全文获取类型
收费全文 | 840篇 |
免费 | 83篇 |
国内免费 | 8篇 |
学科分类
医药卫生 | 931篇 |
出版年
2023年 | 2篇 |
2022年 | 2篇 |
2021年 | 4篇 |
2020年 | 7篇 |
2019年 | 8篇 |
2018年 | 23篇 |
2017年 | 9篇 |
2016年 | 24篇 |
2015年 | 24篇 |
2014年 | 28篇 |
2013年 | 44篇 |
2012年 | 24篇 |
2011年 | 18篇 |
2010年 | 43篇 |
2009年 | 45篇 |
2008年 | 23篇 |
2007年 | 31篇 |
2006年 | 16篇 |
2005年 | 21篇 |
2004年 | 11篇 |
2003年 | 12篇 |
2002年 | 5篇 |
2001年 | 13篇 |
2000年 | 10篇 |
1999年 | 12篇 |
1998年 | 42篇 |
1997年 | 44篇 |
1996年 | 46篇 |
1995年 | 40篇 |
1994年 | 22篇 |
1993年 | 30篇 |
1992年 | 9篇 |
1991年 | 14篇 |
1990年 | 13篇 |
1989年 | 24篇 |
1988年 | 25篇 |
1987年 | 24篇 |
1986年 | 32篇 |
1985年 | 25篇 |
1984年 | 9篇 |
1983年 | 14篇 |
1982年 | 5篇 |
1981年 | 14篇 |
1980年 | 7篇 |
1979年 | 4篇 |
1978年 | 4篇 |
1977年 | 9篇 |
1976年 | 11篇 |
1975年 | 2篇 |
1884年 | 1篇 |
排序方式: 共有931条查询结果,搜索用时 0 毫秒
1.
J K Yliruusi J A Uotila E R Kristoffersson 《American journal of hospital pharmacy》1986,43(11):2795-2799
The effect of flow rate and type of i.v. solution container on adsorption of diazepam to i.v. administration systems was studied. Diazepam solutions were prepared in 500 mL of 0.9% sodium chloride injection in glass, polyethylene, and polyvinyl chloride (PVC) containers to a final theoretical concentration of 50 micrograms/mL. PVC administration sets were attached to the containers, and diazepam solution was infused at flow rates of 30, 45, 60, 90, and 120 mL/hr. Solution samples were taken initially and at 0.25, 0.5, 0.75, 1.00, 1.50, 2.00, 3.00, and 4.00 hours after infusion of the first 5 mL of solution through the system. Three infusion trials were performed using each type of container. Adsorption of diazepam to each type of container was evaluated by serial measurements of diazepam concentration over a 168-hour period using five containers of each type. The effect of shaking the container on diazepam adsorption to PVC containers was tested by comparing concentrations in five containers that were shaken during a two-hour period with concentrations in five unshaken containers. Diazepam concentrations were measured spectrophotometrically in duplicate. Diazepam concentrations in glass containers remained unchanged throughout the 168-hour study period; concentrations decreased by about 5% in polyethylene containers and as much as 75% in PVC bags. Shaking increased diazepam adsorption to the PVC container. In the infusion trials, the percentage of diazepam adsorbed increased as flow rate decreased. The amount of diazepam adsorbed to the i.v. administration system was ore dependent on flow rate and infusion time than on the type of container used.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
2.
3.
4.
Silber SJ; Nagy Z; Devroey P; Tournaye H; Van Steirteghem AC 《Human reproduction (Oxford, England)》1997,12(11):2422-2428
The aim of the study was to determine whether a prior diagnostic testicle
biopsy can predict success or failure of testicular sperm extraction (TESE)
with intracytoplasmic sperm injection (ICSI) in patients with
non-obstructive azoospermia caused by testicular failure, and what is the
minimum threshold of sperm production in the testis which must be surpassed
for spermatozoa to reach the ejaculate. Forty- five patients with
non-obstructive azoospermia caused by testicular failure underwent
diagnostic testicle biopsy prior to a planned future TESE-ICSI procedure.
