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81.
This analysis reviews the available literature on interspecies comparisons of the toxicity of asbestos and synthetic vitreous fibers (SVFs). This topic is of substantial practical importance because most quantitative risk analyses on the effects of inhalation of SVFs are based upon extrapolation of data from rodent inhalation studies. Available information on interspecies comparisons for both dosimetry (the relation between exposure concentration and fiber lung burden) and potency (the relation between lung burden and disease) is summarized. Dosimetry models indicate that, on a normalized basis, fiber deposition and clearance rates are lower in humans than rats. Potency is less well understood than dosimetry, in part because the source of relevant human data is asbestos studies, which are adequate to demonstrate hazard, but are problematic in other regards. There are significant interspecies differences between the mouse, hamster, rat, and human. The available evidence suggests that the rat is preferable as a model for the human. Rats develop fibrosis at comparable lung burdens [10(6) long (> 20 microm length) fibers per gram of dry lung] to those in humans. This analysis concludes that, on a weight-of-evidence basis, there is no reason to conclude that humans are more sensitive to fibers than rats with respect to the development of lung cancer. 相似文献
82.
Carmelita A. Wallace Maxim S. Petrov David I. Soybel Stephen J. Ferzoco Stanley W. Ashley Ali Tavakkolizadeh 《Journal of gastrointestinal surgery》2008,12(1):46-50
Appendectomy is the most common non-gynecologic surgery performed during pregnancy. Little data exist on the accuracy of imaging
studies in the diagnosis of appendicitis in pregnancy. The objective of this study was to evaluate the probability of ultrasound
and computed tomography (CT) scan in diagnosing appendicitis in pregnancy, as reflected in the negative appendectomy rate.
We retrospectively reviewed the charts of 86 pregnant women who underwent an appendectomy between January 1, 1997 and January
1, 2006. Patients were divided into three groups: clinical evaluation, ultrasound, and ultrasound followed by a CT scan. The
clinical evaluation group had 13 patients, with a negative appendectomy rate of 54% (7/13). Fifty-five patients underwent
an ultrasound alone, with a negative appendectomy rate 36% (20/55). In the ultrasound/CT group (n = 13), the negative appendectomy rate was 8% (1/13). There was a significant reduction in the negative appendectomy rate
in the ultrasound/CT scan group compared to clinical evaluation group (54 vs 8%, p < 0.05). This reduction was not achieved in the ultrasound group when compared to the clinical evaluation group or the ultrasound/CT
group (p = 0.05). A significant reduction was achieved when the ultrasound/CT group was compared to the patients in the ultrasound
only group who had a normal or inconclusive ultrasound (p < 0.05). Our data documents a very high negative appendectomy rate in the pregnant patient. We recommend an ultrasound followed
by a CT scan in patients with a normal or inconclusive ultrasound. 相似文献
83.
84.
Immune complexes, serum proteins, cell-mediated immunity, and immune regulation in patients with squamous cell carcinoma of the head and neck 总被引:2,自引:0,他引:2
A collaborative study of the humoral and cellular immune status of patients with carcinoma of the Head and Neck (H&N) was conducted at the West Virginia University (WVU) hospital. In addition, blind-coded serum panels were supplied on H&N cancer patients being treated at the National Cancer Institute (NCI). Serum protein analysis of the WVU study groups revealed that at the pretreatment sampling, the alpha-1 acid glycoprotein (AGP), total complement, and IgA levels were significantly elevated. The AGP levels and total complement levels declined to normal levels in the post-treatment period, whereas the IgA levels remained elevated throughout the entire observation period. Levels of serum immune complexes (SIC) were measured in both the WVU and NCI H&N cancer populations using the polyethylene glycol (PEG) precipitation method. In both survey populations all cancer groups had significantly elevated levels of SIC when compared to any of the control populations. The SIC levels never returned to comparative normal values even in cases after successful treatment. A subpopulation of the WVU-H&N cancer study group underwent a short course of intravenous hyperalimentation prior to their treatment regimen. These patients demonstrated a transient decrease in their SIC levels as well as a concomitant increase in their in vitro cell-mediated immune (CMI) correlates. The analysis of in vitro CMI correlates of the WVU study group using both polyclonal mitogens and specific antigens demonstrated a significant depression in these parameters pretreatment and post-treatment. In addition, it was observed that the time course for elevation of selected serum proteins (i.e., IgA and SIC) correlated with concomitant drops in CMI activity. Investigations were also conducted into the effects of immune complex-rich serum fractions upon selected in vitro CMI correlates. Significant blockage of a normal donor leukocyte migration-inhibition assay was demonstrated. Also, a similar inhibition of the ability of normal human lymphocytes to form high affinity rosettes was accomplished with serum from H&N cancer patients. 相似文献
85.
