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   6605篇
  免费   339篇
  国内免费   66篇
耳鼻咽喉   47篇
儿科学   194篇
妇产科学   146篇
基础医学   652篇
口腔科学   146篇
临床医学   455篇
内科学   1731篇
皮肤病学   128篇
神经病学   390篇
特种医学   383篇
外科学   1269篇
综合类   18篇
预防医学   219篇
眼科学   54篇
药学   301篇
中国医学   8篇
肿瘤学   869篇
  2024年   11篇
  2023年   91篇
  2022年   129篇
  2021年   259篇
  2020年   155篇
  2019年   220篇
  2018年   276篇
  2017年   174篇
  2016年   196篇
  2015年   203篇
  2014年   310篇
  2013年   362篇
  2012年   513篇
  2011年   521篇
  2010年   287篇
  2009年   257篇
  2008年   425篇
  2007年   400篇
  2006年   355篇
  2005年   420篇
  2004年   352篇
  2003年   315篇
  2002年   278篇
  2001年   40篇
  2000年   33篇
  1999年   42篇
  1998年   67篇
  1997年   46篇
  1996年   38篇
  1995年   32篇
  1994年   27篇
  1993年   25篇
  1992年   19篇
  1991年   14篇
  1990年   18篇
  1989年   14篇
  1988年   15篇
  1987年   6篇
  1986年   12篇
  1985年   5篇
  1984年   9篇
  1983年   3篇
  1982年   5篇
  1981年   4篇
  1980年   6篇
  1977年   3篇
  1975年   3篇
  1971年   2篇
  1965年   2篇
  1904年   2篇
排序方式: 共有7010条查询结果,搜索用时 15 毫秒
71.
The effects of different cholecalciferol supplementation regimens on serum inflammatory cytokines in healthy subjects with vitamin D deficiency are still lacking. This is a single-center, open-label, randomized, parallel group study involving healthy subjects deficient in vitamin D (baseline 25OHD < 20 ng/mL) receiving oral cholecalciferol with three different dosing regimens: Group A: 10,000 IU/day for 8 weeks followed by 1000 IU/day for 4 weeks; Group B: 50,000 IU/week for 12 weeks and Group C: 100,000 IU every other week for 12 weeks. IL-17A, IL-6, IL-8, IL-10, IL-23 and TNFα were measured at baseline and at week 4, 8, 12, and 16. 75 healthy subjects were enrolled (58.7% female), with an average age of 34.1 ± 10.2 years. No statistical differences were observed among groups at baseline for either IL-6, IL-17A, IL-23, IL-8 or IL-10 at any time point; TNFα was indetectable. Concerning the whole sample, the time trend analysis showed a statistically significant linear trend for decreasing values over the treatment period for IL-6 (p = 0.016) and IL-17A (p = 0.006), while no significant time trends were observed for the other teste cytokines. No significant differences were found in the serum concentrations of the tested cytokines between week 12 and week 16. In young healthy individuals deficient in vitamin D, cholecalciferol administration showed a decrease in the serum IL-6 and IL-17A concentrations, without marked differences using the three regimens.  相似文献   
72.
The prevention of chemotherapy-induced alopecia still represents an urgent need for every day clinical practice. In this regard, this prospective single-center study included breast cancer (BC) patients who underwent a scalp cooling device (Dignicap®) during (neo)adjuvant chemotherapy with the aim to evaluate the efficacy and safety of this device in preventing alopecia. One hundred and seventy-eight patients (median age 43 years) were enrolled. The chemotherapy regimen included anthracycline and taxane-based chemotherapy (68.1%), docetaxel and cyclophosphamide (25.8%), anthracycline and taxane-based plus carboplatin (3.9%), and paclitaxel alone (2.2%). In 25.3% of cases, a dose dense schedule was used. Overall, the success rate was 68.0%: 100% in paclitaxel alone, 87.0% in docetaxel-cyclophosphamide, 59.5% in anthracycline and taxane, and 71.4% in the sequential regimen plus carboplatin group (anthracycline and taxane-based chemotherapy versus taxane-based chemotherapy, p ≤ 001. No difference in terms of hair preservation between dose-dense or standard schedule was found (p = 0.557). Early discontinuation of the scalp cooling was observed in 50 patients (28.1%). Although 138 patients (77.5%) experienced adverse events, 70.2% of patients were satisfied with this device. In conclusion, this large prospective study confirmed the helpful effect of the scalp cooling system in preventing alopecia in BC patients also undergoing sequential anthracyclines and taxane-based chemotherapy.  相似文献   
73.