The diagnostic testicle biopsy was analysed quantitatively, and correlated
with the quantitative findings of spermatogenesis in patients with normal
spermatogenesis, as well as with the results of subsequent attempts at
TESE-ICSI. Men with non- obstructive azoospermia caused by germinal failure
had a mean of 0-6 mature spermatids/seminiferous tubule seen on a
diagnostic testicle biopsy, compared to 17-35 mature spermatids/tubule in
men with normal spermatogenesis and obstructive azoospermia. These findings
were the same for all types of testicular failure whether Sertoli cell
only, maturation arrest, cryptorchidism, or post-chemotherapy azoospermia.
Twenty-two of 26 men with mature spermatids found in the prior testis
biopsy had successful retrieval of spermatozoa for ICSI, 12 of their
partners became pregnant, and are either ongoing or delivered. The study
suggests that 4-6 mature spermatids/tubule must be present in the testis
biopsy for any spermatozoa to reach the ejaculate. More than half of
azoospermic patients with germinal failure have minute foci of
spermatogenesis which are insufficient to produce spermatozoa in the
ejaculate. Prior diagnostic testicle biopsy analysed quantitatively (for
the presence of mature spermatids) can predict subsequent success or
failure with TESE-ICSI. Incomplete testicular failure may involve a sparse
multi-focal distribution of spermatogenesis throughout the entire testicle,
rather than a regional distribution. Therefore, it is possible that massive
testicular sampling from many different regions of the testes may not be
necessary for successful TESE-ICSI.
相似文献
5.
β-Lactoglobulin was isolated from infant formulae that were ultra high temperature (UHT) -treated, sterilized or spray-dried. The effect of the isolated β-lactoglobulin on SfaII-fimbriae-mediated adhesion of Escherichia coli to human ileostomy glycoproteins was studied in vitro. β-Lactoglobulin isolated from sterilized formulae was found to perform significantly less well than preparations from spray-dried formulae (p = 0:05). Great heterogeneity was observed in the adhesion inhibitory capacity of β-lactoglobulin isolated from UHT-treated formulae. Therefore, no significant difference was observed between UHT-treated and sterilized formulae or spray-dried formulae (p < 0:10). It can be hypothesized that β-lactoglobulin from spray-dried and some UHT-treated infant formulae may affect the colonization of mucous membranes by E. coli strains causing neonatal septicaemia and meningitis. 相似文献
6.
Successful internal arterial embolization with steel coils in life-threatening bleeding after femoral fracture is described in an older patient. 相似文献
7.
Mutations in the retinal guanylate cyclase (RETGC-1) gene in dominant cone-rod dystrophy 总被引:3,自引:0,他引:3
Kelsell RE; Gregory-Evans K; Payne AM; Perrault I; Kaplan J; Yang RB; Garbers DL; Bird AC; Moore AT; Hunt DM 《Human molecular genetics》1998,7(7):1179-1184
The dominant cone-rod dystrophy gene CORD6 has previously been mapped to
within an 8 cM interval on chromosome 17p12-p13. The retinal- specific
guanylate cyclase gene (RETGC-1), which maps to within this genetic
interval and previously was implicated in Leber's congenital amaurosis, was
screened for mutations within this family and in a panel of small families
and individuals with various cone and cone- rod dystrophy phenotypes. A
missense mutation (E837D) was identified in affected members of the CORD6
family, as well as a second missense mutation (R838C) in three other
families with dominant cone-rod dystrophy. RETGC-1 is only the fourth gene
to be implicated in cone-rod dystrophy and this is the first report of
dominant mutations in this gene.
相似文献
8.
Ulf Kristoffersson Sverre Heim Nils Mandahl Lennart Sundkvist Jan Szelest Inga Hägerstrand 《Clinical genetics》1987,32(3):169-171
A child with multiple anomalies, including growth retardation, a left-sided diaphragmatic hernia with lung hypoplasia, and cerebral malformations is described. Cytogenetic investigation demonstrated a deletion of the distal part of one chromosome 15, del(15)(q24qter), an aberration not previously described. Family studies revealed that the mother had a balanced translocation, t(6;15)(p25;q24). Two of her subsequent pregnancies resulted in abortions after prenatal diagnosis: one fetus was trisomic for 15q24→qter, while the other had monosomy 15q24→qter and a left-sided diaphragmatic hernia similar to the first child. 相似文献
9.
