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1.
J Biol Inorg Chem ; 29(1): 139-158, 2024 02.
Artigo em Inglês | MEDLINE | ID: mdl-38175299

RESUMO

The aim to access linked tetravanadate [V4O12]4- anion with mixed copper(II) complexes, using α-amino acids and phenanthroline-derived ligands, resulted in the formation of four copper(II) complexes [Cu(dmb)(Gly)(OH2)]2[Cu(dmb)(Gly)]2[V4O12]·9H2O (1) [Cu(dmb)(Lys)]2[V4O12]·8H2O (2), [Cu(dmp)2][V4O12]·C2H5OH·11H2O (3), and [Cu(dmp)(Gly)Cl]·2H2O (4), where dmb = 4,4'-dimethioxy-2,2'-bipyridine; Gly = glycine; Lys = lysine; and dmp = 2,9-dimethyl-1,10-phenanthroline. The [V4O12]4- anion is functionalized with mixed copper(II) units in 1 and 2; while in 3, it acts as a counterion of two [Cu(dmp)]2+ units. Compound 4 crystallized as a unit that did not incorporate the vanadium cluster. All compounds present magnetic couplings arising from Cu⋯O/Cu⋯Cu bridges. Stability studies of water-soluble 3 and 4 by UV-Vis spectroscopy in cell culture medium confirmed the robustness of 3, while 4 appears to undergo ligand scrambling over time, resulting partially in the stable species [Cu(dmp)2]+ that was also identified by electrospray ionization mass spectrometry at m/z = 479. The in vitro cytotoxicity activity of 3 and 4 was determined in six cancer cell lines; the healthy cell line COS-7 was also included for comparative purposes. MCF-7 cells were more sensitive to compound 3 with an IC50 value of 12 ± 1.2 nmol. The tested compounds did not show lipid peroxidation in the TBARS assay, ruling out a mechanism of action via reactive oxygen species formation. Both compounds inhibited cell migration at 5 µM in wound-healing assays using MCF-7, PC-3, and SKLU-1 cell lines, opening a new window to study the anti-metastatic effect of mixed vanadium-copper(II) systems.


Assuntos
Antineoplásicos , Complexos de Coordenação , Humanos , Cobre/farmacologia , Cobre/química , Antineoplásicos/química , Fenantrolinas/química , Vanádio/farmacologia , DNA/química , Células MCF-7 , Ânions , Fenômenos Magnéticos , Complexos de Coordenação/farmacologia , Complexos de Coordenação/química , Ligantes
2.
Chemistry ; 30(29): e202304146, 2024 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-38687127

RESUMO

In this work a family of multidimensional (2-(1H-tetrazol-5-yl)ethyl) amino acid coordination compounds have been synthesized and thoroughly characterized. For this purpose, glycine, valine, phenylalanine and tyrosine have been selected as starting amino acids and Mn2+, Zn2+ and Cd2+ as metallic nodes. From one side, for Mn2+ based dimer magnetic resonance imaging studies have been conducted, prompted by the number and disposition of the coordinated water molecules and taking into consideration the promising future of manganese-based coordination compounds as bio-compatible substitutes to conventional Gd based contrast agents. From another side, d10 block metal-based complexes allowed exploring photoluminescence properties derived by in situ synthesized ligands. Finally, amino acid preserved structural chirality allowed us to examine chiroptical properties, particularly focusing on circularly polarized luminescence.

3.
Am J Public Health ; 114(4): 387-397, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38478866

RESUMO

Objectives. To describe all-outcome injurious shootings by police and compare characteristics of fatal versus nonfatal injurious shootings nationally. Methods. From July 2021 to April 2023, we manually reviewed publicly available records on all 2015-2020 injurious shootings by US police, identified from Gun Violence Archive. We estimated injury frequency, case fatality rates, and relative odds of death by incident and victim characteristics. Results. A total of 1769 people were injured annually in shootings by police, 55% fatally. When a shooting injury occurred, odds of fatality were 46% higher following dispatched responses than police-initiated responses. Injuries associated with physically threatening or threat-making behaviors, behavioral health needs, and well-being checks were most frequently fatal. Relative to White victims, Black victims were overrepresented but had 35% lower odds of fatal injury when shot. Conclusions. This first multiyear, nationwide analysis of injurious shootings by US police suggests that injury disparities are underestimated by fatal shootings alone. Nonpolicing responses to social needs may prevent future injuries. Public Health Implications. We call for enhanced reporting systems, comprehensive evaluation of emerging reforms, and targeted investment in social services for equitable injury prevention. (Am J Public Health. 2024;114(4):387-397. https://doi.org/10.2105/AJPH.2023.307560).


