bluuebunny/crossref_metadata_2025 huggingface dataset:
Microstructure‐dependent crevice corrosion damage of implant materialsCoCr28Mo6,TiAl6V4andREX734 under severe inflammatory conditions
Authors: Herbster Maria , Rosemann Paul , Michael Oliver , Harnisch Karsten , Ecke Martin , Heyn Andreas , Lohmann Christoph H. , Bertrand Jessica , Halle Thorsten
Published: February 2022

Fretting corrosion is associated with increased risk of premature implant failure. In this complex in vivo corrosion system, the contribution of static crevice corrosion of the joined metal alloys is still unknown. The aim of this study was to develop a methodology for testing crevice corrosion behavior that simulates the physiological conditions of modular taper junctions and to identify critical factors on corrosion susceptibility. Samples of medical grade CoCr28Mo6 cast and wrought alloy, TiAl6V4 wrought alloy and REX 734 stainless steel were prepared metallographically and the microstructure was investigated using scanning electron microscopy (SEM). Crevice formers that mimic typical geometries of taper junctions were developed. Crevice corrosion immersion tests were performed in different physiological fluids (bovine serum or phosphate buffered saline with additives of 30 mM H2O2at pH = 1) for 4 weeks at 37°C. SEM with energy dispersive X‐ray spectroscopy as well as focused ion beam were used to characterize the surface morphology, investigate present damages and identify the chemical composition of residues. Macroscopic inspection showed increased crevice corrosion susceptibility of TiAl6V4 and REX 734 under severe simulated inflammatory conditions. CoCr28Mo6 cast alloy exhibited degraded areas next to Cr‐ and Mo‐rich precipitations that were located within the opposed crevices. The results indicate that aggressive electrolyte composition and crevice heights of 50–500 μm are critical influencing factors on crevice corrosion of biomedical alloys. Furthermore, manufacturing‐related microstructure of common implant alloys determines the deterioration of corrosion resistance. The developed method should be used to enhance the corrosion resistance of common implant biomaterials by an adapted microstructure.
Protective effects of recombinant human golimumab and pentoxifylline in nephrotoxicity induced by cisplatin
Authors: Pavitrakar Vishal N. , Mody Rustom , Ravindran Selvan
Published: February 2022

In cisplatin‐induced nephrotoxicity, the significant role of activation of inflammatory pathways has been reported earlier. Studies indicate elevated expression and activity of tumor necrosis factor‐α (TNF‐α) in both, serum and kidneys of cisplatin‐treated animals. Golimumab, an anti‐TNF biologic, has been approved for the management of many inflammatory conditions. This experiment was planned and executed to evaluate the impact of golimumab on renal function, inflammation in cisplatin‐induced nephrotoxicity in mice, and oxidative stress. Cisplatin (22 mg/kg) as a single intraperitoneal injection was used to induce nephrotoxicity in mice. Golimumab was administered at 24 mg/kg for 7 days by subcutaneous route. Pentoxifylline (PTX) was administered for 7 days (150 mg/kg) as a reference standard. Renal functions, oxidative stress, and inflammation were evaluated on the seventh day. Cisplatin administration in mice caused a significant rise in serum cystatin C, creatinine, blood urea nitrogen, and neutrophil gelatinase‐associated lipocalin. A significant rise of urinary clusterin, kidney injury molecule‐1, and β‐N‐acetylglucosaminidase levels was also seen in cisplatin‐treated animals. Furthermore, cisplatin‐induced nephrotoxicity was associated with a significant increase in oxidative stress and inflammation in serum and kidneys. Golimumab treatment significantly prevented the cisplatin‐induced alteration in markers of renal function and renal damage. There was a significant reduction in oxidative stress and inflammation in golimumab‐treated animals. Furthermore, the histopathological evaluation also revealed inverted changes in the proximal tubules after golimumab treatment in kidneys after cisplatin toxicity. The standard drug, PTX, also prevented nephrotoxicity caused by cisplatin as indicated by the recovery in renal function, reduction in oxidative stress and inflammation. These results indicate that golimumab was effective in nephrotoxicity induced by cisplatin through inhibition of oxidative stress, and inflammatory response.
Long‐term sulfamethazine leaching simulation in two different soils using the MACRO model
Authors: Spill Caroline , Gassmann Matthias
Published: February 2022

Physically based models have been part of many risk assessment studies concerning pesticide or nutrient transport within (sub)catchments or at plot scale, but they are only poorly validated for simulating the transport of veterinary medicinal products. Veterinary medicinal products not only pose a risk to the quality of our waters but also tend to accumulate in soils, where they are associated with the appearance of resistant bacteria and long‐term leaching. In this study, the physically based leaching model MACRO 5.2 was applied for simulating sulfamethazine (SMZ) transport over a period of more than 10 yr. The model was set up using reversible kinetic adsorption and equilibrium adsorption forming non‐extractable residues. Two different calibration periods were used to estimate uncertainties in predicted SMZ leaching associated with calibration based on short‐term data. Using the whole period for model calibration, SMZ leaching could be simulated adequately, but parameter ranges were wide due to correlation between the parameters. When using only the first period for calibration, the quality of the prediction strongly depended on the information content of the data set. The calculation of temporal sensitivity indices revealed that the effect of complex sorption parameters on the model output increased with time. Thus, parameters that appeared insensitive in a short‐term calibration were required for reliable long‐term simulations. In conclusion, a temporal sensitivity analysis beyond the calibration period might identify parameters that were not constrained enough by the calibration procedure. This could help to confirm leaching predictions even for periods without sampling data.
Variation in brain volume in nine populations and three taxa of the African striped mouse Rhabdomys
Authors: Neves Candice Nikita , Pillay Neville
Published: February 2022

