全文获取类型
收费全文 | 4619篇 |
免费 | 240篇 |
国内免费 | 38篇 |
专业分类
耳鼻咽喉 | 61篇 |
儿科学 | 211篇 |
妇产科学 | 160篇 |
基础医学 | 435篇 |
口腔科学 | 212篇 |
临床医学 | 359篇 |
内科学 | 1040篇 |
皮肤病学 | 90篇 |
神经病学 | 293篇 |
特种医学 | 99篇 |
外科学 | 646篇 |
综合类 | 247篇 |
一般理论 | 18篇 |
预防医学 | 221篇 |
眼科学 | 148篇 |
药学 | 370篇 |
中国医学 | 82篇 |
肿瘤学 | 205篇 |
出版年
2024年 | 3篇 |
2023年 | 40篇 |
2022年 | 157篇 |
2021年 | 253篇 |
2020年 | 114篇 |
2019年 | 143篇 |
2018年 | 191篇 |
2017年 | 93篇 |
2016年 | 114篇 |
2015年 | 181篇 |
2014年 | 193篇 |
2013年 | 236篇 |
2012年 | 343篇 |
2011年 | 414篇 |
2010年 | 211篇 |
2009年 | 191篇 |
2008年 | 297篇 |
2007年 | 236篇 |
2006年 | 258篇 |
2005年 | 243篇 |
2004年 | 219篇 |
2003年 | 173篇 |
2002年 | 199篇 |
2001年 | 45篇 |
2000年 | 17篇 |
1999年 | 38篇 |
1998年 | 31篇 |
1997年 | 26篇 |
1996年 | 23篇 |
1995年 | 14篇 |
1994年 | 17篇 |
1993年 | 12篇 |
1992年 | 17篇 |
1991年 | 15篇 |
1990年 | 15篇 |
1989年 | 18篇 |
1988年 | 11篇 |
1987年 | 8篇 |
1986年 | 12篇 |
1985年 | 4篇 |
1984年 | 6篇 |
1983年 | 8篇 |
1982年 | 12篇 |
1981年 | 10篇 |
1980年 | 7篇 |
1979年 | 2篇 |
1978年 | 7篇 |
1977年 | 5篇 |
1976年 | 9篇 |
1974年 | 3篇 |
排序方式: 共有4897条查询结果,搜索用时 15 毫秒
1.
Objectives
Iatrogenic injury of the Profunda Femoris Artery (PFA) at time of hip fixation surgery can increase morbidity and mortality and prolong the hospital stay. This is an injury that tends to pass unnoticed as a cause of postoperative deterioration despite being frequently reported in the literature. Our study aims to describe the anatomy of the PFA in relation to the medial femoral cortex with specific emphasis on its orientation relative to the position of a sliding hip screw side plate construct. By doing so we are able to present clear guidance to orthopaedic surgeons on how to avoid iatrogenic PFA injury at the time of hip fracture fixation.Methods
Using Computed Tomography Angiographic (CTA) studies, the course of the PFA in relation to the medial femoral cortex was traced in 44 patients (28 males and 16 females) with mean age of 65.6 years. Coronal and axial CT sections were cross-linked to specify the position of the PFA at 1?cm intervals.Results
The course of the artery could be divided into three parts relative to a fixed reference point. Proximal and distal parts of the artery were in a safer position in comparison to the middle part of the artery that was found very close to the femoral cortex and along the coronal axis of the femur (mean angle 2.9° from the femoral coronal axis and 13.8?mm from the medial femoral cortex). Using the commercially available side plate constructs, this part of the artery corresponded to the distal part of the plate (third and fourth holes).Conclusion
Special attention needs to be practiced by the operating surgeon while drilling into the third and fourth holes of the side plate. 相似文献2.
INTRODUCTIONThemicrotubule-associatedprotein蚲ishyperphos-phorylatedandglycosylatedinAlzheimerdisease(AD),andtheseabnormalmodificationsformedthebasisofprogressivelyretrogradeneurofibrillarydegenerationseeninADbrainandtherebythedementia(1,2).ADab-normallyphosphorylated蚲notonlyismicrotubuleas-semblyincompetent,butalsoinhibitsassemblyanddis-assemblesthepreassembledmicrotubulesinvitro(3).Inthetangle-bearingneuronsinADbrain,thenormalcytoskeletonisdisruptedandreplacedwi… 相似文献
3.
4.
M. Perwaiz Iqbal M. Khalid Ashfaq Sarfaraz K. Niazi M. Mahboobali Khalid N. Khawaja 《Biopharmaceutics & drug disposition》1994,15(2):173-177
Pharmacokinetic parameters of two antifolates, trimethoprim and aditoprim, were studied in buffalo calves. The elimination half-life of aditoprim (6.14 h) was nearly twice as long as that of trimethoprim (3.08 h) and compares well with values observed in heifers. This longer half-life of aditoprim is a result of its much larger distribution volume (four to five times larger) because the clearance of aditoprim was about twice as high as that of trimethoprim. The longer half-life of aditoprim is expected to give a longer duration of in vivo bacteriostatic activity than that of trimethoprim. 相似文献
5.
6.
Khalid Irshad Samuel Millar Raj Velu Allan W Reid Edward B Diethrich Donald B Reid 《Journal of endovascular therapy》2007,14(2):198-207
PURPOSE: To report early clinical experience with virtual histology intravascular ultrasound (VH IVUS) in carotid endoluminal repair. TECHNIQUE: A 2.9-F, 20-MHz catheter that utilizes computer software to demonstrate the histological components of arteriosclerotic plaque was evaluated during carotid angioplasty and stenting. VH IVUS images were created following a pullback through the carotid stenosis and produced a color-coded map of the different histological constituents of the disease (dark green: fibrous, yellow/green: fibrofatty, white: calcified, and red: necrotic lipid core plaque). CONCLUSION: VH IVUS produces a color-coded map of the different histological components of artery plaque. It has the potential to predict how the plaque is likely to behave at the moment of endoluminal treatment. 相似文献
7.
