全文获取类型
收费全文 | 23318篇 |
免费 | 1249篇 |
国内免费 | 172篇 |
专业分类
耳鼻咽喉 | 327篇 |
儿科学 | 424篇 |
妇产科学 | 542篇 |
基础医学 | 2758篇 |
口腔科学 | 753篇 |
临床医学 | 1847篇 |
内科学 | 6298篇 |
皮肤病学 | 407篇 |
神经病学 | 2309篇 |
特种医学 | 741篇 |
外科学 | 3446篇 |
综合类 | 84篇 |
一般理论 | 9篇 |
预防医学 | 1090篇 |
眼科学 | 309篇 |
药学 | 1566篇 |
1篇 | |
中国医学 | 42篇 |
肿瘤学 | 1786篇 |
出版年
2024年 | 19篇 |
2023年 | 159篇 |
2022年 | 342篇 |
2021年 | 666篇 |
2020年 | 385篇 |
2019年 | 553篇 |
2018年 | 637篇 |
2017年 | 474篇 |
2016年 | 563篇 |
2015年 | 603篇 |
2014年 | 916篇 |
2013年 | 1166篇 |
2012年 | 1800篇 |
2011年 | 1786篇 |
2010年 | 1061篇 |
2009年 | 944篇 |
2008年 | 1627篇 |
2007年 | 1556篇 |
2006年 | 1471篇 |
2005年 | 1477篇 |
2004年 | 1372篇 |
2003年 | 1249篇 |
2002年 | 1149篇 |
2001年 | 157篇 |
2000年 | 155篇 |
1999年 | 178篇 |
1998年 | 189篇 |
1997年 | 183篇 |
1996年 | 180篇 |
1995年 | 160篇 |
1994年 | 132篇 |
1993年 | 123篇 |
1992年 | 109篇 |
1991年 | 70篇 |
1990年 | 89篇 |
1989年 | 71篇 |
1988年 | 81篇 |
1987年 | 79篇 |
1986年 | 64篇 |
1985年 | 67篇 |
1984年 | 75篇 |
1983年 | 74篇 |
1982年 | 71篇 |
1981年 | 61篇 |
1980年 | 58篇 |
1979年 | 34篇 |
1978年 | 41篇 |
1977年 | 27篇 |
1976年 | 22篇 |
1975年 | 18篇 |
排序方式: 共有10000条查询结果,搜索用时 29 毫秒
101.
Immunotherapy I: Cytokine gene transfer strategies 总被引:2,自引:0,他引:2
The cytokine approach to gene therapy of cancer stems from early studies of direct, repeated injection of recombinant cytokines at the tumor site, and extension of the bystander effect that enables a few cytokine gene transduced cells in a tumor to bring about its total destruction. This effect can be extended through the immune system, since cytokine-activated regression of a small mass of tumor cells can afford systemic protection. Transduced cells used as a vaccine provide a local concentration of both cytokine and tumor antigens. Cytokines sustain antigen uptake and presentation by increasing the immunogenic potential of the environment through the recruitment of antigen presenting cells and leukocytes, and activation of a cascade of events which amplify and tone up the efficacy of a vaccine. The promises and difficulties of this approach are discussed by considering what is still missing from experimental studies and what can best be done as soon as possible in animals and humans to reach compelling conclusions. 相似文献
102.
103.
