Esterification for butyl butyrate formation using Candida cylindracea lipase produced from palm oil mill effluent supplemented medium

The ability of Candida cylindracea lipase produced using palm oil mill effluent (POME) as a basal medium to catal yze the esterification reaction for butyl butyrate formation was investi-gated. Butyric acid and n-butanol were used as substrates at different molar ratios. Different con-version yields were observed according to the affinity of the produced lipase toward the substrates. The n -butanol to butyric acid molar ratio of 8 and lipase concentration of 75 U/mg gave the highest butyl butyrate formation of 63.33% based on the statistical optimization using face centered central composite design (FCCCD) after 12 h reaction. The esterification potential of the POME based lipase when compared with the commercial lipase from the same strain using the optimum levels was found to show a similar pattern. It can be concluded therefore that the produced lipase pos-sesses appropriate characteristics to be used as a biocatalyst in the esterification reactions for butyl butyrate formatio

Analysis of the Impact of Relative Humidity and Mineral Nuclei Mode Aerosols Particle Concentration on the Visibility of Desert Aerosols

This paper presents the results of the Analysis of the Impact of relative humidity and water-soluble aerosol particle concentrations on the visibility and particle size distribution of desert aerosols based on microphysical properties of desert aerosols. The microphysical properties (the extinction coefficients, volume mix ratios, dry mode radii and wet mode radii) were extracted from Optical Properties of Aerosols and Clouds (OPAC 4.0) at eight relative humidities (00 to 99%RH) and at the spectral range of 0.4-0.8 mm. the concentrations of mineral nuclie component (MINN) were varied to obtain five different models. The angstrom exponent (a), the turbidity (b), the curvature (a2), humidification factor (g), the mean exponent of aerosol growth curve (µ) and the mean exponent of aerosol size distributions (n) were determined from the regression analysis of some standard equations. It was observed that the values of (a) are less than 1 throughout the 5 models which signifies the dominance of coarse mode particles over fine mode particles. It was observed that the curvature (a2) has both monomodal and bimodal types of distributions all through the 5 models and this signifies the dominance of coarse mode particles with some traces of fine mode particles. The visibility was observed to decrease with the increase in RH and increased with wavelength. The analysis further found that there is an inverse power law relationship between humidification factor, the mean exponent of the aerosol size distribution with the mean exponent of the aerosol growth curve (as the magnitude of (µ) decreases across the five models, the magnitudes of (g) and (n) increase, but the magnitude of both (g) and (n) increases for a given (µ) across the individual models). The mean exponent of aerosol size distribution (µ) being less than 3 indicate hazy condition of the desert atmosphere

Study of rice husk silicate effects on the elastic, physical and structural properties of borotellurite glasses

Successful extraction of high purity SiO₂ (about 99%) from rice husk (waste) was achieved in this work using the cold acid leaching method. Glass series [(TeO₂)0.₇ (B₂O₃)0.₃]1-x (SiO₂)x were fabricated using the rice husk silicate (RHS) by melt-quenching method. The samples were subjected to X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) characterization to study the structural nature of the glass system. Density and ultrasonic velocities were measured to obtain the elastic constants for the various silicate proportions in the glass using ultrasonic data obtained from non-destructive ultrasonic probing technique. The elastic moduli calculated from the obtained data were found to have increased with the addition of more RHS in the glass. Other parameters studied include the microhardness (H), Poisson's ratio (σ), softening temperature (ϴD) and fractal bond connectivity (d) and the fluctuation free volume (fugacity, fg). A very unusual occurrence was observed as microhardness value decreases in the glass system as more RHS (SiO₂) is introduced. The quality of the glass in terms of elastic behavior improved with addition of RHS in the borotellurite glass network

Twelve-month observational study of children with cancer in 41 countries during the COVID-19 pandemic

Introduction Childhood cancer is a leading cause of death. It is unclear whether the COVID-19 pandemic has impacted childhood cancer mortality. In this study, we aimed to establish all-cause mortality rates for childhood cancers during the COVID-19 pandemic and determine the factors associated with mortality. Methods Prospective cohort study in 109 institutions in 41 countries. Inclusion criteria: children <18 years who were newly diagnosed with or undergoing active treatment for acute lymphoblastic leukaemia, non-Hodgkin's lymphoma, Hodgkin lymphoma, retinoblastoma, Wilms tumour, glioma, osteosarcoma, Ewing sarcoma, rhabdomyosarcoma, medulloblastoma and neuroblastoma. Of 2327 cases, 2118 patients were included in the study. The primary outcome measure was all-cause mortality at 30 days, 90 days and 12 months. Results All-cause mortality was 3.4% (n=71/2084) at 30-day follow-up, 5.7% (n=113/1969) at 90-day follow-up and 13.0% (n=206/1581) at 12-month follow-up. The median time from diagnosis to multidisciplinary team (MDT) plan was longest in low-income countries (7 days, IQR 3-11). Multivariable analysis revealed several factors associated with 12-month mortality, including low-income (OR 6.99 (95% CI 2.49 to 19.68); p<0.001), lower middle income (OR 3.32 (95% CI 1.96 to 5.61); p<0.001) and upper middle income (OR 3.49 (95% CI 2.02 to 6.03); p<0.001) country status and chemotherapy (OR 0.55 (95% CI 0.36 to 0.86); p=0.008) and immunotherapy (OR 0.27 (95% CI 0.08 to 0.91); p=0.035) within 30 days from MDT plan. Multivariable analysis revealed laboratory-confirmed SARS-CoV-2 infection (OR 5.33 (95% CI 1.19 to 23.84); p=0.029) was associated with 30-day mortality. Conclusions Children with cancer are more likely to die within 30 days if infected with SARS-CoV-2. However, timely treatment reduced odds of death. This report provides crucial information to balance the benefits of providing anticancer therapy against the risks of SARS-CoV-2 infection in children with cancer

