期刊文献+
共找到1,217篇文章
< 1 2 61 >
每页显示 20 50 100
Lowering ash slagging and fouling tendency of high-alkali coal by hydrothermal pretreatment 被引量:5
1
作者 Mingshun Yang Qiang Xie +3 位作者 Xin Wang He Dong Hao Zhang Chunqi Li 《International Journal of Mining Science and Technology》 SCIE EI CSCD 2019年第3期521-525,共5页
High-alkali species in coal are notorious for causing ash slagging and fouling incidents.In this paper,four high-alkali coals were individually subject to hydrothermal pretreatment(HTP),within a batch-type autoclave a... High-alkali species in coal are notorious for causing ash slagging and fouling incidents.In this paper,four high-alkali coals were individually subject to hydrothermal pretreatment(HTP),within a batch-type autoclave at 300 -C for 1 h,and the treated coals were analyzed,along with the oxygen-containing functional groups determined by Fourier transform infrared spectrometer(FT-IR).Then the alkali species and other components in the coal ash were quantified by X-ray fluorescence(XRF)for evaluating the ash slagging and fouling tendency.Apart from this,FactSage was adopted to simulate the occurrence and transformation of alkali species during coal thermal conversion ending at various temperatures.The findings indicate that the treated coals are superior to the parent ones in terms of certain remarkable changes via HTP.The moisture,oxygen and sulfur of the hydrothermally treated coals decline obviously,while the calorific value rises sharply.HTP could reduce the alkali species to less than 2%(%,by weight,equivalent to Na2O in dry ash),with a maximum removal ratio of 88.9%,lowering the ash slagging and fouling tendency.The proposed mechanism of HTP was that the alkali species in coal matrix became released due to the breakage of the coal functional groups and micropores during HTP. 展开更多
关键词 HYDROTHERMAL PRETREATMENT High-alkali COAL ASH SLAGGING and fouling tendency lowering FactSage
下载PDF
Insulin plus incretin:A glucose-lowering strategy for type 2-diabetes 被引量:5
2
作者 Bo Ahrén 《World Journal of Diabetes》 SCIE CAS 2014年第1期40-51,共12页
There are many advantages of combining incretin therapy[glucagon-like peptide-1(GLP-1)receptor agonists and dipeptidyl peptidase-4(DPP-4)inhibitors]with insulin therapy as a glucose-lowering strategy in type2 diabetes... There are many advantages of combining incretin therapy[glucagon-like peptide-1(GLP-1)receptor agonists and dipeptidyl peptidase-4(DPP-4)inhibitors]with insulin therapy as a glucose-lowering strategy in type2 diabetes.One important advantage is the complementary mode of the mechanistic action of incretin and insulin therapy.Another advantage is the reduction in risk of hypoglycemia and weight gain when adding incretin therapy to insulin.Several clinical trials have studied the addition of GLP-1 receptor agonists[exenatide BID(twice daily),lixisenatide,albiglutide]or DPP-4inhibitors(vildagliptin,sitagliptin,saxagliptin,alogliptin,linagliptin)to ongoing insulin therapy or adding insulin to ongoing therapy with a GLP-1 receptor agonist(liraglutide).These studies show improved glycemia in the presence of limited risk for hypoglycemia and weight gain with the combination of incretin therapy with insulin.This article reviews the background and clinical studies on this combination. 展开更多
关键词 TYPE 2 DIABETES Glucose lowering INSULIN THERAPY Glucagon-like peptide-1 receptor agonists Di-peptidyl peptidase-4 inhibitors INCRETIN THERAPY Combination
下载PDF
Total-Ionizing-Dose-Induced Body Current Lowering in the 130 nm PDSOI I/O NMOSFETs
3
作者 刘小年 戴丽华 +1 位作者 宁冰旭 邹世昌 《Chinese Physics Letters》 SCIE CAS CSCD 2017年第1期90-93,共4页
The body current lowering effect of 130 nm partially depleted silicon-on-insulator(PDSOI) input/output(I/O)n-type metal-oxide-semiconductor field-effect transistors(NMOSFETs) induced by total-ionizing dose is observed... The body current lowering effect of 130 nm partially depleted silicon-on-insulator(PDSOI) input/output(I/O)n-type metal-oxide-semiconductor field-effect transistors(NMOSFETs) induced by total-ionizing dose is observed and analyzed. The decay tendency of current ratio of body current and drain current I_b/I_d is also investigated.Theoretical analysis and TCAD simulation results indicate that the physical mechanism of body current lowering effect is the reduction of maximum lateral electric field of the pinch-off region induced by the trapped charges in the buried oxide layer(BOX). The positive charges in the BOX layer can counteract the maximum lateral electric field to some extent. 展开更多
