bluuebunny/crossref_metadata_2025 huggingface dataset:
Structural characterizations, spectroscopic, electrochemical properties, and antibacterial activities of copper (II) and cobalt (II) complexes containing imidazole ring
Authors: Chai Lan‐Qin , Zhou Ling , Zhang Kong‐Yan , Zhang Hong‐Song
Published: October 2018

Two two‐dimensional and three‐dimensional supramolecular complexes [M (L)2] (NO3)2·2CH3OH (M = Cu(1) and Co(2), L = 2‐(4‐imidazolyl)‐4‐methyl‐1,2‐quinazoline‐N3‐oxide), were synthesized and characterized by FT‐IR and UV–Vis spectroscopy, as well as elemental analysis. The spectroscopic data of both complexes were compared with the ligand L. Both complexes were determined by X‐ray single‐crystal diffraction and display similar coordination geometry and have a 2:1 ligand‐to‐metal ratio. All the central M (II) atoms are hexa‐coordinated with perfect octahedral geometries. In the crystal structures, complexes 1 and 2 form an infinite 1‐D chain‐like and 2‐D, 3‐D supramolecular frameworks. X‐ray photoelectron spectrum (XPS) and thermal stability of 2 was investigated. Moreover, electrochemical properties and antimicrobial activities of both complexes were also studied.
A novel purine derivative‐based colorimetric chemosensor for sequential detection of copper ion and sulfide anion
Authors: Jin Xinxin , Chen Huilian , Zhang Weixia , Wang Biyi , Shen Wei , Lu Hongfei
Published: October 2018

A purine derivative‐based colorimetric chemosensor (PHP) for the detection of Cu2+ and S2− is reported. PHP demonstrated a high selectivity and sensitivity for Cu2+ through color change from colorless to yellow with a detection limit of 74.9 nM. The sensing mechanism of the PHP–Cu complex was confirmed using X‐ray crystal structure analysis and density functional theory calculation. Furthermore, the PHP–Cu complex can be used for selective detection of S2− via competitive complexation of S2− to Cu2+. Finally, PHP was successfully applied as a visible test strip for the detection of cupric ions in water.
Application of a novel, efficient and recyclable photo redox catalyst (Zn–Al layered double hydroxide/eosin) for the synthesis of substituted pyridine derivatives under visible light irradiation
Authors: Rasouli Nahid
Published: October 2018

Layered double hydroxides (LDHs) are a class of anionic clays with brucite‐like layers and interlayer anions and varying in composition and morphology. LDHs show potential as supports for the immobilization of catalytically active species, to synthesize recyclable catalysts, in which catalytic sites can be preferentially orientated, highly dispersed and stabilized to afford high catalytic efficiency and recyclability in reaction media. Redox active organic dyes such as eosin Y with strong absorption in the visible region of the spectrum have been successfully used. In this work, an intercalated photo redox catalyst (Zn–Al LDH/eosin) was synthesized by co‐precipitation of an aqueous solution of zinc nitrate and aluminium nitrate simultaneously with eosin Y as anionic dye. Zn–Al LDH/eosin as a recyclable catalyst was used in the reaction of various aryl ketones and benzylamines under molecular oxygen and visible light, giving good yields of substituted pyridines at room temperature. Also, the Zn–Al LDH/eosin catalyst could be reused three times without any significant changes in the reaction yields.
Ionic liquid‐assisted synthesis of porous BiOBr microspheres with enhanced visible light photocatalytic performance
Authors: Nan Qiuli , Huang Shuang , Zhou Yuming , Zhao Shuo , He Man , Wang Yongjuan , Li Shiwei , Huang Tingyuan , Pan Wenlu
Published: October 2018

Porous BiOBr microspheres have been successfully synthesized through an ethylene glycol‐assisted solvothermal method using reactive ionic liquids as templates and reactants during the synthetic process. The obtained samples were characterized using X‐ray diffraction, scanning and transmission electron microscopies and X‐ray photoelectron, energy‐dispersive X‐ray, Fourier transform infrared, diffuse reflectance and photoluminescence spectroscopies. The photocatalytic activities were evaluated using the degradation of rhodamine B and tetracycline under visible light irradiation. The photocatalytic efficiency of BiOBr photocatalyst synthesized using single‐molecule ionic liquid as template is better than that of BiOBr obtained using polyionic liquid as template. A possible photocatalytic mechanism is also provisionally proposed. And the degradation rate using BiOBr‐IL‐1 was 2.74, 1.24 and 4.84 times higher than that using BiOBr‐IL‐2, BiOBr‐IL‐3 and BiOBr‐KBr. The larger surface area and narrower energy band gap of BiOBr‐IL‐1 could improve the visible light harvesting ability and facilitate the separation of photogenerated electron–hole pairs and the photocatalysis process. This study affords a facile way to develop such novel photocatalysts with special morphology using ionic liquids.
Model‐assisted process characterization and validation for a continuous two‐column protein A capture process
Authors: Baur Daniel , Angelo James , Chollangi Srinivas , Müller‐Späth Thomas , Xu Xuankuo , Ghose Sanchayita , Li Zheng Jian , Morbidelli Massimo
Published: October 2018

