全文获取类型
收费全文 | 5313篇 |
免费 | 368篇 |
国内免费 | 11篇 |
专业分类
耳鼻咽喉 | 27篇 |
儿科学 | 184篇 |
妇产科学 | 134篇 |
基础医学 | 598篇 |
口腔科学 | 53篇 |
临床医学 | 1090篇 |
内科学 | 884篇 |
皮肤病学 | 61篇 |
神经病学 | 618篇 |
特种医学 | 79篇 |
外科学 | 492篇 |
综合类 | 83篇 |
一般理论 | 7篇 |
预防医学 | 612篇 |
眼科学 | 134篇 |
药学 | 257篇 |
中国医学 | 10篇 |
肿瘤学 | 369篇 |
出版年
2023年 | 40篇 |
2022年 | 56篇 |
2021年 | 136篇 |
2020年 | 72篇 |
2019年 | 128篇 |
2018年 | 143篇 |
2017年 | 110篇 |
2016年 | 109篇 |
2015年 | 115篇 |
2014年 | 165篇 |
2013年 | 268篇 |
2012年 | 376篇 |
2011年 | 398篇 |
2010年 | 235篇 |
2009年 | 189篇 |
2008年 | 364篇 |
2007年 | 355篇 |
2006年 | 298篇 |
2005年 | 357篇 |
2004年 | 353篇 |
2003年 | 284篇 |
2002年 | 276篇 |
2001年 | 53篇 |
2000年 | 42篇 |
1999年 | 59篇 |
1998年 | 52篇 |
1997年 | 53篇 |
1996年 | 38篇 |
1995年 | 35篇 |
1994年 | 32篇 |
1993年 | 36篇 |
1992年 | 30篇 |
1991年 | 31篇 |
1990年 | 25篇 |
1989年 | 26篇 |
1988年 | 19篇 |
1987年 | 17篇 |
1986年 | 17篇 |
1985年 | 16篇 |
1984年 | 26篇 |
1983年 | 17篇 |
1982年 | 17篇 |
1981年 | 25篇 |
1980年 | 23篇 |
1979年 | 12篇 |
1978年 | 17篇 |
1977年 | 16篇 |
1975年 | 12篇 |
1974年 | 17篇 |
1972年 | 12篇 |
排序方式: 共有5692条查询结果,搜索用时 15 毫秒
31.
Adrenocorticotropic Hormone Immunoreactivity in the Hippocampal Formation of Temporal Lobe Epilepsy Patients 总被引:1,自引:0,他引:1
Summary: Purpose: We wished to identify immunocytochemically the distribution of proopiomelanocortin-related peptides in the hippocampal formation of patients with epilepsy.
Methods: Surgical hippocampal specimens from temporal lobe epilepsy (TLE) patients and autopsy control tissue were examined immunocytochemically for ACTH, α-melanocyte-stimulating hormone (α-MSH) and α-endorphin.
Results: There was a dense distribution of ACTH-immunoreactive neurons in the hippocampal formation of patients with mesial TLE syndrome (MTLE). These hippocampal specimens showed significant cell loss. ACTH-positive neurons were most prominent in the subiculum, with scattered ACTH-immunoreactive neuronal elements distributed in the cornu ammonis fields and hilus. Light ACTH immunoreactivity was detected in the tumor-related epileptic hippocampal specimens, which showed minimal cell loss. Although autopsy control tissue from the hypothalamus showed intense ACTH staining patterns in cells and fibers, there was little or no ACTH immunoreactivity in the autopsy hippocampal tissue. The expression of ACTH immunoreactive elements was correlated with patterns of cell loss. No α-MSH- or β-endorphin-immunoreactive neurons were detected in any of the hippocampal specimens.
Conclusions: ACTH has anticonvulsant properties, and its novel expression in the glutamatergic subicular neurons, which provide the main outflow of the hippocampal formation, may represent an attempt by the damaged hippocampal circuit to restore the balance of excitatory/inhibitory neurotransmission in TLE. 相似文献
Methods: Surgical hippocampal specimens from temporal lobe epilepsy (TLE) patients and autopsy control tissue were examined immunocytochemically for ACTH, α-melanocyte-stimulating hormone (α-MSH) and α-endorphin.
Results: There was a dense distribution of ACTH-immunoreactive neurons in the hippocampal formation of patients with mesial TLE syndrome (MTLE). These hippocampal specimens showed significant cell loss. ACTH-positive neurons were most prominent in the subiculum, with scattered ACTH-immunoreactive neuronal elements distributed in the cornu ammonis fields and hilus. Light ACTH immunoreactivity was detected in the tumor-related epileptic hippocampal specimens, which showed minimal cell loss. Although autopsy control tissue from the hypothalamus showed intense ACTH staining patterns in cells and fibers, there was little or no ACTH immunoreactivity in the autopsy hippocampal tissue. The expression of ACTH immunoreactive elements was correlated with patterns of cell loss. No α-MSH- or β-endorphin-immunoreactive neurons were detected in any of the hippocampal specimens.
Conclusions: ACTH has anticonvulsant properties, and its novel expression in the glutamatergic subicular neurons, which provide the main outflow of the hippocampal formation, may represent an attempt by the damaged hippocampal circuit to restore the balance of excitatory/inhibitory neurotransmission in TLE. 相似文献
32.
