bluuebunny/crossref_metadata_2025 huggingface dataset:
Enzymatic Extraction of Bioactive and Self‐Assembling Wool Keratin for Biomedical Applications
Authors: Su Chang , Gong Jin‐Song , Ye Jin‐Peng , He Ji‐Meng , Li Rui‐Yi , Jiang Min , Geng Yan , Zhang Yan , Chen Jing‐Hua , Xu Zheng‐Hong , Shi Jin‐Song
Published: July 2020

Keratin is widely recognized as a high‐quality renewable protein resource for biomedical applications. Despite their extensive existence, keratin resources such as feathers, wool, and hair exhibit high stability and mechanical properties because of their high disulfide bond content. Consequently, keratin extraction is challenging and its application is greatly hindered. In this work, a biological extraction strategy is proposed for the preparation of bioactive keratin and the fabrication of self‐assembled keratin hydrogels (KHs). Based on moderate and controlled hydrolysis by keratinase, keratin with a high molecular weight of approximately 45 and 28 kDa that retain its intrinsic bioactivities is obtained. The keratin products show excellent ability to promote cell growth and migration and are conferred with significant antioxidant ability because of their intrinsically high cysteine content. In addition, without the presence of any cross‐linking agent, the extracted keratin can self‐assemble into injectable hydrogels. The KHs exhibit a porous network structure and 3D culture ability, showing potential in promoting wound healing. This enzyme‐driven keratin extraction strategy opens up a new approach for the preparation of keratin that can self‐assemble into injectable hydrogels for biomedical engineering.
Liquid‐Filling Polydimethylsiloxane Composites with Enhanced Triboelectric Performance for Flexible Nanogenerators
Authors: Jing Titao , Xu Bingang , Guan Xiaoyang , Yang Yujue , Wu Mengjie , Jiang Chenghanzhi
Published: July 2020

Material functionalization of triboelectric nanogenerators (TENG) plays an important role in TENG's electric performance for sustainable energy harvesting. In this work, a method for improving polydimethylsiloxane (PDMS) composites triboelectric performance has been proposed, via filling high dielectric constant liquid (instead of solids) into PDMS matrix. The improvement is attributed to the high dielectric constant liquid in PDMS matrix that reduced the effective thickness of PDMS and increased the dielectric constant of PDMS composite synchronously. At 50% filling ratio (PDMS‐HD50), the triboelectric performance exhibits an enhancement of 4.5‐fold in output voltage and 3.9‐fold in output current as compared to pure PDMS. The results, besides higher transparency, are superior to the results from traditional solid dielectric constant doping materials like BaTiO3 nanoparticle in PDMS. This work has proved potentials of dielectric liquid filling materials in fabricating TENGs and could be a guidance for exploring new liquid filling materials.
Covalent Organic Frameworks with Electron‐Rich and Electron‐Deficient Structures as Water Sensing Scaffolds
Authors: Ma Wenyue , Jiang Shan , Zhang Wei , Xu Bin , Tian Wenjing
Published: July 2020

Covalent organic frameworks (COFs) have potential applications in gas storage, catalysis, proton conduction, sensing, and chemical removal etc., due to their highly crystalline structure, good stability, porosity, as well as structural and functional controllability. Herein, by using electron‐rich group, 2,5‐bis(methylthio)terephthalaldehyde (BMTA), and electron–deficient group, 1,3,5‐tris‐(4‐aminophenyl)triazine (TAPT) as building blocks, TAPT‐BMTA‐COF is constructed through Schiff‐base reaction. TAPT‐BMTA‐COF has high crystallinity, porosity, big Brunauer−Emmett−Teller surface area (BET), good chemical and thermal stability, and commendable solvatochromic properties. It can be used as the water sensing scaffold to detect the trace water in organic solvents due to the fluorescence quenching of the COF caused by the interaction between water and TAPT‐BMTA‐COF.
Transcriptome sequencing identifies a noncoding, deep intronic variant in CLCN7 causing autosomal recessive osteopetrosis
Authors: Chorin Odelia , Yachelevich Naomi , Mohamed Khaled , Moscatelli Ilana , Pappas John , Henriksen Kim , Evrony Gilad D.
Published: July 2020

Background

Over half of children with rare genetic diseases remain undiagnosed despite maximal clinical evaluation and DNA‐based genetic testing. As part of an Undiagnosed Diseases Program applying transcriptome (RNA) sequencing to identify the causes of these unsolved cases, we studied a child with severe infantile osteopetrosis leading to cranial nerve palsies, bone deformities, and bone marrow failure, for whom whole‐genome sequencing was nondiagnostic.

Methods

We performed transcriptome (RNA) sequencing of whole blood followed by analysis of aberrant transcript isoforms and osteoclast functional studies.

Results

We identified a pathogenic deep intronic variant in CLCN7 creating an unexpected, frameshifting pseudoexon causing complete loss of function. Functional studies, including osteoclastogenesis and bone resorption assays, confirmed normal osteoclast differentiation but loss of osteoclast function.