Assuntos
Armas de Fogo , Violência com Arma de Fogo , Ferimentos por Arma de Fogo , Humanos , Estados Unidos/epidemiologia , Polícia , Razão de Chances , Homicídio
4.
AIDS Behav ; 28(1): 310-319, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37523049

RESUMO

The Family Resource Scale (FRS) is a three-factor financial vulnerability (FV) measure. FV may impact HIV transmission risks. Cross-sectional data from 279 people who inject drugs (PWID) in Kyrgyzstan surveyed April-October 2021 was used to validate the FRS and estimate associations between FV on past 6-month injection and sexual HIV risk outcomes. The three-factor FRS reflected housing, essential needs, and fiscal independence, and had good internal reliability and structural validity. Greater cumulative, housing, and essential needs FRS scores were associated with increased relative risk on public injection (adjusted risk ratio [aRR], 95% confidence interval [95% CI]: 1.03 [1.01, 1.04]; aRR [95% CI]: 1.06 [1.02, 1.09]; aRR [95% CI]: 1.06 [1.03, 1.08], respectively, all p < 0.001) and preparing injections with unsafe water sources (aRR [95% CI]: 1.04 [1.02, 1.07]; aRR [95% CI]: 1.09 [1.04, 1.15]; aRR [95% CI]: 1.08 [1.03, 1.14], respectively, all p < 0.001). Results suggest that PWID housing- and essential needs-related FV may exacerbate injection HIV transmission risks. Reducing PWIDs' FV may enhance the HIV response in Kyrgyzstan.


RESUMEN: La Escala de Recursos Familiares (FRS, por sus siglas en inglés) es una medida de vulnerabilidad financiera (FV, por sus siglas en inglés) de tres factores. La FV puede afectar los riesgos de transmisión del VIH. Se utilizaron datos transversales de 279 personas que se inyectan drogas (PWID, por sus siglas en inglés) en Kirguistán encuestadas de abril a octubre de 2021 para validar la FRS y estimar las asociaciones entre la FV en la inyección y los resultados de riesgo sexual del VIH en los últimos seis meses. La FRS de tres factores reflejaba la vivienda, las necesidades esenciales y la independencia fiscal, y presentaba una buena confiabilidad interna y validez estructural. Mayores puntajes acumulativos de la FRS en vivienda y necesidades esenciales se asociaron con un mayor riesgo relativo en la inyección pública (Riesgo relativo ajustada [aRR], Intervalo de Confianza del 95% [IC95%]: 1.03 [1.01, 1.04]; aRR [IC95%]: 1.06 [1.02, 1.09]; aRR [IC95%]: 1.06 [1.03, 1.08], respectivamente, todos p < 0.001) y la preparación de inyección con fuentes de agua no seguras (aRR [IC95%]: 1.04 [1.02, 1.07]; aRR [IC95%]: 1.09 [1.04, 1.15]; aRR [IC95%]: 1.08 [1.03, 1.14], respectivamente, todos p < 0.001). Los resultados sugieren que la FV relacionada con la vivienda y las necesidades esenciales de las PWID puede exacerbar los riesgos de transmisión del VIH por la inyección. Reducir la FV de las PWID puede mejorar la respuesta al VIH en Kirguistán.


Assuntos
Usuários de Drogas , Infecções por HIV , Abuso de Substâncias por Via Intravenosa , Humanos , Infecções por HIV/epidemiologia , Infecções por HIV/prevenção & controle , Infecções por HIV/complicações , Abuso de Substâncias por Via Intravenosa/epidemiologia , Abuso de Substâncias por Via Intravenosa/complicações , Quirguistão/epidemiologia , Estudos Transversais , Reprodutibilidade dos Testes , Assunção de Riscos
5.
Ann Intern Med ; 175(8): 1083-1091, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35816712

