全文获取类型
收费全文 | 4159篇 |
免费 | 207篇 |
国内免费 | 45篇 |
专业分类
耳鼻咽喉 | 43篇 |
儿科学 | 47篇 |
妇产科学 | 158篇 |
基础医学 | 443篇 |
口腔科学 | 113篇 |
临床医学 | 335篇 |
内科学 | 977篇 |
皮肤病学 | 81篇 |
神经病学 | 339篇 |
特种医学 | 157篇 |
外科学 | 893篇 |
综合类 | 28篇 |
预防医学 | 182篇 |
眼科学 | 167篇 |
药学 | 191篇 |
中国医学 | 2篇 |
肿瘤学 | 255篇 |
出版年
2023年 | 37篇 |
2022年 | 86篇 |
2021年 | 134篇 |
2020年 | 80篇 |
2019年 | 109篇 |
2018年 | 152篇 |
2017年 | 111篇 |
2016年 | 116篇 |
2015年 | 143篇 |
2014年 | 171篇 |
2013年 | 235篇 |
2012年 | 328篇 |
2011年 | 333篇 |
2010年 | 178篇 |
2009年 | 187篇 |
2008年 | 339篇 |
2007年 | 334篇 |
2006年 | 280篇 |
2005年 | 240篇 |
2004年 | 207篇 |
2003年 | 139篇 |
2002年 | 141篇 |
2001年 | 45篇 |
2000年 | 37篇 |
1999年 | 31篇 |
1998年 | 33篇 |
1997年 | 21篇 |
1996年 | 22篇 |
1995年 | 16篇 |
1994年 | 12篇 |
1993年 | 5篇 |
1992年 | 11篇 |
1991年 | 8篇 |
1990年 | 11篇 |
1989年 | 4篇 |
1988年 | 8篇 |
1987年 | 10篇 |
1986年 | 3篇 |
1985年 | 8篇 |
1984年 | 7篇 |
1983年 | 5篇 |
1982年 | 8篇 |
1981年 | 2篇 |
1980年 | 2篇 |
1978年 | 4篇 |
1977年 | 2篇 |
1976年 | 4篇 |
1975年 | 2篇 |
1964年 | 3篇 |
1963年 | 2篇 |
排序方式: 共有4411条查询结果,搜索用时 31 毫秒
31.
32.
T M Sartori P G Maurizio P Sara L Ugolino A Annalisa T Panagiotis F Massimo G Antonio 《The Journal of heart and lung transplantation》1999,18(7):693-700
BACKGROUND: Thrombotic complications and transplant coronary artery disease are among the main causes of morbidity and mortality after heart transplantation. A thrombophilic state has been described in transplant recipients, and correlated to immunosuppressive therapy with cyclosporine A or azathioprine, whereas the prothrombotic effects of steroids, even though always given, have never been duly considered. A reduced fibrinolytic capacity due to high levels of PAI-1, the most important inhibitor of plasminogen activators, was suggested to play a role in the development of cardiovascular diseases and transplant coronary artery disease. A severe hypofibrinolytic state secondary to PAI-1 increase has been found in patients with Cushing's disease, and in hypercorticism secondary to long-term steroid treatment after renal transplantation. METHODS: We evaluated plasma clotting and fibrinolytic behaviors in 2 groups of heart transplant patients treated with (26 cases) or without (23 cases) steroids together with cyclosporine A and azathioprine. Twenty-five healthy subjects were studied as normal controls. The following tests were assayed at least 1 year after transplantation: fibrinogen, factor VIII coagulant activity, von Willebrand factor antigen, euglobulin lysis time, tissue plasminogen activator antigen and activity, PAI-1 antigen and activity. In addition, the presence of cardiac microthrombi was evaluated on 2 endomyocardial biopsy specimens obtained in each patient both on day 7 after heart transplantation (first control) and usually 1 year or more later (last control). RESULTS: Plasma levels of fibrinogen, factor VIII and von Willebrand factor were significantly higher in both groups of patients than in normal controls. Fibrinolytic activity was significantly reduced in transplant patients treated with steroids, compared with steroid-free patients and normal controls. In steroid-treated heart transplant recipients, the hypofibrinolytic state was due to a significant and pathological increase in PAI-1 antigen and activity levels. The fibrinolytic impairment was more evident in patients transplanted for ischemic heart disease and treated with steroids than in patients with previous dilated cardiomyopathy and treated either with or without steroids. Myocardial microthrombi were found in 2/49 cases at the first biopsy control, and in 12/49 cases at the last biopsy control after transplantation. This different prevalence was statistically significant (chi2 = 8.33, p = .003). Plasma PAI-1 activity was significantly higher and, as a consequence, euglobulin lysis time was more prolonged in microthrombi-positive patients than in microthrombi-negative ones. Among the 12 transplant recipients who developed cardiac microthrombi, 7 patients were treated with steroids and showed higher PAI-1 levels and more reduced fibrinolytic activity than the 5 steroid-free patients. CONCLUSIONS: Our data confirm the prothrombotic state induced by long-term steroid treatment, characterized by an increase in PAI-1 levels and secondary impairment of fibrinolytic capacity. In heart transplant patients, steroid-related hypofibrinolysis might constitute a further risk factor for transplant coronary artery disease. 相似文献
33.
