全文获取类型
收费全文 | 1770篇 |
免费 | 68篇 |
国内免费 | 28篇 |
专业分类
耳鼻咽喉 | 5篇 |
儿科学 | 50篇 |
妇产科学 | 6篇 |
基础医学 | 210篇 |
口腔科学 | 73篇 |
临床医学 | 108篇 |
内科学 | 561篇 |
皮肤病学 | 41篇 |
神经病学 | 94篇 |
特种医学 | 35篇 |
外科学 | 334篇 |
综合类 | 7篇 |
一般理论 | 1篇 |
预防医学 | 37篇 |
眼科学 | 11篇 |
药学 | 154篇 |
中国医学 | 3篇 |
肿瘤学 | 136篇 |
出版年
2023年 | 4篇 |
2022年 | 7篇 |
2021年 | 25篇 |
2020年 | 15篇 |
2019年 | 20篇 |
2018年 | 16篇 |
2017年 | 20篇 |
2016年 | 32篇 |
2015年 | 21篇 |
2014年 | 27篇 |
2013年 | 52篇 |
2012年 | 80篇 |
2011年 | 111篇 |
2010年 | 50篇 |
2009年 | 47篇 |
2008年 | 89篇 |
2007年 | 118篇 |
2006年 | 120篇 |
2005年 | 123篇 |
2004年 | 126篇 |
2003年 | 109篇 |
2002年 | 111篇 |
2001年 | 47篇 |
2000年 | 44篇 |
1999年 | 38篇 |
1998年 | 44篇 |
1997年 | 34篇 |
1996年 | 27篇 |
1995年 | 26篇 |
1994年 | 18篇 |
1993年 | 19篇 |
1992年 | 36篇 |
1991年 | 21篇 |
1990年 | 21篇 |
1989年 | 13篇 |
1988年 | 17篇 |
1987年 | 22篇 |
1986年 | 14篇 |
1985年 | 12篇 |
1984年 | 13篇 |
1983年 | 10篇 |
1982年 | 8篇 |
1981年 | 9篇 |
1980年 | 5篇 |
1979年 | 6篇 |
1974年 | 6篇 |
1973年 | 4篇 |
1972年 | 4篇 |
1968年 | 3篇 |
1966年 | 4篇 |
排序方式: 共有1866条查询结果,搜索用时 15 毫秒
21.
Kazuko Sukegawa Shunji Tomatsu Toshiyuki Fukao Hideki Iwata Xiang-Qian Song Yukiji Yamada Seiji Fukuda Kouji Isogai Tadao Orii 《Human mutation》1995,6(2):136-143
Mucopolysaccharidosis type II (Hunter disease) is a lysosomal storage disorder caused by a deficiency of the enzyme iduronate-2-sulfatase. Varied clinical phenotypes of this disease have been described. To identify mutations in individual patients and to examine possible correlations between mutations and clinical phenotypes, we analyzed the iduronate-2-sulfatase gene in Japanese patients with different clinical phenotypes. Five missense mutations, S333L (severe), R468Q (severe), R468L (severe), W337R (intermediate), R48P (mild), and three nonsense mutations, W345X (severe), R443X (intermediate), Q531X (mild), were identified by the RT-PCR method. Transient expression in the enzyme-deficient fibroblasts revealed that all five missense mutant enzymes were synthesized as the normal-size precursor (73 kD), and the nonsense mutant enzymes were synthesized as truncated ones (W345X:54 kD, R443X:59 kD, and Q531X:69 kD), although stable mature enzymes (45–56 kD) were not detected by Western blot analysis. Further more, expression of the eight mutant cDNAs resulted in severe reductions of iduronate-2-sulfatase enzyme activity in comparison with a normal cDNA. © 1995 Wiley-Liss, Inc. 相似文献
22.
