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Does ovulation affect performance in tennis players?
No full textBackground Scientific data on the performance of collegiate female tennis players during the menstrual phases are scarce. Trial design Double-blind, counter-balanced, crossover trials were conducted to examine whether tennis performance was affected during menstruation, with and without dehydroepiandrosterone sulfate (DHEA-S) supplementation. Methods Ten Division 1 collegiate tennis players (aged 18-22 years) were evenly assigned into placebo-supplemented and DHEA-supplemented (25 mg/day) trials. Treatments were exchanged among the participants after a 28-day washout. Tennis serve performance was assessed on the first day of menstrual bleeding (day 0/28) and on days 7, 14 and 21. Results Mood state was unaltered during the menstrual cycles in both trials. The lowest tennis serve performance score (speed times accuracy) occurred on day 14 (P=0.06 vs day 0; P=0.01 vs day 21) in both placebo and DHEA trials. Decreased performance on day 14 was explained by decreased accuracy (P=0.03 vs day 0/28; P=0.01 vs day 21), but not velocity itself. Isometric hip strength, but not quadriceps strength, was moderately lower on day 14 (P=0.08). Increasing plasma DHEA-S (by ∼65%) during the DHEA-supplemented trial had no effects on mood state, sleep quality or tennis serve performance. Conclusion We have shown that menses does not affect serve performance of collegiate tennis players. However, the observed decrement in the accuracy of serve speed near ovulation warrants further investigation
Deciphering the potential of baicalin as an antiviral agent for Chikungunya virus infection
No full textThe past decade has seen the re-emergence of Chikungunya virus (CHIKV) as a major global health threat, affecting millions around the world. Although fatal infections are rare among infected patients, the occurrence of long-lasting polyarthralgia has a significant impact on patients' quality of lives and ability to work. These issues were the stimuli for this study to determine the potential of baicalin, a bioflavonoid, as the novel antiviral compound against CHIKV. It was found that baicalin was well tolerated by Vero, BHK-21 and HEK 293T cells with maximal nontoxic doses >600 μM, ≈ 350 μM and ≈110 μM, respectively. Antiviral assays indicated that baicalin was the most effective inhibitor when tested for its direct virucidal activity with EC50 ≈ 7 μM, followed by inhibition of virus entry into the host cell, attachment of virus particle to cellular receptors and finally intracellular replication of viral RNA genome. In silico analysis using molecular docking demonstrated close interactions between baicalin and CHIKV envelope protein with considerably strong binding affinity of −9.7 kcal/mol. qRT-PCR analysis revealed that baicalin had the greatest effect on the synthesis of viral negative stand RNA with EC50 ≈ 0.4 μM followed by the inhibition of synthesis of positive-strand genomic (EC50 ≈ 13 μM) and subgenomic RNAs (EC50 ≈ 14 μM). These readings indicate that the compound efficiently inhibits replicase complexes formation but is a less potent inhibitor of existing replicase complexes. Coherent with this hypothesis, the use of recombinant CHIKV replicons harboring Renilla luciferase marker showed that replication of corresponding replicon RNAs was only slightly downregulated at higher doses of baicalin, with EC50 > 100 μM. Immunofluorescence and western blotting experiments demonstrated dose-dependent inhibition of expression of different viral proteins. It was also observed that levels of important protein markers for cellular autophagy (LC3) and apoptosis (Bax) were reduced in baicalin treatment groups as compared with untreated virus infected controls. In summary, given its low toxicity and high efficacy against CHIKV, baicalin has great potential to be developed as the novel antiviral compound for CHIKV. In vivo studies to evaluate its activity in a more complexed system represent a necessary step for future analysis
Analysis and characterization of Cu2CdSnS4 quaternary alloy nanostructures deposited on GaN
No full textThrough using spin coating technique, Cu2CdSnS4 (CCTS) quaternary alloy nanostructures were successfully deposited on GaN substrate using a wide range of spin coating speeds; 1500, 2000, 2500, 3000 and 3500 RPM at annealing temperature 300 °C. The optical properties were investigated through UV–vis which revealed the changing of energy band gap as the spin coating speed increases, in addition, to verify specific models of refractive index and optical dielectric constant. The structural properties were studied by X-ray diffraction which indicated that the number and intensity of the peaks were changed as the spin coating speed changes. The morphological and topographical studies of CCTS were elaborated by field emission-scanning electron microscopy and atomic force microscopy. The obtained results suggest that CCTS nanostructures deposited on GaN substrate are very suitable for optoelectronic applications, that are in accordance with the available theoretical and experimental data
