全文获取类型
收费全文 | 10648篇 |
免费 | 545篇 |
国内免费 | 102篇 |
专业分类
耳鼻咽喉 | 116篇 |
儿科学 | 220篇 |
妇产科学 | 89篇 |
基础医学 | 1324篇 |
口腔科学 | 269篇 |
临床医学 | 560篇 |
内科学 | 2836篇 |
皮肤病学 | 316篇 |
神经病学 | 1067篇 |
特种医学 | 407篇 |
外科学 | 1510篇 |
综合类 | 34篇 |
一般理论 | 1篇 |
预防医学 | 572篇 |
眼科学 | 174篇 |
药学 | 530篇 |
中国医学 | 8篇 |
肿瘤学 | 1262篇 |
出版年
2023年 | 48篇 |
2022年 | 122篇 |
2021年 | 190篇 |
2020年 | 108篇 |
2019年 | 148篇 |
2018年 | 207篇 |
2017年 | 190篇 |
2016年 | 191篇 |
2015年 | 243篇 |
2014年 | 282篇 |
2013年 | 374篇 |
2012年 | 609篇 |
2011年 | 706篇 |
2010年 | 401篇 |
2009年 | 353篇 |
2008年 | 587篇 |
2007年 | 662篇 |
2006年 | 683篇 |
2005年 | 627篇 |
2004年 | 680篇 |
2003年 | 651篇 |
2002年 | 659篇 |
2001年 | 201篇 |
2000年 | 194篇 |
1999年 | 173篇 |
1998年 | 159篇 |
1997年 | 148篇 |
1996年 | 148篇 |
1995年 | 131篇 |
1994年 | 114篇 |
1993年 | 86篇 |
1992年 | 114篇 |
1991年 | 103篇 |
1990年 | 91篇 |
1989年 | 97篇 |
1988年 | 91篇 |
1987年 | 60篇 |
1986年 | 62篇 |
1985年 | 85篇 |
1984年 | 61篇 |
1983年 | 41篇 |
1982年 | 35篇 |
1981年 | 37篇 |
1980年 | 45篇 |
1979年 | 34篇 |
1978年 | 25篇 |
1975年 | 21篇 |
1974年 | 21篇 |
1973年 | 26篇 |
1972年 | 21篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
Kazuhiko Sonoyama Haruaki Ninomiya Osamu Igawa Yasuhiro Kaetsu Yoshiyuki Furuse Toshihiro Hamada Junichiro Miake Peili Li Yasutaka Yamamoto Kazuhide Ogino Akio Yoshida Shin-ichi Taniguchi Yasutaka Kurata Satoshi Matsuoka Toshio Narahashi Goshi Shiota Yoshihisa Nozawa Hiroaki Matsubara Masatsugu Horiuchi Yasuaki Shirayoshi Ichiro Hisatome 《Hypertension research》2006,29(11):923-934
We examined the effects of angiotensin II (Ang II) on inward rectifier K+ currents (IK1) in rat atrial myocytes. [125I]Ang II-binding assays revealed the presence of both Ang II type 1 (AT1) and type 2 (AT2) receptors in atrial membrane preparations. Ang II inhibited IK1 in isolated atrial myocytes with an IC50 of 46 nmol/l. This inhibition was abolished by the AT, antagonist RNH6270 but not at all by the AT2 antagonist PD123319. Treatment of cells with pertussis toxin or a synthetic decapeptide corresponding to the carboxyl-terminus of Gialpha-3 abolished the inhibition by Ang II, indicating the role of a Gi-dependent signaling pathway. Accordingly, Ang II failed to inhibit IK1 in the presence of forskolin, dibutyryl-cAMP or protein kinase A catalytic subunits. In spite of the increased binding capacities for [125I]Ang II, Ang II failed to affect IKI in cells from spontaneously hypertensive rats (SHR). AT, immunoprecipitation from atrial extracts revealed decreased amounts of Gialpha-2 and Gialpha-3 proteins associated with this receptor in SHR as compared with controls. The reduced coupling of AT, with Gialpha. proteins may underlie the unresponsiveness of atrial IK1 to Ang II in SHR cells. 相似文献
42.
