Screening of factors influencing exo-polygalacturonase production by Aspergillus niger ATCC 120120 using two-level fractional factorial design

Exo-polygalacturonase was produced by Aspergillus niger ATCC 120120 in a solid-state fermentation using Nephrolepis biserrata leaves. Factors affecting the production of exo-polygalacturonase were determined using a two-level fractional factorial design. The screening process for six factors; pH, incubation time, temperature, pectin concentration, inoculum size and moisture content, that influence the production of exo-polygalacturonase by A. niger was performed. The result of variance analysis (ANOVA) suggested that there were four statistically significant (P < 0.005) factors in the production of exo-polygalacturonase by A. niger. These factors were incubation time, temperature, pectin concentration and moisture content. The statistical analysis shows that the linear mathematical model is significant with coefficient of determination (R2) value of 0.9711. The optimum production of exo-polygalacturonase obtained using the model in this study was at 40.00 U/g

Analytical attributes of Humic Acids derived from tropical-based resources

Humic acids (HA) are widely researched and exploited compounds due to their exceptional chemical and physical properties. However, information on tropical-based HA is still lacking. This attempted to characterize HA derived from tropical peat and POME using chemical and physical methods. Elemental analysis of the HA showed that C ranged between 48.94 and 57.87%, H between 4.90 and 8.26%, N between 1.93 and 8.05% and 0 between 30.96 and 40.85%. The functional group analysis indicated that peat-derived HA were more reactive than those derived from POME. Optical density and spectral examinations revealed that the HA had varying degrees of aromaticity. Generally, data obtained from the HAs studied (particularly from peat) agreed closely with those reported elsewhere

Physico-chemical attributes of humic acid extracted from tropical pect

Basic research conducted on humic acid (HA) in tropical soils is limited. A study was conducted to characterize HA extracted from tropical peat by elemental and functional group analyses, infrared (IR) spectra and by direct examination on HA using scanning electron microscopy (SEM). From the elemental analysis it was found that C ranged from 40.26 - 53.26%, H 4.84 - 6.36%,038.39 - 51.62%, N 1.51- 2.64%, and P 0.02 - 0.06%. Studies of functional groups indicated that the carboxyl group present in HA of tropical peat was about twice as high as that of phenolic hydroxyl groups. From IR spectra, the HA had an aromatic character. Results of IR analysis also exhibited consistently similar spectra, demonstrating that regardless of place of origin, the extracted humic compound had a similar structure and was composed of the same functional groups. Electron microscopic examination of dried HA showed a sub-angular blocky shape which varied in size. All extracted HA exhibited similar form

Biochemical and physical characterization of immobilized Candida rugosa lipase on metal oxide hybrid support

Enzyme immobilization on inorganic materials is gaining more attention with the potential characteristics of high-surface-area-to-volume ratios, increasing the efficiency of enzyme loading on the support. Metal oxide hybrid support was prepared by a wetness impregnation of five metal precursors, including CaO, CuO, MgO, NiO, and ZnO, on Al2O3 and used as a support for the immobilization of Candida rugosa lipase (CRL) by adsorption. Maximum activity recovery (70.6%) and immobilization efficiency (63.2%) were obtained after optimization of five parameters using response surface methodology (RSM) by Box–Behnken design (BBD). The biochemical properties of immobilized CRL showed high thermostability up to 70 °C and a wide range in pH stability (pH 4–10). TGA-DTA and FTIR analysis were conducted, verifying thermo-decomposition of lipase and the presence of an amide bond. FESEM-EDX showed the homogeneous distribution and high dispersion of magnesium and CRL on MgO-Al2O3, while a nitrogen adsorption–desorption study confirmed MgO-Al2O3 as a mesoporous material. CRL/MgO-Al2O3 can be reused for up to 12 cycles and it demonstrated high tolerance in solvents (ethanol, isopropanol, methanol, and tert-butanol) compared to free CRL

Percutaneous revascularization for ischemic left ventricular dysfunction: Cost-effectiveness analysis of the REVIVED-BCIS2 trial

