全文获取类型
收费全文 | 1805篇 |
免费 | 94篇 |
国内免费 | 21篇 |
专业分类
耳鼻咽喉 | 20篇 |
儿科学 | 48篇 |
妇产科学 | 79篇 |
基础医学 | 139篇 |
口腔科学 | 63篇 |
临床医学 | 113篇 |
内科学 | 419篇 |
皮肤病学 | 36篇 |
神经病学 | 28篇 |
特种医学 | 79篇 |
外国民族医学 | 2篇 |
外科学 | 501篇 |
综合类 | 18篇 |
一般理论 | 2篇 |
预防医学 | 71篇 |
眼科学 | 48篇 |
药学 | 100篇 |
中国医学 | 3篇 |
肿瘤学 | 151篇 |
出版年
2024年 | 1篇 |
2023年 | 33篇 |
2022年 | 69篇 |
2021年 | 115篇 |
2020年 | 65篇 |
2019年 | 82篇 |
2018年 | 115篇 |
2017年 | 68篇 |
2016年 | 59篇 |
2015年 | 55篇 |
2014年 | 83篇 |
2013年 | 100篇 |
2012年 | 155篇 |
2011年 | 183篇 |
2010年 | 106篇 |
2009年 | 73篇 |
2008年 | 87篇 |
2007年 | 72篇 |
2006年 | 54篇 |
2005年 | 72篇 |
2004年 | 70篇 |
2003年 | 56篇 |
2002年 | 45篇 |
2001年 | 8篇 |
2000年 | 12篇 |
1999年 | 6篇 |
1998年 | 6篇 |
1997年 | 3篇 |
1996年 | 7篇 |
1995年 | 2篇 |
1994年 | 2篇 |
1993年 | 1篇 |
1991年 | 2篇 |
1989年 | 2篇 |
1988年 | 7篇 |
1987年 | 1篇 |
1986年 | 7篇 |
1985年 | 9篇 |
1984年 | 8篇 |
1983年 | 5篇 |
1982年 | 3篇 |
1981年 | 1篇 |
1980年 | 2篇 |
1977年 | 3篇 |
1976年 | 1篇 |
1973年 | 1篇 |
1972年 | 1篇 |
1965年 | 2篇 |
排序方式: 共有1920条查询结果,搜索用时 11 毫秒
91.
92.
In the present study the chemopreventive activities of DFMO, the irreversible inhibitor of ornithine decarboxylase, and finasteride, the inhibitor of prostatic 5a-reductase, against the development of chemically induced prostate adenocarcinoma by methylnitrosourea/testosterone propionate in male Wistar rats were investigated. According to histological examination, oral administration of DFMO and finasteride, either alone or combined, for two months to MNU/TP-inoculated rats reduced the tumor incidence to 11.11%, 10% and 10%, respectively, compared to tumored controls (64.3%). DFMO and/or finasteride treatment resulted in significant reductions in the wet weight of the prostate gland and seminal vesicles and its ratio relative to the total body weight, as well as the levels of prostate total protein, DNA, RNA and DNA/RNA ratio, compared to tumored controls. However, the effect of the combined treatment was of no statistical significance compared to single DFMO or finasteride treatment, as demonstrated by the non-significant differences between the mean values of most of the studied parameters. The tumor chemopreventive activity and the prostate growth inhibitory effect of DFMO and finasteride were due to suppression of prostate polyamine synthesis. ANOVA test revealed that the relative weight of the prostate as well as blood and tissue polyamine levels could be used as significant endpoint biomarkers for DFMO and finasteride as cancer chemopreventive agents. 相似文献
93.
We followed up 128 patients with crescentic glomerulonephritis (CGN), having sufficient clinical and histopathological data for a mean period of 34 +/- 28 months. There were 49 males and 79 females, mean age 22.7 +/- 14 years. We studied the effects of clinical, laboratory and histopathological parameters on kidney function and survival at the end point of the study. Multivariate analysis indicated that serum creatinine at presentation, nephrotic range proteinuria during the follow-up period, percentage of glomeruli with crescents, percentage of fibrous crescents and absence of cellular infiltration were significant risk factors affecting kidney function at the end of the study. The only risk factor significantly correlated with mortality was serum creatinine at last follow-up. 相似文献
94.
