bluuebunny/crossref_metadata_2025 huggingface dataset:
Particulate Matter Pollution around a Cement Industry and its Potential Effect
Authors: Amah Victor Emeka , Udeh Ngozi , Effiong Bassey Otuekong
Published: February 2021

Analysis of particulate matter (PM) PM2.5 and PM10 was done around a cement company in Rivers State, Nigeria. Measurements were taken for the concentration of PM2.5 and PM10 and other atmospheric parameters at intervals of 100 m up to 1000 m and field observation was carried out for two days. The temperature of the area varied between 26.6 degrees and 33.3 degrees, relative humidity was between 70.2 and 98.2% and the wind speed ranged from 0.2 to 3.6 m/s. The minimum PM10 and PM2.5 values were 38 and 18 µg/m3 respectively and the maximum PM10 and PM2.5 values were 616 and 298 µg/m3 respectively. A two way analysis of variance was done at 5 % level of significance to determine the influence the time the measurement was taken and the distance from the stack have on the particulate matter concentration. P values were lower than P = .05 therefore, the null hypothesis was rejected. The pollution index for PM10 was determined and about 86% of the pollution index are above 100, 80% are above 150 and about 21% is above 400. About 96% of the pollution index for PM2.5 is above 100, 87% are above 150 and about 21% are above 300. As shown on Air quality index charts, values between 100 and 150 are unhealthy for sensitive groups, values above 150 are unhealthy, and values above 300 are hazardous while values above 400 are very hazardous. It is concluded that the ground level concentration of PM10 and PM2.5 up to 1200 m from the stack is generally unhealthy for the receptors.
Improving Seismic Performance of Structure with Semi-rigid floor using VSL-Gensui Damper
Authors: Pudjisuryadi Pamuda , Halim Andre , Kandiawan Alexander Keith , Lumantarna Benjamin
Published: February 2021

Deficient structures can be strengthened using various methods, and installing damper devices is one of such methods. In this study, effectiveness of Vorspann System Losinger (VSL) Gensui Damper to improve structural performance of deficient building with semi-rigid floors is investigated. The considered building is subjected to spectrum consistent ground accelerations generated from El Centro 18 May 1940 earthquake N-S and E-W components in accordance to Indonesian Seismic Code (SNI 1726:2012) for Mataram City. Modified Simplified Sequential Search Algorithm (MSSSA) and Optimum Damper Allocation Method (ODAM) methods are used to efficiently placed the dampers on the building until allowable drift limits specified by the code are met. Results show that installation of VSL Gensui Dampers can effectively reduce structural drifts. Further, it should be noted that the placement of dampers must be well distributed among frames in the same story, since their drifts may differ significantly in building with semi-rigid floors.
Utilization of low sulfur fly ash from circulating fluidized bed combustion burner as geopolymer binder
Authors: Antoni Antoni , Shenjaya Stacia Dwi , Lupita Maria , Santosa Samuel , Wiyono David , Hardjito Djwantoro
Published: February 2021

Circulating fluidized bed combustion (CFBC) is a newer type of burner that employ a circulating process to burn fuel effectively. CFBC burning process is gaining more popularity due to its compact size, high efficiency and lower burning temperature compared to the pulverized coal combustion (PCC) burner. The CFBC burner produces fly ash with different physical properties compared to the PCC burner, i.e. the fly ash is not rounded, and required higher water content for comparable workability. The CFBC fly ash also has a high sulfur content that is detrimental for hardened concrete. Due to its drawbacks, the CFBC hardly used as cementitious material and geopolymer precursor. This study focuses on comparing variations in the concentration of NaOH solution and variations in the ratio of alkaline activators to the setting time and compressive strength of geopolymer mortars on a new class of CFBC fly ash, which have low sulfur content. The concentrations of NaOH solution were 6M, 8M, 10M, and 12M, while the alkaline activator ratios used were 3.0, 2.5, 2.0, 1.0, and 0.5. It was concluded that the low sulfur CFBC fly ash has a potential to be utilized as geopolymer precursor, however, with a shortcoming in its high water demand. The CFBC fly ash used in this study resulted in a geopolymer matrix with good compressive strength and stability. The water demand varies with the fly ash sampling time shows the challenges in the utilization of the fly ash. The highest mortar’s compressive strength, 33.4 MPa at 90 days was achieved at NaOH concentration of 8M and ratio of sodium silicate solution to sodium hydroxide solution of 2.5 with excellent stability.
Characterization of cardiopathic patients in a thoracic pain unit: admission profile
Authors: Korb Jaqueline Piccoli , Carretta Marisa Basegio , Pesente Tainá Samile , Freitas Tiago Luan Labres de , Castro Alessandra Rodrigues Moreira de
Published: February 2021

Objetivo: Caracterizar os usuários cardiopatas que acessam a Unidade de Dor Torácica (UDT) de um hospital geral no norte do Estado do Rio Grande do Sul. Métodos: Estudo transversal, descritivo, de abordagem quantitativa, que foi realizado na UDT do Hospital da Cidade de Passo Fundo, abordando pacientes com suspeita ou com diagnóstico médico de Doença Cardiovascular (DCV). Resultados: Coleta dos dados realizada com 112 pacientes. Houve o predomínio de idosos, homens com baixas condições socioeconômicas e alta incidência de diagnóstico de Síndrome Coronariana Aguda (SCA) sendo que a dor torácica esteve presente em grande parte dos pacientes.Conclusões: Conhecer a população que acessou a UDT possibilitou reflexões acerca da temática, bem como a importância do referido serviço, no qual serve como porta de entrada para pacientes em condições agudas e crônicas de DCV.
Profile of adolescent user of crack in treatment in the psychosocial care center alcohol and drugs
Authors: Ribeiro Juliane Portella , Gomes Giovana Calcagno , Vicente Bruna Gil , Soares Marilu Correa , Braga Luiza Rocha , Santos Elitiele Ortiz dos
Published: February 2021

