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141.
Our research was made observing 6 infants for a period of 6 months in a group of 13 Macaca Rhesus in captivity conditions. We pointed out that mother-infant body contact behavior in Macaca Rhesus is strictly related to the mothers' rank order. In fact, as the infants of the same age grow up, the higher is the mother's rank order, the more frequent and varied are the infants' interactions with the other members of the group and the more frequently the body contact initiatives are taken by the infants. The behaviors observed in the first months of life can be also considered as the indispensable background of the subjects' future status in the group social structure. 相似文献
142.
Michael F. Dixon Robert M. Genta John H. Yardley Pelayo Correa & for the International Workshop on the Histopathology of Gastritis 《Helicobacter》1997,2(S1):17-24
An international workshop has assessed and revised the Sydney System for the reporting of gastritis. Much of the original approach was retained including division into acute , chronic and special forms, and grading of chronic inflammation, polymorph activity, atrophy, intestinal metaplasia and H. pylori density into mild, moderate and marked categories. Visual analog scales have been introduced as a simple guide to grading. The four biopsy sites have been changed to optimize detection of H. pylori , and supplemented by a fifth biopsy from the incisura angularis, the site which is most likely to yield premalignant changes. Chronic gastritis is classified into non-atrophic and atrophic forms with the latter divided into autoimmune (diffuse corpus atrophy) and multifocal . Histological reporting of gastritis should take into account the topographical pattern ( antral or corpus predominant ), and the final diagnostic term should ideally combine morphology and etiology to maximize the clinical value of gastric biopsy diagnosis. 相似文献
143.
Shinto H Tashiro Y Yamashita M Kobayashi G Sekiguchi T Hanai T Kuriya Y Okamoto M Sonomoto K 《Journal of biotechnology》2007,131(1):45-56
A kinetic simulation model of metabolic pathways that describes the dynamic behaviors of metabolites in acetone-butanol-ethanol (ABE) production by Clostridium saccharoperbutylacetonicum N1-4 was proposed using a novel simulator WinBEST-KIT. This model was validated by comparing with experimental time-course data of metabolites in batch cultures over a wide range of initial glucose concentrations (36.1-295 mM). By introducing substrate inhibition, product inhibition of butanol, activation of butyrate and considering the cessation of metabolic reactions in the case of insufficiency of energy after glucose exhaustion, the revised model showed 0.901 of squared correlation coefficient (r(2)) between experimental time-course of metabolites and calculated ones. Thus, the final revised model is assumed to be one of the best candidates for kinetic simulation describing dynamic behavior of metabolites in ABE production. Sensitivity analysis revealed that 5% increase in reaction of reverse pathway of butyrate production (R(17)) and 5% decrease in reaction of CoA transferase for butyrate (R(15)) highly contribute to high production of butanol. These system analyses should be effective in the elucidation which pathway is metabolic bottleneck for high production of butanol. 相似文献
144.
Hayashi H Nagae G Tsutsumi S Kaneshiro K Kozaki T Kaneda A Sugisaki H Aburatani H 《Human genetics》2007,120(5):701-711
DNA methylation is an epigenetic mark crucial in regulation of gene expression. Aberrant DNA methylation causes silencing
of tumor suppressor genes and promotes chromosomal instability in human cancers. Most of previous studies for DNA methylation
have focused on limited genomic regions, such as selected genes or promoter CpG islands (CGIs) containing recognition sites
of methylation-sensitive restriction enzymes. Here, we describe a method for high-resolution analysis of DNA methylation using
oligonucleotide tiling arrays. The input material is methylated DNA immunoprecipitated with anti-methylcytosine antibodies.
We examined the ENCODE region (∼1% of human genome) in three human colorectal cancer cell lines and identified over 700 candidate
methylated sites (CMS), where 24 of 25 CMS selected randomly were subsequently verified by bisulfite sequencing. CMS were
enriched in the 5′ regulatory regions and the 3′ regions of genes. We also compared DNA methylation patterns with histone
H3 and H4 acetylation patterns in the HOXA cluster region. Our analysis revealed no acetylated histones in the hypermethylated region, demonstrating reciprocal relationship
between DNA methylation and histone H3 and H4 acetylation. Our method recognizes DNA methylation with little bias by genomic
location and, therefore, is useful for comprehensive high-resolution analysis of DNA methylation providing new findings in
the epigenomics.
Electronic supplementary material Supplementary material is available in the online version of this article at
and is accessible for authorized users. 相似文献
145.
Multicellular compartmentation of catharanthus roseus alkaloid biosynthesis predicts intercellular translocation of a pathway intermediate 总被引:6,自引:0,他引:6
In situ RNA hybridization and immunocytochemistry were used to establish the cellular distribution of monoterpenoid indole alkaloid biosynthesis in Madagascar periwinkle (Catharanthus roseus). Tryptophan decarboxylase (TDC) and strictosidine synthase (STR1), which are involved in the biosynthesis of the central intermediate strictosidine, and desacetoxyvindoline 4-hydroxylase (D4H) and deacetylvindoline 4-O-acetyltransferase (DAT), which are involved in the terminal steps of vindoline biosynthesis, were localized. tdc and str1 mRNAs were present in the epidermis of stems, leaves, and flower buds, whereas they appeared in most protoderm and cortical cells around the apical meristem of root tips. In marked contrast, d4h and dat mRNAs were associated with the laticifer and idioblast cells of leaves, stems, and flower buds. Immunocytochemical localization for TDC, D4H, and DAT proteins confirmed the differential localization of early and late stages of vindoline biosynthesis. Therefore, we concluded that the elaboration of the major leaf alkaloids involves the participation of at least two cell types and requires the intercellular translocation of a pathway intermediate. A basipetal gradient of expression in maturing leaves also was shown for all four genes by in situ RNA hybridization studies and by complementary studies with dissected leaves, suggesting that expression of the vindoline pathway occurs transiently during early leaf development. These results partially explain why attempts to produce vindoline by cell culture technology have failed. 相似文献
146.
