Using visible light to activate antiviral and antimicrobial properties of TiO2 nanoparticles in paints and coatings: focus on new developments for frequent-touch surfaces in hospitals.

The COVID-19 pandemic refocused scientists the world over to produce technologies that will be able to prevent the spread of such diseases in the future. One area that deservedly receives much attention is the disinfection of health facilities like hospitals, public areas like bathrooms and train stations, and cleaning areas in the food industry. Microorganisms and viruses can attach to and survive on surfaces for a long time in most cases, increasing the risk for infection. One of the most attractive disinfection methods is paints and coatings containing nanoparticles that act as photocatalysts. Of these, titanium dioxide is appealing due to its low cost and photoreactivity. However, on its own, it can only be activated under high-energy UV light due to the high band gap and fast recombination of photogenerated species. The ideal material or coating should be activated under artificial light conditions to impact indoor areas, especially considering wall paints or frequent-touch areas like door handles and elevator buttons. By introducing dopants to TiO2 NPs, the bandgap can be lowered to a state of visible-light photocatalysis occurring. Naturally, many researchers are exploring this property now. This review article highlights the most recent advancements and research on visible-light activation of TiO2-doped NPs in coatings and paints. The progress in fighting air pollution and personal protective equipment is also briefly discussed. Graphical Abstract: Indoor visible-light photocatalytic activation of reactive oxygen species (ROS) over TiO2 nanoparticles in paint to kill bacteria and coat frequently touched surfaces in the medical and food industries.

Demographics and clinical characteristics of hospitalised patients under investigation for COVID-19 with an initial negative SARS-CoV-2 PCR test result.

BACKGROUND: The COVID-19 pandemic is placing abnormally high and ongoing demands on healthcare systems. Little is known about the full effect of the COVID-19 pandemic on diseases other than COVID-19 in the South African setting. OBJECTIVE: To describe a cohort of hospitalised patients under investigation for SARS-CoV-2 that initially tested negative. METHODS: Consecutive patients hospitalised at Khayelitsha Hospital from April to June 2020, whose initial polymerase chain reaction test for SARS-CoV-2 was negative were included. Patient demographics, clinical characteristics, ICD-10 (International Statistical Classification of Diseases and Related Health Problems 10th Revision) diagnosis, referral to tertiary level facilities and ICU, and all-cause in-hospital mortality were collected. The 90-day re-test rate was determined and comparisons were made using the χ2-test and the independent samples median test. RESULTS: Overall, 261 patients were included: median age 39.8 years, 55.6% female (n = 145). Frequent comorbidities included HIV (41.4%), hypertension (26.4%), and previous or current tuberculosis (24.1%). Nine (3.7%) patients were admitted to ICU and 38 (15.6%) patients died. Ninety-three patients (35.6%) were re-tested and 21 (22.6%) were positive for SARS-CoV-2. The top primary diagnoses related to respiratory diseases (n = 82, 33.6%), and infectious and parasitic diseases (n = 62, 25.4%). Thirty-five (14.3%) had a COVID-19 diagnostic code assigned (26 without microbiological confirmation) and 43 (16.5%) had tuberculosis. Older age (p = 0.001), chronic renal impairment (p = 0.03) and referral to higher level of care (all p < 0.001; ICU p = 0.03) were more frequent in those that died. CONCLUSION: Patients with tuberculosis and other diseases are still presenting to emergency centres with symptoms that may be attributable to SARS-CoV-2 and requiring admission. Extreme vigilance will be necessary to diagnosis and treat tuberculosis and other diseases as we emerge from the COVID-19 pandemic.

NMR data of a Grubbs 2nd generation catalyst p-cresolate derivative.

The data presented in this article is related to the research article entitled "Spectroscopic characterisation of Grubbs 2nd generation catalyst and its p-cresol derivatives" (Swart et al. 2021). The 1D and 2D NMR characterisation data of the p-cresol derivative of the Grubbs 2nd generation catalyst, where one of the chloride ligands is replaced by the p-cresolate to form a Ru-O coordination compound (3) is reported. The characterization data include information obtained from 1H, 13C, Heteronuclear Single Quantum Coherence (HSQC), Heteronuclear Multiple Bond Correlation (HMBC), Homonuclear Correlation Spectroscopy (COSY), Nuclear Overhauser Effect (NOE) and Distortionless Enhancement by Polarization Transfer (DEPT) NMR spectroscopy.

