bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of Micropogonias undulatus Scales Nanoparticulate - Reinforced In Situ Anti-Corrosion Composite Coatings
Authors: Abioye Oluwabunmi Pamilerin , Fayomi Ojo Sunday Isaac , Loto Roland Tolulope
Published: April 2022

The reinforced composite coating has been proven to offer outstanding properties and increased component life span in service. Thus, its development has found a significant place in advanced engineering applications. This study aims to reinforce Zinc-Zinc Oxide composite coatings with an organic and sustainable, eco-friendly product, scales of Micropogonias undulatus (M. undulatus) anti-corrosion composite coating, for mild steel protection in service. The coating was developed via the electrolytic deposition route. The effects of the process parameter, deposition time, on the morphology and electrochemical properties were reported. While the Optical Microscope (O.M.) and Scanning Electron microscopy (S.E.M.) equipped with Energy Dispersive Spectroscopy (E.D.S.) were used for structural study, the PGSTAT 30 potentiostat linked to the electrochemical software NOVA 1.8 was used for the corrosion polarisation studies. The result showed excellent coating adhesion, substrate protection and remarkable corrosion resistant attributes with the Zn-ZnO-M. undulatus scales nanoparticulate coatings. The result also revealed that the deposition done at 25 minutes had the best and most enhanced anti-corrosion attributes.
Utilization of Waste Materials for Eco-Friendly Building Ceilings: An Overview
Authors: Dirisu Joseph O. , Joseph Olufunmilayo Oluwabukola , Babalola Philip , Oyedepo Sunday Olayinka , Fayomi Ojo Sunday Isaac , Oluwasegun K.M. , Udoye Nduka E. , Ajayi Oluseyi O. , Ajibero Michael
Published: April 2022

The pioneers of the industrial revolution, and their successors, left the world’s ecosystem in a devastating state. Global warming became the consequence of activities in the industry that led to climate change, the depletion of the ozone layer, and pollution of the ecosystem. For decades now, concerned researchers have been frantically investigating methods and procedures that can help conserve the ecosystem's left to attain sustainability. The construction industry also poses its challenge as novel solutions to construct sustainable, less hazardous products to the environment and improve human health are diligently investigated and identified yearly. This paper discusses specific steps of this nature and explains how environmentally-friendly construction methods and materials produce ceiling boards.
Effects of Nanoclay on the Tensile Strength and Microstructure of Tigernut Fibre- Epoxy Composites (NFPCs)
Authors: Adeodu Adefemi Omowole , Daniyan Ilesanmi Afolabi , Adewumi Funmilayo Deborah , Orgwara George , Adewale Monisola
Published: April 2022

Natural fibres have gained huge attention of researchers in the field of composite manufacturing due to its low cost, biodegradability, availability and high performance. However, due to its high hydroxyl content of cellulose, natural fibre is susceptible to water absorption which invariably adversely affects properties of the composite. Researchers have proved that nano-materials such as nanoclay mixed with the polymer composites can overcome the problem. This study investigates tensile strength and microstructural property of tigernut fibres reinforced polymer composites tailored to automotive application. Tigernut fibres mixed with nanoclay of size 50≤µm, were used to reinforce epoxy in three levels of loading 2, 4, 6 % respectively. The composite was prepared by shear mixing of polymer and the reinforcements, followed by lamination and curing of the composite. The tensile strength and microstructural property of the composites produced were examined. The results show that tensile strength increases as the percentage weight fraction of the reinforcement increases. The microstructures show good interfacial adhesion between reinforcement and polymer matrix. Tigernut fibre show a sustainable material useful for automotive applications.
Application of Self - Cleaning Filters in the Removal of Turbidity from River Water: Pilot Study
Authors: Lebea Aubrey Kgotso , Ramutshatsha-Makhwedzha Denga , Moropeng - Mavhungu Lucey Mapula
Published: April 2022

Enhanced treatment of river water was investigated by the modified coagulation-flocculation process for the application of self-cleaning filters (SCF’s) in the removal of turbidity using a combination of Alum and Sudfloc 3880. This study is aimed to improve the removal of iron and turbidity concentrations from river water and reduce water loss. This is achieved by piloting innovative water treatment technologies such as the SCF’s Plant. The new technology further assessed the effectiveness, efficiency, and operability of the SCF’s Plant by varying certain operational parameters such as water flow, differential pressures, coagulant, and flocculent dosages. The results established in this study critically analyze the feasibility of deploying water treatment technologies such as the SCF Plant in areas with similar environmental conditions and/or facing similar water treatment challenges. The removal efficiencies of turbidity were about 40 % and further optimization will be continued until 90 % to 100 % is achieved. The average removal efficiency of turbidity was 40 % and achieved at a 250 m3/h flow rate. The average removal across all flow rates was over 20 %. Further optimization of the RF14 will be carried out using other chemical combinations and formulations at various process settings while bypassing the PLF filters. The PLF elements will be brought into service to further reduce the turbidity after the optimization of the RF14. Keywords: Water, Treatment, Coagulation, Flocculation, Processes, Technologies, Filters *
Synergistic Protection of Mild Steel in Sodium Chloride Solutions Using Mixtures of Sustainable Corrosion Inhibitors
Authors: Akpoborie J. , Fayomi Ojo Sunday Isaac , Oluwasegun K.M. , Sanni Omotayo , Ren J. , Wan Nik Wan B. , Daramola D.O.
Published: April 2022

