bluuebunny/crossref_metadata_2025 huggingface dataset:
In Vitro 3D Cultures to Reproduce the Bone Marrow Niche
Authors: Ham Justin , Lever Lauren , Fox Maura , Reagan Michaela R
Published: August 2019

Over the past century, the study of biological processes in the human body has progressed from tissue culture on glass plates to complex 3D models of tissues, organs, and body systems. These dynamic 3D systems have allowed for more accurate recapitulation of human physiology and pathology, which has yielded a platform for disease study with a greater capacity to understand pathophysiology and to assess pharmaceutical treatments. Specifically, by increasing the accuracy with which the microenvironments of disease processes are modeled, the clinical manifestation of disease has been more accurately reproduced in vitro. The application of these models is crucial in all realms of medicine, but they find particular utility in diseases related to the complex bone marrow niche. Osteoblast, osteoclasts, bone marrow adipocytes, mesenchymal stem cells, and red and white blood cells represent some of cells that call the bone marrow microenvironment home. During states of malignant marrow disease, neoplastic cells migrate to and join this niche. These cancer cells both exploit and alter the niche to their benefit and to the patient's detriment. Malignant disease of the bone marrow, both primary and secondary, is a significant cause of morbidity and mortality today. Innovative study methods are necessary to improve patient outcomes. In this review, we discuss the evolution of 3D models and compare them to the preceding 2D models. With a specific focus on malignant bone marrow disease, we examine 3D models currently in use, their observed efficacy, and their potential in developing improved treatments and eventual cures. Finally, we comment on the aspects of 3D models that must be critically examined as systems continue to be optimized so that they can exert greater clinical impact in the future. © 2019 The Authors. JBMR Plus published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research.
3D FEM modeling and study of novel structure of magnetoelectric composites
Authors: Do Tuan Anh , Talleb Hakeim , Gensbittel Aurélie , Ren Zhuoxiang
Published: August 2019

This paper presents a 3D multiphysic modeling based on the coupling between the nonlinear discrete energy‐averaged model and the finite element method for the design optimization of magnetoelectric laminar structures. The model is applied to investigate the influence of the layer width on the output voltage and power performances while taking into account the magnetic losses due to the eddy currents.
Research on spatial reconstruction of arc plasma based on heuristic search and regularization inversion method
Authors: Zhang Guogang , Xu Youdang , Dong Jinlong , Qie Shuang , Kurrat Michael
Published: August 2019

The morphology analysis of arc plasma inside a low‐voltage circuit breaker is a practical approach to investigate its current interruption performance. It is a typical ill‐posed problem to determine the arc current distribution from the induced magnetic field of arc plasma. The regularization method has been proven effective in solving inverse magnetic problems. However, the arrangement of current‐carrying conductors in arc chamber and the time‐varying characteristics of arc plasma make it difficult to yield a reasonable inverse solution. In this paper, a heuristic search algorithm is proposed. The solving procedure is as follows. First, a series of inverse models with supposed arc root positions are created dynamically. Second, the Tikhonov regularization method with quasi‐optimality criterion is applied to solve the inverse problems iteratively. Then each solution is evaluated and the best solution can be found out. After all the models according to the different arcing stages have been solved, an image list of current density distribution of arc plasma is formed. An experimental system measuring the 2D magnetic field of arc plasma has been built, in which a 64‐unit hall‐effect sensor array and the corresponding data acquisition system are adopted to detect the arc magnetic field; meanwhile, the waveforms of arc voltage and current are recorded by a digital oscilloscope and the optical images of arc plasma are captured by a high speed charge‐coupled device camera. The experimental results show that the inverse results of arc current density distribution are in accordance with the optical images. The proposed inverse method provides a noninvasive technique for the diagnosis of arc plasma.
The “other” 15–40%: The Role of Non‐Collagenous Extracellular Matrix Proteins and Minor Collagens in Tendon
Authors: Taye Nandaraj , Karoulias Stylianos Z. , Hubmacher Dirk
Published: August 2019

Extracellular matrix (ECM) determines the physiological function of all tissues, including musculoskeletal tissues. In tendon, ECM provides overall tissue architecture, which is tailored to match the biomechanical requirements of their physiological function, that is, force transmission from muscle to bone. Tendon ECM also constitutes the microenvironment that allows tendon‐resident cells to maintain their phenotype and that transmits biomechanical forces from the macro‐level to the micro‐level. The structure and function of adult tendons is largely determined by the hierarchical organization of collagen type I fibrils. However, non‐collagenous ECM proteins such as small leucine‐rich proteoglycans (SLRPs), ADAMTS proteases, and cross‐linking enzymes play critical roles in collagen fibrillogenesis and guide the hierarchical bundling of collagen fibrils into tendon fascicles. Other non‐collagenous ECM proteins such as the less abundant collagens, fibrillins, or elastin, contribute to tendon formation or determine some of their biomechanical properties. The interfascicular matrix or endotenon and the outer layer of tendons, the epi‐ and paratenon, includes collagens and non‐collagenous ECM proteins, but their function is less well understood. The ECM proteins in the epi‐ and paratenon may provide the appropriate microenvironment to maintain the identity of distinct tendon cell populations that are thought to play a role during repair processes after injury. The aim of this review is to provide an overview of the role of non‐collagenous ECM proteins and less abundant collagens in tendon development and homeostasis. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 38:23–35, 2020
Inhibition of COX‐2 Pathway as a Potential Prophylaxis Against Arthrofibrogenesis in a Rabbit Model of Joint Contracture
Authors: Salib Christopher G. , Reina Nicolas , Trousdale William H. , Limberg Afton K. , Tibbo Megan E. , Jay Anthony G. , Robin Joseph X. , Turner Travis W. , Jones Carter R. , Paradise Christopher R. , Lewallen Eric A. , Bolon Brad , Carter Jodi M. , Berry Daniel J. , Morrey Mark E. , Sanchez‐Sotelo Joaquin , van Wijnen Andre J. , Abdel Matthew P.
Published: August 2019

