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1.
Sci Rep ; 14(1): 9247, 2024 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-38649370

RESUMO

The piezoresistive effect of materials can be adopted for a plethora of sensing applications, including force sensors, structural health monitoring, motion detection in fabrics and wearable, etc. Although metals are the most widely adopted material for sensors due to their reliability and affordability, they are significantly affected by temperature. This work examines the piezoresistive performance of carbon nanoparticle (CNP) bulk powders and discusses their potential applications based on strain-induced changes in their resistance and displacement. The experimental results are correlated with the characteristics of the nanoparticles, namely, dimensionality and structure. This report comprehensively characterizes the piezoresistive behavior of carbon black (CB), onion-like carbon (OLC), carbon nanohorns (CNH), carbon nanotubes (CNT), dispersed carbon nanotubes (CNT-D), graphite flakes (GF), and graphene nanoplatelets (GNP). The characterization includes assessment of the ohmic range, load-dependent electrical resistance and displacement tracking, a modified gauge factor for bulk powders, and morphological evaluation of the CNP. Two-dimensional nanostructures exhibit promising results for low loads due to their constant compression-to-displacement relationship. Additionally, GF could also be used for high load applications. OLC's compression-to-displacement relationship fluctuates, however, for high load it tends to stabilize. CNH could be applicable for both low and high loading conditions since its compression-to-displacement relationship fluctuates in the mid-load range. CB and CNT show the most promising results, as demonstrated by their linear load-resistance curves (logarithmic scale) and constant compression-to-displacement relationship. The dispersion process for CNT is unnecessary, as smaller agglomerates cause fluctuations in their compression-to-displacement relationship with negligible influence on its electrical performance.

2.
RSC Adv ; 14(1): 181-192, 2024 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-38173618

RESUMO

The design mebendazole (MBZ) multicomponent systems is important to obtain new materials that incorporate the API (active pharmaceutical ingredient) with better thermal stability, avoiding the interconversion of desmotropes. Interestingly, the presence of water molecules in the mebendazolium mesylate monohydrate prevents the formation of the R22(8) supramolecular synthon, found in all mebendazolium salts with polyatomic counterions. Here, we designed a new mebendazolium mesylate anhydrous salt based on statistical scrutiny of all mebendazole crystal structures identified in the literature and an exhaustive analysis of the conformational and geometrical requirements for the supramolecular assembly. The synthesis of this new salt and its solid-state characterization through single-crystal X-ray diffraction and complementary techniques are presented. As expected, mebendazole recrystallization in methanol with methanesulfonic acid - a Food and Drug Administration accepted coformer - in the absence of water yields a mesylate anhydrous salt with 1 : 1 stoichiometry. This new salt crystallizes in the P212121 (19) space group. The main intermolecular interactions found in the crystal structure are the hydrogen bonds that form a R22(8) supramolecular motif that assembles the ionic pairs. Additional non-classical H-bond, as well as π⋯π and carbonyl⋯cation interactions, contribute to the final stabilization of the crystal packing. This new salt is stable up to 205 °C when it undergoes the endothermic loss of the ester moiety to yield 2-amino-5-benzoylbenzimidazole. Moreover, preliminary dissolution experiments in aqueous 0.1 mol L-1 HCl suggest an apparent solubility of mebendazolium mesylate anhydride 2.67 times higher than that of the preferred for pharmaceutical formulations MBZ form C.

3.
Medicina (B Aires) ; 84(1): 125-137, 2024.
Artigo em Espanhol | MEDLINE | ID: mdl-38271939

RESUMO

The Argentine Osteoporosis Society convened renowned specialists in the care of transgender people to prepare the first local position on the evaluation of bone health in this population. Law 26.743 on "Gender Identity" recognize all identities and guarantees free care throughout the health system. The impact of different gender affirmation treatments on bone mass has been topic of international debate. To date the evidence remains limited and different societies have issued suggestions and recommendations. For this reason, we believe it is relevant to mention our experience, capturing through this document a series of suggestions to be used in medical care.


