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1.
Acta Trop ; 249: 107075, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37967666

RESUMEN

The human head lice is a cosmopolitan ectoparasite that causes pediculosis. The main way of spreading lice is through direct head-to-head contact. It is popular knowledge that some individuals are more susceptible to contracting head lice than others. Reports of individuals who have never been affected by the disease are common, even living in the same environment and under the same conditions as people who regularly have lice infestations. Previous research has been carried out on the risk of this infection associated with different human factors like gender or age. However, studies on the influence of the individual hair characteristics are scarce. The objective of the study was to analyze the pediculosis risk using geographical location, gender, age and individual hair characteristics as variables. Pediculosis was diagnosed through the detection of living lice in the hair. This cross-sectional school-based epidemiological study was conducted in 310 schoolchildren aged 1 to 13 years of schools in 4 municipalities situated in the State of Paraná, Brazil. The prevalence of head louse infection in primary school students was 49.35 %. The Odds Ratio of presence of pediculosis (OR) was estimated using multivariate logistic regression analysis. The results obtained indicate that hair length and thickness increase the risk of infection. Furthermore, the inclusion of hair color, hair shape, kind of hair-scale as covariates increases the risk of pediculosis, indicating that these variables partly explain this susceptibility and that pediculosis is independent of gender. A smaller hair diameter may favor insect fixation to the hair in the nymphal phases. These results may explain why girls are a greater risk as they let their hair grow for cultural reasons, i.e., being of female gender is an agglutinating variable. The conclusions drawn may explain the discrepancies obtained in previous analyses.


Asunto(s)
Infestaciones por Piojos , Pediculus , Animales , Humanos , Femenino , Niño , Infestaciones por Piojos/epidemiología , Infestaciones por Piojos/parasitología , Estudios Transversales , Factores de Riesgo , Cabello , Prevalencia
2.
MicroPubl Biol ; 20232023.
Artículo en Inglés | MEDLINE | ID: mdl-37680216

RESUMEN

Mutant B.4.1 , generated via EMS mutagenesis in Drosophila melanogaster , was studied by undergraduate students participating in the Fly-CURE. After inducing genetically mosaic tissue in the adult eye, B.4.1 mutant tissue displays a robust increase in cell division and a rough appearance. Complementation mapping and sequence analysis identified a nonsense mutation in the gene CG1603 , which we named clifford ( cliff ) due to observed increases in red-pigmented mutant tissue compared to controls. cliff encodes a zinc finger-containing protein implicated in transcriptional control. RNAi knockdown of cliff similarly results in rough eyes, confirming a role for Cliff in eye development.

3.
J Am Chem Soc ; 145(30): 16355-16364, 2023 Aug 02.
Artículo en Inglés | MEDLINE | ID: mdl-37486221

RESUMEN

Cuneane is a strained hydrocarbon that can be accessed via metal-catalyzed isomerization of cubane. The carbon atoms of cuneane define a polyhedron of the C2v point group with six faces─two triangular, two quadrilateral, and two pentagonal. The rigidity, strain, and unique exit vectors of the cuneane skeleton make it a potential scaffold of interest for the synthesis of functional small molecules and materials. However, the limited previous synthetic efforts toward cuneanes have focused on monosubstituted or redundantly substituted systems such as permethylated, perfluorinated, and bis(hydroxymethylated) cuneanes. Such compounds, particularly rotationally symmetric redundantly substituted cuneanes, have limited potential as building blocks for the synthesis of complex molecules. Reliable, predictable, and selective syntheses of polysubstituted cuneanes bearing more complex substitution patterns would facilitate the study of this ring system in myriad applications. Herein, we report the regioselective, AgI-catalyzed isomerization of asymmetrically 1,4-disubstituted cubanes to cuneanes. In-depth DFT calculations provide a charge-controlled regioselectivity model, and direct dynamics simulations indicate that the nonclassical carbocation invoked is short-lived and dynamic effects augment the charge model.

