bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Impact of Age on Malaria Prevalence among COVID-19 Patients and Healthy Volunteers with some Associated Symptoms in Rivers State, Nigeria
Authors: Orevaoghene Onosakponome, Evelyn , Ugochukwu Nyenke, Clement , Rhoda Nwalozie, , Asikiya Huldah Hanson, 
Published: April 2022

Background: The co-morbidity of malaria and COVID-19 is a growing public health concern since the outbreak of covid-19 especially in low and middle income countries due to poor healthcare facilities, system, personnel manpower and financial resources. It is generally known that age has a significant impact on malaria vulnerability, but with emerging concern on malaria and covid-19 co-infection, age based prevalence are among many studied characteristics of malaria prevalence in covid-19 patients especially in malaria endemic areas.
Aim: The study was aimed at evaluating the impact of age in the prevalence of malaria and COVID-19 co-infection as well as some associated symptoms in Rivers State, Nigeria.
Methodology: The study was a cross-sectional study conducted among 600 covid-19 patients admitted in Rivers State Covid-19 Treatment Centre, Eleme. Consenting subjects were randomly selected and were classified into three groups based on age; 0-25yrs, 26-50yrs and >50yrs. Blood samples were collected using venipuncture technique and blood was collected in EDTA bottles. Thick film was prepared was stained using Giemsa for malaria microscopy. All data generated were analyzed statistically using analysis of variance (ANOVA) and chi-square test with a P<0.05 considered significant.
Result: Results showed that total malaria prevalence was 70.2 while on age group classifications, the prevalence was 100% in all age groups but healthy control group had less prevalence. This study has shown that prevalence of malaria among covid-19 subjects was significantly higher in all age groups (p<0.05). All symptoms were significantly associated with age at P<0.05; individuals >50years and 26 – 50years experienced more symptoms among COVID-19 patients and healthy volunteers respectively (P<0.05).
Conclusion: This study has shown that malarial prevalence is absolutely higher among covid-19 subjects and the level of prevalence does not discriminate among age groups. However, more research work is needed to fully understand the relationship between malaria and COVID-19 co-infection due to the novel nature of the disease globally and their shared clinical symptoms.
Perception of HIV/AIDS among Tertiary Education Students in the Tamale Metropolis and Their Willingness to Take the HIV Test
Authors: Emmanuel Mensah Calvin , Mbiyieba John , Adiyaga Wezena Cletus 
Published: April 2022

Aim: The study assessed the perception of HIV/AIDS among students in tertiary education institutions in northern Ghana and their willingness to take the HIV test.
Study Design: Descriptive cross-sectional study.
Place and Duration of Study: Tamale Metropolis from September 2020 to June 2021.
Methodology: A convenience sampling technique was employed to select 374 students aged 15-30 years. Data from participants was collected using a standardized structure questionnaire and analyzed on Epi Info version 7. Cross tabulation was used to estimate the association between outcome variables and independent variables.
Results: Almost all participants (366; 93.61% [95% CI: 90.73 – 95. 63]) were aware of HIV/AIDS, having acquired information about the disease mostly from a health worker. A very high proportion of the respondents (346; 88.49% [95% CI: 84.95 – 91.29]) were also aware of the modes of transmission of HIV, with 64.41% of participants identifying unprotected sexual intercourse as a major mode of HIV transmission. Though aware of how HIV is transmitted, almost half (46.21%) of sexually active participants did not use a condom in their last sexual intercourse. More than half (221; 56.52% [95% CI: 51.57 – 61.35]) of respondents had never heard of any HIV/AIDS support groups in their schools or communities. Though a majority (58.57%) of respondents were aware of free HCT in the country, the majority (207; 52.94% [95% CI: 47.99 – 57.84]) of the respondents had never taken the HIV test. Close to half (167; 42.71% [95% CI: 37.90 – 47.66]) of respondents had no plans to take the HIV test in the future.
Conclusion: Our results revealed the need to intensify HIV/AIDS education, especially among the youth, emphasizing the increasing risk of HIV infection, importance of regular HIV tests for sexually active persons and the use of protection during casual sex.
Improvement of Three Phase Induction Motor Performance Using Voltage and Frequency Speed Control Techniques
Authors: George Okonkwo Chibuzor , Uju Isidore A. , Nwajuonye Raymond Onyeka 
Published: April 2022

