全文获取类型
收费全文 | 7413篇 |
免费 | 350篇 |
国内免费 | 127篇 |
专业分类
耳鼻咽喉 | 350篇 |
儿科学 | 653篇 |
妇产科学 | 181篇 |
基础医学 | 696篇 |
口腔科学 | 182篇 |
临床医学 | 739篇 |
内科学 | 445篇 |
皮肤病学 | 134篇 |
神经病学 | 901篇 |
特种医学 | 639篇 |
外科学 | 1432篇 |
综合类 | 851篇 |
现状与发展 | 1篇 |
预防医学 | 198篇 |
眼科学 | 54篇 |
药学 | 286篇 |
4篇 | |
中国医学 | 24篇 |
肿瘤学 | 120篇 |
出版年
2024年 | 6篇 |
2023年 | 139篇 |
2022年 | 146篇 |
2021年 | 211篇 |
2020年 | 240篇 |
2019年 | 224篇 |
2018年 | 239篇 |
2017年 | 178篇 |
2016年 | 227篇 |
2015年 | 255篇 |
2014年 | 456篇 |
2013年 | 382篇 |
2012年 | 351篇 |
2011年 | 431篇 |
2010年 | 340篇 |
2009年 | 384篇 |
2008年 | 349篇 |
2007年 | 341篇 |
2006年 | 326篇 |
2005年 | 307篇 |
2004年 | 266篇 |
2003年 | 173篇 |
2002年 | 168篇 |
2001年 | 133篇 |
2000年 | 142篇 |
1999年 | 126篇 |
1998年 | 107篇 |
1997年 | 119篇 |
1996年 | 112篇 |
1995年 | 86篇 |
1994年 | 109篇 |
1993年 | 100篇 |
1992年 | 76篇 |
1991年 | 74篇 |
1990年 | 60篇 |
1989年 | 53篇 |
1988年 | 51篇 |
1987年 | 51篇 |
1986年 | 33篇 |
1985年 | 52篇 |
1984年 | 63篇 |
1983年 | 22篇 |
1982年 | 42篇 |
1981年 | 37篇 |
1980年 | 29篇 |
1979年 | 25篇 |
1978年 | 19篇 |
1977年 | 13篇 |
1976年 | 4篇 |
1974年 | 3篇 |
排序方式: 共有7890条查询结果,搜索用时 359 毫秒
81.
Chuen -Mao Yang Hui -Liang Tsao Chi -Tso Chiu Lir -Wan Fan Sheu -Meei Yu 《Pflügers Archiv : European journal of physiology》1996,432(4):708-716
The effects of increases in cellular adenosine 3′5′-cyclic monophosphate (cAMP) on 5-hydroxytryptamine-(5-HT-) induced generation
of inositol phosphates (IPs) and increases in intracellular Ca2+ ([Ca2+]i) were investigated using canine cultured tracheal smooth muscle cells (TSMCs). Cholera toxin and forskolin induced concentration-
and time-dependent cAMP formation with half-maximal effects (−logEC50) produced at concentrations of 7.0 ± 0.5 and 4.9 ± 0.4 respectively. Pretreatment of TSMCs with either forskolin or dibutyryl
cAMP inhibited 5-HT-stimulated responses. Even after treatment for 24h, these agents still inhibited the 5-HT-induced Ca2+ mobilization. The inhibitory effects of these agents produced both depression of the maximal response and a shift to the
right of the concentration response curves of 5-HT. The water-soluble forskolin analogue L-858051 [7-deacetyl-7β-(γ-N-methylpiperazino)-butyryl forskolin] significantly inhibited the 5-HT-stimulated accumulation of IPs. In contrast, the addition
of 1,9-dideoxy forskolin, an inactive forskolin analogue, had little effect on this response. Moreover, SQ-22536 [9-(tetrahydro-2-furanyl)-9-H-purin-6-amine], an inhibitor of adenylate cyclase, and both H-89 [N-(2-aminoethyl)-5-isoquinolinesulphonamide] and HA-1004[N-(2-guanidinoethyl)-5-isoquinolinesulphonamide], inhibitors of cAMP-dependent protein kinase (PKA), attenuated the ability
of forskolin to inhibit the 5-HT-stimulated accumulation of IPs. These results suggest that activation of cAMP/PKA was involved
in these inhibitory effects of forskolin. The AlF4
−-induced accumulation of IPs was inhibited by forskolin, suggesting that G protein(s) are directly activated by AlF4
−- and uncoupled from phospholipase C by forskolin treatment. These results suggest that activation of cAMP/PKA might inhibit
the 5-HT-stimulated phosphoinositide breakdown and consequently reduce the [Ca2+]i increase or inhibit both responses independently.