In this study we introduce three process characterization approaches toward validation of continuous twin‐column capture chromatography (CaptureSMB), referred to as “standard,” “model assisted,” and “hybrid.” They are all based on a traditional risk‐based approach, using process description, risk analysis, design‐of‐experiments (DoE), and statistical analysis as essential elements. The first approach, the “standard” approach uses a traditional experimental DoE to explore the design space of the high‐ranked process parameters for the continuous process. Due to the larger number of process parameters in the continuous process, the DoE is extensive and includes a larger number of experiments than an equivalent DoE of a single column batch capture process. In the investigated case, many of the operating conditions were practically infeasible, indicating that the design space boundaries had been chosen inappropriately. To reduce experimental burden and at the same time enhance process understanding, an alternative “model assisted” approach was developed in parallel, employing a chromatographic process model to substitute experimental runs by computer simulations. Using the “model assisted” approach only experimental conditions that were feasible in terms of process yield constraints (>90%) were considered for statistical analysis. The “model assisted” approach included an optimization part that identified potential boundaries of the design space automatically. In summary, the “model assisted” approach contributed to increased process understanding compared to the “standard” approach. In this study, a “hybrid” approach was also used containing the general concepts of the “standard” approach but substituting a number of its experiments by computer simulations. The presented approaches contain essential elements of the Food and Drug Administration’s process validation guideline.
Long‐term clinical outcome of persistent left bundle branch block after transfemoral aortic valve implantation
Authors: Keßler Mirjam , Gonska Birgid , Seeger Julia , Rottbauer Wolfgang , Wöhrle Jochen
Published: October 2018

Objective

The impact of persistent left bundle‐branch block (pLBBB) on long‐term clinical outcome remains to be determined.

Background

New‐onset of pLBBB occurs frequently after transfemoral aortic valve implantation (TAVI).

Methods

Seven hundred and seven consecutive patients who underwent TAVI were analyzed for baseline and procedural characteristics and clinical outcome in an up to 2‐year follow‐up. Patients were divided into either a group with pLBBB until hospital discharge or a group without LBBB. We performed propensity‐score matching and analyzed baseline characteristics, procedural data and clinical outcome of both groups. Patients received balloon‐expandable valves in 56.4%, mechanically expandable valves in 37.5%, and self‐expandable valves in 6.3%.

Results

A new‐onset, pLBBB was observed in 47.5% of patients after TAVI. The implantation of a mechanically expandable valve was associated with higher rate of pLBBB (54.2% vs. 20.8%, P < 0.001), whereas implantation of a balloon‐expandable valve was associated with lower incidence of pLBBB (39.8% vs. 73.1%, P < 0.001). Deeper ventricular implantation at left‐coronary side led to higher rates of pLBBB (7.5 ± 2.5 vs. 6.7 ± 2.6 mm, P < 0.001). The occurrence of pLBBB was associated with higher rates of permanent pacemaker implantation (40.9% vs. 15.9%, P < 0.001). By multivariate analysis, implantation of a mechanically expandable valve (Boston Scientific Lotus valve) was identified as independent predictor of occurrence of pLBBB (odds ratio 4.7, confidence interval 3.2–7.0, P < 0.001). In the 2‐year follow‐up, there were no significant differences between “pLBBB” and “no LBBB”—groups regarding mortality and rehospitalization due to heart failure.

Conclusions

The occurrence of pLBBB is associated with the choice of valve type and implantation depth and requires significantly higher rates of permanent pacemaker implantations. Importantly, there are no differences in the 2‐year follow‐up regarding mortality and rehospitalization due to heart failure.
Mechanistic Insights into Manganese (I)‐Catalyzed Chemoselective Hydroarylations of Alkynes: A Theoretical Study
Authors: Wang Zheyuan , Zhu Lei , Zhong Kangbao , Qu Ling‐Bo , Bai Ruopeng , Lan Yu
Published: October 2018

Density functional theory calculations were employed to elucidate the mechanism of Mn‐catalyzed chemoselective hydroarylation reactions. The Mn‐catalyzed [4+2] annulation undergoes a reaction pathway involving sequential imine‐directed C−H bond cleavage, alkyne insertion into the Mn−C bond, β‐oxygen elimination and outer catalytic cycle annulation–aromatization. Computational results demonstrated that the previously proposed chelation‐assisted alkyne insertion process was unfavorable owing to the weak coordination ability of the β‐oxygen leaving group compared with that of CO. Further noncovalent interactions analysis indicated that the origin of the high regioselectivity was contributed to the steric repulsion resulting from significant nonbonding overlap between the reacting aryl moiety and the quaternary carbon group of the reactant in the alkyne insertion step. In addition, in the Brønsted‐acid‐mediated chemoselective alkenylation reaction, the used terminal alkynes had relatively enhanced reactivity in the alkyne insertion step owing to its reduced steric repulsion. From the active alkenyl‐Mn intermediate, the activation free energy of protonation and β‐oxygen elimination are approximate, thus the alkenylated product is obtained after protonation in an acidic system. We expect that this detailed mechanistic study will significantly enhance our ability to develop Mn‐catalyzed arene C−H bond functionalization reactions.
The opioid epidemic in the United States—Overview, origins, and potential solutions
Authors: Jones Greg H. , Bruera Eduardo , Abdi Salahadin , Kantarjian Hagop M.
Published: October 2018