Thermal, structural, textural and optical properties of ZnO/ZnAl2O4 mixed metal oxide-based Zn/Al layered double hydroxide
No full textMixed metal oxides (MMO) with a homogenously distributed ZnAl 2 O 4 in ZnO network were prepared through a novel combination of co-precipitation and thermal treatment approaches using Zn/Al-layered double hydroxide (LDH) as precursor. The effect of thermal treatment temperature of Zn/Al-LDH for the formation of ZnO/ZnAl 2 O 4 -MMO was studied via their thermal, structural, textural and optical properties. The results reveal that the synthesized Zn/Al-LDH was advanced to ZnO/ZnAl 2 O 4 -MMO starting at 200 °C, while heat treatment at 400 °C resulted in the optimum BET surface area of 53 m 2 g -1 with formation of mesoporous structure. Furthermore, diffuse reflectance microscopy showed that there is more than one energy band gap of pristine Zn/Al-LDH, while samples treated at 200 °C and above demonstrated a single energy band gap with redshift from 3.3 to 3.21 eV. Photoluminescence (PL) analysis showed a quench in the PL spectra as the temperature increased to 400 °C, where the sample with the optimum surface area presents the highest I NBE /I DLE ratio of 0.78. A precise control of the thermal treatment temperature provides short pathways for preparing high BET surface area MMO-based materials
Structural, optical and electrical properties of ZnO/ZnAl2O4 nanocomposites prepared via thermal reduction approach
No full textZnO/ZnAl2O4 nanocomposites (ZrA-MMO) with homogeneously distributed ZnAl2O4 nanoparticles in the interpenetrating network of ZnO were successfully prepared via two-step solution process, namely co-precipitation of Zn/Al–NO3 layered double hydroxide (ZrA-LDH) precursor and thermal treatment methods. The effect of cation molar ratio (r) between Zn2+ and Al3+ on the morphological, structural, thermal, optical as well as electrical properties of ZnO-based MMOs was investigated in detail. A mechanism study related to the surface modification, optical band edge alteration as well as improvement of electrical conductivity after phase transformation from LDH to MMO was also elucidated. The optimum Z5A-MMO sample presents the highest electrical conductivity of 8.23 × 10−3 S/cm as compared to 7.26 × 10−7 S/cm for the standard ZnO nanocrystal. It is believed that the bathochromic shift in optical band gap of Z5A-MMO plays a pivotal role in facilitating the photoemission process and leads to the increase in number of carrier concentration in the sample. This method could provide alternative pathways for fabricating a high electrical conductivity MMO-based material and benefit in future optoelectronic devices
Size distribution of bubbles in agitated viscous N ewtonian and non‐ N ewtonian solutions
No full textThe effects of impeller type, Newtonian shear thinning liquid viscosities, and noncoalescing conditions on the impeller gas cavities, impeller power consumption, and Sauter mean bubble diameter (d32) in a multiphase agitated vessel were systematically studied. An underwater recording technique was used to study gas cavities and bubble size in various operating and design conditions. The gas cavity images were used to relate d32 to gas cavity structure. It was observed that d32 values increase with an increase in Newtonian and shear thinning liquid viscosities. Results also indicate that impellers operating in shear thinning liquids consume higher gassed power at the same operating conditions compared with those in Newtonian fluids. In addition, the d32 values in noncoalescing liquids are substantially smaller compared with those in coalescing solutions at the same Pg/V. Mathematical correlations are proposed for estimating the d32 in the impeller discharge stream and Pg/V in viscous Newtonian and non-Newtonian solutions
Neutrophil–lymphocyte ratios in the prognostication of primary non-metastatic nasopharyngeal carcinoma
No full textIntroduction: Nasopharyngeal carcinoma is a geographically and racially variable disease which has a high incidence in Malaysia. Based on current concepts in tumour related inflammation the inflammatory marker, neutrophil–lymphocyte ratio was tested to find its relationship with prognosis in nasopharyngeal carcinoma. Objective: To investigate the effect of the neutrophil–lymphocyte ratio on prognosis in non-metastatic primary nasopharyngeal carcinoma patients and to further refine the cut off between high and low neutrophil–lymphocyte ratio values. Methods: The medical charts of patients with histologically confirmed nasopharyngeal carcinoma from 1st January 2005 until 31st December 2009 were reviewed retrospectively and theneutrophil–lymphocyte ratio was calculated to see if there was any association between their higher values with higher failure rates. Results: Records of 98 patients (n = 98) were retrieved and reviewed. Only neutrophil–lymphocyte ratio (p = 0.004) and tumor node metastasis staging (p = 0.002) were significantly different between recurrent and non-recurrent groups, with the neutrophil–lymphocyte ratio being independent of tumor node metastasis staging (p = 0.007). Treatment failure was significantly higher in the high neutrophil–lymphocyte ratio group (p = 0.001). Disease free survival was also significantly higher in this group (p = 0.000077). Conclusion: High neutrophil–lymphocyte ratio values are associated with higher rates of recurrence and worse disease free survival in non-metastatic nasopharyngeal carcinoma patients undergoing primary curative treatment
