全文获取类型
收费全文 | 77114篇 |
免费 | 6561篇 |
国内免费 | 3438篇 |
专业分类
耳鼻咽喉 | 755篇 |
儿科学 | 1639篇 |
妇产科学 | 1247篇 |
基础医学 | 9239篇 |
口腔科学 | 1341篇 |
临床医学 | 6448篇 |
内科学 | 7373篇 |
皮肤病学 | 982篇 |
神经病学 | 3756篇 |
特种医学 | 3698篇 |
外国民族医学 | 56篇 |
外科学 | 8307篇 |
综合类 | 14400篇 |
现状与发展 | 22篇 |
预防医学 | 2352篇 |
眼科学 | 776篇 |
药学 | 6577篇 |
48篇 | |
中国医学 | 3058篇 |
肿瘤学 | 15039篇 |
出版年
2024年 | 193篇 |
2023年 | 1032篇 |
2022年 | 2246篇 |
2021年 | 2952篇 |
2020年 | 2449篇 |
2019年 | 2193篇 |
2018年 | 2027篇 |
2017年 | 2438篇 |
2016年 | 2699篇 |
2015年 | 2970篇 |
2014年 | 4450篇 |
2013年 | 4736篇 |
2012年 | 4293篇 |
2011年 | 4813篇 |
2010年 | 3927篇 |
2009年 | 3869篇 |
2008年 | 3984篇 |
2007年 | 4232篇 |
2006年 | 3876篇 |
2005年 | 3401篇 |
2004年 | 3031篇 |
2003年 | 2588篇 |
2002年 | 2362篇 |
2001年 | 2081篇 |
2000年 | 1750篇 |
1999年 | 1578篇 |
1998年 | 1319篇 |
1997年 | 1221篇 |
1996年 | 1118篇 |
1995年 | 1008篇 |
1994年 | 864篇 |
1993年 | 734篇 |
1992年 | 602篇 |
1991年 | 488篇 |
1990年 | 409篇 |
1989年 | 374篇 |
1988年 | 369篇 |
1987年 | 305篇 |
1986年 | 248篇 |
1985年 | 326篇 |
1984年 | 304篇 |
1983年 | 166篇 |
1982年 | 237篇 |
1981年 | 213篇 |
1980年 | 146篇 |
1979年 | 126篇 |
1978年 | 100篇 |
1977年 | 76篇 |
1976年 | 68篇 |
1975年 | 29篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
41.
W. Feleszko J. Jaworska R-D. Rha S. Steinhausen A. Avagyan A. Jaudszus B. Ahrens D. A. Groneberg U. Wahn E. Hamelmann 《Clinical and experimental allergy》2007,37(4):498-505
BACKGROUND: Microbial intestinal colonization in early in life is regarded to play a major role for the maturation of the immune system. Application of non-pathogenic probiotic bacteria during early infancy might protect from allergic disorders but underlying mechanisms have not been analysed so far. OBJECTIVE: The aim of the current study was to investigate the immune effects of oral application of probiotic bacteria on allergen-induced sensitization and development of airway inflammation and airway hyper-reactivity, cardinal features of bronchial asthma. METHODS: Newborn Balb/c mice received orally 10(9) CFU every second day either Lactobacillus rhamnosus GG or Bifidobacterium lactis (Bb-12) starting from birth for consecutive 8 weeks, during systemic sensitization (six intraperitoneal injections, days 29-40) and airway challenge (days 54-56) with ovalbumin. RESULTS: The administration of either Bb-12 or LGG suppressed all aspects of the asthmatic phenotype: airway reactivity, antigen-specific immunoglobulin E production and pulmonary eosinophilia (mean: 137 vs. 17 and 13 cellsx10(3)/mL, respectively). Antigen-specific recall proliferation by spleen cells and T-helper type 2 cytokine production (IL-4, IL-5 and IL-10) by mesenteric lymph node cells also showed significant reduction, while TGF production remained unchanged. Oral LGG administration particularly suppressed allergen-induced proliferative responses and was associated with an increase in numbers of TGF-beta-secreting CD4+/CD3+ T cells in mesenteric lymph nodes (6.5, 16.7%) as well as nearly 2-fold up-regulation of Foxp3-expressing cells in peribronchial lymph nodes. CONCLUSIONS: Neonatal application of probiotic bacteria inhibits subsequent allergic sensitization and airway disease in a murine model of asthma by induction of T regulatory cells associated with increased TGF-beta production. 相似文献
42.
