全文获取类型
收费全文 | 11022篇 |
免费 | 618篇 |
国内免费 | 109篇 |
专业分类
耳鼻咽喉 | 185篇 |
儿科学 | 143篇 |
妇产科学 | 239篇 |
基础医学 | 1707篇 |
口腔科学 | 236篇 |
临床医学 | 873篇 |
内科学 | 1955篇 |
皮肤病学 | 561篇 |
神经病学 | 663篇 |
特种医学 | 704篇 |
外科学 | 1794篇 |
综合类 | 50篇 |
一般理论 | 1篇 |
预防医学 | 602篇 |
眼科学 | 183篇 |
药学 | 933篇 |
中国医学 | 156篇 |
肿瘤学 | 764篇 |
出版年
2023年 | 57篇 |
2022年 | 235篇 |
2021年 | 358篇 |
2020年 | 178篇 |
2019年 | 276篇 |
2018年 | 298篇 |
2017年 | 214篇 |
2016年 | 347篇 |
2015年 | 482篇 |
2014年 | 583篇 |
2013年 | 676篇 |
2012年 | 975篇 |
2011年 | 949篇 |
2010年 | 585篇 |
2009年 | 452篇 |
2008年 | 653篇 |
2007年 | 601篇 |
2006年 | 551篇 |
2005年 | 554篇 |
2004年 | 423篇 |
2003年 | 368篇 |
2002年 | 330篇 |
2001年 | 214篇 |
2000年 | 224篇 |
1999年 | 177篇 |
1998年 | 66篇 |
1997年 | 46篇 |
1996年 | 44篇 |
1995年 | 33篇 |
1994年 | 30篇 |
1993年 | 26篇 |
1992年 | 57篇 |
1991年 | 52篇 |
1990年 | 50篇 |
1989年 | 37篇 |
1988年 | 45篇 |
1987年 | 37篇 |
1986年 | 43篇 |
1985年 | 45篇 |
1984年 | 38篇 |
1983年 | 48篇 |
1981年 | 16篇 |
1980年 | 15篇 |
1979年 | 29篇 |
1978年 | 27篇 |
1977年 | 21篇 |
1976年 | 19篇 |
1975年 | 15篇 |
1974年 | 17篇 |
1973年 | 24篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
Won Myung Lee Jong Ho Moon Yun Nah Lee Il Sang Shin Tae Hoon Lee Jae Kook Yang Sang-Woo Cha Young Deok Cho Sang-Heum Park 《Gut and liver》2022,16(4):599
Background/AimsTreatment options for difficult bile duct stones are limited. Direct peroral cholangioscopy (POC)-guided lithotripsy may be an option. A newly developed multibending (MB) ultraslim endoscope has several structural features optimized for direct POC. We evaluated the utility of direct POC using an MB ultraslim endoscope for lithotripsy in patients with difficult bile duct stones.MethodsTwenty patients with difficult bile duct stones, in whom stone removal using conventional endoscopic methods, including mechanical lithotripsy, had failed were enrolled from March 2018 to August 2019. Direct POC-guided lithotripsy was performed by electrohydraulic lithotripsy or laser lithotripsy. The primary outcome was complete ductal clearance, defined as the retrieval of all bile duct stones after lithotripsy confirmed by balloon-occluded cholangiography and/or direct POC.ResultsThe technical success rate of direct POC was 100% (20/20), and the free-hand insertion rate was 95% (19/20). Direct POC-guided lithotripsy, attempted by electrohydraulic lithotripsy in nine patients (45%) and laser lithotripsy in 11 patients (55%), was successful in 95% (19/20) of the patients. Complete ductal clearance after direct POC-guided lithotripsy was achieved in 95% (19/20) of patients. Patients required a median of 2 (range, 1–3) endoscopic retrograde cholangiopancreatography sessions for complete stone removal. Adverse event was observed in one patient (5%) with hemobilia and was treated conservatively.ConclusionsDirect POC using an MB ultraslim endoscope was safe and effective for lithotripsy in patients with difficult bile duct stones. 相似文献
62.
63.
