From field-induced to zero-field SMMs associated with open/closed structures of bis(ZnDy) tetranuclear complexes: a combined magnetic, theoretical and optical study

We have prepared a bis(compartmental) Mannich base ligand H4L (1,4,8,11-tetraaza-1,4,8,11-tetrakis(2-hydroxy-3-methoxy-5-methylbenzyl)cyclotetradecane) specifically designed to obtain bis(TMIILnIII) tetranuclear complexes (TM = transition metal). In this regard, we have succeeded in obtaining three new complexes of the formula [Zn2(μ-L)(μ-OAc)Dy2(NO3)2]·[Zn2(μ-L)(μ-OAc)Dy2(NO3)(OAc)]·4CHCl3·2MeOH (1) and [TM2(μ-H2L)2(μ-succinate)Ln2(NO3)2] (NO3)2·2H2O·6MeOH (TMII = Zn, LnIII = Dy (2); TMII = Co, LnIII = Dy (3)). Compound 1 contains two different bis(ZnDy) tetranuclear molecules that cocrystallize in the structure, in which acetato bridging ligands connect the ZnII and DyIII ions within each ZnDy subunit. This compound does not exhibit slow magnetic relaxation at zero field, but it is activated in the presence of an applied dc magnetic field and/or by Dy/Y magnetic dilution, showing two relaxation processes corresponding to each of the two different bis(ZnDy) units found in the structure. As revealed by the theoretical calculations, magnetic relaxation in 1 is single-ion in origin and takes place through the first excited state of each DyIII ion. When using the succinato dicarboxylate bridging ligand instead of acetate, compounds 2 and 3 were serendipitously formed, which have a closed structure with the succinate anion bridging two ZnDy subunits belonging to two different ligands. It should be noted that only compound 2 exhibits slow relaxation of magnetization in the absence of an external magnetic field. According to experimental and theoretical data, 2 relaxes through the second excited Kramers doublet (Ueff = 342 K). In contrast, 3 displays field-induced SMM behaviour (Ueff = 203 K). However, the Co/Zn diluted version of this compound 3Zn shows slow relaxation at zero field (Ueff = 347 K). Ab initio theoretical calculations clearly show that the weak ferromagnetic coupling between CoII and DyIII ions is at the origin of the lack of slow relaxation of this compound at zero field. Compound 2 and its diluted analogues 2Y and 3Zn show hysteresis loops at very low temperature, thus confirming their SMM behaviour. Finally, compounds 1 and 2 show DyIII based emission even at room temperature that, in the case of 2, allows us to extract the splitting of the ground 6H15/2 term, which matches reasonably well with theoretical calculations.

Asynchronous Video Directly Observed Therapy to Monitor Short-Course Latent Tuberculosis Infection Treatment: Results of a Randomized Controlled Trial

Background

Observing medication ingestion through self-recorded videos (video directly observed therapy [VDOT]) has been shown to be a cost-effective alternative to in-person directly observed therapy (DOT) for monitoring adherence to treatment for tuberculosis disease. VDOT could be a useful tool to monitor short-course latent tuberculosis infection (LTBI) treatment.

Methods

We conducted a prospective randomized controlled trial comparing VDOT (intervention) and clinic-based DOT (control) among patients newly diagnosed with LTBI who agreed to a once-weekly 3-month treatment regimen of isoniazid and rifapentine. Study outcomes were treatment completion and patient satisfaction. We also assessed costs. Pre- and posttreatment interviews were conducted.

Results

Between March 2016 and December 2019, 130 participants were assigned to VDOT (n = 68) or DOT (n = 62). Treatment completion (73.5% vs 69.4%, P = .70) and satisfaction with treatment monitoring (92.1% vs 86.7%, P = .39) were slightly higher in the intervention group than the control group, but neither was statistically significant. VDOT cost less per patient (median, $230; range, $182-$393) vs DOT (median, $312; range, $246-$592) if participants used their own smartphone.

Conclusions

While both groups reported high treatment satisfaction, VDOT was not associated with higher LTBI treatment completion. However, VDOT cost less than DOT. Volunteer bias might have reduced the observed effect since patients opposed to any treatment monitoring could have opted for alternative unobserved regimens. Given similar outcomes and lower cost, VDOT may be useful for treatment monitoring when in-person observation is prohibited or unavailable (eg, during a respiratory disease outbreak). The trial was registered at the National Institutes of Health (ClinicalTrials.gov NTC02641106).

Clinical Trials Registration

ClinicalTrials.gov NTC02641106; registered 24 October 2016.

National Burden of Injury and Deaths From Shootings by Police in the United States, 2015‒2020

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).

Effects of the tetravanadate [V4O12]4- anion on the structural, magnetic, and biological properties of copper/phenanthroline complexes

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.

Spin canting and slow magnetic relaxation in mononuclear cobalt(II) sulfadiazine ternary complexes

Monomeric [Co(SDZ)2phen] (1) and [Co(SDZ)(bq)Cl] (2) complexes (SDZ = sulfadiazine, phen = 1,10-phenanthroline, and bq = 2,2'-biquinoline) have been synthesized and characterized. X-ray diffraction studies indicate that SDZ acts as a bidentate ligand coordinating through the sulfonamide and the pyrimidine N atoms in both compounds. In complex 1, the coordination sphere consists of two SDZ ligands and a bis-chelating phen ligand, giving rise to a CoN6 coordination sphere. On the other hand, 2 has a CoN4Cl core, with two N-atoms from SDZ and two from the bq ligand. Both compounds have been studied by dc and ac magnetometry and shown to display slow magnetic relaxation under an optimum external dc field (1 kOe) at low temperatures. Moreover, compound 2 displays long range magnetic ordering provided by spin-canted antiferromagnetism, which has been characterized by further field-dependent magnetic susceptibility measurements, FC/ZFC curves, hysteresis loops and frequency-independent ac curves. The signs of the calculated D parameters, positive in 1 and negative in 2, have been rationalized according to the two lowest-lying transitions in the orbital energy diagrams derived from ab initio ligand field theory (AILFT). In a subsequent attempt to reveal the possible hidden zero-field SMM behaviour, Ni(II)-based 3 and Co(II)-doped Ni(II)-based (with a Ni : Co ratio of 0.9 : 0.1) heterometallic compound 2Ni were synthesized.

Financial Vulnerability and Its Association with HIV Transmission Risk Behaviors Among People Who Inject Drugs in Kyrgyzstan

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.