4.
Ann Surg ; 277(6): e1313-e1323, 2023 06 01.
Artículo en Inglés | MEDLINE | ID: mdl-35793069

RESUMEN

OBJECTIVE: The purpose of this study was to determine the prevalence of psychiatric diagnoses among a sample of breast reconstruction patients and measure the association between these diagnoses and reconstruction-related, patient-reported outcomes. BACKGROUND: The impact of psychiatric disorders in conjunction with breast cancer diagnosis, treatment, and reconstruction have the potential to cause significant patient distress but remains not well understood. METHODS: A retrospective review of postmastectomy breast reconstruction patients from 2007 to 2018 at Memorial Sloan Kettering Cancer Center was conducted. Patient demographics, comorbidities, cancer characteristics, psychiatric diagnoses, and BREAST-Q Reconstruction Module scores (measuring satisfaction with breast, well-being of the chest, psychosocial, and sexual well-being) at postoperative years 1 to 3 were examined. Mixed-effects models and cross-sectional linear regressions were conducted to measure the effect of psychiatric diagnostic class type and number on scores. RESULTS: Of 7414 total patients, 50.1% had at least 1 psychiatric diagnosis. Patients with any psychiatric diagnoses before reconstruction had significantly lower BREAST-Q scores for all domains at all time points. Anxiety (50%) and depression (27.6%) disorders were the most prevalent and had the greatest impact on BREAST-Q scores. Patients with a greater number of psychiatric diagnostic classes had significantly worse patient-reported outcomes compared with patients with no psychiatric diagnosis. Psychosocial (ß: -7.29; 95% confidence interval: -8.67, -5.91), and sexual well-being (ß: -7.99; 95% confidence interval: -9.57, -6.40) were most sensitive to the impact of psychiatric diagnoses. CONCLUSIONS: Mental health status is associated with psychosocial and sexual well-being after breast reconstruction surgery as measured with the BREAST-Q. Future research will need to determine what interventions (eg, screening, early referral) can help improve outcomes for breast cancer patients with psychiatric disorders undergoing breast reconstruction.


Asunto(s)
Neoplasias de la Mama , Mamoplastia , Trastornos Mentales , Humanos , Femenino , Neoplasias de la Mama/etiología , Mastectomía/efectos adversos , Satisfacción del Paciente , Calidad de Vida , Estudios Transversales , Mamoplastia/efectos adversos , Trastornos Mentales/diagnóstico , Trastornos Mentales/epidemiología , Medición de Resultados Informados por el Paciente , Satisfacción Personal
5.
J Am Chem Soc ; 144(41): 19089-19096, 2022 Oct 19.
Artículo en Inglés | MEDLINE | ID: mdl-36197722

RESUMEN

Despite their favorable properties, azetidines are often overlooked as lead compounds across multiple industries. This is often attributed to the challenging synthesis of densely functionalized azetidines in an efficient manner. In this work, we report the scalable synthesis and characterization of seven azetidines with varying regio- and stereochemistry and their application as novel azetidine-based energetic materials, enabled by the visible-light-mediated aza Paternò-Büchi reaction. The performance and stark differences in the physical properties of these new compounds make them excellent potential candidates as novel solid melt-castable explosive materials, as well as potential liquid propellant plasticizers. This work highlights the scalability and utility of the visible-light aza Paternò-Büchi reaction and demonstrates the impact of stereochemical considerations on the physical properties of azetidine-based energetics. Considering the versatility and efficiency of the presented synthetic strategies, we expect that this work will guide the development of new azetidine-based materials in the energetics space as well as other industries.