关键词 Total-Ionizing-Dose-Induced BODY Current lowering the 130 nm PDSOI I/O NMOSFETS
原文传递
Agglomeration Mechanism of Rich Hematite Sinter with Lowering SiO_2 Content
4
《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2000年第4期256-260,共5页
关键词 SIO RICH Agglomeration Mechanism of Rich Hematite Sinter with lowering SiO2 Content
下载PDF
Study on Response Surface Methodology Optimization for Extraction Process of Cyclocarya paliurus Extract and Its Blood Sugar-lowering Effect
5
作者 Yufeng LI Xiayun LIAO +1 位作者 Gang WANG Lichun ZHAO 《Agricultural Biotechnology》 CAS 2020年第5期127-133,共7页
[Objectives]This study was conducted to discuss the mechanism of the blood sugar-lowering effect of Cyclocarya paliurus extract.[Methods]With C.paliurus leaves as the raw material,the ethyl acetate-butyl acetate micro... [Objectives]This study was conducted to discuss the mechanism of the blood sugar-lowering effect of Cyclocarya paliurus extract.[Methods]With C.paliurus leaves as the raw material,the ethyl acetate-butyl acetate microwave extraction process of C.paliurus was studied.With the yield of C.paliurus extract as an evaluation index,single-factor experiments were carried out on such 6 factors as the dry C.paliurus leaf powder size,solid-to-liquid ratio,extraction time,microwave frequency,microwave power,and microwave extraction time,and the extraction and purification process was further optimized by response surface analysis.The normal mice and the hyperglycemic mice modeled by alloxan were injected with C.paliurus extract to study the blood sugar-lowering effects of different groups of C.paliurus extract.[Results]The optimal process combination for the extraction of C.paliurus leaves was obtained:dry C.paliurus powder size 90-100 mesh,solid-to-liquid ratio 1∶20(g/ml),extraction time 192 min,microwave frequency 2500 MHz,microwave power 490 W,and extraction time 248 s.Under these conditions,the yield of C.paliurus extract reached the maximum,95.10%,reaching 99.83%of the predicted value.The blood sugar-lowering test on mice showed that the C.paliurus extract had a good effect on lowering blood sugar,indicating that C.paliurus extract can improve the free radical scavenging capacity to a certain extent.[Conclusions]This study provides certain reference for the in-depth study of the physiological effects of C.paliurus extract and the comprehensive development and utilization of C.paliurus extract. 展开更多
关键词 Cyclocarya paliurus C.paliurus extract YIELD Blood sugar lowering Radical scavenging
下载PDF
Multi-Scale Organization of the Doumbouo-FokouéBauxites Ore Deposits (West Cameroon): Implication to the Landscape Lowering
6
作者 Momo Nouazi Mathieu Tematio Paul Yemefack Martin 《Open Journal of Geology》 2012年第1期14-24,共11页
Landscape distribution, macroscopic, microscopic, mineral and geochemical characterizations were conducted on the Doumbouo-Fokoué bauxite ore deposit in order to estimate bauxites potential and its implication to... Landscape distribution, macroscopic, microscopic, mineral and geochemical characterizations were conducted on the Doumbouo-Fokoué bauxite ore deposit in order to estimate bauxites potential and its implication to general lowering of the relief. Fourteen bauxitic plateaus covering a surface area of 5.7 km2 were identified. Bauxitic pedons show deep weathered profiles (10.0 - 12.0 m) with thick bauxitic mantle (4.0 - 8.0 m). Saprolite and pisolith bauxitic facies own high aluminium (47.5% - 49.5% Al2O3), relatively low iron (20.0% - 22.0% Fe2O3) and low silica contents (1.8% - 7.6% SiO2). Gibbsite is the dominant mineral (49% - 68% of minerals detected by X-ray);meanwhile hematite, goethite and kaolinite occur in small amounts. Bauxitization corresponds to intense allitization with abundant accumulation of gibbsite and development of lateritic iron bearing ortho-bauxites. Bauxite ores yielded bauxite reserves of 9.2 million tons. They occur as old and residual bauxitic mantles representing remnants of the Miocene residual lateritic deposits in West Cameroon referring to the African surface of Valeton [1]. Its mean altitude (1532 - 1590 m als) below the African surface reveals general lowering of the relief. 展开更多
