bluuebunny/crossref_metadata_2025 huggingface dataset:
A perivascular niche in the bone marrow hosts quiescent and proliferating tumorigenic colorectal cancer cells
Authors: Möhrmann Lino , Zowada Martina K. , Strakerjahn Hendrik , Siegl Christine , Kopp‐Schneider Annette , Krunic Damir , Strunk Dirk , Schneider Martin , Kriegsmann Mark , Kriegsmann Katharina , Herbst Friederike , Ball Claudia R. , Glimm Hanno , Dieter Sebastian M.
Published: February 2020

Disseminated tumor cells (dTCs) can frequently be detected in the bone marrow (BM) of colorectal cancer (CRC) patients, raising the possibility that the BM serves as a reservoir for metastatic tumor cells. Identification of dTCs in BM aspirates harbors the potential of assessing therapeutic outcome and directing therapy intensity with limited risk and effort. Still, the functional and prognostic relevance of dTCs is not fully established. We have previously shown that CRC cell clones can be traced to the BM of mice carrying patient‐derived xenografts. However, cellular interactions, proliferative state and tumorigenicity of dTCs remain largely unknown. Here, we applied a coculture system modeling the microvascular niche and used immunofluorescence imaging of the murine BM to show that primary CRC cells migrate toward endothelial tubes. dTCs in the BM were rare, but detectable in mice with xenografts from most patient samples (8/10) predominantly at perivascular sites. Comparable to primary tumors, a substantial fraction of proliferating dTCs was detected in the BM. However, most dTCs were found as isolated cells, indicating that dividing dTCs rather separate than aggregate to metastatic clones—a phenomenon frequently observed in the microvascular niche model. Clonal tracking identified subsets of self‐renewing tumor‐initiating cells in the BM that formed tumors out of BM transplants, including one subset that did not drive primary tumor growth. Our results indicate an important role of the perivascular BM niche for CRC cell dissemination and show that dTCs can be a potential source for tumor relapse and tumor heterogeneity.
Prevalence and key predictors of perinatal depression among postpartum women in Ghana
Authors: Sefogah Promise E. , Samba Ali , Mumuni Kareem , Kudzi William
Published: February 2020

Objective

To determine the prevalence and key predictors of perinatal depression among women in Accra.

Method

A two‐step hospital‐based cross‐sectional study from May to July 2016. Patient Health Questionnaire version 9 was administered to postpartum mothers, and those aged 18 years or older with scores above 5 who delivered at LEKMA, Ridge, and Korle Bu Hospitals were recruited. A modified Edinburgh Postnatal Depression Scale was used to assess depression at 2 weeks postpartum. Associations between perinatal depression and sociodemographic/obstetric variables were assessed by χ2 and multivariate logistic regression.

Results

Among 1456 women screened, the prevalence of mental health disorders was 27.5% (400/1456). Of 350 women recruited, perinatal depression at 2 weeks postpartum was 8.6%, 31.6%, and 41.1% at LEKMA, Ridge, and Korle Bu, respectively. Mothers younger than 20 years and older than 35 years at Korle Bu had depression. Vaginal delivery increased the odds of perinatal depression at Ridge and Korle Bu. Blood transfusion was associated with depression at all three hospitals.

Conclusion

Blood transfusion, but not other variables, was associated with perinatal depression at 2 weeks postpartum in Accra. Understanding the prevalence of perinatal depression and its associated risk factors in Ghana will aid policy decisions, planning, and clinical management.
Certain interleukin polymorphisms might influence predisposition to lung cancer: A meta‐analysis of 35 published studies
Authors: Gao Juwei , Ying Yinyin , Wang Jue , Cui Yiyi , Zhang Weiping
Published: February 2020

Interleukin polymorphisms might influence predisposition to lung cancer (LC), but the results of already published studies regarding the relationship between interleukin polymorphisms and LC were still controversial and ambiguous. So the authors designed this meta‐analysis to more precisely estimate relationship between interleukin polymorphisms and LC by pooling the results of already published related studies. The authors searched Pubmed, Embase, Web of Science, and CNKI for already published studies. Thirty‐five already published studies were pooled and analyzed in this meta‐analysis. The pooled meta‐analyses results showed that distributions of IL‐4 rs2243250 polymorphism among patients and controls from Asian countries differed significantly (dominant comparison: OR = 1.29, 95% CI 1.07–1.55; overdominant comparison: OR = 0.83, 95% CI 0.73–0.95; allele comparison: OR = 1.26, 95% CI 1.03–1.54), and distributions of IL‐10 rs1800872 polymorphism among patients and controls from Caucasian countries also differed significantly (recessive comparison: OR = 0.54, 95% CI 0.35–0.83; overdominant comparison: OR = 1.26, 95% CI 1.05.1.51). No genotypic distribution differences were observed for IL‐4 rs2070874, IL‐6 rs1800795, IL‐6 rs1800796, IL‐8 rs4073, IL‐10 rs1800871, and IL‐10 rs1800896 polymorphisms in pooled meta‐analyses. This meta‐analysis suggested that IL‐4 rs2243250 might influence predisposition to LC in Asians, whereas IL‐10 rs1800872 polymorphism might influence predisposition to LC in Caucasians.
Good, better, best? The effects of polarization on photobiomodulation therapy
Authors: Tripodi Nicholas , Feehan Jack , Husaric Maja , Kiatos Dimitrios , Sidiroglou Fotios , Fraser Sarah , Apostolopoulos Vasso
Published: February 2020