6.
J Phys Chem A ; 126(38): 6648-6656, 2022 Sep 29.
Artículo en Inglés | MEDLINE | ID: mdl-36126112

RESUMEN

A combined experimental and modeling study of energetic compound N-(1,7-dinitro-1,2,6,7-tetrahydro-[1,3,5]triazino[1,2-c][1,3,5]oxadiazin-8(4H)-ylidene)nitramide [C5H6N8O7, (DTO)] has been performed. We report its crystal structure, solid-phase heat of formation, and its vibrational and electronic structure obtained by single-crystal X-ray diffractometry, Raman spectroscopy, and density functional theory (DFT). DTO exhibits two adjoining six-membered rings, a triazine ring (C3N3) and an oxadiazine ring (C3N2O) ring containing two nitro functional groups and one nitroamino group. DTO crystallizes with four molecules in its unit cell and presents a density of 1.862 kg/m3 at 298 K, in excellent agreement with both DFT calculations performed both at the molecular level using the B3LYP with the 6-311+G** basis set and the solid-state level using the hybrid functional HSE6 optimized with norm-conserving pseudopotentials. The calculated vibrational structure allows for the symmetry assignment of key Raman modes in terms of atomic movements, and the calculated frequency values are in good agreement with experiment. The solid-phase DFT calculations reveal that the N atoms of the triazine ring contribute mostly to the density of states at the Fermi level. In addition, we present and discuss the computed solid-phase heat of formation (215.9 kJ/mol) and molecular electrostatic potential surface of DTO and compare them to complementary materials.

7.
Epilepsia ; 63(5): 1177-1188, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-35174484

RESUMEN

OBJECTIVE: A broad spectrum of emotional-behavioral problems have been reported in pediatric temporal lobe epilepsy (TLE), but with considerable variability in their presence and nature of expression, which hampers precise identification and treatment. The present study aimed to empirically identify latent patterns or behavioral phenotypes and their correlates. METHODS: Data included parental ratings of emotional-behavioral status on the Behavior Assessment System for Children, 2nd Edition (BASC-2) of 81 children (mean age = 11.79, standard deviation [SD] = 3.93) with TLE. The nine clinical subscales were subjected to unsupervised machine learning to identify behavioral subgroups. To explore concurrent validity and the underlying composition of the identified clusters, we examined demographic factors, seizure characteristics, psychosocial factors, neuropsychological performance, psychiatric status, and health-related quality of life (HRQoL). RESULTS: Three behavioral phenotypes were identified, which included no behavioral concerns (Cluster 1, 43% of sample), externalizing problems (Cluster 2, 41% of sample), and internalizing problems (Cluster 3, 16% of sample). Behavioral phenotypes were characterized by important differences across clinical seizure variables, psychosocial/familial factors, everyday executive functioning, and HRQoL. Cluster 2 was associated with younger child age, lower maternal education, and higher rate of single-parent households. Cluster 3 was associated with older age at epilepsy onset and higher rates of hippocampal sclerosis and parental psychiatric history. Both Cluster 2 and 3 demonstrated elevated family stress. Concurrent validity was demonstrated through the association of psychiatric (i.e., rate of Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) disorders and psychotropic medication) and parent-rated HRQoL variables. SIGNIFICANCE: Youth with TLE present with three distinct behavioral phenotypes that correspond with important clinical and sociodemographic markers. The current findings demonstrate the variability of behavioral presentations in youth with TLE and provide a preliminary framework for screening and targeting intervention to enhance support for youth with TLE and their families.


Asunto(s)
Epilepsia del Lóbulo Temporal , Adolescente , Niño , Epilepsia del Lóbulo Temporal/complicaciones , Función Ejecutiva , Humanos , Fenotipo , Calidad de Vida/psicología , Convulsiones/complicaciones
8.
J Int Neuropsychol Soc ; 28(9): 916-925, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-34446126