关键词 Bauxitic PLATEAUS SAPROLITE FACIES Pisolith FACIES RELIEF lowering West Cameroon
下载PDF
Effect of lipid lowering mixture on blood lipid metabolism, LDL oxidation susceptibility and blood viscosity and coagulation in experimental hyperlipidemia rats
7
作者 Xue-Bing Luan Fu-Chen Zhang +2 位作者 Zhi-Yuan Weng Yu Zhang Liang Ma 《Journal of Hainan Medical University》 2019年第4期17-20,共4页
Objective:To investigate the effect of lipid lowering mixture on blood lipid metabolism, LDL oxidative susceptibility and blood viscosity and coagulation in experimental hyperlipidemia rats.Method: Select 60 male Wist... Objective:To investigate the effect of lipid lowering mixture on blood lipid metabolism, LDL oxidative susceptibility and blood viscosity and coagulation in experimental hyperlipidemia rats.Method: Select 60 male Wistar rats were randomly divided into six groups, ten rats in each group were recorded as low as lipid-lowering mixture, high dose group and simvastatin group, model group and control group. Patients in control group were treated with basic feed for feeding, other groups of rats are used high fat diet were fed to establish hyperlipidemia rat model, in the process of modeling and prophylactically, determination of rats after 10 weeks of lipid metabolism and susceptibility of LDL to oxidation and blood viscosity concentration coagulation state.Result: Antioxidant capacity of the model group rat's serum LDL-C decreased significantly, and simvastatin group and three groups of lipid-lowering mixture group rats serum LDL antioxidant capacity were significantly enhanced;and high lipid mixture, LDL antioxidant ability in middle dose group rats were significantly higher than those of the Jiangzhi Decoction low dose group rats (P<0.05). Lipid mixture of high, middle dose group rats of EET and ETA P, ETA B (high, medium and low shear), IED, HCT, the role of the IEA was significantly higher in Jiangzhi Decoction low dose group rats (P<0.05 or P<0.05).Conclusion:Lipid-lowering mixture on experimental hyperlipidemia rats blood lipid metabolism and blood viscosity concentration coagulation state has a good regulatory role, and lipid-lowering mixture on blood lipid and blood flow abnormalities lipid-lowering mixture can also play a good regulation and therapeutic effect. 展开更多
关键词 HYPERLIPEMIA LIPID lowering MIXTURE BLOOD LIPID METABOLISM BLOOD COAGULATION state LIPID carrier protein
下载PDF
Lowering of the piezometric level of ground waters caused by their irrational exploitation
8
《Global Geology》 1998年第1期114-114,共1页
关键词 lowering of the piezometric level of ground waters caused by their irrational exploitation
下载PDF
The concept of gene therapy for glaucoma:the dream that has not come true yet
9
作者 Robert Sulak Xiaonan Liu Adrian Smedowski 《Neural Regeneration Research》 SCIE CAS CSCD 2024年第1期92-99,共8页
Gene therapies,despite of being a relatively new therapeutic approach,have a potential to become an important alternative to current treatment strategies in glaucoma.Since glaucoma is not considered a single gene dise... Gene therapies,despite of being a relatively new therapeutic approach,have a potential to become an important alternative to current treatment strategies in glaucoma.Since glaucoma is not considered a single gene disease,the identified goals of gene therapy would be rather to provide neuroprotection of retinal ganglion cells,especially,in intraocular-pressure-independent manner.The most commonly reported type of vector for gene delivery in glaucoma studies is adeno-associated virus serotype 2 