture and the context of the SPS (Saudi Public Sector). This approach provided a comprehensive assessment of VM at institutional, organization... A VM (value management) approach was developed that better suits the culture and the context of the SPS (Saudi Public Sector). This approach provided a comprehensive assessment of VM at institutional, organizational and project levels. This paper illustrates the procedures that were used to validate the developed VM approach. For the institutional and organizational levels, the VM approach was validated by conducting telephone interviews with three experts from three organizations that use VM and with two senior managers from the MOF (Ministry of Finance). Mainly, it was found that the MOF should be supported by experts to set up a centre of excellence that can set VM policy, guidelines and standards for the promotion of VM in the SPS, in order to ensure achieving value for money spent in SPS projects. The developed VM approach, as it would be applied at the project level, was presented to 11 experts, all of whom completed a validation questionnaire and presented their comments. Subsequently, the questionnaires were analyzed and the VM approach was amended to reflect the inputs provided by these experts. It was concluded that VM should be applied at least twice on SPS projects. Firstly, it is to review and structure strategic and project briefs to sort out soft issues, and secondly, it is to optimize project designs and sort out hard issues. 展开更多
关键词 Value management value engineering project management Saudi public sector Saudi Arabia.
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Composite Nanofibers Made of Polycaprolactone- Exoticwoods
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作者 Karel Klouda Eva Zemanova +4 位作者 Hana Buricova Eva Kostakova Petr Mikes Jiri Chvojka Jaroslav Dobias 《材料科学与工程(中英文B版)》 2014年第2期1-12,共12页
关键词 复合纳米纤维 聚己内酯 制造 绿色复合材料 SEM分析 热稳定性 纺丝技术 材料加工
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Inhibition of Hepatitis C Virus Genotype 1a Non-Structural Proteins by Small Interference RNA in Human Hepatoma Cell Lines
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作者 Imran Shahid Waleed Hassan AlMalki +3 位作者 Shaia Saleh R. Almalki Ismail Muhammad AlTurkestany Hassan Ali AlGhamdi Saleh Ali AlMenshawi 《Pharmacology & Pharmacy》 2015年第11期502-517,共16页
Hepatitis C virus (HCV) infection and associated liver diseases are still challenging and represent a significant health care burden around the world. Although, the treatment strategies have been improved by the devel... Hepatitis C virus (HCV) infection and associated liver diseases are still challenging and represent a significant health care burden around the world. Although, the treatment strategies have been improved by the development of novel direct-acting antivirals, but such therapeutic options are still expensive and beyond the financial range of the most infected individuals in developing or even in resource replete countries. It demands an urgent need to search novel and improved alternate treatment strategies to treat the infection. The present study was aimed to develop an in vitro stable cell culture system, persistently expressing HCV genotype 1a non-structural genes and to characterize the inhibitory effects of synthetic siRNAs (short interference RNA) directed against the most conserved regions of nonstructural genes in an in vitro cell culture model. The continuous expression of nonstructural genes for more than 30 days post transfection was detected by reverse transcription polymerase chain reaction (RT-PCR) and Western blot analysis in stable human hepatoma cell line (Huh-7). The gene expression studies revealed significantly reduced gene expression of HCV nonstructural genes (i.e., NS2, NS4A and NS5A) both at mRNA and protein levels when treated against genome specific synthetic siRNAs in stable cell lines (51%, 47% and 54% respectively, p < 0.05). Similarly, a vivid decrease in HCV viral titer was exhibited by synthetic siRNAs in an in vitro viral replicate cell culture model (58%, 48% and 50%, respectively, p < 0.05) determined by quantitative Real-Time PCR (qPCR). Our data indicate that siRNA mediated gene silencing may be considered a promising alternate treatment strategy against HCV in combination with other effective therapeutic regimens in future. 展开更多
关键词 HEPATITIS C VIRUS NON-STRUCTURAL PROTEINS Stable Cell Line ANTI-HCV DRUGS Short Interference RNA
