Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 127
Filtrar
Más filtros

Tipo del documento
Intervalo de año de publicación
1.
Langmuir ; 40(29): 15332-15352, 2024 Jul 23.
Artículo en Inglés | MEDLINE | ID: mdl-38995997

RESUMEN

This study focuses on the geometrical, electronic, and optical properties of the γ-graphyne-like novel γ-SiC nanoflake of the γ-silicon carbide (SiC) monolayer using density functional theory calculations. γ-SiC was revealed to be a stable semiconducting nanoflake confirmed by a negative cohesive energy, real vibrational frequencies, and a 1.749 eV energy gap. The adsorption of COCl2, HCN, PH3, AsH3, CNCl, and C2N2 toxic gases on the γ-SiC nanoflake is also studied, which revealed an attractive gas-nanoflake interaction with the adsorption energy ranging from -0.21 to -0.38 eV. The adsorption results in a significant charge transfer between gas-adsorbent complexes. A significant variation in the energy gap and electrical conductivity was observed due to gas adsorption. γ-SiC showed maximum sensitivity at room temperature for CNCl gas. The entire process of adsorption is exothermic and thermodynamically stable. γ-SiC showed a high absorption coefficient over 104 orders with a significant variation in the absorption peak intensity and blue peak shifting. According to the quantum theory and reduced density gradient analysis, all of the gases are physisorbed on the γ-SiC nanoflake due to van der Waals interactions. The obtained results signify the usability of γ-SiC as a potential toxic gas sensor.

2.
Phys Chem Chem Phys ; 25(46): 32261-32272, 2023 Nov 29.
Artículo en Inglés | MEDLINE | ID: mdl-37988166

RESUMEN

Heavy metal removal from polluted environments is one of the vital research areas for better and healthier living. In this research, C8 and B4N4 nanocage-like quantum dots are investigated for heavy metal (Cr) removal applications via density functional theory calculations. The adsorption of up to two Cr atoms has been studied in both air and a water medium. The adsorption of Cr atoms results in significant structural deformation of the adsorbents with a high adsorption energy of -8.74 and -5.77 eV for C8 and B4N4 nanostructures, respectively, which is further increased with an increasing number of Cr atoms. All adsorbents and complex structures showed real vibrational frequencies. Mulliken charge and electrostatic potential analysis reveal a significant charge transfer between adsorbate-adsorbent. The adsorption process causes a decrease in the energy gap of the adsorbents. All the reactions in this study were spontaneous and thermodynamically ordered. QTAIM analysis verifies that the interactions of the adsorbents with Cr atoms are strong partial covalent. The study's findings make C8 and B4N4 nanostructures potential candidates for Cr-detection and removal applications.

3.
Environ Res ; 232: 116328, 2023 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-37286126

RESUMEN

Turmeric adulterated with lead chromate pigment has been previously identified as a primary source of lead exposure in Bangladesh. This study assesses the impact of a multi-faceted intervention between 2017 and 2021 to reduce lead-tainted turmeric in Bangladesh. The intervention involved: i) disseminating findings from scientific studies via news media that identified turmeric as a source of lead poisoning, ii) educating consumers and businesspeople about the risks of lead chromate in turmeric via public notices and face-to-face meetings, and iii) collaborating with the Bangladesh Food Safety Authority to utilize a rapid lead detection technology to enforce policy disallowing turmeric adulteration. Before and after the intervention, evidence of lead chromate turmeric adulteration was assessed at the nation's largest turmeric wholesale market and at turmeric polishing mills across the country. Blood lead levels of workers at two mills were also assessed. Forty-seven interviews were conducted with consumers, businesspeople, and government officials to assess changes in supply, demand, and regulatory capacity. The proportion of market turmeric samples containing detectable lead decreased from 47% pre-intervention in 2019 to 0% in 2021 (n = 631, p < 0.0001). The proportion of mills with direct evidence of lead chromate adulteration (pigment on-site) decreased from 30% pre-intervention in 2017 to 0% in 2021 (n = 33, p < 0.0001). Blood lead levels dropped a median of 30% (IQR: 21-43%), while the 90th percentile dropped 49% from 18.2 µg/dL to 9.2 µg/dL 16 months after the intervention (n = 15, p = 0.033). Media attention, credible information, rapid lead detection tools and swift government action to enforce penalties all contributed to the intervention's success. Subsequent efforts should evaluate if this is an example of an effective intervention that can be replicated to reduce lead chromate adulteration of spices globally.


