全文获取类型
收费全文 | 26977篇 |
免费 | 2967篇 |
国内免费 | 518篇 |
专业分类
耳鼻咽喉 | 319篇 |
儿科学 | 380篇 |
妇产科学 | 367篇 |
基础医学 | 1657篇 |
口腔科学 | 9556篇 |
临床医学 | 1924篇 |
内科学 | 2165篇 |
皮肤病学 | 518篇 |
神经病学 | 424篇 |
特种医学 | 298篇 |
外国民族医学 | 1篇 |
外科学 | 1637篇 |
综合类 | 2632篇 |
预防医学 | 1263篇 |
眼科学 | 168篇 |
药学 | 4369篇 |
31篇 | |
中国医学 | 1454篇 |
肿瘤学 | 1299篇 |
出版年
2023年 | 542篇 |
2022年 | 530篇 |
2021年 | 944篇 |
2020年 | 1287篇 |
2019年 | 1236篇 |
2018年 | 1135篇 |
2017年 | 1097篇 |
2016年 | 1107篇 |
2015年 | 1033篇 |
2014年 | 1586篇 |
2013年 | 2103篇 |
2012年 | 1437篇 |
2011年 | 1558篇 |
2010年 | 1218篇 |
2009年 | 1161篇 |
2008年 | 1135篇 |
2007年 | 1112篇 |
2006年 | 1008篇 |
2005年 | 1032篇 |
2004年 | 892篇 |
2003年 | 831篇 |
2002年 | 699篇 |
2001年 | 640篇 |
2000年 | 526篇 |
1999年 | 459篇 |
1998年 | 375篇 |
1997年 | 406篇 |
1996年 | 329篇 |
1995年 | 311篇 |
1994年 | 292篇 |
1993年 | 220篇 |
1992年 | 255篇 |
1991年 | 183篇 |
1990年 | 179篇 |
1989年 | 186篇 |
1988年 | 153篇 |
1987年 | 135篇 |
1986年 | 117篇 |
1985年 | 145篇 |
1984年 | 134篇 |
1983年 | 95篇 |
1982年 | 115篇 |
1981年 | 110篇 |
1980年 | 81篇 |
1979年 | 60篇 |
1978年 | 50篇 |
1977年 | 63篇 |
1976年 | 43篇 |
1975年 | 36篇 |
1974年 | 27篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
口腔鳞状细胞癌(oral squamous cell carcinoma,OSCC)的发病率和死亡率呈年轻化趋势上升,已成为世界范围内的主要公共卫生问题。近年来,慢性牙周炎(chronic periodontitis,CP)与口腔鳞癌之间的关系越来越受到重视,一些研究发现,以慢性炎症和微生物失调为特征的牙周病是口腔肿瘤发生的重要危险因素。本文就慢性牙周炎与口腔鳞癌的相关研究,牙周主要致病菌、细胞因子、NF-κB等在两者中的桥梁作用,以及抗炎药物在口腔鳞癌中的应用做主要阐述。 相似文献
2.
3.
目的 评价自后端摘除舌下腺在治疗舌下腺囊肿中的临床应用价值。方法 收集本科室曾经收治的86例舌下腺囊肿患者资料,均使用摘除患侧舌下腺的手术治疗方案,从术中出血量、手术时长及手术并发症发生率,比较传统舌下腺摘除术和由后端向前逆向摘除术的临床治疗效果。结果 逆向摘除组较传统术式组术中出血量明显减少,统计分析差异有统计学意义(t=8.89,P<0.01)。手术时长明显缩短,统计分析差异有统计学意义(t=14.85,P<0.01)。手术并发症发生率明显降低(10.7%到0%),但统计分析差异无统计学意义。结论 由后端向前端逆向摘除舌下腺降低了手术并发症发生率,减少了术中出血量,缩短了手术时间,提高了手术安全性,适合在舌下腺摘除术中推广使用。 相似文献
4.
《Journal of endodontics》2022,48(1):102-108
IntroductionThe first outbreak of coronavirus disease 2019 (COVID-19) in the United States resulted in a nationwide closure of dental offices that created an oral health crisis. The aim of this observational study was to analyze and compare the characteristics of patients who visited 2 private endodontics offices from March 16 to May 31, 2020, compared with the same period in 2019.MethodsDemographic, diagnostic, and procedural data of 1520 (693 in 2020 and 827 in 2019) patient visits were collected. Bivariate and multiple logistic regression analyses were used to assess the impact of the COVID-19 outbreak on patient-related variables.ResultsBivariate analyses showed that the number of patient visits decreased in April and May 2020 (P < .0001). In 2020, patients’ self-reported pain level was higher, they were more frequently diagnosed with pulp necrosis and acute apical abscess, and they received more incisions for drainage (P < .05). Multiple logistic regression analyses showed that the COVID-19 outbreak was associated with less visits for older patients (>49.5 years) (odds ratio [OR] = 0.720; 95% confidence interval [CI], 0.573–0.906), more patients with kidney diseases (OR = 2.690; 95% CI, 1.143–6.331), higher levels of pain on percussion (OR = 2.277; 95% CI, 1.718–3.016), less cases with previously initiated treatment (OR = 0.242; 95% CI, 0.080–0.731), less periapical diagnoses of asymptomatic apical periodontitis (OR = 0.510; 95% CI, 0.306–0.849), and a higher number of nonsurgical root canal treatments (OR = 2.073; 95% CI, 1.397–3.074) and apicoectomies (OR = 2.799; 95% CI, 1.367-5.729).ConclusionsThese findings show that the public health burden of endodontic infections was more intense during the initial outbreak of COVID-19. 相似文献
5.