The opioid epidemic in the United States has reached a crisis level. Opioid overdose caused about
65,000 deaths in the United States in 2016.
Evaluating the effectiveness of conservation measures for European grassland‐breeding waders
Authors: Franks Samantha E. , Roodbergen Maja , Teunissen Wolf , Carrington Cotton Anne , Pearce‐Higgins James W.
Published: October 2018

Farmland birds are among the most threatened bird species in Europe, largely as a result of agricultural intensification which has driven widespread biodiversity losses. Breeding waders associated with grassland and arable habitats are particularly vulnerable and a frequent focus of agri‐environment schemes (AES) designed to halt and reverse population declines. We review existing literature, providing a quantitative assessment of the effectiveness of policy and management interventions used throughout Europe to improve population and demographic metrics of grassland‐breeding waders. Targeted AES and site protection measures were more likely to be effective than less targeted AES and were ten times more likely to be effective than would be expected by chance, particularly for population trend and productivity metrics. Positive effects of AES and site protection did not appear synergistic. Management interventions which had the greatest chance of increasing population growth or productivity included modification of mowing regimes, increasing wet conditions, and the use of nest protection. Success rates varied according to the species and metric being evaluated. None of the policy or management interventions we evaluated were associated with a significant risk of negative impacts on breeding waders. Our findings support the use of agri‐environment schemes, site protection, and management measures for grassland‐breeding wader conservation in Europe. Due to publication bias, our findings are most applicable to intensively managed agricultural landscapes. More studies are needed to identify measures that increase chick survival. Despite broadly effective conservation measures already in use, grassland‐breeding waders in Europe continue to decline. More research is needed to improve the likelihood and magnitude of positive outcomes, coupled with wider implementation of effective measures to substantially increase favorable land management for these species.
Age and stand structure of oak woodlands along a gradient of conifer encroachment in northwestern California
Authors: Schriver Madelinn , Sherriff Rosemary L. , Varner J. Morgan , Quinn‐Davidson Lenya , Valachovic Yana
Published: October 2018

Many fire‐maintained savannas and woodlands are suffering the effects of fire exclusion and the concomitant invasion of fire‐sensitive trees. In the Pacific West, woodlands dominated by either Oregon white oak (Quercus garryana) or California black oak (Quercus kelloggii) have transitioned from oak‐dominated to conifer‐dominated (primarily by the native Douglas‐fir;Pseudotsuga menziesii) forest conditions with corresponding losses of plant and animal biodiversity. In spite of the prevalence of this transition, few studies have documented these temporal shifts and the consequences for oak woodland ecosystems. To better understand this process, we assessed tree species composition and age structure across 10 sites in northwestern California,USA. Species composition varied, but Douglas‐fir, Oregon white oak, and California black oak had the greatest proportional dominance within and across sites. Across all ten sites, we cored 1747 trees from 10 different species. The majority (>80%) of oak stems dated between 1850 and 1910 (69% plots dated within a 40‐yr period from 1860 to 1900). Less than 1% of the oak stems originated after 1960. Across the gradient of encroachment (i.e., oak to conifer dominance) at each site, the most common encroaching species was Douglas‐fir, which primarily established after 1970 (73% across all sites). Douglas‐fir structural attributes were not associated with any of the abiotic factors evaluated, although non‐significant trends show greater densities of Douglas‐fir in oak stands at the northern end of the study region. Oak seedlings were common in all 10 study sites; however, we documented very few oak saplings regardless of the biophysical conditions. This study highlights that (1) the process and severity of encroachment is consistent across the region, resulting in substantial oak habitat loss and a shift toward conifer dominance and vegetative homogeneity in formerly diverse woodlands of northwestern California; and (2) Oregon white oak and California black oak woodlands require concerted management effort to ensure their survival and future persistence.
Decadal effects of thinning on understory light environments and plant community structure in a subtropical forest
Authors: Tsai Ho‐Chen , Chiang Jyh‐Min , McEwan Ryan W. , Lin Teng‐Chiu
Published: October 2018

Canopy‐opening disturbance such as thinning has immediate and substantive effects on understory microclimate and therefore the establishment and growth of understory plants. A large number of studies have reported the effects of thinning on tree growth, but few studies have examined long‐term effects of thinning on understory light environments and species and functional diversity of understory plants. Even less is known whether the change in understory plant community structure observed following canopy disturbance is short‐lived and would diminish as the canopy closes or a long lasting due to legacy effects. We examined the effects of an experimental removal of 25% and 50% of the woody vegetation on understory light availability and variability on understory plant community structure in a subtropical Cryptomeria japonica plantation nine years after the treatment. Differences in availability of understory light among treatments diminished nine years after the experimental vegetation removal (thinning), but variability of understory light was still two times higher in the thinned treatments than the un‐thinned control. Species diversity of dominant and common understory plants was lower in the control than in the two thinning treatments, which were not different from each other. Community species and functional composition were also different between the un‐thinned control and the two thinning treatments. The thinned plots had proportionally more individuals of grasses and forbs and fewer individuals of ferns. Our results indicate that the effects of thinning on understory light variability last longer than on light availability representing an important and long‐lasting alteration of resource heterogeneity. At both species and functional group levels, greater diversity and unique composition in the thinned treatments compared to undisturbed control suggest a link between resource heterogeneity and biodiversity in the forest understory or legacy effects associated with the thinning‐induced changes in understory plant community.
TGF‐β suppresses RasGRP1 expression and supports regulatory T cell resistance against p53‐induced CD28‐dependent T‐cell apoptosis
Authors: Takami Mariko , Cunha Christina , Motohashi Shinichiro , Nakayama Toshinori , Iwashima Makio
Published: October 2018

