Robust, Narrow-Band Nanorods LEDs with Luminous Efficacy > 200 lm/W: Next-Generation of Efficient Solid-State Lighting.

Energy-efficient white light-emitting diodes (LEDs) are in high demand across the society. Despite the significant advancements in the modern lighting industry based on solid-state electronics and inorganic phosphor, solid-state lighting (SSL) continues to pursue improved efficiency, saturated color performance, and longer lifetime. Here in this article, robust, narrow emission band nanorods (NRs) are disclosed with tailored wavelengths, aiming to enhance the color rendering index (CRI) and luminous efficacy (LE). The fabricated lighting device consists of NRs of configuration CdSe/ZnxCd1-xS/ZnS, which can independently tune CRI R1-R9 values and maximize the luminous efficacy. For general lighting, NRs with quantum yield (QY) up to 96% and 99% are developed, resulting in ultra-efficient LEDs reaching a record high luminous efficacy of 214 lm W-1 (certified by the National Accreditation Service). Furthermore, NRs are deployed onto mid-power (0.3 W@ 50 mA) LEDs, showing significantly enhanced long-term stability (T95 = 400 h @ 50 mA). With these astonishing properties, the proposed NRs can pave the way for efficient lighting with desired optical spectrum.

Chimeric Forecasting: An experiment to leverage human judgment to improve forecasts of infectious disease using simulated surveillance data.

Forecasts of infectious agents provide public health officials advanced warning about the intensity and timing of the spread of disease. Past work has found that accuracy and calibration of forecasts is weakest when attempting to predict an epidemic peak. Forecasts from a mechanistic model would be improved if there existed accurate information about the timing and intensity of an epidemic. We presented 3000 humans with simulated surveillance data about the number of incident hospitalizations from a current and two past seasons, and asked that they predict the peak time and intensity of the underlying epidemic. We found that in comparison to two control models, a model including human judgment produced more accurate forecasts of peak time and intensity of hospitalizations during an epidemic. Chimeric models have the potential to improve our ability to predict targets of public health interest which may in turn reduce infectious disease burden.

Updates on Management of Biochemical Recurrent Prostate Cancer.

OPINION STATEMENT: Patients with biochemical recurrent prostate cancer (BCR) are a heterogeneous group, whereby a personalized approach to management is critical. Patients with high-risk features such as PSA doubling time (PSADT) ≤ 9-12 months warrant earlier imaging for metastasis detection and consideration for intensified therapy (beyond intermittent androgen deprivation alone) during this phase of BCR-only disease. The BCR phase represents a unique opportunity to impact disease survival and delay metastasis progression. There is compelling evidence from the EMBARK trial that ADT monotherapy is no longer the optimal consideration for high-risk BCR patients.

Comparative genomics of a vertically transmitted thiotrophic bacterial ectosymbiont and its close free-living relative.

Thiotrophic symbioses between sulphur-oxidizing bacteria and various unicellular and metazoan eukaryotes are widespread in reducing marine environments. The giant colonial ciliate Zoothamnium niveum, however, is the only host of thioautotrophic symbionts that has been cultivated along with its symbiont, the vertically transmitted ectosymbiont Candidatus Thiobius zoothamnicola (short Thiobius). Because theoretical predictions posit a smaller genome in vertically transmitted endosymbionts compared to free-living relatives, we investigated whether this is true also for an ectosymbiont. We used metagenomics to recover the high-quality draft genome of this bacterial symbiont. For comparison we have also sequenced a closely related free-living cultured but not formally described strain Milos ODIII6 (short ODIII6). We then performed comparative genomics to assess the functional capabilities at gene, metabolic pathway and trait level. 16S rRNA gene trees and average amino acid identity confirmed the close phylogenetic relationship of both bacteria. Indeed, Thiobius has about a third smaller genome than its free-living relative ODIII6, with reduced metabolic capabilities and fewer functional traits. The functional capabilities of Thiobius were a subset of those of the more versatile ODIII6, which possessed additional genes for oxygen, sulphur and hydrogen utilization and for the acquisition of phosphorus illustrating features that may be adaptive for the unstable environmental conditions at hydrothermal vents. In contrast, Thiobius possesses genes potentially enabling it to utilize lactate and acetate heterotrophically, compounds that may be provided as byproducts by the host. The present study illustrates the effect of strict host-dependence of a bacterial ectosymbiont on genome evolution and host adaptation.

An Efficient Multi-Scale Fusion Network for 3D Organs at Risk (OARs) Segmentation.

