全文获取类型
收费全文 | 22436篇 |
免费 | 1005篇 |
国内免费 | 132篇 |
专业分类
耳鼻咽喉 | 199篇 |
儿科学 | 274篇 |
妇产科学 | 200篇 |
基础医学 | 2630篇 |
口腔科学 | 426篇 |
临床医学 | 1374篇 |
内科学 | 5382篇 |
皮肤病学 | 1486篇 |
神经病学 | 1981篇 |
特种医学 | 947篇 |
外科学 | 4052篇 |
综合类 | 121篇 |
预防医学 | 582篇 |
眼科学 | 180篇 |
药学 | 1712篇 |
中国医学 | 45篇 |
肿瘤学 | 1982篇 |
出版年
2023年 | 118篇 |
2022年 | 215篇 |
2021年 | 398篇 |
2020年 | 237篇 |
2019年 | 301篇 |
2018年 | 429篇 |
2017年 | 332篇 |
2016年 | 418篇 |
2015年 | 455篇 |
2014年 | 588篇 |
2013年 | 685篇 |
2012年 | 1062篇 |
2011年 | 1140篇 |
2010年 | 629篇 |
2009年 | 530篇 |
2008年 | 1036篇 |
2007年 | 1147篇 |
2006年 | 1108篇 |
2005年 | 1109篇 |
2004年 | 1136篇 |
2003年 | 1114篇 |
2002年 | 1085篇 |
2001年 | 650篇 |
2000年 | 702篇 |
1999年 | 678篇 |
1998年 | 330篇 |
1997年 | 228篇 |
1996年 | 225篇 |
1995年 | 212篇 |
1994年 | 167篇 |
1993年 | 135篇 |
1992年 | 464篇 |
1991年 | 420篇 |
1990年 | 424篇 |
1989年 | 461篇 |
1988年 | 427篇 |
1987年 | 392篇 |
1986年 | 340篇 |
1985年 | 299篇 |
1984年 | 178篇 |
1983年 | 162篇 |
1982年 | 91篇 |
1979年 | 170篇 |
1978年 | 88篇 |
1977年 | 86篇 |
1975年 | 74篇 |
1974年 | 73篇 |
1973年 | 82篇 |
1972年 | 85篇 |
1970年 | 74篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
BACKGROUND. Some specific chromosome abnormalities for the leukemias have been proven to be associated with the prognosis of acute nonlymphocytic leukemia (ANLL). However, most of these reports included patients treated with different protocols. Therefore, some bias has been involved in the evaluation of the prognostic factors in such reports. METHODS. The authors studied the morphologic, cytogenetic, and clinical features of 136 patients (86 males and 50 females) with de novo ANLL treated with the same protocol of intensive induction chemotherapy using multivariate analyses. RESULTS. Chromosome abnormalities were detected in 62.5% of the patients. The overall complete remission (CR) rate of disease was 85.5% in these patients. More than 90% of the patients with t(8;21) and pseudodiploid abnormalities achieved experienced CR. However, CR rates in the patients with abnormalities of chromosome 5 or 7 were 50%. With multivariate analyses by the type of karyotypic abnormality, CR duration and survival time of the patients with t(8;21) were longer than those of patients with normal karyotype and abnormalities of chromosome 5 or 7. Abnormalities of chromosome 5 or 7 and hyperdiploid were associated with poor prognosis. Older age and lower platelet counts also were factors contributing to shorter survival times. With the analysis with French-American-British (FAB) classification, only hypoplastic leukemia was a poor prognostic factor. CONCLUSIONS. These data suggest that cytogenetic analyses plays an important role in estimating the prognosis of patients treated with intensive induction chemotherapy. 相似文献
52.
