bluuebunny/crossref_metadata_2025 huggingface dataset:
Unusual side effects of levetiracetam
Authors: Badarny Samih , Badarny yazid , Mihilia Fatima
Published: April 2021

We present a 75-year-old man who was admitted to our hospital due to 4 months of general deterioration, gait disturbance and cognition impairment which appeared very close to the start of levetiracetam (LEV) as a new antiepileptic drug. Brain CT shows central and less peripheral atrophy of brain, and diagnosis of normal pressure hydrocephalus was raised; however, removal of 30 cc of cerebrospinal fluid (CSF) by lumbar puncture in order to amend walking did not lead to gait improvement. After excluding metabolic, vascular, infection, inflammatory and other reasons explaining his status. Thinking that may be any correlation between LEV added in the last months and his clinical condition, we stopped LEV. Several days after that, there is marked improvement in his general sensation, alertness and cognitive status and there is marked improvement in walking balance to the point of being able to walk without the use of walker or cane or help from other person. Certain cognitive impairment and gait difficulties are not known as side effects of LEV treatment.
The impact of the DREAMS partnership on HIV incidence among young women who sell sex in two Zimbabwean cities: results of a non-randomised study
Authors: Chabata Sungai T , Hensen Bernadette , Chiyaka Tarisai , Mushati Phillis , Musemburi Sithembile , Dirawo Jeffrey , Busza Joanna , Floyd Sian , Birdthistle Isolde , Hargreaves James R , Cowan Frances M
Published: April 2021

Introduction

Young women who sell sex (YWSS) in Zimbabwe remain at high risk of HIV infection. Effective HIV prevention strategies are needed. Through support to access a combination of evidence-based interventions, including oral pre-exposure prophylaxis (PrEP), the Determined, Resilient, Empowered, AIDS-free, Mentored and Safe (DREAMS) partnership aimed to reduce new HIV infections among adolescent girls and young women by 40% over 24 months.

Methods

Non-randomised ‘plausibility’ evaluation, powered to detect a 40% HIV incidence difference between DREAMS and non-DREAMS sites. Two large cities with DREAMS funding were included, and four smaller non-DREAMS towns for comparison. In all sites, YWSS were enrolled to a cohort through peer-referral. Women were followed up for 24 months. HIV seroconversion was the primary outcome, with secondary outcomes identified through a theory of change. Outcomes were compared between YWSS recruited in DREAMS cities and non-DREAMS towns, adjusting for individual-level confounders and HIV prevalence at enrolment.

Results

From April to July 2017, 2431 women were enrolled, 1859 of whom were HIV negative at enrolment; 1019 of these women (54.8%) were followed up from March to May 2019 and included in endline analysis. Access to clinical services increased, but access to socioeconomic interventions promoted by DREAMS was limited. A total of 79 YWSS HIV seroconverted, with HIV incidence among YWSS in DREAMS cities lower (3.1/100 person-years) than in non-DREAMS towns (5.3/100 person-years). In prespecified adjusted analysis, HIV incidence was lower in DREAMS cities but with weak statistical evidence (adjusted rate ratio (RR)=0.68; 95% CI 0.40 to 1.19; p=0.18). Women in DREAMS cities were more likely to report ever and ongoing PrEP use, consistent condom use, fewer sexual partners and less intimate partner violence.

Conclusion

It is plausible that DREAMS lowered HIV incidence among YWSS in two Zimbabwean cities, but our evaluation provides weak statistical evidence for impact and suggests any reduction in incidence was lower than the anticipated 40% decline. We identified changes to some important ‘pathways to impact’ variables, including condom use.
Overcoming vaccine deployment challenges among the hardest to reach: lessons from polio elimination in India
Authors: Bellatin Alejandra , Hyder Azana , Rao Sampreeth , Zhang Peter Chengming , McGahan Anita M
Published: April 2021

After more than 30 years of efforts to eliminate polio, India was certified polio free by WHO in 2014. The final years prior to polio elimination were characterised by concentrated efforts to vaccinate hard-to-reach groups in the state of Uttar Pradesh, including migrant workers, religious minority Muslims and impoverished communities with poor pre-existing social support systems. This article aims to describe the management strategies employed by India to improve the deployment and acceptance of vaccines among hard-to-reach groups in Uttar Pradesh in the final years prior to polio elimination.

Three main management principles contributed to polio elimination among the hardest to reach in Uttar Pradesh: bundling of health services, local stakeholder engagement and accountability mechanisms for public health initiatives. In an effort to market the polio campaign as an authentic health-oriented programme, vaccine acceptance was improved by packaging other basic healthcare services such as routine check-ups and essential medications. India also prioritised local stakeholder engagement by using influential community leaders to reach vaccine hesitant groups. Lastly, the accountability mechanisms developed between non-profit organisations and decision-makers in the field ensured accurate reporting and identified deficiencies in healthcare worker training. The lessons learnt from India’s polio vaccination programme have important implications for the implementation of future mass vaccination initiatives, particularly when trying to reach vulnerable communities.
Factors affecting the corneal endothelium after selective laser trabeculoplasty in primary open angle and angle closure glaucoma
Authors: Kurysheva Natalia Ivanovna , Lepeshkina Lyudmila Vyacheslavovna , Kapkova Svetlana Georgievna
Published: April 2021

Purpose

To study the factors affecting the corneal endothelium after selective laser trabeculoplasty (SLT) in primary open angle glaucoma (POAG) and primary angle closure glaucoma (PACG).