Kunihiko Sasai Takashi Adachi Kouki Togano Ei Wakabayashi Hiroyuki Ohnari Hirokazu Iida 《The spine journal》2006,6(4):464-467
BACKGROUND CONTEXT: There is no report in the literature of two-level disc herniation in the cervical and thoracic spine presenting with spastic paresis/paralysis exclusively in the bilateral lower extremities. PURPOSE: To identify the clinical characteristics of specific myelopathy resulting from C6-C7 disc herniation through a case with spastic paresis in the lower extremities without upper extremities symptoms due to separate disc herniation in the cervical and thoracic spine, which was surgically removed in two stages. STUDY DESIGN/SETTING: A case report. METHODS: A 48-year-old man developed a gait disturbance as well as weakness and numbness in the lower extremities. Thoracic magnetic resonance imaging (MRI) showed a T11-T12 disc herniation, which was removed under the surgical microscope through a minimally invasive posterior approach. He improved, but 2 months after surgery developed recurrent numbness and spasticity. On this occasion, no evidence of recurrence of the thoracic disc herniation could be identified, but cervical MRI demonstrated a compressed spinal cord at the C6-C7 level. The patient had no neurological findings in the upper extremities. The herniated disc at C6-C7 was removed under the surgical microscope with laminoplasty. RESULTS: The symptoms gradually improved after surgery. At the present time, 2 years and 9 months after the initial operation, the patient had a stable gait and was able to work. CONCLUSIONS: Our experience suggests that in the diagnosis of patients with spastic paresis and sensory disturbances in the lower extremities, spinal cord compression should be explored by imaging studies not only in the thoracic spine but also in the cervical spine, especially at the C6-C7 level, even if the symptoms and abnormal neurological findings are absent in the upper extremities. 相似文献
43.
M Wakabayashi 《Nihon Igaku Hōshasen Gakkai zasshi. Nippon acta radiologica》1992,52(11):1571-1581
Three types of expandable metallic stents were used to relieve obstructive jaundice in 59 patients. They consisted of 3 cases with benign stricture, and 56 with malignant obstruction including 28 of cholangiocarcinoma, 17 of pancreatic carcinoma, 9 of lymph node metastases, and 2 of gall bladder carcinoma. The median age of patients was 68.9 years. Of 56 cases with malignant obstruction, 51 cases were able to remove external drainage catheter. In these 51 cases, 35 patients died, and 16 are still alive. No significant difference was noted in the incidence of stent destruction or migration in three types of stents. The average survival period was 189.9 days in 35 patients who died after withdrawal of external drainage. Twenty-three of 35 patients had no recurrence of obstructive jaundice. Sixteen patients with malignant obstruction are still alive and have been observed for 22 to 764 days. The 30 day mortality rate was 6.8%. Three cases of acute cholecystitis were noted after procedure. It is warranted to say that endoprostheses using expandable metallic stents will be the major treatment of choice for biliary obstruction because of long term patency and low complication rate. 相似文献
44.
Summary An esthesioneuroblastoma in a 16-year-old male was studied ultrastructurally and immunohistochemically, using antiserum against tyrosine hydroxylase (TH), a rate-limiting enzyme in the catecholamine-synthesizing pathway. Tumor cells were fairly uniform in appearance, showing scantly cosinophilic cytoplasm and round to oval hyperchromatic nuclei, and were arranged in nests and cords of various sizes. Ultrastructurally, individual tumor cells had well-developed cell organelles including polyribosomes, microtubules, intermediate filaments, centrioles, Golgi apparatus and mitochondria. Secretory-like granules were occasionally found, predominantly in the cell processes. Immunohistochemically, many tumor cells were shown to be immunoreactive for TH. This finding strongly suggested that the present tumor was capable of producing catecholamines and that it might be derived from certain sympathetic neuronal cell nests in the superior nasal cavity. 相似文献
45.