Mild steel material has broad application in marine construction, due to their availability, low cost, and high tensile strength. Nevertheless, the major limitation of mild steel is its low corrosion resistance. The use of eco-friendly inhibitors in protecting mild steel from aggressive media is one of the cheap and practical means competing with conventional phosphate and chromate inhibitors. Herein, the synergism corrosion inhibition effects between key lime and chlorpheniramine drug were examined as sustainable inhibitors for mild steel in 24.5 M NaCl solutions through electrochemical measurement, and morphology of the same was characterized using scanning electron microscopy equipped with energy-dispersive X-ray spectroscopy (SEM/EDX). The electrochemical investigations revealed that in the presence of 2ml key lime and 8ml chlorpheniramine drug the optimum inhibitive efficiency of 81.82% was achieved, this is connected to the protecting layer build-up on the surface of the mild steel, thus, blocking the harsh ion diffusion pathway. The polarization plot shows that the inhibitors complex the deposition led to the corrosion inhibition mixed-type mechanisms. The films formed on the mild steel surface were proved by the SEM/EDX result. The adsorption result shows that the inhibitors fit the Langmuir adsorption isotherm. Keywords: Synergistic effect, sustainable corrosion inhibition, NaCl solution, electrochemical techniques, mild steel
Influence of Pre-Annealing on Densification, Microstructure, and Microhardness of Spark Plasma Sintered TiO2-MnO2 Composites
Authors: Mohlala Lesego M. , Olubambi Peter Apata , Cele Nonhlanhla Precious , Jen Tien Chien
Published: April 2022

MnO2 and TiO2 composites have garnered substantial research interest for energy applications, including supercapacitor electrodes and photocatalysts. This study investigated the microstructures, densification behaviour, and microhardness of spark plasma sintered TiO2-MnO2 composites. TiO2-MnO2 composites with 10 wt.% MnO2 and 30 wt.% MnO2 were sintered at a temperature of 1000 °C and applied pressure of 25 MPa. To investigate the influence of annealing, the second batch of powders with similar compositions were pre-annealed at a temperature of 500°C for 5 minutes before consolidation. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to characterize the powders and compacts. The results revealed that the pre-annealing stage influences the microstructural constituents, densification, and microhardness. The formation of pores and a new phase was observed in SEM images and XRD patterns. The relative densities of the 10wt.%MnO2 sample increased from 97.48 % to 97.71 %, whereas that of the 30wt.%MnO2 composite increased from 96.11% to 96.46%. Similarly, the microhardness values in the pre-annealed 10wt.% MnO2 and 30wt.%MnO2 composites increased by 1.78% and 0.41%, respectively.
Effect of Ni Doping and Vacancy Defects on the Sensing Characteristics of Graphene for NO2 and CO Detection: A DFT Study
Authors: Mohlala Lesego M. , Jen Tien Chien , Olubambi Peter Apata
Published: April 2022

The sensing characteristics of pristine, Ni-doped, and C-vacancy graphene towards CO and NO2 gas molecules were studied using density functional theory (DFT). The adsorption energies, electronic properties, charge transfer, and stable geometries were calculated to evaluate the gas-surface interaction mechanisms. Both pristine and vacancy graphene have smaller CO and NO2 adsorption energies and charge transfer than the Ni-doped graphene, whereas the adsorption energy on Ni-doped vacancy graphene is higher than that of Ni-doped graphene. The results indicate that both CO and NO2 gas molecules only attach to pristine graphene through weak physical adsorption. Stronger chemisorption occurs when the gas molecules adsorb on the surface of vacancy, Ni-doped, and Ni-doped vacancy graphene. Additionally, the results demonstrated that Ni-doped vacancy graphene has higher sensitivity and selectivity towards the NO2.
Impact of Sodium Silicate Activator on Compressive Strength of Cement- RHA Based Stabilized Lateritic Soil. A Case Study of Kwali, Abuja FCT, Nigeria
Authors: Amu Olugbenga  Oludolapo , Igibah Christopher Ehizemhen , Adedapo Adetayo Oluwaseun
Published: April 2022

The strength of a fine-grained lateritic soil from three (3) different locations on Abuja – Lokoja road where road failure occur was treated with sodium silicate activator (SSA), cement and rice husk ash (RSA) with varying percentage scrutinized by means of Atterberg, compaction and triaxial shear tests. The result reveals that cement additive improved the lateritic soil from Liquid limit values of 41.25 at 0% to 44.36 at 8%, but reduces at 10% to 35.67, while RHA increases at increased percentages. The MDD improved with increase in the quantities of all the additive (SSA, cement and RHA) content, while OMC for both cement and RHA reduces from 18.65% at 0% to 11.71 and 18.05 respectively. It reveals cohesion of the soil at 0, 2, 4, 6, 8 and 10% to be 19, 39, 49, 55, 58 and 65 KN/m2 respectively, with highest angle of 650 and lowest of 370. This implies that the cohesion of the improved sample was satisfied since the improved angle of internal friction is above the angle that makes soil very plastic which is 280. Keywords: Geopolymer. Sodium silicate, rice hush ash, Triaxial, Abuja.
Highly Conductive Polymer Composite Based on Graphite-Filled Immiscible Polyolefin/Epoxy Blends
Authors: Alo Oluwaseun Ayotunde , Otunniyi Iyiola Olatunji
Published: April 2022