RESUMO

BACKGROUND: Hepatitis C virus (HCV) infection can be cured, and the United States has joined the World Health Organization in calling for HCV elimination by 2030. However, historically low uptake of HCV treatment among people who inject drugs (PWID) threatens HCV elimination and exacerbates social and racial health disparities. OBJECTIVE: To assess whether all-oral HCV treatments were accessed by PWID and reduced liver disease burden and mortality. DESIGN: Community-based, longitudinal cohort study of persons with a history of injection drug use. SETTING: Baltimore, Maryland. PARTICIPANTS: 1323 participants enrolled in the ALIVE (AIDS Linked to the IntraVenous Experience) study from 2006 to 2019 and chronically infected with HCV. MEASUREMENTS: Liver stiffness measures (LSMs) by transient elastography, HCV RNA, and mortality from the National Death Index. RESULTS: Among 1323 persons with evidence of chronic HCV infection at baseline, the median age was 49 years. Most were Black (82%), male (71%), and HIV-negative (66%). The proportion in whom HCV RNA was detected decreased from 100% (by definition) in 2006 to 48% in 2019. Across 10 350 valid LSMs, cirrhosis was detected in 15% of participants in 2006, 19% in 2015, and 8% in 2019. Undetectable HCV RNA was significantly associated with reduced odds of cirrhosis (adjusted odds ratio, 0.28 [95% CI, 0.17 to 0.45]) and reduced all-cause mortality risk (adjusted hazard ratio, 0.54 [CI, 0.38 to 0.77]). LIMITATION: Noninvasive markers of liver fibrosis have not been validated in persons with sustained virologic response. CONCLUSION: Many community-based PWID in Baltimore are receiving HCV treatment, which is associated with sharp decreases in liver disease and mortality. Additional efforts will be needed to reduce residual barriers to treatment and to eliminate HCV as a public health threat for PWID. PRIMARY FUNDING SOURCE: National Institutes of Health.


Assuntos
Usuários de Drogas , Hepatite C Crônica , Hepatite C , Abuso de Substâncias por Via Intravenosa , Antivirais/uso terapêutico , Estudos de Coortes , Hepacivirus/genética , Hepatite C/complicações , Hepatite C/tratamento farmacológico , Hepatite C Crônica/complicações , Hepatite C Crônica/tratamento farmacológico , Humanos , Cirrose Hepática/complicações , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , RNA/uso terapêutico , Abuso de Substâncias por Via Intravenosa/complicações , Abuso de Substâncias por Via Intravenosa/tratamento farmacológico
6.
Molecules ; 28(4)2023 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-36838833

RESUMO

As a starting point, a new 3D porous framework with the {[CoL]·0.5DMF·H2O}n chemical formula (where L = 3-amino-4-hydroxybenzoate) is described. Its performance as a single molecule magnet was explored. The study of magnetic properties reveals that Co-MOF shows no frequency-fdependant alternating current (ac) signals under zero direct current (dc) magnetic field, whereas single-molecule magnet behaviour is achieved when CoII ions are diluted in a ZnII based matrix. Interestingly, this strategy renders a bifunctional [CoxZn1-xL]n material that is also characterized by a strong photoluminescent emitting capacity.


Assuntos
Metais , Polímeros , Modelos Moleculares , Zinco/química , Íons , Hidroxibenzoatos , Fenômenos Magnéticos
7.
Molecules ; 28(15)2023 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-37570613

RESUMO

The present study reports on a 2D lamellar coordination polymer (CP) of {[Zn(µ3-pmdc)(H2O)]·H2O}n formula (pmdc = pyrimidine-4,6-dicarboxylate). This CP is synthesized under an appropriate acid-base reaction between the gently mortared reagents in the solid state through a solvent-free procedure that avoids the presence of concomitant byproducts. The X-ray crystal structure reveals the occurrence of Zn2 entities connected through carboxylate groups of pmdc, which behave as triconnected nodes, giving rise to six-membered ring-based layers that are piled up through hydrogen bonding interactions. In addition to a routine physico-chemical characterization, the thermal evolution of the compound has been studied by combining thermogravimetric and thermodiffractometric data. The photoluminescence properties are characterized in the solid state and the processes governing the spectra are described using time-dependent density-functional theory (TD-DFT) with two different approaches employing different program packages. The emissive capacity of the material is further analyzed according to the dehydration and decreasing temperature of the polycrystalline sample.

