检索结果-南通市图书馆

Effective use of FibroTest to generate decision trees in hepatitis C

World Journal of Gastroenterology 2009年第21期15卷 2617-2622页

作者： dana Lau-Corona Luís Alberto Pineda Héctor Hugo Avilés Gabriela Gutiérrez-reyes Blanca Eugenia Farfan-Labonne Rafael Núez-Nateras Alan Bonder Rosalinda Martínez-García Clara Corona-Lau Marco Antonio Olivera-Martínez Maria Concepción Gutiérrez-Ruiz Guillermo Robles-díaz david Kershenobich department of Experimental Medicine School of MedicineUniversidad Nacional Autonoma de MexicoGeneral Hospital of Mexico department of Computer Sciences Institute for Applied Mathematics and SystemsUniversidad Nacional Autonoma de Mexico department of Gastroenterology Lomas Altas Clinic

AIM： To assess the usefulness of FibroTest to forecast scores by constructing decision trees in patients with chronic hepatitis C.METHOdS： We used the C4.5 classification algorithm to construct decision trees with data from 261 patients with chronic hepatitis C without a liver biopsy. The FibroTest attributes of age, gender, bilirubin, apolipoprotein, haptoglobin, α2 macroglobulin, and γ-glutamyl transpeptidase were used as predictors, and the FibroTest score as the target. For testing, a 10-fold cross validation was used.RESULTS： The overall classification error was 14.9% （accuracy 85.1%）. FibroTest＇s cases with true scores of FO and F4 were classified with very high accuracy （18/20 for FO, 9/9 for FO-1 and 92/96 for F4） and the largest confusion centered on F3. The algorithm produced a set of compound rules out of the ten classification trees and was used to classify the 261 patients. The rules for the classification of patients in FO and F4 were effective in more than 75% of the cases in which they were tested.CONCLUSION： The recognition of clinical subgroups should help to enhance our ability to assess differences in fibrosis scores in clinical studies and improve our understanding of fibrosis progression,

关键词： Hepatitis C FibroTest decision trees C4.5algorithm Non-invasive biomarkers

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

XRd Characterization of Crystallinity of Human Tooth Enamel under Influence of Mechanical Grinding

引用

Materials Sciences and Applications 2015年第6期6卷 464-472页

作者： Jose reyes-Gasga Olga Koudriavtseva Raul Herrera-Becerra Arturo Escobosa Instituto de Física UNAM Circuito de la Investigación s/n Ciudad Universitaria México D.F. México dep. Ingeniería Eléctrica—SEES CINVESTAV—IPN México D.F. México

Crystallinity refers to the degree of structural order in a solid and has a big influence on hardness, density, transparency and diffusion. Even within materials that are crystalline completely, the degree of structural perfection can vary, reflecting size and elastic strain of many independent crystalline regions (grains or crystallites) of which these materials are composed. In this work it was attempted to reduce the crystallinity of human enamel using a technique of mechanical grinding (MG) with an ultra-compact FRITSCH Mini-Mill PULVERISETTE 23 machine. Variation in the crystallinity through the MG was monitored by X-ray diffraction (XRd) by broadening of the diffraction peak and examined using the Williamson-Hall plot method. Crystallites in human enamel are regularly arranged and oriented (in the [001] direction) perpendicularly to the interface of enameldentin junction. The results showed an anisotropic feature in crystallinity. Reduction of the crystallinity along the a-axis is due to the crystal strain rather than to the refinement of crystal, and vice versa along the c-axis. After 230 h of the MG, the length of crystallites decreased from 100 nm to 30 nm and width from 40 nm to 37 nm approximately.

关键词： Human Tooth Enamel Crystal Structure Mechanical Grinding X-Ray diffraction Crystallites

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

Optimized combinations of statins and azoles against Acanthamoeba trophozoites and cysts in vitro

引用

Asian Pacific Journal of Tropical Medicine 2019年第6期12卷 283-287页

作者： Ines Sifaoui Carmen M Martín-Navarro Atteneri López-Arencibia María reyes-Batlle Basilio Valladares JoséE.Pinero Sutherland K Maciver Jacob Lorenzo-Morales University Institute of Tropical diseases and Public Health of the Canary Islands University of La LagunaCanary IslandsSpain Centre for Integrative Physiology Biomedical SciencesEdinburgh Medical SchoolUniversity of EdinburghScotlandUK

Objective: To evaluate the combination of several statins(atorvastatin, fluvastatin and simvastatin) and azoles(voriconazole, posaconazole and itraconazole) against Acanthamoeba spp. Methods: The efficiency of the different drug combinations against the trophozoite stage of different Acanthamoeba strains were evaluated by Alamar Blue assay. Effect on the cyst stage was observed by inverted microscope. Cytotoxicity of combinations of azoles and statins was evaluated by measuring the release of lactate dehydrogenase from a murine macrophage cell line. Results: Combinations of any of the tested statins and voriconazole or posaconazole were more efficient in inhibiting Acanthamoeba compared to statins or azoles individually. The drug combinations at the combined inhibitory concentrations 50% showed lower toxicity compared to that of the compounds ***: The combinations of statins together with voriconazole and posaconazole are more efficient than these drugs alone, and these combinations have lower cytotoxicity in mammalian cell lines.