Photobiomodulation therapy (PBMT) is a widely adopted form of phototherapy used to treat many chronic conditions that effect the population at large. The exact physiological mechanisms of PBMT remain unsolved; however, the prevailing theory centres on changes in mitochondrial function. There are many irradiation parameters to consider when investigating PBMT, one of which is the state of polarization. There is some evidence to show that polarization of red and near‐infrared light may promote different and/or increased biological activity when compared to otherwise identical non‐polarized light. These enhanced cellular effects may also be present when the polarized light is applied linear to the tissue direction. Herein, we synthesize the current experimental and clinical evidence pertaining to polarized photobiomodulation therapy; ultimately, to better inform future research into this area of phototherapy.
Red and White Blood Cell Counts Are Associated With Bone Marrow Adipose Tissue, Bone Mineral Density, and Bone Microarchitecture in Premenopausal Women
Authors: Polineni Sai , Resulaj Megi , Faje Alexander T , Meenaghan Erinne , Bredella Miriam A , Bouxsein Mary , Lee Hang , MacDougald Ormond A , Klibanski Anne , Fazeli Pouneh K
Published: February 2020

Bone marrow adipose tissue (BMAT) resides within the bone marrow microenvironment where its function remains poorly understood. BMAT is elevated in anorexia nervosa, a disease model of chronic starvation, despite depletion of other fat depots. In addition to BMAT, the marrow microenvironment also consists of osteoblast and hematopoietic progenitors. BMAT is inversely associated with bone mineral density (BMD) in multiple populations including women with anorexia nervosa, and regulates hematopoiesis in animal models. We hypothesized that BMAT would be associated with circulating populations of hematopoietic cells (red and white blood cells) in humans and performed a post hoc analysis of two studies—a cross-sectional study and a longitudinal study—to investigate this hypothesis. We studied 89 premenopausal women cross-sectionally (median age [interquartile range], 27 [24.5, 31.7] years), including 35 with anorexia nervosa. We investigated associations between red blood cell (RBC) and white blood cell (WBC) counts and BMAT assessed by 1H-magnetic resonance spectroscopy, BMD assessed by DXA, and bone microarchitecture assessed by HR-pQCT. In addition, we analyzed longitudinal data in six premenopausal women with anorexia nervosa treated with transdermal estrogen for 6 months and measured changes in BMAT and blood cell counts during treatment. Cross-sectionally, BMAT was inversely associated with WBC and RBC counts. In contrast, BMD and parameters of bone microarchitecture were positively associated with WBC and RBC. In women with anorexia nervosa treated with transdermal estrogen for 6 months, decreases in BMAT were significantly associated with increases in both RBC and hematocrit (rho = −0.83, p = 0.04 for both). In conclusion, we show that BMAT is inversely associated with WBC and RBC in premenopausal women, and there is a potential association between longitudinal changes in BMAT and changes in RBC. These associations warrant further study and may provide further insight into the role and function of this understudied adipose depot. © 2020 American Society for Bone and Mineral Research.
Prospective Changes in the Distribution of Movement Behaviors Are Associated With Bone Health in the Elderly According to Variations in their Frailty Levels
Authors: Rodríguez-Gómez Irene , Mañas Asier , Losa-Reyna José , Rodríguez-Mañas Leocadio , Chastin Sebastien FM , Alegre Luis M , García-García Francisco J , Ara Ignacio
Published: February 2020

Frailty is associated with poor bone health and osteoporosis, and physical activity (PA) is one of the best treatments for both pathologies in older adults. Nonetheless, because daily time is limited, how the time is distributed during the waking hours is critical. The waking hours are spent according to different movement behaviors: sedentary behaviors (SB), light physical activity (LPA), and moderate-to-vigorous physical activity (MVPA). The aim of this study was to use compositional data analyses to examine the effects of the change in movement behaviors on bone health during aging in older people, related to the changes in their frailty levels. We analyzed 227 older people aged 65 to 94 (125 women and 102 men) over a 4-year period. Movement behaviors were assessed using accelerometry. Both bone mineral density (BMD) and bone mineral content (BMC) were determined using bone densitometry. The Frailty Trait Scale was used to divide the sample by frailty level evolution during aging. The R statistical system was used for the compositional data analysis and, in addition, all models were adjusted for several covariates. The changes in the distribution of all movement behaviors within a waking hour period were significantly associated with spine and femoral neck BMD changes in the subgroup with a positive change in frailty level and spine BMC in the subgroup with no change in frailty level (p ≤ .05). Likewise, MVPA relative to the change in other movement behaviors was also associated in both subgroups with higher BMD and BMC, respectively, in the same body areas (p ≤ .05). No significant associations were found in the negative change in frailty level subgroup. Older people who achieved a positive change in frailty level during a 4-year period showed higher BMD changes compared to those with no changes or increases in their frailty level. Therefore, increasing MVPA relative to the change in the other movement behaviors during a 4-year period could perhaps produce bone health improvements in the elderly that do not worsen their frailty level. © 2020 American Society for Bone and Mineral Research.
MicroRNA‐497/fibroblast growth factor‐23 axis, a predictive indictor for decreased major adverse cardiac and cerebral event risk in end‐stage renal disease patients who underwent continuous ambulatory peritoneal dialysis
Authors: Liu Dianjun , Zhou Silian , Mao Huihui
Published: February 2020

Objective

This study aimed at exploring the correlation of microRNA (miR)‐497/fibroblast growth factor‐23 (FGF‐23) axis with major adverse cardiac and cerebral event (MACCE) occurrence in end‐stage renal disease (ESRD) patients who underwent continuous ambulatory peritoneal dialysis (CAPD).