Arthrofibrosis is a common complication following total knee arthroplasty caused by pathologic fibroblast activation and excessive collagen deposition around a synovial joint leading to debilitating loss of motion. Treatment options are limited because the pathologic mechanisms remain to be characterized. Dysregulation of the inflammatory cascade may lead to communication between myofibroblasts and immune cells triggering tissue metaplasia, and excessive collagen deposition described clinically as arthrofibrosis. We explored the novel use of celecoxib (selective cyclooxygenase‐2 [COX‐2] inhibitor) to disrupt the downstream effects of the post‐traumatic inflammatory cascade and inhibit scar tissue formation in a validated rabbit model of arthrofibrosis combined with new parameters for quantifying the stiffness of the posterior capsule. Biomechanical and molecular analyses, of contracted rabbit knee posterior capsule tissue after COX‐2 inhibition revealed increased maximal passive extension and down‐regulation of collagen messenger RNA compared with controls. Histopathologic examination suggested a trend of decreased quantities of dense fibrous connective tissue with COX‐2 inhibition. These data may suggest that inhibiting the inflammatory cascade could potentially reduce pathologic myofibroblast activation, thereby reducing scar tissue formation and increasing the range of motion in arthrofibrotic joints. Implementing a multi‐modal pharmacologic approach may simultaneously target numerous cellular components contributing to the complex process of arthrofibrogenesis. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:2609–2620, 2019
Bone Stress Injuries Are Associated With Differences in Bone Microarchitecture in Male Professional Soldiers
Authors: Schanda Jakob E. , Kocijan Roland , Resch Heinrich , Baierl Andreas , Feichtinger Xaver , Mittermayr Rainer , Plachel Fabian , Wakolbinger Robert , Wolff Klaus , Fialka Christian , Gruther Wolfgang , Muschitz Christian
Published: August 2019

Bone stress injuries are commonly due to repetitive loading, as often described in competitive athletes or military recruits. The underlying pathophysiology of bone stress injuries is multifactorial. The present cross‐sectional study investigated (i) cortical and trabecular bone microstructure as well as volumetric bone mineral density in subjects with bone stress injuries at the tibial diaphysis, measured at the distal tibia and the distal radius by means of high‐resolution peripheral quantitative computed tomography (CT), (ii) areal bone mineral density using dual‐energy X‐ray absorptiometry as well as calcaneal dual X‐ray absorptiometry and laser, and (iii) the influence on bone turnover markers of formation and resorption at the early phase after injury. A total of 26 Caucasian male professional soldiers with post‐training bone stress injury at the tibial diaphysis were included (case group). A total of 50 male, Caucasian professional soldiers from the same military institution served as controls (control group). High‐resolution peripheral quantitative CT revealed a higher total area at the radius within the case group. Cortical bone mineral density was reduced at the radius and tibia within the case group. The trabecular number and trabecular thickness were reduced at the tibia in the case group. The trabecular network was more inhomogeneous at the radius and tibia within the case group. Calcaneal dual X‐ray absorptiometry and laser was significantly reduced in the case group. This study quantified differences in bone microstructure among otherwise healthy individuals. Differences in bone microarchitecture may impair the biomechanical properties by increasing the susceptibility to sustain bone stress injuries. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:2516–2523, 2019
Aspects of human physical and behavioural evolution during the last 1 million years
Authors: Galway‐Witham Julia , Cole James , Stringer Chris
Published: August 2019

This paper reviews some of the main advances in our understanding of human evolution over the last 1 million years, presenting a holistic overview of a field defined by interdisciplinary approaches to studying the origins of our species. We begin by briefly summarizing the climatic context across the Old World for the last 1 million years before directly addressing the fossil and archaeological records. The main themes in this work explore (i) recent discoveries in the fossil record over the last 15 years, such asHomo nalediandHomo floresiensis; (ii) the implications of palaeogenetics for understanding the evolutionary history of, and relationships between, Neanderthals, Denisovans andHomo sapiens; (iii) the interplay between physiology and metabolic demand, landscape use, and behavioural adaptations in the evolution of morphological and behavioural innovation; and (iv) recent advances in archaeological understanding for the behavioural record, in particular that of the Neanderthals. This paper seeks to provide a broad‐scale, holistic perspective of our current understanding of human evolution for the last 1 Ma, providing a reference point for researchers that can be built upon as new discoveries continue to develop the landscapes of human evolution. © 2019 The Authors.Journal of Quaternary SciencePublished by Wiley Periodicals, Inc.
Pharyngeal‐sparing radiation for head and neck carcinoma of unknown primary following TORS assisted work‐up
Authors: Grewal Amardeep S. , Rajasekaran Karthik , Cannady Steven B. , Chalian Ara A. , Ghiam Alireza F. , Lin Alexander , LiVolsi Virginia , Lukens John N. , Mitra Nandita , Montone Kathleen T. , Newman Jason G. , O'Malley Bert W. , Rassekh Christopher H. , Weinstein Gregory S. , Swisher‐McClure Samuel
Published: August 2019

Objective

In patients with head and neck carcinoma of unknown primary (HNCUP;pT0) following TORS‐assisted workup, we have adopted a pharyngeal‐sparing radiation therapy (PSRT) approach targeting only the at‐risk neck and omitting treatment of the pharynx. We report outcomes following PSRT, and compare to institutional historical control subjects who received pharyngeal‐targeted RT (PRT).