J. Pillgram-Larsen J. Thorvaldson E. Thaulow G. Semb A. Serck-Hanssen 《European journal of cardio-thoracic surgery》1987,1(3):183-185
A rare case of a rhabdomyoma originating from the surface of the right atrium in a 20-year-old female is reported. The tumor showed electrical activity and caused both outflow obstruction and tamponade symptoms. It was successfully removed by a right-sided thoracotomy. The clinical course, diagnostic investigations, and the therapeutical approach of this rare lesion are discussed. 相似文献
43.
Free amino acid concentrations of CSF were measured in bacterial meningitis, aseptic meningitis, meningoradiculitis Garin-Bujadoux-Bannwarth, multiple sclerosis, carcinomatous meningitis, and controls. Almost all CSF amino acids were highly elevated in bacterial but not in aseptic meningitis, meningoradiculitis Garin-Bujadoux-Bannwarth or carcinomatous meningitis thus providing a laboratory tool for their differential diagnosis. In carcinomatous meningitis the amino acid pattern indicates metabolic activity of tumor cells. Minimal alterations were found in multiple sclerosis which have no diagnostic value. 相似文献
44.
Rauhut Friedhelm Reinhardt Volker Budach Volker Wiedemayer Helmut Nau Heinz-Eugen 《Neurosurgical review》1989,12(4):309-313
Ten patients suffering from intramedullary pilocytic astrocytomas (WHO-classification: astrocytoma grade I) were investigated catamnesticly. Combined surgery and radiotherapy was performed. Seven patients received neutron irradiation postoperatively. In four cases the neurological symptoms were improved after follow-up periods ranging from 33 to 89 months. The three other patients died after 6 to 21 months. The autopsy findings of a 14 year old child are presented. Our results are compared with reports in the literature. In addition, long-term problems of the spinal column are discussed. It seems that the combined surgical and neutron therapy improves the prognosis of pencil gliomas. 相似文献
45.
Tamoxifen (TAM) has previously been shown to inhibit growth of the Dunning R3327 rat prostate adenocarcinoma and to elevate serum prolactin levels. The purpose of this study was to determine the role of prolactin in modulating the effects of tamoxifen on growth of the R3327 prostatic adenocarcinoma. Intact and castrated Copenhagen-Fischer male rats bearing the Dunning R3327 rat prostatic tumor were divided into groups and injected sc five times per week for 16 weeks as follows: vehicle; TAM (0.5 mg/kg); haloperidol (HALO; 0.5 mg/kg); bromocriptine (CB-154; 5 mg/kg); TAM plus HALO; or TAM plus CB-154. In both intact and castrated rats, agents that either raised (HALO) or lowered (CB-154) serum prolactin had little effect on prostatic tumor growth when administered singly. In intact rats, average tumor diameter in vehicle-treated controls increased 421% 16 weeks after the start of the experiment, and treatment with TAM or TAM plus HALO reduced this tumor growth by approximately one-half. Interestingly, CB-154 administered in combination with TAM completely blocked TAM inhibition of tumor growth in intact rats. In contrast to these results in intact rats, average tumor diameter increased 129% in TAM- and 118% in TAM plus HALO-treated castrated rats and was significantly greater than the characteristic retardation of tumor growth (49% increase) that occurred in the vehicle-treated castrate controls. In addition, combined treatment of TAM plus CB-154 in castrate rats resulted in an even greater increase (188%) in average tumor diameter. The inhibitory effect of TAM on R3327 prostatic tumor growth in intact rats appears to be an indirect effect resulting from its ability to reduce serum testosterone levels. In contrast, the stimulatory effect of TAM in castrate rats appears to result directly from an estrogen-like action, which can directly enhance prostatic tumor growth in the presence of low levels of circulating androgens; this stimulatory effect of TAM is more pronounced when prolactin levels are suppressed by CB-154. Clearly, castration alone is more effective than TAM therapy alone or in combination with castration in the retardation of the growth of the androgen-dependent R3327 prostatic tumor in rats. 相似文献
46.