that has a high tro pism to retinal ganglion cells,res ulting in long-term expression and low immunogenic profile.The gene thera py studies recruit inducible and genetic animal models of optic neuropathy,like DBA/2J mice model of high-tension glaucoma and the optic nerve crush-model.Reported gene therapy-based neuroprotection of retinal ganglion cells is targeting specific genes translating to growth factors(i.e.,brain derived neurotrophic factor,and its receptor TrkB),regulation of apoptosis and neurodegeneration(i.e.,Bcl-xl,Xiap,FAS system,nicotinamide mononucleotide adenylyl transferase 2,Digit3 and Sarm1),immunomodulation(i.e.,Crry,C3 complement),modulation of neuroinflammation(i.e.,e rythropoietin),reduction of excitotoxicity(i.e.,Com KIlα)and transcription regulation(i.e.,Max,Nrf2).On the other hand,some of gene therapy studies focus on lowering intra ocular pressure,by impacting genes involved in both,decreasing aqueous humor production(i.e.,aquaporin 1),and increasing outflow facility(i.e.,COX2,prostaglandin F2a receptor,RhoA/RhoA kinase signaling pathway,MMP1,Myocilin).The goal of this review is to summarize the current stateof-art and the direction of development of gene therapy strategies for glaucomatous neuropathy. 展开更多
关键词 adeno-associated virus gene editing gene therapy GLAUCOMA IOP lowering IOP-independent mechanisms neuroprotection optic nerve optic neuropathy retinal ganglion cells
下载PDF
Lowering the energy consumption in silicon photonic devices and systems [Invited] 被引量:11
10
作者 Zhiping Zhou Bing Yin +2 位作者 Qingzhong Deng Xinbai Li Jishi Cui 《Photonics Research》 SCIE EI 2015年第5期28-46,共19页
We review current silicon photonic devices and their performance in connection with energy consumption.Four critical issues are identified to lower energy consumption in devices and systems: reducing the influence of ... We review current silicon photonic devices and their performance in connection with energy consumption.Four critical issues are identified to lower energy consumption in devices and systems: reducing the influence of the thermo-optic effect, increasing the wall-plug efficiency of lasers on silicon, optimizing energy performance of modulators, and enhancing the sensitivity of photodetectors. Major conclusions are(1) Mach–Zehnder interferometer-based devices can achieve athermal performance without any extra energy consumption while microrings do not have an efficient passive athermal solution;(2) while direct bonded III–V-based Si lasers can meet system power requirement for now, hetero-epitaxial grown III–V quantum dot lasers are competitive and may be a better option for the future;(3) resonant modulators, especially coupling modulators, are promising for low-energy consumption operation even when the power to stabilize their operation is included;(4) benefiting from high sensitivity and low cost, Ge/Si avalanche photodiode is the most promising photodetector and can be used to effectively reduce the optical link power budget. These analyses and solutions will contribute to further lowering energy consumption to meet aggressive energy demands in future systems. 展开更多
关键词 Invited lowering the energy consumption in silicon photonic devices and systems MZI
原文传递
Four kinds of raising and lowering operators of n-dimensional hydrogen atom and isotropic harmonic oscillator 被引量:1
11
作者 刘宇峰 曾谨言 《Science China Mathematics》 SCIE 1997年第10期1110-1115,共6页
The factorization of the radial Schrodinger equation of n-dimensional (n≥2) hydrogen atoms and isotropic harmonic oscillators was investigated and four kinds of raising and lowering operators were derived.The relatio... The factorization of the radial Schrodinger equation of n-dimensional (n≥2) hydrogen atoms and isotropic harmonic oscillators was investigated and four kinds of raising and lowering operators were derived.The relation between n -dimensional (n≥2) and one-dimensional hydrogen atoms and harmonic oscillators was discussed. 展开更多
关键词 n-dimensional hydrogen atom and ISOTROPIC harmonic oscillator factorization FOUR kinds of raising and lowering operators.
