检索结果-南通市图书馆

Carbon-13 Solid State NMR Techniques to Evaluate the Morphology of PP/TiO₂ Composites

Materials Sciences and Applications 2016年第1期7卷 20-25页

作者： Igor Lopes Soares Maria Inês Bruno Tavares André luis B. B. e Silva Antonio gabriel Malagueta Feio Instituto de Macromoléculas Universidade Federal do Rio de Janeiro Rio de Janeiro Brazil Instituto Federal do Mato Grosso IFMT Mato Grosso Brazil CENIMAT/I3N Departamento de Ciência dos Materiais Faculdade de Ciências e Tecnologia Universidade Nova de Lisboa Caparica Portugal

Solid state NMR was successfully used to determine the proton spin-lattice relaxation time in the rotating frame (T1ρH) for systems based on polypropylene (PP) and PP with titanium dioxide (TiO2) organically modified or unmodified incorporated, in order to understand the molecular behavior of these systems. These techniques were employed in the samples organically modified and unmodified TiO2 to investigate the effect of organic modification on the dispersion and distribution of the particles in the PP matrix. The results were analyzed in terms of the effect of the particles organic modified or not according to the intermolecular interaction in the composites. According to the T1ρH values, all composites showed at least two domains: the short values were related to the rigid part, which included the crystalline and amorphous phase constricted in it, while the longer times were attributed to the amorphous region, which had higher molecular mobility compared to the rigid region of the materials. The increase in the relaxation time parameter in the composites compared to the pure PP was associated to the strong interaction between titanium dioxide particles and the polymer chains. This effect was more pronounced for the systems containing organically modified TiO2. According to the results, it could be inferred that intermolecular interaction occurred in the CH2 and CH groups, being more intense with CH2 groups. Finally, the solid state NMR techniques were able to evaluate the molecular dynamics of those systems.

关键词： NMR PP TiO2 Composites

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

Structural and Electronic Properties of Ruthenium-Doped Germanium Clusters

Structural and Electronic Properties of Ruthenium-Doped Germ...

引用

第六届全国计算原子与分子物理学术会议

作者： Yuanyuan Jin Yonghong Tian Xiaoyu Kuang Cheng Lu Jose? luis Cabellos Sukanta Mondal gabriel Merino Institute of Atomic and Molecular Physics Sichuan University Department of Physics Nanyang Normal University Department of Physics and Optoelectronic Engineering Yangtze University Department of Physics and High Pressure Science and Engineering Center University of Nevada

＜正＞During the past decade,there has been tremendous interest in germanium-based clusters because they are the building blocks of self-assembling semiconductors and are useful in synthesizing new novel materials.[1,2]A large number of experimental and theoretical investigations have been performed on pure germanium clusters.[3,4]According to these studies,such clusters cannot form stable fullerene-like ***,

关键词：

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Relationship of Polymorphisms of Glutathione S-Transferase GSTT1 and GSTM1 With the Response to Chemotherapy In Mexican Women with Advanced Breast Cancer

引用

Journal of Cancer Therapy 2011年第3期2卷 354-361页

作者： Odeth Soto-Quintana Paula Cabrera-Galeana gabriel Téllez-Trevilla José luis Barrera-Franco Alejandro Juárez-Ramiro Julieta Castillo-Cadena 不详

Introduction: Breast cancer is a common disease diagnosed in Mexican women and the first leading cause of death [1]. Heterogeneity in patients’ response to treatment is consistently observed across populations. Glutathione S-transferases (GSTs) are involved in the metabolism of environmental carcinogens, reactive oxygen species and chemotherapeutic agents by catalyzing the glutathione with electrophilic compounds. The deletion of GSTT1 and GSTM1 genes result in loss of enzyme activity. A few studies evaluated the response to treatment and the polymorphisms of GSTT1 and GSTM1. The aim of this work is to make the association of the null polymorphisms of GSTT1 and GSTM1 with the response to chemotherapy basically doxorubicin and cyclophosphamide. Methods: The genotyping of thirty patients with breast cancer was made with the Polymerase chain reaction, to identify the polymorphisms of GSTT1 and GSTM1. We determine the status of Her-2 neu, estrogen and progesterone receptors, then the response to treatment was made with an ultrasound and pathological data. We made the association with the χi2 statistics using a p≤0.05. Results: Using the Sigma Stat 3.5 program and the chi-squared analysis, we do not observe a significant association with the GSTT1+/GSTM1+, GSTT1-/GSTM1+ and GSTT1-/GSTM1-polymorphisms and the better or worse response to cyclophosphamide and doxorubicin. With the Her-2 neu, estrogen and progesterone receptors status, we neither found an association with the response to the therapy. Conclusion: This study suggests that GSTT1 and GSTM1 polymorphisms have no statistical significance between the genotype of women with advanced breast cancer and the response to neoadjuvant chemotherapy, but we can see a clear tendency toward better response with the null genotype.