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Intracoronary Electrocardiography-guided Strategy for the Treatment of Coronary Bifurcation Lesions
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作者 Dobrin Vassilev Niya Mileva +7 位作者 Panayot Panayotov Krasimir Kostov Kenan Yumerov Nikolay Petkov Carlos Collet Gianluca Rigatelli Robert J.Gil Thach Nguyen 《Cardiovascular Innovations and Applications》 2023年第1期469-481,共13页
Introduction:Revascularization of bifurcation lesions remains an interventional challenge.Intracoronary electrocar-diograms can predict the functional significance of side branch stenosis after bifurcation stenting.Ai... Introduction:Revascularization of bifurcation lesions remains an interventional challenge.Intracoronary electrocar-diograms can predict the functional significance of side branch stenosis after bifurcation stenting.Aim:This study was aimed at evaluating the effects of an intracoronary ECG electrocardiography(icECG)-guided revascularization strategy,compared with the currently accepted standard of care,on the clinical outcomes of patients after coronary bifurcation stenting.Methods:Patients with coronary bifurcation lesions who underwent percutaneous revascularization were enrolled in a prospective all-comers’registry.Clinical outcomes were compared between patients who underwent icECG-guided revascularization versus the current standard of care(SOC),provisional stenting.Results:A total of 768 patients were included in the analysis:349 were treated with an icECG-guided strategy,and 419 received SOC.The overall all-cause death rate was 23.2%,and the cardiovascular death rate was 15.9%.Patients with icECG guidance had significantly lower all-cause mortality(20.3%vs.25.5%for icECG vs.SOC,log-rank P=0.006)and cardiovascular mortality(12.6%vs.18.6%for icECG vs.SOC,log-rank P=0.004).The decrease in mortality was most pronounced in patients with no increase or a moderate increase in troponin post-PCI,or with higher-than-normal baseline troponin concentrations.Conclusion:An icECG-guided strategy for coronary bifurcation PCI led to lower patient mortality than the provi-sional stenting strategy. 展开更多
关键词 Coronary bifurcation percutaneous coronary intervention clinical outcomes
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Sex-related differences in patients with chronic hepatitis C infection treated with direct-acting antiviral drugs 被引量:1
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作者 Krystyna Dobrowolska Dorota Zarębska-Michaluk +13 位作者 Malgorzata Pawłowska Magdalena Tudrujek-Zdunek Beata Lorenc Hanna Berak Ewa Janczewska Włodzimierz Mazur Justyna Janocha-Litwin Jakub Klapaczyński Marek Sitko Dorota Dybowska Anna Parfieniuk-Kowerda Anna Piekarska Jerzy Jaroszewicz Robert Flisiak 《World Journal of Hepatology》 2025年第6期125-138,共14页
BACKGROUND Sex is one of the known factors influencing the risk of hepatitis C virus(HCV)infection and the natural course of the disease.AIM To evaluate sex-related differences in the characteristics and outcomes of d... BACKGROUND Sex is one of the known factors influencing the risk of hepatitis C virus(HCV)infection and the natural course of the disease.AIM To evaluate sex-related differences in the characteristics and outcomes of direct-acting antiviral(DAA)treatment in HCV-infected patients.METHODS The study included consecutive 9457 women and 9529 men,treated with DAA for chronic HCV infection from July 2015 to the end of 2023 whose data were collected in the nationwide multicenter retrospective Epiter-2 project.Women were divided into pre-menopausal(15-44 years),menopausal(45-55 years)and post-menopausal(>55 years)and compared with age-matched men.RESULTS Regardless of age,women had a significantly lower body mass index,prevalence of genotype 3 infection and proportion of cirrhosis compared to men.Psychiatric disorders(except depression),hepatitis B virus and human immunodeficiency virus co-infections,as well as alcohol and drug addiction,were significantly less common in women than in men in all age groups.The sustained virologic response was significantly higher in women compared to men in each age group and amounted to 98.4%and 96.6%,respectively(P<0.001).Independent predictors of treatment failure in women were genotype 3 infection,cirrhosis and postmenopausal age.Mild adverse events were reported significantly more often by women,regardless of age with the highest percentage in the postmenopausal group.CONCLUSION DAA treatment is more effective in women than in men,regardless of age,but in postmenopausal women,the effectiveness is relatively the lowest. 展开更多
