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In gram-positive bacteria, phosphorylated arginine functions as a protein degradation signal in a similar manner as ubiquitin in eukaryotes. The protein-arginine phosphorylation is mediated by the McsAB complex, where McsB possesses kinase activity and McsA modulates McsB activity. Although mcsA and mcsB are regulated within the same operon, the role of McsA in kinase activity has not yet been clarified. In this study, we determined the molecular mechanism by which McsA regulates kinase activity. The crystal structure of the McsAB complex shows that McsA binds to the McsB kinase domain through a second zinc-coordination domain and the subsequent loop region. This binding activates McsB kinase activity by rearranging the catalytic site, preventing McsB self-assembly, and enhancing stoichiometric substrate binding. The first zinc-coordination and coiled-coil domains of McsA further activate McsB by reassembling the McsAB oligomer. These results demonstrate that McsA is the regulatory subunit for the reconstitution of the protein-arginine kinase holoenzyme. This study provides structural insight into how protein-arginine kinase directs the cellular protein degradation system.
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Arginina Quinasa , Proteínas Quinasas , Proteínas Quinasas/metabolismo , Arginina Quinasa/metabolismo , Arginina/metabolismo , Proteínas Bacterianas/metabolismo , Fosforilación , ZincRESUMEN
BACKGROUND: Post-kala-azar dermal leishmaniasis (PKDL) is a dermatosis that occurs 2-3 years after an apparently successful treatment of visceral leishmaniasis (VL). In rare cases, PKDL occurs concurrently with VL and is characterized by fever, splenomegaly, hepatomegaly or lymphadenopathy, and poor nutritional status and is known as Para-kala-azar dermal leishmaniasis (Para-KDL). Co-association of active VL in PKDL patients is documented in Africa, but very few case reports are found in South Asia. We present a case of Para-kala-azar Dermal Leishmaniasis (Para-KDL) in a 50-year-old male patient with a history of one primary Visceral Leishmaniasis (VL) and 2 times relapse of Visceral Leishmaniasis (VL). The patient presented with fever, skin lesions, and hepatosplenomegaly. Laboratory tests revealed LD bodies in the slit skin smear and splenic biopsy. The patient was treated with two cycles of Amphotericin B with Miltefosine in between cycles for 12 weeks to obtain full recovery. CONCLUSION: This case report serves as a reminder that Para-kala-azar dermal leishmaniasis can develop as a consequence of prior visceral leishmaniasis episodes, even after apparently effective therapy. Since para-kala-azar is a source of infectious spread, endemics cannot be avoided unless it is effectively recognized and treated.
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Antiprotozoarios , Leishmaniasis Cutánea , Leishmaniasis Visceral , Masculino , Humanos , Persona de Mediana Edad , Leishmaniasis Visceral/complicaciones , Leishmaniasis Visceral/diagnóstico , Leishmaniasis Visceral/tratamiento farmacológico , Leishmaniasis Cutánea/complicaciones , Leishmaniasis Cutánea/diagnóstico , Leishmaniasis Cutánea/tratamiento farmacológico , Antiprotozoarios/uso terapéutico , Anfotericina B/uso terapéutico , RecurrenciaRESUMEN
Global barley production is threatened by plant pathogens, especially the rusts. In this study we used a targeted genotype-by-sequencing (GBS) assisted GWAS approach to identify rust resistance alleles in a collection of 287 genetically distinct diverse barley landraces and historical cultivars available in the Australian Grains Genebank (AGG) and originally sourced from Eastern Europe. The accessions were challenged with seven US-derived cereal rust pathogen races including Puccinia hordei (Ph-leaf rust) race 17VA12C, P. coronata var. hordei (Pch-crown rust) race 91NE9305 and five pathogenically diverse races of P. striiformis f. sp. hordei (Psh-stripe rust) (PSH-33, PSH-48, PSH-54, PSH-72 and PSH-100) and phenotyped quantitatively at the seedling stage. Novel resistance factors were identified on chromosomes 1H, 2H, 4H and 5H in response to Pch, whereas a race-specific QTL on 7HS was identified that was effective only to Psh isolates PSH-72 and PSH-100. A major effect QTL on chromosome 5HL conferred resistance to all Psh races including PSH-72, which is virulent on all 12 stripe rust differential tester lines. The same major effect QTL was also identified in response to leaf rust (17VA12C) suggesting this locus contains several pathogen specific rust resistance genes or the same gene is responsible for both leaf rust and stripe rust resistance. Twelve accessions were highly resistant to both leaf and stripe rust diseases and also carried the 5HL QTL. We subsequently surveyed the physical region at the 5HL locus for across the barley pan genome variation in the presence of known resistance gene candidates and identified a rich source of high confidence protein kinase and antifungal genes in the QTL region.