Methods

Between 2009 and 2018, 172 patients underwent TORS‐assisted endoscopy as part of their workup for HNCUP. Following TORS, 54 patients had pT0 disease, of which 45 received RT. Forty‐nine percent received PSRT and 51% received PRT.

Results

No statistically significant differences existed between the PSRT and PRT groups with respect to overall nodal distribution, p16 positivity (55% vs. 43%, P = .12), neck dissection rates (77% vs. 65%, P = .51), and administration of chemotherapy (55% vs. 65%, P = .55). Median follow‐up for PSRT and PRT groups were 24 and 28 months, respectively (P = .04). Two‐year RFS was 86% and 74% for PSRT and PRT patients, respectively (log‐rank P = .30). Three and six patients recurred after PSRT and PRT, respectively. Two‐year OS for PSRT and PRT patients was 91% and 74%, respectively (log‐rank P = .31). Compared to PRT, PSRT was associated with statistically significantly less: grade 2+ mucositis (18% vs. 91%, P < .01), new opioid requirement (27% vs. 91%, P < .01), mean weight loss during RT (6.2 lbs vs. 17.4 lbs, P < .01), feeding tube placement during RT (5% vs. 43%, P < .01), and treatment‐related unplanned hospitalizations (9% vs. 39%, P = .04).

Conclusion

Following TORS‐assisted management of patients with pT0 HNCUP, we observed reduced toxicity following PSRT compared to PRT without apparent compromise of disease cure.

Level of Evidence

Level 3 evidence, retrospective review comparing cases and controls

Laryngoscope, 130:691–697, 2020
Forest fires as potential triggers for production and mobilization of polycyclic aromatic hydrocarbons to the terrestrial ecosystem
Authors: Campos Isabel , Abrantes Nelson , Pereira Patrícia , Micaelo Ana Cristina , Vale Carlos , Keizer Jan Jacob
Published: August 2019

Abstract

Although forest fires have been identified as an important source of polycyclic aromatic hydrocarbons (PAHs), this problematic has not been thoroughly studied yet. This study addressed the role of wildfires and time since fire in the production and mobilization of PAHs to the terrestrial compartment. Levels of 15 priority PAHs were assessed in topsoil and ash samples (by GC–MS analysis) collected in two burnt areas and an unburnt one, comprising two types of vegetation coverage and four sampling occasions after fire. The fire had triggered an immediately increase of PAH levels in topsoil, according to the comparison of burnt and unburnt samples, but this impact had largely faded 4 months later. Although the fire severity did not play a role in immediate postfire PAH contents in topsoil and ashes, variations were found with the type of vegetation coverage being higher in pine slopes. The wildfire event markedly changed PAHs composition through enrichment in three‐ring PAHs (69% vs. 27%, burnt and unburnt, respectively), which dwindled more markedly in topsoil than in ashes. This study pointed out the key role of wildfires as a source of PAHs to the terrestrial compartment, as unveiled by the increased levels in topsoil and ashes. Additionally, it was found that PAHs could be mobilized from these matrixes over the first year after the fire, possibly leading to aquatic contamination. This finding suggests wildfires as a diffuse source of PAH contamination to freshwater systems, which need to be considering in future monitoring/management programs on the environmental impact of wildfires.
Postprandial Responses of Serum Bile Acids in Healthy Humans after Ingestion of Turmeric before Medium/High‐Fat Breakfasts
Authors: Ghaffarzadegan Tannaz , Zanzer Yoghatama Cindya , Östman Elin , Hållenius Frida , Essén Sofia , Sandahl Margareta , Nyman Margareta
Published: August 2019

Scope

Bile acids (BAs) are known to regulate a number of metabolic activities in the body. However, very little is known about how BAs are affected by diet. This study aims to investigate whether a single dose of turmeric‐based beverage (TUR) before ingestion of medium‐ (MF) or high‐fat (HF) breakfasts would improve the BA profile in healthy subjects.

Methods and results

Twelve healthy subjects are assigned to a randomized crossover single‐blind study. The subjects receive isocaloric MF or HF breakfasts after a drink containing flavored water with or without an extract of turmeric with at least 1‐week wash‐out period between the treatments. Postprandial BAs are measured using protein precipitation followed by ultra‐high‐performance liquid chromatography−mass spectrometry analysis. The concentration of BAs is generally higher after HF than MF breakfasts. Ingestion of TUR before MF breakfast increases the serum concentrations of free and conjugated forms of cholic (CA) and ursodeoxycholic acids (UDCA), as well as the concentrations of chenodeoxycholic acid (CDCA) and its taurine‐conjugated forms. However, the concentration of conjugated forms of deoxycholic acid (DCA) decreases when TUR is taken before HF breakfast.

