全文获取类型
收费全文 | 4227篇 |
免费 | 282篇 |
国内免费 | 26篇 |
专业分类
耳鼻咽喉 | 89篇 |
儿科学 | 55篇 |
妇产科学 | 11篇 |
基础医学 | 578篇 |
口腔科学 | 74篇 |
临床医学 | 240篇 |
内科学 | 1313篇 |
皮肤病学 | 157篇 |
神经病学 | 454篇 |
特种医学 | 81篇 |
外科学 | 578篇 |
综合类 | 23篇 |
预防医学 | 102篇 |
眼科学 | 43篇 |
药学 | 247篇 |
中国医学 | 7篇 |
肿瘤学 | 483篇 |
出版年
2021年 | 48篇 |
2020年 | 23篇 |
2019年 | 48篇 |
2018年 | 49篇 |
2017年 | 44篇 |
2016年 | 65篇 |
2015年 | 68篇 |
2014年 | 82篇 |
2013年 | 87篇 |
2012年 | 155篇 |
2011年 | 173篇 |
2010年 | 120篇 |
2009年 | 103篇 |
2008年 | 186篇 |
2007年 | 200篇 |
2006年 | 185篇 |
2005年 | 191篇 |
2004年 | 191篇 |
2003年 | 200篇 |
2002年 | 196篇 |
2001年 | 134篇 |
2000年 | 166篇 |
1999年 | 119篇 |
1998年 | 60篇 |
1997年 | 57篇 |
1996年 | 65篇 |
1995年 | 59篇 |
1994年 | 47篇 |
1993年 | 57篇 |
1992年 | 138篇 |
1991年 | 105篇 |
1990年 | 129篇 |
1989年 | 113篇 |
1988年 | 105篇 |
1987年 | 102篇 |
1986年 | 74篇 |
1985年 | 76篇 |
1984年 | 47篇 |
1983年 | 45篇 |
1982年 | 37篇 |
1981年 | 27篇 |
1980年 | 23篇 |
1979年 | 26篇 |
1978年 | 35篇 |
1977年 | 22篇 |
1976年 | 24篇 |
1974年 | 27篇 |
1973年 | 21篇 |
1972年 | 23篇 |
1968年 | 19篇 |
排序方式: 共有4535条查询结果,搜索用时 187 毫秒
11.
The purpose of the present study was to determine whether lymphokine activated killer (LAK) cells were involved in the development of coxsackievirus B3 (CB3) myocarditis in both the acute viremic (Experiment I) and the subacute aviremic (Experiment II) stages. To induce LAK cells, recombinant human interleukin-2 (IL-2) was administered to CB3-infected mice subcutaneously daily, starting on day 0 in Experiment I and on day 7 in Experiment II for 7 days, respectively. The treated groups were compared to infected controls. Splenic lymphocytes of IL-2 treated mice were further cultured in vitro in IL-2 containing medium for 7 days, and LAK cell activity, i.e., cytotoxic activity of the lymphocytes against EL-4 tumor cells and against cultured fetal myocytes, was assayed by51Cr-release method. In Experiment I, histologic scores, myocardial virus titers, and LAK cell activity did not differ significantly between IL-2 treated and untreated groups. In contrast, in Experiment II, there were more cellular infiltration associated with severe necrosis and higher LAK cell activity against EL-4 cells and cultured myocytes in IL-2 treated than in untreated groups. The presence of LAK cells was demonstrated in the subacute stage of murine CB3 myocarditis. Thus, the behavior of LAK cell activity may vary with the course of myocarditis, and enhanced LAK cell activity may be involved in the development of the disease.This work was supported by research grants from the Conference on Coronary Artery Disease, Japanese Education of Science and Walfare (Nos. 08877110 and 09470164), Kanae Shinyaku Foundation, and Japan Cardiovascular Research Foundation. 相似文献
12.
