检索结果-南通市图书馆

Accuracy of the Small Field Dosimetry Using the Acuros XB Dose Calculation Algorithm within and beyond Heterogeneous Media for 6 MV Photon Beams

引用

International Journal of Medical Physics, Clinical Engineering and Radiation Oncology 2012年第3期1卷 78-87页

作者： Sotirios Stathakis Carlos Esquivel Luis Vazquez Quino pamela Myers Oscar Calvo Panayiotis Mavroidis Alonso n. Gutiérrez niko Papanikolaou Cancer Therapy and Research Center at University of Texas Health Science Center at San Antonio

Purpose: The dosimetric accuracy of the recently released Acuros XB advanced dose calculation algorithm (Varian Medical Systems, Palo Alto, CA) is investigated for single radiation fields incident on homogeneous and heterogeneous geometries, as well as for two arc (VMAT) cases and compared against the analytical anisotropic algorithm (AAA), the collapsed cone convolution superposition algorithm (CCCS) and Monte Carlo (MC) calculations for the same geometries. Methods and Materials: Small open fields ranging from 1 × 1 cm2 to 5 × 5 cm2 were used for part of this study. The fields were incident on phantoms containing lung, air, and bone inhomogeneities. The dosimetric accuracy of Acuros XB, AAA and CCCS in the presence of the inhomogeneities was compared against BEAMnrc/DOSXYZnrc calculations that were considered as the benchmark. Furthermore, two clinical cases of arc deliveries were used to test the accuracy of the dose calculation algorithms against MC. Results: Open field tests in a homogeneous phantom showed good agreement between all dose calculation algorithms and MC. The dose agreement was +/?1.5% for all field sizes and energies. Dose calculation in heterogenous phantoms showed that the agreement between Acuros XB and CCCS was within 2% in the case of lung and bone. AAA calculations showed deviation of approximately 5%. In the case of the air heterogeneity, the differences were larger for all calculations algorithms. The calculation in the patient CT for a lung and bone (paraspinal targets) showed that all dose calculation algorithms predicted the dose in the middle of the target accurately;however, small differences (2% - 5%) were observed at the low dose region. Overall, when compared to MC, the Acuros XB and CCCS had better agreement than AAA. Conclusions: The Acuros XB calculation algorithm in the newest version of the Eclipse treatment planning system is an improvement over the existing AAA algorithm. The results are comparable to CCCS and MC calculation

关键词： Photon Dose Calculation Inhomogeneities Acuros XB

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Generalizations of the Feline and Texas Chainsaw Josephus Problems

引用

Open Journal of Discrete Mathematics 2019年第4期9卷 144-158页

作者： David Ariyibi Kevin Chang pamela E. Harris Department of Mathematics and Statistics Williams College Williamstown MA USA

We define and study the Extended Feline Josephus Game, a game in which n players, each with ℓlives, stand in a circle. The game proceeds by alternating between hitting k consecutive players—each of whom will consequently lose a life—and skipping s consecutive players. This cycle continues until every player except one loses all of their lives. Given the nonnegative integer parameters n, k, s and ℓ, the goal of the game is to identify the surviving player. In this paper, we show how the defining parameters n, k, s, and ℓaffect the survivor of games with specific constraints on those parameters and our main results provide new closed formulas to determine the survivor of these Extended Feline Josephus Games. Moreover, for cases where these formulas do not apply, we provide recursive formulas for reducing the initial game to other games with smaller parameter values. For the interested reader, we present a variety of directions for future work in this area, including an extension which considers players lying on a general graph, rather than on a circle.

