bluuebunny/crossref_metadata_2025 huggingface dataset:
Ultrasound Strain Imaging to Assess the Biceps Brachii Muscle in Chronic Poststroke Spasticity
Authors: Gao Jing , Chen Johnson , O'Dell Michael , Li Pai‐Chi , He Wen , Du Li‐Juan , Rubin Jonathan M. , Weitzel William , Min Robert
Published: February 2018

Objectives

The aim of the study was to assess the feasibility of ultrasound strain imaging in characterizing the biceps brachii muscle in chronic poststroke spasticity.

Methods

We prospectively analyzed strain imaging data from bilateral biceps brachii muscles in 8 healthy volunteers and 7 patients with poststroke chronic spasticity. Axial deformations of the biceps brachii muscle and overlying subcutaneous tissue were produced by external compression using a sandbag (1.0 kg) attached to a transducer. The lengthening and shortening of the biceps brachii muscle and subcutaneous tissue were produced by manual passive elbow extension (from 90° to 0°) and flexion (from 0° to 90°), respectively. We used offline 2‐dimensional speckle tracking to estimate axial and longitudinal strain ratios (biceps brachii strain/subcutaneous tissue strain), and the longitudinal tissue velocity of the biceps brachii muscle. Statistical analyses included analysis of variance for testing differences in strain imaging parameters among healthy, nonspastic, and spastic biceps brachii muscles, the Bonferroni correction for further testing differences in US strain imaging among paired groups (healthy versus spastic, nonspastic versus spastic, and healthy versus nonspastic), and the Pearson correlation coefficient for assessing the intraobserver reliability of performing strain imaging in stroke survivors.

Results

The differences in strain imaging parameters between healthy and spastic and between nonspastic and spastic biceps brachii muscles were significant at both 90° elbow flexion and maximal elbow extension (P < .01). There was no significant difference in axial strain ratios at 90° of elbow flexion or longitudinal tissue velocities between healthy and nonspastic muscles (P > .05). The intraobserver reliability of performing strain imaging in stroke survivors was good (r = 0.85; P < .01).

Conclusions

Ultrasound strain imaging seems to be feasible for characterizing the biceps brachii muscle in chronic poststroke spasticity.
The Potential Role of Bile Acids in Acquired Laryngotracheal Stenosis
Authors: Aldhahrani Adil , Powell Jason , Ladak Shameem , Ali Mahmoud , Ali Simi , Verdon Bernard , Pearson Jeffrey , Ward Chris
Published: February 2018

Objective

Gastroesophageal reflux is thought to be a risk factor for laryngotracheal stenosis. Bile acids are a component of gastric refluxate and have previously been implicated in the development of fibrosis in other airway subsites. There is clear evidence that bile acids reflux into the upper airway. We therefore investigated the potential role of bile acids in the pathophysiology of laryngotracheal fibrosis and stenosis, specifically investigating the highly conserved process of epithelial–mesenchymal transition (EMT).

Study Design

Translational research study.

Methods

Human primary tracheal epithelial cells (PTECs) were challenged with the four most common digestive bile acids (cholic, chenodeoxycholic, deoxycholic, and lithocholic). EMT markers transforming growth factor (TGF)‐β1, Matrix metalloproteinase (MMP)‐9, and procollagen proteins were measured in the supernatant at 48 hours via enzyme‐linked immunosorbent assay. Real‐time polymerase chain reaction was also used to measure E‐cadherin and fibronectin expression.

Results

Significantly greater concentrations of TGF‐β1 and MMP‐9 were measured in the culture supernatants of cells treated with each bile acid at 10 µmol/L. Lithocholic acid and deoxycholic acid induced significantly increased expression of procollagen protein. Upregulation of fibronectin and downregulation of E‐cadherin were observed with all bile acids, except for deoxycholic acid.

Conclusion

This is the first proof of principle demonstration that physiologically relevant bile acid challenge induces EMT mechanisms in PTECs. This implies a potential role for bile acids in laryngotracheal scarring and airway remodeling of potential translational significance in laryngotracheal stenosis.

Level of Evidence

NA. Laryngoscope, 128:2029–2033, 2018
Circadian anosmia: A rare clinical presentation
Authors: Landis Basile N. , Hsieh Julien W. , Coppin Géraldine
Published: February 2018

We report the case of a 27‐year‐old female who presented with a peculiar story of anosmia fluctuating in a circadian manner. Olfactory function appeared an hour after breakfast, was normal during daytime, and disappeared in the early evening. Imaging confirmed chronic rhinosinusitis (CRS). Initial systemic, followed by topical steroid treatment, rapidly and sustainably reversed this condition. The olfactory fluctuation paralleled the endogenous steroid production. This suggests that slight congestion changes in a chronically inflamed nasal mucosa may have been sufficient to induce this circadian anosmia. The importance of identifying fluctuation of olfactory function as a sign of CRS is emphasized and discussed. Laryngoscope, 128:1537–1539, 2018
Double‐blind, placebo‐controlled study with alginate suspension for laryngopharyngeal reflux disease
Authors: Tseng Wen‐Hsuan , Tseng Ping‐Huei , Wu Jia‐Feng , Hsu Ya‐Chin , Lee Ting‐Yi , Ni Yen‐Hsuan , Wang Hsiu‐Po , Hsiao Tzu‐Yu , Hsu Wei‐Chung
Published: February 2018

Objective

Treatment for laryngopharyngeal reflux disease (LPRD) is challenging because of delays in recognition and poor responsiveness to proton‐pump inhibitor therapy. The aim of this study was to determine the efficacy and safety of liquid alginate suspension for treating LPRD.