Brain size can vary between populations in different environments because of different selection pressures on behaviours, such as learning and memory, related to spatial, social and environmental differences. We investigated the variation in total and broad‐scale regional brain size in the murid rodent genus Rhabdomys from different environments. We assessed taxon‐, population‐ and sex‐level differences in total and regional brain volume in three populations each of three taxa (arid‐occurring Rhabdomys pumilio and mesic‐occurring Rhabdomys dilectus chakae and R. d. dilectus) originating across southern Africa. We μCT‐scanned crania obtained from museums in South Africa and used digital software to create endocasts and extract total endocranium and regional volumes: olfactory bulb, anterior cerebrum, posterior cerebrum, cerebellum volume and petrosal volume. Total endocranial volume scaled with basal skull length and all‐region volumes scaled with total endocranial volume. We found taxon‐, and population‐level differences in total endocranial volume. Relative anterior and posterior cerebrum volume did not differ significantly between taxa or populations, but relative cerebellum volume was larger in arid populations than mesic populations. Relative olfactory bulb volume was larger in mesic R. dilectus than in the R. pumilio, but petrosal lobule volume was larger in R. pumilio populations than in R. dilectus. Males had larger total endocranial volumes than females. Drivers of larger total endocranial volumes in R. pumilio are not immediately clear from our results. Environmental seasonality of food availability, cognitive buffering and locomotion may all correlate with total endocranial volume size, whereas the influence of sociality cannot be excluded. The environment and degree of semi‐arboreality are likely driving variation in cerebellum, olfactory bulb and petrosal lobule volumes.
Evaluation of the duration of dual‐antiplatelet therapy after percutaneous coronary intervention: a retrospective audit on the compliance with guidelines or cardiologist recommendation
Authors: Ho Wing Man , Hill Courtney , Michael Hayley , Winckel Karl
Published: February 2022

Introduction

Clinical guidelines define 12 months or less of dual antiplatelet therapy (DAPT) as standard therapy post‐percutaneous coronary intervention (PCI). The aim of this study was to determine the proportion of patients taking DAPT post‐PCI for the appropriate duration recommended by guidelines or the treating cardiologist at a large tertiary hospital in Brisbane.

Methods

A total of 105 patients, who were first admitted to Princess Alexandra Hospital (PAH) for PCI and were subsequently readmitted at least 12 months later, were audited. The appropriateness of continuation or cessation of DAPT was determined by comparing actual duration with the duration planned by the cardiologist and the duration recommended by clinical guidelines.

Results

Sixty‐six percent (n = 70) of patients were found to be still taking DAPT on readmission. DAPT duration for 32% (n = 34) patients was compliant with the recommendations of guidelines or treating cardiologist, with 10% (n = 11) and 57% (n = 60) being shorter and longer than recommendations of guidelines or treating cardiologist respectively.

Conclusion

Unwarranted extended use of DAPT is highly prevalent at the Princess Alexandra Hospital, and places patients at risk of bleeding complications.
Phenotype and genotype spectrum of variants in guanine nucleotide exchange factor genes in a broad cohort of Iranian patients
Authors: Mosallaei Meysam , Ehtesham Naeim , Beheshtian Maryam , Khoshbakht Shahrouz , Davarnia Behzad , Kahrizi Kimia , Najmabadi Hossein
Published: February 2022

Background

Guanine nucleotide exchange factors (GEFs) play pivotal roles in neuronal cell functions by exchanging GDP to GTP nucleotide and activation of GTPases. We aimed to determine the genotype and phenotype spectrum of GEF mutations by collecting data from a large Iranian cohort with intellectual disability (ID) and/or developmental delay (DD).

Methods

We collected data from nine families with 20 patients extracted from Iranian cohort of 640 families with ID and/or DD. Next‐generation sequencing (NGS) was used to identify the causing variants in recruited families. We also compared our clinical and molecular findings with previously reported patients carrying mutations in these GEF genes in the literature published until mid‐2021.

Results

We identified disease‐causing variants in eight GEF genes including ALS2, IQSEC2, MADD, RAB3GAP1, RAB3GAP2, TRIO, ITSN1, and DENND2A. The major clinical manifestations in 203 previously reported cases along with our 20 patients with disease causing variants in eight GEF genes were as follow; speech disorder (85.2%), ID (81.6%), DD (81.1%), inability to walk (71.3%), facial dysmorphisms features (52.4%), abnormalities in skull morphology (55.6%), hypotonia and muscle weakness (47%), and brain MRI abnormalities (43.4%).

Conclusion

Our study provides new insights into the genotype and phenotype spectrum of mutations in GEF genes.
A horn antenna with circular aperture for pipeline water cut measurement
Authors: Zeng Qunfeng , Liu Qi , Li Gaokai , Jiang Hao
Published: February 2022