Asunto(s)
Cromatos , Plomo , Humanos , Plomo/análisis , Curcuma , Bangladesh , Inocuidad de los Alimentos
4.
Clin Exp Dermatol ; 47(5): 981-982, 2022 May.
Artículo en Inglés | MEDLINE | ID: mdl-34994981

RESUMEN

We comment on a previous letter regarding Achenbach syndrome, and suggest that punch biopsy should be performed in all clinically suspected cases to obtain histological confirmation of the disease.


Asunto(s)
Neoplasias Cutáneas , Biopsia , Hematoma , Humanos , Masculino , Piel/patología , Neoplasias Cutáneas/patología , Síndrome
5.
Am J Primatol ; 84(1): e23345, 2022 01.
Artículo en Inglés | MEDLINE | ID: mdl-34783056

RESUMEN

Rhesus macaques are considered an important reservoir of different gastrointestinal (GI) zoonotic parasites affecting livestock and humans. Loads of GI parasites in the free-ranging rhesus macaques living in close proximity to communities in Bangladesh are still unknown. To estimate the prevalence and diversity of zoonotic GI parasites in rhesus macaques of Bangladesh, a total of 182 freshly voided fecal samples were collected from macaques living in rural (N = 67), peri-urban (N = 57), urban (N = 28), and Safari park (N = 30) between October 2015 and December 2016. All samples were tested by direct smear, sedimentation, flotation, and the McMaster techniques. A total of fourteen different taxa of GI parasites were detected, revealing an overall prevalence of 54.4% (n = 99; 95% confidence interval [CI]: 46.9-61.8). The prevalence of GI parasites was found to be significantly correlated with the mean parasitic taxa per individual in a group (r = 0.90; p = 0.002). The multivariable logistic regression analysis showed that the overall prevalence of GI parasites in macaques was significantly higher in those inhabiting rural areas (62.69%; odds ratio [OR]: 7.22; p = 0.001) and in macaques with interactions with other animals (60.98%; OR: 5.49; p = 0.005). Our results also indicated that the prevalence of Strongyloides spp. and Balantidium coli infections varied significantly between land gradients. Our results also indicate that macaques frequently visit human settlements for food and are found interacting with domestic animals. In conclusion, the high prevalence of zoonotic GI parasite infection in rhesus macaques found in our study may pose a significant public health risk to communities, particularly in rural areas of Bangladesh. Health promotion to at-risk communities focusing on limiting contact with rhesus macaques is necessary to mitigate potential zoonotic transmission.


Asunto(s)
Parasitosis Intestinales , Parásitos , Animales , Bangladesh/epidemiología , Heces , Parasitosis Intestinales/epidemiología , Parasitosis Intestinales/veterinaria , Macaca mulatta , Prevalencia
6.
J Community Health ; 47(1): 136-142, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-34491507

RESUMEN

This study aimed to determine the seroprevalence and determinants of hepatitis B virus (HBV) infection among university students in Bangladesh. This cross-sectional study was conducted among 614 students from five universities in central Bangladesh. Data were collected on demographic information, immunization history, medical and blood transfusion history through the face-to-face interview. Blood samples were collected and screened for anti-HBsAg using ELISA, HBsAg Rapid Test-cassette, and immune chromatographic test. The overall seroprevalence of HBV infection was 5.0%, and vaccination coverage was 19.2% among the participants. Students having a history of surgery (OR 11.004, 95% CI 3.211-37.707), blood transfusion (OR 5.651, 95% CI 0.965-33.068), being married (OR 4.776, 95% CI 1.508-15.127), and not being vaccinated (OR 9.825, 95% CI 1.130-85.367) were at higher risk of being infected by HBV. This study showed the endemicity of HBV infection among the Bangladeshi population. Marriage, surgical or blood transfusion history, not being vaccinated were the determinants of HBV infection within the study population. Public health initiatives for preventing HBV infection at the university levels should be envisaged.


