全文获取类型
收费全文 | 11012篇 |
免费 | 536篇 |
国内免费 | 58篇 |
专业分类
耳鼻咽喉 | 98篇 |
儿科学 | 741篇 |
妇产科学 | 279篇 |
基础医学 | 1187篇 |
口腔科学 | 211篇 |
临床医学 | 647篇 |
内科学 | 2227篇 |
皮肤病学 | 316篇 |
神经病学 | 535篇 |
特种医学 | 589篇 |
外国民族医学 | 1篇 |
外科学 | 1530篇 |
综合类 | 283篇 |
一般理论 | 11篇 |
预防医学 | 437篇 |
眼科学 | 510篇 |
药学 | 1132篇 |
中国医学 | 53篇 |
肿瘤学 | 819篇 |
出版年
2023年 | 70篇 |
2022年 | 166篇 |
2021年 | 320篇 |
2020年 | 168篇 |
2019年 | 233篇 |
2018年 | 273篇 |
2017年 | 216篇 |
2016年 | 269篇 |
2015年 | 272篇 |
2014年 | 364篇 |
2013年 | 514篇 |
2012年 | 717篇 |
2011年 | 771篇 |
2010年 | 425篇 |
2009年 | 320篇 |
2008年 | 555篇 |
2007年 | 541篇 |
2006年 | 455篇 |
2005年 | 430篇 |
2004年 | 405篇 |
2003年 | 336篇 |
2002年 | 327篇 |
2001年 | 295篇 |
2000年 | 294篇 |
1999年 | 255篇 |
1998年 | 138篇 |
1997年 | 104篇 |
1996年 | 138篇 |
1995年 | 106篇 |
1994年 | 79篇 |
1993年 | 81篇 |
1992年 | 126篇 |
1991年 | 169篇 |
1990年 | 136篇 |
1989年 | 137篇 |
1988年 | 142篇 |
1987年 | 103篇 |
1986年 | 110篇 |
1985年 | 128篇 |
1984年 | 85篇 |
1983年 | 90篇 |
1982年 | 44篇 |
1981年 | 47篇 |
1979年 | 69篇 |
1978年 | 49篇 |
1977年 | 61篇 |
1975年 | 48篇 |
1972年 | 41篇 |
1971年 | 44篇 |
1968年 | 44篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
Zelinski-Wooten MB; Slayden OD; Chwalisz K; Hess DL; Brenner RM; Stouffer RL 《Human reproduction (Oxford, England)》1998,13(2):259-267
Large doses of antiprogestin typically disrupt menstrual cyclicity. A
chronic low-dose regimen of the potent new antiprogestin ZK 137 316, which
permits continued menstrual cyclicity but alters gonadal- reproductive
tract activity, was established. Rhesus monkeys received vehicle (n = 6) or
0.01 (n = 8), 0.03 (n = 8) or 0.1 (n = 5) mg ZK 137 316/kg body weight
daily for five menstrual cycles (C-1 to C-5). Oestradiol, progesterone and
gonadotrophin profiles were normal during cycles involving vehicle and 0.01
and 0.03 mg ZK 137 316/kg body weight. In the 0.1 mg/kg group, mid-cycle
oestradiol and gonadotrophin surges, and subsequent progesterone
production, were absent in C-3 and C-5. Ovarian cyclicity was accompanied
by timely menstruation in the vehicle and 0.01 mg/kg groups. By C-3, half
the animals in the 0.03 mg/kg group and all animals in the 0.1 mg/kg group
were amenorrhoeic. A corpus luteum was noted during the mid-luteal phase of
C-5 in the vehicle, 0.01 mg/kg and 0.03 mg/kg groups. Large antral and
cystic follicles were evident in the 0.1 mg/kg group. Thus, a daily
treatment with 0.01 mg/kg ZK 136317 permitted normal menstrual cyclicity in
macaques. While the daily administration of 0.03 mg/kg ZK 136 317 allowed
ovarian cyclicity, menstruation was disrupted in some animals. Increasing
the dose to 0.1 mg/kg antagonized pituitary function and resulted in
anovulation and amenorrhoea. A chronic low-dose regimen of the
antiprogestin ZK 137 316, which permits normal ovarian/menstrual cyclicity,
has potential as a contraceptive in women.