关键词： Keratitis Voriconazole Posaconazole Atorvastatin Fluvastatin Simvastatin

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

Antioxidant,cytotoxic,and anti-venom activity of Alstonia parvifolia ***

引用

Asian Pacific Journal of Tropical Biomedicine 2021年第10期11卷 460-468页

作者： Maria Carmen S.Tan Mary Stephanie S.Carranza Virgilio C.Linis Raymond S.Malabed Yves Ira A.reyes Francisco C.Franco,Jr. Glenn G.Oyong Chemistry department De La Salle University2401 Taft AvenueManila 1004Philippines Biology department De La Salle University2401 Taft AvenueManila 1004Philippines department of Chemistry Graduate School of ScienceOsaka UniversityOsaka 563-0034Japan Molecular Science Unit Laboratory Center for Natural Sciences and Environmental ResearchDe la Salle University2401 Taft AvenueManila 1004Philippines

Objective:To evaluate antioxidant,cytotoxic,and anti-venom capacity of crude bark extracts of Alstonia parvifolia ***:Gas chromatography-mass spectrometry(GC-MS)and energy dispersive X-ray analyses were accomplished to characterize the chemical constituents of Alstonia *** characterization was evaluated using an inhibitory phospholipase A_(2)(PLA_(2))assay,dPPH,and cytotoxicity *** the constituents listed in the GC-MS analyses,molecular docking was conducted to inspect the binding energies between the chosen compounds and selected PLA_(2) ***:GC-MS analyses showed that the Alstonia parvifolia crude extract consisted predominantly of acetylmarinobufogenin(14.89%),γ-sitosterol(10.44%),3-O-methyl-d-glucose(5.88%),3,5-dimethoxy-4-hydroxyphenylacetic acid(5.30%),(2α,5α)-17-methoxyaspidofractinin-3-one(AFM)(4.08%),and 2,3,5,6,7,8,9-heptahydro-1-phenyl-5-(p-chlorophenylimino)-1H-benzo[e][1,4]thiazepine(HPT)(1.37%).The principal elemental components of Alstonia parvifolia were Ca(4.012%)and K(1.496%),as exhibited by energy dispersive X-ray *** parvifolia showed significant free radical scavenging ability(IC_(50):0.287 mg/mL)and was non-cytotoxic to normal HdFn cells(IC_(50)>100μg/mL).Moreover,Alstonia parvifolia was favorably cytotoxic to MCF-7(IC_(50):4.42µg/mL),followed by H69PR,HT-29,and THP-1,with IC_(50) values of 4.94,5.07,and 6.27µg/mL,*** parvifolia also displayed notable inhibition against PLA_(2) activity of Naja philippinensis Taylor venom with IC_(50) of(15.2±1.8)μg/*** and cluster analyses projected negative binding energies from AFM(−6.36 to−9.68 kcal/mol),HPT(−7.38 to−9.77 kcal/mol),and acetylmarinobufogenin(−7.22 to−9.59 kcal/mol).These calculations were for the particular interactions of Alstonia parvifolia constituents to PLA_(2) homologues where the utmost affinity was detected in HPT owing to the dipole interactions with amino acid ***:The bark e

关键词： Alstonia parvifolia Merr. Naja philippinensis Taylor Gas chromatography-electron ionization-mass spectrometry Secretory phospholipase A_(2) Cytotoxicity assay Anti-venom

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

Quantification of Lipid Content and Identification of the Main Lipid Classes Present in Microalgae Extracts Scenedesmus sp. for Obtaining Fatty Compounds for Biofuel Production

引用

Energy and Power Engineering 2020年第6期12卷 273-287页

作者： Carolina Vieira Viegas Leonardo Brantes Bacellar Mendes Rafael Richard João Gisel Chenard díaz donato A. G. Aranda Yordanka reyes Cruz GREETEC Laboratory Federal University of Rio de Janeiro (UFRJ) Rio de Janeiro Brazil CENPES/PETROBRáS—Leopoldo Américo Miguez de Mello Research Center Rio de Janeiro Brazil