Conductive polymer composites (CPCs) based on polypropylene (PP)/epoxy (EP) and high-density polyethylene (HDPE)/EP blends filled with synthetic graphite (SG) were produced and characterized to explore their potential for high electrical conductivity applications. The polymer blends were chosen as matrices due to their immiscibility and potential to enable co-continuous morphology formation and preferential distribution of filler, which allows formation of maximized conducting networks. In-plane and through-plane resistivities of PP/EP/SG composites decreased from 0.083 Ω.cm to 0.015 Ω.cm and 10.16 Ω.cm to 0.31 Ω.cm, respectively, while for HDPE/EP/SG composites, in-plane and through-plane resistivities decreased from 0.086 Ω.cm to 0.014 Ω.cm and 5.02 Ω.cm to 0.24 Ω.cm, respectively, when SG content was increased from 30 to 80 wt%. The immiscible blend-based composites produced in this study have the potential to achieve significantly higher conductivity than filled single polymers due to concentration of filler in one of the polymer phases and the co-continuous structure of the blends. Also, resistivity anisotropy of the PP/EP/SG and HDPE/EP/SG composites generally decreased with increase in SG content, with HDPE/EP/SG composites showing lower resistivity anisotropy than PP/EP/SG composites at the same SG content.
Failure Mode and Cost Effect Analysis of a Model Bone Crushing Hammer
Authors: Edun Bose Mosunmola , Ajayi Oluseyi O. , Babalola Philip
Published: April 2022

Critical investigation of strength properties of materials is required in Engineering practice to ensure an enhanced service life. Globally, industrialists are struggling to increase cost savings from lost production due to the failure of machine, while customers are concerned about the safety and reliability of the products. Hammer mills are prone to various modes of failure like chemical failure, erosive failure, abrasive failure and fatigue failure. The effect of these failure modes is always detrimental to the operation of the machine and its efficiency. Hence, forensic investigation is essential to determine the failure modes and their effects on hammer mills for bone crushing. Field investigation was carried out to monitor the hammer mill in operation for 12 months with a production of 20 bags per hour. The total production per day for 8 hours is expected to be 160 bags at a given speed. Thus, the cost of machine downtime on production is huge. The Pareto method was used to determine the effect of downtime on revenue and production for a period of one year. The hours of failure were between 1 to 2 hours per day. The loss in revenue was calculated using the variation of number of failure with time, as obtained from hammer mill. The outcome showed that hammers investigated failed as a result of abrasive wear, fatigue, impact, and chemical wear, respectively. The cost of downtime was found to be $ 37,745,809,920.00 CAD for the period of study. Based on findings, wide ranging factors are required to evaluate the performance of the hammer mill for improved productivity and efficiency. These are proper material selection, design and appropriate operational parameters. However, there is need for optimisation of the hammer material via heat treatment methods as this will reduce the yearly cost of production, downtime of the milling machine for bone crushing as well as improvement in productivity.
Promoter Proximity Defines Mutation Window for VH and VΚ Genes Rearranged to Different J Genes
Authors: Heltzel Justin H M , Maul Robert W , Yang William , Gearhart Patricia J
Published: April 2022

Somatic hypermutation induced by activation-induced deaminase (AID) occurs at high densities between the Ig V gene promoter and intronic enhancer, which encompasses DNA encoding the rearranged V gene exon and J intron. It has been proposed that proximity between the promoter and enhancer defines the boundaries of mutation in V regions. However, depending on the J gene used, the distance between the promoter and enhancer is quite variable and may result in differential targeting around the V gene. To examine the effect of distance in mutation accumulation, we sequenced 320 clones containing different endogenous rearranged V genes in the IgH and Igκ loci from Peyer’s patch B cells of mice. Clones were grouped by their use of different J genes. Distances between the V gene and enhancer ranged from ∼2.3 kb of intron DNA for rearrangements using J1, ∼2.0 kb for rearrangements using J2, ∼1.6 kb for rearrangements using J3 (H) or 4 (κ), and 1.1 kb for rearrangements using J4 (H) or 5 (κ). Strikingly, >90% of intron mutations occurred within 1 kb downstream of the J gene for both H and κ clones, regardless of which J gene was used. Thus, there is no evidence that the intron sequence or enhancer plays a role in determining the extent of mutation. The results indicate that V region intron mutations are targeted by their proximity to the promoter, suggesting they result from AID interactions with RNA polymerase II over a 1-kb region.
Innate and Adaptive Immunity in Noninfectious Granulomatous Lung Disease
Authors: McKee Amy S , Atif Shaikh M , Falta Michael T , Fontenot Andrew P
Published: April 2022

Sarcoidosis and chronic beryllium disease are noninfectious lung diseases that are characterized by the presence of noncaseating granulomatous inflammation. Chronic beryllium disease is caused by occupational exposure to beryllium containing particles, whereas the etiology of sarcoidosis is not known. Genetic susceptibility for both diseases is associated with particular MHC class II alleles, and CD4+ T cells are implicated in their pathogenesis. The innate immune system plays a critical role in the initiation of pathogenic CD4+ T cell responses as well as the transition to active lung disease and disease progression. In this review, we highlight recent insights into Ag recognition in chronic beryllium disease and sarcoidosis. In addition, we discuss the current understanding of the dynamic interactions between the innate and adaptive immune systems and their impact on disease pathogenesis.
Phytosaurian Nomenclature: Parasuchia, Phytosauria or Belodontia?
Authors: Kischlat Edio-Ernst
Published: April 2022