Objetivo: Caracterizar o perfil dos adolescentes usuários de crack em tratamento no CAPS ADIII de Pelotas/Rio Grande do Sul. Método: Estudo descritivo de abordagem quantitativa realizado com 14 adolescentes usuários de crack em tratamento no CAPS ADIII. A coleta de dados ocorreu por meio de entrevistas utilizando o instrumento Teen Addiction Severity Index. Na análise dos dados empregou-se a estatística descritiva através de frequência simples. Resultados: A maioria é do sexo masculino, entre 13 e 17 anos, solteiros, negros. O início do uso de drogas variou de oito e 17 anos. Apresentam ensino fundamental incompleto e abandono escolar. Identificou-se o uso de cocaína/crack e a relação com atividades ilegais. Constatou-se a existência de conflitos familiares. O uso de substancias também é identificado entre os amigos próximos. Conclusão: Os resultados apontam para a necessidade de investimentos em ações de promoção à saúde e prevenção ao uso de substâncias.
Recent Progress of Flexible Image Sensors for Biomedical Applications
Authors: Yokota Tomoyuki , Fukuda Kenjiro , Someya Takao
Published: February 2021

Flexible image sensors have attracted increasing attention as new imaging devices owing to their lightness, softness, and bendability. Since light can measure inside information from outside of the body, optical‐imaging‐based approaches, such as X‐rays, are widely used for disease diagnosis in hospitals. Unlike conventional sensors, flexible image sensors are soft and can be directly attached to a curved surface, such as the skin, for continuous measurement of biometric information with high accuracy. Therefore, they are expected to gain wide application to wearable devices, as well as home medical care. Herein, the application of such sensors to the biomedical field is introduced. First, their individual components, photosensors, and switching elements, are explained. Then, the basic parameters used to evaluate the performance of each of these elements and the image sensors are described. Finally, examples of measuring the dynamic and static biometric information using flexible image sensors, together with relevant real‐world measurement cases, are presented. Furthermore, recent applications of the flexible image sensors in the biomedical field are introduced.
Liquid Metals and Disulfides: Interactive Metal‐Polymer Hybrids for Flexible and Self‐Healable Conductor
Authors: Xin Yumeng , Lou Yang , Liu Huaizhi , Wu Dongfang , Zhang Jiuyang
Published: February 2021

Growing interests have been received in metal‐polymer hybrid composites for their combined features of metals and polymer. However, the detrimental incompatibility between inorganic and organic polymer matrix makes it challenging to prepare homogenous hybrid composites for advanced applications. This work reports using disulfides, as interactive binding bonds, to interact with liquid metals (LMs) for fabricating the liquid metal‐disulfide (LMDS) composites. The interaction between disulfides and liquid metals lead to uniform dispersion of LM droplets in polymer matrix and strengthen the whole polymer network for improved mechanical performance. Interestingly, this work discovers that the LM droplets could act as efficient initiator to promote the ring‐opening polymerization to obtain the composites. In addition, the interactive LMDS composites exhibit excellent self‐healing ability ascribing to the dynamic LM‐disulfide interaction and disulfide metathesis. The phenomenal electrical conductivity and self‐healing feature enable LMDS composites as stretchable self‐healing conductors with the ability to control the electrical circuits.
Surveillance guidelines for children with trisomy 18
Authors: Kepple Jeffrey W. , Fishler Kristen P. , Peeples Eric S.
Published: February 2021

Trisomy 18 is the second most common aneuploidy syndromes in live born infants. It is associated with high mortality rates, estimated to be 75%–95% in the first year of life, as well as significant morbidity in survivors. The low survival is largely due to the high prevalence of severe congenital anomalies in infants with this diagnosis. However, interventions to repair or palliate those life‐threatening anomalies are being performed at a higher rate for these infants, resulting in increased rates of survival beyond the first year of life. While it is well documented that trisomy 18 is associated with several cardiac malformations, these patients also have respiratory, neurological, neoplastic, genitourinary, abdominal, otolaryngologic, and orthopedic complications that can impact their quality of life. The goal of this review is to present a comprehensive description of complications in children with trisomy 18 to aid in the development of monitoring and treatment guidelines for the increasing number of providers who will be caring for these patients throughout their lives. Where the evidence is available, this review presents screening recommendations to allow for more rapid detection and documentation of these complications.
Rhodium‐Catalyzed Selective C−H Alkenylation of Indole at C4 Position
Authors: Wu Qingyi , Gao Pan , Yuan Yu
Published: February 2021

The indole motifs play a significant role in the pharmaceutical exploitation and the synthesis of naturel products, and transition metal catalyzed selective C−H bond activation of indoles has received extensive attention. However, the functionalization of C−H bonds on the benzene core is still a great challenge. By installing a bulky protecting group on the nitrogen and under the assistance of an ester directing group, we realized the Rh‐catalyzed alkenylation of indole at C4 position with high efficiency. This catalytic method exhibits satisfactory functional group compatibility and regioselectivity.
Shared risk and protective factors between Alzheimer's disease and ischemic stroke: A population‐based longitudinal study
Authors: Wang Rui , Qiu Chengxuan , Dintica Christina S. , Shang Ying , Calderón Larrañaga Amaia , Wang Hui‐Xin , Xu Weili
Published: February 2021

Introduction

Stroke, especially ischemic stroke's (IS) link with Alzheimer's disease (AD) remains unclear.