原文传递
Key chemical composition of walnut(Juglans regia.L)Oils generated with different processing methods and their cholesterol-lowering effects in HepG2 cells 被引量:1
12
作者 Pan Gao Ruijie Liu +1 位作者 Qingzhe Jin Xingguo Wang 《Food Bioscience》 SCIE 2022年第1期96-104,共9页
We systematically evaluated fatty acids and triacylglycerol composition,as well as tocopherol,phytosterol,and phenolics,in walnut oil and compared the cholesterol-lowering effects of oil processed with different metho... We systematically evaluated fatty acids and triacylglycerol composition,as well as tocopherol,phytosterol,and phenolics,in walnut oil and compared the cholesterol-lowering effects of oil processed with different methods(cold pressing,roast-pressing,hexane extraction,subcritical butane extraction,and supercritical CO_(2) extraction).The different methods did not affect the lipid composition of walnut oil.The tocopherol(41.11 mg/100 g)and total phenolic content(TPC,4.26 mg/100 g)of roast-pressed walnut oil and the phytosterol contents of subcritical butane-extracted walnut oil(106.51 mg/100 g)were higher than those of other tested oils.Walnut oil significantly decreased cholesterol synthesis by downregulating the expression of HMGCR,SREBP-2,and CYP51 genes,and increased cholesterol efflux by upregulating the expression of ABCG1,thus significantly reducing total cholesterol and triacylglycerol.Phytosterols and TPC in walnut oil were responsible for lowering cholesterol;the optimal concentration of phytosterols was 10μg/mL,and that of TPC was 12.5×10^(-3)μg/mL.Through process optimization,a new processing method for walnut oil based on biological evaluation was preliminarily established. 展开更多
关键词 Walnut oil Processing method Cholesterol lowering PHENOLIC Phytosterols Juglans regia L
原文传递
Early-diverging Titanosauriform(Dinosauria,Sauropoda)Teeth from the Lower Cretaceous Yixian Formation of Southeastern Inner Mongolia,Northeast China
13
作者 ZHANG Honggang YIN Yalei +1 位作者 PEI Rui ZHOU Changfu 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2024年第2期303-310,共8页
Three eusauropod teeth(SDUST-V1064,PMOL-AD00176,PMOL-ADt0005)are reported from the Lower Cretaceous Yixian Formation of Ningcheng,southeastern Inner Mongolia,China.Two of them(SDUST-V1064,PMOL-AD00176)are assigned to ... Three eusauropod teeth(SDUST-V1064,PMOL-AD00176,PMOL-ADt0005)are reported from the Lower Cretaceous Yixian Formation of Ningcheng,southeastern Inner Mongolia,China.Two of them(SDUST-V1064,PMOL-AD00176)are assigned to early-diverging titanosauriforms in having slightly mesiodistal expansion at the base of the tooth crown,a slenderness index value>2.0 and<4.0,and D-shaped cross section.Furthermore,SDUST-V1064 and PMOL-AD00176 are referred as an Euhelopus-like titanosauriform on the basis of having a sub-circular boss on the lingual surface and an asymmetrical crown-root margin which slants apically,respectively.CT scan data of SDUST-V1064 reveals new dental information of early-diverging titanosauriforms,for example,the enamel on the labial side thicker than that on the lingual side,an enamel/dentine ratio of 0.26 and a boss present on the lingual side of the dentine of the crown. 展开更多
关键词 teeth Titanosauriformes Lower Cretaceous Yixian Formation Ningcheng
下载PDF
Organic Matter Accumulation in the Upper Permian Dalong Formation from the Lower Yangtze Region,South China
14
作者 FANG Chaogang ZHANG Chengcheng +5 位作者 MENG Guixi XU Jinlong XU Naicen LI Hualing LIU Mu LIU Bo 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2024年第1期150-167,共18页
The Late Permian was marked by a series of important geological events and widespread organic-rich black shale depositions,acting as important unconventional hydrocarbon source rocks.However,the mechanism of organic m... The Late Permian was marked by a series of important geological events and widespread organic-rich black shale depositions,acting as important unconventional hydrocarbon source rocks.However,the mechanism of organic matter(OM)enrichment throughout this period is still controversial.Based on geochemical data,the marine redox conditions,paleogeographic and hydrographic environment,primary productivity,volcanism,and terrigenous input during the Late Permian in the Lower Yangtze region have been studied from the Putaoling section,Chaohu,to provide new insights into OM accumulation.Five Phases are distinguished based on the TOC and