全文获取类型
收费全文 | 14734篇 |
免费 | 1402篇 |
国内免费 | 611篇 |
专业分类
耳鼻咽喉 | 132篇 |
儿科学 | 157篇 |
妇产科学 | 198篇 |
基础医学 | 1660篇 |
口腔科学 | 384篇 |
临床医学 | 1326篇 |
内科学 | 1731篇 |
皮肤病学 | 139篇 |
神经病学 | 1380篇 |
特种医学 | 401篇 |
外科学 | 1193篇 |
综合类 | 2188篇 |
现状与发展 | 2篇 |
一般理论 | 1篇 |
预防医学 | 2681篇 |
眼科学 | 298篇 |
药学 | 1748篇 |
7篇 | |
中国医学 | 369篇 |
肿瘤学 | 752篇 |
出版年
2024年 | 183篇 |
2023年 | 263篇 |
2022年 | 405篇 |
2021年 | 554篇 |
2020年 | 522篇 |
2019年 | 559篇 |
2018年 | 522篇 |
2017年 | 585篇 |
2016年 | 608篇 |
2015年 | 591篇 |
2014年 | 861篇 |
2013年 | 1312篇 |
2012年 | 773篇 |
2011年 | 976篇 |
2010年 | 712篇 |
2009年 | 729篇 |
2008年 | 758篇 |
2007年 | 717篇 |
2006年 | 625篇 |
2005年 | 565篇 |
2004年 | 475篇 |
2003年 | 453篇 |
2002年 | 367篇 |
2001年 | 343篇 |
2000年 | 265篇 |
1999年 | 218篇 |
1998年 | 216篇 |
1997年 | 179篇 |
1996年 | 121篇 |
1995年 | 134篇 |
1994年 | 121篇 |
1993年 | 123篇 |
1992年 | 120篇 |
1991年 | 115篇 |
1990年 | 109篇 |
1989年 | 103篇 |
1988年 | 85篇 |
1987年 | 70篇 |
1986年 | 54篇 |
1985年 | 43篇 |
1984年 | 43篇 |
1983年 | 31篇 |
1982年 | 24篇 |
1981年 | 25篇 |
1980年 | 22篇 |
1979年 | 12篇 |
1978年 | 17篇 |
1977年 | 11篇 |
1976年 | 7篇 |
1973年 | 7篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
21.
Organization of sensory input to the nociceptive‐specific cutaneous trunk muscle reflex in rat,an effective experimental system for examining nociception and plasticity 下载免费PDF全文
Jeffrey C. Petruska Darrell F. Barker Sandra M. Garraway Robert Trainer James W. Fransen Peggy A. Seidman Roy G. Soto Lorne M. Mendell Richard D. Johnson 《The Journal of comparative neurology》2014,522(5):1048-1071
Detailed characterization of neural circuitries furthers our understanding of how nervous systems perform specific functions and allows the use of those systems to test hypotheses. We have characterized the sensory input to the cutaneous trunk muscle (CTM; also cutaneus trunci [rat] or cutaneus maximus [mouse]) reflex (CTMR), which manifests as a puckering of the dorsal thoracolumbar skin and is selectively driven by noxious stimuli. CTM electromyography and neurogram recordings in naïve rats revealed that CTMR responses were elicited by natural stimuli and electrical stimulation of all segments from C4 to L6, a much greater extent of segmental drive to the CTMR than previously described. Stimulation of some subcutaneous paraspinal tissue can also elicit this reflex. Using a selective neurotoxin, we also demonstrate differential drive of the CTMR by trkA‐expressing and nonexpressing small‐diameter afferents. These observations highlight aspects of the organization of the CTMR system that make it attractive for studies of nociception and anesthesiology and plasticity of primary afferents, motoneurons, and the propriospinal system. We use the CTMR system to demonstrate qualitatively and quantitatively that experimental pharmacological treatments can be compared with controls applied either to the contralateral side or to another segment, with the remaining segments providing controls for systemic or other treatment effects. These data indicate the potential for using the CTMR system as both an invasive and a noninvasive quantitative assessment tool providing improved statistical power and reduced animal use. J. Comp. Neurol. 522:1048–1071, 2014. © 2013 Wiley Periodicals, Inc. 相似文献
22.
《Journal of adolescence》2014,37(6):863-870
This study presents German and Israeli youth's heroes and role models. Two hundred twenty-six students from 22 high schools took part in small group interviews. Despite differences in the normative place of the family in the two cultures, the comparison reveals significant similarities between their views and what attributes the subjects assign to their families. Three main models of family members as hero arise from the data: The Self-made Person; sacrifice and pro-social action; and contending with everyday reality. The results point to a) the fading of traditional heroes from the imagination of youth in post-industrial societies; b) the substantive place the family holds in young people's lives. I suggest that the rise of uncertainty and risk in the current socio-historical constellation, contributes to adolescents' choice of figures from their immediate environments that embody safety and a moral framework. 相似文献
23.
