bluuebunny/crossref_metadata_2025 huggingface dataset:
In silico modeling of the interaction between TEX19 and LIRE1, and analysis of TEX19 gene missense SNPs
Authors: Alzahrani Faisal A. , Hawsawi Yousef MohammedRabaa , Altayeb Hisham N. , Alsiwiehri Naif O. , Alzahrani Othman R. , Alatwi Hanan E. , Al‐Amer Osama M. , Alomar Suliman , Mansour Lamjed
Published: May 2021

Background

Testis expressed 19 (TEX19) is a specific human stem cell gene identified as cancer‐testis antigen (CTA), which emerged as a potential therapeutic drug target. TEX19.1, a mouse paralog of human TEX19, can interact with LINE‐1 retrotransposable element ORF1 protein (LIRE1) and subsequently restrict mobilization of LINE‐1 elements in the genome.

Aim

This study aimed to predict the interaction of TEX19 with LIRE1 and analyze TEX19 missense polymorphisms. TEX19 model was generated using I‐TASSER and the interaction between TEX19 and LIRE1 was studied using the HADDOCK software.

Methods

The stability of the docking formed complex was studied through the molecular dynamic simulation using GROMACS. Missense SNPs (n=102) of TEX19 were screened for their potential effects on protein structure and function using different software.

Results

Outcomes of this study revealed amino acids that potentially stabilize the predicted interaction interface between TEX19 and LIRE1. Of these SNPs, 37 were predicted to play a probably damaging role for the protein, three of them (F35S, P61R, and E55L) located at the binding site of LIRE1 and could disturb this binding affinity.

Conclusion

This information can be verified by further in vitro and in vivo experimentations and could be exploited for potential therapeutic targets.
Stability for the Kelvin–Voigt variable order equations backward in time
Authors: Straughan Brian
Published: May 2021

Continuous dependence upon the initial data is established for a solution to the equations for a Kelvin–Voigt fluid of variable order, for the backward in time problem. Relatively weak restrictions are required on the base velocity field for a potentially improperly posed problem.
The design of a high voltage responsivity terahertz detector based on improved grounding model
Authors: Liu Si‐yu , Zhang De‐hai , Meng Jin , Zhu Hao‐Tian
Published: May 2021

A high voltage responsivity detector in G‐band is designed in this paper. Different grounding models for the terahertz detector are analyzed and designed. Gold wire grounding design is superior to traditional grounding designs, which reduce the influence caused by the doping concentration, position and thickness error of conductive adhesive. Detectors are based on the Virginia Diodes Inc G‐band zero‐bias Schottky diode with low zero‐bias junction capacitance. The voltage responsivity test result of the gold wire grounding detector is about 1800 mV/mW in 210–220 GHz. The development of the detector provides the device basis for the realization of a terahertz focal plane imaging system.
AAPM Task Group 198 Report: An implementation guide for TG 142 quality assurance of medical accelerators
Authors: Hanley Joseph , Dresser Sean , Simon William , Flynn Ryan , Klein Eric E. , Letourneau Daniel , Liu Chihray , Yin Fang‐Fang , Arjomandy Bijan , Ma Lijun , Aguirre Francisco , Jones Jimmy , Bayouth John , Holmes Todd
Published: May 2021

The charges on this task group (TG) were as follows: (a) provide specific procedural guidelines for performing the tests recommended in TG 142; (b) provide estimate of the range of time, appropriate personnel, and qualifications necessary to complete the tests in TG 142; and (c) provide sample daily, weekly, monthly, or annual quality assurance (QA) forms. Many of the guidelines in this report are drawn from the literature and are included in the references. When literature was not available, specific test methods reflect the experiences of the TG members (e.g., a test method for door interlock is self‐evident with no literature necessary). In other cases, the technology is so new that no literature for test methods was available. Given broad clinical adaptation of volumetric modulated arc therapy (VMAT), which is not a specific topic of TG 142, several tests and criteria specific to VMAT were added.
Gender differences in clinical outcomes in myasthenia gravis: A prospective cohort study
Authors: Thomsen Jan L. S. , Vinge Lotte , Harbo Thomas , Andersen Henning
Published: May 2021

Introduction/Aims

It is uncertain whether clinical outcomes differ between male and female patients with myasthenia gravis (MG) while receiving standard clinical care.

Methods

In a prospective cohort study of 107 patients with MG receiving standard of care from 2012 to 2019, the Quantitative MG (QMG), the MG Composite (MGC), the MG Activities of Daily Living (MG‐ADL), and the MG Quality of Life 15‐Items (QOL15) were determined. Clinical outcomes were analyzed in relation to gender.

Results

Mean follow‐up time was 4.8 (±0.4) y, and 70 patients completed all follow‐up assessments. Patients improved on all clinical scores: QMG ‐1.8 (P < .001), MGC ‐1.5 (P < .001), MG‐ADL ‐1.3 (P < .001), and QOL15 ‐3.0 (P < .001). Females improved less than males on the QMG (P = .01), MGC (P < .001), MG‐ADL (P = .006), and QOL15 (P < .001) independent of potential confounders. Males had moderate to strong correlations between changes in all clinical scales (r range 0.52 to 0.73), whereas females had weak correlations between changes in the QMG and MG‐ADL (r = 0.13), the QMG and QOL15 (r = 0.27), the MGC and MG‐ADL (r = 0.21), the MGC and QOL15 (r = 0.00), and the MG‐ADL and QOL15 (r = 0.31).