Lipase production: An insight in the utilization of renewable agricultural residues

Bioconversion of agricultural residues for lipase production as well as other value added products would hold a prominent position in future biotechnologies, mainly because of its eco friendliness and flexibility to both developing and developed countries. Several residues such as straw, bran, oil cakes, among others attract increasing attention as abundant and cheap renewable feedstock. Many researchers considered improvement of substrate composition, physical parameters (temperature, pH, moisture content and particle size), inoculum concentration, and substrate porosity to upgrade and valorize these bioproducts. Several species of fungi, yeast and bacteria have been used in utilizing the agricultural residues through fermentation techniques due to their ability to grow on particle surfaces as sources of carbon and energy, and produce important industrial enzymes including lipases. This review provides an overview of the present status on the utilization of renewable residues in the form of solid- and liquid-state and their characteristics for production of lipases using different microbial systems

Effect of process parameters on lipase production by Candida cylindracea in stirred tank bioreactor using renewable palm oil mill effluent based medium

A two-level full factorial design (FFD) was employed to determine the effects of process parameters on lipase production by Candida cylindracea ATCC 14830 in palm oil mill effluent (POME)-based medium. Ten experimental runs based on three parameters (temperature, agitation and aeration) as indicated by the FFD were carried out in a stirred-tank bioreactor. On statistical analysis of the results, the optimum temperature, aeration and agitation rates were found to be 30 ◦C, 1.0 vvm and 400 rpm respectively, with a maximum activity of 41.46 U/ml after 36 h of fermentation. Analysis of variance (ANOVA) showed a high coefficient of determination (R2) value of 0.999, indicating a satisfactory fit of the model with the experimental data. All the three parameters were statistically significant at p < 0.05. The validation experiment also confirmed that apart from lipase production, there was an increase in chemical oxygen demand (COD) removal throughout the fermentation period

Optimization of lipase production by Candida cylindracea in palm oil mill effluent based medium using statistical experimental design

Sequential optimization strategy based on statistical experimental design including one-factor-at-a-time (OFAT) method was used to enhance the production of lipase by Candida cylindracea ATCC 14830 using palm oil mill effluent as a basal medium in shake flask cultures. The two-level Plackett–Burman (PB) design was implemented to screen the medium components that significantly influence the production. Following the OFAT method, three significant components influencing lipase production were identified as peptone, Tween-80 and inoculum. The optimum values of these three components were determined by response surface methodology (RSM) based on the face-centered central composite design (FCCCD). The validity of the model developed was verified, and the optimum medium containing 0.45% (w/v) peptone, 0.65% (v/v) Tween-80 and 2.2% (v/v) inoculum led to amaximumlipase production of 20.26 U/ml, which was 5.19-fold higher than the unoptimized medium. The analysis of variance indicated that the established model was significant (P < 0.05). This study innovatively developed a fermentation medium utilizing renewable palm oil mill effluent (POME) to produce lipase at considerable level

Suitability of using palm oil mill effluent as a medium for lipase production

Lipases are enzymes that can be secreted by several microorganisms using agro-industrial residues as potential substrates. This work screened ten microorganisms for their potential to produce lipase in palm oil mill effluent (POME)-based medium. Among the 10 organisms, the most promising strain was Candida cylindracea (ATCC 14830) which showed appreciable activity both on agar plates and liquid cultures. Medium supplementation by NH4Cl and olive oil led to an enzyme activity of 2.07 U/ml. However, supplementation with organic nitrogen sources resulted in better enzyme activity. Addition of malt extract, peptone and olive oil into the medium greatly influenced the lipase production. Among the oils that were tested, olive oil was found to be the best for the expression of extracellular lipase at 0.5% (v/v) with an activity of 4.02 U/ml in an optimized POME supplemented medium

Understanding rural women's preferences for telephone call engagement with primary health care providers in Nigeria: a discrete choice experiment

Background The COVID-19 pandemic has accelerated the use of mobile phones to provide primary health care services and maintain continuity of care. This study aims to understand rural women’s preferences for telephone call engagement with primary health care providers in Nigeria.Methods A discrete choice experiment was conducted alongside an action research project that empowered primary health care workers to develop and implement a telephone call intervention to assess and enhance experiences with facility childbirth care. Between January and March 2022, 30 providers from 10 primary health care facilities implemented the choice experiment among rural women who had institutional childbirth to elicit service user preferences for telephone call engagement. The women were asked to express their preferred scenario for telephone call engagement with their primary health care providers. Generalised linear mixed models were used to estimate women’s preferences.Results Data for 460 women were available for the discrete choice experiment. The study showed that rural women have preferences for telephone call engagement with primary health care providers. Specifically, women preferred engaging with female to male callers (β=1.665 (95% CI 1.41, 1.93), SE=0.13, p&lt;0.001), preferred call duration under 15 min (β=1.287 (95% CI 0.61, 1.96), SE=0.34, p&lt;0.001) and preferred being notified before the telephone engagement (warm calling) (β=1.828 (95% CI 1.10, 2.56), SE=0.37, p&lt;0.001). Phone credit incentive was also a statistically significant predictor of women’s preferences for engagement. However, neither the availability of scheduling options, the period of the day or the day of the week predicts women’s preferences.Conclusions The study highlights the importance of understanding rural women’s preferences for telephone call engagement with healthcare providers in low-income and middle-income countries. These findings can inform the development of mobile phone-based interventions and improve acceptability and broader adoption