全文获取类型
收费全文 | 14707篇 |
免费 | 687篇 |
国内免费 | 128篇 |
专业分类
耳鼻咽喉 | 95篇 |
儿科学 | 283篇 |
妇产科学 | 419篇 |
基础医学 | 1788篇 |
口腔科学 | 362篇 |
临床医学 | 999篇 |
内科学 | 4115篇 |
皮肤病学 | 273篇 |
神经病学 | 1369篇 |
特种医学 | 614篇 |
外科学 | 2171篇 |
综合类 | 51篇 |
一般理论 | 1篇 |
预防医学 | 539篇 |
眼科学 | 168篇 |
药学 | 761篇 |
中国医学 | 24篇 |
肿瘤学 | 1490篇 |
出版年
2024年 | 12篇 |
2023年 | 91篇 |
2022年 | 205篇 |
2021年 | 424篇 |
2020年 | 212篇 |
2019年 | 311篇 |
2018年 | 403篇 |
2017年 | 303篇 |
2016年 | 341篇 |
2015年 | 380篇 |
2014年 | 568篇 |
2013年 | 732篇 |
2012年 | 1019篇 |
2011年 | 1023篇 |
2010年 | 669篇 |
2009年 | 591篇 |
2008年 | 1041篇 |
2007年 | 1044篇 |
2006年 | 951篇 |
2005年 | 990篇 |
2004年 | 876篇 |
2003年 | 817篇 |
2002年 | 736篇 |
2001年 | 96篇 |
2000年 | 102篇 |
1999年 | 121篇 |
1998年 | 157篇 |
1997年 | 117篇 |
1996年 | 138篇 |
1995年 | 96篇 |
1994年 | 104篇 |
1993年 | 82篇 |
1992年 | 79篇 |
1991年 | 69篇 |
1990年 | 58篇 |
1989年 | 49篇 |
1988年 | 37篇 |
1987年 | 27篇 |
1986年 | 39篇 |
1985年 | 40篇 |
1984年 | 40篇 |
1983年 | 28篇 |
1982年 | 38篇 |
1981年 | 35篇 |
1980年 | 34篇 |
1979年 | 29篇 |
1977年 | 15篇 |
1976年 | 10篇 |
1975年 | 12篇 |
1974年 | 10篇 |
排序方式: 共有10000条查询结果,搜索用时 13 毫秒
81.
Federico Belladelli Luca Boeri Paolo Capogrosso Walter Cazzaniga Eugenio Ventimiglia Luigi Candela Edoardo Pozzi Andrea Baudo Massimo Alfano Costantino Abbate Francesco Montorsi Andrea Salonia 《Asian journal of andrology》2021,(5):456-461
Substances of abuse(SoA),as well as smoking and alcohol consumption,are well known for their impact on male fertility status,erectile function,and ejaculation.W... 相似文献
82.
Benzoni E Rossit L Cojutti A Favero A Saccomano E Zompicchiatti A Noce L Bresadola F Intini S 《Chirurgia italiana》2007,59(1):17-25
Surgical treatment of pancreatic cancer is to date the only modality that offers a chance of long-term survival. Potentially curative surgery is an option for only about 15% of patients with pancreatic adenocarcinoma. The aim of this study was to determine the survival and to assess the association of clinical, pathological, and treatment features with survival of patients who underwent resection of pancreatic cancer at the Department of Surgery of Udine University Hospital. From November 1989 to December 2005, 137 consecutive patients, who underwent surgical procedures for pancreatic cancer, were followed in our department. We performed 76 pancreatico-duodenectomy, 26 distal pancreatectomies and 35 total pancreatectomies. The surgical reconstruction after pancreatico-duodenectomy was as follows: 11 closures of the main duct with manual nonabsorbable stitches, 24 closures of the main duct with a linear stapler, 17 occlusions of the main duct with neoprene glue and 24 duct-to-mucosa anastomoses. Mean survival time was 27.7 +/- 26.93 months (mean +/- SD) and mean disease-free survival time was 25.4 +/- 23.06 months (mean +/- SD). 1, 3, 5, 7 and 9-year survival rates were 63.9, 33.7, 21.17, 12.7 and 10.2%, respectively. Significant differences in survival were recorded by the Log-rank test for age > 70 (p = 0.001), surgical procedures (p = 0.00046) and presence of metastases (p = 0.0055) The treatment of pancreatic cancer is undertaken with two different aims. The first is radical surgery for patients with early-stage disease, mainly stage I and partly stage II. In all other cases, the aim of treatment is the palliation of the several distressing symptoms related to this cancer. The standard treatment option for resectable tumours is radical pancreatic resection according to the Whipple procedure or total pancreatectomy. 相似文献
83.
