全文获取类型
收费全文 | 4431篇 |
免费 | 342篇 |
国内免费 | 9篇 |
专业分类
耳鼻咽喉 | 46篇 |
儿科学 | 104篇 |
妇产科学 | 86篇 |
基础医学 | 777篇 |
口腔科学 | 58篇 |
临床医学 | 553篇 |
内科学 | 875篇 |
皮肤病学 | 81篇 |
神经病学 | 531篇 |
特种医学 | 139篇 |
外科学 | 405篇 |
综合类 | 34篇 |
一般理论 | 2篇 |
预防医学 | 384篇 |
眼科学 | 30篇 |
药学 | 259篇 |
中国医学 | 25篇 |
肿瘤学 | 393篇 |
出版年
2024年 | 1篇 |
2023年 | 52篇 |
2022年 | 80篇 |
2021年 | 153篇 |
2020年 | 94篇 |
2019年 | 147篇 |
2018年 | 149篇 |
2017年 | 116篇 |
2016年 | 149篇 |
2015年 | 161篇 |
2014年 | 186篇 |
2013年 | 257篇 |
2012年 | 403篇 |
2011年 | 413篇 |
2010年 | 218篇 |
2009年 | 199篇 |
2008年 | 291篇 |
2007年 | 296篇 |
2006年 | 301篇 |
2005年 | 257篇 |
2004年 | 213篇 |
2003年 | 205篇 |
2002年 | 204篇 |
2001年 | 17篇 |
2000年 | 19篇 |
1999年 | 23篇 |
1998年 | 33篇 |
1997年 | 20篇 |
1996年 | 13篇 |
1995年 | 10篇 |
1994年 | 18篇 |
1993年 | 15篇 |
1992年 | 8篇 |
1991年 | 7篇 |
1990年 | 5篇 |
1989年 | 5篇 |
1988年 | 3篇 |
1987年 | 2篇 |
1986年 | 6篇 |
1985年 | 2篇 |
1984年 | 6篇 |
1983年 | 7篇 |
1982年 | 7篇 |
1981年 | 1篇 |
1976年 | 2篇 |
1974年 | 5篇 |
1970年 | 2篇 |
1894年 | 1篇 |
排序方式: 共有4782条查询结果,搜索用时 343 毫秒
81.
PURPOSE OF REVIEW: Hospitalization and mortality rates associated with heart failure are persistently high. This is due partly to aging of the population but mostly to delayed progress in the pharmacological treatment of decompensated heart failure. We will review the current recommendations and most recent advancement in the pharmacological treatment of acute decompensated heart failure while providing a systematic approach to the management of this prevalent condition. RECENT FINDINGS: Loop diuretics, nitrates and inotropes such as dobutamine and milrinone are the current mainstay of acute heart failure management although their associated morbidity and possible mortality have raised serious concerns. Recent vasoactive agents such as Nesiritide, Tolvaptan and more recently the inotropic agent Levosimedan could offer improved hemodynamics and congestive relief to patients in acute pulmonary edema. SUMMARY: Despite the promising results of these agents, further clinical trials are required prior to their international approval as first-line therapy. Although we can be optimistic that these vasoactive drugs might have favorable clinical outcomes and improve the intricate management of decompensated heart failure, their associated mortality benefit remains unclear and controversial. 相似文献
82.
The role of prolactin and growth hormone in mammary gland development 总被引:12,自引:0,他引:12
Kelly PA Bachelot A Kedzia C Hennighausen L Ormandy CJ Kopchick JJ Binart N 《Molecular and cellular endocrinology》2002,197(1-2):127-131
Development and differentiation of the mammary gland occur primarily during pregnancy. Females homozygous (-/-) for the null mutation of the PRL receptor (PRLR) gene are sterile due to a complete failure of blastocysts to implant. In progesterone-treated mice pregnancy is rescued but the mammary gland is severely underdeveloped. Interestingly, females hemizygous for the PRLR (+/-) in their first lactation show an almost complete failure to lactate. This phenotype disappears in the second and subsequent pregnancies in inbred 129/Sv mice but is maintained in inbred C57BL/6 mice. In GH receptor (GHR) KO mice litter size is markedly decreased, probably due to an ovarian defect. To assess the relevance of the GH and PRLRs in the mammary gland development, GHR and PRLR null epithelia were transplanted into cleared fat pads of wild-type mice. Such studies show that epithelial GHR is not required for functional mammary development. In contrast, epithelial PRLRs are required for mammary development and milk protein gene expression during pregnancy. Since ductal development is impaired in GHR -/- mice, it appears that GH signals through the stromal compartment. In summary, it is now established that GH and PRL activate Stat5 in separate compartments, reflecting their specific roles in ductal and alveolar development and differentiation. 相似文献
83.
84.
Martin Stroedicke Yacine Bounab Nadine Strempel Konrad Klockmeier Sargon Yigit Ralf P. Friedrich Gautam Chaurasia Shuang Li Franziska Hesse Sean-Patrick Riechers Jenny Russ Cecilia Nicoletti Annett Boeddrich Thomas Wiglenda Christian Haenig Sigrid Schnoegl David Fournier Rona K. Graham Michael R. Hayden Stephan Sigrist Gillian P. Bates Josef Priller Miguel A. Andrade-Navarro Matthias E. Futschik Erich E. Wanker 《Genome research》2015,25(5):701-713
85.
