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81.
Ana PM Oliveira Rosana Gentile Arnaldo Maldonado Júnior Eduardo J Lopes Torres Silvana C Thiengo 《Memórias do Instituto Oswaldo Cruz》2015,110(6):739-744
The aim of this study was to analyse the infection dynamics ofAngiostrongylus
cantonensis in its possible intermediate hosts over two years in an urban
area in the state of Rio de Janeiro where the presence ofA.
cantonensis had been previously recorded in molluscs. Four of the seven
mollusc species found in the study were exotic.Bradybaena similaris
was the most abundant, followed byAchatina fulica,
Streptaxis sp., Subulina octona,
Bulimulus tenuissimus, Sarasinula linguaeformis
and Leptinaria unilamellata. Only A. fulica
and B. similaris were parasitised by A.
cantonensis and both presented co-infection with other helminths. The
prevalence of A. cantonensisin A. fulica was more
than 50% throughout the study. There was an inverse correlation between the
population size ofA. fulica and the prevalence of A.
cantonensis and abundance of the latter was negatively related to
rainfall. The overall prevalence of A. cantonensis in B.
similariswas 24.6%. A. fulica was the most important
intermediary host of A. cantonensis in the studied area
andB. similaris was secondary in importance for A.
cantonensis transmission dynamics. 相似文献
82.
83.
The rate of transbilayer movement (flip-flop) of cholesterol was estimated using planar bilayers with defined initial asymmetry, formed by the opposing monolayers technique. Vibrio cholerae cytolysin (VCC) was utilized as a molecular tool for measuring the cholesterol concentration in the cis leaflet of asymmetric bilayers. To quantify cholesterol flip-flop in planar lipid bilayers, a mathematical model was developed. It considers both the lateral diffusion rate of cholesterol within each monolayer and the flip-flop rate. The difference in initial and steady-state cholesterol contents in bilayer leaflets was used as a start point. Assuming the lateral diffusion coefficient to be of 1 × 10−8 cm2 s−1, the characteristic time of cholesterol flip-flop at 25 ± 2 °C was estimated as <10 s. 相似文献
84.
A. M. Nesterenko P. M. Krasilnikov Yu. A. Ermakov 《Biochemistry (Moscow) Supplemental Series A: Membrane and Cell Biology》2011,5(4):370-378
New molecular-dynamic topology of phosphatidylcholine bilayer (DPPC) in total atomic OPLS force field was developed and used
to study the structural characteristics of liquid-crystalline and gel state of lipid bilayer in the absence and in the presence
of Na+ and Be2+ cations adsorbed at the interface and different in their affinity. The parameters of bilayer geometry, the amount of surface
water, and the electrostatic potential distribution were estimated quantitatively from the simulation in both phase states.
The azimuthal angle of hydrocarbon chains was found nearly the same in the region of each monolayer in gel state. The amount
of surface water decreases upon bilayer “freezing” mainly by loss of water molecules not participating in H-bonds between
lipid headgroups. The cation adsorption was shown to have a small effect on these H-bonded water molecules, whereas Be2+ appeared to retain surface water in the bilayer upon its freezing. The electric potential distribution in the normal direction
to the membrane-water interface had a similar shape in any bilayer phase state regardless of the presence of the adsorbed
cations. Analysis of the microscopic nature of the electric potential revealed a mutual compensation of the contributions
of the main structural components of the system (lipids, water, and ions). The boundary potential increased by 116 mV for
pure DPPC, by 212 mV in the presence of Na+, and by 133 mV in the presence of Be2+ upon the phase transition of bilayer to the gel state. The boundary potential difference in the presence of Na+ and Be2+ and its change at the bilayer phase transition are in a good agreement with the experimental data published earlier [Ermakov
Yu.A., 1993]. 相似文献
85.
Mirjafari H Farragher TM Verstappen SM Yates A Bunn D Marshall T Lunt M Symmons DP Bruce IN 《Arthritis research & therapy》2011,13(5):R159
Introduction
Cardiovascular disease (CVD) is the leading cause of death in patients with inflammatory polyarthritis (IP), especially in seropositive disease. In established rheumatoid arthritis (RA), insulin resistance (IR) is increased and associated with CVD. We investigated factors associated with IR in an inception cohort of patients with early IP. 相似文献86.
