全文获取类型
收费全文 | 14026篇 |
免费 | 696篇 |
国内免费 | 74篇 |
专业分类
耳鼻咽喉 | 144篇 |
儿科学 | 279篇 |
妇产科学 | 104篇 |
基础医学 | 1900篇 |
口腔科学 | 347篇 |
临床医学 | 874篇 |
内科学 | 4100篇 |
皮肤病学 | 386篇 |
神经病学 | 851篇 |
特种医学 | 452篇 |
外科学 | 2200篇 |
综合类 | 31篇 |
一般理论 | 1篇 |
预防医学 | 452篇 |
眼科学 | 240篇 |
药学 | 918篇 |
中国医学 | 16篇 |
肿瘤学 | 1501篇 |
出版年
2023年 | 81篇 |
2022年 | 149篇 |
2021年 | 263篇 |
2020年 | 153篇 |
2019年 | 178篇 |
2018年 | 259篇 |
2017年 | 196篇 |
2016年 | 231篇 |
2015年 | 269篇 |
2014年 | 346篇 |
2013年 | 395篇 |
2012年 | 644篇 |
2011年 | 669篇 |
2010年 | 432篇 |
2009年 | 357篇 |
2008年 | 727篇 |
2007年 | 750篇 |
2006年 | 723篇 |
2005年 | 789篇 |
2004年 | 789篇 |
2003年 | 733篇 |
2002年 | 771篇 |
2001年 | 349篇 |
2000年 | 343篇 |
1999年 | 305篇 |
1998年 | 162篇 |
1997年 | 149篇 |
1996年 | 153篇 |
1995年 | 131篇 |
1994年 | 111篇 |
1993年 | 125篇 |
1992年 | 286篇 |
1991年 | 261篇 |
1990年 | 219篇 |
1989年 | 270篇 |
1988年 | 223篇 |
1987年 | 229篇 |
1986年 | 228篇 |
1985年 | 203篇 |
1984年 | 137篇 |
1983年 | 103篇 |
1982年 | 59篇 |
1981年 | 54篇 |
1980年 | 50篇 |
1979年 | 86篇 |
1978年 | 66篇 |
1977年 | 57篇 |
1974年 | 49篇 |
1972年 | 49篇 |
1969年 | 48篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
Neutrophil elastase inhibitor reduces hepatic metastases induced by ischaemia-reperfusion in rats. 总被引:2,自引:0,他引:2
Koji Doi Tetsuya Horiuchi Masaru Uchinami Takanori Tabo Narisato Kimura Jun Yokomachi Makoto Yoshida Kuniyoshi Tanaka 《Acta chirurgica》2002,168(8-9):507-510
OBJECTIVE: To investigate the possibility in rats that ONO-5046 Na, a new recombinant inhibitor of neutrophil elastase, can reduce hepatic metastases induced by ischaemia-reperfusion. DESIGN: Laboratory experimental study. SETTING: Research laboratory, Japan. SUBJECTS: Male Fischer rats. INTERVENTIONS: Rats underwent 60 min of 70% partial hepatic ischaemia, after which rat colon adenocarcinoma cells (RCN-H4) were injected into the spleen. The animals were divided into two test groups and a control group. One group was given ONO-5046 Na intravenously at 10 mg/kg/hour. A second group was given a saline solution for the same period, while the controls were not made ischaemic. MAIN OUTCOME MEASURES: Three weeks after inoculation, the number of tumour nodules on the liver surface was counted. The anti-cancer effect of ONO-5046 Na was measured by monotetrazolium assay. RESULTS: Hepatic ischaemia-reperfusion increased the number of liver metastases of RCN-H4 in both clamped and unclamped hepatic lobes. ONO-5046 Na significantly inhibited this in unclamped lobes, but had no anti-cancer effect. CONCLUSION: Neutrophil elastase may have an important role in increasing haematogenous liver metastases by ischaemia-reperfusion, particularly in unclamped lobes. 相似文献
42.