Conclusion

This is the first report of a pathogenic deep intronic variant in CLCN7, and our approach provides a model for systematic identification of noncoding variants causing osteopetrosis—a disease for which molecular‐genetic diagnosis can be pivotal for potentially curative hematopoietic stem cell transplantation. Our work illustrates that cryptic splice variants may elude DNA‐only sequencing and supports broad first‐line use of transcriptome sequencing for children with undiagnosed diseases.
Simplifying LR‐HSQC spectra using a triple‐quantum filter: The LR‐HTQC experiment
Authors: Bigler Peter , Furrer Julien
Published: July 2020

Long‐range heteronuclear single quantum correlation (LR‐HSQC) experiments may be applied for detecting long‐range correlations but suffer from two disadvantages, common to all heteronuclear long‐range correlation experiments: (i) The information density in LR‐HSQC spectra may be too high to be used directly without “filtering out” shorter range correlations, and (ii) often, substantial differences in intensity among cross peaks exist, potentially hampering the visualization of weak, often crucial cross peaks. In this contribution, we propose a modified LR‐HSQC experiment, the LR‐HTQC experiment (Long‐Range Heteronuclear Triple Quantum Correlation) that partially solves the problems aforementioned. We show theoretically and experimentally that the LR‐HTQC experiment removes the intense cross peaks of CH spin pairs, substantially reduces the medium intensity of cross peaks originating from CHH' spin systems, whereas the typically weak intensity of cross peaks of CHH'H″ and C(H)n, n > 3 spin systems is less affected. Consequently, the LR‐HTQC experiment affords simplified long‐range heteronuclear shift correlation spectra and scales down large intensity differences among different types of cross peaks, although a certain general reduction of signal intensities has to be accepted.
Predicting intensive care unit bed occupancy for integrated operating room scheduling via neural networks
Authors: Schiele Julian , Koperna Thomas , Brunner Jens O.
Published: July 2020

In a master surgery scheduling (MSS) problem, a hospital's operating room (OR) capacity is assigned to different medical specialties. This task is critical since the risk of assigning too much or too little OR time to a specialty is associated with overtime or deficit hours of the staff, deferral or delay of surgeries, and unsatisfied—or even endangered—patients. Most MSS approaches in the literature focus only on the OR while neglecting the impact on downstream units or reflect a simplified version of the real‐world situation. We present the first prediction model for the integrated OR scheduling problem based on machine learning. Our three‐step approach focuses on the intensive care unit (ICU) and reflects elective and urgent patients, inpatients and outpatients, and all possible paths through the hospital. We provide an empirical evaluation of our method with surgery data for Universitätsklinikum Augsburg, a German tertiary care hospital with 1700 beds. We show that our model outperforms a state‐of‐the‐art model by 43% in number of predicted beds. Our model can be used as supporting tool for hospital managers or incorporated in an optimization model. Eventually, we provide guidance to support hospital managers in scheduling surgeries more efficiently.
Polyethersulfone microfiltration membrane modified by an amphiphilic dithiolane‐containing copolymer for improving anti‐protein‐fouling performance and rejection of nanoparticles
Authors: Wang Xiao , Zeng Birong , Chen Ting , Liu Xinyu , Wu Tong , Shen Hong , Luo Weiang , Yuan Conghui , Xu Yiting , Chen Guorong , Dai Lizong
Published: July 2020

To endow polyethersulfone (PES) membranes with enhanced hydrophilicity and anti‐protein adsorption performance, amphiphilic dithiolane‐containing copolymers poly[poly(ethyleneglycol)methylethermethacrylate‐co‐2‐(methacryloyloxy)ethyl 5‐(1,2‐dithiolan‐3‐yl)pentanoate‐co‐(4‐formylphenyl)‐2‐methylprop‐2‐enoate]{abbr. Poly(MAPEG‐co‐MALA‐co‐MAHA)} with different polymerization degree were successfully synthesized, and then blended with PES to prepare microfiltration membranes by immersion precipitation phase inversion process. The chemical structure and molecular weight of poly(MAPEG‐co‐MALA‐co‐MAHA) were characterized by NMR, FTIR and GPC. The morphology and surface property of the as‐prepared blending membranes were also characterized by SEM, AFM and contact angle testing etc. Compared with pure PES membrane, the contact angle of PES/poly(MAPEG‐co‐MALA‐co‐MAHA) membranes decreased from 74.2° to 53.7°, and the bovine serum albumin (BSA) adsorption declined from 121.4 to 58.8 μg cm−2. Meantime, the water flux of PES/poly(MAPEG‐co‐MALA‐co‐MAHA) membranes increased from 38.6 to 89.1 L m−2 h−1, the flux recovery ratio increased from 68.3% to 93.3% and the irreversible flux decline ratio decreased from 31.7% to 6.7%. Furthermore, the mechanical property of PES/poly(MAPEG‐co‐MALA‐co‐MAHA) membrane was better than that of pure PES membrane. In addition, the rejection of BSA and Au nanoparticle reached 77.3% and 66.2% respectively. The results showed that the addition of poly(MAPEG18‐co‐MALA18‐co‐MAHA18) with tiny amount could not only improve the hydrophilicity and antifouling of the membrane, but also endow the microfiltration membrane with the rejection of nanoparticles.
Investigation on shape recovery of 3D printed honeycomb sandwich structure
Authors: Mehrpouya Mehrshad , Gisario Annamaria , Azizi Ali , Barletta Massimiliano
Published: July 2020