84.
introduction: Cancer of the testis is not always early detected and recognised, both by the physician and by the patient: sometimes physicians do not make an accurate genitals exam while patients often underestimate this problem. Case reports: Case I: 42-year-old man accepted from another hospital's Emergency, because of pain and edema of the right testis after a recent trauma on the gonad. At US, evidence of increased volume of the right testis with a large intraparenchymal hematoma. The markers were higher than normal. We performed a right orchiecthomy. The pathologist noted the presence of a mixed cancer of the testis (95% embryonal, 5% seminoma). Case II: 49-year-old man with hematuria, accepted from Emergency. The abdominal US revealed the presence of a voluminous neoformation (diameter of 12 cm) of the right kidney with neoplastic thrombosis of the right kidney vein. At the general physical exam, we detected the presence of an increased right testis, that at the US appared to be suspicious for cancer. Tumor markers were normal with the exception of αFP. We performed right nephro-adrenalectomy, right orchiectomy and removal of local nodes. The definitive histological examination demonstrated the presence of a seminoma of the testis and papillary carcinoma of the kidney with node metastasis. Discussion: Current studies showed an association between trauma and cancer of the testis, even if some authors did not find this association because they consider that patients with trauma undergo US and in that occasion cancer is incidentally detected. Conclusions: The association between trauma and cancer of the testis is controversial in current studies. Furthermore screening for the cancer of the testis does not seem to be useful, even if the self- and the physician's palpation of the testis seem to be very important because in these two cases they should allow the early detection of the condition, with a resulting better prognosis. 相似文献
85.
Positano V Cusi K Santarelli MF Sironi A Petz R Defronzo R Landini L Gastaldelli A 《Journal of magnetic resonance imaging : JMRI》2008,28(2):403-410
PURPOSE: To demonstrate that unsupervised assessment of abdominal adipose tissue distribution by magnetic resonance imaging (MRI) can be improved by integrating automatic correction of signal inhomogeneities. MATERIALS AND METHODS: Twenty subjects (body mass index [BMI] 23.7-44.0 kg/m(2)) underwent abdominal (32 slices) MR imaging with a 1.9T Elscint Prestige scanner. Many images were affected by relevant intensity distortions. Unsupervised segmentation of subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) was performed by a previously validated algorithm exploiting standard fuzzy clustering segmentation. Images were also processed by an improved version of the software, including automatic correction of intensity inhomogeneities. To assess the effectiveness of the two methods SAT and VAT volumes were compared with manual analysis performed by a trained operator. RESULTS: Coefficient of variation between manual and unsupervised analysis was significantly improved by inhomogeneities correction in SAT evaluation. Systematic underestimation of SAT was also corrected. A less important performance improvement was found in VAT measurement. CONCLUSION: The results of this study suggest that the compensation of signal inhomogeneities greatly improves the effectiveness of the unsupervised assessment of abdominal fat. Correction of intensity distortions is important in SAT evaluation and less significant in VAT measurement. 相似文献
86.
Pulmonary resection for metastases from colorectal cancer: factors influencing prognosis. Twenty-year experience. 总被引:7,自引:0,他引:7
Ottavio Rena Caterina Casadio Franco Viano Riccardo Cristofori Enrico Ruffini Pier Luigi Filosso Giuliano Maggi 《European journal of cardio-thoracic surgery》2002,21(5):906-912
OBJECTIVE: We reviewed our experience in the surgical management of 80 patients with colorectal pulmonary metastases and investigated factors affecting survival. MATERIAL AND METHODS: From January 1980 to December 2000, 80 patients, 43 women and 37 men with median age 63 years (range 38-79 years) underwent 98 open surgical procedure (96 muscle-sparing thoracotomy, one clamshell and one median sternotomy) for pulmonary metastases from colorectal cancer (three pneumonectomy, 17 lobectomy, seven lobectomy plus wedge resection, six segmentectomy, three segmentectomy plus wedge resection and 62 wedge resection). Pulmonary metastases were identified at a median interval of 37.5 months (range 0-167) from primary colorectal resection. Second and third resections for recurrent metastases were done in seven and in four patients, respectively. RESULTS: Operative mortality rate was 2%. Overall, 5-year survival was 41.1%. Five-year survival was 43.6% for patients submitted to single metastasectomy and 34% for those submitted to multiple ones. Five-year survival was 55% for patients with disease-free interval (DFI) of 36 months or more, 38% for those with DFI of 0-11 months and 22.6% for those with DFI of 12-35 months (P=0.04). Five-year survival was 58.2% for patients with normal preoperative carcino-embryonic antigen (CEA) levels and 0% for those with pathologic ones (P=0.0001). Patients submitted to second-stage operation for recurrent local disease had 5-year survival rate of 50 vs. 41.1% of those submitted to single resection (P=0.326). CONCLUSIONS: Pulmonary resection for metastases from colorectal cancer may help survival in selected patients. Single metastasis, DFI>36 months, normal preoperative CEA levels are important prognostic factors. When feasible, re-operation is a safe procedure with satisfactory long-term results. 相似文献
87.
