首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   15546篇
  免费   976篇
  国内免费   188篇
耳鼻咽喉   382篇
儿科学   199篇
妇产科学   288篇
基础医学   2694篇
口腔科学   294篇
临床医学   1206篇
内科学   3066篇
皮肤病学   438篇
神经病学   1183篇
特种医学   1043篇
外科学   2081篇
综合类   71篇
现状与发展   3篇
一般理论   10篇
预防医学   605篇
眼科学   429篇
药学   1252篇
中国医学   154篇
肿瘤学   1312篇
  2024年   12篇
  2023年   133篇
  2022年   370篇
  2021年   662篇
  2020年   269篇
  2019年   439篇
  2018年   524篇
  2017年   409篇
  2016年   610篇
  2015年   871篇
  2014年   950篇
  2013年   1041篇
  2012年   1578篇
  2011年   1421篇
  2010年   837篇
  2009年   706篇
  2008年   890篇
  2007年   907篇
  2006年   771篇
  2005年   624篇
  2004年   517篇
  2003年   466篇
  2002年   379篇
  2001年   293篇
  2000年   237篇
  1999年   174篇
  1998年   71篇
  1997年   55篇
  1996年   34篇
  1995年   36篇
  1994年   24篇
  1993年   30篇
  1992年   38篇
  1991年   39篇
  1990年   34篇
  1989年   36篇
  1988年   28篇
  1987年   32篇
  1986年   17篇
  1985年   15篇
  1984年   10篇
  1983年   10篇
  1981年   14篇
  1980年   7篇
  1979年   14篇
  1978年   10篇
  1977年   10篇
  1976年   10篇
  1975年   9篇
  1973年   6篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
91.
Background/AimsWe examined the efficacy and safety of tegoprazan as a part of first-line triple therapy for Helicobacter pylori eradication.MethodsA randomized, double-blind, controlled, multicenter study was performed to evaluate whether tegoprazan (50 mg)-based triple therapy (TPZ) was noninferior to lansoprazole (30 mg)-based triple therapy (LPZ) (with amoxicillin 1 g and clarithromycin 500 mg; all administered twice daily for 7 days) for treating H. pylori. The primary endpoint was the H. pylori eradication rate. Subgroup analyses were performed according to the cytochrome P450 (CYP) 2C19 genotype, the minimum inhibitory concentration (MIC) of amoxicillin and clarithromycin, and underlying gastric diseases.ResultsIn total, 350 H. pylori-positive patients were randomly allocated to the TPZ or LPZ group. The H. pylori eradication rates in the TPZ and LPZ groups were 62.86% (110/175) and 60.57% (106/175) in an intention-to-treat analysis and 69.33% (104/150) and 67.33% (101/150) in a per-protocol analysis (non-inferiority test, p=0.009 and p=0.013), respectively. Subgroup analyses according to MICs or CYP2C19 did not show remarkable differences in eradication rate. Both first-line triple therapies were well-tolerated with no notable differences.ConclusionsTPZ is as effective as proton pump inhibitor-based triple therapy and is as safe as first-line H. pylori eradication therapy but does not overcome the clarithromycin resistance of H. pylori in Korea (ClinicalTrials.gov identifier NCT03317223).  相似文献   
92.
93.
94.
Rationale:Transvaginal evisceration of the small bowel is an extremely rare condition after hysterectomy, which requires urgent surgical intervention to prevent serious bowel morbidity and mortality.Patient concerns:A 65-year-old woman presented with sudden-onset severe abdominal pain and a mass protruding through the vagina. The past surgical history was significant, with an abdominal hysterectomy for cervical cancer performed 11 weeks prior to presentation.Diagnosis:Pelvic examination revealed prolapsed small-bowel loops (18-20 cm in length). Pelvic computed tomography scan confirmed the presence of transvaginal evisceration of the small bowel.Interventions:Bowel reduction and urgent laparotomy were the selected treatment approaches for a detailed inspection and thorough washing of the intrα-abdominal cavity. A Foley catheter was inserted in the emergency room, with the subject in the lithotomy position. The prolapsed bowel loops spontaneously reduced without manual reduction, and the vault defect was repaired transvaginally.Outcomes:The patient experienced no postoperative complications and remained disease-free for 9months postoperatively.Lessons:Transvaginal evisceration of the small bowel should be considered a surgical emergency. A multidisciplinary approach to prompt case management involving clinicians in gynecology, general surgery, and emergency medicine is vital for preventing serious consequences. Hysterectomy is the most frequently performed gynecological surgical procedure, and evisceration occurs most often after hysterectomy. Therefore, patients should be informed about this rare but possible hysterectomy complication.  相似文献   
95.
