Transforming Spirulina maxima Biomass into Ultrathin Bioactive Coatings Using an Atmospheric Plasma Jet: A New Approach to Healing of Infected Wounds

The challenge of wound healing, particularly in patients with comorbidities such as diabetes, is intensified by wound infection and the accelerating problem of bacterial resistance to current remedies such as antibiotics and silver. One promising approach harnesses the bioactive and antibacterial compound C-phycocyanin from the microalga Spirulina maxima. However, the current processes of extracting this compound and developing coatings are unsustainable and difficult to achieve. To circumvent these obstacles, a novel, sustainable argon atmospheric plasma jet (Ar-APJ) technology that transforms S. maxima biomass into bioactive coatings is presented. This Ar-APJ can selectively disrupt the cell walls of S. maxima, converting them into bioactive ultrathin coatings, which are found to be durable under aqueous conditions. The findings demonstrate that Ar-APJ-transformed bioactive coatings show better antibacterial activity against Staphylococcus aureus and Pseudomonas aeruginosa. Moreover, these coatings exhibit compatibility with macrophages, induce an anti-inflammatory response by reducing interleukin 6 production, and promote cell migration in keratinocytes. This study offers an innovative, single-step, sustainable technology for transforming microalgae into bioactive coatings. The approach reported here has immense potential for the generation of bioactive coatings for combating wound infections and may offer a significant advance in wound care research and application.

Antifouling and Antimicrobial Study of Nanostructured Mixed-Matrix Membranes for Arsenic Filtration

Membrane fouling is a major drawback in the membrane filtration industry for water treatment. Mixed-matrix membranes (MMMs) are well known for their enhanced antifouling and antibacterial properties, which could offer potential benefits for membrane filtration processes in the water treatment field. In this work, three electrospun nanofibrous MMMs (P, CP, and MCP, which were, respectively, the pristine polysulfone membrane and mixed-matrix membranes (MMMs) consisting of GO-ZnO and GO-ZnO-iron oxides) were studied for antifouling and antibacterial properties with respect to the arsenic nanofiltration process. The effects of these composites on the antifouling behaviour of the membranes were studied by characterising the bovine serum albumin (BSA) protein adsorption on the membranes and subsequent analysis using microscopic (morphology via scanning electron microscopy) and Brunauer-Emmett-Teller (BET) analyses. The antibacterial properties of these membranes were also studied against Gram-positive Staphylococcus aureus (S. aureus) and Gram-negative Escherichia coli (E. coli). The composite nanoparticle-incorporated membranes showed improved antifouling properties in comparison with the pristine polysulfone (PSF) membrane. The excellent antimicrobial properties of these membranes make them appropriate candidates to contribute to or overcome biofouling issues in water or wastewater treatment applications.

The adverse impact of excessive internet use during the COVID-19 pandemic on adolescents' coping skills: A case study in Hanoi, Vietnam 2021

Introduction

The COVID-19 pandemic has created significant stressors in Vietnamese adolescents' lives. Coping skills play important roles in helping adolescents contend with stress. This study aimed to evaluate adolescents' coping skills during the COVID-19 pandemic and examine how those skills are impacted by excessive internet use during this pandemic.

Methods

The study used respondent-driven sampling and Google online survey forms to collect data. The study sample included 5,315 high school students aged 11- 17 years in Hanoi's rural and urban areas. The Kid Coping Scale was applied to examine adolescents' coping, and the coping score was compared among adolescents with different levels of internet use.

Results

The average coping score measured by Kid Coping Scale was 20.40 (std = 2.13). About half of adolescents often "avoid the problem or the area where it happened" when experiencing a hard time. One-third of adolescents often stopped thinking about the problem they faced. More than one-fourth of respondents stayed online for at least 8 h per day. The online time for learning/other activities showed a reverse dose-response relationship with the coping score; the longer the internet use duration, the lower the coping score.

Conclusion

The mean score of coping of Hanoi adolescents was moderate. Internet use has an adverse impact on their coping skills.

