bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimental evolution supports signatures of sexual selection in genomic divergence
Authors: Wiberg R. Axel W. , Veltsos Paris , Snook Rhonda R. , Ritchie Michael G.
Published: March 2021

Comparative genomics has contributed to the growing evidence that sexual selection is an important component of evolutionary divergence and speciation. Divergence by sexual selection is implicated in faster rates of divergence of the X chromosome and of genes thought to underlie sexually selected traits, including genes that are sex biased in expression. However, accurately inferring the relative importance of complex and interacting forms of natural selection, demography, and neutral processes that occurred in the evolutionary past is challenging. Experimental evolution provides an opportunity to apply controlled treatments for multiple generations and examine the consequent genomic divergence. Here, we altered sexual selection intensity, elevating sexual selection in polyandrous lines and eliminating it in monogamous lines, and examined patterns of allele frequency divergence in the genome of Drosophila pseudoobscura after more than 160 generations of experimental evolution. Divergence is not uniform across the genome but concentrated in “islands,” many of which contain candidate genes implicated in mating behaviors and other sexually selected phenotypes. These are more often seen on the X chromosome, which also shows greater divergence in FST than neutral expectations. There are characteristic signatures of selection seen in these regions, with lower diversity on the X chromosome than the autosomes, and differences in diversity on the autosomes between selection regimes. Reduced Tajima's D within some of the divergent regions may imply that selective sweeps have occurred, despite considerable recombination. These changes are associated with both differential gene expression between the lines and sex-biased gene expression within the lines. Our results are very similar to those thought to implicate sexual selection in divergence between species and natural populations, and hence provide experimental support for the likely role of sexual selection in driving such types of genetic divergence, but also illustrate how variable outcomes can be for different genomic regions.
Detection of fraud in lime juice using pattern recognition techniques and FT‐IR spectroscopy
Authors: Mohammadian Amirhossein , Barzegar Mohsen , Mani‐Varnosfaderani Ahmad
Published: March 2021

The lime juice is one of the products that has always fallen victim to fraud by manufacturers for reducing the cost of products. The aim of this research was to determine fraud in distributed lime juice products from different factories in Iran. In this study, 101 samples were collected from markets and also prepared manually and finally derived into 5 classes as follows: two natural classes (Citrus limetta, Citrus aurantifolia), including 17 samples, and three reconstructed classes, including 84 samples (made from Spanish concentrate, Chinese concentrate, and concentrate containing adulteration compounds). The lime juice samples were freeze‐dried and analyzed using FT‐IR spectroscopy. At first, principal component analysis (PCA) was applied for clustering, but the samples were not thoroughly clustered with respect to their original groups in score plots. To enhance the classification rates, different chemometric algorithms including variable importance in projection (VIP), partial least square‐discriminant analysis (PLS‐DA), and counter propagation artificial neural networks (CPANN) were used. The best discriminatory wavenumbers related to each class were selected using the VIP‐PLS‐DA algorithm. Then, the CPANN algorithm was used as a nonlinear mapping tool for classification of the samples based on their original groups. The lime juice samples were correctly designated to their original groups in CPANN maps and the overall accuracy of the model reached up to 0.96 and 0.87 for the training and validation procedures. This level of accuracy indicated the FT‐IR spectroscopy coupled with VIP‐PLS‐DA and CPANN methods can be used successfully for detection of authenticity of lime juice samples.
Derivation of site-specific selenium water quality criteria: A comparison of two methods and regulatory implications
Authors: Reash Robin J. , Thomas Jeffrey , Vondruska Joe T.
Published: March 2021

In 2016, the US Environmental Protection Agency (USEPA) issued revised aquatic life water quality criteria for selenium (Se). The criteria (“elements”) consisted of threshold concentrations applicable to fish tissue (three tissue types, though the egg and ovary tissue takes precedence over the whole-body and muscle tissue thresholds), and water column. The agency rationalized that measured concentrations of Se in fish tissue were more predictive of potential adverse reproductive effects than those measured in external media. The agency provided two mechanisms for derivation of site-specific Se water criteria: a bioaccumulation factor (BAF) approach, and a partitioning-based bioaccumulation model approach. The use of either approach assumes that fish tissue concentrations exceed one or more of the tissue criteria. We compared the two approaches using fish tissue samples from various species in the Ohio River to evaluate resulting similarities and differences in the calculated Se water quality criteria. Fish (five species) were collected near two coal-fired power plants at sites unaffected by Se from wastewater discharges. Using results for all species and all sites combined, the resulting site-specific Se criteria for the BAF and partitioning-based model approach (median values) were 2.0 and 1.5 µg/L, respectively. Considering all species, resulting criteria differed little between the two power plant locations. Resulting criteria for both methods were strongly influenced by a small (less than detection) background Se water concentration. At least for the upper Ohio River, the BAF approach (requiring less input data) seems adequate for derivation of site-specific Se water criteria. In the current study, however, none of the tissue samples exceeded USEPA's tissue criteria. Thus, the decision to derive site-specific Se water quality criteria should be evaluated on a case-by-case basis, because the process may result in either a more stringent or less stringent value, wholly dependent on local factors. Integr Environ Assess Manag 2021;17:1255–1262. © 2021 SETAC

KEY POINTS

USEPA offers methods to determine site-specific Se water quality criteria where the applicable tissue criteria may be exceeded. Two of these methods were evaluated side-by-side at two power plant sites on the Ohio River. Results indicated very similar site-specific Se water quality criteria for both methods, which was influenced highly by less than detection water concentrations.
MicroRNA‐216a targets WT1 expression and regulates KRT7 transcription to mediate the progression of pancreatic cancer—A transcriptome analysis
Authors: Wang Wei , Wang Jie , Yang Chuanxin , Wang Jian
Published: March 2021

