全文获取类型
收费全文 | 7655篇 |
免费 | 645篇 |
国内免费 | 11篇 |
专业分类
耳鼻咽喉 | 84篇 |
儿科学 | 263篇 |
妇产科学 | 164篇 |
基础医学 | 997篇 |
口腔科学 | 130篇 |
临床医学 | 969篇 |
内科学 | 1389篇 |
皮肤病学 | 59篇 |
神经病学 | 878篇 |
特种医学 | 184篇 |
外科学 | 1150篇 |
综合类 | 60篇 |
一般理论 | 4篇 |
预防医学 | 707篇 |
眼科学 | 214篇 |
药学 | 622篇 |
1篇 | |
中国医学 | 5篇 |
肿瘤学 | 431篇 |
出版年
2021年 | 121篇 |
2020年 | 65篇 |
2019年 | 119篇 |
2018年 | 110篇 |
2017年 | 114篇 |
2016年 | 114篇 |
2015年 | 96篇 |
2014年 | 176篇 |
2013年 | 240篇 |
2012年 | 404篇 |
2011年 | 391篇 |
2010年 | 213篇 |
2009年 | 211篇 |
2008年 | 358篇 |
2007年 | 375篇 |
2006年 | 391篇 |
2005年 | 400篇 |
2004年 | 327篇 |
2003年 | 294篇 |
2002年 | 306篇 |
2001年 | 176篇 |
2000年 | 198篇 |
1999年 | 157篇 |
1998年 | 80篇 |
1997年 | 70篇 |
1996年 | 70篇 |
1995年 | 63篇 |
1994年 | 59篇 |
1993年 | 65篇 |
1992年 | 174篇 |
1991年 | 140篇 |
1990年 | 175篇 |
1989年 | 147篇 |
1988年 | 140篇 |
1987年 | 146篇 |
1986年 | 135篇 |
1985年 | 131篇 |
1984年 | 109篇 |
1983年 | 92篇 |
1982年 | 69篇 |
1981年 | 62篇 |
1980年 | 60篇 |
1979年 | 92篇 |
1978年 | 87篇 |
1977年 | 83篇 |
1976年 | 66篇 |
1975年 | 55篇 |
1974年 | 86篇 |
1973年 | 82篇 |
1970年 | 57篇 |
排序方式: 共有8311条查询结果,搜索用时 15 毫秒
1.
Daniel J. Snyder Thomas R. Kroshus Aakash Keswani Evan B. Garden Karl M. Koenig Kevin J. Bozic David S. Jevsevar Jashvant Poeran Calin S. Moucha 《The Journal of arthroplasty》2019,34(4):613-618
Background
Nursing Home Compare (NHC) ratings, created and maintained by Medicare, are used by both hospitals and consumers to aid in the skilled nursing facility (SNF) selection process. To date, no studies have linked NHC ratings to actual episode-based outcomes. The purpose of this study was to evaluate whether NHC ratings are valid predictors of 90-day complications, readmission, and bundle costs for patients discharged to an SNF after primary total joint arthroplasty (TJA).Methods
All SNF-discharged primary TJA cases in 2017 at a multihospital academic health system were queried. Demographic, psychosocial, and clinical variables were manually extracted from the health record. Medicare NHC ratings were then collected for each SNF. For patients in the Medicare bundle, postacute and total bundle cost was extracted from claims.Results
Four hundred eighty-eight patients were discharged to a total of 105 unique SNFs. In multivariate analysis, overall NHC rating was not predictive of 90-day readmission/major complications, >75th percentile postacute cost, or 90-day bundle cost exceeding the target price. SNF health inspection and quality measure ratings were also not predictive of 90-day readmission/major complications or bundle performance. A higher SNF staffing rating was independently associated with a decreased odds for >75th percentile 90-day postacute spend (odds ratio, 0.58; P = .01) and a 90-day bundle cost exceeding the target price (odds ratio = 0.69; P = .02) but was similarly not predictive of 90-day readmission/complications.Conclusion
Results of our study suggest that Medicare's NHC tool is not a useful predictor of 90-day costs, complications, or readmissions for SNFs within our health system. 相似文献2.
3.
4.