Palladium/graphene oxide nanocomposites with carbon nanotubes and/or magnetite for the reduction of nitrophenolic compounds.

Graphene oxide (GO) was synthesised via the oxidation of graphite and was characterised using ATR FTIR, PXRD, SEM, TEM and TGA. These techniques confirmed the presence of characteristic oxygen-containing functional groups and the resulting increase in interlayer spacing in the nanostructure. GO is used as the support to form nanocomposites composed of combinations of the following: iron oxide nanoparticles (Fe3O4), carbon nanotubes (CNT) and palladium nanoparticles (Pd). The four final nanocomposites formed are: Pd/GO, Pd/Fe3O4/GO, Pd/CNT/GO, and Pd/CNT/Fe3O4/GO. Key intermediates were analysed using ATR FTIR for the confirmation of the modification. Additionally, all composites and their precursors underwent electron microscopic analysis to visually assess composite morphologies and the size distribution of deposited nanoparticles. The Fe3O4 and Pd nanoparticles were indistinguishable from each other in their spherical shape and particle diameters, which were no bigger than 32 nm. From the TGA, incorporation of Fe3O4, CNT and finally Pd into the nanocomposites increased total thermal stability in terms of mass percentage lost over the temperature programme. GO showed significant decomposition, with all nanocomposites remaining relatively stable up to 120 °C. ICP OES results showed total Pd content by mass percentage for each final composite, varied from 7.9% to 9.1% mass Pd/collective mass. XPS confirmed the expected elemental compositions of composites according to their structures and the Pd0 : PdII ratios are obtained. The nanocomposites were tested for the catalytic reduction of nitrophenols. Pd/CNT/Fe3O4/GO gave the highest TOF' for the reduction of 4-NP and 2-NP. For the reduction of 3-NP, Pd/GO showed the highest TOF'. Nitrophenol's pK a and catalyst TOF' correlated in a direct proportional relationship for Pd/GO and Pd/Fe3O4/GO. It was found that Pd0 surpassed PdII in catalytic activity. Reduction of PdII to Pd0 took place during the first catalytic cycle.

Characterisation, electrochemical and oxidative addition data of organophosphorus-containing rhodium(I) complexes.

This data article contains the 1H Nuclear Magnetic Resonance (NMR), ultraviolet and visible (UV-vis) and Attenuated Total Reflectance Fourier Transformed Infra-red (ATR FTIR) characterization of a series of organophosphorus-containing rhodium(I) complexes. The electrochemical data acquired by means of cyclic voltammetry of the three organophosphorus-containing ligands (with the structure C6H5XPPh2, where X = O, S and NH) and their acetylacetonato (monocarbonyl) organophosphorus rhodium(I) compounds, [Rh(acac)CO(C6H5XPPh2)] are reported. Additionally, the kinetic data of the oxidative addition of methyl iodide to the rhodium(I) complexes, are also presented.

In vitro Evaluation of Porous borosilicate, borophosphate and phosphate Bioactive Glasses Scaffolds fabricated using Foaming Agent for Bone Regeneration.

In this work, glasses within the borosilicate borophosphate and phosphate family were sintered into 3D porous scaffolds using 60 and 70 vol. % NH4(HCO3) as a foaming agent. All scaffolds produced remained amorphous; apart from one third of the glasses which crystallized. All produced scaffolds had porosity >50% and interconnected pores in the range of 250-570 µm; as evidenced by µCT. The in-vitro dissolution of the scaffolds in SBF and changes in compression were assessed as a function of immersion time. The pH of the solution containing the borosilicate scaffolds increased due to the typical non-congruent dissolution of this glass family. Borophosphate and phosphate scaffolds induced a decrease in pH upon dissolution attributed to the congruent dissolution of those materials and the large release of phosphate within the media. As prepared, scaffolds showed compressive strength of 1.29 ± 0.21, 1.56 ± 0.63, 3.63 ± 0.69 MPa for the borosilicate, borophosphate and phosphate samples sintered with 60 vol. % NH4 (HCO3), respectively. Evidence of hydroxyapatite precipitation on the borosilicate glass scaffolds was shown by SEM/EDS, XRD and ICP-OES analysis. The borophosphate scaffolds remained stable upon dissolution. The phosphate scaffolds were fully crystallized, leading to very large release of phosphate in the media.

