bluuebunny/crossref_metadata_2025 huggingface dataset:
Retinal imaging analysis based on vessel detection
Authors: Jamal Arshad , Hazim Alkawaz Mohammed , Rehman Amjad , Saba Tanzila
Published: March 2017

With an increase in the advancement of digital imaging and computing power, computationally intelligent technologies are in high demand to be used in ophthalmology cure and treatment. In current research, Retina Image Analysis (RIA) is developed for optometrist at Eye Care Center in Management and Science University. This research aims to analyze the retina through vessel detection. The RIA assists in the analysis of the retinal images and specialists are served with various options like saving, processing and analyzing retinal images through its advanced interface layout. Additionally, RIA assists in the selection process of vessel segment; processing these vessels by calculating its diameter, standard deviation, length, and displaying detected vessel on the retina. The Agile Unified Process is adopted as the methodology in developing this research. To conclude, Retina Image Analysis might help the optometrist to get better understanding in analyzing the patient's retina. Finally, the Retina Image Analysis procedure is developed using MATLAB (R2011b). Promising results are attained that are comparable in the state of art.
Cardiovascular Calcium Channel Blockers: Historical Overview, Development and New Approaches in Design
Authors: Drapak Iryna , Perekhoda Lina , Tsapko Tetiana , Berezniakova Natalia , Tsapko Yevgen
Published: March 2017

The data on historical development and modern design approaches for calcium channels blockers (mainly L‐type) are summarized in this review. Chemical groups such as dihydropyridine and hydropyrimidine derivatives, as well as phenylalkylamines and benzothiazepines are discussed.
Three‐Component Synthesis of Spiro[indoline‐3,4′‐pyrazolo[3,4‐b]pyridines] under Microwave Irradiation
Authors: Gao Xia , Yang Zheng , Hao Wen‐Juan , Jiang Bo , Tu Shu‐Jiang
Published: March 2017

A domino three‐component strategy with high efficiency for the synthesis of spiro[indoline‐3,4′‐pyrazolo[3,4‐b]pyridines] from easily available isatins, pyrazol‐5‐amines and β‐ketonitriles under microwave heating. During reaction process, HOAc plays dual roles as reaction media as well as a Brønsted acid‐promoter. Flexible structural modification, broad functional group compatibility and mild reaction conditions make this strategy a useful and attractive process of library generation for drug discovery.
Creating hemodynamic atlases of cardiac 4D flow MRI
Authors: Cibis Merih , Bustamante Mariana , Eriksson Jonatan , Carlhäll Carl‐Johan , Ebbers Tino
Published: March 2017

Purpose

Hemodynamic atlases can add to the pathophysiological understanding of cardiac diseases. This study proposes a method to create hemodynamic atlases using 4D Flow magnetic resonance imaging (MRI). The method is demonstrated for kinetic energy (KE) and helicity density (Hd).

Materials and Methods

Thirteen healthy subjects underwent 4D Flow MRI at 3T. Phase‐contrast magnetic resonance cardioangiographies (PC‐MRCAs) and an average heart were created and segmented. The PC‐MRCAs, KE, and Hd were nonrigidly registered to the average heart to create atlases. The method was compared with 1) rigid, 2) affine registration of the PC‐MRCAs, and 3) affine registration of segmentations. The peak and mean KE and Hd before and after registration were calculated to evaluate interpolation error due to nonrigid registration.

Results

The segmentations deformed using nonrigid registration overlapped (median: 92.3%) more than rigid (23.1%, P < 0.001), and affine registration of PC‐MRCAs (38.5%, P < 0.001) and affine registration of segmentations (61.5%, P < 0.001). The peak KE was 4.9 mJ using the proposed method and affine registration of segmentations (P = 0.91), 3.5 mJ using rigid registration (P < 0.001), and 4.2 mJ using affine registration of the PC‐MRCAs (P < 0.001). The mean KE was 1.1 mJ using the proposed method, 0.8 mJ using rigid registration (P < 0.001), 0.9 mJ using affine registration of the PC‐MRCAs (P < 0.001), and 1.0 mJ using affine registration of segmentations (P = 0.028). The interpolation error was 5.2 ± 2.6% at mid‐systole, 2.8 ± 3.8% at early diastole for peak KE; 9.6 ± 9.3% at mid‐systole, 4.0 ± 4.6% at early diastole, and 4.9 ± 4.6% at late diastole for peak Hd. The mean KE and Hd were not affected by interpolation.

Conclusion

Hemodynamic atlases can be obtained with minimal user interaction using nonrigid registration of 4D Flow MRI.

