全文获取类型
收费全文 | 45605篇 |
免费 | 3379篇 |
国内免费 | 136篇 |
专业分类
耳鼻咽喉 | 592篇 |
儿科学 | 1151篇 |
妇产科学 | 565篇 |
基础医学 | 5697篇 |
口腔科学 | 486篇 |
临床医学 | 4816篇 |
内科学 | 9186篇 |
皮肤病学 | 482篇 |
神经病学 | 4483篇 |
特种医学 | 1778篇 |
外科学 | 8741篇 |
综合类 | 350篇 |
现状与发展 | 1篇 |
一般理论 | 57篇 |
预防医学 | 3796篇 |
眼科学 | 802篇 |
药学 | 2866篇 |
中国医学 | 34篇 |
肿瘤学 | 3237篇 |
出版年
2024年 | 61篇 |
2023年 | 480篇 |
2022年 | 854篇 |
2021年 | 2066篇 |
2020年 | 1071篇 |
2019年 | 1721篇 |
2018年 | 2071篇 |
2017年 | 1454篇 |
2016年 | 1470篇 |
2015年 | 1624篇 |
2014年 | 2336篇 |
2013年 | 2769篇 |
2012年 | 4372篇 |
2011年 | 4263篇 |
2010年 | 2235篇 |
2009年 | 1886篇 |
2008年 | 2981篇 |
2007年 | 3093篇 |
2006年 | 2589篇 |
2005年 | 2315篇 |
2004年 | 2038篇 |
2003年 | 1717篇 |
2002年 | 1483篇 |
2001年 | 170篇 |
2000年 | 136篇 |
1999年 | 173篇 |
1998年 | 259篇 |
1997年 | 204篇 |
1996年 | 144篇 |
1995年 | 122篇 |
1994年 | 100篇 |
1993年 | 77篇 |
1992年 | 59篇 |
1991年 | 44篇 |
1990年 | 39篇 |
1989年 | 40篇 |
1988年 | 39篇 |
1987年 | 46篇 |
1986年 | 35篇 |
1985年 | 39篇 |
1984年 | 39篇 |
1983年 | 34篇 |
1982年 | 41篇 |
1981年 | 32篇 |
1980年 | 34篇 |
1979年 | 15篇 |
1978年 | 18篇 |
1974年 | 20篇 |
1973年 | 17篇 |
1972年 | 14篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
91.
Sumeer Sathi Eugene Rossitch Jr. Matthew R. Moore Peter McL. Black 《Child's nervous system》1991,7(1):56-58
Harvey Cushing was a man of many talents. Not only was he a premier surgeon and scientist, but a prolific author and artist as well. In this paper, we present two postoperative sketches of pediatric brain tumors drawn by Dr. Cushing. These sketches are representative of drawings which accompany many of his operative notes at the Peter Bent Brigham Hospital. About 25% of Cushing's surgical sketches depict operations performed on children. The most commonly drawn childhood tumors were craniopharyngiomas and gliomas of the brain stem and cerebellum. These drawings reveal how Cushing maintained detailed records of his surgical experience. It is clearly evident from these records that Dr. Cushing gained substantial experience in the treatment of pediatric brain tumors. 相似文献
92.
93.
J Matthew Conoyer David M Kaylie C Gary Jackson 《Otolaryngology--head and neck surgery》2007,137(5):757-761
OBJECTIVES: To investigate common presentations and expected outcomes in patients with traumatically induced otologic dysfunction. STUDY DESIGN: Retrospective case review of patients who underwent otologic surgery for sequelae of otologic trauma over a 28-year period. Patients were stratified into major and minor trauma cohorts. Major trauma was designated as closed head injury with or without temporal bone fracture; lower-energy insults comprised the minor trauma group. Preoperative and postoperative audiograms were obtained and correlated with extent of injury. SETTING: Tertiary referral center. RESULTS: Major trauma accounted for 44.9 percent of all patients. The remaining 55.1 percent suffered minor trauma, of which simple traumatic tympanic membrane perforation was the most common insult (33.6%). Two hundred twenty-seven cases were performed on 214 patients. Pure tone averages improved a significant 20.8 dB to essentially normal levels postoperatively. CONCLUSION: Regardless of injury extent, surgical rehabilitation of conductive losses attains excellent hearing results that surpass those historically reported for the chronic ear population. 相似文献
94.