BACKGROUND: Percutaneous coronary intervention (PCI) is frequently undertaken in patients with ischemic left ventricular systolic dysfunction. The REVIVED (Revascularization for Ischemic Ventricular Dysfunction)-BCIS2 (British Cardiovascular Society-2) trial concluded that PCI did not reduce the incidence of all-cause death or heart failure hospitalization; however, patients assigned to PCI reported better initial health-related quality of life than those assigned to optimal medical therapy (OMT) alone. The aim of this study was to assess the cost-effectiveness of PCI+OMT compared with OMT alone. METHODS: REVIVED-BCIS2 was a prospective, multicenter UK trial, which randomized patients with severe ischemic left ventricular systolic dysfunction to either PCI+OMT or OMT alone. Health care resource use (including planned and unplanned revascularizations, medication, device implantation, and heart failure hospitalizations) and health outcomes data (EuroQol 5-dimension 5-level questionnaire) on each patient were collected at baseline and up to 8 years post-randomization. Resource use was costed using publicly available national unit costs. Within the trial, mean total costs and quality-adjusted life-years (QALYs) were estimated from the perspective of the UK health system. Cost-effectiveness was evaluated using estimated mean costs and QALYs in both groups. Regression analysis was used to adjust for clinically relevant predictors. RESULTS: Between 2013 and 2020, 700 patients were recruited (mean age: PCI+OMT=70 years, OMT=68 years; male (%): PCI+OMT=87, OMT=88); median follow-up was 3.4 years. Over all follow-ups, patients undergoing PCI yielded similar health benefits at higher costs compared with OMT alone (PCI+OMT: 4.14 QALYs, £22 352; OMT alone: 4.16 QALYs, £15 569; difference: −0.015, £6782). For both groups, most health resource consumption occurred in the first 2 years post-randomization. Probabilistic results showed that the probability of PCI being cost-effective was 0. CONCLUSIONS: A minimal difference in total QALYs was identified between arms, and PCI+OMT was not cost-effective compared with OMT, given its additional cost. A strategy of routine PCI to treat ischemic left ventricular systolic dysfunction does not seem to be a justifiable use of health care resources in the United Kingdom

Arrhythmia and death following percutaneous revascularization in ischemic left ventricular dysfunction: Prespecified analyses from the REVIVED-BCIS2 trial

BACKGROUND: Ventricular arrhythmia is an important cause of mortality in patients with ischemic left ventricular dysfunction. Revascularization with coronary artery bypass graft or percutaneous coronary intervention is often recommended for these patients before implantation of a cardiac defibrillator because it is assumed that this may reduce the incidence of fatal and potentially fatal ventricular arrhythmias, although this premise has not been evaluated in a randomized trial to date. METHODS: Patients with severe left ventricular dysfunction, extensive coronary disease, and viable myocardium were randomly assigned to receive either percutaneous coronary intervention (PCI) plus optimal medical and device therapy (OMT) or OMT alone. The composite primary outcome was all-cause death or aborted sudden death (defined as an appropriate implantable cardioverter defibrillator therapy or a resuscitated cardiac arrest) at a minimum of 24 months, analyzed as time to first event on an intention-to-treat basis. Secondary outcomes included cardiovascular death or aborted sudden death, appropriate implantable cardioverter defibrillator (ICD) therapy or sustained ventricular arrhythmia, and number of appropriate ICD therapies. RESULTS: Between August 28, 2013, and March 19, 2020, 700 patients were enrolled across 40 centers in the United Kingdom. A total of 347 patients were assigned to the PCI+OMT group and 353 to the OMT alone group. The mean age of participants was 69 years; 88% were male; 56% had hypertension; 41% had diabetes; and 53% had a clinical history of myocardial infarction. The median left ventricular ejection fraction was 28%; 53.1% had an implantable defibrillator inserted before randomization or during follow-up. All-cause death or aborted sudden death occurred in 144 patients (41.6%) in the PCI group and 142 patients (40.2%) in the OMT group (hazard ratio, 1.03 [95% CI, 0.82–1.30]; P =0.80). There was no between-group difference in the occurrence of any of the secondary outcomes. CONCLUSIONS: PCI was not associated with a reduction in all-cause mortality or aborted sudden death. In patients with ischemic cardiomyopathy, PCI is not beneficial solely for the purpose of reducing potentially fatal ventricular arrhythmias. REGISTRATION: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT01920048