Ahmed M. Abu El-Asrar Eman S. Kahtani Khalid F. Tabbara 《Documenta ophthalmologica. Advances in ophthalmology》1995,89(4):313-320
In this report we describe, herewith, a patient with primary pigmentary dystrophy of the retina (retinitis pigmentosa) associated with unilateral retinal arteriovenous communication and exudative retinal detachment. The patient had complete resolution of the retinal detachment following laser photocoagulation treatment. Such association has not been previously reported. 相似文献
8.
Evolution of Vascular Access 总被引:1,自引:0,他引:1
9.
Steven R. Alexander Gerald S. Arbus Khalid M. H. Butt Susan Conley Richard N. Fine Ira Greifer Alan B. Gruskin William E. Harmon Paul T. McEnery Thomas E. Nevins Nadia Nogueira Oscar Salvatierra Jr Amir Tejani 《Pediatric nephrology (Berlin, Germany)》1990,4(5):542-553
This report of the North American Pediatric Transplant Cooperative Study summarizes data contributed by 57 participating centers on 754 children with 761 transplants from 1 January 1989 to 16 February 1989. Data collection was initiated in October 1987 and follow-up of all patients is ongoing. Transplant frequency increased with age; 24% of the patients were less than 5 years, with 7% being under 2 years. Common frequent diagnoses were: aplastic/dysplastic kidneys (18%), obstructive uropathy (16%), and focal segmental glomerulosclerosis (12%). Preemptive transplant, i.e., transplantation without prior maintenance dialysis, was performed in 21% of the patients. Dialytic modalities pretransplant were peritoneal dialysis in 42% and hemodialysis in 25%. Bilateral nephrectomy was reported in 29%. Live-donor sources accounted for 42% of the transplants. Among cadaveric donors, 41% of the donors were under 11 years old. During the first post-transplant month, maintenance therapy was used similarly for live-donor and cadaver source transplants, with prednisone, cyclosporine, and azathioprine used in 93%, 83%, and 81%, respectively. Triple therapy with prednisone, cyclosporine, and azathioprine was used in 78%, 75%, and 75% of functioning cadaver source transplants at 6 months, 12 months, and 18 months as opposed to 60%, 63%, and 54% for live-donor procedures, with single-drug therapy being uncommon. Rehospitalization during months 1–5 occurred in 62% of the patients, with treatment of rejection and infection being the main causes. Additionally, 9% were hospitalized for hypertension. During months 6–12 and 12–17, 30% and 28% of the patients with functioning grafts were rehospitalized. Times to first rejection differed significantly for cadaver and live-donor transplants. The median time to the first rejection was 36 days for cadaver transplants and 156 days for live-donor transplants. Overall, 57% of treated rejections were completely reversible although the complete reversal rate decreased to 37% for four or more rejections. One hundred and fifty-two graft failures had occurred at the time of writing, with a 1-year graft survival estimate of 0.88 for live-donor and 0.71 for cadaver source transplants. In addition to donor source, recipient age is a significant prognostic factor for graft survival. Among cadaver donors, decreasing donor age is associated with a decreasing probability of graft survival. Thirty-five deaths have occurred; 16 attributed to infection and 19 to other causes. The current 1-year survival estimate is 0.94. There have been 9 malignancies.A list of all participating centers and the names of the investigators is printed on pages 552–553 相似文献
10.
Khalid Ahmed AL-ANAZI Asma Marzouq AL-JASSER David Alan Price EVANS Nasr Abu DAFF 《Asia-Pacific Journal of Clinical Oncology》2006,2(2):91-97
Background: Surgical intervention in patients with malignant hematological disorders is a major undertaking due to the expected risks of bleeding, infection and poor wound healing. Methods and materials: A retrospective study of patients treated at the Riyadh Armed Forces Hospital, Saudi Arabia between January 1991 and December 2002 was conducted. The results of patients with acute leukemia and lymphoma who underwent surgical procedures (study group) were compared with those of a control group composed of patients with the same spectrum of disorders treated over the same period of time and given the same treatment protocols but never required any surgery. Results: No single death occurred intraoperatively or in the immediate postoperative period due to surgical therapy per se. However, follow up of both groups of patients revealed a shorter long‐term survival and higher rates of relapse and severe invasive infections in the surgical group compared to the control group of patients. The mean survival for the study group was 1871 ± 307 days versus 3094 ± 279 days for the control group of patients (P = 0.0027). Thirty (75%) study patients suffered relapses of their malignant hematological disorders versus 23 (37.1%) control patients. Forty‐five relapses were encountered in the study group of patients (1.5 relapses per relapsed patient) versus 26 relapses in the control group (1.13 relapses per relapsed patient). Various infections occurred in 37 (92.5%) study patients and 32 (51.6%) control patients. Recurrent infections developed in 30 (75%) study patients and 22 (35.5%) control patients (P = 0.00008). Infections causing tissue invasion were encountered in 29 (72.5%) study patients and 22 (35.5%) control patients. Conclusion: Even major surgical procedures can be performed in patients with leukemia or lymphoma provided enough preparatory measures are made to minimize bleeding and infectious complications. Surgery may, however, be associated with long‐term complications such as a high incidence of relapse of the primary malignant hematological disorder and an increased rate of severe and invasive infections. 相似文献