La Sociedad Argentina de Osteoporosis convocó a especialistas reconocidos en la atención de personas transgénero para la elaboración del primer posicionamiento local sobre la evaluación de la salud ósea en esta población. La ley 26.743 de "Identidad de género" reconoce todas las identidades y garantiza su atención de manera gratuita en el sistema de salud. El impacto de los diferentes tratamientos de afirmación de género sobre la masa ósea ha sido tópico de debate internacional. Hasta la fecha la evidencia sigue siendo limitada y diferentes sociedades han emitido sugerencias y recomendaciones. Por tal motivo, creemos relevante mencionar nuestra experiencia plasmando mediante este documento una serie de sugerencias para ser utilizadas en la atención médica.


Assuntos
Osteoporose , Pessoas Transgênero , Humanos , Densidade Óssea , Identidade de Gênero , Osteoporose/diagnóstico
4.
Dalton Trans ; 52(40): 14595-14605, 2023 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-37786344

RESUMO

We report the synthesis, crystal structure, and characterisation of a dinuclear Co(II) compound with thiodiacetate (tda) and phenanthroline (phen) as ligands (1), and of a series of metal complexes isomorphous to 1 with different Co : Zn ratios (2, 4 : 1; 3, 1 : 1; 4, 1 : 4; 5, 1 : 10). General characterisation methodologies and X-ray data showed that all the synthesised complexes are isomorphous to Zn(II) and Cu(II) analogues (CSD codes: DUHXEL and BEBQII). 1 consists of centrosymmetric Co(II) ion dimers in which the ions are 3.214 Å apart, linked by two µ-O bridges. Each cobalt atom is in a distorted octahedral environment of the N2O3S type. UV-vis spectra of 1 and 5 are in line with high spin (S = 3/2) Co(II) ions in octahedral coordination and indicate that the electronic structure of both Co(II) ions in the dinuclear unit does not significantly change relative to that of the magnetically isolated Co(II) ion. EPR spectra of powder samples of 5 (Co : Zn ratio of 1 : 10) together with spectral simulation indicated high spin Co(II) ions with high rhombic distortion of the zfs [E/D = 0.31(1), D > 0]. DC magnetic susceptibility experiments on 1 and analysis of the data constraining the E/D value obtained by EPR yielded g = 2.595(7), |D| = 61(1) cm-1, and an intradimer ferromagnetic exchange coupling of J = 1.39(4) cm-1. EPR spectra as a function of Co : Zn ratio for both powder and single crystal samples confirmed that they result from two effective S' = 1/2 spins that interact through dipolar and isotropic exchange interactions to yield magnetically isolated S' = 1 centres and that interdimeric exchange interactions, putatively mediated by hydrophobic interactions between phen moieties, are negligible. The latter observation contrasts with that observed in the Cu(II) analogue, where a transition from S = 1 to S' = 1/2 was observed. Computational calculations indicated that the absence of the interdimeric exchange interaction in 1 is due to a lower Co(II) ion spin density delocalisation towards the metal ligands.

5.
Am J Health Promot ; 37(5): 646-653, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-36608694

RESUMO

PURPOSE: To determine potential unique factors influencing cigarette and e-cigarette use in US Latino youth. APPROACH: We conducted a qualitative study assessing cigarette and e-cigarette perceptions and experiences, including experiences with/perceptions of the products, cultural influences and influences of friends and family. SETTING: Four online discussion boards, conducted in October 2020. PARTICIPANTS: 92 Latino youth aged 15-21 years living in the US. METHOD: Data from the discussion groups were coded and analyzed by three trained coders using a thematic analysis approach. RESULTS: Stress relief emerged as the dominant theme connected with both cigarettes and e-cigarettes. Apart from stress, perceptions of and experiences with the products differed. E-cigarettes were commonly viewed as trendy and cool and participants often reported using them due to curiosity and popularity. Participants commonly compared e-cigarettes to cigarettes, noting benefits of e-cigarettes. Participants also noted more negative short and long-term health effects of cigarette use, and discussed generational differences between the two products. CONCLUSION: Findings from this study help address a dearth of research examining tobacco use among diverse groups of Latino youth. Findings indicate that despite differences in country of heritage, Latino youth are united by similar opinions about cigarettes and e-cigarettes. Additionally, they share cultural values and experiences which could be leveraged for tobacco control communications that cut across populations of Latino youth.


