Explore the vast range of titles available.

The development of high-performance photocatalysts is vital for combating water pollution and microbial contamination. In this study, visible-light-active Z-scheme heterojunction nanocomposites composed of Co3O4 and Nb2O5 (CNNC) were synthesized via co-crystallization and subsequent high-pressure annealing to enhance photocatalytic and antimicrobial performance. Structural and optical analyses via XRD, FESEM, TEM, XPS, and PL confirmed the heterojunction formation between porous Co3O4 nanoparticles (CONP) and columnar orthorhombic Nb2O5 nanoparticles (NONP). The CNNC exhibited significantly improved photocatalytic activity, achieving degradation efficiencies of 95.1% for methylene blue, 72.6% for tetracycline, and 90.0% for Congo red within 150 min. Kinetic studies showed that CNNC’s rate constants were 367% and 466% of those of CONP and NONP, respectively. Moreover, CNNC demonstrated a strong antibacterial effect on Staphylococcus aureus and Escherichia coli with ZOI values of 9.3 mm and 6.8 mm, respectively. Mechanistic analysis revealed that the Z-scheme charge-transfer pathway improved charge separation and reduced electron–hole recombination, contributing to the promoted photocatalytic efficiency. The nanocomposite also showed robust stability and recyclability over five times. These results highlight the promise of CNNC as a bifunctional, visible-light-driven photocatalyst for pollutant decomposition and microbial control.

Efficient photocatalysts based on composite materials are essential for addressing environmental pollution and enhancing water purification. This study presents a novel BiOI/V2O5 nanocomposite (BVNC) with a flower-like layered structure, synthesized via a low-temperature solvothermal process followed by high-pressure annealing for visible light (VL)-driven dye degradation and antibacterial activities. Compared to individual BiOI nanoparticles (BOINP) and V2O5 nanoparticles (VONP), under VL, the BVNC demonstrated significantly enhanced photocatalytic and antibacterial activity. The best-performing BVNC achieved a remarkable methylene blue degradation efficiency of 95.7% within 140 min, with a rate constant value 439% and 430% of those of BOINP and VONP, respectively. Additionally, BVNC exhibited high photocatalytic efficiencies for rhodamine 6G (94.0%), methyl orange (90.4%), and bisphenol A (69.5%) over 160 min, highlighting the superior performance of the composite materials for cationic and anionic dyes. Furthermore, BVNC established outstanding antibacterial capability against Staphylococcus aureus and Escherichia coli, demonstrating zones of inhibition of 12.24 and 11.62 mm, respectively. The improved catalytic and antibacterial capability is ascribed to the presence of a robust p-n heterojunction between BOINP and VONP, which broadens the photo-absorption range, reduces bandgap energy, and facilitates the significant separation of excitons and faster release of reactive oxygen species.

Koala populations in many areas of Australia have declined sharply in response to habitat loss, disease and the effects of climate change. Koalas may face further morbidity from endemic mosquito-borne viruses, but the impact of such viruses is currently unknown. Few seroprevalence studies in the wild exist and little is known of the determinants of exposure. Here, we exploited a large, spatially and temporally explicit koala survey to define the intensity of Ross River Virus (RRV) exposure in koalas residing in urban coastal environments in southeast Queensland, Australia. We demonstrate that RRV exposure in koalas is much higher (> 80%) than reported in other sero-surveys and that exposure is uniform across the urban coastal landscape. Uniformity in exposure is related to the presence of the major RRV mosquito vector, Culex annulirostris , and similarities in animal movement, tree use, and age-dependent increases in exposure risk. Elevated exposure ultimately appears to result from the confinement of remaining coastal koala habitat to the edges of permanent wetlands unsuitable for urban development and which produce large numbers of competent mosquito vectors. The results further illustrate that koalas and other RRV-susceptible vertebrates may serve as useful sentinels of human urban exposure in endemic areas.

Dengue cases in Bangladesh have surged in recent years. The existing insecticide-based control program is challenged by issues of insufficient household coverage and high levels of insecticide resistance in the primary dengue virus (DENV) vector, Aedes aegypti. A more sustainable, effective alternative could be the implementation of a Wolbachia -mediated disease management strategy. Hence, we created and characterised a Wolbachia -infected Ae. aegypti strain with a Dhaka wild-type genetic background, and compared its reproductive compatibility, maternal inheritance, fitness, and virus-blocking ability to the parental strains (Dhaka wild-type and w AlbB2-F4). The new Ae. aegypti strain w AlbB2-Dhaka demonstrated complete cytoplasmic incompatibility with the wild-type and complete maternal transmission, retaining levels of pyrethroid resistance of the Dhaka wild-type. No significant fitness costs were detected during laboratory comparison. Compared to the wild-type, w AlbB2-Dhaka mosquitoes demonstrated a significantly reduced genome copies of DENV in the bodies (44.4%, p  = 0.0034); a two-fold reduction in dissemination to legs and wings (47.6%, p  < 0.0001); and > 13-fold reduction of DENV in saliva expectorates (proxy of transmission potential) (92.7%, p  < 0.0001) 14 days after ingesting dengue-infected blood. Our work indicates that the w AlbB2-Dhaka strain could be used for Ae. aegypti suppression or replacement strategies for dengue management in Bangladesh.