This study aimed to examine the physical and mental Quality of Life (QoL) trajectories in prostate cancer (PCa) patients participating in the Pros-IT CNR study. QoL was assessed using the Physical (PCS) and Mental Component Score (MCS) of Short-Form Health Survey upon diagnosis and two years later. Growth mixture models were applied on 1158 patients and 3 trajectories over time were identified for MCS: 75% of patients had constantly high scores, 13% had permanently low scores and 12% starting with low scores had a recovery; the predictors that differentiated the trajectories were age, comorbidities, a family history of PCa, and the bowel, urinary and sexual functional scores at diagnosis. In the physical domain, 2 trajectories were defined: 85% of patients had constantly high scores, while 15% started with low scores and had a further slight decrease. Two years after diagnosis, the psychological and physical status was moderately compromised in more than 10% of PCa patients. For mental health, the trajectory analysis suggested that following the compromised patients at diagnosis until treatment could allow identification of those more vulnerable, for which a level 2 intervention with support from a non-oncology team supervised by a clinical psychologist could be of help.  相似文献   
74.
Several alkaline earth or rare earth binary monosilicides and -germanides possess complex bonding properties, such as polycation formation exceeding the scope of classical electron counting rules. In this study, we present characterization by powder and single-crystal diffraction and thermal analysis of CeGe, one of the few monogermanides crystallizing in the FeB-type structure. Comparative computational investigations for structure types experimentally observed for monogermanides and alternative structures with different structural motifs were performed to gain energetical insights into this family of compounds, underlining the preference for infinite germanium chains over other structural motifs. Formation enthalpy calculations and structural chemical analysis highlight the special position of FeB-type compounds among the monogermanides.  相似文献   
75.
Purpose: To prospectively evaluate the albumin/globulin ratio (AGR), neutrophil/lymphocyte ratio (NLR), and platelet/lymphocyte ratio (PLR) diagnostic and prognostic predictive value in a stratified population of prostate cancer (PC) cases. Methods: Population was divided based on the clinical and histologic diagnosis in: Group A: benign prostatic hyperplasia (BPH) cases (494 cases); Group B: all PC cases (525 cases); Group B1: clinically significant PC (426 cases); Group B2: non-metastatic PC (416 cases); Group B3: metastatic PC (109 cases). NLR, PLR, and AGR were obtained at the time of the diagnosis, and only in cases with PC considered for radical prostatectomy, determinations were also repeated 90 days after surgery. For each ratio, cut-off values were determined by receiver operating characteristics curve (ROC) analysis and fixed at 2.5, 120.0, and 1.4, respectively, for NLR, PLR, and AGR. Results: Accuracy in predictive value for an initial diagnosis of clinically significant PC (csPC) was higher using PLR (0.718) when compared to NLR (0.220) and AGR (0.247), but, despite high sensitivity (0.849), very low specificity (0.256) was present. The risk of csPC significantly increased only according to PLR with an OR = 1.646. The percentage of cases with metastatic PC significantly increased according to high NLR and high PLR. Accuracy was 0.916 and 0.813, respectively, for NLR and PLR cut-off, with higher specificity than sensitivity. The risk of a metastatic disease increased 3.2 times for an NLR > 2.5 and 5.2 times for a PLR > 120 and at the multivariate analysis. Conclusion: PLR and NLR have a significant predictive value towards the development of metastatic disease but not in relation to variations in aggressiveness or T staging inside the non-metastatic PC. Our results suggest an unlikely introduction of these analyses into clinical practice in support of validated PC risk predictors.  相似文献   
76.
77.
Effectiveness against severe COVID-19 of a second booster dose of the bivalent (original/BA.4–5) mRNA vaccine 7–90 days post-administration, relative to a first booster dose of an mRNA vaccine received ≥ 120 days earlier, was ca 60% both in persons ≥ 60 years never infected and in those infected > 6 months before. Relative effectiveness in those infected 4–6 months earlier indicated no significant additional protection (10%; 95% CI: −44 to 44). A second booster vaccination 6 months after the latest infection may be warranted.  相似文献   
78.
The incidence of testicular cancer, cryptorchidism and defective spermatogenesis is increasing probably due to environmental and lifestyle-related factors. The aim of this review is to briefly describe and comment on the principal lifestyle factors. The recent findings that the electromagnetic waves following the use of the cell phone and the prolonged exposure to the noise stress cause relevant testicular dysfunction in man or animals reinforce the hypothesis of the importance of lifestyle-related factors.  相似文献   
79.
80.
Herpes Simplex Virus type 1 (HSV‐1) is a very common infection often localized in the mucocutaneous junction of the lip. Rarely, it could be detected also in periodontal tissues, associated with an elevated risk of periodontal disease progression and gingival recessions. Recently, HSV‐1 and numerous co‐infections have been reported in literature associated with the Coronavirus and subsequent COVID‐19 disease. This report illustrates a case of HSV‐1 in a patient with Covid‐19 infection, showing the presence of ulcers and vesicles on the gingival margin of maxillary teeth associated with soreness and pain. The histology highlighted the presence of intraepithelial cell ballooning, confirming the diagnosis of HSV‐1 infection.  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