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1.
Chem Sci ; 15(19): 7198-7205, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38756817

RESUMO

Hybrid organic-inorganic perovskites (HOIPs) occupy a prominent position in the field of materials chemistry due to their attractive optoelectronic properties. While extensive work has been done on the crystalline materials over the past decades, the newly reported glasses formed from HOIPs open up a new avenue for perovskite research with their unique structures and functionalities. Melt-quenching is the predominant route to glass formation; however, the absence of a stable liquid state prior to thermal decomposition precludes this method for most HOIPs. In this work, we describe the first mechanochemically-induced crystal-glass transformation of HOIPs as a rapid, green and efficient approach for producing glasses. The amorphous phase was formed from the crystalline phase within 10 minutes of ball-milling, and exhibited glass transition behaviour as evidenced by thermal analysis techniques. Time-resolved in situ ball-milling with synchrotron powder diffraction was employed to study the microstructural evolution of amorphisation, which showed that the crystallite size reaches a comminution limit before the amorphisation process is complete, indicating that energy may be further accumulated as crystal defects. Total scattering experiments revealed the limited short-range order of amorphous HOIPs, and their optical properties were studied by ultraviolet-visible (UV-vis) spectroscopy and photoluminescence (PL) spectroscopy.

3.
Nat Rev Chem ; 7(1): 51-65, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37117822

RESUMO

Owing to its efficiency and unique reactivity, mechanochemical processing of bulk solids has developed into a powerful tool for the synthesis and transformation of various classes of materials. Nevertheless, mechanochemistry is primarily based on simple techniques, such as milling in comminution devices. Recently, mechanochemical reactivity has started being combined with other energy sources commonly used in solution-based chemistry. Milling under controlled temperature, light irradiation, sound agitation or electrical impulses in newly developed experimental setups has led to reactions not achievable by conventional mechanochemical processing. This Perspective describes these unique reactivities and the advances in equipment tailored to synthetic mechanochemistry. These techniques - thermo-mechanochemistry, sono-mechanochemistry, electro-mechanochemistry and photo-mechanochemistry - represent a notable advance in modern mechanochemistry and herald a new level of solid-state reactivity: mechanochemistry 2.0.

4.
Inorg Chem ; 61(45): 18181-18192, 2022 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-36318217

RESUMO

MOF-74 is an archetypal magnetic metal-organic framework (MOF) family, with metal nodes bridged by 2,5-dioxido-1,4-benzenedicarboxylic acid (H4dobdc) and arranged into one of the simplest representations of the 1D Ising magnetic model. Recently, a novel mechano-synthetic approach opened a pathway toward a series of bimetallic multivariate (1:1) M1M2-MOF-74 materials, with the uniform distribution of metal cations in the oxometallic chains, offering a unique opportunity to investigate low-dimensional magnetism in these heterometallic MOFs. We explore here how different mechanochemical procedures affect the interaction between the metal nodes of the model system of three multivariate copper(II)/zinc(II)-MOF-74 materials, two of which were obtained through a template-controlled procedure, and the third one was obtained by recently developed mechanical MOF-alloying combined with subsequent accelerated aging. While the three Cu/Zn-MOF-74 products have almost identical powder X-ray diffraction (PXRD) diffractograms and Fourier transform infrared spectra, they differ significantly in their magnetic properties, as revealed through detailed magnetization and X-band and multifrequency high-field electron spin resonance measurements. The magnetic results of the three multivariate Cu/Zn-MOF-74s were compared to the properties of the monometallic Cu-MOF-74, which shows antiferromagnetic intrachain and weaker ferromagnetic interchain interactions. Energy-dispersive X-ray spectroscopy/scanning electron microscopy and solid-state nuclear magnetic resonance spectroscopy helped rationalize the observed differences in magnetization, and in situ synchrotron PXRD monitoring of template-controlled MOF formation revealed different reaction pathways when using the zinc or copper intermediates, involving even the fleeting occurrence of a rare MOF-74 polymorph.