Discussion

Females improved less compared to males on objective and patient‐reported outcomes. Moreover, females improved more on objective measures than on patient‐reported outcomes. These gender differences should receive attention in clinical care and in the design of future trials.
Urodynamic and clinical features in women with overactive bladder: When to suspect concomitant voiding dysfunction?
Authors: Santis‐Moya Fernanda , Calvo Carlos Ignacio , Rojas Tania , Dell'Oro Arturo , Baquedano Paulina , Saavedra Alvaro
Published: May 2021

Aim

The aim of this study is to describe the prevalence and type of female voiding dysfunction (FVD) in patients with overactive bladder (OAB) who were studied by urodynamics and its relationship with voiding symptoms.

Methods

This is a cross‐sectional study of female adult patients with OAB syndrome who underwent UDS in a University Hospital in Chile between January 2015 and April 2020. FVD was defined either as bladder outlet obstruction (BOO) or detrusor underactivity (DU). BOO was established if the Solomon‐Greenwell BOO index was higher than 18. DU was diagnosed when the invasive maximum flow rate (Qmax) was ≤15 ml/sec, detrusor pressure at Qmax (Pdet@Qmax) was ≤20 cmH2O and postvoid residual (PVR) was greater than 10%. Urodynamic data and clinical features were compared between groups.

Results

Two hundred and ninety‐nine UDS were selected and analyzed. Bladder outlet obstruction was diagnosed in 59 patients (19.7%), whereas DU was found in 10 patients (3.3%). In the multivariate analysis, the logistic regression to predict BOO demonstrated that night‐time frequency, the presence of detrusor overactivity and a higher PVR were independent predictors of BOO. Instead, for DU, the only independent predictor was a smaller voided volume in the pressure‐flow study.

Conclusion

Female voiding dysfunction was found in 23% of patients with overactive bladder. BOO is more frequent than DU, and should be suspected in patients with higher night‐time frequency, presence of detrusor overactivity and a high PVR. Instead, DU should be suspected in patients with a smaller voided volume.
Exploring nursing students' experiences of blindness simulation: A phenomenological study
Authors: Nikbakht Nasrabadi Alireza , Malek Masoumeh , Shali Mahboubeh , Jafari Haleh
Published: May 2021

Aim

The aim of this study was to explore the experiences of blindness simulation among a group of nursing students.

Design

This qualitative study was conducted using an interpretive phenomenological method.

Methods

Using purposeful sampling method, students were informed and invited to participate in the research through the Website of Tehran School of Nursing and Midwifery. We listed the candidates and until data saturation and compilation of the study, 8 students entered the study. They shared their experiences about blindness simulation through individual in‐depth and semi‐structured interviews. We continued the interviews until the data were saturated. The transcribed interviews were analysed by Colaizzi's approach.

Results

The results of data analysis resulted in three major themes and nine sub‐themes, which were conceptually named based on their nature. The major themes included abandoned in the labyrinth puzzle, vision of heart and self‐alienation.
First reported archaeological case of leprosy in Slovakia
Authors: Hukeľová Zuzana , Nováček Jan , Daňová Klaudia , Ruttkay Matej
Published: May 2021

In 2009 and 2010, a rescue excavation at Nitra‐Selenec II (Slovakia) was carried out by the Institute of Archaeology of the Slovak Academy of Sciences. A medieval cemetery dated to the end of 11th century was discovered, yielding 72 individuals, including the skeleton of young female manifesting skeletal changes consistent with leprosy. The lesions of rhino‐maxillary syndrome (facies leprosa) were observed together with atrophied/tapered metatarsal bones of “licked candy” appearance. In addition,cribra orbitalia,cribra cranii, bilateral periostitis of distal ends of the tibiae and fibulae, and vertebral hypervascularization were recorded. The results of light microscopic investigation agreed with the macroscopic diagnosis of leprosy. Reported cases of leprosy from eastern central Europe are few, coming mostly from the region of present‐day Hungary. Until recently, only three probable cases of leprosy (all dated to pre‐Crusade Middle Ages) were discovered in the area of former Czechoslovakia, all of them discovered in the modern Czech Republic. The case from the late 11th century, presented in this paper, can be considered the first evidence of the disease in the region of Slovakia.
Emergent bilingual high school students' social and emotional experiences
Authors: Vera Elizabeth , Heineke Amy , Daskalova Plamena , Schultes Anna K. , Pantoja‐Patiño Juan , Duncan Britt , Yanuaria Chelsea , Furtado Claire
Published: May 2021