Demographic patterns and disparities in new HIV diagnoses attributed to injection drug use in the United States

People who inject drugs (PWID) exhibit disproportionate HIV burdens in the United States. We characterized longitudinal patterns and demographic disparities in new HIV diagnoses attributed to injection drug use (IDU) in 2008-2020. Although new IDU-attributed HIV diagnoses fell by 53.9%, new HIV diagnoses remained disproportionately elevated in female (100.9/100 000), Black (258.8/100 000), and Hispanic (131.0/100 000) PWID. Despite considerable declines in new HIV diagnoses, disparities by race/ethnicity and sex persist among US PWID.

Unlocking deflection: The role of supervisor support in police officer willingness to refer people who inject drugs to harm reduction services

BACKGROUND

Research is needed that investigates the relationship between police behaviors, attitudes, and perceived supervisor support as an implementation strategy of improving drug policy reforms.

METHODS

We hypothesized that officers with more positive attitudes and practices would be more likely to report the perceived support of their supervisors. Data includes a sample of 1227 police officers who completed Project ESCUDO, a police education training program in Tijuana, Mexico. A negative binomial distribution was used to estimate associations between police behaviors and attitudes and perceived supervisor support.

RESULTS

Officers who reported perceived supervisor support accounted for 29.2% (n=470) of the sample. Officers who referred people to social services were more likely and officers who broke syringes were less likely to report perceived supervisor support compared to officers who did not engage in these practices. Officers who believed: MOUD reduced criminal activity, "referring people who use drugs to social services is part of my job", and "laws that treat addiction as a public health problem make my job easier", were more likely to report perceived supervisor support. Beliefs that drug addiction is a disease, laws that treat addiction as a public health problem make their job easier, and talking to other law enforcement officers about infectious diseases were not significantly associated with perceived supervisor support.

CONCLUSIONS

Our research highlights the importance of incorporating police supervisors as key actors in assuring officers' practices reflect current drug law reforms as well as embrace patient-centered approaches to managing encounters people who use opioids and inject drugs.

Estimating the impact of a police education program on hepatitis C virus transmission and disease burden among people who inject drugs in Tijuana, Mexico: A dynamic modeling analysis

BACKGROUND AND AIMS

Criminalization of drug use and punitive policing are key structural drivers of hepatitis C virus (HCV) risk among people who inject drugs (PWID). A police education program (Proyecto Escudo) delivering training on occupational safety together with drug law content was implemented between 2015 and 2016 in Tijuana, Mexico, to underpin drug law reform implementation. We used data from a longitudinal cohort of PWID in Tijuana to inform epidemic modeling and assess the long-term impact of Escudo on HCV transmission and burden among PWID in Tijuana.

METHODS

We developed a dynamic, compartmental model of HCV transmission and incarceration among PWID and tracked liver disease progression among current and former PWID. The model was calibrated to data from Tijuana, Mexico, with 90% HCV seroprevalence. We used segmented regression analysis to estimate impact of Escudo on recent incarceration among an observational cohort of PWID. By simulating the observed incarceration trends, we estimated the potential impact of the implemented (2-year reduction in incarceration) and an extended (10-year reduction in incarceration) police education program over a 50-year follow-up (2016-2066) on HCV outcomes (incidence, cirrhosis, HCV-related deaths and disability adjusted life-years averted) compared with no intervention.

RESULTS

Over the 2-year follow-up, Proyecto Escudo reduced HCV incidence among PWID from 21.5 per 100 person years (/100py) (95% uncertainty interval [UI] = 15.3-29.7/100py) in 2016 to 21.1/100py (UI = 15.0-29.1/100py) in 2018. If continued for 10 years, Escudo could reduce HCV incidence to 20.0/100py (14.0-27.8/100py) by 2026 and avert 186 (32-389) new infections, 76 (UI = 12-160) cases of cirrhosis and 32 (5-73) deaths per 10 000 PWID compared with no intervention over a 50-year time horizon.

CONCLUSIONS

In Tijuana, Mexico, implementation of a police education program delivering training on occupational safety and drug law content appears to have reduced hepatitis C virus incidence among people who inject drugs.

A Lamellar Zn-Based Coordination Polymer Showing Increasing Photoluminescence upon Dehydration

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.

Easy Handling and Cost-Efficient Processing of a Tb3+-MOF: The Emissive Capacity of the Membrane-Immobilized Material, Water Vapour Adsorption and Proton Conductivity

The development of convenient, non-complicated, and cost-efficient processing techniques for packing low-density MOF powders for industry implementation is essential nowadays. To increase MOFs' availability in industrial settings, we propose the synthesis of a novel 3D Tb-MOF (1) and a simple and non-expensive method for its immobilization in the form of pellets and membranes in polymethacrylate (PMMA) and polysulphone (PSF). The photoluminescent properties of the processed materials were investigated. To simulate industrial conditions, stability towards temperature and humidity have been explored in the pelletized material. Water-adsorption studies have been carried out in bulk and processed materials, and because of the considerable capacity to adsorb water, proton-conduction studies have been investigated for 1.

Metal-Organic Frameworks Based on a Janus-Head Biquinoline Ligand as Catalysts in the Transformation of Carbonyl Compounds into Cyanohydrins and Alcohols

A new family of metal-organic frameworks (MOFs) named GR-MOFs with the chemical formula {[M _x (BCA) _y ](H₂O) _z (DMF) _w } (x,y,z,w: 1,1,2,0; 1,1.5,0,1; 1,2,2,1; and 1,1,0,2 for GR-MOF-11 to 14, respectively) based on s-block [M: Sr (GR-MOF-11), Ba (GR-MOF-14)] and d-block [M: Y (GR-MOF-12) and Cd (GR-MOF-13)] metals together with the biquinoline ligand 2,2'-bicinchoninic acid (H₂BCA) has been synthetized by a solvothermal route and fully characterized by elemental and thermogravimetric analysis, Fourier transform infrared spectroscopy, photoluminescence, particle size distribution through optical microscopy, electrophoretic mobility, and finally, X-ray single-crystal and powder diffraction. The structural characterization reveals that these 2D and 3D MOFs possess a rich variety of coordination modes that maintained the Janus-head topology on the ligand in most of the cases. The new MOFs were studied in the catalyzed cyanosilylation and hydroboration of an extensive group of aldehydes and ketones, wherein the s-block metal-based MOFs GR-MOF-11 and GR-MOF-14 provided the highest efficiency ever reported in the MOF-catalyzed cyanosilylation of carbonyl compounds by using only 0.5 mol % of catalyst loading, room temperature, and solvent-free conditions. Furthermore, the hydroboration of ketones has been reported for the first time with this type of s-block metal catalysts obtaining from moderate to good conversions.