Methods

Totally, 360 ESRD patients who underwent CAPD were enrolled. Their plasma samples were collected to detect miR‐497 expression by real‐time quantitative polymerase chain reaction, and FGF‐23 level by enzyme‐linked immunosorbent assay. All patients were followed up for 36 months, and the occurrence of MACCE during the follow‐up was documented.

Results

MiR‐497 expression negatively correlated with FGF‐23 level in ESRD patients who underwent CAPD (P < .001). The MACCE occurrence rate at 1, 2, and 3‐year was 5.6%, 11.9%, and 15.0%, respectively. Furthermore, miR‐497/FGF‐23 axis high level (P < .001) and miR‐497 high expression (P = .034) correlated with reduced accumulating MACCE occurrence, whereas FGF‐23 high level (P = .008) correlated with increased accumulating MACCE occurrence. Forward stepwise multivariate Cox's regression disclosed that miR‐497/FGF‐23 axis high level (P = .008) was an independent predictive factor for lower accumulating MACCE occurrence, whereas age (≥55 years) (P < .001), body mass index (≥21.7 kg/m2) (P = .006), peritoneal dialysis duration (≥61.0 months) (P < .001), C‐reactive protein (≥4.7 mg/L) (P = .001), serum uric acid (≥409.4 μmol/L) (P = .009), β‐fibrinogen (≥5.8 mmol/L) (P < .001), and low‐density lipoprotein cholesterol (≥2.7 mmol/L) (P = .003) were independent factors for predicting higher accumulating MACCE occurrence.

Conclusion

MiR‐497/FGF‐23 axis holds clinical significance for predicting attenuated MACCE risk in ESRD patients who underwent CAPD.
Male HIV‐1 transgenic rats show reduced cocaine‐maintained lever‐pressing compared to F344 wildtype rats despite similar baseline locomotion
Authors: Huynh Y. Wendy , Thompson Brady M. , Larsen Christopher E. , Buch Shilpa , Guo Ming‐Lei , Bevins Rick A. , Murray Jennifer E.
Published: February 2020

The HIV‐1 transgenic (Tg) rat model is valuable for understanding HIV‐associated neurocognitive disorders (HAND) and accompanying substance use and misuse. Tg and F344/NHsd wildtype (WT) rats were allowed to self‐administer intrajugular cocaine. For the first 7 sessions, neither genotype self‐administered cocaine (0.1 mg/kg/infusion) on a fixed ratio 1 schedule. We thus implemented a lever–cocaine “autoshaping” session followed by a series of manipulations changing dose and reinforcement schedule. Tg rats self‐administered much less cocaine than WT rats throughout the study. Of 8 Tg rats, 5 modestly increased self‐administration from sessions 36–50. Of those, only 3 showed a lever discrimination. Of 10 WT rats, 8 acquired robust self‐administration by session 19; all WT rats self‐administered cocaine by the end of the study. WT and Tg rats had similar baseline locomotor activity in the self‐administration chamber suggesting that the low levels of cocaine intake in the Tg rats did not reflect a nonspecific motor impairment in this rat strain. Concomitant measurement of activity with self‐administration revealed activity increases that followed increased cocaine intake. That relation held in Tg rats. Therefore, the present study provides evidence that HIV‐1 Tg rats are less sensitive to the reinforcing effects of cocaine than their F344 WT counterparts.
Bayesian estimation and sensitivity analysis of toluene and trichloroethylene biodegradation kinetic parameters
Authors: Yu Feng , Munoz Breda , Bienkowski Paul R. , Sayler Gary S.
Published: February 2020

Parameter estimation is needed for process management, design, and reactor scaling when values from the literature vary tremendously or are unavailable. A Bayesian approach, implemented via Markov chain Monte Carlo (MCMC) simulations using SAS software, was used to estimate the kinetic parameters of toluene and trichloroethylene (TCE) biodegradation by the microorganism Pseudomonas putida F1 in batch cultures. The prediction capabilities of Bayesian estimation were illustrated by comparing predicted and observed data and reported in goodness‐of‐fit statistics. The sensitivity analysis showed that the parameters obtained using this approach were consistent under the designated toluene and TCE concentration range. Moreover, the impact of TCE on toluene degradation kinetics was numerically exhibited, verifying the fact that TCE was able to stimulate toluene degradation; hence, TCE's presence increased the apparent maximum toluene‐specific rate. Various kinetic models were explored at different degrees of complexity. At a low TCE concentration range (e.g., <2 mg L−1), a simplified Michaelis–Menten model (i.e., substrate half‐saturation parameters approximated the inhibition parameters) was adequate to describe the reaction kinetics. However, at a higher TCE range (e.g., 5 mg L−1), a full‐scale Michaelis–Menten model was needed to discriminate among the inhibition parameters in the model. The results demonstrated that a Bayesian estimation method is particularly useful for determining complex bioreaction kinetic parameters in the presence of a small volume of experimental data.
Detection of enzyme‐triggered peptide self‐assembly via laser confocal Raman microscopy and circular dichroism spectroscopy in cellular environment
Authors: Anwar Shahzad , Ovais Muhammad , Hassan Nouman , Aslam Sonia
Published: February 2020

