全文获取类型
收费全文 | 7480篇 |
免费 | 335篇 |
国内免费 | 22篇 |
专业分类
耳鼻咽喉 | 122篇 |
儿科学 | 86篇 |
妇产科学 | 86篇 |
基础医学 | 927篇 |
口腔科学 | 178篇 |
临床医学 | 370篇 |
内科学 | 1713篇 |
皮肤病学 | 133篇 |
神经病学 | 556篇 |
特种医学 | 182篇 |
外科学 | 1542篇 |
综合类 | 33篇 |
预防医学 | 182篇 |
眼科学 | 192篇 |
药学 | 632篇 |
中国医学 | 34篇 |
肿瘤学 | 869篇 |
出版年
2023年 | 38篇 |
2022年 | 64篇 |
2021年 | 133篇 |
2020年 | 69篇 |
2019年 | 100篇 |
2018年 | 122篇 |
2017年 | 102篇 |
2016年 | 129篇 |
2015年 | 131篇 |
2014年 | 146篇 |
2013年 | 219篇 |
2012年 | 316篇 |
2011年 | 339篇 |
2010年 | 174篇 |
2009年 | 180篇 |
2008年 | 301篇 |
2007年 | 336篇 |
2006年 | 321篇 |
2005年 | 316篇 |
2004年 | 330篇 |
2003年 | 346篇 |
2002年 | 310篇 |
2001年 | 272篇 |
2000年 | 337篇 |
1999年 | 264篇 |
1998年 | 84篇 |
1997年 | 46篇 |
1996年 | 42篇 |
1995年 | 52篇 |
1994年 | 42篇 |
1993年 | 49篇 |
1992年 | 195篇 |
1991年 | 154篇 |
1990年 | 199篇 |
1989年 | 195篇 |
1988年 | 176篇 |
1987年 | 173篇 |
1986年 | 191篇 |
1985年 | 134篇 |
1984年 | 94篇 |
1983年 | 70篇 |
1981年 | 28篇 |
1980年 | 28篇 |
1979年 | 73篇 |
1978年 | 54篇 |
1977年 | 40篇 |
1975年 | 31篇 |
1974年 | 39篇 |
1973年 | 33篇 |
1972年 | 33篇 |
排序方式: 共有7837条查询结果,搜索用时 62 毫秒
21.
Prognostic significance of the expression of ras oncogene product in non-small cell lung cancer. 总被引:5,自引:0,他引:5
The clinical significance of ras oncogene expression in non-small cell lung cancer was evaluated in 116 surgically treated patients. Archival paraffin sections of the tumors were analyzed immunohistochemically using anti-ras p21 monoclonal antibody (MoAb) rp-35, and p21 staining was correlated with clinicopathologic parameters and survival. Positive reactions (+ and ++) were observed in 72.5% of the adenocarcinomas and 55.6% of the squamous cell carcinomas studied. The T1 tumors showed a ++ reaction less frequently than T2 and T3 tumors (P less than 0.05). Stage I tumors also were less reactive with MoAb rp-35 than tumors in more advanced stages (P less than 0.05). Survival analysis showed that patients with p21-negative tumors had significantly longer survival times (a 5-year survival rate of 64.1%) than those with p21 + tumors (38.0%, P less than 0.05) or those with p21 ++ tumors (11.5%, P less than 0.005). The significant correlation between p21 staining and patient survival was independent of histologic type, stage of disease, tumor or node status, and the resectability of tumors. On Cox's multivariate analysis, p21 staining was a major and independent prognostic determinant of survival. These results suggest that enhanced ras p21 expression may be one of the important biologic and clinical markers indicating the malignant potential of non-small cell lung cancer. 相似文献
22.
