bluuebunny/crossref_metadata_2025 huggingface dataset:
EEG Data Quality: Determinants and Impact in a Multicenter Study of Children, Adolescents, and Adults with Attention-Deficit/Hyperactivity Disorder (ADHD)
Authors: Kaiser Anna , Aggensteiner Pascal-M. , Holtmann Martin , Fallgatter Andreas , Romanos Marcel , Abenova Karina , Alm Barbara , Becker Katja , Döpfner Manfred , Ethofer Thomas , Freitag Christine , Geissler Julia , Hebebrand Johannes , Huss Michael , Jans Thomas , Jendreizik Lea , Ketter Johanna , Legenbauer Tanja , Philipsen Alexandra , Poustka Luise , Renner Tobias , Retz Wolfgang , Rösler Michael , Thome Johannes , Uebel-von Sandersleben Henrik , von Wirth Elena , Zinnow Toivo , Hohmann Sarah , Millenet Sabina , Holz Nathalie , Banaschewski Tobias , Brandeis Daniel ,   on behalf of the ESCAlife-Consortium
Published: February 2021

Electroencephalography (EEG) represents a widely established method for assessing altered and typically developing brain function. However, systematic studies on EEG data quality, its correlates, and consequences are scarce. To address this research gap, the current study focused on the percentage of artifact-free segments after standard EEG pre-processing as a data quality index. We analyzed participant-related and methodological influences, and validity by replicating landmark EEG effects. Further, effects of data quality on spectral power analyses beyond participant-related characteristics were explored. EEG data from a multicenter ADHD-cohort (age range 6 to 45 years), and a non-ADHD school-age control group were analyzed (ntotal = 305). Resting-state data during eyes open, and eyes closed conditions, and task-related data during a cued Continuous Performance Task (CPT) were collected. After pre-processing, general linear models, and stepwise regression models were fitted to the data. We found that EEG data quality was strongly related to demographic characteristics, but not to methodological factors. We were able to replicate maturational, task, and ADHD effects reported in the EEG literature, establishing a link with EEG-landmark effects. Furthermore, we showed that poor data quality significantly increases spectral power beyond effects of maturation and symptom severity. Taken together, the current results indicate that with a careful design and systematic quality control, informative large-scale multicenter trials characterizing neurophysiological mechanisms in neurodevelopmental disorders across the lifespan are feasible. Nevertheless, results are restricted to the limitations reported. Future work will clarify predictive value.
Influence of Systematic Gaze Patterns in Navigation and Search Tasks with Simulated Retinitis Pigmentosa
Authors: Neugebauer Alexander , Stingl Katarina , Ivanov Iliya , Wahl Siegfried
Published: February 2021

People living with a degenerative retinal disease such as retinitis pigmentosa are oftentimes faced with difficulties navigating in crowded places and avoiding obstacles due to their severely limited field of view. The study aimed to assess the potential of different patterns of eye movement (scanning patterns) to (i) increase the effective area of perception of participants with simulated retinitis pigmentosa scotoma and (ii) maintain or improve performance in visual tasks. Using a virtual reality headset with eye tracking, we simulated tunnel vision of 20° in diameter in visually healthy participants (n = 9). Employing this setup, we investigated how different scanning patterns influence the dynamic field of view—the average area over time covered by the field of view—of the participants in an obstacle avoidance task and in a search task. One of the two tested scanning patterns showed a significant improvement in both dynamic field of view (navigation 11%, search 7%) and collision avoidance (33%) when compared to trials without the suggested scanning pattern. However, participants took significantly longer (31%) to finish the navigation task when applying this scanning pattern. No significant improvements in search task performance were found when applying scanning patterns.
Quality of Life: Changes in Self-Perception in People with down Syndrome as a Result of Being Part of a Football/Soccer Team. Self-Reports and External Reports
Authors: Camacho Rocío , Castejón-Riber Cristina , Requena Francisco , Camacho Julio , Escribano Begoña , Gallego Arturo , Espejo Roberto , De Miguel-Rubio Amaranta , Agüera Estrella
Published: February 2021

The hypothesis posed was whether being part of a football/soccer team influenced the quality of life (QL) of the people who participated in it since their perception of themselves is enhanced by factors, such as self-determination, social inclusion, emotional well-being, physical well-being, material well-being, rights, personal development, and internal relationships. The objective was to evaluate the QL of people with Down Syndrome (DS) using their self-perception (n = 39) and the perception of the informants (family members, teachers) (n = 39). The KidsLife-Down Scale, with a few modifications, was used. In general, differences of opinion between the subgroups of participants with DS and informants showed that results were higher in terms of perception for participants in the DS subgroup. Scores for all variables were higher for those participants with DS who said they did engage in practicing competitive football/soccer. Although the perception of informants provides a great deal of information regarding the QL of participants with DS, participants with DS should also be involved in the evaluation process and their self-perceptions taken into account. It is not participating in a football team that causes the conclusions of the study, but training (which includes the friendly matches that are played), the cause correlated with the improvements detected in the athlete’s DS.
A Comparative Study on the Influence of Nano and Micro Particles on the Workability and Mechanical Properties of Mortar Supplemented with Fly Ash
Authors: Seifan Mostafa , Mendoza Shaira , Berenjian Aydin
Published: February 2021

