全文获取类型
收费全文 | 8913篇 |
免费 | 396篇 |
国内免费 | 43篇 |
专业分类
耳鼻咽喉 | 79篇 |
儿科学 | 159篇 |
妇产科学 | 75篇 |
基础医学 | 949篇 |
口腔科学 | 247篇 |
临床医学 | 546篇 |
内科学 | 2297篇 |
皮肤病学 | 223篇 |
神经病学 | 856篇 |
特种医学 | 527篇 |
外科学 | 1348篇 |
综合类 | 40篇 |
一般理论 | 1篇 |
预防医学 | 264篇 |
眼科学 | 217篇 |
药学 | 757篇 |
中国医学 | 13篇 |
肿瘤学 | 754篇 |
出版年
2023年 | 41篇 |
2022年 | 126篇 |
2021年 | 215篇 |
2020年 | 108篇 |
2019年 | 135篇 |
2018年 | 161篇 |
2017年 | 132篇 |
2016年 | 160篇 |
2015年 | 164篇 |
2014年 | 193篇 |
2013年 | 288篇 |
2012年 | 403篇 |
2011年 | 466篇 |
2010年 | 252篇 |
2009年 | 232篇 |
2008年 | 404篇 |
2007年 | 438篇 |
2006年 | 426篇 |
2005年 | 443篇 |
2004年 | 459篇 |
2003年 | 468篇 |
2002年 | 454篇 |
2001年 | 264篇 |
2000年 | 296篇 |
1999年 | 247篇 |
1998年 | 110篇 |
1997年 | 102篇 |
1996年 | 85篇 |
1995年 | 65篇 |
1994年 | 69篇 |
1993年 | 61篇 |
1992年 | 179篇 |
1991年 | 173篇 |
1990年 | 161篇 |
1989年 | 151篇 |
1988年 | 143篇 |
1987年 | 126篇 |
1986年 | 114篇 |
1985年 | 121篇 |
1984年 | 88篇 |
1983年 | 67篇 |
1982年 | 41篇 |
1981年 | 32篇 |
1980年 | 37篇 |
1979年 | 57篇 |
1978年 | 34篇 |
1977年 | 36篇 |
1975年 | 33篇 |
1974年 | 41篇 |
1973年 | 31篇 |
排序方式: 共有9352条查询结果,搜索用时 15 毫秒
71.
Toshiie Sakata Masataka Fukushima Koichiro Tsutsui Koichi Arase Kazuma Fujimoto 《Physiology & behavior》1982,28(4):641-647
To test the possibility that theophylline induced circadian disappearance of food intake might depend upon rhythmic disruption of blood glucose, insulin and free fatty acids (FFA), theophylline was administered chronically. This markedly lengthened postprandial intermeal intervals during the dark, and induced approximately identical intermeal intervals and identical meal sizes in the light and dark periods. In contrast to the clear light-dark dependent oscillations of serum glucose, insulin and FFA in the controls, the theophyllinized rats lost circadian fluctuation of each of these three chemical substances. Further, theophyllinized rats, unlike controls, had no time-dependent fluctuation in the levels of these substances at ? 120, ?60 or ?15 min preceding the onset of the first meal before the dark. These findings, together with previous reports, explain the disappearance of nocturnal feeding rhythm in theophyllinized rats in terms of functional destruction of circadian regulation in the hypothalamus which modulate the production of chemical determinants of food intake. 相似文献
72.
The effects of electrical stimulation of ventral subiculum (VSB) of the hippocampus of the thermosensitive neurons in the preoptic area were studied in urethane-anesthetized rats. VSB stimulation affected thermosensitive neurons more frequently (92.1%, 58 of 63) than thermally insensitive neurons (71.4%, 55 of 77). The majority of the VSB-responsive thermosensitive neurons (33 of 44 warm-units and 11 of 14 cold-units) were initially inhibited following stimulation. The result provides further support for the involvement of hippocampus in the central control of thermoregulation. 相似文献
73.
Postsynaptic potentials (PSPs) with long latencies were evoked in cat hindlimb motoneurons by stimulation of the distal stump of a cut ventral root. Measurements of their latency and the threshold in the responsible afferent fibers showed that they were produced mainly by the activity of the unmyelinated fibers in the ventral root that enter the spinal cord through the dorsal root. Patterns of PSPs evoked in flexor and extensor motoneurons by ventral root stimulation were similar to those observed in the flexion reflex. 相似文献
74.
