全文获取类型
收费全文 | 419篇 |
免费 | 18篇 |
国内免费 | 20篇 |
专业分类
儿科学 | 24篇 |
基础医学 | 28篇 |
口腔科学 | 8篇 |
临床医学 | 39篇 |
内科学 | 111篇 |
皮肤病学 | 4篇 |
神经病学 | 6篇 |
特种医学 | 157篇 |
外科学 | 19篇 |
综合类 | 11篇 |
预防医学 | 13篇 |
眼科学 | 2篇 |
药学 | 23篇 |
2篇 | |
肿瘤学 | 10篇 |
出版年
2023年 | 1篇 |
2021年 | 1篇 |
2018年 | 4篇 |
2017年 | 1篇 |
2016年 | 1篇 |
2015年 | 3篇 |
2014年 | 2篇 |
2013年 | 4篇 |
2012年 | 4篇 |
2011年 | 3篇 |
2010年 | 6篇 |
2009年 | 9篇 |
2008年 | 3篇 |
2007年 | 16篇 |
2006年 | 6篇 |
2005年 | 3篇 |
2004年 | 4篇 |
2003年 | 3篇 |
2002年 | 7篇 |
2000年 | 7篇 |
1999年 | 11篇 |
1998年 | 28篇 |
1997年 | 26篇 |
1996年 | 27篇 |
1995年 | 21篇 |
1994年 | 22篇 |
1993年 | 24篇 |
1992年 | 5篇 |
1991年 | 6篇 |
1990年 | 7篇 |
1989年 | 31篇 |
1988年 | 17篇 |
1987年 | 25篇 |
1986年 | 16篇 |
1985年 | 28篇 |
1984年 | 13篇 |
1983年 | 11篇 |
1982年 | 6篇 |
1981年 | 8篇 |
1980年 | 11篇 |
1979年 | 4篇 |
1978年 | 3篇 |
1977年 | 12篇 |
1976年 | 7篇 |
排序方式: 共有457条查询结果,搜索用时 15 毫秒
91.
Safety of outpatient peripheral angioplasty 总被引:2,自引:0,他引:2
92.
Molecular evidence that in situ-transduced fetal liver hematopoietic stem/progenitor cells give rise to medullary hematopoiesis in adult rats 总被引:4,自引:2,他引:2
We exploited the ability to transduce fetal liver hematopoietic stem/progenitor cells in situ with recombinant retrovirus, together with the ability to analyze proviral integration patterns into chromosomal DNA, to detect the cellular and organ fate of hematopoietic stem and progenitor-derived progeny in tissues and in the circulation of neonatal and adult rats. Two hundred seventeen fetuses were injected with retrovirus supernatant on day 16 of gestation, before the development of the bone marrow cavity. The progeny of 41 stem and progenitor cells from 97 liveborn rats were clonally identified. Pluripotent and lineage-restricted stem/progenitor clones derived from the fetal liver consistently gave rise to progeny in the marrow of newborn and adult rats. Patterns of differentiation of transduced stem and progenitor cells fell into distinct subsets. Blood cells derived from in situ transduced cells that originated in the fetal liver circulated throughout the life span of the adult animals. These data provide molecular evidence of the origin of medullary cavity hematopoiesis by cells derived from the fetal liver that were transduced in vivo, homed to the developing medullary cavity and proliferated in a normal medullary hematopoietic microenvironment. 相似文献
93.
Parsons DW; McAndrew PE; Monani UR; Mendell JR; Burghes AH; Prior TW 《Human molecular genetics》1996,5(11):1727-1732
The gene for autosomal recessive spinal muscular atrophy (SMA) has been
mapped to 5q12 in a region that contains repeated markers and genes. Three
cDNAs that detect deletions in SMA patients have been reported. One of
these, the survival motor neuron (SMN) cDNA, is encoded by two genes (SMNT
and SMNC) which are distinguished by base changes in exons 7 and 8. Exon 7
of the SMNT gene is not detectable in approximately 95% of SMA cases, due
either to deletion or sequence conversion. There is limited information on
the mutations in SMA patients that have detectable SMNT, these are critical
for confirmation of SMNT as the SMA gene. Using SSCP analysis of the SMN
exons we screened our SMA patients that possess at least one intact SMNT
allele for mutations in SMNT. We identified one type I SMA patient with an
11 bp duplication in exon 6 which causes a frameshift and premature
termination of the deduced SMNT protein. Dosage and SSCP analysis of SMNT
in this family indicated that the father contributed a SMNT-deleted allele
to the affected child whereas the mother passed on the 11 bp exon 6
duplication SMNT allele. Analysis of RNA by RT-PCR conclusively
demonstrated that the 11 bp duplication is associated with the SMNT locus
and not SMNC. This mutation provides strong support for SMN as the
SMA-determining gene and indicates that disruption of SMNT on its own is
sufficient to produce a severe type I SMA phenotype.