The nomenclatural status of Phytosaurus Jæger is here analyzed in accordance with the International Code of Zoological Nomenclature. In the past, several authors have interpreted it as both a family-group and/or a genus-group name, but each of these approaches fails in several articles of the Code. Phytosaurus Jæger is here interpreted as originally established for a collective-group and cannot be used as a nominal genus in binomina, but takes precedence over any other younger homonym, and the first available one is Phytosaurus Wagler. Being an invalid junior homonym, the class-group name Phytosauria Baur and the family-group name Phytosauridae Lydekker, which are based on Phytosaurus Wagler, are ultimately rejected. Conversely, the class-group names Parasuchia Huxley and Belodontia Brauns, as well as the family-group name Belodontidae Cope, are older but have some taxonomic restrictions in relation to Belodon plieningeri Meyer. To avoid proposing new names for old ones, the solution to fix the higher-order nomenclature for phytosaurs is to designate a neotype for Belodon plieningeri Meyer. Keywords: Parasuchia, Phytosauria, Belodontia, Archosauriformes, Triassic, collective-group.
Neogene ostracods from the Solimões Formation (Atalaia do Norte, Amazonas State, Brazil), with the description of two new species
Authors: Linhares Ana Paula , Ramos Maria Inês Feijó
Published: April 2022

The analysis of the ostracods from three boreholes (1AS-7D-AM, 1AS-8-AM, and 1AS-31-AM) drilled in Atalaia do Norte town, Amazonas State, Brazil, allowed to recognize 30 species and nine genera. Cyprideis is the most abundant and diverse genus and is represented by 19 species already identified for the Solimões Formation, besides two new species described herein: Cyprideis atalaiensis sp. nov. and Cyprideis dictyon sp. nov. Intraspecific morphological variability, as well as the presence of nodes and tubercles, are observed in some species of Cyprideis and interpreted as a response to the paleoenvironmental changes during the Neogene in western Amazon region. Keywords: Cyprideis, morphological variability, paleoenvironmental changes, western Amazonia.
Role of secondary sepsis in COVID-19 mortality: Observations on patients with preexisting diabetes mellitus and newly diagnosed hyperglycemia
Authors: Nair Aiswarya M , Gopalan Sowmya , Rajendran Vaasanthi , Varadaraj Priyadarshini , Marappa Lakshmi , Pandurangan Viswanathan , Madhavan Sudha , Mani Rajkumar , Bhaskar Emmanuel
Published: April 2022

Diabetics who develop severe acute respiratory syndrome coronavirus 2 (SARS CoV-2) are more likely to have severe disease, higher odds of intensive care requirement and mortality. Fifteen percent of patients have new onset hyperglycemia. We studied the comparative outcomes between prior DM, newly detected hyperglycemia and assessed role of secondary sepsis on mortality. RWe performed a r etrospective study of confirmed SARS-CoV-2 patients at a tertiary care hospital in Chennai, India. Patients were divided as 2 groups (Group 1: With preexisting diabetes mellitus, Group 2: With newly diagnosed hyperglycemia due to newly detected diabetes mellitus or non-diabetic hyperglycemia. Clinical and laboratory data was analysed. Two hundred and thirty eight patients had prior-diabetes mellitus (Group 1) and 40 had newly diagnosed hyperglycemia (Group 2). Thirty four of group 1 and 7 of group 2 patients required intensive care. Mean capillary blood glucose (MCBG) during hospital stay was 207 mg/dl (Group 1) and 192 mg/dl (Group 2). Twentysix patients (9.3%) had secondary sepsis of which sixteen died. Logistic regression identified secondary sepsis(p<0.0001), elevated D-dimer >6 fold (p= 0.0001), elderly p=0.0045), male (p=0.0006), NLR >5 (p=0.01),serum creatinine ≥2 mg/dl (p=0.0004), FiO2 requirement >0.6 in first 48 hours (p=0.001) as mortality predictors.Our study observed a 14.38 % prevalence of newly diagnosed DM or non-diabetic hyperglycemia. Secondary sepsis and >6 fold elevation in D-dimer were strong predictors of mortality. Steroid use possibly contributed to secondary sepsis. Early identification and aggressive management of secondary sepsis are necessary for diabetics.
The Dermal Ridges as the Infallible Signature of Skin
Authors: Sudha P Indira , Singh Jyoti , Sodhi G S
Published: April 2022

Our skin is the largest organ and is composed of the dermis and epidermis. The skin surface has lines in the direction of elastic tension. The palmar and plantar skin lines are established before birth in the intrauterine development of the embryo. Dermatoglyphics is the study of epidermal lines on the palmar and plantar surface. It is a branch of biology, anthropology, genetics, and dermatology. Dermatoglyphics are closely associated with genetic factors. These attributes once formed in the womb remain unique and persist throughout the life of an individual unless the dermis is damaged. Digital and palmar dermatoglyphics are represented by fingerprint patterns, atd angle, a, b, c, d triradii, mail line index, etc. Sometimes either due to hereditary reasons, the pressure of intrauterine factors, or external environmental factors, chromosomal aberrations occur in the fetus. These aberrations are reflected in the form of increased angle of atd, variation in pattern frequency or ridge count between a-b triradii (ABRC), presence of unnatural flexion creases, and others in the fingerprints, palmprints, or footprints. These aberrations in dermatoglyphics are useful in studying the genetic abnormalities in ailments, personality disorders, and criminal tendencies.
A retrospective study to evaluate the efficacy and safety of staged purse-string sutures for the reconstruction of surgical defects on skin using computer image analysis program
Authors: Seong Gi Hyun , Yeom Kyujin , Yun Dea Kwan , Choi Mi Soo , Kim Myung Hwa , Park Byung Cheol
Published: April 2022

Background:

Staged purse-string suturing has been recently introduced for the reconstruction of round or oval defects following tumor excision.