Modelling the contribution of incarceration and public health oriented drug law reform to HCV transmission and elimination among PWID in Tijuana, Mexico

BACKGROUND

Incarceration is associated with increased risk of hepatitis C virus (HCV) among people who inject drugs (PWID). Mexico's previous attempt in implementing a public health-oriented drug law reform resulted in minimal impact on incarceration among PWID. However, implementation of reforms alongside Mexico's HCV elimination program has the potential to reshape the HCV epidemic among PWID in the next decade. We use data from a cohort of PWID in Tijuana, Mexico, to inform epidemic modeling to assess the contribution of incarceration and fully implemented drug reform on HCV transmission and elimination among PWID.

METHODS

We developed a dynamic, deterministic model of incarceration, HCV transmission and disease progression among PWID. The model was calibrated to data from Tijuana, Mexico, with 90% HCV seroprevalence among 10,000 PWID. We estimated the 10-year population attributable fraction (PAF) of incarceration to HCV incidence among PWID and simulated, from 2022, the potential impact of the following scenarios: 1) decriminalization (80% reduction in incarceration rates); 2) fully implemented drug law reform (decriminalization and diversion to opiate agonist therapy [OAT]); 3) fully implemented drug law reform with HCV treatment (direct-acting antivirals [DAA]). We also assessed the number DAA needed to reach the 80% incidence reduction target by 2030 under these scenarios.

RESULTS

Projections suggest a PAF of incarceration to HCV incidence of 5.4% (95% uncertainty interval [UI]:0.6-11.9%) among PWID in Tijuana between 2022-2032. Fully implemented drug reforms could reduce HCV incidence rate by 10.6% (95%UI:3.1-19.2%) across 10 years and reduce the number of DAA required to achieve Mexico's HCV incidence reduction goal by 14.3% (95%UI:5.3-17.1%).

CONCLUSIONS

Among PWID in Tijuana, Mexico, incarceration remains an important contributor to HCV transmission. Full implementation of public health-oriented drug law reform could play an important role in reducing HCV incidence and improve the feasibility of reaching the HCV incidence elimination target by 2030.

Influence of Tartrate Ligand Coordination over Luminescence Properties of Chiral Lanthanide-Based Metal-Organic Frameworks

The present work reports on a detailed discussion about the synthesis, characterization, and luminescence properties of three pairs of enantiopure 3D metal-organic frameworks (MOFs) with general formula {[Ln₂(L/D-tart)₃(H₂O)₂]·3H₂O}_n (3D_Ln-L/D, where Ln = Sm(III), Eu(III) or Gd(III), and L/D-tart = L- or D-tartrate), and ten pairs of enantiopure 2D coordination polymers (CPs) with general formula [Ln(L/D-Htart)₂(OH)(H₂O)₂]_n (2D_Ln-L/D, where Ln = Y(III), Sm(III), Eu(III), Gd(III), Tb(III), Dy(III), Ho(III), Er(III), Tm(III) or Yb(III), and L/D-Htart = hydrogen L- or D-tartrate) based on single-crystal X-ray structures. Enantiopure nature of the samples has been further corroborated by Root Mean Square Deviation (RMSD) as well as by circular dichroism (CD) spectra. Solid-state emission spectra of Eu(III), Tb(III), and Dy(III)-based compounds confirm the occurrence of ligand-to-metal charge transfers in view of the characteristic emissions for these lanthanide ions, and emission decay curves were also recorded to estimate the emission lifetimes for the reported compounds. A complete theoretical study was accomplished to better understand the energy transfers occurring in the Eu-based counterparts, which allows for explaining the different performances of 3D-MOFs and 2D-layered compounds. As inferred from the colorimetric diagrams, emission characteristics of Eu-based 2D CPs depend on the temperature, so their luminescent thermometry has been determined on the basis of a ratiometric analysis between the ligand-centered and Eu-centered emission. Finally, a detailed study of the polarized luminescence intensity emitted by the samples is also accomplished to support the occurrence of chiro-optical activity.

Lanthanide(III) Ions and 5-Methylisophthalate Ligand Based Coordination Polymers: An Insight into Their Photoluminescence Emission and Chemosensing for Nitroaromatic Molecules

The work presented herein reports on the synthesis, structural and physico-chemical characterization, luminescence properties and luminescent sensing activity of a family of isostructural coordination polymers (CPs) with the general formula [Ln₂(μ₄-5Meip)₃(DMF)]_n (where Ln(III) = Sm (1_Sm), Eu (2_Eu), Gd (3_Gd), Tb (4_Tb) and Yb (5_Yb) and 5Meip = 5-methylisophthalate, DMF = N,N-dimethylmethanamide). Crystal structures consist of 3D frameworks tailored by the linkage between infinite lanthanide(III)-carboxylate rods by means of the tetradentate 5Meip ligands. Photoluminescence measurements in solid state at variable temperatures reveal the best-in-class properties based on the capacity of the 5Meip ligand to provide efficient energy transfers to the lanthanide(III) ions, which brings intense emissions in both the visible and near-infrared (NIR) regions. On the one hand, compound 5_Yb displays characteristic lanthanide-centered bands in the NIR with sizeable intensity even at room temperature. Among the compounds emitting in the visible region, 4_Tb presents a high QY of 63%, which may be explained according to computational calculations. At last, taking advantage of the good performance as well as high chemical and optical stability of 4_Tb in water and methanol, its sensing capacity to detect 2,4,6-trinitrophenol (TNP) among other nitroaromatic-like explosives has been explored, obtaining high detection capacity (with K_sv around 10⁵ M^-1), low limit of detection (in the 10^-6-10^-7 M) and selectivity among other molecules (especially in methanol).

Mortality by cause of death during year 1 of the COVID-19 pandemic in a cohort of older adults from Baltimore Maryland who have injected drugs

BACKGROUND

In 2020, the first year of the COVID-19 pandemic, overdose deaths increased. However, no studies have characterized changes in mortality during the pandemic in a well-characterized cohort of people who use drugs in active follow-up at the time of pandemic onset.