Assuntos
Sistemas Eletrônicos de Liberação de Nicotina , Produtos do Tabaco , Vaping , Humanos , Adulto Jovem , Vaping/epidemiologia , Uso de Tabaco/epidemiologia , Atitude
6.
Medicina (B Aires) ; 82(6): 873-880, 2022.
Artigo em Espanhol | MEDLINE | ID: mdl-36571526

RESUMO

INTRODUCTION: Our objective was to assess whether physicians who care for people with type 2 diabetes address andrological symptoms such as erectile sexual dysfunction, decreased libido, and symptoms and/or signs of hypogonadism. METHODS: An anonymous survey was carried out with 171 doctors, 113 were females (66.1%), the mean age was 46 ± 10 years (females: 45 ± 10 and males: 49 ± 10, p = 0.006). RESULTS: There were no differences in responses according to gender. Regarding the presence of erectile sexual dysfunction and/or decreased libido, 44.4% (n = 76) and 55.6% (n = 95) did not ask about them, respectively. In patients with symptoms of hypogonadism, 50.9% (n = 87) did not request a testosterone measurement. Regarding the improvement of the metabolic profile of type 2 diabetes mellitus and sexual symptoms after replacement with testosterone, 65.8% of the respondents answered that both conditions could improve after treatment. In the presence of symptoms compatible with hypogonadism, 74.7% of those surveyed stated that the measurement of testosterone should be performed. A total of 108 (63.2%) showed interest in being trained on topics related to type 2 diabetes and disorders of the sexual sphere. CONCLUSION: A large percentage of physicians who take care of men with type 2 diabetes do not inquire about andrological disorders. It is necessary to raise awareness and train doctors to detect, treat and/or refer these frequent health problems, not only to improve the quality of life of patients but also to effectively respond and prevent a major health problem.


Introducción: Los trastornos andrológicos son frecuentes en varones con diabetes tipo 2. El objetivo fue evaluar si los médicos que atienden a personas con diabetes tipo 2 abordan problemas andrológicos como disfunción sexual eréctil, disminución de libido y síntomas de hipogonadismo. Métodos: Se llevó a cabo una encuesta anónima a 171 médicos, de ellos 113 fueron mujeres (66.1%) con una edad media de 46 ± 10 años (mujeres: 45 ± 10 y varones: 49 ± 10, p = 0.006). Resultados: No hubo diferencias en las respuestas según el género. El 44.4% (n = 76) y el 55.6% (n = 95) no preguntan sobre la presencia de disfunción sexual eréctil y/o disminución de libido, respectivamente. El 50.9% (n = 87) no solicitó medición de testosterona en pacientes con síntomas de hipogonadismo. El 65.8% de los participantes respondió que el reemplazo con testosterona puede mejorar el perfil metabólico de la diabetes mellitus tipo 2 y los síntomas sexuales. El 74.7% de los encuestados afirmó que la medición de testosterona debería realizarse ante la presencia de síntomas compatibles con hipogonadismo. El 63.2% (n = 108) mostró interés en formación sobre temas relacionados a diabetes tipo 2 y trastornos de la esfera sexual. Conclusión: Un gran porcentaje de médicos que asisten a varones con diabetes tipo 2 no indaga sobre trastornos andrológicos. Es necesario concientizar y entrenar a los médicos, para detectar, tratar y/o derivar estos problemas de salud tan frecuentes, no solo para mejorar la calidad de vida de los pacientes sino para responder y prevenir efectivamente a un problema mayor de salud.


Assuntos
Diabetes Mellitus Tipo 2 , Disfunção Erétil , Hipogonadismo , Masculino , Humanos , Adulto , Pessoa de Meia-Idade , Diabetes Mellitus Tipo 2/complicações , Qualidade de Vida , Disfunção Erétil/induzido quimicamente , Disfunção Erétil/diagnóstico , Testosterona , Hipogonadismo/etiologia , Hipogonadismo/induzido quimicamente
7.
Medicina (B.Aires) ; 82(6): 873-880, dic. 2022. graf
Artigo em Espanhol | LILACS-Express | LILACS | ID: biblio-1422082

