全文获取类型
收费全文 | 17301篇 |
免费 | 1189篇 |
国内免费 | 522篇 |
专业分类
耳鼻咽喉 | 159篇 |
儿科学 | 431篇 |
妇产科学 | 313篇 |
基础医学 | 3202篇 |
口腔科学 | 265篇 |
临床医学 | 1194篇 |
内科学 | 2997篇 |
皮肤病学 | 461篇 |
神经病学 | 1333篇 |
特种医学 | 442篇 |
外科学 | 1990篇 |
综合类 | 1949篇 |
现状与发展 | 1篇 |
一般理论 | 1篇 |
预防医学 | 739篇 |
眼科学 | 128篇 |
药学 | 1752篇 |
1篇 | |
中国医学 | 505篇 |
肿瘤学 | 1149篇 |
出版年
2024年 | 25篇 |
2023年 | 173篇 |
2022年 | 302篇 |
2021年 | 497篇 |
2020年 | 470篇 |
2019年 | 438篇 |
2018年 | 433篇 |
2017年 | 464篇 |
2016年 | 532篇 |
2015年 | 568篇 |
2014年 | 1014篇 |
2013年 | 1081篇 |
2012年 | 993篇 |
2011年 | 1154篇 |
2010年 | 984篇 |
2009年 | 965篇 |
2008年 | 956篇 |
2007年 | 942篇 |
2006年 | 907篇 |
2005年 | 826篇 |
2004年 | 723篇 |
2003年 | 553篇 |
2002年 | 427篇 |
2001年 | 321篇 |
2000年 | 342篇 |
1999年 | 239篇 |
1998年 | 235篇 |
1997年 | 269篇 |
1996年 | 405篇 |
1995年 | 305篇 |
1994年 | 250篇 |
1993年 | 212篇 |
1992年 | 132篇 |
1991年 | 110篇 |
1990年 | 63篇 |
1989年 | 65篇 |
1988年 | 41篇 |
1987年 | 33篇 |
1986年 | 38篇 |
1985年 | 63篇 |
1984年 | 67篇 |
1983年 | 46篇 |
1982年 | 66篇 |
1981年 | 41篇 |
1980年 | 43篇 |
1979年 | 35篇 |
1978年 | 35篇 |
1977年 | 23篇 |
1976年 | 33篇 |
1975年 | 25篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
151.
Kawano T Matsuse H Kondo Y Machida I Saeki S Tomari S Mitsuta K Fukushima C Obase Y Shimoda T Kohno S 《The Journal of allergy and clinical immunology》2004,114(6):398-1281
BACKGROUND: The exact mechanism of aspirin-induced asthma is not clear. It has been postulated that precipitation of asthma attacks by aspirin is linked to inhibition of COX activity and massive release of cysteinyl leukotriene into the airway. Tacrolimus, a macrolide-derived immunosuppressant, is used for immunosuppression in organ transplantation and also for allergic diseases such as atopic dermatitis. OBJECTIVE: We evaluated the effects of tacrolimus in aspirin-induced asthma by using a double-blind, crossover study design. METHODS: Twelve patients with aspirin-induced asthma (male:female, 3:9; mean age +/- SD, 36.7 +/- 7.2 years) received either tacrolimus (0.1 mg/kg) or placebo 2 hours before the threshold dose of oral aspirin. RESULTS: In the placebo arm, oral aspirin significantly decreased FEV 1 concomitant with significant increases in sputum eosinophilic cationic protein and urinary leukotriene E(4) levels. Tacrolimus significantly inhibited bronchoconstriction and abrogated aspirin-induced increase in both sputum eosinophilic cationic protein and urinary leukotriene E(4) levels. CONCLUSION: The current study suggested that tacrolimus inhibited bronchoconstriction to a threshold dose of aspirin by inhibition of cysteinyl leukotriene excretion. 相似文献
152.
