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1.
Science ; 383(6689): 1337-1343, 2024 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-38513024

RESUMO

The introduction of molecularly woven three-dimensional (3D) covalent organic framework (COF) crystals into polymers of varying types invokes different forms of contact between filler and polymer. Whereas the combination of woven COFs with amorphous and brittle polymethyl methacrylate results in surface interactions, the use of the liquid-crystalline polymer polyimide induces the formation of polymer-COF junctions. These junctions are generated by the threading of polymer chains through the pores of the nanocrystals, thus allowing for spatial arrangement of polymer strands. This offers a programmable pathway for unthreading polymer strands under stress and leads to the in situ formation of high-aspect-ratio nanofibrils, which dissipate energy during the fracture. Polymer-COF junctions also strengthen the filler-matrix interfaces and lower the percolation thresholds of the composites, enhancing strength, ductility, and toughness of the composites by adding small amounts (~1 weight %) of woven COF nanocrystals. The ability of the polymer strands to closely interact with the woven framework is highlighted as the main parameter to forming these junctions, thus affecting polymer chain penetration and conformation.

2.
ACS Cent Sci ; 8(7): 926-932, 2022 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-35912353

RESUMO

We report a postsynthetic strategy and its implementation to make covalent organic frameworks (COFs) with irreversible hydrazide linkages. This involved the synthesis of three 2D and 3D hydrazine-linked frameworks and their partial oxidation. The linkage synthesis and functional group transformation-hydrazine and hydrazide-were evidenced by 15N multi-CP-MAS NMR. In addition, the isothermal water uptake profiles of these frameworks were studied, leading to the discovery of one hydrazine-hydrazide-linked COF suitable for water harvesting from air in arid conditions. This COF displayed characteristic S-shaped water sorption profiles, a steep pore-filling step below 18% relative humidity at 25 °C, and a total uptake capacity of 0.45 g g-1. We found that even small changes made on the molecular level can lead to major differences in the water isotherm profiles, therefore pointing to the utility of water sorption analysis as a complementary analytical tool to study linkage transformations.

3.
Curr Treat Options Psychiatry ; 8(3): 158-165, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34377626

RESUMO

Purpose: The novel coronavirus, SARS-CoV-2, emerged from Wuhan, China, causing a pandemic. Access to outpatient psychiatric care was limited. We conducted a pilot study of telepsychiatry during a national shutdown. Adult patients with post-traumatic stress disorder (PTSD) participated via Zoom. Patient preference comparing televisits to face-to-face visits was assessed. Recent findings: Telemedicine has emerged as new technological tool in the evolution of the patient-physician relationship, changing the way we interact. Physicians and patients now have access to the electronic medical record, remote point-of-care testing, and each other. The present epidemic allows us to test the limits of technology in combating limited access to care for patients with psychiatric illness. Summary: Twenty (90% male) patients with PTSD participated. Most (90 %) were moderately to severely depressed, and 50% used medical cannabis and increased their dosage during the study period. Patients preferred face-to-face meetings for its ease of use (p < .01) and general satisfaction from therapy (p < .01). However, given continued outbreak-limiting access to care, most patients stated they would continue with telepsychiatry. While most patients preferred face-to-face visits, telepsychiatry can be used during times of outbreak-limiting access to care. Future research and development should be directed at improving technological ease of use.

5.
Harefuah ; 160(1): 4-7, 2021 Jan.
Artigo em Hebraico | MEDLINE | ID: mdl-33474871

RESUMO

INTRODUCTION: The case presented discusses a prisoner, Y, in his mid-sixties with longstanding medical conditions, who was sentenced to prolonged incarceration. Y refused conventional medicine because he believed that his medical condition was exacerbated by this treatment and only complementary alternative medicine (CAM) would be helpful. He therefore demanded to be treated only by CAM. He was ready to pay for the treatment out of his own pocket. In the prison where Y was previously incarcerated over the course of 12 years, he had access to CAM remedies which were purchased by his family. After being transferred to the current facility, Y was denied access to these remedies by the prison physicians. He appealed in court against this decision and was supported by a CAM specialist, who ascertained that the remedies under consideration were not hazardous to Y's health. This case report discusses the ethical aspects of a prisoner's autonomy to choose medical treatment even when his/her autonomy has been severely curtailed by virtue of the incarceration.