A horn antenna with circular aperture is proposed and designed based on the variation of the attenuation amplitude and the attenuation of electromagnetic wave in pipeline in the present paper. The simulation and tests show that the gain of the antenna is 15 dB and the return loss is −12.5 dB. The simulation and experimental results of simulated pipeline water cut test also show that the antenna was used to measure the water content in the range of 0%–100% of the water and oil in the pipeline. The water cut measurement of water and oil is less affected by the mixing type of oil–water mixture in the pipeline, because the main lobe of the antenna is located in the pipeline and the antenna has good directivity. The design of antenna in microwave sensor is useful for the field‐testing and fundamental research.
High prevalence of paraspinal muscle involvement in adults with McArdle disease
Authors: Álvarez‐Velasco Rodrigo , Nuñez‐Peralta Claudia Alejandra , Alonso‐Pérez Jorge , Gallardo Eduard , Collet‐Vidiella Roger , Reyes‐Leiva David , Pascual‐Goñi Elba , Martín‐Aguilar Lorena , Caballero‐Ávila Marta , Carbayo‐Viejo Álvaro , Llauger‐Roselló Jaume , Díaz‐Manera Jordi , Olivé Montse
Published: February 2022

Introduction/Aims

Very few studies analyzing the pattern of muscle involvement in magnetic resonance imaging (MRI) of patients with McArdle disease have been reported to date. We aimed to examine the pattern of muscle fat replacement in patients with McArdle disease.

Methods

We performed a retrospective study including all patients with genetically confirmed McArdle disease followed in our center from January 2010 to March 2021. Clinical data were collected from the medical record. Whole‐body MRI was performed as part of the diagnostic evaluation. The distribution of muscle fat replacement and its severity were analyzed.

Results

Nine patients were included. Median age at onset was 7 y (range, 5–58) and median age at the time when MRI was performed was 57.3 y (range, 37.2–72.8). At physical examination, four patients had permanent weakness: in three the weakness was limited to paraspinal muscles, whereas in one the weakness involved the paraspinal and proximal upper limb muscles. Muscle MRI showed abnormalities in six of the seven studied patients. In all of them, fat replacement of paravertebral muscles was found. Other muscles frequently affected were the tongue in three, subscapularis in three, and long head of biceps femoris and semimembranosus in two.

Discussion

Our findings suggest that paraspinal muscle involvement is common in McArdle disease and support the need to include this disease in the differential diagnosis of the causes of paraspinal muscle weakness. Involvement of the tongue and subscapularis are also frequent in McArdle disease.
Psychological stress of emergency medical staff after the largest mass murder incident in post‐World War II era
Authors: Arai Hisatoshi , Inoue Katsuo , Takizawa Takeya , Yamaya Tatsuhiro , Asari Yasushi , Miyaoka Hitoshi
Published: February 2022

Background

A mass‐casualty incident occurred on July 26, 2016, at Tsukui Yamayuri‐en, which is a welfare facility for people with intellectual disabilities. Nineteen residents with intellectual disabilities were killed, and 26 other residents and staff members were injured. Kitasato University Hospital Emergency and Disaster Medical Center treated many patients in serious condition at the site and in the hospital.

Aims

The authors investigated the symptom severity and distributions of posttraumatic stress disorder (PTSD) among the emergency medical staff in charge.

The subjects of this study were the staff members, mostly working at the Emergency and Disaster Medical Center, who treated the people injured in the incident.

Methods

We conducted a questionnaire survey using Impact of Event Scale‐Revised (IES‐R) on 104 staff members, and 79 responded.

Results

The IES‐R scores of nurses were significantly higher than those of doctors. There was no significant difference in the scores between male and female staff members, and there was no correlation between the score of each IES‐R subscale and age.

Conclusion

Results suggest that mental care should be provided to emergency medical staff, especially nurses who treat trauma patients involved in disasters and heinous crimes.
Local Structure Analysis and Modelling of Lignin‐Based Carbon Composites through the Hierarchical Decomposition of the Radial Distribution Function
Authors: Kizzire Dayton G. , García‐Negrón Valerie , Harper David P. , Keffer David J.
Published: February 2022

Carbonized lignin has been proposed as a sustainable and domestic source of activated, amorphous, graphitic, and nanostructured carbon for many industrial applications as the structure can be tuned through processing conditions. However, the inherent variability of lignin and its complex physicochemical structure resulting from feedstock and pulping selection make the Process‐Structure‐Property‐Performance (PSPP) relationships hard to define. In this work, radial distribution functions (RDFs) from synchrotron X‐ray and neutron scattering of lignin‐based carbon composites (LBCCs) are investigated using the Hierarchical Decomposition of the Radial Distribution Function (HDRDF) modelling method to characterize the local atomic environment and develop quantitative PSPP relationships. PSPP relationships for LBCCs defined by this work include crystallite size dependence on lignin feedstock as well as increasing crystalline volume fraction, nanoscale composite density, and crystallite size with increasing reduction temperature.
Preparation and characterization of peroxide‐based dynamically vulcanized thermoplastic elastomer of poly (lactic acid)/chloroprene rubber
Authors: Shahroodi Zahra , Katbab Ali Asghar
Published: February 2022

Thermoplastic vulcanizates (TPVs) composed of crosslinked rubber phase with high chemical and thermal resistance have received great attention in pharmaceutical and biological applications. In the present work, attempts have been made to prepare TPVs based on poly (lactic acid) (PLA) and chloroprene rubber (CR) via a melt mixing process in the presence of dicumyl peroxide (DCP) and a combination of magnesium oxide (MgO) and epoxidized soybean oil (ESBO) as hydrochloric acid (HCl) scavenger to minimize CR degradation by DCP. A honeycomb co‐continuous micromorphology was observed for the fabricated TPVs samples through scanning electron microscopy, significantly different from the classical “sea‐island” micromorphology. However, the PLA/CR vulcanizates prepared by only DCP did not show enhanced mechanical properties due to the CR thermal decomposition by the DCP radicals. Therefore, a novel formulation was designed to prevent thermal decomposition of the CR phase during dynamic vulcanization by the incorporation of a combination of ESBO and MgO as efficient HCl scavenger. The stabilized TPV samples exhibited an intense brittle‐ductile transition effect and improved tensile mechanical. The obtained results implied the effectiveness of ESBO and MgO in stabilizing CR phase during peroxide dynamic vulcanization process.
Facile Synthesis of the Shape‐Persistent 4‐Hydroxybenzaldehyde Based Macrocycles and Exploration of their Key Electronic Properties: An Experimental and DFT Approach
Authors: Ali Mumtaz , Latif Abdul , Bibi Saeeda , Ali Sardar , Ali Akbar , Ahmad Manzoor , Ahmad Rashid , Khan Adnan Ali , Khan Ajmal , Ribeiro Alany Ingrid , Al‐Harrasi Ahmed , Farooq Umar
Published: February 2022