Inductions motors are the most commonly used electric motors because of their robustness, durability, reliability and low cost, and essentially lack the ability to run at variable speed operation. However, the first DC motors were applied to most of electric drives. The advent of power electronics has drastically made a lot of improvement, where alternating current drive is used to control and run the performance of induction motor. This research work presents the use of voltage and Frequency control technique to improve the performance of speed control of three phase 4-pole induction motor. Controlling the speed of motor using traditional method such as controlling the supply voltage ,changing the stator pole and others incurs running motor at full speed, speed instability, and the efficiency of the motor drop when motor speed is varied but the voltage and frequency ratio method of speed control solves this problem .A model and simulation in MATLAB for various method of speed control was analysed with constant voltage and frequency method showing much improvement on electromagnetic torque and the speed characteristic of the induction motor compared to other method such as change in stator resistance, rotor resistance, number of poles, stator leakage resistance and others. Varying the line frequency at a maintained constant 8V/Hz V/F ratio and the effect of the torque-speed characteristics performance of the three phase 4-pole induction motor for line frequencies were investigated: (40Hz, 50Hz, 60Hz, 70Hz, and 80Hz). The result shows that as the line frequency increases, the torque decreases and the speed increases (or slip decreases), and for a line frequency of 40Hz, the torque observed is 43.6Nm while the rotor speed is 1076rpm. But for a line frequency of 80Hz, the peak torque was observed at 22Nm while the corresponding rotor speed was 2152rpm, thereby improving the speed control performances of the three phase 4-pole induction motor and its voltage frequency characteristics.
Evaluation of Microbiological Quality of Water, Sediment and Soil Characteristics in Okrika Local Government Area, Rivers State, Nigeria
Authors: Ibinabo Ogolo , Ogbonna D. N. , Abam T. K. S. 
Published: April 2022

Water is the most important resource on earth and safe drinking water is essential to sustain life. Most rural communities do not treat their water before consumption. Therefore, the aim of this study was to evaluate the microbiological quality of water, sediment and soil characteristic in Okrika LGA, Nigeria. Samples were collected using sterile bottles from boreholes, hand-dug wells, surface water, sediments and soils using standard methods and analysed accordingly. Results show that Total Heterotrophic Bacterial Count (THBC) ranged from in Kalio-Ama to at Okari-Ama. Total Fecal count (TFC) ranged from 0 to at Isaka Town. Total Coliform Count (TCC) ranged from 0 to at Ogan-Ama. Total Salmonella Shigella Count (TSSC) ranged from 0 to in Ogan-Ama. Total Vibio Count (TVC) ranged from 0 to at Kalio-Ama. The most prominent bacterial isolates from all the stations are of the genera such as Bacillus, Staphylococcus, Escherichia Coli, Micrococcus, Kiebsiella, Pseudomonas, Vibrio, Aeromonas, Serratia and Alcaligenes which were isolated across the samples with Bacillus as more frequent with 50%. In the dry season, bacterial isolates were 100% susceptible to Gentamycin and Ofloxacin and 100% resistance to Augumentin, Cefuroxime and Cefixime. In the wet season, isolates had 100% susceptibility to Ciprooflozacin and 100% resistance to Cloxacin, Augmentin and Gentamicine. The result of this study poses a public health risk to consumers who use these sources of water for domestic purposes, recreation and treatments. Diseases like typhoid, cholera, polio, skin and lung infections are eminent.
Near‐Infrared, Self‐Powered and Polarization‐Sensitive Photodetector Based on GeSe–MoTe2 p–n Heterojunction
Authors: Zhang Nan , Wu Liangwei , Gao Wei , Zhao Qixiao , Huo Nengjie , Li Jingbo 
Published: April 2022

AbstractNear‐infrared polarization‐sensitive photodetectors hold the advantages of capturing light signals with high performance while shielding stray light, endowing them the potential applications in target tracking, remote sensing, and computer vision. Here, a 2D polarization‐sensitive, self‐powered, and near‐infrared photodetector is constructed by vertically stacking multilayer p‐type GeSe on n‐type MoTe2. The type‐II energy band alignment and anisotropic crystalline structure of GeSe components allow an effective separation and transmission of polarized light excited carriers, enabling the capability of polarization‐sensitive and self‐powered photodetections. The device exhibits broadband spectral coverage from visible (405 nm) to near‐infrared (1310 nm) wavelength range. At zero bias and 808 nm light, the responsivity (R) and detectivity (D*) can reach 52 mA W–1 and 4.1 × 1011 Jones, respectively. Due to the extremely low dark current of several tens of fA, the photoswitching ratio can reach close to 106. More importantly, because of the strong in‐plane anisotropic orthogonal structure of GeSe, the polarization sensitivity can reach 5.4 under 635 nm polarized light illumination, outperforming the polarization‐sensitive photodetectors based on 2D anisotropic materials and heterostructures. This work provides an effective strategy of using anisotropic/isotropic GeSe/MoTe2 heterojunctions to realize self‐powered, near‐infrared, and polarization‐sensitive photodetectors with integrated angle‐resolved optoelectronic devices.
Gold Micropetals Self‐Assembled by Shadow‐Sphere Lithography for Optofluidic Control
Authors: Namura Kyoko , Hanai Shunya , Kondo Shuji , Kumar Samir , Suzuki Motofumi 
Published: April 2022

