Quantitative assessment and optimization of parallel contact model for flexible paddy straw: a definitive screening and central composite design approach using discrete element method.

To simulate the bending behaviour of paddy straw at varied moisture contents after crop harvesting, we created a flexible paddy straw specimen model based on the Hertz-Mindlin with parallel contact bonding model using the discrete element model (DEM) approach. The research presented in this study aims to investigate a new approach called Definitive Screening Design (DSD) for parameterizing and screening the most significant parameters of the DEM model. This investigation will specifically focus on the three-point bending test as a means of parameterization, and the shear plate test will be used for validation purposes. In addition, the most influential DEM parameters were optimized using another Design of Experiments approach called Central Composite Design. The findings from the DSD indicated that parameters such as bonded disk scale, normal stiffness, and shear stiffness have the highest impact on the bending force, while the coefficient of static friction (Straw-Steel) has the least effect. The three bonding parameters were respectively calibrated with the loading rate (0.42, 0.5, and 0.58 mm s-1) and a good agreement between actual and simulated shear force at moisture content M1-35 ± 3.4%, M2-24 ± 2.2% and M3-17 ± 2.6%. Modelled stem helps simulate the straw with low error and increases the accuracy of the simulation. The validated model, with an average relative error of 5.43, 7.63, and 8.86 per cent, produced reasonable agreement between measured and simulated shear force value and loading rate.

Prevalence of biofilm producing Acinetobacter baumannii clinical isolates: A systematic review and meta-analysis.

BACKGROUND: Acinetobacter baumannii, the first human pathogen to be designated as a "red-alert" pathogen, is on the critical priority list of pathogens requiring new antibiotics. Biofilm-associated diseases are the most common infections caused by the antibiotic-resistant bacteria A. baumannii. Multidrug-resistant strains are more easily transmitted around the world due to A. baumannii's ability to produce biofilms, which allows it to develop antibiotic resistance mechanisms and thrive in healthcare environments. As a result, A. baumannii infections are becoming increasingly common in hospital settings allover the world. As a result, a comprehensive systematic review and meta-analysis were carried out to determine the global prevalence of biofilm-producing A. baumannii clinical isolates. METHODS: Articles were extensively searched in bibliographic databases and grey literatures using entry terms or phrases. Studies meeting eligibility criteria were extracted in MS Excel and exported into STATA version 12 software for statistical analysis. A random-effects model was used to compute the pooled prevalence of biofilm-producing A. baumannii clinical isolates. The heterogeneity was quantified by using the I2 value. Publication bias was assessed using a funnel plot and Egger's test. Sensitivity analysis was done to assess the impact of a single study on pooled effect size. RESULT: Of the 862 studies identified, 26 studies consisted of 2123 A.baumannii clinical isolates of which 1456 were biofilm-producing. The pooled prevalence of biofilm-producing A.baumannii clinical isolates was 65.63% (95% CI = 56.70%-74.56%). There was substantial heterogeneity with an I2 value of 98.1%. Moreover, 41.34%, 33.57%, and 27.63% of isolates of strong, mild, and weak producers of biofilm. Higher prevalence was found in studies published after 2014 (66.31%); Western Pacific region (76.17%); and Asia (66.22%) followed by the African continent (57.29%). CONCLUSION: The pooled prevalence of biofilm-producing A. baumannii clinical isolates has risen alarmingly, posing a public health risk. This indicates the burden of biofilm-producing A. baumannii infections urges routine screening and appropriate treatment for better management of hospitalized patients, as well as effective controlling of the emergence of drug resistance. Furthermore, this finding is an alert call for the stakeholders to develop strong infection prevention and antibiotics stewardship programs for the prevention and control of biofilm-producing bacterial infections.

Intestinal Parasitic Infections among HIV-Infected Patients on Antiretroviral Therapy Attending Debretabor General Hospital, Northern Ethiopia: A Cross-Sectional Study.

BACKGROUND: Parasitic infections are known causes of morbidity among HIV-infected patients with low CD4+ counts who are on antiretroviral therapy (ART), mainly as a result of immuno suppression. This study aimed to assess the extent of intestinal parasitic infection and related risk factors among HIV-infected patients attending ART clinic at Debretabor General Hospital, Northern Ethiopia. METHODS: A health facility-based cross-sectional study was conducted on 383 HIV-infected patients attending the ART clinic of Debretabor General Hospital, northern Ethiopia from December 2018 to March 2019. An interview-based structured questionnaire was used to gather sociodemographic and risk-factor data. About 5 g fresh stool and 4 mL venous blood were collected from each patient, then transported and tested in accordance with laboratory-standard operating procedures. Data obtained were entered into SPSS version 22.0 and analyzed. P<0.05 with 95% CI was considered statistically significant. RESULTS: The overall prevalence of intestinal parasites was 25.3%, with 18% and 23.8% by direct wet-mount and formol ether-concentration technique, respectively. Eight (2.1%) patients were infected by multiple parasites using the concentration technique. Ascaris lumbricoides was the most frequently identified parasite (n=23, 25.3%). Parasitic infection was significantly higher among illiterates (P=0.011), patients with CD4 count <200 cells/mm3 (P<0.001), and those who did not have a toilet in their home (P=0.049) than their counterparts. CONCLUSION: Relatively higher prevalence of intestinal parasitic infection was found among HIV/AIDS patients. The distribution of intestinal parasites was greatly affected by illiteracy, reduced CD4+ counts, and absence of a toilet. Therefore, HIV/AIDS patients with low CD4+ counts should be diagnosed consistently for intestinal parasites with routine stool examinations, and awareness creation should be advocated to be included as an essential component of ART-monitoring strategies for improved patient care.