In Conakry, Guinea, like many other African capitals, traffic congestion is a major obstacle to transporting blood samples from peripheral health centres to laboratories where tests are centralised. This situation complicates early HIV testing of HIV-exposed children (i.e.
View Article and Find Full Text PDFSecond harmonic generation (SHG) is a nonlinear optical phenomenon where two photons at the frequency ω combine to form a single photon at the second-harmonic frequency 2ω. Since that second-order process is very weak in bulk isotropic media, optical SHG responses of interfaces provide a powerful and versatile technique to probe the molecular structure and dynamics of liquid interfaces. Both local dipole contributions and non-local quadrupole contributions can be interesting to investigate different properties of the interface, such as the molecular orientation or the charge density.
View Article and Find Full Text PDFDuring the COVID-19 pandemic, the need for making testing readily available was recognized as an important factor for individuals to help make informed decisions, including to isolate or seek care, and for policymakers to control transmission. Toward this end, FIND and the Access to COVID-19 Tools Accelerator funded 16 rapid operational research studies and one implementation project in Africa, the Caribbean, and Asia evaluating the utility, acceptability, and feasibility of different community-based SARS-CoV-2 testing approaches. Here, we discuss common factors and challenges encountered during study implementation.
View Article and Find Full Text PDFSeveral empirical and theoretical studies suggest the presence of multiple enhancers per gene that collectively regulate gene expression, and that common sequence variation impacting on the activities of these enhancers is a major source of inter-individual gene expression variability. However, for the vast majority of genes, enhancers and the underlying regulatory variation remains unknown. Even for the genes with well-characterized enhancers, the nature of the combined effects from multiple enhancers and their variants, when known, on gene expression regulation remains unexplored.
View Article and Find Full Text PDFWe have previously demonstrated that an appropriately substituted four-membered-ring 1,2-diazacyclobutene is a useful compound in organic synthesis for the introduction of strained 1,2-diazetidine rings. In order to further explore the reactivity of this interesting heterocycle, we sought a method to improve upon the poor synthetic yield reported earlier. A novel route involving the synthesis of a similarly substituted 1,2-diazetidine compound followed by free-radical bromination and base-catalyzed debromination appeared promising.
View Article and Find Full Text PDFSub-equatorial Africa is today inhabited predominantly by Bantu-speaking groups of Western African descent who brought agriculture to the Luangwa valley in eastern Zambia ~2000 years ago. Before their arrival the area was inhabited by hunter-gatherers, who in many cases were subsequently replaced, displaced or assimilated. In Zambia, we know little about the genetic affinities of these hunter-gatherers.
View Article and Find Full Text PDFTo explore the influence of genetics on homeostatic regulation of dendritic cell (DC) numbers, we present a screen of DCs and their progenitors in lymphoid and non-lymphoid tissues in Collaborative Cross (CC) and Diversity Outbred (DO) mice. We report 30 and 71 loci with logarithm of the odds (LOD) scores >8.18 and ranging from 6.
View Article and Find Full Text PDFQuantum mechanical/molecular mechanics (QM/MM) methods are interesting to model the impact of a complex environment on the spectroscopic properties of a molecule. In this context, a FROm molecular dynamics to second harmonic Generation (FROG) code is a tool to exploit molecular dynamics trajectories to perform QM/MM calculations of molecular optical properties. FROG stands for "FROm molecular dynamics to second harmonic Generation" since it was developed for the calculations of hyperpolarizabilities.
View Article and Find Full Text PDFDe novo evolved genes emerge from random parts of noncoding sequences and have, therefore, no homologs from which a function could be inferred. While expression analysis and knockout experiments can provide insights into the function, they do not directly test whether the gene is beneficial for its carrier. Here, we have used a seminatural environment experiment to test the fitness of the previously identified de novo evolved mouse gene Pldi, which has been implicated to have a role in sperm differentiation.
View Article and Find Full Text PDFDocosahexaenoic acid (DHA) is an essential fatty acid (FA) with proven pro-health effects, but improving its bioavailability is becoming a public health issue. The bioavailability of DHA from microalgal (A) oil has been comprehensively assessed, particularly in terms of the molecular structuring capabilities offered by A-oil. Here, we explored the impact of five DHA-rich formulas differing in terms of (i) molecular structure, i.