H Shiozaki T Ide J Nakao T Imamura M Nakamura K Shimada Y Miura T Suda 《Japanese journal of cancer research》1992,83(5):499-504
LD78 is a cDNA newly isolated from human stimulated tonsillar lymphocytes. The expression of LD78 is related to inflammatory responses and its structure has a homology with macrophage inflammatory protein 1-alpha, which is known to have an inhibitory effect on murine CFU-S. Using a colony assay technique, we examined the effects of LD78 on human hemopoietic progenitors. The addition of doses of 100 ng/ml or more of LD78 suppressed the colony formation of KMT-2, a factor-dependent myelomonocytic cell line established from cord blood cells; this suppressive activity was neutralized by the addition of antibody against LD78. The same doses of LD78 suppressed the formation of neutrophil, macrophage, and megakaryocytic colonies which were supported by human interleukin-3 and erythropoietin; however, LD78 did not affect colony formation by either non-phagocytic mononuclear cells or sorted CD34+ cells. The conditioned medium of KMT-2 cells or peripheral blood mononuclear cells cultured with LD78 suppressed colony formation by CD34+ cells. From these findings, it is suggested that LD78 affects phagocytic cells and induces factors that are inhibitory for hemopoiesis. We consider LD78 to be a new cytokine that plays an inhibitory role in hemopoiesis. 相似文献
43.
Genetic alteration in carcinoid tumors of the lung. 总被引:1,自引:0,他引:1
Kenji Sugio Toshihiro Osaki Tsunehiro Oyama Mitsuhiro Takenoyama Takeshi Hanagiri Masaru Morita Koji Yamazaki Akira Nagashima Hisashi Nakahashi Yoshihiko Maehara Kosei Yasumoto 《Annals of thoracic and cardiovascular surgery》2003,9(3):149-154
Surgically resected specimens of 13 carcinoid tumors of the lung including nine typical carcinoids and four atypical carcinoids, and eight salivary gland type carcinomas (six mucoepidermoid carcinomas and two adenoid cystic carcinomas) were analyzed regarding p53 expression, loss of heterozygosity (LOH) in chromosome 3p, 9p, and K-ras mutation. The overexpression of p53 was identified in four atypical carcinoid tumors, one mucoepidermoid carcinoma, and one adenoid cystic carcinoma, however, none of typical carcinoids showed p53 immunoreactivity. LOH in 3p14 was demonstrated in three of seven informative cases in all tumors. LOH in 9p was demonstrated in two of five informative cases in all tumors. Two of three cases with LOH at 3p14 had a poor prognosis, one of which also had LOH at 9p. No mutation of the K-ras gene was observed in any of these tumors. These data thus indicate that p53 overexpression might distinguish atypical carcinoid tumors from typical tumors and might therefore be useful as an adjunct modality in the differential diagnosis of pulmonary carcinoid tumors. The presence of LOH at 3p14 or 9p may thus help to identify lung cancer patients with a poor prognosis. 相似文献
44.
K Ishii M Oda S Kazemoto T Azuma H Kaneko H Yokomori H Saitoh S Miura M Tsuchiya 《Nihon Shokakibyo Gakkai zasshi》1992,89(2):552-557
45.
Detection limit in low-amplitude EEG measurement. 总被引:1,自引:0,他引:1
Electrocerebral inactivity for the determination of cerebral death is defined as no findings of EEG greater than the amplifier's inherent internal noise level when recording at increased sensitivity. A surface biopotential electrode contains two interfaces composed of skin gel (electrolyte) and gel electrode (metal), each forming a noise source. The power spectral density, S(f), of extremely low noise signals was obtained by means of autocorrelation and fast Fourier transformation. Interelectrode resistance, R(f), was measured with synchronous rectification. The formula of equivalent noise resistance R(n) = S(f)/4kT, where k is the Boltzmann constant and T is room temperature in Kelvin, gives a resistance that generates the thermal noise corresponding to the measured S(f). Rn/R is a parameter derived from normalization by R. When Rn/R = 1, measured noise contains thermal noise only. Meanwhile, Rn/R > 1 indicates presence of excess noise, such as 1/f, and tissue noise in addition to the thermal noise. Mean square root (Rn/R) of the scalp noise was 10.8 at 10 Hz, showing existence of excess noise. The study results suggest that it is necessary to take excess noise into consideration in the measurement of low-amplitude EEG for the determination of cerebral death. 相似文献
46.