Asunto(s)
Virus de la Hepatitis B , Hepatitis B , Bangladesh/epidemiología , Estudios Transversales , Hepatitis B/epidemiología , Hepatitis B/prevención & control , Antígenos de Superficie de la Hepatitis B , Humanos , Estudios Seroepidemiológicos , Estudiantes , Universidades
7.
Microbiology (Reading) ; 167(4)2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-33749578

RESUMEN

Microorganisms encounter toxicities inside the host. Many pathogens exist as subpopulations to maximize survivability. Subpopulations of Staphylococcus aureus include antibiotic-tolerant small colony variants (SCVs). These mutants often emerge following antibiotic treatment but can be present in infections prior to antibiotic exposure. We hypothesize that haem toxicity in the host selects for respiration-deficient S. aureus SCVs in the absence of antibiotics. We demonstrate that some but not all respiration-deficient SCV phenotypes are more protective than the haem detoxification system against transient haem exposure, indicating that haem toxicity in the host may contribute to the dominance of menaquinone-deficient and haem-deficient SCVs prior to antibiotic treatment.


Asunto(s)
Hemo/metabolismo , Infecciones Estafilocócicas/metabolismo , Infecciones Estafilocócicas/microbiología , Staphylococcus aureus/crecimiento & desarrollo , Staphylococcus aureus/metabolismo , Antibacterianos/farmacología , Hemo/toxicidad , Humanos , Fenotipo , Staphylococcus aureus/efectos de los fármacos , Staphylococcus aureus/genética , Vitamina K 2/metabolismo
8.
Hum Mol Genet ; 27(18): 3189-3205, 2018 09 15.
Artículo en Inglés | MEDLINE | ID: mdl-29893854

RESUMEN

Mutations in a number of genes cause familial forms of Parkinson's disease (PD), including mutations in the vacuolar protein sorting 35 ortholog (VPS35) and parkin genes. In this study, we identify a novel functional interaction between parkin and VPS35. We demonstrate that parkin interacts with and robustly ubiquitinates VPS35 in human neural cells. Familial parkin mutations are impaired in their ability to ubiquitinate VPS35. Parkin mediates the attachment of an atypical poly-ubiquitin chain to VPS35 with three lysine residues identified within the C-terminal region of VPS35 that are covalently modified by ubiquitin. Notably, parkin-mediated VPS35 ubiquitination does not promote the proteasomal degradation of VPS35. Furthermore, parkin does not influence the steady-state levels or turnover of VPS35 in neural cells and VPS35 levels are normal in the brains of parkin knockout mice. These data suggest that ubiquitination of VPS35 by parkin may instead serve a non-degradative cellular function potentially by regulating retromer-dependent sorting. Accordingly, we find that components of the retromer-associated WASH complex are markedly decreased in the brain of parkin knockout mice, suggesting that parkin may modulate WASH complex-dependent retromer sorting. Parkin gene silencing in primary cortical neurons selectively disrupts the vesicular sorting of the autophagy receptor ATG9A, a WASH-dependent retromer cargo. Parkin is not required for dopaminergic neurodegeneration induced by the expression of PD-linked D620N VPS35 in mice, consistent with VPS35 being located downstream of parkin function. Our data reveal a novel functional interaction of parkin with VPS35 that may be important for retromer-mediated endosomal sorting and PD.