Lightweight sandwich panels have been used in various industry sectors due to their unique properties as well as a high ratio of stiffness‐to‐weight and energy absorption. Three‐dimensional (3D) printing process provides a unique opportunity to fabricate highly complex shapes of sandwich panels and also the application of smart materials, such as shape memory polymers, can create unique functionality for the 3D printed sandwich structure so that they can change their shape in response to external stimuli and give a new dimension to the printing process called four‐dimensional (4D) printing. Polylactic acid is a biodegradable and compostable polymer with a good shape memory effect that can be printed easily with an inexpensive fused deposition modeling. This study investigated the effect of printing and activation parameters on the functionality, in particular shape recovery, of the deformed sandwich structure with honeycomb out‐of‐plane tailored core. The input parameters were the activation temperature, the nozzle temperature, and the printing velocity. The results showed that the optimum recovery ratio can be achieved using a higher activations and nozzle temperatures and lower printing speed.
Fetal spina bifida: What we tell the parents
Authors: Gotha Lara , Pruthi Vagisha , Abbasi Nimrah , Kulkarni Abhaya V. , Church Paige , Drake James M. , Carvalho Jose C.A. , Diambomba Yenge , Thakur Varsha , Ryan Greg , Van Mieghem Tim
Published: July 2020

Worldwide, about 150 000 infants are born with spina bifida yearly, making this condition one of the most common fetal central nervous system anomalies compatible with life. Over the last decade, major changes have been introduced in the prenatal diagnosis and management of spina bifida. In this review, we provide a brief summary of the current management of fetal spina bifida and present essential information that should be provided to expecting parents when their fetus has been diagnosed with spina bifida. This information is focused around common parental questions, as encountered in our typical clinical practice, to facilitate knowledge translation.
Modulating excited‐state intramolecular proton transfer of 2‐(5‐(4‐carboxyphenyl)‐2‐hydroxyphenyl)benzothiazole depending on substituents: A DFT/TD‐DFT study
Authors: Ni Mei , Fang Hua
Published: July 2020

The OH‐based excited‐state intramolecular proton transfer (ESIPT) of 2‐(5‐(4‐carboxyphenyl)‐2‐hydroxyphenyl)benzothiazole (CHBT) derivatives (4R‐CHBT) that were replaced by electron‐donating groups (CH3, OH) and electron‐withdrawing groups (COOH, CF3, CN) have been studied by the time‐dependent density functional theory (TD‐DFT) method. We analyzed structural parameters, infrared (IR) vibrational spectrum, frontier molecular orbitals (FMOs), and electronic spectra, which can describe the trend of ESIPT process. The constructed potential energy surfaces showed that the ESIPT potential energy barriers of 4R‐CHBT are in the range of 0.25 to 0.62 kcal/mol, which are just a little bigger than that value of CHBT. All the chosen substituents, no matter electron‐donating or electron‐withdrawing groups, make ESIPT processes slightly more difficult.
Self‐concept and health anxiety relate to psychological outcomes for BRCA1/2 carriers
Authors: Butler Ellen , Collier Sonya , Boland Michael , Hanhauser Yvonne , Connolly Elizabeth , Hevey David
Published: July 2020

Objective

Leventhal's common sense model of self‐regulation highlights how specific beliefs about illness influence psychological outcomes. Little is known on how such beliefs relate to BRCA1/2 adjustment. Furthermore, beliefs about one's self‐concept may be relevant to genetic conditions and may relate to psychological wellbeing.

Methods

One‐hundred and eighteen female BRCA1/2 carriers from an Irish University Hospital completed questionnaires for this cross‐sectional study. Outcomes measured were state anxiety and physical and mental health‐related quality of life (HRQOL). Explanatory variables included sociodemographics, health anxiety, illness perceptions, coping and self‐concept. Hierarchical multiple regression analyses were conducted.

Results

Then, 44% of participants had clinically significant state anxiety and 12% had clinically significant health anxiety. Vulnerability, stigma, mastery and health anxiety explained 42% of the variance in state anxiety. Previous mental health difficulty, vulnerability, stigma, mastery and health anxiety explained 40% of the variance in mental HRQOL. Dysfunctional coping strategies were strongly related to the physical functioning aspect of quality of life.

Conclusion

BRCA‐specific beliefs related to self and health anxiety are important factors to consider in the adjustment to BRCA1/2 confirmation.
Beating cancer‐related fatigue with the Untire mobile app: Results from a waiting‐list randomized controlled trial
Authors: Spahrkäs Simon Sebastian , Looijmans Anne , Sanderman Robbert , Hagedoorn Mariët
Published: July 2020

Objective

This waiting‐list randomized controlled trial examined the effectiveness of a self‐management mHealth app in improving fatigue and quality of life (QoL) in cancer patients and survivors.

Methods

Persons with cancer‐related fatigue (CRF) were recruited across four English speaking countries, via social media, and randomized into intervention (n = 519) and control (n = 280) groups. Whereas the intervention group received immediate access to the Untire app, the control group received access only after 12‐weeks. Primary outcomes fatigue severity and interference, and secondary outcome QoL were assessed at baseline, 4, 8, and 12‐weeks. We ran generalized linear mixed models for all outcomes to determine the effects of app access (yes/no), over 12‐weeks, following the intention‐to‐treat principle.

Results

Compared with the control group, the intervention group showed significantly larger improvements in fatigue severity (d = 0.40), fatigue interference (d = 0.35), and overall QoL on average (d = 0.32) (P's < .01), but not for overall QoL in the past week (P = .07). Sensitivity analyses indicated that participants with medium or high app use benefited most when compared with nonusers and control participants (P's ≤ .02). The intervention effect on fatigue interference was slightly stronger in younger participants (≤56 vs. >56). Effects did not depend on education and cancer status. Reliable change analyses indicated that significantly more people showed full recovery for fatigue in the intervention vs the control group (P's = .02).

