bluuebunny/crossref_metadata_2025 huggingface dataset:
Protocol for a quasi-experimental study to assess the feasibility, acceptability and costs of multiple first-lines artemisinin-based combination therapies for uncomplicated malaria in the Kaya health district, Burkina Faso
Authors: SIRIBIE Mohamadou , Tchouatieu André-Marie , Soulama Issiaka , Kaboré Jean Moise Tanga , Nombré Yacouba , Hien Denise , Kiba Koumaré Alice , Barry Nouhoun , Baguiya Adama , Héma Alimatou , Dianda Frédéric , Savadogo Yacouba , Kouanda Seni , Tiono Alfred Bewendtaoré , Sirima Sodiomon Bienvenu
Published: February 2021

Introduction

As demonstrated in mathematical models, the simultaneous deployment of multiple first-line therapies (MFT) for uncomplicated malaria, using artemisinin-based combination therapies (ACTs), may extend the useful therapeutic life of the current ACTs. This is possible by reducing drug pressure and slowing the spread of resistance without putting patients’ life at risk. We hypothesised that a simultaneous deployment of three different ACTs is feasible, acceptable and can achieve high coverage rate if potential barriers are properly identified and addressed.

Methods and analysis

We plan to conduct a quasi-experimental study in the Kaya health district in Burkina Faso. We will investigate a simultaneous deployment of three ACTs, artemether–lumefantrine, pyronaridine–artesunate, dihydroartesinin–piperaquine, targeting three segments of the population: pregnant women, children under five and individuals aged five years and above. The study will include four overlapping phases: the formative phase, the MFT deployment phase, the monitoring and evaluation phase and the post-evaluation phase. The formative phase will help generate baseline information and develop MFT deployment tools. It will be followed by the MFT deployment phase in the study area. The monitoring and evaluation phase will be conducted as the deployment of MFT progresses. Cross-sectional surveys including desk reviews as well as qualitative and quantitative research methods will be used to assess the study outcomes. Quantitatives study outcomes will be measured using univariate, bivariate and multivariate analysis, including logistic regression and interrupted time series analysis approach. Content analysis will be performed on the qualitative data.

Ethics and dissemination

The Health Research Ethics Committee in Burkina Faso approved the study (Clearance no. 2018-8-113). Study findings will be disseminated through feedback meetings with local communities, national workshops, oral presentations at congresses, seminars and publications in peer-reviewed scientific journals.

Trial registration number

NCT04265573.
Key elements of effective postgraduate GP educational environments: a mixed methods study
Authors: Malau-Aduli Bunmi S. , Alele Faith O. , Heggarty Paula , Reeve Carole , Teague Peta-Ann
Published: February 2021

Objectives

Evidence in the literature suggests that satisfaction with postgraduate general practice (GP) training is associated with the quality of the educational environment. This study aimed to examine GP registrars’ level of satisfaction with a distributed model of training in a regional educational environment and investigate the relationship between satisfaction and academic performance.

Study design

A longitudinal 3-year study was conducted among GP registrars at James Cook University using a sequential explanatory mixed methods research design. GP registrars’ satisfaction was obtained using the scan of postgraduate educational environment domains tool. A focus group discussion was conducted to explore GP registrars’ perceptions of satisfaction with the educational environment.

Setting

James Cook University General Practice Training (JCU GPT) programme.

Participants

Six hundred and fifty one (651) GP registrars enrolled between 2016 and 2018 at JCU GPT programme.

Results

651 registrars completed the satisfaction survey between 2016 and 2018. Overall, 92% of the registrars were satisfied with the educational training environment. Registrars who had become fellows reported higher satisfaction levels compared with those who were still in training (mean=4.39 vs 4.20, p=0.001). However, academic performance had no impact on level of satisfaction with the educational environment. Similarly, practice location did not influence registrars’ satisfaction rates. Four themes (rich rural/remote educational environment, supportive learning environment, readiness to continue with rural practice and practice culture) emerged from the thematic data analysis.

Conclusion

A clinical learning environment that focuses on and supports individual learning needs is vital for effective postgraduate medical training. This study suggests that JCU GPT programme’s distributed model fostered a satisfying and supportive training environment with rich educational experiences that enhance retention of GP registrars in rural/remote North Queensland, Australia. The findings of this study may be applicable to other settings with similar training models.
Automated mechanical cardiopulmonary resuscitation devices versus manual chest compressions in the treatment of cardiac arrest: protocol of a systematic review and meta-analysis comparing machine to human
Authors: Obermaier Manuel , Zimmermann Johannes B , Popp Erik , Weigand Markus A , Weiterer Sebastian , Dinse-Lambracht Alexander , Muth Claus-Martin , Nußbaum Benedikt L , Gräsner Jan-Thorsten , Seewald Stephan , Jensen Katrin , Seide Svenja E
Published: February 2021

Introduction

Cardiac arrest is a leading cause of death in industrialised countries. Cardiopulmonary resuscitation (CPR) guidelines follow the principles of closed chest compression as described for the first time in 1960. Mechanical CPR devices are designed to improve chest compression quality, thus considering the improvement of resuscitation outcomes. This protocol outlines a systematic review and meta-analysis methodology to assess trials investigating the therapeutic effect of automated mechanical CPR devices at the rate of return of spontaneous circulation, neurological state and secondary endpoints (including short-term and long-term survival, injuries and surrogate parameters for CPR quality) in comparison with manual chest compressions in adults with cardiac arrest.