Objective:

The aim of this study was to evaluate the clinical advantage of staged purse-string suturing for the reconstruction of relatively large skin defects.

Materials and Methods:

Twenty-one patients who received staged purse-string sutures were included in the study. To evaluate the defects and scar sizes objectively, computer-based image analysis was used. A modified observer scar assessment scale (OSAS) was applied for evaluating the clinical efficacy.

Results:

The mean primary postsurgical defect size in the total 21 cases was 1446.2 ± 1187.2 mm2, and the mean final scar size was about 268.1 ± 252.3 mm2. The defect area decreased gradually as staged purse-string suturing was performed. The mean total modified OSAS was 7.96 ± 1.69.

Conclusion:

Staged purse-string sutures might be an alternative reconstructive method for relatively large round or oval skin defects.
CDLQI-based Assessment of Skin Disorders Among Children
Authors: Goyal Sheena , Sajid Naheed , K. Nayak Sudhir U. , Husain Sajid
Published: April 2022

Background:

Skin is the largest organ of the human body, and one of the most sensitive indicators of a child's general health. Skin disorders, especially among children, may cause an additional emotional and psychological stress to the patients and their family.

Aim:

We aim to compare the extent to which various skin diseases affect the quality of life among the pediatric age group (5–12 years) based on Children's Dermatology Life Quality Index (CDLQI) scores.

Materials and Methods:

A cross-sectional study of 453 patients who attended skin clinic at a regional hospital in Northern India between November 2015 and May 2017. The study consists of questions regarding dermatoses. Patients were evaluated using a standardized pro forma and a CDLQI questionnaire. The diseases with abnormal high proportions were evaluated by the control chart technique.

Results:

Out of a total of 453 pediatric patients identified for dermatoses, the average quality of life based on the CDLQI score did not show significant variation across different seasons (P< 0.522). Although the type of skin disorders (P< 0.001) had a significant effect on the quality of life of the children. Based on the CDLQI scores, following diseases have a significant adverse effect on quality of life of the patients – miliaria, atopic dermatitis, scabies, impetigo, and pediculosis capitis.

Conclusion:

Our study has shown that skin diseases, irrespective of the type, adversely impair the quality of life of the child and in turn the family, therefore, calls for an enhanced level of compassion and care.
Emphysematous pyelonephritis
Authors: Wu Shu-Yu , Yang Stephen Shei-Dei , Chang Shang-Jen , Hsu Chun-Kai
Published: April 2022

Urinary tract infections are commonly encountered and managed worldwide, and emphysematous pyelonephritis (EPN) is among the most serious types of urinary tract infections. EPN is an acute necrotizing infection of the kidney, often associated with high rates of renal loss and mortality. The symptoms of EPN infection can be nonspecific, but the clinical triad of fever, flank pain, and nausea represent the most common presentations. The diagnosis and classification are performed with the assistance of computed tomography (CT). The imaging-based classification system created by Huang and Tseng is widely used in clinical assessments. They defined EPN into four different class (1–4), with the higher number the more severe disease. Optimal EPN treatment is controversial, with emergent nephrectomy suggested during early studies, whereas more recent evidence favors more conservative approaches. Escherichia coli, Klebsiella pneumoniae and Proteus mirabilis are most common pathogens. The initial use of broad-spectrum antibiotics such as Third-or fourth-generation cephalosporins and carbapenems are recommended. Diabetes, obstructive uropathy and hypertension are the most common risk factors and often need treatment together. Emergent drainage is indicated with a larger-sized drainage tube to achieve better drainage function. CT guidance has a better success rate than insertion under the guidance of ultrasonography. Nephrectomy should be reserved as the last resort for those who fail to respond to conservative therapy. This review aims to provide comprehensive, evidence-based recommendations for the diagnosis and management of this life-threatening urological infection.
Nonuniqueness of minimizers for semilinear optimal control problems
Authors: Pighin Dario
Published: April 2022

A counterexample to uniqueness of global minimizers of semilinear optimal control problems is given. The lack of uniqueness occurs for a special choice of the state-target in the cost functional. Our arguments also show that, for some state-targets, there exist local minimizers which are not global. When this occurs, gradient-type algorithms may be trapped by local minimizers, thus missing global ones. Furthermore, the issue of convexity of a quadratic functional in optimal control is analyzed in an abstract setting.

As a corollary of nonuniqueness of minimizers, a nonuniqueness result for a coupled elliptic system is deduced.

Numerical simulations have been performed illustrating the theoretical results.

