全文获取类型
收费全文 | 160篇 |
免费 | 9篇 |
专业分类
化学 | 115篇 |
晶体学 | 8篇 |
力学 | 5篇 |
数学 | 6篇 |
物理学 | 35篇 |
出版年
2024年 | 1篇 |
2022年 | 7篇 |
2021年 | 11篇 |
2020年 | 8篇 |
2019年 | 4篇 |
2018年 | 6篇 |
2017年 | 3篇 |
2016年 | 7篇 |
2015年 | 6篇 |
2014年 | 7篇 |
2013年 | 7篇 |
2012年 | 15篇 |
2011年 | 14篇 |
2010年 | 6篇 |
2009年 | 10篇 |
2008年 | 9篇 |
2007年 | 5篇 |
2006年 | 6篇 |
2005年 | 7篇 |
2004年 | 4篇 |
2003年 | 2篇 |
2002年 | 2篇 |
2000年 | 3篇 |
1999年 | 2篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1993年 | 3篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1986年 | 1篇 |
1981年 | 2篇 |
1980年 | 1篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1965年 | 1篇 |
1964年 | 1篇 |
排序方式: 共有169条查询结果,搜索用时 34 毫秒
101.
Mira Syahfriena Amir Rawa Nurul Amira Nurul Azman Suriani Mohamad Toshihiko Nogawa Habibah A. Wahab 《Molecules (Basel, Switzerland)》2022,27(9)
Macaranga tanarius (MT) and Syzygium jambos (SJ) are pharmacologically reported to have anti-oxidant, anti-inflammatory, and anti-diabetic effects, and can be neuroprotective agents. Our previous work revealed that MT and SJ exhibited 76.32% and 93.81% inhibition against acetylcholinesterase (AChE) at 50 μg/mL final concentration in their ethyl acetate and hexane fractions, respectively. This study was aimed to investigate the bioactive constituents of MT and SJ and their molecular mechanism toward AChE inhibition. Bioassay-guided isolation afforded prenylflavonoids 1–3 from MT and anacardic acid derivatives 4 and 5 from SJ that were confirmed by NMR and MS data. Compound 5 exerted the strongest anti-AChE potential (IC50: 0.54 μM), followed by 1, 4, 3, and 2 (IC50: 1.0, 2.4, 6.8, and 33 μM, respectively). In silico molecular docking revealed 5 formed stronger molecular interactions including three H-bonds than its derivative 4 based on the saturation of their alkyl chains. The addition of a five carbon-prenyl chain in 1 increased the number of binding interactions, justifying its greater activity than derivatives 2 and 3. This research reflects the first report of AChE inhibitors from these species, thereby adding pharmacological values to MT and SJ as potential remedies in neuroprotection. 相似文献
102.
Aemi Syazwani Abdul Keyon Mazidatulakmam Miskam Nur Syazwani Ishak Naji Arafat Mahat Mohamad Afiq Mohamed Huri Roswanira Abdul Wahab Sheela Chandren Fazira Ilyana Abdul Razak Nyuk‐Ting Ng Timothy Gandu Ali 《Journal of separation science》2019,42(4):906-924
Depression is a common mental disorder that may lead to major mental health problems, and antidepressant drugs have been used as a treatment of choice to mitigate symptoms of major depressive disorders by ameliorating the chemical imbalances of neurotransmitters in brain. Since abusing antidepressant drugs such as selective serotonin reuptake inhibitors and tricyclic antidepressant drugs can cause severe adverse effects, continuous toxicological monitoring of the parent compounds as well as their metabolites using numerous analytical methods appears pertinent. Among them, capillary electrophoresis has been popularly utilized since the method has a lot of advantages viz. using small amounts of sample and solvents, ease of operation, and rapid analysis. This review paper brings a survey of more than 30 papers on capillary electrophoresis of antidepressant drugs published approximately from 1999 until 2018. It focuses on the reported capillary electrophoresis techniques and their applications and challenges for determining antidepressant drugs and their metabolites. It is organized according to the commonly used capillary zone electrophoresis method, followed by non‐aqueous capillary electrophoresis and micellar electrokinetic chromatography, with details on breakthrough findings. Where available, information is given about the background electrolyte used, detector utilized, and sensitivity obtained. 相似文献
103.
104.
Roswanira Abdul Wahab Mahiran Basri Raja Noor Zaliha Raja Abdul Rahman Abu Bakar Salleh Mohd Basyaruddin Abdul Rahman Leow Thean Chor 《Applied biochemistry and biotechnology》2012,167(3):612-620
In silico and experimental investigations were conducted to explore the effects of substituting hydrophobic residues, Val, Met, Leu, Ile, Trp, and Phe into Gln 114 of T1 lipase. The in silico investigations accurately predicted the enzymatic characteristics of the mutants in the experimental studies and provided rationalization for some of the experimental observations. Substitution with Leu successfully improved the conformational stability and enzymatic characteristics of T1 lipase. However, replacement of Gln114 with Trp negatively affected T1 lipase and resulted in the largest disruption of protein stability, diminished lipase activity and inferior enzymatic characteristics. These results suggested that the substitution of a larger residue in a densely packed area of the protein core can have considerable effects on the structure and function of an enzyme. This is especially true when the residue is next to the catalytic serine as demonstrated with the Phe and Trp mutation. 相似文献
105.