Method

This prospective interventional study included 56 patients (56 eyes) with POAG and 55 patients (55 eyes) with PACG. All participants received a standard SLT session. Patients with PACG were pretreated with laser peripheral iridotomy for at least 2 months before SLT. Corneal endothelium cell count (ECC), pleomorphism and polymegathism were measured before SLT, as well as at the increments of 1 hour, 1 day, 1 week, 1 month, 3 months and 6 months following SLT using confocal microscopy. A multiple regression analysis was applied to detect the factors affecting the ECC in the long-term post-SLT period.

Results

In both groups, the mean ECC significantly decreased from the baseline after SLT. While in POAG, corneal endothelium recovered within 1 month, in PACG, its damage persisted throughout the whole follow-up period.

According to the multiple analysis, baseline ECC (β=0.891, p=0.000 in POAG and β=0.706, p=0.000 in PACG) and age (β=−0.227, p=0.000 in POAG and β=−0.196, p=0.000 in PACG) were the common risk factors affecting ECC in both glaucoma forms, while the initial anterior chamber depth (β=0.254, p=0.000), only in PACG. The duration of glaucoma treatment (β=−0.317, p=0.043 in POAG and β=−0.302, p=0.047 in PACG) and pigmented deposits on the corneal endothelium in PACG (β=−0.326, p=0.019) were the risk factors determined in the univariate analysis.

Conclusion

Age and the baseline ECC are the risk factors for corneal endothelium damage after SLT in POAG and PACG. Shallow anterior chamber may affect corneal endothelium in PACG. These data should be considered when choosing an algorithm for glaucoma treatment.
How can we make self-sampling packs for sexually transmitted infections and bloodborne viruses more inclusive? A qualitative study with people with mild learning disabilities and low health literacy
Authors: Middleton Alan , Pothoulaki Maria , Woode Owusu Melvina , Flowers Paul , Mapp Fiona , Vojt Gabriele , Laidlaw Rebecca , Estcourt Claudia S
Published: April 2021

Objectives

1.5 million people in the UK have mild to moderate learning disabilities. STIs and bloodborne viruses (BBVs) are over-represented in people experiencing broader health inequalities, which include those with mild learning disabilities. Self-managed care, including self-sampling for STIs/BBVs, is increasingly commonplace, requiring agency and health literacy. To inform the development of a partner notification trial, we explored barriers and facilitators to correct use of an STI/BBV self-sampling pack among people with mild learning disabilities.

Methods

Using purposive and convenience sampling we conducted four interviews and five gender-specific focus groups with 25 people (13 women, 12 men) with mild learning disabilities (July–August 2018) in Scotland. We balanced deductive and inductive thematic analyses of audio transcripts to explore issues associated with barriers and facilitators to correct use of the pack.

Results

All participants found at least one element of the pack challenging or impossible, but welcomed the opportunity to undertake sexual health screening without attending a clinic and welcomed the inclusion of condoms. Reported barriers to correct use included perceived overly complex STI/BBV information and instructions, feeling overwhelmed and the manual dexterity required for blood sampling. Many women struggled interpreting anatomical diagrams depicting vulvovaginal self-swabbing. Facilitators included pre-existing STI/BBV knowledge, familiarity with self-management, good social support and knowing that the service afforded privacy.

Conclusion

In the first study to explore the usability of self-sampling packs for STI/BBV in people with learning disabilities, participants found it challenging to use the pack. Limiting information to the minimum required to inform decision-making, ‘easy read’ formats, simple language, large font sizes and simpler diagrams could improve acceptability. However, some people will remain unable to engage with self-sampling at all. To avoid widening health inequalities, face-to-face options should continue to be provided for those unable or unwilling to engage with self-managed care.
Older trauma patients are at high risk of delirium, especially those with underlying dementia or baseline frailty
Authors: Ní Chróinín Danielle , Francis Nevenka , Wong Pearl , Kim Yewon David , Nham Susan , D'Amours Scott
Published: April 2021

Background

Given the increasing numbers of older patients presenting with trauma, and the potential influence of delirium on outcomes, we sought to investigate the proportion of such patients who were diagnosed with delirium during their stay—and patient factors associated therewith—and the potential associations between delirium and hospital length of stay (LOS). We hypothesized that delirium would be common, associated with certain patient characteristics, and associated with long hospital LOS (highest quartile).

Methods

We conducted a retrospective observational cohort study of all trauma patients aged ≥65 years presenting in September to October 2019, interrogating medical records and the institutional trauma database. The primary outcome measure was occurrence of delirium.

Results

Among 99 eligible patients, delirium was common, documented in 23% (23 of 99). On multivariable analysis, adjusting for age, frailty and history of dementia, frailty (OR 4.09, 95% CI 1.08 to 15.53, p=0.04) and dementia (OR 5.23, 95% CI 1.38 to 19.90, p=0.02) were independently associated with likelihood of delirium. Standardized assessment tools were underused, with only 34% (34 of 99) screened within 4 hours of arrival. On univariate logistic regression analysis, having an episode of delirium was associated with long LOS (highest quartile), OR of 5.29 (95% CI 1.92 to 14.56, p<0.001). In the final multivariable model, adjusting for any (non-delirium) in-hospital complication, delirium was independently associated with long LOS (≥16 days; OR 4.81, p=0.005).