In this study, the effects of micro-Al2O3 (MA) and nano-Al2O3 (NA) on the mechanical properties and durability performance of a mortar containing fly ash (FA) were investigated. In the first step, MA and NA were added to the mortar (as a cement replacement) at dosages of 0%, 5%, 10% and 15% by weight. The flowability of the mixture containing NA and MA showed a dosage-dependent behavior, and the addition of MA resulted in a higher flow spread compared with NA. The flow spread increased at 5% (for both NA and MA), and a further increase in the particle content to 10% and 15% decreased the flow spread value. Although the presence of MA and NA contributed to increasing the compressive strength as the particle content increased, the addition of NA resulted in a greater increase in compressive strength (40% increase when adding 15% of NA). The highest splitting tensile strength was obtained when 10% NA was used, and a further increase in the particle content decreased the splitting tensile strength. In the optimization step, the effect of a binder replacement with FA (10, 20 and 30%) in the presence of 10% NA as the optimum level of additive was investigated. Generally, the addition of FA decreased the compressive strength. The highest drop in compressive strength was noticed at early ages, and there was no significant difference in strength development from 14 days to 28 days. A decreasing trend in the splitting tensile strength was observed with the addition of FA content.
SWATH-MS Based Proteomic Profiling of Prostate Cancer Cells Reveals Adaptive Molecular Mechanisms in Response to Anti-Androgen Therapy
Authors: Liyanage Chamikara , Malik Adil , Abeysinghe Pevindu , Clements Judith , Batra Jyotsna
Published: February 2021

Prostate cancer (PCa) is the second most common cancer affecting men worldwide. PCa shows a broad-spectrum heterogeneity in its biological and clinical behavior. Although androgen targeted therapy (ATT) has been the mainstay therapy for advanced PCa, it inevitably leads to treatment resistance and progression to castration resistant PCa (CRPC). Thus, greater understanding of the molecular basis of treatment resistance and CRPC progression is needed to improve treatments for this lethal phenotype. The current study interrogated both proteomics and transcriptomic alterations stimulated in AR antagonist/anti-androgen (Bicalutamide and Enzalutamide) treated androgen-dependent cell model (LNCaP) in comparison with androgen-independent/castration-resistant cell model (C4-2B). The analysis highlighted the activation of MYC and PSF/SFPQ oncogenic upstream regulators in response to the anti-androgen treatment. Moreover, the study revealed anti-androgen induced genes/proteins related to transcription/translation regulation, energy metabolism, cell communication and signaling cascades promoting tumor growth and proliferation. In addition, these molecules were found dysregulated in PCa clinical proteomic and transcriptomic datasets, suggesting their potential involvement in PCa progression. In conclusion, our study provides key molecular signatures and associated pathways that might contribute to CRPC progression despite treatment with anti-androgens. Such molecular signatures could be potential therapeutic targets to improve the efficacy of existing therapies and/or predictive/prognostic value in CRPC for treatment response.
Progression to Metastasis of Solid Cancer
Authors: Zacksenhaus Eldad , Egan Sean E.
Published: February 2021

Metastatic dissemination of cancer cells, their colonization at distal sites, and ultimate disruption of tissue physiology are the root causes of most deaths from solid cancers, particularly in tumor types where the primary lesion can be easily dissected and discarded [...]
Metabolomic Biomarkers for the Detection of Obesity-Driven Endometrial Cancer
Authors: Njoku Kelechi , Campbell Amy E. , Geary Bethany , MacKintosh Michelle L. , Derbyshire Abigail E. , Kitson Sarah J. , Sivalingam Vanitha N. , Pierce Andrew , Whetton Anthony D. , Crosbie Emma J.
Published: February 2021

Endometrial cancer is the most common malignancy of the female genital tract and a major cause of morbidity and mortality in women. Early detection is key to ensuring good outcomes but a lack of minimally invasive screening tools is a significant barrier. Most endometrial cancers are obesity-driven and develop in the context of severe metabolomic dysfunction. Blood-derived metabolites may therefore provide clinically relevant biomarkers for endometrial cancer detection. In this study, we analysed plasma samples of women with body mass index (BMI) ≥ 30 kg/m2 and endometrioid endometrial cancer (cases, n = 67) or histologically normal endometrium (controls, n = 69), using a mass spectrometry-based metabolomics approach. Eighty percent of the samples were randomly selected to serve as a training set and the remaining 20% were used to qualify test performance. Robust predictive models (AUC > 0.9) for endometrial cancer detection based on artificial intelligence algorithms were developed and validated. Phospholipids were of significance as biomarkers of endometrial cancer, with sphingolipids (sphingomyelins) discriminatory in post-menopausal women. An algorithm combining the top ten performing metabolites showed 92.6% prediction accuracy (AUC of 0.95) for endometrial cancer detection. These results suggest that a simple blood test could enable the early detection of endometrial cancer and provide the basis for a minimally invasive screening tool for women with a BMI ≥ 30 kg/m2.
Metformin Reduces Histone H3K4me3 at the Promoter Regions of Positive Cell Cycle Regulatory Genes in Lung Cancer Cells
Authors: Kim Dongho , Kim Yujin , Lee Bo Bin , Cho Eun Yoon , Han Joungho , Shim Young Mog , Kim Duk-Hwan
Published: February 2021