Methods and analysis

A sensitive search strategy will be employed in established bibliographic databases from inception until the date of search, followed by forward and backward reference searching. We will include randomised and quasi-randomised trials in qualitative analysis thus comparing mechanical to manual CPR. Studies reporting survival outcomes will be included in quantitative analysis. Two reviewers will assess independently publications using a predefined data collection form. Standardised tools will be used for data extraction, risks of bias and quality of evidence. If enough studies are identified for meta-analysis, the measures of association will be calculated by dint of bivariate random-effects models. Statistical heterogeneity will be evaluated by I2-statistics and explored through sensitivity analysis. By comprehensive subgroup analysis we intend to identify subpopulations who may benefit from mechanical or manual CPR techniques. The reporting follows the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement.

Ethics and dissemination

No ethical approval will be needed because data from previous studies will be retrieved and analysed. Most resuscitation studies are conducted under an emergency exception for informed consent. This publication contains data deriving from a dissertation project. We will disseminate the results through publication in a peer-reviewed journal and at scientific conferences.

PROSPERO registration number

CRD42017051633.
Psychometric properties of a self-assessment questionnaire concerning symptoms and impairment in urinary tract infections: the UTI-SIQ-8
Authors: Gágyor Ildikó , Rentzsch Katrin , Strube-Plaschke Stephanie , Himmel Wolfgang
Published: February 2021

Objectives

To validate the urinary tract infection-Symptom and Impairment Questionnaire (UTI-SIQ-8), a questionnaire that consists of four items to assess the symptom severity for dysuria, urgency, frequenc, and low abdominal pain and four items to assess the resulting impairment of activity by UTIs.

Design

Prospective observation study.

Setting

German primary care practices.

Participants

An unselected population of women with UTI. Women could participate online via a web application for smartphones, smartwatches and tablets or use a paper-and-pencil version.

Main outcomes

Psychometric properties of the UTI-SIQ-8 regarding reliability, validity and sensitivity to change by using factor analysis and multilevel and network analysis.

Results

Data from 120 women with a total of 769 symptom reports across 7 days of measurement were analysed. The majority of the participating patients (87/120) used the web application via smartphones or other devices. The reliability of the UTI-SIQ-8 was high, with Cronbach’s alpha of .86 at intake; convergent and discriminant validity was satisfactory. Intraclass correlation demonstrated high sensitivity to change, with 68% of the total variance being due to time differences. These daily changes in an individual’s symptoms moved parallel with daily changes in the EQ-5D-5L (b=1.68, SE=0.12, p<0.001) and the visual analogue scale (b=0.03, SE=0.003, p<0.001), also highlighting convergent validity with respect to daily changes in symptom severity.

Conclusions

The present findings support the UTI-SIQ-8 questionnaire as an economic, reliable and valid instrument for the assessment of symptom severity and symptom change in women with uncomplicated UTI. The web application helped patients to report symptoms on a daily basis. These findings may encourage primary care physicians to use the UTI-SIQ-8 in their daily practice and researchers to apply it to studies involving patients with uncomplicated UTI.
Multiomics analysis reveals the presence of a microbiome in the gut of fetal lambs
Authors: Bi Yanliang , Tu Yan , Zhang Naifeng , Wang Shiqing , Zhang Fan , Suen Garret , Shao Dafu , Li Shengli , Diao Qiyu
Published: February 2021

Objective

Microbial exposure is critical to neonatal and infant development, growth and immunity. However, whether a microbiome is present in the fetal gut prior to birth remains debated. In this study, lambs delivered by aseptic hysterectomy at full term were used as an animal model to investigate the presence of a microbiome in the prenatal gut using a multiomics approach.

Design

Lambs were euthanised immediately after aseptic caesarean section and their cecal content and umbilical cord blood samples were aseptically acquired. Cecal content samples were assessed using metagenomic and metatranscriptomic sequencing to characterise any existing microbiome. Both sample types were analysed using metabolomics in order to detect microbial metabolites.

Results

We detected a low-diversity and low-biomass microbiome in the prenatal fetal gut, which was mainly composed of bacteria belonging to the phyla Proteobacteria, Actinobacteria and Firmicutes.Escherichia coliwas the most abundant species in the prenatal fetal gut. We also detected multiple microbial metabolites including short chain fatty acids, deoxynojirimycin, mitomycin and tobramycin, further indicating the presence of metabolically active microbiota. Additionally, bacteriophage phiX174 and Orf virus, as well as antibiotic resistance genes, were detected in the fetal gut, suggesting that bacteriophage, viruses and bacteria carrying antibiotic resistance genes can be transmitted from the mother to the fetus during the gestation period.