Conclusion

TUR ingestion before MF and HF breakfasts improve BA profiles and may therefore have potential health‐promoting effects on BA metabolism.
The mycotoxin beauvericin induces oocyte mitochondrial dysfunction and affects embryo development in the juvenile sheep
Authors: Mastrorocco Antonella , Martino Nicola Antonio , Marzano Giuseppina , Lacalandra Giovanni Michele , Ciani Elena , Roelen Bernard A. J. , Dell'Aquila Maria Elena , Minervini Fiorenza
Published: August 2019

Beauvericin (BEA) is a mycotoxin produced by Beauveria bassiana and Fusarium species recently reported as toxic on porcine oocyte maturation and embryo development. The aim of this study was to assess, in the juvenile sheep, whether its effects are due to alterations of oocyte and/or embryo bioenergetic/oxidative status. Cumulus‐oocyte‐complexes (COCs) were exposed to BEA during in vitro maturation (IVM), evaluated for cumulus cell (CC) apoptosis, oocyte maturation and bioenergetic/oxidative status or subjected to in vitro fertilization (IVF) and embryo culture (IVEC). Oocyte nuclear maturation and embryo development were assessed after Hoechst staining and CC apoptosis was analysed by terminal deoxynucleotidyl transferase‐mediated dUTP nick‐End labeling assay and chromatin morphology after Hoechst staining by epifluorescence microscopy. Oocyte and blastocyst bioenergetic/oxidative status were assessed by confocal microscopy after mitochondria and reactive oxygen species labelling with specific probes. BEA showed various toxic effects, that is, short‐term effects on somatic and germinal compartment of the COC (CCs and the oocyte) and long‐term carry‐over effects on developing embryos. In detail, at 5 µM, it significantly reduced oocyte maturation and immature oocytes showed increased late‐stage (Type C) CC apoptosis and DNA fragmentation while matured oocytes showed unaffected CC viability but abnormal mitochondrial distribution patterns. At lower tested concentrations (3–0.5 µM), BEA did not affect oocyte maturation, but matured oocytes showed reduced mitochondrial activity. At low concentrations, BEA impaired embryo developmental capacity and blastocyst quality after IVF and IVEC. In conclusion, in the juvenile sheep, COC exposure to BEA induces CC apoptosis and oocyte mitochondrial dysfunction with negative impact on embryo development.
Improvement of water vapor barrier and mechanical properties of sago starch‐kaolinite nanocomposites
Authors: Ruamcharoen Jareerat , Munlee Ruszana , Ruamcharoen Polphat
Published: August 2019

The composite films of sago starch were prepared by incorporation of various amount of kaolinite (K) and kaolinite intercalated by dimethyl sulfoxide (DMSO) (KD) via solution blending method in order to reduce the water vapor transmission and enhance mechanical properties of starch based films. The kaolinite intercalation by DMSO and the composite films were characterized by using X‐ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscope techniques. The result showed that well‐dispersed kaolinite layers were delaminated in the starch matrix attesting to intercalate and exfoliate composite films. The effect of kaolinite content on the water vapor transmission and tensile properties of the composite films was investigated. The water vapor transmission of the starch film (neat starch film ca. 0.132 g.cm3/h) decreased with the addition of K and KD to the starch. It was also observed that the maximum tensile strength (5.18 MPa) was attained for the composite film with 4% by weight of clay content. The improvement in the tensile strength and modulus of starch‐based composites was due to the strong interfacial interaction between matrix and kaolinite clay, correlating to the change of morphology of the starch composite films as revealed by scanning electron microscopy.
Homogeneous dispersion of multiwalled carbon nanotubes via in situ bubble stretching and synergistic cyclic volume stretching for conductive LDPE/MWCNTs nanocomposites
Authors: Yang Zhitao , Li Qingsong , Tong Yizhang , Wu Ting , Feng Yanhong
Published: August 2019

Low‐density polyethylene (LDPE)/multiwalled carbon nanotubes (MWCNTs) nanocomposites with different foaming agent (OBSH) contents were innovatively prepared via In Situ Bubble Stretching (ISBS) and synergistic cyclic volume stretching. The cyclic convergent and divergent flow makes the MWCNTs repeatedly subjected to bubble stretching, which is conducive to the efficient dispersion of MWCNTs in the matrix. The thermal weight loss of neat OBSH and nanocomposite were characterized by thermal gravimetric analyzer (TGA), which indicated that the OBSH in the nanocomposite had been completely decomposed into gas during the plasticizing transport process. The results of morphology showed that the moderate content of OBSH had better dispersion effect on MWCNTs. At optimal OBSH content, the OBSH could generate enough gas and larger bubbles per unit time to provide greater expansion forces to do much for the dispersion of MWCNTs. The dynamic mechanical analysis (DMA) was further carried out and also proved that the content of OSBH was an important factor for the dispersion of MWCNTs. Moreover, the relationship between the OBSH content and conductivity was discussed in details. The improvement in conductive properties of nanocomposites associated with the use of the method can be attributed to a more homogeneous dispersion of MWCNTs. POLYM. ENG. SCI., 59:2072–2081, 2019. © 2019 Society of Plastics Engineers
Effect of clay amount and reprocessing cycles on thermal, morphological, and mechanical properties of polypropylene/organovermiculite nanocomposites
Authors: Araújo Elvis A. F. , Visconte Leila L. Y. , da Silva Ana L. N. , Sirelli Lys , Pacheco Élen B. A.V.
Published: August 2019