Assuntos
Prisioneiros , Feminino , Humanos , Masculino
6.
J Am Chem Soc ; 2020 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-33186498

RESUMO

We present a strategy whereby selective formation of imine covalent organic frameworks (COFs) based on linking of triangles and squares into the fjh topology was achieved by the conformational design of the building units. 1,3,5-Trimethyl-2,4,6-tris(4-formylphenyl)benzene (TTFB, triangle) and 1,1,2,2-tetrakis(4-aminophenyl)ethene (ETTA, square) were reticulated into [(TTFB)4(ETTA)3]imine, termed COF-790, which was fully characterized by spectroscopic, microscopic, and X-ray diffraction techniques. COF-790 exhibits permanent porosity and a Brunauer-Emmett-Teller (BET) surface area of 2650 m2 g-1. Key to the formation of this COF in crystalline form is the pre-designed conformation of the triangle and the square units to give dihedral angles in the range of 75-90°, without which the reaction results in the formation of amorphous product. We demonstrate the versatility of our strategy by also reporting the synthesis and characterization of two isoreticular forms of COF-790, COF-791 and COF-792, based on other square building units.

8.
Science ; 370(6515)2020 10 23.
Artigo em Inglês | MEDLINE | ID: mdl-33093081

RESUMO

The valency (connectivity) of building units in covalent organic frameworks (COFs) has been primarily 3 and 4, corresponding to triangles and squares or tetrahedrons, respectively. We report a strategy for making COFs with valency 8 (cubes) and "infinity" (rods). The linker 1,4-boronophenylphosphonic acid-designed to have boron and phosphorus as an isoelectronic combination of carbon-group elements-was condensed into a porous, polycubane structure (BP-COF-1) formulated as (-B4P4O12-)(-C6H4-)4 It was characterized by x-ray powder diffraction techniques, which revealed cubes linked with phenyls. The isoreticular forms (BP-COF-2 to 5) were similarly prepared and characterized. Large single crystals of a constitutionally isomeric COF (BP-COF-6), composed of rod units, were also synthesized using the same strategy, thus propelling COF chemistry into a new valency regime.

9.
ACS Cent Sci ; 6(8): 1255-1273, 2020 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-32875067

RESUMO

Reticular chemistry is a growing field of science with a multitude of practitioners with diverse frames of thinking, making the need for standard practices and quality indicators ever more compelling.

11.
J Am Chem Soc ; 142(10): 4749-4755, 2020 03 11.
Artigo em Inglês | MEDLINE | ID: mdl-32114766

RESUMO

Enantiopure (P)4- and (M)4-configured alleno-acetylenic cage (AAC) receptors offer a highly defined interior for the complexation and structure elucidation of small molecule fragments of the stereochemically complex chlorosulfolipid danicalipin A. Solution (NMR), solid state (X-ray), and theoretical investigations of the formed host-guest complexes provide insight into the conformational preferences of 14 achiral and chiral derivatives of the danicalipin A chlorohydrin core in a confined, mostly hydrophobic environment, extending previously reported studies in polar solvents. The conserved binding mode of the guests permits deciphering the effect of functional group replacements on Gibbs binding energies ΔG. A strong contribution of conformational energies toward the binding affinities is revealed, which explains why the denser packing of larger apolar domains of the guests does not necessarily lead to higher association. Enantioselective binding of chiral guests, with energetic differences ΔΔG293 K up to 0.7 kcal mol-1 between diastereoisomeric complexes, is explained by hydrogen- and halogen-bonding, as well as dispersion interactions. Calorimetric studies (ITC) show that the stronger binding of one enantiomer is accompanied by an increased gain in enthalpy ΔH but at the cost of a larger entropic penalty TΔS stemming from tighter binding.


