全文获取类型
收费全文 | 44191篇 |
免费 | 1965篇 |
国内免费 | 377篇 |
专业分类
耳鼻咽喉 | 442篇 |
儿科学 | 954篇 |
妇产科学 | 490篇 |
基础医学 | 5862篇 |
口腔科学 | 727篇 |
临床医学 | 2653篇 |
内科学 | 11441篇 |
皮肤病学 | 1025篇 |
神经病学 | 3270篇 |
特种医学 | 1779篇 |
外科学 | 7638篇 |
综合类 | 176篇 |
一般理论 | 6篇 |
预防医学 | 1133篇 |
眼科学 | 1002篇 |
药学 | 2759篇 |
中国医学 | 172篇 |
肿瘤学 | 5004篇 |
出版年
2023年 | 243篇 |
2022年 | 496篇 |
2021年 | 884篇 |
2020年 | 471篇 |
2019年 | 655篇 |
2018年 | 913篇 |
2017年 | 693篇 |
2016年 | 883篇 |
2015年 | 971篇 |
2014年 | 1241篇 |
2013年 | 1587篇 |
2012年 | 2554篇 |
2011年 | 2855篇 |
2010年 | 1624篇 |
2009年 | 1487篇 |
2008年 | 2691篇 |
2007年 | 2919篇 |
2006年 | 2942篇 |
2005年 | 2953篇 |
2004年 | 3067篇 |
2003年 | 3110篇 |
2002年 | 3089篇 |
2001年 | 483篇 |
2000年 | 416篇 |
1999年 | 563篇 |
1998年 | 766篇 |
1997年 | 646篇 |
1996年 | 603篇 |
1995年 | 504篇 |
1994年 | 453篇 |
1993年 | 490篇 |
1992年 | 326篇 |
1991年 | 311篇 |
1990年 | 248篇 |
1989年 | 237篇 |
1988年 | 240篇 |
1987年 | 189篇 |
1986年 | 155篇 |
1985年 | 157篇 |
1984年 | 160篇 |
1983年 | 124篇 |
1982年 | 124篇 |
1981年 | 151篇 |
1980年 | 128篇 |
1979年 | 82篇 |
1978年 | 102篇 |
1977年 | 78篇 |
1976年 | 65篇 |
1975年 | 53篇 |
1974年 | 39篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
T Kanamaru S Saeki N Katsumata K Mizuno S Ogawa H Suzuki 《Masui. The Japanese journal of anesthesiology》1990,39(10):1368-1371
The effect of ketamine infusion to control the intractable pain which had not responded to ordinary procedures in 12 patients with advanced cancer were evaluated. Ketamine 250 mg or 500 mg in 500 ml of transfusion fluid with or without 10 to 20 mg of droperidol was administered intravenously at the rate of 3 to 20mg of ketamine per hour. The pain scores by VAS in most of the patients decreased significantly with an averaged value of 8.3 before the treatment to 1 during the procedure. The durations of this therapy lasted from over 6 hours to 48 days. Slight disorientation in one patient and drowsiness in 5 were seen during the infusion. No cardiovascular or respiratory complications were noted. These results indicate that ketamine infusion is a useful therapeutic procedure to treat cancer pain which resist ordinary pain therapies. 相似文献
52.
We studied choline acetyltransferase (CAT) activity in a rat model of brachial plexus injury. In experiment 1, we found that the CAT activity was remarkably high in the anterior roots and low in the posterior roots. In experiment 2, nerve root segments were extracted and examined for CAT activity in the root avulsion group (group A) and the plexus severance group (group B). CAT activity decreased day by day in group A, reaching about 1/20 of the normal 5 days postoperatively. By contrast, in group B activity decreased only slightly, and even at 90 days postoperatively was about 6,000 cpm (one-half normal level). As a result, CAT activity enabled us to distinghish postganglionic from preganglionic injury of the cervical roots. Furthermore, it was a useful adjunct for minimizing nerve loss in intercostal nerve transfer, distinguishing motor and sensory branches of the intercostal nerve, and evaluating the motor nerve activity. © 1995 Wiley-Liss, Inc. 相似文献
53.
Hiroshi Uno Yoshihiro Izawa Kiyoshi Sagara Tamotsu Koyama Tokutaro Makita Chia-Yuan Hsu-Chang Mitsugi Sugiyama 《Journal of bone and mineral metabolism》1990,8(1):10-16
The effect of 1α-hydroxyvitamin D3 (1α(OH)D3) on the metabolic bone disorders developed in gastrectomized rats were investigated biochemically and histomorphologically.