Methods

This prospective cohort study included 2459 AD‐ and cerebrovascular disease‐free older adults at baseline (mean age 71.9 ± 10.3 years, Stockholm, Sweden). Using Cox regressions, shared risk factors (SRFs) and shared protective factors (SPFs) between AD and IS were recognized when their hazard ratios in both AD and IS models were significant and in the same direction.

Results

During the follow‐up period of up to 15 years, 132 AD and 260 IS mutually exclusive cases were identified. SRFs were low education, sedentary lifestyle, and heart diseases. High levels of psychological well‐being, actively engaging in leisure activities, and a rich social network were SPFs. Having ≥1 SPF reduced 47% of AD and 28% of IS risk among people with a low risk profile (<2 SRFs), and 38% of AD and 31% of IS risk with a high risk profile (≥2 SRFs). In total, 57.8% of AD/IS cases could be prevented if individuals have ≥1 SPF and no SRF.

Discussion

AD and IS share risk/protective profiles, and SPFs seem to counteract the adverse effects of SRFs on both AD and IS.
Human Anatomy: Teaching–Learning Experience of a Support Teacher and a Student with Low Vision and Blindness
Authors: Mendonça Carolina Rodrigues , Souza Karla Tais de Oliveira , Arruda Jalsi Tacon , Noll Matias , Guimarães Nilza Nascimento
Published: February 2021

In Brazil, a federal law ensures that all students with disabilities are entitled to enrollment in higher education institutions. Higher courses in human anatomy stand out for their complexity in both theoretical and practical contents. Therefore, adaptation is required to accommodate students with special educational needs. This study aimed to describe the experience of a Support Teacher in the development of inclusive pedagogical practices for the discipline of Human Anatomy offered in the physiotherapy course for a student with low vision and blindness. The challenges and learning difficulties faced by a visually impaired student are reported. Qualitative analysis was performed by interviewing a student with low vision and blindness and a Support Teacher. The audio recordings were transcribed, categorized, and analyzed using content analysis. The Support Teacher created schematics and drawings of anatomical structures, reviewed theoretical and practical contents, developed adaptations of the examinations, and applied palpatory anatomy to facilitate the student’s learning process. The findings illustrate that the student faced the greatest difficulty in dealing with the emotional aspects, due to the inability to visualize the anatomical details in human cadavers. Thus, the presence of a Support Teacher was fundamental to ensure that the student could learn the content and overcome this limitation. In conclusion, personalized adaptation, commitment, and collaborative work between the Support Teacher and students with low vision and blindness improve their learning conditions.
Motor ability, physical self‐concept and health‐related quality of life in pediatric cancer survivors
Authors: Benzing Valentin , Siegwart Valerie , Spitzhüttl Janine , Schmid Jürg , Grotzer Michael , Roebers Claudia M. , Steinlin Maja , Leibundgut Kurt , Everts Regula , Schmidt Mirko
Published: February 2021

Background

Cancer survivorship is frequently associated with severe late effects. However, research into pediatric cancer survivors on late effects in motor ability, physical self‐concept and their relationship to quality of life is limited.

Methods

Using multiple regression analyses, 78 pediatric cancer survivors and 56 typically developing children were compared in motor ability, physical self‐concept and health‐related quality of life. In addition, mediational multi‐group analyses between motor ability (independent variable), physical self‐concept (mediator) and quality of life (dependent variable) were calculated.

Results

Pediatric cancer survivors had a lower motor ability (gHedges = 0.863), a lower physical self‐concept with regard to several scales of the PSDQ‐S (gHedges = 0.318–0.764) and a higher relative risk for a below average quality of life than controls (RR = 1.44). Children with a history of cancer involving the central nervous system showed poorer motor ability compared to those without central nervous system

involvement (gHedges = 0.591). Furthermore, the physical self‐concept significantly mediated the relationship between motor ability and quality of life in pediatric cancer survivors but not in typically developing children.

Conclusions

Results show the importance of monitoring and supporting the development of motor ability in the aftercare of pediatric cancer survivors. Physical activity interventions may be advisable to prevent physical activity‐related late effects and potentially improve related psychosocial variables such as quality of life.
Racial disparities in the treatment of aortic stenosis: Has transcatheter aortic valve replacement bridged the gap?
Authors: Erinne Ikenna , Sethi Ankur , Johannesen Justin , Kassotis John
Published: February 2021

Background

Racial disparities in outcomes and utilization of surgical aortic valve replacement (SAVR) for the treatment of severe aortic stenosis (AS) is well known. While transcatheter aortic valve replacement (TAVR) has become more widespread, its impact on racial disparities remains unclear.

Objectives

Our goal was to assess the utilization of SAVR and TAVR and their clinical outcomes among various racial groups.

Methods

The National Inpatient database (2009–2015) was used to study the racial distribution of admissions for SAVR and TAVR, and their impact on inpatient outcomes. Survey estimation commands were used to determine weighted national estimates.