Thymus‐derived regulatory T cells (tTregs) play pivotal roles in immunological self‐tolerance and homeostasis. A majority of tTregs are reactive to self‐antigens and are constantly exposed to antigenic stimulation. Despite this continuous stimulation, tTreg and conventional T‐cell populations remain balanced during homeostasis, but the mechanisms controlling this balance are unknown. We previously reported a form of activation‐induced cell death, which is dependent on p53 (p53‐induced CD28‐dependent T‐cell apoptosis, PICA). Under PICA‐inducing conditions, tTregs survive while a majority of conventional T cells undergo apoptosis, suggesting there is a survival mechanism that protects tTregs. Here, we report that the expression of RasGRP1 (Ras guanyl‐releasing protein 1) is required for PICA, as conventional T cells isolated from RasGRP1‐deficient mice become resistant to PICA. After continuous stimulation, tTregs express a substantially lower amount of RasGRP1 compared to conventional T cells. This reduced expression of RasGRP1 is dependent on TGF‐β, as addition of TGF‐β to conventional T cells reduces RasGRP1 expression. Conversely, RasGRP1 expression in tTregs increases when TGF‐β signaling is inhibited. Together, these data show that RasGRP1 expression is repressed in tTregs by TGF‐β signaling and suggests that reduced RasGRP1 expression is critical for tTregs to resist apoptosis caused by continuous antigen exposure.
NaI‐Catalyzed Oxidative Amination of Aromatic Sodium Sulfinates: Synergetic Effect of Ethylene Dibromide and Air as Oxidants
Authors: Fu Ying , Li Quan‐Zhou , Xu Qin‐Shan , Hügel Helmut , Li Ming‐Peng , Du Zhengyin
Published: October 2018

A novel NaI‐catalyzed oxidative amination of sodium sulfinates, employing both ethylene dibromide (EDB) and air as the oxidants, is described. EDB was first demonstrated to be a promising mild organic oxidant that in air, converted NaI into molecular iodine to promote the cross‐coupling reactions of aromatic sodium sulfinates with amines to produce arylsulfonamides. Mechanistic studies indicated that a radical pathway might be involved in the reaction process.
Accuracy of anogenital distance and anti‐Müllerian hormone in the diagnosis of endometriosis without surgery
Authors: Sánchez‐Ferrer María L. , Jiménez‐Velázquez Raquel , Mendiola Jaime , Prieto‐Sánchez María T. , Cánovas‐López Laura , Carmona‐Barnosi Ana , Corbalán‐Biyang Shiana , Hernández‐Peñalver Ana I. , Adoamnei Evdochia , Nieto Aníbal , Torres‐Cantero Alberto M.
Published: October 2018

Objective

To assess the predictive ability of a combination of anogenital distance (AGD) and anti‐Müllerian hormone (AMH) to diagnosis the presence of endometriosis without surgery.

Methods

The present study included women diagnosed with endometriosis and a control group who attended the “Virgen de la Arrixaca” University Hospital, Murcia, Spain, between September 1, 2014, and May 31, 2015. Serum concentrations of AMH were measured, and two AGD measurements were obtained: from the anterior clitoral surface to the upper verge of the anus (AGDAC), and from the posterior fourchette to the upper verge of the anus (AGDAF). Data were assessed by receiver operator characteristic (ROC) curves.

Results

Women in the endometriosis group (n=57) had significantly shorter AGDAF (22.8 ± 4.6 vs 27.2 ± 5.7 mm; P<0.001) and lower AMH (2.2 ± 2.5 vs 3.3 ± 1.9 ng/mL; P<0.003) compared with the control group (n=93). Women with serum AMH below the clinical cut‐off (1 ng/mL) were 17.40‐times more likely to have endometriosis (95% confidence interval [CI] 5.64–53.82). The area under the ROC curve of combined AMH and AGDAF was 0.77 (95% CI 0.70–0.85).

Conclusion

The model for predicting endometriosis on the basis of AMH and AGD could be useful for clinicians and epidemiologists to improve diagnosis and prognosis of this condition.
Developing Socially Just Practices and Policies in Assessment
Authors: Dorimé‐Williams Marjorie
Published: October 2018

This chapter discusses assessment practices and their potential contribution to inequitable educational policies that hamper marginalized students. It also provides alternative approaches to the assessment of student learning and outcomes, urging educators to consider more equitable responses.
Front Cover: Photoacoustic microscopy for evaluating combretastatin A4 phosphate induced vascular disruption in orthotopic glioma (J. Biophotonics 10/2018)
Authors: Bi Renzhe , Balasundaram Ghayathri , Jeon Seungwan , Tay Hui Chien , Pu Yang , Li Xiuting , Moothanchery Mohesh , Kim Chulhong , Olivo Malini
Published: October 2018

Optical resolution photoacoustic microscopy (OR‐PAM) imaging system is exploited to evaluate the vascular disruptive effect of Combretastatin A4 Phosphate (CA4P), a solid tumor drug, on a murine orthotopic glioma with intact skull. Hemodynamic changes in tumor vasculature are in agreement with the well documented shutdown and recovery associated CA4P administration. High resolution vasculature images obtained using OR‐PAM enable mapping of each individual blood vessel's response to the treatment.

