全文获取类型
收费全文 | 16368篇 |
免费 | 848篇 |
国内免费 | 87篇 |
专业分类
耳鼻咽喉 | 183篇 |
儿科学 | 403篇 |
妇产科学 | 195篇 |
基础医学 | 2094篇 |
口腔科学 | 551篇 |
临床医学 | 1022篇 |
内科学 | 3937篇 |
皮肤病学 | 348篇 |
神经病学 | 1019篇 |
特种医学 | 710篇 |
外科学 | 2906篇 |
综合类 | 78篇 |
一般理论 | 1篇 |
预防医学 | 458篇 |
眼科学 | 221篇 |
药学 | 1131篇 |
中国医学 | 76篇 |
肿瘤学 | 1970篇 |
出版年
2023年 | 93篇 |
2022年 | 196篇 |
2021年 | 331篇 |
2020年 | 182篇 |
2019年 | 250篇 |
2018年 | 320篇 |
2017年 | 284篇 |
2016年 | 356篇 |
2015年 | 356篇 |
2014年 | 443篇 |
2013年 | 539篇 |
2012年 | 804篇 |
2011年 | 851篇 |
2010年 | 486篇 |
2009年 | 442篇 |
2008年 | 745篇 |
2007年 | 859篇 |
2006年 | 861篇 |
2005年 | 891篇 |
2004年 | 859篇 |
2003年 | 844篇 |
2002年 | 857篇 |
2001年 | 483篇 |
2000年 | 483篇 |
1999年 | 432篇 |
1998年 | 232篇 |
1997年 | 171篇 |
1996年 | 186篇 |
1995年 | 149篇 |
1994年 | 121篇 |
1993年 | 107篇 |
1992年 | 356篇 |
1991年 | 296篇 |
1990年 | 264篇 |
1989年 | 301篇 |
1988年 | 243篇 |
1987年 | 202篇 |
1986年 | 181篇 |
1985年 | 209篇 |
1984年 | 168篇 |
1983年 | 101篇 |
1979年 | 69篇 |
1977年 | 52篇 |
1975年 | 44篇 |
1974年 | 52篇 |
1973年 | 50篇 |
1971年 | 45篇 |
1970年 | 42篇 |
1969年 | 52篇 |
1968年 | 48篇 |
排序方式: 共有10000条查询结果,搜索用时 18 毫秒
41.
Objective. To assess the diagnostic value of magnetic resonance imaging (MRI) as compared with radiographic findings in osteonecrosis in divers. Design and patients. MRI scans and conventional radiographs of the shoulder, hip and knee joints of 23 professional male scuba divers were reviewed together with their clinical findings and personal histories. Correlations between the MRI findings and the radiographic evaluation, clinical symptoms, and personal history were then investigated. Results and conclusions. Lesions found on MRI in 23 divers included 27 in 39 proximal humeri, 17 in 36 proximal femora, 13 in 32 distal femora, and 12 in 32 proximal tibiae. Diffuse, marginated, or irregular patterns were observed. No lesions were seen in epiphyses of the distal femur or proximal tibia. We tried to classify these MRI findings by location and appearance. MRI showed no patients with only one affected bone. A close correlation between the MRI findings and maximum diving depth was observed in the proximal humerus. MRI depicted bone lesions that could not be detected on the radiographs. A routine MRI investigation of the hip joints should be performed in every diver in whom osteonecrosis is diagnosed at another site, for early detection of femoral head osteonecrosis. MRI of the shoulder joint is also the best surveillance in divers who dive deeper than 15?m. 相似文献
42.
43.
44.