Vibrational spectroscopy of peptides and peptide‐based self‐assembled macromolecules plays key role in early stage detection of cancerous and viral diseases. We provide here a rapid and accurate trace detection system for enzyme‐triggered peptide self‐assembly by taking a snapshot of peptide nanostructures to identify specific domains based on amino acid vibrational bands. The enzyme‐triggered peptides present in both aqueous solution and human umbilical vein endothelial cells along with controlled cell lines were excited by a laser line of 543 nm, and intensities of Raman bands were recorded from 500 to 1,800 cm−1. The spectra consisted of several well‐resolved peaks located at 655, 1,081, and 1670 cm−1 for peptide and at 834, 851, 896, and 915 cm−1 for enzyme, indicating vibrational bands of their functional groups. Raman signatures at 768, 1,144, 1,297, 1,305, and 1,571 cm−1 appeared in case of self‐assembled peptides at new positions, indicating the presence of highly stable secondary structure of beta sheets. We studied here the 0.78 μg/ml limit of detection of peptide self‐assembly with this technique in aqueous solution. These self‐assembled nanomachines in cellular environment can be used to monitor and regulate the cellular processes for the diagnosis of biological diseases incorporated with our label‐free laser confocal Raman microscopy methodology.
Prospects for sustainability of pig production in relation to climate change and novel feed resources
Authors: Rauw Wendy M , Rydhmer Lotta , Kyriazakis Ilias , Øverland Margareth , Gilbert Hélène , Dekkers Jack CM , Hermesch Susanne , Bouquet Alban , Gómez Izquierdo Emilio , Louveau Isabelle , Gomez‐Raya Luis
Published: February 2020

Pig production systems provide multiple benefits to humans. However, the global increase in meat consumption has profound consequences for our earth. This perspective describes two alternative scenarios for improving the sustainability of future pig production systems. The first scenario is a high input–high output system based on sustainable intensification, maximizing animal protein production efficiency on a limited land surface at the same time as minimizing environmental impacts. The second scenario is a reduced input–reduced output system based on selecting animals that are more robust to climate change and are better adapted to transform low quality feed (local feeds, feedstuff co‐products, food waste) into meat. However, in contrast to the first scenario, the latter scenario results in reduced predicted yields, reduced production efficiency and possibly increased costs to the consumer. National evaluation of the availability of local feed and feedstuff co‐product alternatives, determination of limits to feed sourced from international markets, available land for crop and livestock production, desired production levels, and a willingness to politically enforce policies through subsidies and/or penalties are some of the considerations to combine these two scenarios. Given future novel sustainable alternatives to livestock animal protein, it may become reasonable to move towards an added general premium price on ‘protein from livestock animals’ to the benefit of promoting higher incomes to farmers at the same time as covering the extra costs of, politically enforced, welfare of livestock animals in sustainable production systems. © 2020 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
The transcription factors regulating intervertebral disc development
Authors: Nakamichi Ryo , Asahara Hiroshi
Published: February 2020

Damage to the intervertebral discs (IVDs) occurs due to aging or excessive mechanical stress, causing a series of IVD‐related degenerative diseases, such as spinal disc herniation and spondylosis. These IVD‐related diseases are difficult to cure, partially because the regeneration ability of IVDs is not sufficient. As a novel strategy for treatment of IVD‐related diseases, mesenchymal stem cell transplantation to the damaged discs has been reported in animal studies. To further develop and improve this approach, it is necessary to gain a better understanding of the molecular network regulating IVD development by critical transcription factors. Recent findings reveal that during IVD development, nucleus pulposus and annuls fibrosus differentiation is coordinated by a series of transcription factors, such as Mkx, Pax1, 9, Shh, Foxa1, 2, T‐Brachyury, and Sox5, 6, 9. The combination of mesenchymal stem cell transplantation with the regulation of these molecules may provide a novel strategy for treatment of degenerative disc diseases.
The Safety and Efficacy of Transnasal Humidified Rapid‐Insufflation Ventilatory Exchange for Laryngologic Surgery
Authors: Nekhendzy Vladimir , Saxena Amit , Mittal Brita , Sun Eric , Sung Kwang , Dewan Karuna , Damrose Edward J.
Published: February 2020

Objectives

Transnasal humidified rapid‐insufflation ventilatory exchange (THRIVE) is an intraoperative ventilatory technique that allows avoidance of tracheal intubation (TI) or jet ventilation (JV) in selected laryngologic surgical cases. Unimpeded access to all parts of the glottis may improve surgical precision, decrease operative time, and potentially improve patient outcomes. The objective of this prospective, randomized, patient‐blinded, 2‐arm parallel pilot trial was to investigate the safety and efficacy of THRIVE use for adult patients undergoing nonlaser laryngologic surgery of short‐to‐intermediate duration.

Methods

Twenty adult, American society of anesthesiology class 1‐3 patients with body mass index (BMI) < 35 kg/m2 were randomly assigned to either an experimental THRIVE group or active comparator conventional ventilation group (TI or supraglottic high‐frequency JV [SHFJV]). Primary outcomes included intraoperative oxygenation, anesthesia awakening/extubation time, time to laryngoscopic suspension, number of intraoperative suspension adjustments, and operative time. Secondary patient outcomes including postanesthesia and functional patient recovery were investigated.

Results

Compared to TI/SHFJV, THRIVE use was associated with significantly lower intraoperative oxygenation (SpO2 93.0 ± 5.6% vs. 98.7 ± 1.6%), shorter time to suspension (1.8 ± 1.1 minutes vs. 4.3 ± 2.1 minutes), fewer suspension adjustments (0.4 ± 0.5 vs. 1.7 ± 0.9), and lower postoperative pain scores on recovery room admission (1.3 ± 1.9 vs. 3.7 ± 2.9) and discharge (0.9 ± 1.3 vs. 2.7 ± 1.8). The study was underpowered to detect other possible outcome differences.

