全文获取类型
收费全文 | 26986篇 |
免费 | 1787篇 |
国内免费 | 290篇 |
专业分类
耳鼻咽喉 | 424篇 |
儿科学 | 414篇 |
妇产科学 | 590篇 |
基础医学 | 3916篇 |
口腔科学 | 697篇 |
临床医学 | 2348篇 |
内科学 | 5140篇 |
皮肤病学 | 586篇 |
神经病学 | 2016篇 |
特种医学 | 1603篇 |
外科学 | 4342篇 |
综合类 | 290篇 |
一般理论 | 10篇 |
预防医学 | 1108篇 |
眼科学 | 663篇 |
药学 | 2354篇 |
1篇 | |
中国医学 | 270篇 |
肿瘤学 | 2291篇 |
出版年
2023年 | 162篇 |
2022年 | 383篇 |
2021年 | 709篇 |
2020年 | 387篇 |
2019年 | 663篇 |
2018年 | 718篇 |
2017年 | 593篇 |
2016年 | 687篇 |
2015年 | 1017篇 |
2014年 | 1255篇 |
2013年 | 1425篇 |
2012年 | 2129篇 |
2011年 | 2088篇 |
2010年 | 1290篇 |
2009年 | 1186篇 |
2008年 | 1626篇 |
2007年 | 1579篇 |
2006年 | 1450篇 |
2005年 | 1377篇 |
2004年 | 1241篇 |
2003年 | 1080篇 |
2002年 | 955篇 |
2001年 | 778篇 |
2000年 | 765篇 |
1999年 | 600篇 |
1998年 | 219篇 |
1997年 | 199篇 |
1996年 | 175篇 |
1995年 | 149篇 |
1994年 | 125篇 |
1993年 | 104篇 |
1992年 | 242篇 |
1991年 | 186篇 |
1990年 | 175篇 |
1989年 | 167篇 |
1988年 | 143篇 |
1987年 | 104篇 |
1986年 | 95篇 |
1985年 | 70篇 |
1984年 | 78篇 |
1983年 | 49篇 |
1982年 | 52篇 |
1981年 | 44篇 |
1980年 | 43篇 |
1979年 | 56篇 |
1978年 | 44篇 |
1977年 | 46篇 |
1974年 | 37篇 |
1972年 | 44篇 |
1971年 | 42篇 |
排序方式: 共有10000条查询结果,搜索用时 78 毫秒
991.
Study Objectives:
To evaluate the short-term efficacy and safety of electroacupuncture for the treatment of primary insomnia.Design:
Randomized, single-blind, placebo-controlled, parallel-group.Setting:
A university-based sleep clinic.Participants:
Community sample of 60 Chinese adult volunteers who report having insomnia 3 or more nights per week, whose symptoms meet the DSM-IV criteria for primary insomnia for at least 3 months, and who have an Insomnia Severity Index total score of at least 15. Participants were screened with polysomnography and the Structured Clinical Interview for the DSM-IV prior to randomization.Intervention:
Electroacupuncture at Yintang (EX-HN3), Baihui (GV20), bilateral ear Shenmen, Sishencong (EX-HN1), and Anmian (EX) 3 times per week for 3 weeks or placebo acupuncture using Streitberger needles at the same points.Measurements and Results:
Self-reported questionnaires, 1-week sleep diaries, and 3-day actigraphy were collected at baseline and 1 week after treatment. The Insomnia Severity Index was used as the primary outcome measure. Both groups showed significant improvement compared with the pretreatment baseline. One-way analysis of covariance adjusted for baseline scores showed that there were significantly greater improvements in sleep efficiency by sleep diary and actigraphy in the electroacupuncture group. However, no significant between-group differences were observed in the Insomnia Severity Index and other outcome measures. The proportions of subjects having less than 30 minutes of wake after sleep onset and a sleep efficiency of at least 85% at the posttreatment visit were significantly higher in the electroacupuncture group. All adverse events were mild in severity.Conclusion:
We found a slight advantage of electroacupuncture over placebo acupuncture in the short-term treatment of primary insomnia. Because of some limitations of the current study, further studies are necessary to verify the effectiveness of acupuncture for insomnia.Citation:
Yeung WF; Chung KF; Zhang SP; Yap TG; Law ACK. Electroacupuncture for primary insomnia: a randomized controlled trial. SLEEP 2009;32(8):1039-1047. 相似文献992.