Assuntos
Alcadienos/química , Alcinos/química , Lipídeos/química , Receptores Artificiais/química , Cristalização , Cristalografia por Raios X , Estereoisomerismo , Termodinâmica
13.
J Am Chem Soc ; 142(6): 2771-2776, 2020 02 12.
Artigo em Inglês | MEDLINE | ID: mdl-31995371

RESUMO

The design and synthesis of 2D and 3D crystalline covalent organic frameworks (COFs) from macromolecular and even infinite building units is largely undeveloped. Here, we report a strategy to link molecules and 1D ribbons into 2D cystalline frameworks. Triangular, tris(4-aminophenyl)amine (TAA), and square, 1,3,6,8-tetrakis(p-formylphenyl)pyrene (TFPPy), organic building units are joined substoichiometrically by imine linkages to produce 1D ribbons, termed COF-76, bearing free amines, which are then used to link the ribbons into 2D frameworks COF-77 and COF-78. In addition to this stepwise approach, we also demonstrate an in situ synthesis of these COFs. We believe our ability to link infinite building blocks, such as the ribbons of COF-76, into higher dimensionality COFs, paves the way to covalent frameworks composed of hierachical chemical structures.


Assuntos
Imidas/química , Iminas/química , Compostos Orgânicos/química , Difração de Pó , Espectroscopia de Infravermelho com Transformada de Fourier
14.
Isr Med Assoc J ; 21(2): 77-81, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30772955

RESUMO

BACKGROUND: A history of childhood sexual abuse (CSA) has been linked to a variety of physical and psychiatric illnesses, including ischemic heart disease and post-traumatic stress disorder (PTSD). OBJECTIVES: To determine the prevalence of past CSA and re-traumatization among hospital psychiatric consultations and to determine whether a CSA group in a hospital setting shared characteristics with community samples described in the literature. METHODS: We divided 228 consecutive psychiatric consultations into two groups. One group comprised patients with a past history of CSA while the other group had no such history. Both groups were further divided into a subgroup that presented with features of re-traumatization. RESULTS: In the cohort, 38% described a history of CSA. Twenty patients were identified as presenting with features of re-traumatization. There were significant differences between the two groups. The patients with a history of CSA were more likely to have arrived at the emergency department (ED) during the preceding 12 months with a diagnosis of PTSD, personality disorder, and substance use disorder. There was a greater proportion of patients in the CSA group who had grown up in an ultra-Orthodox Jewish household and who currently identified as being secular. CONCLUSIONS: The characteristics of the patients with past CSA in this study are similar to community-based samples, except for a significant gender difference. To the best of our knowledge, this study is the first to investigate CSA history during hospital ED psychiatric consultations. A history of CSA should be considered during psychiatric consultations in a general hospital ED admission.


Assuntos
Abuso Sexual na Infância/psicologia , Abuso Sexual na Infância/estatística & dados numéricos , Serviço Hospitalar de Emergência , Transtornos Mentais/epidemiologia , Transtornos Mentais/psicologia , Encaminhamento e Consulta , Adulto , Estudos de Casos e Controles , Criança , Feminino , Hospitais Gerais , Humanos , Israel/epidemiologia , Masculino , Prevalência , Estudos Retrospectivos , Inquéritos e Questionários , Adulto Jovem
15.
Angew Chem Int Ed Engl ; 57(50): 16296-16301, 2018 12 10.
Artigo em Inglês | MEDLINE | ID: mdl-30417963

RESUMO

Enantiopure (P)4 - and (M)4 -alleno-acetylenic cage (AAC) receptors form circular fourfold hydrogen-bonding networks in their closed cage conformation. Theoretical studies reveal a preferential clockwise (cw) orientation of the H-bonding array for (P)4 -configured and counterclockwise (ccw) for (M)4 -configured receptors (ΔEcw-ccw =-2.6 to -3.1 kcal mol-1 ). Solution and solid-state studies show how the H-bonding network of the receptor is expanded upon encapsulation of alcohol-containing guests. Topologies reminiscent of those found in isolated water clusters are observed: circular fourfold & docking, pentagonal, linear fivefold, and hexagonal boat-shaped. Expansion of the H-bonding network together with optimal space occupancy yields very high ligand affinities (ΔG293 K =-9.0 kcal mol-1 for endo-tropine). The H-bonding network in the complexes also contributes substantially to the enantioselective complexation of chiral diols, such as (R,R)- and (S,S)-trans-cyclohexane-1,2-diol.