The surveillance and detection of zoonotic pathogens in animals is essential for predicting disease transmission pathways and the risks of spillover, but challenges include the costs, ethics and technical expertise required for vertebrate trapping, serum sampling and antibody or virus screening. Surveillance using haematophagous arthropods as a sampling tool offers a unique opportunity to obtain blood samples from a wide range of vertebrate species, allowing the study of host-mosquito associations, and host exposure to pathogens. We explored vertebrate diversity and potential Ross River virus (RRV) transmission pathways by analysing blood-fed mosquitoes collected in Brisbane, Australia. Host origins were identified using barcode sequencing, and host exposure to RRV was assessed using a modified plaque reduction neutralisation test. In total, 480 blood-fed mosquitoes were collected between February 2021 and May 2022. The host origins of 346 (72%) bloodmeals were identified, with humans (73%) and cattle (9%) comprising the dominant hosts. RRV seroprevalence was high in both vertebrate species with evidence of RRV exposure in 70% (21/30) of cattle and 52% (132/253) of humans. This is a novel, non-invasive method of estimating seroprevalence in vertebrate host populations. Our results highlight the potential of blood-fed mosquitoes to provide species-specific insights into pathogen transmission dynamics.

A facile two-step synthesis of ternary hetero-composites of ZnO, CuO, and single-walled carbon nanotubes (SWCNTs) was developed through a recrystallization process followed by annealing. A series of nanocomposites were prepared by varying the weight ratio of copper(II) acetate hydrate and zinc(II) acetate dihydrate and keeping the weight ratio of SWCNTs constant. The results revealed the formation of heterojunctions (ZnO–SWCNT–CuO, ZSC) of three crystal structures adjacent to each other, forming a ternary wurtzite-structured nanoparticles along with defects. Enhanced charge separation (electron-hole pairs), reduced band gap, defect-enhanced specific surface area, and promoted oxidation potential were key factors for the enhanced photocatalytic activity of the ternary nanocomposites. OH• radicals were the main active species during dye degradation, and O2−• and h+ were also involved to a lesser extent. A type II heterojunction mechanism approach is proposed based on the charge carrier migration pattern. Among the synthesized nanocomposites, the sample prepared using copper(II) acetate hydrate and zinc(II) acetate dihydrate in a 1: 9 ratio (designated a ZSC3) showed the highest photocatalytic activity. ZSC3 achieved 99.2% photodecomposition of methylene blue in 20 min, 94.1% photodecomposition of Congo red in 60 min, and 99.6% photodecomposition of Rhodamine B in 40 min under simulated sunlight. Additionally, ZSC3 showed excellent reusability and stability, maintaining 96.7% of its activity even after five successive uses. Based on overall results, the ZSC sample was proposed as an excellent candidate for water purification applications.

Many arboviruses of public health significance are maintained in zoonotic cycles with complex transmission pathways. The presence of serum antibody against arboviruses in vertebrates provides evidence of their historical exposure but reveals nothing about the vector-reservoir relationship. Moreover, collecting blood or tissue samples from vertebrate hosts is ethically and logistically challenging. We developed a novel approach for screening the immune status of vertebrates against Ross River virus that allows us to implicate the vectors that form the transmission pathways for this commonly notified Australian arboviral disease. A micro-plaque reduction neutralisation test (micro-PRNT) was developed and validated on koala (Phascolarctos cinereus) sera against a standard PRNT. The ability of the micro-PRNT to detect RRV antibodies in mosquito blood meals was then tested using two mosquito models. Laboratory-reared Aedes aegypti were fed, via a membrane, on sheep blood supplemented with RRV seropositive and seronegative human sera. Aedes notoscriptus were fed on RRV seropositive and seronegative human volunteers. Blood-fed mosquitoes were harvested at various time points after feeding and their blood meals analysed for the presence of RRV neutralising antibodies using the micro-PRNT. There was significant agreement of the plaque neutralisation resulting from the micro-PRNT and standard PRNT techniques (R.sup.2 = 0.65; P<0.0001) when applied to RRV antibody detection in koala sera. Sensitivity and specificity of the micro-PRNT assay were 88.2% and 96%, respectively, in comparison with the standard PRNT. Blood meals from mosquitoes fed on sheep blood supplemented with RRV antibodies, and on blood from RRV seropositive humans neutralised the virus by [greater than or equal to]50% until 48 hr post feeding. The vertebrate origin of the blood meal was also ascertained for the same samples, in parallel, using established molecular techniques. The small volumes of blood present in mosquito abdomens can be used to identify RRV antibodies and therefore host exposure to arbovirus infection. In tandem with the accurate identification of the mosquito, and diagnostics for the host origin of the blood meal, this technique has tremendous potential for exploring RRV transmission pathways. It can be adapted for similar studies on other mosquito borne zoonoses.