environmental variations.In Phase I,anoxic conditions driven by water restriction enhanced OM preservation.In Phase II,euxinic and cycling hydrological environments were the two most substantial controlling factors for the massive OM deposition.During Phase III,intensified terrestrial input potentially diluted the OM in sediment and the presence of oxygen in bottom water weakened the preservation condition.Phase IV was characterized by a relatively higher abundance of mercury(Hg)and TOC(peak at 16.98 wt%),indicating that enhanced volcanism potentially stimulated higher productivity and a euxinic environment.In Phase V,extremely lean OM was preserved as a result of terrestrial dilutions and decreasing primary productivity.Phases I,II and IV are characterized as the most prominent OM-rich zones due to the effective interactions of the controlling factors,namely paleogeographic,hydrographic environment,volcanism,and redox conditions. 展开更多
关键词 GEOCHEMISTRY redox condition primary productivity OM accumulation Lopingian/Changhsingian Lower Yangtze region
下载PDF
Tailoring MXene Thickness and Functionalization for Enhanced Room‑Temperature Trace NO_(2) Sensing
15
作者 Muhammad Hilal Woochul Yang +1 位作者 Yongha Hwang Wanfeng Xie 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第5期71-86,共16页
In this study,precise control over the thickness and termination of Ti3C2TX MXene flakes is achieved to enhance their electrical properties,environmental stability,and gas-sensing performance.Utilizing a hybrid method... In this study,precise control over the thickness and termination of Ti3C2TX MXene flakes is achieved to enhance their electrical properties,environmental stability,and gas-sensing performance.Utilizing a hybrid method involving high-pressure processing,stirring,and immiscible solutions,sub-100 nm MXene flake thickness is achieved within the MXene film on the Si-wafer.Functionalization control is achieved by defunctionalizing MXene at 650℃ under vacuum and H2 gas in a CVD furnace,followed by refunctionalization with iodine and bromine vaporization from a bubbler attached to the CVD.Notably,the introduction of iodine,which has a larger atomic size,lower electronegativity,reduce shielding effect,and lower hydrophilicity(contact angle:99°),profoundly affecting MXene.It improves the surface area(36.2 cm^(2) g^(-1)),oxidation stability in aqueous/ambient environments(21 days/80 days),and film conductivity(749 S m^(-1)).Additionally,it significantly enhances the gas-sensing performance,including the sensitivity(0.1119Ωppm^(-1)),response(0.2% and 23%to 50 ppb and 200 ppm NO_(2)),and response/recovery times(90/100 s).The reduced shielding effect of the–I-terminals and the metallic characteristics of MXene enhance the selectivity of I-MXene toward NO2.This approach paves the way for the development of stable and high-performance gas-sensing two-dimensional materials with promising prospects for future studies. 展开更多
关键词 Controlled MXene thickness Gaseous functionalization approach Lower electronegativity functional groups Enhanced MXene stability Trace NO_(2)sensing
下载PDF
Appendiceal bleeding caused by vascular malformation: A case report
16
作者 Qin Ma Jin-Jie Du 《World Journal of Clinical Cases》 SCIE 2024年第14期2457-2462,共6页
BACKGROUND Acute lower gastrointestinal bleeding(LGIB)is a common occurrence in clinical practice.However,appendiceal bleeding is an extremely rare condition that can easily be overlooked and misdiagnosed.The preopera... BACKGROUND Acute lower gastrointestinal bleeding(LGIB)is a common occurrence in clinical practice.However,appendiceal bleeding is an extremely rare condition that can easily be overlooked and misdiagnosed.The preoperative detection of appen-diceal bleeding often poses challenges due to the lack of related guidelines and consensus,resulting in controversial treatment approaches.CASE SUMMARY We presented a case of a 33-year-old female who complained of hematochezia that had lasted for 1 d.Colonoscopy revealed continuous bleeding in the appen-diceal orifice.A laparoscopic appendectomy was performed immediately,and a pulsating blood vessel was observed in the mesangium of the appendix,accor-dingly,active bleeding into the appendicular lumen was considered.Pathological examination revealed numerous hyperplastic vessels in the appendiceal mucosa and dilated capillary vessels.CONCLUSION The preoperative detection of appendiceal bleeding is often challenging,colo-noscopy is extremely important,bowel preparation is not routinely recommend-ed for patients with acute LGIB or only low-dose bowel preparation is recom-mended.Laparoscopic appendectomy is the most appropriate treatment for appendiceal bleeding. 展开更多