Accurate segmentation of organs-at-risks (OARs) is a precursor for optimizing radiation therapy planning. Existing deep learning-based multi-scale fusion architectures have demonstrated a tremendous capacity for 2D medical image segmentation. The key to their success is aggregating global context and maintaining high resolution representations. However, when translated into 3D segmentation problems, existing multi-scale fusion architectures might underperform due to their heavy computation overhead and substantial data diet. To address this issue, we propose a new OAR segmentation framework, called OARFocalFuseNet, which fuses multi-scale features and employs focal modulation for capturing global-local context across multiple scales. Each resolution stream is enriched with features from different resolution scales, and multi-scale information is aggregated to model diverse contextual ranges. As a result, feature representations are further boosted. The comprehensive comparisons in our experimental setup with OAR segmentation as well as multi-organ segmentation show that our proposed OARFocalFuseNet outperforms the recent state-of-the-art methods on publicly available OpenKBP datasets and Synapse multi-organ segmentation. Both of the proposed methods (3D-MSF and OARFocalFuseNet) showed promising performance in terms of standard evaluation metrics. Our best performing method (OARFocalFuseNet) obtained a dice coefficient of 0.7995 and hausdorff distance of 5.1435 on OpenKBP datasets and dice coefficient of 0.8137 on Synapse multi-organ segmentation dataset. Our code is available at https://github.com/NoviceMAn-prog/OARFocalFuse.

Impact of Listening to Indian Classical Music, or Ragas, on the Electroencephalogram: A Meta-Analysis.

Ancient Indian classical music (ICM) has long been lauded and recognized for influencing emotional responses by influencing the human body's resonance. A meta-analysis of prospective case studies published in the last ten years on the effect of ancient Indian music ragas on brain waves is investigated. This meta-analysis aimed to analyze published prospective studies investigating the effect of ancient Indian ragas on EEG in healthy subjects. The present study included prospective studies published since 2012. Studies were obtained by searching four databases, such as PsychINFO, PubMed, Google Scholar, and JSTOR, and searching related journals. Eligibility criteria included studies assessing the impact of listening to Indian classical music on the EEG. Primary outcomes were changes in the brain waves, frequency, and power and their relationship to activity-related arousal, attention, and mental tasks. The studies were analyzed according to the PRISMA guidelines. There were a total of five included studies with 71 participants in the age range of 19-30, and the conditions for the test groups were generally similar except for varying types of ragas used and time of day. Analysis of the data collected from 71 participants revealed that music interventions had statistically significant effects on increasing alpha activity and attention scores. Fractal analysis was sensitive enough to detect EEG brainwave changes while and after listening to the raga musical intervention. Ragas stimulate arousal in different areas of the brain, depending on the emotions they are designed to evoke. However, the synchronized studies together could not highlight a significant relationship between ragas and EEG fractal dimension values. Although the meta-analysis failed to reproduce the same results from the individual studies, potentially due to the small sample size and study variation, the meta-analysis opens doors to the potential of ragas to elicit distinct emotions and serve as robust predictors of emotional response. Future studies can explore the therapeutic potential of various ragas in the clinical setting, such as in the management of cognitive disorders and stress or in modulating heart rate variability and cognitive performance.

Interplay between autotrophic and heterotrophic prokaryotic metabolism in the bathypelagic realm revealed by metatranscriptomic analyses.

BACKGROUND: Heterotrophic microbes inhabiting the dark ocean largely depend on the settling of organic matter from the sunlit ocean. However, this sinking of organic materials is insufficient to cover their demand for energy and alternative sources such as chemoautotrophy have been proposed. Reduced sulfur compounds, such as thiosulfate, are a potential energy source for both auto- and heterotrophic marine prokaryotes. METHODS: Seawater samples were collected from Labrador Sea Water (LSW, ~ 2000 m depth) in the North Atlantic and incubated in the dark at in situ temperature unamended, amended with 1 µM thiosulfate, or with 1 µM thiosulfate plus 10 µM glucose and 10 µM acetate (thiosulfate plus dissolved organic matter, DOM). Inorganic carbon fixation was measured in the different treatments and samples for metatranscriptomic analyses were collected after 1 h and 72 h of incubation. RESULTS: Amendment of LSW with thiosulfate and thiosulfate plus DOM enhanced prokaryotic inorganic carbon fixation. The energy generated via chemoautotrophy and heterotrophy in the amended prokaryotic communities was used for the biosynthesis of glycogen and phospholipids as storage molecules. The addition of thiosulfate stimulated unclassified bacteria, sulfur-oxidizing Deltaproteobacteria (SAR324 cluster bacteria), Epsilonproteobacteria (Sulfurimonas sp.), and Gammaproteobacteria (SUP05 cluster bacteria), whereas, the amendment with thiosulfate plus DOM stimulated typically copiotrophic Gammaproteobacteria (closely related to Vibrio sp. and Pseudoalteromonas sp.). CONCLUSIONS: The gene expression pattern of thiosulfate utilizing microbes specifically of genes involved in energy production via sulfur oxidation and coupled to CO2 fixation pathways coincided with the change in the transcriptional profile of the heterotrophic prokaryotic community (genes involved in promoting energy storage), suggesting a fine-tuned metabolic interplay between chemoautotrophic and heterotrophic microbes in the dark ocean. Video Abstract.