Level of Evidence: 2

Technical Efficacy: Stage 1

J. Magn. Reson. Imaging 2017;46:1389–1399.
A tree‐ring chronology and paleoclimate record for the Younger Dryas–Early Holocene transition from northeastern North America
Authors: Griggs Carol , Peteet Dorothy , Kromer Bernd , Grote Todd , Southon John
Published: March 2017

Spruce and tamarack logs dating from the Younger Dryas and Early Holocene (YD–EH; ∼12.9–11.3k cal a BP) were found at Bell Creek in the Lake Ontario lowlands of the Great Lakes region, North America. A 211‐year tree‐ring chronology dates to ∼11 755–11 545 cal a BP, across the YD–EH transition. A 23‐year period of higher year‐to‐year ring‐width variability dates to around 11 650 cal a BP, infers strong regional climatic perturbations and may represent the end of the YD. Tamarack and spruce were dominant species throughout the YD–EH interval at the site, indicating that boreal conditions persisted into the EH, in contrast to geographical regions immediately south and east of the lowlands, but consistent with the Great Lakes interior lowlands. This infers that Bell Creek was at the eastern boundary of a boreal ecotone, perhaps a result of its lower elevation and the non‐analog dynamics of the Laurentide Ice Sheet. This finding suggests that the ecotone boundary extended farther east during the YD–EH transition than previously thought.
Upper lateral cartilage composite flap for closure of complicated septal perforations
Authors: Smith David F. , Albathi Monirah , Lee Andrew , Lee Linda N. , Boahene Kofi D.
Published: March 2017

Objectives/Hypothesis

To present a novel technique for the repair of large complicated nasal septal perforations using an upper lateral cartilage composite flap.

Study Design

This is a case series of five patients with large septal perforations seen at an academic tertiary care center, who have failed previous treatment measures and were selected to undergo this novel reconstruction for closure of their defects.

Methods

Patients were followed clinically to determine the success of the repair. Pre‐ and postoperative photographic documentation is presented, as well as a description of the surgical technique.

Results

All patients were found to have large septal perforations exceeding 2 × 3 cm in size. The reconstructed septal perforations remained closed for the duration of follow‐up. There were no long‐term complications related to this technique.

Conclusions

The composite upper lateral cartilage flap is an effective and reliable means of repairing large and complicated septal defects with respiratory mucosa recruited from the nasal cavity. It may be considered in revision cases prior to entertaining regional extranasal flaps or the use of septal buttons.

Level of Evidence

4. Laryngoscope, 127:1767–1771, 2017
Double‐blind randomized controlled trial of the routine perioperative use of terlipressin in adult living donor liver transplantation
Authors: Reddy Mettu Srinivas , Kaliamoorthy Ilankumaran , Rajakumar Akila , Malleeshwaran Selvakumar , Appuswamy Ellango , Lakshmi Sukanya , Varghese Joy , Rela Mohamed
Published: March 2017

Perioperative terlipressin (Tp) during living donor liver transplantation (LDLT) has been shown to reduce intraoperative portal pressures and improve renal function. Its role and safety profile have never been evaluated in a double‐blind randomized controlled trial (RCT). The aim was to evaluate the hemodynamic effects, clinical benefits, and safety of perioperative Tp infusion in adult LDLT. This was a single‐center double‐blind RCT. Consenting adults with chronic liver disease and low risk of posttransplant renal dysfunction undergoing their first LDLT were randomized. The study group (terlipressin group [TpG]) received an initial bolus of Tp during surgery followed by a Tp infusion for 72 hours in the postoperative period. The placebo group (PbG) received a saline infusion. The primary endpoint was portal pressure after arterial reperfusion. Multiple intraoperative and postoperative variables served as secondary endpoints. A total of 41 patients were enrolled in the trial (TpG, 21; PbG, 20). There were no significant differences in intraoperative portal pressures, blood loss, fluid requirement, vasopressor requirement, or urine output. Peak intraoperative and end of surgery lactate levels were significantly higher in the Tp group. There was no difference in postoperative liver function tests. Incidence of acute kidney injury as assessed by Risk, Injury, Failure, Loss, and End‐Stage Kidney Disease criteria was lower in the Tp group (27% versus 60%; P = 0.04). The TpG had less postoperative ascites, a lower need for percutaneous interventions, and a shorter hospital stay. Incidence of bradycardia requiring pharmacological intervention and withdrawal from study was significantly higher in the TpG. In conclusion, this study has not demonstrated a reduction in postreperfusion portal pressure with Tp. However, Tp infusion reduced postoperative ascitic drain output resulting in less frequent percutaneous interventions and reduced hospital stay. Intraoperative hyperlactatemia and symptomatic bradycardia are major concerns. Its use should be restricted to patients with high‐volume ascites, and it needs close monitoring during drug infusion. Liver Transplantation 23 1007–1014 2017 AASLD.
Evaluation of donor workups and exclusions in a single‐center experience of living donor liver transplantation
Authors: Nugroho Adianto , Kim Ok‐Kyung , Lee Kwang‐Woong , Song Sanghee , Kim Hyeyoung , Hong Suk Kyun , Yoon Kyung Chul , Kim Hyo‐Sin , Choi YoungRok , Lee Hae Won , Yi Nam‐Joon , Suh Kyung‐Suk
Published: March 2017

The process of evaluating potential donors in liver transplantation is important to ensure donor safety and provide optimal recipient outcomes. However, there has been no report about donor exclusion rates and reasons for such exclusion in Korea. In this study, we aimed to elucidate the outcomes of potential living liver donor evaluation in a major living donor liver transplantation center. From July 2011 to June 2015, prospectively collected data of 726 potential donors for 588 matched recipients were subsequently evaluated. Among 726 potential donors, 374 potential donors (51.5%) finally reached donation; 352 potential donors (48.5%) were excluded for various reasons. Donor reasons were 29.8%, including medical problems, withdrawal of consent, graft volume issues, and identification of a better suitable donor. Recipient reasons were 20.7%, including recipient death or recovery, allocation to deceased donor, and progressions of hepatocellular carcinoma. A total of 38 (5.2%) potential donors had a fatty liver. Among them, 15 (39.5%) potential donors tried short‐term weight reduction and eventually were able to donate. In conclusion, the main reasons for donor exclusion were medical problems and withdrawal of consent. Therefore, thorough medical screening and careful examination for donor voluntarism are important in the donor evaluation process. Liver Transplantation 23 614–624 2017 AASLD.
Simultaneous vascularized bony reconstruction of the maxilla and mandible using a single fibula: A case report
Authors: Mericli Alexander F. , Friedstat Jonathan S. , Chang Edward I. , Hanasono Matthew M.
Published: March 2017

