全文获取类型
收费全文 | 64989篇 |
免费 | 3724篇 |
国内免费 | 670篇 |
专业分类
耳鼻咽喉 | 1131篇 |
儿科学 | 848篇 |
妇产科学 | 948篇 |
基础医学 | 11062篇 |
口腔科学 | 1586篇 |
临床医学 | 5550篇 |
内科学 | 12175篇 |
皮肤病学 | 2205篇 |
神经病学 | 4765篇 |
特种医学 | 3500篇 |
外科学 | 8657篇 |
综合类 | 263篇 |
现状与发展 | 1篇 |
一般理论 | 18篇 |
预防医学 | 3408篇 |
眼科学 | 1456篇 |
药学 | 5701篇 |
中国医学 | 740篇 |
肿瘤学 | 5369篇 |
出版年
2023年 | 501篇 |
2022年 | 1470篇 |
2021年 | 2337篇 |
2020年 | 1127篇 |
2019年 | 1503篇 |
2018年 | 1997篇 |
2017年 | 1487篇 |
2016年 | 2095篇 |
2015年 | 2972篇 |
2014年 | 3556篇 |
2013年 | 4037篇 |
2012年 | 6092篇 |
2011年 | 5586篇 |
2010年 | 3256篇 |
2009年 | 2738篇 |
2008年 | 3958篇 |
2007年 | 3583篇 |
2006年 | 3153篇 |
2005年 | 2816篇 |
2004年 | 2418篇 |
2003年 | 2011篇 |
2002年 | 1741篇 |
2001年 | 1473篇 |
2000年 | 1352篇 |
1999年 | 1003篇 |
1998年 | 400篇 |
1997年 | 280篇 |
1996年 | 246篇 |
1995年 | 209篇 |
1994年 | 167篇 |
1993年 | 155篇 |
1992年 | 377篇 |
1991年 | 364篇 |
1990年 | 315篇 |
1989年 | 284篇 |
1988年 | 282篇 |
1987年 | 273篇 |
1986年 | 211篇 |
1985年 | 182篇 |
1984年 | 137篇 |
1983年 | 128篇 |
1982年 | 70篇 |
1981年 | 63篇 |
1979年 | 98篇 |
1978年 | 75篇 |
1975年 | 59篇 |
1974年 | 69篇 |
1973年 | 54篇 |
1972年 | 54篇 |
1970年 | 52篇 |
排序方式: 共有10000条查询结果,搜索用时 7 毫秒
991.
992.
Beom Hee Lee Yoo-Mi Kim Sun Hee Heo Gu-Hwan Kim In-Hee Choi Byong Sop Lee Ellen Ai-Rhan Kim Ki-Soo Kim Won Kyoung Jhang Seong Jong Park Han-Wook Yoo 《Molecular genetics and metabolism》2013,108(1):18-24
Type 1 citrullinemia (CTLN1) often presents as a hyperammonemic encephalopathy in the neonatal period, but it can also develop in the late-infantile period and in adults. In addition, some patients can be identified in the presymptomatic period by neonatal or family member screening. In this study, twenty Korean patients with CTLN1 (19 families) were examined; fourteen patients with neonatal-onset, three with late-onset, and three that were identified presymptomatically. The 13 patients with hyperammonemic encephalopathy received continuous venovenous hemofiltration (CVVH) or peritoneal dialysis (PD). Although the hyperammonemia was relieved more effectively in the six patients on CVVH than the seven on PD, most of these patients suffered from severe neurologic deficits. Recurrent hyperammonemic episodes (7 pts, 35%), recurrent and reversible acute hepatic dysfunction (5 pts, 25%), and focal cerebral infarction (2 pts, 10%) were noted. The neonates with hyperammonemic encephalopathy had extensive brain injuries at the onset of hyperammonemia, followed by encephalomalacia and brain atrophy at quite an early age. Genetic testing for the ASS1 gene revealed a different mutation spectrum from those of other ethnicities; Three common mutations, c.421-2A > G (37.8%), c.1128-6_1188dup67 (18.9%), and p.Gly324Ser (16.2%), accounted for 73% of the mutations. The poor outcome was expected in patients with the peak ammonia level at onset over 600 μmol/L, whose proportion was higher in the neonatal presentation group than in the presymptomatic/late presentation group. Our findings add to the current understanding of the ethnic diversity of CTLN1 from both clinical and genetic perspectives. 相似文献
993.