Asunto(s)
Proteínas Relacionadas con la Autofagia/genética , Proteínas de la Membrana/genética , Degeneración Nerviosa/genética , Enfermedad de Parkinson/genética , Ubiquitina-Proteína Ligasas/genética , Proteínas de Transporte Vesicular/genética , Animales , Autofagia/genética , Modelos Animales de Enfermedad , Neuronas Dopaminérgicas/metabolismo , Neuronas Dopaminérgicas/patología , Endosomas/genética , Humanos , Ratones , Ratones Noqueados , Degeneración Nerviosa/patología , Enfermedad de Parkinson/patología , Poliubiquitina/genética , Transporte de Proteínas/genética
9.
BMC Cardiovasc Disord ; 19(1): 87, 2019 04 08.
Artículo en Inglés | MEDLINE | ID: mdl-30961544

RESUMEN

BACKGROUND: The role of intravenous hydration at the time of primary percutaneous intervention (PCI) for ST-segment elevation myocardial infarction (STEMI) remains unclear. Guidelines are vague, supported by low level evidence, and hydration is used less often than other clinical settings.To perform a systematic review and meta-analysis of all randomized controlled trials assessing intravenous hydration compared with non-hydration for prevention of contrast induced nephropathy (CIN) and In-hospital mortality in patients with STEMI undergoing primary PCI. METHODS: Medline, EMBASE and the Cochrane Register were searched to September 2018. Included studies reported the incidence of CIN, In-hospital mortality, requirement for dialysis and heart failure. Relative risks with 95% confidence intervals (CIs) for individual trials were pooled using a random effects model. RESULTS: Three moderate quality trials were identified including 1074 patients. Overall, compared with no hydration, intravenous hydration significantly reduced the incidence of CIN by 42% (RR 0.58; 95% CI: 0.45 to 0.74, p < 0.001). The estimated effects upon all-cause mortality (RR 0.56; 95% CI: 0.30 to 1.02, p = 0.057) and the requirement for dialysis (RR 0.52, 95% CI 0.14-1.88, p = 0.462) were not statistically significant. The outcome of heart failure was not consistently reported. CONCLUSIONS: Intravenous hydration likely reduces the incidence of CIN in patients with STEMI undergoing primary PCI. However, for key clinical outcomes such as mortality, heart failure and dialysis the effect estimates were imprecise. Further high quality studies are needed to clarify the appropriate volume of fluid and effects on outcomes.


Asunto(s)
Medios de Contraste/efectos adversos , Angiografía Coronaria/efectos adversos , Fluidoterapia , Mortalidad Hospitalaria , Enfermedades Renales/prevención & control , Intervención Coronaria Percutánea/efectos adversos , Infarto del Miocardio con Elevación del ST/terapia , Anciano , Medios de Contraste/administración & dosificación , Angiografía Coronaria/mortalidad , Femenino , Fluidoterapia/efectos adversos , Fluidoterapia/mortalidad , Humanos , Incidencia , Infusiones Intravenosas , Enfermedades Renales/inducido químicamente , Enfermedades Renales/diagnóstico , Enfermedades Renales/mortalidad , Masculino , Persona de Mediana Edad , Intervención Coronaria Percutánea/mortalidad , Factores Protectores , Ensayos Clínicos Controlados Aleatorios como Asunto , Diálisis Renal , Medición de Riesgo , Factores de Riesgo , Infarto del Miocardio con Elevación del ST/diagnóstico por imagen , Infarto del Miocardio con Elevación del ST/mortalidad , Factores de Tiempo , Resultado del Tratamiento
10.
Eur Heart J Suppl ; 21(Suppl D): D14-D16, 2019 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-31043866

RESUMEN

Increased blood pressure (BP) is the single biggest contributing risk factor to the global disease burden. May Measurement Month (MMM) is a global initiative of the International Society of Hypertension aimed at raising awareness of high BP. In Australia, hypertension affects around six million adults and continues to remain the greatest attributable cause of cardiovascular mortality and morbidity (48.3%), stroke deaths (28%), and kidney disease (14%). An opportunistic cross-sectional survey was carried out during May 2017 predominantly in capital cities across Australia which included adult volunteers. Blood pressure measurement, the definition of hypertension and statistical analysis followed the standard MMM protocol. Additional information obtained included anthropometric data and responses to questionnaires on demographic, lifestyle, and environmental factors. Data were collected from 3817 individuals. After multiple imputation, of the 3758 individuals for whom a mean of the second and third BP reading was available, 1188 (31.2%) had hypertension. Of 3213 individuals not receiving antihypertensive treatment, 591 (18.4%) were hypertensive, and 239 (40.1%) of the 596 individuals receiving treatment had uncontrolled BP. Adjusted BP was higher in association with antihypertensive medication, cerebrovascular disease, smoking, and alcohol consumption. Blood pressure was higher when measured on the right arm and on Tuesdays. MMM17 was one of the largest BP screening campaigns undertaken in Australia using standardized BP measurements. In line with previous surveys, around one-third of screened adults had hypertension and approximately 40% of treated individuals remained uncontrolled. These results suggest that opportunistic screening can identify significant numbers with raised BP.