Effects of Sintering Temperature on Crystallization and Fabrication of Porous Bioactive Glass Scaffolds for Bone Regeneration.

In this work the sintering ability of borosilicate (S53B50), borophosphate (P40B10) and phosphate (Sr) bioactive glasses was investigated. The glass powders were crushed and sintered in air at a heating rate of 10 °C/min for 2 hours at sintering temperatures between 480 °C-600 °C. The aim was to define the optimum sintering temperature prior to glass crystallization. The density of the samples was found to decrease when the temperature was increased up to 580 °C; probably due to the inhibition of the viscous flow of the particles during sintering thereby reducing the densification of the material. Such low porosity is not suitable in tissue engineering. To process highly porous scaffolds with porosity required for scaffold applicable to tissue engineering, the powders were further mixed with 60 vol.% and 70 vol.% of NH4(HCO3) foaming agent. Meanwhile, the density of the samples sintered with NH4(HCO3) was found to decrease with an increase in NH4(HCO3) content. This indicates an increase in porosity of the samples. The glass compositions reached an open porosity of more than 60% at the addition of 70 vol.% NH4(HCO3). In addition, SEM micrograph revealed large pores with good interconnection between the pores.

Crystallization and sintering of borosilicate bioactive glasses for application in tissue engineering.

Typical silicate bioactive glasses are known to crystallize readily during the processing of porous scaffolds. While such crystallization does not fully suppress the bioactivity, the presence of significantly large amounts of crystals leads to a decrease in the rate of reaction of the glass and an uncontrolled release of ions. Furthermore, due to the non-congruent dissolution of silicate glasses, these materials have been shown to remain within the surgical site even 14 years post-operation. Therefore, bioactive materials that can dissolve more effectively and have higher conversion rates are required. Within this work, boron was introduced, in the FDA approved S53P4 glass, at the expense of SiO2. The crystallization and sintering-ability of the newly developed glasses were investigated by differential thermal analysis. All the glasses were found to crystallize primarily from the surface, and the crystal phase precipitation was dependent on the quantity of B2O3 incorporated. The rate of crystallization was found to be lower for the glasses when 25, 50 and 75% of SiO2 was replaced with B2O3. These glasses were further sintered into porous scaffolds using simple heat sintering. The impact of glass particle size and heat treatment temperature on the scaffold porosity and average pore size was investigated. Scaffolds with porosity ranging from 10 to 60% and compressive strength ranging from 1 to 35 MPa were produced. The scaffolds remained amorphous during processing and their ability to rapidly precipitate hydroxycarbonate apatite was maintained. This is of particular interest in the field of tissue engineering as scaffold degradation and reaction is generally faster and offers higher controllability as opposed to the current partially/fully crystallized scaffolds obtained from the FDA approved bioactive glasses.

Mapping the existing body of health policy implementation research in lower income settings: what is covered and what are the gaps?

This article uses 85 peer-reviewed articles published between 1994 and 2009 to characterize and synthesize aspects of the health policy analysis literature focusing on policy implementation in low- and middle-income countries (LMICs). It seeks to contribute, first, to strengthening the field of LMIC health policy analysis by highlighting gaps in the literature and generating ideas for a future research agenda and, second, to thinking about the value and applicability of qualitative synthesis approaches to the health policy analysis field. Overall, the article considers the disciplinary perspectives from which LMIC health policy implementation is studied and the extent to which the focus is on systems or programme issues. It then works with the more specific themes of the key thrusts of the reviewed articles, the implementation outcomes studied, implementation improvement recommendations made and the theories used in the reviewed articles. With respect to these more specific themes, the article includes explorations of patterns within the themes themselves, the contributions of specific disciplinary perspectives and differences between systems and programme articles. It concludes, among other things, that the literature remains small, fragmented, of limited depth and quite diverse, reflecting a wide spectrum of health system dimensions studied and many different suggestions for improving policy implementation. However, a range of issues beyond traditional 'hardware' health system concerns, such as funding and organizational structure, are understood to influence policy implementation, including many 'software' issues such as the understandings of policy actors and the need for better communication and actor relationships. Looking to the future, there is a need, given the fragmentation in the literature, to consolidate the existing body of work where possible and, given the often broad nature of the work and its limited depth, to draw more explicitly on theoretical frames and concepts to deepen work by sharpening and focusing concerns and questions.

