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Modelling and mathematical results arising from ferromagnetic problems

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Science China Mathematics 2012年第5期55卷 1053-1067页

作者： DESCLOUX jean FLUECK Michel RAPPAZ Jacques Department of Mathematics Ecole Polytechnique Fdrale de Lausanne (EPFL)Lausanne 1015Switzerland

Abstract in this article, we investigate the equations of magnetostaties for a configuration where a ferromagnetic material occupies a bounded domain and is surrounded by vacuum. Furthermore, the ferromagnetic law takes the form B=μ0μr（｜H｜）Hi i.e., the magnetizing field H and the magnetic induction B are collinear, but the relative permeability μr is allowed to depend on the modulus of H. We prove the well-posedness of the magnetostatic problem under suitable convexity assumptions, and the convergence of several iterative methods, both for the original problem set in the Beppo-Levi space W1（R3）, and for a finite-dimensional approximation. The theoretical results are illustrated by numerical examples, which capture the known physical phenomena.

关键词： ferromagnetism nonlinear elliptic problems finite element methods optimisation algorithms

Determinants of invasive strategy in elderly patients with non-ST elevation myocardial infarction

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Journal of Geriatric Cardiology 2017年第7期14卷 465-472页

作者： Antonin Negers Jacques Boddaert Lucie Mora jean-Louis Golmard Laura Moisi Ariel Cohen jean-phi.i.pe Collet Alice Breining Acute Geriatric Care Unit Saint-Antoine University Hospital Paris France Department of Geriatrics Pitie-Salpetriere University Hospital Paris France Department of Biostatistics Pitie-Salpetriere University Hospital Paris France Department of Cardiology Saint-Antoine University Hospital Paris France Department of Cardiology Pitie-Salpetrere University Hospital Paris France Department of Geriatrics Charles Foix University Hospital Paris France

Background Knowledge gaps across literature prevent current guidelines from providing the profile of elderly patients most likely to derive benefit fi^om invasive strategy （iS） in non ST-elevation myocardial infarction （NSTEMi）. Furthermore, the benefit of iS in a real-world elderly population with NSTEMi remains unclear. The aims of this study were to determine factors that lead the cardiologist to opt for an iS in elderly patients with NSTEMi, and to assess the impact of iS on the 6-month all-cause mortality. Methods This multicenter prospective study enrolled all consecutive patients aged 〉 75 years old who presented a NSTEMi and were hospitalized in cardiology intensive care unit between February 2014 and February 2015. Patients were compared on the basis of reperfusion strategy （invasive or conservative） and living status at six months, in order to determine multivariate predictors of the realization of an iS and multivariate predictors of 6-month mor- tality. Results A total of 141 patients were included; 87 （62%） underwent an iS. The strongest independent determinants of iS were younger age [odds ratio （OR）： 0.85, 95%-confidence interval （Ci）： 0.78-0.92; P 〈 0.001） and lower ＂Cumulative illness Rating Scale-Geriatric＂ number of categories score （OR： 0.83, 95%Ci： 0.73-0.95; P = 0.002）. iS was not significantly associated with 6-month survival （OR： 0.80, 95%Ci： 0.27-2.38; P = 0.69）. Conclusions in real-world elderly patients with NSTEMi, younger patients with fewer comorbidities profited more often from an iS. However, iS did not modify 6-month all-cause mortality.

关键词： Comorbidity Coronary angiography Decision making Mortality Myocardial infarction

Second-Order invariant Domain Preserving ALE Approximation of Euler Equations

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Communications on Applied Mathematics and Computation 2023年第2期5卷 923-945页

作者： jean-Luc Guermond Bojan Popov Laura Saavedra Department of Mathematics Texas A&M UniversityCollege StationUSA Departamento de Matemática Aplicada a la ingeniería Aeroespacial Universidad Politécnica de MadridMadridSpain

An invariant domain preserving arbitrary Lagrangian-Eulerian method for solving non-linear hyperbolic systems is *** numerical scheme is explicit in time and the approximation in space is done with continuous finite *** method is made invar-iant domain preserving for the Euler equations using convex limiting and is tested on vari-ous benchmarks.

