全文获取类型
收费全文 | 123篇 |
免费 | 6篇 |
国内免费 | 1篇 |
专业分类
耳鼻咽喉 | 10篇 |
儿科学 | 9篇 |
妇产科学 | 8篇 |
基础医学 | 21篇 |
临床医学 | 9篇 |
内科学 | 27篇 |
神经病学 | 4篇 |
特种医学 | 1篇 |
外科学 | 12篇 |
综合类 | 3篇 |
一般理论 | 1篇 |
预防医学 | 10篇 |
药学 | 14篇 |
肿瘤学 | 1篇 |
出版年
2023年 | 1篇 |
2021年 | 1篇 |
2020年 | 2篇 |
2019年 | 1篇 |
2018年 | 1篇 |
2017年 | 1篇 |
2016年 | 5篇 |
2015年 | 4篇 |
2014年 | 1篇 |
2013年 | 3篇 |
2012年 | 7篇 |
2011年 | 7篇 |
2010年 | 2篇 |
2009年 | 5篇 |
2008年 | 10篇 |
2007年 | 6篇 |
2006年 | 6篇 |
2005年 | 6篇 |
2004年 | 4篇 |
2003年 | 14篇 |
2002年 | 11篇 |
2001年 | 2篇 |
1998年 | 1篇 |
1997年 | 3篇 |
1996年 | 1篇 |
1994年 | 2篇 |
1993年 | 1篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1986年 | 1篇 |
1983年 | 1篇 |
1981年 | 3篇 |
1980年 | 2篇 |
1979年 | 1篇 |
1977年 | 3篇 |
1975年 | 2篇 |
1974年 | 1篇 |
1968年 | 2篇 |
1967年 | 1篇 |
1965年 | 1篇 |
排序方式: 共有130条查询结果,搜索用时 31 毫秒
1.
2.
Eva Ludvigsen Carina Carlsson Eva Tiensuu Janson Stellan Sandler Mats Stridsberg 《Upsala journal of medical sciences》2015,120(3):157-168
Background
Somatostatin acts through five receptor subtypes (SSTRs 1–5). We aimed to investigate SSTRs mRNA expression and protein distribution in whole rat embryos, with special emphasis on the pancreas.Material and methods
Rat embryos were collected on embryonal days 10, 11, 12, 14, 15, 17, 19, 21, and at birth. Presence of SSTRs was investigated with RT-PCR techniques and immunohistochemistry.Results
There was no SSTR5 mRNA expression in the whole rat embryos. All SSTR1–5 proteins were observed at embryonal day 10, but the localization varied between the different subtypes. From day 11 to birth SSTRs protein presence increased with time in major structures such as skin and cartilage. It remained similar over time in the heart and liver. In the fetal pancreas mRNA expression of SSTR2 and 4 was detected at day 14, and there was an increase up to birth. Only SSTR1 protein co-localized to a higher extent with the islet hormones studied. SSTR2 was present in all islet endocrine cells except for β-cells. In contrast, the immunostaining for SSTR3–4 was co-localized with insulin and PP, and, finally, SSTR5 with glucagon and pancreatic polypeptide. In mRNA isolated from whole rat embryos SSTR1-2 and SSTR4 expression showed a peak at day 14, while SSTR3 mRNA was not present until day 15.Conclusion
The present data suggest a role for SSTRs during the development of the rat embryo. Subsequent functional studies may elucidate regulatory roles of specific SSTRs for the growth and differentiation of the pancreas as well as other organs. 相似文献3.
4.
Markus V. Björkström Lina Hall Stina Söderlund Eva Grahn Håkansson Stellan Håkansson Magnus Domellöf 《Acta paediatrica (Oslo, Norway : 1992)》2009,98(11):1762-1767
Aim: To study the early faecal microbiota in very low-birth weight infants (VLBW, <1500 g), possible associations between faecal microbiota and faecal calprotectin (f-calprotectin) and to describe the faecal microbiota in cases with necrotizing enterocolitis (NEC) before diagnosis.
Methods: Stool samples from the first weeks of life were analysed in 48 VLBW infants. Bacterial cultures were performed and f-calprotectin concentrations were measured. In three NEC cases, cultures were performed on stool samples obtained before diagnosis.
Results: Bifidobacteria and lactobacilli were often identified in the first stool sample, 55% and 71% of cases, respectively within the first week of life. A positive correlation between lactic acid bacteria (LAB) and volume of enteral feed was found. Other bacteria often identified were Escherichia coli , Enterococcus and Staphyloccus sp. F-calprotectin was not associated with any bacterial species. All NEC cases had an early colonization of LAB. Prior to onset of disease, all cases had a high colonization of non- E. coli Gram-negative species.
Conclusion: In contrast to the previous studies in VLBW infants, we found an early colonization with LAB. We speculate that this may be due to early feeding of non-pasteurized breast milk. 相似文献
Methods: Stool samples from the first weeks of life were analysed in 48 VLBW infants. Bacterial cultures were performed and f-calprotectin concentrations were measured. In three NEC cases, cultures were performed on stool samples obtained before diagnosis.
Results: Bifidobacteria and lactobacilli were often identified in the first stool sample, 55% and 71% of cases, respectively within the first week of life. A positive correlation between lactic acid bacteria (LAB) and volume of enteral feed was found. Other bacteria often identified were Escherichia coli , Enterococcus and Staphyloccus sp. F-calprotectin was not associated with any bacterial species. All NEC cases had an early colonization of LAB. Prior to onset of disease, all cases had a high colonization of non- E. coli Gram-negative species.
Conclusion: In contrast to the previous studies in VLBW infants, we found an early colonization with LAB. We speculate that this may be due to early feeding of non-pasteurized breast milk. 相似文献
5.
Delaney Hines Neena Modi Shoo K. Lee Tetsuya Isayama Gunnar Sj?rs Luigi Gagliardi Liisa Lehtonen Maximo Vento Satoshi Kusuda Dirk Bassler Rintaro Mori Brian Reichman Stellan H?kansson Brian A. Darlow Mark Adams Franca Rusconi Laura San Feliciano Kei Lui Naho Morisaki Natasha Musrap Prakesh S. Shah the International Network for Evaluating Outcomes of Neonates 《Acta paediatrica (Oslo, Norway : 1992)》2017,106(3):366-374
6.
Bock KW Bock-Hennig BS Münzel PA Brandenburg JO Köhle CT Soars MG Riley RJ Burchell B von Richter O Eichelbaum MF Swedmark S Orzechowski A 《Biochemical pharmacology》2002,63(9):1683-1690
UDP-glucuronosyltransferases (UGTs) are regulated in a species- and tissue-dependent manner by endogenous and environmental factors. The present study was undertaken to further our knowledge about regulation of UGTs in dogs, a species widely used in preclinical safety evaluation. beta-Naphthoflavone (BNF) was selected as a known aryl hydrocarbon receptor agonist and antioxidant-type inducer. The latter group of inducers is intensively investigated as dietary chemoprotectants against colon cancer. Dog UGTs were investigated in comparison with related human UGTs by examples, (i) expression of dog UGT1A6, the first sequenced dog phenol UGT, and (ii) morphine UGT activities, responsible for intestinal and hepatic first-pass metabolism of morphine. The following results were obtained: (i) dog UGT1A6 was found to be constitutively expressed in liver and marginally increased by BNF treatment. Expression was low in small intestine but ca. 6-fold higher in colon than for example in jejunum. Conjugation of 4-methylumbelliferone, one of the substrates of dog UGT1A6, was also enhanced 7-fold in colonic compared to jejunal microsomes. (ii) Compared to the corresponding human tissues, canine 3-O- and 6-O-morphine UGT activities were found to be >10-fold higher in dog liver and ca. 10-fold lower in small intestinal microsomes. Small intestinal morphine and 4-hydroxybiphenyl UGT activities appeared to be moderately (2- to 3-fold) induced by oral treatment with BNF. (iii) In contrast to dogs, morphine UGT activities were found to be similar in homogenates from human enterocytes and liver. The results suggest marked differences in tissue-specific regulation of canine vs. human hepatic and intestinal phenol or morphine UGTs. 相似文献
7.
The effect of ventilation on airborne contamination was studied in a new operating suite containing operating rooms with conventional ventilation (17-20 turnovers/h) and operating rooms with zonal ventilation, where the turnover in the central part of the room was ~ 80/h. The efficacy of the ventilation was first examined with gas tracer experiments and found satisfactory. Experiments using potassium iodide particles showed the transfer between adjacent rooms in the suite to be less than 10-3% with closed doors and from 1% to 2·5 × 10-2% when the doors were opened once a minute. The transfer between two adjacent operating rooms was calculated to be ~ 10-4%. There is thus little risk of spread of airborne infection between operating rooms. 相似文献
8.
Lindqvist P Waldenström A Henein M Mörner S Kazzam E 《Echocardiography (Mount Kisco, N.Y.)》2005,22(4):305-314
The aim of the present study was to describe regional and global right ventricular (RV) function in a wide age range of healthy subjects of both sexes. We studied 255 (125 females) healthy individuals randomly selected from the Umeå General Population Register, age 58 ± 19 (range 22–89) years. RV function was studied using myocardial tissue Doppler imaging of the RV free wall. Isovolumic contraction (IVCv), systolic (Sv), early (Ev), and late (Av) diastolic velocities were measured. Furthermore, isovolumic periods and ejection time intervals were also measured. Conventional Doppler was used to study RV global filling properties. While systolic myocardial velocities were conserved over age, there was a decrease in myocardial E/A ratio with increasing age (r =?0.67, P < 0.001, for base) taken from the RV free wall. A similar age relation was found in RV global filling velocities with a reduced tricuspid E/A ratio (r =?0.57, P < 0.001). Furthermore, a significant correlation was found between global and regional E/A ratios at the basal (r = 0.58, P ≤ 0.001) and mid‐segmental levels (r = 0.46, P ≤ 0.001). Systolic myocardial velocities behaved independent of age whereas regional as well as global E/A ratio were age‐related. No relationship was found between regional isovolumic time intervals and age. Knowledge of these age‐dependent relationships is fundamental when evaluating RV function in patients. 相似文献
9.
10.
K(ATP) channels are important for insulin secretion and depolarization of vascular smooth muscle. In view of the importance of drugs affecting K(ATP) channels in the treatment of diabetes, we investigated the effects of these channels on splanchnic blood perfusion in general and pancreatic islet blood flow in particular. We treated anesthetized Sprague-Dawley rats with the K(ATP) channel openers diazoxide or NNC 55-0118 or the K(ATP) channel closer glipizide. Both diazoxide and NNC 55-0118 dose-dependently increased total pancreatic and islet blood flow in the presence of moderate hyperglycemia, but had no effects on the blood perfusion of other splanchnic organs. Diazoxide markedly lowered the mean arterial blood pressure and thus increased vascular conductance in all organs studied. NNC 55-0118 had much smaller effects on the blood pressure. Glipizide did not affect total pancreatic blood flow, but decreased islet blood flow by 50% in the presence of hypoglycemia. We conclude that K(ATP) channels actively participate in the blood flow regulation of the pancreatic islets and that substances affecting such channels may also influence islet blood flow. 相似文献