Understanding the Crystal Growth of Bismuth Chalcohalide Nanorods through a Self-Sacrificing Template Process: A Comprehensive Study.

Bismuth-based semiconductors are promising candidates for applications in photocatalysis, photodetection, solar cells, etc. BiSI in particular is attracting attention. It has anisotropic optoelectronic properties and comprises relatively abundant elements. However, the synthesis of this ternary compound presents several challenges. Here, we delve into the underlying chemical processes that lead to the crystal growth of BiSI nanorods and optimize a solution-based synthesis. The mechanism of formation of BiSI nanocrystals is the self-sacrifice of Bi2S3 nanostructures, which also act as templates. The crystallographic similarities between the chalcogenide and the chalcohalide allow for the solid state transformation from one to the other. However, there is also a synergy with the I3- species formed in the reaction media needed to obtain BiSI. Our method makes use of a green solvent, avoids complicated media, and drastically reduces the reaction time compared to other methods. The obtained nanorods present a band gap of 1.6 eV, in accordance with the reported values. This work presents insight into the chemistry of bismuth-based semiconductors, while introducing an easy, green, and scalable synthesis of a promising material, which could also be applied to similar compounds and other chalcoiodides, such as SbSI. In addition, the optical properties of the BiSI nanorods show their potential in photovoltaic applications.

Brazilian initial experience with lung transplantation due to irreversible lung fibrosis post-COVID-19 in a national reference center: a cohort study

ABSTRACT BACKGROUND: Lung transplantation (LTx) has been discussed as an option for treating irreversible lung fibrosis post-coronavirus disease 2019 (COVID-19), in selected cases. OBJECTIVES: To report on the initial experience and management of end-stage lung disease due to COVID-19 at a national center reference in Brazil. DESIGN AND SETTING: Cohort study conducted at a national reference center for lung transplantation. METHODS: Medical charts were reviewed regarding patients' demographics and pre-COVID-19 characteristics, post-LTx due to COVID-19. RESULTS: Between March 2020 and September 2021, there were 33 cases of LTx. During this period, we evaluated 11 cases of severe COVID-19-related acute respiratory distress syndrome (ARDS) that were potentially candidates for LTx. Among these, LTx was only indicated for three patients (9.1%). All of these patients were on venovenous extracorporeal membrane oxygenation (ECMO), and the procedure that they underwent was central venoarterial ECMO. All three patients were still alive after the first 30 postoperative days. However, patient #1 and patient #2 subsequently died due to fungal sepsis on the 47th and 52nd postoperative days, respectively. Patient #3 was discharged on the 30th postoperative day. CONCLUSIONS: LTx is feasible among these complex patients. Survival over the first 30 days was 100%, and this favors surgical feasibility. Nonetheless, these were critically ill patients.

Brazilian initial experience with lung transplantation due to irreversible lung fibrosis post-COVID-19 in a national reference center: a cohort study.

BACKGROUND: Lung transplantation (LTx) has been discussed as an option for treating irreversible lung fibrosis post-coronavirus disease 2019 (COVID-19), in selected cases. OBJECTIVES: To report on the initial experience and management of end-stage lung disease due to COVID-19 at a national center reference in Brazil. DESIGN AND SETTING: Cohort study conducted at a national reference center for lung transplantation. METHODS: Medical charts were reviewed regarding patients' demographics and pre-COVID-19 characteristics, post-LTx due to COVID-19. RESULTS: Between March 2020 and September 2021, there were 33 cases of LTx. During this period, we evaluated 11 cases of severe COVID-19-related acute respiratory distress syndrome (ARDS) that were potentially candidates for LTx. Among these, LTx was only indicated for three patients (9.1%). All of these patients were on venovenous extracorporeal membrane oxygenation (ECMO), and the procedure that they underwent was central venoarterial ECMO. All three patients were still alive after the first 30 postoperative days. However, patient #1 and patient #2 subsequently died due to fungal sepsis on the 47th and 52nd postoperative days, respectively. Patient #3 was discharged on the 30th postoperative day. CONCLUSIONS: LTx is feasible among these complex patients. Survival over the first 30 days was 100%, and this favors surgical feasibility. Nonetheless, these were critically ill patients.

