全文获取类型
收费全文 | 6431篇 |
免费 | 385篇 |
国内免费 | 68篇 |
专业分类
耳鼻咽喉 | 64篇 |
儿科学 | 154篇 |
妇产科学 | 63篇 |
基础医学 | 871篇 |
口腔科学 | 74篇 |
临床医学 | 371篇 |
内科学 | 1770篇 |
皮肤病学 | 78篇 |
神经病学 | 430篇 |
特种医学 | 254篇 |
外国民族医学 | 1篇 |
外科学 | 1182篇 |
综合类 | 22篇 |
预防医学 | 173篇 |
眼科学 | 98篇 |
药学 | 370篇 |
中国医学 | 5篇 |
肿瘤学 | 904篇 |
出版年
2024年 | 5篇 |
2023年 | 49篇 |
2022年 | 126篇 |
2021年 | 213篇 |
2020年 | 124篇 |
2019年 | 155篇 |
2018年 | 220篇 |
2017年 | 165篇 |
2016年 | 210篇 |
2015年 | 212篇 |
2014年 | 267篇 |
2013年 | 302篇 |
2012年 | 496篇 |
2011年 | 472篇 |
2010年 | 296篇 |
2009年 | 243篇 |
2008年 | 379篇 |
2007年 | 329篇 |
2006年 | 348篇 |
2005年 | 357篇 |
2004年 | 326篇 |
2003年 | 340篇 |
2002年 | 329篇 |
2001年 | 90篇 |
2000年 | 72篇 |
1999年 | 82篇 |
1998年 | 89篇 |
1997年 | 78篇 |
1996年 | 58篇 |
1995年 | 54篇 |
1994年 | 36篇 |
1993年 | 38篇 |
1992年 | 53篇 |
1991年 | 43篇 |
1990年 | 29篇 |
1989年 | 20篇 |
1988年 | 21篇 |
1987年 | 30篇 |
1986年 | 19篇 |
1985年 | 14篇 |
1984年 | 18篇 |
1983年 | 12篇 |
1982年 | 15篇 |
1981年 | 12篇 |
1980年 | 10篇 |
1979年 | 6篇 |
1978年 | 4篇 |
1977年 | 4篇 |
1975年 | 3篇 |
1970年 | 2篇 |
排序方式: 共有6884条查询结果,搜索用时 31 毫秒
91.
Masaharu Nagata Jun Hata Yoichiro Hirakawa Naoko Mukai Daigo Yoshida Tomoyuki Ohara Hiro Kishimoto Hiroyuki Kawano Takanari Kitazono Yutaka Kiyohara Toshiharu Ninomiya 《Journal of epidemiology / Japan Epidemiological Association》2017,27(12):578-583
Background
Whether the intake of eicosapentaenoic acid (EPA) or arachidonic acid (AA) affects the risk of cancer remains unclear, and the association between the serum EPA:AA ratio and cancer risk has not been fully evaluated in general populations.Methods
A total of 3098 community-dwelling subjects aged ≥40 years were followed up for 9.6 years (2002–2012). The levels of the serum EPA:AA ratio were categorized into quartiles (<0.29, 0.29–0.41, 0.42–0.60, and >0.60). The risk estimates were computed using a Cox proportional hazards model. The same analyses were conducted for the serum docosahexaenoic acid to arachidonic acid (DHA:AA) ratio and individual fatty acid concentrations.Results
During the follow-up period, 121 subjects died of cancer. Age- and sex-adjusted cancer mortality increased with lower serum EPA:AA ratio levels (P trend<0.05). In the multivariable-adjusted analysis, the subjects in the first quartile of the serum EPA:AA ratio had a 1.93-fold (95% confidence interval, 1.15–3.22) greater risk of cancer death than those in the fourth quartile. Lower serum EPA concentrations were marginally associated with higher cancer mortality (P trend<0.11), but the serum DHA or AA concentrations and the serum DHA:AA ratio were not (all P trend>0.37). With regard to site-specific cancers, lower serum EPA:AA ratio was associated with a higher risk of death from liver cancer. However, no such associations were detected for deaths from other cancers.Conclusions
These findings suggest that decreased level of the serum EPA:AA ratio is a significant risk factor for cancer death in the general Japanese population. 相似文献92.