Conclusion

We confirm the safe intraoperative oxygenation profile of THRIVE for selected patients undergoing nonlaser laryngologic surgery of short‐to‐intermediate duration. THRIVE facilitated surgical exposure and improved early patient recovery, suggesting a potential economic benefit for outpatient laryngologic procedures. The results of this exploratory study provide a framework for designing future adequately powered THRIVE trials.

Trial Register

ClinicalTrials.gov (NCT03091179).

Level of Evidence

II Laryngoscope, 2020
Unlocking the black‐box of inorganic carbon‐uptake and utilization strategies among coral endosymbionts (Symbiodiniaceae)
Authors: Ros Mickael , Camp Emma F. , Hughes David J. , Crosswell Joseph R. , Warner Mark E. , Leggat William P. , Suggett David J.
Published: February 2020

Dinoflagellates within the family Symbiodiniaceae are widespread and fuel metabolism of reef‐forming corals through photosynthesis. Adaptation in capacity to harvest and utilize light, and “safely” process photosynthetically generated energy is a key factor regulating their broad ecological success. However, whether such adaptive capacity similarly extends to how Symbiodiniaceae species and genotypes assimilate inorganic carbon (Ci) remains unexplored. We build on recent approaches exploring functional diversity of fitness traits to identify whether Ci uptake and incorporation could be reconciled with evolutionary adaptation among Symbiodiniaceae. We examined phylogenetically diverse Symbiodiniaceae cultures (23 isolates, 6 genera) to track how carbon was invested into cellular uptake, excretion, and growth (cell size, division, storage). Gross carbon uptake rates (GPC) over 1 h varied among isolates grown at 26°C (0.63–3.08 pg C [cell h]−1) with no evident pattern with algal phylogeny. Intriguingly, net carbon uptake rates (24 h) were often higher (1.01–5.54 pg C [cell h]−1) than corresponding values of GPC—we discuss how such GPC measurements may reflect highly conserved biological characteristics for cultured cells linked to high metabolic dependency on photorespiration and heterotrophy. Three isolates from different genera (Cladocopium goreaui, Durusdinium trenchii, and Effrenium voratum) were additionally grown at 20°C and 30°C. Here, Ci uptake consistently decreased with temperature‐driven declines in growth rate, suggesting environmental regulation outweighs phylogenetic organization of carbon assimilation capacity among Symbiodiniaceae. Together, these data demonstrate environmental regulation and ecological success among Symbiodiniaceae likely rests on plasticity of upstream photosynthetic processes (light harvesting, energy quenching, etc.) to overcome evolutionary‐conserved limitations in Ci functioning.
Antimicrobial and Wound Treatment Aspects of Micro‐ and Nanoformulations of Carboxymethyl, Dialdehyde, and TEMPO‐Oxidized Derivatives of Cellulose: Recent Advances
Authors: Alavi Mehran , Nokhodchi Ali
Published: February 2020

The remedy for infected chronic wounds such as diabetic foot ulcers is more complicated particularly in the case of patients with an inefficient immune system. Also, fighting against microbial infections in the wound site by available antibiotics may not be effective because of emerging antibiotic resistance properties among pathogenic bacteria and fungi. Recently, applications of micro‐ and nanoformulations of biomaterials have demonstrated improved therapeutic abilities for wound dressings. In this way, carboxymethyl, dialdehyde, and 2,2,6,6‐tetramethylpiperidine‐1‐oxyl‐oxidized celluloses are common biomaterials having outstanding physicochemical and therapeutic properties compared to unmodified cellulose. Therefore, in this review, recent progress in the field of wound healing and antimicrobial activities of these derivatives are presented and discussed.
Evaluation of 3D Printed Gelatin‐Based Scaffolds with Varying Pore Size for MSC‐Based Adipose Tissue Engineering
Authors: Tytgat Liesbeth , Kollert Matthias R. , Van Damme Lana , Thienpont Hugo , Ottevaere Heidi , Duda Georg N. , Geissler Sven , Dubruel Peter , Van Vlierberghe Sandra , Qazi Taimoor H.
Published: February 2020

Adipose tissue engineering aims to provide solutions to patients who require tissue reconstruction following mastectomies or other soft tissue trauma. Mesenchymal stromal cells (MSCs) robustly differentiate into the adipogenic lineage and are attractive candidates for adipose tissue engineering. This work investigates whether pore size modulates adipogenic differentiation of MSCs toward identifying optimal scaffold pore size and whether pore size modulates spatial infiltration of adipogenically differentiated cells. To assess this, extrusion‐based 3D printing is used to fabricate photo‐crosslinkable gelatin‐based scaffolds with pore sizes in the range of 200–600 µm. The adipogenic differentiation of MSCs seeded onto these scaffolds is evaluated and robust lipid droplet formation is observed across all scaffold groups as early as after day 6 of culture. Expression of adipogenic genes on scaffolds increases significantly over time, compared to TCP controls. Furthermore, it is found that the spatial distribution of cells is dependent on the scaffold pore size, with larger pores leading to a more uniform spatial distribution of adipogenically differentiated cells. Overall, these data provide first insights into the role of scaffold pore size on MSC‐based adipogenic differentiation and contribute toward the rational design of biomaterials for adipose tissue engineering in 3D volumetric spaces.
Fabrication and Optical Modeling of Micro‐Porous Membranes Index‐Matched with Water for On‐Line Sensing Applications
Authors: Lanfranco Roberta , Giavazzi Fabio , Bellini Tommaso , Nicolò Emanuele Di , Buscaglia Marco
Published: February 2020