RESUMEN

OBJECTIVE: Adults with temporal lobe epilepsy (TLE) have been found to have a fairly characteristic pattern of neuropsychological performance, but there is considerably less research and more variability in findings with children. Because the cognitive domains included in most studies with children have been limited, the current study attempted to better characterize the cognitive phenotype of children with TLE using a broader neuropsychological battery. METHODS: The study included 59 children with TLE (59% male) age 7 to 16 (M = 12.67; SD = 3.12) who underwent comprehensive neuropsychological evaluation. Patient results were grouped into cognitive domains (reasoning, language, visuoperceptual, verbal memory, executive function, and motor function) based upon their test performance. These factor scores were subjected to Ward's hierarchical clustering method with squared Euclidean distance. RESULTS: Cluster analysis revealed three distinct cognitive profiles: (1) normal functioning (20% of sample); (2) delayed verbal memory and motor weaknesses (61% of the sample); and (3) global impairment (19% of the sample). Cluster 3 had longer epilepsy duration and a higher incidence of hippocampal sclerosis (HS) compared to Cluster 1 (p < .05). There were no significant differences among the three cluster groups on demographic characteristics or remaining clinical characteristics. CONCLUSIONS: Children with TLE present with distinct cognitive phenotypes ranging from average performance to global impairment. Results partially support previous hypotheses highlighting the cumulative neurobiological burden on the developing brain in the context of chronic epilepsy and provide a preliminary framework for the cognitive domains most vulnerable to the TLE disease process.


Asunto(s)
Epilepsia del Lóbulo Temporal , Epilepsia del Lóbulo Temporal/complicaciones , Función Ejecutiva , Femenino , Humanos , Masculino , Memoria , Pruebas Neuropsicológicas , Fenotipo
9.
In. Alonso Texeira Nuñez, Felicita; Ferreiro Paltre, Patricia B; González Brandi, Nancy Beatriz. Adolescencias: una mirada integral. Montevideo, Bibliomédica, c2022. p.153-163, tab.
Monografía en Español | LILACS, UY-BNMED, BNUY | ID: biblio-1416901
10.
PLoS One ; 16(9): e0257165, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34550994

RESUMEN

BACKGROUND: The burden of the COVID-19 pandemic in Peru has led to people seeking alternative treatments as preventives and treatment options such as medicinal plants. This study aimed to assess factors associated with the use of medicinal plants as preventive or treatment of respiratory symptom related to COVID-19 during the pandemic in Cusco, Peru. METHOD: A web-based cross-sectional study was conducted on general public (20- to 70-year-old) from August 31 to September 20, 2020. Data were collected using a structured questionnaire via Google Forms, it consisted of an 11-item questionnaire that was developed and validated by expert judgment using Aiken's V (Aiken's V > 0.9). Both descriptive statistics and bivariate followed by multivariable logistic regression analyses were conducted to assess factors associated with the use of medicinal plants for COVID-19 prevention and respiratory symptom treatment during the pandemic. Prevalence ratios (PR) with 95% Confidence Interval (CI), and a P-value of 0.05 was used to determine statistical significance. RESULTS: A total of 1,747 respondents participated in the study, 80.2% reported that they used medicinal plants as preventives, while 71% reported that they used them to treat respiratory symptoms. At least, 24% of respondents used medicinal plants when presenting with two or more respiratory symptoms, while at least 11% used plants for malaise. For treatment or prevention, the multivariate analysis showed that most respondents used eucalyptus (p < 0.001 for both), ginger (p < 0.022 for both), spiked pepper (p < 0.003 for both), garlic (p = 0.023 for prevention), and chamomile (p = 0.011 for treatment). The respondents with COVID-19 (p < 0.001), at older ages (p = 0.046), and with a family member or friend who had COVID-19 (p < 0.001) used more plants for prevention. However, the respondents with technical or higher education used less plants for treatment (p < 0.001). CONCLUSION: There was a significant use of medicinal plants for both prevention and treatment, which was associated with several population characteristics and whether respondents had COVID-19.