Ikuo Saiki Jun Murataxd Junya Yoneda Hideo Kobayashi Ichiro Azuma 《International journal of cancer. Journal international du cancer》1994,56(6):867-873
We have examined the influence of fibroblasts on the invasive and migratory potential of highly metastatic melanoma B16-BL6 and weakly metastatic B16-FI cells in vitro. Co-culture of B16-BL6 cells with a fibroblast monolayer without cellular contact in a Transwell chamber more effectively induced tumor-cell invasion into Matrigel basement membrane than co-culture of B16-FI cells with a fibroblast monolayer. The activity was closely correlated with the chemotactic migration of tumor cells toward the fibroblast monolayer. We also found that the conditioned medium (CM) from the co-culture of fibroblasts with B16-BL6 cells without cellular contact, i.e., CM (B16-BL6/fibroblast), rather than from co-culture with B16-FI cells, could potentially promote the migration of tumor cells of both types. Tumor cells did not chemotactically migrate to the CM (B16-BL6), CM (B16-FI) or CM (fibroblast). Antibodies against TGF-β1 or FN almost completely abolished the chemotactic migration of B16-BL6 cells to the CM (B16-BL6/fibroblast) or CM (TGF-β1 -treated fibroblast) when these antibodies were c-incubated with fibroblasts and either B16-BL6 or TGF-β1. In contrast, the anti-EGF antibody did not show any inhibitory effects. Analysis of amounts of TGF-β1 or FN in various CM using ELISA plates, and using their specific antibodies, revealed that the concentration of TGF-β1 in the CM (B16-BL6) was slightly higher than in the CM (B16-FI), and the amount of FN in the CM (B16-BL6/fibroblast) was twice as high as in the CM (B16-FI /fibroblast). These results suggest that TGF-β1 released from B16-BL6 cells can stimulate fibroblasts to produce FN; consequently, the tumor cells were able to chemotactically migrate toward the released FN, and the differences in invasive and migratory activities towards fibroblasts in B16-BL6 and B16-FI cells may in part be due to the amounts of TGF-β1 from tumor cells and of FN from TGF-β1 -stimulated fibroblasts. 相似文献
46.
Yoshiyuki Kaneko Tomohiro Nakayama Kosuke Saito Akihiko Morita Ichiro Sato Aya Maruyama Masayoshi Soma Teruyuki Takahashi Naoyuki Sato 《Hypertension research》2006,29(9):665-671
The risk of cerebral infarction (CI) in an individual is dependent on the interplay between genetic risk factors and environmental influences. Binding of thromboxane A2 (TXA2) to its receptor (TP) modulates thrombosis/hemostasis and plays a significant role in the pathogenesis of CI. The aim of the present study was to investigate the relationship between human TP gene single nucleotide polymorphisms (SNPs) and haplotypes and CI in a Japanese population. A genetic association study was performed in 194 CI patients and 365 non-CI subjects by specifically characterizing 6 SNPs in the human TP gene (rs2271875, rs768963, rs2238634, rs11085026, rs4523 and rs4806942). Analysis demonstrated that there were significant differences in the overall distribution of genotypes and dominant or recessive models of rs2271875 and rs768963 between the CI and the non-CI groups. Multiple logistic regression analysis revealed that the C allele of rs768963 was significantly associated with CI (p = 0.029), even after adjusting for confounding factors (odds ratio: 2.41). Further, the C-T-C haplotype of rs768963-rs2238634-rs4806942 was significantly more frequent in the CI group (23.0%) than in the non-CI group (17.7%). These results suggest that specific SNPs and haplotypes may have utility as genetic markers for the risk of CI and that TP or a neighboring gene is associated with the increased susceptibility to CI. 相似文献
47.
Maki Kihara Tatsuya Sugita Yuichiro Nagai Naokatsu Saeki Ichiro Tatsuno Katsuyoshi Seki 《Gynecological endocrinology》2006,22(2):110-113
OBJECTIVE: We present a case of spontaneous ovarian hyperstimulation caused by pituitary gonadotroph macroadenoma, and include a review of the literature. CASE REPORT: A 27-year-old woman presented with irregular menstruation and bilateral multicystic enlargement of the ovaries. Serum estradiol (E(2)) levels were marginally elevated for the follicular phase but within the physiological range. Serum luteinizing hormone (LH) was extremely low, follicle-stimulating hormone (FSH) was normal, and prolactin (PRL) was high. Magnetic resonance imaging disclosed a pituitary macroadenoma. Immunohistochemical examination of the surgically removed adenoma showed intense reactivity for FSH and LH. After the operation, E(2), LH and PRL levels were normalized, the ovaries returned to a normal morphology, and regular menstrual cycles were resumed. CONCLUSION: A review of the literature showed that ovarian hyperstimulation caused by pituitary gonadotroph adenoma is not always accompanied by elevated FSH levels. High PRL and E(2) and low LH were reported in the majority of the cases, but E(2) may stay within the range observed in normal menstrual cycles. 相似文献
48.
