Worldwide scientific efforts on nursing in the field of SARS-CoV-2: a cross-sectional survey analysis.

INTRODUCTION: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has been a global public health issue. This study aimed to characterize global nursing research on SARS-CoV-2. METHODOLOGY: Nursing-related publications through December 31, 2022, were identified using Scopus. The number of studies, study types, countries, institutions, journals, authors, h-index, total confirmed cases, total deaths, and the highest-cited studies were investigated. RESULTS: In total, 12,427 studies were identified. The number of studies increased rapidly, particularly between 2020 and 2021, with a 2.36-fold increase. The United States published the most studies (3,289, 26.47%), followed by the United Kingdom (1,059, 8.52%) and China (877, 7.06%). Scientific productivity significantly correlated with the total confirmed cases (r = 0.701, p = 0.024) and total deaths (r = 0.804, p = 0.005). The United States had the highest h-index (80), followed by China (59), and the United Kingdom (57). The University of Toronto published the most studies (181), followed by Harvard Medical School (165), and the University of São Paulo (107). Gravenstein S (23) was the most prolific author, followed by Mor V (22), and Rosa WE (19). The International Journal of Environmental Research and Public Health published the most papers (436), followed by PLOS ONE (219), and BMJ Open (185). CONCLUSIONS: Several countries, institutions, journals, and authors contributed greatly to SARS-CoV-2-related nursing studies. Countries with larger numbers of confirmed cases and deaths tended to publish more nursing studies. The United States, United Kingdom, and China had the highest quantity and quality of studies.

One-Pot Synthesis of Alumina-Titanium Diboride Composite Powder at Low Temperature.

Alumina-titanium diboride (Al2O3-TiB2) composite powders were synthesised via aluminothermic reduction of TiO2 and B2O3, mediated by a molten chloride salt (NaCl, KCl, or MgCl2). The effects of salt type, initial batch composition, and firing temperature/time on the phase formation and overall reaction extent were examined. Based on the results and equilibrium thermodynamic calculations, the mechanisms underpinning the reaction/synthesis processes were clarified. Given their evaporation losses at test temperatures, appropriately excessive amounts of Al and B2O3 are needed to complete the synthesis reaction. Following this, phase-pure Al2O3-TiB2 composite powders composed of 0.3-0.6 µm Al2O3 and 30-60 nm TiB2 particles were successfully fabricated in NaCl after 5 h at 1050 °C. By increasing the firing temperature to 1150 °C, the time required to complete the synthesis reaction could be reduced to 4 h, although the sizes of Al2O3 and TiB2 particles in the resultant phase pure composite powder increased slightly to 1-2 µm and 100-200 nm, respectively.

Effects of Sodium Hexametaphosphate Addition on the Dispersion and Hydration of Pure Calcium Aluminate Cement.

The effects of sodium hexametaphosphate (SHMP) addition on the dispersion and hydration of calcium aluminate cement were investigated, and the relevant mechanisms discussed. The content of SHMP and the adsorption capacity of SHMP on the surface of cement particles were estimated using plasma adsorption spectroscopy and the residual concentration method. The rheological behavior of hydrate, ζ-potential value of cement particles, phase transformation and the microstructure of the samples were determined by coaxial cylinder rheometer, zeta probe, X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results indicate that SHMP readily reacted with Ca2+, forming complexes [Ca2(PO3)6]2- ions which were subsequently adsorbed onto the surfaces of cement particles. When the content of SHMP was 0.05%, the adsorption ratio reached 99%. However, it decreased to 89% upon further increasing the addition of SHMP to 0.4%. The complexes [Ca2(PO3)6]2- adsorbed onto the surfaces of cement particles inhibited the concentration of Ca2+ and changed ζ-potential, resulting in enhanced electrostatic repulsive force between the cement particles and reduced viscosity of cement-water slurry. The experimental results indicate that the complexes [Ca2(PO3)6]2- covering the surfaces of cement particles led to a delayed hydration reaction, i.e., they extended the hydration time of the cement particles, and that the optimal addition of SHMP was found to be about 0.2%.