Esophageal spirocercosis with pulmonary egg deposition and secondary hypertrophic osteopathy in a dog from Costa Rica.

Spirocerca lupi is the etiologic agent of spirocercosis in canids from the tropical and subtropical regions of the world. A 1-year-old dog was presented with weight loss and diarrhea. Upon examination, thickened limbs, a mass in the lung's right middle lobe and an esophageal mass were found. The pulmonary mass aspirate revealed S. lupi eggs surrounded by a purulent infiltrate. Limb bone biopsies showed irregular mineralization and cartilaginous metaplasia. Treatment with doramectin resolved the initial clinical signs. However, regurgitation was reported 5 months later. Therefore, the dog received additional doramectin and later vomited a worm morphologically consistent with a S. lupi adult. Herein we report the esophageal migration of S. lupi with egg deposition to the lung parenchyma, accompanied by secondary hypertrophic osteopathy. This report highlights the presence of S. lupi in Costa Rica and the importance of including this parasite as a differential diagnosis when compatible signs are identified.

Sulfur precursor and citric acid effect on SnS2 nanoparticles and their influence on the photodegradation activity of selected organic compounds.

Semiconductor nanoparticle-mediated photocatalysis is an attractive option for water decontamination, being the semiconductors as SnS2 with a bandgap in the visible region, the most promising materials. In the present work, we evaluated the influence of important parameters in the photocatalytic application of SnS2 nanoparticles. Our results show that the presence of citric acid (used as a capping agent) restricts the formation of hexagonal nanoparticles. We also demonstrated that using thioacetamide as a sulfur source results in smaller nanoparticles than thiourea, 24.0 nm and 616 nm respectively. Moreover, small hexagonal nanoparticles play a key role in the photocatalytic activity of SnS2 nanoparticles. Compared with TiO2 performance, SnS2 nanoparticles exhibited faster kinetics for methyl orange (MO) degradation, Kapp = 0.0102 min-1, and 0.029 min-1, respectively. We proved that SnS2 is capable of breaking the azo bond of methyl orange by direct reduction. Furthermore, our analyses indicate that SnS2 nanoparticles do not degrade atrazine and imazapic, but the photocatalytic route of metribuzin competed with photolysis, resulting in a particular transformation product that was not obtained with light irradiation only. We demonstrated that SnS2 nanoparticles have high bond selectivity for azo breaking. Furthermore, they represent an advance for the development of designed materials (such as heterostructures), where the properties of SnS2 can be tuned.

Bismuth chalcohalide-based nanocomposite for application in ionising radiation detectors.

Bismuth sulpho iodide (BiSI) belongs to the family of chalcohalides, which present several attractive electro-optic properties. In particular, BiSI is a semiconductor which could be used in X and gamma ray detection due to a band gap of 1.6 eV, density of 6.4 g cm-3, and absorption coefficient for 60 keV radiation of 5.6 cm2 g-1. This work presents a facile synthesis under solvothermal conditions of a nanocomposite consisting of BiSI nanorods and amorphous carbon structures. Furthermore, it studies its ionising radiation detection properties at room temperature, when prototype detectors were built from pellets. The construction conditions of pellets were also studied, varying the applied pressure and heat treatment to the nanocomposite. Dark current density and response to different exposure rates of a 241Am source were measured for the prototype detectors built. It was found that heat treatment of pellets considerably improves detectors performance. Dark current density was one order of magnitude lower than for the pellets without heat treatment, and its response to the 241Am source, linear, with a signal to noise ratio of 7 for 20 V. Finally, the resistivity for the heat treated detector was in the order of 1011 Ω cm, comparable to other materials studied for this application.