全文获取类型
收费全文 | 422篇 |
免费 | 25篇 |
国内免费 | 11篇 |
专业分类
耳鼻咽喉 | 3篇 |
儿科学 | 16篇 |
妇产科学 | 4篇 |
基础医学 | 27篇 |
口腔科学 | 4篇 |
临床医学 | 36篇 |
内科学 | 49篇 |
皮肤病学 | 6篇 |
神经病学 | 6篇 |
特种医学 | 164篇 |
外科学 | 52篇 |
综合类 | 5篇 |
预防医学 | 13篇 |
眼科学 | 35篇 |
药学 | 18篇 |
肿瘤学 | 20篇 |
出版年
2023年 | 2篇 |
2022年 | 2篇 |
2021年 | 2篇 |
2019年 | 3篇 |
2018年 | 11篇 |
2017年 | 3篇 |
2016年 | 8篇 |
2014年 | 4篇 |
2013年 | 15篇 |
2012年 | 10篇 |
2011年 | 8篇 |
2010年 | 12篇 |
2009年 | 12篇 |
2008年 | 7篇 |
2007年 | 11篇 |
2006年 | 8篇 |
2005年 | 12篇 |
2004年 | 12篇 |
2003年 | 13篇 |
2002年 | 6篇 |
2001年 | 11篇 |
1999年 | 5篇 |
1998年 | 18篇 |
1997年 | 19篇 |
1996年 | 19篇 |
1995年 | 17篇 |
1994年 | 19篇 |
1993年 | 15篇 |
1991年 | 2篇 |
1990年 | 6篇 |
1989年 | 11篇 |
1988年 | 15篇 |
1987年 | 15篇 |
1986年 | 17篇 |
1985年 | 24篇 |
1984年 | 11篇 |
1983年 | 17篇 |
1982年 | 10篇 |
1981年 | 3篇 |
1980年 | 3篇 |
1978年 | 2篇 |
1977年 | 4篇 |
1976年 | 5篇 |
1975年 | 2篇 |
1971年 | 3篇 |
1970年 | 9篇 |
1969年 | 9篇 |
1966年 | 1篇 |
1963年 | 1篇 |
1927年 | 1篇 |
排序方式: 共有458条查询结果,搜索用时 23 毫秒
81.
In previous reports, duration of initial ventilation exceeding 1 month almost always predicts non-survival of babies with congenital myotonic dystrophy. However, a baby with this condition survived beyond infancy after 55 days' ventilation. We describe this case in detail, explain why the baby survived and highlight the importance of individualized assessment, in addition to applying general prognostic terms described in the literature. 相似文献
82.
Anthropomorphic radiologic phantoms 总被引:1,自引:0,他引:1
A technique is being developed for the design and fabrication of anthropomorphic phantoms for diagnostic x-ray imaging. Anatomic information extracted from actual patient radiographs is incorporated into the phantoms using computer image processing and computer-assisted machining methods. In this paper, the technique is described as applied to a breast phantom, and preliminary images that closely mimic human anatomy on radiographs are shown. 相似文献
83.
Sequence Analysis of the RNA Polymerase Gene of Foot-and-Mouth Disease Virus Serotype Asia1 总被引:1,自引:0,他引:1
George M Venkataramanan R Pattnaik B Sanyal A Gurumurthy CB Hemadri D Tosh C 《Virus genes》2001,22(1):21-26
The complete nucleotide (nt.) sequence of the RNA polymerase (3D) gene and 81 nt. in the 3-untranslated region of foot-and-mouth disease virus (FMDV) serotype Asia1 (IND63/72) was determined and compared with the sequence of other FMDV serotypes. The 3D genomic region was 1410 nt. long encoding 470 amino acids with an inframe stop codon (TAA) at nt. position 1411–1413. The deduced amino acid sequence of the protein showed 8 conserved motifs as reported in other picornaviruses, 2 of which are 100% identical across the serotypes. Antigenic regions in the polymerase protein were predicted and found to be located at the N-terminus of the protein. The phylogenetic analysis showed that the FMD viruses were segregated into different clusters based on geographical origin; the Asia1 virus did not cluster tightly with any of the geographical groups. 相似文献
84.