Conclusions

This study provides strong evidence that the prenatal gut harbours a microbiome and that microbial colonisation of the fetal gut commences in utero.
Temperature affects substrate-associated bacterial composition during Ganoderma lucidum hyphal growth
Authors: Zhang Bo , Zhou Jie , Li Xiaolin , Ye Lei , Jia Dinghong , Gan Bingcheng , Tan Wei
Published: February 2021

The growth of the well-known fungus Ganoderma lucidum is influenced by temperature, which has an impact on the associated microbial structure in the substrate. In this study, we analyzed the bacterial diversity of the substrate at different temperatures using next-generation sequencing technology. A total of 513 733 sequences from 15 samples were assigned to 19 bacterial phyla. The samples were dominated by Proteobacteria, followed by Firmicutes; the 2 phyla exhibited opposite changes with elevated temperature. Bacterial genera showed different abundances at different temperatures, in which Sediminibacterium maintained a stable abundance below 40 °C, while Ochrobactrum and Rhodococcus were enriched with elevated temperature and both showed their highest abundances at 40 °C. Functional prediction uncovered 39 identified KEGG pathways, and bacterial genes involved in the membrane transport pathway exhibited the highest abundance subject to heat (40 °C) during the growth of G. lucidum. In general, our findings illustrated the influence of temperatures on G. lucidum mycelial morphology and the bacterial community in the substrate, and the results will facilitate cultivation of this fungus.
Mask Wearing Detection Algorithm Based on Improved Tiny YOLOv3
Authors: Liu Guohua , Zhang Qintao
Published: February 2021

The new coronavirus spreads widely through droplets, aerosols and other carriers. Wearing a mask can effectively reduce the probability of being infected by the virus. Therefore, it is necessary to monitor whether people wear masks in public to prevent the virus from spreading further. However, there is no mature general mask wearing detection algorithm. Based on tiny YOLOv3 algorithm, this paper realizes the detection of face with mask and face without mask, and proposes an improvement to the algorithm. First, the loss function of the bounding box regression is optimized, and the original loss function is optimized as the Generalized Intersection over Union (GIoU) loss. Second, the network structure is improved, the residual unit is introduced into the backbone to increase the depth of the network and the detection of two scales is expanded to three. Finally, the size of anchor boxes is clustered based on [Formula: see text]-means algorithm. The experimental results on the constructed dataset show that, compared with the tiny YOLOv3 algorithm, the algorithm proposed in this paper improves the detection accuracy while maintaining high-speed inference ability.
SQUAT POSTURE AND SPINOPELVIC PARAMETERS — RADIOGRAPHIC ASSESSMENT
Authors: Moon Myung-Sang , Kim Seong-Tae , Shin Seungyup , Jeon Seong Man
Published: February 2021

Purpose: Squat position is still enjoyed by the people for rest, oriental toileting, and field-farm work to implant seed, and to root out the weed with small half-moon hoe. No one has previously studied the influence of squat on the spinopelvic parameters, despite many previous studies related other postures. Our purpose is primarily to investigate the changes of the spinopelvic parameters in squat posture. Methods: Twenty volunteers (12 females and 8 males) without any back-related complaints were subjected to this study. Spinopelvic parameters were examined by utilizing radiograms. Results: LLA, SS, PT, and PI in standing were 32.9∘, 33.2∘, 15.9∘, and 49.2∘, respectively. LLA, SS, PT, and PI in chair sitting were 20.5∘, 29.7∘, 20.7∘, and 50.4∘, respectively. LLA, SS, PT, and PI in squat were 11.7∘, 25.5∘, 23.6∘, and 50.4∘, respectively. Pelvic tilt was larger in squat (23.6∘) and smaller in standing (15.9∘), while sacral slope was larger in standing (33.2∘) and smaller in squat (25.5∘), and intermediate in chair sitting (29.7∘). PI was almost equal in all postures. In squat posture, sacrum was maximally verticalized. Conclusion: Flattening of the lumbar curve with maximum verticalization of the sacrum associated with fully flexed hips and knees in squat posture was most noteworthy finding.
RELATIONSHIP BETWEEN AGE AT ONSET OF HIP PAIN AND RADIOGRAPHIC PARAMETERS OF ACETABULAR DYSPLASIA
Authors: Okano Kunihiko , Yamaguchi Kazumasa
Published: February 2021

In Japan, 88% of secondary osteoarthritis cases are associated with acetabular dysplasia (AD) or developmental dislocation of the hip (DDH). However, it is unknown whether severe AD causes hip pain at a lower age. We therefore investigated whether the age at onset of hip pain correlates with radiographic parameters used for the evaluation of AD. This study included 254 patients (235 women and 19 men; mean age 40.7 years, range 17–59 years) who visited our hospital for consultation regarding hip joint pain. Patients were examined radiographically and questioned regarding any history of DDH treatment in infancy. Of the 254 patients, 89 (35%) had a history of treatment for DDH (DDH group) and 165 (65%) had no history of DDH (non-DDH group). In the DDH group, there were no significant correlations between age and any of the tested radiographic parameters. In the non-DDH group, a moderate correlation was observed between age and acetabular angle ([Formula: see text], [Formula: see text]). Our data suggest that severe AD causes onset of hip pain at a young age in patients without a history of treatment for DDH.
EFFECTS OF GAIT AND ACTIVITIES OF DAILY LIVING MODIFICATIONS FOR IMPROVING KNEE JOINT FUNCTION IN COMMUNITY-DWELLING MIDDLE-AGED AND OLDER PEOPLE: A RANDOMIZED CONTROL STUDY
Authors: Ota Susumu , Fujita Remi , Ohko Hiroshi , Imai Aiko
Published: February 2021