Gene expression profiling has been broadly performed in the field of cancer research. This study aims to explore the key gene regulatory network and focuses on the functions of microRNA (miR)‐216a in pancreatic cancer (PC). PC datasets GSE15471, GSE16515, and GSE32676 were used to screen the differentially expressed genes (DEGs) in PC. A miRNA microarray analysis and gene oncology analysis suggested miR‐216a as an important differentially expressed miRNA in PC. The Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis suggested that miR‐216a and the DEGs are largely enriched on the phosphatidyl inositol 3‐kinase/protein kinase B (PI3K/AKT) signaling pathway. miR‐216a targeted Wilms Tumor 1 (WT1), while WT1 promoted transcription activity of keratin 7 (KRT7). Upregulation of miR‐216a reduced proliferation and invasiveness of PC cells, while further upregulation of WT1 blocked the functions of miR‐216a. Silencing of KRT7 diminished the oncogenic role of WT1. The in vitro results were reproduced in vivo. High expression of miR‐216a while poor expression of WT1 indicated better prognosis of PC patients. The miR‐216a/WT1/KRT7 axis influenced the activity of the PI3K/AKT pathway. To conclude, this study evidenced that miR‐216a suppressed WT1 expression and blocked KRT7 transcription, which inactivated the PI3K/AKT signaling and reduced PC progression.
Exosomal miR‐512‐3p derived from mesenchymal stem cells inhibits oxidized low‐density lipoprotein‐induced vascular endothelial cells dysfunction via regulating Keap1
Authors: Chen Sisi , Zhou Heng , Zhang Bofang , Hu Qi
Published: March 2021

Atherosclerosis (AS) is a prevalent chronic inflammatory vascular disease. Upregulated oxidized low‐density lipoprotein (ox‐LDL) in the serum has been found to induce endothelial cells (ECs) apoptosis by increasing oxidative stress and promoting inflammatory response, which are essential mechanisms of AS development. Mesenchymal stem cells (MSCs), which secrete exosomes to transport microRNAs (miRNAs) and regulate cell functions, have become a research focus in recent years. The results of this study manifested that MSCs‐derived exosomes were phagocytosed by EC. In addition, miR‐512‐3p enriched by MSCs‐ derived exosomes markedly inhibited ox‐LDL‐mediated EC damage, namely, accelerated EC proliferation, inhibited Caspase‐3 activation and cell apoptosis, inhibited the levels of inflammatory cytokines (tumor necrosis factor‐α, interleukin (IL)‐1β, and IL‐6) and oxidative factor MDA, and increased the contents of SOD and GSH‐PX. Mechanistically, Keleh‐like ECH‐associated protein 1 (Keap1) was proved to be a functional target of miR‐512‐3p. Furthermore, silencing Keap1 limited ox‐LDL‐mediated EC cell dysfunction, while over‐expressing Keap1 mitigated the exosomal miR‐512‐3p‐mediated protective effect in Ox‐LDL‐induced EC. The above results confirmed that miR‐512‐3p shuttled by MSCs‐derived exosomes protected EC against ox‐LDL by targeting Keap1.
Higher infectivity of the SARS‐CoV‐2 new variants is associated with K417N/T, E484K, and N501Y mutants: An insight from structural data
Authors: Khan Abbas , Zia Tauqir , Suleman Muhammad , Khan Taimoor , Ali Syed Shujait , Abbasi Aamir Ali , Mohammad Anwar , Wei Dong‐Qing
Published: March 2021

The evolution of the SARS‐CoV‐2 new variants reported to be 70% more contagious than the earlier one is now spreading fast worldwide. There is an instant need to discover how the new variants interact with the host receptor (ACE2). Among the reported mutations in the Spike glycoprotein of the new variants, three are specific to the receptor‐binding domain (RBD) and required insightful scrutiny for new therapeutic options. These structural evolutions in the RBD domain may impart a critical role to the unique pathogenicity of the SARS‐CoV‐2 new variants. Herein, using structural and biophysical approaches, we explored that the specific mutations in the UK (N501Y), South African (K417N‐E484K‐N501Y), Brazilian (K417T‐E484K‐N501Y), and hypothetical (N501Y‐E484K) variants alter the binding affinity, create new inter‐protein contacts and changes the internal structural dynamics thereby increases the binding and eventually the infectivity. Our investigation highlighted that the South African (K417N‐E484K‐N501Y), Brazilian (K417T‐E484K‐N501Y) variants are more lethal than the UK variant (N501Y). The behavior of the wild type and N501Y is comparable. Free energy calculations further confirmed that increased binding of the spike RBD to the ACE2 is mainly due to the electrostatic contribution. Further, we find that the unusual virulence of this virus is potentially the consequence of Darwinian selection‐driven epistasis in protein evolution. The triple mutants (South African and Brazilian) may pose a serious threat to the efficacy of the already developed vaccine. Our analysis would help to understand the binding and structural dynamics of the new mutations in the RBD domain of the Spike protein and demand further investigation in in vitro and in vivo models to design potential therapeutics against the new variants.
The double corpus luteum: A novel sonographic sign of heterotopic pregnancy
Authors: Kluckman Matthew L. , Schwope Ryan B. , Provagna Alyssa J. , Yauger Belinda J. , Ramirez Christina I.
Published: March 2021