8.
Am J Public Health ; 112(6): 860-864, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35446602

RESUMO

Between 2015 and 2018, we provided training for 1806 municipal police officers in Tijuana, Mexico, in an effort to improve their knowledge and behaviors related to HIV and injection drug use. Correct knowledge of syringe possession laws improved from 56% before training to 94% after training and was sustained at 24 months (75%). Knowledge improvement was associated with decreases in arrests for syringe possession over time (adjusted odds ratio [AOR] = 0.87; 95% confidence interval [CI] = 0.85, 0.90). Officers with correct knowledge had significantly lower odds of reporting arrests (AOR = 0.63; 95% CI = 0.44, 0.89). Training was associated with sustained improvements in knowledge and practices that advance public health. (Am J Public Health. 2022;112(6):860-864. https://doi.org/10.2105/AJPH.2021.306702).


Assuntos
Polícia , Abuso de Substâncias por Via Intravenosa , Humanos , Aplicação da Lei , México/epidemiologia , Polícia/educação , Abuso de Substâncias por Via Intravenosa/complicações , Abuso de Substâncias por Via Intravenosa/epidemiologia , Seringas
9.
Inorg Chem ; 61(33): 12977-12990, 2022 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-35939069

RESUMO

Herein, we describe and study a new family of isostructural multifunctional metal-organic frameworks (MOFs) with the formula {[Ln5L6(OH)3(DMF)3]·5H2O}n (where (H2L) is 3-amino-4-hydroxybenzoic acid ligand) for magnetism and photoluminescence. Interestingly, three of the materials (Dy-, Er-, and Yb-based MOFs) present single-molecule magnet (SMM) behavior derived from the magnetic anisotropy of the lanthanide ions as a consequence of the adequate electronic distribution of the coordination environment. Additionally, photoluminescence properties of the ligand in combination with Eu and Tb counterparts were studied, including the heterometallic Eu-Tb mixed MOF that shows potential as ratiometric luminescent thermometers. Finally, the porous nature of the framework allowed showing the CO2 sorption capacity.

10.
Inorg Chem ; 61(3): 1377-1384, 2022 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-35015526

RESUMO

A new Y-based metal-organic framework (MOF) GR-MOF-6 with a chemical formula of {[YL(DMF)2]·(DMF)}n {H3L = 5-[(4-carboxyphenyl)ethynyl] isophthalic acid; DMF = N,N-dimethylformamide} has been prepared by a solvothermal route. Structural characterization reveals that this novel material is a three-dimensional MOF in which the coordination of the tritopic ligand to Y(III) metal ions leads to an intercrossing channel system extending over three dimensions. This material has proven to be a very efficient catalyst in the cyanosilylation of carbonyls, ranking second in catalytic activity among the reported rare earth metal-based MOFs described so far but with the lowest required catalyst loading. In addition, its electrophoretic behavior has been studied in depth, providing a zero-charge point between pH 4 and 5, a peak electrophoretic mobility of -1.553 µm cm V-1 s-1, and a ζ potential of -19.8 mV at pH 10.

11.
Harm Reduct J ; 19(1): 53, 2022 05 25.
Artigo em Inglês | MEDLINE | ID: mdl-35614508

RESUMO

BACKGROUND: In Kyrgyzstan and other Eastern European and Central Asian countries, injection drug use and HIV-related intersectional stigma undermines HIV prevention efforts, fueling a rapidly expanding HIV epidemic. The Kyrgyzstan InterSectional Stigma (KISS) Injection Drug Use Cohort is the first study designed to assess the impact of drug use, methadone maintenance treatment (MMT) and HIV stigma experiences among people who inject drugs (PWID) on HIV prevention service utilization. METHODS: Adult PWID were recruited from Bishkek city and the surrounding rural Chuy Oblast region in northern Kyrgyzstan via modified time location sampling and snowball sampling. All participants completed a baseline rapid HIV test and interviewer-administered survey. A subsample of participants were prospectively followed for three months and surveyed to establish retention rates for future work in the region. Internal reliability of three parallel stigma measures (drug use, MMT, HIV) was evaluated. Descriptive statistics characterize baseline experiences across these three stigma types and HIV prevention service utilization, and assess differences in these experiences by urbanicity. RESULTS: The KISS cohort (N = 279, 50.5% Bishkek, 49.5% Chuy Oblast) was mostly male (75.3%), ethnically Russian (53.8%), median age was 40 years old (IQR 35-46). Of the 204 eligible participants, 84.9% were surveyed at month 3. At baseline, 23.6% had a seropositive rapid HIV test. HIV prevention service utilization did not differ by urbanicity. Overall, we found 65.9% ever utilized syringe service programs in the past 6 months, 8.2% were utilizing MMT, and 60.8% met HIV testing guidelines. No participants reported PrEP use, but 18.5% had heard of PrEP. On average participants reported moderate levels of drug use (mean [M] = 3.25; α = 0.80), MMT (M = 3.24; α = 0.80), and HIV stigma (M = 2.94; α = 0.80). Anticipated drug use stigma from healthcare workers and internalized drug use stigma were significantly higher among PWID from Bishkek (p < 0.05), while internalized HIV stigma among PWID living with HIV was significantly greater among PWID from Chuy Oblast (p = 0.03). CONCLUSION: The KISS cohort documents moderate levels of HIV-related intersectional stigma and suboptimal engagement in HIV prevention services among PWID in Kyrgyzstan. Future work will aim identify priority stigma reduction intervention targets to optimize HIV prevention efforts in the region.