Knee osteoarthritis is highly prevalent in middle-aged and older people, and biomechanical interventions include modifications of the gait and activities of daily living (ADL). This study investigated the effects of gait and ADL modifications compared with conventional exercise for improving knee function in community-dwelling middle-aged and older people. Fifty middle-aged and older people were randomly allocated to the control ([Formula: see text]) or intervention ([Formula: see text]) groups. The control group performed conventional straight leg raising and knee joint range of motion exercises, and the intervention group modified their gait by decreasing the knee adduction moment and increasing hip muscle activities, and performed range of motion exercises in a bathtub. In both groups, the program was implemented for 12 weeks. The Japan knee OA measure score, walking speed, and hip abduction strength significantly improved in both the control and intervention groups. The health-related quality of life (Short Form 8: SF-8) was significantly improved in the intervention group compared with the control group. Gait and ADL modifications achieved effects similar to those of conventional knee joint exercise, and might be more effective for improving physical function-related quality of life.
NEUROLOGICAL IMPROVEMENT AFTER SURGICAL TREATMENT OF INTRADURAL SCHWANNOMA T9-10 WITH PARAPLEGIA INFERIOR — A CASE REPORT
Authors: Ermawan Rieva , Adriansyah Denny
Published: February 2021

Schwannoma is a peripheral nerve sheath tumor, a benign tumor that grows slowly from neural fairy cells in the nerve sheath. These tumors can cause neurological deficits because of their intradural location and suppress the spinal cord so it needs to be decompressed to prevent permanent nerve damage. We reported one case of intradural thoracal schwannoma with a neurologic deficit of paraplegia inferior. We have performed a laminectomy — posterior durotomy and tumor excision with a posterior approach without intraoperative monitoring. The result is a return of motoric and sensory improvement. The patient was satisfied with the result.
PERSONALIZED CUSTOMIZATION METHOD OF HYBRID HUMAN MODEL FOR PEDESTRIAN-VEHICLE ACCIDENT RECONSTRUCTION
Authors: XU SHA , JIN XIANLONG , QIN CHUANG , CHAI XIANGHAI
Published: February 2021

Traffic accident reconstruction is a reverse dynamic problem, which requires hundreds of iterations to reconstruct the whole process of accident. However, in current pedestrian-vehicle accident reconstructions, it is difficult to quickly establish a pedestrian model based on specific cases, and it is hard to solve the contradiction between calculation accuracy and calculation time. In this paper, a personalized pedestrian customization method is proposed. First, the pedestrian structure is divided into independent modules according to obvious bony markers. For each independent module, multi-body (MB) model and finite element (FE) model are established, respectively. Then the appropriate modules are selected to form the whole hybrid pedestrian model. This method can customize the structure of pedestrian model according to the injury characteristics of pedestrians in specific accidents, and customize the parameters of pedestrian model according to the height and weight of pedestrians. The impact simulation tests are carried out on hybrid pedestrian models to verify the reliability of the models. The proposed method can effectively improve the modeling efficiency of pedestrian models and the reconstruction quality of pedestrian traffic accidents.
Parametric Analysis of Laser Beam Percussion Drilling for Thin Titanium Alloy Sheet Using Yb: Yag Fiber Laser
Authors: Singh Mohit , Mishra Sanjay , Yadava Vinod , Ramkumar J.
Published: February 2021

Laser beam percussion drilling (LBPD) can create high density holes in aerospace materials with the repeated application of laser pulses at a single spot. In this study, one-parameter-at-a-time approach has been used to investigate the individual effect of peak power, pulse width and pulse frequency on geometrical accuracy and metallurgical distortion during LBPD of 0.85[Formula: see text]mm thick Ti–6Al–4V sheet using 200[Formula: see text]W Yb:YAG fiber laser. It has been found that the output parameters behave differently at the higher and lower values of a particular input process. The increase of pulse width from 1 to 1.50[Formula: see text]ms increases hole taper by 20% whereas the same corresponding change from 1.50 to 2.00[Formula: see text]ms reduces the taper by 20%. The increase of pulse frequency from 10 to 50[Formula: see text]Hz reduces hole circularity by 40% but the same proportionate change from 50 to 90[Formula: see text]Hz reduces circularity by 79%. Increase of peak power from 1.70 to 2.0[Formula: see text]kW increases hole taper by 8% but the corresponding increase from 2 to 2.30[Formula: see text]kW is 143%.
A Novel TEPA-Load or PEI-Load Beta/KIT-6 Composite and their Application to CO2 Adsorption
Authors: Li Yu , Wei Jianwen , Geng Linlin , Mei Dejun , Liao Lei
Published: February 2021