View Article and Find Full Text PDFSeveral empirical and theoretical studies suggest presence of multiple enhancers per gene that collectively regulate gene expression, and that common sequence variation impacting on the activities of these enhancers is a major source of inter-individual variability in gene expression. However, for vast majority of genes, enhancers and the underlying regulatory variation remains unknown. Even for the genes with well-characterized enhancers, the nature of the combined effects from multiple enhancers and their variants, when known, on gene expression regulation remains unexplored.
View Article and Find Full Text PDFBackground: Early infant diagnosis (EID) for HIV-exposed infants is essential due to high mortality during the first months of their lives. In Conakry (Guinea), timely EID is difficult as traffic congestion prevents the rapid transport of blood samples to the central laboratory. We investigated the cost-effectiveness of transporting EID blood samples by unmanned aerial vehicles (UAV), also known as drones.
View Article and Find Full Text PDFLong-acting injectable antiretroviral therapy (LAI-ART) can offer people living with HIV (PLWH) a promising alternative to daily oral therapy. This article highlights the issues, challenges and conditions related to introducing LAI-ART into the social lives of PLWH and HIV-care practices in Senegal. Semi-structured interviews were conducted with 42 PLWH in two hospital care units in Dakar and with 13 healthcare providers and 6 peer educators.
View Article and Find Full Text PDFDynamic covalent chemistry (DCvC) is a powerful means by which to rapidly prepare complex structures from simple molecular building blocks. Effective DCvC behavior is contingent upon the reversibility of covalent bond formation. Stabilized radical species, therefore, have been effectively used for these applications.
View Article and Find Full Text PDFSecond harmonic scattering (SHS) is a method of choice to investigate the molecular structure of liquids. While a clear interpretation of SHS intensity exists for diluted solutions of dyes, the scattering due to solvents remains difficult to interpret quantitatively. Here, we report a quantum mechanics/molecular mechanics (QM/MM) approach to model the polarization-resolved SHS intensity of liquid water, quantifying different contributions to the signal.
View Article and Find Full Text PDFPurpose: To examine the associations between dietary intake as assessed by a rapid, image-based digital tool and biomarkers of cardiometabolic health.
Design: Retrospective analysis of adults with blood biomarkers performed by Boston Heart Diagnostics (BHD) between December 2020 and March 2022.
Setting: Outpatient centers serviced by BHD.
The role mammalian glutaredoxin 3 (Grx3) plays in iron homeostasis is poorly understood. Here we report the generation and characterization of a Grx3 liver-specific knockout (LKO) mouse strain. Grx3 LKO and WT mice had similar growth however, the LKO mice had elevated iron concentration and ROS production leading to impaired liver function and altered cytosolic and nuclear Fe-S cluster assembly.
View Article and Find Full Text PDFPhys Rev Lett
September 2022
Antiretroviral therapy controls, but does not cure, HIV-1 infection due to a reservoir of rare CD4 T cells harboring latent proviruses. Little is known about the transcriptional program of latent cells. Here, we report a strategy to enrich clones of latent cells carrying intact, replication-competent HIV-1 proviruses from blood based on their expression of unique T cell receptors.
View Article and Find Full Text PDFBackground: Nearly half of HIV-infected children worldwide are born in West and Central African countries where access to prevention of mother-to-child transmission of HIV (PMTCT) programmes is still limited. WHO recommends reinforced antiretroviral prophylaxis for infants at high risk of mother-to-child transmission of HIV (MTCT) but its implementation needs further investigation in the field.
Methods: The prospective ANRS 12344-DIAVINA study evaluated the feasibility of a strategy combining early infant diagnosis (EID) and reinforced antiretroviral prophylaxis in high-risk infants as identified by interviews with mothers at Ignace Deen Hospital, Conakry, Guinea.
The molecular first hyperpolarizability contributes to second-order optical non-linear signals collected from molecular liquids. For the Second Harmonic Generation (SHG) response, the first hyperpolarizability (2, , ) often depends on the molecular electrostatic environment. This is especially true for water, due to its large second hyperpolarizability (2, , ,0).
View Article and Find Full Text PDFHIV-1 infection remains a public health problem with no cure. Anti-retroviral therapy (ART) is effective but requires lifelong drug administration owing to a stable reservoir of latent proviruses integrated into the genome of CD4 T cells. Immunotherapy with anti-HIV-1 antibodies has the potential to suppress infection and increase the rate of clearance of infected cells.
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