Simultaneous maxillary and mandibular reconstruction is exceedingly rare. These are complicated cases, requiring consideration of multiple variables: defect components, donor site morbidity, recipient vessels, and so forth. We describe a unique case of secondary maxillary/mandibular reconstruction in a 59‐year‐old male. The original defect was created after removal of a buccal squamous cell carcinoma, involving the external cheek skin, buccal mucosa, right mandibular body, and right inferior maxilla; a free vertical rectus abdominis musculocutaneous flap was used for the initial reconstruction. At the time of presentation to our clinic, the patient was tube‐feed‐dependent, unable to speak, and distressed regarding his appearance. We revised his reconstruction, rebuilding his maxilla and hemimandible using two free fibula flaps from a single fibula. The fibulae were vascularized via vein grafts and an ALT flap was used for external cheek resurfacing. All flaps survived and there were no complications at seven months since his surgery (when this report was written). The patient had intelligible speech and maintained adequate nutrition with a soft diet. Simultaneous vascularized bony reconstruction of the maxilla and mandible using a single fibula flap may be performed safely and with good outcomes.
Diffusion‐prepared stimulated‐echo turbo spin echo (DPsti‐TSE): An eddy current‐insensitive sequence for three‐dimensional high‐resolution and undistorted diffusion‐weighted imaging
Authors: Zhang Qinwei , Coolen Bram F. , Versluis Maarten J. , Strijkers Gustav J. , Nederveen Aart J.
Published: March 2017

In this study, we present a new three‐dimensional (3D), diffusion‐prepared turbo spin echo sequence based on a stimulated‐echo read‐out (DPsti‐TSE) enabling high‐resolution and undistorted diffusion‐weighted imaging (DWI). A dephasing gradient in the diffusion preparation module and rephasing gradients in the turbo spin echo module create stimulated echoes, which prevent signal loss caused by eddy currents. Near to perfect agreement of apparent diffusion coefficient (ADC) values between DPsti‐TSE and diffusion‐weighted echo planar imaging (DW‐EPI) was demonstrated in both phantom transient signal experiments and phantom imaging experiments. High‐resolution and undistorted DPsti‐TSE was demonstrated in vivo in prostate and carotid vessel wall. 3D whole‐prostate DWI was achieved with four b values in only 6 min. Undistorted ADC maps of the prostate peripheral zone were obtained at low and high imaging resolutions with no change in mean ADC values [(1.60 ± 0.10) × 10−3 versus (1.60 ± 0.02) × 10−3 mm2/s]. High‐resolution 3D DWI of the carotid vessel wall was achieved in 12 min, with consistent ADC values [(1.40 ± 0.23) × 10−3 mm2/s] across different subjects, as well as slice locations through the imaging volume. This study shows that DPsti‐TSE can serve as a robust 3D diffusion‐weighted sequence and is an attractive alternative to the traditional two‐dimensional DW‐EPI approaches.
Skeletal Lead Burden of the British Royal Navy in Colonial Antigua
Authors: Giffin K. L. , Swanston T. , Coulthard I. , Murphy A. R. , Cooper D. M. L. , Varney T. L.
Published: March 2017

Lead (Pb) has been known to be a cause of human poisoning since ancient times, but despite this, it was a widely used metal in the European colonial period. In this study, the relationship between Pb exposure and the demographic variables ancestry and age was explored by comparing the bone Pb levels of individuals that were of either African or European ancestry, excavated from a British Royal Navy hospital cemetery (1793–1822 CE) at English Harbour in Antigua, West Indies. More direct comparisons of Pb levels between the two ancestral groups were possible in this study because of the unsegregated nature of this cemetery. Inductively coupled plasma mass spectrometry was used to determine bulk Pb levels in cortical bone samples from the fibular diaphyses of 23 male individuals. No significant difference was found between the distributions of the Pb levels of the ancestral groups (p = 0.94). Further, no positive correlations or significant differences were found in relation to the individuals' ages and their Pb levels (p = 0.24). Levels of Ba, Ca and rare earth elements support a largely biogenic origin of lead. This is bolstered by Pb deposition patterns, generated by synchrotron X‐ray fluorescence imaging for another study. The data suggest that naval personnel, regardless of ancestry at English Harbour, had very similar experiences with regard to Pb exposure. Their exposure to the toxic metal was likely not consistent over time as steady exposure would have resulted in accumulation of Pb with age. This study contributes to addressing historical questions regarding the prevalence of Pb poisoning within the British Royal Navy during the colonial period. © 2017 The Authors International Journal of Osteoarchaeology Published by John Wiley & Sons Ltd.
A three‐dimensional carbon nanotube–nanofiber composite foam for selective adsorption of oils and organic liquids
Authors: Jin Lin , Hu Bin , Kuddannaya Shreyas , Zhang Yilei , Li Chunyang , Wang Zhenling
Published: March 2017