To elucidate the pathogenesis of angioimmunoblastic lymphadenopathy-like T cell lymphoma (AILD-T) we investigated the T cell receptor Vβ gene repertoires of four AILD-Ts and compared them with those of other histological types of lymphomas and three cases with reactive disorders. All lymphoma patients had rearrangement bands detected by Southern blot analysis. Only 1 of the 4 cases of AILD-T showed a single predominant usage of Vβ 20 gene by PCR with 20 different Vβ specific primers and the others had repertoires somewhat restricted but similar to reactive lesions. Subsequent sequencing of this PCR product revealed that only 2 of 7 clones were identical. These results suggest the monoclonal malignant cells in AILD-T are scant and that the infiltrating T cells show a reactive pattern. In the only AILD-T case with a single dominant Vβ usage, the relationships of this repertoire and lymphoma cells seems to be of some consequence. 相似文献
47.
Late Effects of Childhood Acute Leukemia and Its Treatment 总被引:1,自引:0,他引:1
Masao Yamamoto M.D. Yoshitaka Fukunaga M.D. Ichiroh Tsukimoto M.D. Fumio Bessho M.D. Jun-ichi Akatsuka M.D. Ryohta Hosoya M.D. Shinpei Nakazawa M.D. Minoru Sakurai M.D. Kazuhiro Ueda M.D. Sumio Miyazaki M.D. Masaru Yokoyama M.D. Hideo Mugishima M.D. Kohzoh Nishimura M.D. 《Pediatrics international》1991,33(4):573-588
Late effects of childhood acute leukemia and its treatment were studied in 766 patients (684 ALL, 73 ANLL, and 9 others) in Japan who had remained in remission for more than 1 year after their first complete remission. Delayed adverse sequelae involve a wide variety of organs and their functions. Short stature was present in 2.61%, obesity in 3.79%, abnormalities of growth hormone secretion in 1.5%, delayed secondary sex characteristics in 1.5% of males and 0.6% of females, motor disturbances in 1.17%, sensory disturbances in 0.91%, intellectual and learning disabilities in 2.48%, abnormal findings in routine neurologic examinations in 1.31%, EEG abnormalities in 4.30%, brain CT abnormalities in 5.09% and cardiac dysfunction in 1.07%. Various other disorders were seen in 20 patients. Many of these delayed adverse sequelae are caused by or related to central nervous system prophylaxis and systemic combination chemotherapy. The results suggest that it is needed to improve therapeutic methods through the stratification of patients by risk factors and detailed analysis of prognostic factors. Moreover it is important to render medical and psychosocial support to long-term survivors of childhood leukemia through interactions between the patient, parents and medical staff. 相似文献
48.
49.
Eiichiro SUGIYAMA Takayoshi IKEDA Hiroshi MAEDA Takeshi MATSUO Masaru MATSUMOTO 《Congenital anomalies》1987,27(2):85-93
Abstract True incidence of this malformation is probably greater than that reported since the definitive diagnosis has been made at autopsy in most cases. Various hypotheses on the pathogenesis of tracheal agenesis have been proposed but they are still controversial.
In this report, we present a case of tracheal agenesis with a broncho-esophageal fistula and discuss the formal genesis. 相似文献
In this report, we present a case of tracheal agenesis with a broncho-esophageal fistula and discuss the formal genesis. 相似文献
50.
K Takaori T Takeda H Yamada K Miura T Yukimura F Ikemoto K Yamamoto 《Japanese circulation journal》1988,52(11):1346-1350
Plasma immunoreactive renin was measured by sandwich radioimmunoassay, under various physiological and pathological conditions. Enzymatic activities of active renin and trypsin-activatable inactive renin were also measured. There was a significant correlation between plasma immunoreactive renin concentration (IRRC) and total (active plus inactive) renin concentration, as estimated by enzymatic activity. In plasma from normotensive volunteers and hypertensive patients, the IRRC were 279 +/- 37 pg/ml and 268 +/- 29 pg/ml, respectively. After the intravenous injection of furosemide, the plasma IRRC in normotensive volunteers increased significantly. IRRC was significantly higher in plasma from juvenile diabetics than in plasma from age-matched disease-free children. Thus, renin secretion in children with diabetes mellitus is increased. 相似文献