益肾化浊注射液对慢性肾功能衰竭大鼠残余肾中细胞因子含量的影响 总被引:2,自引:0,他引:2
通过观察益肾化浊注射液对5/6肾切除大鼠残余肾中细胞因子含量的影响,益肾化浊注射液延缓慢性肾功能衰竭(CRF)模型大鼠肾功能减退的作用机理。结果显示:益肾化浊注射液可以降低5/6肾切在鼠血清肌,尿素氮(P<0.01),下调肾组织中白细胞介素-1(IL-1)(P<0.05),白细胞介素-8(IL-8)(P<0.05)及肿瘤坏死因子(TNF)(P<0.05)的总体水平,说明益肾化浊注射液可以通过下调5/6肾切除大鼠残余肾中相关细胞因子含量,抑制促炎细胞因子对肾脏的损害,从而延缓CRF的进展。 相似文献
47.
Electrochemotherapy is a novel antitumor treatment involving the systemic administration of bleomycin followed by the delivery
of electrical pulses to the tumor. The present study investigates the effects of electrochemotherapy on the growth of colon
26 cells inoculated subcutaneously into the backs of BALB/c mice. The mice were divided into the following four experimental
groups: 20 that received no further treatment after the inoculation of colon 26 cells (control group); 20 that received 500
μg of bleomycin intraperitoneally 7 and 9 days after the inoculation (BLM group); 20 that received electric pulses to the
tumor 7 and 9 days after the inoculation (EP group); and 30 that received electrochemotherapy 7 and 9 days after the inoculation
(ECT group). During 28 days of observation, no deaths due to tumor progression occurred in the ECT group, but there were 18
in the control group, 11 in the BLM group, and 18 in the EP group. While weight loss was observed in all groups, it was most
remarkable in the control group. Tumor growth was significantly inhibited in the ECT group, compared to the other experimental
groups (P<0.01). The results of this study demonstrated that electrochemotherapy significantly inhibited the growth of colon 26 tumors
in mice, without causing any remarkable adverse effects. 相似文献
48.
Objective: To study the relationship between transaldolase activity, protein expression and testosterone synthesis in Leydig cells of pubertal mice. Methods: Leydig cells were cultured for 2 hours and 8 hours, to the Stimulation Group, hCG was added and to the Controls, only the vehicle. The testosterone concentration was then determined by enzyme-linked immunoadsordent assay (ELISA) and the transaldolase activity and protein expression by Western blot. Results: (1) Both the testosterone concentration and the transaldolase activity in both Stimulation Groups were significantly higher than those in the corresponding Controls (2 h: p<0.05-0.01; 8 h: P<0.001); (2) The ratios of the A isoform, the B isoform and the total transaldolase protein to β-actin between the Stimulation and Control Groups did not differ signifi-cantly. Conclusion: hCG stimulates the transaldolase activity as well as the testosterone synthesis in the Leydig cells of pubertal mice, indicating a positive relationship between them. 相似文献
49.
Eigo Otsuji Toshiharu Yamaguchi Nozomi Yamaguchi Kunihiko Koyama Jiro Imanishi Nobuki Yamaoka Toshio Takahashi 《Surgery today》1992,22(4):351-356
In a previous study, we used a murine monoclonal antibody, A7, against human colon carcinoma as a drug-carrier to treat colorectal cancer.1 In the present study, we found that MAb A7 also reacted immunohistochemically with 73% of human pancreatic carcinoma cell lines, with the A7 antigen mainly being detected on the cell surface. However, the A7 antigen was found in only 9% of the spent media of these human pancreatic carcinoma cell lines by ELISA. On the other hand, the positive incidence of CA19-9, POA, ferritin, CEA, DU-PAN-2 and SLX in those spent media was 100%, 64%, 64%, 55%, 55% and 36%, respectively. These results suggest that the A7 antigen may only rarely be shed into the sera of pancreatic cancer patients, in which case MAb A7 could be a suitable drug-carrier in targeting chemotherapy for pancreatic cancer patients. 相似文献
50.
恶性肿瘤的皮肤转移确与患者的病种、病理类型、术前后淋巴结转移情况、临床分期、手术类型、放疗及化疗的剂量、遗传因素有关。其出现于任何部位均提示预后不佳。 相似文献