Microalgae biomass has been reported in the literature as one of the most promising sources for obtaining different products of industrial interest such as lipids, fatty acids, carotenoids, proteins and fibers. The lipid fraction of microalgae comprises neutral lipids, free fatty acids and polar lipids. It is of great importance to estimate the composition of the lipid fraction to define the potential for use, either as a raw material for the production of biofuels or for use for nutraceuticals and/or food purposes. The microalgae Scenedesmus sp. cultivated in a photobioreactor, the sky open raceway type,dana;">dana;">dana;font-size:12px;"> was evaluated for lipid content, identification and quantification of lipid components obtained from different extracts. In the quantification of the lipid content, extraction methods were proposed without chemical treatment (use of solvents only) such as chloroform:methanol (2:1 v/v)—Bligh & dyer, Ethanol, Ethyl acetate:Hexane (1:1 v/v) and others with chemical treatment such as J-Schmid-Bondzynski-Ratzlaff (acid) and saponification (basic). For the identification of the main lipid components present in the extracts, the Thin layer chromatography (TLC) technique was used. Th

关键词： Microalgae Lipids Extraction Saponifiable Compounds Biofuels

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

Treatment Patterns and Clinical Characteristics of Patients with Advanced Basal Cell Carcinoma in the Community Oncology Setting

引用

Journal of Cancer Therapy 2013年第6期4卷 24-31页

作者： Mark S. Walker Lee S. Schwartzberg diana M. Chen d. devi Ramanan Arthur C. Houts Carolina reyes ACORN Research LLC Memphis USA Genentech Inc. South San Francisco USA The West Clinic Memphis USA

Advanced basal cell carcinoma (aBCC) includes metastatic and locally advanced BCC that is inoperable (or with surgery contraindicated). We describe patient characteristics and treatment history for aBCC cases from community oncology. Nine cases of aBCC were found within the ACORN data Warehouse, a community oncology database of >180,000 cancer patients. data were summarized descriptively. Three illustrative case histories are presented. Patients were predominantly Caucasian (8/9), male (6/9), and over 60 (6/9). Four had metastatic disease;five had aBCC without metastasis. Five had a history of treatment for early stage BCC, including surgery (5/5), radiation (1/5), and none had chemotherapy. Those with history of early stage BCC had periods of apparent lack of follow-up and treatment. One had chemotherapy for aBCC (platinum based with radiation) and eight had radiation without chemotherapy. Patients had multiple comorbid serious medical conditions. Six were deceased, but only one was documented to have aBCC as cause of death. Advanced BCC is rare in community oncology settings. There appear to be gaps in the care and follow-up of patients with initial early stage BCC. More data and larger samples are needed from multi-specialty databases such as dermatology and head and neck surgery.

关键词： Advanced Basal Cell Carcinoma Community Oncology Treatment Patterns Observational Study Long Term Follow Up

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

Increased Mortality Risk among Early Stage Hormone Receptor Positive Breast Cancer Patients Who did Not Receive Adjuvant or Neoadjuvant Therapy

引用

Journal of Cancer Therapy 2019年第1期10卷 1-20页

作者： Sacha Satram-Hoang Alisha Stein Patricia Cortazar Faiyaz Momin Carolina reyes Q.d. Research Inc. Granite Bay CA USA Genentech Inc. South San Francisco CA USA

Background: Hormone receptor positive (HR+), human epidermal growth factor receptor 2 negative (HER2-) is the most common biologic subtype of breast cancer. Although adjuvant therapy has demonstrated a survival benefit in clinical trials, its use is poorly understood in the real-world among elderly breast cancer patients since age is a barrier to receiving adjuvant therapy. An examination of treatment patterns and outcomes associated with receipt of adjuvant/neoadjuvant therapy among elderly HR + HER2-breast cancer patients was undertaken. Methods: There were 18,470 HR + HER2-breast cancer patients from the linked SEER-Medicare database. Patients were diagnosed with stage I-III disease between 1/1/2007-12/31/2011, ≥66 years, enrolled in Medicare Parts A, B and d, and underwent breast cancer surgery after diagnosis. Time-varying Cox proportional hazards regression assessed overall survival. Results: There were 13,670 (74%) patients treated with adjuvant/neoadjuvant therapy and 4800 (26%) untreated. Compared to treated patients, untreated patients were older, had earlier stage, lower grade, smaller tumors, poorer performance, higher comorbidity score, and less use of a 21-gene recurrence score (RS) assay (p del, increasing age, stage, tumor size, tumor grade, comorbidity score and poor performance were significantly associated with higher mortality risks, while use of an RS assay was associated with lower risks. The Cox model showed a 48% higher risk of death in untreated compared to treated patients. In a subset of 8967 patients with stage I disease, tumor size d grade 1/2;untreated patients had a 22% higher risk of death compared to treated patients. Conclusions: Older patients with favorable clinical characteristics (earlier stage, smaller tumor, lower grade) are less likely to be treated and have a higher risk of death compared to adjuvant/neoadjuvant treated patients. An unmet need among older breast cancer patients persist