Improved rubella hemagglutination inhibtion test: inactivation of non-immunoglobulin hemagglutination inhibitors by phospholipase C.
下载免费PDF全文
![点击此处可从《Journal of clinical microbiology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
A method using phospholipase C (PL-C) for removing nonspecific inhibitors (NSI) of rubella virus hemagglutinin is described. PL-C was found to hydrolyze NSI without altering the hemagglutination inhibition (HI) activity of the specific antibody and could be used to remove NSI in the rubella HI test by using formalinized erythrocytes, which resisted the enzymatic action; fresh erythrocytes were lysed by PL-C. The HI test using PL-C treated sera gave true measurements of actual rubella antibody content, and HI titers of PL-C treated sera were identical or equivalent (+/-1 dilution) to those of sera treated with dextran sulfate and CaCl2 (DS-C). Thus, the PL-C method gave results as reproducible and reliable as the DS-C method and was more convenient. 相似文献
75.
Summary The extracellular matrix around nerve cell bodies in canine lateral and medial superior olivary nuclei was examined by conventional electron microscopy, Golgi impregnation and histochemical techniques. Each neuron is surrounded by a region of myelin-free neuropil embedded amongst the myelinated fibres of the trapezoid body. In the myelin-free neuropil there are astrocytes, axons, synaptic boutons and extracellular matrix. The extracellular matrix fills the spaces between slender axons near the terminals, synaptic boutons and glial processes, but not the synaptic cleft. Golgi impregnation selectively stains the perineuronal nets which cover some or all of the nerve cell bodies and dendrites. The Golgi-EM method revealed that the impregnated profiles of the nets are restricted to the extracellular matrix. Synaptic boutons are situated in the holes of the perineuronal nets. Peanut (PNA) and soybean (SBA) agglutinins bound the extracellular matrix but not the synaptic boutons, glial processes, nerve cell bodies or basal lamina of blood capillaries. Light microscopic immunohistochemistry of the glial fibrillary acidic protein (GFAP) and S-100 protein did not stain a layer corresponding to the extracellular matrix and synapses but showed an intensely positive reaction immediately outside this layer. These data suggest the existence of a unique microenvironment associated with glycoconjugates around nerve cell bodies in canine superior olivary nuclei. 相似文献
76.
J Miyauchi M Mukai K Yamazaki I Kiso S Higashi S Hori 《Acta pathologica japonica》1987,37(8):1347-1355
A patient who had disseminated vascular tumors involving the bilateral ovaries, bilateral lungs and pleura, pericardium, and mediastinum is reported. The tumors were histologically of the capillary, and partly the cavernous, type of hemangioma. However, endothelial cell growth was prominent in some areas, especially in the lung, and the histology of the lung tumor resembled epithelioid hemangioendothelioma or intravascular bronchiolo-alveolar tumor (IVBAT). In the endocardium of the right atrium, an endothelial tumorous projection was observed, and there were tiny foci of tumor cell nests in the abdominal venous wall. Small lymphangiomas were also found in the subcapsular region of the spleen. These findings suggest that there had been an abnormal proliferation of systemic endothelial cells and that tumors of endothelial cell origin with diverse histological patterns developed with this condition as a background. The autopsy finding of fibrin thrombi in multiple organs as well as laboratory data including thrombocytopenia suggest that this case belongs to the "Kasabach-Merritt syndrome." 相似文献
77.