关键词 WOMEN Hepatitis C virus Direct-acting antivirals MENOPAUSE Chronic hepatitis C
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XGBoost Based Multiclass NLOS Channels Identification in UWB Indoor Positioning System
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作者 Ammar Fahem Majeed Rashidah Arsat +2 位作者 Muhammad Ariff Baharudin Nurul Mu’azzah Abdul Latiff Abbas Albaidhani 《Computer Systems Science & Engineering》 2025年第1期159-183,共25页
Accurate non-line of sight(NLOS)identification technique in ultra-wideband(UWB)location-based services is critical for applications like drone communication and autonomous navigation.However,current methods using bina... Accurate non-line of sight(NLOS)identification technique in ultra-wideband(UWB)location-based services is critical for applications like drone communication and autonomous navigation.However,current methods using binary classification(LOS/NLOS)oversimplify real-world complexities,with limited generalisation and adaptability to varying indoor environments,thereby reducing the accuracy of positioning.This study proposes an extreme gradient boosting(XGBoost)model to identify multi-class NLOS conditions.We optimise the model using grid search and genetic algorithms.Initially,the grid search approach is used to identify the most favourable values for integer hyperparameters.In order to achieve an optimised model configuration,the genetic algorithm is employed to fine-tune the floating-point hyperparameters.The model evaluations utilise a wide-ranging dataset of real-world measurements obtained with a Qorvo DW1000 UWB device,covering various indoor scenarios.Experimental results show that our proposed XGBoost achieved the highest overall accuracy of 99.47%,precision of 99%,recall of 99%,and an F-score of 99%on an open-source dataset.Additionally,based on a local dataset,the model achieved the highest performance,with an accuracy of 96%,precision of 96%,recall of 97%,and an F-score of 97%.In contrast to current machine learning methods in the literature,the suggestion model enhances classification accuracy and effectively addresses the NLOS/LOS identification as a multiclass propagation channel.This approach provides a robust solution with generalisation and adaptability across various dataset types and environments for more reliable and accurate indoor positioning technologies. 展开更多
关键词 NLOS prediction propagation channels classification optimization indoor localization XGBoost
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Identification and chemical structure elucidation of synthetic cannabinoids samples seized in Kuwait during 2019-2023 using GC-MS and NMR spectroscopy
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作者 Abdullah Al-Matrouk Khaled Y.Orabi 《Forensic Sciences Research》 2025年第2期23-29,共7页
Cannabinoids,a class of chemical compounds,interact with cannabinoid receptors and are categorized into endocannabinoids,phytocannabinoids,and synthetic cannabinoids(SCs)based on their origin.Among these,SCs constitut... Cannabinoids,a class of chemical compounds,interact with cannabinoid receptors and are categorized into endocannabinoids,phytocannabinoids,and synthetic cannabinoids(SCs)based on their origin.Among these,SCs constitute the largest and most structurally diverse group of novel psychoactive substances(NPS),with around 280 compounds identified globally.They exhibit a high binding affinity to cannabinoid receptors CB1 and CB2,which are distributed throughout the central nervous and immune systems,leading to more potent psychoactive and toxic effects compared with their natural counterparts.Various adverse effects associated with SCs include hypothermia,analgesia,catalepsy,psychosis,respiratory depression,cardiac arrest,nephrotoxicity,acute cerebral ischemia,seizures,and mortality.In a previous study,we reported the detection of several NPS in Kuwait using gas chromatography-mass spectrometry and liquid chromatography-tandem mass spectrometry techniques.However,the identification was tentative,highlighting a limitation of these methods.To address this,the current study aimed to fully identify 17 seized SC samples.Thin-layer chromatography was initially employed to assess the purity of the samples.Twelve pure samples(AKM-1–AKM-12)underwent nuclear magnetic resonance analyses,including^(1)H,^(13)C,DEPT 45°,90°,135°,COSY,HSQC,and HMBC experiments.The identities of five samples(AKM-1,5,6,8,10)were confirmed as MDMB-4en-PINACA,one sample(AKM-2)as 4F-MDMB-BUTICA,one sample(AKM-3)as MPHP-2201,and three samples(AKM-4,9,11)as MMB-022.Additionally,two samples(AKM-7,12)were identified as FUB-144.This comprehensive approach enhances the accuracy of SCs identification compared with previous studies,emphasizing the importance of employing nuclear magnetic resonance alongside other spectral methods for a more robust analysis. 展开更多