This study aimed at understanding the effect of metformin on histone H3 methylation, DNA methylation, and chromatin accessibility in lung cancer cells. Metformin significantly reduced H3K4me3 level at the promoters of positive cell cycle regulatory genes such as CCNB2, CDK1, CDK6, and E2F8. Eighty-eight genes involved in cell cycle showed reduced H3K4me3 levels in response to metformin, and 27% of them showed mRNA downregulation. Metformin suppressed the expression of H3K4 methyltransferases MLL1, MLL2, and WDR82. The siRNA-mediated knockdown of MLL2 significantly downregulated global H3K4me3 level and inhibited lung cancer cell proliferation. MLL2 overexpression was found in 14 (33%) of 42 NSCLC patients, and a Cox proportional hazards analysis showed that recurrence-free survival of lung adenocarcinoma patients with MLL2 overexpression was approximately 1.32 (95% CI = 1.08–4.72; p = 0.02) times poorer than in those without it. Metformin showed little effect on DNA methylation and chromatin accessibility at the promoter regions of cell cycle regulatory genes. The present study suggests that metformin reduces H3K4me3 levels at the promoters of positive cell cycle regulatory genes through MLL2 downregulation in lung cancer cells. Additionally, MLL2 may be a potential therapeutic target for reducing the recurrence of lung adenocarcinoma.
Myosin Motors: Novel Regulators and Therapeutic Targets in Colorectal Cancer
Authors: Naydenov Nayden , Lechuga Susana , Huang Emina , Ivanov Andrei
Published: February 2021

Colorectal cancer (CRC) remains the third most common cause of cancer and the second most common cause of cancer deaths worldwide. Clinicians are largely faced with advanced and metastatic disease for which few interventions are available. One poorly understood aspect of CRC involves altered organization of the actin cytoskeleton, especially at the metastatic stage of the disease. Myosin motors are crucial regulators of actin cytoskeletal architecture and remodeling. They act as mechanosensors of the tumor environments and control key cellular processes linked to oncogenesis, including cell division, extracellular matrix adhesion and tissue invasion. Different myosins play either oncogenic or tumor suppressor roles in breast, lung and prostate cancer; however, little is known about their functions in CRC. This review focuses on the functional roles of myosins in colon cancer development. We discuss the most studied class of myosins, class II (conventional) myosins, as well as several classes (I, V, VI, X and XVIII) of unconventional myosins that have been linked to CRC development. Altered expression and mutations of these motors in clinical tumor samples and their roles in CRC growth and metastasis are described. We also evaluate the potential of using small molecular modulators of myosin activity to develop novel anticancer therapies.
Delayed Surgery after Neoadjuvant Treatment for Rectal Cancer Does Not Lead to Impaired Quality of Life, Worry for Cancer, or Regret
Authors: Meyer Vincent Maurice , Meuzelaar Richtje R , Schoenaker Yvonne , de Groot Jan-Willem , de Boer Edwin , Reerink Onno , de Vos tot Nederveen Cappel Wouter , Beets Geerard L , van Westreenen Henderik L
Published: February 2021

Non operative management of complete clinical responders after neoadjuvant treatment for rectal cancer enjoys an increasing popularity because of the increased functional outcome results. Even a near complete response can evolve in a cCR, and therefore further delaying response assessment is accepted. However, up to 40% of patients will develop a regrowth and will eventually require delayed surgery. It is presently unknown if and to what extent quality of life of these patients is affected, compared to patients who undergo immediate surgery. Between January 2015-May 2020, 200 patients were treated with neoadjuvant therapy of whom 94 received TME surgery. Fifty-one (59%) of 87 alive patients returned the questionnaires: 33 patients who underwent immediate and 18 patients who underwent delayed surgery. Quality of life was measured through the QLQ-C30, QLQ-CR29, and Cancer Worry Scale questionnaires. Regret to participate in repeated response assessment protocol was assessed through the Decision Regret Scale. Exploratory factor analysis (EFA) and a ‘known groups comparison’ was performed to assess QLQ questionnaires validity in this sample. Higher mean physical function scores (89.2 vs. 77.6, p = 0.03) were observed in the immediate surgery group, which lost significance after correction for operation type (p = 0.25). Arousal for men was higher in the delayed surgery group (20.0 vs. 57.1, p = 0.02). There were no differences between surgical groups for the other questionnaire items. Worry for cancer was lower in the delayed surgery group (10.8 vs. 14.0, p = 0.21). Regret was very low (12–16%). EFA reproduced most QLQ C-30 and CR29 subscales with good internal consistency. Quality of life is not impaired in patients undergoing delayed TME surgery after neoadjuvant treatment for rectal cancer. Moreover, there is very low regret and no increase in worry for cancer. Therefore, from a quality of life perspective, this study supports a repeated response assessment strategy after CRTx for rectal carcinoma to identify all complete responders.
Linking Metabolic Reprogramming, Plasticity and Tumor Progression
Authors: Shuvalov Oleg , Daks Alexandra , Fedorova Olga , Petukhov Alexey , Barlev Nickolai
Published: February 2021