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Basidiomycota , Hordeum , Mapeo Cromosómico , Hordeum/genética , Hordeum/microbiología , Resistencia a la Enfermedad/genética , Australia , Fenotipo , Basidiomycota/genética , Enfermedades de las Plantas/genética , Enfermedades de las Plantas/microbiologíaRESUMEN
The dimension of plasmonic nanostructures does matter in localizing electromagnetic (EM) field and improving surface-enhanced Raman scattering (SERS) activity. Zero-dimensional (0D), one-dimensional (1D) and two-dimensional (2D) plasmonic nanostructures are promising candidates to validate SERS enhancement and the mechanisms thereof. In this work, silver (Ag) nanoparticles (NPs), nanoneedles (NNs) and nanorings (NRs) have been considered to demonstrate the impact of EM near-field distributions on SERS of the corresponding 0D (i.e. Ag-NPs), 1D (i.e. Ag-NNs) and 2D (i.e. Ag-NRs) nanostructures. Ag-NPs, Ag-NNs and Ag-NRs fabricated on zinc oxide (ZnO) ultrathin layer through sputtering technique have been characterized thoroughly by high-resolution field emission scanning electron microscopy (FESEM). FESEM micrographs confirmed a relatively narrow size distribution, 48.88 ± 8.32 nm, of Ag-NPs along with an estimated coverage density of â¼4 × 1010 cm-2. In the case of 1D nanostructures, Ag-NNs were estimated to have a relatively broadened length distribution, 534.36 ± 85.61 nm, and relatively narrow base distribution, 77.39 ± 25.25 nm, along with an estimated coverage density of â¼5 × 108 cm-2. However, as for 2D nanostructures, the FESEM micrographs revealed that Ag-NRs consisted of Ag clusters of various shapes and sizes, instead of a perfect ring structure along with much lower coverage density, â¼8.05 × 103 cm-2. The same specimens were used in microscopic SERS measurements and SERS activities were evaluated for individual nanostructures using Rhodamine 6G as Raman-active dye. The SERS activity of Ag-NRs was found to be the highest with reference to those of Ag-NPs and Ag-NNs. The scenario was supported as well by EM near-field distributions extracted from finite difference time domain (FDTD) analysis. Three models were developed according to the FESEM micrographs of Ag-NPs, Ag-NNs and Ag-NRs nanostructures and FDTD analysis was carried out to understand EM near-field distributions for individual nanostructures. EM near-field distributions at different planes for individual models were extracted for s-, p- and 45° incident polarizations. Such a correlated investigation facilitated an understanding and correlation of the impact of EM near-field distributions on SERS of the corresponding 0D (i.e. Ag-NPs), 1D (i.e. Ag-NNs) and 2D (i.e. Ag-NRs) nanostructures.
