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排序方式: 共有151条查询结果,搜索用时 15 毫秒
91.
Nurfatihah Che Abd Rashid Nor Hafizah Ngajikin Asrul Izam Azmi Rashidah Arsat Suhaila Isaak Noran Azizan Cholan Nur Ellina Azmi 《中国光学快报(英文版)》2019,(8)
A spectrophotometer with an LED as the light source for uric acid detection is proposed in this work. The mechanism of uric acid detection is based on energy absorbed by sodium urate, which is a chemical product of uric acid and sodium hydroxide solution. For the performance validation, comparison between the spectrophotometer with an LED and halogen lamp is carried out. Measurement results suggest that the spectrophotometer system with LED light has better sensitivity than that with halogen light. At a 460 nm wavelength,the sensitivity for the spectrophotometer with an LED is 0.0046 dL/mg, which is 73% higher than that with halogen light that records 0.0012 dL/mg. This enhanced sensitivity is attributed to the higher luminous efficacy of the LED light beam. As a result, a larger amount of flux interacts with the sample, leading to the sensitivity enhancement. The spectrophotometer with an LED is also applied for the detection of uric acid in a real human urine sample. Based on the experimental data at a 460 nm wavelength, the method manages to achieve the sensitivity of 0.0016 dL/mg, accuracy of 96.01%, limit of detection of 4.79 mg/dL, and limit of quantification of 14.52 mg/dL. These findings show that the use of LED as the input light source is promising for the spectrophotometer. 相似文献
92.
93.
94.
Abu Bakar Mohamad Hafizi Azmi Mohamad Nurul Shariff Khairul Anuar Tan Joo Shun 《Applied biochemistry and biotechnology》2019,188(1):241-259
Applied Biochemistry and Biotechnology - Withaferin A (WA), a bioactive constituent derived from Withania somnifera plant, has been shown to exhibit many qualifying properties in attenuating... 相似文献
95.
Y Abdollahi A Zakaria AH Abdullah HR Masoumi H Jahangirian K Shameli M Rezayi S Banerjee T Abdollahi 《Chemistry Central journal》2012,6(1):88
ABSTRACT: The optimization processes of photo degradation are complicated and expensive when it is performed with traditional methods such as one variable at a time. In this research, the condition of ortho-cresol (o-cresol) photo degradation was optimized by using a semi empirical method. First of all, the experiments were designed with four effective factors including irradiation time, pH, photo catalyst's amount, o-cresol concentration and photo degradation % as response by response surface methodology (RSM). The RSM used central composite design (CCD) method consists of 30 runs to obtain the actual responses. The actual responses were fitted with the second order algebraic polynomial equation to select a model (suggested model). The suggested model was validated by a few numbers of excellent statistical evidences in analysis of variance (ANOVA). The used evidences include high Fvalue (143.12), very low P-value (<0.0001), non-significant lack of fit, the determination coefficient (R2 = 0.99) and the adequate precision (47.067). To visualize the optimum, the validated model simulated the condition of variables and response (photo degradation %) by a few number of three dimensional plots (3D). To confirm the model, the optimums were performed in laboratory. The results of performed experiments were quite close to the predicted values. In conclusion, the study indicated that the model is successful to simulate the optimum condition of o-cresol photo degradation under visible-light irradiation by manganese doped ZnO nanoparticles. 相似文献
96.
The apoptotic effect of 1's-1'-acetoxychavicol acetate from Alpinia conchigera on human cancer cells
Awang K Azmi MN Aun LI Aziz AN Ibrahim H Nagoor NH 《Molecules (Basel, Switzerland)》2010,15(11):8048-8059
1'-(S)-1'-Acetoxychavicol acetate (ACA) isolated from the Malaysian ethno-medicinal plant Alpinia conchigera Griff. was investigated for its potential as an anticancer drug. In this communication, we describe the cytotoxic and apoptotic properties of ACA on five human tumour cell lines. Data from MTT cell viability assays indicated that ACA induced both time- and dose-dependent cytotoxicity on all tumour cell lines tested and had no adverse cytotoxic effects on normal cells. Total mortality of the entire tumour cell population was achieved within 30 hrs when treated with ACA at 40.0 μM concentration. Flow cytometric analysis for annexin-V and PI dual staining demonstrated that cell death occurred via apoptosis, followed by secondary necrosis. The apoptotic effects of ACA were confirmed via the DNA fragmentation assay, in which consistent laddering of genomic DNA was observed for all tumour cell lines after a 24 hrs post-treatment period at the IC(50) concentration of ACA. A cell cycle analysis using PI staining also demonstrated that ACA induced cell cycle arrest at the G(0)/G(1) phase, corresponding to oral tumour cell lines. In conclusion, ACA exhibits enormous potential for future development as a chemotherapeutic drug against various malignancies. 相似文献
97.