The specific molecular features of cancer cells that distinguish them from the normal ones are denoted as “hallmarks of cancer”. One of the critical hallmarks of cancer is an altered metabolism which provides tumor cells with energy and structural resources necessary for rapid proliferation. The key feature of a cancer-reprogrammed metabolism is its plasticity, allowing cancer cells to better adapt to various conditions and to oppose different therapies. Furthermore, the alterations of metabolic pathways in malignant cells are heterogeneous and are defined by several factors including the tissue of origin, driving mutations, and microenvironment. In the present review, we discuss the key features of metabolic reprogramming and plasticity associated with different stages of tumor, from primary tumors to metastases. We also provide evidence of the successful usage of metabolic drugs in anticancer therapy. Finally, we highlight new promising targets for the development of new metabolic drugs.
A Hybrid Microbial–Enzymatic Fuel Cell Cathode Overcomes Enzyme Inactivation Limits in Biological Fuel Cells
Authors: Evans John Parker , Gervasio Dominic F. , Pryor Barry M.
Published: February 2021

The construction of optimized biological fuel cells requires a cathode which combines the longevity of a microbial catalyst with the current density of an enzymatic catalyst. Laccase-secreting fungi were grown directly on the cathode of a biological fuel cell to facilitate the exchange of inactive enzymes with active enzymes, with the goal of extending the lifetime of laccase cathodes. Directly incorporating the laccase-producing fungus at the cathode extends the operational lifetime of laccase cathodes while eliminating the need for frequent replenishment of the electrolyte. The hybrid microbial–enzymatic cathode addresses the issue of enzyme inactivation by using the natural ability of fungi to exchange inactive laccases at the cathode with active laccases. Finally, enzyme adsorption was increased through the use of a functionally graded coating containing an optimized ratio of titanium dioxide nanoparticles and single-walled carbon nanotubes. The hybrid microbial–enzymatic fuel cell combines the higher current density of enzymatic fuel cells with the longevity of microbial fuel cells, and demonstrates the feasibility of a self-regenerating fuel cell in which inactive laccases are continuously exchanged with active laccases.
Generation of a Highly Efficient Electrode for Ethanol Oxidation by Simply Electrodepositing Palladium on the Oxygen Plasma-Treated Carbon Fiber Paper
Authors: Pei Houg-Yuan , Lin Chen-Han , Lin Wei , Yuan Chiun-Jye
Published: February 2021

In this study, a highly efficient carbon-supported Pd catalyst for the direct ethanol fuel cell was developed by electrodepositing nanostructured Pd on oxygen plasma-treated carbon fiber paper (Pd/pCFP). The oxygen plasma treatment has been shown to effectively remove the surface organic contaminants and add oxygen species onto the CFP to facilitate the deposition of nano-structured Pd on the surface of carbon fibers. Under the optimized and controllable electrodeposition method, nanostructured Pd of ~10 nm can be easily and evenly deposited onto the CFP. The prepared Pd/pCFP electrode exhibited an extraordinarily high electrocatalytic activity towards ethanol oxidation, with a current density of 222.8 mA mg−1 Pd. Interestingly, the electrode also exhibited a high tolerance to poisoning species and long-term stability, with a high ratio of the forward anodic peak current density to the backward anodic peak current density. These results suggest that the Pd/pCFP catalyst may be a promising anodic material for the development of highly efficient direct alcohol fuel cells.
Net-Patterned Fluorine-Doped Tin Oxide to Accelerate the Electrochromic and Photocatalytic Interface Reactions
Authors: Jeong Seock-Joon , Kim Kue-Ho , Ahn Hyo-Jin
Published: February 2021

In this study, the surface morphology of net-patterned fluorine-doped tin oxide (FTO) films was optimized with mesh sizes (60 mesh, 40 mesh, and 24 mesh) using the one-pot horizontal ultrasonic spray pyrolysis deposition (HUSPD) process. The 40M-FTO sample exhibited optimized electrical and optical properties due to the improved crystallinity and net-patterned surface morphology of FTO. The electrochromic (EC) electrodes fabricated with 40M-FTO showed superior EC performance, including transmittance modulation (ΔT, 58.7%), switching speeds (4.1 s for coloration and 5.9 s for bleaching), and coloration efficiency (CE, 52.4 cm2/C). These optimum values were attributed to the combined effect of the enhanced electrical properties from the improved crystallinity of the SnO2 and the high transmittance with a large surface area stemming from the optimization of the net-patterned FTO surface morphology. Moreover, the improved reaction sites with large surface area and enhanced electrical conductivity can facilitate the photocatalytic reaction. Accordingly, we suggest our novel strategy for use in creating promising transparent conducting electrodes that can be fabricated with net-patterned FTO to realize enhanced electrochromic and photocatalytic interface reactions.
Post-Transcriptional Regulation of PARP7 Protein Stability Is Controlled by Androgen Signaling
Authors: Kamata Teddy , Yang Chun-Song , Melhuish Tiffany A. , Frierson Jr. Henry F. , Wotton David , Paschal Bryce M.
Published: February 2021