Heterotopic pregnancy is a rare and highly morbid condition with simultaneous intrauterine and extra‐uterine pregnancies. The early diagnosis of heterotopic pregnancy is difficult, owing to rarity of the condition and nonspecific clinical and laboratory findings. This case report introduces the “double corpus luteum” sign, a new sonographic and magnetic resonance imaging sign which is easily detectable and should raise the index of suspicion for heterotopic pregnancy. We present a surgically confirmed spontaneous heterotopic and angular pregnancy in a young woman without risk factors or assisted reproductive therapy to illustrate the utility of this novel sign.
Use of a sensitive multisugar test for measuring segmental intestinal permeability in critically ill, mechanically ventilated adults: A pilot study
Authors: Tatucu‐Babet Oana A. , Forsyth Adrienne , Udy Andrew , Radcliffe Jessica , Benheim Devin , Calkin Caroline , Ridley Emma J. , Gantner Dashiell , Jois Markandeya , Itsiopoulos Catherine , Tierney Audrey C.
Published: March 2021

Background

Increased intestinal permeability (IP) is associated with sepsis in the intensive care unit (ICU). This study aimed to pilot a sensitive multisugar test to measure IP in the nonfasted state.

Methods

Critically ill, mechanically ventilated adults were recruited from 2 ICUs in Australia. Measurements were completed within 3 days of admission using a multisugar test measuring gastroduodenal (sucrose recovery), small‐bowel (lactulose‐rhamnose [L‐R] and lactulose‐mannitol [L‐M] ratios), and whole‐gut permeability (sucralose‐erythritol ratio) in 24‐hour urine samples. Urinary sugar concentrations were compared at baseline and after sugar ingestion, and IP sugar recoveries and ratios were explored in relation to known confounders, including renal function.

Results

Twenty‐one critically ill patients (12 males; median, 57 years) participated. Group median concentrations of all sugars were higher following sugar administration; however, sucrose and mannitol increases were not statistically significant. Within individual patients, sucrose and mannitol concentrations were higher in baseline than after sugar ingestion in 9 (43%) and 4 (19%) patients, respectively. Patients with impaired (n = 9) vs normal (n = 12) renal function had a higher L‐R ratio (median, 0.130 vs 0.047; P = .003), lower rhamnose recovery (median, 15% vs 24%; P = .007), and no difference in lactulose recovery.

Conclusion

Small‐bowel and whole‐gut permeability measurements are possible to complete in the nonfasted state, whereas gastroduodenal permeability could not be measured reliably. For small‐bowel IP measurements, the L‐R ratio is preferred over the L‐M ratio. Alterations in renal function may reduce the reliability of the multisugar IP test, warranting further exploration.
Quantifying the impact of chemicals on stable carbon and oxygen isotope values of raw pollen
Authors: Müller Carolina , Hennig Julian , Riedel Frank , Helle Gerhard
Published: March 2021

Purification protocols to extract pollen from lake sediments contain chemicals that alter the carbon and oxygen pollen‐isotope values according to pollen characteristics and family affiliation. Modern (raw) pollen of broad‐leaved (Alnus glutinosa, Betula pendula, Carpinus betulus, Corylus avellana, Fagus sylvatica and Quercus robur) and coniferous tree species (Picea abies and Pinus sylvestris) were treated with potassium hydroxide (KOH), hydrofluoric acid (HF), sodium hypochlorite (NaClO) and sulphuric acid (H2SO4) to test the impact on δ13Cpollen and δ18Opollen and assess the applicability in purification protocols. Pollen of broad‐leaved and coniferous trees reacted differently to chemical exposure, but response patterns are generally alike. Alterations of δ13Cpollen values vary between + 1.0‰ (B. pendula, NaClO‐treatment) and −5.0‰ (P. sylvestris, H2SO4‐treatment). The δ13Cpollen values of raw and chemically treated samples seem to be related after treatments with KOH, NaClO and HF, whereas the application of H2SO4 led to inconsistent changes among species. The impact of chemicals on δ18Opollen are more diverse and offsets range between +1.1‰ (C. avellana, NaClO‐treatment) and −17.9‰ (P. sylvestris, H2SO4‐treatment). In general, the use of isotope‐altering chemicals in purification protocols should be brought to a minimum, but the application of KOH and NaClO seems mostly unproblematic before δ13Cpollen and δ18Opollen analysis.
Compact, fast‐response, continuous, and wide‐angle laser beam steerers
Authors: He Ziqian , Wu Shin‐Tson
Published: March 2021

A liquid crystal‐cladding waveguide with resistive electrode configuration is proposed for laser beam steering applications. It can achieve wide‐angle, continuous coverage, two‐dimensional beam control with fast response time. With numerical validation, we find that in comparison with previous prismatic electrode approach, our device demonstrates higher compatibility with high birefringence liquid crystal materials, and thus, a more compact form factor can be realized. Such a beam steerer is attractive for a wide range of applications including automotive LiDAR, eye‐tracking for near‐eye displays, and high‐precision 3D printing.
Hybrid Aptamer‐Molecularly Imprinted Polymer (aptaMIP) Nanoparticles from Protein Recognition—A Trypsin Model
Authors: Sullivan Mark V. , Clay Oliver , Moazami Michael P. , Watts Jonathan K. , Turner Nicholas W.
Published: March 2021