关键词 Lower gastrointestinal bleeding Appendiceal bleeding COLONOSCOPY Vas-cular malformation Laparoscopic appendectomy Case report
下载PDF
The dawn−dusk asymmetry in mesosphere and lower thermosphere temperature disturbances during geomagnetic storms at high latitude
17
作者 GuanChun Wei JianYong Lu +2 位作者 Fen Tang JingYuan Li Meng Sun 《Earth and Planetary Physics》 EI CAS CSCD 2024年第2期356-367,共12页
Utilizing observations by the Sounding of the Atmosphere using Broadband Emission Radiometry(SABER)instrument,we quantitatively assessed the dawn-dusk asymmetry in temperature disturbances within the high-latitude mes... Utilizing observations by the Sounding of the Atmosphere using Broadband Emission Radiometry(SABER)instrument,we quantitatively assessed the dawn-dusk asymmetry in temperature disturbances within the high-latitude mesosphere and lower thermosphere(MLT)during the main phase of geomagnetic storms in this study.An analysis of five geomagnetic superstorm events indicated that during the main phase,negative temperature disturbances were more prevalent on the dawn side than on the dusk side in the high-latitude MLT region.Results of a statistical analysis of 54 geomagnetic storm events also revealed a notable disparity in temperature disturbances between the dawn and dusk sides.At high latitudes,38.2%of the observational points on the dawn side exhibited negative temperature disturbances(less than−5 K),whereas on the dusk side,this percentage was only 29.5%.In contrast,at mid-latitudes,these proportions were 34.1%and 36.5%,respectively,showing no significant difference.We also conducted a statistical analysis of temperature disturbances at different altitudes,which revealed an increase in the proportion of warming disturbances with altitude.Conversely,the proportion of cooling disturbances initially rose with altitude,reaching a peak around 105 km,and subsequently decreased.These temperature disturbance differences could be explained by the day-night asymmetry in vertical wind disturbances during storm conditions. 展开更多
关键词 DAWN dusk asymmetry SABER(Sounding of the Atmosphere using Broadband Emission Radiometry) geomagnetic storms mesosphere and lower thermosphere
下载PDF
Optimization of Generator Based on Gaussian Process Regression Model with Conditional Likelihood Lower Bound Search
18
作者 Xiao Liu Pingting Lin +2 位作者 Fan Bu Shaoling Zhuang Shoudao Huang 《CES Transactions on Electrical Machines and Systems》 EI CSCD 2024年第1期32-42,共11页
The noise that comes from finite element simulation often causes the model to fall into the local optimal solution and over fitting during optimization of generator.Thus,this paper proposes a Gaussian Process Regressi... The noise that comes from finite element simulation often causes the model to fall into the local optimal solution and over fitting during optimization of generator.Thus,this paper proposes a Gaussian Process Regression(GPR)model based on Conditional Likelihood Lower Bound Search(CLLBS)to optimize the design of the generator,which can filter the noise in the data and search for global optimization by combining the Conditional Likelihood Lower Bound Search method.Taking the efficiency optimization of 15 kW Permanent Magnet Synchronous Motor as an example.Firstly,this method uses the elementary effect analysis to choose the sensitive variables,combining the evolutionary algorithm to design the super Latin cube sampling plan;Then the generator-converter system is simulated by establishing a co-simulation platform to obtain data.A Gaussian process regression model combing the method of the conditional likelihood lower bound search is established,which combined the chi-square test to optimize the accuracy of the model globally.Secondly,after the model reaches the accuracy,the Pareto frontier is obtained through the NSGA-II algorithm by considering the maximum output torque as a constraint.Last,the constrained optimization is transformed into an unconstrained optimizing problem by introducing maximum constrained improvement expectation(CEI)optimization method based on the re-interpolation model,which cross-validated the optimization results of the Gaussian process regression model.The above method increase the efficiency of generator by 0.76%and 0.5%respectively;And this method can be used for rapid modeling and multi-objective optimization of generator systems. 展开更多