Nanocomposites of polypropylene (PP) and PP‐grafted‐maleic anhydride (PP‐g‐MA) with and without organophilic vermiculite (OVMT) (5–8%w/w) were evaluated. The nanocomposites and neat PP were submitted to extrusion reprocessing cycles. It was found that the presence of OVMT in PP/PP‐g‐MA was critical for maintaining thermal stability during reprocessing. The exfoliation/intercalation was confirmed, mainly, in the nanocomposite submitted to reprocessing cycles, by X‐ray diffraction. The melt flow index (MFI) values for the 3× and 5× reprocessed PP increased by 40% and 70%, respectively, as compared to the neat PP. The MFI for the 3× and 5× reprocessed PP/PP‐g‐MA/OVMT decreased 26% and 17%, respectively, as compared to the decrease occurred in the 3× and 5× reprocessed PP, indicating that the presence of 5% (w/w) OVMT was sufficient to allow an increase in viscosity. The reprocessed nanocomposites exhibited values for tensile and flexural strengths and Izod impact, in general, greater than or near to those of PP with the same number of reprocessing cycles. The increase or maintenance of mechanical properties seems to depend on a balance between the extent of intercalation/exfoliation and dispersion of OVMT in the PP matrix, and the degree of degradation of the PP matrix. POLYM. ENG. SCI., 59:2110–2120, 2019. © 2019 Society of Plastics Engineers
Dexmedetomidine Alleviates Postpartum Depressive Symptoms following Cesarean Section in Chinese Women: A Randomized Placebo‐Controlled Study
Authors: Yu He‐Ya , Wang Sai‐Ying , Quan Cheng‐Xuan , Fang Chao , Luo Shi‐Chao , Li Dan‐Yang , Zhen Shan‐Shan , Ma Jia‐Hui , Duan Kai‐Ming
Published: August 2019

Objectives

Few studies have investigated the prophylactic efficacy of dexmedetomidine (DEX) in postpartum depressive symptoms (PDS). A randomized double‐blind placebo‐controlled trial was conducted to investigate whether the administration of DEX, immediately after delivery and for patient‐controlled intravenous analgesia (PCIA), can attenuate PDS.

Methods

A total of 600 parturients scheduled for elective cesarean delivery under spinal anesthesia were randomly allocated into the control group (infusion with 0.9% normal saline after delivery and PCIA with sufentanil) and the DEX group (DEX infusion 0.5 μg/kg after delivery and PCIA with DEX plus sufentanil). The prevalence of postpartum depressive disorders was indicated by the Edinburgh Postnatal Depression Scale (EPDS). Postoperative analgesia, sedation, and sleep quality of parturients were also assessed.

Results

Postpartum blues and PDS prevalence in the DEX, versus control, group were significantly lower (5.0% vs 14.1%, p<0.001; 5.7% vs 16.3%, p<0.001, respectively), especially in parturients with antenatal depression or moderate stress during pregnancy. Compared with the control group, the EPDS score at postpartum days 7 and 42 in the DEX group was significantly lower (4.23 ± 4.37 vs 1.93 ± 3.36, p<0.001; 4.68 ± 4.78 vs 1.99 ± 3.18, p<0.001, respectively), as was the incidence of postpartum self‐harm ideation at postpartum days 7 and 42 in the DEX group versus the control group (1.1% vs 4.0%, p=0.03; 0.4% vs 2.9%, p=0.04, respectively). The pain score and the sleep quality in the DEX group were better than that in the control group (p<0.001).

Conclusion

The application of DEX in the early postpartum period can significantly attenuate the incidence of postpartum depressive disorders.
Azobenzene–Hemicyanine Conjugated Polymeric Chemosensor for the Rapid and Selective Detection of Cyanide in Pure Aqueous Media
Authors: Haldar Ujjal , Sharma Rini , Kim Eun‐Jae , Lee Hyung‐Il
Published: August 2019

A water‐soluble polymeric probe was designed and synthesized that can be used for the colorimetric selective detection of cyanide ions in pure aqueous media. In particular, P1, a water‐soluble random terpolymer (P1) of N,N′‐dimethylacrylamide, 2‐((E)‐4‐((E)‐(4‐((2‐(acryloyloxy)ethyl)(methyl)amino)phenyl)diazenyl)styryl)‐1,3,3‐trimethyl‐3H‐indol‐1‐ium (M1), and N‐(4‐benzoylphenyl)acrylamide was synthesized via traditional free‐radical polymerization. Upon the addition of CN− ions to a P1 solution, a macroscopically detectable color change of the solution from brick red to light yellow took place, which was associated with a low limit of analyte detection (1.23 μM). Notably, P1 exhibited excellent selectivity toward CN− over other anions and biothiols, which may be present in the medium. Such highly selective colorimetric response to CN− by P1 originated from the nucleophilic attack of CN− anions onto the electron‐deficient polarized CN bonds of P1's indolium moieties, resulting in the perturbation of the intramolecular charge transfer process occurring within the probe via destruction of the polymer's extended π‐conjugation. P1 was also immobilized on a quartz slide by spin coating and then exposed to ultraviolet light. The resulting polymeric film displayed a rapid response to CN− consisting in a distinct color change, extending the scope of the usefulness of P1 as a cyanide‐ion probe beyond the solution phase. © 2019 Wiley Periodicals, Inc. J. Polym. Sci. 2020, 58, 124–131
Effects of forest fires on the permafrost environment in the northern Da Xing'anling (Hinggan) mountains, Northeast China
Authors: Li Xiaoying , Jin Huijun , He Ruixia , Huang Yadong , Wang Hongwei , Luo Dongliang , Jin Xiaoying , Lü Lanzhi , Wang Lizhong , Li Wei'hai , Wei Changlei , Chang Xiaoli , Yang Sizhong , Yu Shaopeng
Published: August 2019