Assuntos
Alcinos/química , Cicloexanóis/química , Hidrogênio/química , Norbornanos/química , Cristalografia por Raios X , Ligação de Hidrogênio , Modelos Moleculares , Estereoisomerismo , Água/química
16.
Isr J Psychiatry ; 55(2): 32-36, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30351278

RESUMO

BACKGROUND: The prevalence of alcohol related harm (ARH) in Israel has traditionally been low. The lack of familiarity with ARH may derive from the fact that in the past there was limited clinical exposure to these harms. However, ARH is becoming more common in Israel but it is unclear whether the medical and nursing workforce's knowledge is adequate to manage these problems. Our main objective was to assess knowledge regarding ARH among medical and nursing staff (MNS) in an Israeli university affiliated general hospital. We also aimed to compare knowledge of different MNS groups Methods: One hundred and twenty-seven MNS including consultants (senior physicians), residents, interns and nursing staff completed the Knowledge of Psychiatric Aspects of Alcohol Questionnaire (KPAAQ), a validated measure of knowledge concerning ARH comprised of five categories. RESULTS: There was no significant difference between the four MNS groups in overall mean KPAAQ scores that varied from 45% (nurses) to 54% (interns). However, direct comparisons indicate that physicians scored higher than nurses (p=0.02). overall. The mean score for the KPAAQ category "alcohol withdrawal syndrome" was below 40% for all MNS groups. Physicians scored significantly higher than nursing staff (p=0.005). All MNS mean scores were greater than 63% for the category "alcohol in pregnancy." This was the highest category score. CONCLUSIONS: Assessment of knowledge regarding ARH among MNS in a general hospital with a standardized instrument demonstrated no significant difference in knowledge of ARH among nursing staff, interns, residents and consultants apart from knowledge about alcohol withdrawal. However, the overall score of the physicians as a whole was significantly higher than the nursing group. These findings suggest a need to implement educational interventions in MNS to increase knowledge of ARH so as to promote the provision of brief interventions for patients with ARH.


Assuntos
Transtornos Relacionados ao Uso de Álcool , Competência Clínica/estatística & dados numéricos , Conhecimentos, Atitudes e Prática em Saúde , Corpo Clínico Hospitalar/estatística & dados numéricos , Recursos Humanos de Enfermagem Hospitalar/estatística & dados numéricos , Adulto , Feminino , Hospitais Gerais/estatística & dados numéricos , Humanos , Israel , Masculino , Pessoa de Meia-Idade
17.
Isr J Psychiatry ; 55(2): 37-39, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30351279

RESUMO

BACKGROUND: There are no studies that use validated questionnaires on Alcohol Related Harm (ARH) in order to assess retention of educational programs among medical students. Objective of study to assess retention of an educational inter-vention on ARH among medical students. METHOD: Seventeen fifth year medical students were assessed with the Knowledge of Psychiatric Aspects of Alcohol Questionnaire (KPAAQ) 12 months after an educational intervention on ARH and compared with a control group. RESULTS: Significant retention was found in the study group. CONCLUSIONS: This preliminary research is the first controlled study on medical student retention of an ARH educational intervention using a validated questionnaire.