Poly-ADP-ribose polymerases (PARPs) are enzymes that catalyze ADP-ribosylation and play critical roles in normal and disease settings. The PARP family member, PARP7, is a mono-ADP-ribosyltransferase that has been suggested to play a tumor suppressive role in breast, ovarian, and colorectal cancer. Here, we have investigated how androgen signaling regulates PARP7 homeostasis in prostate cancer cells, where PARP7 is a direct target gene of AR. We found that the PARP7 protein is extremely short-lived, with a half-life of 4.5 min. We show that in addition to its transcriptional regulation by AR, PARP7 is subject to androgen-dependent post-transcriptional regulation that increases its half-life to 25.6 min. This contrasts with PARP1, PARP2, PARP9, and PARP14, which do not display rapid turnover and are not regulated by androgen signaling. Androgen- and AR-dependent stabilization of PARP7 leads to accumulation in the nucleus, which we suggest is a major site of action. Mutations in the catalytic domain, the Cys3His1 zinc finger, and WWE (tryptophan–tryptophan–glutamate) domains in PARP7 each reduce the degradation rate of PARP7, suggesting the overall structure of the protein is tuned for its rapid turnover. Our finding that PARP7 is regulated by AR signaling both transcriptionally and post-transcriptionally in prostate cancer cells suggests the dosage of PARP7 protein is subject to tight regulation.
Proteomic Adaptation of Clostridioides difficile to Treatment with the Antimicrobial Peptide Nisin
Authors: Maaß Sandra , Bartel Jürgen , Mücke Pierre-Alexander , Schlüter Rabea , Sura Thomas , Zaschke-Kriesche Julia , Smits Sander H. J. , Becher Dörte
Published: February 2021

Clostridioides difficile is the leading cause of antibiotic-associated diarrhea but can also result in more serious, life-threatening conditions. The incidence of C. difficile infections in hospitals is increasing, both in frequency and severity, and antibiotic-resistant C. difficile strains are advancing. Against this background antimicrobial peptides (AMPs) are an interesting alternative to classic antibiotics. Information on the effects of AMPs on C. difficile will not only enhance the knowledge for possible biomedical application but may also provide insights into mechanisms of C. difficile to adapt or counteract AMPs. This study applies state-of-the-art mass spectrometry methods to quantitatively investigate the proteomic response of C. difficile 630∆erm to sublethal concentrations of the AMP nisin allowing to follow the cellular stress adaptation in a time-resolved manner. The results do not only point at a heavy reorganization of the cellular envelope but also resulted in pronounced changes in central cellular processes such as carbohydrate metabolism. Further, the number of flagella per cell was increased during the adaptation process. The potential involvement of flagella in nisin adaptation was supported by a more resistant phenotype exhibited by a non-motile but hyper-flagellated mutant.
Myocyte Enhancer Factor 2C as a New Player in Human Breast Cancer Brain Metastases
Authors: Galego Sofia , Kauppila Linda Azevedo , Malhó Rui , Pimentel José , Brito Maria Alexandra
Published: February 2021

Myocyte enhancer factor 2C (MEF2C) is increasingly expressed in mice along with breast cancer brain metastases (BCBM) development. We aim to ascertain MEF2C expression in human BCBM, establish the relationship with disease severity, disclose the involvement of vascular endothelial growth factor receptor-2 (VEGFR-2) and β-catenin, also known as KDR and CTNNB1, respectively, and investigate if matched primary tumors express the protein. We studied resected BCBM for the expression of MEF2C, VEGFR-2, and ß-catenin, as well as proliferation (Ki-67) and epithelial (pan Cytokeratin) markers, and related experimental and clinical data. MEF2C expression was further assessed in matched primary tumors and non-BCBM samples used as controls. MEF2C expression was observed in BCBM, but not in controls, and was categorized into three phenotypes (P): P1, with extranuclear location; P2, with extranuclear and nuclear staining, and P3, with nuclear location. Nuclear translocation increased with metastases extension and Ki-67-positive cells number. P1 was associated with higher VEFGR-2 plasma membrane immunoreactivity, whereas P2 and P3 were accompanied by protein dislocation. P1 was accompanied by β-catenin membrane expression, while P2 and P3 exhibited β-catenin nuclear translocation. Primary BC samples expressed MEF2C in mammary ducts and scattered cells in the parenchyma. MEF2C emerges as a player in BCBM associated with disease severity and VEGFR-2 and β-catenin signaling.
Human Placenta Buffers the Fetus from Adverse Effects of Perceived Maternal Stress
Authors: Vuppaladhadiam Lahari , Lager Jeannette , Fiehn Oliver , Weiss Sandra , Chesney Margaret , Hasdemir Burcu , Bhargava Aditi
Published: February 2021

Maternal stress during pregnancy is linked to several negative birth outcomes. The placenta, a unique pregnancy-specific organ, not only nourishes and protects the fetus but is also the major source of progesterone and estrogens. As the placenta becomes the primary source of maternal progesterone (P4) and estradiol between 6–9 weeks of gestation, and these hormones are critical for maintaining pregnancy, maternal stress may modulate levels of these steroids to impact birth outcomes. The objective was to test whether maternal perceived stress crosses the placental barrier to modulate fetal steroids, including cortisol, which is a downstream indicator of maternal hypothalamic–pituitary–adrenal (HPA) axis regulation and is associated with negative fetal outcomes. Nulliparous women, 18 years or older, with no known history of adrenal or endocrine illness were recruited during their third trimester of pregnancy at the University of California San Francisco (UCSF) Mission Bay hospital obstetrics clinics. Simultaneous measurement of 10 steroid metabolites in maternal (plasma and hair) and fetal (cord blood and placenta) samples was performed using tandem mass spectrometry along with assessment of the perceived stress score and sociodemographic status. While the maternal perceived stress score (PSS) and sociodemographic status were positively associated with each other and each with the body mass index (BMI) (r = 0.73, p = 0.0008; r = 0.48, p = 0.05; r = 0.59, p = 0.014, respectively), PSS did not correlate with maternal or fetal cortisol, cortisone levels, or fetal birth weight. Regardless of maternal PSS or BMI, fetal steroid levels remained stable and unaffected. Progesterone was the only steroid analyte quantifiable in maternal hair and correlated positively with PSS (r = 0.964, p = 0.003), whereas cord estradiol was negatively associated with PSS (r = −0.94, p = 0.017). In conclusion, hair progesterone might serve as a better marker of maternal stress than cortisol or cortisone and maternal PSS negatively impacts fetal estradiol levels. Findings have implications for improved biomarkers of stress and targets for future research to identify factors that buffer the fetus from adverse effects of maternal stress.
The NFKB1 Promoter Polymorphism (-94ins/delATTG) Is Associated with Susceptibility to Cytomegalovirus Infection after Kidney Transplantation and Should Have Implications on CMV Prophylaxis Regimens
Authors: Nowak Hartmuth , Vornweg Svenja , Rump Katharina , Rahmel Tim , Unterberg Matthias , Koos Björn , Schenker Peter , Viebahn Richard , Adamzik Michael , Bergmann Lars
Published: February 2021