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In the present study, we propose a novel type of lead-free double halide perovskite Cs2AgAsCl6 material exhibiting exceptional photovoltaic and photocatalytic properties. Density functional theory (DFT) is employed to investigate the photovoltaic and photocatalytic properties based on several significant properties of the Cs2AgAsCl6 material. The thermodynamic stability of Cs2AgAsCl6 has been confirmed by the enthalpy formation, which is -32.36 eV f.u.-1 Dispersion of phonons near the gamma point confirmed the existence of dynamical stability. The constant value of the heat capacity is 59.45 cal per cell K, which is calculated by the Dulong-Petit limit. The GGA-PBE and HSE-06 functional approaches determined indirect bandgaps of 1.31 and 2.49 eV, respectively, for a semiconductor whose electronic properties revealed photocatalytic efficiency. The effective masses of an electron and a hole are 0.46 me and 0.61 me, respectively, which may enhance the photocatalytic dye degradation owing to their low carrier effective mass. Notably, better photocatalytic properties, i.e., dye degradation, are confirmed by the redox potential. The estimated edge potentials of the conduction band (CB) and valence band (VB) are -0.048 and 2.448 eV, respectively, which are greater than the H+/H2 and O2/H2O potentials. The Cs2AgAsCl6 material reveals an outstanding optical property that is suitable for photovoltaic applications. Therefore, Cs2AgAsCl6 can act as a potential candidate in the field of photovoltaic and photocatalytic applications.
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A series of quinazolin-4(3H)-one derivatives were synthesised and evaluated for their cytotoxicity against human Caucasian breast adenocarcinoma (MCF-7) and human ovarian carcinoma (A2780) cell lines. Cytotoxicity of the most tested compounds was 2- to 30-fold more than the positive control lapatinib (IC50 of 2j = 3.79 ± 0.96; 3j = 0.20 ± 0.02; and lapatinib = 5.9 ± 0.74) against MCF7 cell lines except two compounds (IC50 of 2 b = 15.72 ± 0.07 and 2e = 14.88 ± 0.99). On the other hand, cytotoxicity was 4 - 87 folds (IC50 of 3a = 3.00 ± 1.20; 3 g = 0.14 ± 0.03) more the positive control lapatinib (IC50 = 12.11 ± 1.03) against A2780 cell lines except compound 2e (IC50 = 16.43 ± 1.80). Among the synthesised quinazolin-4(3H)-one derivatives, potent cytotoxic 2f-j and 3f-j were investigated for molecular mechanism of action. Inhibitory activities of the compounds were tested against multiple tyrosine protein kinases (CDK2, HER2, EGFR and VEGFR2) enzymes. As expected, all the quinazolin-4(3H)-one derivatives were showed comparable inhibitory activity against those kinases tested, especially, compound 2i and 3i showed potent inhibitory activity against CDK2, HER2, EGFR tyrosine kinases. Therefore, molecular docking analysis for quinazolin-4(3H)-one derivatives 2i and 3i were performed, and it was revealed that compounds 2i and 3i act as ATP non-competitive type-II inhibitor against CDK2 kinase enzymes and ATP competitive type-I inhibitor against EGFR kinase enzymes. However, in case of HER2, compounds 2i act as ATP non-competitive type-II inhibitor and 3i act as ATP competitive type-I inhibitor. Docking results of known inhibitors were compared with synthesised compounds and found synthesised 2i and 3i are superior than the known inhibitors in case of interactions. In addition, in silico drug likeness properties of quinazolin-4(3H)-one derivatives showed better predicted ADME values than lapatinib.
