全文获取类型
收费全文 | 1698篇 |
免费 | 81篇 |
国内免费 | 7篇 |
专业分类
耳鼻咽喉 | 16篇 |
儿科学 | 58篇 |
妇产科学 | 13篇 |
基础医学 | 149篇 |
口腔科学 | 30篇 |
临床医学 | 97篇 |
内科学 | 423篇 |
皮肤病学 | 44篇 |
神经病学 | 117篇 |
特种医学 | 194篇 |
外科学 | 349篇 |
综合类 | 15篇 |
预防医学 | 82篇 |
眼科学 | 28篇 |
药学 | 54篇 |
中国医学 | 9篇 |
肿瘤学 | 108篇 |
出版年
2023年 | 13篇 |
2022年 | 20篇 |
2021年 | 40篇 |
2020年 | 20篇 |
2019年 | 26篇 |
2018年 | 45篇 |
2017年 | 30篇 |
2016年 | 35篇 |
2015年 | 40篇 |
2014年 | 48篇 |
2013年 | 62篇 |
2012年 | 72篇 |
2011年 | 82篇 |
2010年 | 52篇 |
2009年 | 44篇 |
2008年 | 61篇 |
2007年 | 91篇 |
2006年 | 71篇 |
2005年 | 74篇 |
2004年 | 80篇 |
2003年 | 54篇 |
2002年 | 63篇 |
2001年 | 56篇 |
2000年 | 65篇 |
1999年 | 41篇 |
1998年 | 19篇 |
1997年 | 19篇 |
1996年 | 15篇 |
1995年 | 10篇 |
1994年 | 9篇 |
1993年 | 6篇 |
1992年 | 42篇 |
1991年 | 30篇 |
1990年 | 37篇 |
1989年 | 44篇 |
1988年 | 39篇 |
1987年 | 40篇 |
1986年 | 34篇 |
1985年 | 34篇 |
1984年 | 17篇 |
1983年 | 12篇 |
1982年 | 7篇 |
1979年 | 9篇 |
1974年 | 5篇 |
1973年 | 6篇 |
1971年 | 8篇 |
1970年 | 11篇 |
1969年 | 8篇 |
1967年 | 4篇 |
1966年 | 4篇 |
排序方式: 共有1786条查询结果,搜索用时 15 毫秒
991.
Hayashida N Sekitani Y Kozlovsky A Rafalsky R Gutevich A Daniliuk V Yamashita S Takamura N 《Journal of radiation research》2011,52(5):629-633
During the Chernobyl Nuclear Power Plant (CNPP) accident on 26 April 1986, large amounts of radionuclides were released and spread to vast areas. Inhabitants residing around CNPP have been exposed to external and internal irradiation due to the long half-life of (137)Cs (30 years). In this study, we screened for internal whole-body (137)Cs concentration using a whole-body counter in the Zhitomir state of Ukraine. The total number of participants was 144,972 (96,149 females and 48,823 males). The median body burden of (137)Cs per body weight decreased from 1996 to 2008. In particular, after 2003, more than half of subjects had internal exposure doses below the detectable level. A weak seasonal effect was found in measurement data from 1997 to 1999, but no such effects were observed in later years. We also calculated annual dose for each year and confirmed that doses have been decreasing gradually. In particular, after 2003, the annual effective dose decreased to 0.1 mSv y(-1) for 95% of the participants. Only two persons were found to have received more than 5 mSv y(-1) since 2007. Although the health effects of (137)Cs body burden due to the Chernobyl accident remain uncertain, further screening is needed to monitor the health status and to allay the anxiety of inhabitants in the contaminated areas around CNPP. 相似文献
992.