85.
CF Samer Y Daali M Wagner G Hopfgartner CB Eap MC Rebsamen MF Rossier D Hochstrasser P Dayer JA Desmeules 《British journal of pharmacology》2010,160(4):919-930
Background and purpose:
Thrombus formation is commonly associated with pulmonary arterial hypertension (PAH). Thrombin may thus play an important role in the pathogenesis and pathophysiology of PAH. Hence, we investigated the contractile effects of thrombin and its mechanism in pulmonary artery.Experimental approach:
The cytosolic Ca2+ concentrations ([Ca2+]i), 20 kDa myosin light chain (MLC20) phosphorylation and tension development were evaluated using the isolated porcine pulmonary artery.Key results:
Thrombin induced a sustained contraction in endothelium-denuded strips obtained from different sites of a pulmonary artery, ranging from the main pulmonary artery to the intrapulmonary artery. In the presence of endothelium, thrombin induced a transient relaxation. The contractile effect of thrombin was abolished by either a protease inhibitor or a proteinase-activated receptor 1 (PAR1) antagonist, while it was mimicked by PAR1-activating peptide (PAR1AP), but not PAR4AP. The thrombin-induced contraction was associated with a small elevation of [Ca2+]i and an increase in MLC20 phosphorylation. Thrombin and PAR1AP induced a greater increase in tension for a given [Ca2+]i elevation than that obtained with high K+-depolarization. They also induced a contraction at a fixed Ca2+ concentration in α-toxin-permeabilized preparations.Conclusions and implications:
The present study revealed a unique property of the pulmonary artery. In contrast to normal arteries of the systemic circulation, thrombin induces a sustained contraction in the normal pulmonary artery, by activating PAR1 and thereby increasing the sensitivity of the myofilament to Ca2+. This responsiveness of the pulmonary artery to thrombin may therefore contribute to the pathogenesis and pathophysiology of PAH. 相似文献86.
Does cryotherapy before drainage increase the risk of intraocular haemorrhage and affect outcome?. A prospective,randomised, controlled study using a needle drainage technique and sustained ocular compression 下载免费PDF全文
AIMS/BACKGROUND—A prospective, randomised, controlled clinical trial was conducted to investigate the effect of performing cryotherapy before drainage of subretinal fluid (SRF) on the incidence of intraocular haemorrhage (IOH) in the management of retinal detachment.
METHODS—Eighty eyes of 80 patients with rhegmatogenous retinal detachment requiring SRF drainage were recruited. Thirty four cases were randomised to receive drainage before cryotherapy (drainage, air injection, cryotherapy, and explant = DACE group) while 46 cases had drainage after cryotherapy (cryotherapy, drainage, air injection, and explant = CDAE group). All cases had trans-scleral drainage of SRF using a 27 gauge hypodermic needle combined with prolonged, intraocular hypertension.
RESULTS—There was a low incidence of IOH associated with drainage in both groups with no statistically significant difference between the groups (DACE group = 2.9%; CDAE group = 4.3%; p = 0.43). There was no significant difference between the groups in the rate of anatomical success with a single operation (DACE group = 82.4%; CDAE group = 86.9%; p = 0.38). There was no significant difference between the groups in the visual outcome. An improvement of two Snellen lines or more occurred in 52.9% of the DACE group and in 56.5% of the CDAE group (p = 0.93).
CONCLUSION—It was concluded that the surgical sequence of applying cryotherapy before drainage of SRF can be safely and effectively performed. The sequences CDAE and CDE, when air injection is not required, along with DACE should all be part of the surgical repertoire for the management of retinal detachments.
相似文献
METHODS—Eighty eyes of 80 patients with rhegmatogenous retinal detachment requiring SRF drainage were recruited. Thirty four cases were randomised to receive drainage before cryotherapy (drainage, air injection, cryotherapy, and explant = DACE group) while 46 cases had drainage after cryotherapy (cryotherapy, drainage, air injection, and explant = CDAE group). All cases had trans-scleral drainage of SRF using a 27 gauge hypodermic needle combined with prolonged, intraocular hypertension.