33.
34.
35.
36.
Ocular manifestations of Donohue's syndrome. 总被引:2,自引:0,他引:2
INTRODUCTION: Donohue's syndrome, also known as Leprechaunism, is a rare autosomal recessive disease that manifests at birth with symptoms of endocrine dysfunction. Metabolic characteristics of the disease include postprandial hyperglycemia, fasting hypoglycemia, insulin resistance, hyperinsulinemia, and failure to thrive. The physical features most often associated with this condition include hypertrichosis, pachyderma, acanthosis nigricans, prominent genitalia, and elfin-like facial characteristics of prominent eyes, wide nostrils, thick lips, and large, low-set ears. Not only is this syndrome rare, but it often results in infant and early childhood mortality. The literature regarding ocular manifestations is limited. CASE REPORT: We present a case of a 29-year-old male with Donohue's syndrome and significant ocular findings including a subluxated mature cataract, retinal detachment, high myopia, and optic atrophy. DISCUSSION: These ocular sequelae are discussed with regard to the noted endocrine dysfunction and its effects on tissue development and growth. 相似文献
37.
Eileen Mary Grealish Robert P. Hawkins Pamela Meadowcroft Pamela Weaver Sharon S. Frost Percilla Lynch 《Child & youth care forum》1989,18(1):49-61
Many youth, their parents, and social services regard the unification of the family as the most desirable outcome for youth in out-of-home placements. This goal is often difficult to achieve because the families of these troubled/troubling youths are often severely dysfunctional, with multiple problems. A group process model for serving natural parents of youth in placement is described which, in conjunction with one-on-one interactions with professionals, appears to have a positive impact on these families and on youths' return home. Group components that seem particularly important are described, including attendance by invitation only, public commitment to attend and participate, reminder prompts, transportation support, babysitting support, refreshments, opportunity to visit with their child, defined staff roles, an empowering approach, and starting where the parent is. The group process maintained a relatively high level of both attendance and participation by the targeted parents. Participants tended to achieve most goals that they set in the group. Our experience indicates that interventions with natural parents of troubled youth can enable even a very dysfunctional family to improve enough to receive youth back into their home.The authors are grateful for the assistance of Sharon Estill, Jim Bernardo, Anita Mentzer, Dave Walker, and Suni Dague-Lyman for assistance in collecting the data reported here. Debbie Buchanan and others have been a great assistance in transporting families. 相似文献
38.
39.
Mechanical characterization of collagen fibers and scaffolds for tissue engineering 总被引:11,自引:0,他引:11
Engineered tissues must utilize scaffolding biomaterials that support desired cellular functions and possess or can develop appropriate mechanical characteristics. This study assessed properties of collagen as a scaffolding biomaterial for ligament replacements. Mechanical properties of extruded bovine achilles tendon collagen fibers were significantly affected by fiber diameter, with smaller fibers displaying higher tangent moduli and peak stresses. Mechanical properties of 125 micrometer-diameter extruded fibers (tangent modulus of 359.6+/-28.4MPa; peak stress of 36.0+/-5.4MPa) were similar to properties reported for human ligaments. Scaffolds of extruded fibers did not exhibit viscoelastic creep properties similar to natural ligaments. Collagen fibers from rat tail tendon (a well-studied comparison material) displayed characteristic strain-softening behavior, and scaffolds of rat tail fibers demonstrated a non-intuitive relationship between tangent modulus and specimen length. Composite scaffolds (extruded collagen fibers cast within a gel of Type I rat tail tendon collagen) were maintained with and without fibroblasts under standard culture conditions for 25 days; cell-incorporated scaffolds displayed significantly higher tangent moduli and peak stresses than those without cells. Because tissue-engineered products must possess appropriate mechanical as well as biological/chemical properties, data from this study should help enable the development of improved tissue analogues. 相似文献
40.
Long-term wear of ceramic matrix composite materials for hip prostheses under severe swing phase microseparation 总被引:1,自引:0,他引:1
Stewart TD Tipper JL Insley G Streicher RM Ingham E Fisher J 《Journal of biomedical materials research. Part B, Applied biomaterials》2003,66(2):567-573
The purpose of this study was to evaluate the long-term wear performance of alumina matrix composite (AMC) heads against alumina matrix composite inserts and alumina matrix composite heads against alumina (Al) inserts with the use of a hip-joint simulator incorporating severe swing phase joint microseparation. The wear of AMC on Al produced an average wear rate of 0.61 mm3/million cycles over the 5-million-cycle test duration. The wear of AMC on AMC produced an average wear rate of 0.16 mm3/million cycles over the 5-million-cycle test duration. Both the AMC on alumina and AMC on AMC produced significantly lower wear than previously tested HIPed alumina, where an average wear rate of 1.84 mm3/million cycles was reported over 5 million cycles. The wear mechanisms and wear debris of AMC on AMC and AMC on Al were similar to those observed in previous alumina retrieval studies with stripe wear caused by intragranular fracture and wear debris consisting of predominantly uniform 10-20-nm-sized particles and a few irregular particles up to 3 microm in size. 相似文献