Ultralow Roll-Off Quantum Dot Light-Emitting Diodes Using Engineered Carrier Injection Layer.

Quantum dot (QD) light-emitting diodes (QLEDs) have attracted extensive attention due to their high color purity, solution-processability, and high brightness. Due to extensive efforts, the external quantum efficiency (EQE) of QLEDs has approached the theoretical limit. However, because of the efficiency roll-off, the high EQE can only be achieved at relatively low luminance, hindering their application in high-brightness devices such as near-to-eye displays and lighting applications. Here, this article reports an ultralow roll-off QLED that is achieved by simultaneously blocking electron leakage and enhancing the hole injection, thereby shifting the recombination zone back to the emitting QDs layer. These devices maintain EQE over 20.6% up to 1000 mA cm-2 current density, dropping only by ≈5% from the peak EQE of 21.6%, which is the highest value ever reported for the bottom-emitting red QLEDs. Furthermore, the maximum luminance of the optimal device reaches 320 000 cd m-2 , 2.7 times higher than the control device (Lmax : 128 000 cd m-2 ). A passive matrix (PM) QLED display panel with high brightness based on the optimized device structure is also demonstrated. The proposed approach advances the potential of QLEDs to operate efficiently in high-brightness scenarios.

Influencing Best Practices for Genomic and Germline Testing in Urology.

INTRODUCTION: We evaluated germline and somatic testing practices and compared results from tissue and liquid biopsy specimens in a large community urology setting. METHODS: A retrospective analysis was performed on advanced prostate cancer patients from a single community practice between June 2016 and September 2021. Clinical data and sequencing results from tissue and liquid biopsy specimens were available for 389 patients. Genomic data were available for 81 tissues and 74 liquid biopsy specimens. Comparison of genomic findings included 81 tissues and 27 liquid biopsy specimens. The number of actionable biomarkers and patients screened and enrolled in clinical trials was assessed from germline and somatic testing. Frequency of pathogenically altered genes, alteration types, and biomarkers were assessed from tissue and liquid specimens. Alteration frequency was compared between specimen types for the top 25 altered genes. RESULTS: Clinically relevant alterations were found from germline and somatic testing in both tissue and liquid biopsy specimens. The frequency of microsatellite instability-high, tumor mutational burden-high, or alterations in homologous recombination repair genes was consistent with published findings. Concordance between tissue and liquid findings varied with low circulating tumor DNA. CONCLUSIONS: Germline and somatic testing is critical for treatment decisions and should be standard of care for community practices. Liquid biopsy is a viable alternative when circulating tumor DNA is high.

A user-friendly graphical user interface for dynamic light scattering data analysis.

Dynamic light scattering (DLS) is a commonly used analytical tool for characterizing the size distribution of colloids in a dispersion or a solution. Typically, the intensity of a scattering produced from the sample at a fixed angle from an incident laser beam is recorded as a function of time and converted into time autocorrelation data, which can be inverted to estimate the distribution of colloid diffusivity to estimate the colloid size distribution. For polydisperse samples, this inversion problem, being a Fredholm integral equation of the first kind, is ill-posed and is typically handled using cumulant expansions or regularization methods. Here, we introduce a user-friendly graphical user interface (GUI) for analyzing the measured scattering intensity time autocorrelation data using both the cumulant expansion method and regularization methods, with the latter implemented using various commonly employed algorithms, including NNLS, CONTIN, REPES, and DYNALS. The GUI allows the user to modulate any and all of the fit parameters, offering extreme flexibility. Additionally, the GUI also enables a comparison of the size distributions generated by various algorithms and an evaluation of their performance. We present the fit results obtained from the GUI for model monomodal and bimodal dispersions to highlight the strengths, limitations, and scope of applicability of these algorithms for analyzing time autocorrelation data from DLS.