关键词： Breast Cancer GSTT1 GSTM1 Polymorphisms Chemotherapy Response

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

Selective and constructive mechanisms contribute to neural circuit formation in the barrel cortex of the developing rat

引用

Advances in Bioscience and Biotechnology 2013年第7期4卷 785-797页

作者： Eileen Uribe-Querol Eduardo Martínez-Martínez luis Rodrigo Hernández Patricia Padilla Cortés Horacio Merchant-Larios gabriel Gutiérrez-Ospinac Cell Biology and Physiology Department Instituto de Investigaciones Biomédicas Universidad Nacional Autónoma de México Mexico City Mexico División de Estudios de Posgrado e Investigación Facultad de Odontología Universidad Nacional Autónoma de México Mexico City Mexico Unidad de HPLC Instituto de Investigaciones Biomédicas Universidad Nacional Autónoma de México Mexico City Mexico

The cellular strategy leading to formation of neuronal circuits in the rodent barrel cortex is still a matter of controversy. Both selective and constructive mechanisms have been proposed. The selective mechanism involves an overproduction of neuronal processes and synapses followed by activity dependent pruning. Conversely, a constructive mechanism would increase the number of axons, dendrites, and synapses during development to match functionality. In order to discern the contributions of these two mechanisms in establishing a neuronal circuit in the somatosensory cortex, morphometric analysis of dendritic and axonal arbor growth was performed. Also, the number of synapses was followed by electron microscopy during the first month of life. We observed that axonal and dendritic arbors retracted distal branches, and elongated proximal branches, resulting in increased arbor complexity. This neuronal remodeling was accompanied by the steady increase in the number of synapses within barrel hollows. Similarly, the content of molecular markers for dendrites, axons and synapses also increased during this period. Finally, cytochrome oxidase activity rose with age in barrels indicating that the arbors became more complex while synapse density and metabolic demands increased. Our results support the simultaneous use of both selective and constructive mechanisms in establishing the barrel cortex circuitry.

关键词： Barrel Cortex Synaptogenesis Axonal Growth Dendritic Growth Thalamocortical Pathway

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

Mechanical Properties of Composite Mortars Using Flurogypsum and PvC Particles

引用

Materials Sciences and Applications 2014年第4期5卷 212-222页

作者： luisa Maria Flores-vélez Hector valle gabriel García Roberto Torres Martha Lomelí Octavio Domínguez Facultad de Química-UASLP Salvador México Instituto de Metalurgia-UASLP San Luis Potosí México Mexichem Flúor San Luis Potosí México

The present work describes the viability of a mortar binder based on two industrial by-products: poly(vinyl chloride) (PvC) particles from scrap and anhydrite (CaSO4) from fluorgypsum. Mortar composites were made incorporating different amounts of PvC particles and cured at constant room temperature during various periods of time. From X-ray diffraction, it was possible to follow the hydration process and to estimate the effect of the PvC particles on anhydrite transformation to gypsum (CaSO4·2H2O). Compressive strength from uniaxial testing was measured from stress-strain curves carried out at room temperature. According to these results, the hydration rates of the composites depend on the concentration of PvC particles and there is an enhancement in their compressive strength as particle content increases, reaching values of 36 MPa after 28 days.

关键词： Compressive Strength Recycled PvC Hydraulic Binder Alternative Building Materials Gypsum-Composite

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

Energy Conversion Factor for Gasoline Engines in Real-World Driving Emission Cycle

引用

Automotive Innovation 2020年第2期3卷 169-180页

作者： Toshizaemom Noce Sérgio de Morais Hanriot luis Carlos Monteiro Sales JoséRicardo Sodré Matheus Bitarães de Novaes Department of Mechanical Engineering Pontifical University of Minas GeraisAv.Dom JoséGaspar 500Belo HorizonteMG 30535-901Brazil School of Engineering&Applied Science Aston UniversityAston TriangleBirmingham B47ETUK Department of Electrical Engineering Federal University of Minas GeraisAv.Pres.Antônio Carlos6627Belo HorizonteMG 31270-901Brazil

