全文获取类型
收费全文 | 6063篇 |
免费 | 266篇 |
国内免费 | 131篇 |
专业分类
耳鼻咽喉 | 72篇 |
儿科学 | 60篇 |
妇产科学 | 131篇 |
基础医学 | 801篇 |
口腔科学 | 91篇 |
临床医学 | 510篇 |
内科学 | 1353篇 |
皮肤病学 | 94篇 |
神经病学 | 448篇 |
特种医学 | 415篇 |
外科学 | 841篇 |
综合类 | 29篇 |
预防医学 | 175篇 |
眼科学 | 62篇 |
药学 | 668篇 |
中国医学 | 92篇 |
肿瘤学 | 618篇 |
出版年
2023年 | 43篇 |
2022年 | 139篇 |
2021年 | 212篇 |
2020年 | 99篇 |
2019年 | 146篇 |
2018年 | 153篇 |
2017年 | 137篇 |
2016年 | 191篇 |
2015年 | 251篇 |
2014年 | 283篇 |
2013年 | 338篇 |
2012年 | 519篇 |
2011年 | 510篇 |
2010年 | 347篇 |
2009年 | 227篇 |
2008年 | 393篇 |
2007年 | 389篇 |
2006年 | 308篇 |
2005年 | 289篇 |
2004年 | 245篇 |
2003年 | 202篇 |
2002年 | 154篇 |
2001年 | 141篇 |
2000年 | 144篇 |
1999年 | 107篇 |
1998年 | 55篇 |
1997年 | 37篇 |
1996年 | 32篇 |
1995年 | 29篇 |
1994年 | 15篇 |
1993年 | 12篇 |
1992年 | 31篇 |
1991年 | 34篇 |
1990年 | 28篇 |
1989年 | 27篇 |
1988年 | 22篇 |
1987年 | 24篇 |
1986年 | 15篇 |
1985年 | 20篇 |
1984年 | 13篇 |
1983年 | 11篇 |
1981年 | 6篇 |
1980年 | 6篇 |
1979年 | 8篇 |
1978年 | 5篇 |
1974年 | 6篇 |
1973年 | 7篇 |
1971年 | 7篇 |
1969年 | 7篇 |
1968年 | 6篇 |
排序方式: 共有6460条查询结果,搜索用时 15 毫秒
41.
Alveolar soft part sarcoma: MR and angiographic findings 总被引:5,自引:5,他引:0
Suh JS Cho J Lee SH Shin KH Yang WI Lee JH Cho JH Suh KJ Lee YJ Ryu KN 《Skeletal radiology》2000,29(12):680-689
Objective. To present the MR and angiographic findings of alveolar soft part sarcoma (ASPS).
Design and patients. MR examinations (12 tumors of 10 patients) of ASPS performed at multiple hospitals were retrospectively reviewed. The tumors
were found in the thigh (n=4), lower leg (n=4), femur (n=2, local metastasis), scalp (n=1) and arm (n=1). The MR signal characteristics including signal intensity, homogeneity and signal void of lesions and bony invasion including
direct invasion or local metastasis were evaluated. Angiographic findings (n=4) and post-embolotherapy follow-up MR imaging (n=2) findings were also assessed.
Results. Local bony metastasis was found in two cases. Seven tumors showed heterogeneous high signal intensity on T1- and T2-weighted
images with good enhancement. One tumor had a very high signal on T1-weighted images. Eight tumors (67%) showed numerous signal
voids in or near the tumors. All four angiographic studies showed numerous enlarged vessels, arteriovenous shunts and delayed
washout. Two cases mimicked arteriovenous malformations on angiographic studies but MR images demonstrated solid soft tissue
components as well as tortuous vessels.
Conclusions. High signal on T1-weighted image and numerous signal voids are highly suggestive of ASPS, although they are not universal
as has been suggested and arteriovenous malformation should be included in the differential diagnosis. Local bony metastases
in ASPS were seen in two cases and should be carefully investigated.
Received: 12 April 2000 Revision requested: 27 June 2000, 8 August 2000 Revision received: 2 August 2000, 21 August 2000 Accepted:
22 August 2000 相似文献
42.
Development of cyclosporin A-loaded hyaluronic microsphere with enhanced oral bioavailability 总被引:1,自引:0,他引:1
Woo JS Piao MG Li DX Ryu DS Choi JY Kim JA Kim JH Jin SG Kim DD Lyoo WS Yong CS Choi HG 《International journal of pharmaceutics》2007,345(1-2):134-141
To develop a hyaluronic microsphere with the improved oral bioavailability of poorly water-soluble cyclosporin A (CsA), the microspheres were prepared with varying ratios of sodium hyaluronate (HA)/sodium lauryl sulfate (SLS)/CsA using a spray-drying technique. The effects of HA and SLS on the dissolution and solubility of CsA in microspheres were investigated. The CsA-microsphere prepared with HA/SLS/CsA at the ratio of 4/2/1 gave the highest solubility and dissolution rate of CsA among those formulae tested. As solubility and dissolution rate of CsA were increased about 17- and 2-fold compared to CsA powder, respectively, this CsA-microsphere was selected as an optimal formula for oral delivery in rats. The CsA-microsphere and Sandimmun neoral sol gave significantly higher blood levels compared with CsA powder alone. Moreover, the AUC, T(max) and C(max) values of CsA in CsA-microsphere were not significantly different from those in Sandimmun neoral sol in rats, indicating that CsA-microsphere was bioequivalent to the commercial product in rats. Our results demonstrated that the CsA-microsphere prepared with HA and SLS, with improved bioavailability of CsA, might have been useful to deliver a poorly water-soluble CsA. 相似文献
43.