Mario Sanna Abdelkader Taibah Alessandra Russo Maurizio Falcioni Manoj Agarwal 《Otology & neurotology》2004,25(3):379-386
OBJECTIVE: Retrospective study and review of the complications other than those related to the facial nerve and hearing, encountered in acoustic neuroma surgery. Also, an evaluation of hospital stay and its relation with various factors. STUDY DESIGN: Retrospective case review. SETTING: Tertiary neurotologic and skull base referral center. PATIENTS: A series of 707 patients who underwent surgical removal of acoustic neuroma from April 1987 to December 2001. INTERVENTIONS: The surgical approaches used were the enlarged translabyrinthine approach, the enlarged middle fossa approach, and the retrosigmoid approach. In a small number of cases, the operations were performed through other approaches. MAIN OUTCOME MEASURES: The duration of hospital stay and appearance of complications in the perioperative period along with their management. Results related to the facial nerve and hearing were not considered in this study. RESULTS: The most frequent complication was abdominal subcutaneous hematoma (site of fat harvest), which occurred in 23 patients (3.2%). Cerebrospinal fluid leak was present in 20 patients (2.8%), 15 of whom needed revision surgery. Other complications included VIth cranial nerve dysfunction in 12 cases (1.68%), subdural hematoma in 3 cases (0.4%), cerebellopontine angle hematoma in 4 cases (0.6%), cerebellar edema in 2 cases (0.28%), brainstem hematoma in 1 case (0.14%), transitory aphasia in 1 case (0.14%), and lower cranial nerve dysfunction in 1 case (0.14%). Mortality occurred in only one case (0.14%). Medical complications seldom occurred. The postoperative hospital stay ranged from 2 to 36 days, with an average of 6.4 days. The overall hospital stay diminished over time from 10.2 days in 1987 to 1990, to 4.9 days in 2001. There was a significant relation between hospital stay and tumor size, approach used, and presence/absence of complications. CONCLUSIONS: Perioperative complications in acoustic neuroma surgery do exist, but this study demonstrated how low the incidence is. The authors believe that the low percentage of complications is mainly attributable to the majority of operations being carried out in specialized clinics, where they are considered routine operations. They believe that following individualized approaches, depending on tumor size and on the preoperative function of the cranial nerves, is the proper way to reach a significant reduction in complications while maintaining a high percentage of total tumor removal. The results of this study, considered as a basis of comparison with other studies, will certainly be useful in preoperative patient counseling. 相似文献
104.
Mario Sanna Yogesh Jain Giuseppe De Donato Lorenzo RohitLauda Abdelkader Taibah 《Otology & neurotology》2004,25(5):797-804
OBJECTIVE: The objective of this study was to review the outcome of surgical management in patients of jugular paragangliomas. STUDY DESIGN: We conducted a retrospective case review. SETTING: Tertiary care otology and skull base center. MATERIALS AND METHODS: Fifty-five patients with the diagnosis of a jugular paraganglioma (Fisch Class C and D Glomus Jugulare) were managed over a period of 15 years. All patients with adequate follow up and complete records (53 cases) were reviewed with emphasis on the results of surgical management and the factors influencing them. INTERVENTION: All 53 patients were managed with a view to surgically extirpate the tumor. The primary approach was the infratemporal fossa approach-Type A used in the majority of the patients. In eight cases, the procedure was staged owing to the presence of large intracranial extension. Three patients required additional procedures to ameliorate the after-effects of lower cranial nerve resection. RESULTS: Gross total tumor removal was achieved in 49 patients. There were five cases of recurrence. Coupled with the residual tumors in five patients, the surgical control achieved was 83%. There was no perioperative mortality. There were two cases of postoperative cerebrospinal fluid leak, both of which required surgical exploration and closure. The facial nerve was resected in seven patients. The overall preservation rate of clinically uninvolved lower cranial nerves was 75%. CONCLUSIONS: The low level of complications along with a high surgical control achieved makes surgery the primary mode of treatment in the vast majority of these tumors, regardless of the size and location. 相似文献
105.