Asunto(s)
Tratamiento Farmacológico de COVID-19 , COVID-19/prevención & control , Plantas Medicinales , Sistema Respiratorio/efectos de los fármacos , Encuestas y Cuestionarios , Adulto , Anciano , Estudios Transversales , Femenino , Conocimientos, Actitudes y Práctica en Salud , Humanos , Masculino , Persona de Mediana Edad , Perú/epidemiología , Adulto Joven
12.
Chempluschem ; 86(6): 875-878, 2021 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-34114374

RESUMEN

The synthesis of 3-(1,2,4-oxadiazolyl)-5-nitratomethyl isoxazole (C6 H4 N4 O5 ), its physical properties, and its theoretical performances are described. This energetic material was found to have a melting point range of 76.6-79.2 °C, and a thermal onset decomposition temperature of 184.5 °C. These thermal features put this material into the standalone melt-castable explosive class. The material was found to have TNT performance, and was found to be insensitive to impact, friction, and electrostatic discharge, despite having a nitric ester functionality. A critical reaction in making this molecule was the desymmetrization of diaminoglyoxime. The optimization of this transformation is described. Previous reports of this desymmetrization were found to be inaccurate, as the desymmetrization reaction produces a co-crystal of mono- and bi-1,2,4-oxadiazole products.

13.
Epileptic Disord ; 23(2): 274-280, 2021 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-33926855

RESUMEN

The objective of this brief report is to review an assessment paradigm for conducting virtual neuropsychological pre-surgical evaluations in the context of the COVID-19 pandemic. A multidisciplinary epilepsy team at a Level 4 epilepsy center within a large children's academic medical center convened to discuss the challenges and possible solutions for Phase II evaluations for pediatric patients with pharmacoresistant epilepsy during the COVID-19 pandemic. The neuropsychologists explored evidence-based methods of virtual evaluation and developed a systematic decision-making process for youth requiring a Phase II evaluation. We propose models of assessment which prioritize teleneuropsychology when possible to reduce the risk of infection: (1) evaluation with directly administered tests through a completely virtual format; (2) virtual/in-person hybrid evaluation; and (3) clinical observation/interview in a virtual format supplemented by survey data. These models are illustrated by three cases. Using virtual assessment models, the team was able to meet the urgent patient care needs and collect useful data while minimizing the risk of virus spread. The paradigms presented may be useful examples for other multidisciplinary surgical teams interested in incorporating teleneuropsychology into their practices.


Asunto(s)
COVID-19 , Epilepsia Refractaria/diagnóstico , Epilepsia Refractaria/psicología , Pandemias , Telemedicina/métodos , Adolescente , Niño , Toma de Decisiones Clínicas , Epilepsia Refractaria/terapia , Epilepsias Parciales/diagnóstico , Epilepsias Parciales/psicología , Epilepsias Parciales/terapia , Femenino , Humanos , Lactante , Modelos Teóricos , Pruebas Neuropsicológicas , Grupo de Atención al Paciente , Convulsiones/diagnóstico , Convulsiones/terapia , Interfaz Usuario-Computador
14.
Eur Ann Allergy Clin Immunol ; 53(6): 247-251, 2021 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-33182991

RESUMEN

SUMMARY: Adolescence is one of the most rapid phases of human development, in which biological maturity precedes psychosocial maturity. Rhinoconjunctivitis (ARC) is present in around 15 percent of 13-14-year-old children, which indicates a higher prevalence when compared with 6-7-year-old children (8.5 percent). During childhood (0-10 years) prevalence of Allergic Rhinitis (AR) is higher among males compared to females. Quite the reverse, during adolescence (11-17 years) females display higher prevalence of AR compared to males. However, when they reach adulthood (18-79 years), there is no difference in prevalence between genders. AR and ARC have significant physical and mental impacts on the QoL of adolescents and their parents. Apart from de adverse effects of first generation antihistamines, which include sedating effects, AR-ARC leads to school absences and poorer performance due to distraction, fatigue and irritability. The mobile technology facilitates an innovative investigatory approach to better and more precisely characterize allergy symptoms and their association with other allergic diseases. The success of treatment lies in the partnership between adolescents with AR and mobile technology, allowing them to have more information both on the disease and treatment. Adolescence is a special period in which AR is highly prevalent with some sex-dependent differences. There are also peculiarities on how AR affects QoL of adolescent patients.