Methods

A double‐blind, placebo‐controlled, prospective study comparing 8 weeks of treatment with Alginos Oral Suspension (TTY Biopharm Co. Ltd., Taipei, Taiwan) (sodium alginate 1,000 mg three times daily) with a placebo was conducted on patients who fulfilled the criteria of at least one symptom consistent with LPRD, a total reflux symptom index (RSI) score of > 10, and a total reflux finding score (RFS) of > 5. Those with erosive gastroesophageal reflux disease, as evidenced through screened transnasal upper gastrointestinal endoscopy, were excluded. Efficacy was assessed by RSI, RFS, and ambulatory multichannel intraluminal impedance and pH (MII‐pH) monitoring.

Results

A total of 80 patients aged 22 to 72 years were enrolled. Compared with baseline, both Alginos (TTY Biopharm Co. Ltd.) and the placebo significantly reduced the total RSI (P < 0.001) and the total number of reflux episodes shown by MII‐pH monitoring (P < 0.05) after 8 weeks of treatment. However, liquid alginate suspension was unable to show superiority over the placebo. The incidence of various adverse events from Alginos (TTY Biopharm Co. Ltd.) was relatively low (7.7%) and mild.

Conclusion

This study showed that liquid alginate suspension was well tolerated by LPRD patients. It effectively improved symptoms and reflux numbers but was unable to show superiority over placebo. As observed in previous studies, a great placebo effect was present. The importance of lifestyle modification could not be overlooked.

Level of Evidence

2. Laryngoscope, 128:2252–2260, 2018
Completion lymphadenectomy for sentinel node positive cutaneous head & neck melanoma
Authors: Schmalbach Cecelia E. , Bradford Carol R.
Published: February 2018

The application and utility of melanoma sentinel lymph node biopsy (SLNB) has evolved significantly since its inception over two decades ago. The current focus has shifted from a staging modality to potentially a therapeutic intervention. Recent research to include large multi‐institutional randomized trials have attempted to answer the question: is a completion lymph node dissection (CLND) required following a positive SLNB? This review provides an evidence‐based, contemporary review of the utility of CLND for SLNB positive head and neck cutaneous melanoma patients.

Level of Evidence

NA
Effect of high‐frequency near‐infrared diode laser irradiation on periodontal tissues during experimental tooth movement in rats
Authors: Gunji Hidemi , Kunimatsu Ryo , Tsuka Yuji , Yoshimi Yuki , Sumi Keisuke , Awada Tetsuya , Nakajima Kengo , Kimura Aya , Hiraki Tomoka , Hirose Naoto , Yanoshita Makoto , Tanimoto Kotaro
Published: February 2018

Background and Objectives

Tooth movement during orthodontic treatment is associated with bone neoplasticity and bone resorption on the tension and pressure sides. Previous clinical studies have suggested that low‐power laser irradiation can accelerate tooth movement during orthodontic treatment, although the underlying mechanism remains unclear. In this study, we used a high‐frequency near‐infrared diode laser that generates less heat and examined the histologic changes in periodontal tissue during experimental tooth movement with laser irradiation.

Methods

A nickel‐titanium closed coil was mounted between the maxillary left side first molar and incisor of rats to model experimental tooth movement. The laser‐irradiation and the control groups were set, and the amount of movement of the first molar on 7th and 14th days after the start of pulling of the first molar tooth on the maxillary left was measured by three‐dimensional analysis of µCT. After tooth movement, tissue samples from the mesial and tension sides were collected, and successive horizontal sections were prepared and examined using hematoxylin–eosin and TRAP staining and immunohistochemical staining for RANKL, OPG, ALP, and proliferating cell nuclear antigen (PCNA). Changes in tissue temperature following laser irradiation were also examined.

Results

Laser irradiation significantly increased tooth movement compared with non‐irradiated controls. Histologic staining of the pressure‐side mesial root in laser‐irradiated rats revealed enhanced RANKL expression and increased numbers of TRAP‐positive cells compared with controls. By contrast, on the tension side, laser irradiation led to increased expression of ALP and PCNA. These data indicate that high‐frequency near‐infrared diode laser irradiation on the pressure side upregulates RANKL expression and accelerates osteoclast differentiation, facilitating bone resorption, whereas bone formation is induced on the tension side.

Conclusion

This study demonstrates that high‐frequency near‐infrared diode laser irradiation of periodontal tissue leads to metabolic activation, which ultimately increases the rate of tooth movement. Lasers Surg. Med. 50:772–780, 2018. © 2018 Wiley Periodicals, Inc.
Dispersion Polymerization of Substituted Acetylenes in the Presence of Chiral Source for Preparing Monodispersed Chiral Nanoparticles
Authors: Zhao Biao , Deng Jianping
Published: February 2018

Chiral helical polymer nanoparticles have constituted a significant category of advanced functional particles by creatively combining chirality with nanoscale size into one unity. However, their further progress has been confronted with intractable difficulties, especially due to the limited kinds and number of chiral monomers and the lack of effective and universal preparation methods. In this study, the first protocol, that is, dispersion polymerization, for preparing monodispersed, chiral helical polymer nanoparticles derived from substituted acetylenic monomers, is reported. The possible formation mechanism of polymer nanoparticles is proposed. More excitingly, achiral monomers subsequently undergo helix‐sense‐selective dispersion polymerization with d(l)‐lactide as chiral additive, directly leading to optically active helical polymer nanoparticles. The present study not only provides a novel approach for preparing chiral helical polymer nanoparticles but also significantly expands the type and number of monomers for constructing chiral nanoparticles.
Thermally Switchable Fluorescence Resonance Energy Transfer via Reversible Diels–Alder Reaction of π‐Conjugated Oligo‐(Phenylene Ethynylene)s
Authors: Ahner Johannes , Dahlke Jan , Pretzel David , Schubert Ulrich S. , Dietzek Benjamin , Hager Martin D.
Published: February 2018

