全文获取类型
收费全文 | 4071篇 |
免费 | 378篇 |
专业分类
4449篇 |
出版年
2023年 | 23篇 |
2022年 | 29篇 |
2021年 | 60篇 |
2020年 | 45篇 |
2019年 | 51篇 |
2018年 | 53篇 |
2017年 | 57篇 |
2016年 | 103篇 |
2015年 | 187篇 |
2014年 | 213篇 |
2013年 | 202篇 |
2012年 | 307篇 |
2011年 | 295篇 |
2010年 | 227篇 |
2009年 | 174篇 |
2008年 | 252篇 |
2007年 | 223篇 |
2006年 | 227篇 |
2005年 | 215篇 |
2004年 | 212篇 |
2003年 | 207篇 |
2002年 | 224篇 |
2001年 | 30篇 |
2000年 | 27篇 |
1999年 | 47篇 |
1998年 | 58篇 |
1997年 | 44篇 |
1996年 | 42篇 |
1995年 | 35篇 |
1994年 | 35篇 |
1993年 | 43篇 |
1992年 | 29篇 |
1991年 | 44篇 |
1990年 | 16篇 |
1989年 | 41篇 |
1988年 | 34篇 |
1987年 | 25篇 |
1986年 | 22篇 |
1985年 | 18篇 |
1984年 | 24篇 |
1983年 | 17篇 |
1982年 | 28篇 |
1981年 | 19篇 |
1980年 | 17篇 |
1979年 | 14篇 |
1978年 | 16篇 |
1977年 | 13篇 |
1976年 | 13篇 |
1974年 | 15篇 |
1973年 | 14篇 |
排序方式: 共有4449条查询结果,搜索用时 15 毫秒
131.
Martin PD Dutton GR Rhode PC Horswell RL Ryan DH Brantley PJ 《Obesity (Silver Spring, Md.)》2008,16(11):2462-2467
Although the primary care setting offers an innovative option for weight loss interventions, there is minimal research examining this type of intervention with low-income minority women. Further, there is a lack of research on the long-term effects of these programs. The purpose of this investigation was to examine the weight loss maintenance of low-income African-American women participating in a primary care weight management intervention. A randomized controlled trial was conducted with overweight and obese women (N = 144) enrolled at two primary care clinics. Women received a 6-month tailored weight loss intervention delivered by their primary care physician and completed follow-up assessments 9, 12, and 18 months following randomization. The weight loss maintenance of the tailored intervention was compared to a standard care comparison group. The weight loss of intervention participants (-1.52 +/- 3.72 kg) was significantly greater than that of standard care participants (0.61 +/- 3.37 kg) at month 9 (P = 0.01). However, there was no difference between the groups at the 12-month or 18-month follow-ups. Participants receiving a tailored weight loss intervention from their physician were able to maintain their modest weight loss up to 3-6 months following treatment. Women demonstrated weight regain at the 18-month follow-up assessment, suggesting that more intensive follow-up in the primary care setting may be needed to obtain successful long-term weight loss maintenance. 相似文献
132.
133.
In Disney/Pixar's phenomenally popular animated film Finding Nemo (Stanton, 2003), one of the central themes of fish welfare was highlighted when the moorish idol, Gill, commented, “Fish aren't meant to be kept in a box, kid. It does things to you.” The notion that fish might have the capacity to suffer in captivity (Chandroo, Duncan, & Moccia, 2004a, 2004b) links to the larger question of sentiency, which remains a fundamental tenet when justifying concerns for nonhuman animal welfare (Dawkins, 2006; Huntingford et al., 2006). Although terrestrial nonhuman-animal welfare has been discussed and explored for many years, the development of aquatic animal welfare concepts and approaches remains relatively new and beyond public awareness (Braastad, Damsgård, & Juell, 2006; Broom, 2007; Farmed Animal Welfare Council, 1996; Fisheries Society of the British Isles, 2002; Håstein, Scarfe, & Lund, 2005; Iwama, 2007; Schreck, 1981). 相似文献
134.
Induction of interleukin-8 synthesis integrates effects on transcription and mRNA degradation from at least three different cytokine- or stress-activated signal transduction pathways. 下载免费PDF全文
135.
Guang-Sheng Lei Chen Zhang Shoujin Shao Hsin-Wei Jung Pamela J. Durant Chao-Hung Lee 《PloS one》2013,8(1)
Pneumocystis pneumonia (PcP) develops in immunocompromised patients. Alveolar macrophages play a key role in the recognition, phagocytosis, and degradation of Pneumocystis, but their number is decreased in PcP. Our study of various inflammatory components during PcP found that myeloid-derived suppressor cells (MDSCs) accumulate in the lungs of mice and rats with Pneumocystis pneumonia (PcP). We hypothesized that treatment with all-trans retinoic acid (ATRA), a metabolite of vitamin A, may effectively control Pneumocystis (Pc) infection by inducing MDSCs to differentiate to AMs. In rodent models of PcP, we found that 5 weeks of ATRA treatment reduced the number of MDSCs in the lungs and increased the number of AMs which cleared Pc infection. We also found that ATRA in combination with primaquine was as effective as the combination of trimethoprim and sulfamethaxazole for treatment of PcP and completely eliminated MDSCs and Pc organisms in the lungs in two weeks. No relapse of PcP was seen after three weeks of the ATRA-primaquine combination treatment. Prolonged survival of Pc-infected animals was also achieved by this regimen. This is the very first successful development of a therapeutic regimen for PcP that combines an immune modulator with an antibiotic, enabling the hosts to effectively defend the infection. Results of our study may serve as a model for development of novel therapies for other infections with MDSC accumulation. 相似文献
136.
137.
Houghton PE 《In vitro cellular & developmental biology. Animal》1999,35(10):599-605
Summary Numerous musculoskeletal disorders which occur during pregnancy require an effective, nonpharmacological treatment that is
known to have no adverse effects on fetal development. The present report describes morphological and histological changes
occurring in fetal mouse limbs maintained in a serum-free organ culture system. Limbs maintained in this organ culture system
show a progressive rise in limb dimensions including surface area, perimeter, and limb length. Histological analysis of serial
cross sections of the limbs revealed a statistically significant increase in histological scores of limb development, thickness
of epidermal layer, and amount of collagen deposited in the bone and dermis of limbs by Day 4 of culture. Therefore, this
in vitro model combined with contemporary computer image analysis represents an excellent experimental model which can be
used readily to examine the effects of therapeutic modalities on the growth and development of many different organ systems. 相似文献
138.
A human T-cell lymphotropic virus type 1 enhancer of Myc transforming potential stabilizes Myc-TIP60 transcriptional interactions 下载免费PDF全文
139.
140.