Infections with cytomegalovirus (CMV) are one of the most frequent opportunistic infections in kidney transplant recipients. Current risk-adapted CMV chemoprophylaxis regimens are based almost solely on the donor and recipient CMV serostatus. Of note, the NFKB1 -94ins/delATTG promoter polymorphism was recently associated with a higher risk of CMV infection. Since single genetic association studies suffer from poor reliability for drawing therapeutic implications, we performed this confirmatory study and included 256 kidney transplant recipients from 2007 to 2014 in this retrospective study. Patients were genotyped for the -94ins/delATTG NFKB1 promoter polymorphism and followed up for 12 months. The incidence of CMV infection within 12 months after kidney transplantation was 37.5% (33/88) for the ins/ins, 21.5% (28/130) for the ins/del, and 23.7% (9/38) for the del/del genotypes (p = 0.023). Moreover, we evaluated the time of CMV infection onset. Ins/ins carriers had primarily late-onset CMV infection (median 194 days; interquartile range (IQR) 117–267 days) compared with heterozygous (ins/del; median 158 days; IQR 82–195 days) and homozygous deletion allele carriers (del/del; median 95 days; 84–123 days). Multivariate-restricted Cox regression model confirmed the ins/ins genotype to be an independent risk factor for the development of late-onset CMV infections. These findings should have an impact on post-kidney transplantation CMV chemoprophylaxis regimens.
Effect of Irradiation with Si+ Ions on Phase Transformations in Ti–Al System during Thermal Annealing
Authors: Sagdoldina Zhuldyz , Rakhadilov Bauyrzhan , Kurbanbekov Sherzod , Kozhanova Rauan , Kengesbekov Aidar
Published: February 2021

The article deals with the effect of irradiation with Si+ ions on phase transformations in the Ti–Al system during thermal annealing. An aluminum film with a thickness of 500 nm was deposited on VT1-00 titanium samples by magnetron sputtering, followed by ion implantation. Samples before and after irradiation with Si ions were annealed in a vacuum of 10−4 Pa in the temperature range 600–1000 °C. It was established that ion implantation reduces the dissolution of Al in α-Ti with the formation of titanium silicides (TiSi2, Ti5Si3) and stabilizes aluminide phases Ti3Al rich in aluminum. As a result, a composite structure based on titanium silicide/aluminide was obtained on the surface of the sample synthesized by complex treatment: deposition, irradiation with Si+, and thermal annealing at the near-surface layers. The formation of the phase-structural state of the implanted layers is associated with the displacement of atoms of the crystal lattice, a result that is reflected in an increase in the size of the crystal lattice and a decrease in microdistortion of the lattice. The opposite effect is observed with increasing temperature. This fact is explained by the relaxation of unstable large grains with an excess of internal energies. At the annealing temperature of 900–1000 °C, a significant increase in microhardness was observed due to silicide phases.
Current Research Status on Cold Sprayed Amorphous Alloy Coatings: A Review
Authors: Wang Qiang , Han Peng , Yin Shuo , Niu Wen-Juan , Zhai Le , Li Xu , Mao Xuan , Han Yu
Published: February 2021

Compared with traditional crystalline materials, amorphous alloys have excellent corrosion and wear resistance and high elastic modulus, due to their unique short-range ordered and long-range disordered atomic arrangement as well as absence of defects, such as grain boundaries and dislocations. Owing to the limitation of the bulk size of amorphous alloys as structural materials, the application as functional coatings can widely extend their use in various engineering fields. This review first briefly introduces the problems involved during high temperature preparation processes of amorphous coatings, including laser cladding and thermal spraying. Cold spray (CS) is characterized by a low-temperature solid-state deposition, and thus the oxidation and crystallization related with a high temperature environment can be avoided during the formation of coatings. Therefore, CS has unique advantages in the preparation of fully amorphous alloy coatings. The research status of Fe-, Al-, Ni-, and Zr-based amorphous alloy coatings and amorphous composite coatings are reviewed. The influence of CS process parameters, and powders and substrate conditions on the microstructure, hardness, as well as wear and corrosion resistance of amorphous coatings is analyzed. Meanwhile, the deposition mechanism of amorphous alloy coatings is discussed by simulation and experiment. Finally, the key issues involved in the preparation of amorphous alloy coatings via CS technology are summarized, and the future development is also being prospected.
Citric Acid Passivation of Titanium Dental Implants for Minimizing Bacterial Colonization Impact
Authors: Punset Miquel , Vilarrasa Javi , Nart José , Manero José María , Bosch Begoña , Padrós Roberto , Perez Roman A. , Gil Javier
Published: February 2021

