全文获取类型
收费全文 | 1979篇 |
免费 | 165篇 |
国内免费 | 50篇 |
专业分类
耳鼻咽喉 | 13篇 |
儿科学 | 102篇 |
妇产科学 | 80篇 |
基础医学 | 185篇 |
口腔科学 | 71篇 |
临床医学 | 227篇 |
内科学 | 442篇 |
皮肤病学 | 33篇 |
神经病学 | 125篇 |
特种医学 | 177篇 |
外科学 | 296篇 |
综合类 | 89篇 |
一般理论 | 1篇 |
预防医学 | 97篇 |
眼科学 | 51篇 |
药学 | 102篇 |
1篇 | |
中国医学 | 10篇 |
肿瘤学 | 92篇 |
出版年
2023年 | 19篇 |
2022年 | 27篇 |
2021年 | 46篇 |
2020年 | 40篇 |
2019年 | 38篇 |
2018年 | 52篇 |
2017年 | 44篇 |
2016年 | 50篇 |
2015年 | 60篇 |
2014年 | 74篇 |
2013年 | 89篇 |
2012年 | 73篇 |
2011年 | 90篇 |
2010年 | 84篇 |
2009年 | 109篇 |
2008年 | 75篇 |
2007年 | 94篇 |
2006年 | 57篇 |
2005年 | 64篇 |
2004年 | 43篇 |
2003年 | 56篇 |
2002年 | 30篇 |
2001年 | 39篇 |
2000年 | 32篇 |
1999年 | 43篇 |
1998年 | 81篇 |
1997年 | 92篇 |
1996年 | 63篇 |
1995年 | 57篇 |
1994年 | 43篇 |
1993年 | 43篇 |
1992年 | 29篇 |
1991年 | 17篇 |
1990年 | 29篇 |
1989年 | 39篇 |
1988年 | 35篇 |
1987年 | 39篇 |
1986年 | 18篇 |
1985年 | 19篇 |
1984年 | 15篇 |
1983年 | 14篇 |
1982年 | 12篇 |
1981年 | 11篇 |
1980年 | 10篇 |
1978年 | 8篇 |
1977年 | 15篇 |
1975年 | 8篇 |
1974年 | 8篇 |
1973年 | 16篇 |
1972年 | 9篇 |
排序方式: 共有2194条查询结果,搜索用时 14 毫秒
61.
62.
Oon Hoe Teoh Tan Pih Lin Marieke Abrahamse-Berkeveld Antoinette Winokan Yap Seng Chong Fabian Yap Maya Marintcheva-Petrova Eline M. van der Beek Lynette P. Shek 《Nutrients》2022,14(3)
Lipids are essential for healthy infant growth and development. The structural complexity of lipids in human milk is not present in infant milk formula (IF). A concept IF was developed mimicking more closely the structure and composition of human milk fat globules. The current study evaluates whether a concept IF with large, milk phospholipid-coated lipid droplets (mode diameter 3 to 5 μm) is equivalent to standard IF with regard to growth adequacy and safety in healthy, term Asian infants. In this randomized, double-blind, controlled trial, infants were randomized after parents decided to introduce formula. Infants received a standard IF with (Control) or without the specific prebiotic mixture scGOS/lcFOS (9:1 ratio; Control w/o prebiotics), or a Concept IF with large, milk phospholipid-coated lipid droplets and the prebiotic mixture. A group of 67 breastfed infants served as a reference. As a priori defined, only those infants who were fully intervention formula-fed ≤28 days of age were included in the equivalence analysis (Control n = 29; Control w/o prebiotics n = 28; Concept n = 35, per-protocol population). Primary outcome was daily weight gain during the first four months of life, with the difference between the Concept and Control as the key comparison of interest. Additionally, adverse events, growth and tolerance parameters were evaluated. Equivalence of daily weight gain was demonstrated between the Concept and Control group after additional correction for ethnicity and birthweight (difference in estimated means of 0.1 g/d, 90%CI [−2.30, 2.47]; equivalence margin +/− 3 g/d). No clinically relevant group differences were observed in secondary growth outcomes, tolerance outcomes or number, severity or relatedness of adverse events. This study corroborates that an infant formula with large, milk phospholipid-coated lipid droplets supports adequate growth and is well tolerated and safe for use in healthy infants. 相似文献
63.
64.
65.
Review: bioreactor design towards generation of relevant engineered tissues: focus on clinical translation 下载免费PDF全文
Swee‐Hin Teoh 《Journal of tissue engineering and regenerative medicine》2018,12(1):e7-e22
In tissue engineering and regenerative medicine, studies that utilize 3D scaffolds for generating voluminous tissues are mostly confined in the realm of in vitro research and preclinical animal model testing. Bioreactors offer an excellent platform to grow and develop 3D tissues by providing conditions that mimic their native microenvironment. Aligning the bioreactor development process with a focus on patient care will aid in the faster translation of the bioreactor technology to clinics. In this review, we discuss the various factors involved in the design of clinically relevant bioreactors in relation to their respective applications. We explore the functional relevance of tissue grafts generated by bioreactors that have been designed to provide physiologically relevant mechanical cues on the growing tissue. The review discusses the recent trends in non‐invasive sensing of the bioreactor culture conditions. It provides an insight to the current technological advancements that enable in situ, non‐invasive, qualitative and quantitative evaluation of the tissue grafts grown in a bioreactor system. We summarize the emerging trends in commercial bioreactor design followed by a short discussion on the aspects that hamper the ‘push’ of bioreactor systems into the commercial market as well as ‘pull’ factors for stakeholders to embrace and adopt widespread utility of bioreactors in the clinical setting. Copyright © 2017 John Wiley & Sons, Ltd. 相似文献
66.
