全文获取类型
收费全文 | 8390篇 |
免费 | 605篇 |
国内免费 | 255篇 |
专业分类
耳鼻咽喉 | 89篇 |
儿科学 | 261篇 |
妇产科学 | 159篇 |
基础医学 | 862篇 |
口腔科学 | 153篇 |
临床医学 | 755篇 |
内科学 | 1278篇 |
皮肤病学 | 273篇 |
神经病学 | 318篇 |
特种医学 | 260篇 |
外科学 | 1401篇 |
综合类 | 916篇 |
现状与发展 | 2篇 |
一般理论 | 6篇 |
预防医学 | 575篇 |
眼科学 | 425篇 |
药学 | 611篇 |
2篇 | |
中国医学 | 276篇 |
肿瘤学 | 628篇 |
出版年
2023年 | 74篇 |
2022年 | 251篇 |
2021年 | 355篇 |
2020年 | 253篇 |
2019年 | 194篇 |
2018年 | 234篇 |
2017年 | 208篇 |
2016年 | 214篇 |
2015年 | 321篇 |
2014年 | 372篇 |
2013年 | 423篇 |
2012年 | 547篇 |
2011年 | 563篇 |
2010年 | 419篇 |
2009年 | 373篇 |
2008年 | 453篇 |
2007年 | 439篇 |
2006年 | 383篇 |
2005年 | 322篇 |
2004年 | 297篇 |
2003年 | 293篇 |
2002年 | 277篇 |
2001年 | 190篇 |
2000年 | 173篇 |
1999年 | 117篇 |
1998年 | 80篇 |
1997年 | 40篇 |
1996年 | 43篇 |
1995年 | 46篇 |
1994年 | 41篇 |
1992年 | 67篇 |
1991年 | 73篇 |
1990年 | 69篇 |
1989年 | 48篇 |
1988年 | 57篇 |
1987年 | 43篇 |
1986年 | 44篇 |
1985年 | 54篇 |
1984年 | 39篇 |
1983年 | 37篇 |
1979年 | 33篇 |
1977年 | 28篇 |
1974年 | 38篇 |
1973年 | 27篇 |
1972年 | 34篇 |
1971年 | 28篇 |
1970年 | 38篇 |
1969年 | 33篇 |
1968年 | 32篇 |
1967年 | 27篇 |
排序方式: 共有9250条查询结果,搜索用时 46 毫秒
21.
Apoptotic rate in peripheral T-cell lymphomas. A study using a tissue microarray with validation on full tissue sections 总被引:8,自引:0,他引:8
Rassidakis GZ Jones D Thomaides A Sen F Lai R Cabanillas F McDonnell TJ Medeiros LJ 《American journal of clinical pathology》2002,118(3):328-334
Peripheral T-cell lymphomas (PTCLs) are a heterogeneous group of non-Hodgkin lymphomas with a wide spectrum of clinicopathologic features, and apoptosis mechanisms may have a role in lymphomagenesis. We assessed apoptotic rate (AR) in 112 PTCLs using a tissue microarray developed in our laboratory and a modified terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assay. The mean AR was 1.47% +/- 1.38% for the entire group of PTCLs (range, 0.06%-5.15%), and AR varied significantly among different tumor types. In mycosis fungoides, the mean AR was 0.74%; angioimmunoblastic T-cell lymphoma, 1.02%; PTCL, not otherwise specified, 1.38%; cutaneous anaplastic large cell lymphoma (ALCL), 1.41%; anaplastic lymphoma kinase protein (ALK)-negative ALCL, 1.43%; extranodal natural killer/T-cell lymphoma of nasal type, 2.04%; ALK-positive ALCL, 2.95%; and enteropathy-type T-cell lymphoma, 3.06%. Mean AR was higher in PTCL with large cell vs small/medium cell morphologic features (1.66% +/- 1.1% vs 0.99% +/- 1.0%). In a subset of 33 PTCLs, the tissue microarray results comparedfavorably with those obtained in full tissue sections. We conclude that the highest ARs in PTCLs are found in enteropathy-type T-cell lymphoma and ALK-positive ALCL, and that AR can be assessed reliably by using a tissue microarray. 相似文献
22.
Induction of the human protein P56 by interferon, double-stranded RNA, or virus infection 总被引:22,自引:0,他引:22
P56 is the most abundant protein induced by interferon (IFN) treatment of human cells. To facilitate studies on its induction pattern and cellular functions, we expressed recombinant P56 as a hexahistidine-tagged protein in Escherichia coli and purified it to apparent homogeneity using affinity chromatography. A polyclonal antibody raised against this recombinant protein was used to show that P56 is primarily a cytoplasmic protein. Cellular expression of P56 by transfection did not inhibit the replication of vesicular stomatitis virus and encephalomyocarditis virus. P56 synthesis was rapidly induced by IFN-beta, and the protein had a half-life of 6 h. IFN-gamma or poly(A)(+) could not induce the protein, but poly(I)-poly(C) or an 85-bp synthetic double-stranded RNA efficiently induced it. Similarly, infection of GRE cells, which are devoid of type I IFN genes, by vesicular stomatitis virus, encephalomyocarditis virus, or Sendai virus caused P56 induction. Surprisingly, Sendai virus could also induce P56 in the mutant cell line P2.1, which cannot respond to either IFN-alpha/beta or double-stranded RNA. Induction of P56 in the P2.1 cells and the parental U4C cells by virus infection was preceded by activation of IRF-3 as judged by its translocation to the nucleus from the cytoplasm. 相似文献
23.