DESIGN

We compared all-cause and cause-specific mortality in the first year of the pandemic (Mar-Dec 2020) to the five years preceding (Jan 2015-Feb 2020), among participants in the AIDS Linked to the IntraVenous Experience (ALIVE) study: a community-recruited cohort of adults from Baltimore who have injected drugs. 3510 participants contributed 17,498 person-years [py] of follow-up time. Cause and dates of death were ascertained through the National Death Index. Comparisons were made for the full cohort and within subgroups with potentially differential levels of vulnerability.

RESULTS

All-cause mortality in 2020 was 39.6 per 1000 py, as compared to 37.2 per 1000 py pre- pandemic (Adjusted Incidence Rate Ratio = 1.09, 95%: confidence interval: 0.84-1.41). Increases were mostly attributable to chronic disease deaths; injury/poisoning deaths did not increase. No pre-post differences were statistically significant.

CONCLUSION

In this exploratory analysis of an older cohort of urban-dwelling adults who have injected drugs, mortality changes during the first year of the pandemic differed from national trends and varied across potentially vulnerable subgroups. More research is needed to understand determinants of increased risk of mortality during the pandemic among subgroups of people who use drugs.

Multifunctional Lanthanide-Based Metal-Organic Frameworks Derived from 3-Amino-4-hydroxybenzoate: Single-Molecule Magnet Behavior, Luminescent Properties for Thermometry, and CO2 Adsorptive Capacity

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.

A new family of isostructural multifunctional metal−organic frameworks has been described and studied for magnetism and photoluminescence. Interestingly, some materials present single-molecule magnet behavior, and 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.

Combined experimental and theoretical investigation on the magnetic properties derived from the coordination of 6-methyl-2-oxonicotinate to 3d-metal ions

Five new compounds are reported herein starting from 2-hydroxy-6-methylnicotinic acid (H2h6mnic) and first-row transition metal ions, although H2h6mnic shows a prototropy in solution to lead to the 6-methyl-2-oxonicotinate (6m2onic) ligand that is the molecule eventually present in the compounds. The structural and chemical characterization reveals the following chemical formulae: {[MnNa(μ₃-6m2onic)₂(μ-6m2onic)(MeOH)]·H₂O·MeOH}_n (1Mn), {[M₂Na₂(μ₃-6m2onic)₂(μ-6m2onic)₂(μ-H₂O)(H₂O)₆](NO₃)₂}_n [M^II = Co (2Co) and Ni (3Ni)], 2[Cu₂(6m2onic)₃(μ-6m2onic)(MeOH)]·[Cu₂(6m2onic)₂(μ-6m2onic)₂]·2[Cu(6m2onic)₂(MeOH)]·32H₂O (4Cu) and {[Cu(μ-6m2onic)₂]·6H₂O}_n (5Cu) (where 6m2onic = 6-methyl-2-oxonicotinate). An unusual structural diversity is observed for the compounds, ranging from isolated complexes (in 4Cu), 1D arrays (in 1Mn and 5Cu) and 3D frameworks (in 2Co and 3Ni). Magnetic properties have been studied for all compounds. Analysis of the magnetic dc susceptibility and magnetization data for 4Cu and 5Cu suggests the occurrence of ferromagnetic exchange, which is well explained by broken-symmetry and CASSCF calculations. The sizeable easy-plane magnetic anisotropy present in compound 2Co allows for a field-induced magnet behaviour with an experimental effective energy barrier of 16.2 cm^-1, although the slow relaxation seems to be best described through Raman and direct processes in agreement with the results of ab initio calculations.

Cohort profile: the Kyrgyzstan InterSectional Stigma (KISS) injection drug use cohort study

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.

Catalytic Performance and Electrophoretic Behavior of an Yttrium-Organic Framework Based on a Tricarboxylic Asymmetric Alkyne

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.

An experimental and theoretical study of the magnetic relaxation in heterometallic coordination polymers based on 6-methyl-2-oxonicotinate and lanthanide(iii) ions with square antriprismatic environment

Two isostructural lanthanide(iii)-based coordination polymers with square antiprismatic environment are described. Magnetic properties are studied from experimental and theoretical viewpoints to analyze their SIM behavior.

Costs and impact on HIV transmission of a switch from a criminalisation to a public health approach to injecting drug use in eastern Europe and central Asia: a modelling analysis

BACKGROUND

HIV incidence is increasing in eastern Europe and central Asia, primarily driven by injecting drug use. Coverage of antiretroviral therapy (ART) and opioid agonist therapy are suboptimal, with many people who inject drugs (PWID) being incarcerated. We aimed to assess whether use of monies saved as a result of decriminalisation of drug use or possession to scale up ART and opioid agonist therapy could control HIV transmission among PWID in eastern Europe and central Asia.

METHODS

A dynamic HIV transmission model among PWID incorporating incarceration, ART, and opioid agonist therapy was calibrated to Belarus, Kazakhstan, Kyrgyzstan, and St Petersburg (Russia). Country-specific costs for opioid agonist therapy, ART, and incarceration were collated or estimated. Compared with baseline, the model prospectively projected the life-years gained, incremental costs (2018 euros), and infections prevented over 2020-40 for three scenarios. The decriminalisation scenario removed incarceration resulting from drug use or possession for personal use, reducing incarceration among PWID by 24·8% in Belarus, Kazakhstan, and Kyrgyzstan and 46·4% in St Petersburg; the public health approach scenario used savings from decriminalisation to scale up ART and opioid agonist therapy; and the full scale-up scenario included the decriminalisation scenario plus investment of additional resources to scale up ART to the UNAIDS 90-90-90 target of 81% coverage and opioid agonist therapy to the WHO target of 40% coverage. The incremental cost-effectiveness ratios per life-year gained for each scenario were calculated and compared with country-specific gross domestic product per-capita willingness-to-pay thresholds. Costs and life-years gained were discounted 3% annually.

FINDINGS

Current levels of incarceration, opioid agonist therapy, and ART were estimated to cost from €198 million (95% credibility interval 173-224) in Kyrgyzstan to €4129 million (3897-4358) in Kazakhstan over 2020-40; 74·8-95·8% of these total costs were incarceration costs. Decriminalisation resulted in cost savings (€38-773 million due to reduced prison costs; 16·9-26·1% reduction in overall costs) but modest life-years gained (745-1694). The public health approach was cost saving, allowing each setting to reach 81% ART coverage and 29·7-41·8% coverage of opioid agonist therapy, resulting in 17 768-148 464 life-years gained and 58·9-83·7% of infections prevented. Results were similar for the full scale-up scenario.