Forest fires have significantly impacted the permafrost environment, and many research programs looking at this have been undertaken at higher latitudes. However, their impacts have not yet been systematically studied and evaluated in the northern part of northeast China at mid‐latitudes. This study simultaneously measured ecological and geocryological changes at various sites in the boreal forest at different stages after forest fires (chronosequence approach) in the northern Da Xing'anling (Hinggan) Mountains, Northeast China. We obtained results through field investigations, monitoring and observations, remote sensing interpretations, and laboratory tests. The results show that forest fires have resulted in a decreased Normalized Difference Vegetation Index (NDVI) and soil moisture contents in the active layer, increased active layer thickness (ALT) and ground temperatures, and the release of a large amount of C and N from the soils in the active layer and at shallow depths of permafrost. NDVI and species biodiversity have gradually increased in the years since forest fires. However, the vegetation has not fully recovered to the climax community structures and functions of the boreal forest ecosystems. For example, ground temperatures, ALT, and soil C and N contents have been slowly recovering in the 30 years after the forest fires, but they have not yet been restored to pre‐fire levels. This study provides important scientific bases for assessment of the impacts of forest fires on the boreal forest ecosystems in permafrost regions, environmental restoration and management, and changes in the carbon stock of soils at shallow (<3 m) depths in the Da Xingan'ling Mountains in northeast China.
Permafrost zonation index map and statistics over the Qinghai–Tibet Plateau based on field evidence
Authors: Cao Bin , Zhang Tingjun , Wu Qingbai , Sheng Yu , Zhao Lin , Zou Defu
Published: August 2019

Permafrost is prevalent over the Qinghai–Tibet Plateau (QTP), but mapping its distribution is challenging due to the limited availability of ground‐truth data sets and strong spatial heterogeneity in the region. Based on a recently developed inventory of permafrost presence or absence from 1475in situobservations, we developed and trained a statistical model and used it to compile a high‐resolution (30 arc‐seconds) permafrost zonation index (PZI) map. The PZI model captures the high spatial variability of permafrost distribution over the QTP because it considers multiple controlling variables, including near‐surface air temperature downscaled from re‐analysis, snow cover days and vegetation cover derived from remote sensing. Our results showed the new PZI map achieved the best performance compared to available existing PZI and traditional categorical maps. Based on more than 1000in situmeasurements, the Cohen's kappa coefficient and overall classification accuracy were 0.62 and 82.5%, respectively. Excluding glaciers and lakes, the area of permafrost regions over the QTP is approximately 1.54 (1.35–1.66) ×106km2, or 60.7 (54.5–65.2)% of the exposed land, while area underlain by permafrost is about 1.17 (0.95–1.35) ×106km2, or 46 (37.3–53.0)%.
Ground temperature and deformation analysis for an expressway embankment in warm permafrost regions of the Tibet plateau
Authors: Liu Jiankun , Tai Bowen , Fang Jianhong
Published: August 2019

The physical and mechanical processes relating to infrastructure are strongly intertwined in subgrades of road or railway in warm permafrost regions, where the evolution of these processes may influence the functionality of infrastructure. Thus, this study analyzed the embankment thermal regime and thaw settlement behavior based on monitored data for three sections of the newly constructed Gonghe–Yushu expressway (GYE) in a warm permafrost area of Tibet. The efficiencies of crushed rock, ventilated, and insulated embankments in maintaining permafrost temperature were evaluated in relation to the permafrost table (PT) and the annual warming rate of the permafrost. The deformation characteristics of three embankments for different soil layers are summarized, along with analysis of heat balance. The results show that: (a) the permafrost thaw rate has a positive linear correlation with mean annual ground temperature; (b) the permafrost displays a warming trend regardless of whether PT increases or decreases; (c) the total deformation of a given embankment shows a tendency toward settlement; and (d) subgrade peak thaw settlement occurs later than its maximum seasonal thaw depth.
Boosting phosphorylation site prediction with sequence feature‐based machine learning
Authors: Maiti Shyantani , Hassan Atif , Mitra Pralay
Published: August 2019

Protein phosphorylation is one of the essential posttranslation modifications playing a vital role in the regulation of many fundamental cellular processes. We propose a LightGBM‐based computational approach that uses evolutionary, geometric, sequence environment, and amino acid‐specific features to decipher phosphate binding sites from a protein sequence. Our method, while compared with other existing methods on 2429 protein sequences taken from standard Phospho.ELM (P.ELM) benchmark data set featuring 11 organisms reports a higher F1 score = 0.504 (harmonic mean of the precision and recall) and ROC AUC = 0.836 (area under the curve of the receiver operating characteristics). The computation time of our proposed approach is much less than that of the recently developed deep learning‐based framework. Structural analysis on selected protein sequences informs that our prediction is the superset of the phosphorylation sites, as mentioned in P.ELM data set. The foundation of our scheme is manual feature engineering and a decision tree‐based classification. Hence, it is intuitive, and one can interpret the final tree as a set of rules resulting in a deeper understanding of the relationships between biophysical features and phosphorylation sites. Our innovative problem transformation method permits more control over precision and recall as is demonstrated by the fact that if we incorporate output probability of the existing deep learning framework as an additional feature, then our prediction improves (F1 score = 0.546; ROC AUC = 0.849). The implementation of our method can be accessed at http://cse.iitkgp.ac.in/~pralay/resources/PPSBoost/ and is mirrored at https://cosmos.iitkgp.ac.in/PPSBoost.
Facile removal of 4‐methoxybenzyl protecting group from selenocysteine
Authors: Jenny Kaelyn A. , Ste.Marie Emma J. , Mose Gracyn , Ruggles Erik L. , Hondal Robert J.
Published: August 2019