Aromatic annulation with bisphenylthionium ions

The chemospecific production and intramolecular aromatic electrophilic substitution (annulation) of bis(phenylthio)carbocations (bisphenylthionium ions) has been studied using appropriate model compounds. The annulation reaction is very sensitive to the Lewis acid initiator and also the solvent. The best reaction conditions were found to be a suspension of silver trifluoromethanesulfonate in dichloromethane. Annulation of six-membered rings onto alkylbenzenes and five- and seven-membered rings onto activated benzenes have been achieved

Entrapment of free cells within electrospun nanofibers: mini review on parameters influencing nanofibers characteristics and cells viability

Nanotechnology is a growing technology that has been recognized as vital and scientific with bioprocess development especially in dealing with usage of free cells. Limitations such as low bioavailability, storage instability and low substrate inhibition bound the application of free cells in various field thus leading researchers into focusing more on free cells immobilization system. With the increasing knowledge in nanomaterials fabrication techniques, the immobilization of free cells through entrapment approach in highly porous and the high surface area of nanofibers is becoming an interesting subject to be highlighted. The production of free cells entrapped in nanofibers via electrospinning in terms of quality and quantity is highly affected by the electrospinning operating parameters including solution formulation, ambient conditions, operating conditions of electrospinning machine and types of materials used. Hence, this review paper will provide an overview of the operating conditions involved in electrospinning of cells through entrapment process which affect the characteristics of the electrospun nanofibers produced and the viability or growth of cells when entrapped in the electrospun nanofibers mats

Biochemical and Physical Characterization of Immobilized Candida rugosa Lipase on Metal Oxide Hybrid Support

Enzyme immobilization on inorganic materials is gaining more attention with the potential characteristics of high-surface-area-to-volume ratios, increasing the efficiency of enzyme loading on the support. Metal oxide hybrid support was prepared by a wetness impregnation of five metal precursors, including CaO, CuO, MgO, NiO, and ZnO, on Al2O3 and used as a support for the immobilization of Candida rugosa lipase (CRL) by adsorption. Maximum activity recovery (70.6%) and immobilization efficiency (63.2%) were obtained after optimization of five parameters using response surface methodology (RSM) by Box&ndash;Behnken design (BBD). The biochemical properties of immobilized CRL showed high thermostability up to 70 &deg;C and a wide range in pH stability (pH 4&ndash;10). TGA-DTA and FTIR analysis were conducted, verifying thermo-decomposition of lipase and the presence of an amide bond. FESEM-EDX showed the homogeneous distribution and high dispersion of magnesium and CRL on MgO-Al2O3, while a nitrogen adsorption&ndash;desorption study confirmed MgO-Al2O3 as a mesoporous material. CRL/MgO-Al2O3 can be reused for up to 12 cycles and it demonstrated high tolerance in solvents (ethanol, isopropanol, methanol, and tert-butanol) compared to free CRL

Antimicrobial disinfectants and sanitizers: An effective tool for breaking the circle of pandemic disease

The recent outbreak of Covid-19 pandemic has triggered the world in finding and developing efficient disinfectants and sanitizers. This deadly contagious virus has urged all scientist to study the natural characteristic of the virus and thus, to be able to produce the suitable antiviral drug. As developing vaccine is long time-consuming process, the development of disinfectants and sanitizers are necessary to reduce the spread of this pandemic disease. Many types and version of these products have developed and marketed. Several issues, such as the high percentage of alcohol, the high flammability of the product, and many more have arisen. This review provides a comprehensive overview on the type of chemicals used as antimicrobial in general and antiviral in specific agents. In addition, it also discusses the chemical and herbal formulations, factors affecting the performance of antimicrobial agents, the safety precautions, and the future trend of sanitizers and disinfectants. Ultimately, the choice for the best disinfectants and sanitizers formulation would depend on the sensitivity of the surfaces regardless of on skin or other surface materials