全文获取类型
收费全文 | 1316篇 |
免费 | 90篇 |
国内免费 | 7篇 |
专业分类
耳鼻咽喉 | 21篇 |
儿科学 | 33篇 |
妇产科学 | 34篇 |
基础医学 | 160篇 |
口腔科学 | 33篇 |
临床医学 | 212篇 |
内科学 | 279篇 |
皮肤病学 | 22篇 |
神经病学 | 61篇 |
特种医学 | 49篇 |
外科学 | 151篇 |
综合类 | 14篇 |
预防医学 | 131篇 |
眼科学 | 7篇 |
药学 | 85篇 |
中国医学 | 5篇 |
肿瘤学 | 116篇 |
出版年
2023年 | 17篇 |
2022年 | 34篇 |
2021年 | 79篇 |
2020年 | 39篇 |
2019年 | 59篇 |
2018年 | 40篇 |
2017年 | 27篇 |
2016年 | 32篇 |
2015年 | 36篇 |
2014年 | 39篇 |
2013年 | 49篇 |
2012年 | 71篇 |
2011年 | 93篇 |
2010年 | 39篇 |
2009年 | 47篇 |
2008年 | 63篇 |
2007年 | 77篇 |
2006年 | 51篇 |
2005年 | 48篇 |
2004年 | 52篇 |
2003年 | 48篇 |
2002年 | 40篇 |
2001年 | 28篇 |
2000年 | 23篇 |
1999年 | 15篇 |
1998年 | 18篇 |
1997年 | 16篇 |
1996年 | 20篇 |
1995年 | 8篇 |
1994年 | 13篇 |
1993年 | 7篇 |
1992年 | 12篇 |
1991年 | 17篇 |
1990年 | 29篇 |
1989年 | 21篇 |
1988年 | 18篇 |
1987年 | 11篇 |
1986年 | 13篇 |
1985年 | 6篇 |
1984年 | 10篇 |
1983年 | 8篇 |
1982年 | 4篇 |
1981年 | 5篇 |
1980年 | 6篇 |
1979年 | 3篇 |
1976年 | 3篇 |
1974年 | 2篇 |
1973年 | 2篇 |
1968年 | 2篇 |
1966年 | 3篇 |
排序方式: 共有1413条查询结果,搜索用时 15 毫秒
71.
72.
Anh Tuan Tran Duy Ton Mai Nguyen Thi Huyen Viet Ph
ng o Dinh Tho Phung Quang Tho Pham 《Radiology Case Reports》2022,17(2):298
Hemorrhagic stroke due to ruptured brain arteriovenous malformations (AVMs) is a common cause in young stroke patients. When the ruptured AVMs are in deep location, the choice of endovascular intervention with the arterial approach to AVM embolization is routine but in many cases, it is not feasible due to the inability to access because of the small and tortuous arterial branch, however, the intravenous approach also results in high complete obliteration rates but also carries a higher risk of stroke than the intra-arterial route. We describe a 36-year-old female patient diagnosed with intracranial and intraventricular hemorrhage who underwent complete transvenous embolization of the ruptured AVMs, and achieved near-complete clinical recovery after 1 month with the modified Rankin scale 1. 相似文献
73.
Ho Xuan Tuan Nguyen Duy Hung Nguyen Dinh Minh Nguyen-Thi Van Anh Nguyen Ha Vi Ngo Quang Duy Nguyen Minh Duc Tran Cong Hoan 《Radiology Case Reports》2022,17(3):685
Gliosarcoma (GS) is an uncommon central nervous system tumor with several characteristics of a malignant neoplasm and poor prognosis. The majority of GS reports describe a predilection for the cerebral hemispheres, and cases of intraventricular GS are extremely rare, with only a few reported. In addition, intraventricular GS has not been associated with any unique radiographic or clinical features, which can result in misdiagnosis as other intraventricular tumor types. In this report, we present the case of a 32-year-old woman with GS in the trigone of the lateral ventricle and provide a retrospective review of similar, previously reported cases. 相似文献
74.