关键词： Josephus Game Feline Josephus Game Texas Chainsaw Josephus Game

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Laboratory Handling of Didymosphenia geminata (Lyngbye) Schmidt and the Effect of Control Efforts on Viability

引用

Advances in Bioscience and Biotechnology 2015年第8期6卷 508-516页

作者： Jorge Parodi pamela Olivares Viviana Chavez Matías Peredo-Parada Laboratorio Fisiología de la Reproducción Escuela de Medicina Veterinaria Núcleo de Investigaciónen Producción Alimentaria Facultad de Recursos Naturales Universidad Católica de Temuco Temuco Chile Laboratorio de Investigación y Educación Tonalli Ltda Temuco Chile Departamento de Ingenieríaen Obras Civiles Universidad de Santiago de Chile Santiago Chile Plataforma de Investigaciónen Ecohidrología y Ecohidráulica EcoHyd Ltda Santiago Chile

Didymosphenia geminata (Lyngbye) Schmidt is a type of diatom that exists in Chile as an introduced species, invading the country and its rivers. We collected samples of D. geminata from two sampling points in Chile, assessing their viability and response to control agents. Fresh D. geminata showed more than 90% of viable granular forms (containing granules in their cytoplasm);however, the dry form presents near 50% viability. By creating dry D. geminata through exposure to 38°C temperatures for 7 days, viability values of the granular form decreased to 20%. D. geminata kept at room temperature for more than 4 weeks reported values of granular forms at 50%, while samples that were refrigerated at 4°C maintained values of granular forms at 90% for 4 weeks. Previous studies suggest that high salt concentration affects the viability of D. geminata. When taking wet D. geminata samples and exposing them to a solution of 10% naCl for 10 minutes, we observed no differences compared to the control samples, finding granular forms at 90%. When the D. geminata was exposed to a 5% soap solution, reductions of over 90% of the granular forms were observed. Our results suggest that the viability of D. geminata is associated with the granular content within their cytoplasm, and that it is possible to alter laboratory conditions for their study. These early studies are important in order to better manipulate the model in the laboratory, allowing us to obtain new evidence regarding the microalgae’s biology through in vitro studies.

关键词： Plague Viability Laboratory Didymo

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

The action of ethanol on G protein. <i>In silico</i>and cellular/molecular evidences

引用

Advances in Bioscience and Biotechnology 2013年第5期4卷 665-673页

作者： pamela Fernandez Jessica Moreno Claudio Barrientos Sergio A. Aguila Daniela Leon Sebastián Ortiz Ramon Silva Francisco Rodriguez Maritza Leonardi Violeta Morin Ximena Romo Departamento de Bioquimica y Biologia Molecular Facultad de Ciencias Biologicas Universidad de Concepción Concepcion Chile Departamento de Ciencias Biologicas Facultad de Ciencias Biologicas Universidad Andres Bello Sede Concepcion Talcahuano Chile Laboratorio de Virus Oncológicos en Reproducción BIOREN-CEGIN Universidad de La Frontera Temuco Chile Universidad nacional Autonoma de Mexico Centro de Nanociencias y Nanotecnologia Ensenada Mexico

Ethanol (EtOH) enhances glycinergic currents in the central nervous system (CnS). Because evidence for an interaction between the α1 subunit of the glycine receptor (α1GlyR) and the G protein Gβγ subunit exists in vitro and because cAMP levels are known to increase in response to EtOH, we wanted to investigate the interaction between Gβγ and α1GlyR in response to EtOH treatment in HEK293 cells and to explore the possible sites of interaction between EtOH and the Gαs subunit. His pull-down assays in GlyR-His6-transfected HEK293 cells incubated with ethanol or propofol revealed that only EtOH treatment increased the binding of Gβγ heterodimers to α1GlyR. Using molecular modelling (protein structure prediction), was modelled the hGαs protein for the first time and validated this model by site-directed mutagenesis. By molecular docking, we identified some potential regions of interaction between hGαs and EtOH that are located on the SIII and SI regions of the Gαs. Therefore, we conclude that ethanol increases the interaction between α1GlyR and Gβγ in HEK293 cells, an effect that might be attributed to the interaction between EtOH and hGαs, which consequently stimulates hGαs.