24.
25.
26.
《Journal of cranio-maxillo-facial surgery》2014,42(8):2025-2034
PurposeCorrection of post traumatic orbital and zygomatic deformity is a challenge for maxillofacial surgeons. Integration of different technologies, such as software planning, surgical navigation and stereolithographic models, opens new horizons in terms of the surgeons' ability to tailor reconstruction to individual patients. The purpose of this study was to analyze surgical results, in order to verify the suitability, effectiveness and reproducibility of this new protocol.MethodsEleven patients were included in the study. Inclusion criteria were: unilateral orbital pathology; associated diplopia and enophthalmos or exophthalmos, and zygomatic deformities. Syndromic patients were excluded. Pre-surgical planning was performed with iPlan 3.0 CMF software and we used Vector Vision II (BrainLab, Feldkirchen, Germany) for surgical navigation. We used 1:1 skull stereolithographic models for all the patients. Orbital reconstructions were performed with a titanium orbital mesh. The results refer to: correction of the deformities, exophthalmos, enophthalmos and diplopia; correspondence between reconstruction mesh positioning and preoperative planning mirroring; and the difference between the reconstructed orbital volume and the healthy orbital volume.ResultsCorrespondence between the post-operative reconstruction mesh position and the presurgical virtual planning has an average margin of error of less than 1.3 mm. In terms of en- and exophthalmos corrections, we have always had an adequate clinical outcome with a significant change in the projection of the eyeball. In all cases treated, there was a complete resolution of diplopia. The calculation of orbital volume highlighted that the volume of the reconstructed orbit, in most cases, was equal to the healthy orbital volume, with a positive or negative variation of less than 1 cm3.ConclusionThe proposed protocol incorporates all the latest technologies to plan the virtual reconstruction surgery in detail. The results obtained from our experience are very encouraging and lead us to pursue this path. 相似文献
27.
Scott C. Tadler MD Clifton W. Callaway MD PhD James J. Menegazzi PhD 《Academic emergency medicine》1998,5(1):25-30
Objective: Mild cerebral hypothermia improves neurologic outcome in animals resuscitated from cardiac arrest. This study examined whether one practical external cooling method, i.e., local application of ice to the heads and necks of swine, during resuscitation induces cerebral cooling.
Methods: Local external cerebral cooling was examined in a prospective laboratory investigation using 24 female swine in a model of cardiac arrest. The swine were randomized into hypothermia and normothermia groups. Intracerebral temperature was measured in the parietal cortex. Eight minutes after induction of ventricular fibrillation, chest compressions and mechanical ventilation were initiated. The hypothermia group was treated with 1,500 mL of ice in plastic bags applied to the head and neck, while the normothermia group received no extra interventions. Data were analyzed using repeated-measures ANOVA.
Results: In the normothermia group, there was no significant change in nasopharyngeal (-0.8 ± 0.6°C), intracerebral (-0.6 ± 0.8°C), or esophageal (-0.2 ± 0.6°C) temperatures during 20 minutes of resuscitation. However, in the hypothermia group, application of ice during resuscitation significantly reduced nasopharyngeal (-2.9 ± 1.4°C), intracerebral (-2.1 ± 0.6°C), and esophageal (-1.4 ± 0.8°C) temperatures.
Conclusions: External application of ice packs during resuscitation effectively reduced intracerebral temperatures in swine by an amount that improved neurologic outcomes in previous large animal studies. These data suggest that clinically significant cerebral cooling could be accomplished with a noninvasive, inexpensive, and universally available intervention. Further studies are required to assess the clinical feasibility and therapeutic efficacy of this intervention. 相似文献
Methods: Local external cerebral cooling was examined in a prospective laboratory investigation using 24 female swine in a model of cardiac arrest. The swine were randomized into hypothermia and normothermia groups. Intracerebral temperature was measured in the parietal cortex. Eight minutes after induction of ventricular fibrillation, chest compressions and mechanical ventilation were initiated. The hypothermia group was treated with 1,500 mL of ice in plastic bags applied to the head and neck, while the normothermia group received no extra interventions. Data were analyzed using repeated-measures ANOVA.
Results: In the normothermia group, there was no significant change in nasopharyngeal (-0.8 ± 0.6°C), intracerebral (-0.6 ± 0.8°C), or esophageal (-0.2 ± 0.6°C) temperatures during 20 minutes of resuscitation. However, in the hypothermia group, application of ice during resuscitation significantly reduced nasopharyngeal (-2.9 ± 1.4°C), intracerebral (-2.1 ± 0.6°C), and esophageal (-1.4 ± 0.8°C) temperatures.
Conclusions: External application of ice packs during resuscitation effectively reduced intracerebral temperatures in swine by an amount that improved neurologic outcomes in previous large animal studies. These data suggest that clinically significant cerebral cooling could be accomplished with a noninvasive, inexpensive, and universally available intervention. Further studies are required to assess the clinical feasibility and therapeutic efficacy of this intervention. 相似文献
28.