An amine-modified Beta/KIT-6 (BK) micro/mesoporous composite for CO2 capture was synthesized using nonionic tri-block copolymer pluronic (P123) as a template, tetraethyl orthosilicate (TEOS) as a silicon source and Beta zeolite as part of silicon aluminum source by a two-step hydrothermal crystallization method. BK was modified by Tetraethylenepentamine (TEPA) or polyethyleneimine (PEI) to obtain solid amine adsorbent. The structure, uniformity and physical properties of the sample were characterized by FTIR, nitrogen adsorption/desorption and elemental analysis methods and CO2 adsorption/desorption behavior of adsorbents and regeneration performance were investigated by thermal gravimetric analysis (TGA). Experimental results showed that with the increase of amine loading the CO2 adsorption capacity of samples increased first and then decreased at [Formula: see text]C, TEPA-loaded BK and PEI-loaded BK both presented the largest saturated CO2 adsorption capacity when the amine loading reached 60%, and the maximum values were 4.21[Formula: see text]mmol[Formula: see text]g[Formula: see text] and 2.72[Formula: see text]mmol[Formula: see text]g[Formula: see text], respectively. BK-TEPA-60 and BK-PEI-60 reached the maximum adsorption capacity at [Formula: see text]C and [Formula: see text]C. The adsorption kinetics analysis showed that the adsorption process of amine-modified BK was dominated by both physical and chemical adsorption. After five cycles of adsorption/desorption, BK-PEI-60 kept better stability with the equilibrium adsorption capacity of exhibited just 2.9% attrition, whereas a 9.2% decrease was obtained for BK-TEPA-60. Compared with other amine-modified solid materials, the materials we designed show good CO2 adsorption performance, indicating that they are promising efficient adsorbents for CO2 capture.
On a generalization of the CLT for linear eigenvalue statistics of Wigner matrices with inhomogeneous fourth moments
Authors: Wang Zhenggang , Yao Jianfeng
Published: February 2021

For linear spectral statistics of Wigner matrix, we establish a CLT when the entries are independent, standardised with however inhomogeneous fourth moments. Formulas for the expectation and the variance of the Gaussian limiting distribution are given. An application to the normalized stochastic block model is further proposed.
A boundary integral investigation for unsteady modified Helmholtz problems of some other classes of anisotropic functionally graded materials
Authors: Azis Moh. Ivan
Published: February 2021

Numerical solutions for a class of unsteady modified Helmholtz problems of anisotropic functionally graded materials are sought. The governing equation which is a variable coefficients equation is transformed to a constant coefficients equation. The time variable is transformed using the Laplace transform. The resulted partial differential equation of constant coefficients and time free variable is then converted to a boundary integral equation, from which boundary element solutions can be obtained. Some examples are considered to verify the accuracy, convergence and consistency of the numerical solutions. The results show that the numerical solutions are accurate, convergent and consistent.
Analytical Interpretation of the Early Literature on the Theory of Vibrations
Authors: Pierce Allan D.
Published: February 2021

A discussion is given of early literature pertaining to the theory of vibration from the time of Pythagoras up through 1750. The paper attempts to give an analytical interpretation to early anecdotal works concerning Pythagoras and to publications of Galileo, Huygens, Hooke, Taylor, John Bernoulli, Leibniz and Euler. To bridge the “culture gap,” mathematical developments by the latter cited authors are, whenever appropriate, rephrased in modern notation, using, for the most part, only those techniques that should have been well known to the authors at the time. The emphasis is on what might be loosely called the physics (or the mathematical physics) of vibration.
Nature and evolution of the northern Victoria Land lithospheric mantle (Antarctica) as revealed by ultramafic xenoliths
Authors: Coltorti Massimo , Bonadiman Costanza , Casetta Federico , Faccini Barbara , Giacomoni Pier Paolo , Pelorosso Beatrice , Perinelli Cristina
Published: February 2021

A review of northern Victoria Land ultramafic xenoliths, collected and studied over more than 30 years, was carried out. More than 200 samples were gathered and characterized in a coherent and comparative manner, both for mantle-derived and cumulate xenoliths. Almost 2000 analyses of major elements and more than 300 analyses of trace elements of
in situ
and separated olivine, pyroxenes, amphibole, spinel and glass were taken into consideration. Particular attention was devoted to mantle lithologies in order to emphasize the composition and the evolution of this portion of the subcontinental lithosphere. The three main localities in northern Victoria Land where mantle xenoliths were found (i.e. Mount Melbourne (Baker Rocks), Greene Point and Handler Ridge), over a >200 km distance, were described and compared with ultramafic xenoliths in three other localities (Harrow Peaks, Browning Pass and Mount Overlord) that are mainly cumulate in nature. Altogether, these data enabled us to reconstruct a long evolutionary history, from old depletion to most recent refertilization and metasomatic events, for this large sector of the northern Victoria Land subcontinental lithospheric mantle.
Impact of Cathodic Electric Double Layer Composition on the Performance of Aprotic Li-O2 Batteries
Authors: Isaev Valerii V. , Sergeev Artem V. , Zakharchenko Tatiana K. , Itkis Daniil M. , Groß Axel , Yashina Lada V.
Published: February 2021