A precise energy conversion factor is required to define the impact of greenhouse gas emissions by gasoline-powered vehi-cles and policies that will guide the application of future *** current energy conversion factor adopted by many countries is based on the Willans line approach,initially proposed in 1888 for steam engines,later adapted for internal combustion *** actual energy conversion factor,which defines the energy conversion for drivers in real traffic,is *** this article,eight world-class engines are tested in an engine bench for the acquisition of specific fuel consumption 3D ***,their energy conversion factors,calculated by dividing the energy output by the energy input,are simulated in real and urban traffic,acquired according to the real driving emissions(RDE)*** addition,a reference vehicle is instrumented to measure the energy input(fuel flow)and the energy output(mechanical energy in the half axles)under the same RDE cycle *** results of both procedures are very similar,respectively,0.405±0.04 L/kWh for the simulation based on eight benchmark engines,and 0.392±0.04 L/kWh for the reference vehicle driven in RDE traffic conditions,with a 95%confidence *** turbocharged engines,the factor attained by the simulation is 0.395±0.04 L/*** values of the energy conversion factor for gasoline engines got in this research are higher than those obtained through the Willans line approach,suggesting a new standard value of 0.405 L/kWh,replacing the current 0.264 L/*** could substantially change the greenhouse gas emissions in a tank-to-wheel approach for the entire vehicle and add-on eco-innovations.

关键词： Energy conversion factor Willans line EC443 Eco-innovation CO_(2)emission

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

Role of Nitrogen and Nutrients in Crop Nutrition

引用

Journal of Agricultural Science and Technology(B) 2014年第1期4卷 29-37页

作者： vicente Torres-Olivar Oscar gabriel villegas-Torres Martha Lilia Dominguez-Patifio Hoctor Sotelo-Nava Antonio Rodrlguez-Martme Rosa Maria Melgoza-Aleman luis Alonso valdez-Aguilar Irfin Alia-Tejacal Faculty of Agricultural Sciences Universidad Aut6noma del Estado de Morelos Col. Chamilpa 62209 Cuernavaca MorelosM~xico Faculty of Chemical Sciences and Engineering Universidad Aut6noma del Estado de Morelos Col. Chamilpa 62209 CuernavacaMorelos Mdxico Engineering and Applied Science Research Center Universidad Autdnoma del Estado de Morelos Col. Chamilpa 62209Cuernavaca Morelos M6xieo Department of Horticulture University Autonomous Agraria Antonio Narro Saltillo Coahuila 25315 M~xico

Nutrition is an important factor for the growth and development of plants. Among the main nutritional elements, there are nitrogen （N） and calcium （Ca）. The N comes from two forms of inorganic ions, ammonium （NH4＋） and nitrate （NO3） whose functions in the plant are the increase in leaf area and improving the succulence of many crops, among other essential physiological processes. Both the deficit and excess NO3- have a negative impact on plants increasing susceptibility to insect pests and pathogens, while Ca as divalent ion absorbed Ca2＋ plays an important role in control of physiological disorders and the resistance of plants to diseases to increase the mechanical strength. The N and Ca have a close relationship in the nutritional role of the plant, because the Ca absorption acting nitrates, so that a proper balance affects plants better growth and higher strength.

关键词： Ions absorption nitrate ammonium concentration.

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

Nitrogen/Ammonium Concentration Response of vegetable and Flower Crops

引用

Journal of Agricultural Science and Technology(B) 2014年第4期4卷 261-266页

作者： Armando Hemandez-Perez Oscar gabriel villegas-Torres Martha Lilia Dominguez-Patifio Martha Lilia Dominguez-Patino Hector Sotelo-Nava Antonio Rodriguez-Martinez luis Alonso valdez-Aguilar Iria Alia-Tejacal Faculty of Agricultural Sciences University Autonomous of the State of Morelos Cuernavaca 62209 Mexico Faculty of Chemical Sciences and Engineering University Autonomous of the State of Morelos Cuernavaca 62209 Mexico EngineeringandAppliedScience Research Center UniversityAutonomous of the State ofMorelos Cuernavaca 62209 Mexico Department of Horticulture University Autonomus Agrarian Antonio Narro Saltillo 25315 Mexico

Nitrogen （N） is the element with the greatest influence on the growth of vegetables and ornamentals, however, form of delivery, either as nitrate （NO3） or ammonium （NH4＋） has different effects on plant development. The NO3 is the main form of N that plants absorb, but when it is the only source of N that has slight effects on root growth, no effects over enzymatic activities, and stimulates the absorption and translocation of cations within the plant. The NH4＋ is the easiest way of assimilation but is highly toxic when the only source or with respect to the concentration of NO3 is too high. To avoid toxicity, the NH4＋ must not exceed 20% of the total N amount in the formulation, however, it is important to consider the species, variety and environmental conditions. The N as supplied also affects the resistance or susceptibility of plants to diseases, but depends on the species and the type of pathogen.

关键词： Nitrate ammonium vegetables ornamental toxicity nutrition.