Assuntos
Infecções por HIV , Abuso de Substâncias por Via Intravenosa , Adulto , Estudos de Coortes , Feminino , Infecções por HIV/epidemiologia , Infecções por HIV/prevenção & controle , Humanos , Quirguistão/epidemiologia , Masculino , Metadona , Reprodutibilidade dos Testes , Abuso de Substâncias por Via Intravenosa/epidemiologia , Abuso de Substâncias por Via Intravenosa/terapia
12.
Sensors (Basel) ; 22(9)2022 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-35591082

RESUMO

Two novel metal-organic frameworks (MOFs), based on dysprosium as the metal and the 5-aminoisophthalic acid (5aip) ligand, have been solvothermally synthesized, with the aim of studying and modulating their luminescence properties according to the variation of solvent in the structure. These materials display intense photo-luminescence properties in the solid state at room temperature. Interestingly, one fascinating sensory capacity of compound 2 regards obtaining a variation of the signal, depending on the solvent to which it is exposed. These results pave the way for a new generation of sensitive chemical sensors.

13.
Sensors (Basel) ; 22(4)2022 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-35214565

RESUMO

Herein, we present the syntheses of a novel coordination polymer (CP) based on the perylene-3,4,9,10-tetracarboxylate (pery) linkers and sodium metal ions. We have chosen sodium metal center with the aim of surmising the effect that the modification of the metal ion may have on the relative humidity (RH) experimental measurements of the material. We confirm the role of the ions in the functionalization of the deposited layer by modifying their selectivity towards moisture content, paving the way to the generation of sensitive and selective chemical sensors.

14.
Am J Transplant ; 21(2): 657-668, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-32777173

RESUMO

Outcomes following hepatitis C virus (HCV)-viremic heart transplantation into HCV-negative recipients with HCV treatment are good. We assessed cost-effectiveness between cohorts of transplant recipients willing and unwilling to receive HCV-viremic hearts. Markov model simulated long-term outcomes among HCV-negative patients on the transplant waitlist. We compared costs (2018 USD) and health outcomes (quality-adjusted life-years, QALYs) between cohorts willing to accept any heart and those willing to accept only HCV-negative hearts. We assumed 4.9% HCV-viremic donor prevalence. Patients receiving HCV-viremic hearts were treated, assuming $39 600/treatment with 95% cure. Incremental cost-effectiveness ratios (ICERs) were compared to a $100 000/QALY gained willingness-to-pay threshold. Sensitivity analyses included stratification by blood type or region and potential negative consequences of receipt of HCV-viremic hearts. Compared to accepting only HCV-negative hearts, accepting any heart gained 0.14 life-years and 0.11 QALYs, while increasing costs by $9418/patient. Accepting any heart was cost effective (ICER $85 602/QALY gained). Results were robust to all transplant regions and blood types, except type AB. Accepting any heart remained cost effective provided posttransplant mortality and costs among those receiving HCV-viremic hearts were not >7% higher compared to HCV-negative hearts. Willingness to accept HCV-viremic hearts for transplantation into HCV-negative recipients is cost effective and improves clinical outcomes.