In the current study, a series of stabilized bis‐acetylene incorporated 4‐hydroxybenzaldehyde based macrocycles using the alkyne‐homocoupling approach were synthesized in moderate yields. A total of six newly stiff macrocycles were synthesized in a stepwise manner starting from 4‐hydroxybenzaldehyde. In the first step, base mediated propargylation was performed followed by copper mediated terminal alkyne homocoupling. The alkyne homocoupled substrate having carbonyl at both the terminals is cyclized in the final step via double imine formation reactions using substituted diamines as linker. All the newly synthesized rigid framework of the macrocycles were optimized at B3LYP/6‐31G (d,p) level of theory. Nonlinear optical behaviors of the synthesized macrocycles were explored by the DFT calculations where high values of first‐order hyperpolarizability and dipole moment were examined. In the reported study, a good agreement between experimental and theoretical parameters was observed that may play a significant contribution for the NLO applications.
A Novel Chemosensor for Selective Detection of L‐Arginine and L–Cysteine via Macroscopic Sol‐Gel Transition
Authors: Zali‐boeini Hassan , Khayat Zohreh
Published: February 2022

To develop chemosensors for biomolecule recognition, a multi stimuli responsive supramolecular gelator, [(E)‐4‐((4‐(benzyloxy)phenyl)diazenyl)benzaldehyde], comprised of azo and formyl units, was designed and synthesized from readily available starting materials. The gelator was found to be capable of forming gels in light alcohols and alcohol/water mixtures at low concentrations (0.7–1.5 g/100 mL). The gel rheological analyses showed the dominance of storage modulus (G′) values (ca 5000 Pa) within the range of analysis, confirming the gel stiffness. The xerogel scanning electron microscopy (SEM) studies showed a flake‐like pattern of thin sheets. Our investigations on the gelator sensing abilities revealed that, in addition to the photo‐responsive function due to the presence of azo moiety, its ethanol/water gel exhibited excellent ability to detect l‐arginine among 19 various amino acids, via gel to sol transition and colour change. Furthermore, the gelator could successfully recognize l‐cysteine among 19 amino acids, through macroscopic sol to gel transition and colour change of its alkaline methanolic solution. Moreover, the photo‐ and chemo‐responsive functions of the gelator were demonstrated as two combinational logic gates.
Recent Advances on Synthesis of Fused Chromeno‐Quinoline Heterocycles under Transition Metal‐Free Condition
Authors: Mal Sourav , Jana Manoranjan
Published: February 2022

Among the various other organic compounds, the compounds having heterocyclic core are extensively circulated in nature and are often crucial for life. The concerned heterocyle may or may not be aromatic. They often show a variety of physiological, industrial and also theoretical significance. Quinoline derivatives are very popular anti‐biotics and benzopyran or chromenes is another important heterocyclic moiety found widely in naturally occurring plant products like fruits and vegetables. However, when chromene and quinoline are present in a molecule in fused form, a subclass of very important bio‐active chromene‐fused quinoline heterocycles is formed. This review covers recent reports on transition metal‐free synthesis of chromeno‐quinoline derivatives in short and hassle‐free reaction protocols.
Adsorption of Carbon Dioxide Gas by Modified Graphene: A Theoretical Study
Authors: Lu Yunhua , Xu Yanjie , Zhang Jun'an , Zhang Qingwei , Li Lei , Tian Jiangling
Published: February 2022

This work is devoted to an investigation on the carbon dioxide (CO2) sensing properties of pristine graphene (PG), vacancy defect graphene (VG), Stone‐Wales defect graphene (SWG), and Pd‐doped graphene (PdG), based on density functional theory. To do so, we first relax all the models sufficiently to select the appropriate adsorption configuration and the results show that CO2 molecule reacts weakly on PG and SWG, while strong interaction occurs on VG and PdG. Then, the response to the CO2 molecule of all the graphene‐based substrates, in terms of charge transfer, density of states and band structure are examined. To account for the effects of defects and doping on adsorption, we have made the evaluation, for different systems, while before and after adsorbing CO2 molecule. Our results demonstrate that vacancy defect and Pd doping can significantly enhance the response of graphene to CO2 molecule with the optimum adsorption energy of −1.76 eV and −4.63 eV, respectively, and thus indicate that VG and PdG may be used as CO2 sensing materials.
Thermal Self‐Protection Behavior of Energy Storage Devices Using a Thermally Responsive Smart Polymer Electrolyte
Authors: Yu Tiantian , Xue Pan , Ma Shaoshuai , Gu Yifan , Wang Yutian , Xu Xinhua
Published: February 2022

