全文获取类型
收费全文 | 622篇 |
免费 | 37篇 |
国内免费 | 46篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 47篇 |
妇产科学 | 20篇 |
基础医学 | 64篇 |
口腔科学 | 37篇 |
临床医学 | 89篇 |
内科学 | 165篇 |
皮肤病学 | 10篇 |
神经病学 | 19篇 |
特种医学 | 115篇 |
外科学 | 24篇 |
综合类 | 10篇 |
预防医学 | 20篇 |
眼科学 | 3篇 |
药学 | 51篇 |
1篇 | |
肿瘤学 | 28篇 |
出版年
2023年 | 5篇 |
2022年 | 6篇 |
2021年 | 6篇 |
2019年 | 4篇 |
2018年 | 10篇 |
2017年 | 9篇 |
2016年 | 11篇 |
2015年 | 15篇 |
2014年 | 19篇 |
2013年 | 26篇 |
2012年 | 9篇 |
2011年 | 12篇 |
2010年 | 20篇 |
2009年 | 20篇 |
2008年 | 6篇 |
2007年 | 39篇 |
2006年 | 15篇 |
2005年 | 9篇 |
2004年 | 3篇 |
2003年 | 4篇 |
2002年 | 10篇 |
2001年 | 4篇 |
2000年 | 7篇 |
1999年 | 11篇 |
1998年 | 44篇 |
1997年 | 52篇 |
1996年 | 54篇 |
1995年 | 44篇 |
1994年 | 30篇 |
1993年 | 30篇 |
1992年 | 2篇 |
1991年 | 11篇 |
1990年 | 7篇 |
1989年 | 14篇 |
1988年 | 24篇 |
1987年 | 19篇 |
1986年 | 14篇 |
1985年 | 14篇 |
1984年 | 6篇 |
1983年 | 8篇 |
1982年 | 9篇 |
1981年 | 8篇 |
1980年 | 11篇 |
1979年 | 2篇 |
1978年 | 4篇 |
1977年 | 8篇 |
1976年 | 2篇 |
1975年 | 4篇 |
1967年 | 1篇 |
1960年 | 1篇 |
排序方式: 共有705条查询结果,搜索用时 0 毫秒
71.
Aníbal E Carbajo Carolina Vera Paula LM González 《International journal of health geographics》2009,8(1):44-10
Background
Oligoryzomys longicaudatus (colilargo) is the rodent responsible for hantavirus pulmonary syndrome (HPS) in Argentine Patagonia. In past decades (1967–1998), trends of precipitation reduction and surface air temperature increase have been observed in western Patagonia. We explore how the potential distribution of the hantavirus reservoir would change under different climate change scenarios based on the observed trends. 相似文献72.
高效液相色谱法测定消痰咳片的含量 总被引:2,自引:0,他引:2
目的:采用反相色谱法同时测定消痰咳片中两种主要成分甲氧苄啶和磺胺体的含量。方法:以乙腈:0.1%H3PO4(15:85)为流动相,检测波长254nm,HPLC法测定含量。结果:试验表明,甲氧苄啶和磺胺林在0.8-8ug范围内呈良好的线性关系,回归方程分别为Y=-1127.1+110.2x(r=0.9994),Y=-1852.3 256.2x(r=0.9996),相对标准偏差分别为2.1%和0.8%。结论:该方法简便、准确、可靠。 相似文献
73.
The EuroQoL EQ-5D and MOS SF-36 are two generic quality of life measures that differ significantly in their design (the former being an index and the latter a profile). Both have been extensively used in evaluating interventions in acute disease. This study tested their comparative performance in a survey of patients with relapsing-remitting multiple sclerosis (MS).
METHODS: 309 patients with diagnosed relapsing-remitting MS were identified through the records of 5 specialist centers in North West England. Patients were contacted by telephone by a specialist MS nurse and asked to complete a set of questionnaires distributed by mail. The questionnaire booklet reproduced the English version of SF-36, together with the EQ-5D and a self completion form of the Barthel. Minimal additional background information was obtained from all respondents; 4 weeks following their completion of the initial booklet, a second identical booklet was sent to the first 200 initial respondents. Patients in this re-test sub-group were asked whether their health status had improved, deteriorated, or remained unchanged over the intervening period.