Yasunori Cho Satoru Suzuki Masakazu Yokoi Muneaki Shimada Saburo Kuwabara Akira Murayama 《The Japanese Journal of Thoracic and Cardiovascular Surgery》2004,52(10):476-479
Lymphoblastic lymphoma, an aggressive mediastinal mass, is recognized as serious threat to the patient in developing cardiac
tamponade or airway obstruction. Surgical procedure is often required to relieve clinical emergency and to establish prompt
pathological diagnosis. However, in such a patient, acute respiratory occlusion in the spine position can be a life-threatening
complication during general anesthesia. We describe a 17-year-old man whose cardiac tamponade was treated by pericardial-pleural
window through a left anterior thoracotomy in the lateral position. The patient recovered from hemodynamic compromise without
showing respiratory occlusion during general anesthesia and remained in the lateral position until extubation. Pathological
diagnosis was precursor T-lymphoblastic lymphoma. There were no complications attributable to the operative procedure. Further
chemotherapy reduced the mediastinal mass in size after two weeks when the patient developed sepsis and died. Lateral position
prevents respiratory occlusion during surgical procedure under general anesthesia in the patient of huge anterior mediastinal
tumor with airway obstruction. 相似文献
13.
In the present study, we examined the expression of various protooncogenes and the specific binding of nuclear factor to c-myc gene in peripheral blood mononuclear cells (PBMC) from progressive systemic sclerosis (PSS) patients. We demonstrated first amplified expression of c-myc and c-myb gene and the existence of a nuclear protein specifically bound to 5'-non-coding fragment of c-myc gene. We then found a positive correlation between the degree of expression and/or affinity for the c-myc gene fragment of the nuclear protein and clinical disease activity. The amount of the factor was significantly reduced along with or prior to the amelioration of clinical symptoms and laboratory abnormalities with treatment. The significance of c-myc and c-myb proto-oncogene expression and nuclear factor specifically bound to c-myc gene is discussed. 相似文献
14.
A murine IgG1 monoclonal antibody, termed 68-12, was produced against purified human saposin C. Immunoprecipitation and binding analysis indicated that the antibody reacted only with saposin C. Dot blotting and Western analysis demonstrated that antibody 68-12 also reacted with prosaposin and a higher molecular weight protein(s) in murine spleen and cerebral grey matter. Solid phase competitive radioimmunoassay against 125I labeled saposin C (0.25 micrograms/ml) showed no cross reactivity for saposin A, B and D up to 15 micrograms/ml. At a concentration of 50 micrograms/ml saposin A, B and D cross reacted 21, 1.5, and 49% respectively. Monoclonal antibody 68-12 appears to have potential utility in the purification, detection and quantitation of human saposin C and its precursor. 相似文献
15.
Kimiyoshi Ozawa Kenji Hashimoto Takashi Kishimoto Eiji Shimizu Hiroshi Ishikura Masaomi Iyo 《Neuropsychopharmacology》2006,59(6):546-554
BACKGROUND: Maternal viral infection is associated with increased risk for schizophrenia. It is hypothesized that the maternal immune response to viruses may influence fetal brain development and lead to schizophrenia. METHODS: To mimic a viral infection, the synthetic double strand RNA polyriboinosinic-polyribocytidilic acid (poly I:C) was administered into pregnant mice. Behavioral evaluations (thigmotaxis, methamphetamine [MAP]-induced hyperactivity, novel-object recognition test [NORT]), sensorimotor gating (prepulse inhibition [PPI]), and biochemical evaluation of the dopaminergic function of the offspring of phosphate-buffered saline (PBS)-treated dams (PBS-mice) and that of poly I:C-treated dams (poly I:C-mice) were examined. RESULTS: In juveniles, no difference was found between the poly I:C-mice and PBS-mice. However, in adults, the poly I:C-mice exhibited attenuated thigmotaxis, greater response in MAP-induced (2 mg/kg) hyperlocomotion, deficits in PPI, and cognitive impairment in NORT compared with the PBS-mice. Cognitive impairment in the adult poly I:C-mice could be improved by subchronic administration of clozapine (5.0 mg/kg) but not haloperidol (.1 mg/kg). Increased dopamine (DA) turnover and decreased receptor binding of D2-like receptors, but not D1-like receptors, in the striatum were found in adult poly I:C-mice. CONCLUSIONS: Prenatal poly I:C administration causes maturation-dependent increased subcortical DA function and cognitive impairment in the offspring, indicating a neurodevelopmental animal model of schizophrenia. 相似文献
16.