With the growth of high performance electronics, more consideration should be given to the safety issues associated with thermal runaway. Previous strategies have often been limited by shutdown efficiency and shutdown temperature. Here, we present a MXene supercapacitor loaded with a smart thermally responsive electrolyte to cope with thermal runaway at high temperatures. At room temperature, the ions in the electrolyte containing the poly (N‐isopropylacrylamide‐co‐glycidyl methacrylate) (PNGM) can migrate freely and the devices can operate normally. The smart electrolyte system forms a hydrophobic network that effectively inhibits ion migration to achieve thermal shutdown at high temperatures. The electrolyte system exhibits different electrochemical properties during heating up, reaching nearly 90 % capacity suppression at 85 °C. The proposed smart electrolyte system provides a promising solution to the thermal safety suitable for current electronic devices by achieving a proactive protection strategy.
Enantioselective Synthesis of 3‐Amino‐3’‐carbazole Oxindole Derivatives via Friedel‐Crafts Aminoalkylation Reaction
Authors: Muthusamy Subramaniam , Kumarswamyreddy Nandarapu , Kesavan Venkitasamy
Published: February 2022

Organocatalytic Friedel‐Crafts aminoalkylation reaction is demonstrated in this study for the construction of biologically important hybrid molecular architectures of carbazole containing 3‐amino oxindoles using bifunctional cinchonidine derived thiourea organocatalyst. The Friedel‐Crafts functionalization of 4‐hydroxy carbazole with isatin derived ketimines well performed with a wide range of substrates resulted in excellent yields (up to 95 %) and enantioselectivities (up to 99 % ee) of the desired products. A minimal catalyst loading (0.5 mol%) was utilized at ambient temperatures under mild reaction conditions.
DNA‐Assisted Creation of a Library of Ultrasmall Multimetal/Metal Oxide Nanoparticles Confined in Silica
Authors: Azhati Arepati , Zhu Haiyin , Ouyang Tianwei , He Tianyao , Zeng Yifei , Wu Peng , Jiang Jingang , Peng Honggen , Che Shunai
Published: February 2022

Supported ultrasmall metal/metal oxide nanoparticles (UMNPs) with sizes in the range of 1–5 nm exhibit unique properties in sensing, catalysis, biomedicine, etc. However, the metal–support and metal–metal precursor interactions were not as well controlled to stabilize the metal nanoparticles on/in the supports. Herein, DNA is chosen as a template and a ligand for the silica‐supported UMNPs, taking full use of its binding ability to metal ions via either electrostatic or coordination interactions. UMNPs thus are highly dispersed in silica via self‐assembly of DNA and DNA–metal ion interactions with the assistance of a co‐structural directing agent (CSDA). A large number of metal ions are easily retained in the mesostructured DNA–silica materials, and their growth is controlled by the channels after calcination. Based on this directing concept, a material library, consisting of 50 mono‐ and 54 bicomponent UMNPs confined within silica and with narrow size distribution, is created. Theoretical calculation proves the indispensability of DNA with combination of several organics in the synthesis of ultrasmall metal nanoparticles. The Pt–silica and Pt/Ni–silica chosen from the library exhibit good catalytic performance for toluene combustion. This generalizable and straightforward synthesis strategy is expected to widen the corresponding applications of supported UMNPs.
Tuning Catalyst Activation and Utilization Via Controlled Electrode Patterning for Low‐Loading and High‐Efficiency Water Electrolyzers
Authors: Yu Shule , Li Kui , Wang Weitian , Xie Zhiqiang , Ding Lei , Kang Zhenye , Wrubel Jacob , Ma Zhiwen , Bender Guido , Yu Haoran , Baxter Jefferey , Cullen David A. , Keane Alex , Ayers Kathy , Capuano Christopher B. , Zhang Feng‐Yuan
Published: February 2022

An anode electrode concept of thin catalyst‐coated liquid/gas diffusion layers (CCLGDLs), by integrating Ir catalysts with Ti thin tunable LGDLs with facile electroplating in proton exchange membrane electrolyzer cells (PEMECs), is proposed. The CCLGDL design with only 0.08 mgIr cm−2 can achieve comparative cell performances to the conventional commercial electrode design, saving ≈97% Ir catalyst and augmenting a catalyst utilization to ≈24 times. CCLGDLs with regulated patterns enable insight into how pattern morphology impacts reaction kinetics and catalyst utilization in PEMECs. A specially designed two‐sided transparent reaction‐visible cell assists the in situ visualization of the PEM/electrode reaction interface for the first time. Oxygen gas is observed accumulating at the reaction interface, limiting the active area and increasing the cell impedances. It is demonstrated that mass transport in PEMECs can be modified by tuning CCLGDL patterns, thus improving the catalyst activation and utilization. The CCLGDL concept promises a future electrode design strategy with a simplified fabrication process and enhanced catalyst utilization. Furthermore, the CCLGDL concept also shows great potential in being a powerful tool for in situ reaction interface research in PEMECs and other energy conversion devices with solid polymer electrolytes.
Self‐healing of engineered cementitious composites under reversed and sustained loading conditions
Authors: Mahmoodi Sina , Sadeghian Pedram
Published: February 2022