Jae Joon Kim Siyoung Ha Lina Kim Yutaro Kato Yan Wang Chihiro Okutani Haoyang Wang Chunya Wang Kenjiro Fukuda Sunghoon Lee Tomoyuki Yokota Oh Seok Kwon Takao Someya 《Proceedings of the National Academy of Sciences of the United States of America》2022,119(24)
The functional support and advancement of our body while preserving inherent naturalness is one of the ultimate goals of bioengineering. Skin protection against infectious pathogens is an application that requires common and long-term wear without discomfort or distortion of the skin functions. However, no antimicrobial method has been introduced to prevent cross-infection while preserving intrinsic skin conditions. Here, we propose an antimicrobial skin protection platform copper nanomesh, which prevents cross-infectionmorphology, temperature change rate, and skin humidity. Copper nanomesh exhibited an inactivation rate of 99.99% for Escherichia coli bacteria and influenza virus A within 1 and 10 min, respectively. The thin and porous nanomesh allows for conformal coating on the fingertips, without significant interference with the rate of skin temperature change and humidity. Efficient cross-infection prevention and thermal transfer of copper nanomesh were demonstrated using direct on-hand experiments.The functional support and advancement of our body while preserving the inherent naturalness is one of the ultimate goals of bioengineering (1–4). A functional layer is placed on the skin to complement the intrinsic biological and interactive functions (5, 6) and to add functions that do not yet exist (7–9). During use, the second skin layer should completely exploit its function and underlay skin functions without deforming the skin or interfering with the skin’s external interaction. Materials and structures need to be conformal and mechanically similar to the skin to minimize the distortion of natural sensations and movements. In addition, the air and heat transfer on the skin must be unimpeded to obtain a natural and comfortable wear fit (10).Body protection that requires common and long-term wear is an application in which both functionality and naturalness are important. As the outermost layer connecting our body to the environment, the skin is exposed to physical damage, hazardous chemicals, and infectious pathogens (11, 12). Therefore, we add a protective layer on the skin that blocks or filters out external contaminants. This entails the isolation and accumulation of biochemical compounds, which can lead to self-contamination and the subsequent cross-contamination/infection by interacting with other objects. In contrast to chemical contamination, which is not self-reproductive, the biological contamination of infectious microbes, such as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is a considerable issue to be addressed.By containing an antimicrobial material on the surface of the skin protective layer, cross-infection can be prevented in the long term. Unlike temporary rinsing or disinfection, the use of antibacterial or antiviral substances such as chemical or natural disinfectants and metal nanomaterials inhibits the growth of microorganisms on the surface (13–17). These materials are embedded in a complete covering polymer layer, such as gloves (18, 19), to isolate and protect both the inner and outer surfaces from the infection. To add breathability to the textile especially for the mask (13, 20, 21), many antibacterial fibers have been developed based on these materials. Moreover, various skin-attachable platforms with antimicrobial properties have been developed for convenient usage in daily lives. Antimicrobial nanofibers with conformal attachment to the skin have been developed for drug delivery, wound healing (22, 23), and electrophysiology (24, 25). In addition, stretchable and antibacterial hydrogels have been developed to allow more natural skin movement in wound-healing applications (26–28).However, there has been no practical skin protective solution to prevent cross-infection while preserving intrinsic skin conditions such as surface morphology, thermal transfer, and skin humidity. The thickening of the additional skin layer frequently results in a significant modification of the surface morphology, heat transfer, and the corresponding sensation. Thin layers have limited performance in terms of antimicrobial duration