Asunto(s)
Calidad de Vida , Rinitis Alérgica , Adolescente , Adulto , Niño , Femenino , Antagonistas de los Receptores Histamínicos , Humanos , Masculino , Prevalencia , Rinitis Alérgica/terapia
15.
Chempluschem ; 85(1): 237-239, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31961517

RESUMEN

The synthesis and crystal structure of the heterocyclic explosive bis(nitroxymethylisoxazolyl) furoxan, C10 H6 N6 O10 , are described. In addition, we report its physical properties and theoretical performance. This material was found to exhibit standalone melt-castable explosive properties, with a melting point of 89.8 °C and an onset decomposition temperature of 193.8 °C. Bis(nitroxymethylisoxazolyl) furoxan features an insensitive behavior to impact, friction, and electrostatic discharge, with a calculated detonation pressure about 25 % higher than the state-of-the-art melt-castable explosive TNT.

16.
J Am Chem Soc ; 141(32): 12531-12535, 2019 08 14.
Artículo en Inglés | MEDLINE | ID: mdl-31361955

RESUMEN

The synthesis, physical properties, and calculated performances of six stereo- and regioisomeric cyclobutane nitric ester materials are described. While the calculated performances of these isomers, as expected, were similar, their physical properties were found to be extremely different. By alteration of the stereo- and regiochemistry, complete tunability in the form of low- or high-melting solids, stand-alone melt-castable explosives, melt-castable explosive eutectic compounds, and liquid propellant materials was obtained. This demonstrates that theoretical calculations should not be the main factor in driving the design of new materials and that stereo- and regiochemistry matter in the design of compounds of potential relevance to energetic formulators.

17.
Nutrition ; 58: 134-139, 2019 02.
Artículo en Inglés | MEDLINE | ID: mdl-30391692

RESUMEN

OBJECTIVES: Globally, although progress in eliminating iodine deficiency disorders (IDD) has been reported, IDD is still considered to be a global health problem. As school-aged children are the most accessible population group, their urinary iodine (UI) concentration data are accepted and used as an indicator of IDD for the general population. The aim of this study was to reassess the national, regional, and provincial estimates of UI as a measure of IDD among Filipino school-aged children. METHODS: Casual urine samples were collected from 22 588 children, 6 to 12 y of age, from participating households in the eighth National Nutrition Survey. UI was determined based on the catalytic action of iodine in the Sandell-Kolthoff reaction and IDD was evaluated using criteria from the World Health Organization, United Nations Children's Fund, International Council for Control of Iodine Deficiency Disorders criteria. RESULTS: The median UI level among Filipino school-aged children was 168 µg/L, corresponding to optimal iodine nutrition; whereas 23.2% had UI reflective of excessive iodine intake. Cjildren in the Zamboanga Peninsula Region had median UI level of 68 µg/L and 41.1% of participants had UI values <50 µg/L, which is indicative of mild iodine deficiency. Children from Guimaras and Zamboanga del Norte, or 2.4% of the provinces, had moderate iodine deficiency. CONCLUSION: Although the median UI level of school-age children was optimal, there are pockets of inadequacy and excessive intake that need special concern for targeted intervention.


