The lived experiences of frontline nurses during the coronavirus disease 2019 (COVID-19) pandemic in Qatar: A qualitative study

This study aims to explore the lived experiences of frontline nurses providing nursing care for COVID-19 patients in Qatar. Qualitative, Phenomenological. Nurses were recruited from a designated COVID-19 facility using purposive and snowball sampling. The participants were interviewed face-to-face using semi-structured interview questions from 6 September-10 October 2020. The interviews were transcribed and analyzed using Colaizzi's phenomenological method. A total of 30 nurses were interviewed; (76.7%) were deployed for >6 months. Three major themes were drawn from the analysis: (a) Challenges of working in a COVID-19 facility (subthemes: working in a new context and new working environment, worn out by the workload, the struggle of wearing protective gear, fear of COVID-19, witnessing suffering); (b) Surviving COVID-19 (subthemes: keeping it safe with extra measures, change in eating habits, teamwork and camaraderie, social support); and (c) Resilience of Nurses (subthemes: a true calling, a sense of purpose).This study was funded by the Medical Research Center at Hamad Medical Corporation (MRC-01-20-423

Evaluation of Wuchereria bancrofti GST as a Vaccine Candidate for Lymphatic Filariasis

Lymphatic parasites survive for years in a complex immune environment by adopting various strategies of immune modulation, which includes counteracting the oxidative free radical damage caused by the host. We now know that the filarial parasites secrete antioxidant enzymes. Among these, the glutathione-S-transferases (GSTs) have the potent ability to effectively neutralize cytotoxic products arising from reactive oxygen species (ROS) that attack cell membranes. Thus, GSTs have the potential to protect the parasite against host oxidative stress. GSTs of several helminthes, including schistosomes, fasciola and the filarial parasite Seteria cervi, are also involved in inducing protective immunity in the host. The schistosome 28 kDa GST has been successfully developed into a vaccine and is currently in Phase II clinical trials. Thus, GST appears to be a potential target for vaccine development. Therefore, in the present study, we cloned W. bancrofti GST, and expressed and purified the recombinant protein. Immunization and challenge experiments showed that 61% of protection could be achieved against B. malayi infections in a jird model. In vitro studies confirm that the anti-WbGST antibodies participate in the killing of B. malayi L3 through an ADCC mechanism and enzymatic activity of WbGST appears to be critical for this larvicidal function

Attempts to Image the Early Inflammatory Response during Infection with the Lymphatic Filarial Nematode Brugia pahangi in a Mouse Model

Helminth parasites remain a major constraint upon human health and well-being in many parts of the world. Treatment of these infections relies upon a very small number of therapeutics, most of which were originally developed for use in animal health. A lack of high throughput screening systems, together with limitations of available animal models, has restricted the development of novel chemotherapeutics. This is particularly so for filarial nematodes, which are long-lived parasites with a complex cycle of development. In this paper, we describe attempts to visualise the immune response elicited by filarial parasites in infected mice using a non-invasive bioluminescence imaging reagent, luminol, our aim being to determine whether such a model could be developed to discriminate between live and dead worms for in vivo compound screening. We show that while imaging can detect the immune response elicited by early stages of infection with L3, it was unable to detect the presence of adult worms or, indeed, later stages of infection with L3, despite the presence of worms within the lymphatic system of infected animals. In the future, more specific reagents that detect secreted products of adult worms may be required for developing screens based upon live imaging of infected animals

Biochemical Characterization and Evaluation of a Brugia malayi Small Heat Shock Protein as a Vaccine against Lymphatic Filariasis

Filarial nematodes enjoy one of the longest life spans of any human pathogen due to effective immune evasion strategies developed by the parasite. Among the various immune evasion strategies exhibited by the parasite, Interleukin 10 (IL-10) productions and IL-10 mediated immune suppression has significant negative impact on the host immune system. Recently, we identified a small heat shock protein expressed by Brugia malayi (BmHsp12.6) that can bind to soluble human IL-10 receptor alpha (IL-10R) and activate IL-10 mediated effects in cell lines. In this study we show that the IL-10R binding region of BmHsp12.6 is localized to its N-terminal region. This region has significant sequence similarity to the receptor binding region of human IL-10. In vitro studies confirm that the N-terminal region of BmHsp12.6 (N-BmHsp12.6) has IL-10 like activity and the region containing the alpha crystalline domain and C-terminus of BmHsp12.6 (BmHsp12.6αc) has no IL-10 like activity. However, BmHsp12.6αc contains B cell, T cell and CTL epitopes. Members of the sHSP families are excellent vaccine candidates. Evaluation of sera samples from putatively immune endemic normal (EN) subjects showed IgG1 and IgG3 antibodies against BmHsp12.6αc and these antibodies were involved in the ADCC mediated protection. Subsequent vaccination trials with BmHsp12.6αc in a mouse model using a heterologous prime boost approach showed that 83% protection can be achieved against B. malayi L3 challenge. Results presented in this study thus show that the N-BmHsp12.6 subunit of BmHsp12.6 has immunoregulatory function, whereas, the BmHsp12.6αc subunit of BmHsp12.6 has significant vaccine potential