High school students labeled as English learners, referred to in this article as emergent bilinguals, participated in a mixed‐methods study of their social and emotional well‐being. Relationships with school personnel, peer relations, and involvement in support activities were connected to well‐being while experiences of microaggressions from teachers and peers, lack of access to advanced curricula, and poor integration with mainstream peers were related to negative well‐being. A variety of school, peer, and family themes both promoted and compromised well‐being. Students' sense of connection to mainstream students was positively related to school belonging and positive affect. A sense of connection to ethnic peers and a positive ethnic identity were related to positive affect but not school belonging. This pattern of findings suggests that connecting with members of both one's ethnic and the mainstream community may lead to greater well‐being but integrating into the mainstream community prompts greater school belonging. Implications for practice and policy are discussed.
Burnout in Portuguese physiotherapists during COVID‐19 pandemic
Authors: Jácome Cristina , Seixas Adérito , Serrão Carla , Teixeira Andreia , Castro Luísa , Duarte Ivone
Published: May 2021

Objective

This study described the burnout experienced by physiotherapists during the COVID‐19 pandemic and analysed the role of possible factors of this occupational phenomenon.

Methods

Cross‐sectional study based on a web‐based survey applied to physiotherapists living in Portugal. The survey included sociodemographic, health status and clinical practice questions. The Copenhagen Burnout Inventory (personal, work‐ and patient‐related burnout), the Resilience Scale, the Depression Anxiety and Stress Scales and the Satisfaction with Life Scale were used.

Results

A total of 511 physiotherapists (median 33 years old, 82% females) completed the survey. The participants worked mainly in private practice (50%) and wards (35%). During COVID‐19, 52% were working directly with patients, but only 18% were working with COVID‐19 patients. Personal (42%), work‐ (42%) and patient‐related burnout (25%) was observed. Three significant models explained personal‐ (R2 = 51%), work‐ (R2 = 31%) and patient‐related burnout (R2 = 16%). Lower levels of resilience and higher levels of depression and stress were significantly associated with personal, work‐ and patient‐related burnout. Being female and working directly with patients were additionally associated with both personal and work‐related burnout. Having health problems and working with COVID‐19 patients were only associated with personal burnout.

Conclusions

More than 40% of physiotherapists experienced personal and work‐related burnout and 25% patient‐related burnout, with resilience, depression and stress having a relevant role in the three burnout dimensions. Early detection and management strategies need to be implemented to address physiotherapists' physical and psychological fatigue and exhaustion.
A hybrid search based synthesis of static output feedback controllers for uncertain systems with application to multivariable PID control
Authors: Gopmandal Falguni , Ghosh Arun
Published: May 2021

This article proposes a hybrid search (involving the performance level and a positive scalar variable in sequence) based method for synthesis of linear time‐invariant (LTI) static output feedback (SOF) controllers for a class of linear systems with norm‐bounded time‐varying parametric uncertainties. Using an available extended linear matrix inequality (LMI) formulation of bounded real lemma, a new sufficient condition in terms of LMIs is obtained for existence of SOF controllers, where a triangular structure in the variable part of the Lyapunov matrix is introduced, unlike the diagonal structure existing in direct synthesis methods in literature. To obtain as less as possible, the part of the Lyapunov matrix which is kept fixed while computing the variable part is first obtained using a ‐search based method. Then with this fixed part, the final variable triangular part of the Lyapunov matrix is obtained using a single positive scalar search based LMI method to further reduce . The efficacy of the proposed method is studied on a number of benchmark examples. The method is also extended for structured SOF design. Finally, the proposed method is applied to design two‐degree‐of‐freedom (2‐DOF) multivariable proportional‐integral‐derivative (PID) controllers for compensation of norm‐bounded uncertain plants. A case study on designing roll–pitch–yaw integrated missile autopilots is also considered to show the efficacy of the proposed multivariable PID compensation.
Facile Synthesis of Holey Phosphorene via Low Temperature Electrochemical Exfoliation for Electrocatalytic Nitrogen Reduction
Authors: He Ludong , Lu Qiuju , Yang Ying , Liu Yanqi , Zhu Yuanzhi , Mei Yi
Published: May 2021

Nano black phosphorus (BP) has been widely used in many fields due to its outstanding properties. The novel morphology and structure of nano BP would bring new properties and expand its application. In this work, a novel holey phosphorene was prepared by a low temperature electrochemical exfoliation method for the first time. The low temperature condition plays a significant role in reducing the oxidizing reaction rate, thus facilitating the formation of pore in the basal plane of BP during the exfoliation process. The as‐prepared holey phosphorene can act as a metal‐free electrocatalyst for electroreduction of nitrogen, which exhibits a high NH3 yield of 46.04 μg h−1 mg−1cat. with a Faradaic efficiency of 8.78 % at −0.7 V vs. RHE.
Catalytic Ozonation of Cinnamaldehyde to Benzaldehyde over Ca(OH)2
Authors: Luo Xuan , Wang Yiyuan , Xie Xinling , Su Tongming , Chen Jianhua , Qin Zuzeng , Ji Hongbing
Published: May 2021