Results

There were 3,445,267; 294,108; and 52,913 inpatient visits for AS, SAVR, and TAVR, respectively. SAVR visits were 86% White, 3.8% Black, 5.5% Hispanic, 1.2% Asian/Pacific Islander (A/PI), 0.4% Native American (NA), and 2.9%; TAVR were 87.7% White, 3.7% Black, 3.8% Hispanic, 1.0% A/PI, 0.2% NA, and 3.5% Other while AS visits were 83.7% White, 6.7% Black, 5.3% Hispanic, 1.7% A/PI, 0.4% NA, and 2.2% Other. Racial minorities generally had more co‐morbidities compared with Whites. After SAVR, Black patients had a higher unadjusted inpatient mortality than Whites, however, there was no difference after adjustment for other variables. A/PI were more likely to require a permanent pacemaker after SAVR. Need for blood transfusion was significantly higher among the minorities compared with Whites, except for NA, but there were no racial differences in stroke rates. There was no difference in inpatient mortality, pacemaker implantation, stroke, and bleeding after TAVR, but acute kidney injury occurred more often in Hispanics, A/PI, and “others” compared with Whites.

Conclusions

Racial disparities in the treatment of AS continues in the contemporary era; however it was found that TAVR resulted in comparable inpatient outcomes, despite higher comorbidities, and adverse socioeconomic factors in minorities.
Clinical outcomes of patients with and without chronic kidney disease undergoing endovascular revascularization of infrainguinal peripheral artery disease: Insights from the XLPAD registry
Authors: Kabir Ryan , Vuppala Suchith , Liu Yulun , Tejani Ishita , Weideman Rick , Banerjee Avantika , Tsai Shirling , Huffman Lynn , Niazi Khusrow , Brilakis Emmanouil S. , Shishehbor Mehdi H. , Banerjee Subhash
Published: February 2021

Objectives

The purpose of the present study was to define clinical outcomes of chronic kidney disease (CKD) patients undergoing endovascular revascularization of infrainguinal peripheral artery disease (PAD).

Background

CKD is an established predictor of advanced PAD. However, clinical outcomes for these patients following endovascular revascularization remain inadequately defined.

Methods

Using the ongoing multicenter Excellence in Peripheral Artery Disease (XLPAD) registry (NCT01904851), we analyzed all‐cause death, target limb amputation, and need for repeat revascularization for patients with and without CKD undergoing infrainguinal endovascular revascularization between the years 2005 and 2018.

Results

Of 3,699 patients, 15.1% (n = 559) had baseline CKD. CKD patients had significantly higher incidence of heavily calcified lesions (48.4% vs. 38.1%, p < .001) and diffuse disease (66.9% vs. 61.5%, p = .007). Kaplan–Meier analysis showed significant differences between CKD and non‐CKD patient outcomes at 12 months for freedom from target limb amputation (79.9% vs. 92.7%, p < .001) and all‐cause death (90.1% vs. 97.6%, p < .001). However, freedom from target vessel revascularization was similar between the groups. After adjusting for baseline comorbidities in the CKD and non‐CKD groups, the hazard ratios for target limb amputation and death at 12 months were 2.28 (95% confidence interval or CI 1.25–4.17, p < .001) and 4.38 (95% CI 2.58–7.45, p < .001), respectively.

Conclusions

Following endovascular revascularization for infrainguinal PAD, CKD was an independent predictor of all‐cause death and target limb amputation at 12 months.
Virtual support for remote proctoring in TAVR during COVID‐19
Authors: Arslan Fatih , Gerckens Ulrich
Published: February 2021

Objectives

The current report describes a single operator's experience of the first use of smartglass technology as a facilitator of virtual support during TAVR proctoring.

Background

Restricted gatherings and containment measures during the ongoing COVID‐19 pandemic have a major impact on daily clinical practice. Interaction between peers is crucial in science, clinical practice, and education. In addition, there is also a growing importance of proctoring in interventional cardiology for structural heart disease. Virtual support may facilitate the wide implementation of remote proctoring.

Methods

A collaboration between a smartglass provider (Rods & Cones) and self‐expandable transcatheter aortic heart valve system (Medtronic) was initiated and tested extensively prior to TAVR procedures. Two cases were randomly selected for remote support. The light‐weight smartglass consisted of a full HD central camera, a 720p ×5 optical zoom camera, built‐in LED light, speaker and earphone jack, and an external visor to project data in a nonobstructive manner in the operators' view.

Results

Preprocedural detailed discussion of the cases between the proctor and the operator occurred via teleconferencing. Successful procedural virtual support was determined by the presence of a session coordinator, high quality of the central camera, high‐speed and stable wireless internet connection. Limitations were the relative discomfort of the earpieces, discordance between the central and zoom camera and the absence of visual fixation during head motions.

Conclusion

In a highly complex and demanding context such as TAVR, remote proctoring by means of virtual support is feasible and efficacious.
Nickel‐Catalyzed Acyl Group Transfer of o‐Alkynylphenol Esters Accompanied by C−O Bond Fission for Synthesis of Benzo[b]furan
Authors: Doi Ryohei , Shimizu Koji , Ikemoto Yuma , Uchiyama Masashi , Koshiba Mikiko , Furukawa Atsushi , Maenaka Katsumi , Watanabe Satoshi , Sato Yoshihiro
Published: February 2021

