21 research outputs found
Isolation and Antibiotic Susceptibility Testing of Haemophilus influenzae from Nasopharynx of Children under Five Years Attending Maternal and Child Health Clinic in Mbarara Regional Referral Hospital
No full textBackground. H. influenzae remains an organism of a major public health challenge worldwide despite the availability of the Hib vaccine, particularly among children under 5 years. Information on the current carriage status and antibiotic susceptibility is key on proper health-care provision. Therefore, we conducted a study to determine H. influenzae carriage rate and antibiotic susceptibility testing of the isolates among the children. Methods. This was a cross-sectional study conducted between January and May 2018, among clinically healthy children under five years attending Maternal and Child Health (MCH) Clinic in Mbarara Regional Referral Hospital (MRRH). We carried out standard microbiology methods to culture, isolate, and identify H. influenzae, and then, we tested for their susceptibility to commonly used antibiotics following the CLSI standards. Results. Of the 248 participants included in the study, 116 (46.77%) were females and 132 (53.23%) males and 78 (31.45%) were below the age of 3 months. Fifty one of the study participants had H. influenzae in their nasopharynx, which represents 20.56% carriage (95% CI 15.49 to 25.63). There was a general high susceptibility of the isolates to the antimicrobial agents commonly used. There was 100% susceptibility to ciprofloxacin and imipenem antibiotic agents, though 6 (11.76%) and 4 (7.84%) of the isolates showed resistance to chloramphenicol and ampicillin, respectively. Conclusion. The high burden presented by H. influenzae and the resultant impact on child health require much attention to prevention of infections associated with the organism. A well-funded molecular study focusing on typing the isolates would determine the impact of the vaccine, given the carriage rates are still high
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Evaluation of the SD BIOLINE HIV/syphilis Duo assay at a rural health center in Southwestern Uganda
No full textBackground: Point-of-care tests have the capacity to improve healthcare delivery by reducing costs and delay associated with care. A novel point-of-care immunochromatographic test for dual diagnosis of both HIV and syphilis by detecting IgG, IgM and IgA antibodies to HIV, and specific and recombinant Treponema pallidum antigens has recently been developed, but has not been evaluated in rural field settings. We evaluated the performance of the SD Bioline Syphilis/HIV Duo (Duo) assay at a healthcare center in rural Uganda. Methods: A convenience sample of pregnant women attending Kinoni Health Centre IV from March to May, 2013 was enrolled. Venous blood was collected and centrifuged for plasma isolation. Samples were tested with the Duo assay and compared with the Treponema pallidum hemaglutination assay and paired HIV rapid antibody tests as the reference standards. The ease of use and time required for the Duo assay were also assessed by laboratory technicians. Results: Two hundred twenty women were enrolled with a mean age of 25.00 years (SD 5.41). The sensitivity and specificity of the Duo assay were 100% (95% CI 79.0 – 100%) and 100% (95% CI 97.6 – 100.0) respectively, for syphilis, and, 100% (75.9 – 100%) and 99.5% (96.8 – 99.9%) respectively, for HIV. The duo kit was found to be faster and easier to use than the current HIV and syphilis testing techniques. Conclusion: The sensitivity and specificity of the SD Bioline HIV/Syphilis Duo test were excellent in a field setting in Uganda. The Duo assay should be further evaluated in alternate populations and with point-of-care specimens (e.g. whole blood from finger stick specimens), but shows promise as a tool for improved HIV and syphilis surveillance, diagnosis, and treatment in field settings.Version of Recor
Positional isomeric triphenylphosphine appended tetrahedral Cu(I) 2-/3-/4-methylpyridyldithiocarbonates as heterogeneous molecular electrocatalysts for OER and HER