One of the difficulties limiting the development of high capacity Li-O2 batteries is the positive electrode passivation by the discharge product Li2O2 which is deposited mostly due to the second electron transfer of oxygen reductionwhich requires the presence of Li+ in the Stern layer. To suppress the passivation and shift the reaction zone of Li2O2 formation towards the electrolyte bulk, we propose to use additional cations in the electrolyte. Using molecular dynamics simulations, we investigate the ability of various cations to replace Li+ ions in the first cation layers near the electrode, with EMI+ (1-ethyl-3-methylimidazolium) and PP13+ (N-methyl-N-propylpiperidinium) showing pronounced effects. However, our experimental studies including cycling voltammetry and discharge capacity measurements in high and low donor number solvents reveal practically no effect of such addition. Therefore, Li+ should be fully eliminated from electron transfer zone, and this is possible by anchoring of additional cations according to the simulations. We optimized the surface density for these cations, although the experimental support of this approach looks challenging.
Effect of Laser Cleaning and Hyperpassivation on the Electrochemical Behavior of AA2024-T3
Authors: McFall-Boegeman Sarah , Yancey David F. , O’Neill Tyler , Davidson Nick , Swain Greg M.
Published: February 2021

Environmentally sustainable surface pretreatments and coating systems are needed in the aerospace industry. Laser cleaning is one such surface pretreatment method that reduces the need of hazardous chemicals, and their associated monitoring and disposal, for cleaning metal parts. Research was conducted to investigate how two laser surface pretreatments, (i) cleaning and (ii) hyperpassivation, affect the electrochemical behavior of aluminum alloy 2024-T3. The difference between the two pretreatments was the laser fluence per pulse, 5.2 (cleaning) vs 10.8 J cm−2 (hyperpassivation), respectively. Comparison studies were performed using specimens pretreated by standard wet chemical cleaning and deoxidation. The laser pretreated and solution processed specimens were characterized using electrochemical methods, digital optical microscopy, optical profilometry, scanning electron microscopy, and depth profiling X-ray photoelectron spectroscopy. The laser cleaning and hyperpassivation pretreatments both clean the surface and improve the corrosion resistance of this alloy in naturally aerated 0.5 M Na2SO4, as compared to the solution processed specimen. This is evidenced by suppressed anodic and cathodic polarization curve currents, increased polarization resistance, and increased low frequency impedance modulus values. The improved corrosion resistance results from the formation of a thicker and presumably less defective oxide layer on the aluminum and reduced exposure of Cu-rich second-phase particles.
Electrochemical Behavior of p-nitroaniline at Silver/Chitosan/Graphite Electrodes Using Electrochemical Impedance Spectroscopy
Authors: Laghrib F. , Aghris S. , Hrioua A. , Ajermoun N. , Ettadili F. , Farahi A. , Bakasse M. , Lahrich S. , El Mhammedi M. A.
Published: February 2021

This study aims to study and compare the electrochemical properties of variously silver-based carbon paste electrodes towards the catalytic reduction of hazardous nitroaromatic compound p-nitroaniline (PNA). Silver-based carbon paste electrodes have been manufactured and electrochemically characterized by using Cyclic Voltammetry (CV) and electrochemical impedance spectroscopy (EIS) to better define the electrochemical characteristics for their use as electrocatalytic sensors. The morphology and the distribution of silver on the electrode surface were evaluated by Scanning electron microscopy (SEM). The electro-active surface area of the as prepared electrodes was estimated to be 0.095, 0.06, 0.12 and 0.10 cm2 for electrode modified with silver via electrodeposition (CPE/Ag-Edp), impregnation (CPE/Ag-Imp), graphite electrode modified with silver nanoparticles (CPE/Ag-NPs) and graphite electrode modified graphite with silver adsorbed onto Chitosan (CS) (CPE/Ag-CS), respectively, using [Fe(CN)6]3−/4− as redox probe. EIS measurements of the silver-based graphite carbon electrodes were registered in 0.1 HCl solutions. The equivalent circuit might have been used to interpret the achieved impedance spectra which included one resistor in series with parallel circuit comprised of a capacitor and resistor (1R//C). The results show that the silver nanoparticles greatly reduced the electronic transfer resistance (Rct). The electrocatalytic activity of silver based electrodes for the reduction of PNA is discussed on the basis of the real electro-active surface area and particle size which results from varying modification modes.
1.3 kW Continuous Wave Output Power of Ytterbium-Doped Large-Core Fiber Laser
Authors: Sohail Muhammad , Khan Noor Zamin , Chen Tenghui , Ullah Asmat , Ahmed Jahangeer , Alshehri Saad M. , Ahmad Faisal , Ali Khan Sayed
Published: February 2021

A very efficient key cladding-pumped trivalent ytterbium (Yb3+) doped fiber laser has been developed. The whole fiber laser system generated 1.3 kW of continuous-wave (CW) maximum output power with very high efficiency at 1.1 μm and near the diffraction beam quality (M2 = 1.27). The measure slop efficiency is 76% and shows no limit of temperature and nonlinear effects. In a preliminary proof of principle study, efficient single-mode operation of a cladding-pumped ytterbium-doped fiber laser with a diameter core and a numerical aperture of 0.09 has been demonstrated. When pumped to the ends of both fibers, they have strong beam quality and display no signs of rolling over even at the highest output power. The large core ytterbium doped fiber laser (YDFL’s) is end pumped with diodes stack source through opposite ends of fiber. This design of fiber can delivers maximum output power which is restricted mostly by accessible pump power.
Three Successful Pregnancies in a Patient with Recurrent Cushing’s Disease
Authors: Benothman W. , Saad G. , Kacem M. , Ach K.
Published: February 2021