11.
BMC Health Serv Res ; 19(1): 424, 2019 Jun 26.
Artículo en Inglés | MEDLINE | ID: mdl-31242900

RESUMEN

BACKGROUND: How the informal providers deliver health services are not well understood in Bangladesh. However, their practices are often considered inappropriate and unsafe. This study attempted to fill-in this knowledge gap by exploring their perceptions about diagnosis and appropriate treatment, as well as identifying existing barriers to provide appropriate treatment. METHODS: This exploratory study was conducted in two peri-urban areas of metropolitan Dhaka. Study participants were selected purposively, and an interview guideline was used to collect in-depth data from thirteen providers. Content analysis was applied through data immersion and themes identification, including coding and sub-coding, as well as data display matrix creation to draw conclusion. RESULTS: The providers relied mainly on the history and presenting symptoms for diagnosis. Information and guidelines provided by the pharmaceutical representatives were important aids in their diagnosis and treatment decision making. Lack of training, diagnostic tools and medicine, along with consumer demands for certain medicine i.e. antibiotics, were cited as barriers to deliver appropriate care. Effective and supportive supervision, training, patient education, and availability of diagnostics and guidelines in Bangla were considered necessary in overcoming these barriers. CONCLUSION: Informal providers lack the knowledge and skills for delivering appropriate treatment and care. As they provide health services for substantial proportion of the population, it's crucial that policy makers become cognizant of the fact and take measures to remedy them. This is even more urgent if government's goal to reach universal health coverage by 2030 is to be achieved.


Asunto(s)
Conocimientos, Actitudes y Práctica en Salud , Personal de Salud/psicología , Personal de Salud/normas , Adulto , Bangladesh , Femenino , Personal de Salud/estadística & datos numéricos , Humanos , Masculino , Persona de Mediana Edad , Investigación Cualitativa , Población Suburbana
12.
Emerg Infect Dis ; 24(5): 926-928, 2018 05.
Artículo en Inglés | MEDLINE | ID: mdl-29664373

RESUMEN

Dromedary camels are bred domestically and imported into Bangladesh. In 2015, of 55 camels tested for Middle East respiratory syndrome coronavirus in Dhaka, 17 (31%) were seropositive, including 1 bred locally. None were PCR positive. The potential for infected camels in urban markets could have public health implications and warrants further investigation.


Asunto(s)
Camelus , Infecciones por Coronavirus/veterinaria , Coronavirus del Síndrome Respiratorio de Oriente Medio/aislamiento & purificación , Animales , Bangladesh/epidemiología , Infecciones por Coronavirus/epidemiología , Infecciones por Coronavirus/virología , Femenino , Masculino
13.
Proteomics ; 15(4): 739-51, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25504979

RESUMEN

The zebrafish owns remarkable regenerative capacities allowing regeneration of several tissues, including the heart, liver, and brain. To identify protein dynamics during fin regeneration we used a pulsed SILAC approach that enabled us to detect the incorporation of (13) C6 -lysine (Lys6) into newly synthesized proteins. Samples were taken at four different time points from noninjured and regrowing fins and incorporation rates were monitored using a combination of single-shot 4-h gradients and high-resolution tandem MS. We identified more than 5000 labeled proteins during the first 3 weeks of fin regeneration and were able to monitor proteins that are responsible for initializing and restoring the shape of these appendages. The comparison of Lys6 incorporation rates between noninjured and regrowing fins enabled us to identify proteins that are directly involved in regeneration. For example, we observed increased incorporation rates of two actinodin family members at the actinotrichia, which is a hairlike fiber structure at the tip of regrowing fins. Moreover, we used quantitative real-time RNA measurements of several candidate genes, including osteoglycin, si:ch211-288h17.3, and prostaglandin reductase 1 to correlate the mRNA expression to Lys6 incorporation data. This novel pulsed SILAC methodology in fish can be used as a versatile tool to monitor newly synthesized proteins and will help to characterize protein dynamics during regenerative processes in zebrafish beyond fin regeneration.


