全文获取类型
收费全文 | 6570篇 |
免费 | 273篇 |
国内免费 | 29篇 |
专业分类
耳鼻咽喉 | 136篇 |
儿科学 | 279篇 |
妇产科学 | 263篇 |
基础医学 | 844篇 |
口腔科学 | 83篇 |
临床医学 | 465篇 |
内科学 | 1536篇 |
皮肤病学 | 111篇 |
神经病学 | 492篇 |
特种医学 | 124篇 |
外科学 | 471篇 |
综合类 | 315篇 |
一般理论 | 1篇 |
预防医学 | 491篇 |
眼科学 | 186篇 |
药学 | 642篇 |
1篇 | |
中国医学 | 11篇 |
肿瘤学 | 421篇 |
出版年
2024年 | 7篇 |
2023年 | 46篇 |
2022年 | 158篇 |
2021年 | 249篇 |
2020年 | 101篇 |
2019年 | 124篇 |
2018年 | 147篇 |
2017年 | 139篇 |
2016年 | 161篇 |
2015年 | 179篇 |
2014年 | 241篇 |
2013年 | 290篇 |
2012年 | 455篇 |
2011年 | 499篇 |
2010年 | 317篇 |
2009年 | 249篇 |
2008年 | 383篇 |
2007年 | 467篇 |
2006年 | 443篇 |
2005年 | 415篇 |
2004年 | 443篇 |
2003年 | 384篇 |
2002年 | 352篇 |
2001年 | 47篇 |
2000年 | 35篇 |
1999年 | 39篇 |
1998年 | 58篇 |
1997年 | 61篇 |
1996年 | 48篇 |
1995年 | 42篇 |
1994年 | 31篇 |
1993年 | 16篇 |
1992年 | 20篇 |
1991年 | 12篇 |
1990年 | 7篇 |
1989年 | 15篇 |
1988年 | 13篇 |
1987年 | 13篇 |
1986年 | 14篇 |
1985年 | 13篇 |
1984年 | 14篇 |
1983年 | 13篇 |
1982年 | 18篇 |
1981年 | 15篇 |
1980年 | 9篇 |
1978年 | 10篇 |
1977年 | 8篇 |
1976年 | 8篇 |
1975年 | 9篇 |
1974年 | 9篇 |
排序方式: 共有6872条查询结果,搜索用时 15 毫秒
41.
Madziarska K Weyde W Krajewska M Zukowska Szczechowska E Gosek K Penar J Klak R Golebiowski T Kozyra C Klinger M 《International urology and nephrology》2012,44(3):955-961
Purpose
To assess factors influencing the long-term survival of elderly dialysis patients.Methods
The study group consisted of 51 prevalent dialysis patients aged over 70?years (32 F and 19?M, all caucasians), who had been on a chronic hemodialysis (27) or peritoneal dialysis program (24) for at least 2?months; median age was 77?years, median time on dialysis before inclusion was 16?months, and median residual diuresis was 600?ml. The patients were prospectively followed up to 4?years, and an analysis of factors affecting survival was performed.Results
Thirteen patients from the initial cohort of 51 (25.5?%) survived the whole 48-month observation period: 10 HD patients (37?%) and 3 PD patients (12.5?%). Annual mortality rate was 28.2?%: 37.4?% on PD vs. 20.9?% on HD. The dialysis modality had a significant impact on patients?? survival (p?=?0.049; Cox F-test). The independent mortality risk factors in the Cox proportional hazard regression model were higher plasma pro-atrial natriuretic peptide (pro-ANP) (p?=?0.006), lower residual diuresis (p?=?0.048), and lower systolic blood pressure (BP) value (p?=?0.039).Conclusions
Paramount for the survival of the elderly on dialysis is adequate extracellular volume control. Residual renal function is a protective factor for the survival of elderly HD patients. This observation is novel, not previously reported in an elderly dialysis population. 相似文献42.
43.