Hidekazu Shigematsu Yutaka Kobayashi Sumio Tateno Yoshiyuki Hiki Sadahito Kuwao 《Pathology international》1992,42(2):91-98
The correlation between glomerular immune deposition and histological alteration was studied in serial paraffin sections of kidney biopsy specimens from patients with IgA nephritis using the peroxidase antiperoxidase (PAP) method. IgA deposition was detected in preserved glomerular extracellular matrix or in newly formed interposed matrix along the capillary loops (mesangial interposition). On the other hand, deposition of IgA was scanty or absent in the distorted extracellular matrix where severe exudative inflammation or extracapillary escape of exudates was occurring segmentally. Ultrastructurally such extracellular matricial destruction was expressed as splitting or thinning of the lamina densa, as well as mesangial edema, reticulation or mesangiolysis of the axial matrix. Therefore it appears that at least two types of change in the extracellular matrix are induced by IgA immune complexes in IgA nephritis; immunogenic deposition and destruction. 相似文献
23.
Suzuki K Kokai Y Sawada N Takakuwa R Kuwahara K Isogai E Isogai H Mori M 《Virchows Archiv : an international journal of pathology》2002,440(3):318-324
Helicobacter pylori induces severe neutrophilic infiltration in the lamina propria of the stomach, which leads to gastritis in humans. The possible involvement of a paracellular route for bacterial nutrients and etiologic agents that may play an important role in colonization of the bacteria and cause gastritis has been suggested. To study the functions of the paracellular barrier of gastric surface epithelium, SS1, a strain of H. pylori adapted to the murine stomach, was inoculated into the stomachs of C57BL/6 mice. At 4 months after inoculation, SS1 had achieved a high level of colonization (10(6)-10(7) colony-forming units/g tissue) associated with neutrophilic infiltration in the lamina propria of the junctional zone. Disruption of the paracellular barrier was observed in the SS1-infected stomachs, as revealed by the invasion of a lanthanum tracer into the paracellular space of the surface epithelium. Only 2% of junctions were permeable in control stomachs, whereas 72% of the paracellular barrier was disrupted in the SS1-infected gastric epithelia. Furthermore, distribution of tight junction-related molecules such as 7H6 antigen, occludin, and cortical actin was affected in the surface epithelium by SS1 infection. The linear expression pattern of occludin was disrupted and became irregular or punctuated. The 7H6 antigen accumulated as aggregates in the apical portion of the surface epithelium and cortical actin became irregular and punctuated. Taken together, these results indicate that infection by SS1 directly or indirectly caused an increase in paracellular permeability and altered the localization of tight junction-related molecules of the gastric surface epithelium. This observation suggests that the paracellular pathway may play a significant role in establishing H. pylori-induced gastritis in the clinical setting. 相似文献
24.
Renal glomerulogenesis in medaka fish, Oryzias latipes 总被引:2,自引:0,他引:2
Svetlana Fedorova Rieko Miyamoto Tomohiro Harada Sumio Isogai Hisashi Hashimoto Kenjiro Ozato Yuko Wakamatsu 《Developmental dynamics》2008,237(9):2342-2352
We provide an overview of glomerulogenesis in medaka from the embryo to the adult by means of in situ hybridization with the wt1 gene as a marker as well as histology and three-dimensional images. The pronephric glomus starts to develop in the intermediate mesoderm during early somitogenesis, is completed before hatching, and persists throughout the lifetime of the fish. Within 5 days after hatching, mesonephric glomerulus formation begins in the caudomedial end of the pronephric sinus and duct area. The number of glomeruli reaches approximately 200-300 in each kidney within 2 months after hatching. wt1 expression during nephron maturation served as a marker for the formation of the mesenchymal condensate and the nephrogenic body. Existence of mesenchymal condensates and persistence of wt1 expression in the adult kidney suggest that the mesonephros retains precursor cells that may be capable of contributing to neoglomerulogenesis during adulthood. Developmental Dynamics 237:2342-2352, 2008. (c) 2008 Wiley-Liss, Inc. 相似文献
25.