The epidemiology and clinical features of anaphylactic and anaphylactoid reactions in the perioperative period in Japan] 总被引:3,自引:0,他引:3
H Mitsuhata S Matsumoto J Hasegawa 《Masui. The Japanese journal of anesthesiology》1992,41(10):1664-1669
In an attempt to review the Japanese epidemiology of the anaphylactic and/or anaphylactoid reactions in the perioperative period, we investigated 105 cases with clinical features of anaphylactic and/or anaphylactoid reaction, which are reported in the Japanese anesthesiology-related journals from 1952 to 1990. Eighty-nine percent of the cases were reported during the last decade. There were 66 males and 34 females. The majority of the patients were below 60 years of age, and most of the patients were in their teens and fifties. Ninety percent of the patients had no past history of drug-induced allergy nor tendencies of atopy. Ninety-four percent of the patients recovered completely without any sequelae, and 0.95 percent of them recovered with serious complications. Deaths occurred in 4.67% of the patients. Most frequent clinical signs were cardiovascular (91.4%) and cutaneous (84.8%) manifestations. Respiratory, signs appeared in 41% of the patients. Patients are frequently unconscious and covered with drapes, and early signs and symptoms of anaphylaxis can be masked. In 25% of the patients cardiovascular collapse, including cardiac arrest and undetected blood pressure, appeared as the first noticeable sign. Causative drugs were confirmed immunologically in 5.7% of the patients. In other cases, causative drugs were presumed based on clinical course. Causative drugs and presumed causative drugs were varied, including blood and blood products (24 cases), intravenous anesthetics (19 cases), local anesthetics (15 cases), and muscle relaxants (9 cases), which were used generally in the perioperative period. 相似文献
45.
Susumu Ishikawa M.D. Akio Ohtaki M.D. Toru Takahashi M.D. Tetsuya Koyano M.D. Yutaka Hasegawa M.D. Satoshi Ohki M.D. Yukitaka Isa M.D. Kennichi Arai M.D. Fumio Kunimoto M.D. Yasuo Morishita M.D. 《Journal of cardiac surgery》1997,12(3):176-179
A bstract The purpose of this study was to assess the efficacy of nasal mask bi-level positive airway pressure (BiPAP) support in managing respiratory failure following cardiovascular surgery. A total of 20 patients requiring postoperative prolonged respiratory support of 72 hours or longer were studied. BiPAP support was used for eight patients (BiPAP group); the other 12 patients were managed using ordinary oxygen mask treatment (control group). The mean age of the BiPAP group and control group was 65 and 58 years of age, respectively. The mean period of postoperative endotracheal intubation of the BiPAP group and control group was 12 ± 5 days and 7 ± 1 days, respectively. Reintubation was necessary in two patients of the control group. The BiPAP group patients required no reintubation. BiPAP support was discontinued within 48 hours in 6 out of 8 patients. The respiratory rates of control group increased (p < 0.1) 24 hours after extubation, however, the respiratory rates of the BiPAP group remained unchanged. The values of the respiratory index of the BiPAP group improved significantly (p < 0.01) after BiPAP management (from 1.5 ± 0.2 to 0.9 ± 0.2). The values of the control group, however, remained unchanged. A-aDO2 and Qs/Qt decreased (p < 0.1) in the BiPAP group. There were no significant differences in central venous pressure or circulatory status between the two groups. In conclusion, BiPAP support is a noninvasive management technique for postoperative respiratory failure and may also prevent prolonged endotracheal intubation. 相似文献
46.
H Kinoshita T Kameyama T Hasegawa T Nabeshima 《Pharmacology, biochemistry, and behavior》1992,42(1):19-23
We investigated the effects of vinconate, a novel vinca alkaloid, on spatial learning deficits induced by the basal forebrain (BF) lesion in rats. Bilateral BF lesions were produced by injecting ibotenic acid (6 micrograms/0.5 microliter/side). In BF-lesioned rats, impairment of spatial learning in escaping onto the platform during training and decrease in spatial bias during the spatial probe trial in Morris's water maze task were both observed. Vinconate (5 and 10 mg/kg) treatment shortened the increase of escape latency to the platform in BF-lesioned rats and significantly reversed the decrease in spatial bias induced by the BF lesion. Vinconate (10 mg/kg) attenuated the decrease in choline acetyltransferase activity in the frontoparietal cortex caused by the BF lesion. The present study suggests that vinconate has an antiamnesic effect on the BF-lesion-induced amnesia by ameliorating the dysfunction in cholinergic neurons. 相似文献
47.