and speed. The skin coverage of polymer or hydrogel film blocks the transfer of air, moisture, and heat. In addition, the antimicrobial performance is focused on the skin side rather than the external side that affects cross-infection. Voids owing to the stiffness of the film or fiber and morphological differences compared to the skin further limit conformality, heat transfer, and water/air permeability (29).Here, we propose an antimicrobial skin protection platform copper nanomesh, which prevents cross-infection while minimizing modification of intrinsic skin properties such as interfacial morphology, temperature change rate, and skin humidity. The thin thickness and porous structure of the nanomesh allow conformal attachment to the fingertips, regardless of the mechanical and structural variations of the fingerprints, nails, and interfaces. To impart antimicrobial properties, copper, one of the most well-known antimicrobial (nano)materials (30–33), was coated with maintaining the nanomesh structure (copper nanomesh, from here onward). The measured inactivation rates of copper nanomesh against Escherichia coli bacteria and influenza virus A (H1N1) were 99.99% within 1 min and 10 min, respectively. It was found that the nanomesh structure contributed to the acceleration of bacterial inactivation compared to the copper film. Furthermore, it exhibited high biocompatibility with the skin cells and stable antibacterial performance even after long-term use (more than 6 h), including water immersion (more than 1 h).In addition, we investigated the naturalness of the copper nanomesh compared to that of the copper film and conventional gloves. As confirmed using the artificial skin and fingerprint recognition, the proposed copper nanomesh exhibited a higher conformability compared to that of the copper film. The copper nanomesh showed a high hydrophobicity to block external contaminants in solution while having high gas permeability and maintaining the skin humidity in a safe range. Additionally, the insertion of copper nanomesh did not affect the temperature change rate, which is important to maintain the sensation and comfort fit of the skin. Finally, the copper nanomesh was compared to the glove by wearing on our hands and interacting with various real-life objects. Using the proposed copper nanomesh, we successfully achieved an effective prevention of cross-infection and less-hindered thermal recognition of objects. 相似文献
93.
Daisuke Yabe Yuichiro Yamada Kohei Kaku Tomoyuki Nishida Toshihiro Sato Yutaka Seino 《Journal of diabetes investigation.》2022,13(7):1161
Aims/IntroductionMany East Asians with type 2 diabetes are elderly and have a low body mass index (BMI), especially in ''super‐aged'' populations, such as Japan. This post‐hoc analysis assessed once‐weekly semaglutide efficacy and safety in Japanese individuals with type 2 diabetes across baseline age and BMI subgroups.Materials and MethodsData were derived from the Semaglutide Unabated Sustainability in Treatment of Type 2 Diabetes (SUSTAIN) Japan monotherapy and SUSTAIN Japan oral antidiabetes drug (OAD) combination trials comparing once‐weekly semaglutide with sitagliptin or OADs, respectively. Participants were grouped by baseline age (<65 and ≥65 years) and/or BMI (<25 and ≥25 kg/m2). Reductions from baseline in glycosylated hemoglobin and bodyweight (efficacy), and adverse events (safety) were assessed.ResultsIn this analysis, participants from the SUSTAIN Japan monotherapy trial (n = 308; n per subgroup; range, 8–73) and SUSTAIN Japan OAD combination trial (n = 601; n per subgroup; range, 20–168) were included. Reductions in glycosylated hemoglobin and bodyweight were numerically greater with semaglutide versus comparators across all age and BMI subgroups. Reductions from baseline in glycosylated hemoglobin ranged from –1.7 to –2.1 with semaglutide 0.5 mg, –1.8 to –2.4 with semaglutide 1.0 mg and –0.6 to –1.0 with comparators. Corresponding ranges for bodyweight (kg) were –1.0 to –2.5, –2.4 to –4.3 and 1.0 to –1.0 kg, respectively. The safety profile of semaglutide was broadly similar across BMI and age subgroups.ConclusionsIn this post‐hoc analysis with modest subgroup numbers, once‐weekly semaglutide appeared consistently more efficacious versus comparators across age and BMI subgroups in Japanese patients, with a similar safety profile. 相似文献
94.