Received: 14 March 1996/Accepted: 10 April 1996 相似文献
82.
氟尿嘧啶引起大鼠气管损伤修复过程中干细胞的定位 总被引:10,自引:2,他引:10
目的 气管干细胞的原位观察。方法 使用5-氟尿嘧啶(5-FU)造成大鼠离体气管环的严重损伤,采用光镜、PCNA免疫组织化学,以及Hoechst33342染色观察气管黏膜的修复过程。结果 5-Fu作用12h后,气管上皮脱落,可见少量间隔分布的类似裸核的细胞呈钉状位于基底膜上,PCNA染色阴性(Go期细胞),其中少数细胞Hoechst33342染色阴性。去除5-FU6h后,气管黏膜由扁平上皮覆盖;48h后,气管环恢复假复层纤毛柱状上皮。结论 5-Fu能杀死处于细胞周期的气管上皮细胞,对Go期细胞作用很小,残留于基底膜上的裸核样的Go期细胞中含有干细胞,其Hoechst33342染色阴性,并具有排出荧光染料的能力,正是这些细胞的增殖分化,修复了损伤的气管环。 相似文献
83.
Fukunaga M 《APMIS : acta pathologica, microbiologica, et immunologica Scandinavica》2000,108(4):287-292
A case of a rare vascular tumor, intravenous tufted angioma, is described. A 51-year-old Japanese man presented with a 12x8 mm solitary reddish nodule on the right foot, which had been found at birth. Histologically, the tumor was confined to a malformed vein and was characterized by nodular aggregates of plump cells. The aggregates showed a compact proliferation of round cells, including capillary-forming cells. Venous angiomatous areas were also observed. No multinucleated giant cells were seen. Immunohistochemically, the capillary-forming cells in the aggregates and the endothelial cells in the angiomatous areas were positive for endothelial markers (factor VIII-related antigen, CD31, CD34). Pericyte-like cells expressing alpha-smooth muscle actin and muscle actin, and macrophage-like cells, which stained for factor XIIIa, were intermingled in the cellular aggregates. Flow cytometric analysis showed diploidy. The tumor may be a hamartomatous lesion modified by secondary reactive changes, and it may represent a distinctive clinicopathological entity that is closely related histogenetically and perhaps pathologically to tufted angioma and the recently described "giant cell angioblastoma". 相似文献
84.
This paper describes an 8-year-old girl with Klippel-Feil syndrome (KFS) associated with frontonasal dysplasia, Sprengel deformity and postaxial polydactyly. These findings are tentatively explained on the basis of a single mutant gene for KFS with broad action in the morphogenesis of the skeletal system. 相似文献
85.
Israel Shapiro Zvi Borochowitz Shimon Degani Hanna Dar Izu Ibschitz Mordechai Sharf 《American journal of medical genetics. Part A》1992,43(3):602-605
A diagnosis of the Neu-Laxova syndrome (NLS) was made by ultrasonography at 32 wks of gestation. Ultrasonographic examination showed intrauterine growth retardation (IUGR), Dandy-Walker anomaly, choroid plexus cysts, receding forehead and microcephaly, bilateral cataract without prominent eyes, scalp edema with no generalized edema, retrognathia, curved penis, and flexion deformities of limbs. The findings in this case are consistent with NLS; however, they did not fit any of Curry's [1982] groups. Massive swelling of hands and feet were among the main manifestations in classic NLS cases. In the case presented herein, edema was noted only in the scalp. This might shed further light on the question of variability vs. heterogeneity in the NLS. This case shows the existing possibility of an early diagnosis of NLS and adds Dandy-Walker anomaly and choroid plexus cysts as new findings to this syndrome. © 1992 Wiley-Liss, Inc. 相似文献
86.
Perrine Brunelle Anne‐Sophie Jourdain Fabienne Escande Jelena Martinovic Juliette Dupont Tiffany Busa Anne Moncla Frédéric Frénois Morgane Stichelbout Sylvie Manouvrier‐Hanu Florence Petit 《American journal of medical genetics. Part A》2019,179(7):1351-1356
Split‐hand/foot malformation (SHFM) is a genetically heterogeneous congenital limb malformation typically limited to a defect of the central rays of the autopod, presenting as a median cleft of hands and feet. It can be associated with long bone deficiency or included in more complex syndromes. Among the numerous genetic causes, WNT10B homozygous variants have been recently identified in consanguineous families, but remain still rarely described (SHFM6; MIM225300). We report on three novel SHFM families harboring WNT10B variants and review the literature, allowing us to highlight some clinical findings. The feet are more severely affected than the hands and there is a frequent asymmetry without obvious side‐bias. Syndactyly of third–fourth fingers was a frequent finding (62%). Polydactyly, which was classically described in SHFM6, was only present in 27% of patients. No genotype–phenotype correlation is delineated but heterozygous individuals might have mild features of SHFM, suggesting a dose‐effect of the WNT10B loss‐of‐function. 相似文献
87.