G. N. Kryzhanovskii V. V. Ruseev V. I. Ivanov 《Bulletin of experimental biology and medicine》1976,82(6):1764-1767
Experiments on cats showed that injury to the medial forebrain bundle (MFB) and also partly to the preoptic region on the side of application of penicillin to the cerebral cortex (middle suprasylvian gyrus) causes depression of paroxysmal activity (spike potentials) in the penicillin focus, and also in a secondary mirror focus arising in the symmetrical zone of the opposite cortex. Injury to MFB on the side of the mirror focus causes depression of paroxysmal spike potentials only in that focus and does not affect activity in the primary epileptiform focus. The effects described are examined from the standpoint of views regarding the role of the determinant dispatch station (DDS) in the activity of the CNS: A primary epileptiform focus is a hyperactive DDS which induces the appearance of secondary foci, supports them, and determines the character of their activity. The results of the investigation suggests a role for MFB in the modulation of cortical epileptiform activity.Laboratory of General Pathology of the Nervous System, Institute of General Pathology and Pathophysiology, Academy of Medical Sciences of the USSR, Moscow. Laboratory of Electrophysiology, V. F. Filatov Odessa Research Institute for Eye Diseases and Tissue Therapy, Ministry of Health of the Ukrainian SSR. Translated from Byulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 82, No. 12, pp. 1413–1416, December, 1976. 相似文献
153.
Rachel Rabin Yoel Hirsch Martin M. Johansson Joseph Ekstein David A. Zeevi Beth Keena Elaine H. Zackai John Pappas 《American journal of medical genetics. Part A》2019,179(10):2144-2151
Warsaw breakage syndrome (WABS), caused by bi‐allelic variants in the DDX11 gene, is a rare cohesinopathy characterized by pre‐ and postnatal growth retardation, microcephaly, intellectual disability, facial dysmorphia, and sensorineural hearing loss due to cochlear hypoplasia. The DDX11 gene codes for an iron–sulfur DNA helicase in the Superfamily 2 helicases and plays an important role in genomic stability and maintenance. Fourteen individuals with WABS have been previously reported in the medical literature. Affected individuals have been of various ethnic backgrounds with different pathogenic variants. We report two unrelated individuals of Ashkenazi Jewish descent affected with WABS, who are homozygous for the c.1763‐1G>C variant in the DDX11 gene. Their phenotype is consistent with previously reported individuals. RNA studies showed that this variant causes an alternative splice acceptor site leading to a frameshift in the open reading frame. Carrier screening of the c.1763‐1G>C variant in the Jewish population revealed a high carrier frequency of 1 in 68 in the Ashkenazi Jewish population. Due to the high carrier frequency and the low number of affected individuals, we hypothesize a high rate of miscarriage of homozygous fetuses and/or subfertility for carrier couples. If the carrier frequency is reproducible in additional Ashkenazi Jewish populations, we suggest including DDX11 to Ashkenazi Jewish carrier screening panels. 相似文献
154.
Ascoli V Scalzo CC Andreoni M Manente L Pistilli A Lo Coco F 《Virchows Archiv : an international journal of pathology》1999,435(6):612-615
We report the unusual occurrence of Kaposi’s sarcoma following asbestos-related malignant mesothelioma, in a human deficiency
virus (HIV)-negative Italian man. Seropositivity to human herpes virus 8 (HHV8) was documented at the time of mesothelioma
diagnosis and preceded the onset of Kaposi’ sarcoma with a time lapse of 13 months. HHV8 DNA was detected by polymerase chain
reaction in lesional Kaposi’s sarcoma but not within mesothelioma. By immunostaining, mesothelioma cells expressed interleukin-6
and platelet-derived growth factor, which are important for survival of Kaposi’s sarcoma cells. Besides the possibility of
a casual association, we hypothesize that mesothelioma-linked factors may have contributed to the development of Kaposi’sarcoma
in the presence of HHV8 infection.
Received: 12 April 1999 / Accepted: 24 June 1999 相似文献
155.