We present our experience with reconstruction after resection of tumors around the knee, using free vascularized fibular grafting. The study included 23 patients. The lower femur was involved in 17 cases, the upper tibia in 6. The cases included giant cell tumor of the lower femur (2 patients), giant cell tumor of the upper tibia (1 patient), malignant fibrous histiocytoma of the lower femur (1 patient), parosteal osteosarcoma (1 patient), and periosteal osteosarcoma (1 patient). The remaining patients suffered from conventional osteogenic sarcomas. The size of the defect ranged from 12 to 16 cm in length. Skin flap necrosis after tumor resection was the most common complication encountered. Other complications included peroneal nerve involvement in one case and rupture of the arterial anastomosis in another. All transferred fibulas progressed to union within 7-9 months. Union time of both upper and lower ends of the fibula and time of appearance of periosteal reaction were identical. In evaluating periosteal hypertrophy of the fibula, the hypertrophy (de Boer) index (de Boer HD, Wood MB, J Bone Joint Surg 1989;71B:374-378) proved unreliable. False positive results are obtained, when callus formation around the lower end of the femur is far more abundant than at the upper end of the fibula. For this reason, we introduced the graft index. The latter is the ratio between the diameter of the graft at its thinnest portion at latest follow-up to its diameter on the day of operation, as calculated on plain radiographs. Two of the viable fibulas developed stress fractures after plate removal. Functional and quality-of -life results were satisfactory. It is concluded that the free vascularized fibular graft remains a valuable reconstruction option after the resection of tumors around the knee, provided certain precautions are followed. First, before closure of the wound, the skin flaps should be assessed for their viability. Necrotic parts should be excised. Stable fixation is a necessary prerequisite at the time of operation. Removal of the fixation device should not be guided by union or periosteal hypertrophy, but by true widening of the medullary canal. 相似文献
95.
Amr A. El-Husseini Amgad E. El-Agroudy Ehab W. Wafa Tarek Mohsen Mohamed A. Sobh Mohamed A. Ghoneim 《International urology and nephrology》2003,36(1):95-100
Successful kidney transplantation corrects many of the metabolic abnormalities associated with development of renal osteodystrophy,
but despite a well-functioning graft, osteopenia, remains prevalent in adult and pediatric kidney recipients. The factors
that affect the bone mineral density (BMD) and the long term course of BMD after transplantation in children is still unknown.
We performed a cross sectional study to determine BMD in 83 recipients who received living renal allotransplants in Mansoura
Urology & Nephrology Center between 1981 and 2002 (mean age at transplantation 13.2 ± 3.1 years) by dual energy x-ray absorptiometry
at various time intervals up to 16 years after transplantation (mean duration after transplantation was 48 ± 34 months, range
12–192 months). The mean ± SD for BMD was −2.28 ± 2.06 for lumbar 2-4 spine and −1.44 ± 1.44 for the total body BMD as corrected
for body surface area. Osteopenia/osteoporosis were present in about two thirds of our kidney transplant recipients. The significant
risk factors for osteopenia/osteoprosis using univariate analysis were the cyclosporine based immunosuppressive regimen, cumulative
dose of steroids/m2 surface area, graft dysfunction and the urinary deoxypyridinoline. Using logistic regression analysis the cumulative steroid
dose/m2 surface area and the urinary deoxypyridinoline were the major significant predictors for bone loss. In conclusion, osteopenia
and osteoprosis are common in pediatric and adolescent renal transplant patients. The cumulative steroid dose and the urinary
deoxypyridinoline were the major predictors for bone loss.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
96.
A prospective randomized study for prevention of postrenal transplantation bone loss 总被引:2,自引:0,他引:2
El-Agroudy AE El-Husseini AA El-Sayed M Mohsen T Ghoneim MA 《Kidney international》2005,67(5):2039-2045
BACKGROUND: We aimed to investigate different treatment drugs for the prevention of post-transplant bone loss. METHODS: Sixty adult male recent renal transplant recipients were enrolled into the study. Patients were randomized into 4 groups: group I received daily alfacalcidol 0.5 microg PO; group II received oral alendronate 5 mg/day; group III received intranasal salmon calcitonin 200 IU every other day; and group IV was considered a control group. Every patient was supplemented with daily 500 mg oral calcium carbonate. Parameters of bone metabolism were measured before and at 12 months after starting treatment. Bone mineral density (BMD) was measured by (DEXA) at lumber spine, femoral neck, and forearm before and after treatment period. RESULTS: BMD was increased at lumber spine by 2.1%, 0.8%, 1.7%, by 1.8%, 0.6%, 1.6% at femoral neck, and by 3.2%, 1.9%, 2.6% at forearm in groups I, II, and III, respectively, while it decreased by 3.2%, 3.8%, and 1.8% at the same sites, respectively, in control group (P= <0.05). iPTH level decreased significantly in group I, while the decrease was insignificant in other groups (P= 0.003). All other parameters were not statistically significant between treatment groups. Apart from transient hypocalcaemia in 3 patients in group II, and 2 patients in group III, no other significant adverse effects were noted. CONCLUSION: This study proves that early bone loss that occurs during the first 12 months after renal transplantation could be prevented by alfacalcidol, calcitonin, or alendronate. Among the treatment groups, alfacalcidol significantly improved the hyperparathyroidism. All treatment drugs are safe and tolerable. 相似文献
97.