The present study investigates the effects of reversed and sustained flexural loading cycles on the repeatability of self‐healing in engineered cementitious composites (ECC). The experimental work is designed to test three cases of normal (REF), reverse (REV), and reverse‐sustained (RES) loading and three different exposure conditions of tap water, sea water, and open air. A total of 27 prism specimens (100 × 100 × 350 mm) were fabricated, and a four‐point bending test was used for flexural load application at different stages and to further measure the recovery in mechanical properties. The research is proposed to elaborate on the positive/negative impact of compression cycle on the self‐healing of cracks. Ultrasonic pulse velocity (UPV) test was carried out before and after each loading and the wave travel time was compared as an indicator of healing efficiency. To monitor crack propagation patterns and crack widths, digital image correlation (DIC) technique was used. To further analyze the mineralogy and microstructure of the healing products, X‐ray diffraction (XRD) test was conducted on two groups of tap water and sea water exposures. Concluding results proved that sea water and tap water are suitable environments for autogenous self‐healing process. Furthermore, reverse loading cycles were demonstrated to impact the self‐healing results and should be considered for repeatable self‐healing evaluations.
Empowering Reading with Home Language Texts
Authors: Howard Deborah
Published: February 2022

Research from dual and bilingual education programs shows that the use of a student's home language for reading instruction is one of the most beneficial practices for multilingual learners. Given the plethora of home languages encountered in public schools, how can teachers who do not speak the languages of their students utilize a student's home language as an asset during reading instruction? This article describes a case study of a second grade Japanese student. During instruction, the student read texts in both Japanese and English.
Improved Low‐Temperature Solution‐Growth of CsPbBr3‐nCln Single Crystals for X‐Ray Detection
Authors: Hua Yunqiu , Cui Fucai , Zhang Peng , Zhang Guodong , Zhang Qichun , Tao Xutang
Published: February 2022

The dark current drift caused by severe ion migration in all‐inorganic perovskite CsPbBr3 degrades the stability of X‐ray detection performance under a high electric field. The halogen doping is an effective method to improve the properties of the perovskites. In this work, the all‐inorganic Cl‐doped perovskites CsPbBr3‐nCln (n=0, 0.1 and 0.5) single crystals were grown by a modified low‐temperature inverse temperature crystallization (ITC) method with the growth temperature lower than the phase transition point. The trap density decreased to 3.05×1010 cm−3 and the carrier mobility increased to 124.75 cm2 V−1 s−1 for the optimum component of CsPbBr2.9Cl0.1. Furthermore, by designing the detector with an asymmetric electrode configuration, CsPbBr2.9Cl0.1 detector showed super low dark current and an outstanding hard X‐ray induced photo‐response under a high voltage of 200 V. Consequently, the CsPbBr2.9Cl0.1 perovskite detector delivers a high sensitivity (5593.24 μC Gyair−1 cm−2) and a low detection limit (0.68 μGyair s−1). Our low temperature solution grown Cl‐doped all‐inorganic perovskite single crystals efficiently improve the photoelectric properties and enhance the X‐ray detection performance.
Torsional string Newton-Cartan geometry for non-relativistic strings
Authors: Bidussi Leo , Harmark Troels , Hartong Jelle , Obers Niels A. , Oling Gerben
Published: February 2022

Abstract

We revisit the formulation of non-relativistic (NR) string theory and its target space geometry. We obtain a new formulation in which the geometry contains a two-form field that couples to the tension current and that transforms under string Galilei boosts. This parallels the Newton-Cartan one-form that couples to the mass current of a non-relativistic point particle. We show how this formulation of the NR string arises both from an infinite speed of light limit and a null reduction of the relativistic closed bosonic string. In both cases, the two-form originates from a combination of metric quantities and the Kalb-Ramond field. The target space geometry of the NR string is seen to arise from the gauging of a new algebra that is obtained by an İnönü-Wigner contraction of the Poincaré algebra extended by the symmetries of the Kalb-Ramond field. In this new formulation, there are no superfluous target space fields that can be removed by fixing a Stückelberg symmetry. Classically, there are no foliation/torsion constraints imposed on the target space geometry.
Action complexity in the presence of defects and boundaries
Authors: Auzzi Roberto , Baiguera Stefano , Bonansea Sara , Nardelli Giuseppe
Published: February 2022

Abstract

The holographic complexity of formation for the AdS3 2-sided Randall-Sundrum model and the AdS3/BCFT2 models is logarithmically divergent according to the volume conjecture, while it is finite using the action proposal. One might be tempted to conclude that the UV divergences of the volume and action conjectures are always different for defects and boundaries in two-dimensional conformal field theories. We show that this is not the case. In fact, in Janus AdS3 we find that both volume and action proposals provide the same kind of logarithmic divergences.
Aspects of 5d Seiberg-Witten theories on $$ {\mathbbm{S}}^1 $$
Authors: Jia Qiang , Yi Piljin
Published: February 2022

Abstract

We study the infrared physics of 5d $$ \mathcal{N} $$
N
= 1 Yang-Mills theories compactified on $$ {\mathbbm{S}}^1 $$

S
1

, with a view toward 4d and 5d limits. Global structures of the simplest Coulombic moduli spaces are outlined, with an emphasis on how multiple planar 4d Seiberg-Witten geometries are embedded in the cigar geometry of a single 5d theory on $$ {\mathbbm{S}}^1 $$

S
1

. The Coulomb phase boundaries in the decompactification limit are given particular attention and related to how the wall-crossings by 5d BPS particles turn off. On the other hand, the elliptic genera of magnetic BPS strings do wall-cross and retain the memory of 4d wall-crossings, which we review with the example of dP2 theory. Along the way, we also offer a general field theory proof of the odd shift of electric charge on Sp(k)π instanton solitons, previously observed via geometric engineering for low-rank supersymmetric theories.
Localized magnetic field in the O(N) model
Authors: Cuomo Gabriel , Komargodski Zohar , Mezei Márk
Published: February 2022