AbstractThe self‐assembly of gold micropetals and microfluidic control using their photothermal properties are demonstrated experimentally in this work. Gold micropetals are fabricated on a glass substrate using the shadow‐sphere lithography technique. Each micropetal consists of two areas with thin gold films of different thicknesses resulting in an inhomogeneous optical absorption distribution. The photothermal property of the micropetal results in the generation of a water vapor microbubble on the micropetal when the micropetal is immersed in degassed water and irradiated by a continuous wave laser. By applying a temperature gradient to the microbubble, Marangoni flow in the direction parallel to the substrate is successfully induced. The direction of the flow varies with the combination of the optical absorption distribution in the micropetal and the laser power. This variation can be explained by the position of the bubble on the micropetal and the resulting temperature gradient around the bubble. Controlling the position at which the bubble is generated on the micropetal is found to be important for controlling the flow direction. This technique allows microfluids to be pumped through the irradiation of light with a simple intensity distribution on spatially arranged micropetals.
Pull‐Pull Alkenes in the Aza‐Michael Reaction
Authors: Rulev Alexander Yu. , Tyumentsev Ilya A. 
Published: April 2022

AbstractAza‐Michael addition is known to be one of the most exploited reactions in organic chemistry. Taking into account the fact that each seventh reaction in pharmaceutical industry involves the formation of at least one C−N bond, it is not surprising that this reaction is especially valuable for the synthesis of bioactive compounds and drugs. Traditionally, only push‐pull alkenes are regarded as starting material for this reaction. The participation of pull‐pull alkenes as Michael acceptors is much less studied. The presence of two vicinal electron‐withdrawing groups makes them highly reactive in nucleophilic reactions especially with nitrogen‐centered nucleophiles. This feature allows them to be excellent building blocks in the synthesis of bioactive molecules and polyfunctional materials. The review considers the most important and sometimes unexpected results obtained over the last two decades on the conjugate addition of nitrogen nucleophiles to pull‐pull alkenes bearing various acceptor moieties (alkoxycarbonyl‐, carbonyl‐, formyl‐, cyano‐, trifluoromethyl‐ or nitro group) in various combinations.magnified image
Pushing Lithium Cobalt Oxides to 4.7 V by Lattice‐Matched Interfacial Engineering
Authors: Yang Xuerui , Wang Chuanwei , Yan Pengfei , Jiao Tianpeng , Hao Jialiang , Jiang Yuyuan , Ren Fucheng , Zhang Wenguang , Zheng Jianming , Cheng Yong , Wang Xianshu , Yang Wen , Zhu Jianping , Pan Siyu , Lin Min , Zeng Leiying , Gong Zhengliang , Li Juntao , Yang Yong 
Published: April 2022

AbstractThe utilization of high‐voltage LiCoO2 is imperative to break the bottleneck of the practical energy density of lithium‐ion batteries. However, LiCoO2 suffers from severe structural and interfacial degradation at >4.55 V. Herein, a novel lattice‐matched LiCoPO4 coating is rationally designed for LiCoO2 which works at 4.6 V (vs Li/Li+) or above. This LiCoPO4 coating, derived by an in situ chemical reaction, grows epitaxially on LiCoO2 crystallite with strong bonding and complete coverage to LiCoO2, ensuring a stable cathode–electrolyte interface with fewer side reactions and alleviated intergranular cracking and phase collapse during repeated high‐voltage lithiation/delithiation processes. In addition, the formed strong covalent P–O tetrahedron configuration at the interface effectively decreases the surface oxygen activity of LiCoO2, further suppressing oxygen release and irreversible phase transition. Therefore, the LiCoPO4‐LiCoO2ǁLi cells display excellent capacity retention of 87% after 300 cycles at 4.6 V and stable operation at 4.6 V/55 °C or 4.7 V/30 °C. The strategy of lattice‐matching growth affords a new way to impact the development of high‐voltage LiCoO2 and beyond.
Decompensation of cardiorespiratory function and emergence of anemia during pregnancy in a case of mitochondrial myopathy, lactic acidosis, and sideroblastic anemia 2 with compound heterozygous YARS2 pathogenic variants
Authors: Rudaks Laura I. , Watson Eloise , Oboudiyat Carly , Kumar Kishore R. , Sullivan Patricia , Cowley Mark J. , Davis Ryan L. , Sue Carolyn M. 
Published: April 2022