BACKGROUND AND METHODS. A univariate and multivariate analysis for the correlation between histomorphologic factors and prognosis was made using data from 1116 patients with soft tissue sarcoma, including 1005 cases available with complete histologic and follow-up data. RESULTS. The overall 5-year survival rate was 43.6%. The univariate analysis using Kaplan-Meier survival curves showed that tumor differentiation, cellularity, nuclear atypia, cellular pleomorphism, mitotic activity, amount of fibrous stroma, extent of myxoid areas, extent of tumor necrosis, and histologic grading (determined by the estimated range of malignancy for each type of sarcoma using a reported guideline) were all significant prognostic factors in the overall soft tissue sarcoma group. By a multivariate analysis using a procedure based on the Weibull model to failure data, the histologic grading and extent of tumor necrosis were proved to be prognostically significant in the overall sarcoma group. However, after additional analysis on each histologic type of sarcoma, it was determined that both tumor necrosis and histologic grading were applicable in only two types: malignant fibrous histiocytoma and leiomyosarcoma. Liposarcoma, synovial sarcoma, and malignant schwannoma each also showed some determinable factor of prognostic significance. CONCLUSIONS. It was concluded that there seemed to be no single universal prognostic parameter that could be applied to each soft tissue sarcoma type. These results suggest that the predictive significance of the various histologic parameters should be based on each specific type of sarcoma. 相似文献
53.
Three cases of tubular adenoma of the gallbladder with squamoid spindle cell metaplasia are reported. Two of the three patients, who were middle-aged Japanese, had a solitary polyp in the gallbladder, and the other had three polyps. All the lesions were detected incidentally by ultrasonography. The polyps were pedunculated with a fine or frail stalk, and ranged from 0.5 to 3.9 cm in diameter. Histologically, they were tubular adenomas accompanied by scattered foci composed of a compact collection of short-spindle or oval cells with mild atypia. These cells did not retain intercellular bridges, and lacked intracellular keratinization. Immunohistochemically, the spindle cells stained positively for high-molecular-weight cytokeratin (EAB 903, a marker of squamous cell differentiation), whereas adenoma cells lining the tubules were negative for this antigen. Therefore, the spindle cell component is considered to represent squamoid metaplasia of adenoma cells. 相似文献
54.
55.
Shinichi Suzuki Kiyotaka Imoto Keiji Uchida Naoki Hashiyama Yoshinori Takanashi 《Annals of thoracic and cardiovascular surgery》2005,11(6):424-428
This report describes the use of transluminal endovascular grafting for the treatment of a presumed aortoduodenal fistula. The patient was a 71-year-old man who had undergone resection and graft replacement for an abdominal aortic aneurysm. Three years after operation, melena was caused by perforation of the duodenal wall by a pseudoaneurysm at the proximal graft anastomosis. The pseudoaneurysm was treated by transluminal endovascular grafting. The pseudoaneurysm was subsequently thrombosed and absorbed. The ulcer-like lesions at the site of the duodenal wall perforated by the pseudoaneurysm also resolved. Endovascular stent-grafts may have a role to play in management of aortoduodenal fistula. 相似文献
56.
57.
T Urakawa Y Nagahata Y Azumi Y Hashimoto A Itoh K Takeda I Sano Y Saitoh 《Scandinavian journal of gastroenterology》1988,23(6):705-711
We experimentally studied the influence of vagotomy on hepatic regeneration in rats after hepatectomy of cirrhotic livers. In animals that underwent hepatectomy plus vagotomy the reduction in gastric pH was suppressed, but gastric mucosal blood flow was less than that in control animals that received hepatectomy alone. The suppression of 3H-thymidine uptake percentage and thymidine kinase activity after hepatectomy was more marked in animals treated with hepatectomy plus vagotomy than in controls treated with hepatectomy alone. Hepatic DNA level tended to be lower in animals treated with hepatectomy plus vagotomy than in controls. In animals treated with hepatectomy plus vagotomy, the peak level of the mitotic index was lower and the hepatic regeneration rate was evidently suppressed. These results suggest that it is not appropriate to apply vagotomy, during hepatectomy of cirrhotic livers, for the prevention of postoperative stress ulcer because it causes a marked reduction in gastric mucosal blood flow and suppresses hepatic regeneration. 相似文献
58.