RESULTS: Of the 200 patients in the test/re-test subgroup, 144 (72%) replied on both occasions. Paired t-tests for the PCS, MCS, and general health perception scores on the SF-36 failed to generate comprehensive evidence of reliability. The weighted index form of the EQ-5D and the visual analogue scale self-ratings provided superior evidence of reliability. Standardized response means for both measures confirmed this general pattern.
CONCLUSION: EQ-5D performs satisfactorily as a generic measure of health-related quality of life in patients with MS. 相似文献
METHODS: 309 patients with diagnosed relapsing-remitting MS were identified through the records of 5 specialist centers in North West England. Patients were contacted by telephone by a specialist MS nurse and asked to complete a set of questionnaires distributed by mail. The questionnaire booklet reproduced the English version of SF-36, together with the EQ-5D and a self completion form of the Barthel. Minimal additional background information was obtained from all respondents; 4 weeks following their completion of the initial booklet, a second identical booklet was sent to the first 200 initial respondents. Patients in this re-test sub-group were asked whether their health status had improved, deteriorated, or remained unchanged over the intervening period.
RESULTS: Of the 200 patients in the test/re-test subgroup, 144 (72%) replied on both occasions. Paired t-tests for the PCS, MCS, and general health perception scores on the SF-36 failed to generate comprehensive evidence of reliability. The weighted index form of the EQ-5D and the visual analogue scale self-ratings provided superior evidence of reliability. Standardized response means for both measures confirmed this general pattern.
CONCLUSION: EQ-5D performs satisfactorily as a generic measure of health-related quality of life in patients with MS. 相似文献
74.
Stimulus generalization of fear responses: effects of auditory cortex lesions in a computational model and in rats 总被引:3,自引:2,他引:1
Armony JL; Servan-Schreiber D; Romanski LM; Cohen JD; LeDoux JE 《Cerebral cortex (New York, N.Y. : 1991)》1997,7(2):157-165
The conditioning of fear responses to a simple acoustic stimulus (pure
tone) paired with footshock can be mediated by the transmission of auditory
information to the lateral nucleus of the amygdala from either the auditory
thalamus or the auditory cortex. We examined the processing capacity of the
thalamo-amygdala pathway by making lesions of the auditory cortex and
testing the extent to which conditioned fear responses generalized to tones
other than the one paired with footshock. Two studies were performed, one
in an anatomically constrained computational model of the fear conditioning
network and the other in rats. Stimulus generalization was unaffected in
both. These findings support the validity of the model as an approach to
studying the neural basis of conditioned fear learning, and in addition
suggest that the thalamo-amygdala pathway, possibly by the use of
population coding, is capable of performing at least crude stimulus
discriminations.
相似文献
75.
There is increasing evidence to suggest that abnormalities in apoptosis may
play a part in the pathogenesis of systemic lupus erythematosus (SLE). For
example, there is now considerable evidence that bel-2 expression is
enhanced in a proportion of peripheral T cells, but not in B cells, in SLE
patients and correlates with overall disease activity regardless of the
activity index employed. Further work is required to establish whether
enhanced bel-2 expression by some T cells in SLE patients is related to
their activation or intrinsically enhanced by genetic predisposition.
Mutations in Fas result in a lymphoproliferative syndrome and may play a
role in accelerating autoimmune disease. A report of three children with
mutations in Fas has once again focused attention on this regulator of
apoptosis. The relationships between inducers and inhibitors of apoptosis
may differ in different cell types, and must be elucidated before the
implications of observations made in lymphocytes from SLE patients can be
fully understood.
相似文献
76.
77.
提出了非相关成分参比一倍率导数光谱法用于测定混合组分体系的基本原理和实验方法。本法可用于待测成分和非相关成分导数光谱严重重叠且待测成分含量较低时的不经分离直接测定。试用本法消除了甲氧苄啶(TMP)和磺胺甲嚼唑(SMZ)及附加剂之间的相互干扰,从而测定了部分制剂中的TMP:用“零交法”测定了SMZ,平均回收率分别为:102.5±1.63%(CV)和100.3±0.99%(CV)。 相似文献
78.