Abstract

We consider the critical O(N) model in the presence of an external magnetic field localized in space. This setup can potentially be realized in quantum simulators and in some liquid mixtures. The external field can be understood as a relevant perturbation of the trivial line defect, and thus triggers a defect Renormalization Group (RG) flow. In agreement with the g-theorem, the external localized field leads at long distances to a stable nontrivial defect CFT (DCFT) with g < 1. We obtain several predictions for the corresponding DCFT data in the epsilon expansion and in the large N limit. The analysis of the large N limit involves a new saddle point and, remarkably, the study of fluctuations around it is enabled by recent progress in AdS loop diagrams. Our results are compatible with results from Monte Carlo simulations and we make several predictions that can be tested in the future.
Stellenwert wasserbezogener Rehabilitationsmaßnahmen bei Stomaträgern
Authors: Putz Juliane , Borkowetz Angelika , Schlumberger Gina Benita , Huber Johannes , Thomas Christian
Published: February 2022

Hintergrund

Die Anlage eines Hautstomas nach exenterativen Beckeneingriffen stellt für Betroffene einen drastischen Einschnitt in die körperliche Integrität dar. Vielfach führen ästhetische und funktionelle Bedenken dazu, dass wasserbezogene Angebote zur Rehabilitation nicht genutzt werden.

Fragestellung

Ziel war es, im Rahmen des Pilotprojekts „UROAquaFIT“ die Möglichkeit einer wasserbezogenen Rehabilitationsmaßnahme für Patienten nach Zystektomie mit inkontinenter Harnableitung zu evaluieren.

Methode

Im Rahmen des Pilotkurses „UROAquaFIT“ wurde Patienten nach radikaler Zystektomie mit inkontinenter Harnableitung die Möglichkeit einer wasserbezogenen Rehabilitationsmaßnahme angeboten. Aufgeteilt in Kleingruppen erfolgte ein Wassergymnastikkurs unter Anleitung einer Physiotherapeutin und einer Stomatherapeutin unter ärztlicher Aufsicht. Daten zur Lebensqualität und der persönlichen Beurteilung des Kurses mittels Fragebögen wurden vor Beginn und 6 Monate nach Kursende erhoben und qualitativ ausgewertet. Darüber hinaus erfolgte eine Literaturrecherche (MEDLINE) zum Thema Aquagymnastik in der Onkologie.

Ergebnis und Diskussion

Das Kursangebot wurde von allen Teilnehmern als durchweg positiv und bereichernd empfunden. Wohlbefinden und Selbstwertgefühl der Probanden konnten gesteigert werden. Wassergymnastik unter gezielter physio- und stomatherapeutischer Anleitung kann somit eine höchst effektive Rehabilitationsmaßnahme für Patienten nach inkontinenter Harnableitung darstellen. Darüber hinaus stärkt sie die körperliche Integrität der Betroffenen und erweitert somit die Möglichkeiten der sozialen Reintegration. Diese Form der Therapie sollte als fester Baustein in der Rehabilitation nach exenterativen Beckeneingriffen mit Stomaanlage verankert werden.
A Detailed PAH and Soot Model for Complex Fuels in CFD Applications
Authors: Eigentler Florian , Gerlinger Peter
Published: February 2022

A model to predict soot evolution during the combustion of complex fuels is presented. On one hand, gas phase, $$\hbox {polycyclic aromatic hydrocarbon (PAH)}$$

polycyclic aromatic hydrocarbon (PAH)

and soot chemistry are kept large enough to cover all relevant processes in aero engines. On the other hand, the mechanisms are reduced as far as possible, to enable complex computational fluid dynamics (CFD) combustion simulations. This is important because all species transport equations are solved directly in the $$\hbox {CFD}$$
CFD
. Moreover, emphasis is placed on the applicability of the model for a variety of fuels and operating conditions without adjusting it. A kinetic scheme is derived to describe the chemical breakdown of short- and long-chain hydrocarbon fuels and even blends of them. $$\hbox {PAHs}$$
PAHs
are the primary soot precursors which are modeled by a sectional approach. The reversibility of the interaction between different $$\hbox {PAH}$$
PAH
classes is achieved by the introduction of $$\hbox {PAH}$$
PAH
radicals. Soot particles are captured by a detailed sectional approach too, which takes a non-spherical growth of particles into account. In this way the modeling of surface processes is improved. The applicability and validity of the gas phase, $$\hbox {PAH}$$
PAH
, and soot model is demonstrated by a large number of shock tube experiments, as well as in atmospheric laminar sooting flames. The presented model achieves excellent results for a wide range of operating conditions and fuels. One set of model constants is used for all simulations and no case-dependent optimization is required.
Enhancement of physico-chemical, optical, dielectric and antimicrobial properties of polyvinyl alcohol/carboxymethyl cellulose blend films by addition of silver doped hydroxyapatite nanoparticles
Authors: Nasrallah Doaa A. , Ibrahim Manar A.
Published: February 2022