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Antineoplásicos/farmacología , Inhibidores de Proteínas Quinasas/farmacología , Proteínas Tirosina Quinasas/antagonistas & inhibidores , Quinazolinonas/farmacología , Antineoplásicos/síntesis química , Antineoplásicos/química , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Ensayos de Selección de Medicamentos Antitumorales , Humanos , Estructura Molecular , Inhibidores de Proteínas Quinasas/síntesis química , Inhibidores de Proteínas Quinasas/química , Proteínas Tirosina Quinasas/metabolismo , Quinazolinonas/síntesis química , Quinazolinonas/química , Relación Estructura-ActividadRESUMEN
Mutations in the SMPX gene can disrupt the regular activity of the SMPX protein, which is involved in the hearing process. Recent reports showing a link between nonsynonymous single-nucleotide polymorphisms (nsSNPs) in SMPX and hearing loss, thus classifying deleterious SNPs in SMPX will be an uphill task before designing a more extensive population study. In this study, damaging nsSNPs of SMPX from the dbSNP database were identified by using 13 bioinformatics tools. Initially, the impact of nsSNPs in the SMPX gene were evaluated through different in silico predictors; and the deleterious convergent changes were analyzed by energy-minimization-guided residual network analysis. In addition, the pathogenic effects of mutations in SMPX-mediated protein-protein interactions were also characterized by structural modeling and binding energy calculations. A total of four mutations (N19D, A29T, K54N, and S71L) were found to be highly deleterious by all the tools, which are located at highly conserved regions. Furthermore, all four mutants showed structural alterations, and the communities of amino acids for mutant proteins were readily changed, compared to the wild-type. Among them, A29T (rs772775896) was revealed as the most damaging nsSNP, which caused significant structural deviation of the SMPX protein, as a result reducing the binding affinity to other functional partners. These findings reflect the computational insights into the deleterious role of nsSNPs in SMPX, which might be helpful for subjecting wet-lab confirmatory analysis.
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Simulación por Computador , Bases de Datos Genéticas , Pérdida Auditiva/genética , Proteínas Musculares/genética , Proteínas Musculares/metabolismo , Polimorfismo de Nucleótido Simple , Pérdida Auditiva/patología , Humanos , Modelos Moleculares , Proteínas Musculares/química , Conformación Proteica , Mapas de Interacción de Proteínas , Estabilidad ProteicaRESUMEN
Isatin derivatives potentially act on various biological targets. In this article, a series of novel isatin-hydrazones were synthesized in excellent yields. Their cytotoxicity was tested against human breast adenocarcinoma (MCF7) and human ovary adenocarcinoma (A2780) cell lines using MTT assay. Compounds 4j (IC50 = 1.51 ± 0.09 µM) and 4k (IC50 = 3.56 ± 0.31) showed excellent activity against MCF7, whereas compound 4e showed considerable cytotoxicity against both tested cell lines, MCF7 (IC50 = 5.46 ± 0.71 µM) and A2780 (IC50 = 18.96± 2.52 µM), respectively. Structure-activity relationships (SARs) revealed that, halogen substituents at 2,6-position of the C-ring of isatin-hydrazones are the most potent derivatives. In-silico absorption, distribution, metabolism and excretion (ADME) results demonstrated recommended drug likeness properties. Compounds 4j (IC50 = 0.245 µM) and 4k (IC50 = 0.300 µM) exhibited good inhibitory activity against the cell cycle regulator CDK2 protein kinase compared to imatinib (IC50 = 0.131 µM). A molecular docking study of 4j and 4k confirmed both compounds as type II ATP competitive inhibitors that made interactions with ATP binding pocket residues, as well as lacking interactions with active state DFG motif residues.
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Neoplasias de la Mama/enzimología , Quinasa 2 Dependiente de la Ciclina , Citotoxinas , Hidrazonas , Isatina , Simulación del Acoplamiento Molecular , Proteínas de Neoplasias , Neoplasias Ováricas/enzimología , Inhibidores de Proteínas Quinasas , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/patología , Quinasa 2 Dependiente de la Ciclina/antagonistas & inhibidores , Quinasa 2 Dependiente de la Ciclina/química , Citotoxinas/química , Citotoxinas/farmacología , Femenino , Humanos , Hidrazonas/química , Hidrazonas/farmacología , Isatina/química , Isatina/farmacología , Células MCF-7 , Proteínas de Neoplasias/antagonistas & inhibidores , Proteínas de Neoplasias/química , Proteínas de Neoplasias/metabolismo , Neoplasias Ováricas/tratamiento farmacológico , Neoplasias Ováricas/patología , Inhibidores de Proteínas Quinasas/química , Inhibidores de Proteínas Quinasas/farmacologíaRESUMEN
A biomedical sensor was developed to measure local pH near orthopedic implants to detect and study implant-associated infection. The sensor is read using plain radiography, a technique which is noninvasive, inexpensive, ubiquitously available in medical facilities, and routinely used in diagnosis and follow-up. The sensor comprises a radiopaque tungsten indicator pin embedded within a chemically responsive hydrogel that exhibits a pH-dependent swelling. A stainless steel well holds this hydrogel and attaches to an orthopedic plate. The local pH may be determined from the extent of hydrogel swelling by radiographically measuring the indicator position relative to the well. We calibrated the sensor in a series of standard pH buffers and tested it during bacterial growth in culture. The sensor was robust: its response was negligibly affected by changes in temperature, ionic strength within the normal physiological range, or long-term incubation with reactive oxygen species generated from hydrogen peroxide and copper. Pooled data from several sensors fabricated at different times and tested in different conditions had a root-mean-square deviation from a pH electrode reading of 0.24 pH units. Radiographic measurements were also performed in cadaveric tissue with the sensor attached to an orthopedic plate fixed to a tibia. Pin position readings varied by 100 µm between observers surveying the same radiographs, corresponding to 0.065 pH units precision in the range pH 4-8. The sensor was designed to augment standard radiographs of tissue, bony anatomy, and hardware by also indicating local chemical concentrations.