Policy interventions that attract nurses to rural areas: a multicountry discrete choice experiment.

OBJECTIVE: To evaluate the relative effectiveness of different policies in attracting nurses to rural areas in Kenya, South Africa and Thailand using data from a discrete choice experiment (DCE). METHODS: A labelled DCE was designed to model the relative effectiveness of both financial and non-financial strategies designed to attract nurses to rural areas. Data were collected from over 300 graduating nursing students in each country. Mixed logit models were used for analysis and to predict the uptake of rural posts under different incentive combinations. FINDINGS: Nurses' preferences for different human resource policy interventions varied significantly between the three countries. In Kenya and South Africa, better educational opportunities or rural allowances would be most effective in increasing the uptake of rural posts, while in Thailand better health insurance coverage would have the greatest impact. CONCLUSION: DCEs can be designed to help policy-makers choose more effective interventions to address staff shortages in rural areas. Intervention packages tailored to local conditions are more likely to be effective than standardized global approaches.

Amino-acid depletion induced by abnormal amino-acid conjugation and protein restriction in isovaleric acidemia.

BACKGROUND: Previously, we detected 19 'new' amino-acid conjugates in the urine of patients with isovaleric acidemia. There is currently a poor understanding of the relationship between the clinical symptoms and the excreted metabolites occurring in these patients, owing to insufficient metabolite characterization and quantification. Consequently, controversial treatment protocols exist, particularly pertaining to dietary protein restriction. OBJECTIVE: To determine the effect of the previously identified amino-acid conjugates and conventional dietary protein restriction therapy, on the free amino-acid concentrations in isovaleric acidemia patients, to better explain the clinical symptoms and develop more effective therapy. DESIGN: Free amino-acid quantification via liquid chromatography mass spectrometry (LC-MS-MS) was performed on pre- and post-treatment urine or serum samples collected from six isovaleric acidemia patients, previously investigated for the presence of new induced N-isovaleryl and N-acetyl-amino-acid conjugates. RESULTS: Depleted amino-acid concentrations were detected in varying degrees in all six patients and did not recover after conventional treatment. CONCLUSIONS: The 19 potentially toxic metabolites previously identified and the consequent amino-acid depletions detected in this study, may explain many of the clinical symptoms associated with isovaleric acidemia. Furthermore, the occurrence of amino-acid depletions in these patients, steers away from the controversial dietary protein restriction treatment protocols, and towards dietary leucine restriction alone with essential amino-acid supplementation, in combination with glycine and L-carnitine supplementation.

Chemical analyses of Ukrain, a semi-synthetic Chelidonium majus alkaloid derivative, fail to confirm its trimeric structure.

Ukrain has been described as a semi-synthetic Chelidonium majus alkaloid derivative, consisting of three chelidonine alkaloids combined to triaziridide. We found the actions of Ukrain to be similar to the Chelidonium alkaloids it is prepared from, and therefore became concerned about its chemical integrity. Chemical analyses of Ukrain by thin layer chromatography, high-performance liquid chromatography and liquid chromatography-mass spectrometry was inconsistent with the proposed trimeric structure and demonstrated that at least some commercial preparations of Ukrain consist of a mixture of C. majus alkaloids (including chelidonine).

The utilization of alanine, glutamic acid, and serine as amino acid substrates for glycine N-acyltransferase.

The conjugation of benzoyl-CoA with the aliphatic and acidic amino acids by glycine N-acyltransferase, as well as the amides of the latter group, was investigated. Bovine and human liver benzoyl-amino acid conjugation were investigated using electrospray ionization tandem mass spectrometry (ESI-MS-MS). Bovine glycine N-acyltransferase catalyzed conjugation of benzoyl-CoA with Gly (Km(Gly) = 6.2 mM), Asn (Km(Asn) = 129 mM), Gln (Km(Gln) = 353 mM), Ala (Km(Ala) = 1573 mM), Glu (Km(Glu) = 1148 mM) as well as Ser in a sequential mechanism. In the case of the human form, conjugation with Gly (Km(Gly) = 6.4 mM), Ala (Km(Ala) = 997 mM), and Glu was detected. The presence of these alternative conjugates did not inhibit bovine glycine N-acyltransferase activity significantly. Considering the relatively low levels at which these conjugates are formed, it is unlikely that they will have a significant contribution to acyl-amino acid conjugation under normal conditions in vivo. However, their cumulative contribution to acyl-amino acid conjugation under metabolic disease states may prove to have a useful contribution to detoxification of elevated acyl-CoAs.