Satoshi Yamagiwa Yuh Kuwano Katsuhiko Hasegawa Kazunari Sato Kazuo Ohtsuka Tsuneo Iiai Katsuhiro Tomiyama Hisami Watanabe Satoshi Sugahara Shuhji Seki Hitoshi Asakura Toru Abo 《European journal of immunology》1996,26(7):1409-1416
Mice carrying the lpr gene, SCG and MRL-lpr/lpr mice, were used to characterize the phenotype and lpr gene of abnormally proliferating T cells in these mice. A major population which expanded in these mice were T cells expressing intermediate (int) levels of T cell receptor (TCR) (and CD3) and the phenotype of interleukin-2 receptor (IL-2R)βlo α? (possibly abnormal TCRint cells). The levels of TCRhi cells of thymic origin (generated through the mainstream of T cell differentiation in the thymus) profoundly decreased after the onset of disease. However, a small population of normal TCRint cells (i.e. IL-2Rβhi α?) were also found to exist in all tested organs. For example, the majority of abnormal IL-2Rβlo TCRint cells were CD4?8? CD2?, while normal IL-2Rβhi TCRint cells were a mixture of single-positive cells (mainly CD8+), CD4?8? cells and CD2+ cells. Moreover, normal TCRint cells preferentially produced normal Fas mRNA and Fas molecules from the lpr gene. This phenomenon explains the leaky appearance of normal Fas mRNA and Fas molecules in mice carrying the lpr gene. It is suggested that a small population of IL-2RβhiTCRint cells are resistant to the lpr genetic abnormality. 相似文献
156.
Hajime Kimata 《European journal of immunology》1994,24(11):2910-2913
The effects of gangliosides on human plasma cell responses were studied. Among the various gangliosides tested, only GM1 enhanced immunoglobulin (Ig) production and proliferation in the human plasma cell lines, IM-9 and AF-10, while other gangliosides (GM2, GM3, GD1a, GD1b, GD3, GT1b, and GQ1b) had no effect. Among the various cytokines tested, including interleukin (IL)-1β, IL-2, IL-3, IL-4, IL-5, IL-6, IL-9, IL-10, IL-12, IL-13, interferon (IFN)-α and IFN-γ, only IL-6 enhanced Ig production and proliferation in IM-9 and AF-10 cells. However, the enhancement of plasma cell responses by GM1 was specific and was not mediated by IL-6, since GM1 activity was blocked by anti-GM1 monoclonal antibody (mAb), but not by control IgM, anti-IL-6 Ab or the anti-IL-6 receptor mAb, PM1. Conversely, the enhancement by IL-6 was blocked by anti-IL-6 Ab and PM1, but not by anti-GM1 mAb. GM1, but not other gangliosides, also enhanced Ig production and proliferation in freshly separated plasma cells from patients with plasma cell leukemia and in plasma cells generated in vitro. These actions of GM1 were specifically blocked by anti-GM1 mAb, but not by anti-IL-6 Ab or PM1. These results indicate that GM1 may be an important regulator of plasma cell responses. 相似文献
157.
Natural killer (NK) cells and cytotoxic T lymphocytes (CTL), the functional coordination of which are governed by various signal substances, are crucial in the body’s defense of tumor and virus-infected cells. We investigated the role of various neurotransmitters and hormones on the regulation of functional parameters, including NK cell cytotoxicity, and the migration of NK cells and CTL within a three-dimensional collagen lattice. Using peripheral blood CTL and NK cells, we show that the neurotransmitters endorphin, histamine and substance P increase NK cell cytotoxicity, while norepinephrine inhibits cytotoxicity. Moreover, substance P reduces migratory activity, while norepinephrine increases NK cell and CTL migration. Furthermore, all three steroid hormones which were investigated, namely cortisone, testosterone, and estradiol, had regulatory influence on both cytotoxicity and migration of NK cells. These results further specify the functional basis of the complex interconnection between the immune and neuro-endocrine systems. 相似文献
158.