In this study, the ozonation of cinnamaldehyde to benzaldehyde catalyzed by Ca(OH)2 was studied by using the bubbling reactor with in situ diffuse reflectance infrared Fourier transform spectrum (DRIFTS) and Density Function Theory (DFT). After the preparation, characterization, and catalytic activity evaluation of Ca(OH)2, the data showed that specific surface area, average pore diameter, and pore volume of Ca(OH)2 had a 1.77‐, 1.44‐, and 3.06‐fold larger than those of CaO, respectively. Compared with CaO catalysis, the activation energy of cinnamaldehyde ozonation decreased 41 % under Ca(OH)2 catalysis. in situ DRIFTS and DFT results indicated that alkaline‐earth metal ozonide was the yield on the Ca(OH)2 surface after the adsorption, and the ozonide selectively oxidated the carbon‐carbon double bond of cinnamaldehyde with the Criegee mechanism.
Scandium(III)‐Triflate‐Catalyzed Multicomponent Reactions for the Synthesis of Nitrogen Heterocycles
Authors: Longo Luiz S. , Siqueira Fernanda A. , Anjos Nicolas S. , Santos Gabriela F. D.
Published: May 2021

The need of understanding the interactions between small organic molecules and biological targets has stimulated the development of new methodologies for the synthesis of compounds with potential biological properties. In this scenario, multicomponent reactions have been considered as high atom‐efficient strategies which allow the generation of high levels of molecular diversity and complexity, using relatively simple and eco‐friendly experimental procedures. Among the plethora of catalysts used in multicomponent reactions, rare earth metal triflates, especially scandium(III) triflate [Sc(OTf)3], emerged as water‐resistant Lewis acids with remarkable catalytic activity in water‐containing environments. This review describes the recent progress on the use of scandium(III) triflate as Lewis acid catalyst for multicomponent reactions applied to the synthesis of nitrogen‐containing heterocycles, valuable privileged scaffolds in Organic and Medicinal Chemistry.
Type I Photosensitizers Revitalizing Photodynamic Oncotherapy
Authors: Chen Dapeng , Xu Qian , Wang Wenjun , Shao Jinjun , Huang Wei , Dong Xiaochen
Published: May 2021

Photodynamic therapy (PDT) has shown great potential for tumor treatment with merits of non‐invasiveness, high selectivity, and minimal side effects. However, conventional type II PDT relying on 1O2 presents poor therapeutic efficacy for hypoxic tumors due to the oxygen‐dependent manner. Alternatively, emerging researches have demonstrated that type I PDT exhibits superiority over type II PDT in tumor treatment owing to its diminished oxygen‐dependence. In this review, state‐of‐the‐art studies concerning recent progress in type I photosensitizers are scrutinized, emphasizing the strategies to construct highly effective type I photosensitizers. As the foundation, basic principles of type I PDT are presented, and up‐to‐date type I photosensitizers are summarized and classified based on their attributes. Then, a literature review of representative type I photosensitizers (including nanomaterials and small molecules) is presented with impetus to delineate their novel designs, action mechanisms, as well as anticancer PDT applications. Finally, the remaining challenges and development directions of type I photosensitizers are outlined, highlighting key scientific issues toward clinical translations.
Transformable Spinose Nanodrums with Self‐Supplied H2O2 for Photothermal and Cascade Catalytic Therapy of Tumor
Authors: Liu Miao‐Deng , Guo Deng‐Ke , Zeng Run‐Yao , Guo Wen‐Hui , Ding Xing‐Lan , Li Chu‐Xin , Chen Ying , Sun Yunxia , Zhang Xian‐Zheng
Published: May 2021

Advances in enzymes involve an efficient biocatalytic process, which has demonstrated great potential in biomedical applications. However, designing a functional carrier for enzymes equipped with satisfactory degradability and loading efficiency, remains a challenge. Here, based on transformable liquid metal (LM), a spinose nanodrum is designed as protein carrier to deliver enzyme for tumor treatment. With the assistance of spines and a special drum‐like shape, it is found that the spiny LM can carry much more enzymes than spherical LM under the same condition. Benefiting from the satisfactory enzyme loading efficiency of spiny LM, a plasma amine oxidase immobilized spinose LM nanosystem enveloped with epigallocatechin gallate (EGCG)‐Fe3+ (LMPE) is fabricated for photothermal and cascade catalytic tumor therapy. Activated by the acidic condition in the tumor microenvironment, the LMPE can oxidize spermine (Spm) and spermidine (Spd) to generate hydrogen peroxide (H2O2) for Fenton catalytic reaction to produce the lethal hydroxyl radical (•OH) for tumor cell killing. Combined with remarkable photothermal performance of LM, LMPE exhibits significant inhibition of tumor in vivo.
Nanocrystalline Cellulose from Kapok Fiber (Ceiba pentandra) and its Reinforcement Effect on Alginate Hydrogel Bead
Authors: Sartika Dewi , Syamsu Khaswar , Warsiki Endang , Fahma Farah , Arnata I. Wayan
Published: May 2021