RESUMO

Resumen Introducción: Los trastornos andrológicos son frecuentes en varones con diabetes tipo 2. El objetivo fue evaluar si los médicos que atienden a personas con diabetes tipo 2 abordan problemas andro lógicos como disfunción sexual eréctil, disminución de libido y síntomas de hipogonadismo. Métodos: Se llevó a cabo una encuesta anónima a 171 médicos, de ellos 113 fueron mujeres (66.1%) con una edad media de 46 ± 10 años (mujeres: 45 ± 10 y varones: 49 ± 10, p = 0.006). Resultados: No hubo diferencias en las res puestas según el género. El 44.4% (n = 76) y el 55.6% (n = 95) no preguntan sobre la presencia de disfunción sexual eréctil y/o disminución de libido, respectivamente. El 50.9% (n = 87) no solicitó medición de testosterona en pacientes con síntomas de hipogonadismo. El 65.8% de los participantes respondió que el reemplazo con testosterona puede mejorar el perfil metabólico de la diabetes mellitus tipo 2 y los síntomas sexuales. El 74.7% de los encuestados afirmó que la medición de testosterona debería realizarse ante la presencia de síntomas compatibles con hipogonadismo. El 63.2% (n = 108) mostró interés en formación sobre temas relacionados a diabetes tipo 2 y trastornos de la esfera sexual. Conclusión: Un gran porcentaje de médicos que asisten a varones con diabetes tipo 2 no indaga sobre trastornos andrológicos. Es necesario concientizar y entrenar a los médicos, para detectar, tratar y/o derivar estos problemas de salud tan frecuentes, no solo para mejorar la calidad de vida de los pacientes sino para responder y prevenir efectivamente a un problema mayor de salud.


Abstract Introduction: Our objective was to assess whether physicians who care for people with type 2 dia betes address andrological symptoms such as erectile sexual dysfunction, decreased libido, and symptoms and/ or signs of hypogonadism. Methods: An anonymous survey was carried out with 171 doctors, 113 were females (66.1%), the mean age was 46 ± 10 years (females: 45 ± 10 and males: 49 ± 10, p = 0.006). Results: There were no differences in responses according to gender. Regarding the presence of erectile sexual dysfunction and/or decreased libido, 44.4% (n = 76) and 55.6% (n = 95) did not ask about them, respectively. In patients with symptoms of hypogonadism, 50.9% (n = 87) did not request a testosterone measurement. Regarding the improvement of the metabolic profile of type 2 diabetes mellitus and sexual symptoms after replacement with testosterone, 65.8% of the respondents answered that both conditions could improve after treatment. In the presence of symptoms compatible with hypogonadism, 74.7% of those surveyed stated that the measurement of testosterone should be performed. A total of 108 (63.2%) showed interest in being trained on topics related to type 2 diabetes and disorders of the sexual sphere. Conclusion: A large percentage of physicians who take care of men with type 2 diabetes do not inquire about andrological disorders. It is necessary to raise awareness and train doctors to detect, treat and/or refer these frequent health problems, not only to improve the quality of life of patients but also to effectively respond and prevent a major health problem.

8.
Langmuir ; 38(49): 15209-15219, 2022 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-36449450

RESUMO

Copper is extensively used in a wide range of industrial and daily-life applications, varying from heat exchangers to electrical wiring. Although it is protected from oxidation by its native oxide layer, when subjected to harsh environmental conditions─such as in coastal regions─this metal can rapidly degrade. Therefore, in this study, we analyze the potential use of carbon nanoparticle coatings as protective barriers due to their intrinsic hydrophobic wetting behavior. The nanocarbon coatings were produced via electrophoretic deposition on Cu platelets and characterized via scanning electron microscopy, confocal laser scanning microscopy, and sessile drop test; the latter being the primary focus since it provides insights into the wetting behavior of the produced coatings. Among the measured coatings, graphite flakes, graphene oxide, and carbon nanotube (CNT) coatings showed superhydrophobic behavior. Based on their wetting behavior, and specifically for electrical applications, CNT coatings showed the most promising results since these coatings do not significantly impact the substrate's electrical conductivity. Although CNT agglomerates do not affect the wetting behavior of the attained coatings, the coating's thickness plays an important role. Therefore, to completely coat the substrate, the CNT coating should be sufficiently thick─above approximately 1 µm.