AbstractMyopathy, lactic acidosis, and sideroblastic anemia 2 (MLASA2) is an autosomal recessive mitochondrial disorder caused by pathogenic variants in YARS2. YARS2 variants confer heterogeneous phenotypes ranging from the full MLASA syndrome to a clinically unaffected state. Symptom onset is most common in the first decade of life but can occur in adulthood and has been reported following intercurrent illness. Early death can result from respiratory muscle weakness and cardiomyopathy. We report a case of MLASA2 with compound heterozygous YARS2 pathogenic variants; a known pathogenic nonsense variant [NM_001040436.3:c.98C>A (p.Ser33Ter)] and a likely pathogenic missense variant not previously associated with disease [NM_001040436.3:c.948G>T (p.Arg316Ser)]. The proband initially presented with a relatively mild phenotype of myopathy and lactic acidosis. During pregnancy, anemia emerged as an additional feature and in the postpartum period she experienced severe decompensation of cardiorespiratory function. This is the first reported case of pregnancy‐related complications in a patient with YARS2‐related mitochondrial disease. This case highlights the need for caution and careful counseling when considering pregnancy in mitochondrial disease, due to the risk of disease exacerbation and pregnancy complications.
The Mechanochemistry of Carboranes
Authors: Sha Ye , Zhou Zhou , Zhu Miao , Luo Zhenyang , Xu Enhua , Li Xiang , Yan Hong 
Published: April 2022

AbstractWe developedo‐carborane as a new mechanophore by showing that theo‐carborane cluster is the preferred scission site in chain‐centered polymers through ultrasonication mechanochemistry. Mechanistic studies are consistent with a predominately homolytic mechanism of chain scission. The mechanically generated monocarbaborane fragments are highly reactive toward alcohol nucleophiles. By contrast, carborane with a different regiochemistry (m‐carborane) maintained its high mechanical stability. DFT simulations provide insights into the origins of carborane's mechanical lability. This fundamental research provides a new stimulus for carborane cage activation.
Quantitative evaluation of glycan‐binding specificity of recombinant concanavalin A produced in lettuce (Lactuca sativa)
Authors: Oinam Lalhaba , Hayashi Ryoma , Hiemori Keiko , Kiyoi Kayo , Sage‐Ono Kimiyo , Miura Kenji , Ono Michiyuki , Tateno Hiroaki 
Published: April 2022

AbstractConcanavalin A (ConA), a mannose (Man)‐specific leguminous lectin isolated from the jack bean (Canavalia ensiformis) seed extracts, was discovered over a century ago. Although ConA has been extensively applied in various life science research, recombinant mature ConA expression has not been fully established. Here, we aimed to produce recombinant ConA (rConA) in lettuce (Lactuca sativa) using an Agrobacterium tumefaciens‐mediated transient expression system. rConA could be produced as a fully active form from soluble fractions of lettuce leaves and purified by affinity chromatography. From 12 g wet weight of lettuce leaves, 0.9 mg rConA could be purified. The glycan‐binding properties of rConA were then compared with that of the native ConA isolated from jack bean using glycoconjugate microarray and frontal affinity chromatography. rConA demonstrated a glycan‐binding specificity similar to nConA. Both molecules bound to N‐glycans containing a terminal Man residue. Consistent with previous reports, terminal Manα1‐6Man was found to be an essential unit for the high‐affinity binding of rConA and nConA, while bisecting GlcNAc diminished the binding of rConA and nConA to Manα1‐6Man‐terminated N‐glycans. These results demonstrate that the fully active rConA could be produced using the A. tumefaciens‐mediated transient expression system and used as a recombinant substitute for nConA.
Foam fractionation methods in aerobic fermentation processes
Authors: Oraby Amira , Weickardt Isabell , Zibek Susanne 
Published: April 2022