Further details can be found in the article by Renzhe Bi, Ghayathri Balasundaram, Seungwan Jeon, et al. (e201700327)

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First chemical and sensory characterization of Moribel and Tinto Fragoso wines using HPLC‐DAD‐ESI‐MS/MS, GC‐MS, and Napping® techniques: comparison with Tempranillo
Authors: Pérez‐Navarro José , Izquierdo‐Cañas Pedro M , Mena‐Morales Adela , Martínez‐Gascueña Jesús , Chacón‐Vozmediano Juan L , García‐Romero Esteban , Gómez‐Alonso Sergio , Hermosín‐Gutiérrez Isidro
Published: October 2018

BACKGROUND

Due to the current dominance of a few grape varieties in the wine market, the aim of this work was to study the detailed phenolic and volatile composition, chromatic characteristics, and sensorial properties of red wines elaborated with new Vitis vinifera grapes (Moribel and Tinto Fragoso) identified using the High Perfomance Liquid Chromatography‐Diode Array Detector‐Electrospray Ionization‐Tandem Mass Spectrometry (HPLC‐DAD‐ESI‐MS/MS), Gas Chromatography‐ Mass Spectrometry (GC‐MS), CIELab color space, and Napping ® techniques.

RESULTS

Tinto Fragoso wine showed higher phenolic content than Moribel, with more anthocyanins, flavonols, and stilbenes. These wines also contained anthocyanin diglucosides not reported for Vitis vinifera wines. The odor activity values of free volatile compounds were calculated to indicate their influence on wine aroma, the fruity aromas of Moribel standing out particularly. The wines studied were positively evaluated by the tasters. Moribel's sensory profile was characterized by red fruit aromas and Tinto Fragoso showed more aromatic intensity and persistence in the mouth.

CONCLUSION

The results obtained from the first characterization of red wines made from novel Vitis vinifera grapes suggest that Moribel and Tinto Fragoso could be appropriate raw materials for the elaboration of quality young red wines. Tinto Fragoso provided wines with sensorial properties different from those of Tempranillo, and could be an alternative to the well known red wines on the market. © 2018 Society of Chemical Industry
Efficiently activated ε‐poly‐L‐lysine production by multiple antibiotic‐resistance mutations and acidic pH shock optimization in Streptomyces albulus
Authors: Wang Liang , Li Shu , Zhao Junjie , Liu Yongjuan , Chen Xusheng , Tang Lei , Mao Zhonggui
Published: October 2018

ε‐Poly‐L‐lysine (ε‐PL) is a food additive produced by Streptomyces and is widely used in many countries. Working with Streptomyces albulus FEEL‐1, we established a method to activate ε‐PL synthesis by successive introduction of multiple antibiotic‐resistance mutations. Sextuple mutant R6 was finally developed by screening for resistance to six antibiotics and produced 4.41 g/L of ε‐PL in a shake flask, which is 2.75‐fold higher than the level produced by the parent strain. In a previous study, we constructed a double‐resistance mutant, SG‐31, with high ε‐PL production of 3.83 g/L and 59.50 g/L in a shake flask and 5‐L bioreactor, respectively. However, we found that R6 did not show obvious advantages in fed‐batch fermentation when compared with SG‐31. For further activation of ε‐PL synthesis ability, we optimized the fermentation process by using an effective acidic pH shock strategy, by which R6 synthetized 70.3 g/L of ε‐PL, 2.79‐fold and 1.18‐fold greater than that synthetized by FEEL‐1 and SG‐31, respectively. To the best of our knowledge, this is the highest reported ε‐PL production to date. This ε‐PL overproduction may be due to the result of R99P and Q856H mutations in ribosomal protein S12 and RNA polymerase, respectively, which may be responsible for the increased transcription of the ε‐poly‐lysine synthetase gene (pls) and key enzyme activities in the Lys synthesis metabolic pathway. Consequently, ε‐PL synthetase activity, intracellular ATP, and Lys concentrations were improved and directly contributed to ε‐PL overproduction. This study combined ribosome engineering, high‐throughput screening, and targeted strategy optimization to accelerate ε‐PL production and probe the fermentation characteristics of hyperyield mutants. The information presented here may be useful for other natural products produced by Streptomyces.
Dual‐band bidirectional circularly polarized microstrip antenna for CubeSat system
Authors: Lee Sunghee , Pyo Seongmin , Kim Jae‐Hyun
Published: October 2018

This article proposes a novel dual‐band bidirectional microstrip antenna with an identical right‐handed circularly polarized sense for a CubeSat system application. The asymmetrical arrow‐ended cross slot embedded only on the ground layer is dually utilized as the backward slot antenna at 1.575 GHz and the perturbing element of the microstrip antenna with forward radiations at 2.23 GHz. The implemented antenna successfully demonstrates dual‐band bidirectional right‐handed circular polarizations in good agreement with the simulation results for the global positioning system and the satellite telemetry of a CubeSat system.
Demonstration of an optical wireless communication link with pre‐emphasis circuit for high‐speed application
Authors: Silveira David , Wijekoon Wimansha , Lee Ghang‐Ho
Published: October 2018