Importance of residue 248 in Escherichia coli RNase P RNA mediated cleavage.

tRNA genes are transcribed as precursors and RNase P generates the matured 5' end of tRNAs. It has been suggested that residue - 1 (the residue immediately 5' of the scissile bond) in the pre-tRNA interacts with the well-conserved bacterial RNase P RNA (RPR) residue A248 (Escherichia coli numbering). The way A248 interacts with residue - 1 is not clear. To gain insight into the role of A248, we analyzed cleavage as a function of A248 substitutions and N-1 nucleobase identity by using pre-tRNA and three model substrates. Our findings are consistent with a model where the structural topology of the active site varies and depends on the identity of the nucleobases at, and in proximity to, the cleavage site and their potential to interact. This leads to positioning of Mg2+ that activates the water that acts as the nucleophile resulting in efficient and correct cleavage. We propose that in addition to be involved in anchoring the substrate the role of A248 is to exclude bulk water from access to the amino acid acceptor stem, thereby preventing non-specific hydrolysis of the pre-tRNA. Finally, base stacking is discussed as a way to protect functionally important base-pairing interactions from non-specific hydrolysis, thereby ensuring high fidelity during RNA processing and the decoding of mRNA.

Assessment of in situ stabilization and heavy metal toxicity reduction of sugar mill pressmud through pilot scale composting.

Owing to a huge amount of industrial organic waste generation in the recent past, concerned industries are facing immense challenges for in situ treatment and disposal of such wastes. Therefore, in this study, the efficacy assessment of in situ windrow composting of pressmud (PM) produced by sugar industry has been investigated. Samples were grabbed and mixed from windrows having composting days of 15 (PM15), 30 (PM30), and 45 (PM45) and were collected along with a compost sample from the 60th day (PMC) windrow. An investigation of physico-chemical parameters including pH, electrical conductivity, moisture content, volatile solids (VS), ash content, biochemical oxygen demand, chemical oxygen demand, total nitrogen, and C/N ratio was performed for raw PM and other aforementioned samples. Moreover, speciation of heavy metals (Cu, Cr, Ni, Pb, Cd, and Zn), X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopic analyses were performed for PM and PMC to evaluate the heavy metal toxicity and mineralogical and chemical changes. The analysis showed 20.33% reduction in VS content and 53.65% increase in TN content after 60 days of in situ windrow composting. The pH and EC values of PMC were found to be lesser than that of upper values recommended for agricultural purposes. Furthermore, the speciation analysis showed significant reduction in bioavailability of heavy metals. The XRD and FTIR results were confirmatory for transformation of heavy metals into relatively stable forms. The study recommends the windrow composting practice as effective bioconversion technique that stabilizes organic content, enhances humification, and diminishes heavy metal bioavailability for PM and similar other sludges.

Transverse oscillations and an energy source in a strongly magnetized sunspot.

The solar corona is two to three orders of magnitude hotter than the underlying photosphere, and the energy loss of coronal plasma is extremely strong, requiring a heating flux of over 1,000 W m-2 to maintain its high temperature. Using the 1.6 m Goode Solar Telescope, we report a detection of ubiquitous and persistent transverse waves in umbral fibrils in the chromosphere of a strongly magnetized sunspot. The energy flux carried by these waves was estimated to be 7.52 × 106 W m-2, three to four orders of magnitude stronger than the energy loss rate of plasma in active regions. Two-fluid magnetohydrodynamic simulations reproduced the high-resolution observations and showed that these waves dissipate significant energy, which is vital for coronal heating. Such transverse oscillations and the associated strong energy flux may exist in a variety of magnetized regions on the Sun, and could be the observational target of next-generation solar telescopes.

Disease Burden and Treatment Patterns Among US Patients with Hidradenitis Suppurativa: A Retrospective Cohort Study.

