检索结果-南通市图书馆

Effect of treatment failure on the Cag A EPIYA motif in Helicobacter pylori strains from Colombian subjects

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2017年第11期23卷 1980-1989页

作者： Javier Andres Bustamante-Rengifo Andres Jenuer Matta alvaro Jairo Pazos luis Eduardo Bravo Department of Microbiology School of Basic ScienceUniversidad del Valle Registro Poblacional de Cáncer de Cali Department of PathologySchool of MedicineUniversidad del Valle Department of Biology Universidad de Narino

AIM To evaluate effect of treatment failure on cag A and vac A genotypes in Helicobacter pylori(H. pylori) isolates from Colombia.METHODS One hundred and seventy-six participants infected with H. pylori from Colombia were treated during 14 d with the triple-standard therapy. Six weeks later, eradication was evaluated by 13C-Urea breath test. Patients with treatment failure were subjected to endoscopy control; biopsies obtained were used for histopathology and culture. DNA from H. pylori isolates was amplified using primers specific for cag A and vac A genes. The phylogenetic relationships among isolates obtained before and after treatment were established by conglomerate analysis based on random amplified polymorphic DNA(RAPD) fingerprinting.RESUlTS Treatment effectiveness was at 74.6%. Of the par-ticipants with treatment failure, 25 accepted subjected to a second endoscopy. Prevalence of posttreatment infection was 64%(16/25) and 40%(10/25) by histology and culture, respectively. Upon comparing the cag A and vac A genotypes found before and after therapy, multiple cag A genotypes(cag A-positive and cag A-negative) were found before treatment; in contrast, cag A-negative genotypes decreased after treatment. vac A s1m1 genotype was highly prevalent in patients before and after therapy. The 3'cag A region was successfully amplified in 95.5%(21/22) of the isolates obtained before and in 81.8%(18/22) of the isolates obtained after treatment. In the isolates obtained from patients with treatment failure, it was found that 72.7%(16/22) presented alterations in the number of EPIYA motifs, compared to isolates found before treatment.CONClUSION Unsuccessful treatment limits colonization by lowvirulence strains resulting in partial and selective eradication in mixed infections, and acts on the cag A-positive strains inducing genetic rearrangements in cag A variable region that produces a loss or gain of EPIYA repetitions.

关键词： Helicobacter pylori RAPD-PCR Treatment failure EPIYA motifs 3’ cag A variable region

Symptomatic accommodative and binocular dysfunctions from the use of flat-panel displays

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Ophthalmology(English edition) 2018年第3期11卷 501-505页

作者： Esteban Porcar Juan Carlos Montalt alvaro M. Pons Enrique Espana-Gregor Department of Optics Optometry and Vision Sciences Physics College University of Valencia Burjassot (Valencia) 46100 Spain Department of Surgery Ophthalmology Unit Faculty of Medicine and Odontology la Fe University and Polytechnic Hospital Valencia 46026 Spain

AIM： To determine the presence of symptomatic accommodative and non-strabismic binocular dysfunctions （A.sBD） in a non-presbyopic population of video display unit （VDU） users with flat-panel displays. METHODS： One hundred and one VDU users, aged between 20 to 34y, initially participated in the study. This study excluded contact-lens wearers and subjects who had undergone refractive surgery or had any systemic or ocular disease. First, subjects were asked about the type and nature of eye symptoms they experienced during VDU use. Then, a thorough eye examination excluded those subjects with a significant uncorrected refractive error or other problem, such as ocular motility disorders, vertical deviation, strabismus and eye diseases. Finally, the remaining participants underwent an exhaustive assessment of their accommodative and binocular vision status. RESUlTS： Eighty-nine VDU users （46 females and 43 males） were included in this study. They used flat-panel displays for an average of 5±1.9h a day. Twenty subjects presented A.sBD （22.5%）. Convergence excess was the most frequent non-strabismic binocular dysfunction （9 subjects）, followed by fusional vergence dysfunction （3 subjects） and convergence insufficiency （2 subjects）. Within the accommodative dysfunctions, accommodative excess was the most common （4 subjects）, followed by accommodative insufficiency （2 subjects）. Moderate to severe eye symptoms were found in 13 subjects with ANSBD. CONClUSION： Significant eye symptoms in VDU users with accommodative and/or non-strabismic binocular dysfunctions often occur and should not be underestimated; therefore, an appropriate evaluation of accommodative and binocular vision status is more important for this population,

关键词： general binocular dysfunctions accommodativedysfunctions non-strabismic binocular dysfunctions eyesymptoms video display unit