关键词： Alcoholism Ethanol Glycine Receptor G Proteins Signals Transduction

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Fish nutrition Additives in SHK-1 Cells: Protective Effects of Silymarin

引用

Advances in Bioscience and Biotechnology 2016年第2期7卷 55-62页

作者： Rodrigo Sanchez pamela Olivares Erico Carmona Allisson Astuya Hector Herrera Jorge Parodi Laboratorio Fisiología de la Reproducción Escuela de Medicina Veterinaria Núcleo de Investigación en Producción Alimentaria Facultad de Recursos Naturales Universidad Católica de Temuco Temuco Chile Empresa Vitapro Chile Castro Región de Los Lagos Chile Grupo de Genotoxicología Escuela de Medicina Veterinaria Núcleo de Estudios Ambientales Facultad de Recursos Naturales Universidad Católica de Temuco Temuco Chile Laboratory of Cell Culture and Marine Genomics Marine Biotechnology Unit Faculty of Natural and Oceanographic Sciences University of Concepcion and Sur-Austral COPAS Program University of Concepcion Concepción Chile

In nutrition for productive species, additives play an important role in boosting physiological processes. Only in recent years studies include models of the effects on fish cells of these additives. We observed effects of silymarin, a compound highly utilized in aquaculture. The cell line SHK-1 was used derived from the upper liver of the Atlantic salmon as a biological model. Samples were exposed to silymarin in incrementing time and concentrations, to evaluate by MTT and number of cells, the effects on cell viability. Also, oxidative stress models were used to find the protector effects of silymarin against these agents. Our data indicate that a dose of 100 ppm of silymarin is sufficient to stimulate cellular proliferation. Cultures were exposed to high glucose (15 mM) or H2O2 (0.1 mM) in presence of or absence of silymarin at 100 ppm. We observed that the toxic effects of both compounds were blocked by the presence of silymarin. Our results indicate that it is important to evaluate additive effects at a cellular level. Also, silymarin does have proliferative effects, and protect against cellular injury in our models. Our study helps to generate more rational applications of additives in the industry and presents new challenges in order to better manipulate the model in the laboratory, allowing us to obtain new evidence regarding the microalgae’s biology through in vitro studies.

关键词： Fish nutrition Silymarin Cell Cultures

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Hepatitis C virus molecular evolution:Transmission,disease progression and antiviral therapy

引用

World Journal of Gastroenterology 2014年第43期20卷 15992-16013页

作者： Maria Victoria Preciado pamela Valva Alejandro Escobar-Gutierrez Paula Rahal Karina Ruiz-Tovar Lilian Yamasaki Carlos Vazquez-Chacon Armando Martinez-Guarneros Juan Carlos Carpio-Pedroza Salvador Fonseca-Coronado Mayra Cruz-Rivera Laboratorio de Biología Molecular División PatologíaHospital de Ni?os "Ricardo Gutiérrez"Buenos Aires C1425EFDArgentina Instituto de Diagnóstico y Referencia Epidemiológicos Mexico 01480Mexico Department of Biology Institute of BioscienceLanguage and Exact ScienceS?o Paulo State UniversityS?o José do Rio PretoSP 13560-970Brazil Laboratorio de Inmunobiología de Enfermedades Infecciosas Unidad de Investigación MultidisciplinariaFacultad de Estudios Superiores CuautitlánUniversidad Nacional Autónoma de MéxicoCuautitlán IzcalliEstado de México 54714Mexico Departmento de Microbiología y Parasitología Facultad de MedicinaUniversidad Nacional Autónoma de MéxicoMexico City 04510Mexico