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Resinas Acrílicas/química , Hidrogeles/química , Prótesis e Implantes/microbiología , Radiografía/métodos , Humanos , Concentración de Iones de Hidrógeno , Staphylococcus aureus/metabolismoRESUMEN
Tissue Banking and Biomaterial Research Unit (TBBRU), the only tissue bank of Bangladesh, has been established to create an available supply of human tissue allografts for transplantation in Bangladesh. Since its establishment in 2003, TBBRU strictly follows the guidelines of tissue banking setup by the International Atomic Energy Agency, the European Association of Tissue Banks and the American Association of Tissue Banks. Though started serving from earlier, regular supply of tissue allografts from this bank were documented at the end of 2006. From January 2007 to December 2014, 3747 bones and 5772 amniotic sacs were collected from live tissue donors. During this period, 59,489 cc bone allografts and 23,472 pieces of amniotic membrane allografts were processed. In the same period, 58,483 cc bone allografts and 20,786 pieces membrane were supplied to different hospitals throughout the country on the basis of demand. The outcomes of the concerted efforts of tissue banking professionals and physicians were the restoration of health and hope of 3662 patients during the last 8 years.
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Bancos de Tejidos , Aloinjertos , Bangladesh , Trasplante Óseo , Humanos , Donantes de Tejidos , Recolección de Tejidos y ÓrganosRESUMEN
BACKGROUND: Root is the prime organ that sucks water and nutrients from deep layer of soil. Wild barley diversity exhibits remarkable variation in root system architecture that seems crucial in its adaptation to abiotic stresses like drought. In the present study, we performed quantitative trait locus (QTL) mapping of root and related shoot traits under control and drought conditions using a population of wild barley introgression lines (ILs). This population (S42IL) comprising of genome-wide introgressions of wild barley accession ISR42-8 in the cultivar Scarlett background. Here, we aimed to detect novel QTL alleles for improved root and related shoot features and to introduce them in modern cultivars. RESULTS: The cultivar Scarlett and wild barley accession ISR42-8 revealed significant variation of root and related shoot traits. ISR42-8 showed a higher performance in root system attributes like root dry weight (RDW), root volume (RV), root length (RL) and tiller number per plant (TIL) than Scarlett. Whereas, Scarlett exhibited erect type growth habit (GH) as compared to spreading growth habit in ISR42-8. The S42IL population revealed significant and wide range of variation for the investigated traits. Strong positive correlations were found among the root related traits whereas GH revealed negative correlation with root and shoot traits. The trait-wise comparison of phenotypic data with the ILs genetic map revealed six, eight, five, five and four QTL for RL, RDW, RV, TIL and GH, respectively. These QTL were linked to one or several traits simultaneously and localized to 15 regions across all chromosomes. Among these, beneficial QTL alleles of wild origin for RL, RDW, RV, TIL and GH, have been fixed in the cultivar Scarlett background. CONCLUSIONS: The present study revealed 15 chromosomal regions where the exotic QTL alleles showed improvement for root and related shoot traits. These data suggest that wild barley accession ISR42-8 bears alleles different from those of Scarlett. Hence, the utility of genome-wide wild barley introgression lines is desirable to test the performance of individual exotic alleles in the elite gene pool as well as to transfer them in the cultivated germplasm.