Historically, methods to remove the 4‐methoxybenzyl (Mob)–protecting group from selenocysteine (Sec) in peptides have used harsh and toxic reagents. The use of 2,2′‐dithiobis‐5‐nitropyridine (DTNP) is an improvement over these methods; however, many wash steps are required to remove the by‐product contaminant 5‐nitro‐2‐thiopyridine. Even with many washes, excess DTNP adheres to the peptide. The final product needs excess purification to remove these contaminants. It was recently discovered by our group that hindered hydrosilanes could be used to reduce Cys(Mob). We sought to apply a similar methodology to reduce Sec(Mob), which we expected to be even more labile. Here, we present a gentle and facile method for deprotection of Sec(Mob) using triethylsilane (TES), phenol, and a variety of other scavengers often used in deprotection cocktails. The different cocktails were all incubated at 40 °C for 4 hours. The combination of TFA/TES/thioanisole (96:2:2) appeared to be the most efficient of the cocktails tested, providing complete deprotection and yielded peptide that was mainly in the diselenide form. This cocktail also showed no evidence of side reactions or significant contaminants in the high‐performance liquid chromatography (HPLC) and mass spectral (MS) analyses. We envision that our new method will allow for a simple and gentle “one‐pot” deprotection of Sec(Mob) following solid‐phase peptide synthesis and will minimize the need for extensive purification steps.
Surface temperature distribution on a spherical ice particle growing by accretion in wet growth regime
Authors: Luque Melina Y. , Bürgesser Rodrigo E. , Castellano Nesvit E.
Published: August 2019

Experimental evidence has demonstrated that temperature on the surface of an ice particle growing by accretion is not uniform. This non‐uniformity is relevant because the ice particle surface temperature is an important microphysical parameter that influences the sign and magnitude of the charge transfer during ice particles collisions. In particular, when high values of ambient temperature and liquid water content are reached, the ice particle surface temperature is expected to reach 0 °C, which is known as wet growth regime. Previous experimental results have shown that wet growth is not uniformly reached on the ice particle surface and a surface temperature distribution is developed. In order to know the surface temperature distribution of a fixed ice particle growing by accretion of supercooled water, numerical calculations were carried out. It was found that the surface temperature distribution has a strong dependence on liquid water content, ambient temperature, airflow velocity and water droplet size. The stagnation point always reaches higher temperatures and, in many cases, its temperature is near 0 °C. For some values of the liquid water content, ambient temperature and airflow velocity, it was possible to determine temperature differences up to 7 °C between the stagnation point and the equator. This variation in the surface temperature implies that the region near the stagnation point would experience wet growth, while the rest of the ice particle surface would remain in dry growth regime, supporting the partial wet growth hypothesis. This could also explain the charge transfer reported during ice particles collisions under wet growth conditions.
Identification of novel biomarkers of hepatocellular carcinoma by high‐definition mass spectrometry: Ultrahigh‐performance liquid chromatography quadrupole time‐of‐flight mass spectrometry and desorption electrospray ionization mass spectrometry imaging
Authors: Nagai Koshi , Uranbileg Baasanjav , Chen Zhen , Fujioka Amane , Yamazaki Takahiro , Matsumoto Yotaro , Tsukamoto Hiroki , Ikeda Hitoshi , Yatomi Yutaka , Chiba Hitoshi , Hui Shu‐Ping , Nakazawa Toru , Saito Ritsumi , Koshiba Seizo , Aoki Junken , Saigusa Daisuke , Tomioka Yoshihisa
Published: August 2019

Rationale

Hepatocellular carcinoma (HCC) is a highly malignant disease for which the development of prospective or prognostic biomarkers is urgently required. Although metabolomics is widely used for biomarker discovery, there are some bottlenecks regarding the comprehensiveness of detected features, reproducibility of methods, and identification of metabolites. In addition, information on localization of metabolites in tumor tissue is needed for functional analysis. Here, we developed a wide‐polarity global metabolomics (G‐Met) method, identified HCC biomarkers in human liver samples by high‐definition mass spectrometry (HDMS), and demonstrated localization in cryosections using desorption electrospray ionization MS imaging (DESI‐MSI) analysis.

Methods

Metabolic profiling of tumor (n = 38) and nontumor (n = 72) regions in human livers of HCC was performed by an ultrahigh‐performance liquid chromatography quadrupole time‐of‐flight MS (UHPLC/QTOFMS) instrument equipped with a mixed‐mode column. The HCC biomarker candidates were extracted by multivariate analyses and identified by matching values of the collision cross section and their fragment ions on the mass spectra obtained by HDMS. Cryosections of HCC livers, which included both tumor and nontumor regions, were analyzed by DESI‐MSI.

Results

From the multivariate analysis, m/z 904.83 and m/z 874.79 were significantly high and low, respectively, in tumor samples and were identified as triglyceride (TG) 16:0/18:1(9Z)/20:1(11Z) and TG 16:0/18:1(9Z)/18:2(9Z,12Z) using the synthetic compounds. The TGs were clearly localized in the tumor or nontumor areas of the cryosection.