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

Alterations in fibrinolytic system proteins PAI-1,MMP-3,MMP-8,TIMP-1 and TIMP-2 in post-cholecystectomy bile duct injury

引用

Journal of Biomedical Science and Engineering 2013年第8期6卷 58-67页

作者： Jose Manuel Hermosillo-Sandoval luis Miguel Román-Pintos Adolfo Daniel Rodriguez-Carrizález Ernesto Germán Cardona-Munoz Fermin Paul Pacheco-Moisés Genaro gabriel Ortiz Alejandra Guillermina Miranda-Diaz Department of Surgery Specialties Hospital of the National Occidental Medical CentreSocial Security Institute of Mexico(Departamento de CirugíaHospital de Especialidades del Centro Médico Nacional de OccidenteInstituto Mexicano del Seguro Social)GuadalajaraMéxico University Health Sciences Centre University of Guadalajara(Centro Universitario de Ciencias de la SaludUniversidad de Guadalajara)GuadalajaraMéxico University Centre for Exact and Engineering Sciences University of Guadalajara(Centro Universitario de Ciencias Exactas e IngenieríasUniversidad de Guadalajara)GuadalajaraMéxico Pathology and Oxidative Stress Laboratory Division of NeurosciencesOccidental Biomedical Research CentreSocial Security Institute of Mexico(Laboratorio de Estrés Oxidativo&PatologíaDivision de NeurocienciasCentro de Investigacion Biomédica de OccidenteInstituto Mexicano del Seguro Social)GuadalajaraMéxico

Introduction: In bile duct injuries (BDI), cholestasis and cholangitis can alter the fibrinolytic system by promoting an increase of extracellular matrix depositions which favor an imbalance between metalloproteinases (MMPs) and their tissue inhibitors (TIMPs). Materials and Methods: Levels of PAI-1, MMP-3, MMP-8, TIMP-1 and TIMP-2 in 35 patients with post-cholecystectomy BDI by complete biliary obstruction were measured and compared to a healthy control group. Sirius red staining and immune staining for MMP-3 and MMP-8 were also undertaken in liver biopsies. Results: Levels of PAI-1, TIMP-1, TIMP-2 and MMP-8 were higher in BDI than healthy controls: 15 ± 2 ng/mL vs 7.1 ± 2 ng/mL (p 0.024);539 ± 64 ng/mL vs 256 ± 13 ng/mL (p p p 2 vs. 22865.7 ± 3865 μm2 in healthy controls (p 2 vs. 30744.2 ± 5810.2 μm2 (p 2 vs. 116337.9 ± 24803.3 μm2 (p 0.55). These results suggest an imbalance between fibrogenic/fibrinolytic protein levels. Interestingly, expression of the fibrinolytic protein MMP-8 was increased in serum and liver biopsies in BDI. Conclusion: We found an imbalance of profibrogenic molecules which promote extracellular matrix deposition. The over-expression of fibrinolytic proteins such as MMP-8 could limit liver fibrosis, preventing hepatic dysfunction in post-cholecystectomy BDI.

关键词： Cholecystectomy Bile Duct Injury(BDI) Plasminogen Activator Inhibitor Type 1(PAI-1) Tissue Inhibitors of Metalloproteinases(TIMP’s) Metalloproteinases(MMP’s)

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

New Evidence on Rotational Dynamics

引用

World Journal of Mechanics 2013年第3期3卷 174-177页

作者： luis Alberto Pérez Curiosity & Intuition for Understanding and Knowledge Valladolid Spain

In this paper, the author confirmed a new theory to explain the mechanical behavior of macroscopic bodies. The confirmed hypothesis is the Theory of Dynamics Interaction by the Professor gabriel Barceló. Barceló explained his theory in an article called “Analysis of Dynamics Fields in Noninertial Systems”, World Journal of Mechanics, vol. 2, No. 3, 2012, pp. 175-180. This hypothesis holds that the mechanical behavior of macroscopic bodies in a non-inertial environment opens new assumptions on inertial fields and rotational dynamics. An associated experiment was presented to support the discussion in the paper. The author first became aware of the proposals of Professor gabriel Barceló’s Theory of Dynamics Interaction through his 2006 article on Saturn planet rings, which suggested unsolved phenomena in rotational dynamics and the inception of a novel theory [1]. Intuitively, the author realized himself about the fact that the cosmos is mechanical from its smallest to its widest comprehensible appreciation. If material behavior is mechanical everywhere and every time, from a subatomic particle, wave or string, to a cluster of galaxies, then our understandable solutions must comply with the Laws of Motion, it could be believed.

关键词： Rotational Dynamics Field Theory Superposition of Simultaneous Motions Macroscopic Bodies Mechanics Inertial Fields Torque Angular Momentum

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：