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Hordeum/genética , Raíces de Plantas/genética , Adaptación Fisiológica , Mapeo Cromosómico , Cromosomas de las Plantas/genética , Genes de Plantas , Estudios de Asociación Genética , Hordeum/crecimiento & desarrollo , Raíces de Plantas/crecimiento & desarrollo , Sitios de Carácter CuantitativoRESUMEN
In the title compound, C16H8N6O2S2·2C2H6OS, the phenanthroline mol-ecule resides on a twofold axis, and the asymmetric unit also contains a slightly disordered [occupancy ratio for S atom of 0.95â (3):0.047â (3)] mol-ecule of dimethyl sulfoxide. The O atoms of the solvent mol-ecule accept hydrogen bonds from the N-H groups of the five-membered 2,3-di-hydro-1,3,4-oxa-diazole-2-thione ring. This ring is nearly coplanar with the phenanthroline ring, with a dihedral angle between their least-squares planes of 8.86â (6)°. In the crystal, the mol-ecules are linked by C-Hâ¯O inter-actions.
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In the cutting-edge world, semiconductor metal oxides usually tend to have a high optical band gap (>3.0 eV), significantly acceptable for potential optoelectronic applications. The present study discusses the synthesize of pristine tungsten trioxide (WO3) and Silver (Ag) doped WO3 (Ag: WO3) thin films onto a glass substrate at 450 °C, with varying concentrations of Ag doping (2, 4, 6, 8 and 10 at.%) using a simple Spray Pyrolysis Technique. Field emission scanning electron microscopy (FESEM) analysis showed the presence of particles in the WO3 and Ag: WO3 materials. The X-ray diffraction (XRD) pattern confirmed that the samples' hexagonal structure remained intact. In addition, Rietveld refinement was used for the samples to study the crystal structure meticulously. Because of the surface plasmon resonance effect, the samples' distinguishing characteristics were visible in their optical nature. For pristine WO3, the experimental band gap was determined to be 3.20 eV, and for varying doping concentrations, it was found to be 3.15 eV-2.90 eV, respectively. Furthermore, the fracture has remained imperceptible at elevated concentrations, resulting in a substantial influence on the optical characteristics of 10% Ag: WO3 thin films. The estimated redox potential for 2% Ag: WO3 shows a considerable influence of the band edge potential of the Conduction Band (CB) and Valance Band (VB). The activation energy was determined using temperature-dependent electrical resistivity and exhibited an ohmic nature. The synthesized material exhibited a negative temperature coefficient (NTC) effect at higher concentrations of doping, suggesting its potential applicability as a thermistor. A comprehensive analysis of this present study indicates that Ag can be a viable candidate for doping on WO3 thin films for use in optoelectronic devices.
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This study focuses on investigating the use of mobile phones among young drivers by employing an online questionnaire survey data. Ordinal logistic regression model was used for modelling the probabilities of crashes due to different uses of mobile phone while driving. Moreover, binary logistic regression models were used for predicting the probabilities of different uses of mobile phone. Logistic regression models revealed that texting and internet use have the same likelihood of causing crashes. Drivers having prior experience of being fined for mobile phone use, also showed a higher tendency to be involved in 2 crashes. Moreover, these drivers had a higher likelihood of being involved in texting, as compared to other uses of mobile phones. Drivers with more education had a higher tendency for internet use during driving. Drivers who use mobile phone for long periods during driving have a lesser tendency to get involved in texting, internet use or GPS navigation. Moreover, drivers with a previous crash record have less likelihood of being involved in texting. The models of this study can be useful in developing effective road safety measures. Clustering was also applied in this study which reinforced the findings of the statistical analysis and models.
