Dielectric, elastic and optical properties of 80TeO2-(20-x) MnO2-xFe2O3 and 30Li2O-4MoO3-(66-x)TeO2-xV2O5 mixed oxide tellurite glasses in the conductivity anomaly region / Rosdiyana Hasham @ Hisam

In this study, two series of mixed oxide tellurite based glasses with composition 80TeO2-(20-x)MnO2-xFe2O3 (x = 5 mol% to 20 mol%) and 30Li2O-4MoO3-(66-x)TeO2-xV2O5 (x = 0.2–1.2 mol%) were prepared using melt-quenching method to investigate their dielectric, AC conductivity, elastic and optical properties. For the 80TeO2-(20-x)MnO2- xFe2O3 glass samples, the dielectric constant showed strong variation with Fe2O3 at a frequency ≥ 10 kHz, where ε′ decreased to a minimum value at x = 10 mol% before increasing for x >10%. The decrease in ε′ may be attributed to some form of hindrance effect on heavy dipoles caused by the mixed transition-ion effect (MTE). Meanwhile, variation of AC conductivity with Fe2O3 showed non-linear increase for x ≤ 10 mol% before dropping to a minimum at 15 mol% Fe2O3. This result is attributed to Anderson localization because of the disorder in the glass system. On the other hand, DC conductivity for the same glass system showed a strong increase for x ≤ 10 mol% Fe2O3 before reaching a saddle-like behavior between 10 mol % ≤ x ≤ 15 mol%, followed by a large increase for x > 15 mol%. Independent longitudinal modulus (CL), shear modulus (μ) and bulk modulus (Ke) showed increased values for x ≤ 10 mol% with an anomalous drop at x = 15 mol% Fe2O3, followed by a large increase at x > 15 mol%. The anomalous region between 10 mol% ≤ x ≤ 15 mol% coincided with DC conductivity saddle-like region and is suggested to be related to the MTE. Meanwhile, in the same region, optical band gap (Eopt) exhibited a maxima, whereas refractive index showed a minima, thereby indicating a variation in polarizability due to changes in concentration of bridging and non-bridging oxygens. For the 30Li2O-4MoO3-(66-x) TeO2-xV2O5 glasses, the variation of AC conductivity with V2O5 showed This thesis presents a simulation study on parameter estimation for binary and multinomial logistic regression, and the extension of the clustering partitioning strategy for goodness-of-fit test to multinomial logistic regression model. The motivation behind this study is influenced by two main factors. Firstly, parameter estimation is often sensitive to sample size and types of data. Simulation studies are useful to assess and confirm the effects of parameter estimation for binary and multinomial logistic regression under various conditions. The first phase of this study covers the effect of different types of covariate, distributions and sample size on parameter estimation for binary and multinomial logistic regression model. Data were simulated for different sample sizes, types of covariate (continuous, count, categorical) and distributions (normal or skewed for continuous variable). The simulation results show that the effect of skewed and categorical covariate reduces as sample size increases. The parameter estimates for normal distribution covariate apparently are less affected by sample size. For multinomial logistic regression model with a single covariate, a sample size of at least 300 is required to obtain unbiased estimates when the covariate is positively skewed or is a categorical covariate. A much larger sample size is required when covariates are 21 22 a non-linear increase for x ≤ 0.6 mol% before decreasing to a minimum at 0.8 mol% V2O5

Ebola Contact Tracing Study data

The collection contains four datasets captured in the Ebola Contact Tracing Study: [1] 'summary_data_cases' contains details of the 41 confirmed Ebola cases included in the study; [2] 'app_data_contacts' contains details of the 646 Ebola contacts registered on the Ebola Contact Tracing App (ECT) smartphone app. These originate from 18 Ebola cases (16 were laboratory confirmed and 2 were “secret burials” that were not confirmed); [3] 'paper_data_contacts' describes 408 Ebola contacts who were identified from 25 Ebola cases for monitoring using the standard paper-based system for contact tracing; and [4] 'main_analysis_dataset' contains information on 804 Ebola contacts and their contact tracing monitoring status collected using both the ECT app and paper-based system

Optimization of processing parameters on the yield of oleoresin from zingiber zerumbet and its antibacterial activity