Herein, we report the nickel‐catalyzed cascade C−O bond cleavage/cyclization of ortho‐alkynylphenyl ester to construct a 3‐acylbenzo[b]furan skeleton. As a result of reaction condition screening, the Ni(0)/IAd (1,3‐Di(1‐adamantyl)imidazole‐2‐ylidene) system was found to be optimal for catalytic conversion. Interestingly, the reaction exclusively gives 3‐acylbenzo[b]furan instead of a decarbonylated product frequently observed in reactions mediated by acyl‐nickel species. The catalyst loadings could be reduced to 5–10 mol %. We demonstrated the synthesis of a variety of functionalized 3‐acylbenzofuran derivatives. We conducted stoichiometric study of nickel complexes as well as density functional theory (DFT) calculations to support a possible reaction mechanism.
A high voltage pulse generator using avalanche‐mode thyristors
Authors: Naito Takashi , Akemoto Mitsuo
Published: February 2021

A high voltage and high current pulse switch using avalanche mode thyristor has been developed for the high voltage pulse generator. When the break‐over voltage is applied to a thyristor, the thyristor turns on without the gate input current. We call avalanche mode thyristor (AMT) which operates such a switch mode. AMT has many advantages, for example, turn on function without trigger input circuit in the series connection, high speed switching characteristics, etc. A magnetic switch (MS) using the saturation of the core is adopted for the high current pulse shaping. Twelve stages of AMTs generate 11 kV and 1.36 kA with 260 nanoseconds pulse width. A high voltage pulse has been produced up to 65 kV, 43A by using the AMT pulse generator and a pulse trans. The behavior of AMT and the performance of the circuit are discussed.
INTERVENE‐HF: feasibility study of individualized, risk stratification‐based, medication intervention in patients with heart failure with reduced ejection fraction
Authors: Zile Michael R. , Costanzo Maria Rosa R. , Ippolito Ekaterina M. , Zhang Yan , Stapleton Russell , Sadhu Ashish , Jimenez Javier , Hobbs Joe , Sharma Vinod , Warman Eduardo N. , Streeter Lindsay , Butler Javed
Published: February 2021

Aims

Determine the feasibility of implementing a heart failure (HF) management strategy that (i) uses a device‐based, remote, dynamic, multimetric risk stratification model to predict the risk of HF events and (ii) uses a standardized, centrally administered, ambulatory medication intervention protocol to reproducibly and safely decrease elevated risk scores.

Methods and results

Prospective, non‐randomized, single‐arm, multicenter feasibility study (Intervene‐HF) was conducted in HF patients implanted with a cardiac resynchronization therapy with implantable cardio defibrillator (CRT‐D) with TriageHF risk score feature. Certified HF nurses (CHFN) in the Medtronic Care Management Services Program implemented an ambulatory medication intervention strategy by following a standardized guided action pathway triggered by risk‐based alert. When CHFN received notification of increased risk score (HF care alert), they implemented a 3 day course of diuretic up‐titration (PRN) previously prescribed by a physician. Safety was monitored daily. Recovery after PRN was defined as ≥70% recovery of impedance toward baseline levels. Sixty‐six patients followed for 8.2 ± 3.9 months had 49 HF care alerts. Twenty‐three of 49 alerts did not receive PRN due to protocol‐mandated criteria. Twenty‐six of 49 alerts received PRN, 22 were completed, and 19 led to impedance recovery. Four interventions were stopped for safety without leading to an adverse event (AE). One of 26 PRNs was followed by a HF event. Eighty‐five per cent (22/26) of PRNs were completed without an AE; 69% (18/26) met the recovery criteria.

Conclusions

The Intervene‐HF study supports the feasibility of testing, in a large randomized clinical trial, an ambulatory medication intervention strategy that is physician‐directed, CHFN‐implemented, and based on individualized device risk stratification.
Numerical study of the vortex‐induced electroosmotic mixing of non‐Newtonian biofluids in a nonuniformly charged wavy microchannel: Effect of finite ion size
Authors: Mehta Sumit Kumar , Pati Sukumar , Mondal Pranab Kumar
Published: February 2021

We propose a micromixer for obtaining better efficiency of vortex induced electroosmotic mixing of non‐Newtonian bio‐fluids at a relatively higher flow rate, which finds relevance in many biomedical and biological applications. To represent the rheology of non‐Newtonian fluid, we consider the Carreau model in this study, while the applied electric field drives the constituent components in the micromixer. We show that the spatial variation of the applied field, triggered by the topological change of the bounding surfaces, upon interacting with the non‐uniform surface potential gives rise to efficient mixing as realized by the formation of vortices in the proposed micromixer. Also, we show that the phase‐lag between surface potential leads to the formation of asymmetric vortices. This behavior offers better mixing performance following the appearance of undulation on the flow pattern. Finally, we establish that the assumption of a point charge in the paradigm of electroosmotic mixing, which is not realistic as well, under‐predicts the mixing efficiency at higher amplitude of the non‐uniform zeta potential. The inferences of the present analysis may guide as a design tool for micromixer where rheological properties of the fluid and flow actuation parameters can be simultaneously tuned to obtain phenomenal enhancement in mixing efficiency.
Redox series assessment, petrogenetic, and geodynamic appraisal of Neoarchean granites from the Bundelkhand Craton, Central India: Constraints from phase petrology and bulk rock geochemistry
Authors: Kumar Gajender , Kumar Santosh , Mohan Mekala Ram
Published: February 2021