Hepatitis C virus(HCV)infection represents an important public health problem *** of HCV morbidity and mortality is a current challenge owned to several viral and host *** molecular evolution plays an important role in HCV transmission,disease progression and therapy *** high degree of genetic heterogeneity characteristic of HCV is a key element for the rapid adaptation of the intrahost viral population to different selection pressures(e.g.,host immune responses and antiviral therapy).HCV molecular evolution is shaped by different mechanisms including a high mutation rate,genetic bottlenecks,genetic drift,recombination,temporal variations and *** evolutionary processes constantly rearrange the composition of the HCV intrahost population in a staging *** advances in the understanding of the molecular mechanism controlling HCV replication have facilitated the development of a plethora of direct-acting antiviral agents against *** a result,superior sustained viral responses have been *** rapidly evolving field of anti-HCV therapy is expected to broad its landscape even further with newer,more potent antivirals,bringing us one step closer to the interferon-free era.

关键词： Hepatitis C virus Evolution Phylogenetics Drug resistance Clinical outcome

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Bilateral Gluteal Reconstruction with Double Flap Secondary to Biopolymers Injection

引用

Journal of Biosciences and Medicines 2021年第7期9卷 174-183页

作者： Miguel Ángel Sánchez-Morán García Carlos I. navarro-Delgadillo pamela Sánchez-Morán Pérez Rogelio Cordova-López Vanessa Moreno-Diaz Oscar Pérez-Osorio Donovan Magaña-Vega Willian Bautista-Santos Providence Medical Clinic Ciudad de México México

The injection of adjuvant substances for aesthetic purposes is a public health problem, for 40 years this problem has been described throughout our continent, the vast majority of women patients are affected by the infiltration of silicon, mineral oils, automotive oil, methyl methacrylate, cement and various oily substances. This is a 54-year-old female patient who for about 30 years for cosmetic purposes was injected with mineral oil (quantity unknown) in both glutei with the aim of buttock augmentation. Physical examination was observed an important deformity in each buttock, hyperkeratosis with discoloration in both buttocks, loss of bilateral projection, right buttock with a secondary tumor of 22 cm × 11 cm and left 22 cm × 10 cm, stony appearance, local hyperthermia, painful on manipulation, with diffuse nodular lesions measuring 2 cm × 2 cm, without evidence of loss of continuity that would condition secretion leakage. Surgical planning is based on the very important size of the initial defect that we would have to reconstruct, so that the rotation of two wide-based flaps could guarantee better survival and occlusion of the defect, since the realization of a graft would cause a significant deformity, and the realization of a microsurgical flap in a fibrous tissue would inevitably result in its necrosis. The pathophysiology of the adjuvant disease is extremely complex, therefore it must be addressed by a multidisciplinary group with extensive experience.

关键词： Gluteal Reconstruction Biopolymers Foreign Materials Biomaterials Modelants

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Anal cancer treatment:Current status and future perspectives

引用

World Journal of Gastroenterology 2015年第8期21卷 2294-2302页

作者： Marwan Ghosn Hampig Raphael Kourie pamela Abdayem Joelle Antoun Dolly nasr Hematology-Oncology Department Faculty Of Medicine Saint Joseph University

Anal cancers(AC)are relatively rare *** incidence is increasing,particularly among men who have sex with other men due to widespread infection by human papilloma *** majority of anal cancers are squamous cell carcinomas,and they are treated according to *** local and locally advanced AC,concomitant chemoradiation therapy based on mitomycin C and 5-Fluorouracil(5-FU)is the current best treatment,while metastatic AC,chemotherapy with 5-FU and cisplatin remains the gold *** are no indications for induction or maintenance therapies in locally advanced *** novel strategies,such as targeted therapies,vaccination,immunotherapy and photodynamic therapy are in clinical trials for the treatment of AC,with promising results in some indications.