Assuntos
Transtornos Relacionados ao Uso de Álcool , Educação Médica , Avaliação Educacional/métodos , Conhecimentos, Atitudes e Prática em Saúde , Estudantes de Medicina , Adulto , Currículo , Educação Médica/métodos , Feminino , Seguimentos , Humanos , Masculino , Retenção Psicológica , Adulto Jovem
18.
Isr Med Assoc J ; 20(9): 561-566, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30221870

RESUMO

BACKGROUND: There is scant research on the psychopathology of Israeli soldiers who present to a general hospital emergency department (ED). OBJECTIVES: To assess the psychopathology among a cohort of Israeli soldiers who presented to a general hospital ED for mental health assessment. METHODS: The demographic and clinical characteristics of 124 consecutive soldiers who presented to the ED for psychiatric assessment between January 2008 and September 2012 were reviewed. Twenty-seven soldiers from the cohort were contacted for follow-up by telephone on average 52 months later. RESULTS: The reasons for presentation to the ED, usually during the early stages of military service, included self-harming behavior, suicidal ideation, somatoform complaints, and dissatisfaction with their military service. Psychiatric diagnoses included adjustment disorder and personality disorder. Self-harming behavior/suicidal ideation was significantly correlated with unspecified adjustment disorder (P = 0.02) and personality disorder (P = 0.001). At follow-up, there was a lack of substantial psychopathology: none of the subjects engaged in self-harming behavior/suicidal ideation and a consistent trend was observed toward clinical improvement. CONCLUSIONS: Psychiatric intervention of soldiers who present to a general hospital ED because of emotional difficulties may provide the opportunity for crisis intervention and validation of the soldier's distress. To the best of our knowledge this is the first Israeli study of psychopathology among soldiers who presented to an ED.


Assuntos
Serviço Hospitalar de Emergência , Hospitais Gerais , Transtornos Mentais/diagnóstico , Militares/psicologia , Adolescente , Adulto , Estudos de Coortes , Feminino , Humanos , Masculino , Transtornos Mentais/psicologia , Transtornos Mentais/terapia , Militares/estatística & dados numéricos , Médicos , Psiquiatria , Encaminhamento e Consulta , Estudos Retrospectivos , Fatores de Risco , Adulto Jovem
19.
Chimia (Aarau) ; 72(4): 245-248, 2018 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-29720318

RESUMO

Single crystal X-ray diffraction is a powerful method to unambiguously characterize the structure of molecules with atomic resolution. Herein, we review the molecular recognition of the (di)axial conformers of Mono- and (±)-trans-1,2-disubstituted cyclohexanes by enantiopure alleno-acetylenic cage receptors in solution and in the solid state. Single crystals of the host-guest complexes suitable for X-ray diffraction allow for the first time to study the dihedral angles of a series of Mono- and (±)-trans-1,2-disubstituted cyclohexanes in their (di)axial chair conformation. Theoretical studies indicate negligible influence of the host structure on the guest conformation, suggesting that the structural information obtained from the host-guest complexes give insight into the innate structures of Mono- and (±)-trans-1,2-disubstituted cyclohexanes. Strong deviation of the dihedral angles a,a(X-C(1)-C(2)-X) from the idealized 180° are observed, accompanied by substantial flattening of the ring dihedral angles ρ(X-C(1)-C(2)-C(3)).

20.
J Am Chem Soc ; 140(8): 2705-2717, 2018 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-29451782

RESUMO

The development of synthetic host-guest chemistry to investigate and quantify weak, non-covalent interactions has been key to unraveling the complexity of molecular recognition in chemical and biological systems. Macrocycles have shown great utility in the design of receptors, enabling the development of highly preorganized structures. Among macrocycles, resorcin[4]arene-based cavitands have become privileged scaffolds due to their synthetic tunability, which allows access to structures with precisely defined geometries, as well as receptors that display conformational switching between two distinct states with a large difference in guest-binding properties. Here, we highlight three case studies demonstrating redox- and photoredox-controlled switching of molecular recognition properties, the formation of guest-binding supramolecular capsules based solely on halogen-bonding interactions, and enantioselective encapsulation of chiral, substituted cyclohexanes by enantiopure cage compounds as a result of perfect shape complementarity, dispersion interactions, and halogen bonding. The high geometrical and conformational control that can be achieved with resorcin[4]arene-derived host systems will continue to be a powerful resource in future molecular recognition studies.

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