László Prónai Hiroe Nakazawa Kohji Ichimori Yoshinori Saigusa Tomoichi Ohkubo Kazuko Hiramatsu Shigeru Arimori János Fehér 《Inflammation》1992,16(5):437-450
This study was performed to examine the pattern of Superoxide (O
2
–
·) generation from leukocytes using the O
2
–
· specific chemiluminescence (CL) method.Cypridina luciferin analog, 2-methyl-6-(p-methoxyphenyl)-3,7-dihydroimidazo[1,2-alpha]pyrazin-3-one (MCLA) was used as a CL probe. The appropriate conditions of the MCLA method was first determined for the evaluation of the time course of O
2
–
· generation by leukocytes. The time course of O
2
–
· generation obtained by the MCLA-CL system was compared with that by the luminol-dependent CL, electron spin resonance (ESR)/spin trapping, and cytochromec systems. Following stimulation by three different stimulants (PMA, OZ, FMLP), leukocytes continuously generated O
2
–
· for up to 5 h in the MCLA-CL system, irrespective of the kind of stimulation. The curves obtained by generation ceased more rapidly in the luminol-CL, ESR/spin trapping, and cytochromec systems. A 50% activity of the initial value was observed at 70 min in the MCLA-CL system, but 30, 10 and 35 min in the other systems, respectively. The CL or O
2
–
· generation value decreased to less than 1% (possible termination) at 300, 90, 120 and 180 min, respectively. With the exception of ESR studies with OZ, the cell viability was not significantly affected in any of the trials. These results indicate that leukocytes can generate O
2
–
· much longer than previously estimated and that the MCLA-CL-system is the most suitable system for the measurement of the O
2
–
· generation by leukocytes. 相似文献
48.
Makoto Ishitobi Yasuo Miyoshi Akiko Ando Seiichi Hasegawa Chiyomi Egawa Yasuhiro Tamaki Morito Monden Shinzaburo Noguchi 《Clinical cancer research》2003,9(4):1376-1380
PURPOSE: The association of BRCA2 polymorphisms at codon 372 [Asn (N)/His (H)]and codon 784 [Met (M)/Val (V)] with breast cancer risk was evaluated in Japanese women. In addition, the prognostic significance of these polymorphisms was studied in breast cancer patients. EXPERIMENTAL DESIGN: A case-control study was conducted to examine the association of the BRCA2 N/H372 polymorphism and M/V 784 polymorphism with breast cancer risk (cases = 149, controls = 154). The prognostic significance of these polymorphisms was evaluated in 139 patients with primary breast cancer. RESULTS: No significant association was observed between the N/H372 polymorphism and breast cancer risk. In contrast, a significant increase in breast cancer risk (odds ratio, 2.03; 95% confidence interval, 1.07-3.87) was observed in carriers of the variant allele (V784) of the M/V784 polymorphism as compared with noncarriers after adjustment for the classical risk factors, age, family history, parity, body mass index, and so forth. Among breast cancer patients, various clinicopathological parameters including menopausal status, tumor size, lymph node status, histological grade, and estrogen-receptor status were not significantly different between the carriers and noncarriers of the variant allele with regard to both N/H372 and M/V784 polymorphisms. The N/H 372 polymorphism was not significantly associated with patient prognosis. On the other hand, breast cancer patients carrying the variant allele of M/V784 polymorphism showed a significantly (P = 0.014) lower 3-year disease-free survival rate (63%) than noncarriers (92%). Multivariate analysis has revealed that the M/V784 polymorphism is a significant prognostic factor, being independent of the other conventional prognostic factors such as lymph node status and estrogen receptor status. CONCLUSION: These results suggest that the M/V784 polymorphism, but not the N/H372 polymorphism, would be useful in the selection of women at high risk for developing breast cancer and would also serve as a clinically useful prognostic factor in breast cancer patients. 相似文献
49.
A Sasaki K Matsumiya M Arao K Hasegawa N Horiuchi 《Rinsho byori. The Japanese journal of clinical pathology》1991,39(1):91-96
Screening methods for diabetes mellitus, based on fasting glucose (FPG), HbA1C and fructosamine (FRA) levels were compared with regard to their screening power. The subjects studied were 699 health examinees. A significant elevation of the mean level of each screening index was observed in diabetic subjects, but not in borderline cases compared with that of normal subjects. The FPG, HbA1C and FRA levels in diabetic subjects distributed over a wide range overlapping largely with the distributions of non-diabetic subjects. No appreciable difference in the screening power was observed between FPG and HbA1C but specificity was low in FRG for the comparable sensitivity level. In the screening methods based on the combination of two or more indices, elevation of the sensitivity was noted, but the specificity declined, resulting in an increase of re-examination rate. Among them, the combination of FPG and HbA1C indicated the highest sensitivity. 相似文献
50.