No full textThree Cu(I) complexes with positional isomeric methylpyridyldithiocarbonates as main ligands and two triphenylphosphine as co-ligands with compositions [Cu{(P(C6H5)3}2(2-Py-CH2OCS2)] (2PyCu), [Cu{(P(C6H5)3}2(3-Py-CH2OCS2)] (3PyCu) and [Cu{(P(C6H5)3}2(4-Py-CH2OCS2)] (4PyCu) (Py = Pyridyl) are reported herein. The single crystal X-ray diffraction investigations for all three complexes suggest a distorted tetrahedral geometry around Cu(I) that is satisfied by two S centers of methylpyridyldithiocarbonate ligand in bidentate chelating mode and two PPh3 phosphorus centers. All three complexes exhibits interesting supramolecular frameworks sustained by C∙∙∙H, O∙∙∙H, S∙∙∙H and N∙∙∙H non-covalent interactions. The nature of these interactions have been assessed with the aid of Hirshfeld surface analyses and energy framework calculations. These complexes have been employed as molecular heterogeneous electrocatalysts in the oxygen/hydrogen evolution reactions (O/HERs). The electrocatalytic results indicate that 2PyCu exhibits the best electrocatalytic performance with onset potential of 1.67 V, η10 of 705.5 mV and a Tafel slope of 220 mV·dec‑1 for OER. For HER also 2PyCu displays superior performance with an onset potential, η10, and a Tafel slope of -0.507 V, -658 mV and 168 mV·dec‑1, respectively. Overall, because of the presence of Cu(I)-center, the electrocatalytic HER performances of all three complexes have been observed to be superior than their corresponding electrocatalytic OER performances.</p
New 1,2-bis(diphenylphosphino)ethane-laden Co(iii) dithiolate anions:dithiolate-mediated tuning of electrocatalytic performance for non-aqueous hydrogen evolution reaction
No full textFour new heteroleptic 1,2-bis(diphenylphosphino)ethane (dppe) laden cobalt(III) dithiolates having compositions NEt4 [Co(cdc)2(dppe)] (Co-cdc), NEt4 [Co(ecda)2(dppe)] (Co-ecda), NEt4 [Co(NED)2(dppe)] (Co-NED) and NEt4 [Co(i-mnt)2(dppe)] (Co-i-mnt) (cdc = cyanodithioimidocarbonate; ecda = 1-ethoxycarbonyl-1-cyanoethylene-2,2-dithiolate; NED = 1-nitroethylene-2,2-dithiolate and i-mnt = 1,1-dicyanoethylene-2,2-dithiolate) have been synthesized and characterized. Single crystal X-ray analysis for Co-i-mnt reveals that the immediate geometry around the Co(III) metal is distorted octahedral, and is satisfied by four sulfur atoms of two i-mnt2− ligands and two phosphorus atoms of dppe. These complexes have been employed as homogeneous electrocatalysts for the hydrogen evolution reaction (HER) using trifluoroacetic acid (TFA) as a proton source. The electrocatalytic proton reduction activity results suggest that amongst all the four complex anions, Co-NED showcases the best HER electrocatalysis with the lowest overpotential of 1.04 V and highest turnover frequency of 493 s−1 following the trend Co-NED > Co-cdc > Co-i-mnt > Co-ecda. Additionally, controlled potential electrolysis (CPE) experiments for these complexes indicated that the amount of charge passed correlates directly to the amount of hydrogen evolved. Furthermore, rinse tests on the most active electrocatalyst, Co-NED, confirm its chemical stability during electrocatalysis, with no detectable conversion to cobalt chalcogenide species. Computational studies reveal that superior HER performance in Co-NED arises from the highest natural charge over cobalt-center charge and minimal steric bulk of dithiolate pendants, thereby highlighting the importance of electronic tuning via strategic ligand substitution in cobalt–dithiolate complexes
Tertiary phosphane-modified Ni(II) 1,3-Benzothiazol-2-ylacetonitriledithiolates:Tuning heterogeneous OER electrocatalysis through phosphane denticity, steric modulation, and chelate ring-size variation