Jihyoun Lee Ji Sung Lee Jong Eun Lee Zisun Kim Sun Wook Han Sung Mo Hur Young Jin Choi Sungmin Park 《JOURNAL OF BREAST CANCER》2021,24(3):280
PurposeRaloxifene is a selective estrogen receptor modulator (SERM), and raloxifene treatment for osteoporosis is reimbursable under the Korean National Health Insurance. Evidence suggests that SERMs use reduces the risk of breast cancer in Asian population. Herein, we retrospectively investigated the protective effect of raloxifene on breast cancer rates in Korean population.MethodsUsing the Health Insurance Review and Assessment Service database, we selected women with osteoporosis aged 50 years and above. Patients treated for at least 2 years with raloxifene were assigned to the user group, whereas the remaining patients were assigned to the non-user group. The effect on breast cancer risk was assessed using the Cox proportional-hazards model with a time-dependent covariate to adjust for immortal time bias.ResultsA total of 322,870 women who were registered between 2010 and 2011 were included. The user group comprised 0.7% (n = 2,307) of the total population. The mean age was 65.7 ± 8.0 years and 67.2 ± 8.6 years in the user and non-user groups, respectively (p < 0.001). There was no difference in the previous use of estrogen replacement between the 2 groups (p = 0.087). The incidence of breast cancer per 1,000 person-years was 0.49 (n = 8) and 0.68 (n = 1,714) in the user and non-user groups, respectively (hazard ratio [HR], 0.63, 95% confidence interval [CI], 0.32–1.27). HR decreased with increase in the treatment duration, but this change was not statistically significant (HR, 1.00, 95% CI, 0.32–3.11 in 2–3 years; HR, 0.63, 95% CI, 0.20–1.94 in 3–4 years; and HR, 0.41, 95% CI, 0.10–1.65 in 4–5 years).ConclusionLong-term treatment with raloxifene in women with osteoporosis was not significantly associated with a reduction in breast cancer rates. However, further investigation is required for a conclusive proof. 相似文献
994.
Introduction. Accurately identifying gaze direction is an important component of successful social interaction. Preliminary research indicates that schizophrenia patients have deficits in gaze perception, but the nature of this deficit is still unclear. The current study investigates whether nonspecific perceptual abnormalities could explain gaze perception deficits and whether schizophrenia patients show a direct gaze bias in their judgement. Methods. Fifteen chronic schizophrenia patients and nineteen normal control participants made a direct gaze judgement for eyes in a face, and a centre judgement for a geometric shape in a scrambled face. Results. The data show that schizophrenia patients are as accurate as healthy control subjects at identifying direct gaze when it occurs but they are more likely to misinterpret averted gaze as directed at them. The pattern of results indicates that this tendency to endorse direct gaze is not a consequence of a perceptual deficit in judging angular displacement. Conclusions. Schizophrenia patients have a self-referential bias in judging the direction of gaze that could lead to the misinterpretation of another person's intentions during the course of social interaction. 相似文献
995.
Sung-Hyun Jo Won-Suk Song Han-Gyu Park Jae-Seung Lee Hyo-Jin Jeon Yeon-Hee Lee Wooseong Kim Hwang-Soo Joo Yung-Hun Yang Jae-Seok Kim Yun-Gon Kim 《RSC advances》2020,10(46):27864
As demands for new antibiotics and strategies to control methicillin-resistant Staphylococcus aureus (MRSA) increase, there have been efforts to obtain more accurate and abundant information about the mechanism of the bacterial responses to antibiotics. However, most of the previous studies have investigated responses to antibiotics without considering the genetic differences between MRSA and methicillin-susceptible S. aureus (MSSA). Here, we initially applied a multi-omics approach into the clinical isolates (i.e., S. aureus WKZ-1 (MSSA) and S. aureus WKZ-2 (MRSA)) that are isogenic except for the mobile genetic element called staphylococcal cassette chromosome mec (SCCmec) type IV to explore the response to β-lactam antibiotics (oxacillin). First, the isogenic pair showed a similar metabolism without oxacillin treatment. The quantitative proteomics demonstrated that proteins involved in peptidoglycan biosynthesis (MurZ, PBP2, SgtB, PrsA), two-component systems (VrsSR, WalR, SaeSR, AgrA), oxidative stress (MsrA1, MsrB), and stringent response (RelQ) were differentially regulated after the oxacillin treatment of the isogenic isolates. In addition, targeted metabolic profiling showed that metabolites belonging to the building blocks (lysine, glutamine, acetyl-CoA, UTP) of peptidoglycan biosynthesis machinery were specifically decreased in the oxacillin-treated MRSA. These results indicate that the difference in metabolism of this isogenic pair with oxacillin treatment could be caused only by SCCmec type IV. Understanding and investigating the antibiotic response at the molecular level can, therefore, provide insight into drug resistance mechanisms and new opportunities for antibiotics development.We introduce clinical isogenic strain isolates and a multi-OMICS approach to observe a response to oxacillin of methicillin- susceptible/-resistant Staphylococcus aureus. 相似文献
996.
