全文获取类型
收费全文 | 7509篇 |
免费 | 422篇 |
国内免费 | 51篇 |
专业分类
耳鼻咽喉 | 29篇 |
儿科学 | 147篇 |
妇产科学 | 74篇 |
基础医学 | 858篇 |
口腔科学 | 155篇 |
临床医学 | 633篇 |
内科学 | 2323篇 |
皮肤病学 | 132篇 |
神经病学 | 571篇 |
特种医学 | 226篇 |
外科学 | 1290篇 |
综合类 | 24篇 |
一般理论 | 1篇 |
预防医学 | 242篇 |
眼科学 | 142篇 |
药学 | 450篇 |
中国医学 | 16篇 |
肿瘤学 | 669篇 |
出版年
2023年 | 20篇 |
2022年 | 96篇 |
2021年 | 141篇 |
2020年 | 67篇 |
2019年 | 95篇 |
2018年 | 118篇 |
2017年 | 105篇 |
2016年 | 130篇 |
2015年 | 181篇 |
2014年 | 170篇 |
2013年 | 207篇 |
2012年 | 376篇 |
2011年 | 451篇 |
2010年 | 212篇 |
2009年 | 224篇 |
2008年 | 351篇 |
2007年 | 422篇 |
2006年 | 396篇 |
2005年 | 412篇 |
2004年 | 362篇 |
2003年 | 395篇 |
2002年 | 370篇 |
2001年 | 245篇 |
2000年 | 301篇 |
1999年 | 227篇 |
1998年 | 108篇 |
1997年 | 68篇 |
1996年 | 83篇 |
1995年 | 57篇 |
1994年 | 68篇 |
1993年 | 47篇 |
1992年 | 160篇 |
1991年 | 152篇 |
1990年 | 129篇 |
1989年 | 160篇 |
1988年 | 106篇 |
1987年 | 86篇 |
1986年 | 87篇 |
1985年 | 86篇 |
1984年 | 53篇 |
1983年 | 61篇 |
1982年 | 29篇 |
1981年 | 27篇 |
1980年 | 26篇 |
1979年 | 48篇 |
1978年 | 28篇 |
1976年 | 24篇 |
1975年 | 28篇 |
1972年 | 24篇 |
1971年 | 20篇 |
排序方式: 共有7982条查询结果,搜索用时 15 毫秒
21.
H M Kim S Hirota H Onoue T Hirata K Suzuki S Ohno T Kuroki Y Kitamura S Nomura 《Brain research. Developmental brain research》1992,70(2):239-244
The expression and localization of a novel protein kinase C delta (nPKC delta) mRNA were investigated using Northern blotting and in situ hybridization in the developmental process of mouse brain. In adult mice, nPKC delta was abundantly expressed in the thalamus, moderately in the pons and the cerebellum, but faintly in the cerebral cortex and the spinal cord. By in situ hybridization, the signals were observed specifically at the sensory and motor relay nuclei of the thalamus, the dorsal cochlear nuclei of the pons, and the molecular layer of the cerebellum. When developmental changes in the expression of nPKC delta gene were analyzed by in situ hybridization, it was not detectable in embryonic and neonatal brains, very weakly expressed in the thalamus in the first week, and highly expressed at two weeks of age. These results suggest that the gene expression of nPKC delta is strictly controlled by both the cell type and the developmental process. 相似文献
22.
A sensitive enzyme-linked immunosorbent assay (ELISA) was used in a retrospective study of placental alkaline phosphatase (PLAP) levels in serum, cerebrospinal fluid (CSF), and intratumoral cyst fluid in primary intracranial germinoma. The ELISA showed no cross-reactivity with intestinal alkaline phosphatase except in very high concentrations, after samples had been heat-treated. Three patients with germinoma were studied for serum PLAP levels and in all the levels were elevated (3.78, 0.52, and 2.11 IU/liter). Two of the germinoma patients were studied for PLAP levels in the CSF, and both had elevated levels (0.83 and 9.83 IU/liter). The intratumoral cyst fluid in one case of germinoma was tested for PLAP and the level was found to be very high (603 IU/liter). These PLAP levels decreased concomitantly with the reduction in tumor size during irradiation. Serum PLAP levels were measured in 40 control adult male individuals and in the CSF of 20 nonpregnant patients with subarachnoid hemorrhage. The upper normal limits were 0.20 and 0.11 IU/liter in the serum and the CSF, respectively. All PLAP levels measured in the serum of patients with various brain tumors were 0.18 IU/liter or less. This study strongly suggests that PLAP is a clinically useful tumor marker for primary intracranial germinoma. 相似文献
23.