In this article, we experimentally demonstrate an optical wireless communication link based on Non‐Return to Zero (NRZ) On‐Off Keying (OOK) modulation with pre‐emphasis circuit for high‐speed application. We propose an economical hardware pre‐emphasis circuit comprise of one operational amplifier and an RC filter stage with a high‐pass frequency response to enhance passband characteristic of optical wireless communication link. The validity of the pre‐emphasis circuit has been demonstrated by using existing fiber optic and optical wireless communication link and components in our laboratory operating at 1550 nm. But the same pre‐emphasis circuit can be used in other wavelength applications including visual light wavelength range via light‐emitting diodes (LED). By using proposed pre‐emphasis circuit, 3 dB bandwidth of optical wireless link can be extended from 225 to 942 MHz (compared to 289 to 469 MHz without pre‐emphasis circuit). We observed the Bit‐Error‐Rate (BER) optical power penalty improvement of 2.5 dB at BER of 2 × 10−3 (forward error correction [FEC] limits) and 3.6 dB improvement at BER of 1 × 10−9, with a data rate of 1.244 Gb/s.
Prospective motion correction improves high‐resolution quantitative susceptibility mapping at 7T
Authors: Mattern Hendrik , Sciarra Alessandro , Lüsebrink Falk , Acosta‐Cabronero Julio , Speck Oliver
Published: October 2018

Purpose

Recent literature has shown the potential of high‐resolution quantitative susceptibility mapping (QSM) with ultra‐high field MRI for imaging the anatomy, the vasculature, and investigating their magnetostatic properties. Higher spatial resolutions, however, translate to longer scans resulting, therefore, in higher vulnerability to, and likelihood of, subject movement. We propose a gradient‐recalled echo sequence with prospective motion correction (PMC) to address such limitation.

Methods

Data from 4 subjects were acquired at 7T. The effect of small and large motion on QSM with and without PMC was assessed qualitatively and quantitatively. Full brain QSM and QSM‐based venograms with up to 0.33 mm isotropic voxel size were reconstructed.

Results

With PMC, motion artifacts in QSM and QSM‐based venograms were largely eliminated, enabling—in both large‐ and small‐amplitude motion regimes—accurate depiction of the cortex, vasculature, and other small anatomical structures that are often blurred as a result of head movement or indiscernible at lower image resolutions. Quantitative analyses demonstrated that uncorrected motion could bias regional susceptibility distributions, a trend that was greatly reduced with PMC.

Conclusion

Qualitatively, PMC prevented image degradation because of motion artifacts, providing highly detailed QSM images and venograms. Quantitatively, PMC increased the reproducibility of susceptibility measures.
Introducing a dynamic framework to jointly address policy impacts on environmental and human health in a regional produce recovery and redistribution system
Authors: Feingold Beth J. , Xue Xiaobo , Neff Roni A. , Bozlak Christine , Hosler Akiko S. , Jurkowski Janine M.
Published: October 2018

Regular consumption of fruits and vegetables is associated with a decreased risk of cardiovascular disease and all‐cause mortality. Access to fresh produce is limited for individuals and families experiencing food insecurity. Emergency food programs, including food pantries, are important institutions for assuring access to nutritional foods for this population, including fresh produce. Produce availability at such institutions is on the rise thanks to donation, gleaning, food bank purchases, recovery programs multiscale policy interventions. These efforts also have coupled economic and environmental benefits for producers and retailers as surplus food is redirected from the waste stream, where it would otherwise produce greenhouse gases that contribute to climate change. Although varied surplus produce recovery programs have been implemented around the country and the world, little modeling of potentially synergistic impacts has accompanied their implementation. Thus, there remains sparse understanding of system‐wide joint implications economically, environmentally, nutritionally, and epidemiologically. The goal of this paper is to offer a novel dynamic modeling framework capable of assessing environmental, nutritional, and health impacts of policies and programs in the food recovery and redistribution system. This unique framework serves as a scientific basis for implementing best management practices and policies to improve the sustainability of U.S. food systems.
Nitroxide mediated polymerization of sustainably sourced isobornyl methacrylate and tridecyl methacrylate with acrylonitrile co‐monomer
Authors: Hajiali Faezeh , Métafiot Adrien , Benitez‐Ek Laura , Alloune Lea , Marić Milan
Published: October 2018

Nitroxide‐mediated polymerization (NMP) of isobornyl methacrylate (IBOMA) and tridecyl methacrylate (TDMA), derived from sustainable feedstocks, with a low fraction of acrylonitrile (AN) co‐monomer were conducted with unimolecular initiator BlocBuilder‐MA™ (BB) and the succinimidyl ester‐functionalized form, NHS‐BB. IBOMA and TDMA‐rich compositions were both polymerized at 100 °C in a controlled manner (i.e., linear increase in number average molecular weight [Mn] with conversion up to ∼40% and low dispersity, Đ < 1.5). SG1‐terminated poly(IBOMA‐stat‐AN) macroinitiator was then cleanly chain‐extended with poly(TDMA‐stat‐AN) and the diblock copolymers exhibited two distinct glass transition temperatures (Tgs), indicative of microphase separation. IBOMA/TDMA/AN terpolymers with different IBOMA/TDMA molar ratios were also synthesized where terpolymers with higher IBOMA content had higher apparent rate constants and higher Tgs. Moreover, chain growth was linear up to conversions of ∼60% and all Đs were 1.51 to 1.64. Finally, 2‐hydroxyethyl methacrylate (HEMA) was incorporated into the IBOMA/TDMA/AN system, resulting in statistical quadripolymers. The quadripolymer Tg decreased with increasing TDMA content and Mn ranged from 12 to 15.4 kg mol−1 and the Đ were 1.39 to 1.54, suggesting the successful incorporation of sustainably sourced monomers into quadripolymers with a broad range of tunable Tgs via NMP with additional functionalities from HEMA. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018, 56, 2422–2436
Heteroatom‐Doped Carbon Materials: Synthesis, Mechanism, and Application for Sodium‐Ion Batteries
Authors: Chen Weimin , Wan Min , Liu Qing , Xiong Xiaoqin , Yu Faquan , Huang Yunhui
Published: October 2018