Cataneo C Canini SR e Castro Pde T Hayashida M Gir E 《Revista latino-americana de enfermagem》2011,19(5):1072-1079
Early isolation of patients possibly colonized by multi-resistant microorganisms can minimize their spread, reducing cases of hospital infection and the related costs. This study aimed to identify the sensitivity and specificity of the criteria for isolation of patients admitted to a specialized cancer hospital. Cross-sectional study with a population of 61 patients coming from other hospitals who were admitted to the hospital between March 1st and August 31th, 2009. At the moment of admission, a data collection instrument was filled out and nasal and anal swabs were collected for microbiological culture. Of the 56 patients who met the isolation criteria, 30 (49.2%) presented positive cultures for multi-resistant microorganisms and methicillin-resistant Staphylococcus aureus was the most frequently identified microorganism. Most patients colonized by multi-resistant microorganisms were isolated at the moment of admission. The sensitivity of the isolation criteria was 90% and the specificity was 6.5%. 相似文献
993.
Ectopic pancreas formation in Hes1 -knockout mice reveals plasticity of endodermal progenitors of the gut, bile duct, and pancreas
下载免费PDF全文
![点击此处可从《The Journal of clinical investigation》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Fukuda A Kawaguchi Y Furuyama K Kodama S Horiguchi M Kuhara T Koizumi M Boyer DF Fujimoto K Doi R Kageyama R Wright CV Chiba T 《The Journal of clinical investigation》2006,116(6):1484-1493
Ectopic pancreas is a developmental anomaly occasionally found in humans. Hes1, a main effector of Notch signaling, regulates the fate and differentiation of many cell types during development. To gain insights into the role of the Notch pathway in pancreatic fate determination, we combined the use of Hes1-knockout mice and lineage tracing employing the Cre/loxP system to specifically mark pancreatic precursor cells and their progeny in Ptf1a-cre and Rosa26 reporter mice. We show that inactivation of Hes1 induces misexpression of Ptf1a in discrete regions of the primitive stomach and duodenum and throughout the common bile duct. All ectopic Ptf1a-expressing cells were reprogrammed, or transcommitted, to multipotent pancreatic progenitor status and subsequently differentiated into mature pancreatic exocrine, endocrine, and duct cells. This process recapitulated normal pancreatogenesis in terms of morphological and genetic features. Furthermore, analysis of Hes1/Ptf1a double mutants revealed that ectopic Ptf1a-cre lineage-labeled cells adopted the fate of region-appropriate gut epithelium or endocrine cells similarly to Ptf1a-inactivated cells in the native pancreatic buds. Our data demonstrate that the Hes1-mediated Notch pathway is required for region-appropriate specification of pancreas in the developing foregut endoderm through regulation of Ptf1a expression, providing novel insight into the pathogenesis of ectopic pancreas development in a mouse model. 相似文献
994.
Orhan D Kale G Cağlar M Göğüş S Karaağaoğlu E 《Virchows Archiv : an international journal of pathology》2006,448(5):591-596
Diffuse large B-cell lymphoma (DLBCL) with spindle cell components is extremely rare and often misdiagnosed as carcinoma or
sarcoma. Here, we present a case of primary DLBCL with spindle cell components arising in the liver, for which a preoperative
diagnosis by needle biopsies was unsuccessful. The patient was a 70-year-old man with a continuous cough. Thoracic computed
tomography incidentally detected a mass of 5 cm in diameter in his liver. The initial and second needle biopsies from the
liver mass were pathologically diagnosed as suspicious for sarcomatoid hepatocellular carcinoma. He underwent an extended
left hepatectomy. Histological examination revealed a diffuse or epithelioid arrangement of round and polygonal cells, mixed
with the fascicles of spindle-shaped cells. Immunohistochemically, all the morphological types of tumor cells showed positive
reactions for a lymphocytic marker (CD45RB) and B-cell markers (CD20 and CD79a). Double-immunostaining revealed that the spindle-shaped
tumor cells expressed CD20, but never expressed alpha-smooth muscle actin. Malignant lymphoma with a spindle cell morphology
is quite uncommon, and this variant can be a diagnostic pitfall, especially in tiny biopsy specimens. We emphasize that pathologists
should be reminded of lymphoma as a differential diagnosis of spindle cell tumors. 相似文献
995.