Jean M. Panneton MD Peter Gloviczki MD Linda G. Canton RN BSN Thomas C. Bower MD Matthew S. T. Chow MD Peter C. Pairolero MD Hartzell V. Schaff MD John W. Hallett Jr. MD Kenneth J. Cherry Jr. MD 《Annals of vascular surgery》1996,10(2):97-108
Renal transplantation has increased the longevity of patients with uremia. An increasing number undergo aortic reconstruction, which exposes the transplanted kidney to ischemic injury. To evaluate the risk for renal failure, loss of the transplant, and methods of renal protection, we reviewed our experience. Clinical data were reviewed for 10 consecutive patients (7 men, 3 women; mean age 52.7 years [range 32 to 75 years]) with a transplanted kidney who underwent aortic reconstruction between 1977 and 1994 at our institution. Mean interval between renal transplantation and aortic reconstruction was 5.9 years (range 1 month to 12.7 years). Seven patients required emergency repair because of dissection (2 patients), aneurysm rupture (4 patients), or symptomatic aneurysm (1 patient); three underwent elective repair. Reasons for reconstruction included aortic dissection (2 patients), aneurysm of the descending thoracic (2 patients), thoracoabdominal (1 patient), or abdominal aorta (3 patients), and aortoiliac occlusive disease (2 patients). Patients with thoracic or thoracoabdominal reconstructions underwent repair with atriofemoral, aortofemoral, or femorofemoral shunt placement or bypass. Of the five abdominal aortic reconstructions, the kidney was protected with aortofemoral shunt placement in one patient and cold renal perfusion in three. In two of them, topical cooling of the kidney also was used. One patient with acute aortic dissection died at 39 days as a result of respiratory failure. Loss of the recently transplanted kidney was caused by acute rejection. One patient had a transient increase in serum creatinine concentration. Eight had no worsening of renal function, and none of the nine survivors lost the transplanted kidney. We conclude that aortic reconstruction can be safely performed in kidney transplant recipients. Patients in whom thoracic or thoracoabdominal aortic reconstruction was required were protected with an atriofemoral or aortofemoral bypass or shunt. Patients undergoing abdominal aortic reconstruction did well when cold renal perfusion with or without local cooling of the transplant was used for renal protection. Transplanted kidneys appeared to tolerate ischemic injury similarly to native kidneys.Presented at the Twentieth Annual Meeting of the Peripheral Vascular Surgery Society, New Orleans, La., June 10, 1995. 相似文献
95.
Bartels MN Jelic S Ngai P Gates G Newandee D Reisman SS Basner RC De Meersman RE 《Respiratory physiology & neurobiology》2004,144(1):91-98
Heart rate variability (HRV) and systolic blood pressure variability (BPV) during incremental exercise at 50, 75, and 100% of previously determined ventilatory threshold (VT) were compared to that of resting controlled breathing (CB) in 12 healthy subjects. CB was matched with exercise-associated respiratory rate, tidal volume, and end-tidal CO(2) for all stages of exercise. Power in the low frequency (LF, 0.04-0.15 Hz) and high frequency (HF, >0.15-0.4 Hz) for HRV and BPV were calculated, using time-frequency domain analysis, from beat-to-beat ECG and non-invasive radial artery blood pressure, respectively. During CB absolute and normalized power in the LF and HF of HRV and BPV were not significantly changed from baseline to maximal breathing. Conversely, during exercise HRV, LF and HF power significantly decreased from baseline to 100% VT while BPV, LF and HF power significantly increased for the same period. These findings suggest that the increases in ventilation associated with incremental exercise do not significantly affect spectral analysis of cardiovascular autonomic modulation in healthy subjects. 相似文献
96.
Hardwick M Cavalli LR Barlow KD Haddad BR Papadopoulos V 《Cancer Genetics and Cytogenetics》2002,139(1):48-51
Recent studies using human breast cancer cell lines, animal models, and human tissue biopsies have suggested a close correlation between the expression of the peripheral-type benzodiazepine receptor (PBR) and the progression of breast cancer. This study investigates the genetic status of the PBR gene in two human breast cancer cell lines: MDA-MB-231 cells, which are an aggressive breast cancer cell line that contains high levels of PBR, and MCF-7 cells, which are a nonaggressive cell line that contains low levels of PBR. Both DNA (Southern) blot and fluorescence in situ hybridization analyses indicate that the PBR gene is amplified in MDA-MB-231 relative to MCF-7 cells. These data suggest that PBR gene amplification may be an important indicator of breast cancer progression. 相似文献
97.
