CdS nanoparticles incorporated onion-like mesoporous silica films: Ageing-induced large stokes shifted intense PL emission

CdS nanoparticles (NPs) were generated in onion-like ordered mesoporous SiO2 films through a modified sol–gel process using P123 as a structure directing agent. Initially Cd2+ doped (12 equivalent mol% with respect to the SiO2) mesoporous SiO2 films were prepared on glass substrate.These films after heat-treatment at 350 �C in air yielded transparent mesoporous SiO2 films having hexagonally ordered onion-like pore channels embedded with uniformly dispersed CdO NPs. The generated CdO NPs were transformed into CdS NPs after exposing the films in H2S gas at 200 �C for 2 h. The as-prepared CdS NPs incorporated mesoporous SiO2 films (transparent and bright yellow in color) showed a band-edge emission at 485 nm and a weak surface defect related emission at 530 nm. During ageing of the films in ambient condition the band-edge emission gradually weakened with time and almost disappeared after about 15 days with concomitant increase of defect related strong surface state emission band near 615 nm. This transformation was related to the decay of initially formed well crystalline CdS to relatively smaller and weakly crystalline CdS NPs with surface defects due to gradual oxidation of surface sulfide. At this condition the embedded CdS NPs show large Stokes shifted (�180 nm) intense broad emission which could be useful for luminescent solar concentrators. The detailed process was monitored by UV–Visible, FTIR and Raman spectroscopy, XPS, XRD and TEM studies. The evolution of photoluminescence (PL) and life times of CdS/SiO2 films were monitored with respect to the ageing time

A Comprehensive Review on Seasonal Incidence of Fall Army Worm, Spodoptera frugiperda (J.E. Smith) and Their Management

The Fall Armyworm (FAW), Spodoptera frugiperda, represents a formidable challenge to global agriculture due to its rapid spread and significant impact on crop yields. This comprehensive review focuses on providing an in-depth exploration of FAW's biology, its seasonal dynamics, and the multifaceted strategies employed for its management. Leveraging datasets from multiple geographical regions, we examined the patterns of FAW infestations and their correlation with various climatic and environmental factors. The research emphasized the criticality of predictive modeling tools in forecasting pest incidence and highlighted the potential of machine learning and big data analytics in enhancing the accuracy of these predictive tools. Innovative management solutions, spanning from genetic interventions to the application of nanotechnology, were also discussed, underlining their potential in mitigating FAW damage. Central to our findings was the recurrent theme of international collaboration; the need for globally coordinated efforts in research, monitoring, and the sharing of resources emerged as a pivotal component in the fight against this pest. By incorporating diverse perspectives, including field insights from farmers and advancements in modern technology, this review aims to provide a holistic overview of the present scenario and proffers strategies for future action against the FAW threat

Bacterial and viral pathogen spectra of acute respiratory infections in under-5 children in hospital settings in Dhaka city.

The study aimed to examine for the first time the spectra of viral and bacterial pathogens along with the antibiotic susceptibility of the isolated bacteria in under-5 children with acute respiratory infections (ARIs) in hospital settings of Dhaka, Bangladesh. Nasal swabs were collected from 200 under-five children hospitalized with clinical signs of ARIs. Nasal swabs from 30 asymptomatic children were also collected. Screening of viral pathogens targeted ten respiratory viruses using RT-qPCR. Bacterial pathogens were identified by bacteriological culture methods and antimicrobial susceptibility of the isolates was determined following CLSI guidelines. About 82.5% (n = 165) of specimens were positive for pathogens. Of 165 infected cases, 3% (n = 6) had only single bacterial pathogens, whereas 43.5% (n = 87) cases had only single viral pathogens. The remaining 36% (n = 72) cases had coinfections. In symptomatic cases, human rhinovirus was detected as the predominant virus (31.5%), followed by RSV (31%), HMPV (13%), HBoV (11%), HPIV-3 (10.5%), and adenovirus (7%). Streptococcus pneumoniae was the most frequently isolated bacterial pathogen (9%), whereas Klebsiella pneumaniae, Streptococcus spp., Enterobacter agglomerans, and Haemophilus influenzae were 5.5%, 5%, 2%, and 1.5%, respectively. Of 15 multidrug-resistant bacteria, a Klebsiella pneumoniae isolate and an Enterobacter agglomerans isolate exhibited resistance against more than 10 different antibiotics. Both ARI incidence and predominant pathogen detection rates were higher during post-monsoon and winter, peaking in September. Pathogen detection rates and coinfection incidence in less than 1-year group were significantly higher (P = 0.0034 and 0.049, respectively) than in 1-5 years age group. Pathogen detection rate (43%) in asymptomatic cases was significantly lower compared to symptomatic group (P<0.0001). Human rhinovirus, HPIV-3, adenovirus, Streptococcus pneumonia, and Klebsiella pneumaniae had significant involvement in coinfections with P values of 0.0001, 0.009 and 0.0001, 0.0001 and 0.001 respectively. Further investigations are required to better understand the clinical roles of the isolated pathogens and their seasonality

Comparison of pathogen detection rates between asymptomatic and symptomatic cases of under five children.

<p>Comparison of pathogen detection rates between asymptomatic and symptomatic cases of under five children.</p

Resistance pattern of the isolated bacteria to first line of antibiotics.

<p>Resistance pattern of the isolated bacteria to first line of antibiotics.</p

Comparison of frequencies of each pathogen identified in single infections and coinfections.

<p>Fig 3A compares the frequencies of viruses and Fig 3B compares the bacterial pathogen frequencies in single infections and coinfections. Fisher's exact test was performed for each group. P< 0.05 was considered significant. SPn = <i>S</i>. <i>pneumoniae</i>, KPn = <i>K</i>. <i>pneumoniae</i>, SSp = <i>Streptococcus</i> species.</p

The table displays the coinfection spectrum found in this study.

<p>The table displays the coinfection spectrum found in this study.</p

Resistance patterns of two multi-drug resistant bacteria to second line of antibiotics isolated in this study.

<p>Resistance patterns of two multi-drug resistant bacteria to second line of antibiotics isolated in this study.</p

Prevalence and comparison of different respiratory pathogens between ≤ 1 year and 1–5 years age group.

<p>Prevalence and comparison of different respiratory pathogens between ≤ 1 year and 1–5 years age group.</p

The frequency of specimen collection during the study period.

<p>Y-axis indicates the number of specimens, whereas X-axis indicates months of the year.</p