Shigesaburo Miyakoshi Eiji Kusumi Tomoko Matsumura Akiko Hori Naoko Murashige Tamae Hamaki Koichiro Yuji Naoyuki Uchida Kazuhiro Masuoka Atsushi Wake Yoshinobu Kanda Masahiro Kami Yuji Tanaka Shuichi Taniguchi 《Biology of blood and marrow transplantation》2007,13(7):771-777
Invasive fungal infection (IFI) is a significant complication after allogeneic hematopoietic stem cell transplantation (HSCT); however, we have little information on its clinical features after reduced intensity cord blood transplantation (RICBT) for adults. We reviewed medical records of 128 patients who underwent RICBT at Toranomon Hospital between March 2002 and November 2005. Most of the patients received purine-analogbased preparative regimens. Graft-versus-host disease (GVHD) prophylaxis was a continuous infusion of either tacrolimus 0.03 mg/kg or cyclosporine 3 mg/kg. IFI was diagnosed according to the established EORTC/NIH-MSG criteria. IFI was diagnosed in 14 patients. Thirteen of the 14 had probable invasive pulmonary aspergillosis and the other had fungemia resulting from Trichosporon spp. Median onset of IFI was day 20 (range: 1-82), and no patients developed IFI after day 100. Three-year cumulative incidence of IA was 10.2%. Four of the 13 patients with invasive aspergillosis (IA) developed grade II-IV acute GVHD, and their IA was diagnosed before the onset of acute GVHD. The mortality rate of IFI was 86%. Multivariate analysis revealed that the use of prednisolone >0.2 mg/kg (relative risk 7.97, 95% confidence interval 2.24-28.4, P = .0014) was a significant risk factor for IA. This study suggests that IFI is an important cause of deaths after RICBT, and effective strategies are warranted to prevent IFI. 相似文献
78.
Summary The fragile X syndrome is a common familial form of mental retardation and is associated with a rare fragile site at Xq27.3 (FRAXA). This disorder has recently been reported to correlate with length variations of restriction genomic DNA fragments which may due to the amplification of (CCG)n trinucleotide repeats located at the FRAXA locus. We described here a rapid preparation method of diagnostic DNA probes for the fragile X syndrome by direct enzymatic amplification of human chromosomal DNA. ThePstI-assay, which is Southern blot analysis of DNA samples probed by PCR products, was shown to be sensitive method for diagnostic purposes to detect the size variations specific in the fragile X syndrome. 相似文献
79.
Hiroshi Tsuji Koichiro Murai Kimihiro Akagi Masatoshi Fujishima 《Journal of clinical immunology》1990,10(1):38-44
To investigate immune effects of interferon (IFN) therapy in hepatitis B e antigen (HBeAg)-positive chronic hepatitis B, serum immunoglobulin concentrations and peripheral lymphocyte subpopulations were sequentially studied before, during, and after therapy in nine patients who were treated with recombinant human -IFN in doses ranging from 3 to 10 million units per day for 28 days. Serum immunoglobulin A levels decreased significantly, from 414±23 mg/dl (mean ± SE) to 379±28 mg/dl (P<0.05), after the first week of therapy and to a bottom value of 323±20 mg/dl (P<0.001) at the fourth week. Immunoglobulin G levels decreased significantly, from 2603±175 to 2328±169 mg/dl (P<0.005), after the first week of therapy and to a bottom value of 2005±199 mg/dl (P<0.001) at the fourth week. Immunoglobulin M levels were also reduced significantly after 3 weeks of therapy (from 229±23 to 188±15 mg/dl;P<0.01). These reductions in immunoglobulins A, G, and M returned to pretreatment levels by 4 months after the end of the therapy. In lymphocyte subpopulations, significant depressions were found in CD3-, CD4-, CD8-, and B1-positive cells in peripheral blood after the first week of therapy (CD3, from 1700±114 to 1234±114/mm3,P<0.005; CD4, from 1036±88 to 780±64/mm3,P<0.005; CD8, from 620±57 to 426±60/mm3,P<0.05; and B1, from 519±84 to 276±48/mm3,P<0.01) followed during therapy, while Leul la-positive cells did not change significantly. During the 6-month follow-up period, three patients had a sustained clinical remission in which HBeAg disappeared from serum. Disappearance of HBeAg was unassociated with initial levels or percentage changes of serum immunoglobulins and peripheral lymphocytes expressing each of the test markers in these patients. These findings suggest that immune effects of IFN therapy are independent from its antiviral effects. 相似文献
80.
A case of infantile XX male syndrome with bilateral scrotal testes and penoscrotal hypospadias is presented. No evidence of XX/XY mosaicism or Y chromatin was obtained in preparations from cultures of the peripheral blood, skin fibroblast, or other tissues. Although true hermaphroditism was suspected, exploration of the bilateral gonadal structures failed to detect the presence of ovarian structures, either grossly or microscopically. Furthermore, exploratory laparotomy revealed no Mullerian structures. The difficulty of early diagnosis of XX males in infancy is emphasized. 相似文献