We also discuss the possible impact of the multiplicity of minimizers on the turnpike property in long time horizons.
Commensurated subgroups and micro-supported actions (with an appendix by Dominik Francoeur)
Authors: Caprace Pierre-Emmanuel , Le Boudec Adrien
Published: April 2022

Let

\Gamma

be a finitely generated group and

X

be a minimal compact

\Gamma

-space. We assume that the

\Gamma

-action is micro-supported, i.e. for every non-empty open subset

U \subseteq X

, there is an element of

\Gamma

acting non-trivially on

U

and trivially on the complement

X \setminus U

. We show that, under suitable assumptions, the existence of certain commensurated subgroups in

\Gamma

yields strong restrictions on the dynamics of the

\Gamma

-action: the space

X

has compressible open subsets, and it is an almost

\Gamma

-boundary. Those properties yield in turn restrictions on the structure of

\Gamma

:

\Gamma

is neither amenable nor residually finite. Among the applications, we show that the (alternating subgroup of the) topological full group associated to a minimal and expansive Cantor action of a finitely generated amenable group has no commensurated subgroups other than the trivial ones. Similarly, every commensurated subgroup of a finitely generated branch group is commensurate to a normal subgroup; the latter assertion relies on an appendix by Dominik Francoeur, and generalizes a result of Phillip Wesolek on finitely generated just-infinite branch groups. Other applications concern discrete groups acting on the circle, and the centralizer lattice of non-discrete totally disconnected locally compact (tdlc) groups. Our results rely, in an essential way, on recent results on the structure of tdlc groups, on the dynamics of their micro-supported actions, and on the notion of uniformly recurrent subgroups.
What should an intensivist know about pneumocephalus and tension pneumocephalus?
Authors: Wankhade Bhushan Sudhakar , Beniamein Maged Mohsen Kamel , Alrais Zeyad Faoor , Mathew Jyoti Ittoop , Alrais Ghaya Zeyad
Published: April 2022

Collection of air in the cranial cavity is called pneumocephalus. Although simple pneumocephalus is a benign condition, accompanying increased intracranial pressure can produce a life-threatening condition comparable to tension pneumothorax, which is termed tension pneumocephalus. We report a case of tension pneumocephalus after drainage of a cerebrospinal fluid hygroma. The tension pneumocephalus was treated with decompression craniotomy, but the patient later died due to the complications related to critical care. Traumatic brain injury and neurosurgical intervention are the most common causes of pneumocephalus. Pneumocephalus and tension pneumocephalus are neurosurgical emergencies, and anesthetics and intensive care management like the use of nitrous oxide during anesthesia and positive pressure ventilation have important implications in their development and progress. Clinically, patients can present with various nonspecific neurological manifestations that are indistinguishable from a those of a primary neurological condition. If the diagnosis is questionable, patients should be investigated using computed tomography of the brain. Immediate neurosurgical consultation with decompression is the treatment of choice.
Eighth order Predictor-Corrector Method to Solve Quadratic Riccati Differential Equations
Authors: Kassahun Wase , Shiferaw Alemayehu , Gebregiorgis Solomon
Published: April 2022

In this paper, the eighth-order predictor-corrector method is presented for solving quadratic Riccati differential equations. First, the interval is discretized and then the method is formulated by using Newton’s backward difference interpolation formula. The stability and convergence of the method have been investigated. To validate the applicability of the proposed method, two model examples with exact solutions have been considered and numerically solved. Maximum absolute errors are presented in tables and figures for different values of mesh size h and the present method gives better results than some existing numerical methods reported in the literature.
Tree Height Estimation from Unmanned Aerial Vehicle Imagery and Its Sensitivity on Above Ground Biomass Estimation in Dry Afromontane Forest, Northern Ethiopia
Authors: Hadush Tigistu , Girma Atkilt , Zenebe Amanuel
Published: April 2022

Tree height is a parameter useful for calculating above-ground forest biomass and is mostly measured traditionally by ground survey. On the other hand, measuring the forest tree height and biomass estimation through field survey is labor-intensive and time-consuming. The application of remote sensing for forest above-ground biomass (AGB) estimation without forest destruction is important in order to estimate the carbon sequestration potential of the forest. The unmanned aerial vehicle (UAV) is an elating technology, which can help to estimate tree height and it is evolving at a rapid speed. Moreover, assessing the relationship between estimated and measured tree height is necessary for the future application of estimated tree height on AGB estimation. However, tree height estimation from photogrammetric UAV imagery in the dry Afromontane Forest and its sensitivity to AGB estimation are not investigated. Thus, this study aimed to assess the accuracy of tree height estimated from photogrammetric UAV imagery and the sensitivity of the estimated tree height on AGB estimation. Photogrammetric UAV acquired images and sample trees height measured on the ground were collected in Desa’a dry Afromontane Forest, Northern Ethiopia. Tree height was estimated from photogrammetric UAV acquired images and compared with tree heights measured on the ground. Moreover, the sensitivity of the estimated tree height on AGB estimation was investigated. The estimated tree height explained 89% of the tree height measured in the field. A considerable difference between estimated and measured tree height has an insignificant effect on AGB estimation. Thus, in the dry land Afromontane Forest the application of UAV aerial imagery for tree height estimation is promising to estimate AGB.
The role of a medical doctor in war-thoughts over Russian soldiers and Ukraine
Authors: Muula Adamson
Published: April 2022

In 1992, I interviewed for both medical school and the Malawi Army to join my country’s medical corps in preparation for a military hospital that was soon to be established. From that time many things changed. Although I graduated from medical school, I did not become a military doctor. I have fond images of what it would have been, had my dreams of joining the uniformed forces of my country come to fruition.
Mothers’ breastfeeding attitudes when lactation overlaps with a new pregnancy
Authors: Çınar Nursan , Suzan Özge Karakaya , Topal Sümeyra , Pekşen Sultan
Published: April 2022