1α(OH)D3 was suspended in 0.2 % Triton-X-100 aqueous solution after dissolving in a very small amount of ethanol, was given orally
to the rats for 10 weeks. The sham operated animals and the gastrectomy control animals received the vehicle alone. Gastrectomy
was followed by the development of the metabolic bone disorders after 10 weeks of observation. This was characterized by reduction
in ash content of the femur and histologically by a disappearance of the trabecular bone in tibial metaphysis. Decrease Ca
absorption from the intestines was demonstrated by a radiotracer technique. Biochemical studies showed significant decreases
in serum 25(OH)D concentration in gastrectomized rats. These findings suggest that gastrectomy partially impairs intestinal
absorption of calcium and results in a negative calcium balance, which may contribute to the development of bone metabolic
disorders in rats. The administration of 1α(OH)D3 increased dose-dependently serum calcium and Ca absorption from the intestine and prevented the development of bone metabolic
disorders histomorphologically. 相似文献
54.
Shigeki Ohgitani Akimitsu Miyauchi Yasuyuki Takagi Yoshio Fujii Takuo Fujita Misa Nakamura Zhi-qiang Zhang Liang Shan Mitsuyo Sasaki Ryuichi Tsukino Toyoharu Yokoi Kennichi Kakudo Tomitaka Nakayama Junya Toguchida Hiroshi Kanoe Shinichi Aizawa Masao S. Sasaki Takashi Nakamura M. Suda K. Tanaka Y. Ogawa N. Tamura A. Yasoda H. Itoh M. Uehira N. Nishimoto T. Takigawa K. Shiota K. Nakao 《Journal of bone and mineral metabolism》1997,15(3):165-171
55.
Masanori Hisaoka Takatoshi Aoki Hiromi Kouho Hirofumi Chosa Hiroshi Hashimoto 《Skeletal radiology》1997,26(3):191-194
The case of a 49-year-old man with Maffucci’s syndrome, who developed multiple spindle cell hemangioendotheliomas, is presented.
The case provides support for recent reports suggesting an association between this peculiar vascular lesion and skeletal
enchondromatosis. 相似文献
56.
Tsuyoshi Satoh Tadashi Watanabe Masanori Tadokoro Junichi Sakamoto Hiroki Murayama Katsuki Itoh Sadayuki Sakuma Hiroshi Takagi 《Cancer science》1992,83(4):379-386
Anti-carcinoembryonic antigen monoclonal antibody (MAb) CEA102 was produced by immunization with purified CEA and the specific accumulation of radiolabeled CEA102 in colorectal cancers was investigated by autoradiography of surgical specimens using Fuji Computed Radiography (FCR). Five patients with colorectal cancer were injected intravenously with 131 I-labeled intact CEA102 or its F(ab')2 . Primary tumor and liver metastases were successfully detected by external scanning with a gamma camera in 4 cases. Autoradiographic study of the surgical specimens using FCR showed predominant localization of 131 I-labeled CEA102 in primary tumors and liver metastases in all cases. Even a small liver metastasis (0.5 cm) was clearly visualized in the autoradiogram by FCR. The pixel distribution curves of the density of the respective tissues in the autoradiograms by FCR showed the heterogeneity of the distribution of administered radiolabeled MAb in individual tumors, but the density of the tumors was higher than that of the normal tissues. In the quantitative distribution analysis of CEA102, the uptake of the primary tumor (mean 1.10%ID/kg) was ten-fold greater than that of the normal colon mucosa (mean G.10%ID/kg). These results revealed that the application of MAb has great potential in radioimmunodetection as well as in antibody-directed therapy. 相似文献
57.
Naoya Emoto Eiji Ohmura Osamu Isozaki Toshio Tsushima Kazuo Shizume Hiroshi Demure 《Clinical endocrinology》1991,34(5):377-382
In order to study the mechanism of GH secretion from somatotroph adenoma cells, we have compared the effect of 12–O-tetradecanoyl phorboi-13-acetate (TPA) with that of growth hormone releasing factor (GRF) on GH secretion from human somatotroph adenoma cells cultured in monolayer. Pituitary adenoma cells were obtained from 13 patients with acromegaly undergoing surgery. On the 7th day of culture, the cells were exposed for 2 h to secretagogues. All 13 adenoma cell cultures (100%) responded to TPA (1·6–16·0 nmol/I) with a two- to six-fold increase in GH release (240·37% Increase of control: mean±SE). The response was detectable within 10 min, and was maximal at 2 h. Phosphollpase C (7·7 mmol/I) also stimulated a two-to ten-fold Increase In GH release in all four adenomas examined (100%). GH release was stimulated by GRF (2·0 nmol/I) in eight out of 12 adenoma cells (67%), but the magnitude of the responses to GRF (60·18% Increase of control: mean ± SE) were much smaller than that of TPA. Five out of 13 adenomas secreted detectable amount of PRL Into the medium and these five adenomas (100%) responded to TPA (16·0 nmol/I) with a two- to six-fold Increase. These observations indicate that the activation of protein kinase C is the consistent stimulator in GH and PRL secretion In human somatotroph adenoma cells. However, It is not determined whether the protein kinase C 相似文献
58.
