全文获取类型
收费全文 | 5538篇 |
免费 | 363篇 |
国内免费 | 21篇 |
专业分类
耳鼻咽喉 | 37篇 |
儿科学 | 194篇 |
妇产科学 | 133篇 |
基础医学 | 615篇 |
口腔科学 | 34篇 |
临床医学 | 1006篇 |
内科学 | 1003篇 |
皮肤病学 | 166篇 |
神经病学 | 580篇 |
特种医学 | 93篇 |
外科学 | 584篇 |
综合类 | 61篇 |
一般理论 | 8篇 |
预防医学 | 663篇 |
眼科学 | 102篇 |
药学 | 286篇 |
中国医学 | 3篇 |
肿瘤学 | 354篇 |
出版年
2024年 | 6篇 |
2023年 | 56篇 |
2022年 | 48篇 |
2021年 | 192篇 |
2020年 | 82篇 |
2019年 | 170篇 |
2018年 | 197篇 |
2017年 | 133篇 |
2016年 | 156篇 |
2015年 | 157篇 |
2014年 | 216篇 |
2013年 | 341篇 |
2012年 | 433篇 |
2011年 | 445篇 |
2010年 | 228篇 |
2009年 | 223篇 |
2008年 | 349篇 |
2007年 | 371篇 |
2006年 | 353篇 |
2005年 | 380篇 |
2004年 | 340篇 |
2003年 | 325篇 |
2002年 | 264篇 |
2001年 | 46篇 |
2000年 | 31篇 |
1999年 | 43篇 |
1998年 | 49篇 |
1997年 | 47篇 |
1996年 | 30篇 |
1995年 | 46篇 |
1994年 | 24篇 |
1993年 | 19篇 |
1992年 | 16篇 |
1991年 | 10篇 |
1990年 | 10篇 |
1989年 | 5篇 |
1988年 | 4篇 |
1987年 | 11篇 |
1986年 | 5篇 |
1985年 | 13篇 |
1984年 | 4篇 |
1983年 | 5篇 |
1982年 | 6篇 |
1981年 | 4篇 |
1980年 | 3篇 |
1977年 | 2篇 |
1976年 | 4篇 |
1972年 | 6篇 |
1970年 | 3篇 |
1968年 | 5篇 |
排序方式: 共有5922条查询结果,搜索用时 15 毫秒
41.
OBJECTIVE: To review the diagnosis and treatment of postoperative femoral motor neuropathy without neurologic consultation or testing. STUDY DESIGN: A retrospective review of 6 consecutive patients with postoperative femoral motor neuropathy following gynecologic surgery. Diagnosis was made on clinical evaluation: history of falling during postoperative ambulation, quadriceps weakness, straight leg raise weakness, diminished knee jerk response, and no evidence of psoas hematoma or abscess. Neurologic consultation, electromyography, nerve conduction study and radiologic imaging, such as computed tomography, were not obtained. Instead, a physical therapy consultation was obtained for a knee orthotic and rehabilitation. RESULTS: Four postoperative femoral motor neuropathies developed following 3,014 cases of major gynecologic surgery (0.1%). Two additional cases were seen in consultation. The median age was 57 years. All patients fell while attempting ambulation on postoperative day 1. Recovery occurred at a median of 3 months (1-4). At a median follow-up of 4 years, no patient had developed additional neurologic sequelae. A history of prior postoperative femoral motor neuropathy was noted in 2 of 6 patients (33%). CONCLUSION: This was the first study of diagnosis and treatment of postoperative femoral motor neuropathy following gynecologic surgery without neurologic consultation or testing. Because of the significant expense of neurologic consultation and testing, patients with postoperative femoral motor neuropathy can have the condition diagnosed by the gynecologist and be referred directly to physical therapy without adversely affecting outcome. This also was the first study to elicit a prior history offemoral neuropathy in 33% of patients. Thus, a prior history may be a risk factor for recurrence. 相似文献
42.
43.
44.
45.