Robert B. Hawkins J. Hunter Mehaffey Kenan W. Yount Leora T. Yarboro Clifford Fonner Irving L. Kron Mohammed Quader Alan Speir Jeffrey Rich Gorav Ailawadi 《The Journal of thoracic and cardiovascular surgery》2018,155(1):182-188
Objectives
The Centers for Medicare and Medicaid Services plans to institute a 5-year trial of bundled payments for coronary artery bypass grafting through 90 days after discharge. To investigate the impact, we reviewed actual inpatient costs for patients undergoing bypass surgery relative to the target price.Methods
A total of 13,276 Medicare patients with estimated cost data underwent isolated coronary artery bypass grafting from 2008 to 2015 in 18 hospitals over 8 Medicare-defined regions within the Commonwealth of Virginia. Actual 2015 inpatient costs were compared with estimated target prices for each year of the pilot, based on the previous 3 years and stratified by Diagnosis-Related Group.Results
The mean 2015 cost per patient was $50,394 with high variation (range, $27,862-$74,169). On average, hospitals would receive a refund of $17,682 in year 1, but then owe Medicare increasing amounts up to $367,985 in year 5. If 2015 were the final year of the pilot, 13 of the 18 hospitals (72%) would have owed Medicare for cost overruns averaging $614,270 (range, $67,404-$2,102,292). Costs were below the target price at 5 of 18 hospitals, and the Centers for Medicare and Medicaid Services would have paid them an extra $272,355 on average (range, $88,628-$567,429).Conclusions
Hospitals will face immediate financial pressure due to average cost increases of 3.6% per year and an automatic reduction in payment. As regional pricing is phased in, hospitals can expect to owe Medicare increasing amounts. The net effect is shifting of financial risks to hospitals, which could restrict access to care for higher-risk patients. 相似文献29.
L.M. Vernooij W.A. van Klei M. Machina W. Pasma W.S. Beattie L.M. Peelen 《British journal of anaesthesia》2018,120(5):1080-1089
Background
Associations between intraoperative hypotension (IOH) and postoperative complications have been reported. We examined whether using different methods to model IOH affected the association with postoperative myocardial injury (POMI) and acute kidney injury (AKI).Methods
This two-centre cohort study included 10 432 patients aged ≥50 yr undergoing non-cardiac surgery. Twelve different methods to statistically model IOH [representing presence, depth, duration, and area under the threshold (AUT)] were applied to examine the association with POMI and AKI using logistic regression analysis. To define IOH, eight predefined thresholds were chosen.Results
The incidences of POMI and AKI were 14.9% and 14.8%, respectively. Different methods to model IOH yielded effect estimates differing in size and statistical significance. Methods with the highest odds were absolute maximum decrease in blood pressure (BP) and mean episode AUT, odds ratio (OR) 1.43 [99% confidence interval (CI): 1.15–1.77] and OR 1.69 (99% CI: 0.99–2.88), respectively, for the absolute mean arterial pressure 50 mm Hg threshold. After standardisation, the highest standardised ORs were obtained for depth-related methods, OR 1.12 (99% CI: 1.05–1.20) for absolute and relative maximum decrease in BP. No single method always yielded the highest effect estimate in every setting. However, methods with the highest effect estimates remained consistent across different BP types, thresholds, outcomes, and centres.Conclusions
In studies on IOH, both the threshold to define hypotension and the method chosen to model IOH affects the association of IOH with outcome. This makes different studies on IOH less comparable and hampers clinical application of reported results. 相似文献30.
Between‐center disparities in access to heart transplantation in France: contribution of candidate and center factors — A comprehensive cohort study 下载免费PDF全文
Christelle Cantrelle Richard Dorent Emilie Savoye Philippe Tuppin Guillaume Lebreton Camille Legeai Olivier Bastien 《Transplant international》2018,31(4):386-397
Transplantation represents the last option for patients with advanced heart failure. We assessed between‐center disparities in access to heart transplantation in France 1 year after registration and evaluated the contribution of factors to these disparities. Adults (n = 2347) registered on the French national waiting list between January 1, 2010, and December 31, 2014, in the 23 transplant centers were included. Associations between candidate and transplant center characteristics and access to transplantation were assessed by proportional hazards frailty models. Candidate blood groups O and A, sensitization, and body mass index ≥30 kg/m2 were independently associated with lower access to transplantation, while female gender, severity of heart failure, and high serum bilirubin levels were independently associated with greater access to transplantation. Center factors significantly associated with access to transplantation were heart donation rate in the donation service area, proportion of high‐urgency candidates among listed patients, and donor heart offer decline rate. Between‐center variability in access to transplantation increased by 5% after adjustment for candidate factors and decreased by 57% after adjustment for center factors. After adjustment for candidate and center factors, five centers were still outside of normal variability. These findings will be taken into account in the future French heart allocation system. 相似文献