Adipose tissues differentiated by adipose-derived stem cells harvested from transgenic mice 总被引:2,自引:1,他引:1
Objective: To induce adipocyte differentiation in vitro by adipose-derived stromal cells (ASCs) harvested from transgenic mice with green fluorescent protein (GFP) and assess the possibility of constructing adipose tissues via attachment of ASCs to typeⅡcollagen scaffolds. Methods: Inguinal fat pads from GFP transgenic mice were digested by enzymes for isolation of ASCs (primary culture). After expansion to three passages of ASCs, the cells were incubated in an adipogenic medium for two weeks, and the adipocyte differentiation by ASCs in vitro was assessed by morphological observation and Oil Red O staining. Then they were attached to collagen scaffolds and co-cultured for 12 hours, followed by hypodermic implantation to the dorsal skin of nude mice for 2 months. The newly-formed tissues were detected by HE staining. Results: The cultured primary stem cells were fibroblast-like and showed active proliferation. After being incubated in an adipocyte differentiation medium, the lipid droplets in the cytoplasm accumulated gradually and finally developed into mature adipocytes, which showed positive in Oil Red O staining. A 0. 5-cm3 new tissue clot was found under the dorsal skin of the nude mice and it was confirmed as mature adipose tissues by fluorescent observation and HE staining. Conclusions: ASCs can successfully differentiate adipose tissues into mature adipocytes, which exhibit an adipocyte-like morphology and express as intracytoplasmic lipid droplets. It is an efficient model of adipose tissues engineered with ASCs and type I collagen scaffolds. 相似文献
59.
Kazuki Tamura Tadayuki Oka Kazutaka Ohsawa Takehiko Koji Yoji Watanabe Shigeru Katamine Hiroshi Sato Hiroyoshi Ayabe 《The Journal of heart and lung transplantation》2003,22(4):452-459
BACKGROUND: Cytomegalovirus (CMV) diseases commonly occur in allograft recipients in the early post-transplant period. However, factors responsible for the high incidence of CMV diseases during this period are not yet fully defined. METHODS: Wistar-Furth (WF; RT-1(u)) rats were inoculated with 10(4) plaque-forming units (PFU) of rat CMV (RCMV) intraperitoneally, and then transplanted with allogeneic lungs from Dark Agouti (DA; RT-1avl) rats or stimulated with 10(7) mitomycin C-treated spleen cells from DA rats by daily sub-cutaneous injections for 2 weeks. No immunosuppressive agent was used. Naive WF rats and WF rats grafted with syngeneic lungs or cells were used as controls. The level of RCMV replication in rats was assessed by infectious virus titers in tissues. RESULTS: The virus titers in salivary glands of allogeneic and syngeneic lung graft recipients were significantly higher than in naive WF rats. The level of RCMV replication in rats stimulated with allogeneic spleen cells was significantly higher than in the syngeneic recipient rats: virus titers in the salivary gland of allogeneic and syngeneic recipients reached 4.61 +/- 0.33 and 4.00 +/- 0.37 log(10) PFU/g tissue, respectively, at 14 days post-infection (p = 0.015). The augmented viral replication in allogeneic recipients was confirmed by an increase in the number of RCMV antigen-positive macrophages present in tissue sections of the salivary gland. CONCLUSIONS: Acute lung allograft rejection and allogeneic spleen cell stimulation enhance CMV replication in the salivary gland of rats. Various responses to allogeneic antigens occurring in the process of acute allograft rejection could be risk factors for post-transplant CMV replication and infection. 相似文献
60.
Yoshihiro Handa MD Naoki Yamanaka MD Hiroshi Inagaki MD Yasushi Tomita MD 《Dermatologic surgery》2003,29(7):790-792
BACKGROUND: Hidradenoma papilliferum is an uncommon benign tumor that is located almost exclusively in the vulvar and anal areas. It is usually very small and asymptomatic, and to make a correct diagnosis is clinically very difficult. Occasionally the tumor becomes elevated to form a reddish brown papillary mass, and the surface ulcerates, which may erroneously suggest malignancy. OBJECTIVE: We report a case of a large, perianal hidradenoma papilliferum with suspected malignancy in a young Japanese female. RESULTS: A 22-year-old female had been aware of a perianal nodule for approximately 1 year. Examination of the perianal area revealed a wide pedunculated, reddish nodule with several white maculae. It was ulcerated and bleeding, 2.0 x 1.2 x 0.8 cm in size, and located in the 3 o'clock position. The nodule was totally excised with a narrow margin. The histopathologic diagnosis was hidradenoma papilliferum. No recurrence was observed for 23 months. CONCLUSION: When dermatologists encounter tumors of the anogenital area of adult females, it is important to keep hidradenoma papilliferum in mind as the differential diagnosis. Dermatologists should recognize that the tumor is benign, eliminating the need for wide resection. 相似文献