6.
7.
Elvin S. Cheng Louiza S. Velentzis Marianne Weber Julia Steinberg Karen Canfell Xue Qin Yu 《International journal of cancer. Journal international du cancer》2023,152(12):2528-2540
There is growing, but inconsistent evidence suggesting oestrogen may play a key role in lung cancer development, especially among never-smoking women for whom lung cancer risk factors remain largely elusive. Using the China Kadoorie Biobank, a large-scale prospective cohort with 302 510 women aged 30 to 79 years recruited from 10 regions in China during 2004 to 2008, we assessed the risk of lung cancer death among self-reported never-smoking women who were cancer-free at baseline, in relation to age at menarche, age at menopause, time since menopause, prior use of oral contraceptives (OCP), number of livebirths, breastfeeding and age at first livebirth. Women were followed up to December 31, 2016 with linkage to mortality data. Hazard ratios (HR) and 95% confidence intervals (CI) were estimated using Cox regression, adjusting for key confounders including several socio-demographic, environmental and lifestyle factors. Among 287 408 never-smoking women, 814 died from lung cancer with a median follow-up of 10.3 years. Women who had used OCP within 15 years prior to baseline had a significantly higher hazard of lung cancer death compared with never-users: HR = 1.85 (95% CI: 1.14-3.00) and risk increased by 6% with each additional year of use: HR = 1.06 (1.01-1.10). Among parous women, the hazard of lung cancer death increased by 13% with each single livebirth: HR = 1.13 (1.05-1.23); and among post-menopausal women, the risk increased by 2% with each year since menopause: HR = 1.02 (1.01-1.04). These results suggest that reproductive factors which were proxies for lower endogenous oestrogen level, for example, longer duration of OCP use, could play a role in lung cancer development. 相似文献
8.
《Mayo Clinic proceedings. Mayo Clinic》2022,97(8):1525-1533
The importance of the left atrial appendage (LAA) as the source of thromboembolism including stroke in patients with nonvalvular atrial fibrillation is well documented, with more than 90% of ischemic strokes related to a LAA thrombus. Although oral anticoagulation has been the standard of care, approximately 50% to 60% of patients either have contraindications to oral anticoagulation or do not continue the medication beyond the first year. This led to the development of local site-specific therapy to occlude the LAA by either surgical or transcatheter means. Despite marked advancements, incomplete LAA closure with surgical and transcatheter approaches remains frequent. The etiology of incomplete LAA closure and its clinical implications remain unclear. Multiple strategies are in development including changes in deployment techniques, a new device design, and alternative approaches to leak closure. 相似文献
9.
A Comparison of the Characteristics of Cytokine Storm between Lichen Planus and Oral Squamous Cell Carcinoma 下载免费PDF全文
Salmeh KalbassiLida RadfarMohammadreza AzimiSimin ShadanpoorAli Ghorbani Ranjbary 《Asian Pacific journal of cancer prevention》2022,23(11):3843-3849
Introduction: Lichen planus (LP) is a relatively common chronic mucocutaneous disease that affects the skin and mucous membranes, including oral mucosa. The etiology of the disease is unknown. Some evidence suggests that the immune system and inflammation may play a role in the formation and progression of lichen planus. Some authorities believe that LP is a precancerous condition. The purpose of this study was to investigate the serum levels of the inflammatory cytokines CRP, IL-1, IL-6, and TNF- in patients with oral lichen planus and oral squamous cell carcinoma (OSCC), as well as to assess the relationship between these cytokine levels and clinical symptoms. Methods: A total of 75 subjects, with 25 in each group of oral lichen planus, healthy control, and oral squamous cell carcinoma, participated in this cross-sectional study. Serum levels of IL-1α, TNF-α, IL-6, and CRP were determined and compared. In comparison to the healthy control group, the lichen planus and oral squamous cell carcinoma groups had higher levels of CRP, IL-1α, IL-6, and TNF-α. Results: We discovered that the mean mRNA and protein levels of CRP, IL-1α, IL-6, and TNF-α were significantly higher in the blood and tissue of lichen planus and OSCC patients than in normal controls. Conclusion: Higher levels of CRP, IL-1α, IL-6, and TNF-α may be linked to OLP and oral carcinogenesis. More research with larger groups is required. 相似文献
10.
《Acta otorrinolaringologica espanola》2022,73(3):151-156
IntroductionAlthough free flaps have been used predominantly in past decades for the soft tissue reconstruction of head and neck malignancies, Pectoralis major myocutaneous flap (PMMF) is still a reliable workhorse for patients with co-existing co-morbidities or low economic status where free flaps are not feasible.Patients and methodsIt was a retrospective study done on 36 patients of head and neck malignancies over the period of 5 years in which PMMF was used as a method of reconstruction in our hospital. Patients were followed up for a period of one year and outcome of PMMF was evaluated.ResultsOut of 36 patients 31 were of oral cancer and 5 were of carcinoma hypopharynx. Incidence of total flap necrosis was nil and partial flap necrosis was 16.6%. Orocutaneous fistula was found in 16.6%, wound dehiscence was in 19.4% and infection was found in 13.5% of patients. Non-flap related complications were found in 13.8% of patients. 35 out of 36 patients (97.2%) eventually achieved satisfactory surgical outcome of PMMF reconstruction.ConclusionPMMF is a reliable method of reconstruction for head and neck malignancies especially in basic healthcare settings. With minimal expertise and groundwork, it is still a cost-effective workhorse flap for head and neck reconstruction. 相似文献