Antibacterial Longevity of a Novel Gallium Liquid Metal/Hydroxyapatite Composite Coating Fabricated by Plasma Spray

Hydroxyapatite (HAp)-coated metallic implants are known for their excellent bioactivity and osteoconductivity. However, infections associated with the microstructure of the HAp coatings may lead to implant failures as well as increased morbidity and mortality. This work addresses the concerns about infections by developing novel composite coatings of HAp and gallium liquid metal (GaLM) using atmospheric plasma spray (APS) as the coating technique. Five weight percent Ga was mixed into a commercially supplied HAp powder using an orbital shaker; then, the HAp-Ga particle feedstock was coated onto Ti₆Al₄V substrates using the APS technique. The X-ray diffraction results indicated that Ga did not form any Ga-related phases in either the HAp-Ga powder or the respective coating. The GaLM filled the pores of the HAp coating presented both on the top surface and within the coating, especially at voids and cracks, to prevent failures of the coating at these locations. The wettability of the surface was changed from hydrophobic for the HAp coating to hydrophilic for the HAp-Ga composite coating. Finally, the HAp-Ga coating presented excellent antibacterial efficacies against both initial attachments and established biofilms generated from methicillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa after 18 h and 7 days of incubation in comparison to the control HAp coating. This study shows that GaLM improves the antibacterial properties of HAp-based coatings without sacrificing the beneficial properties of conventional HAp coatings. Thus, the HAp-Ga APS coating is a viable candidate for antibacterial coatings.

Micro- to nano-scale chemical and mechanical mapping of antimicrobial-resistant fungal biofilms

A fungal biofilm refers to the agglomeration of fungal cells surrounded by a polymeric extracellular matrix (ECM). The ECM is composed primarily of polysaccharides that facilitate strong surface adhesion, proliferation, and cellular protection from the surrounding environment. Biofilms represent the majority of known microbial communities, are ubiquitous, and are found on a multitude of natural and synthetic surfaces. The compositions, and in-turn nanomechanical properties, of fungal biofilms remain poorly understood, because these systems are complex, composed of anisotropic cellular and extracellular material, and importantly are species and environment dependent. Therefore, genomic variation, and/or mutations, as well as environmental and growth factors can change the composition of a fungal cell's biofilm. In this work, we probe the physico-mechanical and biochemical properties of two fungal species, Candida albicans (C. albicans) and Cryptococcus neoformans (C. neoformans), as well as two antifungal resistant sub-species of C. neoformans, fluconazole-resistant C. neoformans (Fluc^RC. neoformans) and amphotericin B-resistant C. neoformans (AmB^RC. neoformans). A new experimental methodology of characterization is proposed, employing a combination of atomic force microscopy (AFM), instrumented nanoindentation, and Synchrotron ATR-FTIR measurements. This allowed the nano-mechanical and chemical characterisation of each fungal biofilm.

How to manage medications in the setting of liver disease with the application of six questions

OBJECTIVE

Reviewing the current literature to guide clinicians managing medications in the setting of liver disease.

LITERATURE SOURCES

Using the terms liver disease, medication management, and therapeutic monitoring, a literature review was conducted to identify peer-reviewed articles in MEDLINE (1966-April 2009). Reference citations were reviewed as an additional resource. Published English-language literatures, articles and trials were reviewed. Emphasis was placed on prospective, randomised, double-blind, placebo-controlled clinical trials.

QUESTION SYNTHESIS

An informed decision on how to manage medications in the setting of liver disease should account for changes that transpire in a medication's first-pass metabolism, protein binding, volume of distribution, clearance and pharmacodynamic interactions. To incorporate these issues within one's thought process, clinicians can utilise the following six questions to evaluate a medication use: (i) Is the patient experiencing acute or chronic liver failure? (ii) Does the drug have high hepatic first-pass metabolism? (iii) Is the medication highly protein-bound? (iv) Is there a change in the volume of distribution for the medication? (v) Is the clearance of the medication significantly altered? and (vi) Is there a pharmacodynamic interaction with the medication?

CONCLUSIONS

The introduction and use of six clinically relevant questions in the setting of liver disease can serve as a guide to clinicians who manage patients with liver disease.

Evaluating the appropriateness of thromboprophylaxis in an acute care setting using a computerised reminder, through order-entry system

AIMS

Evidence suggests that thromboprophylaxis is still significantly underutilised across the United States despite its relationship with morbidity, mortality and resource expenditure. Previous randomised trials that have incorporated computerised reminders, through order-entry systems, have resulted in increased rates of thromboprophylaxis and lower incidences of clinically diagnosed deep-vein thrombosis or pulmonary embolism. The primary purpose of this prospective, observational study is to evaluate the use and appropriateness of preset computerized thromboprophylaxis regimens for patients in a major county metropolitan hospital over a 1-month period by evaluating the proportion of patients actually receiving recommended thromboprophylaxis according to established hospital guidelines.