9.
BMJ Open ; 12(10): e051055, 2022 10 05.
Artigo em Inglês | MEDLINE | ID: mdl-36198454

RESUMO

OBJECTIVES: Lack of anaesthesia services is a frequent barrier to emergency surgeries such as caesarean delivery in Kenya. This study aimed to estimate the survival gains and cost-effectiveness of scaling up the Every Second Matters (ESM)-Ketamine programme that trains non-anaesthetist providers to administer and monitor ketamine during emergency caesarean deliveries. SETTING: Hospitals in Kenyan counties with low rates of caesarean delivery. PARTICIPANTS: Patients needing emergency caesarean delivery in settings without availability of standard anaesthesia service. INTERVENTIONS: Simulated scales up of the ESM-Ketamine programme over 5 years (2020-24) was compared with status quo. OUTCOME MEASURES: Cost of implementing the programme and corresponding additional emergency caesarean deliveries. Maternal and fetal/neonatal deaths prevented, and corresponding life-years gained due to increased provision of emergency caesarean procedures. Cost-effectiveness was assessed by comparing the cost per life-year gained of the ESM-Ketamine programme compared with status quo. RESULTS: Over 5 years, the expected gap in emergency caesarean deliveries was 157 000. A US$1.2 million ESM-Ketamine programme reduced this gap by 28 700, averting by 316 maternal and 4736 fetal deaths and generating 331 000 total life-years gained. Cost-effectiveness of scaling up the ESM-Ketamine programme was US$44 per life-year gained in the base case and US$251 in the most pessimistic scenario-a very good value for Kenya at less than 20% of per capita GDP per life-year gained. CONCLUSION: In areas of Kenya with significant underprovision of emergency caesarean delivery due to a lack of availability of traditional anaesthesia, an ESM-Ketamine programme is likely to enable a substantial number of life-saving surgeries at reasonable cost.


Assuntos
Anestesia , Ketamina , Anestesia/métodos , Cesárea , Análise Custo-Benefício , Feminino , Humanos , Recém-Nascido , Quênia , Gravidez
10.
LGBT Health ; 9(8): 589-594, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-35905057

RESUMO

Purpose: The purpose of this study was to assess perception of competency and comfort level of internal medicine (IM) residents in caring for gender and sexual diverse (GSD) patients, and to identify residents' preferred educational modalities and perceived facilitators and barriers to GSD curriculum implementation. Methods: A survey was distributed among IM residents during a mandatory didactic session between November 9 and December 18, 2020. Categorical variables were analyzed using Fisher's exact test. Open-ended questions were analyzed using content and theme analysis. Results: Of 138 residents, 89 (64%) completed the survey. Residents had varying levels of comfort and perceived competence. Small group (n = 61, 69%) and case-based learning (n = 58, 66%) formats were preferred. Content and theme analysis resulted in four major themes on facilitators and three major themes on barriers to GSD curricular implementation. Conclusion: This study provides unique insight to facilitate implementation of a learner-centered and developmentally appropriate curricular approach to GSD health education.


Assuntos
Internato e Residência , Humanos , Avaliação das Necessidades , Currículo , Inquéritos e Questionários , Educação Sexual
11.
Acta Crystallogr B Struct Sci Cryst Eng Mater ; 78(Pt 3 Pt 2): 520-536, 2022 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-35702969

RESUMO

Metalloproteins involved in oxidation-reduction processes in metabolism are fundamental for the wellbeing of every organism. The use of amino-acid-based compounds as ligands for the construction of biomimetic coordination systems represents a promising alternative for the development of new catalysts. Herein is presented a new family of copper, zinc and nickel coordination compounds, which show four-, five- and six- coordination geometries, synthesized using Schiff base ligands obtained from the amino acids L-alanine and L-phenylalanine. Structural analysis and property studies were performed using single-crystal X-ray diffraction data, spectroscopic and electrochemical experiments and DFT calculations. The analysis of the molecular and supramolecular architectures showed that the non-covalent interactions developed in the systems, together with the identity of the metal and the amino acid backbone, are determinants for the formation of the complexes and the stabilization of the resultant geometries. The CuII complexes were tested as candidates for the electrochemical conversion reduction of nitrite to NO, finding that the five-coordinate L-phenylalanine complex is the most suitable. Finally, some insights into the rational design of ligands for the construction of biomimetic complexes are suggested.