Conic hyperspectral dispersion mapping applied to semiconductor plasmonics

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

light(Science & Applications) 2012年第1期1卷 48-55页

作者： Dominic lepage alvaro Jimenez Jacques Beauvais Jan J Dubowski Department of Electrical and Computer Engineering Interdisciplinary Institute for Technological Innovation(3IT)Universite´de SherbrookeSherbrookeQue´.Canada

The surface plasmon resonance tracking over metal surfaces is a well-established,commercially available,biochemical quantification tool primarily applied in research.The utilization of such a tool is,however,constrained to highly specialized industries,capable of justifying the human and instrumental resource investments required by the characterization method.We have proposed to expand the field of application of this biosensing approach by redesigning this method through the integration and miniaturization within a semiconductor platform.Uncollimated and broadband emission from a light-emitting semiconductor is employed to couple a continuum of surface plasmon modes over a metal–dielectric architecture interfaced with a GaAs–AlGaAs substrate.A tensor version of rigorous coupled wave theory is employed to optimize the various fabrication specifications and to predict the light scatterings over a wide range of variables.We then present a hyperspectral characterization microscope capable of directly mapping the dispersion relation of scattered light,including diffracted surface plasmons,as an intensity distribution versus photon energy and surface wavevectors.Measurements carried out in a buffered solution demonstrate the accurate description of the uncollimated and broadband surface plasmon states.Finally,we introduce a simplified method of dispersion mapping,in which quasi-conic cross-sections of the light’s scattering can be acquired directly,thus monitoring surficial responses in as fast as 1.2 s.This is over 300 times faster than required by implementing full dispersion mapping.While compromising on the volume of collected information,this method,combined with the solid-state integration of the platform,shows great promise for the fast detection of biochemical agents.

关键词： biosensors light scattering optical devices semiconductors surface plasmon resonance

Physical activation of graphene: An effective, simple and clean procedure for obtaining microporous graphene for high-performance li/S batteries

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano Research 2019年第4期12卷 759-766页

作者： Almudena Benitez alvaro Caballero Julian Morales Jusef Hassoun Enrique Rodriguez-Castellon Jesus Canales-Vazquez Dpto. Quimica Inorganica e Ingenieria Qutmica Instituto de Quimica Fina y Nanoquimica Universidad de Cordoba 14071 Cordoba Spain Departm ent of Chemical and Pharmaceutical Sciences University of Ferrara Via Fossato di Mortara 17 44121 Ferrara Italy Dpto. de Quimica Inorganica Cristalografia y Mineralogia Facultad de Ciencias Universidad de Malaga 29071 Malaga Spain Instituto de Energias Renovables Universidad de Castilla-La Mancha Paseo de La Investigacion 1 Albacete 02071 Spain

Graphe ne nano sheets are a promising scaffold to accommodate S for achievi ng high performa nee li/S battery. Nano sheet activation is used as a viable strategy to induce a micropore system and further improve the battery performance. Accordingly, chemical activation methods dominate despite the need of multiple stages, which slow down the process in addition to making them tiresome. Here, a three-dimensional (3D) N-doped graphene specimen was physically activated with CO2, a clean and single step process, and used for the preparation of a sulfur composite (A-3DNG/S). The A-3DNG/S composite exhibited outstanding electrochemical properties such as an excellent rate capability (1,000 mAh·g^-1 at 2C), high reversible capacity and cycling stability (average capacity ~ 800 mAh·g^-1 at 1C after 200 cycles), values which exceed those measured in chemically activated graphene. Therefore, these results support the use of physical activation as a simple and efficient alternative to improve the performance of carbons as an S host for high-performance li-S batteries.

关键词： physical activation 3D-graphene solvothermal microwave synthesis li-S battery

Cardiovascular impact of COVID-19 with a focus on children: A systematic review

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Clinical Cases 2020年第21期8卷 5250-5283页

作者： Moises Rodriguez-Gonzalez Ana Castellano-Martinez Helena Maria Cascales-Poyatos alvaro Antonio Perez-Reviriego Pediatric Cardiology Division Puerta del Mar University HospitalCadiz 11009Spain Biomedical Research and Innovation Institute of Cadiz Puerta del Mar University HospitalCadiz 11009Spain Pediatric Nephrology Division Puerta del Mar University HospitalCadiz 11009Spain Pediatrics Division Motril-San Antonio Primary Care CenterMotril 18600Spain Pediatrics Division UGC Pediatria AG Sur GranadaSanta Ana HospitalMotril 18600Spain