This study aims to develop highly durable, mineral carbonation-based, resource-recycling, secondary cement products based on supercritical carbon dioxide (CO2) curing as part of carbon capture utilization technology that permanently fixes captured CO2. To investigate the basic characteristics of secondary cement products containing concrete sludge waste (CSW) as the main materials after supercritical CO2 curing, the compressive strengths of the paste and mortar (fabricated by using CSW as the main binder), ordinary Portland cement, blast furnace slag powder, and fly ash as admixtures were evaluated to derive the optimal mixture for secondary products. The carbonation curing method that can promote the surface densification (intensive CaCO3 formation) of the hardened body within a short period of time using supercritical CO2 curing was defined as “Lean Carbonation”. The optimal curing conditions were derived by evaluating the compressive strength and durability improvement effects of applying Lean Carbonation to secondary product specimens. As a result of the experiment, for specimens subjected to Lean Carbonation, compressive strength increased by up to 12%, and the carbonation penetration resistance also increased by more than 50%. The optimal conditions for Lean Carbonation used to improve compressive strength and durability were found to be 35 °C, 80 bar, and 1 min. 相似文献
44.
45.
46.
Hirotoshi IMAMURA Shoichi TANI Hidemitsu ADACHI Ryu FUKUMITSU Tadashi SUNOHARA Nobuyuki FUKUI Yoshihiro OMURA Natsuhi SASAKI Tomoaki AKIYAMA Tatsumaru FUKUDA Shinji KAJIURA Masashi SHIGEYASU Kento ASAKURA Ryo HORII Nobuyuki SAKAI 《Neurologia medico-chirurgica》2022,62(5):223
Vasospasm, initial neurological damage, rebleeding, and periprocedural complications are associated prognostic factors for clinical outcomes after aneurysmal subarachnoid hemorrhage (SAH). In this study, factors related to delayed ischemic neurological deficit (DIND) are evaluated using data from our institute for the last 18 years. Data from 2001 to 2018 of patients with aneurysmal SAH who underwent surgical clipping (SC) or endovascular coiling (EC) within 7 days of onset were retrospectively analyzed. Cases of mortality within 5 days after treatment were excluded. Multivariate analysis was used to identify the risk factors for DIND. In total, 840 cases of SAH were assessed; among these cases, 384 (45.7%) and 456 (54.3%) were treated with SC and EC, respectively. The frequency of DIND in the EC group was significantly less than that in the SC group (11.8% vs. 17.7%; p = 0.016). In the results of multivariate analysis, internal carotid artery (ICA) aneurysm and hemorrhagic complications were the risk factors for DIND. Cilostazol administration and EC were significant factors for vasospasm prevention after aneurysmal SAH (odds ratio of ICA aneurysm: 1.59, hemorrhagic complications: 1.76, SC: 1.51, and cilostazol administration: 0.51, respectively). Cilostazol administration was also a significant factor in patients who were treated with EC. ICA aneurysm, treatment strategy, hemorrhagic complications, and cilostazol administration were associated with DIND. Oral administration of cilostazol and avoiding hemorrhagic complications were effective in DIND prevention. If both treatments are available for ruptured aneurysms, clinicians should choose EC on the basis of its ability to prevent DIND. 相似文献
47.
Sung-Wan Kim Woo-Young Park Honey Kim Min Jhon Ju-Wan Kim Hee-Ju Kang Seon-Young Kim Seunghyoung Ryu Ju-Yeon Lee Il-Seon Shin Jae-Min Kim 《Psychiatry investigation》2022,19(6):470
Objective The aim of the study was to develop a checklist for mental health clinicians to predict and manage suicidality. Methods A literature review of the risk and protective factors for suicide was conducted to develop a checklist for evaluating suicidality. Results The fixed risk factors included sex (male), age (older individuals), history of childhood adversity, and a family history of suicide. Changeable risk factors included marital status (single), economic status (poverty), physical illness, history of psychiatric hospitalization, and history of suicide attempts. Recent discharge from a mental hospital and a recent history of suicide attempts were also included. Manageable risk factors included depression (history and current), alcohol problems (frequent drinking and alcohol abuse), hopelessness, agitation, impulsivity, impaired reality testing, and command hallucinations. Protective factors included responsibility to family, social support, moral objections to suicide, religiosity, motivation to get treatment, ability to cope with stress, and a healthy lifestyle. A final score was assigned based on the sum of the risk and protective factor scores. Conclusion We believe that the development of this checklist will help mental health clinicians to better assess those at risk for suicidal behavior. Further studies are necessary to validate the checklist. 相似文献
48.