The spread of COVID-19 is posing significant challenges to the household (HH) waste management sectors putting waste personnel and concerned bodies under massive pressure. The chain of collection, segregation, recycling, and disposal of household generated wastes is interrupted. This study aimed to assess how the household waste management chain was disrupted by novel coronavirus in Nepal and find the perception of the people towards the existing household waste management system (HHWMS). A descriptive online survey was carried out among 512 people using a cross-sectional research design and data was collected through a self-administered questionnaire method. Both descriptive, as well as inferential tests, were conducted using SPSS software. The finding of this study showed that 62.3% of respondents were not satisfied with the present HHWMS. Furthermore, there was a significant association of the satisfaction level of household waste management during coronavirus outbreak with gender, waste volume change in lockdown, PPE for waste collectors, and education on waste handling techniques provided by the government sector at 5% level of significance ( p  < 0.05). Proper HH waste management has become a challenge, and to address this some innovative works such as awareness programs for people, health and hygiene related support to waste workers, and effective policy formulation and implementation should be done by the Government of Nepal.

Japanese encephalitis (JE) is the leading cause of viral encephalitis in Asia. Until 2022, only six locally transmitted human JE cases had been reported in Australia; five in northern Queensland and one in the Northern Territory. Thus, JE was mainly considered to be a disease of travellers. On 4 March 2022, JE was declared a ‘Communicable Disease Incident of National Significance’ when a locally acquired human case was confirmed in southern Queensland. By 11 May 2022, 41 human JE cases had been notified in four states in Australia, in areas where JE has never been detected before. From this perspective, we discuss the potential reasons for the recent emergence of the JE virus in Australia in areas where JE has never been previously reported as well as the implications of and options for mass immunisation programs if the outbreak escalates in a JE virus-immunologically naïve population.

Background More than 70 arboviruses have been identified in Australia and the transmission cycles of most are poorly understood. While there is an extensive list of arthropods from which these viruses have been recovered, far less is known about the non-human hosts that may be involved in the transmission cycles of these viruses and the relative roles of different mosquito species in cycles of transmission involving different hosts. Some of the highest rates of human infection with zoonotic arboviruses, such as Ross River (RRV) and Barmah Forest (BFV) viruses, occur in coastal regions of north-eastern Australia. Methods Engorged mosquitoes collected as a part of routine surveillance using CO 2 -baited light traps in the Rockhampton Region and the adjoining Shire of Livingstone in central Queensland, north-eastern Australia, were analysed for the source of their blood meal. A 457 or 623 nucleotide region of the cytochrome b gene in the blood was amplified by PCR and the amplicons sequenced. The origin of the blood was identified by comparing the sequences obtained with those in GenBank®. Results The most common hosts for the mosquitoes sampled were domestic cattle (26/54) and wild birds (14/54). Humans (2/54) were an infrequent host for this range of mosquitoes that are known to transmit arboviruses causing human disease, and in an area where infections with human pathogens like RRV and BFV are commonly recorded. The blood meals identified in the most abundant vector analysed, Culex annulirostris , were from 10 different vertebrate hosts. The notable detection of chimpanzee blood in two mosquitoes, presumably obtained from a nearby zoo, extends the known range of hosts for this species. Culex quinquefasciatus and Cx. sitiens fed almost exclusively on a variety of bird species. Conclusions While human-mosquito-human transmission of arboviruses like RRV can occur, this study highlights the potential importance of zoonotic cycles of transmission, including avian species, of arboviruses that are indigenous to Australia. Further studies on larger samples of blood-engorged mosquitoes are required to validate the trends observed herein. Moreover, serological and virological evidence that the hosts on which the mosquitoes are feeding are being infected with arboviruses of interest are required.