Roberto B Bazotte Lorena G Silva Fabiana PM Schiavon 《Cell cycle (Georgetown, Tex.)》2014,13(16):2494-2500
In insulin-resistant states (obesity, pre-diabetes, and type 2 diabetes), hepatic production of glucose and lipid synthesis are heightened in concert, implying that insulin deficiency and insulin excess coexists in this setting. The fact that insulin may be inadequate or excessive at any one point in differing organs and tissues has many biologic ramifications. In this context the concept of metabolic compartmentalization in the liver is offered herein as one perspective of this paradox. In particular, we focus on the hypothesis that insulin resistance accentuates differences in periportal and perivenous hepatocytes, namely periportal glucose production and perivenous lipid synthesis. Subsequently, excessive production of glucose and accumulation of lipids could be expected in the livers of patients with obesity and insulin resistance. Overall, in this review, we provide our integrative perspective regarding how excessive production of glucose in periportal hepatocytes and accumulation of lipids in perivenous hepatocytes interact in insulin resistant states. 相似文献
87.
Sheep prions with molecular properties intermediate between classical scrapie,BSE and CH1641–scrapie
Jan PM Langeveld Jorg G Jacobs Jo HF Erkens Thierry Baron Olivier Andréoletti Takahashi Yokoyama 《朊病毒》2014,8(4):296-305
Efforts to differentiate bovine spongiform encephalopathy (BSE) from scrapie in prion infected sheep have resulted in effective methods to decide about the absence of BSE. In rare instances uncertainties remain due to assumptions that BSE, classical scrapie and CH1641–a rare scrapie variant–could occur as mixtures. In field samples including those from fallen stock, triplex Western blotting analyses of variations in the molecular properties of the proteinase K resistant part of the disease‑associated form of prion protein (PrPres) represents a powerful tool for quick discrimination purposes. In this study we examined 7 deviant ovine field cases of scrapie for some typical molecular aspects of PrPres found in CH1641‑scrapie, classical scrapie and BSE. One case was most close to scrapie with respect to molecular mass of its non-glycosylated fraction and N-terminally located 12B2‑epitope content. Two cases were unlike classical scrapie but too weak to differentiate between BSE or CH1641. The other 4 cases appeared intermediate between scrapie and CH1641 with a reduced molecular mass and 12B2‑epitope content, together with the characteristic presence of a second PrPres population. The existence of these 2 PrPres populations was further confirmed through deglycosylation by PNGaseF. The findings indicate that discriminatory diagnosis between classical scrapie, CH1641 and BSE can remain inconclusive with current biochemical methods. Whether such intermediate cases represent mixtures of TSE strains should be further investigated e.g. in bioassays with rodent lines that are varying in their susceptibility or other techniques suitable for strain typing. 相似文献
88.
89.
Abstract Many albatross populations are declining and a major cause is believed to be incidental mortality from fishing. We investigated the effect of fishing on southern Buller's albatross Thalassarche bulleri bulleri, using a new approach to seabird population modelling that allows estimation of demographic parameters from multiple data types. Three types of data were used: a 60-year set of mark–recapture observations, four censuses of the breeding population, and estimates of fishing effort and bycatch. The fisheries risk to the viability of this population over the last 60 years appears to have been small, since the adult population is estimated to have increased about five-fold over that time. There is some cause for concern in recent changes (population growth has slowed, and perhaps reversed, and adult survival rates are falling). The most common age at first breeding was 12 years, and about 80% of adults breed each year. Annual survival was estimated to be 0.91 for juveniles, and varied between this value and 1 for adults. Though this population is not in immediate danger from fishing, there is a need for continued monitoring to see whether the recent fall in survival rates persists and causes a decline in abundance. Our analysis showed that when, as is common, mark–recapture data do not provide good estimates of all demographic rates, the assessment of seabird population trends can be improved by the use of other types of data, particularly abundance. 相似文献
90.
Jesper Knoop Joost Dekker Jan-Paul Klein Marike van der Leeden Martin van der Esch Dick Reiding Ramon E Voorneman Martijn Gerritsen Leo D Roorda Martijn PM Steultjens Willem F Lems 《Arthritis research & therapy》2012,14(5):R212