全文获取类型
收费全文 | 299篇 |
免费 | 13篇 |
国内免费 | 4篇 |
专业分类
儿科学 | 11篇 |
妇产科学 | 2篇 |
基础医学 | 16篇 |
口腔科学 | 13篇 |
临床医学 | 21篇 |
内科学 | 66篇 |
皮肤病学 | 1篇 |
神经病学 | 3篇 |
特种医学 | 91篇 |
外科学 | 23篇 |
综合类 | 18篇 |
预防医学 | 15篇 |
眼科学 | 2篇 |
药学 | 12篇 |
肿瘤学 | 22篇 |
出版年
2021年 | 4篇 |
2020年 | 4篇 |
2019年 | 3篇 |
2018年 | 6篇 |
2017年 | 4篇 |
2016年 | 5篇 |
2015年 | 12篇 |
2014年 | 6篇 |
2013年 | 18篇 |
2012年 | 10篇 |
2011年 | 2篇 |
2010年 | 15篇 |
2009年 | 9篇 |
2008年 | 9篇 |
2007年 | 6篇 |
2006年 | 4篇 |
2005年 | 4篇 |
2004年 | 4篇 |
2001年 | 2篇 |
2000年 | 3篇 |
1999年 | 3篇 |
1998年 | 18篇 |
1997年 | 20篇 |
1996年 | 16篇 |
1995年 | 12篇 |
1994年 | 14篇 |
1993年 | 9篇 |
1991年 | 4篇 |
1990年 | 6篇 |
1989年 | 10篇 |
1988年 | 5篇 |
1987年 | 4篇 |
1986年 | 7篇 |
1985年 | 5篇 |
1984年 | 6篇 |
1982年 | 3篇 |
1981年 | 5篇 |
1980年 | 8篇 |
1978年 | 5篇 |
1977年 | 5篇 |
1976年 | 3篇 |
1975年 | 4篇 |
1973年 | 1篇 |
1968年 | 1篇 |
1966年 | 1篇 |
1960年 | 1篇 |
1958年 | 2篇 |
1954年 | 2篇 |
1953年 | 2篇 |
1952年 | 1篇 |
排序方式: 共有316条查询结果,搜索用时 125 毫秒
81.
A large number of microfilaria (MF) positive cases were reported at a Military Hospital in 1994. The epidemiological investigations included mass night blood survey, detection of sector breeding places and entomological studies. Control measures were instituted concurrently and this included treatment of positive cases, sector control measures, personal protection and health education. The mass blood survey was continued in 1995 as well to find the outcome of control measures. A total of 215 MF positive cases were detected in 1994 with MF rate of 9.63. The only MF species identified was Wuchereria bancrofti. 203% cases were in the station for less than six months. 71.3% of MF positive cases were asymptomatic. As per state health authorities, Culex quinquefasciatus was the known vector for spread of the disease in the region. However, in present study, it could not be implicated as dissection of over 200 mosquitoes of this species was negative for filarial parasite. Our study stresses the importance of close monitoring of the disease by night blood surveys and effective integrated vector control measures.KEY WORDS: Control, Epidemiology, Filariasis 相似文献
82.
Mutation rate at the hprt locus in human cancer cell lines with specific mismatch repair-gene defects 总被引:1,自引:1,他引:1
Spontaneous mutation rates at the hypoxanthine-guanine phosphoribosyl
transferase (hprt) locus were measured in human cancer cell lines defective
in the mismatch repair (MMR) genes hMLH1, hPMS2, or GTBP, as well as in a
cell line carrying mutations in both hMLH1 and hPMS2. The mutation rate was
determined by quantitating mutant frequency increases within a single
culture as a function of cell division. These MMR- deficient cell lines
exhibited a 50- to 750-fold increase in mutation rate relative to a
MMR-proficient cancer cell line. From lowest to highest, the spontaneous
mutation rates relative to the MMR-gene defects studied here are as
follows: hMLH1- < GTBP- < hPMS2- < hMLH1- / hPMS2-. In addition, a
cell line in which MMR was restored by chromosome transfer exhibited a
mutation rate 12-fold below the MMR- deficient parental cell line. These
data support the notion that MMR plays an important role in controlling the
rate of spontaneous mutation and suggest that different MMR-gene defects
may vary in their ability to repair different types of DNA mismatches, thus
leading to measurable quantitative differences in spontaneous mutagenesis.
Furthermore, a difference in mutation rates was observed between a
hPMS2-defective cell line (3.1 x 10(-5) mutations/cell/generation) and two
hMLH1- defective cell lines (4.0 x 10(-6) and 7.3 x 10(-6)
mutations/cell/generation). Assuming the hPMS2- and hMLH1-gene products
only function in the proposed hMutL alpha heterodimer, then defects in
either gene should yield comparable mutation rates. These data suggest that
hPMS2 plays a critical role in MMR, while additional hMLH1 homologues or
hPMS2 alone may function to partially complement defects in hMLH1.
相似文献
83.
DA Connell KR Thomson RN Gibson AJ Wall 《Journal of Medical Imaging and Radiation Oncology》1995,39(1):68-70
The main trunks of both coeliac and superior mesenteric arteries were sheared off the abdominal aorta by an anterior dissection that spared the renal arteries. Both vessels were cannulated and a Walstent inserted across the false lumen to restore normal coeliac and superior mesenteric perfusion. This produced a successful haemodynamic and angiographic result with improvement in the patient's clinical condition. 相似文献
84.