INTERPRETATION

Cost savings from decriminalisation of drug use could greatly reduce HIV transmission through increased coverage of opioid agonist therapy and ART among PWID in eastern Europe and central Asia.

FUNDING

Alliance for Public Health, US National Institute of Allergy and Infectious Diseases and National Institute for Drug Abuse, and Economist Intelligence Unit.

Impact of cumulative incarceration and the post-release period on syringe-sharing among people who inject drugs in Tijuana, Mexico: a longitudinal analysis

BACKGROUND AND AIMS

Syringe-sharing among people who inject drugs, which can occur during incarceration and post-release, has been linked with increased risk of blood-borne infections. We aimed to investigate the cumulative effect of repeated incarceration and the post-release period on receptive syringe-sharing.

DESIGN

Ongoing community-based cohort, recruited through targeted sampling between 2011 and 2012 with 6-month follow-ups.

SETTING

Tijuana, Mexico.

PARTICIPANTS

Sample of 185 participants (median age 35 years; 67% female) with no history of incarceration at study entry, followed to 2017.

MEASUREMENTS

Cumulative incarceration and post-release period were constructed from incarceration events reported in the past 6 months for each study visit. Receptive syringe-sharing in the past 6 months was assessed as a binary variable. We used logistic regression with generalized estimating equations to examine the association between cumulative incarceration events and the post-release period with receptive syringe-sharing over time. Missing data were handled through multiple imputation.

FINDINGS

At baseline, 65% of participants engaged in receptive syringe-sharing in the prior 6 months. At follow-up, 150 (81%) participants experienced a total of 358 incarceration events [median = 2, interquartile range (IQR) = 1-3]. The risk of receptive syringe-sharing increased with the number of repeated incarcerations. Compared with never incarcerated, those with one incarceration had 1.28 [95% confidence interval (CI) = 0.97-1.68] higher adjusted odds of syringe-sharing; two to three incarcerations, 1.42 (95% CI = 1.02-1.99) and more than three incarcerations, 2.10 (95% CI = 1.15-3.85). Participants released within the past 6 months had 1.53 (95% CI = 1.14-2.05) higher odds of sharing syringes compared with those never incarcerated. This post-release risk continued up to 1.5 years post-incarceration (adjusted odds ratio = 1.41, 95% CI = 1.04-1.91), but then waned.

CONCLUSIONS

A longitudinal community cohort study among people who inject drugs suggested that the effects of incarceration on increased injecting risk, measured through syringe-sharing, are cumulative and persist during the post-release period.

A novel yttrium-based metal-organic framework for the efficient solvent-free catalytic synthesis of cyanohydrin silyl ethers

A new porous metal-organic framework (MOF) with the chemical formula [Y₅L₆(OH)₃(DMF)₃]·5H₂O (1) (where L = 3-amino-4-hydroxybenzoate) has been prepared by a solvothermal procedure. The structural characterization reveals that this material consists of a robust three-dimensional metal-organic framework (MOF) grown with clusters formed by Y(iii) and hydroxide anions joined to one another by the ligand, giving rise to an open structure with interconnected microchannels with variable dimensions. This assembled set has shown to possess a fascinating catalytic activity for the cyanosilylation of a broad range of aldehydes and ketones with exceptional recyclability, a solvent-free medium, and one order of magnitude lower catalyst loading compared to all related lanthanide-based MOFs described so far in the literature.

Towards correlating dimensionality and topology in luminescent MOFs based on terephthalato and bispyridyl-like ligands

Herein, we report on the synthesis, structural analysis, physicochemical characterization and photoluminescence performance of two ternary compounds based on dicarboxylate and bispyridyl-like ligands and metal ions of group 12, namely [Zn2(μ4-bdc)(μ-pbptz)(DMF)2(NO3)2]n (1-Zn) and {[Cd(μ3-bdc)(μ-pbptz)]·DMF}n (2-Cd) (where bdc = benzene-1,4-dicarboxylate, pbptz = 3,6-bis(4-pyridyl)-1,2,4,5-tetrazine, and DMF = N,N-dimethylformamide). 1-Zn, consisting of a 2D-layered framework, can be considered as the lower-dimensional analogue of the previously reported {[Zn2(μ4-bdc)2(μ-pbptz)]·2DMF·3H2O}n 3D MOF (1'-Zn), which is shown to recrystallize into 1-Zn undergoing a kind of exfoliation. 2-Cd presents a 3D doubly interpenetrated framework whose porosity is reduced to approximately half of the available solvent-accessible voids contained in the non-interpenetrated homologue reported so far, {[Cd(μ3-bdc)(μ-pbptz)]·3DMF}n (2'-Cd). Structural factors leading to each of the alternative frameworks are detailed by analysing the building units with a perusal of the Cambridge Structural Database and providing a comparative description of the structures. The photoluminescence properties of herein reported compounds (1-Zn and 2-Cd) are also measured and the processes governing the spectra are described using time-dependent density-functional theory (TD-DFT), which allows establishing some structural correspondences by comparing these results with those of the 1'-Zn and 2'-Cd analogues.

Risk of non-fatal overdose and polysubstance use in a longitudinal study with people who inject drugs in Tijuana, Mexico

INTRODUCTION

Among people who inject drugs (PWID), polysubstance use has been associated with fatal and non-fatal overdose (NFOD). However, the risk of overdose due to the cumulative number of various recently used drug types remains unexplored. We estimated the risk of NFOD for different polysubstance use categories among PWID in Tijuana, Mexico.

METHODS

Data came from 661 participants followed for 2 years in Proyecto El Cuete-IV, an ongoing prospective cohort of PWID. A multivariable Cox model was used to assess the cumulative impact of polysubstance use on the time to NFOD. We used the Cochran-Armitage test to evaluate a dose-response relationship between number of polysubstance use categories and NFOD.

RESULTS

We observed 115 NFOD among 1029.2 person-years of follow-up (incidence rate: 11.2 per 100 person-years; 95% confidence interval [CI] 9.3-13.3). Relative to those who used one drug class, the adjusted hazard ratio of NFOD for individuals reporting using two drug classes was 1.11 (95% CI 0.69-1.79), three drug classes was 2.00 (95% CI 1.16-3.44) and for those reporting three compared to two was 1.79 (95% CI 1.09-2.97). A significant Cochran-Armitage trend test (P < 0.001) suggested a dose-response relationship.