Initial graft size and not the innate immune response limit survival of engrafted neural stem cells
下载免费PDF全文
![点击此处可从《Journal of tissue engineering and regenerative medicine》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Stefanie Vogel Markus Aswendt Melanie Nelles Nadine Henn Gabriele Schneider Mathias Hoehn 《Journal of tissue engineering and regenerative medicine》2018,12(3):784-793
Transplantation of neural stem cells (NSCs) appears to be a promising regenerative therapy for a variety of neurological disorders. Nevertheless, NSC engraftment is limited by the number of surviving cells. To maximize stem cell‐mediated effects, timing of implantation and cell number have to be precisely evaluated. Here, a transgenic murine NSC line was optimized for high expression levels of the imaging reporters Luc2 and copGFP. NSCs of 150 000, 75 000, 15 000 or 1500 cells or Hanks buffered salt solution were implanted into the striatum of nude mice. The survival of NSCs was monitored with in vivo bioluminescence imaging (BLI) over 2 weeks and brain sections were histologically analysed for glial cells of the innate immune system. The longitudinal in vivo BLI data revealed a significantly reduced viability with the highest rate for 150 000 engrafted NSCs. The cell loss was not correlated with the number of Iba‐1+ immune cells nor GFAP+ astrocytes. Histological quantification of copGFP+ cells at 14 days postimplantation confirmed the in vivo data with the highest density of copGFP+ cells in the 150 000‐cell graft and the highest survival rate for 1500 cells/graft. In conclusion, regenerative therapies should strictly evaluate the maximal number of stem cells to be transplanted in one location, as the results suggest that there is a critical limit of cells able to survive in the adult brain. Survival is limited by availability of oxygen and nutrients but not the inflammatory response induced by the implantation. 相似文献
86.
Andrew J. Vickers Emily A. Vertosick George Lewith Hugh MacPherson Nadine E. Foster Karen J. Sherman Dominik Irnich Claudia M. Witt Klaus Linde 《The journal of pain》2018,19(5):455-474
Despite wide use in clinical practice, acupuncture remains a controversial treatment for chronic pain. Our objective was to update an individual patient data meta-analysis to determine the effect size of acupuncture for 4 chronic pain conditions. We searched MEDLINE and the Cochrane Central Registry of Controlled Trials randomized trials published up until December 31, 2015. We included randomized trials of acupuncture needling versus either sham acupuncture or no acupuncture control for nonspecific musculoskeletal pain, osteoarthritis, chronic headache, or shoulder pain. Trials were only included if allocation concealment was unambiguously determined to be adequate. Raw data were obtained from study authors and entered into an individual patient data meta-analysis. The main outcome measures were pain and function. An additional 13 trials were identified, with data received for a total of 20,827 patients from 39 trials. Acupuncture was superior to sham as well as no acupuncture control for each pain condition (all P?<?.001) with differences between groups close to .5 SDs compared with no acupuncture control and close to .2 SDs compared with sham. We also found clear evidence that the effects of acupuncture persist over time with only a small decrease, approximately 15%, in treatment effect at 1 year. In secondary analyses, we found no obvious association between trial outcome and characteristics of acupuncture treatment, but effect sizes of acupuncture were associated with the type of control group, with smaller effects sizes for sham controlled trials that used a penetrating needle for sham, and for trials that had high intensity of intervention in the control arm. We conclude that acupuncture is effective for the treatment of chronic pain, with treatment effects persisting over time. Although factors in addition to the specific effects of needling at correct acupuncture point locations are important contributors to the treatment effect, decreases in pain after acupuncture cannot be explained solely in terms of placebo effects. Variations in the effect size of acupuncture in different trials are driven predominantly by differences in treatments received by the control group rather than by differences in the characteristics of acupuncture treatment.
Perspective
Acupuncture is effective for the treatment of chronic musculoskeletal, headache, and osteoarthritis pain. Treatment effects of acupuncture persist over time and cannot be explained solely in terms of placebo effects. Referral for a course of acupuncture treatment is a reasonable option for a patient with chronic pain. 相似文献87.
88.
Machiko R. Tomita Nadine M. Fisher Sujata Nair Dan Ramsey Kimberley Persons 《Physical & occupational therapy in geriatrics》2018,36(1):107-119
Aims: The aim of the study was to determine whether increased physical activities (PA) affect frailty for old women, 75 years and older (OO), compared to 60–74 years old (YO). Methods: This cross-sectional study measured 19 frailty indicators (muscle strength and endurance, balance, gait characteristics, and function), using 46 community-dwelling women. PA were divided into three levels by caloric expenditure per week (<2,000 kcal/week, 2,000–3,999 kcal/week, >4,000 kcal/week). Results: As PA level increased, a gap (=difference) between OO and YO narrowed for step length and function, but for quadriceps strength and endurance, a gap widened. Conclusions: Frailty progresses with aging but older women who engage in a high level of physical activity (>4,000 kcal/week) can increase mobility and functional capacity, but not for muscle strength and endurance. Starting regular resistance training activities early in the aging process is critical to improve or maintain muscle quality to offset age-related frailty. 相似文献
89.