No full textDeveloping robust and active transition metal-based electrocatalysts for the generation of oxygen is crucial for enhancing the performance of numerous energy conversion systems. In this study, syntheses and characterization of three new heteroleptic Ni(II) dithiolate complexes: [(Bzdt)Ni(PPh3)2] (NiBz1), [(Bzdt)Ni(dppe)] (NiBz2), and [(Bzdt)Ni(dppf)] (NiBz3), (where Bzdt2-, PPh3, dppe, and dppf represents 1,3-benzothiazol-2-ylacetonitriledithiolate, triphenylphosphine, 1,2-bis(diphenylphosphino)ethane, and 1,1ʹ-bis(diphenylphosphino)ferrocene, respectively) have been presented. These complexes have been characterized using several spectroscopic techniques, FESEM-EDX, and for NiBz2 using single crystal X-ray diffraction. Structural investigations reveal that Ni(II) center in NiBz2 is coordinated to two S atoms from dithiolate ligand and two P atoms from dppe ligand forming a distorted square planar geometry. Hirshfeld surface analysis indicates the presence of key non-covalent interactions, including C-H···S, C-H···C, C-H···Ni, and C-H···N, which support the stability of the supramolecular framework. Electrochemical investigations of these complexes as OER electrocatalysts in alkaline media reveal that all three show notable activity (j > 46.11 mA.cm-2 at 10 mV·s-1), with NiBz2 standing out due to its lowest overpotential (η = 354 mV at j = 10 mA.cm-2) and Tafel slope (53 mV.dec‑1). This performance places NiBz2 among the best heterogeneous Ni(II)-dithiolate based OER electrocatalysts so far reported. Its outstanding activity is attributed to a combination of favorable electronic properties, such as a reduced charge-transfer gap and charge transfer resistance, which facilitate efficient electron transfer during catalysis. Overall, this study showcases that phosphine-derived steric and electronic tuning enables charge-transfer gap engineering within Ni(II)-dithiolate frameworks, and establishes a clear correlation between ligand-dependent electronic structure and OER performance.</p
New heteroleptic tertiary phosphane-based Ni(ii) 3,4-dimethoxyphenylacetonitriledithiolates:bifunctional electrocatalysts for homogeneous HER and heterogeneous OER
No full textConstruction of highly efficient non-platinum complexes as catalysts for electrochemical water splitting is the need of time. Herein, three new Ni(II)-based dithiolates, with formulas of [(dpdt)Ni(dppe)] (Ni-dpe), [(dpdt)Ni(dppf)] (Ni-dpf) and [(dpdt)Ni(PPh3)2] (Ni-pph) (dpdt = 3,4-dimethoxyphenylacetonitriledithiolate, dppe = 1,2-bis(diphenylphosphino)ethane, dppf = 1,1′-bis(diphenylphosphino)ferrocene and PPh3 = triphenylphosphane), were synthesized and characterized. Single-crystal X-ray diffraction analysis of Ni-dpe revealed a distorted square planar coordination environment around nickel(II) fulfilled by two S and two P of the dpdt2− and dppe ligands, respectively. Various non-covalent interactions, such as C–H⋯C, C–H⋯S and C–H⋯O, stabilized the lattice of Ni-dpe, and their nature was investigated using Hirshfeld surface analysis. Furthermore, the activities of these complexes as homogeneous electrocatalysts for HERs using trifluoroacetic acid (TFA) as a proton source and heterogeneous electrocatalysts for OERs in an aqueous KOH solution were evaluated. For homogeneous electrocatalysis, turnover frequencies (TOFs) of 402, 655 and 1761 s−1 for Ni-dpe, Ni-dpf and Ni-pph were observed, respectively, at 100 mM TFA. The better electrocatalytic activity of Ni-pph was ascribed to the spatial flexibility of the PPh3 ligands, which facilitated attainment of a more stable transition state than those of other complexes. For heterogeneous OERs, the results suggested that Ni-dpf displayed the lowest Tafel slope of 64 mV dec−1 and the highest current density of 53.47 mA cm−2, thereby exhibiting the best electrocatalytic activity
Supramolecular and homogeneous electrocatalytic HER properties of new heteroleptic cyanoacetamide dithiolate-based Ni(ii) tertiary phosphanes:effect of co-ligand flexibility on electrocatalytic performance†