M. Asghar F. Iqbal S. Faraz V. Jokubavicius Q. Wahab M. Syväjärvi 《Physica B: Condensed Matter》2012,407(15):3041-3043
In this study deep level transient spectroscopy has been performed on boron–nitrogen co-doped 6H-SiC epilayers exhibiting p-type conductivity with free carrier concentration (NA–ND)∼3×1017 cm−3. We observed a hole H1 majority carrier and an electron E1 minority carrier traps in the device having activation energies Ev+0.24 eV, Ec −0.41 eV, respectively. The capture cross-section and trap concentration of H1 and E1 levels were found to be (5×10−19 cm2, 2×1015 cm−3) and (1.6×10−16 cm2, 3×1015 cm−3), respectively. Owing to the background involvement of aluminum in growth reactor and comparison of the obtained data with the literature, the H1 defect was identified as aluminum acceptor. A reasonable justification has been given to correlate the E1 defect to a nitrogen donor. 相似文献
106.
B. Riscob Mohd. Shakir V. Ganesh N. Vijayan M. A. Wahab G. Bhagavannarayana 《Journal of Thermal Analysis and Calorimetry》2012,110(3):1225-1232
Transparent single crystals of diglycine cadmium chloride were grown by slow evaporation solution technique. To confirm the crystal structure, the grown crystals were subjected to single crystal as well as powder X-ray diffraction measurements and the structure was found to be monoclinic. The elemental analysis was carried out by energy dispersive X-ray spectroscopy. The crystalline perfection of the grown crystal was assessed by high-resolution X-ray diffractometry and found that the crystal quality is fairly good. The optical study reveals that the grown crystal is highly transparent in the region 250?C900?nm. Thermal studies reveal that the grown crystal is stable up to 245?°C. The michrohardness analysis revealed that the grown crystal belongs to soft material category. The high dielectric constant (>30) and low loss (<0.01) value also confirms that the grown crystal is a good candidate for device fabrications. 相似文献
107.
Wickenbrock A Holz PC Wahab NA Phoonthong P Cubero D Renzoni F 《Physical review letters》2012,108(2):020603
We demonstrate theoretically and experimentally the phenomenon of vibrational resonance in a periodic potential, using cold atoms in an optical lattice as a model system. A high-frequency (HF) drive, with a frequency much larger than any characteristic frequency of the system, is applied by phase modulating one of the lattice beams. We show that the HF drive leads to the renormalization of the potential. We used transport measurements as a probe of the potential renormalization. The very same experiments also demonstrate that transport can be controlled by the HF drive via potential renormalization. 相似文献
108.
E. Bretin L. Guadarrama Bustos A. Wahab 《Mathematical Methods in the Applied Sciences》2011,34(7):819-830
In this work, we present an explicit expression for the Green function in a visco‐elastic medium. We choose Szabo and Wu's frequency power law model to describe the visco‐elastic properties and derive a generalized visco‐elastic wave equation. We express the ideal Green function (without any viscous effect) in terms of the viscous Green function using an attenuation operator. By means of an approximation of the ideal Green function, we address the problem of reconstructing a small anomaly in a visco‐elastic medium from wavefield measurements. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
109.
Horia M. Nizam El-Din Safaa G. Abd Alla Abdel Wahab M. El-Naggar 《Radiation Physics and Chemistry》2010,79(6):725-730
Hydrogels based on acrylamide monomer (AM) and different ratios (5–20 wt%) of carboxymethyl cellulose (CMC) were synthesized by gamma irradiation. The hydrogels were characterized in terms of gel content, swelling and drug release characters. The effect of temperature and pH on the degree of swelling was also studied. The results showed that the gel fraction of AM/CMC hydrogels decreases greatly with increasing the contents of CMC in the initial feeding solution. The kinetic study showed that the swelling of all the hydrogels tends to reach the equilibrium state after 5 h. However, the swelling of AM/CMC hydrogels was greater than the hydrogel based on pure AM. On the other hand, it was found that the swelling of all the hydrogels changes within the temperature range 30–40 °C and within the pH range 4–8. The AM/CMC hydrogels was evaluated for the possible use in drug delivery systems. In this respect, the release properties of methylene blue indicator, as a drug model, was investigated. It was found that the percentage release from the hydrogels increase with time to reach ~80% after 3 h at pH of 2 compared to ~100% at pH of 8. 相似文献