Assuntos
Hepacivirus , Hepatite C , Antivirais/uso terapêutico , Análise Custo-Benefício , Hepatite C/tratamento farmacológico , Humanos , Viremia/tratamento farmacológico
15.
Harm Reduct J ; 18(1): 76, 2021 07 26.
Artigo em Inglês | MEDLINE | ID: mdl-34311765

RESUMO

BACKGROUND: Police constitute a structural determinant of health and HIV risk of people who inject drugs (PWID), and negative encounters with law enforcement present significant barriers to PWID access to harm reduction services. Conversely, police may facilitate access via officer-led referrals, potentiating prevention of HIV, overdose, and drug-related harms. We aimed to identify police characteristics associated with support for officer-led referrals to addiction treatment services and syringe service programs (SSP). We hypothesized that officers who believe harm reduction services are contradictory to policing priorities in terms of safety and crime reduction will be less likely to support police referrals. METHODS: Between January and June 2018, police officers (n = 305) in Tijuana, Mexico, completed self-administered surveys about referrals to harm reduction services during the 24-month follow-up visit as part of the SHIELD police training and longitudinal cohort study. Log-binomial regression was used to estimate adjusted prevalence ratios and model policing characteristics and attitudes related to officers' support for including addiction treatment and SSP in referrals. RESULTS: Respondents were primarily male (89%), patrol officers (86%) with a median age of 38 years (IQR 33-43). Overall, 89% endorsed referral to addiction services, whereas 53% endorsed SSP as acceptable targets of referrals. Officers endorsing addiction services were less likely to be assigned to high drug use districts (adjusted prevalence ratio [APR] = 0.50, 95% CI 0.24, 1.08) and more likely to agree that methadone programs reduce crime (APR = 4.66, 95% CI 2.05, 9.18) than officers who did not support addiction services. Officers endorsing SSPs were younger (adjusted prevalence ratio [APR] = 0.96 95% CI 0.93, 0.98), less likely to be assigned to high drug use districts (APR = 0.50, 95% CI 0.29, 0.87), more likely to believe that methadone programs reduce crime (APR = 2.43, 95% CI 1.30, 4.55), and less likely to believe that SSPs increase risk of needlestick injury for police (APR = 0.44, 0.27, 0.71). CONCLUSIONS: Beliefs related to the occupational impact of harm reduction services in terms of officer safety and crime reduction are associated with support for referral to related harm reduction services. Efforts to deflect PWID from carceral systems toward harm reduction by frontline police should include measures to improve officer knowledge and attitudes about harm reduction services as they relate to occupational safety and law enforcement priorities. TRIAL REGISTRATION: NCT02444403.


Assuntos
Abuso de Substâncias por Via Intravenosa , Adulto , Feminino , Redução do Dano , Humanos , Aplicação da Lei , Estudos Longitudinais , Masculino , México , Polícia , Encaminhamento e Consulta , Abuso de Substâncias por Via Intravenosa/complicações , Abuso de Substâncias por Via Intravenosa/epidemiologia
16.
Nano Lett ; 20(12): 8476-8482, 2020 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-33170013

RESUMO

An enantiopure, conductive, and paramagnetic crystalline 3-D metal-organic framework (MOF), based on Dy(III) and the l-tartrate chiral ligand, is proved to behave as an almost ideal electron spin filtering material at room temperature, transmitting one spin component only, leading to a spin polarization (SP) power close to 100% in the ±2 V range, which is conserved over a long spatial range, larger than 1 µm in some cases. This impressive spin polarization capacity of this class of nanostructured materials is measured by means of magnetically polarized conductive atomic force microscopy and is attributed to the Chirality-Induced Spin Selectivity (CISS) effect of the material arising from a multidimensional helicity pattern, the inherited chirality of the organic motive, and the enhancing influence of Dy(III) ions on the CISS effect, with large spin-orbit coupling values. Our results represent the first example of a MOF-based and CISS-effect-mediated spin filtering material that shows a nearly perfect SP. These striking results obtained with our robust and easy-to-synthesize chiral MOFs constitute an important step forward in to improve the performance of spin filtering materials for spintronic device fabrication.

17.
J Am Chem Soc ; 142(42): 17989-17996, 2020 10 21.
Artigo em Inglês | MEDLINE | ID: mdl-32941015

RESUMO

We report herein on a NMR-based enantiospecific response for a family of optically active metal-organic frameworks. Cross-polarization of the 1H-13C couple was performed, and the intensities of the 13C nuclei NMR signals were measured to be different for the two enantiomers. In a direct-pulse experiment, which prevents cross-polarization, the intensity difference of the 13C NMR signals of the two nanostructured enantiomers vanished. This result is due to changes of the nuclear spin relaxation times due to the electron spin spatial asymmetry induced by chemical bond polarization involving a chiral center. These experiments put forward on firm ground that the chiral-induced spin selectivity effect, which induces chemical bond polarization in the J-coupling, is the mechanism responsible for the enantiospecific response. The implications of this finding for the theory of this molecular electron spin polarization effect and the development of quantum biosensing and quantum storage devices are discussed.