Based on field relationships, microstructure, phase petrology, and whole‐rock elemental geochemistry, we have unravelled the redox conditions and petrogenetic evolution of Neoarchean granites (sensu lato) from the central part of the Bundelkhand Craton, Central India. The studied Neoarchean granites are sanukitoids (sensu lato), high‐K, low‐magnesian granites (HKLMG), and oxidized A‐type granites (OAG). Chemistry of biotite in conjunction with amphibole compositions from sanukitoids indicates their crystallization in calc‐alkaline felsic host magma formed in a subduction setting at elevated fugacity of oxygen (fO2), buffered at +2 fayalite‐magnetite‐quartz (FMQ), corresponding to magnetite series granite. Chemistry of biotite and amphiboles from HKLMG suggests that host melts of these phases buffered above +1 FMQ, that is, moderate fO2 condition corresponding to magnetite series granites. The nature of the HKLMG magma is peraluminous to alkaline which originated at a relatively high‐P condition. The biotites from OAG exhibit pronounced Al‐Fe substitution buffered above +0.5 FMQ to represent oxidized A‐type host granite magma, belonging to magnetite series granite. The sanukitoids bear high ferromagnesian minerals (FeOt + MgO + MnO + TiO2 (FMMT) >4.5; Mg# = 28–45), and enriched incompatible elements without significant Eu anomalies, probably originated from melt‐enriched mantle source in a subduction setting. The HKLMG are characterized by relatively low Mg#, TiO2, high K‐LILEs‐REEs with negative Eu anomalies, and high Th/Nb, Ce/Pb, and La/Nb ratios, which suggest mixed source signatures, derived from the enriched mantle and continental crust. A‐type granites (OAG) bear high NK/A (molar Na2O + K2O/Al2O3 ~ 1.17), FeOt/MgO, K2O/Na2O, Ga/Al, and Ce–Y, which indicate the emplacement of OAG magmas in syn‐ to post‐collisional tectonic environments. Thus, the Neoarchean granites from the Bundelkhand Craton represent a collage of subduction related sanukitoids to high‐K magnesian granites, and syn‐ to post‐collisional oxidized A‐type granites.
Towards understanding organic matter fluxes and reactivity in surface waters: Filtering impact on DOC and POC degradation
Authors: Moody Catherine Sarah , Worrall Fred
Published: February 2021

Peatlands cover a very small area of the Earth, but store globally significant quantities of carbon and export disproportionate quantities of fluvial organic carbon, especially when the peatlands are degraded or disturbed. Peatland headwater catchments with high concentrations of dissolved and particulate organic carbon (DOC and POC) provide an opportunity to investigate the possibility of competing effects that could lead to enhanced or diminished turnover of DOC in the presence of POC. Both POC and DOC can be degraded by light and microbes, producing smaller molecules and releasing CO2 and CH4 to the atmosphere, and POC can inhibit light penetration, stabilize DOC by providing adsorption sites and providing surfaces for microbes to interact with DOC. However, the majority of peatland fluvial carbon studies are conducted using filtered water samples, and measure only the DOC concentration, so the impact of the particulate organic matter (POM) on in‐stream processing of organic carbon is relatively unknown. It is therefore possible that studies have underestimated carbon transformations in rivers as they have not considered the interaction of the particulate material on the dissolved concentrations; there could be higher losses than previously estimated, increasing the contribution of peatland headwaters to GHG emissions. In this study, we assessed if the current approach of DOC degradation studies accurately represent the impact of POM on DOC degradation, by quantifying DOC production from POM, and therefore POC, over time in water with manipulated POM concentrations. Both filtered and unfiltered water lost 60% of the DOC over 70 hours, whereas the treatment with additional POM lost only 35%. The results showed that filtering does not significantly impact the DOC degradation rates; however, when the POC concentration was doubled, there was a significant reduction in DOC degradation, suggesting that filtering would still be necessary to get accurate rates of DOC transformations in waters with high POC concentrations.
Investigating the fluctuations of exchange rate based on monetary‐behaviour approach
Authors: Tajdini Saeid , Mehrara Mohsen , Taiebnia Ali
Published: February 2021

The purpose of this study is to investigate the excessive changes in the exchange rate in Iran during 2018 due to extreme speculation in the monetary and currency markets caused by numerous economic and political factors such as accumulated excessive liquidity, severe sanctions and foreign pressures. Based on purchasing power parity (PPP) theory, the foreign exchange rate has to be adjusted with the inflation rate. However, this study showed that in the critical situations the PPP theory, which adopts a long‐term and backward‐looking approach, no longer works, and instead the market tends to adopt a short‐term and prospective approach to exchange rates. In this study, the economic data of Iran and the United States were gathered from late 1978 to 21 September 2018, and by adding three other economic factors, including the difference of average annual growth rate of GDP per capita of 2% between the two countries, indicator of risk in low volatility period (1.16%) and high volatility one (1.49%), a new and risk‐based approach is presented based on the low and high volatility of the exchange rates to address the excessive changes not explained by conventional theories.
The impact of COVID‐19 pandemic on hospitality stock returns in China
Authors: Lee Chi‐Chuan , Lee Chien‐Chiang , Wu Yizhong
Published: February 2021