Nutritional status of HIV-1 seropositive patients in the Free State Province of South Africa: anthropometric and dietary profile.

OBJECTIVE: To evaluate the nutritional intake and status of HIV-1 seropositive patients, as well as the relationship between malnutrition and disease stage. DESIGN: A cross-sectional study. SETTINGS: The Immunology Clinic at the Pelonomi Hospital in Bloemfontein, South Africa. SUBJECTS: Eighty-one HIV/AIDS patients in different stages of disease were recruited consecutively from January to May 1995. Eleven of these patients were followed in 1997. MAIN OUTCOME MEASURES: Anthropometric data including current weight, height, triceps skinfold thickness, mid-upper-arm circumference, body mass index and bone-free arm muscle area were collected. Nutrient intake was estimated using a diet history in combination with a standardised food frequency questionnaire. The patients were divided into 3 groups according to their CD4+ T cell counts. RESULTS: The men were leaner (BMI = 18.9) than the women (BMI = 22.7) and patients with a CD4+ T cell count < 200 (stage III) tended to have the lowest median values for all anthropometric measurements. More than half the patients had a low intake (< 67% of the recommended dietary allowances) of vitamin C, vitamin B6, vitamin D, vitamin A, calcium, iron and zinc. CONCLUSIONS: The results confirms that HIV/AIDS patients from this population are malnourished. There was, however, no association between disease stage and nutritional status. Nutritional supplementation of HIV/AIDS patients should be considered, as this might lead to improved immune function in these patients.

Carnitine palmitoyltransferase I activity monitoring in fibroblasts and leukocytes using electrospray ionization mass spectrometry.

Carnitine palmitoyltransferase I (CPT I) is one of the enzymes associated with normal mitochondrial membrane transport of certain metabolites. The importance of the enzyme in normal energy production is well illustrated during fasting conditions when a large flux of long-chain fatty acids must be transported over the mitochondrial membrane to undergo beta-oxidation. Up to now CPT I activity has been assayed in various tissues, including liver, leukocytes, platelets, and fibroblasts by the use of an isotope exchange forward assay which measures the rate of palmitoyl-l-[methyl-3H]carnitine formation from palmitoyl-CoA and l-[methyl-3H]carnitine. We have developed an electrospray ionization mass spectrometric method for detecting palmitoylcarnitine formation from palmitoyl-CoA and carnitine, thus avoiding the use of radiolabeled isotopes. In this assay, time-dependent conversion of free carnitine by CPT I to palmitoylcarnitine is measured quantitatively, relative to isotopically labelled palmitoylcarnitine, by parent ion monitoring of fragment ion m/z 85. The specific activity of CPT I in fibroblasts and leukocytes compared well with the activity determined with the isotope exchange method, however, the combination of high sensitivity and selectivity of tandem mass spectrometry along with the environment-friendly nature of the electrospray method makes it an ideal technique to measure CPT I activity.

Effect of sperm preincubation time on GIFT pregnancy outcome.

This investigation was conducted to evaluate the effect of human sperm preincubation time on the pregnancy outcome in gamete intrafallopian tube transfers. This was determined in a retrospective study on gamete intrafallopian transfer patients (ideopathic infertility) using logistic regression with the covariates, preincubation time (< or = 60 and > 60 min) and age (< or = 35 and > 35 years). The study included 485 consecutive gamete intrafallopian transfer cycles in which 3 metaphase II oocytes were transferred. Pregnancy outcome was evaluated by beta hCG levels on days 12 and 16 and was confirmed by the presence of a fetal heart 8 weeks after the procedure by means of sonography. The wife's age and sperm preincubation time were significant covariates in the prediction of ongoing pregnancy. The odds ratio for age (< or = 35 years) was 2.2 in the prediction of ongoing pregnancy, while the age-adjusted odds ratios for preincubation time (< or = 60 min) was 1.9. There was a critical relationship between sperm preincubation time and GIFT success, which confirms the effect of the wife's age on pregnancy. Close coordination is of importance between the clinical scientist and the physician to restrict the preincubation time to 1 h. The sperm preincubation time is a significant factor that has to be considered in the prediction of ongoing pregnancy in GIFT patients.