The GAP-related domain of tuberin, the product of the TSC2 gene, is a target for missense mutations in tuberous sclerosis 总被引:5,自引:0,他引:5
Maheshwar MM; Cheadle JP; Jones AC; Myring J; Fryer AE; Harris PC; Sampson JR 《Human molecular genetics》1997,6(11):1991-1996
Tuberous sclerosis is an autosomal dominant trait in which the
dysregulation of cellular proliferation and differentiation results in the
development of hamartomatous growths in many organs. The TSC2 gene is one
of two genes determining tuberous sclerosis. Inactivating germline
mutations of TSC2 in patients with tuberous sclerosis and somatic loss of
heterozygosity at the TSC2 locus in the associated hamartomas indicate that
TSC2 functions as a tumour suppressor gene and that loss of function is
critical to expression of the tuberous sclerosis phenotype. The TSC2
product, tuberin, has a region of homology with the GTPase activating
protein rap1GAP and stimulates the GTPase activity of rap1a and rab5a in
vitro. Here we show that the region of homology between tuberin and human
rap1GAP and the murine GAP mSpa1 is more extensive than previously reported
and spans approximately 160 amino acid residues encoded within exons 34-38
of the TSC2 gene. Single strand conformation polymorphism analysis of these
exons in 173 unrelated patients with tuberous sclerosis and direct
sequencing of variant conformers together with study of additional family
members enabled characterisation of disease associated mutations in 14
cases. Missense mutations, which occurred in exons 36, 37 and 38 were
identified in eight cases, four of whom shared the same recurrent change
P1675L. Each of the five different missense mutations identified was shown
to occur de novo in at least one sporadic case of tuberous sclerosis. The
high proportion of missense mutations detected in the region of the TSC2
gene encoding the GAP-related domain supports its key role in the
regulation of cellular growth.
相似文献
10.
Marjolijn Bornebroek Joost Haan Marion LC Maat-Schieman Sjoerd G Van Duinen Raymund AC Roos 《Brain pathology (Zurich, Switzerland)》1996,6(2):111-114
Hereditary cerebral hemorrhage with amyloidosis - Dutch type (HCHWA-D) is an autosomal dominant disease caused by deposition of β-amyloid in the leptomeningeal arteries and cortical arterioles, in addition to preamyloid deposits and amyloid plaques in the brain parenchyma.
The disease is due to a point mutation at codon 693 of the amyloid precursor protein (βPP) gene at chromosome 21. Since this point mutation is diagnostic for HCHWA-D, presymptomatic testing is feasible and offered, together with genetic counselling and psychological support, to subjects at risk. HCHWA-D is clinically characterized by recurrent strokes, in addition to dementia, which can occur after the first stroke but also preceding it. Radiological studies revealed focal lesions (hemorrhages, hemorrhagic and non-hemorrhagic infarctions) and diffuse white matter damage. Diffuse white matter hyperintensities on MRI are an early symptom of HCHWA-D since they have been found on MRI scans of subjects who had not suffered a stroke.
The presence of the diagnostic point mutation makes HCHWA-D a useful model to study the effects of cerebral amyloid angiopathy in vivo. The characteristic pathological abnormalities and its implications for Alzheimer's disease will be discussed in Part II of this article 相似文献
The disease is due to a point mutation at codon 693 of the amyloid precursor protein (βPP) gene at chromosome 21. Since this point mutation is diagnostic for HCHWA-D, presymptomatic testing is feasible and offered, together with genetic counselling and psychological support, to subjects at risk. HCHWA-D is clinically characterized by recurrent strokes, in addition to dementia, which can occur after the first stroke but also preceding it. Radiological studies revealed focal lesions (hemorrhages, hemorrhagic and non-hemorrhagic infarctions) and diffuse white matter damage. Diffuse white matter hyperintensities on MRI are an early symptom of HCHWA-D since they have been found on MRI scans of subjects who had not suffered a stroke.
The presence of the diagnostic point mutation makes HCHWA-D a useful model to study the effects of cerebral amyloid angiopathy in vivo. The characteristic pathological abnormalities and its implications for Alzheimer's disease will be discussed in Part II of this article 相似文献