Hsun-Pi Su Seng-Kai Tung Lei-Ron Tseng Wen-Cherng Tsai Tung-Ching Chung Tsung Chain Chang 《Journal of clinical microbiology》2009,47(5):1386-1392
The genus Legionella contains a diverse group of motile, asaccharolytic, nutritionally fastidious gram-negative rods. Legionella pneumophila is the most important human pathogen, followed by L. micdadei, L. longbeachae, L. dumoffii, and other rare species. Accurate identification of Legionella spp. other than L. pneumophila is difficult because of biochemical inertness and phenotypic identity of different species. The feasibility of using an oligonucleotide array for identification of 18 species of Legionella was evaluated in this study. The method consisted of PCR amplification of the macrophage infectivity potentiator mip gene, followed by hybridization of the digoxigenin-labeled PCR products to a panel of 30 oligonucleotide probes (16- to 24-mers) immobilized on a nylon membrane. A collection of 144 target strains (strains we aimed to identify) and 50 nontarget strains (44 species) were analyzed by the array. Both test sensitivity (144/144 strains) and specificity (50/50 strains) of the array were 100%. The whole procedure for identification of Legionella species by the array can be finished within a working day, starting from isolated colonies. It was concluded that species identification of clinically relevant Legionella spp. by the array method is very reliable and can be used as an accurate alternative to conventional or other molecular methods for identification of Legionella spp.The genus Legionella currently contains 50 validly named species (http://www.dsmz.de/bactnom/bactname.htm), and among them, 20 have been found to be human pathogens (6, 10). Legionnaires'' disease (LD) is caused mainly by inhalation of aerosols generated from water sources contaminated with Legionella spp. (6, 40). While most species of Legionella are normal environmental flora, many are implicated in opportunistic infections in immunocompromised patients (14). Pulmonary infections caused by Legionella may be subclinical or severe (27), and the fatality rate can approach 50% in immunocompromised patients (49).Legionella pneumophila accounts for about 85 to 90% of cases of LD (6, 26, 49). Other Legionella spp. implicated in human infections include L. micdadei, L. longbeachae, L. dumoffii, and some less encountered species, such as L. anisa, L. bozemanae, L. feeleii, and L. wadsworthii (49). L. pneumophila is normally identified by immunofluorescent-antibody assay. A specific FDA-cleared fluorescein isothiocyanate-labeled monoclonal antibody (Bio-Rad, Hercules, CA) for all serogroups of L. pneumophila and fluorescein isothiocyanate-labeled polyclonal antisera specific for L. pneumophila serogroup 1 (m-TECH, Atlanta, GA) are commercially available (6). Accurate identification of Legionella spp. other than L. pneumophila and L. pneumophila serogroup 1 can be quite difficult due to serological cross-reactivities between serogroups and species, biochemical inertness, and phenotypic identity of different species (6). Legionella isolates which fail to react with L. pneumophila antibodies are recommended to be identified by public health or reference laboratories (6). Antigen detection in urine specimens is also commonly used in hospitals for diagnosing infection caused by L. pneumophila (46).Molecular approaches have been developed to provide more rapid and accurate identification of Legionella spp. These methods include PCR (20, 25, 34), gene probe hybridization (24, 41), restriction fragment length polymorphism analysis (21, 38), and sequence analysis of the rRNA gene (47) and the macrophage infectivity potentiator gene mip (35, 41). Since diagnostic delay may result in increased mortality for patients with LD (15), real-time PCR assay has been a focus of many studies in recent years (5, 13, 14, 17, 19, 34, 36, 41, 48). However, with real-time PCR assay, only L. pneumophila and a very limited number of Legionella spp. can be detected or identified.Recently, DNA array technology has been applied to identify a wide variety of bacteria that are difficult to be differentiated by phenotypic traits or whose identification may take a long time (12, 31, 43). This study aimed to develop an oligonucleotide array based on mip gene sequences to identify 18 species of Legionella that have been found to cause human infections in the literature (10). 相似文献
993.