Takeshi Murata Hiromitsu Jinno Maiko Takahashi Masayuki Shimoda Tetsu Hayashida Kaori Kameyama Yuko Kitagawa 《The breast journal》2019,25(1):9-15
The number of long‐term breast cancer survivors with a risk of late recurrence is increasing. Hormone‐receptor‐positive patients have greater risks of late recurrence. Although several studies demonstrated that extended adjuvant endocrine therapy reduces the incidence of late recurrence, it remains unclear which hormone‐receptor‐positive patients have greater risks of late recurrence. Hormone‐receptor‐positive breast cancer patients were retrospectively selected from the prospective database of primary breast cancer patients treated at Keio University Hospital from January 1989 to December 2003. Late recurrence was defined as initial recurrence after 5 years from the initial surgery. We evaluated the clinicopathologic features of breast cancer patients with late recurrence. At a median follow‐up of 10.9 years (range, 5.1‐23.8), 371 patients had no recurrence, 90 had early recurrence (within 5 years), and 83 had late recurrence. Multivariate analysis revealed that >4 involved lymph nodes were significant risk factors for late recurrence (P < .001), whereas 1‐3 positive nodes were not. Endocrine therapy significantly reduced the incidence of late recurrence (P < .001). After menopause, adjuvant therapy with aromatase inhibitors resulted in longer disease‐free survival than tamoxifen (10‐year disease‐free survival: 97.6% vs 89.7%, P = .0955). High nodal involvement was significantly correlated with late recurrence in hormone‐receptor‐positive breast cancer patients. Hormone‐receptor‐positive breast cancer patients who receive adjuvant endocrine therapy with tamoxifen alone might be candidates for extended endocrine therapy. 相似文献
996.
997.
Rocio Rivera-Egea Nicolas Garrido Nerea Sota Marcos Meseguer Jose Remohí Francisco Dominguez 《Journal of assisted reproduction and genetics》2018,35(11):1973-1985
Although assisted reproduction techniques involve the use of semen samples, there is little scientific methodology applied when selecting sperm. To select the most appropriate spermatozoa, first we need to define the optimal molecular characteristics. Sperm lipids may contribute to sperm function, thus our aim was to compare the lipidic profiles of sperm samples used in intracytoplasmic sperm injection cycles that ultimately led to a pregnancy with those that did not.Spermatozoa from infertile patients after intracytoplasmic sperm injection (group non-pregnant, n?=?16; vs. group pregnant, n?=?22) were analyzed for lipid composition using ultra-high performance liquid chromatography coupled to mass spectrometry, by means two platforms for measuring fatty acyls, bile-acids, lysoglycerophospholipids, glycerolipids, cholesteryl-esters, sphingolipids, and glycerophospholipids. Lipid levels were compared using a univariate test and multivariate analyses after logarithmic transformation.We detected 151 different lipids in the sperm samples, 10 of which were significantly increased in sperm samples from the NP group, ranging from 1.10- to 1.30-fold change. These were primarily ceramides, sphingomyelins and three glycerophospholipids, a lysophosphatidylcholine, and two plasmalogen species. Additionally, 2-Monoacylglycerophosphocholine were also found in higher levels in non-pregnant group.Our results describe the composition of sperm lipids linked to optimal sperm function, opening new possibilities for the development of male fertility diagnostic tools and culture media formulations to improve sperm quality and enhance reproductive results. Given that lipids compose the majority of the sperm plasma membrane, this information is also useful in designing new sperm selection tools that will allow for the selection of the best spermatozoa. 相似文献
998.
999.
1000.
Fabiani Claudia Vitale Antonio Rigante Donato Emmi Giacomo Lopalco Giuseppe Sota Jurgen Vannozzi Lorenzo di Scala Gerardo Guerriero Silvana Orlando Ida Franceschini Rossella Capozzoli Marco Frediani Bruno Galeazzi Mauro Iannone Florenzo Tosi Gian Marco Cantarini Luca 《Clinical rheumatology》2018,37(6):1715-1720
Clinical Rheumatology - To identify clinical variables capable of predicting long-term treatment duration of TNF-α inhibition in patients with Behçet’s disease (BD)-related uveitis.... 相似文献