气管组织工程的研究策略及其展望 总被引:1,自引:0,他引:1
气管组织工程是近10年来国内外研究的热点和难点问题,取得了一些进展.但如何更好地遴选基质材料、实现种子细胞共培养、上皮化以及再血管化来构建组织工程化气管仍需要不断寻求新的研究思路和策略.本文从气管重建和理想化气管替代物的角度,回顾了近年来在组织工程气管方面的研究进展,并对未来的研究作出展望. 相似文献
88.
Margaux Serey‐Gaut Marcello Scala Bruno Reversade Lyse Ruaud Christelle Cabrol Francesco Musacchia Annalaura Torella Andrea Accogli Nathalie Escande‐Beillard Jean Langlais Gianluca Piatelli Alessandro Consales Vincenzo Nigro Valeria Capra Lionel Van Maldergem 《American journal of medical genetics. Part A》2020,182(6):1466-1472
The clinical and radiological spectrum of spondylocostal dysostosis syndromes encompasses distinctive costo‐vertebral anomalies. RIPPLY2 biallelic pathogenic variants were described in two distinct cervical spine malformation syndromes: Klippel–Feil syndrome and posterior cervical spine malformation. RIPPLY2 is involved in the determination of rostro‐caudal polarity and somite patterning during development. To date, only four cases have been reported. The current report aims at further delineating the posterior malformation in three new patients. Three patients from two unrelated families underwent clinical and radiological examination through X‐ray, 3D computed tomography and brain magnetic resonance imaging. After informed consent was obtained, family‐based whole exome sequencing (WES) was performed. Complex vertebral segmentation defects in the cervico‐thoracic spine were observed in all patients. WES led to the identification of the homozygous splicing variant c.240‐4T>G in all subjects. This variant is predicted to result in aberrant splicing of Exon 4. The current report highlights a subtype of cervical spine malformation with major atlo‐axoidal malformation compromising spinal cord integrity. This distinctive mutation‐specific pattern of malformation differs from Klippel–Feil syndrome and broadens the current classification, defining a sub‐type of RIPPLY2‐related skeletal disorder. Of note, the phenotype of one patient overlaps with oculo‐auriculo‐vertebral spectrum disorder. 相似文献
89.
A family with cardiac malformation, cleft lip-palate, short stature, microcephaly, distally placed thumbs, short 2nd and 5th fingers, long and broad 1st toes, broad distance between 1st and 2nd toes and mediodorsal curvature of the 4th toes with syndactyly of the 2nd and 3rd toes has been described as having a new syndrome. While some members of the family had full signs of the syndrome, others had similar but fewer and less severe anomalies of the same structures. The presence of common findings in three generations, its variable expressivity and pleiotropism, and the non-consanguineous history in the parents suggest that the inheritance is autosomal dominant. 相似文献
90.
Philipp Kasten Gerrit Schnöink Astrid Bergmann Maria Papoutsi Kerstin Buttler Jochen Rössler Herbert A. Weich Jörg Wilting 《Developmental dynamics》2007,236(10):2952-2961
Lymphangioma is a disfiguring malformation of early childhood. A mouse lymphangioma model has been established by injecting Freund's incomplete adjuvant (FIA) intraperitoneally, but has not been compared with the human disease. We show that, in accordance with studies from the 1960s, the mouse model represents an oil-granuloma, made up of CD45-positive leukocytes and invaded by blood and lymph vessels. Several markers of lymphatic endothelial cells are expressed in both mouse and human, like CD31, Prox1, podoplanin, and Lyve-1. However, the human disease affects all parts of the lymphovascular tree. We observed convolutes of lymphatic capillaries, irregularly formed collectors with signs of disintegration, and large lymph cysts. We observed VEGFR-2 and -3 expression in both blood vessels and lymphatics of the patients, whereas in mouse VEGFR-2 was confined to activated blood vessels. The experimental mouse FIA model represents a vascularized oil-granuloma rather than a lymphangioma and reflects the complexity of human lymphangioma only partially. 相似文献