Coronavirus disease (COVID‐19) has already devastated the world, and the economy becomes the most critical challenge for any country worldwide. The increasing uncertainty of the COVID‐19 outbreak has made stock markets in China more turbulent and less predictable. Under the current exceptional circumstances, the hospitality industry suffered the most due to the travel restrictions. This research thus assesses the dynamic relationship among the COVID‐19 outbreak, macroeconomic fluctuations and hospitality stock returns based on a structural VAR framework from 13 January to 11 May 2020, in China. Evidence reveals that macroeconomic fluctuations and hospitality stock returns are significantly affected by shocks from the COVID‐19 outbreak. An unanticipated positive change of the COVID‐19 explosion triggers an addition in exchange rates and causes a reduction in the stock market and hospitality industry returns. For the impacts of the exchange rate, findings reveal that a surprise increase in exchange rates (currency depreciation) exerts a significant negative influence on stock market returns. Additionally, a positive change of stock market returns is linked to a decline in exchange rates and a rise in hospitality industry returns. Therefore, knowledge of these relationships can enable policymakers to evaluate and implement effective policies to stabilize the stock markets and help investors to make appropriate investment strategies.
Spectrophotometric evaluation of hemolysis in plasma by quantification of free oxyhemoglobin, methemoglobin, and methemalbumin in presence of bilirubin
Authors: Heckl Christian , Lang Alexander , Rühm Adrian , Sroka Ronald , Duffield Thomas , Vogeser Michael , Paal Michael
Published: February 2021

Severe intravascular hemolysis leads to the simultaneous presence of free heme pigments (oxyhemoglobin, methemoglobin, and methemalbumin) and bilirubin in human plasma. Standard spectrophotometric methods used to assess in vivo hemolysis inadequately address this complex analytical situation. Thus, we propose a novel quantification algorithm to ensure the highest analytical specificity. A corresponding second‐derivative fitting algorithm was validated according to the guideline of bioanalytical method validation from the European Medicines Agency using plasma specimens (n = 1759) spiked with different concentrations of oxyhemoglobin and methemoglobin. The results were compared to standard spectrophotometric quantification methods described by Harboe, Noe, and Fairbanks. Based on the second‐derivative method, simultaneous quantification of oxyhemoglobin and methemoglobin/methemalbumin in samples with total bilirubin concentrations ≤4.9 mg/dL (83.8 μmol/L) provided robust results (inaccuracy ≤20%, imprecision ≤16%). Analyzing UV/VIS spectra of plasma from patients with confirmed severe intravascular hemolysis evidenced an underestimation of up to 33% for the combined free heme pigment content. The employed second‐derivative algorithm allows for automated and highly specific quantification of the free heme pigment content in diluted human plasma, which cannot be realized with standard spectrophotometric evaluation methods. An Excel‐based tool readily applicable to clinical datasets accompanies this manuscript.
Forensic and reliability analyses of fixed dental prostheses
Authors: Mecholsky John J. , Hsu Shu‐Min , Jadaan Osama , Griggs Jason , Neal Daniel , Clark Arthur E. , Xia Xinyi , Esquivel‐Upshaw Josephine F.
Published: February 2021

This article describes the protocol for determining the cause of failure for retrieved failed implant supported fixed dental prostheses (FDPs) in a clinical study of three‐unit bridges. The results of loading of flexure bars of different veneer compositions at different stress rates were presented for two veneer materials (leucite reinforced and fluorapatite glass–ceramic veneers) and a Y‐TZP core zirconia ceramic used in the clinical study. From these results, the strengths of the fast loading conditions were used to determine the fracture toughness of these materials. Fractal dimension measurements of the flexure bars and selected FDPs of the same materials demonstrated that the values were the same for both the bars and the FDPs. This allowed the use of fracture toughness values from the flexure bars to determine the strengths of the FDPs. The failure analysis of clinically obtained FDP replicates to determine the size of the fracture initiating cracks was then performed. Using the information from the flexure bars and the size of the fracture initiating cracks for the failed FDPs, the strengths of the FDPs were determined. The clinical failures were determined to be most likely the result of repeated crack growth due to initial overload and continuous use after initial cracking.
Cellulose from oil palm empty fruit bunch fiber and its conversion to carboxymethylcellulose
Authors: Yimlamai Benyathip , Choorit Wanna , Chisti Yusuf , Prasertsan Poonsuk
Published: February 2021

BACKGROUND

Higher‐value products, such as cellulose and carboxymethylcellulose (CMC), may be produced from lignocellulosic agroindustrial residues, such as oil palm empty fruit bunch (EFB) fibers that are presently underutilized or discarded. Recovery of cellulose from EFB and its conversion of CMC are discussed as methods of creating value and reducing the environmental impact of EFB.

RESULTS

Cellulose was recovered from EFB fibers and converted to water soluble CMC. Cellulose isolation used a two‐step sequential treatment involving peracetic acid (PA) (50 g dry EFB L−1 PA, 35 °C, 9 h) for initial delignification, and then alkaline peroxide (AP) (50 g delignified‐EFB L−1 AP, 45 °C, 12 h). This treatment removed 91.5% of lignin in the original EFB fiber. The recovered solids, designated as cellulose‐EFB, were comprised of 83.7 ± 3.4% cellulose, 5.6 ± 0.3% hemicellulose, 1.7 ± 0.0% lignin, and 1.7 ± 0.1% ash. A two‐step process with an initial alkalization {3 g cellulose‐EFB in 99 mL solvent [10:1 by vol mixture of ethanol (95%) and 35% NaOH], 30 °C, 2 h} followed by etherification was used to convert cellulose‐EFB to CMC sodium salt. The conversion yield was 50% of the theoretical maximum.