Aptamers offer excellent potential for replacing antibodies for molecular recognition purposes however their performance can compromise with biological/environmental degradation being a particular problem. Molecularly imprinted Polymers (MIPs) offer an alternative to biological materials and while these offer the robustness and ability to work in extreme environmental conditions, they often lack the same recognition performance. By slightly adapting the chemical structure of a DNA aptamer it is incorporated for use as the recognition part of a MIP, thus creating an aptamer‐MIP hybrid or aptaMIP. Here these are developed for the detection of the target protein trypsin. The aptaMIP nanoparticles offer superior binding affinity over conventional MIP nanoparticles (nanoMIPs), with KD values of 6.8 × 10−9 (±0.2 × 10−9) m and 12.3 × 10−9 (±0.4 × 10−9) m for the aptaMIP and nanoMIP, respectively. The aptaMIP also outperforms the aptamer only (10.3 × 10−9 m). Good selectivity against other protein targets is observed. Using surface plasmon resonance, the limit of detection for aptaMIP nanoparticles is twofold lower (2 nm) compared to the nanoMIP (4 nm). Introduction of the aptamer as a “macro‐monomer” into the MIP scaffold has beneficial effects and offers potential to improve this class of polymers significantly.
Polyrotaxane Crosslinked Self‐Healing Hydrogels for Switchable Bioadhesion
Authors: Wang Yushi , Dong Jiyu , Jin Jiahong , Jia Yong‐Guang
Published: March 2021

As an effective alternative to suture in wound closure, tissue adhesives often need to have excellent biocompatibility and suitable bioadhesion. To achieve long‐term adhesion on moist tissue, polyrotaxane (PR) crosslinked self‐healing hydrogels have been prepared by the introduction of dynamic borate bonds between PR bearing phenylboronic acid moieties (PR‐PBA) and dopamine grafted poly(vinyl alcohol) (PVA‐DOP). Synthesis of these precursor polymers PR‐PBA and PVA‐DOP is quite simple and the hydrogels combine dynamic borate bonds with the sliding motion of the phenylboronic acid moieties on PR. The sliding nature of the crosslinking points along the axle in the PR is thought to enhance the mechanical properties and adhesion ability of the resultant hydrogels. Meanwhile, catechol groups on dopamine units have been protected by borate bonds under alkaline conditions to avoid oxidation, and they then are released to react with various functional groups on tissue surface to ensure the switchable tissue adhesion. The self‐healing test and adhesion of hydrogels on pigskin demonstrate the ability to restore the original performance after repeated strain cycles and maintain strong tissue adhesion. The components of these hydrogels have satisfying biocompatibility. These results indicate that these self‐healing hydrogels have great potentials in tissue adhesion.
MRzero ‐ Automated discovery of MRI sequences using supervised learning
Authors: Loktyushin A. , Herz K. , Dang N. , Glang F. , Deshmane A. , Weinmüller S. , Doerfler A. , Schölkopf B. , Scheffler K. , Zaiss M.
Published: March 2021

Purpose

A supervised learning framework is proposed to automatically generate MR sequences and corresponding reconstruction based on the target contrast of interest. Combined with a flexible, task‐driven cost function this allows for an efficient exploration of novel MR sequence strategies.

Methods

The scanning and reconstruction process is simulated end‐to‐end in terms of RF events, gradient moment events in x and y, and delay times, acting on the input model spin system given in terms of proton density, and , and . As a proof of concept, we use both conventional MR images and maps as targets and optimize from scratch using the loss defined by data fidelity, SAR penalty, and scan time.

Results

In a first attempt, MRzero learns gradient and RF events from zero, and is able to generate a target image produced by a conventional gradient echo sequence. Using a neural network within the reconstruction module allows arbitrary targets to be learned successfully. Experiments could be translated to image acquisition at the real system (3T Siemens, PRISMA) and could be verified in the measurements of phantoms and a human brain in vivo.

Conclusions

Automated MR sequence generation is possible based on differentiable Bloch equation simulations and a supervised learning approach.
The birth of informed decisions: Pregnancy and muscular dystrophy
Authors: Mandeville Ross M. , Narayanaswami Pushpa
Published: March 2021

See article on pages 812–817 in this issue.
A Nonlethal Genetic Assay for Discriminating Sex in Brook Trout
Authors: Webster N. , Price S. , Gowan C. , Coster S. S.
Published: March 2021

Identifying sex in salmonids using nonlethal methods is valuable for controlled breeding in aquaculture and understanding behavior and dispersal for conservation. Although salmonids are male heterogametic, genetic sex identification has been problematic because a specific sex determination locus has been elusive. We implemented a blind analysis to identify sex in Brook Trout Salvelinus fontinalis using genetic primers (sdY) developed for Brown Trout Salmo trutta along with cytochrome c oxidase subunit I (COI_BT1) as an internal control. Fin clips were taken from 35 Brook Trout and analyzed via PCR and gel electrophoresis, and fish were simultaneously sacrificed and dissected to identify sex via gonads. The genetic and phenotypic analysis matched in 97% of the Brook Trout that were sampled, suggesting that this primer combination is successful in genetic sex determination. The ability to sex Brook Trout genetically will allow scientists to observe the difference in male and female Brook Trout behavior in the lab and natural stream ecosystems without using lethal methods.
Validated quantitative needs assessment differences in the management of children with central nervous system cancer between Brazil, an upper middle‐income country, and the United States of America, a high income country
Authors: Fischer Allison N. , Roecker Roberto , Saba da Silva Nasjla , Cavalheiro Sergio , Finlay Jonathan L. , Cappellano Andrea , Osorio Diana S.
Published: March 2021

Background

Pediatric cancer cure rates differ among high‐income countries (HIC) and upper middle‐income countries (UMIC). We have compared individual capacities of two major referral pediatric centers from a HIC and an UMIC caring for children with central nervous system (CNS) cancer.