Kapok fiber (Ceiba pentandra) is a potential source of cellulose, but its utilization is still minimal. This study aims to isolate nanocrystalline cellulose (NCC) from kapok fibers using acid hydrolysis at various times and characterize its properties as reinforcement for alginate‐nanocrystalline cellulose (Alg‐NCC) hydrogel beads. NCCs are characterized using various techniques, and hydrogel beads are characterized by syneresis and strength (TPA). Variations in hydrolysis time cause changes in functional groups, decrease length and diameter, increase degree of crystallinity, and thermal stability. Nanocrystalline cellulose isolation from BKF by chemical hydrolysis is better done at 60% sulfuric acid concentration, for 50 min to produce a yield of 38.92%, L/d aspect ratio ranges from 8.53 to 12.23, degree of crystallinity 71.00%, and thermal stability with maximum degradation temperature 298.69 °C. The incorporation of NCC on the Alg hydrogel beads leads to increase hardness 67.70% and decrease syneresis 4.14%. Thus, NCC can be used as a reinforcement agent because it has been shown to improve the physical, mechanical, and thermal properties of Alg‐NCC hydrogel beads. Alg‐NCC hydrogel beads have the potential to be widely applied in various fields.
From feeling forces to understanding forces: The impact of bodily engagement on learning in science
Authors: Zohar Asnat R. , Levy Sharona T.
Published: May 2021

Embodied cognition theories view sensorimotor activity as fundamental to learning, knowing, and reasoning. To investigate the role of physical movement in conceptual learning, we developed and explored an Embodied Learning Interactive Chemistry environment (ELI‐Chem). The ELI‐Chem learning environment includes a computer simulation, a device for interacting with the simulation, and an online activity guide. In particular, we focused on the topic of chemical bonding—an abstract and nonintuitive phenomenon that is crucial to chemistry learning and that presents pervasive problems in learning. The ELI‐Chem learning environment embodies atoms' movement through four increasing degrees of bodily engagement in terms of range of motion and forces—movie, simulation, joystick, and haptic device (applies force feedback). A randomly assigned pretest‐intervention‐posttest four‐group comparison design was used with a mixed‐methods research approach. Quantitative analysis of pretest and posttest questionnaires tested the conceptual learning. Qualitative analysis of students' filled activity guides explored students' perceptions of the learning process and features of understanding. The participants were 48 high school chemistry students, 12 students in each degree of bodily engagement. During the activity, students were prompted to discover the forces underlying chemical bonding and to explore the energy changes involved. We found an increase in students' conceptual understanding in all four degrees of bodily engagement, with significantly higher learning gains and causal understanding in the haptic condition with a greater range of motion and forces. This study highlights the states in which embodied learning uniquely contributes to understanding and perception: absence of prior embodied experience, learning about a nonvisual concept related to forces, and a high congruence with the concept learned.
Influence of Achyranthes japonica extracts supplementation in the diets of finishing pigs
Authors: Liu Xiao , Kim In Ho
Published: May 2021

Background

Herbs and their extracts have been used for a long time in animal industries as alternatives to an antibiotic.

Objectives

This study was evaluated the effects of dietary supplementation of Achyranthes japonica extracts (AJE) on the performance and production parameters in finishing pigs.

Methods

Totally, 100 pigs with an average body weight of 50.33 ± 4.61 kg were used as a 10‐week feeding trial. Pigs (five replicates, three barrows and two gilts per pen) were allotted randomly to four treatments as the addition of 0%, 0.05%, 0.10% and 0.20% of AJE in basal diets.

Results

A linear increase (p < .05) in average daily gain was observed during week 5, week 10 and overall period, and a linear decrease (p < .05) was observed in the feed conversion ratio during week 5. A linear increase (p < .05) in dry matter, protein digestibility and faecal ammonia emission on week 5 and week 10 and a linear increase (p < .05) in serum total protein concentration on week 10 of pigs fed diets supplemented with graded levels of AJE was observed. Faecal lactic acid bacteria counts showed a linear increase (p < .05) on week 5 with the increasing levels of AJE.

Conclusions

In conclusion, there existed improvements in growth performance, nutrients digestibility, serum total protein, faecal coliform bacteria and lactic acid bacteria counts and faecal ammonia emission in the finishing pigs fed with AJE‐supplemented diet.
Delayed traumatic pneumocephalus and cervical pneumorrhachis in a dog
Authors: Moral Meritxell , Blanco Carlos , Martínez Jerónimo , Lorenzo Valentina
Published: May 2021

A 7‐year‐old female spayed Labrador Retriever was referred for generalised seizures which initiated 48 hours prior to presentation. Physical examination revealed facial asymmetry and enucleation of the right eye due to head trauma 6 years earlier. Neurological examination showed depressed mental status, absent menace response of the left eye, non‐ambulatory tetraparesis, absent postural reactions in all four limbs and normal spinal reflexes. Neuroanatomical localisation was prosencephalic (forebrain). MRI study of the brain allowed a diagnosis of pneumocephalus and pneumorrhachis as the cause of neurological signs. The dog was hospitalised and treated conservatively with anticonvulsants, antimicrobials and oxygen therapy. During hospitalisation, no further seizures were observed, the neurological condition improved progressively, and the dog was discharged with oral anticonvulsant treatment 4 days after admission. Eight months later, the dog was still seizure‐free, and the follow‐up MRI showed no lesions consistent with the previously diagnosed pneumocephalus and pneumorrhachis.
Limber tail syndrome in a Labrador Retriever with confirmed hypothyroidism
Authors: Coelho Ana , Mateus Nathália , Araújo Joyce , Silva Márcio , Eguchi Gabriel
Published: May 2021

