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41.
Sbracia M Baldi M Cao D Sandrelli A Chiandetti A Poverini R Aragona C 《Human reproduction (Oxford, England)》2002,17(2):320-324
BACKGROUND: In babies born after ICSI procedures, an increase of de-novo sex chromosome abnormalities has been observed. Several hypotheses have been proposed to explain these findings: an increased rate of sex chromosome aneuploidy in sperm of oligozoospermic men, or a preferential location of the sex chromosomes in the sub-acrosomal region of the sperm nucleus which leads to a reduced DNA decondensation of this region. In order to investigate which theory may be more reliable, we studied the localization of sex chromosomes and their aneuploidy rate in sperm in men undergoing ICSI. METHODS: Using fluorescent in-situ hybridization we studied sex chromosome localization and the aneuploidy rate for sex chromosomes and chromosome 18 in 20 oligospermic men undergoing ICSI and in 10 controls. RESULTS: In 40.94 and 52.92% of cases, the X and Y chromosomes respectively were localized in the sub-acrosomal region of the sperm nucleus compared with only 14.29% of cases of chromosome 18 (P < 0.001). An increase of sex chromosome aneuploidy in sperm of oligospermic men was observed; 2.91 versus 0.69% of controls (P < 0.001). CONCLUSIONS: Sex chromosomes are localized preferentially in the sub-acrosomal region of sperm and sex chromosome aneuploidy rate in the sperm of oligozoospermic men is higher than in controls. 相似文献
42.
In this paper, we report a pregnancy at risk for beta thalassaemia in which the fetal red blood cell volume was reduced while that of the mother was relatively great, so that the presence of a fetal red blood cell population in a mixed maternal-fetal sample was difficult to recognise. The molecular basis for these haematological phenotypes was clarified by follow up examination and alpha globin gene mapping. These indicated that the fetus was heterozygous for beta thalassaemia and had deletion of three alpha globin structural genes, while the mother, heterozygous for beta thalassaemia, also had deletion of two alpha globin structural genes. When the coinheritance of alpha thalassaemia is suspected, it is necessary to examine carefully the red blood cell distribution of a placental sample, so that the presence of a population of fetal red blood cells is not missed. 相似文献
43.
The deltaccr5 mutation conferring protection against HIV-1 in Caucasian populations has a single and recent origin in Northeastern Europe 总被引:6,自引:0,他引:6
Libert F; Cochaux P; Beckman G; Samson M; Aksenova M; Cao A; Czeizel A; Claustres M; de la Rua C; Ferrari M; Ferrec C; Glover G; Grinde B; Guran S; Kucinskas V; Lavinha J; Mercier B; Ogur G; Peltonen L; Rosatelli C; Schwartz M; Spitsyn V; Timar L; Beckman L; Vassart G 《Human molecular genetics》1998,7(3):399-406
The chemokine receptor CCR5 is encoded by the CMKBR5 gene located on the
p21.3 region of human chromosome 3, and constitutes the major co- receptor
for the macrophage-tropic strains of HIV-1. A mutant allele of the CCR5
gene, Delta ccr5 , was shown to provide to homozygotes with a strong
resistance against infection by HIV. The frequency of the Delta ccr5 allele
was investigated in 18 European populations. A North to South gradient was
found, with the highest allele frequencies in Finnish and Mordvinian
populations (16%), and the lowest in Sardinia (4%). Highly polymorphic
microsatellites (IRI3.1, D3S4579 and IRI3.2, D3S4580 ) located respectively
11 kb upstream and 68 kb downstream of the CCR5 gene deletion were used to
determine the haplotype of the chromosomes carrying the Delta ccr5 variant.
A strong linkage disequilibrium was found between Delta ccr5 and specific
alleles of the IRI3.1 and IRI3.2 microsatellites: >95% of the Delta ccr5
chromosomes carried the IRI3.1-0 allele, while 88% carried the IRI3.2-0
allele. These alleles were found respectively in only 2 or 1.5% of the
chromosomes carrying a wild-type CCR5 gene. From these data, it was
inferred that most, if not all Delta ccr5 alleles originate from a single
mutation event, and that this mutation event probably took place a few
thousand years ago in Northeastern Europe. The high frequency of the Delta
ccr5 allele in Caucasian populations cannot be explained easily by random
genetic drift, suggesting that a selection advantage is or has been
associated with homo- or heterozygous carriers of the Delta ccr5 allele.