Discussion

In this study, delirium was common. History of dementia and baseline frailty were associated with increased risk. Delirium was independently associated with long LOS. However, many patients did not undergo standardized screening at admission. Early identification and targeted management of older patients at risk of delirium may reduce incidence and improve care of this vulnerable cohort. These data are hypothesis generating, but support the need for initiatives which improve delirium care, acknowledging the complex interplay between frailty and other geriatric syndromes in the older trauma patients.

Level of evidence

III.
Radiating stars with composite matter distributions
Authors: Maharaj Sunil D. , Brassel Byron P.
Published: April 2021

In this paper we study the junction conditions for a generalised matter distribution in a radiating star. The internal matter distribution is a composite distribution consisting of barotropic matter, null dust and a null string fluid in a shear-free spherical spacetime. The external matter distribution is a combination of a radiation field and a null string fluid. We find the boundary condition for the composite matter distribution at the stellar surface which reduces to the familiar Santos result with barotropic matter. Our result is extended to higher dimensions. We also find the boundary condition for the general spherical geometry in the presence of shear and anisotropy for a generalised matter distribution.
Academics’ Knowledge Sharing Intentions and Behaviours: The Influence of Espoused Culture, Social Norm, and Attitude
Authors: Khalil Omar , Marouf Laila , Khalil Nadia
Published: April 2021

Knowledge sharing (KS) is a social phenomenon, and whether or not academics practise KS depends mostly on their individual and social characteristics. Although KS is informed by culture, the external validity of the empirical results of most of the research investigating the influence of culture, defined and operationalised at the macro (national or organisational) level, on KS is problematic since the cultural orientation of individuals in a particular society or organisation may not be homogeneous. This study adopted a Theory of Reasoned Action-based model to analyze the influence of espoused individualism–collectivism (IC), espoused uncertainty avoidance (UCA), social norm (SN), and attitude (ATT) on academics’ KS intentions and behaviours. The results are derived using a data set from a large public Arabian University. SN, ATT, and intention positively influence KS behaviour. Collectivism positively influences SN, ATT, intention, and behaviour. Unexpectedly, uncertainty tolerance positively influences ATT and intention. These results provide significant statistical support for the explanatory power of the model. They also put forward empirically based evidence that adds much-needed nuance to the current discourse on KS intention and behaviour and informs policies and strategies that enhance KS in the academe.
Scientometric Analysis of Solar Cell Research: A Comparison between Africa and India
Authors: Anku Ankudey Selorm
Published: April 2021

The concerned study invariably presents the key findings of the scientometric analysis of Solar Cell Research (SCR) in the specific context of Africa and India. The outstanding contributions explicitly delivered by the successful collaboration of African and Indian authors are satisfactorily accounted for in specific terms of published author, year-wise, research area, funding agencies, published citations, and h-index. The necessary data for the needed research was retrieved from the Web of Science from 2009–2018. The raw data was further analysed and properly presented using MS Excel and VOSviewer as the keyword network tool. An aggregate number of scholarly publications in the global scenario at 117,605, Africa and India typically contributed 2,932 and 7,848, respectively. Joint research of 92 academic journals, receiving citations of 1,348, was usually observed. The highest source of 394 (29.23%) was received overwhelmingly in 2018. Out of the 652 published authors contributing constructively to the remarkable collaboration, H. C. Swart, of the University of the Free State, Bloemfontein, South Africa, contributed 14 publications, allegedly giving a 2.147% of the total count. This is followed by V. Kumar of the Indian Institute of Technology New Delhi (India); UCA (France); UFS (South Africa), which also contributed 12 publications measured at 1.84% of the total count of publications.
A Hybrid Inpainting Model Combining Diffusion and Enhanced Exemplar Methods
Authors: I. J. Sreelakshmy , Kovoor Binsu C.
Published: April 2021

Image inpainting is a technique in the world of image editing where missing portions of the image are estimated and filled with the help of available or external information. In the proposed model, a novel hybrid inpainting algorithm is implemented, which adds the benefits of a diffusion-based inpainting method to an enhanced exemplar algorithm. The structure part of the image is dealt with a diffusion-based method, followed by applying an adaptive patch size–based exemplar inpainting. Due to its hybrid nature, the proposed model exceeds the quality of output obtained by applying conventional methods individually. A new term, coefficient of smoothness, is introduced in the model, which is used in the computation of adaptive patch size for the enhanced exemplar method. An automatic mask generation module relieves the user from the burden of creating additional mask input. Quantitative and qualitative evaluation is performed on images from various datasets. The results provide a testimonial to the fact that the proposed model is faster in the case of smooth images. Moreover, the proposed model provides good quality results while inpainting natural images with both texture and structure regions.
The Habitat Filters of Microbiota-Nourishing Immunity
Authors: Miller Brittany M. , Bäumler Andreas J.
Published: April 2021

An imbalance in the microbiota may contribute to many human illnesses, which has prompted efforts to rebalance it by targeting the microbes themselves. However, by supplying the habitat, the host wields a prominent influence over microbial growth at body surfaces, raising the possibility that rebalancing the microbiota by targeting our immune system would be a viable alternative. Host control mechanisms that sculpt the microbial habitat form a functional unit with the microbiota, termed microbiota-nourishing immunity, that confers colonization resistance against pathogens. The host components of microbiota-nourishing immunity can be viewed as habitat filters that select for microbial traits licensing growth and survival in host habitat patches. Here we review current knowledge of how host-derived habitat filters shape the size, species composition, and spatial heterogeneity of the microbiota and discuss whether these host control mechanisms could be harnessed for developing approaches to rebalance microbial communities during dysbiosis.
Decoding Cell Death: From a Veritable Library of Babel toVade Mecum?
Authors: Hughes Lindsey D. , Wang Yaqiu , Meli Alexandre P. , Rothlin Carla V. , Ghosh Sourav
Published: April 2021