We obtain the inhomogeneous invariance quantum group for the multi-dimensional q-deformed bosonic Newton oscillator algebra. The homogenous part of this quantum group is given by the multiparameter quantum
group $
GL_{X;q_{ij} }
$
GL_{X;q_{ij} }
of Schirrmacher where q
ij’s take some special values. We find the R-matrix which gives the non-commuting structure of the quantum group for the two dimensional case. 相似文献
98.
Determination of Vanadium(IV) and Vanadium(V) in Benfield Samples by IEC with Conductivity Detection
In this study, the determination of vanadium valence state, V(IV) and V(V) has been achieved using ion-exchange chromatography with conductivity detector. In this method, V(IV) was determined as V(IV)-EDTA complex and V(V) as vanadate ion. Determination of V(IV) was successfully done using 3 mM carbonate/bicarbonate/EDTA at pH 8.6 as the eluent. The additive, EDTA in the mobile phase did not seem to interfere with the V(IV) analysis. The detection of V(V) was achieved with 5 mM disodium hydrogen phosphate buffer at pH 10.4. A linear calibration graph over VO3 ? and V(IV) with concentration ranges 5–15 mg L?1 gave the detection limit at 0.09 and 0.1 mg L?1, respectively. Both V(IV) and V(V) were successfully determined in Benfield sample, with concentrations of V(IV) and V(V) at 4 and 11,000 mg L?1, respectively. 相似文献
99.
Nor Azrini Nadiha Azmi Amal A. M. Elgharbawy Hamzah Mohd Salleh Muhammad Moniruzzaman 《Molecules (Basel, Switzerland)》2022,27(19)
Fish by-product oil and lemon oil have potential applications as active ingredients in many industries, including cosmetics, pharmaceuticals and food. However, the physicochemical properties, especially the poor stability, compromised the usage. Generally, nanoemulsions were used as an approach to stabilize the oils. This study employed an ultrasonication method to form oil-in-water nanoemulsion of lemon and fish by-product oils (NE-FLO). The formulation is produced at a fixed amount of 2 wt% fish by-product oil, 8 wt% lemon oil, 10 wt% surfactant, 27.7 wt% co-surfactants and 42 min of ultrasonication time. The size, polydispersity index (PDI) and zeta potential obtained were 44.40 nm, 0.077, and −5.02 mV, respectively. The biological properties, including antioxidant, antibacterial, cell cytotoxicity, and anti-inflammatory, showed outstanding performance. The antioxidant activity is comparable without any significant difference with ascorbic acid as standard and is superior to pure lemon oil. NE-FLO successfully inhibits seven Gram-positive and seven Gram-negative bacterial strains. NE-FLO’s anti-inflammatory activity is 99.72%, comparable to nordihydroguaiaretic acid (NDGA) as the standard. At a high concentration of 10,000 µg·mL−1, NE-FLO is non-toxic to normal skin cells. These findings demonstrate that the NE-FLO produced in this study has significant potential for usage in various industries. 相似文献
100.
Jumiah Hassan Farm Mooi Yen Mansor Hashim Zulkifly Abbas Zaidan Abdul Wahab W. Mohd. Daud W. Yusoff Azmi Zakaria 《Ionics》2007,13(4):219-222
NiFe2O4 prepared via the sol–gel technique were pre-sintered at 900 °C and synthesized at different sintering temperatures from 1,000 °C
to 1,200 °C at 100 °C intervals. The samples were characterized for microwave dielectric properties. These samples were measured
using Agilent Impedance/Material Analyzer at frequencies 1 MHz to 1.8 GHz. Results showed a decrease in the dielectric constant
and loss factor with frequency except at the turning point, around 150 MHz, where the loss factor showed a gradual increase.
However, both the dielectric constant and loss factor increase with increasing sintering temperature. The grain size and density
also increased with increasing sintering temperature, but the porosity and grain boundary density showed a decrease.
This paper was presented at the International Conference on Solid State Science and Technology 2006, Kuala Terengganu, Malaysia,
Sept. 4–6, 2006. 相似文献