Membranes made of perfluorinated materials having a refractive index close to that of water enable straightforward detection of water solutes at the interface, hence providing a novel sensing tool for fluidic systems. Here it is reported the production by non‐solvent induced phase separation and characterization of microporous membranes made of Hyflon AD, an amorphous copolymer of tetrafluoroethylene. Their optical turbidity when soaked in liquids having different refractive indices is studied and the data are interpreted with an optical model linking scattered light and structural features of the membrane. The average polymer and pore chord lengths obtained in this way scale with the filtering pore size measured by capillary flow porometry. Then, the optical response of the membranes when soaked in aqueous surfactant solutions is investigated and the effects of the molecular adsorption on the internal membrane surface is successfully interpreted by an extension of the model. Overall, the results show that index‐matched membranes can be designed and produced to provide a simple optical detection of the composition of the soaking liquid or to monitor the initial stage of membrane fouling.
Polyaniline/Poly(acrylamide‐co‐sodium acrylate) Porous Conductive Hydrogels with High Stretchability by Freeze‐Thaw‐Shrink Treatment for Flexible Electrodes
Authors: Chen Lizhang , Zhang Weiying , Dong Yuefeng , Chen Qiuyue , Ouyang Wanjun , Li Xiao , Ying Xiaoguang , Huang Jianying
Published: February 2020

With the development of alternatives to traditional fossil energy and the rise of wearable technology, flexible energy storage devices have attracted great attention. In this paper, a polyaniline/poly(acrylamide‐sodium acrylate copolymer) hydrogel (PASH) with high flexibility and excellent electrochemical properties for flexible electrodes is fabricated by freeze‐thaw‐shrink treatment of a highly water‐absorptive hydrogel, together with in‐situ polymerization of aniline at a low aniline concentration (0.1 mol L−1). The PASH exhibits a conductivity of 4.05 S m−1 and an elongation at break of 1245%. The freeze‐thaw‐shrink treatment greatly improves the electrochemical performance and stability of the conductive PASH. The area specific capacitance of PASH reaches 849 mF cm−2 and the capacitance maintains 89% after 1000 galvanostatic charge–discharge cycles. All the raw materials are conventional industrialized materials and no additional templating agent is needed during the entire synthesis process. This study provides a cost‐efficient approach for the fabrication of conductive polymer hydrogels, which has a broad application prospect in flexible energy storage electronic devices.
Tensile Fatigue of Poly(Vinyl Alcohol) Hydrogels with Bio‐Friendly Toughening Agents
Authors: Koshut William J. , Smoot David , Rummel Caleb , Kirillova Alina , Gall Ken
Published: February 2020

Inspired by the avoidance of toxic chemical crosslinkers and harsh reaction conditions, this work describes a poly(vinyl alcohol)‐based (PVA) double‐network (DN) hydrogel aimed at maintaining biocompatibility through the combined use of bio‐friendly additives and freezing–thawing cyclic processing for the application of synthetic soft‐polymer implants. This DN hydrogel is studied using techniques that characterize both its chemical and mechanical behavior. A variety of bio‐friendly additives are screened for their effectiveness at improving the toughness of the PVA hydrogel system in monotonic tension. Starch is selected as the best additive for further tensile testing as it brings about a near 30% increase in ultimate tensile strength and maintains ease of processing. This PVA–starch DN sample is then studied for its tensile fatigue properties through cyclic, strain‐controlled testing to develop a fatigue life curve. Though an increase in monotonic tensile strength is observed, the PVA–starch DN hydrogel does not bring about an improvement in the fatigue behavior as compared to the control. Although synthetic hydrogel reinforcement is widely researched, this work presents the first fatigue analysis of its kind and it is intended to serve as a guide for future fatigue studies of reinforced hydrogels.
In Situ Electrospinning Wound Healing Films Composed of Zein and Clove Essential Oil
Authors: Qin Mei , Mou Xiao‐Ju , Dong Wen‐Hao , Liu Jia‐Xu , Liu Hao , Dai Zhang , Huang Xiao‐Wei , Wang Na , Yan Xu
Published: February 2020

Electrospun fibrous membranes have the potential to be effective wound dressings for promoting wound healing. However, the fabrication and application of the common electrospun fibrous wound dressings are usually complicated and separated. Here, electrospun zein/clove essential oil (CEO) fibrous membranes are fabricated and applied as a potential wound dressing through in situ electrospinning process by a portable electrospinning device. The in situ electrospinning process can directly electrospin zein/CEO membranes onto a wound site to cover the wound well and improve the convenience and comfort in use. The as‐spun zein/CEO membranes show a porous structure and exhibit higher gas permeability at 168.2 ± 43.3 mm s−1, with superhydrophilicity to absorb the wound exudate and good biocompatibility as well as antibacterial effects to protect from infection. Moreover, the mice wound model study suggests that in situ electrospun zein/CEO promotes the wound healing process.
Fly Ash Filled Geopolymers: Preparation and Thermal Study
Authors: Blanco Ignazio , Poggetto Giovanni Dal , Morrone Biagio , Tranquillo Elisabetta , Barrino Federico , Catauro Michelina
Published: February 2020