We investigated whether dining with companions is correlated with the alleviation of depression and differs by sex among Korean adults. We used 4-year data from the 2014, 2016, 2018, and 2020 Korea National Health and Nutrition Examination Survey. We surveyed 11,055 participants (4699 men, 6356 women) using the Patient Health Questionnaire-9 to measure their depression scores. We evaluated participants’ meal companionship status by asking whether they had usually dined with companions for breakfast, lunch, or dinner during the past year. Statistical analysis was performed using chi-square tests and multivariate/multinomial logistic regression. We found depression to be less prevalent among participants who dined with companions at least once a day (adjusted OR: 0.26, 95% CI: 0.15–0.45, men; adjusted OR: 0.50, 95% CI: 0.34–0.74, women). In the moderate depression subgroup, participants who dined with companions at least once a day showed lower OR (adjusted OR: 0.28, 95% CI: 0.16–0.50, men; adjusted OR: 0.50, 95% CI: 0.32–0.76, women). Among participants who dined together, men’s severe depression dramatically decreased (adjusted OR: 0.05, 95% CI: 0.01–0.31). Thus, we found an association between dining with companions and the prevalence of depression among Korean adults. Dining with companions compared with dining alone signified a lower depression rate, especially among men. This study can provide an initiative to further analyze psychological and physiological effects of dining together and be applied to practical fields as education and societal campaigns. 相似文献
49.
The coronavirus disease 2019 (COVID-19) resulted in a marked decrease in the number of patient visits for acute myocardial infarction and delayed patient response and intervention in several countries. This study evaluated the effect of the COVID-19 pandemic on the number of patients, patient response time (pain-to-door), and intervention time (door-to-balloon) for patients with ST-segment elevation myocardial infarction (STEMI) and non-ST-segment elevation myocardial infarction (NSTEMI).Patients with STEMI or NSTEMI visiting a hospital in South Korea who underwent primary coronary intervention during the COVID-19 pandemic (January 29, 2020, to December 31, 2020) were compared with those in the equivalent period from 2018 to 2019. Patient response and intervention times were compared for the COVID-19 pandemic window (2020) and the equivalent period from 2018 to 2019.We observed no decrease in the number of patients with STEMI (P = .88) and NSTEMI (P = 1.00) during the COVID-19 pandemic compared to that in the previous years. Patient response times (STEMI: P = .39; NSTEMI: P = .59) during the overall COVID-19 pandemic period did not differ significantly. However, we identified a significant decrease in door-to-balloon time among patients with STEMI (14%; P < .01) during the early COVID-19 pandemic.We found that the number of patients with STEMI and NSTEMI was consistent during the COVID-19 pandemic and that no time delays in patient response and intervention occurred. However, the door-to-balloon time among patients with STEMI significantly reduced during the early COVID-19 pandemic, which could be attributed to decreased emergency care utilization during the early pandemic. 相似文献
50.
Sang Eok Lee MD Young-Woo Kim MD Jun Ho Lee MD Keun Won Ryu MD Soo Jeong Cho MD Jong Yeul Lee MD Chan Gyoo Kim MD Il Ju Choi MD Myeong-Cherl Kook MD Byung-Ho Nam PhD Sook Ryun Park MD Min Ju Kim MD Jong Seok Lee MD 《Annals of surgical oncology》2009,16(8):2231-2236
Background The technical difficulty of lymph node dissection in laparoscopy-assisted distal gastrectomy (LADG) remains a barrier for
extending the indication for this modality and limits its widespread clinical practice. The aim of this study was to evaluate
our institutional guidelines for LADG, limiting the indications for this modality to only clinical stage T1N0 or T1N1 gastric
cancer.
Methods From January 2002 to October 2006, a total of 294 cases of LADG and 664 cases of open distal gastrectomy (ODG) for clinical
T1N0 or T1N1 gastric cancer were performed at the National Cancer Center, Korea. The two groups’ clinicopathologic characteristics,
surgical outcome, morbidity, and survival were compared.
Results The mean operating time for the LADG group was significantly longer than that for the ODG group (265.8 ± 56.3 vs. 171.4 ± 43.1
minutes, P < .001). The mean number of retrieved lymph nodes in the LADG group was higher than that of the ODG group (39.5 ± 14.7 vs.
37.2 ± 12.9, P = .017). The postoperative hospital stay was shorter in the LADG group (8.0 ± 3.3 vs. 10.5 ± 4.1 days, P < .001). The complications rate was lower for the LADG group than that for the ODG group (6.8% vs. 11.3%, P = .032). The overall survival rate was not significantly different between the two groups (P = .880).
Conclusions Before considering expanding the indications for LADG, developing a carefully thought-out guideline and conducting an audit
are mandatory. 相似文献