Assuntos
Estruturas Metalorgânicas/química , Espectroscopia de Ressonância Magnética , Estruturas Metalorgânicas/síntese química , Fenômenos Ópticos
18.
Epidemiol Rev ; 42(1): 27-40, 2020 01 31.
Artigo em Inglês | MEDLINE | ID: mdl-33184637

RESUMO

Drug-law enforcement constitutes a structural determinant of health among people who inject drugs (PWID). Street encounters between police and PWID (e.g., syringe confiscation, physical assault) have been associated with health harms, but these relationships have not been systematically assessed. We conducted a systematic literature review to evaluate the contribution of policing to risk of human immunodeficiency virus (HIV) infection among PWID. We screened MEDLINE, sociological databases, and gray literature for studies published from 1981 to November 2018 that included estimates of HIV infection/risk behaviors and street policing encounters. We extracted and summarized quantitative findings from all eligible studies. We screened 8,201 abstracts, reviewed 175 full-text articles, and included 27 eligible analyses from 9 countries (Canada, China, India, Malaysia, Mexico, Russia, Thailand, Ukraine, and the United States). Heterogeneity in variable and endpoint selection precluded meta-analyses. In 5 (19%) studies, HIV infection among PWID was significantly associated with syringe confiscation, reluctance to buy/carry syringes for fear of police, rushed injection due to a police presence, fear of arrest, being arrested for planted drugs, and physical abuse. Twenty-one (78%) studies identified policing practices to be associated with HIV risk behaviors related to injection drug use (e.g., syringe-sharing, using a "shooting gallery"). In 9 (33%) studies, policing was associated with PWID avoidance of harm reduction services, including syringe exchange, methadone maintenance, and safe consumption facilities. Evidence suggests that policing shapes HIV risk among PWID, but lower-income settings are underrepresented. Curbing injection-related HIV risk necessitates additional structural interventions. Methodological harmonization could facilitate knowledge generation on the role of police as a determinant of population health.


Assuntos
Infecções por HIV/prevenção & controle , Aplicação da Lei/métodos , Abuso de Substâncias por Via Intravenosa , Humanos , Medição de Risco , Estados Unidos
19.
Lancet ; 394(10209): 1652-1667, 2019 11 02.
Artigo em Inglês | MEDLINE | ID: mdl-31668409

RESUMO

We did a global review to synthesise data on the prevalence, harms, and interventions for stimulant use, focusing specifically on the use of cocaine and amphetamines. Modelling estimated the effect of cocaine and amphetamine use on mortality, suicidality, and blood borne virus incidence. The estimated global prevalence of cocaine use was 0·4% and amphetamine use was 0·7%, with dependence affecting 16% of people who used cocaine and 11% of those who used amphetamine. Stimulant use was associated with elevated mortality, increased incidence of HIV and hepatitis C infection, poor mental health (suicidality, psychosis, depression, and violence), and increased risk of cardiovascular events. No effective pharmacotherapies are available that reduce stimulant use, and the available psychosocial interventions (except for contingency management) had a weak overall effect. Generic approaches can address mental health and blood borne virus infection risk if better tailored to mitigate the harms associated with stimulant use. Substantial and sustained investment is needed to develop more effective interventions to reduce stimulant use.


Assuntos
Anfetaminas/efeitos adversos , Transtornos Relacionados ao Uso de Cocaína/mortalidade , Cocaína/efeitos adversos , Adolescente , Adulto , Anfetaminas/uso terapêutico , Doenças Cardiovasculares/induzido quimicamente , Doenças Cardiovasculares/mortalidade , Estimulantes do Sistema Nervoso Central/uso terapêutico , Transtornos Relacionados ao Uso de Cocaína/epidemiologia , Transtornos Relacionados ao Uso de Cocaína/prevenção & controle , Inibidores da Captação de Dopamina/efeitos adversos , Feminino , Infecções por HIV/induzido quimicamente , Infecções por HIV/mortalidade , Hepatite C/induzido quimicamente , Hepatite C/mortalidade , Humanos , Incidência , Masculino , Transtornos Mentais/induzido quimicamente , Transtornos Mentais/mortalidade , Pessoa de Meia-Idade , Prevalência , Viroses/sangue , Viroses/induzido quimicamente , Viroses/mortalidade , Adulto Jovem
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