关键词 Generator optimization Gaussian Process Regression(GPR) Conditional Likelihood Lower Bound Search(CLLBS) Constraint improvement expectation(CEI) Finite element calculation
下载PDF
Effect of ankle versus thigh tourniquets on post-operative pain in foot and ankle surgery
19
作者 Ashish Mishra Ahmed Barakat +5 位作者 Jitendra Mangwani Jakub Kazda Sagar Tiwatane Sana Mohammed Aamir Shaikh Linzy Houchen-Wolloff Vipul Kaushik 《World Journal of Orthopedics》 2024年第2期163-169,共7页
BACKGROUND Tourniquets are commonly used in elective extremity orthopaedic surgery to reduce blood loss,improve visualization in the surgical field,and to potentially reduce surgical time.There is a lack of consensus ... BACKGROUND Tourniquets are commonly used in elective extremity orthopaedic surgery to reduce blood loss,improve visualization in the surgical field,and to potentially reduce surgical time.There is a lack of consensus in existing guidelines regarding the optimal tourniquet pressure,placement site,and duration of use.There is a paucity of data on the relationship between the site of a tourniquet and postoperative pain in foot and ankle surgery.AIM To explore the relationship between tourniquet site and intensity of post-operative pain scores in patients undergoing elective foot and ankle surgery.METHODS Retrospective analysis of prospectively collected data on 201 patients who underwent foot and ankle surgery in a single institution was undertaken.Intraoperative tourniquet duration,tourniquet pressure and site,and postoperative pain scores using Visual Analogue Score were collected in immediate recovery,at six hours and at 24 h post-op.Scatter plots were used to analyse the data and to assess for the statistical correlation between tourniquet pressure,duration,site,and pain scores using Pearson correlation coefficient.RESULTS All patients who underwent foot and ankle surgery had tourniquet pressure of 250 mmHg for ankle tourniquet and 300 mmHg for thigh.There was no correlation between the site of the tourniquet and pain scores in recovery,at six hours and after 24 h.There was a weak correlation between tourniquet time and Visual Analogue Score immediately post-op(r=0.14,P=0.04)but not at six or 24 h post-operatively.CONCLUSION This study shows that there was no statistically significant correlation between tourniquet pressure,site and postop pain in patients undergoing foot and ankle surgery.The choice of using a tourniquet is based on the surgeon's preference,with the goal of minimizing the duration of its application at the operative site. 展开更多
关键词 Lower limb surgery Tourniquet time Tourniquet pressure Tourniquet site Post-operative pain Pain scores
下载PDF
Emphysematous Cystitis: Report of Two Cases and Review of the Literature
20
作者 Roland Bertile Banga-Mouss Nestor Ghislain Andzouana Mbamognoua +7 位作者 Yanick Dimi Nyanga Armel Melvin Atipo Ondongo Steve Aristid Ondziel-Opara Raïssa Laure Mayanda Ohouanda Nick Arnaud Monabeka Evariste Bouenizabila Anani Séverin Wences Odzébé Prosper Alain Bouya 《Health》 2024年第4期309-318,共10页
Emphysematous cystitis is a rare complication of lower urinary tract infection whose prognosis is conditioned by the delay in treatment. The predisposition of diabetic patients to urinary infections caused by gas-prod... Emphysematous cystitis is a rare complication of lower urinary tract infection whose prognosis is conditioned by the delay in treatment. The predisposition of diabetic patients to urinary infections caused by gas-producing bacteria is considered one of the most common factors in the occurrence of emphysematous cystitis. The currently recommended diagnostic test is CT scanning, which has definite value in assessing gas accumulation in the bladder wall and lumen. The authors report the observations of two patients aged 68 and 80 who were treated for emphysematous cystitis complicating diabetes mellitus. The evolution was favorable under treatment with antibiotic therapy, insulin therapy and bladder drainage. 展开更多
关键词 Emphysematous Cystitis Computed Tomography Lower Urinary Tract Infection Diabetes Mellitus
下载PDF
上一页 1 2 61 下一页 到第
使用帮助 返回顶部