Alpinia Roxb. is the largest genus of the Zingiberaceae family. A large number of Alpinia species has been used as food and traditional medicines. Alpinia essential oils have been studied for their chemical profiles, in which 1,8-cineole, β-pinene, α-pinene, β-myrcene, camphor, γ-terpinene, p-cymene, geraniol, α-fenchyl acetate, ocimene, methyl cinnamate, and β-caryophyllene have been found to be the major compounds. Essential oils isolated from Alpinia plants have been reported to have antimicrobial, cytotoxic, antioxidant, anti-inflammatory, anti-asthmatic, tyrosinase inhibitory, insecticidal, and larvicidal activities and slimming aromatherapy. In this review, the comprehensive information regarding the volatile components of various Alpinia plants, the bioactivities of Alpinia essential oils and their major compounds are provided. Alpinia Roxb. is the largest genus of the Zingiberaceae family. 相似文献
75.
Thi Le Anh Nguyen Thi Hoai Nam Doan Dinh Hieu Truong Nguyen Thi Ai Nhung Duong Tuan Quang Dorra Khiri Sonia Taamalli Florent Louis Abderrahman El Bakali Duy Quang Dao 《RSC advances》2021,11(35):21433
Antioxidant and UV absorption activities of three aaptamine derivatives including piperidine[3,2-b]demethyl(oxy)aaptamine (C1), 9-amino-2-ethoxy-8-methoxy-3H-benzo[de][1,6]naphthyridine-3-one (C2), and 2-(sec-butyl)-7,8-dimethoxybenzo[de]imidazo[4,5,1-ij][1,6]-naphthyridin-10(9H)-one (C3) were theoretically studied by density functional theory (DFT). Direct antioxidant activities of C1–C3 were firstly evaluated via their intrinsic thermochemical properties and the radical scavenging activity of the potential antioxidants with the HOO˙/HO˙ radicals via four mechanisms, including: hydrogen atom transfer (HAT), single electron transfer (SET), proton loss (PL) and radical adduct formation (RAF). Kinetic calculation reveals that HOO˙ scavenging in water occurs via HAT mechanism with C1 (kapp, 7.13 × 106 M−1 s−1) while RAF is more dominant with C2 (kapp, 1.40 × 105 M−1 s−1) and C3 (kapp, 2.90 × 105 M−1 s−1). Antioxidant activity of aaptamine derivatives can be classified as C1 > C3 > C2. Indirect antioxidant properties based on Cu(i) and Cu(ii) ions chelating activity were also investigated in aqueous phase. All three studied compounds show spontaneous and favorable Cu(i) ion chelating activity with ΔG0 being −15.4, −13.7, and −15.7 kcal mol−1, whereas ΔG0 for Cu(ii) chelation are −10.4, −10.8, and −2.2 kcal mol−1 for C1, C2 and C3, respectively. In addition, all compounds show UVA and UVB absorption; in which the excitations are determined mostly as π–π* transition. Overall, the results suggest the potential applications of the aaptamines in pharmaceutics and cosmetics, i.e. as a sunscreen and antioxidant ingredient.Antioxidant and UV absorption activities of three aaptamine derivatives were theoretically studied by density functional theory (DFT) and time-dependent density functional theory (TD-DFT). 相似文献
76.
Nguyen Tuan Anh Ngo Xuan Dinh Tuyet Nhung Pham Le Khanh Vinh Le Minh Tung Anh-Tuan Le 《RSC advances》2021,11(49):30544
The rational design of nanomaterials for electrochemical nanosensors from the perspective of structure–property–performance relationships is a key factor in improving the analytical performance toward residual antibiotics in food. We have investigated the effects of the crystalline phase and copper loading amount on the detection performance of Cu–MoS2 nanocomposite-based electrochemical sensors for the antibiotic chloramphenicol (CAP). The phase composition and copper loading amount on the MoS2 nanosheets can be controlled using a facile electrochemical method. Cu and Cu2O nanoparticle-based electrochemical sensors showed a higher CAP electrochemical sensing performance as compared to CuO nanoparticles due to their higher electrocatalytic activity and conductivity. Moreover, the design of Cu–MoS2 nanocomposites with appropriate copper loading amounts could significantly improve their electrochemical responses for CAP. Under optimized conditions, Cu–MoS2 nanocomposite-based electrochemical nanosensor showed a remarkable sensing performance for CAP with an electrochemical sensitivity of 1.74 μA μM−1 cm−2 and a detection limit of 0.19 μM in the detection range from 0.5–50 μM. These findings provide deeper insight into the effects of nanoelectrode designs on the analytical performance of electrochemical nanosensors.In this work, we clarify the roles of phase composition and copper loading amount on the CAP sensing performance of Cu–MoS2 nanocomposite-based electrochemical nanosensors. 相似文献
77.