Conclusions

The Untire app can be an effective mHealth solution for cancer patients and survivors with moderate to severe CRF.
Classification of Inflammatory Bowel Disease from Formalin‐Fixed, Paraffin‐Embedded Tissue Biopsies via Imaging Mass Spectrometry
Authors: Klein Oliver , Fogt Franz , Hollerbach Stephan , Nebrich Grit , Boskamp Tobias , Wellmann Axel
Published: July 2020

Purpose

Discrimination between ulcerative colitis (UC) and Crohn's disease (CD) by histologic features alone can be challenging and often leads to inaccurate initial diagnoses in inflammatory bowel disease (IBD) patients. This is mostly due to an overlap of clinical and histologic features. However, exact diagnosis is not only important for patient treatment but it also has a socioeconomic impact. It is therefore important to develop and improve diagnostic tools complementing traditional histomorphological approaches.

Experimental Design

In this retrospective proof‐of‐concept study, the utilization of MALDI imaging is explored in combination with multi‐variate data analysis methods to classify formalin‐fixed, paraffin‐embedded (FFPE) colon biopsies from UC (87 biopsies, 14 patients), CD (71 biopsies, 14 patients), and normal colonic (21 biopsies, 14 patients) tissues.

Results

The proposed method results in an overall balanced accuracy of 85.7% on patient and of 80.4% on sample level, thus demonstrating that the assessment of IBD from FFPE tissue specimens via MALDI imaging is feasible.

Conclusions and Clinical Relevance

The results emphasize the high potential of this method to distinguish IBD subtypes in FFPE tissue sections, which is a prerequisite for further investigations in retrospective multicenter studies, as well as for a future implementation into clinical routine.
Rugosic acid A, derived from Rosa rugosa Thunb., is novel inhibitory agent for NF‐κB and IL‐6/STAT3 axis in acute lung injury model
Authors: Kim Kang‐Hoon , Park Ye‐Ji , Jang Hyun‐Jae , Lee Seung‐Jae , Lee Soyoung , Yun Bong‐Sik , Lee Seung Woong , Rho Mun‐Chual
Published: July 2020

Rosa rugosa Thunb., is as a medicinal plant known for anti‐diabetic, and anti‐inflammatory activities. However, the specific active compounds responsible for the individual pharmacological effects of in R. rugosa extract (95% EtOH) remain unknown. Here, we hypothesized that terpenoid structure, the most abundant constituents in R. rugosa extract, are responsible for its anti‐inflammatory activity. We investigated the phytochemical substituents (compounds 1–13) and newly purified 11‐methoxy polisin A, and 13‐methoxy bisaborosaol F using NMR and ESI‐MS and to screened their effects on NO production in LPS‐induced macrophages. Rugosic acid A (RA) induced to ameliorate NO production, iNOS, and pro‐inflammatory cytokines associated with the NF‐κB. And, RA suppressed IL‐6 secretion and IL‐6‐mediated STAT3 activation in LPS‐mediated inflammation. In addition, RA was evaluated in LPS‐mediated acute lung injury (ALI) model similar to acute pneumonia. Our results suggested that RA was suppressed to translocate nuclear NF‐κB and IL‐6‐mediated STAT3 activation. Finally, RA led to amelioration of ALI by decreasing myeloperoxidase (MPO) and inhibiting phosphorylation of NF‐κB and STAT3. Our group originally found that R. rugosa extract had new methoxy compounds and RA may be alternative natural agent for acute pneumonia similar to severe acute respiratory syndrome by coronavirus.
The leading edge: Emerging neuroprotective and neuroregenerative cell-based therapies for spinal cord injury
Authors: Ahuja Christopher S. , Mothe Andrea , Khazaei Mohamad , Badhiwala Jetan H. , Gilbert Emily A. , Kooy Derek , Morshead Cindi M. , Tator Charles , Fehlings Michael G.
Published: July 2020

Spinal cord injuries (SCIs) are associated with tremendous physical, social, and financial costs for millions of individuals and families worldwide. Rapid delivery of specialized medical and surgical care has reduced mortality; however, long-term functional recovery remains limited. Cell-based therapies represent an exciting neuroprotective and neuroregenerative strategy for SCI. This article summarizes the most promising preclinical and clinical cell approaches to date including transplantation of mesenchymal stem cells, neural stem cells, oligodendrocyte progenitor cells, Schwann cells, and olfactory ensheathing cells, as well as strategies to activate endogenous multipotent cell pools. Throughout, we emphasize the fundamental biology of cell-based therapies, critical features in the pathophysiology of spinal cord injury, and the strengths and limitations of each approach. We also highlight salient completed and ongoing clinical trials worldwide and the bidirectional translation of their findings. We then provide an overview of key adjunct strategies such as trophic factor support to optimize graft survival and differentiation, engineered biomaterials to provide a support scaffold, electrical fields to stimulate migration, and novel approaches to degrade the glial scar. We also discuss important considerations when initiating a clinical trial for a cell therapy such as the logistics of clinical-grade cell line scale-up, cell storage and transportation, and the delivery of cells into humans. We conclude with an outlook on the future of cell-based treatments for SCI and opportunities for interdisciplinary collaboration in the field.