Arg60 to Leu mutation of the human thromboxane A2 receptor in a dominantly inherited bleeding disorder. 总被引:7,自引:2,他引:5 下载免费PDF全文
T Hirata A Kakizuka F Ushikubi I Fuse M Okuma S Narumiya 《The Journal of clinical investigation》1994,94(4):1662-1667
Recent advances in molecular genetics have revealed the mechanisms underlying a variety of inherited human disorders. Among them, mutations in G protein-coupled receptors have clearly demonstrated two types of abnormalities, namely loss of function and constitutive activation of the receptors. Thromboxane A2 (TXA2) receptor is a member of the family of G protein-coupled receptors and performs an essential role in hemostasis by interacting with TXA2 to induce platelet aggregation. Here we identify a single amino acid substitution (Arg60-->Leu) in the first cytoplasmic loop of the TXA2 receptor in a dominantly inherited bleeding disorder characterized by defective platelet response to TXA2. This mutation was found exclusively in affected members of two unrelated families with the disorder. The mutant receptor expressed in Chinese hamster ovary cells showed decreased agonist-induced second messenger formation despite its normal ligand binding affinities. These results suggest that the Arg60 to Leu mutation is responsible for the disorder. Moreover, dominant inheritance of the disorder suggests the possibility that the mutation produces a dominant negative TXA2 receptor. 相似文献
24.
Tumor vascularity under angiotensin II-induced hypertension--angiographic observations 总被引:1,自引:0,他引:1
The selective increase in tumor blood flow under angiotensin II-induced hypertension was observed to be the result of passive vascular beds irresponsive to angiotensin II. We investigated whether or not increased tumor blood flow resulting from angiotensin II-induced hypertension could be recognized on angiographic findings. Angiography under angiotensin II-induced hypertension was performed in 51 patients with various cancers, and angiographic findings indicating increased tumor vascularity were recognized in 40 (78.4%) of them. Based on the assumption that the increase in tumor oxygen tension was brought about by increased tumor blood flow, the possibility of utilizing this phenomenon in hyperbaric oxygenation radiotherapy was suggested. 相似文献
25.
Yuki Mawatari Akira Hirata Mikiko Fukushima Hidenobu Tanihara 《Albrecht von Graefes Archiv fur klinische und experimentelle Ophthalmologie》2006,244(8):1056-1059
Purpose To evaluate quantitative choroidal dye filling velocity in patients with Vogt-Koyanagi-Harada disease (VKH) before and after corticosteroid treatment using indocyanine green (ICG) angiography.Methods ICG angiography was performed in seven VKH patients before and after systemic corticosteroid treatment. Choroidal dye curves were obtained by image analysis software and analyzed using an exponential model. The model’s time constant (τ) was used to evaluate choroidal dye filling velocity.Results Compared with controls, acute phase choroidal τ values in VKH patients were significantly longer, suggesting choroidal circulation disturbance. During the recovery phase, choroidal τ values were significantly shortened, suggesting choroidal circulatory disturbance improvement.Conclusion Choroidal dye filling velocity may be useful for VKH diagnosis and verification of corticosteroid treatment effectiveness. 相似文献
26.
Takahide Nagashima Hideaki Tanaka Masafumi Ito Koichi Hirata Soichi Katayama Kazuo Watanabe 《Clinical neurology》2006,46(1):40-44
We report a patient of relapsing polychondritis (RP) with antecedent aseptic meningitis. A 65-year-old man has developed headache and fever. Neurological examination showed meningeal signs, and cerebrospinal fluid (CSF) examination revealed meningeal inflammation which contained 450 polymorphonuclear cells/microl, 302 mononuclear cells/microl, and 0 red cells/microl, with 79 mg protein/dl. Serologic testing for autoimmune disease as well as the culture and cytology of CSF were negative. He admitted our hospital as having aseptic meningitis and experienced antibiotic therapy. However, his pyrexia continued and he developed repeating visual and hearing impairment reacting to steroid. Three months later, he became behaviorally deaf, and bilateral auricular chondritis occurred with nonerosive seronegative inflammatory polyarthritis. The result of condral biopsy was consistent with the diagnosis of RP showing cartilage surrounded by an intense inflammatory cell response with a decreased number of chondrocytes. A clinical diagnosis was made and prednisolone 60 mg/day was begun with the result of resolution of the auricular chondritis, and slight improvement of his deafness. Aseptic meningitis is a rare complication of RP. Only one report detailed RP patient who had preceding meningitis. RP is a potentially lethal disease resulting from suffocation by airway collapse, the complications of a cardiac large vessel, and so on. For improvement of a life prognosis, an early diagnosis and treatment are indispensable. Although RP is a rare discovery, it is necessary that RP should be taken into consideration and be differentiated as a cause of relapsing aseptic meningitis. 相似文献
27.