Giant prolactinomas presenting as skull base tumors 总被引:2,自引:0,他引:2
Minniti G Jaffrain-Rea ML Santoro A Esposito V Ferrante L Delfini R Cantore G 《Surgical neurology》2002,57(2):99-103; discussion 103-4
BACKGROUND: Prolactinomas invading the skull base are rare, and could easily be confused with skull base tumors of nonpituitary origin. CASE DESCRIPTION: We report a series of 4 cases of giant prolactinomas invading the skull base and presenting with atypical symptoms. Case 1 presented with a short history of headache and nasal obstruction. Case 2 presented with progressive hypoacusia, dizziness, and ophthalmoplegia. In Case 3, the patient developed rapid progressive visual failure and psychiatric symptoms. Case 4 presented with a 1-year history of headache and retrorbital pain. The diagnosis of prolactinoma was made on the basis of tumor immunohistochemistry and/or high plasma prolactin levels (range from 650-6,500 ng/mL). Medical treatment with the dopamine agonist cabergoline was given; it was effective in normalizing prolactin levels and inducing tumor shrinkage. CONCLUSION: Prolactin levels should be measured in all large skull base tumors involving the pituitary region before any surgery or inappropriate radiotherapy is performed. 相似文献
88.
Lymphocyte costimulatory receptors in renal disease and transplantation 总被引:12,自引:0,他引:12
Cell-to-cell signal exchange during antigen presentation deeply influences the profile and extent of the immune response. Together with the TCR/MHC-mediated signal, accessory signals are provided to the T cell by the antigen-presenting cell (APC), through specific receptor-ligand interactions that represent indispensable costimulation for T-cell activation and survival. The main costimulatory pathways are the B7 family members and the CD40-CD154 receptor-ligand pair. B7-1 and B7-2 costimulate T-cells by binding to CD28. Their binding is prevented by the neoexpression of CTLA4, a CD28 homologue that can deliver a negative signal. Another CD28-like molecule, called ICOS (inducible costimulator), has been described and binds B7RP-1, a third member of the B7 family, but not B7-1 and B7-2. The CD40-CD154 interaction works as a two way costimulatory system by triggering activation signals to both T-cell and APCs. Its importance is highlighted by the discovery that mutations of the CD154 gene are responsible for a severe human immunodeficiency. Disruption of the natural costimulatory interaction was highly effective for prevention and treatment in several experimental models of autoimmune disease and transplant rejection. This review focuses on the most significant advances in understanding the physiopathological events involving costimulatory molecules, and their impact on renal diseases and transplantation. 相似文献
89.
Berruti A Dogliotti L Terrone C Cerutti S Isaia G Tarabuzzi R Reimondo G Mari M Ardissone P De Luca S Fasolis G Fontana D Rossetti SR Angeli A;Gruppo Onco Urologico Piemontese 《The Journal of urology》2002,167(6):2361-2367
PURPOSE: We characterize the consequences of androgen deprivation therapy on body composition in elderly men. MATERIALS AND METHODS: Using a dual energy x-ray absorptiometry instrument, we determined the changes in bone mineral density, bone mineral content, fat body mass and lean body mass in 35 patients with prostate cancer without bone metastases who received luteinizing hormone releasing hormone analogue for 12 months. RESULTS: At baseline conditions 46% of cases were classified as osteopenic and 14% as osteoporotic at the lumbar spine and 40% were osteopenic and 4% osteoporotic at the hip. Androgen deprivation significantly decreased bone mineral density either at the lumbar spine (mean gm./cm.2 [SD] 1.00 [0.194], 0.986 [0.172] and 0.977 [0.182] at baseline, and 6 and 12 months, respectively, p <0.002) or the hip (0.929 [0.136], 0.926 [0.144] and 0.923 [0.138], p <0.03). A more than 2% decrease in bone mineral density was found at the lumbar spine in 19 men (54.3%) and at the hip in 15 (42.9%). Bone mineral content paralleled the bone mineral density pattern. Lean body mass decreased (mean gm. [SD] 50,287 [6,656], 49,296 [6,554] and 49,327 [6,345], p <0.003), whereas fat body mass consistently increased (18,115 [6,209], 20,724 [6,029] and 21,604 [5,923] p <0.001). CONCLUSIONS: Serial bone densitometry evaluation during androgen deprivation therapy may allow the detection of patients with prostate cancer at risk for osteoporotic fractures, that is those with osteopenia or osteoporosis at baseline and fast bone loss. The change in body composition may predispose patients to accidental falls, thus increasing the risk of bone fracture. 相似文献
90.
Maiuri F Stella L Sardo L Buonamassa S 《Archives of orthopaedic and trauma surgery》2002,122(4):245-247
Hypertrophic anterior cervical osteophytes have been reported as a cause of dysphagia, with about 100 cases described in the literature; on the other hand, chronic or acute dyspnea due to edema of the laryngeal inlet or bilateral vocal cord adduction-fixation is rare. We report a 57-year-old patient with a 2-year history of dysphagia and episodic dyspnea, who suffered sudden, severe respiratory distress necessitating emergency tracheotomy. A voluminous anterior cervical osteophyte at the C5 level was diagnosed by computed tomography (CT) and barium swallow test and removed by an anterior approach to the cervical spine, with clinical remission. The incidence, pathogenetic mechanisms, radiological diagnosis, and surgical indications of anterior cervical osteophytes associated with dysphagia and dyspnea are discussed. We advise examining cervical spine patients with dysphagia and/or dyspnea by radiography and CT when other investigations are not conclusive for a digestive or respiratory pathology. 相似文献