Woo Sik Yoo Hyung Soo Han Jung Gon Kim Kitaek Kang Hyo-Sung Jeon Jin-Young Moon Hyeonmi Park 《RSC advances》2020,10(54):32946
There has been a strong and urgent demand to diagnose community transmission-driven coronavirus disease 2019 (COVID-19) after it crossed borders. A large number of rapid and accurate tests and diagnoses are required at drive-through test stations, community clinics and hospitals. Isothermal amplification technology, such as loop-mediated isothermal amplification (LAMP) and recombinase polymerase amplification (RPA), provides excellent alternatives for resource limited test environments. LAMP has been shown to be comparable with polymerase chain reaction (PCR) and can be performed in less than 30 min by non-laboratory staff without ribonucleic acid (RNA) extractions commonly associated with PCR. LAMP tests on assays with SARS-CoV-2 and other pathogenic microorganisms, such as Dengue, Malaria, and Influenza viruses and Helicobacter pylori show color changes allowing test results to be interpreted by the color change of the assays. However, visual inspection of a large number of assays is prone to human error and manual record keeping makes test result tracking for an epidemiologic investigation very difficult and inefficient. The epidemiologic investigation is an essential part of the fight against community transmission-driven viruses. We have developed a very accurate and reliable, human error free, tablet PC-based portable device for colorimetric determination of assays including SARS-CoV-2 and other pathogenic microorganisms.There has been a strong and urgent demand to diagnose community transmission-driven coronavirus disease 2019 (COVID-19) after it crossed borders. Tablet PC-based portable device for colorimetric determination and 3D printed sample holders. 相似文献
997.
This study proposes new optical roughness parameters that can be objectively quantified using image processing techniques, and presents an analysis of how these parameters are correlated with the degree of superhydrophobicity. To this end, photolithography and dry etching processes were used to form regular square pillars with different heights and spacings with a length of tens of micro-meters on silicon wafers. Optical roughness parameters of the specimens were obtained using image processing, and surface wettability was characterized using static contact angle and sliding angle measurements for water droplets of volume VD = 3.5 μl or 12 μl. As a result, seven optical roughness parameters were derived to describe the surface roughness topography in a multi-faceted way. Between the Cassie–Baxter state and the Wenzel state, two distinct wetting states intermediate state I, and intermediate state II were observed. Multiple linear regression of optical roughness parameters and superhydrophobicity demonstrated that in the stable Cassie–Baxter state, the contact angle can be increased or sliding angle decreased more effectively by adjusting the spacing between pillars than by just tuning the solid area fraction. However, in the metastable state where the Cassie–Baxter state can be changed to intermediate state I and vice versa by adjusting VD or surface geometry, reducing the solid area fraction is a priority to ensure a stable Cassie–Baxter state. Horizontal-perspective roughness parameters had a great effect on dynamic wettability in the Cassie–Baxter state. The results confirmed that the proposed optical roughness parameters may be useful for quantitative analysis of the complex effects of roughness on superhydrophobic surfaces.This study proposes new optical roughness parameters that can be objectively quantified using image processing techniques, and presents an analysis of how these parameters are correlated with the degree of superhydrophobicity. 相似文献
998.
Jong-Moon Chae Jae Hyun Park Kiyoshi Tai Kyosuke Mizutani Satoshi Uzuka Wataru Miyashita Hye Young Seo 《The Angle orthodontist》2020,90(2):224
Objectives:To evaluate the condyle-fossa relationship in adolescents with various skeletal patterns using cone-beam computed tomography (CBCT).Materials and Methods:CBCT images obtained in 120 adolescent patients were used for this study. The patients were divided into 3 groups according to 3 criteria: (1) age (early, middle, and late adolescence); (2) facial height ratio or Jarabak quotient (hyperdivergent, normodivergent, and hypodivergent); and (3) ANB classification (Class I, Class II, and Class III). Temporomandibular joint space (TMJS: AS, anterior space; SS, superior space; PS, posterior space; MS, medial space; LS, lateral space), width and depth of the condyle (MLT, mediolateral thickness; APT, anteroposterior thickness), articular slope (ArS) and vertical height of the fossa (VHF) were measured and compared using CBCT.Results:Differences in condyle-fossa relationships were not significantly different between male and female adolescents, but were significantly different (P < .05) between left and right sides. The mean values showed no statistical differences according to age and skeletal pattern. Most measurements in the sagittal view showed that SS was the greatest, and the mean ratio of AS to SS to PS was 1.00 to 1.27 to 1.19, respectively. The mean values of coronal MS and LS were not significantly different.Conclusions:There were almost no statistical differences in the TMJS in adolescents across various factors except between left and right sides. 相似文献
999.
Digital workflow expedites the procedure of retrofitting a surveyed crown against an existing removable partial denture (RPD). This article describes a simple and straightforward technique of digital workflow where an existing RPD is scanned as an antagonist to design the rest seat, guide plane, and height of contour of a surveyed crown. 相似文献
1000.