Background and Aim There is usually a strong cultural taboo when breastfeeding overlaps with pregnancy. A lot of mothers cease breastfeeding their infants when they conceive again due to social pressure, professional advice, or their own beliefs. The present research aimed to reveal the attitudes of mothers who conceived again while breastfeeding their infants and their experiences in this process.MethodsThe data of the study, were collected between November 2018 and March 2019 in Sakarya University Education and Research Hospital, Sakarya. The study conducted in 40 women in whom lactation overlapped with pregnancy, and the face-to-face interview technique was employed for data collection. Data were collected using an information form containing information about the participants and a semi-structured interview form. The interviews conducted were then examined using the interpretative phenomenological analysis method, one of the qualitative research methods. The codes and themes were created using the NVIVO 9.0 program. In the report of this study, the Consolidated criteria for reporting qualitative research (COREQ) checklist was utilized as a guide.ResultsThe mean age of the mothers is 26.70±4.58 (min: 20, max: 36), 62.5% (n=25) of the mothers were in the third trimester. While 5% of the mothers (n=2) continued breastfeeding during pregnancy, 95% (n=38) ceased breastfeeding at certain periods of pregnancy. It was observed that the mothers who conceived again during the lactation period considerably hesitated how to act about breastfeeding, they were significantly influenced by the people in their environment concerning how to overcome this, and they were often misguided.Conclusion There is obviously an urgent need for evidence-based studies on the subject. Studies to be carried out in this regard will increase the self-confidence of healthcare professionals and will enable them to perform effective training and counseling on the subject
A Malawian pharmaceutical response to the COVID-19 Pandemic
Authors: Kachingwe Baxter , Kumpalume Peter , Khuluza Felix , Nyirenda Kumbukani , Matambo Ernest , Mponda John , Dzabala Nettie , Chiumia Francis , Chikowe Ibrahim , Chimimba Frider , Nyoloka Nelson , Alfazema Louisa , Nyirongo Happy , Smith Dallas
Published: April 2022

The COVID-19 pandemic has elicited swift and innovative responses due to the severity of the outbreak. Higher education institutions worldwide with pharmacy programs have identified vital gaps in COVID-19 care and has undertaken proactive steps to aid in the fight against the coronavirus. In Malawi, the Kamuzu University of Health Science’s Department of Pharmacy initiated the production of a modified formulation of the World Health Organization’s (WHO) recommended hand sanitizer. This manufacturing venture involved mobilizing the pharmacy faculty, identifying gaps in supplies and equipment, and utilizing evidenced-based information to create a high-quality sanitation product, which passed the requirements as tested by the Malawi Bureau of Standards. The department of pharmacy is expanding their distribution of the product to meet the needs of frontline healthcare workers and vulnerable populations. With historical issues of accessing care in Malawi and with COVID-19’s spread among healthcare workers, this hand sanitizer venture is vital in the public healthcare’s system response. The department of pharmacy will continue to lead the pharmacy profession in Malawi to provide targeted interventions in this unprecedented time.
A rare lesıon of breast: Hydatıd cyst
Authors: Sozutok Sinan , Kaya Omer , Akkaya Huseyin , Gulek Bozkurt
Published: April 2022

Hydatid cyst (HC) is a lesion most commonly seen in the liver but can occur in many parts of the body. Breast involvement with HC  is extremely rare. It can be isolated or accompanied by other organ involvements. In this report, we present a 46-year-old female with  isolated HC located in the right breast. In the ultrasonography and MR images of the patient, the lesion was compatible with the HC,  and homogenous dens lesion was shown on mammography. Diagnosis of HC was confirmed pathological. With this study, it was aimed to emphasize the radiological findings of isolated breast HC.
Antimicrobial susceptibility profiles of clinically important bacterial pathogens at the Kamuzu Central Hospital in Lilongwe, Malawi
Authors: Choonara Faheema E , Haldorsen Bjørg C. , Ndhlovu Isaac , Saulosi Osborne , Maida Tarsizio , Lampiao Fanuel , Simonsen Gunnar S. , Essack Sabiha Y. , Sundsfjord Arnfinn
Published: April 2022