Preferential inhibitions of hepatic P450IA2 expression and induction by lead nitrate in the rat 总被引:3,自引:0,他引:3
Degawa Masakuni; Arai Hiroshi; Miura Shin-ichi; Hashimoto Yoshiyuki 《Carcinogenesis》1993,14(6):1091-1094
Male F344 rats were treated with lead nitrate and changes inthe expression and induction of P450IA subfamily enzymes anda placental form of glutathione-S-transferase (GST-P) in theliver were assessed by means of a bacterial mutation test, immunoblottingwith a monoclonal antibody reactive to P450IA1/IA2 and anti-GST-Psera and Northern blotting with P450IA2 cDNA as a probe. Treatmentof rats with lead nitrate (20, 50 or 100 µmol/kg bodywt) decreased P450IA2 mRNA and protein in the liver in the dose-dependentfashion and also decreased the microsomal activity for P450IA2-dependentmutagenization of aromatic amines. Pretreatment of rats withlead nitrate suppressed the inductions of both P450IA2 mRNAand protein by an inducer of P450IA subfamily enzymes in theliver. In addition, amount of the induced P450IA2 was decreasedalong with increase in that of the induced GST-P. 相似文献
59.
Shunsuke Endo Yukio Sato Tsuyoshi Hasegawa Kenji Tetsuka Shinichi Otani Noriko Saito Yasuhiro Tezuka Yasunori Sohara 《European journal of cardio-thoracic surgery》2004,26(4):787-791
OBJECTIVE: Many phase II trials have shown that preoperative chemotherapy for lung cancer is feasible but associated with postoperative morbidity and mortality. However, little is known about the effect of preoperative chemotherapy on surgical stress and postoperative complications associated with surgical intervention. We evaluated the effect of preoperative chemotherapy on perioperative inflammatory cytokine production as a surgical stress marker. METHODS: The study group comprised 38 patients undergoing anatomical lung resection and mediastinal nodal dissection for clinical stage IB/II non-small cell lung cancer during the period October 2001-December 2003. Nineteen patients received a single cycle of cisplatin (80 mg/m(2)) and docetaxel (60 mg/m(2)) chemotherapy prior to surgery (neoadjuvant group), and 19 patients underwent surgery without any previous chemotherapy (control group). White blood cell and neutrophil counts and serum concentrations of C-reactive protein (CRP), interleukin-6 (IL-6), and granulocyte colony-stimulating factor (GCSF) were determined before surgery and on postoperative days 1 and 3. Postoperative complications were reviewed. Differences were assessed by repeated analysis of variance. RESULTS: Serum concentrations of IL-6 and GCSF rose significantly on postoperative days 1 and 3 in the neoadjuvant group in comparison to concentrations in the control group, but white blood cell count, neutrophil count, and CRP did not differ between the groups. No major complication occurred in either group. CONCLUSIONS: A single cycle of cisplatin and docetaxel chemotherapy followed by surgery can exacerbate overproduction of inflammatory cytokines during the perioperative period in lung cancer patients. 相似文献
60.
Bassam Alchi Arimasa Shirasaki Ichiei Narita Shinichi Nishi Mitsuhiro Ueno Takako Saeki Shoji Miyamura Fumitake Gejyo 《Hypertension research》2006,29(3):203-207
A 48-year-old man presented with malignant hypertension and massive proteinuria. Renal angiography showed complete obstruction of the left renal artery and 99mTc-mercaptoacetylglycine (MAG3) renography showed a nonfunctioning left kidney. Percutaneous transluminal renal angioplasty of the left renal artery was unsuccessful; hence, the patient underwent left nephrectomy because of uncontrolled hypertension and proteinuria. Histological examination of a right kidney specimen revealed lesions of focal segmental glomerulosclerosis with benign nephrosclerosis. In contrast, histology of the left kidney showed typical ischemic kidney with hypertrophy of arteriolar smooth muscle cells. The patient responded favorably to the nephrectomy, as his blood pressure and urinary protein dramatically decreased with no antihypertensive medication. This case illustrates the heterogeneous effect of the renin-angiotensin system on either kidney in patients with renovascular hypertension due to unilateral renal artery stenosis. 相似文献