关键词： Hormone Receptor Positive Breast Cancer Elderly Patients Adjuvant Therapy Survival

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

巴拿马椰子树薄壁生物启发结构的耐撞行为

巴拿马椰子树薄壁生物启发结构的耐撞行为

引用

作者： reyes BATISTA ESTEPHANY dEL CARMEN（任巴缇）中南大学

学位级别：硕士

对材料特性的研究在研究和工业领域进行,作为获得材料的优势和寻找潜在应用的工具。因此,生物启发材料领域有助于结构的设计和材料的制造,目的是将已知的自然结构与特定的材料相结合。毫无疑问,对具有改进的机械性能的结构和材料的需求... 详细信息

对材料特性的研究在研究和工业领域进行,作为获得材料的优势和寻找潜在应用的工具。因此,生物启发材料领域有助于结构的设计和材料的制造,目的是将已知的自然结构与特定的材料相结合。毫无疑问,对具有改进的机械性能的结构和材料的需求正在上升,以及为提高抗震性和内部缓冲而提供定制性能的材料组合。本文介绍的吸能结构的一些应用,将在下文中说明。根据Lu和Yu书,吸能结构/材料的主要应用可以归纳为以下五个方面。提高车辆耐撞性的结构,用于道路安全的结构,用于保护工作中的事故的结构,用于个人保护的结构和用于商品包装的结构.有许多关于这种结构的科学研究,也有多个模型经过测试和优化,以实现拯救生命和减少损失的目的。这项研究旨在测试新的生物启发设计。大自然作为一个伟大的灵感来源,已经进化了数百万年。将对薄壁模型进行分析。这些可以在用于能量吸收应用的结构领域进行评估。在Lazarus等人的研究中,总结了生物材料的一般特征,如分层、复合、多孔和界面。另一方面,还介绍了在抗冲击生物材料中发现的具体结构:它们是分层、梯度、管状、夹层和缝合。这样的研究解释了在自然界中发现的许多管状型材料由于典型的塑性变形和裂纹偏转机制而增强了抗冲击性。通过这种方式,这项研究希望了解和理解在自然界发现的特定植物的主要结构特征,以模仿其结构并在三维建模软件的帮助下进行模拟,使我们能够分析和评估生物启发的薄壁结构的能量吸收。为了实现目的和目标,首先回顾了现有的科学研究,然后从巴拿马和美洲大陆的植被中获取灵感,以确定、解释、设计、验证和优化用于吸收能量的薄壁结构(直管)。这就是我们如何在以前的研究基础上着手验证FE方法,以便能够应用这种方法。然后,我们生成了受巴拿马椰树启发的薄壁圆管和方管的模型,在轴向和斜向载荷下进行数值试验,通过这些试验评估防撞性能,观察可用于能量吸收应用的替代结构的变形模式。本研究在第二章中介绍了一些基本知识,以及在薄壁结构设计中使用生物灵感的研究,特别是对圆形和方形结构。根据Lu&Yu的观点,无论应用何种结构设计来吸收能量,都有一些基本原则需要考虑,因为它们是一种指导原则。其中包括。不可逆的能量转换,受限和恒定的反作用力,长效冲击,稳定和可重复的变形模式,轻质和高比能量吸收能力以及简单和低成本的安装。有了生物启发设计的定义,下一步就是管子的制造、实验测试和数值分析。所查阅的科学文献研究中使用的实验方法包括不同的制造方法,如传统方法(车床加工、深拉工艺、成型、激光切割/雕刻、精密铸造工艺和线放电加工技术)、增材制造(使用3d打印技术)、层压,和其他新的制造技术。关于机械测试或试验的性能,我们可以提到蠕变和应力测试、准静态测试、低和高应变动态测试和冲击测试等方法。这些测试在生物启发设计领域的应用对于验证天然材料和由生物启发设计制造的材料的机械性能至关重要。科学文献中报道的数值分析方法包括使用有限元分析(FEA)工具,如Abaqus,ANSYS,Cosmos Works,deform和LS-dYNA。关于数值模拟,已知的情况如下。当评估测试方法的类型以测量生物启发设计的能量吸收时,根据Lazarus等人,有不同的静态和动态方法。这些方法根据结构的可实现的变形率进行分组,即变形量对时间的变化。静态和准静态方法的应变速率小于100s-1,动态方法则高于这个范围。在决定方法时,区别在于要考虑到在动态试验中,载荷在短时间内快速施加,导致结构振动,必须考虑到结构的惯性力。而在静态和准静态试验中,载荷是缓慢施加的,它不依赖于时间,惯性力可以忽略不计。为了评估薄壁管的能量吸收特性(在轴向和斜向载荷下),在类似的研究中,很常见的是利用载荷-位移曲线评估这种结构在某些防撞标准下的性能,其中有以下几种:能量吸收(EA),比能量吸收(SEA),平均压溃力(MCF),峰值破碎力(PCF),压碎力效率(CFE).本研究的灵感来自于椰子树(Cocos nucifera)的茎。Fathi进行了一项研究,调查椰子树、油棕榈树和枣树木材的结构和机械/物理特性的关系。椰子树在整个巴拿马境内非常普遍;因此,这种植物被选为生物启发设计的对象。椰树茎的稳定性和椰树茎材料机械性能测试的良好结果,主要是由于维管束和实质细胞的组合,它们共同作为加固材料。在下一章中,首先解释了灵感的过程,圆柱形和方形的薄壁结构的设计,其几何形状,管子材料的机械性能,以及用于模拟的方法。然后介绍了有限元方法的验证结果。最后,介绍了每种设计的图表和模拟结果,绘制了不同的防撞标准,并比较了圆柱形和方形管在轴向破碎力和斜向冲击力下的设计效率。在一个名为***的免费在线工具上搜索植物管理结构力的生物策略,我发现树木和那些用于获得木材的树木都是实心圆柱体,因为它们有强大的维管束分布在茎中。这些维管束在外缘具有较高的强度和密度。椰