相似文献
62.
63.
Mallikarjuna Rao GN Hussain T Geetha Devi N Jain S Chandak GR Ananda Raj MP 《Indian journal of medical sciences》2003,57(1):1-6
66 unrelated patients from Southern India with Duchenne Muscular Dystrophy (DMD) were studied for intragenic deletion in 18 exons and Pm region of the DMD gene using multiplex PCR. Of these 41 (62.1%) showed intragenic deletions. 78% of the deletions were located at the distal hotspot region (44-55 exons) and 22% of the deletions were located at the proximal region (exon 2-19). Exon 50 is most frequently deleted. Deletions in isolated cases were significantly more compared to familial cases. The lower incidence reported from South India compared to North India, is suggestive of variations in the Southern and Northern population. 相似文献
64.
Kochar DK Thanvi I Joshi A Shubhakaran Agarwal N Jain N 《The Journal of the Association of Physicians of India》1999,47(8):774-778
Falciparum malaria in pregnancy is a significant health problem in India. Pregnant women constitute an important high risk group for malaria infection which may cause abortions, stillbirths, intra-uterine growth retardation (IUGR) and premature labour. In this hospital based study on 602 admitted patients of falciparum malaria which included 314 males, 243 non-pregnant females and 45 pregnant females, there was significantly increased mortality rate in females (18.4%) in comparison to males (7.64%, p < 0.001). The mortality rate was highly significant in pregnant females (37.77%) in comparison to non-pregnant females (14.81%) and males (7.64%; p < 0.001). Severe anaemia with Hb < 5 gm% was observed more commonly in pregnant patients (20.0%) in comparison to non-pregnant patients (4.11%). Incidence of malaria infection was more in primi gravida and second gravida. Pregnancy related complications in the form of preterm live births, intra-uterine death (IUD), still births and abortions were more in primi parous than multiparous patients. As the pregnancy is associated with increased incidence and adverse outcome of P.falciparum malaria infection, chemoprophylaxis should be made an integral part of antenatal care along with antianaemia therapy to reduce the risk of serious maternal and fetal complications. 相似文献
65.
Jain P Giustolisi GM Atkinson S Elnenaei MO Morilla R Owusu-Ankomah K Rafiq-Mohammed F Matutes E Wotherspoon A Catovsky D 《Journal of clinical pathology》2002,55(12):940-945
AIMS: To describe and revise a flow cytometric assay for evaluating cyclin D1 overexpression in B cell lymphoproliferative disorders (B-LPDs). METHODS: Cyclin D1 expression was evaluated in 11 healthy controls and 51 patients with B-LPD by flow cytometry using the 5D4 monoclonal antibody. In 25 cases, experiments were repeated up to four times with mononuclear cells (MNC) fixed in ethanol for 1-120 days to evaluate the consistency of cyclin D1 expression. Flow cytometry results were compared with fluorescence in situ hybridisation (FISH) for the t(11;14) translocation in 19 patients and with immunohistochemistry (IHC) using the DCS-6 monoclonal antibody in nine patients. RESULTS: A mean fluorescence intensity ratio (MFIR) of 4.8 was defined as the cut off point for positivity based on cyclin D1 expression in healthy controls (mean + 3 SD). Ten patients overexpressed cyclin D1 by flow cytometry. These included five of eight patients with mantle cell lymphoma, four of 19 with chronic lymphocytic leukaemia, and one with follicular lymphoma. MFIR in the repeat experiments differed less than 25% in 20 of 25 patients and in no cases did it cross the cut off point. There was a good correlation between cyclin D1 expression by flow cytometry and FISH for t(11;14) in 15 of 19 patients and six of nine had concordant results with flow cytometry, FISH, and IHC. CONCLUSION: Cyclin D1 expression remains fairly stable once MNC are fixed in ethanol and the flow cytometric assay can be used for the routine screening of B-LPD. Further comparisons between flow cytometry, IHC, and FISH may be needed to ascertain the diagnostic value of the flow cytometric assay. 相似文献
66.