Carbon nanotubes (CNTs) have attracted tremendous research interest area as promising sorbent material due to the large surface area for adsorption, excellent mechanical and chemical properties. To practically employ CNTs as a potential commercial sorbent, it is essential to form loosely packed architecture of CNTs in 3D space. In recent years, a series of CNTs‐based composites have been fabricated. However, these composites showed a highly compact structure and/or junctions with uneven/excessive CNTs deposition, which significantly limit their performance as sorbents. Herein, we report the direct fabrication of three‐dimensional flower‐like CNTs‐nanofibers foams (3D CNTs‐NFs) by freeze‐drying aqueous solutions of electrospun poly‐acetonitrile (PAN) nanofibers and CNTs. As a result, fully expanded multiple layered CNTs nanosheets with sufficient large surface area could be successfully integrated within the 3D nano‐fibrous architecture. The 3D CNFs‐NFs showed excellent mechanical properties and adsorption capacities, which permit this kind of CNTs composite foam could be used in selective adsorption processes and environmental applications. POLYM. COMPOS., 39:E271–E277, 2018. © 2017 Society of Plastics Engineers
Identifying atrial fibrillation in outpatients initiating oral anticoagulants based on medico‐administrative data: results from the French national healthcare databases
Authors: Billionnet Cécile , Alla François , Bérigaud Éric , Pariente Antoine , Maura Géric
Published: March 2017

Purpose

Identifying atrial fibrillation (AF) in outpatients treated with oral anticoagulants (OACs) from claims databases is challenging when the outpatient indication is not available, as OACs are also prescribed for deep vein thrombosis/pulmonary embolism (DVT/PE) that may be treated in the ambulatory setting. An algorithm was developed to identify AF in outpatients initiating OAC from medico‐administrative data.

Methods

Among patients initiating OAC in 2013 in the French healthcare databases, those treated for orthopaedic indications were excluded. Patients with a history of AF or DVT/PE directly identified from available medical data, mainly hospital discharge diagnoses, were considered to be ‘confirmed AF or DVT/PE patients’. Demographics of these patients and their healthcare utilization data prior to OAC initiation were then included in a logistic regression model discriminating AF versus DVT/PE indications. The final model selected, comparing c‐index, provided an algorithm identifying AF from among initially unclassified patients assumed to be either AF or DVT/PE outpatients.

Results

Among 256 418 patients initiating OAC, 37 388 were excluded; 61 329 AF and 59 859 DVT/PE patients were directly identified, leaving 88 488 unclassified patients. The final model (c‐index: 0.93) included demographics, cardiologist prescriber, hospitalization for stroke, use of antiarrhythmics/beta‐blockers/antihypertensive drugs and undergoing a Holter/echocardiography procedure, thyroid function tests, but no D‐dimer tests. With a specificity of 95% (sensitivity: 65%), 41% of the unclassified patients were assumed to be AF outpatients. Similar results were obtained on 250 159 new users in 2014.

Conclusion

This algorithm combining inpatient and outpatient claims data performed relatively well to identify AF outpatients initiating OAC. Copyright © 2017 John Wiley & Sons, Ltd.
Controlled and sustained release of a corticosteroid drug from block copolymers synthetized by ATRP
Authors: Valenti Graziella , La Carta Stefania , Mazzotti Giovanni , Rapisarda Marco , Perna Stefania , Di Gesù Roberto , Giorgini Loris , Carbone Domenico Carmelo , Recca Giuseppe , Rizzarelli Paola
Published: March 2017

During last decades, implantable drug delivery systems (DDS) have been developed to optimize therapeutic properties of drugs and ensure their release in a specific site. Acrylic polymers have obtained growing interest in biomedical applications for their biocompatibility and chemical properties that make them extremely versatile. In this work, we focused on the realization of polymeric systems for controlled and sustained release of betamethasone 17,21‐dipropionate (BDP), a corticosteroid drug, in the treatment of the posterior eye diseases (PED). The investigated DDS were made of opportunely designed methacrylic block copolymers. Different series of methylmethacrylate/2‐hydroxyethylmethacrylate (MMA/HEMA) block copolymers, with various monomeric compositions (20‐60 mol% HEMA), were synthetized by Atom Transfer Radical Polymerization to find the best hydrophilic/hydrophobic ratio, able to ensure optimal kinetic release. Copolymers were characterized by nuclear magnectic resonance, size exclusion chromatography, and differential scanning calorimetry. Monitoring of drug release from films loaded with BDP was carried out by HPLC analysis. In particular, PMMA‐b‐PHEMA with 47 mol% of HEMA showed the best release profile to achieve the therapeutic reference dose, used in the treatment of PED (1‐3 µg/day), up to four months. Additionally, intraocular inserts with different shapes were prepared using silicon molds made by means of a 3D printer. POLYM. ENG. SCI., 57:570–578, 2017. © 2017 Society of Plastics Engineers
Fabrication of polymer‐dispersed liquid crystals with low driving voltage based on the thiol‐ene click reaction
Authors: Shi Zhiqing , Shao Leishan , Zhang Yuliang , Guan Yu , Wang Fei , Deng Feifei , Liu Yawei , Wang Yinghan
Published: March 2017