Omori K Valiente L Orr C Rawson J Ferreri K Todorov I Medicherla S Protter AA Schreiner GF Riggs AD Kandeel F Mullen Y 《Transplantation proceedings》2005,37(8):3422-3423
The development of an optimal islet cryopreservation method will permit transplantation of islets from multiple donors in a single procedure and contribute to alleviation of the islet shortage. In this study, we have improved human islet cryopreservation methods under serum-free conditions using an intracellular-based islet cryopreservation solution (ICS), especially supplemented with a p38 pathway inhibitor (p38IH) to suppress p38 mitogen-activated protein kinase (MAPK) activation. Three different solutions were compared for freezing and thawing of human islets (1) conventional RPMI1640 medium, (2) ICS, and (3) ICS supplemented with a p38IH, SD-282 (ICS-p38IH). Islet cryopreservation with ICS-p38IH significantly improved islet recovery, viability, and quality after thawing of cryopreserved islets. This improvement may allow the use of cryopreserved islets in clinical islet transplantation. 相似文献
98.
With advances in neonatology, there is an increasing need for central vascular access in extremely small (<1,000 g) premature
infants. Although the use of peripherally inserted central venous lines have become common practice, surgeons still frequently
perform central venous line placements via cut-down in difficult access patients. The advantages of general anesthesia for
vascular access procedures are obvious for optimal pain control and ideal operative exposure; however, extremely premature
infants are at significant risk for prolonged endotracheal intubation with postoperative apneas. We report two cases where
regional caudal anesthesia with bupivacaine and clonidine without intubation was successfully utilized at bedside during central
venous line placements in premature infants weighing <600 g. The operative field was ideal with adequate motor and sensory
block with caudal anesthesia and both infants received only oxygen by nasal cannula. 相似文献
99.
Abbas AE Brewington SD Dixon SR Boura JA Grines CL O'Neill WW 《Journal of the American College of Cardiology》2005,46(5):793-798
OBJECTIVES: We sought to investigate the benefit, predictors of procedural success, and safety of pre-procedural intra-coronary fibrin-specific lytic infusion (ICL) in patients with failed prior percutaneous coronary intervention (PCI) for chronic total occlusions (CTO). BACKGROUND: Percutaneous coronary intervention for CTO remains a challenge with a high incidence of procedural failure secondary to inability to cross the occlusion with the guidewire. METHODS: Eighty-five patients who underwent unsuccessful PCI procedures of CTO (more than three months' duration) had a repeat attempt of recanalization with the use of pre-procedural ICL. Patients received a weight-adjusted dose of either alteplase (tPA) (2 to 5 mg/h) or tenecteplase (TNK) (0.5 mg/h) for a total of 8 h. The total dose of ICL therapy was infused split between the guiding catheter and an intracoronary infusion catheter. A step-down multivariate logistic regression analysis was completed to determine the best predictors of procedural success. In-hospital major adverse cardiac events (MACE) including myocardial infarction, acute reocclusion, stroke, and death, as well as bleeding complications, were also examined. RESULTS: The procedure was successful in 46 of 85 cases (54%). Four of 85 (5%) contained dissections that did not result in perforations, tamponade, or MACE. The incidence of groin complications was 7 of 85 (8%) and of bleeding complications requiring transfusions was 3 of 85 (3.5%). On multivariate analysis, predictors of success were tapering morphology (odds ratio, 15.5; 95% confidence interval, 3.73 to 63; p = 0.0002) and lack of bridging collaterals (odds ratio, 5.08; 95% confidence interval, 1.53 to 17; p = 0.008). CONCLUSIONS: Intracoronary infusion of fibrin-specific thrombolytic therapy may provide a valuable and safe option for facilitating percutaneous revascularization of CTO. 相似文献
100.
Congenital absence of the pericardium is an uncommon finding that may or may not be symptomatic. Asymptomatic patients are discovered incidentally during cardiac surgery for an unrelated condition or postmortem. However, symptomatic patients may experience non-exertional paroxysmal stabbing chest pain. It may occur with other cardiac or extracardiac abnormalities and a variety of imaging modalities may identify the condition. Complete cases are more rare than partial effects. However, complications are more common with partial absence due to strangulation of the heart into the defect thus requiring surgical intervention. 相似文献