AbstractInherently occurring foam formation during aerobic fermentation of surface‐active compounds can be exploited by fractionating the foam. This also serves as the first downstream processing step for product concentration and is used for in situ product recovery. Compared to other foam prevention methods, it does not interfere with fermentation parameters or alter broth composition. Nevertheless, parameters affecting the foaming behavior are complex. Therefore, the specific foam fractionation designs need to be engineered for each fermentation individually. This still hinders a widespread industrial application. However, few available commercial approaches demonstrate the applicability of foam columns on an industrial scale. This systematic literature review highlights relevant design aspects and process demands that need to be considered for an application to fermentations and proposes a classification of foam fractionation designs and methods. It further analyses substance‐specific characteristics associated with foam fractionation. Finally, solutions for current challenges are presented, and future perspectives are discussed.
Adductor longus: An anatomical study to better understand groin pain
Authors: Kato Takuya , Taniguchi Keigo , Kodesho Taiki , Nakao Gakuto , Yokoyama Yu , Saito Yuhei , Katayose Masaki 
Published: April 2022

AbstractWe investigated the shear modulus–passive force relationship in the hip adductor longus (AL) muscles of human cadavers and explored the effect of muscle architecture on the elastic properties of the AL muscle using shear wave elastography (SWE). Nine AL muscles were harvested from a soft, embalmed cadaver. The AL muscles were affixed to a custom‐built device comprising two clamps, a pulley, and a cable to provide passive loads, which were increased from 0 to 600 g in 60‐g increments. The shear modulus of the AL muscle was measured in the proximal (Pro), middle (Mid), and distal (Dis) regions. The masses and anatomical cross‐sectional areas (ACSAs) of the AL muscles were measured. The shear modulus‐passive load relationship of each tested muscle region was analyzed by fitting a least‐squares regression line. Moreover, the rate of increase in the shear modulus per unit load (s) was calculated. The shear modulus and passive force were linearly correlated for all AL muscles in each region (p < 0.01). The mean coefficients of determination (R2) for Pro, Mid, and Dis were 0.989, 0.986, and 0.982, respectively. The rate of increase in the shear modulus per unit load significantly correlated with the reciprocal of the muscle mass (r = 0.77, p = 0.02) and ACSA (r = 0.43, p = 0.03). Shear wave elastography can be used as an indirect measure of passive force in any region of the AL muscle. Additionally, the rate of increase in the shear modulus per unit load could be associated with muscle architectural parameters.
Bioactive Scalarane‐Type Sesterterpenoids from Marine Sources
Authors: Yu Hao‐Bing , Chen Hai‐Yan , Duan Song , Zhu Yu‐Ping , Hu Bo , He Ying , Cheng Si‐Tong , Jiao Bing‐Hua , Liu Xiao‐Yu 
Published: April 2022

AbstractScalarane‐type sesterterpenoids have received considerable attention in the scientific literature due to their diverse carbon skeletons and various biological activities and pharmacological properties. Among all these derivatives are commonly isolated from marine sponges and are occasionally derived from shell‐less mollusks, such as nudibranchs. This review comprehensively discusses the marine‐derived natural sources that give rise to these scalarane‐type sesterterpenoids, providing the names, their chemical structures, biological properties, with emphasis on anticancer activity and literature references related to these metabolites. A critical summary of the 221 compounds generated from January 2010 up to December 2021 for their potential as anticancer agents is presented.
Congenital primary obstructed megaureter presenting as inguinal hernia in an infant
Authors: Wishahi Mohamed 
Published: April 2022

AbstractA 4‐month‐old boy presented with left inguinal swelling, and the examination was notable for an inguinal hernia; ultrasonography and CT revealed that the hernia content was hugely dilated ureter of ureteral‐inguinal hernia caused by primary obstructed megaureter. Imaging of pediatric inguinal hernia elucidates contents, etiology, and guide for proper surgery.
Relationship between patients’ characteristics and efficacy of calcimimetics for primary hyperparathyroidism in the elderly
Authors: Yamamoto Koichiro , Nakano Yasuhiro , Tokumasu Kazuki , Honda Hiroyuki , Hasegawa Kou , Sato Asuka , Ogawa Hiroko , Obika Mikako , Hanayama Yoshihisa , Otsuka Fumio 
Published: April 2022

AbstractCalcimimetic treatment has been reported to be effective for primary hyperparathyroidism (PHPT). Nine elderly PHPT patients who had been treated with calcimimetics were retrospectively analyzed. It was found that calcimimetics can reduce elevated serum calcium levels in elderly PHPT patients with low femoral DEXA %YAM and low urinary cAMP levels.