M. Shiraki M. Fukunaga K. Kushida H. Kishimoto Y. Taketani H. Minaguchi T. Inoue R. Morita H. Morii K. Yamamoto Y. Ohashi H. Orimo 《Osteoporosis international》2003,14(3):225-234
To determine the clinical recommended dosage regimen of risedronate for the treatment of involutional osteoporosis in Japanese patients, dose-response relationships for the efficacy and safety of this drug were investigated using a multi-center, randomized, double-blind, parallel group comparative design with four dose levels of risedronate (placebo, 1 mg, 2.5 mg and 5 mg per day). A total of 211 patients diagnosed with involutional osteoporosis according to the criteria proposed by the Japanese Society for Bone and Mineral Research were randomized and received one of the four doses once daily for 36 weeks. All patients were supplemented with 200 mg of calcium daily in the form of calcium lactate. The primary efficacy endpoint was the percent change in bone mineral density of the lumbar spine (L2-L4 BMD) determined by dual-energy X-ray absorptiometry (DXA) from baseline to the time of final evaluation. Changes in biochemical markers of bone turnover and safety profile were also compared. Percent changes in L2-L4 BMD at final evaluation in the placebo, and 1-, 2.5-, and 5-mg risedronate groups were 0.79+/-5.30, 2.71+/-4.93, 5.29+/-3.96, and 5.15+/-4.25% (mean+/-SD), respectively. A linear dose-response relationship was obtained up to a dose of 2.5 mg, whereas no further increase in BMD was observed at 5 mg. The decrease in bone turnover markers, including N-terminal osteocalcin, phosphorus, and urinary deoxypyridinoline, also showed a linear dose-response relationship up to a dose of 2.5 mg. Alkaline phosphatase level decreased linearly up to a dose of 5 mg. Risedronate was well tolerated in this 36-week study with 1- to 5-mg doses. Neither the overall incidence of adverse events nor the percentage of patients without problem in overall safety assessment differed significantly among the dose groups including the placebo group. Based on these results, a once-daily dose of 2.5 mg of risedronate, which is half that used in Caucasians, is recommended for the treatment of involutional osteoporosis in Japanese patients. 相似文献
17.
Tadahito Kanda Takashi Onda Soichi Zanma Toshiharu Yasugi Akemi Furuno Sumie Watanabe Takashi Kawana Motoyasu Sugase Kuniaki Ueda Takahiko Sonoda Saburo Suzuki Takenobu Yamashiro Hiroyuki Yoshikawa Kunito Yoshiike 《Virology》1992,190(2)
The E4 open reading frame (ORF) of human papillomaviruses (HPVs) is transcribed in abundant mRNAs encoding an
fusion gene during the productive infection, and the HPV 16 E7 ORF encodes an oncoprotein detectable in the cell lines derived from cervical carcinoma. We examined 421 human sera, which included 108 samples from the patients with cervical carcinoma, for the presence of IgG antibodies against the HPV 16 E4 and E7 proteins by enzyme-linked immunosorbent assay. Bacterially expressed fusion protein lac-
and nonfusion protein E7 were purified and used as antigens. All of the 22 serum samples positive for anti-E7 antibody and the 11 out of 15 samples positive for anti-
antibody were from the patients with cervical carcinoma, but only one sample was found to contain both anti-
and anti-E7 antibodies. These findings show specific and independent association of these antibodies with cervical carcinoma. 相似文献
18.