DISCUSSION AND CONCLUSIONS

Polysubstance use was associated with increased risk of NFOD with a dose-response relationship over 2 years. We identified a subgroup of PWID at high risk of NFOD who reported concurrent use of opioids, stimulants and benzodiazepines. Prioritising tailored harm reduction and overdose prevention interventions for PWID who use multiple substances in Tijuana is needed.

Reducing police occupational needle stick injury risk following an interactive training: the SHIELD cohort study in Mexico

Objective

At a time of unprecedented attention to the public health impact of policing, it is imperative to understand the role of occupational safety in shaping officer behaviours. We assessed the longitudinal impact of police training in a quasi-experimental hybrid type-1 trial to reduce syringe-related occupational risk, while realigning police practices with public health prevention among people who inject drugs (PWID).

Setting

Tijuana, Mexico.

Participants

Of 1806 Tijuana municipal police trainees, 771 reporting previous exposure to syringes were randomly selected for follow-up. All participants completed at least one follow-up visit; attrition at 24 months was 8%.

Intervention

Between 2015 and 2016, officers received a training intervention (Safety and Health Integration in the Enforcement of Laws on Drugs, SHIELD) bundling occupational needle stick injury (NSI) prevention with health promotion among PWID.

Outcome measures

Longitudinal analysis with generalised linear mixed models to evaluate training impact on occupational NSI risk via NSI incidence and prevalidated Syringe Threat and Injury Correlates (STIC) score. This composite indicator integrates five self-reported risky syringe-handling practices (eg, syringe confiscation, breaking) and was used as a proxy for NSI risk due to reporting bias and concerns about reliability of NSI incidence reports.

Results

No change in self-reported NSI incidence was observed, but significant reductions in risk (16.2% decrease in STIC score) occurred at 3 months, with a sustained decrease of 17.8% through 24 months, compared with pretraining (p<0.001). Police assignment (patrol vs administration) moderated the training effect (p=0.01). Younger age, male gender, lower rank and previous NSI were independently and significantly associated with higher NSI risk overtime, although all groups demonstrated significant reductions post-training.

Conclusions

SHIELD is the first intervention to be associated with significant sustained changes in police practices that pose risk for both occupational and the public’s health. Integrating occupational safety and public health education should inform other interventions to mitigate the community health detriments of policing behaviours.

Trial registration number

NCT02444403.

Experience in a Pediatric Prolonged Mechanical Ventilation Unit from a public hospital in Chile

INTRODUCTION

Hospitalized patients with high respiratory technology dependency are increasingly common and result in lengthy stays in intensive care units. Strategies mitigating its impact have been scarcely described.

OBJECTIVE

To describe a 6-year experience in a Pediatric Prolonged Mechanical Ventilation Unit.

METHODS

Retrospective study. All children admitted to the unit between October 2012 and December 2018 were included. Descriptive and inferential statistical methods were used, analyzing lengths of stay and readmissions. Different outcome measures were compared according to the type of pathology and mechanical ventilation.

RESULTS

A total of 113 patients had 310 admissions to the unit. Age at admission: 2.2 years (0.6-8.8); males: 60.2 %.

PATHOLOGIES

neuromuscular disease (22.1 %), chronic lung disease (20.4 %), neurological damage (34.5 %), upper airway obstruction (9.7 %), heart disease (3.5 %), Down syndrome (9.7 %). A total of 10 507 bed-days were used; with a 92.6 % occupancy rate, 54.8 % of transfers to the intensive care unit, and 66.1 % of readmissions. Mean length of stay: 16 days (6.5- 49.0); differences in age at admission observed by pathology (p = 0.032). More readmissions were observed in children with neurological damage and Down syndrome (p = 0.004). Children with invasive ventilation were observed to have a longer length of stay (p < 0.001) and more readmissions (p < 0.001).

CONCLUSION

The occupancy rate at the PMVU was over 90 %, which allowed more available intensive care beds and discharging all patients. Children with invasive ventilation had a longer length of stay and more readmissions.

Cost-effectiveness of using hepatitis C viremic hearts for transplantation into HCV-negative recipients

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.

Magneto-structural correlations of cyclo-tetravanadates functionalized with mixed-ligand copper(ii) complexes

Bimetallic materials based on tetravanadate anions and mixed ligand copper(ii) complexes were readily synthesized under non-hydrothermal conditions. The compounds show interesting structural and magnetic diversity mediated by copper symmetry.

Strontium-Based MOFs Showing Dual Emission: Luminescence Thermometers and Toluene Sensors

This work reports on the preparation and optical characterization of two metal-organic frameworks (MOFs) based on strontium ions and 2-amino-1,4-benzenedicarboxylate (NH₂-bdc) ligand: i.e., [Sr(NH₂-bdc)(DMF)]_n (1) and {[Sr(NH₂-bdc)(Form)]·H₂O}_n (2) (where DMF = dimethylformamide and Form = formamide). Compound 1 has a 3D architecture built up from the linkage established by NH₂-bdc among metal-carboxylate rods, leaving significant microchannels that are largely occupied by DMF molecules coordinated to strontium centers. The solvent molecules play a crucial role in the photoluminescence (PL) properties, which has been deeply characterized by diffuse reflectance and variable-temperature emission. Interestingly, both materials present intriguing photoluminescence (PL) properties involving intense short-lived and long-lasting phosphorescence (LLP), though the latter is especially remarkable for compound 2 with a lifetime of 815 ms at low temperature. Conversely, the strong PL shown by 1 may be successfully exploited due to both its luminescent thermochromism observed in the RT to 10 K range and its solvent-dependent PL sensing capacity, imbuing this material with potential activity as a PL thermometer as well as a toluene detector in water solutions.

An Ideal Spin Filter: Long-Range, High-Spin Selectivity in Chiral Helicoidal 3-Dimensional Metal Organic Frameworks

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.