Differential host range of viruses of feline leukemia-sarcoma complex. 总被引:15,自引:0,他引:15
Selected strains of feline leukemia and sarcoma viruses of subgroups A, B, and C show a differential pattern in their ability to cross species barrier and productively infect cells of heterologous host species. A virus of subgroup B showed the widest host range; it caused productive infection of cells of diverse host species including cells from cat, human, monkey, dog, bovine, pig, and hamster species. Two virus strains of subgroup A showed the narrowest host range; of the cells of several mammalian species examined, they only caused productive infection of cat and dog cells. Preliminary studies indicated that certain other strains of subgroup A viruses cause productive infection of whole human embryo cells. One strain of subgroup C virus examined showed a host range that was intermediate between that of A and B subgroup viruses. This strain caused productive infection of cat, dog, and certain human cells. In addition, the subgroup C virus caused productive infection of guinea pig cells found to be resistant to subgroup A as well as subgroup B virus strains examined.Preliminary studies suggested that certain, but not all, virus mixtures of A and B viruses can be purified into B type by passage of virus in heterologous human cells.The factor(s) that may govern the differential susceptibilities of heterologous host cells to the described strains of feline viruses are discussed. 相似文献
67.
Jain AN Tokuyasu TA Snijders AM Segraves R Albertson DG Pinkel D 《Genome research》2002,12(2):325-332
DNA microarrays are now widely used to measure expression levels and DNA copy number in biological samples. Ratios of relative abundance of nucleic acids are derived from images of regular arrays of spots containing target genetic material to which fluorescently labeled samples are hybridized. Whereas there are a number of methods in use for the quantification of images, many of the software systems in wide use either encourage or require extensive human interaction at the level of individual spots on arrays. We present a fully automatic system for microarray image quantification. The system automatically locates both subarray grids and individual spots, requiring no user identification of any image coordinates. Ratios are computed based on explicit segmentation of each spot. On a typical image of 6000 spots, the entire process takes less than 20 sec. We present a quantitative assessment of performance on multiple replicates of genome-wide array-based comparative genomic hybridization experiments. By explicitly identifying the pixels in each spot, the system yields more accurate estimates of ratios than systems assuming spot circularity. The software, called, runs on Windows platforms and is available free of charge for academic use. 相似文献
68.
O Mukherjee P Meera S Ghosh S Kubendran K Kiran K R Manjunath M N Subhash V Benegal S K Brahmachari P P Majumder S Jain 《American journal of medical genetics. Part B, Neuropsychiatric genetics》2006,(8):868-873
The genetic basis of bipolar disorder (BPD) and schizophrenia (SCZ) has been established through numerous clinical and molecular studies. Although often considered separate nosological entities, evidence now suggests that the two syndromes may share some genetic liability. Recent studies have used a composite phenotype (psychosis) that includes BPD, SCZ, psychosis not otherwise specified, and schizoaffective disorder, to identify shared susceptibility loci. Several chromosomal regions are reported to be shared between these syndromes (18p, 6q, 10p, 13q, 22q). As a part of our endeavor to scan these regions, we report a positive linkage and association finding at 18p11.2 for psychosis. Two-point linkage analysis performed on a series of 52 multiplex pedigrees with 23 polymorphic markers yielded a LOD score of 2.02 at D18S37. An independent set of 159 parent offspring trios was used to confirm this suggestive finding. The TDT analysis yielded support for association between the marker D18S453 and the disease allele (chi2 = 4.829, P < 0.028). This region has been implicated by several studies on BPD [Sjoholt et al. (2004); Mol Psychiatry 9(6):621-629; Washizuka et al. (2004); Biol Psychiatry 56(7):483-489; Pickard et al. (2005); Psychiatr Genet 15(1):37-44], SCZ [Kikuchi et al. (2003); J Med Dent Sci 50(3):225-229; Babovic-Vuksanovic et al. (2004); Am J Med Genet 124(3):318-322] and also as a shared region between the two diseases [Ishiguro et al. (2001); J Neural Transm 108(7):849-854; Reyes et al. (2002); Mol Psychiatry 7(4):337-339; Craddock et al. (2005); J Med Genet 42(3):193-204]. Our findings provide an independent validation of the above reports, and suggest the presence of susceptibility loci for psychoses in this region. 相似文献
69.
70.