CONCLUSION

The best conditions for preparing CMC from cellulose‐EFB were a 2 h treatment with 35% (wt/vol) NaOH during alkalization at 30 °C, followed by etherification at 55 °C. The CMC had a degree of substitution of 0.16 and a water solubility of 6.8 g L−1 at 30 °C. © 2021 Society of Chemical Industry
Brain tumor segmentation using K‐means clustering and deep learning with synthetic data augmentation for classification
Authors: Khan Amjad Rehman , Khan Siraj , Harouni Majid , Abbasi Rashid , Iqbal Sajid , Mehmood Zahid
Published: February 2021

Image processing plays a major role in neurologists' clinical diagnosis in the medical field. Several types of imagery are used for diagnostics, tumor segmentation, and classification. Magnetic resonance imaging (MRI) is favored among all modalities due to its noninvasive nature and better representation of internal tumor information. Indeed, early diagnosis may increase the chances of being lifesaving. However, the manual dissection and classification of brain tumors based on MRI is vulnerable to error, time‐consuming, and formidable task. Consequently, this article presents a deep learning approach to classify brain tumors using an MRI data analysis to assist practitioners. The recommended method comprises three main phases: preprocessing, brain tumor segmentation using k‐means clustering, and finally, classify tumors into their respective categories (benign/malignant) using MRI data through a finetuned VGG19 (i.e., 19 layered Visual Geometric Group) model. Moreover, for better classification accuracy, the synthetic data augmentation concept i s introduced to increase available data size for classifier training. The proposed approach was evaluated on BraTS 2015 benchmarks data sets through rigorous experiments. The results endorse the effectiveness of the proposed strategy and it achieved better accuracy compared to the previously reported state of the art techniques.
Enamel demineralization model in primary teeth: Micro‐CT and SEM assessments of artificial incipient lesion
Authors: González‐Sotelo Arlete , Contreras‐Bulnes Rosalía , Rodríguez‐Vilchis Laura E. , Moyaho‐Bernal Maria de los Angeles , Rubio‐Rosas Efraín , Cerna‐Cortez Jorge R.
Published: February 2021

Many studies have analyzed different tooth demineralization models, which generate artificial incipient lesions; however, most of them are complex, slow, not clear and results could not be employed in both primary and permanent teeth because of chemical content differences among them. This study evaluates a demineralization model on primary enamel, under three incubation periods; quantifying artificial incipient lesions formation, and depth by micro‐CT, complementing with SEM for morphological characterization. Sixteen healthy human anterior primary teeth extracted for prolonged retention and orthopedic/orthodontic reasons were included in this study, previous informed consent. The sample was randomly assigned to four groups n = 4: G_Control, G_2D, G_4D, and G_7D. Micro‐CT and SEM were performed during two stages: before demineralization (BD) and after demineralization (AD). A t‐student test was carried out to determine differences among groups (p ≤ .05). No incipient lesions were observed in control group. Artificial lesion depth was similar among experimental groups; values were from 38.16 ± 05.40 μm to 42.61 ± 04.75 μm. An amount of 14 to 17 artificial incipient lesions were formed per group, the extension and distribution were different for each incubation period. Five erosive lesions were produced in G_7D. All experimental groups were able to form incipient artificial lesions in primary enamel. SEM characterization revealed more pronounced changes on the enamel surface, as the days of immersion in the demineralization solution increased. The 4‐day incubation period is the most recommended for the demineralization model, due to the formation of incipient lesions only and its extension, which facilitates their assessment.
Stress response of police officers during COVID‐19: A moderated mediation model
Authors: Jiang Qi
Published: February 2021

During the COVID‐19 pandemic, police officers have been at the frontline of danger. Their mental health should arouse the attention of society. To test the relationship between the psychological support they received and their stress response, the present study built a moderated mediation model to examine this and the effects of underlying mechanisms. A total of 553 Chinese police officers participated in this study; four scales were measured by standardised questionnaires (Emotional Identity of Profession Scale; DSM‐5 Self‐Rated Level 1 Cross‐Cutting Symptom Measure‐Adult; Psychological Support Scale; Active Work Adaptation Scale). Stress response was negatively correlated with psychological support, emotional identity of profession and active work adaptation. Psychological support, emotional identity of profession and active work adaptation were all positively correlated. Psychological support had a negative direct effect on stress response, and emotional identity of profession's mediating effect was distinct and was moderated by active work adaptation.
Large‐scale synoptic atmospheric moisture circulation patterns associated with variability of daily precipitation overEast China
Authors: Liu Bingjun , Chen Shiling , Tan Xuezhi
Published: February 2021

This study identifies the variability of large‐scale atmospheric patterns (LSMPs) and atmospheric moisture circulation patterns associated with the variability of daily precipitation over East China using the self‐organizing maps (SOM) method. The spatiotemporal characteristics of the occurrence and intensity of daily precipitation were linked with the variabilities of LSMPs. Results show that the synoptic moisture transport over East China in both dry season and rainy season can be classified into eight patterns, and the occurrence frequency and primary occurring months of the eight patterns are varied. In the dry season, the wetter pattern (the drier pattern) exhibits a significant decreasing (increasing) trend with a slope of −0.23 (0.63)% year−1at the confidence level of 0.95 during 1979–2018. The LSMPs corresponding to each atmospheric moisture circulation pattern, including the composite mean values of vertically integrated water vapour transport fields, 500 hPa geopotential height (Z500) anomalies and sea surface temperature anomalies (SSTA) in surrounding oceans, indicate that the primary oceanic moisture source of the dry season is western North Pacific (WNP), while that of the rainy season is WNP and the Indian Ocean. The location and intensity variabilities of subtropical high affect the transport and amount of water vapour along with its western flank to arrive in East China. SSTA has an influential link with the regional circulations and convection activity, and thus plays an important role in affecting water vapour transport.