METHODS

This prospective, observational study was conducted in a large county hospital that recently established an evidence-based routine computerised policy to decrease risk of venous thromboembolism. Physicians, residents, medical interns, medical students, pharmacy students, and nurses were the targets of the investigation. Data were randomly collected between 10 internal medicine teams from 10 October 2006 to 10 November 2006. Investigators completed one DVT/PE risk assessment form for each patient reviewed and compared this to actual prescribed therapy to determine appropriateness of therapy.

RESULTS

Pharmacological or non-pharmacological thromboprophylaxis was administered to 100% of patients evaluated. Eighty-six patients received recommended DVT/PE prophylaxis based on established hospital guidelines.

DISCUSSION

Reported values seem to indicate that computerized reminders are capable of providing venous thromboprophylaxis for medically ill (non-surgical) patients relative to published norms.

CONCLUSION

Results of this observational study reinforces the evidence that computerized, reminders, through order-entry systems might increase the delivery of thromboprophylaxis for hospitalized patients.

Ranolazine: a novel agent that improves dysfunctional sodium channels

Treatment for coronary heart disease is usually directed at either increasing myocardial oxygen supply or decreasing myocardial oxygen demand. Although combination therapy with beta-blockers, calcium-channel blockers and nitrates are effective, many patients suffer from adverse effects of hypotension and bradycardia. Ranolazine is a novel medication that reduces ischaemia by preventing sodium induced calcium overload in myocardial cells without adversely affecting haemodynamic parameters. This agent is the first in the USA to be approved to treat angina in over 10 years. The purpose of this review is to evaluate the pharmacology, pharmacokinetics, clinical trials for safety and efficacy, precautions, adverse effects, drug interactions, and dosage and administration of ranolazine in the treatment of chronic stable angina and acute coronary syndrome.

Structure and location of a ferritin gene of the yellow fever mosquito Aedes aegypti

We have isolated and sequenced a genomic clone encoding the 24- and 26-kDa ferritin subunits in the mosquito Aedes aegypti (Rockefeller strain). The A. aegypti gene differs from other known ferritin genes in that it possesses an additional intron and an unusually large second intron. The additional intron is located within the 5' untranslated region, between the CAP site and the start codon. The second intron contains numerous putative transposable elements. In addition, unlike the human and rat ferritin genes, the A. aegypti ferritin gene is a single copy gene, located at 88.3% FLpter on the q-arm of chromosome 1. Primer extension analysis indicates that the A. aegypti ferritin gene has multiple transcriptional start sites. A differential usage of these sites is observed with varied cellular iron concentrations.

Predictive intervals for age-specific fertility

A multivariate ARIMA model is combined with a Gamma curve to predict confidence intervals for age-specific birth rates by 1-year age groups. The method is applied to observed age-specific births in Norway between 1900 and 1995, and predictive intervals are computed for each year up to 2050. The predicted two-thirds confidence intervals for Total Fertility (TF) around 2010 agree well with TF errors in old population forecasts made by Statistics Norway. The method gives useful predictions for age-specific fertility up to the years 2020-30. For later years, the intervals become too wide. Methods that do not take into account estimation errors in the ARIMA model coefficients underestimate the uncertainty for future TF values. The findings suggest that the margin between high and low fertility variants in official population forecasts for many Western countries are too narrow.

Transcriptional control is relevant in the modulation of mosquito ferritin synthesis by iron

In yellow fever mosquito cells (Aag2 clone), iron treatment induces a threefold increase in ferritin message (fer mRNA) and protein (ferritin) by 16 h. These data contrast with work in mammalian hepatocytes and fibroblasts in which fer mRNA levels do not change with iron stimulation, but ferritin levels increase 50-fold. Pretreatment of the Aag2 cells with actinomycin D blocks induction of fer mRNA and reduces the ferritin subunit synthesis, suggesting that iron induction of ferritin subunit synthesis is subjected to transcriptional control. A putative iron-regulatory protein has also been identified in cytoplasmic extracts from Aag2 cells.

Purification of an expressed insect transferrin from cell culture media using high-capacity Ni(2+)-dipicolylamine gel

Vertebrate transferrin is a well characterized iron transport protein. In contrast, little is known concerning the role of transferrin in insects. Yet, study of iron metabolism in insects could give insights into strategies for insect control, particularly for insects that transmit disease.