Anti-cancer and anti-inflammatory activities of a new family of coordination compounds based on divalent transition metal ions and indazole-3-carboxylic acid

A new family of mononuclear coordination compounds has been synthetized and characterized: [M(3-ind)₂(H₂O)₂] (M = Co (1), Ni (2), Zn (3), Fe (4), Mn (5); 3-ind = indazole-3-carboxylate). These materials are mononuclear coordination compounds that possess strong hydrogen bond interactions. The anti-inflammatory effects of these compounds were assayed in lipopolysaccharide activated RAW 264.7 macrophages by inhibition of NO production. Moreover, the cytotoxicity of the complexes and the ligand in RAW 264.7 cells were determined for the first time. The most significant results were obtained for the compounds 4 and 5 reaching values of NO inhibition close to 80% at 48 h, and above to 90% at 72 h of treatment. The highest inhibitory effects on NO production were showed at the range 7-23 μg/mL for compounds 4 and 5. As a consequence, compounds 4 and 5 could be potential drugs due to the interesting anti-inflammatory properties showed. The anti-cancer potential of these compounds has been also tested against different tumor cell lines. The cytotoxicity of the ligand and of compounds 2 and 3 were assayed in three cell lines: HT29, colon cancer cells, Hep-G2, hepatoma cells and B16-F10 melanoma cells. The best results have been achieved with compound 2 in HepG2 and B16-F10 cell lines, being between 1.5 and 2 times more effective that the ligand in HepG2 cells, and B16-F10 cells. All in all, indazole-3-carboxylic acid is a promising ligand for the formation of coordination compounds with biochemical properties.

Modulating Magnetic and Photoluminescence Properties in 2-Aminonicotinate-Based Bifunctional Coordination Polymers by Merging 3d Metal Ions

Herein, the synthesis and study of bifunctional coordination polymers (CPs) with both magnetic and photoluminescence properties, derived from a heterometallic environment, are reported. As a starting point, three isostructural monometallic CPs with the formula [M(μ-2ani)₂ ]_n (M^II =Mn (1_Mn ), Co (3_Co ) and Ni (4_Ni ); 2ani=2-aminonicotinate), crystallise as chiral 2D-layered structures stacked by means of supramolecular interactions. These compounds show high thermal stability in the solid state (above 350 °C), despite which, in aqueous solution, compound 1_Mn is shown to partially transform into a novel 1D chain CP with the formula [Mn(2ani)₂ (μ-H₂ O)₂ ]_n (2_Mn ). A study of the direct current (dc) magnetic properties of 1_Mn , 3_Co and 4_Ni reveals a spin-canted structure derived from antisymmetric antiferromagnetic weak exchanges along the chiral network (as confirmed by DFT calculations) and magnetic anisotropy of the ions, in such a way that long-range ordering is observed with variable magnitude for the spin carriers. Moreover, compounds 3_Co and 4_Ni show no frequency-dependent alternating current (ac) susceptibility curves under zero dc field; this is characteristic behaviour of a glassy state that may be partially supressed for 3_Co by applying an external dc field. To overcome long-range magnetic ordering, Co^II ions are diluted in a diamagnetic Zn^II -based matrix, which enables single-molecule magnet behaviour. Interestingly, this strategy allows a bifunctional Co_x Zn_1-x 2ani material, which is imbued with a strong photoluminescent emitting capacity, as characterised by an intense blue light followed by a green afterglow, to be obtained.

Enantiospecific Response in Cross-Polarization Solid-State Nuclear Magnetic Resonance of Optically Active Metal Organic Frameworks

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.

Anti-diabetic and anti-parasitic properties of a family of luminescent zinc coordination compounds based on the 7-amino-5-methyl-1,2,4-triazolo[1,5-a]pyrimidine ligand

We report on the formation of a triazolopyrimidine derivative ligand, 7-amino-5-methyl-1,2,4-triazolo[1,5-a]pyrimidine (7-amtp), and a new family of coordination compounds based on this ligand and zinc as metal ion, synthesized by conventional routes. These materials possess different mononuclear structures, namely [ZnCl₂(7-amtp)₂] (1), [Zn(7-amtp)₂(H₂O)₄](NO₃)₂·2(7-amtp)·6H₂O (2) and [Zn(7-amtp)₂(H₂O)₄](SO₄)·1.5H₂O (3) derived from the use of different zinc (II) salts, in such a way that the counterions govern the crystallization to a large extent. These compounds present and show variable luminescent properties based on ligand-centred charge transfers which have been deeply studied by Time Dependent Density Functional Theory (TD-DFT) calculations. When these compounds are transferred to solution, preserving complex entities as corroborated by NMR studies, they present interesting anti-diabetic and anti-parasitic capabilities, with a comparatively higher selectivity index than other previously reported triazolopyrimidine-based materials. The results derived from in vivo experiments conducted in mice also confirm their promising activity as anti-diabetic drug being capable of dropping glucose levels after oral administration. Therefore, these new materials may be considered as excellent candidates to be further investigated in the field of luminescent coordination compounds with biomedical applications.

Rational design of an unusual 2D-MOF based on Cu(i) and 4-hydroxypyrimidine-5-carbonitrile as linker with conductive capabilities: a theoretical approach based on high-pressure XRD

Herein, we present, for the first time, a 2D-MOF based on copper and 4-hydroxypyrimidine-5-carbonitrile as the linker. Each MOF layer is perfectly flat and neutral, as is the case for graphene. High pressure X-ray diffraction measurements reveal that this layered structure can be modulated between 3.01 to 2.78 Å interlayer separation, with an evident piezochromism and varying conductive properties. An analysis of the band structure indicates that this material is conductive along different directions depending on the application of pressure or H doping. These results pave the way for the development of novel layered materials with tunable and efficient properties for pressure-based sensors.

Integrating HIV pre-exposure prophylaxis and harm reduction among men who have sex with men and transgender women to address intersecting harms associated with stimulant use: a modelling study

INTRODUCTION

Among men who have sex with men (MSM) and transgender women (TW), stimulant use is high and has been associated with an increased risk of HIV infection, suicide and cardiovascular disease (CVD) mortality. We used epidemic modelling to investigate these intersecting health harms among MSM/TW in Lima, Peru and assess whether they could be mitigated by prioritizing HIV pre-exposure prophylaxis (PrEP) and harm reduction interventions among MSM/TW who use stimulants.

METHODS

We adapted a dynamic model of HIV transmission among MSM/TW in Lima to incorporate stimulant use and increased HIV risk, suicide and CVD mortality. Among 6% to 24% of MSM/TW using stimulants (mostly cocaine), we modelled an increased risk of unprotected anal sex (RR = 1.35 [95%CI: 1.17 to 1.57]) obtained from local data, and increased risk of suicide (SMR = 6.26 [95%CI: 2.84 to 13.80]) and CVD (SMR = 1.83 [95%CI: 0.39 to 8.57]) mortality associated with cocaine use based on a global systematic review. We estimated the proportion of health harms occurring among MSM/TW who use stimulants in the next year (01-2020/01-2021). We also investigated the 10-year impact (01-2020/01-2030) of: (1) PrEP prioritization for stimulant-using MSM/TW compared to random allocation, and (2) integrating PrEP with a theoretical intervention halving stimulant-associated risk.