关键词： Conservation equations Hyperbolic systems Arbitrary Lagrangian-Eulerian Moving meshes invariant domains High-order method Convex limiting Finite element method

Evaluation of remediation process with soapberry derived saponin for removal of heavy metals from contaminated soils in Hai-Pu, Taiwan

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Journal of Environmental Sciences 2013年第6期25卷 1180-1185页

作者： Jyoti Prakash Maity Yuh Ming Huang Cheng-Wei Fan Chien-Cheng Chen Chun-Yi Li Chun-Mei Hsu Young-Fo Chang Ching-i Wu Chen-Yen Chen Jiin-Shuh jean Department of Earth and Environmental Sciences "National" Chung Cheng University 168University Rd. Department of Soil Environmental Science "National" Chung-Hsing University Department of Biotechnology "National" Kaohsiung Normal University Graduate School of Landscape "National" Chin-Yi University of Technology Department of Earth sciences "National" Cheng Kung University

The use of a biodegradable natural plant-based surfactant extracted from soapberry is proposed for the remediation of Ni, Cr and Mn from industrial soil site in Hai-Pu, Taiwan. Batch experiments were performed under variation of fundamental factors （saponin concentration, pH, and incubation time） for metal remediation. Removal of Ni and Mn were increased with increasing saponin concentration （0.015-0.150 g/L）, whereas the removal of Cr was increased upto 0.075 g/L saponin. The Ni, Cr and Mn were removed significantly （p 〈 0.05） at near to the neutral and slightly acidic （pH 5 to 8） conditions. Removal efficiency of Ni （99%） from the soil was found to be greater than that of Cr （73%） or Mn （25%） in the presence of saponin at a concentration of 0.150 g/L at pH 5. The removal percentage increased with incubation time where the removal of Ni was faster than that of Cr and Mn. The result indicates the feasibility of cco-friendly removal of heavy metal （Ni, Cr and Mn） from industrial soil by soil washing process in presence of plant derived saponin.

关键词： heavy metal remediation contaminated soil soapberry

Accurate surface potential determination in Schottky diodes by the use of a correlated current and capacitance voltage *** to n-inP

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Journal of Semiconductors 2011年第10期32卷 39-43页

作者： Ali Ahaitouf Abdelaziz Ahaitouf jean Paul Salvestrini Hussein Srour Laboratoire Signaux Systemes et Composants DGE Faculty of Sciences and TechnologyUniversite Sidi Mohammed Ben AbdellahP.O.Box 2202FES Morocco LiMAO Faculte polydisciplinaire de Taza Universite Sidi Mohammed Ben Abdellah de FesBP 1223 Taza-GareMorocco Laboratoire Materiaux Optiques Photonique et SystemesEA 4423Universite Paul Verlaine-MetzSupelec2 rue E.Belin57070 MetzFrance

Based on current voltage（i-Vg） and capacitance voltage（C-Vg） measurements,a reliable procedure is proposed to determine the effective surface potential Vd（Vg） in Schottky *** the framework of thermionic emission,our analysis includes both the effect of the series resistance and the ideality factor,even voltage dependent. This technique is applied to n-type indium phosphide（n-inP） Schottky diodes with and without an interfacial layer and allows us to provide an interpretation of the observed peak on the C-Vg *** study clearly shows that the depletion width and the flat band barrier height deduced from C-Vg,which are important parameters directly related to the surface potential in the semiconductor,should be estimated within our approach to obtain more reliable information.