BackgroundThis study investigated whether the empirical dietary inflammatory index (eDII) score is associated with the inflammatory burden as well as the depressive status in patients with antineutrophil cytoplasmic antibody‐associated vasculitis (AAV).MethodsEighty‐four patients with AAV participated in this study. Birmingham vasculitis activity score (BVAS) and short‐form 36‐item Health Survey mental component summary (SF‐36 MCS) were considered as indices assessing the inflammatory burden and depressive status, respectively. The eDII includes 16 food components and consists of three groups: −9 to −2, the low eDII group; −1 to +1, the moderate eDII group; and +2 to +10, the high eDII group. Furthermore, the lower eDII group includes both the low and moderate eDII groups.ResultsThe median age was 64.5 years (36 men). The eDII scores inversely correlated with SF‐36 MCS (r = −0.298, p = 0.006) but not with BVAS. SF‐36 MCS significantly differ between the lower and higher eDII groups (69.7 vs. 56.7, p = 0.016), but not among the low, moderate and high eDII groups. Additionally, when patients with AAV were divided into two groups according to the upper limit of the lowest tertile of SF‐36 MCS of 55.31, patients in the higher eDII group exhibited a significantly higher risk for the lowest tertile of SF‐36 MCS than those in the lower eDII group (RR 3.000).ConclusionWe demonstrated for the first time that the eDII could predict the depressive status by estimating SF‐36 MCS without utilising K‐CESD‐R ≥ 16 in patients with AAV.  相似文献   
96.
BackgroundAs the coronavirus disease 2019 (COVID-19) pandemic continues, there are concerns regarding waning immunity and the emergence of viral variants. The immunogenicity of Ad26.COV2.S against wild-type (WT) and variants of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) needs to be evaluated.MethodThis prospective cohort study was conducted between June 2021 and January 2022 at two university hospitals in South Korea. Healthy adults who were scheduled to be vaccinated with Ad26.COV2.S were enrolled in this study. The main outcomes included anti-spike (S) IgG antibody and neutralizing antibody responses, S-specific T-cell responses (interferon-γ enzyme-linked immunospot assay), solicited adverse events (AEs), and serious AEs.ResultsFifty participants aged ≥ 19 years were included in the study. Geometric mean titers (GMTs) of anti-S IgG were 0.4 U/mL at baseline, 5.2 ± 3.0 U/mL at 3–4 weeks, 55.7 ± 2.4 U/mL at 5–8 weeks, and 81.3 ± 2.5 U/mL at 10–12 weeks after vaccination. GMTs of 50% neutralizing dilution (ND50) against WT SARS-CoV-2 were 164.6 ± 4.6 at 3-4 weeks, 313.9 ± 3.6 at 5–8 weeks, and 124.4 ± 2.6 at 10–12 weeks after vaccination. As for the S-specific T-cell responses, the median number of spot-forming units/106 peripheral blood mononuclear cell was 25.0 (5.0–29.2) at baseline, 60.0 (23.3–178.3) at 5-8 weeks, and 35.0 (13.3–71.7) at 10–12 weeks after vaccination. Compared to WT SARS-CoV-2, ND50 against Delta and Omicron variants was attenuated by 3.6-fold and 8.2-fold, respectively. The most frequent AE was injection site pain (82%), followed by myalgia (80%), fatigue (70%), and fever (50%). Most AEs were grade 1–2, and resolved within two days.ConclusionSingle-dose Ad26.COV2.S was safe and immunogenic. NAb titer and S-specific T-cell immunity peak at 5–8 weeks and rather decrease at 10–12 weeks after vaccination. Cross-reactive neutralizing activity against the Omicron variant was negligible.  相似文献   
97.
98.