Takao Obara MD Yoshihide Fujimoto Reiko Tanaka Yukio Ito Takaya Kodama Tohru Yashiro Yoshiharu Kanaji Tomoyuki Yamashita Atsushi Fukuuchi 《Surgery today》1990,20(4):481-486
Although hyperfunctioning mediastinal parathyroid lesions that require median sternotomy or thoracotomy for removal are occasionally
present, the majority are located in the anterior mediastinum closely associated with the thymus. Only eight cases of ectopic
hyperfunctioning parathyroid tumors in the middle mediastinum have been reported. We experienced two cases of either persistent
or recurrent hyperparathyroidism in which abnormal parathyroid tissue was located in the aorticopulmonary window. One of the
patients had a parathyroid adenoma and the other had metastatic lesions of parathyroid carcinoma. In both cases, thallium
scanning proved useful in identifying the lesions while computed tomography scan was effective for mediastinal three-dimensional
localization. In one case, single photon emission computed tomography imaging with thallium proved beneficial for both identification
and localization of the middle mediastinal lesion. The surgical approach used in both cases was different. In one case, left
thoracotomy was performed, after which the ligamentum arteriosum was divided, and an adenoma anterior to the left main bronchus
and posterior to the left pulmonary artery removed. In the other case, two metastatic tumors of parathyroid carcinoma anterior
to the right main bronchus and posterior to the right pulmonary artery were resected through a median sternotomy and opening
of the pericardium. 相似文献
95.
Suzuki O Kondo S Hirano S Tanaka E Kato K Tsuchikawa T Yano T Okamura K Shichinohe T 《Surgery today》2012,42(5):509-513
Laparoscopic pancreatic surgery is evolving rapidly; however, the surgical treatment of periampullary tumors is still fraught
with challenges, such as technical difficulty and the appropriateness of oncologic treatment for these patients. We describe
how we performed laparoscopic pancreaticoduodenectomy (LPD) combined with minilaparotomy successfully in six consecutive patients.
This procedure consisted of two surgical phases: safe laparoscopic surgery, including the Kocher maneuver, tunneling behind
the pancreatic neck, and dissecting along the uncinate process with magnified vision; and a secure open approach with complete
skeletonization of the hepatoduodenal ligament and alimentary tract reconstruction, performed similarly to conventional pancreaticoduodenectomy,
under direct visualization through the minilaparotomy. By performing this procedure, we combined a safe and secure minilaparotomy
approach under direct vision with a less invasive laparoscopic approach providing a magnified image. Our experience demonstrates
that LPD combined with minilaparotomy is technically feasible for selected patients with periampullary tumors. 相似文献
96.
97.
ABSTRACT: INTRODUCTION: The Endotoxin Activity Assay (EAA) is a useful test to risk stratify patients with severe sepsis and assess for Gram negative infection. However, the significance of intermediate levels of EAA (0.4-0.59) at the bedside has not been well elucidated. The purpose of this study was to interpret intermediate EAA levels in clinical practice. METHODS: This retrospective observational study included all adult patients with suspected sepsis admitted to our medico-surgical intensive care unit (ICU) in whom EAA was measured from July 2008 to September 2011. Data collected included EAA, white blood cell (WBC) count and differential, C-reactive protein (CRP), procalcitonin (PCT) and bacterial cultures. Data were analyzed by comparative statistics. RESULTS: Two hundred and ten patients were studied. Ninety two (43%) patients had culture documented gram negative infection. Patients with Gram-negative organisms in cultures had significantly higher EAA levels (0.47, IQR 0.27) than those without any Gram-negative organisms in cultures (0.34, IQR 0.22) (p < 0.0001). For patients with intermediate EAA levels (0.40 to 0.59), PCT levels and presence of left shift of WBC significantly differed between patients with Gram negative organisms in their blood or other cultures and those who had no organisms in any of the cultures (4.9 versus 1.7 ng/mL, p < 0.05; 57.9 versus 18.9%, p < 0.0004, respectively). CONCLUSIONS: We confirm that high levels of EAA in our cohort of patients with suspected sepsis are strongly associated with gram negative infection. In those patients with intermediate elevation in EAA levels, use of PCT and WBC differential can provide additional diagnostic value to clinicians at the bedside. 相似文献
98.
99.
100.
Yosuke Ando Takahiro Hayashi Kaori Ito Eri Suzuki Naoyuki Mine Ayumi Miyamoto Miyuki Oya Hidezo Matsuda Ami Isaji Toru Nakanishi Kazuyoshi Imaizumi Tomoyuki Shibata Tatsuyoshi Okada Kazuo Sakurai Kensei Naito Ichiro Uyama Kenji Kawada Hiroshi Takahashi Shigeki Yamada 《Supportive care in cancer》2016,24(2):871-878