关键词： Schottky diode interface states surface potential ideality factor barrier height capacitance voltage current measurements

interendoscopist variability in proximal colon polyp detection is twice higher for serrated polyps than adenomas

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World Journal of Gastroenterology 2016年第38期22卷 8549-8557页

作者： jean-François Bretagne Stéphanie Hamonic Christine Piette jean-François Viel Guillaume Bouguen Service des maladies de l'appareil digestif hopital PontchaillouCentre hospitalo-universitaire de Rennes35033 RennesFrance Service d'épidémiologie et de santé publique Centre hospitalo-universitaire de Rennes35033 Rennes France Association pour le dépistage des cancers en ille et Vilaine 35033 RennesFrance

AiM To assess the interendoscopist variability in the detection of colorectal polyps according to their location and histological *** This study was a retrospective analysis of prospectively collected data from a regional colorectal cancer(CRC) screening program; 2979 complete colonoscopies from 18 endoscopists were included. Variability in performance between endoscopists for detection of at least one adenoma(A), one proximal adenoma(PA), one distal adenoma(DA), and one proximal serrated polyp(PSP) was assessed by using multilevel logistic regression *** The observed detection rates among the 18 endoscopists ranged from 24.6% to 47.6%(mean = 35.7%) for A, from 19.1% to 39.0%(mean = 29.4%) for DA, from 6.0% to 22.9%(mean = 12.4%) for PA, and from 1.3% to 19.3%(mean = 6.9%) for *** adjusting for patient-level variables(sex, age), the interendoscopist detection rates variability achieved a significant level for A, PA, and PSP but not for DA(P = 0.03, P = 0.02, P = 0.02 and P = 0.08, respectively). This heterogeneity, as measured by the variance partition coefficient, was approximately threefold higher for PA(6.6%) compared with A(2.1%), and twofold higher for PSP(12.3%) compared with *** These results demonstrate significant interendoscopist variability for proximal polyp particularly for serrated p o l y p s, b u t n o t f o r d i s t a l a d e n o m a d e t e c t i o n. These findings contribute to explain the decreased effectiveness of complete colonoscopies at preventing proximal CRCs and the need to carefully assess the proximal colon during scope procedure.

关键词： Colonoscopy Colorectal cancer Adenoma Serrated polyp Proximal polyp Detection rate Quality performance

Clinical Presentation, Therapeutic Aspects and Results of Urogental Prolapse in Yaounde

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Open Journal of Urology 2024年第2期14卷 83-94页

作者： Junior Barthelemy Mekeme Mekeme Pierre Joseph Fouda Marie Josiane Ntsama Essomba jean Cedric Fouda Marie Salome Eko’o Neme Marcel Junior Yon Mekeme Achille Y. Kpanou Bright Che Awondo philip Fernandez Owon’Abessolo Marcella Biyouma Achille Aurele Mbassi Robinson Mbu Robinson Fru Angwafo iii Department of Urology and Andrology Yaounde Central Hospital Yaounde Cameroon Faculty of Medicine and Biomedical Sciences University of Yaounde I Yaounde Cameroon Department of Surgery Yaounde University Teaching Hospital Yaounde Cameroon Faculty of Medicine and Pharmaceutical Sciences Douala Douala Cameroon Department of Urology and Andrology Laquintini Hospital Douala Douala Cameroon Department of Obstetrics and Gynaecology Yaounde Obstetrics Gynaecology and Pediatrics Hospital Yaounde Cameroon