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Conducción de Automóvil , Teléfono Celular , Humanos , Accidentes de Tránsito , Modelos Logísticos , Análisis por ConglomeradosRESUMEN
Plastics have advanced society as a lightweight, inexpensive material of choice, and consequently over 400 million metric tons of plastics are produced each year. The difficulty with their reuse, due to varying chemical structures and properties, is leading to one of the major global challenges of the 21st century-plastic waste management. While mechanical recycling has been proven successful for certain types of plastic waste, most of these technologies can only recycle single types of plastics at a time. Since most recycling collection streams today have a mixture of different plastic types, additional sorting is required before the plastic waste can be processed by recyclers. To combat this problem, academics have devoted their efforts to developing technologies such as selective deconstruction catalysts or compatibilizer for commodity plastics and new types of upcycled plastics. In this review, the strengths and challenges of current commercial recycling processes are discussed, followed by examples of the advancement in academic research. Bridging a gap to integrate new recycling materials and processes into current industrial practices will improve commercial recycling and plastic waste management, as well as create new economies. Furthermore, establishing closed-loop circularity of plastics by the combined efforts of academia and industry will contribute toward establishing a net zero carbon society by significant reduction of carbon and energy footprints. This review serves as a guide to understand the gap and help to create a path for new discovery in academic research to be integrated into industrial practices.
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Ferrocement panels are thin-section panels that are widely used in lightweight construction. Due to lesser flexural stiffness, they are susceptible to surface cracking. Water may penetrate through these cracks and may cause corrosion of conventional thin steel wire mesh. This corrosion is one of the major factors which affect the load-carrying and durability of ferrocement panels. There is a need to improve the mechanical performance of ferrocement panels either through using some non-corrodible reinforcing mesh or through improving the cracking behavior of the mortar mix. In the present experimental work, PVC plastic wire mesh is employed to address this problem. SBR latex and polypropylene (PP) fibers are also utilized as admixtures to control the micro-cracking and improve the energy absorption capacity. The main idea is to improve the structural performance of ferrocement panels that may be utilized in lightweight, low-cost house construction and sustainable construction. The ultimate flexure strength of ferrocement panels employing PVC plastic wire mesh, welded iron mesh, SBR latex, and PP fibers is the subject of the research. Test variables are the type of mesh layer, the dosage of PP fiber, and SBR latex. Experimental tests are conducted on 16 simply supported panels of size 1000 × 450 mm and subjected to four-point bending test. Results indicate that the addition of latex and PP fibers only controls the initial stiffness and does not have any significant effect on ultimate load. Due to the increased bonding between cement paste and fine aggregates, the addition of SBR latex improves the flexural strength by 12.59% and 11.01% for iron mesh (SI) and PVC plastic mesh (SP), respectively. The results also indicate an improvement in the flexure toughness of specimens with PVC mesh as compared to specimens with iron welded mesh; however, a smaller peak load is observed (i.e., 12.21% for control specimens) compared with the specimen with welded iron mesh. The failure patterns of the specimens with PVC plastic mesh exhibit a smeared cracking pattern that shows that they are more ductile compared to samples with iron mesh.
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Burn has terrible consequences for the affected patients, making them vulnerable to wound infections and septicemia, which results in physical and mental disability and death, necessitating superior treatment options. Human amniotic membrane (HAM) has been utilized in burn wounds for decades for its low immunogenicity, angiogenic, anti-inflammatory, and antimicrobial properties and for promoting epithelialization. Silver nanoparticles (AgNPs), on the other hand, have antimicrobial properties and promote fibroblast migration. This study aimed to determine the burn wound healing potential of HAM + AgNPs. The gel was prepared using HAM (1% and 2%), AgNPs, carbopol 934, acrylic acid, glycerine, and triethanolamine, and different physical properties (pH, water absorption, swelling variation, spreadability, etc.) of the gel were determined; nuclear magnetic resonance (NMR) spectroscopy, antibacterial activity, brine shrimp lethality test, and histopathological observation were conducted. In vivo studies with Wistar rats demonstrated better healing capabilities than individual components of the gel. Wound contraction percentage after 20 days was 96.1 ± 0.27% which was highly significant (p < 0.0001), and the epithelialization period was 23.67 ± 2.05 days (p < 0.01) for HAM + AgNPs which was preferable to the positive control, AgNPs, HAM, and negative control; also, the histopathologic observation using hematoxylin and eosin, and Masson's trichrome staining were showed the better healing progress for HAM + AgNPs. Both HAM and AgNPs had antibacterial activities against gram-positive and gram-negative bacteria. These results indicated that the formulated HAM + AgNPs gel had remarkable effectiveness in burn wound healing compared to others. Further studies will be conducted to determine the molecular mechanism behind wound healing.