Objective. Since stroke symptoms are often vague, and acute therapies for stroke are more recently available, it has been hypothesized that stroke patients may not be treated with the same urgency as myocardial infarction (MI) patients by emergency medical services (EMS). To examine this hypothesis, EMS transport times were examined for both stroke and MI patients who used a paramedic-level, county-based EMS system for transportation to a single hospital during 1999. Methods. Patients were first identified by their hospital discharge diagnosis as stroke (ICD-9 430–436, n = 50) or MI (ICD-9 410, n = 55). Trip sheets with corresponding transport times were retrospectively obtained from the 911 center. A separate analysis was performed on patients identified by dispatchers with a chief complaint of stroke (n = 85) or MI (n = 372). Results. Comparing stroke and MI patients identified by ICD-9 codes, mean EMS transport times in minutes did not meaningfully differ with respect to dispatch to scene arrival time (8.3 vs 8.9, p = 0.61), scene time (19.5 vs 21.4, p = 0.23), and transport time (13.7 vs 16.2, p = 0.10). Mean total call times in minutes from dispatch to hospital arrival were similar between stroke and MI patients (41.5 vs 46.4, p = 0.22). Results were similar when comparing patients identified by dispatchers with a chief complaint indicative of stroke or MI. Conclusion. In this single county, EMS response times were not different between stroke and MI patients. Replication in other EMS settings is needed to confirm these findings. 相似文献
46.
Karen L. Hanson Dawn M. Schiehser Alexandra L. Clark Scott F. Sorg Russell T. Kim Mark W. Jacobson 《Journal of clinical and experimental neuropsychology》2016,38(10):1115-1130
Introduction: Given that little is known about the associations between alcohol use, cognition, and psychiatric symptoms among veterans with a history of mild traumatic brain injury (mTBI), we aimed to (a) characterize how they differ from veteran controls on a measure of problem drinking; (b) investigate whether problem drinking is associated with demographic or mTBI characteristics; and (c) examine the associations between alcohol use, mTBI history, psychiatric functioning, and cognition. Method: We assessed 59 veterans (n = 32 with mTBI history; n = 27 military controls) for problem alcohol use (Alcohol Use Disorders Identification Test: AUDIT), psychiatric symptoms, and neuropsychological functioning. Results: Compared to controls, veterans with mTBI history were more likely to score above the AUDIT cutoff score of 8 (p = .016), suggesting a higher rate of problem drinking. Participants with mTBI history also showed elevated psychiatric symptoms (ps < .001) and lower cognitive scores (ps < .05 to < .001). Veterans with higher AUDIT scores were younger (p = .05) and had less education (p < .01) and more psychiatric symptoms (ps < .01), but mTBI characteristics did not differ. After controlling for combat and mTBI history (R2 = .04, ns) and posttraumatic stress disorder (PTSD) symptoms (ΔR2 = .08, p = .05), we found that higher AUDIT scores were associated with poorer attention/processing speed, F(9, 37) = 2.55, p = .022; ΔR2 = .26, p = .03. Conclusions: This preliminary study suggested that veterans with mTBI history may be at increased risk for problem drinking. Problem alcohol use was primarily associated with more severe PTSD symptoms and poorer attention/processing speed, though not with combat or mTBI characteristics per se. Importantly, findings emphasize the importance of assessing for and treating problematic alcohol use and comorbid psychiatric symptoms among veterans, including those with a history of neurotrauma. 相似文献
47.