introduction: Urogenital prolapse is the descent of one or more elements of the abdominal-pelvic contents into the vaginal cavity. The anterior, middle and posterior anatomical compartments may be involved giving rise to several types of genital prolapse. However, there are various therapeutic modalities ranging from observational procedures to surgery. in Yaounde, urogenital prolapse appears to be a rare clinical entity, and its treatment has not been clearly stated. There is limited data about this subject in our context. Our aim was to study the clinical and therapeutic aspects of urogenital prolapse in Yaounde. Methods: We conducted a descriptive cross-sectional study with retrospective data collection at the Yaounde Gynaecological Obstetric and pediatric Hospital (YGOPH) and the Yaounde Central Hospital (YCH) over a period of 05 months (from February 2022 to June 2022). All women aged ≥30 years and all women with documented urogenital prolapse admitted to the maternity and urology departments of these two health facilities were included. Data were collected using a structured questionnaire. Data was analyzed using iBM SPSS (statistical package for social sciences) software version 23.0 and the data were reported as mean, standard deviation, frequencies and percentages. Results: A total of 50 patients were recruited;the mean age was 45.8 ± 17 years. The age range was from 21 to 72 years. Majority of the patients were aged more than 55 years (32%). Most of the patients attended primary education (48%). Forty percent of the patients were housewives. The majority of the patients were from West Cameroon (26%). The most common reason for consultation was pelvic heaviness (54%). The most prevalent clinical sign was cystocele (56%), followed by hysterocele (54%). According to the Baden Walker classification, one-third of the patients were classified as first degree (36%). More than half (58%) of patients had the condition located at the first stage. Surgery was perform

关键词： Urogenital Prolapse Cystocele Hysterocele Clinical Surgery

Elevated intracellular Ca^(2+) Signals by Oxidative Stress Activate Connexin 43 Hemichannels in Osteocytes

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Bone Research 2013年第4期1卷 355-361页

作者： Manuel A.Riquelme jean X.Jiang Department of Biochemistry the University of Texas Health Science Center San Antonio

Elevated oxidative stress （OS） during aging leads to bone loss. OS increases intracellular Ca2＋（[Ca2＋]i）, resulting in cellular damage and death. We show earlier that Cx43 hemichannels open in response to OS, which serves as a protective mechanism for osteocytes. However, the underlying mechanism is unknown. Here, we found that treatment with H202 increased [Ca2＋]i in osteocytes with [Ca2＋]i being primarily derived from an extracellular Ca2~ source. Hemichannel opening induced by OS was inhibited by the depletion of [Ca2＋]i with BAPTA-AM, a Ca2＋ chelator, suggesting that [Ca2＋]i influenced the activity of Cx43 hemichannels. Conversely, blockade of hemichannels had no effect on [Ca2＋]i. A biotinylation assay showed that cell surface-expressed Cx43 was increased by OS, which could be inhibited by BAPTA-AM, suggesting that [Ca2＋]i is necessary for Cx43 migration to the cell surface in response to OS. Together, these data suggest that increased hemichannel activity induced by OS was likely to be caused by elevated [Ca2＋]i through increased Cx43 on the cell surface.

关键词： connexin hemichannels calcium osteocytes

Optimal Control of Hepatitis B in a sub-Saharan African rural area

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Applied Mathematics(A Journal of Chinese Universities) 2023年第4期38卷 523-544页

作者： jean Pierre ii KOUENKAM Joseph MBANG Gilbert CHENDJOU Yves EMVUDU Department of Mathematics Faculty of ScienceUniversity of Yaounde IP.O.Box 812 YaoundeCameroon

in this paper,we ameliorate the model proposed in[13],by incorporating the influence of hepatitis B e antigen(HBeAg)status of mothers on vertical *** use the improved model to fit reported HBV new infections in the Zhejiang Province of *** to predict the course of the Hepatitis B(HBV)infection in this Chinese area,and in Tokombere,located in sub-Saharan Africa(SSA).Furthermore,we apply optimal control techniques in view to re-examine the effects of the newborn vaccination,the universal vaccination and the treatment of chronic carriers in preventing the HBV *** results show that treatment slightly steps in the optimal strategy,while immunisation is an effective *** the other hand,they indicate that the control measures and immunization programs implemented in Zhejiang Province are ***,they suggest that in SSA,a package of several policies centred on birth dose vaccination should be implemented.

关键词： hepatitis B virus chronic carriers vaccine treatment Pontryagin