Methods

A quantitative needs assessment questionnaire and key informant interviews, distributed in March of 2017, were used to evaluate the treatment of children with CNS cancer at Grupo de Apoio ao Adolescente e à Criança com Câncer (GRAACC) children's cancer center in São Paulo, Brazil and Nationwide Children's Hospital (NCH) in Columbus, Ohio, United States of America (USA).

Results

Both hospitals had 24‐hour pediatric oncology, nursing and intensivist coverage. Supportive care available at both institutions included social workers, psychologists, child life specialists, and physical/occupational/speech therapists. Differences included two part‐time neuroradiologists and one pathologist specializing in neuropathology at IOP/GRAACC/UNIFESP, whereas eight full‐time neuroradiologists and two neuropathologists at NCH/OSU. There were four pediatric neurosurgeons on staff at each hospital; however, there were only 2 operative days per week at IOP/GRAACC/UNIFESP, compared with 7 days at NCH/OSU. Additionally, time to initiation of radiation therapy at IOP/GRAACC/UNIFESP extended 2–4 weeks compared with less than 1 week at NCH/OSU.

Conclusions

Center‐specific differences in resources exist in highly specialized hospitals caring for children with CNS cancer in HIC and UMIC. This quantitative needs assessment may facilitate the development of targeted strategies for effective interventions to improve on the management of children with CNS cancers.
Consensus recommendations from the EXPeRT/PARTNER groups for the diagnosis and therapy of sex cord stromal tumors in children and adolescents
Authors: Schneider Dominik T. , Orbach Daniel , Ben‐Ami Tal , Bien Ewa , Bisogno Gianni , Brecht Ines B. , Cecchetto Giovanni , Ferrari Andrea , Godzinski Jan , Janic Dragana , Lopez Almaraz Ricardo , Pourtsidis Apostolos , Roganovic Jelena , Schultz Kris Ann P. , Stachowicz‐Stencel Teresa , Fresneau Brice
Published: March 2021

As part of the European Union‐funded project designated Paediatric Rare Tumours Network ‐ European Registry (PARTNER), the European Cooperative Study Group for Pediatric Rare Tumors (EXPeRT) is continuously developing consensus recommendations in order to harmonize standard care for very rare solid tumors of children and adolescents. This paper presents the internationally recognized recommendations for the diagnosis and treatment of sex cord stromal tumors (SCST). The clinical approach to sex cord stromal tumors of the testis (TSCST) and ovary (OSCST) depends on histological differentiation and tumor stage. Virtually all TSCSTs present as localized nonmetastatic tumors, with excellent prognosis after complete resection. In contrast, the prognosis of OSCSTs may be adversely affected by tumor spillage during surgery or presence of metastases. In these cases, cisplatin‐based chemotherapy is recommended. Of note, some SCSTs may develop in the context of tumor predisposition syndromes, for example, DICER‐1, so that specific follow‐up is indicated. SCSTs should be diagnosed and treated according to standardized recommendations that include reference pathology, genetic testing for tumor predisposition syndromes in selected cases, and stratified adjuvant chemotherapy in patients with unfavorable risk profile. To ensure high quality of diagnosis and therapy, patients should be enrolled into prospective registries.
Preparation, characterization, and influence of polyurea coatings on their layered composite materials based on flexible rebonded polyurethane
Authors: Temizkan Emir , Eroğlu Gülden , Ergün Ayça , Deligöz Hüseyin
Published: March 2021

Preparation and characterization of a series of polyurea (PU) coatings and their influences on layered composite materials based on rebonded polyurethane (PUr) for floor application are described in terms of the raw materials, formulation, and application performance. While PU coatings show almost the same FTIR peaks, thermogravimetric analyses results reveal that thermal stabilities of the PU coatings are slightly enhanced with the use of trifunctional polyamine compound and one step degradation takes place beyond 300°C. All PU coatings have very dense, smooth, and bubble‐free surfaces whereas the cross‐sectional SEM images exhibit pores of different sizes. Contact angle values of all PU coatings are bigger than 90° indicating that the surfaces are hydrophobic. Using propylene carbonate in the preparation of methylene diphenyl diisocyanate (MDI) prepolymer and the chain extender in the PU coating formulation impacts the mechanical and electrical properties of the PU coatings as well as layered PU/PUr composite materials. In conclusion, not only the controllable physicochemical and mechanical properties of layered PUr/PU composites but also the usage potential of recycled PU scraps in these layered composites are very promising for better floor applications.
Network analyses of associations between cancer‐related physical and psychological symptoms and quality of life in gastric cancer patients
Authors: Shim Eun‐Jung , Ha Hyeju , Suh Yun‐Suhk , Kong Seong‐Ho , Lee Hyuk‐Joon , Yang Han‐Kwang , Hahm Bong‐Jin
Published: March 2021

Objective

This study applied network analyses to illustrate patterns of associations between cancer‐related physical and psychological symptoms (CPPS) and quality of life (QOL) before and after surgery.

Methods

Participants consisted of 256 gastric cancer patients admitted for curative section surgery at the surgical department in a teaching hospital in Korea between May 2016 and November 2017. Participants completed the survey, including MD Anderson Symptom Inventory, Hospital Anxiety and Depression Scale, and Functional Assessment of Cancer Therapy‐Gastric Cancer before surgery (T0), 1 week after surgery (T1), and 3–6 months after surgery (T2).