Rats with thalamic taste nuclei lesions were adapted to a 23 hr 50 min deprivation schedule and then presented with 0.125 percent saccharin followed by an injection of LiCl or saline. When retested with saccharin, animals with lesions showed a marked attenuation in taste aversion as compared to controls. 相似文献
98.
Romer LM Bridge MW McConnell AK Jones DA 《European journal of applied physiology》2004,91(5-6):656-663
Exercise in the heat has detrimental effects on circulation that might negatively influence endurance performance. If blood is diverted away from the inspiratory muscles to the skin during exercise in the heat, exercise-induced inspiratory muscle fatigue might be exacerbated. Thus, we hypothesised that prolonged heavy endurance exercise in the heat would impair exercise performance and exacerbate inspiratory muscle fatigue compared to exercise in a thermo-neutral environment. Using a crossover design, seven male endurance trained subjects [mean (SEM) maximum oxygen uptake = 62.2 (1.5) ml·kg–1·min–1] were assigned at random to either a group that exercised in the heat at an ambient temperature of 35°C (H) or a group that exercised in the cool at 15°C (C). Maximum inspiratory mouth pressure at zero flow (P
0), pressure normalised maximum relaxation rate (MRR/P
0), time constant for the pressure decay (), and maximum inspiratory flow at 30% P
0 (
30) were assessed immediately before and reassessed within 2, 30, and 60 min of completing a pre-loaded time trial [40 min at 65% peak power, plus ~30 min time trial] on a cycle ergometer . Group H completed the time trial 432 (135) s slower than group C [2,285 (180) vs 1,852 (122) s, respectively; =24 (8)%, P=0.0094]. Repeat measurements within 2 min post-exercise revealed significant declines in P
0, MRR/P
0, , and
30 from baseline values, but no between-group differences were observed. In conclusion, heavy sustained exercise in the heat impaired subsequent time-trial performance but did not exacerbate inspiratory muscle fatigue in endurance-trained subjects. 相似文献
99.
Korthuis PT Asch SM Anaya HD Morgenstern H Goetz MB Yano EM Rubenstein LV Lee ML Bozzette SA 《Journal of acquired immune deficiency syndromes (1999)》2004,35(3):253-260
BACKGROUND: Lipid screening is recommended for patients taking protease inhibitors (PIs). METHODS: We examined data from the Veterans Administration Immunology Case Registry to assess lipid screening among HIV-infected veterans who received PIs for at least 6 consecutive months during 1999 and 2001. We estimated crude and adjusted associations between lipid screening and patient characteristics (age, gender, HIV exposure, and race/ethnicity), comorbidities (AIDS, cardiovascular disease, diabetes, hypertension, smoking, and hyperlipidemia), and facility characteristics (urban location, case management, guidelines, and quality improvement programs). RESULTS: Among 4065 patients on PIs, clinicians screened 2395 (59%) for lipids within 6 months of initiating treatment. Adjusting for patient characteristics, comorbidities, facility traits, and clustering, lipid screening was more common among patients who were cared for in urban areas (relative risk [RR] = 1.3, confidence limits: 1.0-1.5), diabetic (RR = 1.2, confidence limits: 1.1-1.3), or previously hyperlipidemic (RR = 1.4, confidence limits: 1.3-1.5) and less common among patients with a history of intravenous drug use (IVDU) (RR = 0.90, confidence limits: 0.79-1.0) or unknown HIV risk (RR = 0.85, confidence limits: 0.75-0.95). CONCLUSIONS: Six in 10 patients taking PIs receive lipid screening within 6 months of PI use. Systemic interventions to improve overall HIV quality of care should also address lipid screening, particularly among patients with unknown or IVDU HIV risk and those cared for in nonurban areas. 相似文献
100.
Samuels L Entwistle J Holmes E Eaton D Thomas MP Menzano G Promisloff R 《ASAIO journal (American Society for Artificial Internal Organs : 1992)》2004,50(3):234-236
The traditional extracorporeal membrane oxygenation circuit uses a centrifugal pump. These pumps require close monitoring and are subject to complications. In addition, they do not take advantage of the potential benefits of pulsatile flow. These extracorporeal membrane oxygenation circuits use a single pump with an inline oxygenator. If cardiac failure persists after respiratory recovery has occurred, removal of the oxygenator requires an additional procedure to convert the patient to biventricular support. This report describes a circuit in which an oxygenator is connected to a pulsatile ventricular assist device. Single and dual circuit configurations are illustrated. Recommendations for pulmonary care during support are also described. 相似文献