Programmed cell death (PCD) is a requisite feature of development and homeostasis but can also be indicative of infections, injuries, and pathologies. In concordance with these heterogeneous contexts, an array of disparate effector responses occur downstream of cell death and its clearance—spanning tissue morphogenesis, homeostatic turnover, host defense, active dampening of inflammation, and tissue repair. This raises a fundamental question of how a single contextually appropriate response ensues after an event of PCD. To explore how complex inputs may together tailor the specificity of the resulting effector response, here we consider ( a) the varying contexts during which different cell death modalities are observed, ( b) the nature of the information that can be passed on by cell corpses, and ( c) the ways by which efferocyte populations synthesize signals from dying cells with those from the surrounding microenvironment.
Active-Passive Transition of an Fe-6 mass% Cr Surface in Acidic Sodium Sulfate Solutions Under a Laminar Flow Condition Evaluated by Ellipso-Microscopy and Channel Flow Electrode Method
Authors: Fujimura Akihiro , Kitagawa Yuichi , Hasegawa Yasuchika , Doi Takashi , Fushimi Koji
Published: April 2021

Electrochemical ellipso-microscopy was combined with the channel flow triple electrode method to evaluate the active-passive transition behavior of Fe-6 mass% Cr in acidic sodium sulfate solutions under the control of mass-transport reaction. During potentiodynamic polarization of the Fe-6 mass% Cr specimen electrode (SE), the SE surface was monitored by ellipso-microscopy and generated Fe(II) and Cr(III) species from the SE were detected at two detector electrodes arranged downstream in parallel. Forced convection of the electrolyte solution affected the mass-transport process of Cr(III) species on the SE surface in the latter half of the active region. In addition, the electrolyte solution flow resulted in enhancement of the passivation process and Cr enrichment on the passive surface. The effects of the electrolyte solution flow on active-passive transition and improvement of the passive film resistance are discussed.
Effects of Sputtered InxSy Buffer on CIGS with RbF Post-Deposition Treatment
Authors: Witte Wolfram , Hempel Wolfram , Paetel Stefan , Menner Richard , Hariskos Dimitrios
Published: April 2021

Indium sulfide (InxSy) is an attractive candidate to be used as a buffer layer for Cu(In,Ga)Se2 (CIGS) thin-film solar cells and modules. InxSy sputtering would be the preferred deposition method of choice as it allows for much higher growth rates compared to all other current deposition methods. A key feature of CIGS absorber processing, established during the last years, is the use of a post-deposition treatment (PDT) with alkali compounds. In this work, we apply rf-magnetron sputtered InxSy buffers from ceramic targets, optionally doped with NaF, on industrially relevant CIGS absorbers with or without RbF-PDT prepared in an in-line coater. We analyze the influence of wet chemical treatments of the CIGS surface after RbF-PDT and alkali accumulation at the InxSy/CIGS interface on the solar cell performance. Good efficiencies could be achieved with sputtered InxSy on CIGS with RbF in an all-dry process. An InxSy deposition temperature around 200 °C and/or a post-annealing step of the complete cell in air emerged as a key feature for decent efficiencies. This is also due for sputtering from a NaF-doped In2S3 target. Our best cell with sputtered InxSy on CIGS with RbF-PDT shows an efficiency of 18.0% with a high open-circuit voltage of 701 mV.
Review—Radiation Damage in Wide and Ultra-Wide Bandgap Semiconductors
Authors: Pearton S. J. , Aitkaliyeva Assel , Xian Minghan , Ren Fan , Khachatrian Ani , Ildefonso Adrian , Islam Zahabul , Jafar Rasel Md Abu , Haque Aman , Polyakov A. Y. , Kim Jihyun
Published: April 2021

The wide bandgap semiconductors SiC and GaN are already commercialized as power devices that are used in the automotive, wireless, and industrial power markets, but their adoption into space and avionic applications is hindered by their susceptibility to permanent degradation and catastrophic failure from heavy-ion exposure. Efforts to space-qualify these wide bandgap power devices have revealed that they are susceptible to damage from the high-energy, heavy-ion space radiation environment (galactic cosmic rays) that cannot be shielded. In space-simulated conditions, GaN and SiC transistors have shown failure susceptibility at ∼50% of their nominal rated voltage. Similarly, SiC transistors are susceptible to radiation damage-induced degradation or failure under heavy-ion single-event effects testing conditions, reducing their utility in the space galactic cosmic ray environment. In SiC-based Schottky diodes, catastrophic single-event burnout (SEB) and other single-event effects (SEE) have been observed at ∼40% of the rated operating voltage, as well as an unacceptable degradation in leakage current at ∼20% of the rated operating voltage. The ultra-wide bandgap semiconductors Ga2O3, diamond and BN are also being explored for their higher power and higher operating temperature capabilities in power electronics and for solar-blind UV detectors. Ga2O3 appears to be more resistant to displacement damage than GaN and SiC, as expected from a consideration of their average bond strengths. Diamond, a highly radiation-resistant material, is considered a nearly ideal material for radiation detection, particularly in high-energy physics applications. The response of diamond to radiation exposure depends strongly on the nature of the growth (natural vs chemical vapor deposition), but overall, diamond is radiation hard up to several MGy of photons and electrons, up to 1015 (neutrons and high energetic protons) cm−2 and >1015 pions cm−2. BN is also radiation-hard to high proton and neutron doses, but h-BN undergoes a transition from sp2 to sp3 hybridization as a consequence of the neutron induced damage with formation of c-BN. Much more basic research is needed on the response of both the wide and ultra-wide bandgap semiconductors to radiation, especially single event effects.
Proton Irradiation in Simplified PERC Silicon Solar Cells: A Simulation-Based Framework
Authors: Siddiqui Amna , Usman Muhammad
Published: April 2021