Results

Three networks featured several salient connections with varying magnitudes between CPPS and QOL across all time points. Particularly, anxiety was tightly connected to emotional wellbeing (EWB) across all time points and physical wellbeing (PWB) at T1. On the other hand, depression was connected to functional wellbeing at T0 and T2, gastric cancer concerns (CS) at T1, and PWB at T2. Distress and sadness were the most central symptoms in the three networks. Other central symptoms included shortness of breath at T0, fatigue at T0 and T1, and PWB and CS at T2. Anxiety, depression, and EWB served as bridges connecting CPPS to QOL across all time points with varying degrees of importance, as did PWB at T1 and T2.

Conclusions

Treating psychological distress and enhancing EWB and PWB can be high impact intervention targets throughout the cancer trajectory.
Quality Assessment of In Situ Plasma‐Etched Diamond Surfaces for Chemical Vapor Deposition Overgrowth
Authors: Langer Julia , Cimalla Volker , Prescher Mario , Ligl Jana , Tegetmeyer Björn , Schreyvogel Christoph , Ambacher Oliver
Published: March 2021

In situ plasma etching is a common method to prepare diamond substrates for epitaxial overgrowth to effectuate higher quality. However, there is no feasible direct qualitative method established so far to assess the performance of the etching pretreatment. An optimization of the pretreatment process on grounds of high‐resolution X‐ray diffraction measurements is proposed to judge the structural quality gain of the diamond substrates and the effectiveness of the polishing‐induced subsurface damage removal. The obtained data shows that parameters such as thickness and misorientation angle of the diamond substrates seem to have no clear‐cut influence on the gain of structural quality. The process duration, however, is an important key factor when the amount of material removal and the arising roughness are discussed. Furthermore, the impact of the oxygen‐to‐hydrogen ratio is examined. With rising oxygen percentage, the structural quality gain remains similar; only the overall as well as local mean roughness increases strongly. Within the utilized reactor setup, the best results are obtained after a 20 min in situ hydrogen plasma‐etching step. The optimal pretreatment process, however, changes for each reactor type and will always embody a trade‐off. Due to the introduced method, a better evaluation and comparison of the achievements is accomplishable.
Quantitative Phase Prediction in Dual‐Phase High‐Entropy Alloys: Computationally Aided Parametric Approach
Authors: Singh Negi Ankit , Sourav Ayush , Heilmaier Martin , Biswas Somjeet , Thangaraju Shanmugasundaram
Published: March 2021

Dual‐phase high‐entropy alloys (HEAs) have shown remarkable mechanical properties. However, type and fraction of the secondary phase play a significant role in determining their physical and mechanical properties. CALPHAD is generally used to predict the phases and their fraction in HEAs. Herein, a parameter‐based empirical model is used to predict the phase fraction in dual‐phase HEAs. Valence electron concentration and various measures of atomic size mismatch are utilized for that purpose. A new parameter, namely, critical mismatch factor (, is proposed in this work. Experimental verification is done on a series of AlxCoCrFeNi (x = 0.3, 0.5, 0.7) alloys synthesized by vacuum arc melting. Phase fraction is determined by X‐ray diffraction and electron backscatter diffraction analysis. The experimentally determined volume fraction of BCC phase in Al0.3, Al0.5, and Al0.7 is 0%, 6%, and 28–37%, respectively, which agrees closely with the predicted values proving the chosen approach useful.
Benefits from sustainable development using bioplastics: A comparison between the food and fashion industries
Authors: Friedrich Daniel
Published: March 2021

The textile industry could become more sustainable by offering bioplastics‐based fashion. The question arises if another product category can serve as a benchmark, provided that the two industries are sufficiently similar in their business models. Therefore, an in‐depth empiric expert survey (n = 200) was carried out across sectors. For 20 items derived from the Industry‐Economics and Resource‐based Theory, the degree of consent was measured and by means of explorative factor analysis, the loadings were derived and put as weights for sector characterization. From this, the industry‐specific regression equation was established and finally, the item‐distribution was illustrated in a classification‐matrix, divided into retail‐sector and economic theory. The food sector is mainly market oriented in the plastics change, whereas clothing retailers tend to measure success in relation to company resources. Both saw bioplastics as a driver for new products, and for the textile industry it offers even more innovation potential. The demand for state intervention was also equally pronounced. All in all, it makes sense that fashion supply chains orient their transition on the food sector and achieve a change with bioplastics through differentiated and innovative products and, in particular, through strategic alliances with the retail industry.
Synergistic Additive‐Assisted Growth of 2D Ternary In2SnS4 with Giant Gate‐Tunable Polarization‐Sensitive Photoresponse
Authors: Zuo Nian , Nie Anmin , Hu Chunguang , Shen Wanfu , Jin Bao , Hu Xiaozong , Liu Zhongyuan , Zhou Xing , Zhai Tianyou
Published: March 2021