Assuntos
Complexos de Coordenação , Aminoácidos , Complexos de Coordenação/química , Cristalografia por Raios X , Ligantes , Fenilalanina , Bases de Schiff/química
13.
World J Mens Health ; 40(2): 308-315, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34169681

RESUMO

PURPOSE: Vitamin D (VD) acts on sperm motility, capacitation and survival but its role in steroidogenesis is less clear. Aims: To analyze seasonal variations in sex steroids and VD in a healthy male population. MATERIALS AND METHODS: Twenty-nine healthy males, 34.0±4.8 years were included. Blood collection in winter (W) and summer (S) was performed to measure: 25OHD, total testosterone (TT), free testosterone (FT), estradiol (E2), luteinizing hormone (LH), and sex hormone binding globulin (SHBG). Testosterone/estradiol (T/E2) ratio was calculated. RESULTS: In W, lower levels of 25OHD: 18.8±7.2 ng/mL vs. 38.8±11.9 ng/mL (p<0.0001) and LH: 3.5±1.2 mU/mL vs. 3.9±1.5 mU/mL (p=0.05), and higher levels of TT: 501.9±157.7 ng/dL vs. 405.0±128.0 ng/dL (p=0.0003), FT: 11.8±4.1 ng/dL vs. 10.2±3.7 ng/dL (p=0.017), SHBG: 28.5±10.9 nmol/L vs. 23.6±7.9 nmol/L (p=0.002) and T/E2 ratio: 30.7±19.7 ng/dL/pg/mL vs. 17.3±3.6 ng/dL/pg/mL (p=0.0015) with no variation in E2 levels were observed. A positive correlation between 25OHD and E2 (r=0.28, p=0.04) and negative correlations between 25OHD and TT (r=-0.27, p=0.049), 25OHD and FT (r=-0.32, p=0.01), and 25OHD and T/E2 (r=-0.44, p=0.0008) were found. CONCLUSIONS: In healthy young male population, seasonal variations were observed in 25OHD and LH levels (higher in S) and in TT, FT, SHBG levels, and T/E2 (higher in W). Lower values of TT and FT in S are accompanied by higher levels of LH, which rules out a central mechanism for lowering testosterone. 25OHD negatively correlated with TT, FT, and T/E2 and positively correlated with E2, suggesting a relationship between VD status and changes in gonadal steroids.

14.
Cogn Psychol ; 132: 101444, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34861584

RESUMO

Induction benefits from useful priors. Penalized regression approaches, like ridge regression, shrink weights toward zero but zero association is usually not a sensible prior. Inspired by simple and robust decision heuristics humans use, we constructed non-zero priors for penalized regression models that provide robust and interpretable solutions across several tasks. Our approach enables estimates from a constrained model to serve as a prior for a more general model, yielding a principled way to interpolate between models of differing complexity. We successfully applied this approach to a number of decision and classification problems, as well as analyzing simulated brain imaging data. Models with robust priors had excellent worst-case performance. Solutions followed from the form of the heuristic that was used to derive the prior. These new algorithms can serve applications in data analysis and machine learning, as well as help in understanding how people transition from novice to expert performance.


Assuntos
Algoritmos , Encéfalo , Heurística , Humanos
15.
MethodsX ; 8: 101498, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34754769

RESUMO

Electrical contacts are pervasively found on countless modern devices and systems. It is imperative that connecting components present adequate electrical, mechanical, and chemical characteristics to fulfill the crucial role that they play in the system. To develop an electrical contact material that is tailored for a specific application, different approaches are pursued (e.g., coatings, reinforced composites, alloyed metals, duplex systems, etc.). The manufacturing of electrical contact materials demand a thorough characterization of their electrical properties, mechanical properties, and their resistance to wear, as well as their resistance to atmospheric conditions. Accordingly, commissioning of a novel setup enables a more comprehensive study of the materials that are developed. Therefore, a complete understanding of the material's electrical and tribological characteristics are attained, allowing the production of a material that is compliant with the particular demands of the application for which it is intended. This multipurpose setup was built with higher precision stages and higher accuracy 3-axis force sensor, thus providing the following improvement over the preceding setup:•Elevated load-bearing capacity (double), higher precision and stability.•Tribo-electrical characterization (implementation of scratch and fretting tests).•Environmental control (climate and external vibration).