目的:探讨当归对兔肾缺血再灌注损伤的防治作用及其机制。方法:健康成年日本大耳白兔25只, 随机均分为假手术对照(control)组、单纯缺血再灌注(IR)组和缺血再灌注+当归(RAS+IR)组。在肾缺血1h再灌注48h后取肾组织作电镜检查, 并测血清肌酐(Cr)、肾组织肿瘤坏死因子(TNF-α)、白细胞介素-6(IL-6)和碱性成纤维细胞生长因子(bFGF)含量。结果:IR组肾组织变性改变显著, RAS+IR组病变轻微;IR组Cr、TNF-α和IL-6含量显著高于control组(P<0.05, P<0.05和P<0.01);RAS+IR组上述指标显著低于IR组。IR组bFGF含量显著低于control组(P<0.01), RAS+IR组bFGF含量显著高于IR组(P<0.01)和control组(P<0.05).结论:当归具有防治肾IR损伤的作用, 其机制可能与其对TNF-α、IL-6和bFGF等细胞因子的调控有关。 相似文献
159.
Gender-specific haplotype association of collagen α2 (XI) gene in ossification of the posterior longitudinal ligament of the spine 总被引:5,自引:0,他引:5
Maeda S Koga H Matsunaga S Numasawa T Ikari K Furushima K Harata S Takeda J Sakou T Komiya S Inoue I 《Journal of human genetics》2001,46(1):1-4
Among Japanese, ossification of the posterior longitudinal ligament of the spine (OPLL) is a leading cause of myelopathy,
showing ectopic bone formation in the paravertebral ligament. We have provided genetic evidence that the collagen α2 (XI)
(COL11A2) locus of chromosome 6 constitutes susceptibility for OPLL. Five distinct single nucleotide polymorphisms (SNPs), identified
in COL11A2, were combined to construct possible haplotypes by the use of a maximum likelihood program. Estimated haplotype frequency
was compared in OPLL patients and non-OPLL controls. We report a gender-specific association of the COL11A2 haplotype with OPLL. The frequency of the most commonly observed haplotype was significantly higher in male patients (P = 0.0003) compared with controls, but not in female patients (P = 0.21). OPLL is predominantly observed in males, with a prevalence ratio of 2 : 1, and our gender-specific associations
indicate that genetic factors involving COL11A2 play a specific role in the etiology of OPLL exclusively in males.
Received: September 5, 2000 / Accepted: October 2, 2000 相似文献
160.
Ferdinando Nicoletti Roberto di Marcou Wilma Barcelliniu Gaetano Magro Hans U. Schorlemmeru Roland Kurrleu Michele Lunettau Sebastiano Grasso Paola Zacconeu Pierluigi Meronif 《European journal of immunology》1994,24(8):1843-1847
We have evaluated the effects of a treatment with soluble interleukin-1 receptor (sIL-1R) in the accelerated model of autoimmune diabetes induced by cyclophosphamide (CY) in the non-obese diabetic (NOD) mouse. Prior to the CY challenge (350 mg/kg body weight), female euglycemic NOD mice were randomly divided into three groups (A–C). Groups B and C were treated daily from 1 day before to 13 days after the CY challenge with sIL-1R at doses of 0.2 and 2 mg/kg body weight. Group A was treated with PBS. By 2 weeks after CY administration, an acute form of autoimmune diabetes with glycosuria, hyperglycemia and severe insulitis occurred in the majority (13/20, 65%) of the control mice (group A). In contrast, repeated injections with sIL-1R protected NOD mice from insulin-dependent diabetes mellitus (IDDM) development in a dose-dependent fashion; the incidence of IDDM was 53.3% (8/15) in the mice treated with 0.2 mg/kg and only 6.7% (1/15) in those treated with 2 mg/kg. However, none of the doses of the sIL-1R reduced the extent of insulitis in NOD mice. Importantly, the anti-diabetogenic property of sIL-1R may not involve major T cell function impairment; accordingly, in parallel experiments, splenic lymphoid cells from NOD mice not challenged with CY, but treated with 2 mg/kg sIL-1R for 5 consecutive days showed a normal distribution of mononuclear cell subsets and maintained their capacity to secrete interferon-γ and IL-2 and to proliferate in response to polyclonal mitogenic stimulation with concanavalin A. 相似文献