A 4‐year‐old, female, neutered Labrador Retriever was referred with tail flaccidity of acute onset after an extensive period of swimming. There were no other neuromuscular clinical signs on physical examination and no pain of tail palpation. Comorbidity was reported, with previous diagnosis of hypothyroidism (9 months before), but the disease was considered controlled since levothyroxine supplementation. Despite the impossibility to confirm nonrelated neuromuscular impairment associated with hypothyroidism, the fast resolution of clinical signs without intervention was more likely to confirm a limber tail syndrome rather than an endocrine neuromyopathy, but, to the authors' knowledge, this is the first report of its kind, and further investigations are required.
Empirical analysis of the impact of urbanization on groundwater quality within the slums of Accra, Ghana
Authors: Ketadzo Joan A. , Nkongolo Nsalambi V. , Akrofi Mark M.
Published: May 2021

A significant proportion of city dwellers in Ghana reside in slums where groundwater is the major source of water for domestic uses. This study examined the quality of groundwater from boreholes (seven) and hand‐dug wells (13) in five major slums in the city of Accra, Ghana. Water samples were tested for a total of 27 microbial and physicochemical contaminants at the central laboratory of the Ghana Water Company Limited. Overall, the water quality in the slums was poor as most of the parameters tested did not meet the 2017 WHO standards. Four out of the five slums (in Nima, Chorkor, Jamestown, and Abokobi‐Pantang), for instance, recorded high amounts of lead, with average values of 0.25 mg/L, 1.00 mg/L, 0.25 mg/L, and 1.5 mg/L, respectively, which are above the WHO standard of 0.01 mg/L. pH values in Nima (5.09), Sabon Zongo, Chorkor (6.09), and Abokobi‐Pantang (6.17) did not meet the WHO standard of 6.5–8.5. All five slums indicated various degrees of bacteriological contamination. The average Escherichia coli values per slum ranged between 12.50 CFU/100 ml and 249.00 CFU/100 ml, while the mean total coliform per slum ranged from 90.75 CFU/100 ml to 490.25 CFU/100 ml. The poor quality of groundwater found is attributable to improper disposal of waste, siting of boreholes/wells close to toilets, and the coastal location of some of the slums. Strict enforcement of water‐quality control checks, intensive sensitization on the dangers of improper waste disposal to groundwater quality, and the provision of sanitation facilities in the slums by city authorities are highly recommended.
Two new metal‐organic frameworks constructed by 4,5‐bis(pyrazol‐1‐yl) phthalic acid for photocatalytic properties
Authors: Yang Yan , Zhu Chengbiao , Li Rui , Gu Xingye , She Shixiong
Published: May 2021

Two new metal‐organic frameworks (MOFs), namely {[Zn2(L)2(4,4′‐bipy)1.5] ⋅ H2O}n (1) and {[Ni(L)(4,4′‐bipy)(H2O)2] ⋅ (H2O)5}n (2), where H2L=4,5‐bis(pyrazol‐1‐yl) phthalic acid, have been solvothermally synthesized and characterized. The single‐crystal X‐ray analyses showed that 1 and 2 present a 3D ths network and a cds network, respectively. The photocatalytic properties for both frameworks showed that they can photodegrade dye methylene blue (MB) and methylene orange (MO) under UV light irradiation. The possible photocatalytic mechanism has been addressed using band gap calculation by taking assistance of density of states (DOS) and partial DOS (pDOS) calculations.
Ontology-Based Calculation of Complexity Metrics for Components in CAD Systems
Authors: Weber Moritz , Anderl Reiner
Published: May 2021

The high complexity of assemblies and components in Computer-Aided Design (CAD) leads to a high effort in the maintenance of the models and increases the time required for adjustments. Metrics indicating the complexity of a CAD Model can help to reduce it by showing the results of changes. This paper describes a concept to calculate metrics aiming to describe the extent of complexity of components in CAD systems based on an ontology-based representation in a first step. The representation is initially generated from CAD models using an automated process. This includes both a boundary representation and the history of the feature-based design. Thus, the design strategy also contributes to measuring the complexity of the component so that the same shape can lead to different complexity metrics. Semantic rules are applied to find patterns of the design and to identify and evaluate various strategies. Different metrics are proposed to indicate the particular influence factors of complexity and a single measure for the overall complexity. Furthermore, the influencing factors can also be used to allow the designer to see how to reduce the complexity of the component or assembly.
Identification of Imprecision in Data Using $$\epsilon $$-Contamination Advanced Uncertainty Model
Authors: Shariatmadar Keivan , Hallez Hans , Moens David
Published: May 2021

One of the importance of the contamination uncertainty model is to consider in-determinism in the uncertainty. We consider this advanced property and develop two methods. These methods identify if there is imprecision in a given model or data. In the first approach, we build two different—a probability distribution and an interval—models for a test function f via given data/model. Then, we identify the level of imprecision by assessing, so-called model trust, $$\epsilon \in (0,1)$$

ϵ
∈
(
0
,
1
)

in the contamination model whether the weight is higher for the probabilistic/interval model or not. In the second approach, we calculate the lowest and highest previsions for the test function and identify the imprecision interval out of them. We further discuss and show the idea via two simple production and clutch design problems to illustrate our novel results.
Approach to Assess Basic Deterministic Data and Model Form Uncertaint in Passive and Active Vibration Isolation
Authors: Platz Roland
Published: May 2021