A complete technological computer aided design (TCAD) based framework to study the proton radiation effects in silicon Passivated Emitter and Rear solar Cell (PERC) is presented. This novel approach combines the capabilities of the Radiation Effects Module (REM) in Silvaco device simulator with the vacancy information extracted from SRIM code. It is the first time that the parameters in both the tools are linked together to study the radiation effects without relying on previous experiments, which would not be possible if REM alone is used. The fluence levels used to study the radiation effects are present in the space environment but are well beyond the capabilities of laboratory settings. A simplified PERC solar cell is modeled where the average percentage difference between simulated and experimental parameters is <0.25%. The model is used for irradiation studies by the incident protons through Non-Ionizing Energy Loss (NIEL). The results agree well with experimentally studied maximum displacement damage results. It is found that the external quantum efficiency loss in the infrared region is primarily responsible for the overall efficiency degradation due to irradiation. Through this, the qualification of radiation hardness is possible, thereby opening new avenues to explore new radiation tolerant solar cell structures.
Response of Healthcare Workers to COVID‐19 Protocols after the Index Case at 37 Military Hospital, Ghana
Authors: Afeng-Nkansah D. , Asumanu E. , Nyinaku P. , Acheampong F. , Lamptey R.
Published: April 2021

The diagnosis and management of COVID‐19 are much dependent on the adherence to standardized protocols. Healthcare workers play a crucial role in the case management of COVID‐19 in many institutions. Globally, the disease burden is increasing, and the mortality has reached over 2 041 426 compared with 323 000 in May 2020. In West Africa, the pandemic has shown a slow but steady rise in many countries. Existing protocols and their utilization are best assessed after the occurrence of the index case. General aim. The study assessed the health worker’s response to COVID‐19 protocols at three designated areas of the in‐hospital management care triaging, holding area, and treatment centers. Method. A qualitative design was used to assess the response of healthcare workers with regards to early case detection, infection prevention, risk communication to clients and compliance to protocols. The study conducted observational visits and purposively selected healthcare workers comprising of clinicians, nurses, emergency medical technicians, and laboratory technicians who perform routine duties at the triaging, holding, and treatment centers. A total of 41 observations were made over two weeks. Results. Participants comprised 23 males and 18 females. At all observed units, the case definition was being used to screen attendants presenting, and appropriate categorization of patients was ensured. The use of temperature in screening for COVID‐19 at the units was generally adhered to. Only 50% of participants used the prescribed PPEs. The physical distancing between healthcare workers and client and between clients and caregivers were not enforced; however, hand hygiene was practiced. Disinfection of working surfaces and equipment with 0.5% chlorine or 70% alcohol‐based rubs were used most of the time. It was observed however that no psychological counselling was given to suspected cases or their relatives. Conclusion. Healthcare workers showed discordant response to different parts of the protocols for COVID‐19 especially appropriate distancing. There was an enhanced awareness among healthcare workers and improvement in infection prevention protocols. The study also observed that as the risk of infection increased from triaging to holding area and to treatment centers, the response of healthcare workers to COVID‐19 protocols also improved. Risk communication is an essential part of the COVID‐19 management strategy. At the treatment centers, healthcare workers adhered to this protocol, whereas it was a major gap at the triaging and holding areas.
Dynamic Sliding Mode Controller with Variable Structure for Fast Satellite Attitude Maneuver
Authors: Shan Gao , You Li , Huifeng Xue , ShuYue Yao
Published: April 2021

In order to deal with the low convergence rate of the standard sliding mode in satellite attitude control, a novel variable structure sliding mode is constructed in this paper by designing the update law of the sliding mode parameter. By implementing this method, the advantage such as simple structure and strong robustness of the standard sliding mode are maintained and the system convergence rate is largely improved. The fixed sliding mode parameter is modified, and the update law is designed. When the system state is away from the sliding mode surface, the parameter is fixed, and when the system state approaches the sliding mode surface, the parameter begins to update. The constraint on control torque and angular velocity is taken into consideration, and the constraint on control parameters is given to ensure that the system state do not exceed its upper bound. System stability is proved by the Lyapunov stability theorem, and the superiority of the proposed controller is demonstrated by numerical simulation.
Effect of Dynamic Imbibition on the Development of Ultralow Permeability Reservoir
Authors: Hu Yafei , Ren Fei , Li Junshi , Wu Zhiying , Peng Huanhuan , Hou Jianfeng
Published: April 2021