Rationale:Oblique lumbar interbody fusion (OLIF) is an effective and safe surgical technique widely used for treating spondylolisthesis; however, its use is controversial because of several associated complications, including endplate injury. We report a rare vertebral body fracture following OLIF in a patient with poor bone quality.Patient concerns:A 72-year-old male patient visited our clinic for 2 years with lower back pain, leg radiating pain, and intermittent neurogenic claudication.Diagnoses:Lumbar magnetic resonance imaging revealed L4-5 stenosis.Intervention:We performed OLIF with percutaneous pedicle screw fixation and L4 subtotal decompressive laminectomy. We resected the anterior longitudinal ligament partially for anterior column release and inserted a huge cage to maximize segmental lordosis. No complications during and after the operation were observed. Further, the radiating pain and back pain improved, and the patient was discharged. Two weeks after the operation, the patient visited the outpatient department complaining of sudden recurred pain, which occurred while going to the bathroom. Radiography and computed tomography revealed a split fracture of the L5 body and an anterior cage displacement. In revision of OLIF, we removed the dislocated cage and filled the bone cement between the anterior longitudinal ligament and empty disc space. Further, we performed posterior lumbar interbody fusion L4-5, and the screw was extended to S1.Outcomes:After the second surgery, back pain and radiating pain in the left leg improved, and he was discharged without complications.Lesson:In this case, owing to insufficient intervertebral space during L4-5 OLIF, a huge cage was used to achieve sufficient segmental lordosis after anterior column release, but a vertebral body coronal fracture occurred. In patients with poor bone quality and less flexibility, a huge cage and over-distraction could cause a vertebral fracture; hence, selecting an appropriate cage or considering a posterior approach is recommended. 相似文献
64.
Kakyeong Kim Yoonjung Yoonie Joo Gun Ahn HeeHwan Wang SeoYoon Moon Hyeonjin Kim WooYoung Ahn Jiook Cha 《Human brain mapping》2022,43(12):3857
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, = .011–.034; adjusted for covariates) and higher cognitive genome‐wide polygenic scores (GPSs) (p fdr < .001, < .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
65.
Joo Won Han Jihyun Park Jung Ha Kim Siti Aisyah Nurmaulia Entifar Ajeng Prameswati Anky Fitrian Wibowo Soyeon Kim Dong Chan Lim Jonghee Lee Myoung-Woon Moon Min-Seok Kim Yong Hyun Kim 《Materials》2022,15(14)
Conductive composite materials have attracted considerable interest of researchers for application in stretchable sensors for wearable health monitoring. In this study, highly stretchable and conductive composite films based on carboxymethyl cellulose (CMC)-poly (3,4-ethylenedioxythiopehe):poly (styrenesulfonate) (PEDOT:PSS) (CMC-PEDOT:PSS) were fabricated. The composite films achieved excellent electrical and mechanical properties by optimizing the lab-synthesized PEDOT:PSS, dimethyl sulfoxide, and glycerol content in the CMC matrix. The optimized composite film exhibited a small increase of only 1.25-fold in relative resistance under 100% strain. The CMC-PEDOT:PSS composite film exhibited outstanding mechanical properties under cyclic tape attachment/detachment, bending, and stretching/releasing tests. The small changes in the relative resistance of the films under mechanical deformation indicated excellent electrical contacts between the conductive PEDOT:PSS in the CMC matrix, and strong bonding strength between CMC and PEDOT:PSS. We fabricated highly stretchable and conformable on-skin sensors based on conductive and stretchable CMC-PEDOT:PSS composite films, which can sensitively monitor subtle bio-signals and human motions such as respiratory humidity, drinking water, speaking, skin touching, skin wrinkling, and finger bending. Because of the outstanding electrical properties of the films, the on-skin sensors can operate with a low power consumption of only a few microwatts. Our approach paves the way for the realization of low-power-consumption stretchable electronics using highly stretchable CMC-PEDOT:PSS composite films. 相似文献
66.
Jeong Min Yang Su bin Lee Ye ji Kim Douk young Chon Jong Youn Moon Jae Hyun Kim 《Medicine》2022,101(32)
This empirical study identifies the negative aspects of private health insurance (PHI) by analyzing the association between subjective health conditions, 2 weeks of outpatient care, chronic diseases, and hospitalizations for 1 year. We used frequency analysis, χ2 testing, an analysis of variance, and logistic and multiple logistic regression models to analyze the association between PHI and subjective health conditions, outpatient care, chronic disease status, and hospitalization. The PHI group had good subjective health but had more outpatient care for 2 weeks. There were few chronic diseases in the private insurance group, and there was no significant difference in hospitalizations for 1 year. Hospitalization may occur when essential medical care is required, regardless of health insurance type. This study confirmed that as the PHI lowers the burden of personal medical expenses, the PHI can lead to an increase in the medical resource expenditures on the outpatient medical service and higher public health costs. The government should work to redefine the role of private and national health insurance. Also, the effectiveness of PHI should be reevaluated so that it does not lead to indiscriminate use of medical services by minimizing the burden of private insurance. 相似文献
67.