147.
Dorati R Colonna C Serra M Genta I Modena T Pavanetto F Perugini P Conti B 《AAPS PharmSciTech》2008,9(2):718-725
To evaluate the effects of different gamma irradiation doses on PEGd,lPLA and PEG-PLGA multiblock copolymers. The behaviour
of the multiblock copolymers to irradiation was compared to that of PLA, PLGA polymers. PEGd,lPLA, PEG-PLGA, PLA and PLGA
polymers were irradiated by using a 60Co irradiation source at 5, 15, 25 and 50 kGy total dose. Characterization was performed on all samples before and after irradiation,
by nuclear magnetic resonance (NMR), infrared absorption spectrophotometry (FTIR) and gel permeation chromatography (GPC).
The effect of gamma irradiation on polymer stability was also evaluated. Results of NMR and FTIR suggest an increase in -OH
and -COOH groups, attributed to scission reactions induced by irradiation treatment. Data of GPC analysis showed that the
weight average molecular weight (Mw) of polymer samples decreased with increasing irradiation dose. The extent of Mw degradation
expressed as percentage of Mw reduction was more prominent for polymers with high molecular weight as PEGd,lPLA and PLA. The
dominant effect of gamma-irradiation on both polymer samples was chain scission. The multiblock copolymer PEGd,lPLA presented
higher sensitivity to irradiation treatment with respect to PLA, likely due to the presence of PEG in the matrix. The effect
of gamma irradiation continues over a much longer period of time after gamma irradiation has been performed. It is suggested
that the material reacts with oxygen to form peroxyl free radicals, which may further undergo degradation reactions during
storage after irradiation. 相似文献
148.
Seroepidemiology of strongyloidiasis in a Thai village 总被引:1,自引:0,他引:1
R W Douce A E Brown C Khamboonruang P D Walzer R M Genta 《International journal for parasitology》1987,17(7):1343-1348
Strongyloidiasis is a potentially fatal disease for which existing methods of diagnosis lack sensitivity. A recently developed ELISA for IgG antibodies against the infective larval stage was used to screen a leprosy resettlement village in an area endemic for strongyloidiasis. The results of the ELISA were compared with the results of stool examination for 177 villagers. Eleven per cent of the village had S. stercoralis present on stool examination and 45% had antibodies detected by ELISA. Eighteen of 21 (85%) villagers with S. stercoralis infection proven by stool examination had positive ELISA values. No cross reactivity with intraluminal parasites was present. Linear correlation between per cent eosinophils and the ELISA revealed a correlation coefficient of 0.402 (P < 0.001). Forty-two days after sucessful treatment in 14 villagers, the IgG antibody levels had decreased (P < 0.001). Leprosy did not affect the sensitivity of the assay. These results suggest that ELISA is a simple, sensitive and specific method for surveying exposure to S. stercoralis in an endemic area. 相似文献
149.
Genta RM 《Parasitology today (Personal ed.)》1986,2(9):241-246
In the highly competitive world of parasites, where survival is indissolubly tied to the presence of suitable hosts in the same ecological niche, Strongyloides stercoralis occupies a unique position. This versatile nematode has developed a successful relationship with two ecosystems, the terrestrial environment and the mammalian body, by becoming facultatively independent of either (Box 1). It requires external maturation for transmission, but it also has the ability to multiply within a single host. It prefers man, but may infect apes, monkeys, dogs and cats. As a human parasite, S. stercoralis establishes self-perpetuating intestinal colonies and negotiates their survival with the host's defense mechanisms. In this article, Robert Genta reviews the immunobiological aspects of this unusual relationship. 相似文献
150.
华北石质山地侧柏人工林C、N、P生态化学计量特征的季节变化 总被引:5,自引:0,他引:5
以北京九龙山自然保护区幼龄侧柏人工林为研究对象,对其不同生长季节叶、枝、根(0—10 cm、10—20 cm土层)的碳(C)、氮(N)、磷(P)含量及其生态化学计量学特征进行了分析,深入探讨了生长季节与器官以及两因素交互作用对以上特征的影响,研究有助于理解植物各性状之间的相互作用以及植物生长过程中资源的利用和分配状况。结果表明:1)不同器官间C含量为414.97—461.58 g/kg,枝最大,根(0—10 cm)最小;N含量为6.57—14.28 g/kg,叶最大,枝最小;P含量为0.39—1.28 g/kg,叶最大,根(10—20 cm)最小;C∶N为31.76—70.98,枝最大,叶最小;C∶P为369.93—1099.20,根(10—20 cm)最大,叶最小;N∶P为9.21—23.81,根(0—10 cm)最大,枝最小。整个生长季节中侧柏各器官C含量最稳定,变异系数均小于7%;P含量变异性最大,变异系数均超过15%,N含量变异性介于两者之间;各器官中C∶N和N∶P较C∶P更为稳定,C、N与P具有较好的耦合协同性,C∶P和N∶P的变化主要取决于P的变化。2)器官对C、N、P含量及其化学计量关系均存在显著影响,生长季节对N和P含量存在显著影响,两者交互作用只对P含量存在显著影响,器官对侧柏C、N、P含量及其化学计量变异的贡献大于生长季节。3)侧柏各器官间C、N、P含量及其化学计量比相关性多数未达到显著性水平,仅有叶与枝中的P及C∶P显著相关,说明侧柏器官分化过程中各器官对元素的吸收利用具有特异性。侧柏叶片N∶P14,说明生长季节里幼龄侧柏人工林更多受到N限制。 相似文献