RESULTS

MSM/TW in Lima will experience high HIV incidence, suicide mortality and CVD mortality (1.6/100 py, and 0.018/100 py, 0.13/100 py respectively) in 2020. Despite stimulant using MSM/TW comprising an estimated 9.5% (95%CI: 7.8 to 11.5) of all MSM/TW, in the next year, 11% 95%CI (i.e. 2.5% to 97.5% percentile) 10% to 13%) of new HIV infections, 39% (95%CI: 18% to 60%) of suicides and 15% (95%CI: 3% to 44%) of CVD deaths could occur among this group. Scaling up PrEP among all stimulant using MSM/TW could prevent 19% (95%CI: 11% to 31%) more HIV infections over 10 years compared to random allocation. Integrating PrEP and an intervention to halve stimulant-associated risks could reduce new HIV infections by 20% (95%CI: 10% to 37%), suicide deaths by 14% (95%CI: 5% to 27%) and CVD deaths by 3% (95%CI: 0% to 16%) over a decade.

CONCLUSIONS

MSM/TW who use stimulants experience a disproportionate burden of health harms. Prioritizing PrEP based on stimulant use, in addition to sexual behaviour/gender identity criteria, could increase its impact. Integrated substance use, harm reduction, mental health and HIV care among MSM/TW is needed.

5-Aminopyridine-2-carboxylic acid as appropriate ligand for constructing coordination polymers with luminescence, slow magnetic relaxation and anti-cancer properties

Five new coordination polymers (CPs) constructed of aminopyridine-2-carboxylate (ampy) ligand have been synthesized and fully characterized. Three of them correspond to metal-organic chains built from the coordination of ampy to sodium and lanthanides with formulae [MNa(ampy)₄]_n (M = terbium (2), erbium (1) and ytterbium (3)) resembling a previously reported dysprosium material which shows anticancer activity. On another level, the reaction of Hampy with cobalt and copper ions ({[CoK(ampy)₃(H₂O)₃](H₂O)₃}_n (4) and [Cu(ampy)₂]_n (5)) lead to CPs with variable dimensionalities, which gives the opportunity of analyzing the structural properties of this new family. Lanthanide materials display solid state intense photoluminescent emissions in both the visible and near-infrared region and exhibit slow relaxation of magnetization with frequency dependence of the out-of-phase susceptibility. More interestingly, in our search for multifunctional materials, we have carried out antitumor measurements of these compounds. These multidisciplinary studies of metal complexes open up the possibility for further exploring the applications in the fields of metal-based drugs.

Designing Single-Molecule Magnets as Drugs with Dual Anti-Inflammatory and Anti-Diabetic Effects

We have designed and synthesized two novel cobalt coordination compounds using bumetanide (bum) and indomethacin (ind) therapeutic agents. The anti-inflammatory effects of cobalt metal complexes with ind and bum were assayed in lipopolysaccharide stimulated RAW 264.7 macrophages by inhibition of nitric oxide production. Firstly, we determined the cytotoxicity and the anti-inflammatory potential of the cobalt compounds and ind and bum ligands in RAW 264.7 cells. Indomethacin-based metal complex was able to inhibit the NO production up to 35% in a concentration-dependent manner without showing cytotoxicity, showing around 6–37 times more effective than indomethacin. Cell cycle analysis showed that the inhibition of NO production was accompanied by a reversion of the differentiation processes in LPS-stimulated RAW 264.7 cells, due to a decreased of cell percentage in G0/G1 phase, with the corresponding increase in the number of cells in S phase. These two materials have mononuclear structures and show slow relaxation of magnetization. Moreover, both compounds show anti-diabetic activity with low in vitro cell toxicities. The formation of metal complexes with bioactive ligands is a new and promising strategy to find new compounds with high and enhanced biochemical properties and promises to be a field of great interest.

Policing Practices and Risk of HIV Infection Among People Who Inject Drugs

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.

Drugs, discipline and death: Causes and predictors of mortality among people who inject drugs in Tijuana, 2011-2018

BACKGROUND

People who inject drugs (PWID) experience multiple risk factors for mortality; yet, we know little about causes of death among PWID in Tijuana, Mexico, an area with high levels of injecting and changes in policy/law enforcement responses to substance use. This study examines rates, causes, and predictors of mortality among Tijuana PWID.

METHODS

Data come from a community-based cohort of PWID aged ≥18 who injected drugs in the past month. Mortality was confirmed by death certificate over 78 months during 2011-2018. Predictors of mortality were identified using time-updated Cox regression, controlling for age.

RESULTS

Among 734 participants, there were 130 deaths (54 confirmed, 76 unconfirmed), with an incidence rate of 17.74 deaths per 1000 person-years for confirmed deaths (95% Confidence Interval (CI)=13.01, 22.48) and 39.52 for unconfirmed deaths (CI=32.72, 46.31). Confirmed deaths resulted from homicide/trauma (26%), overdose (26%), septic shock (18%) and HIV-related causes (9%). In multivariable analysis of confirmed deaths, baseline HIV seropositivity (adjusted Hazard Ratio [aHR]=6.77, CI=1.98, 23.17), incident HIV infection (aHR=3.19, CI=1.02, 9.96), and number of times being beaten by police in the past 6 months at baseline (aHR=1.08 per time, CI=1.04, 1.12) were predictive of death; whereas, injection cessation for 6+ months during time at risk (aHR=0.25, CI=0.33, 0.79) was protective.

CONCLUSION

In addition to overdose and HIV prevention efforts, attention to structural conditions that potentiate mortality is needed, including improved access to medication-assisted treatment to support injection cessation and a shift from police as a source of harm to harm reduction.

2D-Coordination polymers based on 1H-indazole-4-carboxylic acid and transition metal ions: magnetic, luminescence and biological properties

Five novel multifunctional coordination polymers (CPs) based on 1H-indazole-4-carboxylic acid are reported. These complexes, the first examples of CPs with this novel ligand, show interesting magnetic, luminescence and biological properties.