A new spontaneous mouse mutation of Hoxd13 with a polyalanine expansion and phenotype similar to human synpolydactyly 总被引:2,自引:2,他引:2
Johnson KR; Sweet HO; Donahue LR; Ward-Bailey P; Bronson RT; Davisson MT 《Human molecular genetics》1998,7(6):1033-1038
Human synpolydactyly (SPD) is an inherited congenital limb malformation
caused by mutations in the HOXD13 gene. Heterozygotes are typically
characterized by 3/4 finger and 4/5 toe syndactyly with associated
duplicated digits; hands and feet of homozygotes are very small because of
a shortening of the phalanges, metacarpal and metatarsal bones. Here we
describe the phenotype and molecular basis of a spontaneous mutation of
Hoxd13 in mice that provides a phenotypically and molecularly accurate
model for human SPD. The new mutation, named synpolydactyly homolog (spdh),
is a 21 bp in-frame duplication within a polyalanine- encoding region at
the 5'-end of the Hoxd13 coding sequence. The duplication expands the
stretch of alanines from 15 to 22; the same type of expansion occurs in
human SPD mutations. spdh/spdh homozygotes exhibit severe malformations of
all four feet, including polydactyly, syndactyly and brachydactylia. The
phenotype of spdh is much more severe than that exhibited by mice with a
genetically engineered, presumably null, disruption of Hoxd13. Thus spdh
probably acts in a dominant-negative manner and will be valuable for
examining interactions with other Hox genes and their protein products
during limb development. Homozygous mice of both sexes also lack preputial
glands and males do not breed; therefore, spdh/spdh mice may also be
valuable in studies of reproductive physiology and behavior.
相似文献
85.
86.
Yeast artificial chromosome (YAC) transgenesis is associated with a high
frequency of deletions in the integrated transgenes. To determine the
impact of these rearrangements on the ability to derive structure- function
relationships using YACs, transgenic mice were generated with 248 or 155 kb
beta-globin locus YACs. The transgenics were examined for structural
integrity of the YAC using an approach of structural analysis that
unambiguously demonstrates intactness of YAC transgene copies. Globin gene
expression per copy of each integrated transgene and the profiles of globin
gene expression during development were determined. Diverse deletion
patterns were observed in one or more integrated YACs in all the 248 and
most of the 155 kb transgenic lines we analyzed. However, when the
structure of the major regulatory element of the beta-globin locus, the
locus control region, was preserved, the genes of the beta-globin locus
functioned normally and globin transgenes of both the 248 and 155 kb
beta-YACs were expressed in a position-independent, copy number-dependent
manner. Furthermore, the globin genes of both beta-YACs displayed normal
developmental regulation. We conclude that YACs can be used for analysis of
structure- function relationships of large genes or multigene loci in spite
of the tendency for rearrangements and deletions of the integrated
transgenes. However, detailed structural evidence for integrity and
continuity of locus sequences is required for correct interpretation of
functional data.
相似文献
87.
用(+)-FLEC手性试剂自动柱前衍生高效液相色谱法拆分麻黄碱类药物对映体 总被引:5,自引:0,他引:5
报道了以(+)-FLEC作为手性衍生化试剂,用反相高效液相色谱技术分离麻黄碱类药物对映异构体的方法。dl-麻黄碱、dl-伪麻黄碱、dl-去甲麻黄碱、dl-去甲伪麻黄碱先与(+)-FLEC形成衍生物后,经过一ODSHypersil柱分离,以水和乙腈为流动相梯度洗脱.二极管阵列检测器在266nm检测。该法从样品衍生化到最终报告全部自动完成。上述各对对映体均达到基线分离,分离度R均大于1.5,方法灵敏度高,最低检出限达10pmo1,保留时间和峰面积的上现性较好,RSD分别为1.1/和3.0%。 相似文献
88.
Intraoperative blood salvage: a review 总被引:3,自引:0,他引:3
89.
90.
MF Given BC McDonald P Brookfield L Niggemeyer T Kossmann DK Varma KR Thomson SM Lyon 《Journal of Medical Imaging and Radiation Oncology》2008,52(5):452-457
The aim of our study was to assess our experience with the retrievable Gunther Tulip (GT) inferior vena cava (IVC) filter, with regard to its insertion, efficacy, ease of placement and retrieval, and associated complications. Between November 2001 and October 2005, 322 GT filters were placed in 317 patients. Insertion indications included the following: pulmonary embolus (PE) prophylaxis in trauma patients (n = 232), PE prophylaxis in perioperative patients (n = 27), PE prophylaxis in moribund intensive care unit patients (n = 22), recent PE (n = 48), extensive deep venous thrombosis (n = 66), contraindication to anticoagulation (n = 63), anticoagulation complication (n = 8) and deep venous thrombosis with failed anticoagulation (n = 8). Some patients had more than one indication for caval filter placement. Two hundred and five attempted retrievals have been carried out, with 15 failures. Our successful retrieval rate is 92%. Nineteen filters were originally inserted permanently. There have been three minor complications associated with insertion and five with retrieval. The mean time from filter insertion to attempted retrieval was 76.95 days. The ideal filter implantation time gives the patient the benefit of PE protection, while avoiding the long‐term risks associated with caval filters. Although GT retrieval times have lengthened considerably, our data suggest that this is at the expense of successful retrieval rates. 相似文献