The effect of processing parameters on the yield of oleoresin from Zingiber zerumbet and its antibacterial activity was investigated. The preliminary experiments were carried out to determine the main parameters that affect the yield of oleoresin, zerumbone content and antibacterial activity on the Escherichia coli and Staphylococcus aureus of Z. zerumbet oleoresin. The main parameters were found to be extraction time, type of solvent used and blanching treatment. The range of those parameters that was investigated to get the highest of all yield were blanching treatments (untreated, boiled, steamed), solvent (acetone, ethanol and methanol) and extraction time (6 hours to 18 hours). A D-optimal design was employed to study the effect of different range parameter of Z. zerumbet oleoresin on four response variables; the yield of oleoresin, the zerumbone content, the antibacterial activity on the E. coli and S. aureus. Analysis of variance and response surface methodology were applied to identify the optimal processing parameter. The optimal processing parameters that fulfilled the requirement for yield of oleoresin, zerumbone content, antibacterial activity on the E. coli and S. aureus with high desirability were found to be 18 hours of extraction time, methanol as the solvent used and steaming as the blanching treatment. The desirability value was 84 %. Meanwhile, the optimal yield of Z. zerumbet oleoresin was 31.50 % (w/w), the zerumbone content was 0.56 % (w/w) and the antibacterial activities (inhibition zone) on the E. coli and S. aureus were 14.58 mm and 13.51 mm respectively. Processing optimization has resulted in an increase of overall antibacterial activity on the E. coli and S. aureus of Z. zerumbet oleoresin as well as the increment yield of oleoresin and zerumbone conten

Optimization of extraction conditions of antioxidant activity from zingiber zerumbet oleoresin

The health promoting capacity of natural antioxidant from phytochemicals has increase attention from researchers and public. However, processing is affecting the activity and the bioavailability of bioactive compounds. Therefore, the optimization of extraction condition of antioxidant activity from Zingiber zerumbet oleoresin was investigated. A Box-Behnken design technique was employed to study the effect of different range parameters of soxhlet extraction. Analysis of variance and response surface methodology were applied to identify the optimal processing parameter. Independent variables were extraction time (8, 10 and 12), type of solvent used (hexane, acetone, ethanol) and blanching treatment (steam treated, boil treated, untreated). The response and variables were fitted well to each other by multiple regressions. All the independent parameters affected oleoresin yield and antioxidant activity significantly. The optimal processing parameter that fulfilled the requirement for yield of oleoresin and antioxidant activity were found to be 12 h extraction time, ethanol as the solvent used and untreated sample. While, the optimal yield of oleoresin was 13.05% w/w and antioxidant activity was 16.01% w/w

Postoperative sore throat after elective surgical procedures

Postoperative sore throat is a common complication of anaesthesia and can lead to dissatisfaction after surgery. Many factors can contribute to postoperative sore throat and the incidence varies with the method of airway management Methods: In this prospective observational study elective gynaecological and general surgical patients were interviewed 24 hours postoperatively to determine the presence of sore throat. Information collected included demographic data, surgical procedure, duration of surgery, airway device used and position of patient during surgery. This study was done over a period of 3 months. Results: 312 patients were interviewed. 81(26%) patients suffered with sore throat postoperatively. 28% of patients with endotracheal intubation (ETT) and 3.5% of patients with laryngeal mask airway had a sore throat. Female patients reported more sore throat than male patients (27.1% vs. 19.1%). Sore throat was found to be more common with older age group, grade of difficulty in intubation, duration of surgery and patient’s position during surgery. Conclusion: Awareness of the factors responsible for increased incidence of postoperative sore throat and appropriate care especially during endotracheal intubation can help to reduce the incidence of postoperative sore throat

A comparative study on yield of extract, chemical marker content and antioxidant activity of Zingiber zerumbet and Zingiber officinale

Zingiber officinale (ZO) and Zingiber zerumbet (ZZ) are widely found in Southeast Asia and commonly used in herbal medicine practice for treating various diseases. This study was aimed to evaluate the yield of extract, chemical marker content and antioxidant activity of these Zingeberaceae species. Essential oils and hydrosols were obtained using turbo-extraction-distillation (TED). The highest yield of essential oil was obtained by the ZZ sample, which was 0.35 ± 0.09%, while the ZO showed the lowest yield (0.17 ± 0.02%). In hydrosol extracts the highest yield was obtained by the water extract of ZZ (2.50 ± 0.78%), while the ethanol/water (30:70) extract of ZO showed the lowest yield (0.90 ± 0.15%). The analysis of chemical marker content of ZO and ZZ showed 6-gingerol and zerumbone as the major component, respectively. The DPPH method showed the highest antioxidant activity for ZO essential oil (129.4 ± 14.47%), followed by ZZ essential oil (78.88 ± 9.35%) and hydrosol extracts. Collectively, these findings suggest that both ZO and ZZ can be used as potential sources of natural antioxidant in foods and herbal medicines

Influence of clay nanoparticles on the physical and rheological characteristics of short term aged asphalt binder