Gerald T Voelbel Marsha E Bates Jennifer F Buckman Gahan Pandina Robert L Hendren 《Neuropsychopharmacology》2006,60(9):942-950
BACKGROUND: Impaired neuropsychological test performance, especially on tests of executive function and attention, is often seen in children diagnosed with autism spectrum disorders (ASD). Structures involved in fronto-striatal circuitry, such as the caudate nucleus, may support these cognitive abilities. However, few studies have examined caudate volumes specifically in children with ASD, or correlated caudate volumes to cognitive ability. METHODS: Neuropsychological test scores and caudate volumes of children with ASD were compared to those of children with bipolar disorder (BD) and of typically developing (TD) children. The relationship between test performance and caudate volumes was analyzed. RESULTS: The ASD group displayed larger right and left caudate volumes, and modest executive deficits, compared to TD controls. While caudate volume inversely predicted performance on the Wisconsin Card Sorting Test in all participants, it differentially predicted performance on measures of attention across the ASD, BD and TD groups. CONCLUSIONS: Larger caudate volumes were related to impaired problem solving. On a test of attention, larger left caudate volumes predicted increased impulsivity and more omission errors in the ASD group as compared to the TD group, however smaller volume predicted poorer discriminant responding as compared to the BD group. 相似文献
5.
Treatment of primary hypogonadism in men by the transdermal administration of testosterone 总被引:2,自引:0,他引:2
J C Findlay V Place P J Snyder 《The Journal of clinical endocrinology and metabolism》1989,68(2):369-373
We tested the efficacy of a thin flexible testosterone-impregnated membrane applied to the scrotum for the long term treatment of male hypogonadism. Ten men with primary hypogonadism were treated for 3 months (2 men) or 13 months (8 men). Serum testosterone concentrations increased in all 10 men, to within the normal range in 8. Serum dihydrotestosterone concentrations increased to supranormal values in all of the men, decreased to the normal range in 6, indicating the biological effectiveness of the testosterone in those subjects. Two men whose serum LH concentrations did not fall to normal had small or distorted scrotal surfaces. Seven of the 8 men whose serum testosterone concentrations became normal said that their hypogonadal symptoms were corrected by this treatment. We conclude that the transdermal administration of testosterone is an effective means of treating the majority of hypogonadal men who have a normal scrotum. 相似文献
6.
Efficient high-frequency body coil for high-field MRI. 总被引:1,自引:0,他引:1
J T Vaughan G Adriany C J Snyder J Tian T Thiel L Bolinger H Liu L DelaBarre K Ugurbil 《Magnetic resonance in medicine》2004,52(4):851-859
The use of body coils is favored for homogeneous excitation, and such coils are often paired with surface coils or arrays for sensitive reception in many MRI applications. While the body coil's physical size and resultant electrical length make this circuit difficult to design for any field strength, recent efforts to build efficient body coils for applications at 3T and above have been especially challenging. To meet this challenge, we developed an efficient new transverse electromagnetic (TEM) body coil and demonstrated its use in human studies at field strengths up to 4 T. Head, body, and breast images were acquired within peak power constraints of <8 kW. Bench studies indicate that these body coils are feasible to 8 T. RF shimming was used to remove a high-field-related cardiac imaging artifact in these preliminary studies. P41RR13230 相似文献
7.
Infections are the most common complication in patients receiving treatment for cancer with neutropenia being the primary risk factor for the development of an infection. In the neutropenic patient, bacteremia remains a significant cause of mortality. Although the literature reports that prompt empiric antibiotic therapy to prevent death caused by virulent organisms is the standard of care, the literature fails to identify what prompt antibiotic administration means. Door/fever-to-patient antibiotic delivery was evaluated as a quality control measure in a new children's hospital. Initially, door/fever-to-patient time was significantly delayed. Collaboration between pharmacy, hospital bed control, medical, and nursing staff resulted in many changes in practice by all groups. As a result, the goal for prompt antibiotic delivery of thirty minutes or less is now achievable. 相似文献
8.
9.
Specific factors have limited the interpretation of studies regarding the efficacy, effectiveness and efficiency of technology in anaesthesia. Some of these problems are reviewed, including the lack of specific outcomes necessitating the use of intermediate measures (e.g., hypoxaemia, myocardial ischaemia), which are not necessarily related to ultimate patient outcomes. This emphasizes the need for anaesthesia investigators to define fundamental issues specifically and design studies accordingly. With respect to anaesthesia monitors, the “lead time” or early warning provided by a monitor relative to that required to alter therapy effectively needs to be defined better and compared with the “lead time” without the monitor. After defining the benefit of a monitor, investigators should analyze the cost relative to alternatives (cost-benefit and cost-effectiveness). A hierarchical model to guide technology assessment is presented that addresses in order, the scientific basis of the technology, and the influence on the patient followed by societal issues. Anaesthetists have relied on traditional methods of technology assessment adopted from other disciplines. These methodologies do not address specific issues related to anaesthesia practice (such as “lead time”). In defining problems specific to the specialty of anaesthesia, new outcome measures that focus on the human factors related to decision-making in the operating room need to be developed. Future evaluations of anaesthesia technology require innovative approaches that address specific anaesthesia-related problems. One such approach is the use of simulation-based studies of response patterns to critical incidents. 相似文献
10.