Vikas Madan Zeya Cao Weoi Woon Teoh Pushkar Dakle Lin Han Pavithra Shyamsunder Maya Jeitany Siqin Zhou Jia Li Hazimah Binte Mohd Nordin Jizhong Shi Shuizhou Yu Henry Yang Md Zakir Hossain Wee Joo Chng H. Phillip Koeffler 《Haematologica》2022,107(3):680
Recurrent loss-of-function mutations of spliceosome gene, ZRSR2, occur in myelodysplastic syndromes (MDS). Mutation/loss of ZRSR2 in human myeloid cells primarily causes impaired splicing of the U12-type introns. In order to further investigate the role of this splice factor in RNA splicing and hematopoietic development, we generated mice lacking ZRSR2. Unexpectedly, Zrsr2-deficient mice developed normal hematopoiesis with no abnormalities in myeloid differentiation evident in either young or ≥1-year old knockout mice. Repopulation ability of Zrsr2-deficient hematopoietic stem cells was also unaffected in both competitive and non-competitive reconstitution assays. Myeloid progenitors lacking ZRSR2 exhibited mis-splicing of U12-type introns, however, this phenotype was moderate compared to the ZRSR2-deficient human cells. Our investigations revealed that a closely related homolog, Zrsr1, expressed in the murine hematopoietic cells, but not in human cells contributes to splicing of U12-type introns. Depletion of Zrsr1 in Zrsr2 KO myeloid cells exacerbated retention of the U12-type introns, thus highlighting a collective role of ZRSR1 and ZRSR2 in murine U12-spliceosome. We also demonstrate that aberrant retention of U12-type introns of MAPK9 and MAPK14 leads to their reduced protein expression. Overall, our findings highlight that both ZRSR1 and ZRSR2 are functional components of the murine U12-spliceosome, and depletion of both proteins is required to accurately model ZRSR2-mutant MDS in mice. 相似文献
67.
The modified respiratory index score (RIS) guides resource allocation in acute bronchiolitis 下载免费PDF全文
68.
Management of upper gastrointestinal (UGI) tract gastrointestinal stromal tumor (GIST) has evolved significantly over the past two decades. For GIST size smaller than 5 cm, laparoscopic resection has become the current standard. To avoid postoperative gastric deformity and preserve gastric function, laparoscopic endoscopic cooperative surgery (LECS) was developed and various modifications have been reported and utilized successfully. Pure endoscopic resection techniques have also been reported at a similar period of time, which further push the boundary of incisionless surgery in managing these lesions. Both tunneling and nontunneling exposed type endoscopic full thickness resection are well described procedures for resection of small UGI GIST. In this review, a summary of these procedures is provided, and the pros and cons of each technique from the perspective of a surgical endoscopist are discussed in detail. LECS and endoscopic resection are complementary to each other. The choice of technique should be tailored to the location, morphology, and size of the target lesions, taking into account the experience of the laparoscopic surgeons and endoscopists. 相似文献
69.
Transcatheter closure of patent ductus arteriosus using the AMPLATZER™ duct occluder II (ADO II) 下载免费PDF全文
70.
Zhang ZY Teoh SH Chong MS Schantz JT Fisk NM Choolani MA Chan J 《Stem cells (Dayton, Ohio)》2009,27(1):126-137
Mesenchymal stem cells (MSCs) from human adult bone marrow (haMSCs) represent a promising source for bone tissue engineering. However, their low frequencies and limited proliferation restrict their clinical utility. Alternative postnatal, perinatal, and fetal sources of MSCs appear to have different osteogenic capacities, but have not been systematically compared with haMSCs. We investigated the proliferative and osteogenic potential of MSCs from human fetal bone marrow (hfMSCs), human umbilical cord (hUCMSCs), and human adult adipose tissue (hATMSCs), and haMSCs, both in monolayer cultures and after loading into three-dimensional polycaprolactone-tricalcium-phosphate scaffolds.Although all MSCs had comparable immunophenotypes, only hfMSCs and hUCMSCs were positive for the embryonic pluripotency markers Oct-4 and Nanog. hfMSCs expressed the lowest HLA-I level (55% versus 95%-99%) and the highest Stro-1 level (51% versus 10%-27%), and had the greatest colony-forming unit-fibroblast capacity (1.6x-2.0x; p < .01) and fastest doubling time (32 versus 54-111 hours; p < .01). hfMSCs had the greatest osteogenic capacity, as assessed by von-Kossa staining, alkaline phosphatase activity (5.1x-12.4x; p < .01), calcium deposition (1.6x-2.7x in monolayer and 1.6x-5.0x in scaffold culture; p < .01), calcium visualized on micro-computed tomography (3.9x17.6x; p < .01) and scanning electron microscopy, and osteogenic gene induction. Two months after implantation of cellular scaffolds in immunodeficient mice, hfMSCs resulted in the most robust mineralization (1.8x-13.3x; p < .01).The ontological and anatomical origins of MSCs have profound influences on the proliferative and osteogenic capacity of MSCs. hfMSCs had the most proliferative and osteogenic capacity of the MSC sources, as well as being the least immunogenic, suggesting they are superior candidates for bone tissue engineering. 相似文献