Polymer‐dispersed liquid crystals (PDLCs) with a well‐defined polymer matrix were successfully fabricated by the thiol‐ene click reaction based on poly(ethylene glycol) diacrylate (PEGDA) and trimethylolpropanetris‐(3‐mercaptopropionate) (TMTP). UV−visible spectrophotometry, Fourier transform IR spectroscopy, SEM and polarized optical microscopy were employed to explore the PDLC films obtained. Electro‐optical properties were studied with a UV−visible spectrophotometer. It was found that the PDLC films with optimal thiol content fabricated by the thiol‐ene click reaction showed high transmittance, low driving voltage and a low memory effect. It was concluded that the driving voltage change of PDLCs with different thiol concentrations was caused by the polymerization rate and the structure of the polymer matrix. © 2017 Society of Chemical Industry
Nonconjugated diene homopolymerization and copolymerization with ethylene catalyzed by α‐diimine Ni(II) complex/Et2AlCl
Authors: Song Shaofei , Wu Anyang , Yu Yan , Yang Pengjia , Fu Zhisheng , Fan Zhiqiang
Published: March 2017

Four nonconjugated diene comonomers 1,9‐decadiene (19DD), 6‐ethylundeca‐1,10‐diene (EUD), 1,5‐cyclooctadiene (COD) and cinene (1‐methyl‐4‐(prop‐1‐en‐2‐yl) cyclohex‐1‐ene) (CE) were used in copolymerization with ethylene catalyzed by α‐diimine Ni(II) complex ([2,6‐(iPr)2C6H3N = C(CH3)−(CH3)C = N2,6‐(iPr)2C6H3)]NiBr2 (1)) activated by Et2AlCl. These dienes showed quite distinct copolymerization behaviors. Ethylene‐19DD copolymerization formed highly branched polyethylene with cyclic units and pendent vinyls, and a large part of crosslinked polymer when the 19DD concentration was relatively high. Using EUD as comonomer lead to evidently reduced gel formation and increased content of pendent vinyl. COD can be incorporated in the copolymer with evidently lower catalyst efficiency than the ethylene homopolymerization, and CE behaves like an inert compound as it was not incorporated in the copolymer. Homopolymerization of 19DD with the same catalyst produced polymer containing both cyclic units and pendent vinyls. The cyclic units were formed by cyclopolymerization of the inserted 19DD after several steps of chain walking. Crosslinking through the pendent vinyl took place when the initial 19DD concentration was relatively high, forming large amount of gel in the product. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 1900–1909
Balancing high thermal stability with high activity in diaryliminoacenaphthene‐nickel(II) catalysts for ethylene polymerization
Authors: Chen Yanjun , Du Shizhen , Huang Chuanbing , Solan Gregory A. , Hao Xiang , Sun Wen‐Hua
Published: March 2017

The N,N‐diaryliminoacenaphthenes, 1,2‐[2,4‐{(4‐FC6H4)2CH}2‐6‐MeC6H4N]2‐C2C10H6 (L1) and 1‐[2,4‐{(4‐FC6H4)2CH}2‐6‐MeC6H4N]‐2‐(ArN)C2C10H6 (Ar = 2,6‐Me2C6H3 L2, 2,6‐Et2C6H3 L3, 2,6‐i‐Pr2C6H3 L4, 2,4,6‐Me3C6H2 L5, 2,6‐Et2‐4‐MeC6H2 L6), incorporating at least one N−2,4‐bis(difluoro benzhydryl)‐6‐methylphenyl group, have been synthesized and fully characterized. Interaction of L1–L6 with (DME)NiBr2 (DME = 1,2‐dimethoxyethane) generates the corresponding nickel(II) bromide N,N‐chelates, LNiBr2 (1–6), in high yield. The molecular structures of 3 and 6 reveal distorted tetrahedral geometries at nickel with the ortho‐substituted difluorobenzhydryl group providing enhanced steric protection to only one side of the metal center. On activation with various aluminum alkyl co‐catalysts, such as methylaluminoxane (MAO) or Et2AlCl, 1–6 displayed outstanding activity toward ethylene polymerization (up to 1.02 × 107 g of PE (mol of Ni)−1 h−1). Notably 1, bearing equivalent fluorobenzhydryl‐substituted N‐aryl groups, was able in the presence of Et2AlCl to couple high activity with exceptional thermal stability generating high molecular weight branched polyethylenes at temperatures as high as 100 °C. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 1971–1983
Proteins mediating DNA loops effectively block transcription
Authors: Vörös Zsuzsanna , Yan Yan , Kovari Daniel T. , Finzi Laura , Dunlap David
Published: March 2017