To explore the methodology for improving ultralow permeability reservoir recovery, cores of ultralow permeability reservoirs in China’s Ordos Basin were selected to study the dynamic imbibition micromechanism of crude oil in nanopore throat through core-flooding laboratory experiment and nuclear magnetic resonance (NMR) observation. In the meantime, the microimbibition characteristics and dynamic discharge of oil between matrix and fracture in partially closed boundary reservoirs were simulated to utmostly reflect the actual reservoir conditions. Our findings suggest that dynamic imbibition between fracture and matrix serves the core technology for improving the recovery of ultralow permeability reservoirs, while the main factors affecting dynamic imbibition efficiency include wettability, permeability, injection rate, fracture, water huff and puff cycles, and soaking time. Wettability, in particular, weighs the most, and imbibition can take place either on water-wet rocks or transformed oil-wet rocks with an imbibition agent added in during the waterflooding process. Meanwhile, the higher the permeability is in place, the greater the dynamic imbibition recovery might achieve. The experiments indicate that the dynamic imbibition recovery of a fractured core is 16.26% higher than that of a nonfractured core. Additionally, fractures can not only enhance imbibition recovery but also accelerate the occurrence of dynamic imbibition. The optimal water injection rate of dynamic imbibition is 0.1 mL/min; the reasonable huff and puff cycle of the ultralow permeability reservoirs tends to be two to three cycles; the optimal soaking time of ultralow permeability reservoir is speculated to be 30 days. Finally, the field practice shows that after Stimulated Reservoir Volume (SRV) and dynamic imbibition in 5 horizontal wells in An83 oilfield, there is a remarkable drop in water cut and a noticeable rise in oil production. This research underpins the significance of a dynamic imbibition effect in the development of ultralow permeability oilfield.
The Pittsburgh Sleep Quality Index: Reliability, Factor Structure, and Related Clinical Factors among Children, Adolescents, and Young Adults with Chronic Pain
Authors: Larche Cynthia L. , Plante Isabelle , Roy Mathieu , Ingelmo Pablo M. , Ferland Catherine E.
Published: April 2021

This study is aimed at assessing the psychometric properties and the factorial structure of the Pittsburgh Sleep Quality Index (PSQI) in a clinical sample of children, adolescents, and young adults with chronic pain. Data of 482 participants (aged 8-21 years) from two crosssectional studies and a chronic pain services outpatient clinic were analyzed. Exploratory and confirmatory factor analysis and reliability analysis of PSQI component scores were performed. Relationships between the PSQI global score and various clinical measures were investigated to assess external validity. The findings exhibit the reliability and validity of a single-factor model of the PSQI in a clinical sample of youth with chronic pain and support the relationship in this specific population between poor sleep quality and important clinical measures of well-being. These results support an informed decision regarding its use with this specific population and underscore the clinical relevance of assessing sleep quality.
Posterior Reversible Leukoencephalopathy Syndrome in a Patient after Acute COVID-19 Infection
Authors: Kobaidze Ketino , Shin Yoo Mee , Japaridze Mariam , Karakis Ioannis , Wu Xin
Published: April 2021

The SARS-CoV-2 infection affects numerous organs, including the central nervous system. The neuroinvasive abilities and neuroinflammation may lead to short- and long-term neurological manifestations. Among neurological disorders associated with SARS-CoV-2 infection, posterior reversible encephalopathy syndrome (PRES) has been described in a few case-based observational studies during the acute phase of COVID-19 hospitalization. We present a case of a patient who developed seizures and PRES after recovering from an acute severe COVID-19 infection.A 90-year-old African American female with multiple comorbidities and a severe COVID-19 infection was discharged home in stable condition after two weeks of hospitalization. A week later, she developed new-onset generalized tonic-clonic seizures requiring readmission to the hospital. The patient’s clinical course and brain imaging supported PRES. Her mentation returned to baseline with supportive care and anticonvulsant treatment. Follow-up brain MRI four months later demonstrated resolution of FLAIR signal abnormalities confirming PRES. SARS-CoV-2 insult on the cerebrovascular endothelial cells likely continued and despite the clinical recovery eventually resulted in PRES. We believe that this is the first case describing the presentation of PRES after recovery from severe acute COVID-19 infection.
Interactive Application of Virtual Reality and Intelligent Big Data in Landscape Design
Authors: Zhan Huashan
Published: April 2021

In order to improve the accuracy and efficiency of performance evaluation, the interactive application of virtual reality and intelligent big data in landscape design is proposed. Clara algorithm is used to mine the performance evaluation index data of landscape simulation design. The performance evaluation index system of landscape simulation system is established based on the data mined. BP network is used to build a comprehensive evaluation model. The expert scoring method is the evaluation index system scoring, which is used as the input of BP network, and the expected output is a neuron. The value of the neuron represents the comprehensive performance evaluation value of the landscape simulation system. The experimental results show that the evaluation results of the research method are consistent with the expert evaluation results, with high accuracy; with the increasing number of systems, the evaluation efficiency of the research method is faster.
Existence and Regularity of Solutions for Unbounded Elliptic Equations with Singular Nonlinearities
Authors: Bouhlal Aziz , Igbida Jaouad
Published: April 2021

For

q
,
γ
>
0

, we study existence and regularity of solutions for unbounded elliptic problems whose simplest model is

−
div

1
+

u

q

∇
u

=

f
/

u

γ

in 
Ω

u
=
0

on 
∂
Ω

, where

f
∈

L

m

Ω

,

m
≥
1

.
A Monitoring Approach Based on Fuzzy Stochastic P-Timed Petri Nets of a Railway Transport Network
Authors: M’hala Anis
Published: April 2021