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The Intergovernmental Panel on Climate Change (IPCC) 6th Assessment Report (AR6) forecasts a sea level rise (SLR) of up to 2 m by 2100, which poses significant risks to regional geomorphology. As a country with a rapidly developing economy and substantial population, Bangladesh confronts unique challenges due to its extensive floodplains and 720 km-long Bay of Bengal coastline. This study uses nighttime light data to investigate the demographic repercussions and potential disruptions to economic clusters arising from land inundation attributable to SLR in the Bay of Bengal. By using geographical information system (GIS)-based bathtub modeling, this research scrutinizes potential risk zones under three selected shared socioeconomic pathway (SSP) scenarios. The analysis anticipates that between 0.8 and 2.8 thousand km2 of land may be inundated according to the present elevation profile, affecting 0.5-2.8 million people in Bangladesh by 2150. Moreover, artificial neural network (ANN)-based cellular automata modeling is used to determine economic clusters at risk from SLR impacts. These findings emphasize the urgency for land planners to incorporate modeling and sea inundation projections to tackle the inherent uncertainty in SLR estimations and devise effective coastal flooding mitigation strategies. This study provides valuable insights for policy development and long-term planning in coastal regions, especially for areas with a limited availability of relevant data.
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Plastic represents an essential material in our society; however, a major imbalance between their high production and end-of-life management is leading to unrecovered energy, economic hardship, and a high carbon footprint. The adoption of plastic recycling has been limited, mainly due to the difficulty of recycling mixed plastics. Here, we report a versatile organocatalyst for selective glycolysis of diverse consumer plastics and their mixed waste streams into valuable chemicals. The developed organocatalyst selectively deconstructs condensation polymers at a specific temperature, and additives or other polymers such as polyolefin or cellulose can be readily separated from the mixed plastics, providing a chemical recycling path for many existing mixed plastics today. The Life Cycle Assessment indicates that the production of various condensation polymers from the deconstructed monomers will result in a significant reduction in greenhouse gas emissions and energy input, opening a new paradigm of plastic circularity toward a net-zero carbon society.
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Inorganic metal-halide cubic perovskite semiconductors have become more popular in industrial applications of photovoltaic and optoelectronic devices. Among various perovskites, lead-free materials are currently most explored due to their non-toxic effect on the environment. In this study, the structural, electronic, optical, and mechanical properties of lead-free cubic perovskite materials FrBX3 (B = Ge, Sn; X = Cl, Br, I) are investigated through first-principles density-functional theory (DFT) calculations. These materials are found to exhibit semiconducting behavior with direct bandgap energy and mechanical phase stability. The observed variation in the bandgap is explained based on the substitutions of cations and anions sitting over B and X-sites of the FrBX3 compounds. The high absorption coefficient, low reflectivity, and high optical conductivity make these materials suitable for photovoltaic and other optoelectronic device applications. It is observed that the material containing Ge (germanium) in the B-site has higher optical absorption and conductivity than Sn containing materials. A systematic analysis of the electronic, optical, and mechanical properties suggests that among all the perovskite materials, FrGeI3 would be a potential candidate for optoelectronic applications. The radioactive element Fr-containing perovskite FrGeI3 may have applications in nuclear medicine and diagnosis such as X-ray imaging technology.