Loops are ubiquitous topological elements formed when proteins simultaneously bind to two noncontiguous DNA sites. While a loop‐mediating protein may regulate initiation at a promoter, the presence of the protein at the other site may be an obstacle for RNA polymerases (RNAP) transcribing a different gene. To test whether a DNA loop alters the extent to which a protein blocks transcription, the lac repressor (LacI) was used. The outcome of in vitro transcription along templates containing two LacI operators separated by 400 bp in the presence of LacI concentrations that produced both looped and unlooped molecules was visualized with scanning force microscopy (SFM). An analysis of transcription elongation complexes, moving for 60 s at an average of 10 nt/s on unlooped DNA templates, revealed that they more often surpassed LacI bound to the lower affinity O2 operator than to the highest affinity Os operator. However, this difference was abrogated in looped DNA molecules where LacI became a strong roadblock independently of the affinity of the operator. Recordings of transcription elongation complexes, using magnetic tweezers, confirmed that they halted for several minutes upon encountering a LacI bound to a single operator. The average pause lifetime is compatible with RNAP waiting for LacI dissociation, however, the LacI open conformation visualized in the SFM images also suggests that LacI could straddle RNAP to let it pass. Independently of the mechanism by which RNAP bypasses the LacI roadblock, the data indicate that an obstacle with looped topology more effectively interferes with transcription.
MxaJ structure reveals a periplasmic binding protein‐like architecture with unique secondary structural elements
Authors: Myung Choi Jin , Cao Thinh‐Phat , Wouk Kim Si , Ho Lee Kun , Haeng Lee Sung
Published: March 2017

MxaJ is a component of type II methanol dehydrogenase (MDH) that mediates electron transfer during methanol oxidation in methanotrophic bacteria. However, little is known about how MxaJ structurally cooperates with MDH and Cytochrome cL. Here, we report for the first time the crystal structure of MxaJ. MxaJ consists of eight α‐helices and six β‐strands, and resembles the “bi‐lobate” folding architecture found in periplasmic binding proteins. Distinctive features of MxaJ include prominent loops and a β‐strand around the hinge region supporting the ligand‐binding cavity, which might provide a more favorable framework for interacting with proteins rather than small molecules. Proteins 2017; 85:1379–1386. © 2017 Wiley Periodicals, Inc.
Investigating Transporter‐Mediated Drug‐Drug Interactions Using a Physiologically Based Pharmacokinetic Model of Rosuvastatin
Authors: Wang Q , Zheng M , Leil T
Published: March 2017

Rosuvastatin is a frequently used probe in transporter‐mediated drug‐drug interaction (DDI) studies. This report describes the development of a physiologically based pharmacokinetic (PBPK) model of rosuvastatin for prediction of pharmacokinetic (PK) DDIs. The rosuvastatin model predicted the observed single (i.v. and oral) and multiple dose PK profiles, as well as the impact of coadministration with transporter inhibitors. The predicted effects of rifampin and cyclosporine (6.58‐fold and 5.07‐fold increase in rosuvastatin area under the curve (AUC), respectively) were mediated primarily via inhibition of hepatic organic anion‐transporting polypeptide (OATP)1B1 (Inhibition constant (Ki) ∼1.1 and 0.014 µM, respectively) and OATP1B3 (Ki ∼0.3 and 0.007 µM, respectively), with cyclosporine also inhibiting intestinal breast cancer resistance protein (BCRP; Ki ∼0.07 µM). The predicted effects of gemfibrozil and its metabolite were moderate (1.88‐fold increase in rosuvastatin AUC) and mediated primarily via inhibition of hepatic OATP1B1 and renal organic cation transporter 3. This model of rosuvastatin will be useful in prospectively predicting transporter‐mediated DDIs with novel pharmaceutical agents in development.
Idealized numerical simulations of Mesoscale Convective Systems and their implications for forecast error
Authors: Shutts Glenn
Published: March 2017

Deep convective mass transfer in a rotating, stratified fluid is capable of generating characteristic potential vorticity features and, if of sufficient spatial scale, these may affect baroclinic wave development and hence weather predictability. In current global numerical prediction models, it is still necessary to include convection parametrization even though these algorithms are ill‐suited to representing singular, mesoscale convective events. Some stochastic representations of the non‐equilibrium convective process in ensemble prediction systems perturb the vertical component of vorticity in order to crudely represent the upscale impact of deep convection (i.e. kinetic energy backscatter schemes). These use ad hoc assumptions about the structure of random wind errors associated with convection. The idealized, explicit convection simulations described here form the basis of a study of these convectively generated vorticity perturbations, and their implications for stochastic convective forcing in ensemble prediction systems is considered. Cases with no initial flow and constant shear are examined with emphasis on the impact on vertical vorticity within the mesoscale cloud shield. The results are interpreted in the wider context of operational forecast error in the simulated infrared radiance for cases of intense convective activity over the North American Great Plains. A Met Office Unified Model forecast made with 2.2 km horizontal resolution during the Hazardous Weather Testbed project provides additional support for the idealized model findings. The Stochastic Convective Backscatter scheme proposed by the author is integrated forward in time using the simulated convective mass transport as a driver for the random forcing term. In its ensemble forecast model implementation, this term uses parametrized convective mass fluxes. The results suggest a retuning of the scheme's filter scales in order to obtain a representation of model wind error more consistent with the simulations.
Chemical pleurodesis using mistletoe extracts via spray catheter during medical thoracoscopy for management of malignant pleural effusion
Authors: Eom Jung Seop , Kim Tae Hwa , Lee Geewon , Ahn Hyo Yeong , Mok Jeong Ha , Lee Min Ki
Published: March 2017

We present three cases of successful chemical pleurodesis with a liquid solution of mistletoe extract using a spray catheter during medical thoracoscopy. The medical thoracoscopy was performed in all presented cases to remove pleural effusion and conduct chemical pleurodesis to manage symptomatic malignant pleural effusion. A spray catheter was used to instil the mistletoe extract evenly into the pleural cavity, and there were no pleurodesis‐related complications. Respiratory symptoms caused by pleural effusion improved after pleurodesis, and successful pleurodesis was maintained for more than 3 months after medical thoracoscopy in all three patients.
Adaptive disturbance observer‐based finite‐time continuous fault‐tolerant control for reentry RLV
Authors: Dong Qi , Zong Qun , Tian Bailing , Zhang Chaofan , Liu Wenjing
Published: March 2017