Surface topography and physical-chemical properties usually play a key-role in both osseointegration improvement and bacterial colonization reduction over the surface of dental implants. The aim of this study is to compare the chemical and bacteriological behavior of two different acid passivation surface treatments on titanium c.p. grade 3 used for dental implant manufacturing. Surface roughness was evaluated using White Light Interferometry (WLI) in order to determine different roughness parameters such as average roughness (Sa), the spacing parameter (Sm) and the hybrid parameter of surface index area (SIA). Contact angle (CA) and surface free energy (SFE) were evaluated in order to establish the surface wettability of the different groups of samples. Titanium ion-release from the different samples was also been analyzed in Hank’s solution medium at 37 °C by using Inductively Coupled Plasma Mass Spectrometry (ICP-MS) at different immersion times. Bacterial viability adhesion assays were done using S. sanguinis (CECT 480, Spain) as a bacterial strain model of primary colonizer in oral biofilm formation. The bacteria attachment and morphology on Ti surfaces were determined using a live/dead staining method after 4 h of incubation and further analyzed by scanning electron microscope (SEM). Acid passivation surface treatments produced a statistically-significant (p < 0.05) roughness increase in all the evaluated parameters (Sa, Sm, SAI). The treatment with citric acid decreased the static contact angle (CA) and caused an increase in surface free energy (SFE) with a high polarization and oxidizing character. These physical-chemical surface characteristics obtained by means of citric acid passivation caused the bactericidal behavior as it has been proved in bacterial studies.
The Cytotoxicity Assessment of Novel Formulation Developed to Reduce Dentin Hypersensitivity Utilizing Dehydrogenase Assay
Authors: Pawlak Justyna , Trzcionka Agata , Mertas Anna , Dziedzic Arkadiusz , Hildebrandt Tomasz , Tanasiewicz Marta
Published: February 2021

The problem of real treatment of teeth hypersensitivity is still important and unsolved. The main goal of the experiment was to calculate the possible toxic effects on the fibroblasts cells CCL-1™ (NCTC clone 929) caused by original preparation to reduce tooth surfaces’ hypersensitivity, compared to the marketable preparation Seal & Protect (Dentsply). The assessment was made through measuring lactate dehydrogenase (LDH assay). Lactate dehydrogenase releases from the cell’s cytoplasm to the culture medium as a result of cell membrane damage and lysis of the cells. The measurement is based on an assessment of the ability of LDH to oxidize lactic acid to pyruvic acid, which is dependent on the increase of the release level. The increase of LDH activity in the supernatants of cell cultures shows a relationship with the percentage of dead cells (increased cytotoxicity correlates with the increasing content of dead cells). In the LDH assay, both formulations evaluated after 24 h obtained results which were located below the control values. After seven days, the mean values obtained in cytotoxicity assay LDH are measurable and lower for the original formulation in comparison to the commercial one at the dilution of 1:5. At the dilution with 1:10 ratio, they are comparable and within the range of accepted values. At the maximal dilution of 1:15, the results are higher for the experimental formulation in comparison to the marketable formulation. The polymerization process is beneficial for the cytotoxicity test results in case of both tested preparations. Average values of cytotoxicity of both preparations attain an acceptable level of less than 22.6 ± 8.1%, reliant on the degree of dilution and the remark time. Original formulation is characterized by a greater homogeneity of results. The marketable preparation has a larger diversity of effects, dependent on the time of observation and attenuation; however, the cytotoxicity values are lower when paralleled to the experimental formulation in the test conducted after seven days. This should not have a disastrous effect on the pulp, as the values of both as the values of both preparations are within expected ranges. The obtained results allows to assume that will be possible to introduce the original formulation to the stage of clinical trials in the future.
Structure and Tribological Properties of Ni–Cr–Al-Based Gradient Coating Prepared by Detonation Spraying
Authors: Rakhadilov Bauyrzhan , Maulet Meruyert , Abilev Madi , Sagdoldina Zhuldyz , Kozhanova Rauan
Published: February 2021

In this paper, Ni–Cr–Al coatings were deposited using the detonation spraying method. The aim was to investigate how technological parameters influence coating structure formation, phase composition and tribological performances. We observed that the degree to which the barrel is filled with an O2/C2H2 gas mixture strongly influences the chemical composition of manufactured coatings. High degrees of barrel filling led to a decrease in aluminum content in the coating. Filling degrees of 40% and 50% produced sprayed coatings in which only Ni–Cr phases could be found. When the filling degree was reduced up to 25%, Ni–Al phases began to form in the sprayed coatings. Gradient Ni–Cr–Al coatings were produced by gradually reducing the filling degree from 50% to 25%. These coatings are characterized by Ni–Cr near the substrate level with Ni–Cr and Ni–Al phases at higher levels. The results obtained confirm that gradient Ni–Cr–Al coatings exhibit high hardness as well as good wear resistance.
Active Biodegradable Polyvinyl Alcohol–Hemicellulose/Tea Polyphenol Films with Excellent Moisture Resistance Prepared via Ultrasound Assistance for Food Packaging
Authors: Wang Yining , Li Jinhui , Guo Xin , Wang Haisong , Qian Fang , Lv Yanna
Published: February 2021