关键词 synthetic cannabinoids Kuwait nuclear magnetic resonance
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Breastfeeding and chronic HBV infection: Clinical and social implications 被引量:41
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作者 Mihaela Petrova Victor Kamburov 《World Journal of Gastroenterology》 SCIE CAS CSCD 2010年第40期5042-5046,共5页
Mother-to-child transmission of hepatitis B virus (HBV) is among the most important causes of chronic HBV infection and is the commonest mode of transmission worldwide. Currently, the presence of HBsAg, HBeAg and HBV ... Mother-to-child transmission of hepatitis B virus (HBV) is among the most important causes of chronic HBV infection and is the commonest mode of transmission worldwide. Currently, the presence of HBsAg, HBeAg and HBV DNA in breast milk is confirmed. Several studies have reported that breastfeeding carries no additional risk that might lead to vertical transmission. Beyond some limitations, the surveys have not demonstrated any differences in HBV transmission rate regarding feeding practices in early childhood. Promotion of breastfeeding is substantial, especially for low-income individuals and regions with uncertain, unfeasible, and unsafe water supplies. Lactoferrin, minimal inflammation or activation within the infant gut during exclusive breastfeeding, and nonspecific biological molecules in the milk are identified as major factors of breast-milk defense. This review discusses preemptive antiviral therapy during pregnancy and lactation. Long-term follow up of breast-milk HBV concentrations and correlation with serum viral load; nucleos(t)ide analogue concentrations in breast milk in HBV-positive mothers in the setting of chronic HBV infection; safety of antiviral therapy during pregnancy and lactation; and the difference in viral load in the milk in exclusive or non-exclusive breastfeeding are still open questions. The paper reviews the current data and outlines the course of further investigation into this often underestimated issue. 展开更多
关键词 BREASTFEEDING LAMIVUDINE TENOFOVIR Hepatitis B virus Chronic hepatitis B
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Fluid resuscitation in acute pancreatitis: Normal saline or lactated Ringer's solution? 被引量:22
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作者 Michal Lipinski Alicja Rydzewska-Rosolowska +1 位作者 Andrzej Rydzewski Grazyna Rydzewska 《World Journal of Gastroenterology》 SCIE CAS 2015年第31期9367-9372,共6页
AIM: To investigate whether administration of Ringer's solution(RL) could have an impact on the outcome of acute pancreatitis(AP).METHODS: We conducted a retrospective study on 103 patients [68 men and 35 women,me... AIM: To investigate whether administration of Ringer's solution(RL) could have an impact on the outcome of acute pancreatitis(AP).METHODS: We conducted a retrospective study on 103 patients [68 men and 35 women,mean age 51.2 years(range,19-92 years)] hospitalized between 2011 and 2012. All patients admitted to the Department of Gastroenterology of the Central Clinical Hospital of the Ministry of Interior(Poland) with a diagnosis of AP who had disease onset within 48 h of presentation were included in this study. Based on the presence of persistent organ failure(longer than 48 h) as a criterion for the diagnosis of severe AP(SAP) and the presence of local complications [diagnosis of moderately severe AP(MSAP)],patients were classified into 3 groups: mild AP(MAP),MSAP and SAP. Data were compared between the groups in terms of severity(using the revised Atlanta criteria) and outcome. Patients were stratified into 2 groups based on the type of fluid resuscitation: the 1-RL group who underwent standard fluid resuscitation with a RL 1000 m L solution or the 2-NS group who underwent standard fluid resuscitation with 1000 m L normal saline(NS). All patients