Gargling-induced reduction in urinary Na/K ratio in dehydrated humans: Is there a dual role for oropharnygeal receptors in vasopressin regulation?

Background: A linear relationship exists between plasma osmolality (Posm) and thirst perception (TP) and also between plasma arginine vasopressin (Pavp) and Posm. Thus, an increase in Posm leads to an increase in Pavp secretion, which are systemic indicators of thirst. Recent studies have also shown that Pavp secretion is associated with sodium retention. The role of Pavp in termination of thirst during drinking while Posm remains unchanged is however inconclusive. This informed the basis for the present study. Methods: Ten (10) apparently healthy male volunteers aged between 20 and 30 years, non-smokers and not on any medication prior to the experiments, were recruited for this study. They dehydrated for 18hrs and their 12-hour urine samples as well as thirst perception were measured with standard methods and compared with those of 10 euhydrate control subjects. Urine volume as well sodium and potassium concentrations were estimated. Results: We observed a gradual decrease in TP of the subject who gargled with D/H2o; this decrease became significant (P<0.05, respectively) after 30mins and remained so till the end of the experiment. Gargling with various concentrations of saline (0.9 - 2.7%) did not show any significant change; however, in comparison with controls, the Na+/K+ ratio significantly decreased in all samples collected after gargling at every 30mins for 1Hr and after ad libitum distilled water drinking (P<0.05, respectively). Also, the Na/K ratio obtained during gargling (30mins and 60mins) were relatively stable but decreased significantly (P<0.05) at 90mins; which was 30mins after ad libitum drinking. Conclusion: We conclude that oropharygeal receptors play a dual role in stimulating immediate inhibition of vasopressin as well as aldosterone release in the regulation of thirst during dehydration and gargling, to eliminate thirst

SARS-CoV-2 vaccination modelling for safe surgery to save lives: data from an international prospective cohort study

Background Preoperative SARS-CoV-2 vaccination could support safer elective surgery. Vaccine numbers are limited so this study aimed to inform their prioritization by modelling. Methods The primary outcome was the number needed to vaccinate (NNV) to prevent one COVID-19-related death in 1 year. NNVs were based on postoperative SARS-CoV-2 rates and mortality in an international cohort study (surgical patients), and community SARS-CoV-2 incidence and case fatality data (general population). NNV estimates were stratified by age (18–49, 50–69, 70 or more years) and type of surgery. Best- and worst-case scenarios were used to describe uncertainty. Results NNVs were more favourable in surgical patients than the general population. The most favourable NNVs were in patients aged 70 years or more needing cancer surgery (351; best case 196, worst case 816) or non-cancer surgery (733; best case 407, worst case 1664). Both exceeded the NNV in the general population (1840; best case 1196, worst case 3066). NNVs for surgical patients remained favourable at a range of SARS-CoV-2 incidence rates in sensitivity analysis modelling. Globally, prioritizing preoperative vaccination of patients needing elective surgery ahead of the general population could prevent an additional 58 687 (best case 115 007, worst case 20 177) COVID-19-related deaths in 1 year. Conclusion As global roll out of SARS-CoV-2 vaccination proceeds, patients needing elective surgery should be prioritized ahead of the general population

The Cholecystectomy As A Day Case (CAAD) Score: A Validated Score of Preoperative Predictors of Successful Day-Case Cholecystectomy Using the CholeS Data Set

Background Day-case surgery is associated with significant patient and cost benefits. However, only 43% of cholecystectomy patients are discharged home the same day. One hypothesis is day-case cholecystectomy rates, defined as patients discharged the same day as their operation, may be improved by better assessment of patients using standard preoperative variables. Methods Data were extracted from a prospectively collected data set of cholecystectomy patients from 166 UK and Irish hospitals (CholeS). Cholecystectomies performed as elective procedures were divided into main (75%) and validation (25%) data sets. Preoperative predictors were identified, and a risk score of failed day case was devised using multivariate logistic regression. Receiver operating curve analysis was used to validate the score in the validation data set. Results Of the 7426 elective cholecystectomies performed, 49% of these were discharged home the same day. Same-day discharge following cholecystectomy was less likely with older patients (OR 0.18, 95% CI 0.15–0.23), higher ASA scores (OR 0.19, 95% CI 0.15–0.23), complicated cholelithiasis (OR 0.38, 95% CI 0.31 to 0.48), male gender (OR 0.66, 95% CI 0.58–0.74), previous acute gallstone-related admissions (OR 0.54, 95% CI 0.48–0.60) and preoperative endoscopic intervention (OR 0.40, 95% CI 0.34–0.47). The CAAD score was developed using these variables. When applied to the validation subgroup, a CAAD score of ≤5 was associated with 80.8% successful day-case cholecystectomy compared with 19.2% associated with a CAAD score >5 (p < 0.001). Conclusions The CAAD score which utilises data readily available from clinic letters and electronic sources can predict same-day discharges following cholecystectomy