The control effectors of reusable launch vehicle (RLV) can produce significant perturbations and faults in reentry phase. Such a challenge imposes tight requirements to enhance the robustness of vehicle autopilot. Focusing on this problem, a novel finite‐time fault‐tolerant control strategy is proposed for reentry RLV in this paper. The key of this strategy is to design an adaptive‐gain multivariable finite‐time disturbance observer (FDO) to estimate the synthetical perturbation with unknown bounds, which is composed of model uncertainty, external disturbance, and actuator fault considered as the partial loss of actuator effectiveness in this work. Then, combined with the finite‐time high‐order observer and differentiator, a continuous homogeneous second‐order sliding mode controller based on the terminal sliding mode and super‐twisting algorithm is designed to achieve a fast and accurate RLV attitude tracking with chattering attenuation. The main features of the integrated control strategy are that the adaptation algorithm of FDO can achieve non‐overestimating values of the observer gains and the second‐order super‐twisting sliding mode approach can obtain a more elegant solution in finite time. Finally, simulation results of classical RLV (X‐33) are provided to verify the effectiveness and robustness of the proposed fault‐tolerant controller in tracking the guidance commands. Copyright © 2017 John Wiley & Sons, Ltd.
Addressing Inadequacies of the Observation Survey of Early Literacy Achievement
Authors: D'Agostino Jerome V. , Rodgers Emily , Mauck Susan
Published: March 2017

The authors used nationally based, random sample data from three different years (2009–2010, 2011–2012, and 2014–2015) for nearly 20,000 first‐grade students (n = 9,760, 3,657, and 3,121, respectively) to examine long‐reported inadequacies of a commonly used early literacy assessment tool, the Observation Survey of Early Literacy Achievement (OSELA), chief among them the skewness and nonequal interval nature of the scores that are obtained on its six individual tasks. Such inadequacies prevented the individual task scores from being used for program evaluation, screening, and progress monitoring. To mitigate these OSELA limitations, the authors employed Rasch analysis to create a scale that can be used to track a student's literacy achievement based on the combination of OSELA task scores. Dimensionality analyses revealed that the OSELA measures one factor, which supported the decision to combine the individual tasks to compute one total score. The equal‐interval total score was normally distributed at the beginning, middle, and end of first grade. Further, the authors conducted a predictive validation study of the total score to identify a range of cut scores that can be used in the fall of first grade to predict reading failure by year end. The authors maintain that the total score provides a more precise and efficient means of screening young students for reading failure and evaluating their progress over time. Implications for using the total score to make screening decisions and measure early reading progress are discussed.
Pre‐Market Entry Experience and Post‐Market Entry Learning of the Board of Directors: Implications for Post‐Entry Performance
Authors: Chen Pao‐Lien , Kor Yasemin , Mahoney Joseph T. , Tan Danchi
Published: March 2017

Research summary

We investigate how board directors’ expertise influences post‐entry performance of start‐ups and diversifying entrants in an emerging market. Empirical analysis based on firms in the U.S. wireless communications service industry from 1983 to 1998 reveals that post‐entry growth increases with directors’ post‐entry firm‐specific board experience, but decreases with directors’ inherited pre‐entry firm‐specific board experience. In addition, outside directors’ intra‐industry managerial experience stimulates post‐entry growth while intra‐industry directorial experience reduces it. We also find that firms benefit from having true industry outsiders who are experienced in other—not the focal—industries. Taking this evidence together, boards with a mix of directors with post‐entry firm‐specific board expertise and complementary other industry expertise are most suitable for the governance of post‐entry venture growth.

Managerial summary

Careful board composition design can facilitate post‐entry performance of new entrants into an emerging industry. Specifically, entrants should retain some of the initial recruits to the board in order to steadily build firm‐specific board expertise. They should also introduce genuine industry outsiders (with no experience in the focal industry) to the board in order to inject fresh thinking into board governance, which is critical for renewal of the firm's growth strategy and market positioning over time. For diversifying entrants, if the new market entry is a strategic investment for the parent firm, it is worth setting up a separate board of directors where directors are not linked with the parent firm board, as a preexisting board is likely to be too deeply engaged with existing businesses. Copyright © 2017 Strategic Management Society.
Cu(II)‐Et‐S@MCM‐41: A Green and Cost‐Effective Catalytic System for S‐arylation of Aryl Halides Using Thiourea and Benzyl Bromide
Authors: Hajipour Abdol R. , Hosseini Seyed Mostafa , Jajarmi Saeideh
Published: March 2017

Using reaction of 2‐chloroethyl phenyl sulfide with 3‐aminopropyl functionalized mesoporous MCM‐41, applicable substrate was prepared for fixing Cu2+ NPs. The Cu(II)‐Et‐S@MCM‐41 was characterized by FT‐IR, CHNS, XRD, FE‐SEM, TEM, EDX, ICP‐AES, BET and TG analysis. This novel heterogeneous nanocatalyst showed high catalytic performance and reusability for S‐arylation of aryl bromides and chlorides using thiourea, benzyl bromide and K2CO3 at 100°C in aqueous medium.
Triphenylamine‐BODIPY Fluorescent Dendron: Click Synthesis and Fluorometric Chemodosimeter for Hg2+, Fe3+ Based on the C=N Bond
Authors: Shen Bao X. , Qian Ying
Published: March 2017