BACKGROUND Since the beginning of the pandemic,coronavirus disease-2019(COVID-19)in children has shown milder cases and a better prognosis than adults.Although the respiratory tract is the primary target for severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),cardiovascular involvement is emerging as one of the most significant and life-threatening complications of SARS-CoV-2 infection in adults.AIM To summarize the current knowledge about the potential cardiovascular involvement in pediatric COVID-19 in order to give a perspective on how to take care of them during the current pandemic emergency.METHODS Multiple searches in MEDlINE,PubMed were performed using the search terms“COVID-19”or“SARS-CoV-2"were used in combination with“myocardial injury”or"arrhythmia"or“cardiovascular involvement”or"heart disease"or"congenital heart disease"or“pulmonary hypertension”or"long QT"or“cardiomyopathies”or“channelopathies”or"Multisystem inflammatory system"or"PMIS"or“MIS-C”or”Pediatric multisystem inflammatory syndrome"or"myocarditis"or"thromboembolism to identify articles published in English language from January 1st,2020 until July 31st,2020.The websites of World Health Organization,Centers for Disease control and Prevention,and the Johns Hopkins Coronavirus Resource Center were reviewed to provide up to date numbers and infection control recommendations.Reference lists from the articles were reviewed to identify additional pertinent articles.Retrieved manuscripts concerning the subject were reviewed by the authors,and the data were extracted using a standardized collection tool.Data were subsequently analyzed with descriptive statistics.For Pediatric multisystemic inflammatory syndrome temporally associated with COVID-19(PMIS),multiple meta-analyses were conducted to summarize the pooled mean proportion of different cardiovascular variables in this population in pseudo-cohorts of observed patients.RESUlTS A total of 193 articles were included.Most publications used in this review were single case reports,small case

关键词： COVID-19 SARS-CoV-2 Congenital heart diseases Myocardial dysfunction Pediatric Multisystem Inflammatory Syndrome Cardiac Biomarkers

Imaging resolution of biocatalytic activity using nanoscale scanning electrochemical microscopy

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano Research 2018年第8期11卷 4232-4244页

作者： Jase M .Abad alvaro Y. Tesio EmUiano Martinez-Perinan Felix Pariente Encamacion lorenzo Departamento de Qufmica Analftica y Andlisis Instrumental Universidad Aut6noma de Madrid Cantoblanco 28049 Madrid Spain Centro de Investigaci6n y Desarrollo en Materiales Avanzados y Almacenamiento de Energfa de Jujuy-CIDMEJu (CONICET-UniversidadNacional de Jujuy) Centro de Desarrollo Tecnol6gico General Savio Av. Martijena s/n 4612-Palpald Jujuy Argentina Instituto Madrileno de Estudios Avanzados en Nanociencia (IMDEA-Nanociencia) Campus UAM Cantoblanco 28049 Madrid Spain

扫描电气化学的显微镜学代表一个强大的工具因为表面的电镀物品(化学药品) 描述，而是它的适用性在 microscale 在大多数情况中被限制了空间分辨率，和最大的挑战是为制造和纳米大小的尖端的使用按比例缩小到 nanoscale。这里，有纳米 e... 详细信息

扫描电气化学的显微镜学代表一个强大的工具因为表面的电镀物品(化学药品) 描述，而是它的适用性在 microscale 在大多数情况中被限制了空间分辨率，和最大的挑战是为制造和纳米大小的尖端的使用按比例缩小到 nanoscale。这里，有纳米 electroactive 区域的磅 nanoelectrodes 为成像被制作并且采用金 nanoparticles (AuNPs ) 和在金表面上使不能调动的氧化还原作用活跃的酶的 bioelectrocatalytic 活动的分布。

关键词：成像分辨率电气化学显微镜扫描氧化还原作用空间分辨率按比例缩小金表面

Exploratory study on bitumen content determination for foamed bitumen mixes based on porosity and indirect tensile strength

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Traffic and Transportation Engineering(English Edition) 2017年第2期4卷 131-144页

作者： May Namutebi Bjorn Birgisson alvaro Guarin Denis Jelagin Division of Highway and Railway Engineering KTH Royal Institute of Technology Stockholm Sweden Department of Civil and Environmental Engineering Makerere University Kampala Uganda