Natalia Martin‐Orozco Yeonseok Chung Seon Hee Chang Yi‐Hong Wang Chen Dong 《European journal of immunology》2009,39(1):216-224
IDDM is characterized by leukocyte invasion to the pancreatic tissues followed by immune destruction of the islets. Despite the important function of Th17 cells in other autoimmune disease models, their function in IDDM is relatively unclear. In this study, we found association of elevated Th17 cytokine expression with diabetes in NOD mice. To understand the function of Th17 cells in IDDM, we differentiated islet‐reactive BDC2.5 TcR transgenic CD4+ cells in vitro into Th17 cells and transferred them into NOD.scid and neonate NOD mice. NOD.scid recipient mice developed rapid onset of diabetes with extensive insulitic lesions, whereas in newborn NOD mice, despite extensive insulitis, most recipient mice did not develop diabetes. Surprisingly, BDC2.5+ cells recovered from diabetic NOD.scid mice, in comparison with those from neonate NOD mice, showed predominant IFN‐γ over IL‐17 expression, indicating conversion of donor cells into Th1 cells. Moreover, diabetes progression in NOD.scid recipients was dependent on IFN‐γ while anti‐IL‐17 treatment reduced insulitic inflammation. These results indicate that islet‐reactive Th17 cells promote pancreatic inflammation, but only induce IDDM upon conversion into IFN‐γ producers. 相似文献
994.
When‐Chang Chen Dr. Fu‐Kuo Huang Shu‐Chuan Cheng Feng‐Yuan Tsai Chung‐Liang Lin 《Journal of basic microbiology》2009,49(6):513-520
Co‐production of γ ‐glutamylcysteine (γ ‐GC) and glutathione (GSH) by a novel mutant strain Saccharomyces cerevisiae FC‐3 and its kinetic analysis were investigated. The strain could produce γ ‐GC and GSH with high yields (4.22 and 14.3 mg/g‐DCW, respectively) in batch submerged cultures. Effects of medium components and cultivation conditions on cell growth and the contents of intracellular γ ‐GC and GSH were examined. Results show that 2% (w/v) sucrose and 2.5% (w/v) yeast extract are the best carbon and nitrogen sources, respectively, and supplement of three amino acids (glycine, cysteine and glutamate), each at 0.08% (w/v), in the medium could enhance γ ‐GC and GSH production. In addition, optimal operating conditions are at the initial pH value of 7.0, 30 °C and 200 rev/min. Moreover, results obtained from kinetic analyses reveal that γ ‐GC production is mixed‐type growth associated, but GSH production is growth‐associated. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
995.
Chiu CC Huang YT Chuang HL Chen HH Chung TC 《Immunopharmacology and immunotoxicology》2009,31(1):75-82
Pseudomonas aeruginosa Exotoxin A (PEA) induces hepatotoxicity in experimental animals. Lipopolysaccharide (LPS) interacts synergistically with xenotoxics to induce severe organ injury. We examined the combination of non-injurious doses of LPS and sub-hepatotoxic PEA in the induction of multiple organ injury (MOI). Rats treated with 20 or 40 microg/kg LPS plus 10 microg/kg PEA developed severe liver, kidney, and lung injury; elevation of TNF-alpha, IFN-gamma, and IL-2; and high mortality. Depletion of Kupffer cells or T-cells by pretreatment with Gadolinium Chloride or FK506, respectively, attenuated MOI. Thus LPS + PEA acted synergistically on Kupffer and T-cells to induce proinflammatory cytokines contributing to MOI. 相似文献
996.
Nickel release behavior and surface characteristics of porous NiTi shape memory alloy modified by different chemical processes 总被引:1,自引:0,他引:1
Wu S Liu X Chan YL Chu PK Chung CY Chu C Yeung KW Lu WW Cheung KM Luk KD 《Journal of biomedical materials research. Part A》2009,89(2):483-489
As a non-line-of-sight surface modification technique, chemical treatment is an effective method to treat porous NiTi with complex surface morphologies and large exposed areas due to its liquidity and low temperature. In the work described here, three different chemical processes are used to treat porous NiTi alloys. Our results show that H(2)O(2) treatment, NaOH treatment, and H(2)O(2) pre-treatment plus subsequent NaOH treatment can mitigate leaching of nickel from the alloy. The porous NiTi samples modified by the two latter processes favor deposition of a layer composed of Ca and P due to the formation of bioactive Na(2)TiO(3) on the surface. Among the three processes, H(2)O(2) pre-treatment plus subsequent NaOH modification is the most effective in suppressing nickel release. Small area X-ray photoelectron spectroscopy reveals that the surfaces treated by different chemical processes have different structures and compositions. The sample modified by the H(2)O(2) treatment is composed of rough TiO(2) on the outer surface and an oxide transition layer underneath whereas the sample treated by NaOH comprises a surface layer of titanium oxide and Na(2)TiO(3) together with a transition layer. The sample processed by the H(2)O(2) and NaOH treatment has a pure Na(2)TiO(3) layer on the surface and a transition layer underneath. These results help to elucidate the different nickel release behavior and bioactivity of porous NiTi alloys processed by different methods. 相似文献
997.