RESULTS—There was a low incidence of IOH associated with drainage in both groups with no statistically significant difference between the groups (DACE group = 2.9%; CDAE group = 4.3%; p = 0.43). There was no significant difference between the groups in the rate of anatomical success with a single operation (DACE group = 82.4%; CDAE group = 86.9%; p = 0.38). There was no significant difference between the groups in the visual outcome. An improvement of two Snellen lines or more occurred in 52.9% of the DACE group and in 56.5% of the CDAE group (p = 0.93).
CONCLUSION—It was concluded that the surgical sequence of applying cryotherapy before drainage of SRF can be safely and effectively performed. The sequences CDAE and CDE, when air injection is not required, along with DACE should all be part of the surgical repertoire for the management of retinal detachments.
相似文献
87.
Six human hematopoetic cell lines were successfully heterotransplanted into athymic (nude) and asplenic-athymic (lasat) neonatal mice. The tumors arising from leukemia and lymphoma cells could then be serially transplanted into adult nude mice. Seven days after the fourth serial mouse passage, each mouse was treated with goat immune gamma globulin against K-562 cells. One control group was treated similarly, but with nonimmune (normal) gamma globulin, while another control group was not treated. The goat gamma globulin was not toxic for nude and lasat mice, and the immune, but not the normal, gamma globulin suppressed local subcutaneous growth of myelosarcomas, lymphosarcomas, and Burkitt lymphoma cells. On the other hand, the growth of lung, breast, and prostatic carcinomas and a melanoma of human origin were not altered by the immune gamma globulin. Since suppression of cell growth occurred equally well in decomplemented mice, a complement-mediated cytotoxicity apparently cannot be considered as responsible for the abrogation. The Fab fragment of the immunoglobulin did not suppress the growth of the myelosarcomas. We conclude that antibody suppression of the in vivo proliferation was specific for malignant hematopoietic cells and that the Fc portion of IgG is necessary for in vivo cytolysis of leukemia cells. The most probable mechanisms are direct antibody cytolysis and antibody-dependent macrophage-mediated cytotoxicity. 相似文献
88.
89.
90.
Weissengruber GE Egger GF Hutchinson JR Groenewald HB Elsässer L Famini D Forstenpointner G 《Journal of anatomy》2006,209(6):781-792
The uniquely designed limbs of the African elephant, Loxodonta africana, support the weight of the largest terrestrial animal. Besides other morphological peculiarities, the feet are equipped with large subcutaneous cushions which play an important role in distributing forces during weight bearing and in storing or absorbing mechanical forces. Although the cushions have been discussed in the literature and captive elephants, in particular, are frequently affected by foot disorders, precise morphological data are sparse. The cushions in the feet of African elephants were examined by means of standard anatomical and histological techniques, computed tomography (CT) and magnetic resonance imaging (MRI). In both the forelimb and the hindlimb a 6th ray, the prepollex or prehallux, is present. These cartilaginous rods support the metacarpal or metatarsal compartment of the cushions. None of the rays touches the ground directly. The cushions consist of sheets or strands of fibrous connective tissue forming larger metacarpal/metatarsal and digital compartments and smaller chambers which were filled with adipose tissue. The compartments are situated between tarsal, metatarsal, metacarpal bones, proximal phalanges or other structures of the locomotor apparatus covering the bones palmarly/plantarly and the thick sole skin. Within the cushions, collagen, reticulin and elastic fibres are found. In the main parts, vascular supply is good and numerous nerves course within the entire cushion. Vater-Pacinian corpuscles are embedded within the collagenous tissue of the cushions and within the dermis. Meissner corpuscles are found in the dermal papillae of the foot skin. The micromorphology of elephant feet cushions resembles that of digital cushions in cattle or of the foot pads in humans but not that of digital cushions in horses. Besides their important mechanical properties, foot cushions in elephants seem to be very sensitive structures. 相似文献