Shear wave elastography in the evaluation of renal parenchymal stiffness in patients with chronic kidney disease
No full textobjective: To investigate the use of shear wave elastography (SWE)-derived estimates of Young's modulus (YM) as an indicator to detect abnormal renal tissue diagnosed by estimated glomerular filtration rate (eGFR). methods: The study comprised 106 chronic kidney disease (CKD) patients and 203 control subjects. Conventional ultrasound was performed to measure the kidney length and cortical thickness. SWE imaging was performed to measure renal parenchymal stiffness. Diagnostic performance of SWE and conventional ultrasound were correlated with serum creatinine, urea levels and eGFR. results: Pearson's correlation coefficient revealed a negative correlation between YM measurements and eGFR (r = −0.576, p < 0.0001). Positive correlations between YM measurements and age (r = 0.321, p < 0.05), serum creatinine (r = 0.375, p < 0.0001) and urea (r = 0.287, p < 0.0001) were also observed. The area under the receiver operating characteristic curve for SWE (0.87) was superior to conventional ultrasound alone (0.35-0.37). The cut-off value of less or equal to 4.31 kPa suggested a non-diseased kidney (80.3% sensitivity, 79.5% specificity). conclusion: SWE was superior to renal length and cortical thickness in detecting CKD. A value of 4.31 kPa or less showed good accuracy in determining whether a kidney was diseased or not
The implications of legislative controls on private hospitals in Malaysia
No full textThe emergence of proprietary private hospitals in the 1980s has led to a rise in cost of health care services, variation in care and increase in adverse events. These have contributed to societal concerns prompting the authorities to enforce Private Healthcare Facilities and Services Act 1998 (Act 586) that regulates all private hospitals nationwide in 2006. Employing a case study approach, this paper discusses some salient themes on the impact of Act 586 on 15 purposively selected private hospitals in the Klang Valley in terms of achieving the national objectives of accessibility, equity and quality care. This study reveals several interrelated themes such as of policy, power, governance, compliance, and quality of care in achieving the national objective. Findings point to high investment of the state in private hospitals. Although a private hospital is stipulated to be a physician-led institution, in reality the majority of these hospitals are owned by government-linked corporations. Many private hospitals face major challenges in terms of compliance with the new regulations meant to improve patient safety and quality of care. However, full compliance to the regulations remains an insurmountable challenge as the private providers are influential. Faced with political constraints, asymmetric information and inadequate human resources, the regulatory authority seems hampered in its enforcement capacity
Effects of Cobalt Loading, Particle Size, and Calcination Condition on Co/CNT Catalyst Performance in Fischer–Tropsch Reactions
No full textThe strong electrostatic adsorption (SEA) method was applied to the synthesis of a cobalt (Co) catalyst on a multi-walled carbon nanotube (CNT) support. In order to uptake more of the cobalt cluster with higher dispersion, the CNT was functionalized via acid and thermal treatment. The Co/CNT catalyst samples were characterized by a range of methods including the Brunauer-Emmet-Teller (BET) surface area analyzer, transmission electron microscopy (TEM), X-ray powder diffraction (XRD) analysis, atomic absorption spectroscopy (AAS), and H2-temperature programmed reduction (H2-TPR) analysis. The data from the TEM images revealed that the catalyst was highly dispersed over the external and internal walls of the CNT and that it demonstrated a narrow particle size of 6-8 nm. In addition, the data from the H2-TPR studies showed a lower reduction temperature (420 °C) for the pre-treated catalyst samples. Furthermore, a Fischer-Tropsch synthesis (FTS) reaction was chosen to evaluate the Co/CNT catalyst performance by using a fixed-bed microreactor at different parameters. Finally finding the optimum value of the cobalt loading percentage, particle size, and calcination conditions of Co/CNT catalyst resulted in a CO conversion and C5+ selectivity of 58.7% and 83.2%, respectively. © 2018 by the authors