In advanced uremia, parathyroid hormone (PTH) levels should be controlled at a moderately elevated level in order to promote normal bone turnover. As such, a certain degree of parathyroid hyperplasia has to be accepted. Uremia is associated with parathyroid growth. In experimental studies, proliferation of the parathyroid cells is induced by uremia and further promoted by hypocalcemia, phosphorus retention, and vitamin D deficiency. On the other hand, parathyroid cell proliferation might be arrested by treatment with a low-phosphate diet, vitamin D analogs, or calcimimetics. When established, parathyroid hyperplasia is poorly reversible. There exists no convincing evidence of programmed parathyroid cell death or apoptosis in hyperplastic parathyroid tissue or of involution of parathyroid hyperplasia. However, even considerable parathyroid hyperplasia can be controlled when the functional demand for increased PTH levels is removed by normalization of kidney function. Today, secondary hyperparathyroidism can be controlled in patients with long-term uremia in whom considerable parathyroid hyperplasia is to be expected. PTH levels can be suppressed in most uremic patients and this suppression can be maintained by continuous treatment with phosphate binders, vitamin D analogs, or calcimimetics. Thus modern therapy permits controlled development of parathyroid growth. When nonsuppressible secondary hyperparathyroidism is present, nodular hyperplasia with suppressed expression of the calcium-sensing receptor (CaR) and vitamin D receptor (VDR) has been found in most cases. An altered expression of some autocrine/paracrine factors has been demonstrated in the nodules. The altered quality of the parathyroid mass, and not only the increased parathyroid mass per se, might be responsible for uncontrollable hyperparathyroidism in uremia and after kidney transplantation. 相似文献
44.
Background
Even though there are several region-specific functional outcome questionnaires measuring neck disorders that have been developed in English-speaking countries, no Polish version has ever been validated. The purpose of our study was to translate, culturally adapt and validate the Neck Disability Index (NDI) and Copenhagen Neck Functional Disability Scale (CDS) for Polish-speaking patients with neck pain. 相似文献45.
Background:
The treatment of displaced intracapsular femoral neck fracture is still an unsolved problem. Non-union and avascular necrosis are the two main complications of this fracture, especially if patient presents late. Muscle pedicle bone grafting has been advocated to provide additional blood supply. We present analysis of our 32 cases of displaced femoral neck fracture treated by internal fixation and quadratus femoris based muscle pedicle bone grafting.Materials and Methods:
Open reduction and internal fixation with muscle pedicle grafting was done in 32 patients. The age of patients varied from 14-62 years (average age 45 years) with male to female ratio of 13:3. Twenty-nine fractures were more than three weeks old. All the cases were treated by Meyers'' procedure. The fracture was internally fixed after open reduction and then a muscle pedicle graft was applied. It was supplemented by cancellous bone graft in seven cases. Fixation was done by parallel cancellous lag screws (n = 19), crossed Garden''s screws (n = 7), parallel Asnis screws (n = 5) and Moore''s pin (n = 1).Quadratus femoris muscle pedicle graft was used in 32 cases. In the initial 12 cases the graft was fixed with circumferential proline sutures, but later, to provide a secure fixation, the graft was fixed with a cancellous screw (n = 20). Postoperative full weight bearing was deferred to an average of 10 weeks.Results:
Union was achieved in 26/29 (89.65%) cases which could be followed for an average period of 3.4 years, (2-8.5 years) with good functional results and had the ability to squat and sit cross-legged. Results were based on hip rating system given by Salvatti and Wilson. The results were excellent in 15 cases, good in four cases, fair in four cases and poor in six cases. Complications were avascular necrosis (n = 2), transient foot drop (n = 2), coxa-vara (n = 1) and temporary loss of scrotal sensation (n = 1).Conclusion:
Muscle pedicle bone grafting with internal fixation is a viable treatment option in displaced femoral neck fractures with late presentation. 相似文献46.
Anterior cruciate ligament injury about 20 years post‐treatment: A kinematic analysis of one‐leg hop 下载免费PDF全文
E. Tengman H. Grip AK. Stensdotter C. K. Häger 《Scandinavian journal of medicine & science in sports》2015,25(6):818-827
Reduced dynamic knee stability, often evaluated with one‐leg hops (OLHs), is reported after anterior cruciate ligament (ACL) injury. This may lead to long‐standing altered movement patterns, which are less investigated. 3D kinematics during OLH were explored in 70 persons 23 ± 2 years after ACL injury; 33 were treated with physiotherapy in combination with ACL reconstruction (ACLR) and 37 with physiotherapy alone (ACLPT). Comparisons were made to 33 matched controls. We analyzed (a) maximal knee joint angles and range of motion (flexion, abduction, rotation); (b) medio‐lateral position of the center of mass (COM) in relation to knee and ankle joint centers, during take‐off and landing phases. Unlike controls, ACL‐injured displayed leg asymmetries: less knee flexion and less internal rotation at take‐off and landing and more lateral COM related to knee and ankle joint of the injured leg at landing. Compared to controls, ACLR had larger external rotation of the injured leg at landing. ACLPT showed less knee flexion and larger external rotation at take‐off and landing, and larger knee abduction at Landing. COM was more medial in relation to the knee at take‐off and less laterally placed relative to the ankle at landing. ACL injury results in long‐term kinematic alterations during OLH, which are less evident for ACLR. 相似文献
47.