The association of pregnancy and Cushing’s disease (CD) is rare. A 28-year-old woman was admitted for clinical suspicion of Cushing’s syndrome. The investigations confirmed the diagnosis of CD with secondary hypogonadotropic hypogonadism due to an invasive pituitary macroadenoma. The patient underwent transsphenoidal adenomectomy, and histopathology showed an adrenocorticotropic hormone pituitary adenoma. Initial remission of CD ensued, and fertility was restored as the patient had 2 uncomplicated pregnancies. Five years and 10 months after surgery, a third spontaneous pregnancy was confirmed with underlying recurrent CD. Having mild hypercortisolism, CD was managed expectantly. The outcome was a healthy full-term neonate with no maternal complications during pregnancy or labor. Our case highlights the challenge faced by physicians of choosing the optimal approach to active CD in pregnancy. In cases where maternal and fetal complications are mild, conservative approach may be used and specific treatment can be postponed until after delivery.
A Novel Approach for Transcatheter Management of Perimembranous Ventricular Septal Defect with a Subaortic Ridge
Authors: Wahab Hussein A. , Alsalkhi Hussein A. , Khalid Khalid A. , Abusuda Ahmmed F.
Published: February 2021

Introduction. Surgical closure of the perimembranous ventricular septal defect (PM VSD) and resection of the subaortic ridge are the standard methods of management, but there is no definitive agreement regarding the timing of surgery. Objectives. To evaluate the safety and efficacy of the management of patients with PM VSD and subaortic ridge with or without AR via transcatheter closure of the defect and compressing the ridge against the ventricular septum using Amplatzer ductal occluder type I (ADO-I). Patients and Methods. We introduced a new approach for transcatheter management of PM VSD and subaortic ridge by closing the VSD and capturing or compressing the ridge against the interventricular septum (IVS) using the ADO-I device. Thirty-eight (9.5%) of 398 patients with a PM VSD were found to have subaortic ridge and were enrolled in this study from August 1, 2014, to February 1, 2018, at the Ibn Albitar Center for Cardiac Surgery, Baghdad, Iraq. Results. The ages and weights of patients ranged from 1.5 to 25 years and 7 to 73 kg, respectively. The male-to-female ratio was 2.2 : 1. The VSD sizes ranged from 4 to 8 mm, and the median distance of the ridge from the proximal edge of the VSD was 2.5 mm. Prior to closure, 13 patients (34.2%) had mild and mild-to-moderate aortic regurgitation (AR), and nine patients (23.7%) had mild-to-moderate left ventricular outflow tract (LVOT) obstruction. The mean AR pressure half-time increased significantly after intervention (from 385 ± 38 ms to 535 ± 69 ms (significant

P

value, 0.001)), and the mean of the peak pressure gradient across the LVOT decreased from 33 ± 7 mmHg to 15 ± 2.4 mmHg (significant

P

value, 0.001). Successful procedures were achieved in 33 patients (86.8%). Conclusion. Transcatheter management of patients with PM VSD and subaortic ridges with or without AR is feasible and effective.
An Optimization Method for Mobile Edge Service Migration in Cyberphysical Power System
Authors: Cao Qian , Wu Qilin , Liu Bo , Zhang Shaowei , Zhang Yiwen
Published: February 2021

To relieve the pressure of processing computation‐intensive applications on mobile devices and avoid high latency during data transmission, edge computing is proposed to solve this problem. Mobile edge computing (MEC) allows the deployment of MEC servers at the edge of the network to interact with users on the premise of low transmission delay, thereby improving the quality of service (QoS) for users. However, due to the high mobility of users, with the continuous change of geographical location, when users exceed the signal range of the MEC server, the services they request on the MEC server will also be migrated to other MEC servers. The handoff process may involve high response delays caused by service forwarding, thereby greatly degrading QoS. For the above problems, in this paper, a service migration optimization method based on transmission power control is proposed. First, according to the transmission power of the MEC server, the user’s activity range is divided into multiple subregions based on a Voronoi diagram. Therefore, there is one MEC server in each subregion, and the size of each subregion is adjusted by controlling the transmission power of the MEC server to minimize the number of wireless handoffs and the energy consumption of the MEC server. Then, the particle swarm optimization (PSO) is adopted to solve the above multiobjective optimization problem. Finally, the effectiveness of the proposed method is verified through extensive experiments.
Performance Evaluation and Sensitivity Analysis of Rural Land Circulation Mode
Authors: Sun Shanhui , Lu Wei
Published: February 2021

To evaluate the performance of rural land circulation mode through the analytic network hierarchy process, based on the results of the performance evaluation with analytic network process, we implemented efficiency analysis on five types of rural land circulation mode by two improved efficiency analytic procedures. Finally, we implemented sensitivity analysis for each criterion layer of the evaluation index system with the performance evaluation data, interpreted five types of rural land circulation mode from three perspectives including benefits, costs, and risks with sensitivity analysis results, and drew related conclusions including higher revenue which will lead to smaller difficulty of the rural land circulation. Cost variables were negative variables of the selected rural land circulation mode, and higher risk would lead to the greater difficulty of rural land circulation and related conclusions.
Chronic Effects of Pediatric Ear Infections on Postural Stability
Authors: Sabir Ohud A. , Johnson Eric G. , Hafiz Ammar E. , Nelson Rhonda N. , Hudlikar Mitali , Sheth Isha , Daher Noha S.
Published: February 2021