The combination of reversible, dynamic covalent bonds and π‐conjugated oligo‐(phenylene ethynylene)s is utilized for exchange reactions between two acceptors and one donor containing copolymer in the solid state upon thermal treatment. The specific molecular design of the polymers allows upon thermally triggering the reshuffling of the π‐conjugated donor and acceptor moieties. Depending on the nature of the acceptor, an increased and a decreased fluorescence resonance energy transfer (FRET), respectively, can be observed for the mixing of the copolymers or the demixing of a donor–acceptor copolymer.
Forehead Tremor: A Clinical Presentation of Myasthenia Gravis?
Authors: Sciacca Giorgia , Reggio Ester , Donzuso Giulia , Nicoletti Alessandra , Drago Filippo , Salomone Salvatore , Zappia Mario
Published: February 2018

View Supplementary Video 1
Absorbed dose distributions from ophthalmic 106Ru/106Rh plaques measured in water with radiochromic film
Authors: Hermida‐López Marcelino , Brualla Lorenzo
Published: February 2018

Purpose

Brachytherapy with 106Ru/106Rh plaques offers good outcomes for small‐to‐medium choroidal melanomas and retinoblastomas. The dose measurement of the plaques is challenging, due to the small range of the emitted beta particles and steep dose gradients involved. The scarce publications on film dosimetry of 106Ru/106Rh plaques used solid phantoms. This work aims to develop a practical method for measuring the absorbed dose distribution in water produced by 106Ru/106Rh plaques using EBT3 radiochromic film.

Methods

Experimental setups were developed to determine the dose distribution at a plane perpendicular to the symmetry axis of the plaque and at a plane containing the symmetry axis. One CCA and two CCX plaques were studied. The dose maps were obtained with the FilmQA Pro 2015 software, using the triple‐channel dosimetry method. The measured dose distributions were compared to published Monte Carlo simulation and experimental data.

Results

A good agreement was found between measurements and simulations, improving upon published data. Measured reference dose rates agreed within the experimental uncertainty with data obtained by the manufacturer using a scintillation detector, with typical differences below 5%. The attained experimental uncertainty was 4.1% (k = 1) for the perpendicular setup, and 7.9% (k = 1) for the parallel setup. These values are similar or smaller than those obtained by the manufacturer and other authors, without the need of solid phantoms that are not available to most users.

Conclusions

The proposed method may be useful to the users to perform quality assurance preclinical tests of 106Ru/106Rh plaques.
Material elemental decomposition in dual and multi‐energy CT via a sparsity‐dictionary approach for proton stopping power ratio calculation
Authors: Shen Chenyang , Li Bin , Chen Liyuan , Yang Ming , Lou Yifei , Jia Xun
Published: February 2018

Purpose

Accurate calculation of proton stopping power ratio (SPR) relative to water is crucial to proton therapy treatment planning, since SPR affects prediction of beam range. Current standard practice derives SPR using a single CT scan. Recent studies showed that dual‐energy CT (DECT) offers advantages to accurately determine SPR. One method to further improve accuracy is to incorporate prior knowledge on human tissue composition through a dictionary approach. In addition, it is also suggested that using CT images with multiple (more than two) energy channels, i.e., multi‐energy CT (MECT), can further improve accuracy. In this paper, we proposed a sparse dictionary‐based method to convert CT numbers of DECT or MECT to elemental composition (EC) and relative electron density (rED) for SPR computation.

Method

A dictionary was constructed to include materials generated based on human tissues of known compositions. For a voxel with CT numbers of different energy channels, its EC and rED are determined subject to a constraint that the resulting EC is a linear non‐negative combination of only a few tissues in the dictionary. We formulated this as a non‐convex optimization problem. A novel algorithm was designed to solve the problem. The proposed method has a unified structure to handle both DECT and MECT with different number of channels. We tested our method in both simulation and experimental studies.

Results

Average errors of SPR in experimental studies were 0.70% in DECT, 0.53% in MECT with three energy channels, and 0.45% in MECT with four channels. We also studied the impact of parameter values and established appropriate parameter values for our method.

Conclusion

The proposed method can accurately calculate SPR using DECT and MECT. The results suggest that using more energy channels may improve the SPR estimation accuracy.
Inhibition of Dr‐dut gene causes DNA damage in planarian
Authors: Alam Md. Shahanoor , Moriyama Hideaki , Matsumoto Midori
Published: February 2018