Sodium‐ion batteries (SIBs) show promising application in large‐scale energy storage as future alternatives to lithium‐ion batteries. Carbonaceous materials are attractive anode candidates for SIBs due to low cost, abundance, and high safety. In general, doping heteroatoms such as N, B, O, S, and P in carbon‐based materials gives rise to high electronic mobility, good sodium mobility, and enhanced capacity, showing a great potential in sodium storage. This review summarizes the recent progress in the design, synthesis, and electrochemical properties of heteroatom‐doped carbon anodes, including one‐element doped carbons and several‐elements codoped carbons, aiming to help the readers comprehensively learn how to fabricate heteroatom‐doped carbons and use them in SIBs. Additionally, the advantages, mechanism, critical issues, and possible solutions of heteroatom‐doped carbons are discussed and the future research trends are proposed. This will provide a deep insight into the development of SIBs anode materials.
Synthesis and Photocatalytic Activity of Cerium‐Modified CdS‐TiO2 Photocatalyst for the Formaldehyde Degradation at Room Temperature
Authors: Xie, Junliang , Hong, Wei , Meng Mianwu , Tian Mengke , Kang Caiyan , Zhou Zhenming , Chen Chaoshu , Tang Yuhong , Luo Guangyu
Published: October 2018

The Ce‐CdS‐TiO2 photocatalysts were successfully synthesized by a simple sol‐gel way and loaded on the nickel foam. The specific surface area, crystalline phase, microstructure and surface functional groups of prepared photocatalysts were characterized by Brunauer‐Emmett‐Teller (BET) surface area, X‐ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscope (TEM), and Fourier transform infrared spectroscopy (FT‐IR). The photocatalytic tests of Ce‐CdS‐TiO2 samples demonstrated that Ce as the active component plays an irreplaceable role in degradation of gaseous formaldehyde. The results showed that high Ce doping levels restrained the photocatalytic activity due to lower specific surface area, whereas moderate doping levels showed the highest photocatalytic performance due to higher specific surface area and evenly dispersion of the active component. The rate of formaldehyde degradation on 0.9 wt % Ce‐CdS‐TiO2, 1.5 wt % Ce‐CdS‐TiO2, and 2.1 wt % Ce‐CdS‐TiO2 photocatalysts can reach to 59, 84, and 49 %, respectively, which are higher than pure TiO2 (20 %). Ce‐doping into CdS‐TiO2 photocatalyst produce the Ce‐O‐Ti bonds, which enhanced the interaction between Ce and TiO2. The introduction of Ce increased the UV/Vis absorption of Ce‐CdS‐TiO2 photocatalyst. Furthermore, Ce‐CdS‐TiO2 possesses high photocatalytic performance, since Ce may reduce the recombination of photoexcited electrons and holes.
Pollen Development
Authors: Halbritter Heidemarie , Ulrich Silvia , Grímsson Friðgeir , Weber Martina , Zetter Reinhard , Hesse Michael , Buchner Ralf , Svojtka Matthias , Frosch-Radivo Andrea
Published: October 2018

Pollen is source and transport unit for the male gametes (or their progenitor cell). The unicellular pollen grain represents the microspore of seed plants, the multicellular pollen grain the male gametophytic generation. The development of a pollen grain includes microsporogenesis and microgametogenesis (Figs. 1 and 2, Gomez et al. 2015; Keijzer and Willemse 1988). Microsporogenesis starts with the differentiation of microspore mother cells (MMC) respectively pollen mother cells (PMC). These diploid cells become enclosed by a thick callose wall and undergo meiosis, forming a tetrad of four haploid microspores, each encased in another callose wall insulating them from each other and from the surrounding diploid tapetal cells (Figs. 1 C-E, and 2). Cytokinesis following meiotic nuclear divisions is accompanied by the formation of cleavage planes determined by the configuration and orientation of the meiotic spindle axes. In the case of successive cytokinesis, planes are formed after the first and second meiotic divisions leading to the formation of various microspore tetrad types (see “Pollen Morphology and Ultrastructure”). During simultaneous cytokinesis the cleavage planes are formed simultaneously after the second meiotic division and microspores become arranged in a tetrahedral tetrad (Furness and Rudall 1999, 2001).
Fixed effects in rare events data: a penalized maximum likelihood solution
Authors: Cook Scott J. , Hays Jude C. , Franzese Robert J.
Published: October 2018