Kekis P Seretis C Lagoudianakis E Gemenetzis G Koronakis N Keramidaris D Manouras I Manouras A 《International journal of surgery case reports》2012,3(7):279-282
INTRODUCTIONAdrenocortical oncocytomas are extremely rare tumors, considered to be non-functional and of low malignant potential. Despite the great advance in laparoscopic techniques, there are extremely limited reports of laparoscopic approach of adrenocortical oncocytomas. Herein is presented a challenging case of laparoscopic approach to a large adrenocortical oncocytoma, underlining the safety and feasibility of laparoscopy in the surgical management of these extremely rare adrenal tumors.PRESENTATION OF CASEA 34 year-old male was referred for surgical evaluation after the incidental discovery of a large right adrenal mass, during ultrasound examination due to renal colic. Further imaging evaluation revealed a well circumscribed capsule around the mass was demonstrated, with no evidence of infiltration of the neoplasm to periadrenal tissues. The patient was scheduled for laparoscopic right adrenalectomy, running an uneventful postoperative period. Histopathology revealed the presence of an adrenal oncocytoma.DISCUSSIONRecent studies have demonstrated that approximately one third of adrenocortical oncocytomas are associated with hormonal hypersecretion, as well as that one fifth of them demonstrate malignant biological behavior. From this point of view, there is emerging evidence in favor of the necessity of surgical excision as the treatment of choice. In spite of the progress of laparoscopic surgery, only three cases of laparoscopic excision of these tumors have been reported up to date.CONCLUSIONLaparoscopic surgery offers a safe alternative in confronting adrenocortical neoplasms, even when the biological behavior of the tumors cannot be pre-operatively evaluated in a definite way. 相似文献
34.
Ten percent of all fractures lead to problems with healing. Smoking is said to be a cause. There are 13.5 million smokers in the U.K. Healing of tibial fractures, for instance, requires two more months in smokers. Nicotine, carbon monoxide and hydrogen cyanide are most often seen as the offenders, among the 4000 chemicals found in cigarettes. Many studies plead for the negative effect of smoking in general, yet there is uncertainty as to the precise role of nicotine. The authors recommend that patients should attempt smoking cessation therapy before elective orthopaedic treatment. 相似文献
35.
The Role of Donor Bone Marrow Infusions in Withdrawal of Immunosuppression in Adult Liver Allotransplantation 总被引:3,自引:0,他引:3
Panagiotis Tryphonopoulos reas G. Tzakis Debbie Weppler Rolando Garcia-Morales Tomoaki Kato Juan R. Madariaga David M. Levi Seigo Nishida Jang Moon Gennaro Selvaggi Arie Regev Caio Nery Pablo Bejarano Amr Khaled Gary Kleiner Violet Esquenazi Joshua Miller Philip Ruiz Camillo Ricordi 《American journal of transplantation》2005,5(3):608-613
We investigated the role of donor bone marrow cell (DBMC) infusions in immunosuppression withdrawal in adult liver transplantation. Patients enrolled were at least 3 years post-transplantation, with stable graft function. Forty-five (study group: G1) received DBMC, and 59 (control group: G2) did not. Immunosuppression was reduced by one third upon enrollment, by another third the second year of the study and was completely withdrawn the third year. Patient and graft survival were similar between the two groups. Although rejection episodes were significantly less in G1 the first 2 years of the study (35% vs. 57%, p = 0.016), there was no significant difference overall (74% vs. 81%, p = 0.14). Until February 2004, 20 patients, 10 in each group, were immunosuppression free for 1-3 years. Approximately 20% of long-term survivors of liver transplantation can successfully discontinue their immunosuppression. DBMC infusions, do not increase this likelihood. 相似文献
36.
Anastasia Antoniou Anastasia Nikolaou Nikolas Evripidou Andreas Georgiou Antria Filippou Vasiliki Zinonos Marinos Giannakou Antreas Chrysanthou Cleanthis Ioannides Christakis Damianou 《The international journal of medical robotics + computer assisted surgery : MRCAS》2023,19(5):e2526
Background
The current study proposes simple methods for assessing the performance of robotic devices intended for Magnetic Resonance Imaging (MRI)-guided needle biopsy.Methods
In-house made agar-based breast phantoms containing biopsy targets served as the main tool in the evaluation process of an MRI compatible positioning device comprising a needle navigator. The motion accuracy of mechanical stages was assessed by calliper measurements. Laboratory evaluation of needle targeting included a repeatability phantom test and a laser-based method. The accuracy and repeatability of needle targeting was also assessed by MRI.Results
The maximum error of linear motion for steps up to 10 mm was 0.1 mm. Needle navigation relative to the phantom and alignment with the various biopsy targets were performed successfully in both the laboratory and MRI settings. The proposed biopsy phantoms offered tissue-like signal in MRI and good haptic feedback during needle insertion.Conclusions
The proposed methods could be valuable in the process of validating the accuracy of MRI-guided biopsy robotic devices in both laboratory and real environments. 相似文献37.