The DUT gene encodes Deoxyuridine triphosphatase (dUTPase), which is involved in nucleotide metabolism. dUTPase prevents uracil misincorporation in DNA by balancing the intracellular ratio between dUTP and dTTP. This study aimed to investigate the role of Dr‐dut gene in the planarian Dugesia ryukyuensis by assessing the consequences of Dr‐dut silencing on known phenomena, including regeneration following amputation and radiation damage. We functionally disrupted planarian Dr‐dut mRNA by feeding RNAi‐containing food to animals. Dr‐dut RNAi resulted in the death of planarians in 28 days, and elevated double‐stranded DNA breakage. Expression of the DNA damage response gene Dr‐atm and the DNA repair genes Dr‐rad51 and Dr‐rad51c temporarily increased, and then decreased following the onset of feeding. When RNAi‐treated planarians were amputated, both head and tail parts failed to regenerate, and the animals died in 25 and 29 days, respectively. Administration of 5‐fluorouracil (5‐FU) also resulted in death and DNA damage, and synergistically caused higher genotoxicity in planarian fed Dr‐dut RNAi‐containing food.
T1‐based sensing of mammographic density using single‐sided portable NMR
Authors: Tourell Monique C. , Ali Tonima S. , Hugo Honor J , Pyke Chris , Yang Samuel , Lloyd Thomas , Thompson Erik W. , Momot Konstantin I.
Published: February 2018

Purpose

A single‐sided NMR instrument was used to investigate the ability of the T1 relaxation constant to distinguish between regions of low and high mammographic density in human breast tissue.

Methods

Measurements were performed on 5 breast slices obtained from 3 women undergoing breast reduction surgery or prophylactic mastectomy.

Results

T1 values measured in regions of high mammographic density in both the full breast slices (T1 = 170 ± 30 ms) and excised regions (T1 = 160 ± 30 ms) were found to be significantly different (P < .001) from those measured in regions of low mammographic density, in which T1 = 120 ± 10 ms was observed both in full slices and excised regions. There was no statistically significant difference between the T1 values measured in the full breast slices and those measured in the excised regions.

Conclusion

The findings suggest that portable NMR may provide a low‐cost means of assessing mammographic density in vivo.
An isogeometric extension of Trefftz method for elastostatics in two dimensions
Authors: Horák Martin , Patzák Bořek , Novák Jan
Published: February 2018

In this paper, an approach to blend the Hybrid‐Trefftz Finite Element Method (HTFEM) and the Isogeometric Analysis (IGA) called the Isogeometric Trefftz (IGAT) method is presented. The structure of the isogeometric extension of the Trefftz method is formally the same as for its conventional counterpart, except the approximation of the boundary displacements and geometry that are carried out using the Non‐Uniform Rational B‐Splines (NURBS) instead of polynomials. In other words, only the element boundaries are approximated using NURBS basis while the Trefftz approximation is used in the interior of the elements. For that reason, IGAT can be ranked alongside recently developed Isogeometric Boundary Element Method (IGABEM), the NURBS‐Enhanced Finite Element Method (NEFEM), the Isogeometric Local Maximum Entropy (IGA‐LME) method, and the Isogeometrically enhanced Scaled‐Boundary element method (SBFEM), which all use NURBS approximation at the domain boundary only. Theoretical conjectures made in this paper are accompanied by three examples that show that IGAT leads to excellent results using only a few elements.
Artistic consumption and well‐being: A song of two countries
Authors: Kemp Elyria , Martic Kristina , Anaza Nwamaka A.
Published: February 2018

Efforts are being made to examine how the arts help people reach their full potential and contribute to subjective well‐being. The purpose of this research is to examine the relationship between artistic consumption and consumer well‐being. Specifically, consumer motives, represented as emotion regulation, and arts engagement are examined to assess the relationship between arts participation and life satisfaction. This assessment is carried out in 2 countries, the United States and Croatia. Findings from both countries indicate that emotion regulation is positively related to arts engagement. In turn, arts engagement is positively related to arts participation for consumers in both countries. Results, however, diverge for both countries with respect to the influence that artistic consumption has on global life satisfaction. For U.S. consumers, arts participation is positively related to life satisfaction; yet arts participation is not related to satisfaction for Croatian consumers. Implications for the role the arts play in contributing to consumer well‐being are discussed.
Effect of pre‐tension on tensile strength of glass fibers‐epoxy composite reinforced with shape memory alloy wire
Authors: Khazaie M. , Eslami‐Farsani R. , Khalili S. M. R.
Published: February 2018

In this study, the potential of superelastic shape memory alloy (SMA) wire to enhance the tensile strength of a glass fibers reinforced epoxy composite was evaluated. Composite specimens with one embedded SMA wire fabricated with hand‐layup method. The specimens were placed under tensile loading (pre‐tension) and unloaded before ultimate tensile strength. The pre‐tension amounts were 65, 75, and 85% of ultimate tensile strength. After unloading, SMA wire wants to transform to the austenite phase and recover its primary shape and a large amount of compressive stress will be released over the composite specimens. Results show that the ultimate tensile strength for specimen with 75% pre‐tension was 32% higher than the composite without pre‐tension. This pre‐tension has the best effect on ultimate tensile strength and pretension of specimens before ultimate tensile strength leads to higher tensile strength due to the high superelasticity of the SMA wires. POLYM. COMPOS., 39:E2454–E2459, 2018. © 2018 Society of Plastics Engineers
The influence of using sodium dithionite as SARA agent in miniemulsion ATRP
Authors: Mendes Joana P. , Gois Joana R. , Trino Andreia S. M. , Catalão Francisco , Serra Arménio C. , Coelho Jorge F. J.
Published: February 2018