High tidal volume ventilation induces proinflammatory signaling in rat lung endothelium 总被引:9,自引:0,他引:9
Bhattacharya S Sen N Yiming MT Patel R Parthasarathi K Quadri S Issekutz AC Bhattacharya J 《American journal of respiratory cell and molecular biology》2003,28(2):218-224
Alveolar overdistension during mechanical ventilation causes leukocyte sequestration, leading to lung injury. However, underlying endothelial cell (EC) mechanisms are undefined. In a new approach, we exposed isolated blood-perfused rat lungs to high tidal volume ventilation (HV) for 2 h, then obtained fresh lung endothelial cells (FLEC) by immunosorting at 4 degrees C. Immunoblotting experiments indicated that as compared with FLEC derived from lungs ventilated at low volume (LV), HV markedly enhanced tyrosine phosphorylation (TyrP). The tyrosine kinase blocker, genistein, inhibited this response. HV also induced focal adhesion (FA) formation in FLEC, as detected by immunofluorescent aggregates of the alpha(v)beta(3) integrin that co-localized with aggregations of focal adhesion kinase (FAK). Immunoprecipitation and blotting experiments revealed that HV increased TyrP of the FA protein, paxillin. In addition, HV induced a paxillin-associated P-selectin expression on FLEC that was also inhibited by genistein. However, HV did not increase lung water. These results indicate that in HV, EC signaling in situ causes FA formation and induces TyrP-dependent P-selectin expression. These signaling mechanisms may promote leukocyte-mediated responses in HV. 相似文献
24.
25.
26.
Gromkowski Stanislaw H.; Mama Khuzaima; Yagi Junji; Sen Ranjan; Rath Satyajit 《International immunology》1990,2(9):903-908
The effect of double-stranded RNA (dsRNA) and bacterial lipopolysaccharideon the sensitivity to tumor necrosis factor (TNF)--medlatedcell death was studied In an In vitro system. Since secretionof TNF- Is a part of the early host response to viral and bacterialinfection, we examined whether mimicking the Infection withviral and bacterial products could affect the response of cellsto TNF-. Incubation of WEHI 164 fibrosarcoma cells with dsRNAor lipopolysaccharide (LPS) significantly increased their sensitivityto TNF--mediated lysis and to TNF-secreting inflammatory T cell-mediatedlysis. Thus, these products could induce Increased sensitivityto TNF- In cells In an inflammatory focus, possibly contributingto selective elimination of Infected but not healthy cells bythis non-specific cytokine. Additionally, our data show thatboth dsRNA and LPS, as well as TNF- Itself, rapidly Induce nuclearfactor-xB (NF-*B), a DNA-bindlng protein Implicated In regulationof gene expression. We suggest that NF-xB could regulate genescrucial for the induction of cell death by TNF-. 相似文献
27.
PreliminaryevaluationofpelvicvascularbedisolationchemotherapyinthetreatmentofadvancedcervicalcarcinomaJiangSenandPostgraduate... 相似文献
28.
Khatri ML Shafi M Sen NK 《Indian journal of dermatology, venereology and leprology》1996,62(5):322-324
A 24-year old male patient developed multiple lesions of keratoacanthoma in the epidermal verrucous naevus. He also had multiple papillomatous lesions on the lips, buccal mucosa, gingiva and tongue, with positive family history of similar lesions. He also had multiple skin tags and patchy palmoplantar keratoderma and minimal kyphoscoliosis. 相似文献
29.
Urken ML Catalano PJ Sen C Post K Futran N Biller HF 《Archives of otolaryngology--head & neck surgery》1993,119(12):1318-1325
OBJECTIVE: The role of free flaps in skull base reconstruction is discussed in detail. Twenty-six microvascular free tissue transfers performed in 22 patients are reviewed in detail. A classification scheme for skull base defects is presented. SETTING: Tertiary referral center. PATIENTS: Twenty-two patients with neoplasms that involve the skull base underwent a combined craniotomy and facial approach for resection. The resultant defects were reconstructed with a variety of microvascular free flaps. RESULTS: All 22 patients were ultimately successfully reconstructed with a free flap. One patient required a second free flap following ablative surgery for a recurrent tumor. The initial free flaps in three patients were unsuccessful and a second flap was required. The classification scheme was applied to all defects. CONCLUSIONS: The creation of a functional separation of the intracranial and extracranial cavities can be extremely difficult to accomplish, especially when multiple cavities (nasal, oral, pharyngeal) are violated. Free flaps provide a solution to this problem in select cases. Skull base defects can and should be classified for the purpose of communication, treatment planning, prognosis of reconstruction, and judging therapeutic outcome. 相似文献
30.