Jiro Okochi Kenji Toba Tai Takahashi Kozo Matsubayashi Masanori Nishinaga Ryutaro Takahashi Takashi Ohrui 《Geriatrics & Gerontology International》2006,6(4):223-227
Background: The aim of this study is to construct a simple screening test for the risk of falls in community-dwelling elder persons.
Methods: A total of 1378 community-dwelling people aged 65 years and older in five different communities in Japan were asked to answer a self rated questionnaire including 22 items covering physical, cognitive, emotional and social aspects of functioning and environmental factors. At a six-month follow-up, the outcome of fall occurrence and the number of falls was ascertained by social workers, health visitors or nurses.
Results: Five out of 22 items were selected using a logistic regression model. Using this five-item version, a screening test was constructed, and at the best cut-off point, the sensitivity and specificity were 68% and 70%, respectively. The validity of this scale was tested on persons with cognitive dysfunction.
Conclusion: The simplicity and the predictive validity of the screening test support the use of this test in health check ups or general outpatient facilities. 相似文献
Methods: A total of 1378 community-dwelling people aged 65 years and older in five different communities in Japan were asked to answer a self rated questionnaire including 22 items covering physical, cognitive, emotional and social aspects of functioning and environmental factors. At a six-month follow-up, the outcome of fall occurrence and the number of falls was ascertained by social workers, health visitors or nurses.
Results: Five out of 22 items were selected using a logistic regression model. Using this five-item version, a screening test was constructed, and at the best cut-off point, the sensitivity and specificity were 68% and 70%, respectively. The validity of this scale was tested on persons with cognitive dysfunction.
Conclusion: The simplicity and the predictive validity of the screening test support the use of this test in health check ups or general outpatient facilities. 相似文献
28.
29.
Shigeki Yamagishi Kiyoshi Koizumi Tomomi Hirata Kyoji Hirai Jiro Kurita Kazuo Shimizu 《The Japanese Journal of Thoracic and Cardiovascular Surgery》2005,53(6):313-316
We report a 59-year-old woman who underwent thoracoscopic extirpation of the intrapulmonary cystic lymphangioma which was located in the subpleural space of the left upper lobe. A chest X-ray showed a solitary round nodule in the left pulmonary hilum. A computed tomography scan revealed a mass shadow at the interlobar region surrounding the interlobar pulmonary artery. A round nodule was recognized as low signal intensity on T1-weighted images by magnetic resonance imaging. There was biphasic signal intensity on T2-weighted images as well. Radiologically, we diagnosed this lesion as a benign cystic tumor in the lung. Thoracoscopic observation revealed a cystic lesion just beneath the visceral pleura of the upper lobe adjacent to the interlobular pulmonary artery. As this suggested a benign bronchogenic cyst, we performed extirpation of the cyst under thoracoscopy. After this operation, the cyst was diagnosed as an intrapulmonary cystic lymphangioma pathologically. 相似文献
30.
Hiroyuki Oka Taiji Kondoh Atsushi Seichi Takahiro Hozumi Kozo Nakamura 《Journal of orthopaedic science》2006,11(1):13-19
Background Few previous studies have analyzed the incidence of bone metastases in a defined population of Japanese breast cancer patients
and their prognosis after chemotherapy.
Methods This is a retrospective cohort study. We investigated 695 patients who underwent surgery for breast cancer. The strategy of
adjuvant therapy was as follows. Patients with both estrogen receptors (ERs) and progesterone receptors (PgRs) had endocrine
therapy as initial adjuvant therapy (n = 239). Patients with neither ERs nor PgRs had chemotherapy. When metastasis to other organs, including bone, was identified,
patients received chemotherapy. The survival rates after surgery and after the onset of bone metastasis, as well as the incidence
of bone metastasis, were calculated. We also evaluated the prognostic and predictive factors.
Results Bone metastases developed in 148 of 695 patients. All 148 received chemotherapy, and 121 of them developed spinal metastases.
The 5-year survival rate after bone metastases was 26.1%. Prognostic factors for bone metastases were visceral metastases
and PgR status. Cord compression was observed in 17 of the 148 patients, with the thoracic spine being the most common. The
1-year survival rate for patients with bone metastases who received chemotherapy was 66.3%, whereas that of patients with
paralysis after spinal metastases was 17.6%. Within 6 months of the development of spinal cord compression, 70.6% of the patients
died.
Conclusions We reported the incidence and prognostic factors for a defined population of Japanese breast cancer patients with bone and
spinal metastases. Our results suggest that the expected survival time for patients with paralysis who received adequate endocrine
therapy or chemotherapy is generally poor. However, to detect a predictive factor of long survival after paralysis and establish
the indications for surgery, a comparative study among large groups of patients with paralysis and with different backgrounds
is necessary. 相似文献