INTRODUCTION: Hidradenitis suppurativa (HS) is a chronic, autoinflammatory skin disease associated with many comorbidities. One biologic (adalimumab) is approved for HS. This study assessed the sociodemographic characteristics, comorbidities, treatment patterns, healthcare resource utilization (HCRU) and associated costs of patients with HS following biologic approval. METHODS: This non-interventional, retrospective cohort study involved adult (≥ 18 years) and adolescent (12-17 years) patients diagnosed with HS in the United States (US) using Optum's de-identified Clinformatics® Data Mart Database during the period 1 January 2016 to 31 December 2018. RESULTS: Of 42,843 identified patients, 10,909 met the incident HS patient criteria (10,230 adults, 628 adolescents, 51 patients aged <12 years). Patients were mostly diagnosed by a general practitioner/pediatrician (adults: 41.6%; adolescents: 39.6%) or dermatologist (adults: 22.1%; adolescents: 30.6%). Commonly reported Charlson comorbidities at pre-index in adult patients were diabetes without complications (20.4%), chronic pulmonary disease (16.4%) and diabetes with complications (9.0%), and the most frequent Elixhauser comorbidities were uncomplicated hypertension (38.3%), obesity (22.5%), uncomplicated diabetes (19.0%) and depression (17.4%). The burden of comorbidities generally increased over time after diagnosis in both adults and adolescents. HS-related surgical procedures were uncommon in the 2-years post-index period: an incision and drainage procedure was reported in 7.6% of adults and 6.4% of adolescents. Patients were predominantly treated with both topical and systemic antibiotic treatments (adults: 25.0% and 65.1%, respectively; adolescents: 41.7% and 74.5%, respectively). Biologic prescription was higher in adults than adolescents (3.5% vs. 1.8%). Total healthcare costs for adult and adolescent patients in the 2-years post-index period were US$42,143 and US$16,057, respectively, with outpatient costs accounting for the majority of these costs (US$20,980 and US$8408, respectively). CONCLUSION: In adult and adolescent patients with HS, comorbidity burden continues to increase after diagnosis. All-cause and HS-specific HCRU and costs are high in adults and adolescents with HS. These findings support the need for a multidisciplinary comprehensive care strategy for patients with HS.

Impact of Variant Histology on Oncological Outcomes in Upper Tract Urothelial Carcinoma: Results From the ROBUUST Collaborative Group.

INTRODUCTION: Oncologic implications of variant histology (VH) have been extensively studied in bladder cancer; however, further investigation is needed in upper tract urothelial carcinoma (UTUC). Our study aims to evaluate the impact of VH on oncological outcomes in UTUC patients treated with radical nephroureterectomy (RNU). METHODS: A retrospective analysis was performed on patients who underwent a robotic or laparoscopic RNU for UTUC using the ROBUUST database, a multi-institutional collaborative including 17 centers worldwide. Logistic regression was used to assess the effect of VH on urothelial recurrence (bladder, contralateral upper tract), metastasis, and survival following RNU. RESULTS: A total of 687 patients were included in this study. Median (IQR) age was 71 (64-78) years and 470 (68%) had organ confined disease. VH was present in 70 (10.2%) patients. In a median follow-up of 16 months, the incidence of urothelial recurrence, metastasis, and mortality was 26.8%, 15.3%, and 11.8%, respectively. VH was associated with increased risk of metastasis (HR 4.3, P <.0001) and death (HR 2.0, P =.046). In multivariable analysis, VH was noted to be an independent risk factor for metastasis (HR 1.8, P =.03) but not for urothelial recurrence (HR 0.99, P =.97) or death (HR 1.4, P =.2). CONCLUSION: Variant histology can be found in 10% of patients with UTUC and is an independent risk factor for metastasis following RNU. Overall survival rates and the risk of urothelial recurrence in the bladder or contralateral kidney are not affected by the presence of VH.

Recent advances in conducting polymer-based magnetic nanosorbents for dyes and heavy metal removal: fabrication, applications, and perspective.

Globally, treating and disposing of industrial pollutants is a techno-economic challenge. Industries' large production of harmful heavy metal ions (HMIs) and dyes and inappropriate disposal worsen water contamination. Much attention is required on the development of efficient and cost-effective technologies and approaches for removing toxic HMIs and dyes from wastewater as they pose a severe threat to public health and aquatic ecosystems. Due to the proven superiority of adsorption over other alternative methods, various nanosorbents have been developed for the efficient removal of HMIs and dyes from wastewater and aqueous solutions. Being a good adsorbent, conducting polymer-based magnetic nanocomposites (CP-MNCPs) has drawn more attention for HMIs and dye removal. Conductive polymers' pH-responsiveness makes CP-MNCP ideal for wastewater treatment. The composite material absorbed dyes and/or HMIs from contaminated water could be removed by changing the pH. Here, we review the production strategies and applications of CP-MNCPs for HMIs and dye removal. The review also sheds light on the adsorption mechanism, adsorption efficiency, kinetic and adsorption models, and regeneration capacity of the various CP-MNCPs. To date, various modifications to conducting polymers (CPs) have been explored to improve the adsorption properties. It is evident from the literature survey that the combination of SiO2, graphene oxide (GO), and multi-walled carbon nanotubes (MWCNTs) with CPs-MNCPs enhances the adsorption capacity of nanocomposites to a large extent, so future research should lean toward the development of cost-effective hybrid CPs-nanocomposites.