Significance statement Traumatic spinal cord injuries (SCIs) result in tremendous lifelong disability and financial burden for millions of patients and caregivers worldwide. Cell-based therapies have emerged as an exciting neuroprotective and neuroregenerative strategy for SCI. This review highlights key preclinical and clinical data in cell therapy with an emphasis on the pathobiology and mechanisms of recovery. Also discussed are adjunct treatments to maximize the efficacy of the grafts. Finally, important translational considerations such as clinical-grade scale-up and delivery techniques are discussed. The article succinctly provides readers with a working knowledge of SCI and cell therapies at the leading edge of research.
Fabrication and Application of Magnetically Catalytic Imprinting Nanozymes
Authors: Hu Yufeng , Liu Jie , Xing Hanwen , Zhou Hao , Wu Minghuo
Published: July 2020

Nanozymes exhibit excellent enzyme‐like activities but lack specificity. Here, molecularly imprinted polymers (MIPs) based on polypyrrole (PPy) and using methylene blue (MB) as template were grown on Fe3O4 nanozymes to enhance the catalytic selectivity. The obtained composite Fe3O4@PPy MIPs were characterized using a scanning electron microscope, transmission electron microscope, powder X‐ray diffractometer, and vibrating sample magnetometer. The PPy‐encapsulated Fe3O4 nanozymes retained their catalytic ability and almost completely removed MB within 30 min in the presence of sodium persulfate. In comparison with bare Fe3O4 nanozymes, the Fe3O4@PPy MIPs showed superior catalytic selectivity for MB. The apparent rate constants (kapp) for MB, rhodamine B, and methyl orange were 0.073, 0.035, and 0.012 min−1, respectively. Even after five recycling steps, the obtained Fe3O4@PPy MIPs could degrade more than 80% of MB.
Approaching to High Elongation of Automotive Steel by Controlled Cooling Strategy
Authors: Xue Yi , Yin Sheng , Tian Qingchao , Pei Xinhua
Published: July 2020

Automobile steel with moderate tensile strength demands for higher total elongation, whereas present production cannot satisfy such requirement. To cope with the challenge for desired ductility, Ti, Nb, and V microalloyed steel is applied to a late‐stage ultrafast cooling (LUC) method as well as an interrupted ultrafast cooling (IUC) strategy to explore the effect of cooling process on the total elongation. It is found that an IUC can increase the total elongation and the lűders strain to about 45% and 60% higher in comparison with the LUC counterpart, respectively. Metallographic microscopy (OM), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and orientation distribution function (ODF) are used to characterize the microstructure and texture components. It is revealed that the multiscale grain distribution and the multiphase constituent, especially the existence of ultrafine pearlite microstructure with several atomic layers of grain boundaries, are greatly important for the ductility enhancement. It is inferred that larger undercooling caused by ultrafast cooling strategy makes the dislocation density much higher, whereas Nb precipitation tends to induce the formation of lamellar pearlite structure.
Significant Improvement in Strength and Toughness of Nanoscale Precipitate–Strengthened Steel by Direct Quenching and Tempering Process
Authors: Hu Jun , Liu Kang-Kang , Ma Li , Misra R. Devesh Kumar , Zhang Wei-Na , Du Han-Chen , Xu Wei
Published: July 2020

Herein, the microstructural evolution and mechanical properties of a low‐carbon Nb–Ti–Mo‐bearing steel subjected to hot rolling followed by four different processing schedules (air cooling, direct quenching, low‐temperature tempering, and high‐temperature tempering) are studied to elucidate the significance of structural refinement and nanoscale precipitates for obtaining the optimized combination of strength and toughness. The microstructure of air‐cooled steel composed of coarse polygonal ferrite and granular bainite, and minimum yield strength of 473 MPa and lowest impact energy at −40 °C of 40 J are obtained. The microstructure of steel direct quenched and tempered at 520 °C consists of sub‐micron tempered martensitic and bainitic laths with a high relative fraction of high misorientation boundaries and high density of 3–5 nm (Nb, Ti, Mo)C precipitates, and maximum yield strength of 726 MPa and highest impact energy at −40 °C of 213 J are obtained. The formation of nanoscale precipitates coupled with fine tempered martensitic and bainitic blocks contributes to 253 MPa improvement of yield strength and more than five times enhancement of impact energy. The small blocks of tempered martensite and bainite can deviate and finally arrest the crack propagation, whereas the coarse polygonal ferrite and bainite provide inadequate resistance for crack propagation.
Experimental investigations on actively bent concrete shells
Authors: Berger Johannes , Gericke Oliver , Feix Jürgen , Sobek Werner
Published: July 2020

This paper concerns a novel method of constructing shell structures from flat concrete plates by means of active bending. The method is described together with a series of experimental investigations. The theoretical background for this method is given in Berger et al., Actively bent concrete shells, Struct Concrete, 2020. The method makes use of the high capacity for rotation exhibited by thin concrete plates that are reinforced with highly elastic tensile reinforcement. When these plates are subjected to eccentrical forces introduced by external tendons they are raised and bent precisely into a desired curved shape. The method was investigated and refined along with a series of experiments which are the subject of this paper: uniaxial tensile tests on rovings to determine their elongation at fracture, bending tests on small concrete plates to determine possible radii of curvature, and large‐scale tests to demonstrate the erection process of actively bent shells.
An overview of unsupervised drift detection methods
Authors: Gemaque Rosana Noronha , Costa Albert França Josuá , Giusti Rafael , dos Santos Eulanda Miranda
Published: July 2020

Practical applications involving big data, such as weather monitoring, identification of customer preferences, Internet log analysis, and sensors warnings require challenging data analysis, since these are examples of problems whose data are generated in streams and usually demand real‐time analytics. Patterns in such data stream problems may change quickly. Consequently, machine learning models that operate in this context must be updated over time. This phenomenon is called concept drift in machine learning and data mining literature. Several different directions have been pursued to learn from data stream and to deal with concept drift. However, most drift detection methods consider that an instance's class label is available right after its prediction, since these methods work by monitoring the prediction results of a base classifier or an ensemble of classifiers. Nevertheless, this constraint is unrealistic in several practical problems. To cope with this constraint, some works are focused on proposing efficient unsupervised or semi‐supervised concept drift detectors. While interesting and recent overview papers dedicated to supervised drift detectors have been published, the scenario is not the same in terms of unsupervised methods. Therefore, this work presents a comprehensive overview of approaches that tackle concept drift in classification problems in an unsupervised manner. Additional contribution includes a proposed taxonomy of state‐of‐the‐art approaches for concept drift detection based on unsupervised strategies.