关键词： Anal cancer Optimum treatment Updates Guidelines n

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Saffron (Crocus sativus L.) and major depressive disorder:a meta-analysis of randomized clinical trials

引用

Journal of Integrative Medicine 2013年第6期11卷 377-383页

作者： Heather Ann Hausenblas Debbie Saha pamela Jean Dubyak Stephen Douglas Anton Department of Sport and Exercise Sciences Jacksonville University Department of Aging and Geriatric Research University of Florida

Due to safety concerns and side effects of many antidepressant medications, herbal psychopharmacology research has increased, and herbal remedies are becoming increasingly popular as alternatives to prescribed medications for the treatment of major depressive disorder （MDD）. Of these, accumulating trials reveal positive effects of the spice saffron （Crocus sativus L.） for the treatment of depression. A comprehensive and statistical review of the clinical trials examining the effects of saffron for treatment of MDD is warranted. OBJECTIVE： The purpose of this study was to conduct a meta-analysis of published randomized controlled trials examining the effects of saffron supplementation on symptoms of depression among participants with MDD. SEARCH STRATEGY： We conducted electronic and non-electronic searches to identify all relevant randomized, double-blind controlled trials. Reference lists of all retrieved articles were searched for relevant studies. InCLUSIOn CRITERIA： The criteria for study selection included the following：（1） adults （aged 18 and older） with symptoms of depression, （2） randomized controlled trial, （3） effects of saffron supplementation on depressive symptoms examined, and （4） study had either a placebo control or antidepressant comparison group. DATA EXTRACTIOn AnD AnALYSIS： Using random effects modeling procedures, we calculated weighted mean effect sizes separately for the saffron supplementation vs placebo control groups, and for the saffron supplementation vs antidepressant groups. The methodological quality of all studies was assessed using the Jadad score. The computer software Comprehensive Meta- analysis 2 was used to analyze the data. RESULTS： Based on our pre-specified criteria, five randomized controlled trials （n = 2 placebo controlled trials, n = 3 antidepressant controlled trials） were included in our review. A large effect size was found for saffron supplementation vs placebo control in treating depressive symptoms （M ES = 1.62, P 〈

关键词： Crocus depressive disorder dietary supplements mood disorders quality of life medicine, herbal meta-analysis

来源：

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

Prevalence and Incidence of HIV and Sexual Risk Behaviors in Crack Users in the San Salvador Metropolitan Area, El Salvador

引用

World Journal of AIDS 2013年第4期3卷 357-363页

作者： Julia Dickson-Gomez Julia Lechuga Laura Glasman Steven Pinkerton Gloria Bodnar pamela Klein Center for AIDS Intervention Research Department of Psychiatry and Behavioral Medicine The Medical College of Wisconsin Milwaukee USA Departamento de Investigación Fundación Antidrogas de El Salvador (FUNDASALVA) San Salvador El Salvador University of Texas El Paso USA

Objective: It is in order to estimate the prevalence and incidence of HIV, the frequency of sexual risk behaviors, and perceptions of available resources to prevent and treat HIV among crack users in the San Salvador Metropolitan Area. Methods: We conducted a survey of 420 crack users by using respondent-driven sampling to measure demographic characteristics, the quantity and frequency of drug use, history of STIs, including HIV, and experiences with organizations which provide prevention and treatment of HIV. Each participant offered a free and voluntary HIV test and was asked permission to share the results of the test with the study. Bernoullian modeling was used to estimate the prevalence and incidence of HIV among heterosexual males in this population. Results: The estimated prevalence was 7% (95% CI: 2.3% -9.8%) among participants who agreed to take the test and share the results, and 4.9% (95% CI: 2.8% -7.8%) assuming that those who did not take the test or share results were seronegative. Participants reported a high frequency of sexual risk behaviors. In addition, participants were reported to have little knowledge of organizations to prevent or treat HIV/AIDS;58% had never taken an HIV test prior to survey administration. Conclusions: Crack users in San Salvador are at high risk for HIV acquisition. HIV prevention interventions are urgently needed, especially interventions increasing access to HIV testing and prevention.

关键词： Incidence and Prevalence of HIV Sexual Risk Behavior Crack El Salvador

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：