Fibrate for treatment of primary biliary cirrhosis 总被引:1,自引:0,他引:1
Shinji Iwasaki Naoaki Akisawa Toshiji Saibara Saburo Onishi 《Hepatology research》2007,37(S3):S515-S517
Recent studies of the effectiveness of ursodeoxycholic acid (UDCA) therapy in patients with primary biliary cirrhosis (PBC) reported that UDCA therapy did not necessarily stop the progression of liver fibrosis in all patients, even those with early stage PBC. Thus, there is a need for more effective treatments that could prevent asymptomatic PBC from progressing to the icteric stage. Bezafibrate is effective in approximately two-thirds of non-icteric patients who have not shown a complete response to UDCA. Serum bilirubin, aspartate aminotransferase and γ-guanosine 5'-triphosphate levelswere significantly lower in patients who responded to additional bezafibrate on univariate analysis. The putative mechanism by which bezafibrate acts in cholestasis is by increasing phospholipid output into bile, which forms micelles with the hydrophobic bile acid that reduces its toxicity. 相似文献
19.
Relevance of inflammatory cell infiltrates for complete atrioventricular block in experimental murine myocarditis. 总被引:2,自引:0,他引:2
BACKGROUND: There are few systemic pathologic studies on myocarditis. This study aimed to clarify the pathologic characteristics of murine myocarditis. METHODS: We recorded serial electrocardiograms in experimental viral myocarditis in mice and then examined their cardiac pathology. After taking baseline electrocardiograms, we inoculated the mice intraperitoneally with the encephalomyocarditis virus. Electrocardiograms were serially recorded until 220 days after the virus inoculation. RESULTS: Serial electrocardiograms revealed ectopic beats, low voltage of the QRS complex, and the appearance of complete atrioventricular (AV) block. Corresponding myocardial lesions were found in the hearts of mice with these ectopic beats. Mononuclear cell infiltrations into the His bundle were most frequently found in mice with complete AV block. CONCLUSIONS: Inflammatory change with cellular infiltrations was the most common pathologic finding in mice with complete AV block. In clinical settings, anti-inflammatory therapy might be recommended for patients with myocarditis complicated with conduction disturbances. 相似文献
20.
Clinical Course and Autopsy Findings of a Patient with Clival Chordoma Who Underwent Multiple Surgeries and Radiation during a 10-Year Period. 下载免费PDF全文
Masashi Tamaki Masaru Aoyagi Toshihiko Kuroiwa Masaaki Yamamoto Seiji Kishimoto Kikuo Ohno 《Skull base》2007,17(5):331-340
The management of clival chordoma remains problematic. We present the case of a 48-year-old woman with clival chordoma who underwent multiple surgeries and radiation therapy, including gamma knife stereotactic radiosurgery (GK-SRS), during a 10-year clinical course. The tumor was initially removed by gross total resection via the trans-sphenoidal approach, followed by external linac radiation therapy. The tumor recurred at the clivus 5 years after the initial operation. After repeated trans-sphenoidal removal of recurrent tumors, she twice underwent GK-SRS for a tumor remnant adjacent to the brainstem. Although this part of the tumor was controlled by GK-SRS, there was further tumor extension toward the sphenoid and maxillary sinuses. Ultimately, lower cranial nerve dysfunction developed due to tumor extension into the lower part of the clivus and the patient died of respiratory failure. Autopsy revealed the tumor to extend from the lower clivus to the bilateral middle fossae. The lower part of the tumor extended to the nasal cavity and to the posterior wall of the pharynx, resulting in compression of the upper pharyngeal region. The tumor around the jugular foramen compressed the lower cranial nerves bilaterally. Tumor cells did not, however, invade the intradural space microscopically. Although chordoma is not biologically malignant, this tumor can show massive extension with destruction of bony structures and extracranial invasion of connective tissues. Therefore, the optimal treatment strategy is to remove the tumor mass as extensively as possible, including normal bony structures and connective tissues surrounding the tumor, using skull base surgical techniques. 相似文献