检索结果-南通市图书馆

Clinical oncology 英文影印三

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Alcohol-induced steatosis in liver cells

2003年

作者： Raymond e.Lenhard jr. robert T.Osteen Ted Gansle

来源：畅想之星图书光盘版（南... 评论

在线全文

畅想之星图书光盘版（南通市图书馆镜像）

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2007年第37期13卷 4974-4978页

作者： Terrence M Donohue jr Liver Study Unit The Omaha Veterans Affairs Medical Center the Department of Internal Medicine University of Nebraska Medical Center Omaha Nebraska 68105 United States

Alcohol-induced fatty liver (steatosis) was believed to result from excessive generation of reducing equivalents from ethanol metabolism, thereby enhancing fat accumulation. Recent findings have revealed a more complex picture in which ethanol oxidation is still required, but specific transcription as well as humoral factors also have important roles. Transcription factors involved include the sterol regulatory element binding protein 1 (SReBP-1) which is activated to induce genes that regulate lipid biosynthesis. Conversely, ethanol consumption causes a general down-regulation of lipid (fatty acid) oxidation, a reflection of inactivation of the peroxisome proliferator- activated receptor-alpha (PPAR-α) that regulates genes involved in fatty acid oxidation. A third transcription factor is the early growth response-1 (egr-1), which is strongly induced prior to the onset of steatosis. The activities of all these factors are governed by that of the principal regulatory enzyme, AMP kinase. Important humoral factors, including adiponectin, and tumor necrosis factor-α (TNF-α), also regulate alcohol-induced steatosis. Their levels are affected by alcohol consumption and by each other. This review will summarize the actions of these proteins in ethanol-elicited fatty liver. Because steatosis is now regarded as a significant risk factor for advanced liver pathology, an understanding of the molecular mechanisms in its etiology is essential for development of effective therapies.

关键词： ethanol metabolism Fatty liver Sterolregulatory element binding protein Peroxisomeproliferator activated receptor early growth response-i Fatty acid toxicity Triglycerides Acetaldehyde Reactiveoxygen species

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

高性能电源转换器引进同步整流技术的好处

电子技术应用 2006年第11期32卷 I0001-I0007页

作者： robert Selders.jr. 美国国家半导体应用技术工程师

越来越多电子设备生产商及供应商喜欢采用电源转换器，希望能藉此进一步提高电源供应系统的性能，例如，降低输入输出电压、提高输出电流以及加快瞬态响应，以满足新产品的严格要求。

关键词：电源转换器同步整流技术性能引进设备生产商供应系统输出电压瞬态响应

Hematomas and Limb Skeletal Malformations in Chicken embryos Following exposure to 5-Fluoro-2'-Deoxyuridine

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Biomedical and environmental Sciences 1998年第1期11卷 15-30页

作者： robert S. NOLAN GARRY SCHWARTZ SeAN FARQUHARSON DAVID R.HOOTNICK e. MARK LeVINSOHN MARY MILLeR LISA A. MANZ AND DAVID S. PACKARD, jr (Departments of Anatomy and Cell Biology, Orthopedic Surgery,and Pediatrics, State University of New York Health Department of Anatomy and Cell Biology State University of New York Health Science Center Syracuse 13210 USA.

Vascular injury or interruption may play a role in vertebrate limb teratogenesis. Since 5fluoro- 2'- deoxyuridine (FdU) can cause vascular injury in the murine limb and skull prior to the appearance of skeletal malformations in these structures, we studied the effects of this chemical on skeletal development in the chick embryo and noted any vascular injury. The yolk sacs of day three ehick embryos (Hamburger and Hamilton states 17-19) were injected with solutions of vary concentrations of FdU in saline. The embryos developed until the 10th day of incubation when they were fixed for study. Uninjected, saline injected, and sham injected control embryo were similarly fixed. Upon gross inspection, frequent diffuse and saccular hernatomas, as well as fluid-filled blisters, were noted in the limbs of embryos treated with FdU. After the embryos were fixed and cleared, and the skeletons stained, significant skeletal malformations were observed in these limbs. Bony elements of both the upper and lower limbs were affected in at least some of the embryos. The combination of FdU-induced hematomas and blisters with associated skeletal malformations in the same regions of some embryos suggests a relationship between these phenomena.