Alicja Szymczyszyn Adrian Doroszko Ewa Szahidewicz-Krupska Piotr Rola Radosław Gutherc Jakub Jasiczek Grzegorz Mazur Arkadiusz Derkacz 《Lasers in medical science》2016,31(7):1301-1307
The effect of low-level laser therapy (LLLT) on the cardiovascular system is not fully established. Since the endothelium is an important endocrine element, establishing the mechanisms of LLLT action is an important issue.The aim of the study was to evaluate the effect of transdermal LLLT on endothelial function.In this study, healthy volunteers (n?=?40, age?=?20–40 years) were enrolled. N?=?30 (14 female, 16 male, mean age 30?±?5 years) constituted the laser-irradiated group (LG). The remaining 10 subjects (6 women, 4 men, mean age 28?±?5 years) constituted the control group (CG). Participants were subjected to LLLT once a day for three consecutive days. Blood for biochemical assessments was drawn before the first irradiation and 24 h after the last session. In the LG, transdermal illumination of radial artery was conducted (a semiconductor laser λ?=?808 nm, irradiation 50 mW, energy density 1.6 W/cm2 and a dose 20 J/day, a total dose of 60 J). Biochemical parameters (reflecting angiogenesis: vascular endothelial growth factor (VEGF), fibroblast growth factor (FGF), angiostatin; antioxidative status: glutathione (GSH) and the nitric oxide metabolic pathway: symmetric dimethylarginine (SDMA), asymmetric dimethylarginine (ADMA) and l-arginine) were assessed. In the LG, a significant increase in GSH levels and considerable decrease in angiostatin concentration following the LLLT were observed. No significant differences in levels of the VEGF, FGF, SDMA, ADMA were observed.LLLT modifies vascular endothelial function by increasing its antioxidant and angiogenic potential. We found no significant differences in levels of the nitric oxide pathway metabolites within 24 h following the LLLT irradiation. 相似文献
48.
Marek Szolkiewicz Elzbieta Sucajtys Wojciech Wolyniec Przemyslaw Rutkowski Ewa Stelmanska Justyna Korczynska Julian Swierczynski Boleslaw Rutkowski 《Journal of renal nutrition》2005,15(1):166-172
OBJECTIVE: Hyperlipidemia is a permanent finding in advanced renal failure. It is supposed to be responsible for the accelerated arteriosclerosis and cardiovascular complications observed in patients with that disease. The background is partially determined, however, our knowledge in this matter is not yet satisfactory. METHODS: This study is based on the experimental rat model of chronic renal failure (CRF). Considering white adipose tissue (WAT) lipogenesis upregulation in CRF, along with the determination of acetyl coenzyme A carboxylase (ACC) and fatty acid synthase (FAS) genes expression, we have measured WAT gene expression for sterol regulatory binding protein 1 (SREBP-1) at the level of protein mass and mRNA abundance. Furthermore, we have determined glucose uptake, glucose-to-CO 2 conversion rate, and glucose translocator (GLUT-4) gene expression in WAT. RESULTS: Upregulation of both FAS and ACC gene expression was found in WAT of CRF rats. It was accompanied by WAT SREBP-1 gene overexpression. Moreover, we have observed the increased glucose uptake, glucose to CO 2 conversion rate, and GLUT-4 gene expression in WAT of CRF rats in comparison with controls. CONCLUSION: SREBP-1 gene overexpression may contribute to enhanced lipogenesis upregulation in WAT of CRF rats. It is not excluded that the increased WAT glucose metabolism activity is also induced by this mechanism, although there is no evidence currently to that end. We hypothesize that the increased WAT lipogenesis capacity could be a part of mechanism(s) leading to CRF-induced hyperlipidemia. 相似文献
49.
An epidemic amongst recruits who presented with acute viral exudative pleural effusion with lymphocytic pleocytosis is analysed. Histologic and bacteriologic proof of tuberculosis was lacking in majority. Most of them recovered without pleural thickening. Overcrowding, inadequate clothing protection, stress and strain of vigorous recruit training could be important precipitating factors. None reported with parenchymal tuberculosis in two year follow up.KEY WORDS: Pleural effussion, Viral 相似文献
50.
P Bharadwaj A Banerji R Datta H Singh AK Ghosh G Keshavamurthy 《Medical Journal Armed Forces India》2008,64(2):131-135