Palladium(II) chloride complexes of bis(pyrazolyl)cyclotriphosphazenes

Reactions of the bis(3,5-dimethylpyrazolyl)cyclotriphosphazene derivatives gem-N3P3(MeNCH(2)CH(2)O)(2)(dmp)(2) (1) and nongeminal cis-N3P3(OPh)(4)(dmp)(2) (2) with PdCl2 afford complexes of the type [PdCl2.(L)] (L = 1 or 2). In these complexes, the phosphazenes act as bidentate NN-donor ligands with the two pyrazolyl pyridinic nitrogen atoms bonded to the metal, thus forming a six- and an eight-membered chelate ring, respectively. The structures of 2 and [PdCl2.(2)] (4) have been confirmed by single-crystal X-ray diffraction. Crystal data for 2: a = 16.759(2) Angstrom, b = 10.788(3) Angstrom, c = 19.635(9) Angstrom, beta = 101.61(3)degrees, P2(1/c), Z = 4, R = 0.038 for 4688 reflections with F > 5 sigma(F). Crystal data for 4: a = 9.701(3) Angstrom, b = 24.853(4) Angstrom, c = 15.794(4) Angstrom, beta = 101.46(2)degrees, P2(1/n), Z = 4, R = 0.030 for 5416 reflections with F > 5 sigma(F)

Antibiotic Resistance: Mono- and Dinuclear Zinc Complexes as Metallo-β{\beta}-Lactamase Mimics

Biomimetic systems containing one or two zinc(II) ions supported by phenolate ligands were developed as functional mimics of metallo-beta-lactamase. These complexes were shown to catalytically hydrolyze beta-lactam substrates, such as oxacillin and penicillin G. The dinuclear zinc complex 1, which has a coordinated water molecule, exhibits high beta-lactamase activity, whereas the dinuclear zinc complex 2, which has no water molecules, but labile chloride ligands, shows a much lower activity. The high beta-lactamase activity of complex 1 can be ascribed to the presence of a zinc-bound water molecule that is activated by being hydrogen bonded to acetate substituents. The kinetics of the hydrolysis of oxacillin by complex I and the effect of pH on the reaction rates are reported in detail. In addition, the kinetic parameters obtained for the synthetic analogues are compared with those of the natural metallo-beta-lactamase from Bacillus cereus (Bell). To understand the role of the second metal ion in hydrolysis, the syntheses and catalytic activities of two mononuclear complexes (3 and 4) that include coordinated water molecules are described. Interestingly, the mononuclear zinc complexes 3 and 4 also exhibit high activity, supporting the assumption that the second zinc ion is not crucial for the beta-lactamase activity

EFFECTS OF THE CANADA-U.S. TRADE AGREEMENT ON U.S. AGRICULTURAL EXPORTS

This paper investigates the effects of the Canada-U.S. Trade Agreement (CUSTA) on U.S. exports of agricultural products. Econometric analysis found that CUSTA has had a large impact on many U.S. agricultural export categories. All of the consumer-oriented products (except wine and beer), five of the intermediate products, and four of the bulk products had significant CUSTA effects. It is clear that the CUSTA effects have been larger for consumer-oriented food products. There is also evidence that U.S. affiliate sales in Canada have stimulated U.S. exports of consumer-oriented products and intermediate products

Small molecule binding and activation on a cationic ruthenium center of a pincer complex

Ruthenium pincer complex RuHCl(PPh3)(PNP)] (PNP = Me-N(CH2CH2PPh2)(2)) (1) was synthesized by reaction of RuHCl(PPh3)(3) with Me-N(CH2CH2PPh2)(2) and characterized. Abstraction of chloride ligand in complex 1 using NaBA(4)(f) in the presence of small molecules such as N-2, H-2, O-2, and CO resulted in the formation of trans-RuH(L)(PPh3)(PNP)]BAr4f {L = N-2 (2), H-2 (4), O-2 (5), CO (6)} complexes. Complexes 2, 4, 5, and 6 have been characterized by various techniques. The reaction of RuHCl(PPh3)(PNP)] complex with NaBH4 gave a borohydrido complex RuH(eta(1)-BH4)(PPh3)(PNP)] (7) which upon reaction with NEt3 generates a mixture of cis and trans dihydrides RuH2(PPh3)(PNP)] (8). The reaction of dihydride complexes with CO2 leads to the formation of formate complex RuH(eta(1)-HCO2)(PPh3)(PNP)] (9). In addition, dihydrogen complexes Ru(eta(2)-H-2)(L)(PPh3)(PNP)](n+) (L = Cl (10), CO (11)) having different trans donor ligands were synthesized by protonation of trans-RuH(L)(PPh3)(PNP)](n+) {n = 0, L = CI; n = 1, L = CO} complexes with HOTf at low temperature. Complexes I and 6 have been characterized by X-ray crystallography. (C) 2016 Elsevier B.V. All rights reserved

Contrasting reactivity behaviour of the [RuHCl(CO)(PNP)] complex with electrophilic reagents XOTf (X = H, CH₃, Me₃Si)

A new ruthenium pincer complex [RuHCl(CO)(PNP)] (PNP = PhCH₂N(CH₂CH₂PPh₂)₂) (1) was synthesized and characterized. The reactivity of complex 1 with electrophilic reagents XOTf (X = H, CH₃, and Me₃Si; OTf = CF₃SO₃) was studied by variable temperature NMR spectroscopy with an aim to observe and characterize sigma complexes of type [Ru(η²-HX)Cl(CO)(PNP)][OTf] (X = H (2), CH₃ (3), Me₃Si (4)). Reaction of complex 1 with HOTf resulted in the formation of the dihydrogen complex, [Ru(η²-H₂)Cl(CO)(PNP)[OTf] (2). On the other hand, the reaction between complex 1 and MeOTf and Me₃SiOTf resulted in the direct elimination of MeCl and Me₃SiCl via a S_N2 type of reaction without the intermediacy of the respective sigma complexes 3 and 4. This contrasting reactivity behaviour has been rationalized taking into consideration the approach of the relatively bulky electrophiles CH₃⁺ and Me₃Si⁺ onto the hydride moiety of the ruthenium fragment, which is sterically hindered