Mario Sanna Paolo Piazza Giuseppe Ditrapani Manoj Agarwal 《Otology & neurotology》2004,25(6):998-1005
OBJECTIVE: To present our experience with permanent preoperative balloon occlusion of the internal carotid artery while dealing with different abnormalities of the lateral skull base and a comparison with the results mentioned in the literature. STUDY DESIGN: Retrospective case review. SETTING: Private neurotologic and skull base tertiary referral center. PATIENTS: Fifteen patients who underwent preoperative balloon occlusion of the internal carotid artery and surgery subsequently for various abnormalities of the lateral skull base between 1989 and 2002. INTERVENTIONS: Each patient was subjected to four-vessel angiography along with the manual cross-compression test and balloon test occlusion to assess the efficacy of the collateral circulation. After angiography, each patient underwent a preoperative balloon occlusion, after which a lateral skull base procedure was performed for removal of the abnormality. MAIN OUTCOME MEASURES: Only those patients showing evidence of adequate collateral cerebral circulation and a less than 1-second delay between the angiographic phases of the two cerebral hemispheres on angiography were considered fit for preoperative balloon occlusion. While under going the preoperative balloon occlusion, the patients were clinically assessed for the development of any neurologic symptoms and signs. Long-term follow-up after surgery was also based on the development of symptoms and signs of neurovascular compromise. RESULTS: A major complication in the form of long-lasting hemiplegia occurred in one patient (6.7%). This complication was the result of technical factors rather than an effect of cerebral ischemia, because it was caused by an intimal dissection produced by the catheter. A defect in the visual field occurred in one patient (6.7%) that resolved partially after antiplatelet therapy. There was no mortality in our series related to preoperative balloon occlusion of the internal carotid artery. CONCLUSION: Preoperative balloon occlusion of the internal carotid artery can still be considered a viable option for the management of the internal carotid artery during lateral skull base surgery. Proper preoperative evaluation of the adequacy and efficacy of the collateral cerebral circulation reduces the chances of postoperative neurovascular complications. 相似文献
106.
Palmiero Monteleone Michele Fabrazzo Mario Maj 《Neuropsychopharmacology》2005,30(9):1769; author reply 1770-1769; author reply 1771
107.
Outcome after major renovascular injuries: a Western trauma association multicenter report 总被引:4,自引:0,他引:4
Knudson MM Harrison PB Hoyt DB Shatz DV Zietlow SP Bergstein JM Mario LA McAninch JW 《The Journal of trauma》2000,49(6):1116-1122
BACKGROUND: Major renal vascular injuries are uncommon and are frequently associated with a poor outcome. In addition to renal dysfunction, posttraumatic renovascular hypertension may result, although the true incidence of this complication is unknown. The objective of this study was to describe the factors contributing to outcome after major renovascular trauma. We hypothesized that the highest percentage of renal salvage would be achieved by minimizing the time from injury to repair. METHODS: This was a retrospective chart review over a 16-year period conducted at six university trauma centers of patients with American Association for the Surgery of Trauma grade IV/V renal injuries surviving longer than 24 hours. Postinjury renal function with poor outcome was defined as renal failure requiring dialysis, serum creatinine greater than or equal to 2 mg/dL, renal scan showing less than 25% function of the injured kidney, postinjury hypertension requiring treatment, or delayed nephrectomy. Data collected for analysis included demographics, mechanism of injury, presence of shock, presence of hematuria, associated injuries, type of renal injury (major artery, renal vein, segmental artery), type of repair (primary vascular repair, revascularization, observation, nephrectomy), time from injury to definitive renal surgery, and type of surgeon performing the operation (urologist, vascular surgeon, trauma surgeon). RESULTS: Eighty-nine patients met inclusion criteria; 49% were injured from blunt mechanisms. Patients with blunt injuries were 2.29 times more likely to have a poor outcome compared with those with penetrating injuries. Similarly, the odds ratio of having a poor outcome with a grade V injury (n = 32) versus grade IV (n = 57) was 2.2 (p = 0.085). Arterial repairs had significantly worse outcomes than vein repairs (p = 0.005). Neither the time to definitive surgery nor the operating surgeon's specialty significantly affected outcome. Ten percent (nine patients) developed hypertension or renal failure postoperatively: three had immediate nephrectomies, four had arterial repairs with one intraoperative failure requiring nephrectomy, and two were observed. Of the 20 good outcomes for grade V injuries, 15 had immediate nephrectomy, 1 had a renal artery repair, 1 had a bypass graft, 1 underwent a partial nephrectomy, and 2 were observed. CONCLUSION: Factors associated with a poor outcome following renovascular injuries include blunt trauma, the presence of a grade V injury, and an attempted arterial repair. Patients with blunt major vascular injuries (grade V) are likely to have associated major parenchymal disruption, which contributes to the poor function of the revascularized kidney. These patients may be best served by immediate nephrectomy, provided that there is a functioning contralateral kidney. 相似文献
108.