Conclusions

Novel biomarkers for HCC were identified by a comprehensive and reproducible G‐Met method with HDMS using a mixed‐mode column. The combination analysis of UHPLC/QTOFMS and DESI‐MSI revealed that the different molecular species of TGs were associated with tumor distribution and were useful for characterizing the progression of tumor cells and discovering prospective biomarkers.
Differential processing of high‐molecular‐weight kininogen during normal pregnancy
Authors: Droll Stephenie H. , Hsu Yen‐Michael Sheng , Drake Steven K. , Kim Ashley , Wang Weixin , Calvo Katherine R. , Cao Zheng , Hu Tony Y. , Zhao Zhen
Published: August 2019

Rationale

Studies identified kininogen as a potential biomarker of preeclampsia, a major cause of adverse maternal outcomes. High‐molecular‐weight kininogen (HK) and its activated form participate in numerous pathways associated with establishing and maintaining pregnancy. However, dynamic changes in HK and naturally occurring HK‐derived peptides during the natural course of pregnancy are largely unknown.

Methods

Longitudinal serum samples during the course of normal pregnancy (trimesters T1, T2, T3) from 60 pregnant women were analyzed by western blot with an anti‐HK antibody. Circulating peptides in longitudinal serum specimens derived from 50 participants were enriched using nanoporous silica thin films. Peptides were identified by liquid chromatography/tandem mass spectrometry (LC/MS/MS) and database searching. Relative quantification was performed using MaxQuant and in‐house scripts. Normality was evaluated by either ANOVA or Friedman tests with p < 0.05 for statistical significance.

Results

Western blotting revealed that HK significantly decreased during normal pregnancy (T1 vs T2, p < 0.05; T1 vs T3, p < 0.0001). A 100 kDa intermediate increased during pregnancy (T1 vs T2, p < 0.005; T1 vs T3, p < 0.01). Moreover, the heavy chain (T1 vs T2, p < 0.0001; T1 vs T3, p < 0.0001; T2 vs T3, p < 0.01) and light chain (T1 vs T2, p < 0.0001; T1 vs T3, p < 0.0001; T2 vs T3, p < 0.05) significantly increased during pregnancy. LC/MS/MS analysis identified 180 kininogen‐1 peptides, of which 167 mapped to domain 5 (D5). Seventy‐three peptides with ten or more complete data sets were included for further analysis. Seventy peptides mapped to D5, and 3, 24, and 43 peptides showed significant decrease, no trend, and significant increase, respectively, during pregnancy.

Conclusions

This study demonstrates dynamic changes in HK and naturally occurring HK‐derived peptides during pregnancy. Our study sheds light on the gestational changes of HK and its peptides for further validation of them as potential biomarkers for pregnancy‐related complications.
The nanoeconomics of firm‐level decision‐making and industry evolution: Evidence from 200 years of paper and pulp making
Authors: Lamberg Juha‐Antti , Peltoniemi Mirva
Published: August 2019

Research Summary

We explore the qualitative differences in entries and exits over time. Using qualitative and quantitative data on 96 firms over 200 years, we study industry evolution from the perspective of individual decision‐making situations. Our historical and statistical analyses reveal the vital role of technology investments in determining firm outcomes, and the technological, institutional and governance dynamics that lead firms to invest or to abstain. Our main theoretical and methodological contribution concerns the importance of the multiplicity of firm‐level rationalities and decisions as fundamentals in theorizing on industry evolution.

Managerial Summary

What determines firm outcomes in terms of acquisition, dissolution, and survival? This article answers this crucial question of strategy and elaborates on the extent to which the outcome is under top management control. Our findings highlight the importance of technology investments and we identify factors that make such investments possible and profitable. Our results emphasize that firms weighing options must assess the economic meaningfulness of generational technology investments which result in narrowing profit margins and intensifying competition. Another insight concerns the management of political risks. Long‐term fluctuations in regulation and foreign trade policy make it hazardous to optimize to the contemporary political regime. Skillful strategists invest in geographical and technological complexity, which in combination increase the chances of survival in rapidly changing political regimes.
Location and survival of MNEs' subsidiaries: Agglomeration and heterogeneity of firms
Authors: Mariotti Sergio , Mosconi Rocco , Piscitello Lucia
Published: August 2019

Research summary

Our study provides a quasi–replication of Shaver and Flyer (2000), which was among the first studies that challenged the positive role of agglomeration in determining companies' location choice and performances, thus changing the way management scholars view companies' attitude towards agglomeration forces. We employ the same research design, specification and tests, and a different population, to discuss the generalizability of the original study. Building on the framework of Shaver and Flyer (2000), our findings offer intriguing new empirical evidence highlighting the importance of the differential between entering foreign firms and host country firms as a crucial condition in understanding agglomeration forces and adverse selection mechanisms.

Managerial summary

Our exercise confirms that agglomeration forces act differently on stronger versus weaker multinational enterprises (MNEs). However, we find that stronger MNEs tend to avoid location in highly specialized areas when they are afraid of knowledge leakages towards host country–based rivals that have enough absorptive capacity to benefit and improve their competitive advantages. Managerial implications are quite relevant. Indeed, when MNEs avoid co–location in highly specialized areas, they also limit their own access to local knowledge and other agglomeration economies, such as supply networks and qualified workforce. Thus, MNEs managers need to design and implement devices that, on the one hand prevent local leakages of their knowledge and, on the other, do not hinder their access to local unique knowledge and resources.