BackgroundThe aim of this prospective study was to ascertain antimicrobial resistance (AMR) in clinical bacterial pathogens from in-hospital adult patients at a tertiary hospital in Lilongwe, Malawi.Methods Clinical specimens (blood culture, pus, urine and cerebrospinal fluid) collected during June to December 2017 were examined for bacterial growth in standard aerobic conditions. One specimen per patient was included. Antimicrobial susceptibility testing (AST) was performed using the disk diffusion method and interpreted according to EUCAST guidelines. ResultsA total of 694 specimens were collected during the study period, of which 336 (48%) specimen yielded visible bacterial growth. Of the 336 specimens, a total of 411 phenotypically different isolates were recovered. Of the 411 isolates, 84 isolates (20%) were excluded and the remaining 327 (80%) were further characterised. The characterised isolates were identified as ESKAPE pathogens (n=195/327; 60%), Escherichia coli (n=92/327; 28%), Proteus mirabilis (n=33/327; 10) or Salmonella spp. (n=7/327; 2%) and were included for further analysis. The excluded isolates (n=84) comprised of coagulase-negative staphylococci (n=25), streptococci (n=33), and low-prevalence Gram-negative bacilli (n=26). E. coli (n=92; 28%) and S. aureus (n=86; 26%) were the most dominant species. A multidrug resistant (MDR) extended spectrum β- lactamase (ESBL)-positive phenotype was detected in Klebsiella pneumoniae (n=20/29; 69%) and E. coli (n=49/92; 53%). One third of the Pseudomonas aeruginosa isolates were resistant to meropenem (MEM), but did not appear to be carbapenemase-producers. Methicillin resistant Staphylococcus aureus (MRSA) was molecularly confirmed in 10.5% of S. aureus (n=9/86). Conclusion The high proportion of the MDR ESBL-phenotype in clinical isolates of Enterobacterales, strongly limits antimicrobial treatment options and has consequences for empirical and targeted antimicrobial treatment as well as clinical microbiology services and hospital infection control. There is need for a continuous surveillance and an antimicrobial stewardship (AMS) program to contain and prevent the spread of AMR.
Socio-demographic characteristics of children and young adults with varied asthma control- does it make a difference?
Authors: Joy Eze N , Adaeze Ayuk C , Maduka Ughasoro D , Tagbo Oguonu
Published: April 2022

Background The socioeconomic status and caregiver perception of asthma as a disease, the availability of specialty care and medication adherence have major influence on outcome of asthma control in children with asthma. The control of asthma therefore depends on the optimizing the interplay of these factors taking into consideration the regional and racial variations.ObjectiveThe objective of this study was to evaluate the association between socio-demographic factors and asthma control outcome in children with asthma.Materials and MethodsThis was a cross-sectional study involving 66 consecutively enrolled participants with asthma whose economic burden for asthma was assessed in a previous study. Based on the number of registered children attending the clinic, a minimum sample size of 66 calculated for this study was obtained.The participants were consenting children and young adults between the ages of 1 and 20 years. Using standard methods, data on socio-economic status, personal and family demographics, including household number, mothers’ educational attainments and employment status; and asthma control were collected and analyzed. Asthma control was assessed using Asthma control test (ACT) and guided by the original developers scoring, participants were grouped into well controlled, partly controlled and uncontrolled. The Chi-square test was used to test for association between participants’ socio-demographic characteristics (age, socioeconomic status, mothers’ education and employment, and number of children in the household) and asthma control status at 5% level of significance. ResultsOf all study participants, 34 (51.55%) were male, with mean age (SD) of 11.6 (4.8) years. The mean (SD) age at initial asthma diagnosis was 6.2 (4.6) years. The majority 49(76.5%) of the mothers had tertiary education. Study participants belonging to the poorest; very poor; poor; and least poor socio-economic cadres were, 16 (24.2%); 17 (25.8%); 17 (25.8%); and 16 (24.2%) respectively. Asthma control classification showed that, 26 (39.4%); 31 (47%) and 9 (13.6%) participants had well controlled asthma, partially controlled asthma and uncontrolled asthma respectively. The factors like age, socioeconomic status, mothers ‘educational level, employment status and number of children in the household did not show any statistically significant association with the asthma control status of participants.Conclusions Asthma control outcome remains multifactorial as participants’ socio-demographic characteristics did not impact on the level of control of asthma, among participants in the south eastern parts of Nigeria, despite being in a LMIC. A larger study is recommended to further explore this.
Systematic assessment of complications after laparoscopic colorectal surgery for advanced colorectal cancer: A retrospective study using Clavien–Dindo classification, 5-year experience
Authors: Degerli Mahmut Said , Canturk Alp Omer , Bozkurt Hilmi , Canturk Alp Omer , Canturk Alp Omer , Alpay Orcun , Akinci Muzaffer , Altundal Yusuf  Emre , Yildiz Turgay , Yildirim Dogan
Published: April 2022

AimThe presence and frequency of surgical complications indicate the quality of the surgery performed. However, a standard classification system should specify, describe, and compare complications. Clavien Dindo classification is an easily applicable classification in the evaluation of complications. Our study aimed to reveal the severity of complications and the factors affecting them by using the Clavien Dindo classification in patients undergoing laparoscopic colorectal surgery.MethodsBetween January 2015 and December 2020, we retrospectively collected the laparoscopic colorectal surgery complications using Clavien Dindo grading in patients in our colorectal surgery unit in the database. The outcome variables studied were age, gender, BMI, ASA score, postoperative length of hospital stay, operation procedure, cancer size, postoperative mortality.ResultsThere were 53 males and 17 female patients, with a mean age of 56,9±13,4.(19-81). Seventy patients, 32 (45%), had at least one postoperative complication. About complications; 58.6% were rated as Clavien I, 22.9% as Clavien II, 8.6% as Clavien IIIa, 4.3% as Clavien IIIb, 2.9% as Clavien IVa, and 2.9% as Clavien V. There was no Clavien grade IVb complication in any of the patients. Length of hospital stays was significantly higher in patients with had major complex surgery and had higher scores. Clavien Dindo classification was positively statistically significantly related to the day of hospitalization in male and female sex (p<0.001 for all). In addition, positively significantly related to Clavien Dindo classation and tumor diameter in the female sex (p=0.014) detected.ConclusionsIn laparoscopic colorectal surgery, the Clavien-Dindo classification can be easily applied and used safely to determine complication rates. The reason for this statistical difference that we detected in our study and that occurs in women may be due to anatomical differences or the surgeon’s experience.