Moon MK Kang DG Lee AS Yeom KB Kim JS Lee HS 《The American journal of Chinese medicine》2008,36(3):555-568
The present study was designed to investigate whether the aqueous extract of rhubarb (AR) could prevent the development of atherosclerosis through regulating vascular inflammatory processes in rats fed with an atherogenic diet. AR significantly reduced plasma low-density lipoprotein-cholesterol, and increased plasma high-density lipoprotein-cholesterol in rats fed with an atherogenic diet. AR inhibited vascular expressions of endothelin-1 (ET-1) and endothelin-converting enzyme (ECE) induced in rats with an atherogenic diet. On the other hand, AR augmented the vascular expression of endothelial nitric oxide synthase (ecNOS) and restored vascular nitric oxide (NO) production. Furthermore, AR suppressed the elevated expression of vascular nuclear factor-kappaB (NF-kappaB) p65 as well as adhesion molecules, including intracellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and E-selectin in rats fed with an atherogenic diet. Also, AR decreased endothelial expression of ICAM-1 and ET-1 in aorta. These results suggest that AR suppresses the development of atherosclerosis in the atherogenic-diet rat model through inhibiting vascular expressions of proinflammatory and adhesion molecules via the regulation of nitric oxide and endothelin system. 相似文献
68.
Kim KW Song KH Lee JM Kim KS Kim SI Moon SK Kang BS Kim DS Chung KH Chang YC Kim CH 《Journal of ethnopharmacology》2008,118(2):280-283
AIM OF THE STUDY: To elucidate the pharmacological activities of deer antler acupuncture and TGF61538;1 on the acute and chronic phases of rheumatoid arthritis diseases. MATERIALS AND METHODS: Polyarthritis rats were administered with TGF61538;1 and water extract of deer antler acupunture (DAA), prepared from the pilose antler of Cervus korean TEMMINCK var. mantchuricus Swinhoe. TGF61538; (0.1 to 2 61549;g/animal) and DAA (5-100 61549;g/kg animal) were initiated 1 day before an arthritogenic dose of streptococcal cell wall fragments to see the effects on the joint swelling and distortion during the acute phase and the chronic phase of the disease. Arthritic index suppression of rat arthritis model was examined by TGF61538; and DAA administrations. RESULTS: TGF61538;1 and DAA diminished the polyarthritis development in rats. TGF61538; and DAA eliminated the joint swelling and distortion observed during the acute phase and the chronic phase of the disease. The TGF61538; and DAA suppressed the arthritis progress when administration was begun after acute phase of arthritis. DISCUSSION: Consistent with the inhibition of inflammatory cell recruitment into the synovium, TGF61538;1 and DAA reversed the leukocytosis associated with the chronic phase of the arthritis, respectively. 相似文献
69.
OBJECTIVES: The purpose of our study is to provide reference values for the great vessels obtained from images of the three-vessel view of the fetal heart, with an emphasis on the size discrepancy of the great vessels. METHODS: From February 2003 to May 2003, the main pulmonary artery (MPA), ascending aorta (AA), and SVC were measured in well-dated, nonanomalous fetuses scanned at 14-38 weeks of gestation. RESULTS: The size of each great vessel had a significant positive relationship with advance in gestation (P < 0.001); MPA (mm) = -2.76 + 0.34 x GA, ascending aorta (AA) (mm) = -1.73 + 0.26 x GA - 1.18E - 05 x GA(3), and SVC (mm) = 0.33 + 0.01 x GA(2) - 4.12E - 05 x GA(3). The AA/MPA ratio was significantly decreased with advance in gestation, while the SVC/AA ratio was significantly increased; AA/MPA ratio = -1.24 - 0.03 x GA + 3.88E - 04 x GA(2); P < 0.001, SVC/AA ratio = 0.63 - 5.43E - 03 x GA + 1.96E - 04 x GA(2); P < 0.001. CONCLUSION: On the three-vessel view of the fetal heart, the interpretation of the size discrepancy of the great vessels needs to be adjusted according to fetal growth. 相似文献
70.
Silicon-based anodes can increase the energy density of Li-ion batteries (LIBs) owing to their large weights and volumetric capacities. However, repeated charging and discharging can rapidly deteriorate the electrochemical properties because of a large volume change in the electrode. In this study, a commercial Fe-Si powder was coated with Al2O3 layers of different thicknesses via atomic layer deposition (ALD) to prevent the volume expansion of Si and suppress the formation of crack-induced solid electrolyte interfaces. The Al2O3 content was controlled by adjusting the trimethyl aluminum exposure time, and higher Al2O3 contents significantly improved the electrochemical properties. In 300 cycles, the capacity retention rate of a pouch full-cell containing the fabricated anodes increased from 69.8% to 72.3% and 79.1% depending on the Al2O3 content. The powder characterization and coin and pouch cell cycle evaluation results confirmed the formation of an Al2O3 layer on the powder surface. Furthermore, the expansion rate observed during the charging/discharging of the pouch cell indicated that the deposited layer suppressed the powder expansion and improved the cell stability. Thus, the performance of an LIB containing Si-alloy anodes can be improved by coating an ALD-synthesized protective Al2O3 layer. 相似文献