This paper proposes a monitoring approach based on stochastic fuzzy Petri nets (SFPNs) for railway transport networks. In railway transport, the time factor is a critical parameter as it includes constraints to avoid overlaps, delays, and collisions between trains. The temporal uncertainties and constraints that may arise on the railway network may degrade the planned schedules and consequently affect the availability of the transportation system. This leads to many problems in the decision and optimization of the railway transport systems. In this context, we propose a new fuzzy stochastic Petri nets for monitoring (SFPNM). The main goal of the proposed supervision approach is to allow an early detection of traffic disturbance to avoid catastrophic scenarios and preserve stability and security of the studied railway networks. Finally, to demonstrate the effectiveness and accuracy of the approach, an application to the case study of the Tunisian railway network is outlined.
lncRNA HHIP-AS1 Promotes the Osteogenic Differentiation Potential and Inhibits the Migration Ability of Periodontal Ligament Stem Cells
Authors: Qin Qianyi , Yang Haoqing , Zhang Chen , Han Xiao , Guo Jing , Fan Zhipeng , Guo Jie
Published: April 2021

Alveolar bone remodeling under orthodontic force is achieved by periodontal ligament stem cells (PDLSCs), which are sensitive to mechanical loading. How to regulate functions of PDLSCs is a key issue in bone remodeling during orthodontic tooth movement. This study is aimed at investigating the roles of lncRNA Hedgehog-interacting protein antisense RNA 1 (HHIP-AS1) in the functional regulation of PDLSCs. First, HHIP-AS1 expression was downregulated in PDLSCs under continuous compressive pressure. Then, we found that the alkaline phosphatase activity, in vitro mineralization, and expression levels of bone sialoprotein, osteocalcin, and osterix were increased in PDLSCs by HHIP-AS1. The results of scratch migration and transwell chemotaxis assays revealed that HHIP-AS1 inhibited the migration and chemotaxis abilities of PDLSCs. In addition, the RNA sequencing data showed that 356 mRNAs and 14 lncRNAs were upregulated, including receptor tyrosine kinase-like orphan receptor 2 and nuclear-enriched abundant transcript 1, while 185 mRNAs and 6 lncRNAs were downregulated, including fibroblast growth factor 5 and LINC00973, in HHIP-AS1-depleted PDLSCs. Bioinformatic analysis revealed several biological processes and signaling pathways related to HHIP-AS1 functions, including the PI3K-Akt signaling pathway and JAK-STAT signaling pathway. In conclusion, our findings indicated that HHIP-AS1 was downregulated in PDLSCs under compressive pressure, and it promoted the osteogenic differentiation potential and inhibited the migration and chemotaxis abilities of PDLSCs. Thus, HHIP-AS1 may be a potential target for accelerating tooth movement during orthodontic treatment.
E2F1 Maintains Gastric Cancer Stemness Properties by Regulating Stemness-Associated Genes
Authors: Fu Yan , Hu Cheng’en , Du Peizhun , Huang Guangjian
Published: April 2021

Purpose. To determine the regulatory role of E2F1 in maintaining gastric cancer stemness properties and the clinical significance of E2F1 in gastric cancer. Materials and Methods. We conducted a tumor spheroid formation assay to enrich gastric cancer stem-like cells. The protein and mRNA expression levels of genes were measured using Western Blot and qRT-PCR. Lentivirus-mediated overexpression and downregulation of E2F1 were performed to evaluate the effect of E2F1 on the stemness properties of gastric cancer cells. The effect of E2F1 on gastric cancer cell sensitivity of 5-Fu was evaluated using cell viability assay and TdT-mediated dUTP Nick-End Labeling staining. We also analyzed the association between E2F1 expression and clinical characteristics in gastric cancer patients. The KM plotter database was used to analyze the relationship between E2F1 and overall survival in GC patients. Results. We found that E2F1 expression was significantly higher in gastric cancer tissues than in the paired adjacent normal tissues (

p
<
0.05

) and was positively correlated with tumor size (

p
<
0.05

), T stage (

p
<
0.05

), and differentiation degree (

p
<
0.05

). KM plotter database demonstrated a close association between higher E2F1 expression level and worse overall survival of gastric cancer patients (

p
<
0.05

). In vitro assay illustrated that E2F1 could regulate the expression of stemness-associated genes, such as BMI1, OCT4, Nanog, and CD44, and maintain the tumor spheroid formation ability of gastric cancer cells. E2F1 enhanced 5-Fu resistance in gastric cancer cells, and the E2F1 expression level was correlated with the prognosis of gastric cancer patients receiving 5-Fu therapy. The expression levels of stemness-associated genes were also significantly higher in gastric cancer tissues than the paired adjacent normal tissues (

p
<
0.05

). A positive correlation was observed between E2F1 and BMI1 (r = 0.422,

p
<
0.05

), CD44 (r = 0.634,

p
<
0.05

), OCT4 (r = 0.456,

p
<
0.05

), and Nanog (r = 0.337,

p
<
0.05

) in gastric cancer tissues. The co-overexpression of E2F1 and stemness-associated genes was associated with worse overall survival. Conclusion. E2F1 plays a significant role in gastric cancer progression by maintaining gastric cancer stemness properties through the regulation of stemness-associated genes. The close association between E2F1 and poor prognosis of patients suggests that E2F1 could serve as a prognostic biomarker and a therapeutic target in gastric cancer patients.
Valorisation of Pine Cone as an Efficient Biosorbent for the Removal of Pb(II), Cd(II), Cu(II), and Cr(VI)
Authors: Amar Marwa Ben , Walha Khaled , Salvadó Victoria
Published: April 2021