Hydroxyapatite nanoparticles doped with silver AgHA-NPs were synthesized successfully then added with various mass fractions to a mixed solution of polyvinyl alcohol (PVA)/ carboxymethyl cellulose (CMC) using the casting technique. Experimentally, the influence of silver doped hydroxyapatite nanoparticles on the structural, optical, dielectric and antimicrobial properties of nanocomposite films was investigated. X-ray diffraction and Fourier transformation infrared spectroscopy were used to explore the structural features of these films. The XRD analysis revealed the amorphous nature of PVA/CMC blend and the intensity of the characteristic peak of the virgin polymers in the nanocomposite spectrum being much reduced as the doping level was increased. The FT-IR spectra indicated that the blend components were miscible by revealing the functional groups of two polymers that interacted through the formation of a hydrogen bond while, the FT-IR spectra of nanocomposite confirmed the good interaction between the blend chains and AgHA-NPs. The morphological graphs of the prepared blend were formed as hexagonal grains with size distribution around 18.36–24.11 μm. The addition of AgHA-NPs changed the surface morphology of the blend significantly. The optical properties of PVA/ CMC blend and nanocomposites films were measured in the 200–800 nm wavelength range. Optical measurements showed that the optical transmittance for pure blend was nearly 90% while it decreased to 50% with increasing AgHA-NPs contents up to 40 wt.%. The energy gap values calculated by Tauc's model and those determined by ASF model are consistent, where their values reduced by AgHA-NPs incorporation. The dielectric constant of all samples were studied in range of temperatures (303–405 K) and from100 kHz to 1.0 MHz, range of frequencies. The Correlated Barrier Hopping (CBH) is the most appropriate conduction mechanism based on the frequency dependence of the ac conductivity. Silver ion release was examined showed that he film loaded with 10 wt.% AgHA-NPs has a small release of silver ion, while the amount of the Ag+ released from the samples increased slowly with increasing the content of AgHA-NPs. PVA/CMC/AgHA films were tested for antibacterial activity against both (Bacillus subtilis) and (Escherichia coli) as well as the anti-fungal activity against (Candida albicans),their results showing an increase in the activity index as the filling level of AgHA-NPs increases. The study confirmed that doping of AgHA-NPs into PVA/CMC improves both electrical conductivity and antimicrobial efficiency and these nanocomposites might be recommended for further work in biomedical applications such as wound dressing and infection control.
Methodology for the integrative adaption of manufacturing process and inspection sequences to component changes of safety–critical medical products
Authors: Stauder Lars , Knott Anna-Lena , Schmitt Robert H. , Bergs Thomas
Published: February 2022

Ever-shorter product lifecycles and more frequently changing customer demands challenge manufacturing companies to change their products and the components these products are composed of in ever-shorter periods. As a result, the existing manufacturing process and inspection sequences (MPISs) of the corresponding components must be adapted. Particularly in the production of safety–critical components, such as in the medical industries, component changes represent a major challenge, as very high quality requirements are placed on the components and a costly re-certification of the adapted processes is necessary. Due to the high quality requirements, not only the manufacturing process but also the inspection processes must be adapted for the realization of a component change. Furthermore, a high degree of planning reliability is necessary when deriving adaptations of MPISs for component changes to keep the re-certification effort and adaptation costs for safety–critical components as low as possible. Therefore, a methodology is introduced for the integrative derivation of adaptation options of MPISs due to component changes that supports users in identifying suitable adaptations in a systematic and time-efficient way. The methodology is successfully applied to a use case from the medical industry and supports users in identifying adaptations in established MPISs to implement a component change.
‘There’s Just Something Really Peaceful About It’: a Qualitative Exploration of Mothers with Young Children and Engagement in Group-Based Physical Activity Programs
Authors: Peralta Louisa R. , Yager Zali , Prichard Ivanka
Published: February 2022

Background

Many mothers with young children often do not achieve recommendations of at least 150-min moderate-to-vigorous physical activity (MVPA) each week. Previous qualitative work has generally focused on getting inactive mothers with young children to be active, so the characteristics of women who are active during early postpartum period are not well understood. This research set out to capture the characteristics of mothers with young children who engage in MVPA and how these women manage barriers and harness enablers to sustain in engagement in physical activity (PA) over an extended period.

Method

Thirty-two participants ranging in age from 27 to 42 years (35.2 ± 4.8), with age of their youngest child ranging from 6 weeks old to 5 years, participated in semi-structured interviews.

Results

Inductive thematic analysis revealed three overarching themes and fourteen sub-themes relating to the characteristics of active mothers with young children and the engagement and maintenance factors that recruit and sustain these women in group-based physical activity programs. Specifically, mothers with young children relish a welcoming and supportive environment that accommodates babies and young children, is affordable and convenient, focuses on building strength and functionality, and is non-judgmental.

Conclusion

These findings advance knowledge by providing considerations and recommendations that support intervention and program designers to be able to develop group-based physical activity programs for mothers with young children.
Validation of a Developed Enterprise Architecture Framework for Digitalisation of Smart Cities: a Mixed-Mode Approach
Authors: Jnr Bokolo Anthony , Petersen Sobah Abbas
Published: February 2022

To support smart cities in aligning information technology (IT) and business strategies to achieve urban digitalization, this study aims to present an Enterprise Architecture Framework (EAF) to facilitate the digitalization of urban environments. Technology Acceptance Model (TAM) was employed to design a research model, and a mixed-mode methodology was employed. Quantitative data from survey questionnaires was used to gather data from practitioners in enterprises within Norway and Ireland that currently adopt Enterprise Architecture (EA) in a smart city project to empirically validate the developed EAF. Additionally, the developed EAF layers were validated through a qualitative focus group workshop with participants that utilize the developed EAF to provide digital services in smart cities. The findings suggest that the developed EAF can aid enterprises that provided digital services in identifying and assessing their digitalization initiatives and how EA benefits can be realized. Drawing on the TAM, the developed research model presents factors that influence practitioner’s adoption of EA towards the digitalization of urban environments. More importantly, this study provides empirically validated research on EAF adoption which is scarce.