Manduca sexta hemolymph ferritin: cDNA sequence and mRNA expression

A cDNA clone encoding a subunit of the tobacco hornworm Manduca sexta (Ms) hemolymph (serum) ferritin (Fer) has been identified and sequenced. The deduced amino acid (aa) sequence shows approx. 50% similarity to vertebrate Fer subunit sequences, and the nucleotide sequence contains a stem-loop structure in the 5' untranslated region that could serve as an iron-responsive element (IRE). The stem-loop of this putative IRE exhibits high identity to vertebrate IRE that play an essential role in the control of Fer synthesis. The Ms Fer subunit lacks one of the three Tyr residues required for the rapid biomineralization of iron shown in vertebrate heavy-chain Fer. In addition, aa residues that comprise the putative ferroxidase centers generally are not conserved, suggesting that the Ms Fer subunit more closely resembles the vertebrate light-chain subunit. Northern blot analyses indicate that the fer mRNA is expressed in the midgut, fat body and hemocytes, with the greatest expression in the midgut.

Purification of recombinant insect transferrin from large volumes of cell culture medium using high capacity Ni(2+)-dipicolylamine gel

We report the purification of secreted recombinant Manduca sexta transferrin from Spodoptera frugiperda (Sf9) cell culture medium in a single step using high capacity Ni(2+)-dipicolylamine (DPA)-Novarose gel. Although the original sample was highly diluted (approximately 10 micrograms transferrin/ml medium) and the cell culture medium contained 10% surfactant (Pluronic F68) and a lipid emulsion, we were able to recover the recombinant transferrin (1 mg protein/100 ml) under gentle elution conditions with 70% yield at > 90% homogeneity. This work demonstrates the versatility of immobilized metal ion affinity chromatography using a high metal ion capacity gel to purify a recombinant protein and illustrates the potential of this affinity technique for protein separations from large volumes of cell culture media that contain surfactants.

The 1629-bp open reading frame of the Autographa californica multinucleocapsid nuclear polyhedrosis virus encodes a virion structural protein

A 1629-bp open reading frame (ORF) of Autographa californica multinucleocapsid nuclear polyhedrosis virus (AcMNPV) is shown to encode a 78-kDa virion structural protein. To determine this, polyclonal antibody was made to a fusion protein synthesized in Escherichia coli from a chimeric gene that contained 1415 bp of the 1629-bp gene. In Western blot analyses, this antibody cross-reacted with a protein of about 78 kDa in both extracellular virions (ECV) and virions isolated from polyhedra (PDV), and with a 78-kDa protein in PDV envelope preparations, but not with PDV nucleocapsids. This suggests that the protein encoded by the 1629-bp ORF is a virion envelope protein or a protein that occurs in the virion intermediate layer between the envelope and nucleocapsid.

Sequence and in vitro translational analysis of a 1629-nucleotide ORF in Autographa californica nuclear polyhedrosis virus strain E2

The complete nucleotide (nt) sequence of an open reading frame (ORF) (map unit 5.1 to 3.8) from Autographa californica nuclear polyhedrosis virus strain E2 (AcMNPV-E2) has been determined. This 1629-nt ORF has a coding potential for a 61-kDa Pro-rich protein. However, in vitro translation of the 1629-nt ORF and sodium dodecyl sulfate-polyacrylamide-gel electrophoresis (SDS-PAGE) revealed a 78-kDa protein product. The discrepancy between the M(r) predicted by the nt sequence and that obtained from the in vitro translational analysis is due to the high Pro content of this protein. The high Pro content causes anomalous migration of this protein during SDS-PAGE.

In vivo transcriptional analysis of three baculovirus genes: evidence of homology between viral and host transcripts

Transcripts for the gp64 and polyhedrin genes as well as a 1629 open reading frame (1629 ORF) of the Autographa californica nuclear polyhedrosis virus were examined in the midgut tissues and hemocytes of uninfected and infected host Trichoplusia ni larvae and Sf21 cells. Polyhedrin-specific transcripts of 1.2, 3.4, and 4.9 kb were expressed in both infected larval tissues and infected Sf21 cells. The highest level of expression for polyhedrin-specific transcripts was observed in hemocytes, whereas the lowest level occurred in midgut. The expression of the 2.0-kb transcript for the gp64 gene increased continuously through 72 hr postinfection in the infected midgut tissues. This transcript was also observed in infected hemocytes, though its expression declined at 72 hr postinfection, as the expression for polyhedrin-specific transcripts peaked. The 1629 ORF transcripts of 2.0 and 3.2 kb were expressed in both types of infected tissues. More significantly, a 1629-ORF-specific probe detected host transcripts of 0.7 and 2.5 kb in uninfected midgut tissues as well as transcripts of 2.5, 8.8, and 11.0 kb in uninfected hemocytes under high stringency conditions. The latter results indicate that these host transcripts share homology with the 1629 ORF gene.