16.
Chem Sci ; 12(31): 10410-10425, 2021 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-34447533

RESUMO

HNO (nitroxyl, azanone), joined the 'biologically relevant reactive nitrogen species' family in the 2000s. Azanone is impossible to store due to its high reactivity and inherent low stability. Consequently, its chemistry and effects are studied using donor compounds, which release this molecule in solution and in the gas phase upon stimulation. Researchers have also tried to stabilize this elusive species and its conjugate base by coordination to metal centers using several ligands, like metalloporphyrins and pincer ligands. Given HNO's high reactivity and short lifetime, several different strategies have been proposed for its detection in chemical and biological systems, such as colorimetric methods, EPR, HPLC, mass spectrometry, fluorescent probes, and electrochemical analysis. These approaches are described and critically compared. Finally, in the last ten years, several advances regarding the possibility of endogenous HNO generation were made; some of them are also revised in the present work.

17.
Inorg Chem ; 60(21): 15997-16007, 2021 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-34450017

RESUMO

The chemical reactivity of NO and its role in several biological processes seem well established. Despite this, the chemical reduction of •NO toward HNO has been historically discarded, mainly because of the negative reduction potential of NO. However, this value and its implications are nowadays under revision. The last reported redox potential, E'(NO,H+/HNO), at micromolar and picomolar concentrations of •NO and HNO, respectively, is between -0.3 and 0 V at pH 7.4. This potential implies that the one-electron-reduction process for NO is feasible under biological conditions and could be promoted by well-known biological reductants with reduction potentials of around -0.3 to -0.5 V. Moreover, the biologically compatible chemical reduction of •NO (nonenzymatic), like direct routes to HNO by alkylamines, aromatic and pseudoaromatic alcohols, thiols, and hydrogen sulfide, has been extensively explored by our group during the past decade. The aim of this work is to use a kinetic modeling approach to analyze electrochemical HNO measurements and to report for the first-time direct reaction rate constants between •NO and moderate reducing agents, producing HNO. These values are between 5 and 30 times higher than the previously reported keff values. On the other hand, we also showed that reaction through successive attack by two NO molecules to biologically compatible compounds could produce HNO. After over 3 decades of intense research, the •NO chemistry is still there, ready to be discovered.


Assuntos
Sulfeto de Hidrogênio
19.
J Inorg Biochem ; 223: 111535, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34298305

RESUMO

We present a novel nitroxyl (HNO) generation method, which avoids the need of using a liquid system or extreme experimental conditions. This method consists of the reaction between a gaseous base and an HNO donor (Piloty's acid) in the solid phase, allowing the formation of gaseous HNO in a fast and economical way. Detection of HNO was carried out indirectly, measuring the nitrous oxide (N2O) byproduct of HNO dimerization using infrared spectroscopy, and directly, using mass spectrometry techniques and an electrochemical HNO sensor.


Assuntos
Óxidos de Nitrogênio/síntese química , Amônia/química , Gases/química , Ácidos Hidroxâmicos/química , Sulfonamidas/química
20.
Prim Care ; 48(2): 191-212, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33985699

RESUMO

The annual examination is a comprehensive evaluation of patients in which all aspects of health and well-being are considered, including proper screening, appropriate preventive care, and recommendations and resources for healthy living. Clinicians commonly avoid certain topics with lesbian, gay, bisexual, transgender, and queer (LGBTQ) patients because they may be unprepared to address their health needs. Therefore, clinicians should learn how to conduct an LGBTQ-friendly annual examination in order to provide high-quality care. This article focuses on both the general and unique health needs of lesbian, gay, bisexual, and queer patients; care for transgender and gender-diverse patients is considered elsewhere.


Assuntos
Minorias Sexuais e de Gênero , Pessoas Transgênero , Feminino , Disparidades em Assistência à Saúde , Humanos , Comportamento Sexual
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