No full textThree new tertiary phosphane-appended heteroleptic Ni(II)-dithiolates with the formula [Ni(CAM)(dppe)] (Ni-1), [Ni(CAM)(dppf)] (Ni-2) and [Ni(CAM)(PPh3)2] (Ni-3) (CAM = cyanoacetamide dithiolate; dppe = 1,2-bis-(diphenylphosphinoethane); dppf = 1,1′-bis-(diphenylphosphino)ferrocene and PPh3 = triphenylphosphane) have been synthesized and characterized spectroscopically and using single crystal X-ray diffraction technique. The single crystal X-ray analysis of Ni-1, Ni-2 and Ni-3 reveal distorted square planar geometry around Ni(II), wherein Ni(II) is coordinated to the two sulfur centres of a CAM ligand in the bidentate chelating mode and two phosphorus centers of dppe, dppf and PPh3 ligands. Solid-state frameworks in these complexes are stabilized by C–O⋯H, C–N⋯H, C–S⋯H and C–H⋯C non-covalent intermolecular interactions. Ni-2 exhibits intramolecular (Ar)C–H⋯Ni anagostic interaction, which is absent in Ni-1 and Ni-3. Ni-3 exhibits intramolecular π⋯π stacking between the phenyl rings. The nature of these interactions have been assessed using Hirshfeld surface analyses, density functional theory (DFT) and quantum theory of atoms-in-molecules (QTAIM) calculations. Furthermore, the complexes have been employed as a homogeneous electrocatalyst for electrochemical hydrogen evolution reactions (HERs) using trifluoroacetic acid (TFA) as the hydrogen source. Electrochemical studies reveal turnover frequency (TOF) values of 319, 341 and 543 s−1 for Ni-1, Ni-2 and Ni-3, respectively, at 50 mM concentration of TFA. The plausible reason for the relatively better electrocatalytic activity of Ni-3 is ascribed to the coordination flexibility of the PPh3 ligand and the relatively larger positive natural charge over the nickel center and smaller HOMO–LUMO energy gap
Homoleptic nickel(II)-dithiocarbamates as potent homogeneous electrocatalysts for hydrogen evolution reaction:Effect of positional isomeric –OH group on electrocatalytic properties
No full textThree positional isomeric homoleptic Ni(II) dithiocarbamate complexes having general formula [Ni(L)2] (L=N-benzyl-1-(2-hydroxyphenyl) dithiocarbamate (Ni-1); N-benzyl-1-(3-hydroxyphenyl) dithiocarbamate (Ni-2) and N-benzyl-1-(4-hydroxyphenyl) dithiocarbamate (Ni-3)) have been synthesized and characterized by elemental analysis, FT-IR, UV–Vis., multinuclear NMR spectroscopy and single crystal X-ray diffraction. The single crystal X-ray analysis for Ni-2 reveals distorted square planar geometry around Ni(II), that is satisfied by four sulfur centers of two N-benzyl-1-(3-hydroxyphenyl) dithiocarbamate ligands. The nature of weak interactions in Ni-2 have been explored using Hirshfeld surface analysis, which suggest that the percentage contribution of O···H interactions is more than S···H interactions. These complexes have been employed as homogeneous catalysts for electrochemical hydrogen evolution reaction suggesting turnover frequency (TOF) of 566.2, 457.2 and 867.9 s−1 for Ni-1, Ni-2 and Ni-3, respectively on adding 30 mM trifluoroacetic acid (TFA). Also, the overpotential (η) values for Ni-1, Ni-2 and Ni-3 are 0.862, 0.872 and 0.723 V, respectively. The variation in the electrocatalytic properties was explained on the basis of theoretical calculations which suggested that the para-OH isomer complex possess relatively larger HOMO-LUMO energy gap, compared to ortho-OH and meta-OH isomeric complexes and indicated the relative less stable nature of para-OH isomer complex and its better susceptibility towards electrons at a lower negative potential.</p
Probing the effect of isomeric -OH group in heteroleptic Copper(I)-triphenylphosphine appended dithiocarbamates on their electrocatalytic properties for homogeneous hydrogen evolution reactions
No full textDue to increasing interest in alternative cost-effective electrocatalysts containing transition metals, three new heteroleptic triphenylphenylphosphine appended copper(I) dithiocarbamate complexes [Cu(S2CN(CH2C6H5)(CH2C6H4-o-OH))(PPh3)2] (Cu-o-OH), [Cu(S2CN(CH2C6H5)(CH2C6H4-m-OH))(PPh3)2] (Cu-m-OH) and [Cu(S2CN(CH2C6H5)(CH2C6H4-p-OH))(PPh3)2] (Cu-p-OH), have been synthesized, characterized spectroscopically and by single crystal X-ray diffraction. The single crystal X-ray studies suggest that for Cu-o-OH and Cu-m-OH, copper(I) possess a distorted P2S2 coordinate tetrahedral geometry. The solid-state framework of Cu-o-OH has been found to be majorly stabilized by O-H···S intermolecular interactions, while that of Cu-m-OH is sustained by C-H···C and O-H···S interactions, whose nature has been assessed by Hirshfeld surface analysis. The homogeneous electrocatalytic properties of the complexes for proton reduction reveal that the icat/iPc values of complexes are greater than 28, while utilizing trifluoroacetic