5.
FAVE, Secc. Cienc. vet. (En línea) ; 21: 9-9, 2022. tab, graf
Artigo em Espanhol | LILACS-Express | LILACS | ID: biblio-1421456

RESUMO

Resumen En los últimos 4 años, Uruguay ha experimentado una creciente demanda por el consumo de alimentos a base de pescado crudo, tales como sushi, sashimi y ceviche. Este escenario generó la necesidad de evaluar la presencia y concentración de parásitos zoonóticos (Nematoda: Anisakidae) en porciones comestibles de especies de pescado comercializadas en el mercado local. Se analizaron 233 ejemplares de tres especies de pescado comercializadas en Uruguay: Macrodon ancylodon, Micropogonias furnieri y Cynoscion guatucupa. Se cuantificaron e identificaron, a nivel de género, nematodos en cavidad celómica y músculo, estableciendo finalmente los descriptores ecológicos para cada género encontrado y para cada especie de pescado evaluada. Dos de las especies evaluadas se encontraban parasitadas a nivel de cavidad celómica y tejido muscular, M. ancylodon y C. guatucupa. Cynoscion guatucupa resultó la especie mayormente parasitada con una prevalencia de 46%, mientras que el género de anisákido más prevalente fue Contracaecum (prevalencia de 35,1% en C. guatucupa y 32,4% en M. ancylodon). El hallazgo de anisákidos en la especie M. ancylodon representa un nuevo registro de hospedador en Uruguay. Por otra parte, se reporta por primera vez en el país la presencia de estos parásitos zoonóticos en porciones comestibles (músculo).


Abstract In the last 4 years, Uruguay has experienced a growing demand of raw fish-based foods, such as sushi, sahimi and ceviche. This scenario generated the need to assess the presence and concentration of zoonotic parasites (Nematodoes: Anisakidae) in edible parts of fish species traded in the local market. 233 fish specimens of 3 species commercialized in Uruguay were analyzed: Macrodon ancylodon, Micropogonias furnieri and Cynoscion guatucupa. The nematodes were quantified and identified at genus level, from coelomic cavity and muscle of the fishes, to finally stablish the ecological descriptors for each genus founded and for each fish species evaluated. Two of the three species of fish were parasitized with anisakids in both location (coelomic cavity and muscle), M. ancylodon and C. guatucupa. C. guatucupa was the most parasitized with a prevalence of 46%, while, the anisakid genus most prevalente was Contracaecum (prevalence of 35,1% in C. guatucupa and 32,4% in M. ancylodon). The finding of anisakids in M. ancylodon represents a report of a new host in Uruguay. Moreover, the finding for the first time in the country of these zoonotic parasites in edible parts of fish (muscle) is highlighted.

6.
ACS Appl Mater Interfaces ; 13(2): 3070-3077, 2021 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-33406367

RESUMO

Selective catalytic reduction of CO2 to methanol has tremendous importance in the chemical industry. It mitigates two critical issues in the modern society, the overwhelming climate change and the dependence on fossil fuels. The most used catalysts are currently based on mixed copper and zinc phases, where the high surface of active copper species is a critical factor for the catalyst performance. Motivated by the recent breakthrough in the controllable synthesis of bimetallic MOF-74 materials by ball milling, we targeted to study the potential of ZnCu-MOF-74 for catalytic CO2 reduction. Here, we tested whether the nanosized channels decorated with readily accessible and homogeneously distributed Zn and Cu metal sites would be advantageous for the catalytic CO2 reduction. Unlike the inactive monometallic Cu-MOF-74, ZnCu-MOF-74 shows moderate catalytic activity and selectivity for the methanol synthesis. Interestingly, the postsynthetic mechanochemical treatment of desolvated ZnCu-MOF-74 resulted in amorphization and a significant increase in both the activity and selectivity of the catalyst despite the destruction of the well-ordered and porous MOF-74 architecture. The results emphasize the importance of defects for the MOF catalytic activity and the potential of amorphous MOFs to be considered as heterogeneous catalysts. Scanning electron microscopy (SEM), X-ray powder diffraction (XRD) and 13C magic angle-spinning nuclear magnetic resonance (MAS NMR) were applied to establish quantitative structure-reactivity relationships. The apparent activation energy of rate reaction kinetics has indicated different pathway mechanisms, primarily through reverse water-gas shift (RWGS). Prolonged time on stream productivity, stability and deactivation were assessed, analysing the robustness or degradation of metal-organic framework nanomaterials. Scalable MOF production processes are making the latter more appealing within emerging industrial decarbonisation, in particular for carbon capture and utilisation (CCU) or hydrogen carrier storage. Acknowledging scale, the costs of fabrication are paramount.

