全文获取类型
收费全文 | 751篇 |
免费 | 46篇 |
国内免费 | 4篇 |
专业分类
耳鼻咽喉 | 6篇 |
儿科学 | 13篇 |
妇产科学 | 18篇 |
基础医学 | 85篇 |
口腔科学 | 13篇 |
临床医学 | 59篇 |
内科学 | 173篇 |
皮肤病学 | 16篇 |
神经病学 | 42篇 |
特种医学 | 38篇 |
外科学 | 99篇 |
综合类 | 11篇 |
预防医学 | 42篇 |
眼科学 | 16篇 |
药学 | 69篇 |
中国医学 | 11篇 |
肿瘤学 | 90篇 |
出版年
2023年 | 4篇 |
2022年 | 11篇 |
2021年 | 20篇 |
2020年 | 13篇 |
2019年 | 15篇 |
2018年 | 26篇 |
2017年 | 24篇 |
2016年 | 15篇 |
2015年 | 21篇 |
2014年 | 30篇 |
2013年 | 45篇 |
2012年 | 49篇 |
2011年 | 57篇 |
2010年 | 28篇 |
2009年 | 42篇 |
2008年 | 43篇 |
2007年 | 50篇 |
2006年 | 35篇 |
2005年 | 40篇 |
2004年 | 31篇 |
2003年 | 20篇 |
2002年 | 34篇 |
2001年 | 23篇 |
2000年 | 11篇 |
1999年 | 13篇 |
1998年 | 7篇 |
1997年 | 11篇 |
1996年 | 12篇 |
1995年 | 4篇 |
1993年 | 5篇 |
1992年 | 2篇 |
1990年 | 6篇 |
1989年 | 4篇 |
1988年 | 5篇 |
1987年 | 5篇 |
1986年 | 5篇 |
1985年 | 2篇 |
1984年 | 2篇 |
1983年 | 3篇 |
1982年 | 2篇 |
1980年 | 2篇 |
1978年 | 3篇 |
1976年 | 3篇 |
1975年 | 3篇 |
1973年 | 4篇 |
1969年 | 1篇 |
1968年 | 3篇 |
1967年 | 1篇 |
1961年 | 2篇 |
1959年 | 1篇 |
排序方式: 共有801条查询结果,搜索用时 31 毫秒
1.
2.
3.
P Hercz P Siklos L Ungár R G Farquharson K Mohári L Kocsár 《European journal of obstetrics, gynecology, and reproductive biology》1987,24(3):189-193
The authors examined the possible role of HPL in the onset of labour. The HPL level of the maternal vein, the umbilical cord vein and artery was compared in vaginal mature (n = 16) and premature (n = 52) deliveries. The HPL concentration was also examined in mature (n = 18) and premature (n = 18) deliveries performed by caesarean section prior to the onset of labour. The results showed that: the serum HPL level in the maternal vein, the umbilical cord vein and artery was lower during the 33rd-36th and the 40th weeks in cases of vaginal delivery compared to elective caesarean section; The artery/vein ratio decreases during labour (A/V X 100 value), indicating that HPL metabolism in the fetus decreases during regular labour pains; The onset of premature labour and delivery was associated with lower HPL levels compared to normal pregnancy. The authors assume that the lower HPL level found in cases of vaginal delivery may be due to reduced placental perfusion, but they do not exclude the possible association of lower HPL concentrations in cases of premature delivery. 相似文献
4.
5.
6.
Detection of YMDD motif mutants by oligonucleotide chips in lamivudine-untreated patients with chronic hepatitis B virus infection 总被引:9,自引:0,他引:9
Heo J Cho M Kim HH Shin YM Jang HJ Park HK Kim CM Kim GH Kang DH Song GA Yang US 《Journal of Korean medical science》2004,19(4):541-546
Lamivudine, a nucleoside analogue, has been used widely as an effective antiviral agent for the treatment of patients with chronic hepatitis B virus (HBV) infection. However, the YMDD motif mutation of HBV polymerase resistant to lamivudine occurs very frequently after long term therapy. We developed an oligonucleotide chip for the detection of YMDD motif mutants resistant to lamivudine and investigated the prevalence of the mutants in patients with chronic HBV infection who had not been treated by lamivudine before. Forty patients who had not been treated with lamivudine were included in this study. Serum samples were tested by the oligonucleotide chips designed for detection of wild-type YMDD motif, M552V and M552I. Samples were confirmed by restriction fragment length polymorphism (RFLP) and direct sequencing. M552I mutants were detected by the oligonucleotide chips in 7.5% (3/40) of chronic HBV infected patients (2 chronic hepatitis and 1 cirrhosis). The results were in accordance with those of RFLP. YMDD motif mutants occur as natural genome variabilities in patients with chronic HBV infection who had not been treated with lamivudine before. Oligonucleotide chip technology is a reliable and useful diagnostic tool for the detection of mutants resistant to antiviral therapy in chronic HBV infection. 相似文献
7.