Clinical characteristics of thrombotic microangiopathy following ABO incompatible living donor liver transplantation. 总被引:1,自引:0,他引:1
Ryohei Miyata Motohide Shimazu Minoru Tanabe Shigeyuki Kawachi Ken Hoshino Go Wakabayashi Yoko Kawai Masaki Kitajima 《Liver transplantation》2007,13(10):1455-1462
Thrombotic microangiopathy (TMA) may develop after living donor liver transplantation (LDLT), but the mechanism is not fully understood. We retrospectively analyzed all patients undergoing LDLT at our center, including TMA patients, to elucidate the clinical characteristics and presentation and to determine which patients have a higher risk of occurrence of TMA. In all, 57 adult patients were reviewed after LDLT at our institution. TMA was diagnosed by sudden and severe thrombocytopenia, followed by hemolytic anemia with fractionated erythrocytes in the blood smear. Clinical features were compared between the TMA group and the non-TMA group. Of the 57 patients, 4 were diagnosed with posttransplantation TMA. ABO blood group (ABO)-incompatibility, cyclophosphamide (CPA), and recipient blood group (type O) were closely correlated with the occurrence of TMA. Thrombocytopenia appeared 1 to 5 days before hemolytic anemia. Coagulative function markers stayed at the same level after TMA, while marked elevation was shown in fibrinolytic function markers such as plasminogen activator inhibitor type 1 (PAI-1). TMA occurred at a higher prevalence in ABO-incompatible graft recipients. Additional factors associated with ABO-incompatible transplantation, such as an overdose of immunosuppressants, may affect the likelihood of TMA. Sudden and severe thrombocytopenia presented before hemolytic anemia and the serum levels of PAI-1 correlated well with the clinical course of TMA. In conclusion, early recognition of thrombocytopenia and elevation of PAI-1 is crucial to diagnose TMA especially in ABO-incompatible LDLT. 相似文献
49.
Shunsuke Kobayashi Makoto Tanno Ichiro Nakamura Katsumi Ito Yoshikazu Ugawa 《Clinical neurology》2007,47(2-3):96-99
TNFalpha plays an important role as an inflammatory mediator in both several autoimmune diseases and multiple sclerosis. Anti-TNFalpha antibody has been widely used to treat rheumatoid arthritis and Crohn's disease. On the. other hand, anti-TNFalpha antibody treatment increased recurrence rate in clinical trials for multiple sclerosis. We report a patient with rheumatoid arthritis without past history of any neurological disorders, who developed diplopia, ataxia, and visual agnosia specific to line drawing in the course of anti-TNFalpha antibody treatment. MRI studies detected multiple demyelinating lesions in the cerebral white matter and brainstem. The present case indicates that careful observation of neurological symptoms is important in the course of anti-TNFalpha antibody treatment, even in patients without past history of demyelinating diseases. 相似文献
50.
Mitsuru Masaki Tadashi Kuroda Naoki Hosen Hisao Hirota Kazuo Terai Yuichi Oshima Yoshikazu Nakaoka Shoko Sugiyama Ryusuke Kimura Satoshi Yoshihara Manabu Kawakami Norishige Iizuka Yasuhiko Tomita Hiroyasu Ogawa Ichiro Kawase Keiko Yamauchi-Takihara 《Journal of the American Society of Echocardiography》2004,17(4):397-398
A 57-year-old man with a history of renal cell carcinoma presented with presyncope. He underwent nephrectomy years earlier followed by HLA-matched allogeneic peripheral-blood stem-cell transplantation. Echocardiographic investigation revealed a solitary right ventricle mass without contiguous vena caval or right atrial involvement. The mass was pathologically confirmed to be metastatic carcinoma in the right ventricular cavity. This case highlights the need to consider an underlying neoplastic syndrome in patients presenting isolated right ventricle mass by echocardiography. 相似文献