The supplemental activator and reducing agent atom transfer radical polymerization (SARA ATRP) of butyl acrylate (nBA) and styrene (Sty) using miniemulsion is reported for the first time. The polymerization was carried out in the presence of Cu(II)Br2‐based catalytic systems using EHA6TREN or BPMODA* and sodium dithionite (Na2S2O4) as SARA agent. Kinetic data revealed a controlled polymerization for both monomers, with a very stringent control over the molecular weight distribution (Ð ≤ 1.2) but low monomer conversion. Reaction conditions were optimized in an attempt to understand the kinetics of polymerization, aiming to increase the final monomer conversion while maintaining the control over the polymerization. Self‐chain extension reactions revealed low chain end fidelity, which corroborate the impossibility of increasing monomer conversion even after the judicious variation of the main polymerization parameters (monomers, surfactant, deactivator, and Na2S2O4 concentrations, and its method of addition). The data presented suggest a particular feature of Na2S2O4 in these polymerization systems involving the significant formation of dead chains ends, which has never been observed for any other reported system using this SARA agent. In contrast, control ARGET miniemulsion experiments under the same reaction conditions and using ascorbic acid as reducing agent allowed to achieve high monomer conversions. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018, 56, 879–888
Side‐chain glycylglycine‐based polymer for simultaneous sensing and removal of copper(II) from aqueous medium
Authors: Choudhury Neha , Mete Sourav , Kambalapalli Srikanth , De Priyadarsi
Published: February 2018

Since glycylglycine (Gly‐Gly) residue in the N‐terminal region of human prion protein, a copper binding protein, binds with Cu(II), N‐terminus Gly‐Gly side‐chain containing water soluble block copolymer was synthesized and used for simultaneous sensing and removal of Cu(II) ion from aqueous medium. The polymer has amide nitrogen atom and ester carbonyl group as potential binding sites in the side‐chain Gly‐Gly pendants. Job's plot experiment confirms 2:1 binding stoichiometry of polymer with Cu(II). This polymer is able to sense parts per billion level of Cu(II) very selectively in an aqueous medium and remove Cu(II) ions quantitatively by precipitating out the Cu(II) via complex formation in the pH range 7–9. The binding mode of polymer with Cu(II) in polymer‐Cu(II) complex was characterized by 1H NMR, FTIR, and UV–vis spectroscopy. The attachment of Cu(II) in the polymer‐Cu(II) complex was confirmed by cyclic voltammetry experiment. Cu(II) release from the complex was achieved at pH 5 due to the protonation of amide nitrogen atoms in the Gly‐Gly moiety. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018, 56, 914–921
Controllable synthesis of bio‐based polylactide diols using an organocatalyst in solvent‐free conditions
Authors: Li Hui , Gu Lin
Published: February 2018

Controllable synthesis of bio‐based polylactide (PLA) diols was realized by the ring‐opening polymerization (ROP) of lactide (LA) in the presence of 1,4‐butanediol (BDO) using 1,8‐diazabicyclo[5.4.0]undec‐7‐ene (DBU) as an organocatalyst in solvent‐free conditions. The catalytic activity and conversion of LA could reach ∼1 kg g−1 DBU and >97%, respectively, and the polymerization yielded polymers with narrow polydispersity index (PDI) (1.15–1.29). Interestingly, the number average molecular weight (Mn) of the obtained PLA diol was in excellent linear relation with the molar ratio of LA and BDO, and hence can be precisely controlled. The structure of the diol was clearly confirmed by 1H and 13C NMR, FTIR, and MALDI‐TOF mass spectra, proving BDO as an initiation‐transfer agent to participate in the polymerization. Kinetic study of the ROP demonstrates a pseudo‐first‐order kinetic model and a controlled “living” nature. Notably, it is found that the glass transition temperature (Tg) of the diol significantly depends on the Mn. Furthermore, various chain transfer agents and organocatalysts can also be used to successfully synthesize well‐defined PLA diols. Especially, functional bio‐based dihydric alcohols such as 2,5‐furandimethanol (FDMO)‐initiated ROP in this system could result in fully bio‐based PLA diols with functionality. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018, 56, 968–976
Corrigendum on: E‐ and H‐mode transition in a low pressure inductively coupled ammonia plasma
Authors: Draškovič‐Bračun Aljaž , Mozetič Miran , Zaplotnik Rok
Published: February 2018

The article by Aljaž Draškovič‐Bračun et al. (ppap.201700105), published online on 18 September 2017, contains a wrong version of Figure . This corrigendum is published to correct this.
Fault detection and fault‐tolerant control over signal‐to‐noise ratio constrained channels
Authors: Guo Fumin , Ren Xuemei , Li Zhijun , Han Cunwu
Published: February 2018

This paper investigates the problems of fault detection (FD) and fault‐tolerant control for a class of discrete‐time systems with signal‐to‐noise ratio constrained channels. For the purpose of detecting the fault, an observer‐based FD scheme is proposed by using a descriptor system approach. In this scheme, an augmented robust FD filter is designed such that the residual generation system is admissible and the estimations of the system state and fault are both obtained; then, a dynamic threshold is constructed based on stochastic characteristics of the channel noise, a constant α is introduced to reduce the conservatism of threshold, and false alarm rate of the threshold is given. Subsequently, in order to keep the post‐fault system robust asymptotically stable, an output feedback fault‐tolerant control strategy is established on the basis of the fault estimation information. Finally, two simulation examples are provided to illustrate the effectiveness and feasibility of the proposed method.
The stripping process can be slow: Part I
Authors: Gao Pu , Molloy Michael
Published: February 2018