acid (TFA) as a proton source. In all complexes, the ratio ic/iwc have been found to be greater than 1, indicating that these complexes can effectively catalyze proton reduction to hydrogen in acetonitrile. Amongst all the three complexes, Cu-p-OH has been found to be the best electrocatalyst with low overpotential (η) of 0.876 V and a highest turnover frequency (TOF) of 539.60 s−1 on adding 70 mM TFA. The best catalytic activity of Cu-p-OH has been attributed to its larger HOMO-LUMO energy gap and a more positive charge on copper(I) compared to other isomeric complexes that assists the complex to attract more electron density that could have readily enhanced its electrocatalytic performance.</p
Acceptability of pre-exposure prophylaxis and associated factors among HIV-negative young men in Kagwara fishing community-Serere district, Uganda: A cross-sectional study
No full textAbbreviations: AGYW, adolescent girls
and young women; AIDS, Acquired
Immunodeficiency Syndrome; AVERT, Aid
Virus Education and Research Trust; AYFRHS,
Adolescent and Youth Friendly Reproductive
Health Care Services; CDC, Centers for Disease
Control and Prevention; DHIS2, District Health
Information System Software version 2; HIV,
Human Immunodeficiency Virus; HMIS, Health
Management Information System; MSM, Men
who have sex with Men; MSMW, Men who have
Sex with Men and Women; NRTIs, Nucleotide
Reverse Transcriptase Inhibitors; PrEP, pre-
exposure prophylaxis; PWID, People Who Inject
Drugs; PWUD, People Who Use Drugs; STD,
Sexually Transmitted Disease (s); UN, United
Nations; UNAIDS, United Nations Joint Program
on HIV; UNFPA, United Nations Fund for
Population Activities; UNICEF, United Nations
International Children’s Emergency Fund; WHO,
World Health OrganizationBackground
Despite the potential efficacy of Pre-Exposure Prophylaxis (PrEP) in reducing HIV
risk, Oral PrEP acceptability remains strikingly varied by populations and locations.
We assessed PrEP acceptability and associated factors among at-risk HIV-negative
young men.
Methods
A cross-sectional analytical study design was used. Data were collected among
409 at-risk HIV-negative young men aged 15–24 years living in Kagwara fishing
community- Serere district, Uganda between August and October 2023. Quantitative
data were collected on socio-demographic characteristics, sexual risk behaviors
and concerns about PrEP. Data was analyzed using Stata version 15.0 statistical
software. Summary statistics were computed and presented as tables, frequencies
and proportions. Bivariate analysis was conducted using binary logistic regression to
identify independent factors associated with PrEP acceptability. All factors that had
p < 0.10 at the bivariate analysis and confounders were entered into the final logistic
regression model. All factors with p < 0.05 were considered significantly associated
with the primary outcome
Results
The average age of 409 respondents was 21.8 (Standard Deviation [SD]=1.9) years.
Majority, (97.8%, n = 393) had unprotected penetrative sex. PrEP acceptability was high as majority of the participants accepted to use PrEP based on the six constructs
of acceptability (93.6%, n = 383). Participants with perceived risk of getting HIV
infection had higher odds of PrEP acceptability, (adjusted odds ratio [aOR]=4.23,
95%CI = 1.05–17.04). Participants who knew their partner’s HIV status (aOR=0.25,
95%CI = 0.07–0.88), those who felt embarrassed to ask for PrEP from the facility
(aOR=0.12, 95%CI = 0.04–0.39), and those who had stigma associated with use of
PrEP (aOR=0.13, 95%CI = 0.04–0.41) had reduced odds of PrEP acceptability.
Conclusion
We found a high level of PrEP acceptability among young men at risk of HIV acqui
sition in Kagwara fishing community. Improving access to PrEP services among
high risk young men in the fishing communities may increase PrEP uptake in this
population and across similar settings. The Ministry of health needs to use multiple
approaches to provide PrEP such as peer-led models, drug distribution points, short
message reminders for refills, pharmacies and retail drug shops.he author(s) received no specific funding for this work