Aortic arch replacement with proximal first technique. 总被引:2,自引:0,他引:2
Yuji Miyamoto Kenji Onishi Masataka Mitsuno Koichi Toda Masao Yoshitatsu Kazuo Abe 《Annals of thoracic and cardiovascular surgery》2003,9(6):389-393
BACKGROUND: Deep hypothermic circulatory arrest (DHCA) without retrograde cerebral perfusion (RCP) has a strict time limit. We modified a surgical technique for anastomosis to shorten the period of DHCA and unilateral cerebral perfusion (UCP). METHODS: Between March 1993 and August 2001, retrospective analysis was done on 23 consecutive patients, who underwent aortic arch replacement with branches. The patients were divided into two groups: DHCA group and UCP group. The DHCA group, in which DHCA alone and without additional cerebral perfusion was performed, comprised of nine patients. Proximal aortic anastomosis was performed first during systemic cooling; then both the brachiocephalic artery and left carotid artery were reconstructed with the branches of the artificial graft during circulatory arrest; thereafter, cerebral and coronary perfusions were resumed. The UCP group, in which DHCA was not used but right hemisphere perfusion during deep hypothermia was performed when the origin of brachiocephalic artery was safely clamped, consisted of 14 patients. RESULTS: Mean time of DHCA was 18.8+/-4.2 minutes and that of right hemisphere perfusion time was 11.0+/-3.8 minutes, respectively. Twenty-one patients survived the surgery (91.3%), and two (8.7%) died during hospitalization. Transient cerebral complication occurred in four patients in the DHCA group and all recovered. Logistic regression analysis revealed that DHCA was the only parameter to significantly influence temporary neurological dysfunction. There was no other significant difference between the two groups. CONCLUSION: With our modified and simple surgical technique for aortic arch repair, we were able to successfully shorten the DHCA time and right hemisphere perfusion time. However, because DHCA was the only parameter to significantly influence temporary neurological dysfunction, some form of continuous cerebral perfusion at deep hypothermia may be a safer method to preserve cerebral function. 相似文献
23.
Y C Park H Kiwamoto T Nishioka H Tsujihashi S Mitsubayashi T Matsuura T Akiyama T Kurita T Miyamoto 《Hinyokika kiyo. Acta urologica Japonica》1987,33(6):883-888
Combined measurement of serum prostate-specific antigen (PA) and prostatic acid phosphatase (PAP) was performed in 235 patients with various urologic diseases including 55 patients with prostatic cancer. A PA level of over 24.7 ng/ml and a PAP level of over 3.1 ng/ml were considered to be positive. The positive rate of PA was 57% in the patients with untreated prostatic cancer and 3% in the patients without prostatic cancer. The positive rate of PAP was 52% in the patients with untreated prostatic cancer and 1% in the patients without prostatic cancer. PA and PAP were considered to be equally sensitive and specific serum markers of prostatic cancer. However, the positive rate increased to 65% without increasing the false positive rate when the PA and PAP were both measured simultaneously. The combined assay of PA and PAP is recommended for screening prostatic cancer. The cross-over titer of PA and gamma-Sm using standard samples in each kit revealed linearity, which suggested that PA and gamma-Sm possess the same antigenicity. 相似文献
24.
K Miyamoto 《Shinrigaku kenkyu : The Japanese journal of psychology》1987,58(4):233-239
The present study was intended to evaluate the hypothesis that the nursing-suckling relationship of rats proceeds from the mother-leading-type in early postpartum days to the infants-leading-type in later postpartum. Four groups were organized to make tests on the effects of different kinds of mother-infant separation (8-hr) upon nursing-suckling behaviors. Groups were Groups MIS (a separated mother and infants group), MS (mother-separated and infants-fostered group), IS (a foster-mother and separated-infants group), and C (non-separated control group). The separation of each group, lasting for 8-hr, was made at 1-2, 6-7, 11-12, 16-17, 21-22, 26-27, and 31-32 days after parturition. In Exp. I, nursing behavior of mother and suckling and/or eating behavior of infants in mother-infant interactions were observed by time-sampling method for 30 min following 8-hr of separation. In Exp. II, the suckling test of infants (half of the litter) was made on the anesthetized mother at the presence of food pellets. The results of Exp. I showed that nursing-suckling episodes were more frequent in Groups MIS, MS, and IS than in Group C (fig. 1). Further, the differences among the first three groups were not significant before 11-12 days of age. However, the infant-separated group (Group IS) showed higher level of response at 16-17, 21-22 days of age, suggesting the active role of infants in starting nursing-suckling episodes at these ages.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
25.