关键词： Hematomas and Limb Skeletal Malformations in Chicken embryos Following exposure to 5-Fluoro-2 Deoxyuridine

AIDS and associated malignancies

在线全文

学校读者我要写书评

暂无评论

Cell Research 2005年第Z1期15卷 947-952页

作者： Charles WOOD William HARRINGTON jr Nebraska Center for Virology & School of Biological Sciences University of Nebraska Lincoln NE 68588 USA Sylvester Cancer Center University of Miami Miami FL 33136 USA

AIDS associated malignancies (ARL) is a major complication associated with AIDS patients upon immunosuppression. Chronically immunocompromised patients have a markedly increased risk of developing lymphoproliferative disease. In the era of potent antiretrovirals therapy (ARV), the malignant complications due to HIV-1 infection have decreased in developed nations where ARV is administered, but still poses a major problem in developing countries where HIV-1 incidence is high and ARV is still not yet widely available. even in ARV treated individuals there is a concern that the prolonged survival of many HIV-1 carriers is likely to eventually result in an increased number of malignancies diagnosed. Malignancies that were found to have high incidence in HIV-infected individuals are Kaposi’s sarcoma (KS), Hodgkin’s disease (HD) and non-Hodgkin’s lymphoma (NHL). The incidence of NHL has increased nearly 200 fold in HIV-positive patients, and accounts for a greater percentage of AIDS defining illness in the US and europe since the advent of HAART therapy. These AIDS related lymphomas are distinct from their counterparts seen in HIV-1 seronegative patients. For example nearly half of all cases of ARL are associated with the presence of a gamma herpesvirus, epstein Barr virus (eBV) or human herpesvirus-8 (HHV-8)/ Kaposi’s sarcoma associated herpesvirus (KSHV). The pathogenesis of ARLs is complex. B-cell proliferation driven by chronic antigenemia resulting in the induction of polyclonal and ultimately monoclonal lymphoproliferation may occur in the setting of severe immunosuppression.

关键词： Kaposi’s sarcoma lymphomas epstein-Barr virus KS-associated herpesvirus human herpesvirus 8.

Deformation‑Induced Strengthening Mechanism in a Newly Designed L‑40 Tool Steel Manufactured by Laser Powder Bed Fusion

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(english Letters) 2023年第1期36卷 21-34页

作者： Yuan Tian Kanwal Chadha Clodualdo Aranas jr Voestalpine Additive Manufacturing Centre Ltd MississaugaON L5N 7Y3Canada Department of Mechanical engineering University of New BrunswickFrederictonNB E3B 5A3Canada Planetary and Space Science Centre University of New BrunswickFrederictonNB E3B 5A3Canada

The microstructural and mechanical properties of a newly designed tool steel(L-40),specifcally designed to be employed in the laser powder bed fusion(LPBF)technique,were *** pool boundaries with submicron dendritic structures and about 14%retained austenite phase were evident after *** grain orientation after high cooling rate solidifcation is mostlyα∥building direction(BD).Then,the heat treatment converted the microstructure into a conventional martensitic phase,reduced the retained austenite to about 1.5%,and increasedα∥BD *** heat-treated sample exhibits higher tensile strength(1720±14 MPa)compared to the as-printed sample(1540±26 MPa)along the building direction,mainly due to hardening caused by a lower volume fraction of retained austenite phase and precipitation of *** a consequence of the strength-to-ductility trade-of,the heat-treated sample showed lower elongation(10%±2%)than that of the as-printed sample(18%±2%).It was observed that transformation-induced plasticity(TRIP)occurs in both the as-printed and heat-treated samples during tensile testing,which dynamically transforms the retained austenite into martensite,leading to improved *** minimum driving force to initiate the displacive phase transformation is about 6000 J/mol,which was achieved during tensile *** strength and ductility of LPBF-produced L-40 were compared with the other LPBF-produced tool steels in literature;the data indicate that heat-treated L-40 has an excellent combination of strength and ductility complemented with high printability.

关键词： Additive manufacturing Laser powder bed fusion L-40 tool steel Phase transformation

Mitogenomes of historical type specimens unravel the taxonomy of sportive lemurs(Lepilemur spp.)in Northwest Madagascar

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Zoological Research 2021年第4期42卷 428-432页

作者： Christian Roos roberto Portela Miguez Richard Sabin edward e.Louis jr Michael Hofreiter Dietmar Zinner Gene Bank of Primates and Primate Genetics Laboratory German Primate CenterLeibniz Institute for Primate ResearchGoettingen 37077Germany Natural History Museum London SW7 BDUK Center for Conservation and Research Omaha’s Henry Doorly Zoo and AquariumOmahaNebraska 68107USA Institute for Biochemistry and Biology University of PotsdamPotsdam 14476Germany Cognitive ethology Laboratory German Primate CenterLeibniz Institute for Primate ResearchGoettingen 37077Germany Leibniz Science Campus Primate Cognition Goettingen 37077Germany Department of Primate Cognition Georg-August-UniversityGoettingen 37083Germany