This research paper presents laboratory investigation on the physical and rheological properties of asphalt binder modified with Organic Montmorillonite Nanoclay (OMMT). Two different concentrations (1% and 7% by weight of base asphalt) of OMMT was selected toblendwith80/100 penetration grade asphalt binder. The base as well as the OMMT modified asphalt binders was subjected to short term aging process by means of Rolling Thin Film Oven test (RTFO) in order to investigate the influence of the addition of OMMT nano clay in the asphalt binder properties after aging. Bituminous binder properties were investigated by both physical and rheological methods .In general, the physical test results demonstrated prominent increment in softening point; viscosity and decrement in penetration for both concentration of OMMT modified binder as compared to non-modified binder. The results of the experiments indicated that the addition of nano particles was helpful in increasing the complex modulus values and in improving rutting resistance of the RTFO binder. The phase angle of the binders generally decreased with an increase in nano content and RTFO aging procedure. Also, the results indicated that modified binders show better rheological properties compared to standard bitumen. The addition of OMMT to base asphalt binder has led to noticeable improvements in aging resistance this may be due to the homogeneous dispersion of nano particles consisting of layer silicate in the asphalt medium. Thus, nano clay is foreseen as a novel kind of resistance to aging and permanent deformation potential for bitumen

Effect of organic montmorillonite nanoclay concentration on the physical and rheological properties of asphalt binder

This study explores the effect of the addition of various concentration of organic nanoclay on the physical and rheological properties of asphalt binder. Two types (N3 and N4) of Organic Montmorillonite Nanoclay (OMMT) were used and blended with 80/100 penetration grade asphalt in various concentrations (0%, 3%, 5%, and 9%) by weight of bitumen. The physical properties of unaged base and nanoclay modified asphalt were characterized using viscosity, softening point, and penetration tests. The rheological properties of unmodified and nanoclay modified asphalt were determined using Dynamic Shear Rheometer (DSR) in accordance with AASHTO T315 in order to evaluate the effectiveness of OMMT type and concentration on the physical and rheological properties of asphalt binder. The results indicated remarkable increment in softening point; viscosity and decrement in asphalt binder's penetration for both types and contents of organic nanoclay as compared with unmodified bitumen. By increasing the amount of nanoclay content, the DSR results showed tremendous improvement on the rheological properties of nanoclay modified asphalt such as Complex Shear Modulus G* and Phase Angle δ at medium and high temperatures. As a consequence, the results showed that the organic nanoclay modified asphalts had higher rutting resistance and lower dissipated energy per load cycle this may contributed to the dispersion of the silicate platelet in bitumen that reinforce the binder. In comparison, N3 showed better effect in improving physical and rheological properties of asphalt binders and rutting resistance than N4, which may contributed to the homogenously dispersion of nanoclay particles that led to form an exfoliated structure in OMMT modified asphalt. The two-way ANOVA statistical analysis was carried out which indicated that OMMT concentration was more significant than OMMT type on rutting parameter, viscosity at high and intermediate temperature, and softening point while nanoclay type was more significant on penetration

Cytotoxicity assessment of Labisia pumila on prostate cancer cell lines (DU145)

Labisia pumila or locally known as Kacip Fatimah devours the great prospective in the herbal industry. This herbaceous undershrub of the Myrsinaceae family has been used a long time ago and has been exploited aggressively as drinks, cosmetics and health supplement There are three varieties of L pumila, which is L pumila var alata, L pumila var pumila and L pumila var lanceolata and each has their own use and properties. It is believed that L pumila var alata may demonstrate some anticancer activities exerted by certain phytochemical abundant such as gallic acid in this plant. The leaves of L pumila var alata were extracted using three different types of extraction which are maceration, direct and indirect ultrasound assisted extraction. Water was used as the solvent for each type of extraction. MTT, viability test and morphological studies were carried out to determine the cytotoxicity effects of three types of plant extracts on human prostate cancer cell tines (DU 145). The phenolic compound such as gallic acid, kaemferol and caffeic was detected via HPLC. The MTT assay indicated that plant extracts from maceration induce apoptosis and inhibit around 42% of the cell population compare to negative controls. In case of viability studies, maceration extracts have killed a!! the cells within 9 days white the negative control recorded 12 days for alt cells to die. The morphological changes were observed using an inverted microscope to perceive the irregular detachment and clumping of the cells. There was some morphological changing of the cells from hexagonal to round shape after treatment with the extracts. Blabbing cells, chromatin condensation, apoptotic cells and late apoptotic body can be seen after staining. As conclusion, L pumila shows the significant inhibition of growth of prostate cancer cell tines and can be applied as cytotoxic agents in the future treatment of prostate cancer