Asunto(s)
Aletas de Animales/metabolismo , Proteoma/análisis , Regeneración/fisiología , Proteínas de Pez Cebra/análisis , Aletas de Animales/química , Aletas de Animales/fisiología , Animales , Regulación de la Expresión Génica/genética , Regulación de la Expresión Génica/fisiología , Marcaje Isotópico , Reacción en Cadena de la Polimerasa , Proteoma/química , Proteoma/metabolismo , Proteómica , Regeneración/genética , Espectrometría de Masas en Tándem , Cicatrización de Heridas/genética , Cicatrización de Heridas/fisiología , Pez Cebra , Proteínas de Pez Cebra/química , Proteínas de Pez Cebra/genética , Proteínas de Pez Cebra/metabolismo
14.
Cureus ; 16(1): e52228, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38352077

RESUMEN

Isolated jejunal diverticular (JD) perforation is extremely rare; it usually presents as a diagnostic dilemma and is often discovered incidentally on laparotomy. Most of these perforations are single. Literature has revealed only one case of multiple small bowel diverticular perforations. We report the first case of simultaneous perforation of four jejunal diverticulae in an 85-year-old male. Small bowel resection and primary anastomosis were performed. The patient had an uneventful post-operative recovery. This case highlights the importance of prompt diagnosis and timely management to reduce the morbidity and mortality of these patients. It should be included in the differential diagnosis in all elderly patients presenting with acute abdomen.

15.
ChemistryOpen ; 13(1): e202300207, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38047541

RESUMEN

Organometallic perovskites have become one of the most common multifunctional materials in optoelectronic research fields. This research studies density functional theory calculation on orthorhombic hydrazinium lead iodide (N2 H5 PbI3 ) perovskite by replacing A-site cation with a borane ammonium (BH2 NH3 + ) ion. The perovskite showed a significant structural deformation and an orthorhombic to triclinic phase transition due to A-site ion replacement. The N2 H5 PbI3 perovskite has a band gap of 1.64 eV, suitable for the solar cell absorber layer. The band gap has increased to 2.12 eV after complete A-site ion replacement. All structures showed a high absorption coefficient over 104  cm-1 in the low wavelength region and an increase in refractive index from 2.5 to 2.75 due to ion replacement. All the structures showed high optical conductivity of 1015  s-1 order in the blue wavelength region. These new perovskite structures hold the potential to provide a revolution in optoelectronic research.

16.
Cureus ; 16(9): e69712, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39429321

RESUMEN

Dengue fever is a febrile viral disease transmitted by mosquitoes. The symptoms of dengue fever are numerous and varied; however, cardiac tamponade is a particularly rare and atypical complication. This study describes a case of a 30-year-old male who presented with acute respiratory distress and chest pain on the ninth day after diagnosis of dengue fever. On admission, a computed tomography scan revealed a large pericardial effusion. The patient went into shock and was urgently treated with pericardial drainage, which resulted in rapid improvement of his symptoms. Emergent management of this rare but potentially fatal complication of dengue fever resulted in a favorable outcome in this case.

17.
Sci Rep ; 14(1): 15282, 2024 Jul 03.
Artículo en Inglés | MEDLINE | ID: mdl-38961091

RESUMEN

This study presents a comprehensive analysis of a nonlinear telecommunications model, exploring bifurcation, stability, and wave solutions using Hamiltonian and Jacobian techniques. The investigation begins with a thorough examination of bifurcation behavior, identifying critical points and their stability characteristics, leading to the discovery of diverse bifurcation scenarios. The stability of critical points is further assessed through graphical and numerical methods, highlighting the sensitivity to parameter variations. The study delves into the derivation of both numerical and analytical wave solutions, aligning them with energy orbits depicted in phase portraits, revealing a spectrum of wave behaviors. Additionally, the analysis extends to traveling wave solutions, providing insights into wave propagation dynamics. Notably, the study underscores the efficacy of the planar dynamical approach in capturing system behavior in harmony with phase portrait orbits. The findings have significant implications for telecommunications engineers and researchers, offering insights into system behavior, stability, and signal propagation, ultimately advancing our understanding of complex nonlinear dynamics in telecommunications networks.