Optimum bitumen content determination is one of the major aims for foamed bitumen mix design. However, mix design procedures for foamed bitumen mixes are still under development. In this paper a method to determine the optimum bitumen content for given foamed bitumen mix based on primary aggregate structure porosity and indirect tensile strength criterion is proposed. Using packing theory concepts, the aggregate gradation is divided into three aggregate structures which are oversize, primary and secondary struc- tures. Porosity for the primary aggregate structure is determined for given bitumen contents. A maximum value for porosity of 50% for the primary aggregate structure is used to choose initial bitumen content. Furthermore, a minimum indirect tensile strength criteria is suggested to refine this bitumen content. This method enables a bitumen content value to be chosen prior to the start of experimental work, as porosity is expressed in terms of physical parameters such as aggregate and binder specific gravity, and aggregate gradation which are known before the mix design process. The bitumen content is then later refined when the indirect tensile strength is determined in the laboratory. This method would reduce resources such as time and materials that may be required during the mix design procedure.

关键词： Foamed bitumen Bitumen content Aggregate Porosity Gradation framework Indirect tensile strength

Grid-connected Converters with Virtual Electromechanical Characteristics:Experimental Verification

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

CSEE Journal of Power and Energy Systems 2017年第3期3卷 286-295页

作者： Weiyi Zhang Daniel Remon Ignacio Candela alvaro luna Pedro Rodriguez Electrical Engineering Department Technical University of CataloniaBarcelona 08222Spain Department of Engineering University Loyola Andaluc´ıaSeville 41014Spain

Grid-connected power converters,which are frequently used to link renewable generation plants with the grid,are required to provide a better functionality for large scale integration of renewables.They are expected to be gridfriendly,or even grid-supportive,instead of simply grid-feeding or grid-demanding.This paper designs a synchronous power controller for grid-connected converters in detail,emulating the electromechanical characteristics of synchronous machines and improving even its actual performance,as it is based on a virtual approach.Based on this design,the grid-interfacing units are capable of showing inertia,damping,and droop characteristics as synchronous machines and presenting thus a grid-supporting behavior.The detailed control design and experimental validation on a 10 kW laboratory setup acts as the main contribution of this paper,compared with the existing studies on generator emulation controls.

关键词： DC-AC power conversion power generation control synchronous power controller virtual electromechanical characteristics

Post-transplant biliary complications using liver grafts from deceased donors older than 70 years:Retrospective case-control study

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

世界胃肠外科杂志:英文版(电子版) 2023年第8期15卷 1615-1628页

作者： Carlos Jimenez-Romero Iago Justo-Alonso Pilar del Pozo-Elso Alberto Marcacuzco-Quinto Cristina Martín-Arriscado-Arroba Alejandro Manrique-Municio Jorge Calvo-Pulido alvaro García-Sesma Ricardo San Román Oscar Caso-Maestro Unit of HPB Surgery and Abdominal Organs Transplantation `12 de Octubre´University HospitalMadrid 28041Spain Clinical Research Unit(I+12) `12 de Octubre´University HospitalMadrid 28041Spain Department of Radiology `12 de Octubre´University HospitalMadrid 28041Spain

BACKGROUND The shortage of liver grafts and subsequent waitlist mortality led us to expand the donor pool using liver grafts from older donors.AIM To determine the incidence,outcomes,and risk factors for biliary complications(BC)in liver transplantation(lT)using liver grafts from donors aged>70 years.METHODS Between January 1994 and December 31,2019,297 lTs were performed using donors older than 70 years.After excluding 47 lT for several reasons,we divided 250 lTs into two groups,namely post-lT BC(n=21)and without BC(n=229).This retrospective case-control study compared both groups.RESUlTS Choledocho-choledochostomy without T-tube was the most frequent technique(76.2%in the BC group vs 92.6%in the non-BC group).Twenty-one patients(8.4%)developed BC(13 anastomotic strictures,7 biliary leakages,and 1 nonanastomotic biliary stricture).Nine patients underwent percutaneous balloon dilation and nine required a Rouxen-Y hepaticojejunostomy because of dilation failure.The incidence of post-lT complications(graft dysfunction,rejection,renal failure,and non-BC reoperations)was similar in both groups.There were no significant differences in the patient and graft survival between the groups.Moreover,only three deaths were attributed to BC.While female donors were protective factors for BC,donor cardiac arrest was a risk factor.CONClUSION The incidence of BC was relatively low on using liver grafts>70 years.It could be managed in most cases by percutaneous dilation or Roux-en-Y hepaticojejunostomy,without significant differences in the patient or graft survival between the groups.

关键词： Older liver liver transplant Biliary complications Biliary strictures Septuagenarian donors Octogenarian donors