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

Response surface methodology for silicon production from bamboo leaves

This study investigated the production of silicon from bamboo leaves to solve the challenge of silicon in solar market using Optimization approach. The effect of three independent variables of: temperature, time and amount of bamboo leaves were studied using Box Behnken design. The best process level observed from the Box Benhken Design and optimal predicted process were used to produce silica. It was then subjected to X-Ray Diffractometer to determine the most reactive silica. The most reactive silica observed was used to produce silicon. Silicon obtained was subjected to X-Ray Diffraction and Scanning Electron microscope. It was concluded that nanosilicon was produced which can be used as a solar cell component to solve the challenge presently in the solar market

EXPERIMENTAL STUDY ON THE MECHANICAL BEHAVIOUR OF FIRED SAND-CLAY AND GLASS POWDER-CLAYBRICKS

Mechanical behaviour of fired bricks containing varied amount of fine sand (FS) and waste glass powder (GP) was investigated.FS and GP were added to bricks at varied amount of 0, 5, 10, 15, 20, 25, 30, 35 and 40 wt. %. Firing was done at 1200 oC and samples produced were evaluated for compressive and flexural strengths while microstructural analyses of 25 wt. % FS and GP-clay bricks were examined. Results showed that compressive strength was highest at 30 wt. % GP for GP-bricks while for FS-clay bricks, compressive strength rose to 11.4 and 12.8, at 35 and 40 wt. % FS addition. Flexural strength for GP-clay and FS-clay bricks peaked at 30 wt. % GP (3.63 MPa) and 40 wt. % FS (2.45) respectively. Flexural modulus increased progressively and exponential-ly as FS and GP proportion increased. Work donein resisting deformation and deflection during bending reduced with increased amount inboth additives. Flexural strain was inversely related to load and stiffness. In conclusion, addition of GP and FS in increas-ing amount resulted in improved mechanical properties in the bricks. Also, increased proportion of GP and FS was found to im-prove response to loading in fired bricks

Experimental Study on the Properties of Fired Sand–Clay Ceramic Products for Masonry Applications

This study reports the effect of fine sand addition on the properties of fired clay bricks. Fine sand was sieved to −75 μm and incorporated at varied weight proportions (5, 10, 15, 20, 25, 30, 35, and 40 wt.%) to clay in the preparation of fired bricks. The samples produced were oven dried at 110°C for 12 h, and fired at a temperature of 1,200°C in an electric furnace. The samples were examined for physical, thermal, and mechanical properties. Result of the tests showed a reduction in porosity, water absorption, weight loss, and firing shrinkage with increasing sand addition, although the bulk density increased as the percentage weight content of sand increased. Thermal properties such as thermal conductivity, thermal diffusivity, and thermal emissivity increased with fine sand addition while reduction in coefficient of thermal expansion and specific heat capacity was observed. Also, the thermal shock resistance improved with increase in fine sand addition up to 25 wt.%, before further decline was observed. The hardness and impact value were enhanced with increasing additives. It is noted that samples immersed in rainwater were found to experience depreciation in hardness, resistance to impact, compressive and flexural strengths as the number of days of immersion increased. It was concluded that bricks produced are good for building in temperate region in which much flooding is not experienced

Effect of Surface Modification on the Properties of Polypropylene Matrix Reinforced with Coir Fibre and Yam Peel Particulate

Polypropylene composites reinforced with coir fibre and yam peel particulate were produced using compression moulding machine. Treated and untreated coir fibres were used; 1.5 M NaOH was used for the treated coir fibres. Yam peel was grouped into two, treated and untreated; the treated was modified using 1 M solution of NaOH and HCl in the proportion of 30% and 70%, respectively. 'e yam peel which was sun-dried for 14 days was pulverized and sieved to −45 µm. Samples were developed using treated and untreated reinforcements (TCF/YPP and UCF/YPP) at constant coir fibre proportion (15%) and varied amount of yam peel particulate (2, 4, 6, and 8 wt.%). 'e hybrid composite samples developed were probed for mechanical properties and thermal and wear behaviour. 'e level of particles agglomeration at the fibre-matrix interface was examined using scanning electron microscope. 'e results show that sample reinforced with treated 4 wt.% coir fibre and yam peel particulate had optimum mechanical properties. However, the thermal conductivity of composite samples increased with fibre addition. All composite samples developed had better resistance to abrasion when compared to the control sample

Effect of Surface Modification on the Properties of Polypropylene Matrix Reinforced with Coir Fibre and Yam Peel Particulate

Polypropylene composites reinforced with coir fibre and yam peel particulate were produced using compression moulding machine. Treated and untreated coir fibres were used; 1.5 M NaOH was used for the treated coir fibres. Yam peel was grouped into two, treated and untreated; the treated was modified using 1 M solution of NaOH and HCl in the proportion of 30% and 70%, respectively. 'e yam peel which was sun-dried for 14 days was pulverized and sieved to −45 µm. Samples were developed using treated and untreated reinforcements (TCF/YPP and UCF/YPP) at constant coir fibre proportion (15%) and varied amount of yam peel particulate (2, 4, 6, and 8 wt.%). 'e hybrid composite samples developed were probed for mechanical properties and thermal and wear behaviour. 'e level of particles agglomeration at the fibre-matrix interface was examined using scanning electron microscope. 'e results show that sample reinforced with treated 4 wt.% coir fibre and yam peel particulate had optimum mechanical properties. However, the thermal conductivity of composite samples increased with fibre addition. All composite samples developed had better resistance to abrasion when compared to the control sample