2D ternary materials exhibit great promise in the field of polarization‐sensitive photodetectors due to the low‐symmetry crystal structure. However, the realization of ternary material growth is still a huge challenge because of the complex reaction process. Here, for the first time, 2D ternary In2SnS4 flakes are obtained via synergistic additive of salt and molecular sieve‐assisted chemical vapor deposition. Raman vibration mode of In2SnS4 flakes exhibits polarization‐dependent properties. The polarization‐resolved absorption spectroscopy and azimuth‐dependent reflectance difference microscopy further confirm its anisotropy of in‐plane optical absorption and reflection. Besides, the In2SnS4 flake based device on mica shows ultrafast rising and decay rates of ≈20 and 20 µs. Impressively, In2SnS4 flake based phototransistor demonstrates giant gate‐tunable polarization‐sensitive photoresponse: the dichroic ratio can be adjusted in the range of 1.13–1.70 with gate voltage varying from −35–35 V. This work provides an effective means for modulating the polarization‐sensitive photoresponse, which may significantly promote the research progress of polarization‐sensitive photodetectors.
Biomimetic Nanozymes Based on Coassembly of Amino Acid and Hemin for Catalytic Oxidation and Sensing of Biomolecules
Authors: Geng Rui , Chang Rui , Zou Qianli , Shen Guizhi , Jiao Tifeng , Yan Xuehai
Published: March 2021

Nanoassemblies based on self‐assembly of biological building blocks are promising in mimicking the nanostructures, properties, and functionalities of natural enzymes. However, it remains a challenge to design of biomimetic nanozymes with tunable nanostructures and enhanced catalytic activities starting from simple biomolecules. Herein, the construction of nanoassemblies through coassembly of an amphiphilic amino acid and hemin is reported. The nanostructures and morphologies of the resulting nanoassemblies are readily controlled by tuning the molar ratio between the amino acid and hemin, thus leading to tailored peroxidase‐mimicking activities of the nanoassemblies. Importantly, the optimized nanoassemblies exhibit a remarkable catalytic efficiency that is comparable to the natural counterpart when considering molecular mass along with good robustness in multiple catalytic cycles. The nanoassemblies are effectively integrated as biomimetic nanozymes in a sensing system for catalytic detection of glucose. Therefore, this work demonstrates that nanozymes with advanced catalytic capabilities can be constructed by self‐assembly of minimalist biological building blocks and may thus promote the rational design and catalytic applications of biomimetic nanozymes.
Strategies to Improve Luminescence Efficiency and Stability of Blue Perovskite Light‐Emitting Devices
Authors: Qian Xiao-Yan , Tang Ying-Yi , Zhou Wei , Shen Yang , Guo Ming-Lei , Li Yan-Qing , Tang Jian-Xin
Published: March 2021

Metal halide perovskite materials hold great potential as a core element in full‐color display and lighting applications due to their unique optoelectronic properties, such as high photoluminescence efficiency, good color purity, tunable bandgap, and low‐temperature solution processability. However, the performance of blue perovskite light‐emitting diodes (PeLEDs) lags far behind their red and green counterparts, impeding their practical use. Herein, the recent progress on blue PeLEDs based on different restrictions and some feasible strategies to improve luminescence efficiency and stability are summarized. The methods to optimize blue‐emission perovskite materials with different dimensions are addressed. The major factors affecting luminescence stability, the approaches to balance charge injection and minimize the optical loss are also discussed. Several problems in blue PeLEDs, particularly the toxicity of lead‐based perovskites and the alternative solutions of lead‐free perovskites, are emphasized. Finally, the perspective of future development in blue PeLEDs is provided.
Understanding Performance Limitations of Cu(In,Ga)Se2 Solar Cells due to Metastable Defects—A Route toward Higher Efficiencies
Authors: Weiss Thomas Paul , Ehre Florian , Serrano-Escalante Valentina , Wang Taowen , Siebentritt Susanne
Published: March 2021

Thin‐film Cu(In,Ga)Se2 solar cells reach power conversion efficiencies exceeding 23% and nonradiative recombination in the bulk is reported to limit device performance. The diode factor has not received much attention, although it limits the fill factor, and therefore the efficiency, for state‐of‐the‐art solar cells. Herein, the diode factor of Cu(In,Ga)Se2 absorbers, measured by photoluminescence spectroscopy, and of solar cells, measured by current–voltage and capacitance–voltage characteristics, are compared, supported by simulations using rate equations of generation and recombination. It is found that the diode factor is already increased in the neutral zone of the absorber due to metastable defects, such as the VSe–VCu defect found in Cu(In,Ga)Se2, because of an increased net acceptor density upon minority‐carrier injection. The metastable and persistent increase of the net acceptor density has a detrimental effect on the device performance. Diode factors of 1 and efficiencies exceeding 24% are expected when, in current state‐of‐the‐art Cu(In,Ga)Se2 solar cells, the formation of metastable defects is suppressed.
Characterization of Mechanical Properties, Macroscopic Deformation Behavior, and Microstructure of Functionally Graded 22MnB5 Steel
Authors: Scharifi Emad , Schade Thomas , Ademaj Agim , Sajadifar Seyed Vahid , Weidig Ursula , Niendorf Thomas , Steinhoff Kurt
Published: March 2021

The focus of this study is on the characterization of the local plastic deformation and failure of functionally graded 22MnB5 plates after hot stamping using an in situ approach. Various forming strategies at elevated temperatures are performed using differentially tempered forming tools to locally tailor the microstructure. By controlling the cooling rate, graded as well as martensitic and ferritic–pearlitic microstructures are obtained. Experimental analysis includes evaluation of the material‐ and geometry‐dependent local strain evolution by tensile tests coupled with digital image correlation conducted on two different sample geometries, tapered and nontapered. Experimental results reveal a much more complex deformation behavior for the functionally graded than for homogenous samples. As expected, the distribution of plastic strain of the graded sample is depending on the mixture of its constituting microstructures; however, different types of localized failure after necking are found. Obviously, failure evolution also depends on the sample geometry. Failure patterns observed include shear bands, crossed bands, or homogenous localization of strain, i.e., traditional necking. Eventually, in the case of the nontapered geometry, a lower level of local plastic strain with multiple necking sites is observed. Based on findings presented, detailed process‐microstructure‐property‐damage relationships are established.
Influence of Microalloying Elements and Deformation Parameters on the Recrystallization and Precipitation Behavior of Two Low‐Alloyed Steels
Authors: Monschein Stefan , Kapp Marlene , Zügner Dominik , Fasching Josef , Landefeld Andreas , Schnitzer Ronald
Published: March 2021