Metakaolin‐based geopolymers are prepared using recycled fly ash, aiming to reduce this waste otherwise disposed in landfills. Geopolymers with different amounts of fly ash (20, 50, and 70 wt%) are obtained and the occurring bond formation between the matrix and the filler is investigated by Fourier transform infrared spectroscopy. The consolidation of the materials has been confirmed by pH and conductivity at 28 days of hardening. The thermal behavior of the prepared geopolymers is studied by differential scanning calorimetry and thermogravimetric analysis.
Biomaterials Containing the Natural Antioxidant Quercetin: Synthesis and Health Benefits
Authors: Pacifico Severina , Piccolella Simona , Barrino Federico , Catauro Michelina
Published: February 2020

Quercetin, whose health‐promoting effects are acclaimed, is entrapped in a silica‐based and silica/polymer hybrid material via sol–gel route, to develop new antioxidant biomaterials for preventing the onset of ROS‐related diseases. The materials’ morphology is detected by SEM analysis, whereas the chemical characterization is achieved by spectroscopic and spectrometric techniques. Despite an oxidation reaction in the quercetin structure, DPPH (2,2‐diphenyl‐1‐picrylhydrazyl) and ABTS [2,2′‐azinobis‐(3‐ethylbenzothiazolin‐6‐sulfonic acid)] data show that all the materials preserve its antioxidant efficacy. MTT [3‐(4,5‐dimethyl‐2‐thiazolyl)‐2,5‐diphenyl‐2H‐tetrazolium bromide] test indicates a mild cytotoxicity in NIH‐3T3, PC12, and U251 cells. Furthermore, materials with the highest quercetin percentage are able to inhibit the H2O2‐induced intracellular ROS production in murine fibroblasts.
Metal‐Chitosan Nanocomposites: A Perspective Way to Preparation, Morphology, and Structural Studies
Authors: Rubina Margarita , Shulenina Alexandra , Svetogorov Roman , Vasilkov Alexander
Published: February 2020

The metal vapor synthesis is used to prepare sols of nanoparticles (Cu, Ag, and Au) in various solvents (isopropanol, triethylamine, and acetone). The sols are then used to deposit metal nanoparticles onto chitosan. The successful introduction of metal into the chitosan matrix is confirmed with X‐ray spectroscopic and diffraction methods. The morphology and size distribution of metal particles in nanocomposite materials are characterized by transmission electron microscopy and small‐angle X‐ray scattering.
Infiltration in Composite Materials Polymer Matrix Using a Self‐Interference Long Period Fiber Sensor
Authors: Miclos Sorin , Baschir Laurentiu , Savastru Dan , Savastru Roxana , Lancranjan Ion
Published: February 2020

The concentration of infiltrated water molecules into polymer matrix of composite materials is an important mechanical and chemical functional parameter of smart composite materials during exploitation in various research, medical, industrial, and security applications and it is important to design a setup as simple and as efficient as possible for measuring and monitoring this important parameter. The paper presents simulation/design results obtained using self‐interference long period grating fiber sensors in measuring and monitoring the concentration of infiltrated water molecules into polymer composite materials. The investigated long period grating fiber sensors are used as they are or mounted in interferometric setups. Self‐interference long period grating fiber sensors are manufactured by inscribing diffraction gratings into or on single mode commercial communication optical fibers and are used in smart composite materials as signal generators of their feedback loop being embedded into the polymer matrix.
Finite Elements Modeling of the Delamination Process at Polymeric Composite Structures
Authors: Roxana Gheţa , Dan Niţoi , Gabriel Iacobescu , Constantin Opran , Constantin Petriceanu
Published: February 2020

The delamination process is the main cause of the process of destruction of composite materials and of any technological process of deposition of different layers. This paper presents finite elements modeling of this type of multi‐layer structure failure from a practice experiment. It is thus attempted to create a mathematical model able to predict the behavior of similar structures under different working conditions.
Composite Insoles for Improving the Distribution of Plantar Pressure
Authors: Cotoros Diana , Stanciu Anca
Published: February 2020

Plantar pressure is a physiological parameter whose values provide a comprehensive image of the general health of a person. Also by improving the distribution of the plantar pressure, the posture, balance, and comfort of a person can be significantly enhanced. This improvement can be accomplished with the help of personalized insoles with carefully designed shapes and selected composite materials, following advanced processing technologies. The present paper proposes some solutions for a proper choice of the insole materials according to the type of illness that affects the foot. These materials should meet a multitude of conditions that are impossible to accomplish by using classic footwear materials, so a carefully selected combination of composite materials is the obvious choice. The recommendations for the best materials are the object of the present research.
Electrospinning and Mechanotropic Phenomena in Polymer Solutions
Authors: Kotomin Sergey , Malkin Alexander , Skvortsov Ivan
Published: February 2020

The mechanism of electrospinning traditionally is related to fast evaporation of solvent from thin liquid jets of polymer solution observed in high‐voltage electric fields. Another mechanism, called mechanotropic spinning, is more reasonable for polymer solutions in solvents having low vapor pressure and high boiling temperature, that is, dimethylacetamide (DMAc), DMF, dimethyl sulfoxide (DMSO). Under elongation, the solution undergoes phase separation as a result of high‐speed stretching and the solvent reveals on the surface of the fiber without its complete evaporation. Microfibers obtained by mechanotropic spinning as well as by electrospinning of PAN solutions in DMSO and polyamidbenzamidazol in DMAc have stable droplets of the solvent on the fiber surface.
Aspects Regarding Perception of Wearing Eyeglasses Frames Made of Composite Materials and/or Contact Lenses
Authors: Lazar Alexandra‐Maria
Published: February 2020