A novel Triphenylamine‐BODIPY Schiff base fluorescent sensor (Probe 1) was designed and synthesized by “Click reaction”. It is a reaction‐based probe for Hg2+ and Fe3+ with high selectivity and sensitivity. The fluorescent quantum yield of Probe 1 at band 515 nm is 0.07. After treatment with Fe3+ or Hg2+, the fluorescence intensity enhanced, and the fluorescent quantum yield is 0.64 for Probe 1/Fe3+ and 0.58 for Probe 1/Hg2+ respectively. The results of Job's plot experiment shows stoichiometry between Probe 1 and Fe3+ or Hg2+ is 1 : 2. The detection limit is 6.69× 10−8 M for Fe3+ and 2.24×10−7 M for Hg2+. Water‐soluble fluorescent nanoparticles (FNPs) that encapsulate the probe are prepared, and the fluorescent quantum yield of FNPs is 0.16. Probe 1 has a great application prospect in biomedical, ion detection and is an excellent platform for developing multichannel reaction‐based probes.
Enhanced Photocatalytic Performance of Porphyrin/Phthalocyanine and Bis(4‐pyridyl)pyrrolidinofullerene modified Titania
Authors: Regulska Elzbieta , Rivera‐Nazario Danisha M. , Karpinska Joanna , Plonska‐Brzezinska Marta E. , Echegoyen Luis
Published: March 2017

Zinc(II), copper(II) and cobalt(II) metallated porphyrins/phthalocyanines and bis(4‐pyridyl) pyrrolidinofullerene (9) were used in a supramolecular approach for the sensitization of titania. Spectral properties of the chromophores were examined in the solid state showing strong absorptions at 700 and 800 nm for porphyrins and phthalocyanines, respectively. The interaction between the chromophores and a dual ligand was investigated spectroscopically. Titania‐based composites sensitized with 9 and cobaltous porphyrin exhibited the highest photocatalytic activity against both phenol and methylene blue under solar irradiation. Photodegradation intermediates were determined based on LC‐UV‐Vis‐MS analysis. It is expected that the composites will be applied for remediation of aqueous environmental samples from transparent and colorful pollutants.
Name analysis for modern languages: a general solution
Authors: Kastens Uwe , Waite William
Published: March 2017

Classical strategies for matching identifier uses with declarations cannot handle the complexities of modern languages: arbitrarily qualified superclass names, cyclic dependence among lookup operations, and contextual access constraints. We have developed a language‐independent algorithm and supporting data structure that overcome these problems. A well‐defined interface allows introduction of arbitrary code to enforce language‐specific constraints within the basic lookup operations. This paper explains the limitations of the classical strategies, presents the concepts on which our approach is based, and showcases an implementation based on attribute grammars. We explore the major issues through a series of examples and show how one can deal with those issues in a general framework. Many of the issues are specific to a particular language, and in those cases, we explain the solutions that our general interface supports. Although attribute grammars simplify the task of incorporating the model into a compiler, the model itself is completely independent of attribute grammars. We validated our model by using an implementation to process programs in several representative languages. In particular, we mechanically compared the results produced by that implementation with those produced by the Java SE 8 compiler on complete Java programs that are in general use. Performance data obtained during this processing show that our implementation is efficient. Copyright © 2017 John Wiley & Sons, Ltd.
Agent‐oriented and ontology‐driven digital libraries: the IndianaMAS experience
Authors: Briola Daniela , Deufemia Vincenzo , Mascardi Viviana , Paolino Luca
Published: March 2017

This paper describes IndianaMAS, a multiagent system able to automatically classify and manage images, sketches, and multilingual documents in a cultural heritage domain. The latter has been formalized by means of an ontology, which enables the semantic integration of heterogeneous data from different sources, drives the agent communication with the internal and external environment, and provides an abstract and human‐readable interface between the system and the user. IndianaMAS is able to expose to the world the classified data via a digital library. Modularity and reusability are the key engineering principles followed in the system design and implementation. We present the details of the IndianaMAS system and discuss how its architecture can be generalized to create – with the minimal effort – systems addressing similar classification, storage, and management problems, but operating in different domains and driven by different ontologies. The concrete problems we faced and their solutions are described to share our lesson learned and, at the same time, to show the applicability and reusability of our modular approach based on ontologies, agents, and digital libraries. Copyright © 2017 John Wiley & Sons, Ltd.
Written Feedback to Support Students’ Higher Level Thinking About Texts in Writing
Authors: Wang Elaine , Matsumura Lindsay Clare , Correnti Richard
Published: March 2017

Supporting upper elementary students’ higher level (i.e., analytic) thinking about texts in writing is a challenge for many teachers, in large part because what it means to analyze text is not well defined and because this skill is a relatively new expectation in elementary grades. In this article, the authors clarify the goal of three common types of writing assignments that guide students to apply higher level thinking: analysis of literary elements, comparing and contrasting, and interpreting theme. The authors identify some common ways that students’ responses can fall short of the intended thinking demands and offer suggestions for written feedback that teachers can give to get students back on track.