7.
Rev. ANACEM (Impresa) ; 15(1): 63-71, 2021. tab
Artigo em Espanhol | LILACS | ID: biblio-1281434

RESUMO

La literatura ha estudiado los efectos de anteriores epidemias en la salud mental de la población. En el contexto de la actual pandemia COVID-19, resulta de interés estudiar lo publicado referente a esta temática, considerando que, a diferencia de epidemias recientes, la actual se ha presentado a nivel mundial, con mayores cifras de contagio y mortalidad, con períodos de restricciones sociales más prolongados, alterando diversas dimensiones en la vida de la población. Las distintas implicaciones de la pandemia COVID-19 en la salud mental y las enfermedades psiquiátricas se recopilaron, de forma general, mediante la literatura publicada en PubMed durante los primeros meses de pandemia. La literatura evidencia que la actual pandemia ha influido negativamente en diversas dimensiones de la salud mental de la población general y específicas. Otras implicaciones revisadas son: abuso de alcohol y drogas, reacciones de duelo, agravamiento de trastornos mentales previos, y el rol e importancia de las redes sociales, servicios de salud mental y telepsiquiatría, entre otros.


The literature has studied the effects of previous epidemics on the mental health of the population. In the context of the current COVID-19 pandemic, it is of interest to study what has been published regarding this issue, considering that unlike recent epidemics, the current one has occurred worldwide, with higher numbers of contagion and mortality, with periods of longer social restrictions, altering various dimensions in the life of the population. The different implications of the COVID-19 pandemic with mental health and psychiatric diseases were collected in a general form, using the literature published in PubMed during the first months of the pandemic. The literature shows that the current pandemic has negatively influenced various dimensions of mental health in the general and specific population. Other implications reviewed are: alcohol and drugs, grief, patients with previous mental disorders, social networks, mental health services, telepsychiatry, among others.


Assuntos
Humanos , Saúde Mental , Pandemias , COVID-19 , Transtornos Mentais/psicologia , Transtornos Mentais/epidemiologia , Ansiedade/etiologia , Ansiedade/epidemiologia , Transtornos do Sono-Vigília , Estresse Psicológico , Depressão/epidemiologia , Rede Social , Serviços de Saúde Mental
8.
Materials (Basel) ; 13(10)2020 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-32455679

RESUMO

In this work, we explore the halogen-bonded cocrystallization potential of cobaloxime complexes in the synthesis of cocrystals with perhalogenated benzenes. We demonstrate a strategy for synthesizing halogen-bonded metal-organic cocrystals by utilizing cobaloximes whose pendant bromide group and oxime oxygen enable halogen bonding. By combining three well-known halogen bond donor molecules differing in binding geometry and composition with three cobaloxime units, we obtained a total of four previously unreported cocrystals. Single crystal X-ray diffraction experiments showed that the majority of obtained cocrystals exhibited the formation of the targeted I···O and I···Br motives. These results illustrate the potential of cobaloximes as halogen bond acceptors and indicate that this type of halogen bond acceptors may offer a novel route to metal-organic halogen-bonded cocrystals.

9.
Plant Pathol J ; 35(2): 100-111, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31007640

RESUMO

Glomerella leaf spot (GLS) caused by Colletotrichum spp. is a destructive disease of apple restricted to a few regions worldwide. The distribution and evolution of GLS symptoms were observed for two years in Uruguay. The recurrent ascopore production on leaves and the widespread randomized distribution of symptoms throughout trees and orchard, suggest that ascospores play an important role in the disease dispersion. The ability of ascospores to produce typical GLS symptom was demonstrated by artificial inoculation. Colletotrichum strains causing GLS did not result in rot development, despite remaining alive in fruit lesions. Based on phylogenetic analysis of actin, ß-tubulin and glyceraldehyde-3-phosphate dehydrogenase gene regions of 46 isolates, 25 from fruits and 21 from leaves, C. karstii was identified for the first time causing GLS in Uruguay and C. fructicola was found to be the most frequent (89%) and aggressive species. The higher aggressiveness of C. fructicola and its ability on to produce abundant fertile perithecia could help to explain the predominance of this species in the field.