This article is categorized under:

Technologies > Classification

Technologies > Machine Learning
Genomic, transcriptomic and physiological analyses of silver‐resistant Saccharomyces cerevisiae obtained by evolutionary engineering
Authors: Terzioğlu Ergi , Alkım Ceren , Arslan Mevlüt , Balaban Berrak Gülçin , Holyavkin Can , Kısakesen Halil İbrahim , Topaloğlu Alican , Yılmaz Şahin Ülkü , Gündüz Işık Sema , Akman Süleyman , Çakar Zeynep Petek
Published: July 2020

Silver is a non‐essential metal used in medical applications as an antimicrobial agent, but it is also toxic for biological systems. To investigate the molecular basis of silver resistance in yeast, we employed evolutionary engineering using successive batch cultures at gradually increased silver stress levels up to 0.25‐mM AgNO3 in 29 populations and obtained highly silver‐resistant and genetically stable Saccharomyces cerevisiae strains. Cross‐resistance analysis results indicated that the silver‐resistant mutants also gained resistance against copper and oxidative stress. Growth physiological analysis results revealed that the highly silver‐resistant evolved strain 2E was not significantly inhibited by silver stress, unlike the reference strain. Genomic and transcriptomic analysis results revealed that there were mutations and/or significant changes in the expression levels of the genes involved in cell wall integrity, cellular respiration, oxidative metabolism, copper homeostasis, endocytosis and vesicular transport activities. Particularly the missense mutation in the RLM1 gene encoding a transcription factor involved in the maintenance of cell wall integrity and with 707 potential gene targets might have a key role in the high silver resistance of 2E, along with its improved cell wall integrity, as confirmed by the lyticase sensitivity assay results. In conclusion, the comparative physiological, transcriptomic and genomic analysis results of the silver‐resistant S. cerevisiae strain revealed potential key factors that will help understand the complex molecular mechanisms of silver resistance in yeast.
NMR Lineshape Analysis of Intrinsically Disordered Protein Interactions
Authors: Waudby Christopher A. , Christodoulou John
Published: July 2020

Interactions of intrinsically disordered proteins are central to their cellular functions, and solution-state NMR spectroscopy provides a powerful tool for characterizing both structural and mechanistic aspects of such interactions. Here we focus on the analysis of IDP interactions using NMR titration measurements. Changes in resonance lineshapes in two-dimensional NMR spectra upon titration with a ligand contain rich information on structural changes in the protein and the thermodynamics and kinetics of the interaction, as well as on the microscopic association mechanism. Here we present protocols for the optimal design of titration experiments, data acquisition, and data analysis by two-dimensional lineshape fitting using the TITAN software package.
Indigenous and Scientific Forecasts on Climate Change Perceptions of Arable Farmers: Rwenzori Region, Western Uganda
Authors: Nkuba Michael Robert , Chanda Raban , Mmopelwa Gagoitseope , Adedoyin Akintayo , Mangheni Margaret Najjingo , Lesolle David , Kato Edward
Published: July 2020

Despite the dissemination of climate information from national meteorological systems, arable farmers still have challenges of dealing with climate-related risks. This study investigated the effect of using indigenous knowledge-based forecasts (IFs) and scientific knowledge-based forecasts (SFs) on the climate change perceptions of arable farmers in the Rwenzori region, Western Uganda. Data on socio-economic characteristics, use of forecasts, and climate change perceptions was collected from 580 arable farmers and the probit model was used in the analysis. The findings indicated that use of IFs only increased the likelihood of perceiving increase in the frequency in occurrences of droughts and floods. Using both SFs and IFs had a significant positive effect on perception of unpredictable rains and the increase in drought incidence among arable farmers. Although forecasts are important drivers of perceptions, other factors, such as gender, social capital, and dissemination of climate change information by radio, enhance climate change perceptions. Active participation of arable farmers in the dissemination of forecasts by national meteorological services could improve perceptions of climate related risks.
Composite dark matter phenomenology in the presence of lighter degrees of freedom
Authors: Ramos Maria
Published: July 2020

Abstract

Scalar singlet dark matter in anomaly-free composite Higgs models is accompanied by exotic particles to which the dark matter annihilates. The latter can therefore freeze out even in the absence of couplings to the Standard Model. In this regime, both current and future direct detection constraints can be avoided. Moreover, due to the different decay modes of the extra particles, the dark matter candidate can even escape indirect detection constraints. Assessing this issue requires dedicated simulations of the gamma ray spectrum, that we provide in the present article in the context of SO(7)/SO(6). For the parameter space region that evades constraints from dark matter experiments, we develop new analyses to be performed at a future 100 TeV collider based on the search of the new particles produced in the decay of heavy vector-like quarks.
Classification of equation of state in relativistic heavy-ion collisions using deep learning
Authors: Kvasiuk Yu. , Zabrodin E. , Bravina L. , Didur I. , Frolov M.
Published: July 2020