Low Temperature Synthesis of Phase Pure MoAlB Powder in Molten NaCl.

MoAlB fine powders were prepared in molten NaCl from Al, B and Mo powders. The effects of key parameters affecting the synthesis process and phase morphology were examined and the underpinning mechanisms proposed. MoAlB product particles exhibited different shapes/sizes, as follows: spherical grains (1~3 µm), plate-like particles (<5 µm in diameter) and columnar crystals with lengths up to 20 µm and diameters up to 5 µm, resultant from different reaction processes. Phase pure MoAlB was synthesised under the following optimal conditions: use of 140% excess Al and 6 h of firing at 1000 °C. This temperature was at least 100 °C lower than required by other methods/techniques previously reported. At the synthesis condition, Mo first reacted with Al and B, forming Al8Mo3 and MoB, respectively, which further reacted with excess Al to form Al-rich Al-Mo phases and MoAlB. The Al-rich Al-Mo phases further reacted with the residual B, forming additional MoAlB. The molten NaCl played an important role in accelerating the overall synthesis process.

Low-Temperature Molten Salt Synthesis and the Characterisation of Submicron-Sized Al8B4C7 Powder.

Submicron-sized (~200 nm) aluminium boron carbide (Al8B4C7) particles were synthesised from Al, B4C and carbon black raw materials in a molten NaCl-based salt at a relatively low temperature. The effects of the salt type/assembly and the firing temperature on the synthesis process were examined, and the relevant reaction mechanisms discussed. The molten salt played an important role in the Al8B4C7 formation process. By using a combined salt of 95%NaCl + 5%NaF, an effective liquid reaction medium was formed, greatly facilitating the Al8B4C7 formation. As a result, essentially phase-pure Al8B4C7 was obtained after 6 h of firing at 1250 °C. This temperature was 350-550 °C lower than that required by the conventional direct reaction and thermal reduction methods.

Effects of the Preparation Method on the Formation of True Nimodipine SBE-ß-CD/HP-ß-CD Inclusion Complexes and Their Dissolution Rates Enhancement.

The aims of this study were to enhance the solubility and dissolution rate of nimodipine (ND) by preparing the inclusion complexes of ND with sulfobutylether-b-cyclodextrin (SBE-ß-CD) and 2-hydroxypropyl-b-cyclodextrin (HP-ß-CD) and to study the effect of the preparation method on the in vitro dissolution profile in different media (0.1 N HCl pH 1.2, phosphate buffer pH 7.4, and distilled water). Thus, the inclusion complexes were prepared by kneading, coprecipitation, and freeze-drying methods. Phase solubility studies were conducted to characterize the complexes in the liquid state. The inclusion complexes in the solid state were investigated with differential scanning calorimetry (DSC), X-ray diffractometry (X-RD), and Fourier transform infrared spectroscopy (FT-IR). Stable complexes of ND/SBE-ß-CD and ND/HP-ß-CD were formed in distilled water in a 1:1 stoichiometric inclusion complex as indicated by an AL-type diagram. The apparent stability constants (Ks) were 1334.4 and 464.1 M(-1) for ND/SBE-ß-CD and ND/HP-ß-CD, respectively. The water-solubility of ND was significantly increased in an average of 22- and 8-fold for SBE-ß-CD and HP-ß-CD, respectively. DSC results showed the formation of true inclusion complexes between the drug and both SBE-ß-CD and HP-ß-CD prepared by the kneading method. In contrast, crystalline drug was detectable in all other products. The dissolution studies showed that all the products exhibited higher dissolution rate than those of the physical mixtures and ND alone, in all mediums. However, the kneading complexes displayed the maximum dissolution rate in comparison with drug and other complexes, confirming the influence of the preparation method on the physicochemical properties of the products.