Given an integer k, we consider the parallel k‐stripping process applied to a hypergraph H: removing all vertices with degree less than k in each iteration until reaching the k‐core of H. Take H as : a random r‐uniform hypergraph on n vertices and m hyperedges with the uniform distribution. Fixing with , it has previously been proved that there is a constant such that for all m = cn with constant , with high probability, the parallel k‐stripping process takes iterations. In this paper, we investigate the critical case when . We show that the number of iterations that the process takes can go up to some power of n, as long as c approaches sufficiently fast. A second result we show involves the depth of a non‐k‐core vertex v: the minimum number of steps required to delete v from where in each step one vertex with degree less than k is removed. We will prove lower and upper bounds on the maximum depth over all non‐k‐core vertices.
Extremes of the internal energy of the Potts model on cubic graphs
Authors: Davies Ewan , Jenssen Matthew , Perkins Will , Roberts Barnaby
Published: February 2018

We prove tight upper and lower bounds on the internal energy per particle (expected number of monochromatic edges per vertex) in the anti‐ferromagnetic Potts model on cubic graphs at every temperature and for all . This immediately implies corresponding tight bounds on the anti‐ferromagnetic Potts partition function. Taking the zero‐temperature limit gives new results in extremal combinatorics: the number of q‐colorings of a 3‐regular graph, for any , is maximized by a union of 's. This proves the d = 3 case of a conjecture of Galvin and Tetali.
Digit Tip Regeneration: Merging Regeneration Biology with Regenerative Medicine
Authors: Dolan Connor P. , Dawson Lindsay A. , Muneoka Ken
Published: February 2018

Regeneration Biology is the study of organisms with endogenous regenerative abilities, whereas Regenerative Medicine focuses on engineering solutions for human injuries that do not regenerate. While the two fields are fundamentally different in their approach, there is an obvious interface involving mammalian regeneration models. The fingertip is the only part of the human limb that is regeneration-competent and the regenerating mouse digit tip has emerged as a model to study a clinically relevant regenerative response. In this article, we discuss how studies of digit tip regeneration have identified critical components of the regenerative response, and how an understanding of endogenous regeneration can lead to expanding the regenerative capabilities of nonregenerative amputation wounds. Such studies demonstrate that regeneration-incompetent wounds can respond to treatment with individual morphogenetic agents by initiating a multi-tissue response that culminates in structural regeneration. In addition, the healing process of nonregenerative wounds are found to cycle through nonresponsive, responsive and nonresponsive phases, and we call the responsive phase the Regeneration Window. We also find the responsiveness of mature healed amputation wounds can be reactivated by reinjury, thus nonregenerated wounds retain a potential for regeneration. We propose that regeneration-incompetent injuries possess dormant regenerative potential that can be activated by targeted treatment with specific morphogenetic agents. We believe that future Regenerative Medicine-based-therapies should be designed to promote, not replace, regenerative responses.
Testing causal effects in observational survival data using propensity score matching design
Authors: Lu Bo , Cai Dingjiao , Tong Xingwei
Published: February 2018

Time‐to‐event data are very common in observational studies. Unlike randomized experiments, observational studies suffer from both observed and unobserved confounding biases. To adjust for observed confounding in survival analysis, the commonly used methods are the Cox proportional hazards (PH) model, the weighted logrank test, and the inverse probability of treatment weighted Cox PH model. These methods do not rely on fully parametric models, but their practical performances are highly influenced by the validity of the PH assumption. Also, there are few methods addressing the hidden bias in causal survival analysis. We propose a strategy to test for survival function differences based on the matching design and explore sensitivity of the P‐values to assumptions about unmeasured confounding. Specifically, we apply the paired Prentice‐Wilcoxon (PPW) test or the modified PPW test to the propensity score matched data. Simulation studies show that the PPW‐type test has higher power in situations when the PH assumption fails. For potential hidden bias, we develop a sensitivity analysis based on the matched pairs to assess the robustness of our finding, following Rosenbaum's idea for nonsurvival data. For a real data illustration, we apply our method to an observational cohort of chronic liver disease patients from a Mayo Clinic study. The PPW test based on observed data initially shows evidence of a significant treatment effect. But this finding is not robust, as the sensitivity analysis reveals that the P‐value becomes nonsignificant if there exists an unmeasured confounder with a small impact.
Dicarboxylic Acid‐Functionalized MCM‐41 with Embedded Palladium Nanoparticles as an Efficient Heterogeneous Catalyst for C–C Coupling Reactions
Authors: Amini Mostafa Mohammadpour , Mohammadkhani Abolfazl , Bazgir Ayoob
Published: February 2018

Palladium nanoparticles were supported on 1,2‐dicarboxylic acid‐functionalized MCM‐41 (Pd@DCA‐MCM) and characterized by Fourier‐transform infrared spectroscopy (FT‐IR), thermogravimetric analysis (TGA), X‐ray diffraction (XRD), atomic absorption spectroscopy (AAS), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and energy‐dispersive X‐ray spectroscopy (EDS) measurements. The Pd@DCA‐MCM nanocomposite exhibited good performance as a reusable catalyst in selected coupling reactions.
An Efficient Synthesis of Pyrido[3, 2‐c]coumarins under Microwave Irradiation in Solvent‐Free Conditions
Authors: Kolita Sinki , Bhuyan Pulak J.
Published: February 2018