In this study, Mn2O3/MIL-100(Fe) composite was successfully synthesized by the hydrothermal method and applied for photocatalytic removal of rhodamine B (RhB) in water. The physical and chemical properties of the synthesized materials were characterized by XRD, FTIR, SEM, UV-visible, and BET analyses. Experimental results showed a great enhancement in the photocatalytic ability of the Mn2O3/MIL-100(Fe) composite as compared to individual Mn2O3 or MIL-100(Fe) under visible light and persulfate activation. The affecting factors such as pH, photocatalyst dose, RhB concentration, and Na2S2O8 concentration were investigated to find out the best conditions for efficient photocatalysis. By conducting a radical quenching test, all radicals of HO˙, SO4˙−, 1O2, and O2˙− were found to be important in photocatalytic decomposition. The mechanism was proposed for the enhancement of photocatalytic RhB removal via band potential calculation, charge separation, surface redox reaction, and key reactive oxidation species. With its durability, reusability, and high efficiency, the Mn2O3/MIL-100(Fe) composite emerges as a potential photocatalyst working under visible light for application in wastewater treatment.Effective charge transfer enhances the persulfate activation of Mn2O3/MIL-100(Fe) for photocatalytic removal of RhB under LED-generated visible light. 相似文献
78.
The breathing patterns of identical twins 总被引:3,自引:0,他引:3
The resting breathing patterns of healthy adult identical twins were compared to see if there was any possible genetic component in the determination of this pattern. From breath-by-breath analysis of airflow, measured with a pneumotachometer (9 pairs of twins), the pattern of breathing was quantified in terms of individual respiratory variables; inspiratory time (TI), expiratory time (TE), total breath duration (TTOT), VT/TI, TI/TTOT, and by taking TI, TE and VT all together (TRIAD). Also, the airflow shape was quantified by harmonic analysis (ASTER). A second study was performed under more strictly defined conditions of rest and where the respiratory variables were estimated with respiratory inductance plethysmography to eliminate the possible effect of a facemask (5 pairs of twins). In each study, for each variable, the differences within twin-pairs were compared to the differences within random-pairs from the same subject population. In both studies, there were highly significant similarities within twin-pairs in the pattern of breathing, being best demonstrated when the entire 'shape' of the pneumotachogram (ASTER) or the spirogram (TRIAD) was considered. 相似文献
79.
G Benchetrit S A Shea T P Dinh S Bodocco P Baconnier A Guz 《Respiration physiology》1989,75(2):199-209
Sixteen healthy adult subjects underwent two studies separated by 4-5 years to test whether their resting pattern of breathing was reproducible over time. From breath-by-breath analysis of airflow, measured with a pneumotachometer, the pattern of breathing was quantified in terms of individual respiratory variables; inspiratory time (TI), expiratory time (TE), total breath duration (TTOT), tidal volume (VT), VT/TI, TI/TTOT, and by taking TI, TE and VT all together (TRIAD). Also, the shape of the entire airflow profile was quantified by harmonic analysis (ASTER). A statistical analysis was designed to compare differences between the 1st and the 2nd recording within individuals with those differences observed between random pairs of recordings from the two studies in the same 16 individuals. It was found that all variables were significantly more similar within-individuals than between-individuals; this is best demonstrated when considering the ASTER and/or the TRIAD. It was concluded that the individuality of breathing pattern is maintained over a long period despite changes in smoking habit, weight, mild respiratory diseases, and other changes which occurred between the two studies in our subjects. 相似文献
80.
Vincent P. Diego Bernadette W. Luu Marco Hofmann Long V. Dinh Marcio Almeida Jerry S. Powell Raja Rajalingam Juan M. Peralta Satish Kumar Joanne E. Curran Zuben E. Sauna Roberta Kellerman Yara Park Nigel S. Key Miguel A. Escobar Huy Huynh Anne M. Verhagen Sarah Williams‐Blangero Paul V. Lehmann Eugene Maraskovsky John Blangero Tom E. Howard 《Journal of thrombosis and haemostasis》2020,18(1):201-216