Background. Ear infections in children often cause abnormal postural stability. However, the long-term effects of recurrent ear infections on postural stability have not been investigated. Purpose. The purpose of this study was to examine the long-term effects of multiple ear infections on pediatric postural stability. Methods. Forty children aged 10-12 years were divided into two groups (18 participants with a history of tympanostomy tubes and/or 3 or more ear infections prior to age five and 22 participants without a history of tympanostomy tubes and/or 0-2 ear infections prior to age five). Computerized Stability Evaluation Test (SET) and noncomputerized postural stability were measured for all participants. Results. A significant difference was found in median postural stability scores in the SET during a tandem stance on an unstable surface between the two groups (median (minimum, maximum) of 9.1 (1.4, 11.4) versus 5.8 (1.7, 12.8),

p
=
0.04

). In addition, there was a significant difference in median Pediatric Balance Scale scores between participants with versus without ear infection (54 (47, 56) versus 56 (55, 56),

p
=
0.001

). Conclusions. Results suggest that children ages 10-12 with a history of tympanostomy tubes and/or 3 or more ear infections prior to age five have decreased postural stability.
Evaluation Model of Low‐Carbon Circular Economy Coupling Development in Forest Area Based on Radial Basis Neural Network
Authors: Liu Chang
Published: February 2021

In this paper, we study the radial neural network algorithm for low‐carbon circular economy in forest area, design a coupled development evaluation model, study its algorithmic ideas operation mode and the update formula obtained by standard algorithm, and finally optimize the RBF neural network by particle swarm algorithm. After an in‐depth analysis of the particle swarm algorithm, an improved particle swarm algorithm is proposed to improve the search accuracy and capability of the algorithm by nonlinearly adjusting the inertia weights and introducing the average extreme value factor, in response to the problems of premature convergence and poor search capability that appear in the particle swarm algorithm. Through the analysis and evaluation of the interaction between industrial ecosystem and carbon emission, the main influencing factors of carbon emission are identified, and the size and magnitude of the influence of economic growth, industrial structure, energy intensity, and energy structure on carbon emission are determined; the current situation of the industrial ecological structure is evaluated, and the direction of optimization and adjustment of industrial economic structure, energy structure, and ecological structure is clarified. We construct a multidimensional multiconstraint multimodel industrial ecological structure optimization prediction model, set the development scenarios of economy and society, and optimize the prediction of low‐carbon industrial ecological structure in forest areas; based on the simulation analysis of the prediction results, we propose the direction of industrial ecological structure adjustment and the path of industrial ecological system construction.
Coordination Strategy for a New Retail Supply Chain Based on Combination Contract
Authors: Zhang Shuiwang , Mei Yu , Bao Qiang , Shao Lingzhi
Published: February 2021

The supply chain in the new retail context demands higher requirements on the price, service, and logistics level. It is very important to seek the coordination among the optimal price, service level, and logistics level. In this paper, we propose the coordination of pricing, the service level, and delivery time of a new retail supply chain composed of one product supplier, one platform service provider, and one logistics provider. Firstly, the profit function mode of product pricing, platform service level, and logistics distribution level that influence the consumers’ demand is constructed in two modes, namely, the centralized and decentralized decision mode. Then, we calculate and compare the optimal product price, the optimal platform service level, the optimal delivery time, and the profit of each member of the supply chain from both decision modes. We discovered that cooperation improves the service level, logistics level, and the income of each member of the new retail supply chain. Therefore, we propose a novel mode called the coordination mode as a strategy for the supply chain based on the combination contract. We performed a numerical analysis to demonstrate the feasibility and effectiveness of the coordination contract.
Ligustrum japonicum Thunb. Fruits Exert Antiosteoporotic Properties in Bone Marrow-Derived Mesenchymal Stromal Cells via Regulation of Adipocyte and Osteoblast Differentiation
Authors: Oh Jung Hwan , Karadeniz Fatih , Lee Jung Im , Seo Youngwan , Kong Chang-Suk
Published: February 2021

Ligustrum japonicum fruits have been used as a part of traditional medicinal practices and supplements in Korea and Japan. It has been reported to possess various bioactivities, but its antiosteoporotic potential and active substances have not been reported yet. The present study followed an ALP activity and lipid accumulation-guided screening of L. japonicum fruits for antiosteoporotic compounds and isolated salidroside as an active compound. Antiosteoporotic effects of L. japonicum fruits and salidroside were examined in mesenchymal stromal cells by their ability to enhance osteoblast formation by increased ALP activity and osteogenic marker gene expression while suppressing adipogenesis by inhibition of lipid accumulation and adipocyte marker gene expressions. Results showed that salidroside was able to enhance osteoblast differentiation via Wnt/BMP signaling pathway overactivation and suppress the PPARγ-mediated adipocyte differentiation, both through the MAPK pathway. In conclusion, L. japonicum fruits were suggested to possess antiosteoporotic activities and to be a source of antiosteoporotic substances such as salidroside.