Synthesized some novel functionalized pyrido[3, 2‐c] coumarins from the reaction of 4‐chloro‐3‐formylcoumarins obtained from 4‐hydroxycoumarins, and aryl methyl ketones/ethyl acetoacetate/ethyl cyanoacetate in the presence of ammonium acetate under microwave irradiation in solvent‐free condition in excellent yields.
Endohedral Regulator for Metallofullerene Chemical Property: Diels–Alder Reaction Studies of ScxY3‐xN@C80‐Ih (x=0‐3)
Authors: Zhang Zhuxia , Xue Wenhua , Jia Wei , Zhang Caili , Zhang Jie , Zhang Yong , Wang Lan , Guo Zhen , Cui Peng
Published: February 2018

Chemical functionalization is an important method modulating the chemical properties of endohedral metallofullerene. In this study, Diels–Alder reaction of ScxY3‐xN@C80‐Ih (x=0‐3) with o‐quinodimethane was investigated both experimentally and theoretically. There is only one regioselective mono‐[5, 6]‐adduct isolated for Sc3N@C80, Sc2YN@C80 and ScY2N@C80, respectively and one mono‐[5, 6] and one mono‐[6, 6]‐adduct obtained for Y3N@C80. The calculated results showed that the entrapped ScxY3‐xN clusters in the cage have the same orientation with two metal atoms toward adduct sites in the thermodynamically stable DA‐[5, 6]‐adducts. They all have higher chemical reactivity. The similar stabilizing and destabilizing effects on reactivity were found by the Activation Strain Model of reactivity and Energy Decomposition Analysis method.
Formal Synthesis of Angiopterlactone B via Enantioselective Reduction of Ketone with Daucus Carota Root
Authors: Khomane Navnath B. , Patel Javed S. , Shirsat Prashishkumar K. , Mali Prakash R. , Meshram Harshadas M.
Published: February 2018

Formal synthesis of angiopterlactone B has been accomplished via. enantioselective reduction of ketone with Daucus carota, Sharpless dihydroxylation and Andos modified Horner‐Wadsworth‐Emmons (HWE) reagent to introduce Z‐olefination. Here we evolved a new path for the synthesis of (S,S)‐osmundalactone and 3–5 dihydroxy γ‐caprolactone. The initial synthetic route for both caprolactone and osmundalcactone build on biocatalytic process while in later case Sharpless dihydroxylation delivered required stereocentres. Z‐selective olefination was utilized to furnish caprolactone which was further recycled in to 1‐(5‐oxotetrahydrofuran‐2yl) ethyl 2‐phenyl acetate. Both synthetic routes found to be applicable for many synthetic reactions.
Proton‐Gated Rectification Regimes in Nanofluidic Diodes Switched by Chemical Effectors
Authors: Pérez‐Mitta Gonzalo , Marmisolle Waldemar A. , Burr Loïc , Toimil‐Molares María Eugenia , Trautmann Christina , Azzaroni Omar
Published: February 2018

During the last decade, nanofluidic devices based on solid‐state nanopores and nanochannels have come into scene in materials science and will not leave anytime soon. One of the main reasons for this is the excellent control over ionic transport exerted by such devices that promises further important advances when integrated into more complex molecular devices. As a result, pH, temperature, and voltage‐regulated devices have been obtained. However, nowadays, there is still a necessity for molecule‐driven nanofluidic devices. Here, a sugar‐regulated pH‐responsive nanofluidic diode is presented obtained by surface modification of conical polycarbonate nanochannels with electropolymerized 3‐aminophenylboronic acid. Control over the ionic transport has been achieved by a successful decoration of asymmetric nanochannels with integrated molecular systems. The as‐synthesized boronate‐appended zwitterionic polymer exhibits an acid‐base equilibrium that depends on the concentration of sugar, which ultimately acts as a chemical effector setting different pH‐dependent rectification regimes. As a result, the same nanodevice can perform completely different proton‐regulated nanofluidic operations, i.e., anion‐driven rectification, cation‐driven rectification, and no rectification, by simply varying the concentration of fructose in the electrolyte solution.
Experimental assessment of the effects of biaxial bending moment and axial force on reinforced concrete corner columns
Authors: Dang Hoang V. , Lee Kihak , Han Sang W. , Kim Sung J.
Published: February 2018

In this research, corner columns of low‐rise residential buildings, which might be unstable and vulnerable to seismic loadings during earthquake due to vertical and horizontal irregularities, are tested under different effects from bending moment and axial force. Here, biaxial loading is focused and developed, representing a rhombus path with 100% force in the main direction, versus 30% force in the perpendicular direction. Two of eight test specimens are subjected to axial compressive force at 30% of column capacity, while other specimens are at 10%. The eight test specimens were constructed with varying transverse reinforcement details, to control the column‐failure mechanism. The objective of this research was to investigate the seismic behavior of the corner columns of low‐rise buildings that used ordinary‐moment‐resisting‐frames (OMRF). The test results were discussed to interpret the effect of biaxial loading on the overall performance of the columns using comparison between global and local responses. It could be very helpful in deeply understanding the seismic behavior of structures which were designed in accordance with OMRF requirements. Furthermore, this information might affect decisions about using intermediate‐moment‐resisting frames or special‐moment‐resisting frames, where more demanding seismic requirements are applied.
Oil and natural gas development influence nest‐site selection and nest survival of upland‐nesting waterfowl and shorebirds
Authors: Ludlow Sarah M. , Davis Stephen K.
Published: February 2018