Dipesh E. Patel Phillippa M. Cumberland Bronwen C. Walters Joseph Abbott John Brookes Beth Edmunds Peng Tee Khaw Ian Christopher Lloyd Maria Papadopoulos Velota Sung Mario Cortina-Borja Jugnoo S. Rahi For the OPTIC Study Group 《Eye (London, England)》2022,36(6):1281
BackgroundPerimetry is important in the management of children with glaucoma, but there is limited evidence-based guidance on its use. We report an expert consensus-based study to update guidance and identify areas requiring further research.MethodsExperts were invited to participate in a modified Delphi consensus process. Panel selection was based on clinical experience of managing children with glaucoma and UK-based training to minimise diversity of view due to healthcare setting. Questionnaires were delivered electronically, and analysed to establish ‘agreement’. Divergence of opinions was investigated and resolved where possible through further iterations.Results7/9 experts invited agreed to participate. Consensus (≥5/7 (71%) in agreement) was achieved for 21/26 (80.8%) items in 2 rounds, generating recommendations to start perimetry from approximately 7 years of age (IQR: 6.75–7.25), and use qualitative methods in conjunction with automated reliability indices to assess test quality. There was a lack of agreement about defining progressive visual field (VF) loss and methods for implementing perimetry longitudinally.Panel members highlighted the importance of informing decisions based upon individual circumstances—from gauging maturity/capability when selecting tests and interpreting outcomes, to accounting for specific clinical features (e.g. poor IOP control and/or suspected progressive VF loss) when making decisions about frequency of testing.ConclusionsThere is commonality of expert views in relation to implementing perimetry and interpreting test quality in the management of children with glaucoma. However, there remains a lack of agreement about defining progressive VF loss, and utilising perimetry over an individuals’ lifetime, highlighting the need for further research.Subject terms: Paediatrics, Glaucoma 相似文献
109.
Debora Soncini Claudia Martinuzzi Pamela Becherini Elisa Gelli Samantha Ruberti Katia Todoerti Luca Mastracci Paola Contini Antonia Cagnetta Antonella Laudisi Fabio Guolo Paola Minetto Maurizio Miglino Sara Aquino Riccardo Varaldo Daniele Reverberi Matteo Formica Mario Passalacqua Alessio Nencioni Antonino Neri Mehmet K. Samur Nikhil C. Munshi Mariateresa Fulciniti Roberto M. Lemoli Michele Cea. 《Haematologica》2022,107(6):1410
110.
Francisco Esparza-Ros Ana Catarina Moreira Raquel Vaquero-Cristbal Carlos Barrigas Mario Albaladejo-Saura Filomena Vieira 《Nutrients》2022,14(10)
Background: The aim of this study was to analyze the validity of four different skinfold calipers, as well as to establish the differences between them in a healthy young adult population. Methods: The present study followed a cross-sectional design, including 138 participants, with 69 males (21.46 ± 2.52 years) and 69 females (22.19 ± 2.85 years). The measurement protocol included basic measurements of body mass and stretch stature and eight skinfolds with a Harpenden, Holtain, Slim Guide, and Lipowise. The ∑6 and ∑8 skinfolds and fat mass were calculated. The order in which the skinfold calipers were used was randomized. Results: No significant differences were found in either the Σ6 and Σ8 skinfolds or masses and fat percentages calculated with the skinfolds obtained with the different calipers (p > 0.05), and the inclusion of the covariates of sex, BMI, and hydration status of the participants showed no effect on the differences. The Bland–Altman test showed significant differences between the calipers (p < 0.001). Conclusion: It has been observed that the analyzed calipers have shown validity for the assessment of adiposity-related variables in a male and female sample of non-overweight, young healthy adults, but they are not interchangeable with each other when the assessment is meant to be compared over time or with other samples. 相似文献