from both groups received an additional 5% glucose solution(1000-1500 m L) and a multi-electrolyte solution(500-1000 m L).RESULTS: We observed 64(62.1%) patients with MAP,26(25.24%) patients with MSAP and 13(12.62%) patients with SAP. No significant difference in the distribution of AP severity between the two groups was found. In the 1-RL group,we identified 22(55.5%) MAP,10(25.5%) MSAP and 8(20.0%) SAP patients,compared with 42(66.7%) MAP,16(24.4%) MSAP and 5(7.9%) SAP cases in the 2-NS group(P = 0.187). The volumes of fluid administered during the initial 72-h period of hospitalization were similar among the patients from both the 1-RL and 2-NS groups(mean 3400 m L vs 3000 m L,respectively). No significant differences between the 1-RL and 2-NS groups were found in confirmed pancreatic necrosis [10 patients(25%) vs 12 patients(19%),respectively,P = 0.637]. There were no statistically significant differences between the 1-RL and 2-NS groups in the percentage of patients who required enteral nutrition(23 patients vs 17 patients,respectively,P = 0.534). Logistic regression analysis confirmed these findings(OR = 1.344,95%CI: 0.595-3.035,P = 0.477). There were no significant differences between the 1-RL and 2-NS groups in mortality and the duration of hospital stay(median of 9 d for both groups,P = 0.776).CONCLUSION: Our study failed to find any evidence that the administration of RL in the first days of AP leads to improved clinical outcomes. 展开更多
关键词 ACUTE PANCREATITIS Fuid THERAPY Lactated Ringer’s
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Chronic Epstein-Barr virus-related hepatitis in immunocompetent patients 被引量:7
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作者 Mihaela Petrova Maria Muhtarova +4 位作者 Maria Nikolova Svetoslav Magaev Hristo Taskov Diana Nikolovska Zahariy Krastev 《World Journal of Gastroenterology》 SCIE CAS CSCD 2006年第35期5711-5716,共6页
AIM: To investigate reactivated Epstein-Barr virus (EBV) infection as a cause for chronic hepatitis. METHODS: Patients with occasionally established elevated serum aminotransferases were studied. HIV, HBV and HCV-infe... AIM: To investigate reactivated Epstein-Barr virus (EBV) infection as a cause for chronic hepatitis. METHODS: Patients with occasionally established elevated serum aminotransferases were studied. HIV, HBV and HCV-infections were excluded as well as any other immunosuppressive factors, metabolic or toxic disorders. EBV viral capsid antigen (VCA) IgG and IgM, EA-R and EA-D IgG and Epstein-Barr nuclear antigen (EBNA) were measured using IFA kits. Immunophenotyping of whole blood was performed by multicolor flow cytometry. CD8+ T cell responses to EBV and PHA were determined according to the intracellular expression of IFN-γ. RESULTS: The mean alanine aminotransferase (ALT) and gamma glutamyl transpeptidase (GGTP) values exceeded twice the upper normal limit, AST/ALT ratio < 1. Serology tests showed reactivated EBV infection in all patients. Absolute number and percentages of T, B and NK cells were within the reference ranges. Fine subset analysis, in comparison to EBV+ healthy carriers, revealed a significant decrease of naive T cells (P < 0.001), accompanied by increased percentage of CD45RA- (P < 0.0001), and terminally differentiated CD28-CD27- CD8+ T cells (P < 0.01). Moderately elevated numbers of CD38 molecules on CD8+ T cells (P < 0.05) proposed a low viral burden. A significantly increased percentage of CD8+ T cells expressing IFN-γ in response to EBV and PHA stimulation was registered in patients, as compared to controls (P < 0.05). Liver biopsy specimens from 5 patients revealed nonspecific features of low-grade hepatitis.CONCLUSION: Chronic hepatitis might be a manifestation of chronic EBV infection in the lack of detectable immune deficiency; the expansion of CD28- CD27- and increase of functional EBV-specific CD8+ T cells being the only surrogate markers of viral activity. 展开更多
关键词 Chronic hepatitis EPSTEIN-BARR Epstein-Barr virus-specific CD8+ T cell
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A New Statistic Approach towards Landslide Hazard Risk Assessment 被引量:2
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作者 George Gaprindashvili Jianping Guo +2 位作者 Panisara Daorueang Tian Xin Pooyan Rahimy 《International Journal of Geosciences》 2014年第1期38-49,共12页