Native grasslands provide important breeding habitat for many upland‐nesting waterfowl and shorebirds. However, recent increases in oil and gas development in native grassland may alter the quantity and quality of this globally threatened habitat. Oil and natural gas development involves construction of roads, trails, and wells; often facilitating invasion by exotic vegetation. Our objectives were to determine 1) whether nest placement by upland‐nesting waterfowl and shorebirds varied with proximity to oil and gas infrastructure; and 2) the extent to which nest survival was influenced by proximity to wells, roads, and trails, as well as percent cover of the exotic crested wheatgrass in southeastern Alberta, Canada, 2010–2011. Mallard (Anas platyrhynchos) and blue‐winged teal (Spatula discors) nests were located within 100 m of wells more than expected by chance, and northern shoveler (Spatula clypeata) and northern pintail (Anas acuta) tended to nest more frequently within 200 m of wells. In contrast, more shorebird nests were located farther from wells than expected. Mallards and blue‐winged teal were also more likely to place their nests near roads. Shorebirds tended to place their nests either close to roads or far from these structures more often than expected by chance. The proportion of mallard nests located in close proximity to trails was greater than expected, but fewer blue‐winged teal nests were located near trails than expected by chance. The top‐ranked models explaining variation in daily nest survival rates of northern shoveler, mallard, and shorebirds included distance to infrastructure variables, although these relationships were weak. Northern shovelers appear to benefit from placing nests closer to trails; daily nest survival rate increased with proximity to trails. However, trails may act as an ecological sink for shorebirds; they were more likely to place nests near trails but daily survival rates were lower near trails. © 2018 The Wildlife Society.
Confronting the wildlife trade through public education at zoological institutions in Chengdu, P.R. China
Authors: Clayton Susan , Bexell Sarah , Ping Xu , Zhihe Zhang , Jing Li Wen , Wei Chen Hong , Yan Hu
Published: February 2018

The wildlife trade poses substantial threats to global biodiversity. China is a significant source of threatened species and also a market for wildlife products. Zoological parks (zoos), which are a popular leisure attraction in China as elsewhere, are increasingly conceptualized as places to educate visitors about both animals and environmental threats more generally. This paper reports on an attempt to inform Chinese zoo visitors about the threats presented by the wildlife trade, and about the opportunity to take personal actions to help protect wildlife. Results from a baseline survey of attitudes among 524 adult visitors to animal exhibits in Chengdu, China showed a high degree of concern about wildlife paired with a lack of confidence about what could be done. A sense of connection to nature, along with a perception of personal efficacy, were the strongest predictors of concern about the wildlife trade. Based in part on these results, an informational exhibit was designed and implemented in two locations in Chengdu. A survey of 533 visitors to assess the impact of the new exhibit showed that connection and perceived efficacy continued to predict concern, and that talking about the exhibit was associated with increased knowledge and concern. Though causality cannot be definitively concluded, results suggest that zoos have the potential to influence attitudes and perceived norms regarding the wildlife trade. By affirming the importance of a feeling of connection, the findings indicate that animal facilities may have an important role in fostering the human relationship to the natural world.
Defining Early Recurrence of Hilar Cholangiocarcinoma After Curative‐intent Surgery: A Multi‐institutional Study from the US Extrahepatic Biliary Malignancy Consortium
Authors: Zhang Xu‐Feng , Beal Eliza W. , Chakedis Jeffery , Chen Qinyu , Lv Yi , Ethun Cecilia G. , Salem Ahmed , Weber Sharon M. , Tran Thuy , Poultsides George , Son Andre Y. , Hatzaras Ioannis , Jin Linda , Fields Ryan C. , Buettner Stefan , Scoggins Charles , Martin Robert C. G. , Isom Chelsea A. , Idrees Kamron , Mogal Harveshp D. , Shen Perry , Maithel Shishir K. , Schmidt Carl R. , Pawlik Timothy M.
Published: February 2018

Background

Time to tumor recurrence may be associated with outcomes following resection of hepatobiliary cancers. The objective of the current study was to investigate risk factors and prognosis among patients with early versus late recurrence of hilar cholangiocarcinoma (HCCA) after curative‐intent resection.

Methods

A total of 225 patients who underwent curative‐intent resection for HCCA were identified from 10 academic centers in the USA. Data on clinicopathologic characteristics, pre‐, intra‐, and postoperative details and overall survival (OS) were analyzed. The slope of the curves identified by linear regression was used to categorize recurrences as early versus late.

Results

With a median follow‐up of 18.0 months, 99 (44.0%) patients experienced a tumor recurrence. According to the slope of the curves identified by linear regression, the functions of the two straight lines were y = −0.465x + 16.99 and y = −0.12x + 7.16. The intercept value of the two lines was 28.5 months, and therefore, 30 months (2.5 years) was defined as the cutoff to differentiate early from late recurrence. Among 99 patients who experienced recurrence, the majority (n = 80, 80.8%) occurred within the first 2.5 years (early recurrence), while 19.2% of recurrences occurred beyond 2.5 years (late recurrence). Early recurrence was more likely present as distant disease (75.1% vs. 31.6%, p = 0.001) and was associated with a worse OS (Median OS, early 21.5 vs. late 50.4 months, p < 0.001). On multivariable analysis, poor tumor differentiation (HR 10.3, p = 0.021), microvascular invasion (HR 3.3, p = 0.037), perineural invasion (HR 3.9, p = 0.029), lymph node metastases (HR 5.0, p = 0.004), and microscopic positive margin (HR 3.5, p = 0.046) were independent risk factors associated with early recurrence.

Conclusions

Early recurrence of HCCA after curative resection was common (~35.6%). Early recurrence was strongly associated with aggressive tumor characteristics, increased risk of distant metastatic recurrence and a worse long‐term survival.