The alloy design of modern high‐strength low‐alloy (HSLA) steels aims for a well‐balanced combination of high toughness and strength. Using niobium and titanium as microalloying elements together with thermomechanical processing is a common way to obtain a fine‐grained microstructure and therefore enhance the strength and toughness of HSLA steels. Herein, a low‐alloyed steel and a microalloyed HSLA steel are investigated in the as‐rolled condition and by double‐hit experiments using various deformation parameters. Atom probe tomography, scanning transmission electron microscopy inside a scanning electron microscope, transmission kikuchi diffraction, and energy‐dispersive X‐ray spectroscopy are used to investigate the precipitates in the as‐rolled condition and after deformation. It is shown that Nb‐enriched TiN precipitates with an average size of around 15 nm are responsible for grain refinement in the as‐rolled condition. The annealing temperature prior to the rolling process is set below the solution temperature of Nb(C,N). Enhancing the annealing temperature in the double‐hit deformation tests above the solution temperature of Nb(C,N) leads to the precipitation of fine NbC precipitates with a size of around 5 nm. These precipitates are responsible for inhibited static recrystallization behavior.
Electrochemical Sensing Platforms of Dihydroxybenzene: Part 1 – Carbon Nanotubes, Graphene, and their Derivatives
Authors: Abu Nayem S. M. , Shaheen Shah Syed , Sultana Nasrin , Aziz Md. Abdul , Saleh Ahammad A. J.
Published: March 2021

Dihydroxybenzene is regarded as a serious environmental pollutant. Its detection through electrochemical methods is still challenging due to having a similar structure and overlapping signals with the conventional bare electrode. Thanks to the unique features and wide applicability of carbon nanotubes, graphene, and their derivatives, they can be used as modifiers to overcome the poor resolution ability of bare electrodes in the detection of dihydroxybenzene. This review focuses on the use of carbon nanotubes, graphene, and their derivatives and nanocomposites to enhance the electrocatalytic activity of conventional bare electrodes for dihydroxybenzene sensing. The reports from 2011–2020 on the simultaneous and/or individual detection of three different dihydroxybenzenes – hydroquinone, catechol, and resorcinol – are summarized. This review also highlights the challenges and prospects surrounding the sensitive and selective detection of dihydroxybenzene.
Safety and efficacy of sargramostim (GM‐CSF) in the treatment of Alzheimer's disease
Authors: Potter Huntington , Woodcock Jonathan H. , Boyd Timothy D. , Coughlan Christina M. , O'Shaughnessy John R. , Borges Manuel T. , Thaker Ashesh A. , Raj Balaibail A. , Adamszuk Katarzyna , Scott David , Adame Vanesa , Anton Paige , Chial Heidi J. , Gray Helen , Daniels Joseph , Stocker Michelle E. , Sillau Stefan H.
Published: March 2021

Introduction

Inflammatory markers have long been observed in the brain, cerebrospinal fluid (CSF), and plasma of Alzheimer's disease (AD) patients, suggesting that inflammation contributes to AD and might be a therapeutic target. However, non‐steroidal anti‐inflammatory drug trials in AD and mild cognitive impairment (MCI) failed to show benefit. Our previous work seeking to understand why people with the inflammatory disease rheumatoid arthritis are protected from AD found that short‐term treatment of transgenic AD mice with the pro‐inflammatory cytokine granulocyte‐macrophage colony‐stimulating factor (GM‐CSF) led to an increase in activated microglia, a 50% reduction in amyloid load, an increase in synaptic area, and improvement in spatial memory to normal. These results called into question the consensus view that inflammation is solely detrimental in AD. Here, we tested our hypothesis that modulation of the innate immune system might similarly be used to treat AD in humans by investigating the ability of GM‐CSF/sargramostim to safely ameliorate AD symptoms/pathology.

Methods

A randomized, double‐blind, placebo‐controlled trial was conducted in mild‐to‐moderate AD participants (NCT01409915). Treatments (20 participants/group) occurred 5 days/week for 3 weeks plus two follow‐up (FU) visits (FU1 at 45 days and FU2 at 90 days) with neurological, neuropsychological, blood biomarker, and imaging assessments.

Results

Sargramostim treatment expectedly changed innate immune system markers, with no drug‐related serious adverse events or amyloid‐related imaging abnormalities. At end of treatment (EOT), the Mini‐Mental State Examination score of the sargramostim group increased compared to baseline (P = .0074) and compared to placebo (P = .0370); the treatment effect persisted at FU1 (P = .0272). Plasma markers of amyloid beta (Aβ40 [decreased in AD]) increased 10% (P = .0105); plasma markers of neurodegeneration (total tau and UCH‐L1) decreased 24% (P = .0174) and 42% (P = .0019), respectively, after sargramostim treatment compared to placebo.

Discussion

The innate immune system is a viable target for therapeutic intervention in AD. An extended treatment trial testing the long‐term safety and efficacy of GM‐CSF/sargramostim in AD is warranted.