Accurate information on name-bearing types,including corresponding type localities,is essential for proper ***,such geographic information is often missing or *** localities of type specimens collected 100–200 years ago can be difficult to trace due to changes in local names or simple *** a case can be found for the gray-backed sportive lemur(Lepilemur dorsalis),with its type locality imprecisely fixed as Northwest *** recent years,eight species have been newly described for the Inter-River-Systems(IRSs)of this region,however the designation of *** remains controversial due to a lack of a precise type ***,we sequenced the complete mitochondrial genomes(mitogenomes)of type specimens of *** and ***,which is currently recognized as a synonym of *** and compared their sequences with those of samples of known provenance from different *** showed that the two type specimens of *** and *** had identical mitogenome sequences and clustered closely with samples collected in IRS V,indicating that the type locality could be fixed to IRS ***,*** occurs in IRS V,and *** and *** are junior synonyms of *** finding demonstrates the value of type specimens for clarifying phylogeographic and taxonomic questions and clarifies the taxonomy of sportive lemurs in Northwest Madagascar.

关键词： precise identical finding

effects of a regenerating matrix on the survival of birds in tropical forest fragments

在线全文

学校读者我要写书评

暂无评论

Avian Research 2020年第1期11卷 16-24页

作者： Jared D.Wolfe Philip C.Stouffer Richard O.Bierregaard jr David A.Luther Thomas e.Lovejoy College of Forest Resources and environmental Science Michigan Technological UniversityHoughtonMI 49931USA Biological Dynamics of Forest Fragments Project Instituto Nacional de Pesquisas da AmazoiaManaus 69011Brazil College of Renewable Natural Resources Louisiana State University AgCenterLouisiana State UniversityBaton RougeLA 70803USA Biology Department George Mason University4400 University Drive MS3EFairfaxVA 22030USA

Background: Vast areas of lowland neotropical forest have regenerated after initially being cleared for agricultural purposes. The ecological value of regenerating second growth to forest-dwelling birds may largely depend on the age of the forest, associated vegetative structure, and when it is capable of sustaining avian demographics similar to those found in pristine ***: To determine the influence of second growth age on bird demography, we estimated the annual survival of six central Amazonian bird species residing in pristine forest, a single 100 and a single 10 ha forest fragment, taking into consideration age of the surrounding matrix(i.e. regenerating forest adjacent to each fragment) as an explanatory ***: Study species exhibited three responses: arboreal, flocking and ant-following insectivores(Willisornis poecilinotus, Thamnomanes ardesiacus and Pithys albifrons) showed declines in survival associated with fragmentation followed by an increase in survival after 5 years of matrix regeneration. Conversely, Percnostola rufifrons, a gap-specialist, showed elevated survival in response to fragmentation followed by a decline after 5 years of regeneration. Lastly, facultative flocking and frugivore species(Glyphorynchus spirurus and Dixiphia pipra, respectively) showed no response to adjacent clearing and subsequent ***: Our results in association with previous studies confirm that the value of regenerating forest surrounding habitat patches is dependent on two factors: ecological guild of the species in question and second growth age. Given the rapid increase in survival following succession, we suggest that the ecological value of young tropical forest should not be based solely on a contemporary snapshot, but rather, on the future value of mature second growth as well.

关键词： Amazon fragmentation Brazil Matrix Second growth Survival Tropical bird

Dietary free fatty acids complex with amylose creating another form of resistant starch: Gastrointestinal formation with fowl and swine

在线全文

学校读者我要写书评

暂无评论

Animal Nutrition 2021年第4期7卷 1124-1132页

作者： edwin T.Moran jr. Poultry Science Department Auburn UniversityAL36849-5416USA

Fat added to poultry and swine feeds often contains abundant free fatty acids(FFA)that can impair digestible energy(De).Placement of the fatty acid(FA)hydrocarbon chain in the helix core reformed from amylose creates a complex of both *** modifications create a new structure termed the V-helix that becomes resistant toα-*** in grain naturally contain minimal amounts of these complexes with more being generated during food manufacturing when moisture and heat release amylose in the presence of FFA.A paucity of FFA usually exists in complete feeds without sources of poorquality *** fats and by-product meals from rendering are prominent in their saturated FFA content which favorably complex within the helix.V-helix-FA complexes may arise during their concurrent encounter of FFA together with amylose during feed manufacture,particularly *** in the gastrointestinal tract(GIT)are speculated to further form complexes when present together with *** amylose may be dissolved in the gastric and small intestinal milieu,FFA separately coalesce into hydrophobic fat droplets along with other dietary *** of complexes is likely restricted until FFA are released into the aqueous phase during fat ***α-amylase may be prominent,V-helix-FA complexes being resistant to enzymic attack pass into the large *** microbial catabolism of V-helices may generate volatile fatty acids that are absorbed by the mucosa;however,an inability to use FFA once released leads to their excretion and basis for decreased *** microbial populations with young animals usually lack the capacity to fully catabolize the V-helix,further extending the loss in De.

关键词： Amylose Digestible energy Free fatty acid Feed manufacture