关键词：轴向挤压能量吸收生物启发设计耐撞性椰子树结构斜向冲击血管束

来源：

同方学位论文库评论

在线全文

同方学位论文库

学校读者我要写书评

暂无评论

Spectral Comparison of Real Spectra with Site Effects Included vs MOC-2008 Teorical Spectra for Guadalajara City, Mexico

引用

Open Journal of Civil Engineering 2013年第3期3卷 194-201页

作者： Héctor E. Rodríguez Lozoya Tonatiuh domínguez reyes Alfredo reyes Salazar Edén Bojórquez Mora Héctor E. Rodríguez Leyva Facultad de Ingeniería Universidad Autónoma de Sinaloa México D.F. México Observatorio Vulcanológico Universidad de Colima México D.F. México

Guadalajara city is the capital of the Mexican federal state of Jalisco. It is located close to the Pacific coast and is subjected to a large seismic risk. We present a seismic response study for some sites along the city. We calculated response spectra of shear-waves by using seismic records of actual earthquakes registered on rock and near the source as Green functions and propagated them trough a flat and horizontal layered media using a linear equivalent method to compare them with the response spectra calculated according to the Federal Commission of Electricity (CFE) seismic design buildings Manual (MOC-2008, 2008) which is widely used as reference on construction projects in Mexico. Our results show that MOC-2008 manual underestimates the spectral amplitudes and frequency band for the response spectra.

关键词： Response Spectra Guadalajara Seismic Records Green Function

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

Melatonin Avoids Anatomofunctional Changes Associated to Aging in a Rat Model

引用

Advances in Aging Research 2014年第4期3卷 318-325页

作者： Bertha Prieto Gómez Cruz reyes-Vázquez Mireya Velázquez-Paniagua departamento de Fisiología Facultad de Medicina UNAM México D.F. México

Melatonin is a hormone synthesized and released primarily by the pineal gland. Its secretion fol-lows a circadian rhythm with a peak overnight. Its secretion is initiated approximately to the three months of age and continues to rise during the childhood. Previous to the puberty there is a de-crease of melatonin secretion that continues until the old age. Melatonin has effects in the body and acts through at least four mechanisms: membrane receptors, orphan nuclear receptors, calmodulin and free radicals. It has been suggested that aging can be a consequence of the oxidation of cells that eventually become vulnerable to injury and die. This work reviews the antioxidant effects of melatonin in a rodent model, on the formation of free radicals, on the MAP2 protein expression and on the electrophysiology of the hippocampus at different ages. The results indicate that melatonin maintains in a “best” state to the experimental animals compared to controls. It suggests the use of melatonin as a therapy to prevent or delay the aging effects on the cells.

关键词： Rat Melatonin Hippocampus Antioxidant Aging

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：