To quantitatively assess the landslide hazard in Khelvachauri, Georgia, the statistic method of hazard index was applied. A spatial database was constructed in Geographic Information System (GIS) including topographic... To quantitatively assess the landslide hazard in Khelvachauri, Georgia, the statistic method of hazard index was applied. A spatial database was constructed in Geographic Information System (GIS) including topographic data, geologic maps, land-use, and active landslide events (extracted from the landslide inventory). After that, causal factors of landslides (such as slope, aspect, lithology, geomorphology, land-use and soil depth) were produced to calculate the corresponding weights, and thereby we defined a relevant set of spatial criteria for the latter landslide hazard assessment. On top of that, susceptibility assessment was performed in order to classify the area to low, moderate and high susceptible regions. Results showed that NW aspect, mountain geomorphology, private land-use, laterite loam and clay, slope between 19 to 24 degrees, and soil depth between 10 - 20 cm were found to have the largest contribution to high landslide susceptibility. The high success rate (72.35%) was obtained using area under the curve from the landslide susceptibility map. Meanwhile, effect analysis was carried out to assess the accuracy of the landslide susceptibility, indicating that the factor of slope played the most important role in determining the occurring probability of landslide although it did not deviate as much as other factors. Finally, the vulnerability analyses were carried out by means of the Spatial Multi-Criteria Estimation model, which in turn, led to the risk assessment. It turned out that not so much of the number of buildings (~ 34.13%) was associated with high-risk zone and that governmental and private land-use almost accounted for the same risk (39.9% and 40.9%, respectively). 展开更多
关键词 LANDSLIDE WEIGHT SUSCEPTIBILITY VULNERABILITY Statistic
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Oral candidiasis and potential risk factors among disabled and nondisabled in Al-Baha region, Saudi Arabia
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作者 Abdullah Ali H Alzahrani Nagesh Bhat +4 位作者 Pankaj Kukreja Eltayeb Mohammed Alhassan Abdallah Ibrahim A Mudawi Faisal A Alzahrani Mohammad A Albanghali 《World Journal of Clinical Cases》 SCIE 2024年第27期6077-6086,共10页
BACKGROUND Oral candidiasis(OC)is an oral health disease that could influence patients’oral health quality of life.AIM To estimate prevalence of OC among disabled and non-disabled individuals and its potential risk f... BACKGROUND Oral candidiasis(OC)is an oral health disease that could influence patients’oral health quality of life.AIM To estimate prevalence of OC among disabled and non-disabled individuals and its potential risk factors in the Al-Baha region,Saudi Arabia.METHODS An observational cross-sectional study was carried out among 148 disabled and non-disabled participants.The technique of concentrated oral rinse employing the Sabouraud Dextrose Agar medium accompanied with 0.05%chloramphenicol was conducted to assess and isolate candida.Oral examination using the World Health Organization guidelines was conducted to examine participants’oral hea-lth status.A pre-designed questionnaire was also used to evaluate sociodemo-graphic,medical history,and oral hygiene habits of the studied population.RESULTS Out of 148 participants(n=57,38%)had colonized candida.None of the studied population had visible Candida lesions.However,Candida was found in the oral rinses without the subject presenting any lesions or issues caused by Candida(asymptomatic colonization).The most common prevalent OC among participants were Candida albicans,Candida glabrata,Candida dubliniensis,Candida krusei,Candida tropicalis,and Candida parapsilosis(n=35,61%;n=8,14%;n=6,10%;n=5,9%;n=2,4%;and n=1,2%)respectively.Diabetes,smoking,poor plaque,and gingival status were key potential risk factors that significantly associated with candida’s density and presence(P=0.001,P=0.001,P=0.01,and P=0.01)respectively.Disability status had no statistically significant effect on presence and density of Candida.CONCLUSION The prevalence of OC is almost third of the studied population;thus,may provoke a need to develop preventive strategies to reduce the OC rate and establish solid treatment plans. 展开更多
关键词 Oral health CANDIDA Oral candidiasis Dental public health DISABLED DISABILITY Risk factors EPIDEMIOLOGY
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