The effects of different molecular weights of hyaluronic acid (HA), a major component of extracellular matrix, on gap junctional intercellular communication (GJIC) in normal human dermal fibroblasts (NHDF cells) were investigated. NHDF cells were cultured for 4 days with different molecular weights of HA and then the extent of GJIC was assessed by the scrape-loading dye transfer method, using Lucifer yellow. The area of dye transfer was greater in the dishes coated with HA than in those to which HA was added. Thus, NHDF cells cultured on surfaces coated with high molecular weight (HMW) HA (MW, 800 kDa) showed greatly enhanced GJIC. Furthermore, another aim of this study was to evaluate the effects of different molecular weights of HA on the production of FGF-2 and KGF, because both are important cytokines produced by NHDF cells. When FGF-2 and KGF cultured levels of cell extracts and media were determined by ELISA, both levels were significantly enhanced when cells were grown on plates coated with HMW HA. This finding indicated that the function of gap junction channels in NHDF cells grown on plates coated with HMW HA may promote the biosynthesis of growth factors such as FGF-2 and KGF. 相似文献
8.
Analysis of HL and O serotypes of Campylobacter strains by the flagellin gene typing system. 总被引:4,自引:1,他引:4
下载免费PDF全文
![点击此处可从《Journal of clinical microbiology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
We recently developed a molecular typing system for Campylobacter jejuni and Campylobacter coli based on restriction fragment length polymorphism analysis of the flagellin gene,flaA (I.Nachamkin, K. Bohachick, and C.M. Patton, J. Clin. Microbiol. 31:1531-1536, 1993). We extended the typing system to 83 flagellin types (designated flaA-1,flaA-2, etc.) on the basis of analysis of 404 isolates of C. jejuni and C. coli including common serotypes isolated in the United States, a selection of less common serotypes, and serotype reference strains. Of the 295 strains previously shown to belong to common HL and O serotypes (C. M. Patton, M.A. Nicholson, S.M. Ostroff, A.A. Ries, I.K. Wachsmuth, and R.V. Tauxe, J. Clin. Microbiol. 31:1525-1530, 1993), six flaA types accounted for 53.6% of strains as follows: flaA-1, 21.7%; flaA-7, 14.9%; flaA-27, 5.1%; flaA-49, 4.4%; flaA-13, 3.7%; and flaA-21, 3.7%. Seventy-five percent of the strains were within 15 flaA types, 90% were within 30 flaA types, and all 295 strains were contained within 52 flaA types. Within each HL or O serotype, there usually were multiple flaA types. For 12 common HL serotypes and 7 common O serotypes, more than 50% of these isolates were a single flaA type. A database was developed by using commercially available restriction fragment length polymorphism analysis software (ProRFLP; DNA ProScan, Inc., Nashville, Tenn.) that should allow other investigators to perform typing with this system. 相似文献
9.
Mittal N Zhou Y Ung S Linares C Molloi S Kassab GS 《Annals of biomedical engineering》2005,33(8):1015-1026
A rigorous analysis of blood flow must be based on the branching pattern and vascular geometry of the full vascular circuit
of interest. It is experimentally difficult to reconstruct the entire vascular circuit of any organ because of the enormity
of the vessels. The objective of the present study was to develop a novel method for the reconstruction of the full coronary
vascular tree from partial measurements. Our method includes the use of data on those parts of the tree that are measured
to extrapolate the data on those parts that are missing. Specifically, a two-step approach was employed in the reconstruction
of the entire coronary arterial tree down to the capillary level. Vessels > 40 μm were reconstructed from cast data while
vessels < 40 μm were reconstructed from histological data. The cast data were reconstructed one-bifurcation at a time while
histological data were reconstructed one-sub-tree at a time by “cutting” and “pasting” of data from measured to missing vessels.
The reconstruction algorithm yielded a full arterial tree down to the first capillary bifurcation with 1.9, 2.04 and 1.15
million vessel segments for the right coronary artery (RCA), left anterior descending (LAD) and left circumflex (LCx) trees,
respectively. The node-to-node connectivity along with the diameter and length of every vessel segment was determined. Once
the full tree was reconstructed, we automated the assignment of order numbers, according to the diameter-defined Strahler
system, to every vessel segment in the tree. Consequently, the diameters, lengths, number of vessels, segments-per-element
ratio, connectivity and longitudinal matrices were determined for every order number. The present model establishes a morphological
foundation for future analysis of blood flow in the coronary circulation. 相似文献
10.
Identification of the multiple endocrine neoplasia type 1 (MEN1) gene. The European Consortium on MEN1 总被引:10,自引:0,他引:10
Lemmens I; Van de Ven WJ; Kas K; Zhang CX; Giraud S; Wautot V; Buisson N; De Witte K; Salandre J; Lenoir G; Pugeat M; Calender A; Parente F; Quincey D; Gaudray P; De Wit MJ; Lips CJ; Hoppener JW; Khodaei S; Grant AL; Weber G; Kytola S; Teh BT; Farnebo F; Thakker RV 《Human molecular genetics》1997,6(7):1177-1183