The continuous need for change and adaptability, the increased access to information, the high buying capacity, client perceptiveness, or skepticism are reasons which prompt manufacturers to be competitive, by producing and launching superior quality products on the market. The same applies to the lens manufacturing (for eyeglasses or contacts), which aims to persistently develop new materials and technologies that will satisfy even the most demanding customers.
Analysis of the Spectacles Behavior Made by Composite Structures
Authors: Apostoaie Mirela Gabriela , Baritz Mihaela Ioana
Published: February 2020

Frames of corrective or protective spectacles are orthoses that, during their use, must meet a series of aesthetic, functional, stability, and reliability criteria. Any patient, who needs to wear corrective/protective spectacles must, from the frame and lens construction, be assured of system reliability for as long as possible, postural accuracy, and comfort. The first part of the paper presents the theoretical aspects related to the frame/lens system's constructive parameters as a composite structure. In the second part the aspects of behavior analysis in mechanical tests of the frame material are presented. In the final part of the paper the conclusions regarding the behavior of the composite structure of the glasses’ frames from the point of view of determining their quality are presented.
Mathematical Model of Vacuum–Resin Transfer Molding for Polymeric Composites Products
Authors: Ion Sorin Mihai , Opran Constantin Gheorghe , Lamanna Giuseppe
Published: February 2020

Resin Transfer Molding process (RTM), is the most used technology to create large parts made by polymer matrix composites because: the production time is relative small; the consumption of materials is reduced to minimum; the obtained parts are in a constant tolerance of ±0.5 mm after de‐molding; both sides of the part are shiny and smooth; determinate resistance of the wall; it can be used with gelcoat on both sides or only on one; the reinforcement materials can be fiber glass, carbon fiber, sandwich materials, or metallic inserts; it does not need pressing during the curing of the resin; reduced cycle time, and low styrol emissions. In this paper the results of research regarding mathematical model of vacuum–RTM process for polymeric composites products are presented. It is taken into account that during mold filling and curing thin mold cavities, the thermal physical properties may vary from location to location and may change as a function of time. The studied material can be considered as homogeneous and isotropic. The results of applying some numerical schemes to solve the above model, corroborated with the results of the experimental measurements, can highlight the advantages of this method of mold filling.
Mode I Fracture Toughness Evaluation of Adhesively Bonded Joints via J‐Integral and DIC
Authors: Perrella Michele , Berardi Valentino Paolo , Armentani Enrico
Published: February 2020

Amorphous polymers, such as epoxy resins, are commonly used in the realization of adhesively bonded joints. In this paper an evaluation of mode I fracture toughness of bonded joints is presented. Moreover, an identification of cohesive zone model parameters via Rice's J‐integral is described. Experimental tests are performed on double cantilever beam specimens and relative displacements between adherends are acquired by using the digital image correlation technique. The obtained interface law can be implemented in a finite element code for simulating the decohesion process of complex bonded structures.
Endoscopic Injection of the Longus Capiti Muscle in the Treatment of Dystonic Head Flexion
Authors: Hicklin Lucy A. , Marion Marie‐Helene
Published: February 2020

Background

Anterocollis posture is a relatively rare finding among patients with cervical dystonia and often the cause of treatment failure. The dystonic posture can be complex to analyze, and the deep flexor muscles of the neck, longus capiti, and longus coli can be challenging to access.

Methods

We present a modification of a previously described endoscopic technique that allows straightforward access to the longus capiti muscles in an outpatient setting under local anesthetic.

Results

We describe the technique based on our experience on 6 patients during a 2‐year period with a total of 22 injections, and we review the literature.

Conclusion

The injection is well tolerated and has led to significant improvement in the majority of patients.
Generalized focal surfaces of spacelike curves lying in lightlike surfaces
Authors: Liu Siyao , Wang Zhigang
Published: February 2020

The main work of this paper is to investigate two kinds of generalized focal surfaces and two kinds of evolutes generated by spacelike curve
lying in lightlike surfaces in Minkowski three‐space. Applying the method of unfolding theory in singularity theory to our study, it is shown that there exist the cuspidal edge and the swallowtail types of singularities in each of two classes of generalized focal surfaces under certain conditions; the only cusps will appear in each of evolutes. Two new geometric invariants are presented to classify the singularities of generalized focal surfaces and evolutes. Much more importantly, we reveal the correspondence among the geometric invariants, the types of singularities on generalized focal surfaces and evolutes, the singularities of two kinds of evolutes, and the contact of
with the osculating spheres. Finally, several examples are presented to demonstrate the correctness of the theoretical results.
Experimental demonstration and analysis of underwater wireless optical communication link: Design, BCH coded receiver diversity over the turbid and turbulent seawater channels
Authors: Ramavath Prasad Naik , Udupi Shripathi Acharya , Krishnan Prabu
Published: February 2020

In this article, we demonstrate an experimental underwater wireless optical communication (UWOC) system in the presence of air bubbles and weak turbulence for varying turbidity levels of the aquatic optical medium. The major limiting factors of the UWOC system are: absorption, scattering, and beam fluctuations; these effects can be mitigated by employing transmitter/receiver diversity schemes and channel codes. In this proposed system, we have employed receiver diversity (selection combining (SC), majority logic combining (MLC), and equal gain combining (EGC)) techniques augmented with Bose‐Chaudhuri‐Hocquenghem (BCH) codes to improve the performance of on‐off keying modulated UWOC system. The bit error rate (BER) expressions are derived for the proposed system and results are validated using analytic and experimental means. The results show that the proposed system, that is, the receiver employing SC, MLC, and EGC receiver combining techniques augmented with the BCH code provides a transmit power gain of 4, 6, and 8 dB respectively, when compared with the uncoded single‐input single‐output system, at a BER of 10−5.