Mo Saffarini Panagiotis G. Ntagiopoulos Guillaume Demey Benoit Le Negaret David H. Dejour 《Knee surgery, sports traumatology, arthroscopy》2014,22(10):2574-2581
Purpose
The design of the trochlear compartment is crucial in patellofemoral arthroplasty (PFA), because 78 % of patients with isolated patellofemoral arthritis present concomitant trochlear dysplasia with patellar maltracking and therefore remain predisposed to post-operative patellar subluxation and dislocation. The study investigated whether current PFA implants are designed with anatomic trochlear parameters such as the sulcus angle, lateral facet height and groove orientation.Methods
Five trochlear components of commercially available PFA implants were scanned, and the generated three-dimensional surfaces were measured using engineering design software. The mediolateral trochlear profiles were plotted at various flexion angles (0°, 15°, 30° and 45°) to deduce the following variables: sulcus angle, height of lateral facet and trochlear groove orientation.Results
Four specimens had sulcus angle >144° in the 45° of flexion, and all five specimens had sulcus angle >143° in 30° of flexion. Three specimens had a facet <5 mm high through the entire range of early flexion (0°–30°), and two specimens had a facet <5 mm high beyond early flexion (30°–45°). The trochlear groove was oriented laterally in all specimens (range 1.6°–13.5°).Conclusion
Current PFA trochlear components are not always designed with anatomic parameters, and some models exhibit characteristics of trochlear dysplasia. Surgeons are therefore advised to implant components with a deep sulcus, particularly in patients with history of patellofemoral disorders, and to adapt the surgical technique and extensor mechanism if the component implanted has a shallow sulcus, to ensure normal patellar tracking.Level of evidence
III. 相似文献38.
OBJECTIVES: Although the short-term results of supracondylar periprosthetic fractures treated with retrograde nailing have been satisfactory, there is always a concern about the long-term survival of the prosthesis. The aim of the study was to evaluate fracture healing and knee functional outcome with a follow-up time of at least 2 years in periprosthetic fractures of the knee treated with a supracondylar nail. DESIGN: Cohort study. PATIENTS: There were 9 patients with 10 periprosthetic fractures. In 1 patient, the fracture occurred intraoperatively. In the others, the time between the total knee arthroplasty and the periprosthetic fracture ranged between 2 weeks and 7 years (average time: 2.78 years). The mean follow-up was 34.5 months (25-52 months). MAIN OUTCOME MEASUREMENTS: The Western Ontario and McMaster Universities index was used to evaluate the functional result postoperatively using the paired t test as the statistical test. Fracture union was assessed with plain x-rays. RESULTS: All the fractures united within 3 months. One fracture united in extreme valgus (35 degrees) and was revised to a stemmed total knee replacement. There were no infections and no prosthesis loosening. The paired t test before the fracture and after the operation demonstrated no statistically significant differences; however, there was a trend toward lower functional score postoperatively. CONCLUSIONS: It appears that retrograde nailing is a reliable technique to treat periprosthetic supracondylar fractures. It provides adequate stability until fracture union. The morbidity of the operation is minimal, and the complication rate is low. The midterm results in our study showed that none of the prostheses required revision. In our opinion, it is the treatment of choice for a periprosthetic fracture when the prosthesis is stable. 相似文献
39.
Omer Burak Argun Panagiotis Mourmouris Ilter Tufek Can Obek Mustafa Bilal Tuna Selcuk Keskin Ali Riza Kural 《JSLS, Journal of the Society of Laparoendoscopic Surgeons》2016,20(2)
Methods:Data on 11 robot-assisted laparoscopic partial nephrectomies performed by using our technique from February 2015 through June 2015 were retrospectively analyzed. The robotic platform used was DaVinci Xi (Intuitive Surgical, Inc., Sunnyvale, California, USA) with a 3-arm setup. The AirSeal system (SurgiQuest, Milford, Connecticut, USA) was used as a port allowing simultaneous introduction of 2 instruments for the bedside surgeon, obviating the need for an additional (fourth) robotic arm. A long suction-and-irrigation device and atraumatic grasping forceps were used. Both instruments were introduced through the trocar of the AirSeal system, making simultaneous introduction and use possible. We preferred the long suction-and-irrigation device, because it minimizes collision of the instruments.Results:Mean age and BMI of the patients were 55 ±14.6 y and 29.18 ± 6.85, respectively. Seven tumors were on the right side and 4 were on the left. The mean size of the tumors was 32.45 mm (± 11.31). Surgical time was 132.2 minutes (±37.17), with an estimated blood loss and ischemia time of 103.63 mL (±65.92) and 16.72 minutes (±9.52), respectively. One patient had postoperative bleeding that was resolved without transfusion. The median hospitalization period was 3.9 d (±0.53). Loss of intra-abdominal pressure was not observed, and pressure was stable at 10 mm Hg.Conclusion:The AirSeal System and its valveless trocar eliminated the need for an additional port placement in our series. The technique is feasible, safe, and reproducible; therefore, it may be implemented in selected cases of robot-assisted partial nephrectomies. 相似文献
40.