Y Miyamoto M Nakatani M Ida T Ishikawa N Okazawa M Ariizumi F Tsujimoto K Mizunuma Y Fukuda S Tada 《Journal of clinical ultrasound : JCU》1989,17(5):309-318
Ultrasonography was performed in 45 cases of gastric cancer. Specimens from all 45 cases of gastric cancer were subjects to ultrasonographic study by the water immersion method for comparison with histology. In 32 of these 45 cases in vivo ultrasonographic evaluation was performed prospectively. The overall accuracy rates for the diagnosis of the depth of cancerous invasion were almost 80% in both in vitro and in vivo studies. In vivo ultrasonographic findings agreed well with those from the specimen studies. Ultrasonography was considered to be useful in the diagnosis of gastric malignancies. 相似文献
26.
27.
H Dosaka S Abe M Sasaki H Miyamoto Y Kawakami 《International journal of cancer. Journal international du cancer》1987,39(3):329-332
The inducibility of sister chromatid exchanges (SCEs) by benzo(a)pyrene (BP) was studied in cultured peripheral blood lymphocytes of 15 untreated lung cancer patients and 25 healthy persons including 11 high- and 14 low-cancer-risk individuals tentatively classified by the familial history of lung cancer and other neoplasms. The baseline SCE frequency in cultured lymphocytes was significantly high in lung cancer patients, as compared with all healthy persons or low-cancer-risk individuals. Following exposure to BP, the lymphocytes of lung-cancer patients and high-cancer-risk individuals exhibited significantly greater SCE yields than those of persons at low risk, although no significant difference was observed in the lymphocyte SCE yields when the levels of lung cancer patients were compared with those of all healthy persons. A comparison of the net SCE increase (delta SCE) in BP-exposed lymphocytes among the study groups, however, revealed a significant difference in delta SCE values only between high- and low-cancer-risk individuals. The present findings on both the observed SCE yields and delta SCE values suggest that lymphocytes of high-risk individuals may be more susceptible to BP-induced DNA damage than those of persons at low risk, and that such a chromosomal hypersensitivity to genotoxins may be associated with a high risk of neoplasms. 相似文献
28.
29.
The dynamic responses of minute ventilation, heart rate, cardiac output, oxygen uptake, and carbon dioxide output to cyclic ramp exercise were studied on six healthy male subjects. Exercise was performed in the sitting position using a cycle ergometer. On separate occasions, three different ramp slopes, i.e. 33.3 (repeated for three cycles), 20 (two cycles), and 14.3 W/min (one cycle), were applied over the load range from 0 to 100 W. Mean response times (MRTs) were determined by adopting an exponential function with a time delay to the transient responses. The MRTs of the ascending phase of the first cycle were elongated with a decreasing ramp slope in almost all variables, while those for the descending phase remained unchanged. This resulted in notable asymmetry of the responses in the first cycle. However, there was negligible asymmetry observed in subsequent cycles and the MRTs gradually attained their proper values. Asymmetry in cardiac output was less noticeable compared with that of the respiratory variables. The correlation between the MRTs for ventilation and carbon dioxide output was highly significant, suggesting that a cardiodynamic or humoral mechanism may be related to this phenomenon. 相似文献
30.
Noriaki Tsubota Masahiro Myoshimura Akihiro Murotani Yoshifumi Miyamoto Yasumi Matoba 《Surgery today》1994,24(11):978-981
The results of 101 consecutive bronchoplasties performed between 1979 and 1993, including 8 cases of pneumonectomy, 88 cases of lobectomy, 3 cases of segmentectomy, and 2 cases of bronchial resection, are herein reported. Squamous cell carcinoma was the most common disease (59%) followed by adenocarcinoma (30%) and other diseases (11%). Anastomosis was satisfactory in 96 cases. Among the five stenosed cases, local recurrence was found in two cases, and there were three benign strictures. Two of the three benign strictures were treated with bouginage. The pulmonary artery was concomitantly reconstructed in seven cases with satisfactory results. Preoperative chemoradiotherapy was performed in 15 advanced cases and was followed by acceptable surgical results. The 5-year survival rate, according to the post-operative staging of the 86 patients without induction therapy, was 86% in stage I (19 patients), 49% in stage II (21 patients), and 27% in stage IIIA (40 patients). The overall survival rate was 46% at 5 years. There were two indications for this procedure i.e., a positive resection margin in 59 cases and positive hilar nodes in 42 cases. Better survival was noted in patients with squamous cell carcinoma, stage I, and surgery was thus selected for a positive resection margin, and not for a positive node. 相似文献