This contribution continues ongoing own research on uncertainty quantification in structural vibration isolation in early design stage by various deterministic and non-deterministic approaches. It takes into account one simple structural dynamic system example throughout the investigation: a one mass oscillator subject to passive and active vibration isolation. In this context, passive means that the vibration isolation only depends on preset inertia, damping, and stiffness properties. Active means that additional controlled forces enhance vibration isolation. The simple system allows a holistic, consistent and transparent look into mathematical modeling, numerical simulation, experimental test and uncertainty quantification for verification and validation. The oscillator represents fundamental structural dynamic behavior of machines, trusses, suspension legs etc. under variable mechanical loading. This contribution assesses basic experimental data and mathematical model form uncertainty in predicting the passive and enhanced vibration isolation after model calibration as the basis for further deterministic and non-deterministic uncertainty quantification measures. The prediction covers six different damping cases, three for passive and three for active configuration. A least squares minimization (LSM) enables calibrating multiple model parameters using different outcomes in time and in frequency domain from experimental observations. Its adequacy strongly depends on varied damping properties, especially in passive configuration.
Mastering Uncertain Operating Conditions in the Development of Complex Machine Elements by Validation Under Dynamic Superimposed Operating Conditions
Authors: Germann Thiemo , Martin Daniel M. , Kubik Christian , Groche Peter
Published: May 2021

Machine elements produced in large quantities undergo several development cycles and can be adapted from generation to generation. Thus, experiences from real operation can be taken into account in further development. This is not possible for innovative investment goods such as special purpose machines, as these are usually individual items. Therefore, functionality and quality of newly developed components must be assured by previous investigations.

Conventional methods are inadequate at this point, as they cannot represent the actual, complex operating conditions in the later application. A reliable statement about the behavior of the system through a comprehensive validation in laboratory tests under standardized conditions is not achievable in this way due to a multitude of diversified load cases.

In previous work, a method was developed to allow testing of machine elements in the laboratory under detuned operating conditions. For this purpose, disturbance variables are applied to the system using paraffin wax phase change actuators in order to simulate real operation states and to analyze the behavior of the machine element under these conditions. The investigated disturbance variables are fluctuations and asymmetries of the operating load through superimposed temperature gradients. Complex interactions between the machine element and the adjacent components or the overall system can thus be taken into account.

The functionality of the methodology has been developed and briefly demonstrated so far. This paper presents the next level within the development process of the methodology. The necessary components are explained in detail and an AI black box evaluation tool is discussed. This work is based on a test bench that applies dynamically changing states of detuning under superimposed disturbances. Additionally, energy efficiency and performance of the test setup is advanced. As presented, the method opens up the possibility of validating new machine elements in the laboratory under realistic conditions.
Towards CAD-Based Mathematical Optimization for Additive Manufacturing – Designing Forming Tools for Tool-Bound Bending
Authors: Reintjes Christian , Reuter Jonas , Hartisch Michael , Lorenz Ulf , Engel Bernd
Published: May 2021

The trend towards flexible, agile, and resource-efficient production systems requires a continuous development of processes as well as of tools in the area of forming technology. To create load-adjusted and weight-optimized tool structures, we present an overview of a new algorithm-driven design optimization workflow based on mixed-integer linear programming. Loads and boundary conditions for the mathematical optimization are taken from numerical simulations. They are transformed into time-independent point loads generating physical uncertainty in the parameters of the optimization model. CAD-based mathematical optimization is used for topology optimization and geometry generation of the truss-like structure. Finite element simulations are performed to validate the structural strength and to optimize the shape of lattice nodes to reduce mechanical stress peaks. Our algorithm-driven design optimization workflow takes full advantage of the geometrical freedom of additive manufacturing by considering geometry-based manufacturing constraints. Depending on the additive manufacturing process, we use lower and upper bounds on the diameter of the members of a truss and the associated yield strengths. An additively manufactured flexible blank holder demonstrates the algorithm-driven topology design optimization.
Detection of Model Uncertainty in the Dynamic Linear-Elastic Model of Vibrations in a Truss
Authors: Matei Alexander , Ulbrich Stefan
Published: May 2021

Dynamic processes have always been of profound interest for scientists and engineers alike. Often, the mathematical models used to describe and predict time-variant phenomena are uncertain in the sense that governing relations between model parameters, state variables and the time domain are incomplete. In this paper we adopt a recently proposed algorithm for the detection of model uncertainty and apply it to dynamic models. This algorithm combines parameter estimation, optimum experimental design and classical hypothesis testing within a probabilistic frequentist framework. The best setup of an experiment is defined by optimal sensor positions and optimal input configurations which both are the solution of a PDE-constrained optimization problem. The data collected by this optimized experiment then leads to variance-minimal parameter estimates. We develop efficient adjoint-based methods to solve this optimization problem with SQP-type solvers. The crucial test which a model has to pass is conducted over the claimed true values of the model parameters which are estimated from pairwise distinct data sets. For this hypothesis test, we divide the data into k equally-sized parts and follow a k-fold cross-validation procedure. We demonstrate the usefulness of our approach in simulated experiments with a vibrating linear-elastic truss.
Development of an Annotation Schema for the Identification of Semantic Uncertainty in DIN Standards
Authors: Stegmeier Jörn , Hartig Jakob , Leštáková Michaela , Logan Kevin , Bartsch Sabine , Rapp Andrea , Pelz Peter F.
Published: May 2021