相似文献
44.
Sun Chang-ti孙昌惕 Cao Lu-cheng曹履诚and Han Ke-han韩可汉Institute of Urology Beijing Medical University Beijing 《中华医学杂志(英文版)》1987,100(12):935-939
The formation of calcium oxalate nephrolithiasis
can be estimated by measuring the concentration of
calcium oxalate versus the inhibitory role of crystal
formation in the urine. In recent studies, the
calcium oxalate saturation index and the inhibitory
activity (by modified Sarig's method) of the urine
during fasting and after oral calcium loading in
normal subjects and in patients with calcium nepliro-
lithiasis were determined. It was shown that, in
normal comrols after calcium loading the inhibitory
activity of the urine increased in parallel with the
increase in urinary excretion of calcium oxalate; in
contrast, in patients with kidney stones, it remained
unchanged or fell slightly. This abnormal response
might result in a disturbance of the saturation-inhibi-
tion balance and formation of kidney stone. In
normal individuals, there may be a "protective re-
sponse" to prevent the precipitation of calcium
oxalate when the urrine is oversaturated with calcium
oxalate while a defect of the "protective response"
in patients may be an important factor in calcium
oxalate stone formation. 相似文献
45.
术前孤立性CRP升高与体外循环术后并发症的相关性 总被引:1,自引:0,他引:1
目的探讨无感染的、术前孤立性C-反应蛋白(CRP)增加,对于体外循环心脏术后的结果,是否有预测性价值。方法分术前孤立性CRP升高(10.5~70.2mg/L)50例(A组)与CRP正常(<10mg/L)50例对照(B组),B组匹配A组在年龄、性别和疾病种类,两组均进行体外循环心脏手术。结果A组脓毒性并发症(20%)比对照组(2%)多(P<0.01)。这些病人微生物学阳性仅10%。A组中需要儿茶酚胺支持的占28%,而B组仅12%(P<0.05)。A组较B组术后需呼吸机支持的时间明显延长(25.2±6.2h比6.6±0.5h)(P<0.01)、ICU滞留时间也较B组长(4.6±0.8d比2.6±0.3d)(P<0.05)。结论术前孤立性CRP升高的病人,体外循环术后,发生脓毒性并发症的可能性明显增加。且大多数病例微生物学实验阴性,推测大多数脓毒性并发症是由于全身炎症反应综合征的原因。 相似文献
46.
目的:总结颈部囊肿与瘘管的诊治经验。方法:93例行手术治疗,其中鳃裂囊肿15例,鳃裂瘘管10例,皮样囊肿1例,囊状淋巴管瘤4例,甲状舌骨囊肿37例,甲状舌管瘘管25例,癌性淋巴液囊肿1例,随访1-10年。结果:93例中,囊性淋巴管瘤1例复发后失访,另1例行2次手术,癌性淋巴液囊肿1例半年后死于肺转移,鳃裂瘘管2例3次手术,甲状舌管瘘管1例复发,鳃裂瘘管术后1例迟发性面瘫,一次手术治愈,无术后并发症。结论:颈部囊肿与瘘管的诊断除依据术前检查外,主要是依据术中的发现和术后病理检查。B超、CT等是有效的辅助检查.手段治疗上应彻底切除囊壁与瘘管,避免复发。术中应避免损伤颈部的大血管和神经。甲状舌管瘘管须切除舌骨中段2cm,这是防止术后复发的关键。 相似文献
47.
48.
Lei Cao Chuzhong Li Chunhui Liu Peng Zhao Jiwei Bai Xinsheng Wang Yazhuo Zhang Songbai Gui 《Neurosurgical review》2021,44(3):1737-1746
Neurosurgical Review - Since there are many approaches for successful craniopharyngioma resection, how to choose a suitable approach remains problematic. The aim of this study was to summarize... 相似文献
49.
50.