相似文献
94.
Smith TP; Vlodaver Z; Darcy MD; Hunter DW; Castaneda-Zuniga WR; Amplatz K 《Radiology》1987,163(1):271-272
Three commercial vessel dilators and a dilator of an improved design were tested during percutaneous catheterization in 16 mongrel dogs to evaluate arterial damage produced with their use. The results indicate that, although all dilators often produce arterial damage, the improved design produced much less damage. In addition, lesions were less severe overall. The dilator has been safely and successfully used in patients for percutaneous vessel catheterization for the past 30 years at the authors' institution. 相似文献
95.
A new technique for vascular embolization using two Gianturco steel coils is described. The authors used a "coil-in-coil" technique to embolize the arteries of 12 dogs. In this technique a large coil is introduced into the artery followed by a smaller coil, which is delivered with a special introducer into the lumen of the first coil. Two coils can therefore be introduced into a shorter length of vessel. This method was as effective as "packing" the vessel with two coils in a row. The coil-in-coil technique is especially advantageous for use in infants and children with short, anomalous vessels, minimizing the risk of coil dislodgment into normal peripheral vessels. 相似文献
96.
97.
OBJECTIVE: To estimate prevalence of xerophthalmia and to assess dietary intake of vitamin A in Indian children aged under 6 y. DESIGN: Cross sectional study. STUDY SETTING: Urban slums under Urban Health Centre affiliated to Department of Preventive and Social Medicine, Government Medical College, Nagpur, India. PARTICIPANTS: The study included 1094 all children under 6 y of age, from two randomly selected urban slums. METHODS: Xerophthalmia was diagnosed on the basis of ocular signs and symptoms (WHO recommendations). Dietary intake of vitamin A was assessed by using one year recall method recommended by International Vitamin A Consultative Group. RESULTS: Prevalence of xerophthalmia was estimated to be 8.7%. Nine hundred and ninety-five (90.9%) study subjects were identified as inhabitants consuming dietary vitamin A at below recommended levels. (UPF score < 210). Five hundred and ninety-three (54.2%) study subjects were consuming dietary vitamin A at approximately less than 200 RE/d (UPF score < 120) while 402 (36.2%) were consuming approximately 200-300 RE/d (UPF score 120-210). The prevalence of xerophthalmia was found to be decreasing as the score of usual pattern of food consumption (UPF) increased. CONCLUSIONS: Children with a dietary intake represented by a UPF score of less than 120 were at high risk of developing xerophthalmia, whereas, those consuming vitamin A equal to a UPF score greater than 120 were at comparatively less risk despite being below the recommended levels. 相似文献
98.
婴儿心肺转流20例无死亡的灌注体会 总被引:2,自引:2,他引:0
0 引言 1997-03/1998-07,我科曾对70例小于3岁有先心病患儿进行体外循环下心内畸形矫治,其中小于1岁婴儿20例无1例死亡.现将20例婴儿患者的体外循环预充及转流体会总结如下.1 对象和方法1.1 对象 婴儿20(男11,女9)例.年龄2~12mo.3mo3例,4~6mo6例,7~9mo6例,12mo5例.体质量3~7.5(平均5.7)kg.病种包括:室缺10例,室缺合并肺动脉高压4例,室缺合并肺动脉高压和动脉导管未闭2例,法乐三联症1例,法乐四联症3例.1.2 方法 1体外循环预充:血液稀释度为HCT20%,不足部分预充新鲜库血,一般晶体醋酸钠平衡盐250~400mL,血浆100~150mL或200g.L… 相似文献
99.
血小板激活因子对大鼠脑血管通透性的影响及药物的保护作用 总被引:1,自引:0,他引:1
颈内动脉注射血小板激活因子(PAF),再给伊文思蓝,可见脑实质染色程度加深,而颈内动脉只注射伊文思蓝,脑实质未见染色。而我们合成的新药SZ-1可剂量依赖性地抑制PAF诱导的脑实质伊文思蓝染色程度的加深。在体外培养的脑微血管平滑肌细胞上,PAF能显著刺激~(14)-花生四烯酸的释放,而SZ-1能剂量依赖性地抑制这种释放,提示PAF在脑内产生的损害除与其他因素相关外,还与其刺激花生四烯酸释放有密切关系,SZ-1对PAF引起的脑部损害有保护作用。 相似文献
100.
ME Felice RA Feinstein MM Fisher DW Kaplan LF Olmedo ES Rome BC Staggers 《Pediatrics》1999,103(2):516-520
Although the prevention of unintended adolescent pregnancy is a primary goal of the American Academy of Pediatrics and society, many adolescents continue to become pregnant. Since the last statement on adolescent pregnancy was issued by the Academy in 1989, new observations have been recorded in the literature. The purpose of this new statement is to review current trends and issues on adolescent pregnancy to update practitioners on this topic. 相似文献