10.
Exp Cell Res ; 360(2): 390-396, 2017 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-28947133

RESUMO

Targeting cyclin D-CDK4/6 kinase complexes has recently been shown to increase the survival of breast cancer patients with estrogen receptor positive breast tumors. Based on these outcomes, CDK4/6 inhibitors are currently being tested, alone o in combination with other drugs, in the treatment of other malignancies characterized by hyper-activation of cyclin D-CDK4/6 complexes. Nonetheless, a better understanding of the cellular processes that are implemented in response to CDK4/6 inhibition is necessary to expand the therapeutic window and confront the development of drug resistance. Herein, we show that, similar to mammary cells, gastric cancer cells are sensitive to the CDK4/6 inhibitor Palbociclib. Inhibition of CDK4/6 in gastric cancer cells leads to the implementation of cellular senescence. However, whether or not this response is accompanied by induction of autophagy seems to depend on both the pRB and p53 status. In cells retaining expression of both tumor suppressive proteins (AGS gastric cancer cells), exposure to Palbociclib induces senescence and autophagy. However, the simultaneous blockade of CDK4/6 and autophagy in these cells exacerbates the senescence phenotype, an indication that autophagy in these experimental settings represents an adaptive mechanism that promotes cell survival rather than being an effector mechanism of senescence. Interestingly, knocking down p53 resulted in senescence reduction and autophagy blockade, the latter apparently involving a disruption of the degradation of autophagosome cargo.


Assuntos
Autofagia/efeitos dos fármacos , Senescência Celular/efeitos dos fármacos , Piperazinas/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Piridinas/farmacologia , Neoplasias Gástricas/patologia , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Quinase 4 Dependente de Ciclina/metabolismo , Quinase 6 Dependente de Ciclina/metabolismo , Células HEK293 , Humanos
11.
Artigo em Espanhol | LILACS | ID: lil-773294

RESUMO

En esta investigación cualitativa se abordaron los procesos de atención integral a los problemas de convivencia familiar, en la Comisaria de Familia del sector Ladera en Cali, teniendo en cuenta la perspectiva de los modelos alternativos de resolución del conflicto. La Comisaría cuenta con un protocolo definido para la atención de los casos, además de una ruta de atención. De acuerdo con los Informes Anuales de Labores, en el período comprendido entre 2007 y 2011, se registró la atención de 39.189 personas, siendo más frecuentes las quejas por violencia familiar; adicionalmente, se reciben casos de alimentos, custodias y visitas de menores. La Comisaria prescribe medidas conciliatorias y de protección provisional con las que busca velar por la convivencia familiar.


This qualitative research addressed the processes of integral attention to the problems of family life, in the Family Commissioner in Cali, taking into account the perspective of alternative conflict resolution models. The Commissioner has a defined protocol for the attention of cases, in addition to a route of attention. According to annual reports of work, in the period between 2007 and 2011, the care of 39.189 people registered, being most frequent complaints it by family violence; in addition, cases of food, custody and visits by minors are received. The Commissioner prescribes conciliatory and interim protective measures which seeks to ensure the family life.

12.
Angle Orthod ; 85(3): 454-60, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25181252

RESUMO

OBJECTIVE: To describe, using a three-dimensional finite element (FE) model, the initial force system generated during bodily movement of upper canines with plastic aligners with and without composite attachments. MATERIALS AND METHODS: A CAD model of an upper right canine, its alveolar bone and periodontal ligament, thermoformed plastic aligner, and two light-cured composite attachments were constructed. A FE model was used to analyze the effects of imposing a distal movement condition of 0.15 mm on the aligner (simulating the mechanics used to produce a distal bodily movement) with and without composite attachments. RESULTS: In terms of tension and compression stress distribution, without composite attachments a compression area in the cervical third of the distal root surface and a tension area in the apical third of the mesial surface were observed. With composite attachments, uniform compression areas in the distal root surface and uniform tension area in the mesial root surface were observed. Compression areas in the active surfaces of the composite attachments were also observed. In terms of movement patterns, an uncontrolled distal inclination, with rotation axis between the middle and cervical root thirds, was observed without composite attachment. Distal bodily movement (translation) was observed with composite attachment. CONCLUSIONS: In a three-dimensional FE analysis of a plastic aligner system biomechanically supplementary composite attachments generate the force system required to produce bodily tooth movement; the absence of biomechanically supplementary composite attachments favors the undesired inclination of the tooth during the translation movements.


Assuntos
Dente Canino/patologia , Análise de Elementos Finitos , Imageamento Tridimensional/métodos , Desenho de Aparelho Ortodôntico , Técnicas de Movimentação Dentária/instrumentação , Processo Alveolar/patologia , Fenômenos Biomecânicos , Resinas Compostas/química , Desenho Assistido por Computador , Materiais Dentários/química , Humanos , Ligamento Periodontal/patologia , Plásticos/química , Pressão , Estresse Mecânico , Colo do Dente/patologia , Raiz Dentária/patologia
13.
Cochabamba; UMSS-Dpto. de Medicina Soc. y Familiar; 1993. 159 p.
Monografia em Espanhol | LIBOCS, LIBOSP | ID: biblio-1307671
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