A neuromorphic bionic eye with filter-free color vision using hemispherical perovskite nanowire array retina.

Spherical geometry, adaptive optics, and highly dense network of neurons bridging the eye with the visual cortex, are the primary features of human eyes which enable wide field-of-view (FoV), low aberration, excellent adaptivity, and preprocessing of perceived visual information. Therefore, fabricating spherical artificial eyes has garnered enormous scientific interest. However, fusing color vision, in-device preprocessing and optical adaptivity into spherical artificial eyes has always been a tremendous challenge. Herein, we demonstrate a bionic eye comprising tunable liquid crystal optics, and a hemispherical neuromorphic retina with filter-free color vision, enabled by wavelength dependent bidirectional synaptic photo-response in a metal-oxide nanotube/perovskite nanowire hybrid structure. Moreover, by tuning the color selectivity with bias, the device can reconstruct full color images. This work demonstrates a unique approach to address the color vision and optical adaptivity issues associated with artificial eyes that can bring them to a new level approaching their biological counterparts.

Use of intra-operative internal distraction for the application of magnetically controlled growth rods (MCGR): a technique for maximizing correction in the rigid immature spine during index surgery.

OBJECTIVE: Operative treatment of early onset scoliosis (EOS) with Magnetically Controlled Growing Rod (MCGR) in moderate-to-severe curves poses a challenge due to the limited amount of force and length available with the implant. The purpose of this study was to assess the use of the intra-operative internal spine distraction using Harrington Outrigger, before definitive implantation of MCGR, with regard to initial correction, maintenance of correction, truncal balance, and complication rates. PATIENTS AND METHODS: 16 EOS patients treated with the application of MCGR using the intra-operative internal distractor technique were included in the study. More than 50% of cases were congenital scoliosis with multiple vertebral anomalies. All patients were followed up for a minimum of 2 years. Radiological measurement of change in Cobb angle, thoracic kyphosis, lumbar lordosis, T1-S1 length, T1-T12l length, and sagittal balance were done at pre-op, immediate post-op, after 1 year, and 2 years. All the complications were noted and documented. RESULTS: The mean age of the operated patients was 8 ± 1.7 years, range (4-10 years). Mean pre-operative Cobb angle was 70.4 degrees. The mean correction of major Cobb angle was 34.6°. The percentage correction achieved in post-operative Cobb angle was about 51%. Mean change in post-operative thoracic kyphosis was 18.5° (40%). The average gain in immediate post-operative spinal length (T1-S1) and thoracic height (T1-T12) was 46.7 mm (18.3%) and 41 mm (23%), respectively. CONCLUSION: Large and rigid curves in EOS can achieve a significant correction of Cobb angle and coronal imbalance during the index operation, by the use of intra-operative internal distraction at the time of MCGR insertion. LEVEL AND TYPE OF STUDY: Retrospective clinical study, level 4.

Enhancement of CO gas sensing performance by Mn-doped porous ZnSnO3 microspheres.

This work reports the synthesis of Mn-doped ZnSnO3 microspheres (Zn1-x Mn x SnO3) using a simple co-precipitation method with (x = 0 to 0.15) and characterized for structural, morphological, surface area, and sensing properties. X-ray diffraction (XRD) analysis revealed the face-centered cubic structure of Mn-doped ZnSnO3 samples. Brunauer-Emmett-Teller (BET) analysis demonstrated the variation in surface area from 15.229 m2 g-1 to 42.999 m2 g-1 with x = 0 to 0.15 in Zn1-x Mn x SnO3. XPS indicates the change in the defect levels by Mn doping, which plays a crucial role in chemical sensors. Indeed a significant increase (≈311.37%) in CO gas sensing response was observed in the x = 0.10 sample compared to pure ZnSnO3 with a simultaneous reduction in operating temperature from 250 to 200 °C. Moreover, remarkable enhancements in response/recovery times (≈6.6/34.1 s) were obtained in the x = 0.10 sample. The Mn-doped ZnSnO3 could be a promising candidate for CO gas sensing devices used for maintaining air quality.