Poor water-vapor barriers and mechanical properties are common problems of biobased films. To maintain food quality, the barrier and its strength performance need to be improved. Tea polyphenols (TP) are a natural active substance, and their benzene ring structure provides a barrier for them as a film material. Films that incorporate TP also have enriched functionalities, e.g., as antioxidants. Here, active poly (vinyl alcohol) (PVA)-hemicellulose (HC)/TP films with good moisture resistance and antioxidant capacity were prepared via ultrasound assistance. The effects of TP incorporation and ultrasonication on the physical, antioxidant, and micromorphological properties of the films were investigated. Results showed that the addition of TP improved the thermal stability and water-vapor permeability (WVP) of the composite films. When a PVA-HC/TP composite film with a PVA-HC to TP mass ratio of 100:10 was treated with ultrasonication for 45 min, tensile strength was 25.61 Mpa, which was increased by 54% from the film without any treatment, and water-vapor permeability (WVP) value declined from 49% to 4.29 × 10−12 g·cm/cm2·s·Pa. More importantly, the films’ DPPH scavenging activity increased to the maximal levels of 85.45%. In short, these observations create a feasible strategy for preparing high-performance biodegradable active-packaging films.
Hydrodynamic Boundary Layers at Solid Wall—A Tool for Separation of Fine Solids
Authors: Nikolov Ljubomir
Published: February 2021

A theoretical study is performed about the hydrodynamic interaction of fine species entrapped in the boundary layer (BL) at solid wall (plate). The key starting point is the analysis of the disturbance introduced by solid spheres in the background fluid flow. For a neutrally buoyant entity, the type of interaction is determined by the size of the spheres as compared to the thickness of the BL region. The result is granulometric separation of the solids inside the BL domain at the wall. The most important result in view of potential applications concerns the so-called small particles Rp < L/ReL5/4 (ReL is the Reynolds number of the background flow and Rp is the radius of the entrapped sphere). In the case of non-neutrally buoyant particles, gravity interferes with the separation effect. Important factor in this case is the relative density of the solid species as compared to this of the fluid. In view of further practical uses, particles within the range of Δρ/ρ < Fr2/ReL1/2 (Fr is Froude number and Δρ/ρ is the relative density of the entrapped solids) are systematically studied. The trajectories inside the BL region of the captured species are calculated. The obtained data show that there are preferred regions along the wall where the fine solids are detained. The results are important for the assessment of the general efficiency of entrapment and segregation of fine species in the vicinity of solid walls and have high potential for further design of industrial separation processes.
Pre-Load Effect on CFRP-Confinement of Concrete Columns: Experimental and Theoretical Study
Authors: Micelli Francesco , Cascardi Alessio , Aiello Maria Antonietta
Published: February 2021

The axial compression strength of concrete columns has been proved to be significantly enhanced by external confinement. In this perspective, the use of Fiber-Reinforced Polymers (FRPs) has been extensively studied. In practical applications, the FRP-confinement is installed on loaded columns, which can already be significantly deformed, while theoretical models neglect this aspect. This paper concerns a new experimental investigation on the possibility that a pre-existing axial load affects the FRP-confinement of concrete. The research program also aimed at the development of a new analysis-oriented-model for the prediction of the compressive strength of FRP-jacketed concrete columns, depending on the level of the axial load, acting before the confinement. For this purpose, series of small-scale concrete cylinders were first loaded, then confined with Carbon FRP, and finally subjected to destructive pure axial compression tests. Four different levels of pre-existing loads were simulated, including the un-loaded condition.
Photoionization-Induced Broadband Dispersive Wave Generated in an Ar-Filled Hollow-Core Photonic Crystal Fiber
Authors: Fu Jianhua , Chen Yifei , Huang Zhiyuan , Yu Fei , Wu Dakun , Pan Jinyu , Zhang Cheng , Wang Ding , Pang Meng , Leng Yuxin
Published: February 2021

The resonance band in hollow-core photonic crystal fiber (HC-PCF), while leading to high-loss region in the fiber transmission spectrum, has been successfully used for generating phase-matched dispersive wave (DW). Here, we report that the spectral width of the resonance-induced DW can be largely broadened due to plasma-driven blueshifting soliton. In the experiment, we observed that in a short length of Ar-filled single-ring HC-PCF the soliton self-compression and photoionization effects caused a strong spectral blueshift of the pump pulse, changing the phase-matching condition of the DW emission process. Therefore, broadening of DW spectrum to the longer-wavelength side was obtained with several spectral peaks, which correspond to the generation of DW at different positions along the fiber. In particular, we numerically used the super-Gauss windows with different central wavelengths to filter out these DW spectral peaks and studied the time-domain characteristics of these peaks respectively using Fourier transform method. We observed that these multiple-peaks on the DW spectrum have different delays in the time domain, which is in good agreement with our theoretical prediction. More interestingly, we found that the broadband DW with several spectral peaks can be compressed to ~29 fs after proper dispersion compensation. The results reported here, on the one hand, provide some useful insights into the resonance-induced DW generation process in gas-filled HC-PCFs. On the other hand, the DW-emission mechanism could be used to generate the ultrashort light sources with a wide spectral range through using the proper design of the resonance bands of the HC-PCFs, which has many applications in the ultrafast related experiments.