K Haug LM Irgens V Baste T Markestad R Skjærven P Schreuder 《Acta paediatrica (Oslo, Norway : 1992)》1998,87(10):1023-1027
To explore the association between smoking and breastfeeding, we obtained data from a retrospective questionnaire-based national survey comprising a random sample (n = 34 799) of all mothers giving birth in Norway 1970-91. Variables studied were postpartum smoking habits for both parents, duration of breastfeeding, infant's year of birth and parental age. The response rate was 70% (n = 24 438). During the study period, the maternal postpartum smoking prevalence decreased from 38% to 26%. The proportion breastfeeding at 6 months increased from 15% to 44% among smokers, and from 30% to 72% among non-smokers. In spite of a considerable increase in breastfeeding both among smokers and non-smokers, the proportion of breastfeeding, non-smoking women at 6 months was twice that of smoking women during the whole period. Furthermore, the duration of breastfeeding was shorter among young mothers and when the fathers were smoking. There was epidemiological evidence that the effect on breastfeeding of smoking might represent both biological and social mechanisms. 相似文献
79.
鼠尾静脉流体力学转染技术对绿色荧光蛋白表达质粒器官靶向分布的影响 总被引:1,自引:1,他引:1
目的:观察流体力学尾静脉注射对绿色荧光蛋白基因器官靶向性的影响,为今后质粒载体的基因治疗和功能研究寻找潜在的靶器官。方法:实验于2005-12/2006-04在江西省分子医学重点实验室完成。选用健康雄性昆明鼠40只,将32只小鼠按随机数字表法分为流体力学注射和常规注射两大组,每大组再分为转染组和对照组两个小组(n=8),并设正常对照组(n=8)。①流体力学转染组将100μg/只绿色荧光蛋白表达质粒溶液2mL在5s内快速注入尾静脉;对照组仅在5s内注入林格氏液2mL。②常规注射组则将2mL林格氏液或绿色荧光蛋白表达质粒溶液在30s左右注入尾静脉。注射结束后24h采集各组小鼠血清检测转氨酶,并采集肝、脾、心、肾、肺和脑组织进行冰冻切片,部分肝组织采用多聚甲醛固定后切片,荧光显微镜下观察。结果:40只小鼠全部进入结果分析,无脱失。①流体力学注射组和常规注射组小鼠血清转氨酶与正常对照组比较差异均无显著性意义(P>0.05)。②常规尾静脉注射引起少数肾小球细胞表达绿色荧光蛋白,而肝、脾、心、肺及脑等组织未见明显绿色荧光蛋白表达。③流体力学注射引起肝内绿色荧光蛋白高水平表达,肝细胞表达率接近45%,其他组织则无绿色荧光蛋白表达。结论:流体力学方法是肝靶向性的活体基因转染方法,绿色荧光蛋白可作为该方法进行目的基因研究的一个可靠和方便的示踪剂。 相似文献
80.
We investigated the ability of blood B cells, bone marrow (BM) plasma cells, and terminal leukemic plasma cells (T-PCL) from patients with multiple myeloma (MM) to migrate on extracellular matrix proteins. Hyaluronan (HA), but not collagen type I, collagen type IV, or laminin, promoted migration of MM blood B cells, as determined by time-lapse video microscopy. Between 13% and 20% of MM blood B cells migrated on HA with an average velocity of 19 micron/min, and greater than 75% of MM blood B cells exhibited vigorous cell movement and plasma membrane deformation, as did circulating T-PCL and extraskeletal plasma cells from patients with MM. In contrast, plasma cells obtained from BM of patients with MM lacked motility on all substrates tested and did not exhibit cell membrane protrusions or cellular deformation. MM blood B cells and MM plasma cells from all sources examined expressed the HA- binding receptors receptor for HA-mediated motility (RHAMM) and CD44. On circulating MM B cells, both RHAMM and CD44 participated in HA- binding, indicating their expression ex vivo in an activated conformation. In contrast, for the majority of BM plasma cells in the majority of patients with MM, expression of RHAMM or CD44 was not accompanied by HA binding. A minority of patients did have HA-binding BM plasma cells, involving both RHAMM and CD44, as evidenced by partial blocking with monoclonal antibodies (MoAbs) to RHAMM or to CD44. Despite HA binding by both RHAMM and CD44, migration of MM blood B cells on HA was inhibited by anti-RHAMM but not by anti-CD44 MoAbs, indicating that RHAMM but not CD44 mediates motility on HA. Thus, circulating B and plasma cells in MM exhibit RHAMM- and HA-dependent motile behavior indicative of migratory potential, while BM plasma cells are sessile. We speculate that a subset(s) of circulating B or plasma cells mediates malignant spread in myeloma. 相似文献