It has been believed that the primary arterial trunk of the mammalian forelimb is derived from the 7th intersegmental artery.
Here we examined the early morphogenesis of the arteries and nerves in the forelimb region by adopting a method that combined
intravascular dye-injection with nerve staining to whole mounted rat embryos. The study was carried out on greater numbers
of specimens at smaller intervals of embryonic stages and from earlier stages than those in previous reports. We report that:
(1) The multiple primary arterial trunks in the forelimb region (primary subclavians) originate directly from the lateral
surface of the dorsal aorta independently of the intersegmental arteries, previous to the formation of limb buds. (2) The
tips of the 8th (and the 9th) primary subclavians that originate from the aorta near the origin of the 8th (or the 9th) intersegmental
artery bend cranially and/or caudally. With the formation of limb bud, they extend to form the longitudinal trunks in the
presumptive axillary region. The primary arteries in the free arm region branch off from this longitudinal trunk, and one
of them develops into the axial artery. (3) The origins of the primary subclavians shift their positions on the surface of
the dorsal aorta and approach the origins of the neighboring intersegmental arteries to join them, and then replace the latter.
Consequently, the primary subclavians appear to be ”the lateral branches of the in tersegmental arteries.” (4) The 8th primary
subclavian is dominant at first, but is replaced by the 7th primary subclavian, which develops into the definitive subclavian
artery. (5) With the brachial nerve plexus formation, the axillary arterial plexus derived from the longitudinal trunk develops
to form two stems of the axillary artery.
Accepted: 15 April 1999 相似文献
26.
27.
Hidekazu SHIGEMATSU Yutaka KOBAYASHI Sumio TATBNO Yasuyuki HIKI Sadahito KUWAO 《Pathology international》1983,33(2):367-380
The glomerular lesions In 129 cases of IgA nephritis were analyzed. The development of glomerular injury occurred in two ways, one being a chronic mesangial depositive and sclerosing lesion commonly found in most glomeruli, and the other an acute but local injury initiating from the local peripheral glomerular basement membrane abnormality, i.e., thinning and/or splitting, which was seen at least in one third of all cases. The activation of the local coagulatory process could add segmental glomerular changes including small crescents, adhesion, and local tuft necrosis to the mesangial lesion. ACTA PATHOL. JPN. 33; 367–380, 1983. 相似文献
28.
Induction of immunoglobulin-secreting cells from human peripheral blood lymphocytes in a serum-free culture medium was studied. Albumin, transferrin, insulin and fibronectin can replace serum entirely for support of pokeweed mitogen (PWM)-stimulated B lymphocytes, measured by a reverse hemolytic plaque assay using protein A-coated red cells. In this serum-free system, growth and maturation to IgM and IgG secretion occur at the same or higher efficiency as in conventional serum-containing medium, with maximum numbers of plaque-forming cells on day 6 at optimal dose of PWM, 0.5 ~ 5 μg/ml. This system can be used to avoid the interference from undefined serum components. 相似文献
29.
30.
Barley chromosomes were prepared for high-resolution scanning electron microscopy using a combination of enzyme maceration, treatment in acetic acid and osmium impregnation using thiocarbohydrazide. Using this technique, the three-dimensional ultra-structure of interphase nuclei and mitotic chromosomes was examined. In interphase, different levels of chromatin condensation were observed, consisting of fibrils 10 nm in diameter, 20- to 40-nm fibres and a higher order complex. In prophase, globular and strand-like structures composed of 20- to 40-nm fibres were dominant. As the cells progressed through the cell cycle and the chromatin condensed, globular and strand-like structures (chromomeres) were coiled and packed to form chromosomes. Chromomeres were observed as globular protuberances on the surface of metaphase chromosomes. These findings indicate that the chromomere is a fundamental substructure of the higher order architecture of the chromosome. In the centromeric region, there were no globular protuberances, but 20- to 40-nm fibres were folded compactly to form a higher level organization surrounding the chromosomal axis. 相似文献