Serum high mobility group box-1 (HMGB1) is closely associated with the clinical and pathologic features of gastric cancer 总被引:1,自引:0,他引:1
Hye Won Chung Sang-Guk Lee Heejung Kim Duck Jin Hong Jae Bock Chung David Stroncek Jong-Baeck Lim 《Journal of translational medicine》2009,7(1):38
Background
High mobility group box-1 (HMGB1) is a newly recognized factor regulating cancer cell tumorigenesis, expansion and invasion. We investigated the correlation between the serum HMGB1 levels and the clinical and pathologic features of gastric cancer and evaluated the validity of HMGB1 as a potential biomarker for the early diagnosis of gastric cancer. 相似文献998.
Son WY Chung JT Dahan M Reinblatt S Tan SL Holzer H 《Journal of assisted reproduction and genetics》2011,28(6):539-544
Purpose
To examine the fertilization and developmental potential of sibling mature oocytes collected from different follicle sizes on day of retrieval in in vitro maturation (IVM) cycles.Methods
Two hundred thirty eight hCG-primed IVM cycles were performed in 213 patients with polycystic ovaries. If sibling mature oocytes were retrieved on day of collection, they were divided into two groups, Group 1 (n = 78): M-II oocytes obtained from follicles size 10–14 mm; Group 2 (n = 192): M-II oocytes obtained from follicles size <10 mm.Results
Of the 238 cycles, 63 cycles had more than one M-II oocytes retrieved (total M-II oocytes = 270) both from Groups 1 and 2. There were no significant differences between the two groups for oocyte diameter (117.2 mm vs. 116.9 mm), fertilization (79.5% vs. 72.4%) and good quality embryo on day 3 (66.1% vs. 56.8%).Conclusions
The M-II oocytes retrieved from the cohort of follicles (<10 mm diameter) can produce the same quality of embryos as that from large follicles, likely contributing to improve the clinical outcome. 相似文献999.
1000.
Anne P. Hutchinson Eric R. Chung Nirali J. Shah Megi Zeku Pak H. Chung 《Gynecological endocrinology》2019,35(1):49-52
This retrospective cohort study investigates the risk factors and beta-human chorionic gonadotropin (β-hCG) trends in patients with ruptured tubal ectopic pregnancies (EPs) despite methotrexate (MTX) treatment. All patients receiving MTX for sonographically confirmed tubal EPs at our fertility center between 2004 and 2014 were included. Baseline demographics and β-hCG trends of patients with EP rupture after MTX were compared to patients with resolved EPs after MTX. One-hundred-thirty-seven patients with EPs were treated with MTX during the study duration; 27 experienced EP rupture and 110 EP resolution. There was no difference in the baseline demographics or β-hCG levels on the day of MTX between the groups. Patients with ruptured EPs after MTX had higher β-hCG levels on day-4 (1223.9?±?243.5 vs. 1111.2?±?179.7 mIU/mL; p?<?.001) and day-7 (1156.9?±?206.2 vs. 872.4?±?690.2 mIU/mL; p?<?.001). The odds of EP rupture compared to EP resolution was 6.2 (95% CI 2.1–19.1), 13.7 (95% CI 4.8–38.9), and 3.0 (95% CI 1.2–7.2) times higher when the change in β-hCG levels was <5% between day-7 vs. day of MTX, day-7 vs. day-4, and day-4 vs. day of MTX, respectively. Our results demonstrate that ruptured tubal EPs despite MTX have <5% change in β-hCG levels between the day of MTX and day-4 or day-7 after MTX. 相似文献