This paper presents the results of a pilot study carried out in cooperation between Linguistics and Mechanical Engineering, funded by the collaborative research centre (CRC) 805 “Beherrschung von Unsicherheit in lasttragenden Systemen des Maschinenbaus”. Our goal is to help improve norm compliant product development and engineering design by focusing on ambiguous language use in norm texts (= “semantic uncertainty”). Depending on the country and product under development, industry standards may be legally binding. Thus, standards play a vital role in reducing uncertainty for manufacturers and engineers by providing requirements for product development and engineering design. However, uncertainty is introduced by the standards themselves in various forms, the most notable of which are the use of underspecified concepts, modal verbs likeshould, and references to texts which contain semantically uncertain parts. If conformity to standards is to be ensured, the person using the standards must interpret them and document the interpretation. In order to support users in these tasks, we

developed an annotation schema which allows the identification and classification of semantically uncertain segments of standards,

used the schema to create a taxonomy of semantic uncertainty in standards,

developed a proof-of-concept information system.

The results of this project can be used as a starting point for automated annotation. The information system alerts users to semantically uncertain segments of standards, provides background information, and allows them to document their decisions how to handle the semantically uncertain parts.
W-representation of Rainbow tensor model
Authors: Kang Bei , Wang Lu-Yao , Wu Ke , Yang Jie , Zhao Wei-Zhong
Published: May 2021

Abstract

We analyze the rainbow tensor model and present the Virasoro constraints, where the constraint operators obey the Witt algebra and null 3-algebra. We generalize the method of W-representation in matrix model to the rainbow tensor model, where the operators preserving and increasing the grading play a crucial role. It is shown that the rainbow tensor model can be realized by acting on elementary function with exponent of the operator increasing the grading. We derive the compact expression of correlators and apply it to several models, i.e., the red tensor model, Aristotelian tensor model and r = 4 rainbow tensor model. Furthermore, we discuss the case of the non-Gaussian red tensor model and present a dual expression for partition function through differentiation.
Nilpotent symmetries as a mechanism for Grand Unification
Authors: Andersson Lars , László András , Ruba Błażej
Published: May 2021

Abstract

In the classic Coleman-Mandula no-go theorem which prohibits the unification of internal and spacetime symmetries, the assumption of the existence of a positive definite invariant scalar product on the Lie algebra of the internal group is essential. If one instead allows the scalar product to be positive semi-definite, this opens new possibilities for unification of gauge and spacetime symmetries. It follows from theorems on the structure of Lie algebras, that in the case of unified symmetries, the degenerate directions of the positive semi-definite invariant scalar product have to correspond to local symmetries with nilpotent generators. In this paper we construct a workable minimal toy model making use of this mechanism: it admits unified local symmetries having a compact (U(1)) component, a Lorentz (SL(2, ℂ)) component, and a nilpotent component gluing these together. The construction is such that the full unified symmetry group acts locally and faithfully on the matter field sector, whereas the gauge fields which would correspond to the nilpotent generators can be transformed out from the theory, leaving gauge fields only with compact charges. It is shown that already the ordinary Dirac equation admits an extremely simple prototype example for the above gauge field elimination mechanism: it has a local symmetry with corresponding eliminable gauge field, related to the dilatation group. The outlined symmetry unification mechanism can be used to by-pass the Coleman-Mandula and related no-go theorems in a way that is fundamentally different from supersymmetry. In particular, the mechanism avoids invocation of super-coordinates or extra dimensions for the underlying spacetime manifold.
A surprising similarity between holographic CFTs and a free fermion in (2 + 1) dimensions
Authors: Cheamsawat Krai , Fischetti Sebastian , Wallis Lucas , Wiseman Toby
Published: May 2021

Abstract

We compare the behavior of the vacuum free energy (i.e. the Casimir energy) of various (2 + 1)-dimensional CFTs on an ultrastatic spacetime as a function of the spatial geometry. The CFTs we consider are a free Dirac fermion, the conformally-coupled scalar, and a holographic CFT, and we take the spatial geometry to be an axisymmetric deformation of the round sphere. The free energies of the fermion and of the scalar are computed numerically using heat kernel methods; the free energy of the holographic CFT is computed numerically from a static, asymptotically AdS dual geometry using a novel approach we introduce here. We find that the free energy of the two free theories is qualitatively similar as a function of the sphere deformation, but we also find that the holographic CFT has a remarkable and mysteriousquantitativesimilarity to the free fermion; this agreement is especially surprising given that the holographic CFT is strongly-coupled. Over the wide ranges of deformations for which we are able to perform the computations accurately, the scalar and fermion differ by up to 50% whereas the holographic CFT differs from the fermion by less than one percent.