18.
Nanoscale Adv ; 6(4): 1218-1226, 2024 Feb 13.
Artículo en Inglés | MEDLINE | ID: mdl-38356625

RESUMEN

The sensitivity of a RbSnCl3 perovskite 2D layer toward NH3, SO2, and NO toxic gases has been studied via DFT analysis. The tri-atomic layer of RbSnCl3 possessed a tetragonal symmetry with a band gap of 1.433 eV. The adsorption energies of RbSnCl3 for NH3, SO2 and NO are -0.09, -0.43, and -0.56 eV respectively with a recovery time ranging from 3.4 × 10-8 to 3.5 ms. RbSnCl3 is highly sensitive toward SO2 and NO compared to NH3. The adsorption of SO2 and NO results in a significant structural deformation and a semiconductor-to-metal transition of RbSnCl3 perovskite. A high absorption coefficient (>103 cm-1), excessive optical conductivity (>1014 s-1), and a very low reflectivity (<3%) make RbSnCl3 a potential candidate for numerous optoelectronic applications. A significant shift in optical responses is observed through SO2 and NO adsorption, which can enable identification of the adsorbed gases. The studied characteristics signify that RbSnCl3 can be a potential candidate for SO2 and NO detection.

19.
Cureus ; 16(6): e63063, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-39055423

RESUMEN

Adult intestinal malrotation along with congenital transverse-mesocolic internal hernia causing small bowel obstruction is extremely rare. Most of these patients don't have any obvious clinical symptoms. Only a few cases have been documented in the English literature. We present the unique case of a 43-year-old male without any prior surgical history who presented with nonspecific abdominal pain and was diagnosed with malrotation of the small intestine by computed tomography (CT) scan and underwent exploratory laparotomy found to have internal herniation through the transverse-mesocolon. The patient underwent an emergency laparotomy; a Ladd's procedure and repair of the hernial orifice were performed. This case highlights the association of adult intestinal malrotation with internal hernias and small bowel obstruction; it also explores the importance of timely diagnosis and adequate management of this condition.

20.
Sci Rep ; 14(1): 3467, 2024 Feb 12.
Artículo en Inglés | MEDLINE | ID: mdl-38342938

RESUMEN

Tetragonal graphene nano-capsule (TGC), a novel stable carbon allotrope of sp2 hybridization is designed and doped with phosphorus (P) to study the O3 and SO2 gas sensitivity via density functional theory calculation. Real frequencies verified the natural existence of both TGC and P-doped TGC (PTGC). Both TGC and PTGC suffer structural deformations due to interaction with O3 and SO2 gases. The amount of charge transfer from the adsorbent to the gas molecule is significantly greater for O3 adsorption than SO2 adsorption. The adsorption energies for TGC + O3 and PTGC + O3 complexes are - 3.46 and - 4.34 eV respectively, whereas for TGC + SO2 and PTGC + SO2 complexes the value decreased to - 0.29 and - 0.30 eV respectively. The dissociation of O3 is observed via interaction with PTGC. A significant variation in electronic energy gap and conductivity results from gas adsorption which can provide efficient electrical responses via gas adsorption. The blue/red shift in the optical response proved to be a way of detecting the types of adsorbed gases. The adsorption of O3 is exothermic and spontaneous whereas the adsorption of SO2 is endothermic and non-spontaneous. The negative change in entropy verifies the thermodynamic stability of all the complexes. QTAIM analysis reveals strong covalent or partial covalent interactions between absorbent and adsorbate. The significant variation in electrical and optical response with optimal adsorbent-gas interaction strength makes both TGC and PTGC promising candidates for O3 and SO2 sensing.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA