全文获取类型
收费全文 | 269篇 |
免费 | 27篇 |
国内免费 | 1篇 |
专业分类
儿科学 | 12篇 |
妇产科学 | 4篇 |
基础医学 | 37篇 |
口腔科学 | 10篇 |
临床医学 | 38篇 |
内科学 | 49篇 |
皮肤病学 | 3篇 |
神经病学 | 29篇 |
特种医学 | 7篇 |
外科学 | 37篇 |
综合类 | 8篇 |
预防医学 | 27篇 |
眼科学 | 5篇 |
药学 | 19篇 |
中国医学 | 2篇 |
肿瘤学 | 10篇 |
出版年
2024年 | 1篇 |
2023年 | 7篇 |
2022年 | 8篇 |
2021年 | 19篇 |
2020年 | 16篇 |
2019年 | 13篇 |
2018年 | 15篇 |
2017年 | 11篇 |
2016年 | 11篇 |
2015年 | 13篇 |
2014年 | 10篇 |
2013年 | 11篇 |
2012年 | 21篇 |
2011年 | 37篇 |
2010年 | 12篇 |
2009年 | 12篇 |
2008年 | 8篇 |
2007年 | 11篇 |
2006年 | 13篇 |
2005年 | 15篇 |
2004年 | 5篇 |
2003年 | 7篇 |
2002年 | 9篇 |
2001年 | 2篇 |
2000年 | 1篇 |
1999年 | 1篇 |
1998年 | 1篇 |
1996年 | 3篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1988年 | 1篇 |
1974年 | 1篇 |
排序方式: 共有297条查询结果,搜索用时 15 毫秒
21.
Barduagni P Ahmed AS Curtale F Raafat M Soliman L 《Tropical medicine & international health : TM & IH》2003,8(7):615-618
Our aim was to compare the performance of the Sahli and Colour Scale methods in diagnosing anaemia in school children, where the prevalence of anaemia is low and the haemoglobin level ranges from mild to moderate (8-11 g/dl). The study was conducted in February 2001, in Qena Governorate, Upper Egypt. The haemoglobin level measured by the two methods in each child were compared with the result obtained by using a portable haemoglobin photometer 'HemoCue'. A total of 149 school children were included in the study. Using HemoCue, 17.4% children were anaemic; using the Sahli method (SM), 66.4% children were anaemic; and using the Haemoglobin Colour Scale (HCS) method, 57.7% children were anaemic. Neither method detected any cases of severe anaemia (Hb < 7 g/dl). Both the Sahli and Colour Scale methods are sensitive but have low specificity, giving a high rate of false positive results. Both methods perform perform very similarly in haemoglobin measurement; they fulfil many of the criteria for their use at primary health care level and detect almost all cases of anaemia in a given population, even if the level of anaemia is mild. Standards for collection, handling and disposal of blood samples are guaranteed more easily by the HCS than the SM. Moreover, lay people can easily manage the HCS with success after brief training. We suggest to gradually replace the SM by the HCS method in primary health care (PHC) centres. Where anaemia levels are moderate to mild, the use of SM and HCS as tools to define anaemia prevalence might be limited, as they often label healthy individuals as anaemic. Both methods remain a useful diagnostic tool to confirm the diagnosis of clinically suspected anaemia in areas where the prevalence of anaemia is low and the haemoglobin level ranges from mild to moderate. 相似文献
22.
23.
24.
Analogs of alpha-conotoxin MII are selective for alpha6-containing nicotinic acetylcholine receptors
McIntosh JM Azam L Staheli S Dowell C Lindstrom JM Kuryatov A Garrett JE Marks MJ Whiteaker P 《Molecular pharmacology》2004,65(4):944-952
Neuronal nicotinic acetylcholine receptors (nAChRs) both mediate direct cholinergic synaptic transmission and modulate synaptic transmission by other neurotransmitters. Novel ligands are needed as probes to discriminate among structurally related nAChR subtypes. Alpha-conotoxin MII, a selective ligand that discriminates among a variety of nAChR subtypes, fails to discriminate well between some subtypes containing the closely related alpha3 and alpha6 subunits. Structure-function analysis of alpha-conotoxin MII was performed in an attempt to generate analogs with preference for alpha6-containing [alpha6(*) (asterisks indicate the possible presence of additional subunits)] nAChRs. Alanine substitution resulted in several analogs with decreased activity at alpha3(*) versus alpha6(*) nAChRs heterologously expressed in Xenopus laevis oocytes. From the initial analogs, a series of mutations with two alanine substitutions was synthesized. Substitution at His9 and Leu15 (MII[H9A;L15A]) resulted in a 29-fold lower IC(50) at alpha6beta4 versus alpha3beta4 nAChRs. The peptide had a 590-fold lower IC(50) for alpha6/alpha3beta2 versus alpha3beta2 and a 2020-fold lower IC(50) for alpha6/alpha3beta2beta3 versus alpha3beta2 nAChRs. MII[H9A;L15A] had little or no activity at alpha2beta2, alpha2beta4, alpha3beta4, alpha4beta2, alpha4beta4, and alpha7 nAChRs. Functional block by MII[H9A;L15A] of rat alpha6/alpha3beta2beta3 nAChRs (IC(50) = 2.4 nM) correlated well with the inhibition constant of MII[H9A;L15A] for [(125)I]alpha-conotoxin MII binding to putative alpha6beta2(*) nAChRs in mouse brain homogenates (K(i) = 3.3 nM). Thus, structure-function analysis of alpha-conotoxin MII enabled the creation of novel selective antagonists for discriminating among nAChRs containing alpha3 and alpha6 subunits. 相似文献
25.
Dental unit water lines harbour considerable amounts of bacteria, derived from the biofilm on their inner surfaces, and the continuous reservoir of bacteria carries the potential to infect patients and dental workers alike. This article reviews the different methods of control and provides recent recommendations for ensuring that water of satisfactory quality is delivered to the patient. 相似文献
26.
27.
Many behavioral effects of nicotine result from activation of nigrostriatal and mesolimbic dopaminergic systems. Nicotine regulates dopamine release not only by stimulation of nicotinic acetylcholine receptors (nAChRs) on dopamine cell bodies within the substantia nigra and ventral tegmental area (SN/VTA), but also on presynaptic nAChRs located on striatal terminals. The nAChR subtype(s) present on both cell bodies and terminals is still a matter of controversy. The purpose of this study was to use double-labeling in situ hybridization to identify nAChR subunit mRNAs expressed within dopamine neurons of the SN/VTA, by using a digoxigenin-labeled riboprobe for tyrosine hydroxylase as the dopamine cell marker and (35)S-labeled riboprobes for nAChR subunits. The results reveal a heterogeneous population of nAChR subunit mRNAs within midbrain dopamine neurons. Within the SN, almost all dopamine neurons express alpha2, alpha4, alpha5, alpha6, beta2, and beta3 nAChR mRNAs, with more than half also expressing alpha3 and alpha7 mRNAs. In contrast, less than 10% express beta4 mRNA. Within the VTA, a similar pattern of nAChR subunit mRNA expression is observed except that most subunits are expressed in a slightly lower percentage of dopamine neurons than in the SN. Within the SN, alpha4, beta2, alpha7, and beta4 mRNAs are also expressed in a significant number of nondopaminergic neurons, whereas within the VTA this only occurs for beta4. The heterogeneity in the expression of nAChR subunits within the SN/VTA may indicate the formation of a variety of different nAChR subtypes on cell bodies and terminals of the nigrostriatal and mesolimbic pathways. 相似文献
28.
Panahipour Layla Nasserzare Shayesteh Amer Zeinab Brücke Friedrich Stähli Alexandra Kreissl Alexandra Haiden Nadja Gruber Reinhard 《Clinical oral investigations》2019,23(4):1959-1966
Clinical Oral Investigations - Milk can reduce intestinal tissue damage in colitis models, and protects infants against necrotizing enterocolitis. However, whether milk can decrease inflammation... 相似文献
29.
Al-Nakkash L Hu S Li M Hwang TC 《The Journal of pharmacology and experimental therapeutics》2001,296(2):464-472
We have investigated the mechanism of action of two benzimidazolone analogs (NS004 and NS1619) on DeltaF508-CFTR using both whole-cell and cell-attached patch-clamp techniques and compared their effects with those of genistein. We conclude that benzimidazolone analogs and genistein act through a common mechanism, based on the following evidence: 1) both act only on phosphorylated CFTR, 2) the maximal DeltaF508-CFTR current activated by benzimidazolone analogs is identical to that induced by genistein, 3) benzimidazolone analogs increase the open probability of the forskolin-dependent DeltaF508-CFTR channel activity through an increase of the channel open time and a decrease of the channel closed time (effects indistinct from those reported for genistein), and 4) the prolonged K1250A-CFTR channel open time (in the presence of 10 microM forskolin) is unaffected by benzimidazolone analogs or genistein, supporting the hypothesis that these compounds stabilize the open state by inhibiting ATP hydrolysis at nucleotide binding domain 2 (NBD2). In addition, we demonstrate that NS004 and NS1619 are more potent CFTR activators than genistein (EC(50) values are 87 +/- 14 nM, 472 +/- 88 nM, and 4.4 +/- 0.5 microM, respectively). From our studies with the double mutant DeltaF508/K1250A-CFTR, we conclude that benzimidazolone analogs and genistein rectify the DeltaF508-CFTR prolonged closed time independent of their effects on channel open time, since these agonists enhance DeltaF508/K1250A-CFTR activity by shortening the channel closed time. These studies should pave the way toward understanding the agonist binding sites at a molecular level. 相似文献
30.
Layla Diab-Cáceres Rosa María Girón-Moreno María Teresa Pastor-Sanz Esther Quintana-Gallego Isabel Delgado-Pecellín Marina Blanco-Aparicio Luis Maiz Marta María García-Clemente Carmen Luna-Paredes Pedro Mondéjar-López Marta Ruiz-de-Valbuena Ofelia Fernández Maribel Barrio Maribel González Alejandro López-Neyra María Cols-i-Roig Alexandre Palou-Rotger Francisco Javier Gómez-de-Terreros-Caro 《Archivos de bronconeumología》2018,54(12):614-618