Valorisation of pine cone as an efficient, low-cost, and eco-friendly biosorbent for the removal of heavy metals from aqueous solutions is evaluated. The morphology and surface chemistry of the biosorbent are characterized by scanning electron microscopy, energy-dispersive elemental analysis, and Fourier transform infrared spectroscopy, revealing the presence of carboxylic and alcoholic functional groups that interact with metal ions. The effect of the contact time, pH, amount of adsorbent, and initial metal concentration in the adsorption is studied, resulting in removal percentages for Cd(II), Cu(II), Pb(II), and Cr(VI) (metal concentration of 5 mg L-1) of 82.24%, 93.71%, 94.67%, and 88.8%, respectively ([Formula: see text], 2 g L-1 of adsorbent), except for Cr(VI) ([Formula: see text], 10 g L-1). The equilibrium data of Pb(II) and Cd(II) were found to follow the Langmuir-Freundlich model, with maximum adsorption capacities of 100.01 and 78.73 mg g-1, respectively, whereas Cu(II) followed the Langmuir model with 33.55 mg g-1. Cr(VI) adsorption data also fitted the Langmuir model, and the maximum adsorption capacity was 57.36 mg g-1. Adsorption data was obtained at pH 5.4 for divalent metal ions and at pH 2 for Cr(VI) and in a range of metal concentrations ranging from 1 to 500 mg L-1 at 298.2 K. The presence of the three metal ions in the solution does not affect the percentage of the target metal ion adsorbed, proving the absence of competition between them and showing the pine cone to be an efficient adsorbent to treat multimetal effluents allowing water reuse.
Chest-to-Back Skin-to-Skin Contact to Regulate Body Temperature for Low Birth Weight and/or Premature Babies: A Crossover Randomized Controlled Clinical Trial
Authors: Gere Sisay , Berhane Yemane , Worku Alemayehu
Published: April 2021

Skin-to-skin contact (SSC) is one of the critical components of kangaroo mother care (KMC), which is an intervention to enhance the survival of low birth weight (LBW) and/or premature infants in low-income settings. Chest-to-chest (CC) contact has been practiced widely; however, mothers face practical challenges to continuously provide CC-SSC. Hence, we assessed the efficacy of chest-to-back (CB) SSC as an alternative to CC-SSC in regulating body temperature for LBW and/or premature babies in Ethiopia. We applied a noninferiority clinical trial among LBW and/or premature infants admitted to a referral hospital neonatal intensive care unit (NICU) in Ethiopia. The study randomized the infants into two crossover arms; arm 1 applied first CB-SSC followed by CC-SSC, and arm 2 applied first CC-SSC followed by CB-SSC. The outcome measure was a change in skin temperature. We used a linear mixed-effect model for analysis. The result showed no statistically significant difference in the mean temperature between the comparison arms. In conclusion, we found that the CB-SSC was not inferior to the CC-SSC in regulating body temperature of the babies. Thus, CB-SSC can be further investigated as an alternative to CC-SSC in the kangaroo care model in low-income settings.
Ceftriaxone as an Alternative Therapy for the Treatment of Methicillin-Susceptible Staphylococcus aureus Bacteremia after Initial Clearance of Bloodstream Infection
Authors: Barber Katie E. , Cramer Rachel A. , Bell Allison M. , Wagner Jamie L. , Stover Kayla R
Published: April 2021

Introduction. Staphylococcus spp. represent the leading cause of hospital-acquired infections and second-most frequent pathogen in bloodstream infections. Methicillin-susceptible S. aureus (MSSA) comprise approximately half of all S. aureus isolates. Standard-of-care therapies (SOCTs) display high treatment success but require frequent dosing, are problematic in penicillin allergic patients, and are nephrotoxic. Ceftriaxone may represent an alternative treatment option. Methods. Adult patients hospitalized from January 2015 through June 2016 with positive MSSA blood cultures and treated with SOCT or ceftriaxone for ≥48 hours were included. Exclusion criteria were receipt of vancomycin or concomitant systemic antimicrobials with activity against MSSA, polymicrobial infections, and pregnant patients. Additional data collected included demographics, source/site of infection, and treatment. The primary endpoint was clinical cure (normalization of white blood cell count and temperature within 7 days and clearance of bloodstream within 7 days). Readmission within 60 days, length of stay, and discharge disposition were collected. Results. A total of 43 patients were included: 23 receiving SOCT and 20 receiving ceftriaxone group. Sixteen patients received SOCT prior to ceftriaxone while 4 patients were initiated on ceftriaxone. Clinical cure was observed in 18/23 (78%) and 10/20 (50%), respectively (

P
=
0.052

). Clinical failure was driven by leukocytosis despite clearance of their bloodstream infection in 3/23 (13%) SOCT group compared to 8/20 (40%) in the ceftriaxone group (

P
=
0.043

). Six patients (SOCT: 2, ceftriaxone: 4;

p
=
0.669

) had infection-related readmissions, and 1 death per group was observed. Conclusion. Ceftriaxone poses a reasonable alternative to consider for MSSA bacteremia when cost and feasibility are concerns for outpatient parenteral therapy after initial clearance of bloodstream infections.