Abstract

Convolutional Neural Nets, which is a powerful method of Deep Learning, is applied to classify equation of state of heavy-ion collision event generated within the UrQMD model. Event-by-event transverse momentum and azimuthal angle distributions of protons are used to train a classifier. An overall accuracy of classification of 98% is reached for Au+Au events at $$ \sqrt{s_{NN}} $$

s
NN

= 11 GeV. Performance of classifiers, trained on events at different colliding energies, is investigated. Obtained results indicate extensive possibilities of application of Deep Learning methods to other problems in physics of heavy- ion collisions.
Detection of Coalescent Acute Mastoiditis on MRI in Comparison with CT
Authors: Saat R. , Kurdo G. , Laulajainen-Hongisto A. , Markkola A. , Jero J.
Published: July 2020

Purpose

Current imaging standard for acute mastoiditis (AM) is contrast-enhanced computed tomography (CT), revealing inflammation-induced bone destruction, whereas magnetic resonance imaging (MRI) outperforms CT in detecting intracranial infection. Our aim was to compare the diagnostic performance of MRI with CT in detecting coalescent AM and see to which extent MRI alone would suffice to diagnose or rule out this condition.

Methods

The MR images of 32 patients with AM were retrospectively analyzed. Bone destruction was evaluated from T2 turbo spin echo (TSE) and T1 Gd magnetization-prepared rapid acquisition with gradient echo (MPRAGE) images. Intramastoid enhancement and diffusion restriction were evaluated subjectively and intramastoid apparent diffusion coefficient (ADC) values were measured. The MRI findings were compared with contrast-enhanced CT findings of the same patients within 48 h of the MR scan.

Results

Depending on the anatomical subsite, MRI detected definite bone defects with a sensitivity of 100% and a specificity of 54–82%. Exception was the inner cortical table where sensitivity was only 14% and specificity was 76%. Sensitivity for general coalescent mastoiditis remained 100% due to multiple coexisting lesions. The absence of intense enhancement and non-restricted diffusion had a high negative predictive value for coalescent mastoiditis: an intramastoid ADC above 1.2 × 10−3 mm2/s excluded coalescent mastoiditis with a negative predictive value of 92%.

Conclusion

The MRI did not miss coalescent mastoiditis but was inferior to CT in direct estimation of bone defects. When enhancement and diffusion characteristics are also considered, MRI enables dividing patients into low, intermediate and high-risk categories with respect to coalescent mastoiditis, where only the intermediate risk group is likely to benefit from additional CT.
The Quasiconvex Envelope of Conformally Invariant Planar Energy Functions in Isotropic Hyperelasticity
Authors: Martin Robert J. , Voss Jendrik , Ghiba Ionel-Dumitrel , Sander Oliver , Neff Patrizio
Published: July 2020

We considerconformally invariantenergiesWon the group$${{\,\mathrm{GL}\,}}^{\!+}(2)$$GL+(2)of$$2\times 2$$2×2-matrices with positive determinant, i.e.,$$W:{{\,\mathrm{GL}\,}}^{\!+}(2)\rightarrow {\mathbb {R}}$$W:GL+(2)→Rsuch that$$\begin{aligned} W(A\, F\, B) = W(F) \quad \text {for all }\; A,B\in \{a\, R\in {{\,\mathrm{GL}\,}}^{\!+}(2) \,|\,a\in (0,\infty ),\; R\in {{\,\mathrm{SO}\,}}(2)\}, \end{aligned}$$W(AFB)=W(F)for allA,B∈{aR∈GL+(2)|a∈(0,∞),R∈SO(2)},where$${{\,\mathrm{SO}\,}}(2)$$SO(2)denotes the special orthogonal group and provides an explicit formula for the (notoriously difficult to compute)quasiconvex envelopeof these functions. Our results, which are based on the representation$$W(F)=h\bigl (\frac{\lambda _1}{\lambda _2}\bigr )$$W(F)=h(λ1λ2)ofWin terms of the singular values$$\lambda _1,\lambda _2$$λ1,λ2ofF, are applied to a number of example energies in order to demonstrate the convenience of the singular-value-based expression compared to the more common representation in terms of the distortion$${\mathbb {K}}:=\frac{1}{2}\frac{\Vert F \Vert ^2}{\det F}$$K:=12‖F‖2detF. Applying our results, we answer a conjecture by Adamowicz (in: Atti della Accademia Nazionale dei Lincei. Classe di Scienze Fisiche, Matematiche e Naturali. Rendiconti Lincei. Serie IX. Matematica e Applicazioni, vol 18(2), pp 163, 2007) and discuss a connection between polyconvexity and the Grötzsch free boundary value problem. Special cases of our results can also be obtained from earlier works by Astala et al. (Elliptic partial differential equations and quasiconformal mappings in the plane, Princeton University Press, Princeton, 2008) and Yan (Trans Am Math Soc 355(12):4755–4765, 2003). Since the restricted domain of the energy functions in question poses additional difficulties with respect to the notion of quasiconvexity compared to the case of globally defined real-valued functions, we also discuss more general properties related to the$$W^{1,p}$$W1,p-quasiconvex envelope on the domain$${{\,\mathrm{GL}\,}}^{\!+}(n)$$GL+(n)which, in particular, ensure that a stricter version ofDacorogna’s formulais applicable to conformally invariant energies on$${{\,\mathrm{GL}\,}}^{\!+}(2)$$GL+(2).
Rising extreme sea levels in the German Bight under enhanced $${{\mathrm {CO}}_2}$$ levels: a regionalized large ensemble approach for the North Sea
Authors: Lang Andreas , Mikolajewicz Uwe
Published: July 2020

We quantify the change in extreme high sea level (ESL) statistics in the German Bight under rising $${{\mathrm {CO}}_2}$$