Sex impacts the development of the brain and cognition differently across individuals. However, the literature on brain sex dimorphism in humans is mixed. We aim to investigate the biological underpinnings of the individual variability of sexual dimorphism in the brain and its impact on cognitive performance. To this end, we tested whether the individual difference in brain sex would be linked to that in cognitive performance that is influenced by genetic factors in prepubertal children (N = 9,658, ages 9–10 years old; the Adolescent Brain Cognitive Development study). To capture the interindividual variability of the brain, we estimated the probability of being male or female based on the brain morphometry and connectivity features using machine learning (herein called a brain sex score). The models accurately classified the biological sex with a test ROC–AUC of 93.32%. As a result, a greater brain sex score correlated significantly with greater intelligence (p fdr < .001, ηp2 = .011–.034; adjusted for covariates) and higher cognitive genome‐wide polygenic scores (GPSs) (p fdr < .001, ηp2 < .005). Structural equation models revealed that the GPS‐intelligence association was significantly modulated by the brain sex score, such that a brain with a higher maleness score (or a lower femaleness score) mediated a positive GPS effect on intelligence (indirect effects = .006–.009; p = .002–.022; sex‐stratified analysis). The finding of the sex modulatory effect on the gene–brain–cognition relationship presents a likely biological pathway to the individual and sex differences in the brain and cognitive performance in preadolescence.  相似文献   
99.
Dry foam formulation technology is alternative approach to enhance dissolution of the drug. Sildenafil citrate was suspended in sodium dodecyl sulfate solution and adding a mixture of maltodextrin and mannitol as diluent to form a paste. Sildenafil citrate paste was passed through a nozzle spray bottle to obtain smooth foam. The homogeneous foam was dried in a vacuum oven and sieved to obtain dry foam granules. The granules were mixed with croscarmellose sodium, magnesium stearate and compressed into tablet. All formulations were evaluated for their physicochemical properties and dissolution profiles. All the tested excipients were compatible with sildenafil citrate by both differential scanning calorimetry (DSC) and infrared (IR) analysis. There are no X-ray diffraction (XRD) peaks representing crystals of sildenafil citrate observed form dry foam formulations. The hardness of tablets was about 5?kg, friability test <1% with a disintegration time <5?min. The sildenafil citrate dry foam tablet had higher dissolution rate in 0.1 N HCl in comparison with commercial sildenafil citrate tablet, sildenafil citrate prepared by direct compression and wet granulation method. Sildenafil citrate dry foam tablet with the high-level composition of surfactant, water and diluent showed enhanced dissolution rate than that of the lower-level composition of these excipients. This formulation was stable under accelerated conditions for at least 6 months.  相似文献   
100.
Voice outcomes of polyacrylamide hydrogel injection laryngoplasty   总被引:1,自引:0,他引:1  
Lee SW  Son YI  Kim CH  Lee JY  Kim SC  Koh YW 《The Laryngoscope》2007,117(10):1871-1875
OBJECTIVES: Polyacrylamide hydrogel (PAAG, Aquamid) is widely used as permanent facial tissue filler during facial plastic surgery. In this study, we examined the long-term effects and safety aspects of PAAG as a vocal fold augmentation material for patients with permanent unilateral vocal cord paralysis. STUDY DESIGN: Prospective clinical trials. METHODS: PAAG injection laryngoplasty was performed in 34 consecutive patients with permanent unilateral vocal cord paralysis. Percutaneous injection was performed under local anesthesia into the vocalis muscle using disposable 25 gauge long needles. Of the 34 patients, 16 completed acoustic, perceptual, stroboscopic, and subjective evaluations prior to the injection and at 6 and 12 months after the injection. RESULTS: Acoustic and perceptual parameters (GRBAS [Overall grade of dysphonia, Roughness, Breathiness, Aesthenia, Strain], Maximal phonation time [MPT], jitter, and shimmer) were significantly improved (P < .05) after injection and remained stable over 12 months. The grades of mucosal waves and glottic closure were also significantly improved (P < .01). The voice handicap index (VHI), as well as the visual analogue scale (VAS) of hoarseness and aspiration significantly improved over 12 months. No adverse effects were observed except for a decrease in the mucosal wave of one patient, after injection into a superficial area of the vocal fold. CONCLUSION: Based on the preliminary results of this trial, PAAG appears to be a long-lasting and safe injection material that is suitable for the treatment of glottal insufficiency caused by permanent unilateral vocal cord paralysis.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号