Asunto(s)
Yodo/deficiencia , Encuestas Nutricionales/estadística & datos numéricos , Niño , Femenino , Humanos , Yodo/orina , Masculino , Estado Nutricional , Filipinas
18.
Int J Biol Macromol ; 129: 1056-1068, 2019 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-30240714

RESUMEN

It has been synthesized, characterized and tested a new biomaterial AlgS (sodium alginate functionalized with cysteine) to remove Pb(II) in aqueous media. The maximum Pb(II)-sorption capacity of AlgS (Qmax = 770 mg·g-1) is between almost two and nine times higher than other alginate-materials reported in the literature. Techniques, such as TGA/DSC, SEM/EDS, BET, FTIR, UV-Vis, XRD and 13C solid state-NMR have been used to study the chemical-modification of alginate at oxidation and aminofication stages. The formation of the imine intermediate (C=N), after 24 h of reaction was identified by a UV band at 348 nm. Typical IR-bands of AlgS were identified at 2970, 955, 949 and 1253 cm-1 which are associated to CH, SPb, SH and CN stretching vibrations, respectively. 13C solid state-NMR spectra of AlgS, show peaks at 33-38 ppm and 55-60 ppm associate to δ (HS-CH2-) of cysteine and δ (CN) respectively. The ΔH° and ΔG° negative values for Pb(II) sorption indicate that it is an exothermic process and occur spontaneously. Finally, it was found that the Pb(II) sorption on AlgS is significantly affected by the presence of cationic (Na+, Mg2+ and Al3+) and anionic (Cl-, NO3-) co-ions.


Asunto(s)
Alginatos/química , Cisteína/química , Plomo/química , Plomo/aislamiento & purificación , Contaminantes Químicos del Agua/química , Contaminantes Químicos del Agua/aislamiento & purificación , Agua/química , Adsorción , Aminación , Concentración de Iones de Hidrógeno , Cinética , Oxidación-Reducción , Temperatura
19.
Chempluschem ; 84(4): 319-322, 2019 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-31939207

RESUMEN

A scalable synthesis of bis(1,2,4-oxadiazoyl) furoxan, C6 H2 N6 O4 , its physical properties, and its theoretical performance values are described. Previous attempts to synthesize this compound required expensive reagents, and/or time-consuming synthesis processes and low overall yields. In addition to disclosing a streamlined synthesis of bis(1,2,4-oxadiazolyl) furoxan, we report its molecular configuration and crystal structure, as well as its correct melting point. Bis(1,2,4-oxadiazolyl) furoxan exhibits a very insensitive behavior to impact, friction, and electrostatic discharge, with a calculated detonation pressure 20 % higher than that of TNT. Given its physical properties and theoretical performance values, this material can be classified as a promising ingredient in the development of melt-castable eutectic technology.

20.
Acta Crystallogr E Crystallogr Commun ; 74(Pt 12): 1872-1877, 2018 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-30574391

RESUMEN

The title compounds 5,5'-(propane-2,2-di-yl)bis-(2-hy-droxy-benzaldehyde), C17H16O4, (1), and 5,5'-(propane-2,2-di-yl)bis-(2-hy-droxy-isophthalaldehyde), C19H16O6, (2), crystallize with one mol-ecule in the asymmetric unit. In mol-ecule (1), a >C(CH3)2 group bridges two nearly planar salicyl-aldehyde groups [r.m.s deviations = 0.010 (1) and 0.025 (2) Å], each comprising a planar phenyl ring bonded with a hydroxyl and an aldehyde group. Similarly, compound (2) has the same bridging group, but it connects two nearly planar appendants [r.m.s deviations = 0.034 (1) and 0.035 (1) Å], each comprising a phenyl ring bonded with a hydroxyl and two aldehyde groups. Mol-ecule (1) exhibits a bridge angle of 109.5 (2)° with the salicyl-aldehyde planes subtending a dihedral angle of 88.4 (1)°. In contrast, mol-ecule (2) presents a bridge angle of 108.9 (2)° with its appendants subtending a dihedral angle of 79.6 (3)°. Both mol-ecules exhibit two intra-molecular O-H⋯O hydrogen bonds involving the phenolic H atoms and carboxyl O-atom acceptors. In the crystal of (2), O-H⋯O hydrogen bonds between one of the hydroxyl H atoms and a carboxyl O atom from a symmetry-related mol-ecule form a chain along [10]. In addition, (2) exhibits a strong visible luminescence when excited with ultraviolet radiation.

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