CO
2

concentrations by downscaling a large ensemble of global climate model simulations using the regionally coupled climate system model REMO-MPIOM. While the model setup combines a regionally high resolution with the benefits of a global ocean model, the large ensemble size of 32 members allows the estimation of high return levels with much lower uncertainty. We find that ESLs increase with atmospheric $${{\mathrm {CO}}_2}$$

CO
2

levels, even without considering a rise in the background sea level (BSL). Local increases of up to 0.5 m are found along the western shorelines of Germany and Denmark for ESLs of 20–50 years return periods, while higher return levels remain subject to sampling uncertainty. This ESL response is related to a cascade of an enhanced large-scale activity along the North Atlantic storm belt to a subsequent local increase in predominantly westerly wind speed extremes, while storms of the major West-Northwest track type gain importance. The response is seasonally opposite: summer ESLs and the strength of its drivers decrease in magnitude, contrasting the response of the higher winter ESLs, which governs the annual response. These results have important implications for coastal protection. ESLs do not only scale with the expected BSL rise, but become even more frequent, as preindustrial 50-year return levels could be expected to occur almost every year by the end of the century. The magnitude of the relative change in ESL statistics is hereby up to half of the expected rise in BSL, depending on the location. Changes in the highest extremes are subject to large multidecadal variations and remain uncertain, thus potentially demanding even further safety measures.
Ist eine Delegation ärztlicher Leistungen auf rheumatologische Fachassistenten bei der Evaluierung von Patienten mit Verdacht auf ankylosierende Spondylitis möglich? – Ergebnisse der PredAS-Studie
Authors: Kiltz U. , Spiller I. , Sieper J. , Braun J.
Published: July 2020

Hintergrund

Der oft langsame Beginn einer axialen Spondyloarthritis (axSpA), die initial zum Teil wenig spezifischen Symptome (Rückenschmerzen), aber auch begrenzte Ressourcen und die damit verbundenen Verzögerungen in der rheumatologischen Versorgung sind Faktoren, die zu verspäteter Diagnose und Therapie dieser meist jungen Patienten mit beitragen. Rheumatologische Fachassistenten (RFA) können zur Verbesserung der Versorgung beitragen, indem sie vom Rheumatologen delegierte ärztliche Leistungen übernehmen.

Ziel der Arbeit

Ziel ist, zu untersuchen, ob geschulte RFA bei Patienten mit chronischem Rückenschmerz und noch unklarer Diagnose mithilfe eines strukturierten Fragebogens anamnestische und klinische Befunde wie Rheumatologen erheben können.

Material und Methoden

In der multizentrisch durchgeführten PredAS-Studie wurden bei Patienten mit dem Leitsymptom chronischer Rückenschmerz demografische Basisdaten, Anamnese und patientenberichtete Endpunkte mittels strukturierter Fragebögen von RFA und Rheumatologen unabhängig voneinander erfasst. Zudem wurden Funktion (BASFI) und Wirbelsäulenbeweglichkeit (BASMI) standardisiert gemessen. Um die mögliche Erleichterung durch Nutzung digitaler Medien zu testen, wurden 2 Patientengruppen getrennt untersucht: Die Ergebnisse der einen Kohorte wurden mittels papierbasierter Case Report Forms (CRF) und die Ergebnisse der anderen elektronisch mittels iPad dokumentiert. Die Konkordanz der Dokumentationen zwischen RFA und Rheumatologen wurde als Kappa-Koeffizient, als prozentuale Übereinstimmung und auf individueller Patientenebene berechnet.

Ergebnisse

Bei fast drei Viertel der 141 Patienten mit chronischen Rückenschmerzen wurden Charakteristika des entzündlichen Rückenschmerzes identifiziert. Die Konkordanz bei Dokumentation durch RFA und Arzt war bei den anamnestischen Angaben zum Rückenschmerz höher als bei der Angabe zur Lokalisation des Rückenschmerzes. Bei der Erhebung des BASMI zeigte sich kein Unterschied zwischen RFA und Arzt (ICC 0,925) (95 %-CI 0,879–0,953). Der Zeitaufwand für die strukturierte Dokumentation betrug beim Arzt 20 ± 6,7 min und bei der RFA 28,5 ± 13 min.

Diskussion

Die Ergebnisse sprechen dafür, dass geschulte RFA die Rheumatologen bei der anamnestischen Aufarbeitung und ersten körperlichen Untersuchung im Rahmen der Diagnosestellung erheblich und qualifiziert unterstützen können.
Mutual conditional independence and its applications to model selection in Markov networks
Authors: Gauraha Niharika , Parui Swapan K.
Published: July 2020

The fundamental concepts underlying Markov networks are the conditional independence and the set of rules called Markov properties that translate conditional independence constraints into graphs. We introduce the concept of mutual conditional independence in an independent set of a Markov network, and we prove its equivalence to the Markov properties under certain regularity conditions. This extends the notion of similarity between separation in graph and conditional independence in probability to similarity between the mutual separation in graph and the mutual conditional independence in probability. Model selection in graphical models remains a challenging task due to the large search space. We show that mutual conditional independence property can be exploited to reduce the search space. We present a new forward model selection algorithm for graphical log-linear models using mutual conditional independence. We illustrate our algorithm with a real data set example. We show that for sparse models the size of the search space can be reduced from$\mathcal {O} (n^{3})$O(n3)to$\mathcal {O}(n^{2})$O(n2)using our proposed forward selection method rather than the classical forward selection method. We also envision that this property can be leveraged for model selection and inference in different types of graphical models.