Dawn Hastreiter MD PhD ; Jeannie Chao BS ; QI Wang MD ; Richard M. Ozuna MD ; Myron Spector PhD 《Wound repair and regeneration》2004,12(4):430-438
That a contractile actin isoform has been found in cells of other cartilage tissues in healing and disease states prompted this investigation of the presence of alpha-smooth muscle actin (alpha-SMA) in pathological human intervertebral disc tissue. The presence of this isoform has been reported in human intervertebral disc specimens obtained at autopsy from subjects for whom there were no reported symptoms. An objective of this study was to evaluate the cell density and percentage of alpha-SMA-containing cells in pathological nucleus pulposus tissue obtained from lumbar disc surgery from 17 patients. Additionally, explants of nucleus pulposus material were cultured to determine how alpha-SMA expression changed with time in vitro. Seventy-six 5-mm diameter explants (approximately 2 mm thick) pooled from six lumbar surgeries were cultured for 1, 2, 4, or 6 weeks. Microtomed sections of paraffin-embedded specimens were stained with hematoxylin and eosin or a monoclonal antibody to alpha-SMA. Histologically, cells were categorized as to alpha-SMA phenotype (positive or negative), and the areal cell density was determined. The evaluation of the cultured nucleus pulposus explants also included documentation of the percentage of cells that were round or elongated and the percentage of the cells that were part of a group (group: >/= 2 cells). Every nucleus pulposus section exhibited the presence of alpha-SMA-containing cells, which accounted for approximately 24 percent of the cells in vivo. In vivo, the cell density was significantly higher in older individuals (p = 0.02). The average time for cell outgrowth from the explants was 8.6 days. Approximately 10-15 percent of the cells in the explants stained positive for alpha-SMA. The time in culture had no significant effect on any of the outcome measures except the percentage of alpha-SMA-containing cells that were round (p = 0.008), with values decreasing through 4 weeks and then slightly rising at 6 weeks. The role of alpha-SMA in intervertebral disc pathology warrants further investigation. 相似文献
48.
49.
Robert M. Merion Sarah H. Rush Dawn M. Dykstra Nathan Goodrich Richard B. Freeman Jr. Robert A. Wolfe 《American journal of transplantation》2004,4(11):1792-1797
Split liver transplantation allows 2 recipients to receive transplants from one organ. Comparisons of predicted lifetimes for two alternatives (split liver for an adult and pediatric recipient vs. whole liver for an adult recipient) can help guide the use of donor livers. We analyzed mortality risk for 48,888 waitlisted candidates, 907 split and 21,913 whole deceased donor liver transplant recipients between January 1, 1995 and February 26, 2002. Cox regression models for pediatric and adult patients assessed average relative wait list and post-transplant death risks, for split liver recipients. Life years gained compared with remaining on the waiting list over a 2-year period were calculated. Seventy-six splits (152 recipients) and 24 re-transplants resulted from every 100 livers (13.1% [adult] and 18.0% [pediatric] 2-year re-transplant rates, respectively). Whole livers used for 93 adults also utilized 100 livers (re-transplant rate 7.0%). Eleven extra life years and 59 incremental recipients accrued from each 100 livers used for split compared with whole organ transplants. Split liver transplantation could provide enough organs to satisfy the entire current demand for pediatric donor livers in the United States, provide more aggregate years of life than whole organ transplants and result in larger numbers of recipients. 相似文献
50.
Crystal adherence to the renal epithelium is widely regarded as a probable mechanism of stone formation. Intracrystalline proteins may provide access to the core of urinary crystals and thereby facilitate the dismantling of these crystals after their attachment to and phagocytosis by renal epithelial cells. The present study investigated the role of proteolysis and limited dissolution of urinary calcium oxalate (CaOx) crystals in South Africas white and black populations with a view to understanding the remarkably low stone incidence in the black population compared with the whites. CaOx crystals were precipitated from filtered urine or ultrafiltered urine dosed with an intracrystalline protein, urinary prothrombin fragment 1 (UPTF1), isolated from white and black subjects. The crystals were fractured and subjected to proteolysis and/or limited dissolution before examination using field emission scanning electron microscopy (FESEM). FESEM data showed that CaOx crystals from white and black subjects were eroded by treatment with proteases. Cathepsin D caused the most significant crystal erosion, and more noticeable degradation of CaOx monohydrate (COM) crystals compared to CaOx dihydrate (COD). Limited dissolution studies showed the unique ultrastructures and fragmentation processes of COM and COD crystals. COM crystals appeared to be more susceptible to degradation and dissolution than CODs. Since COMs are predominant in blacks, compared with COD crystals from whites, it is speculated that the lower stone rate amongst South African blacks might be attributed partly to their more efficient destruction of retained COM crystals. 相似文献