Maxim C. -J. Cheeran Manohar B. Mutnal Shuxian Hu Anibal Armien James R. Lokensgard 《Journal of neurovirology》2009,15(4):334-342
Interleukin (IL)-10 deficiency results in highly elevated levels of interferon (IFN)-γ, as well as the IFN-γ-inducible chemokines
CXCL9 and CXCL10 within murine cytomegalovirus (MCMV)-infected brains. To test the hypothesis that these elevated chemokine
levels would result in enhanced brain infiltration, we compared immune cell infiltration in response to MCMV brain infection
between wild-type and IL-10 knockout (KO) mice. Longitudinal analysis following adoptive transfer of cells from β-actin-luciferase
transgenic wild-type mice showed maximal brain infiltration by peripheral immune cells occurred at 5 days post infection.
Although the overall percentage of CD45(hi) cells infiltrating the brain was not altered by IL-10 deficiency, paradoxically,
despite elevated chemokine levels, reduced T lymphocyte (CD8+) and natural killer (NK) (CD49b+) cell infiltration into the
brain was observed in IL-10-deficient animals. This decreased lymphocyte infiltration was associated with elevated levels
of the lymph node homing receptor L-selectin/CD62L on CD8+ T cells. Lymph node cells obtained from MCMV-infected mice deficient
in IL-10 also displayed reduced migration towards CXCL10 when compared to wild-type animals. Taken together, these data show
that despite elevated chemokine levels, absence of IL-10 results in reduced lymphocyte infiltration into MCMV-infected brains. 相似文献
86.
A. V. Kostylev V. N. Shuvaeva O. P. Gorshkova D. P. Dvoretsky 《Bulletin of experimental biology and medicine》2008,146(2):182-184
Differential characteristic of the reaction of pial arteries of various generations to intravenous administration of norepinephrine
was obtained in experiments on rats under artificially stabilized systemic blood pressure.
Translated from Byulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 146, No. 8, pp. 147–149, August, 2008 相似文献
87.
88.
Russell Rising Maxim Signaevsky Leonard A Rosenblum John G Kral Fima Lifshitz 《Nutrition & metabolism》2008,5(1):1-11
Conjugated linoleic acid (CLA) is a mixture of positional and geometric isomers of octadecadienoic acid [linoleic acid (LA), 18:2n-6]. Although ruminant milk and meat products represent the largest natural source of CLA and therefore, their concentration in ruminant lipids are of interest to human health, chemical or physical modifications of CLA should be needed as a means to enhance oxidative stability, to improve post-ruminal bioavailability, and to increase the clinical application. In fact, CLA are rapidly decomposed to form furan fatty acids when its are oxidized in air, and the effectiveness of dietary supplements of CLA may be related to the extent that their metabolisms by rumen bacteria are avoided. For these reasons, many scientists have examined the effect of manufacturing and protection on the stability of CLA in ruminants and food products. In this review, physico-chemical modifications of CLA for ruminal protection such as calcium salt (Ca), formaldehyde protection (FP), lipid encapsulation (LE), and amide linkage (AL), and for oxidative stability such as green tea catechin (GTC), cyclodextrin (CD), arginine (Arg), amylase, and PEGylation are proposed. 相似文献
89.
IL-1–induced Bhlhe40 identifies pathogenic T helper cells in a model of autoimmune neuroinflammation
90.
Igor S. Sidorov Maxim A. Volynsky Alexei A. Kamshilin 《Biomedical optics express》2016,7(7):2469-2474
Imaging photoplethysmography (IPPG) is a recently developed technique for noncontact assessment of cardiovascular function. However, its wide use is limited by low signal-to-noise ratio due to motion artifacts. The aim of this work is to estimate the polarization-filtration impact on discriminating artifacts in IPPG measurements. Experiments were carried out in-vivo by almost simultaneous illumination of subject’s palm with polarized and non-polarized light during video recording of 41 subjects. It was found that the light-polarization filtration efficiently reduces motion artifacts compared to the non-polarized illumination while the pulsation amplitude measured at the heartbeat frequency remains unaffected. The polarization filtration improves reliability of IPPG system in non-contact monitoring of subject’s heart rate and its variability.OCIS codes: (170.0170) Medical optics and biotechnology, (170.3880) Medical and biological imaging, (280.0280) Remote sensing and sensors, (170.3660) Light propagation in tissues 相似文献