Most agree that models of binary time-series-cross-sectional data in political science often possess unobserved unit-level heterogeneity. Despite this, there is no clear consensus on how best to account for these potential unit effects, with many of the issues confronted seemingly misunderstood. For example, one oft-discussed concern with rare events data is the elimination of no-event units from the sample when estimating fixed effects models. Many argue that this is a reason to eschew fixed effects in favor of pooled or random effects models. We revisit this issue and clarify that the main concern with fixed effects models of rare events data is not inaccurate or inefficient coefficient estimation, but instead biased marginal effects. In short, only evaluating event-experiencing units gives an inaccurate estimate of the baseline risk, yielding inaccurate (often inflated) estimates of predictor effects. As a solution, we propose a penalized maximum likelihood fixed effects (PML-FE) estimator, which retains the complete sample by providing finite estimates of the fixed effects for each unit. We explore the small sample performance of PML-FE versus common alternatives via Monte Carlo simulations, evaluating the accuracy of both parameter and effects estimates. Finally, we illustrate our method with a model of civil war onset.
14C leaching and speciation studies on Irradiated graphite from vandellós I Nuclear Power Plant
Authors: Magro Enrique , Márquez Eva María , Piña Gabriel , Rodríguez Marina , Gascón José Luís , Lara Esperanza , Sevilla Lucía
Published: October 2018

The understanding of the 14C behavior in waste packages could lead, in the Spanish context, to a revision of the management strategies for radioactive waste and a revaluation of the near surface repository devoted to the disposal of waste containing this radionuclide in high concentrations. To achieve this objective, and in the context of the EU project Carbon-14 Source Term (CAST), the authors of the work presented in this paper have performed leaching experiments with irradiated graphite considering two different scenarios. One, in which the leaching solution simulates some of the expected conditions in a repository where a granite/bentonite mixture has been used as backfill material, and the other, using deionized water as a high efficiency chemical removal agent and for comparison purposes. The analytical approach to measure the release rate and speciation of 14C from irradiated graphite samples in the aqueous and gaseous phase is also described. The main results obtained shows that, after 359 days of leaching, no 14C activity was detected above the detection limits, and only leaching rates regarding beta-gamma emitters were observed: 2×10–6 cm/day for 137Cs and 1×10–5 cm/day for 60Co in granite/bentonite water media and 4×10–6 cm/day for 137Cs in pure water.
MODERN MOUNTAINS FROM THE ENLIGHTENMENT TO THE ANTHROPOCENE
Authors: SIMPSON THOMAS
Published: October 2018

Recent scholarship across a range of historical sub-disciplines shows that uplands are where many forms of modernity are both crafted and overwhelmed. Maintaining multiple tensions – between assimilation and distinction, between projections of power and material and human resistance, and between knowledge and elusiveness – is essential to the modernities crafted in mountain spaces. This review highlights a number of common threads running through recent writings on modern mountains. These include heightened attention to the importance of mountains as arenas for the performance of gendered, racial, national, and class-based subjectivities, and the persistence of earlier attitudes and activities in avowedly disenchanted modern visions of uplands. For all of the successes of recent scholarship, more work remains in order to consider mountains in global contexts and to come to terms with our continued entanglement in modern ways of understanding and acting in high places. Looking ahead, it is vital that historians think with and about mountains in order to contribute positively and persuasively to discussions on the human and environmental impacts of global change.
SIR JOHN ELIOT'STHE MONARCHIE OF MANAND EARLY STUART POLITICAL THOUGHT
Authors: WHITE WILLIAM
Published: October 2018

This article seeks to revise existing interpretations of the political writings composed by the early Stuart MP, Sir John Eliot (1592–1632), while imprisoned in the Tower of London between 1629 and 1632. In particular, it challenges the common understanding of Eliot as an absolutist writer. This characterization is shown to be based on a misreading of his principal treatise,The monarchie of man, and the problematic assumption thatDe jure– a translation he undertook of the continental absolutist, Arnisaeus – should be taken to epitomize Eliot's own views. The article also refutes the notion thatThe monarchie of manis an uncontroversial text that ignores contemporary political context. It is argued that the treatise can, in fact, only be read in relation to the constitutional crisis of the late 1620s: Eliot's work is presented as a subversive attack on Charles I's tyrannical pretensions, which supplies a remedy in the form of a Ciceronian insistence on active virtue. These findings in turn have implications for how we understand the political thought and culture of early Stuart England more generally.
EXPERIENCING SYNDEMIC: DISENTANGLING THE BIOSOCIAL COMPLEXITY OF TUBERCULOSIS THROUGH QUALITATIVE RESEARCH
Authors: Zvonareva Olga , van Bergen Willemien , Kabanets Nadezhda , Alliluyev Aleksander , Filinyuk Olga
Published: October 2018

Tuberculosis (TB) remains a major global public health problem that has become a crisis fuelled by HIV and the increasing occurrence of antimicrobial resistance. What has been termed the biosocial nature of TB challenges effective control of the disease. Yet, biosocial interactions involved in the persistence of TB in diverse settings are difficult to systematically account for. The recently developed framework of syndemics provides a way to capture how complex health problems result from the interactions between diseases such as HIV and TB, and harmful social conditions such as unemployment, malnutrition and substance abuse. This article advances the syndemics scholarship by examining health conditions that cluster together with TB in the Russian Federation, by eliciting a set of social processes that precipitate this clustering and exacerbate health outcomes, and by analysing interactions between these health conditions and social processes. To provide an account of this complexity, the article takes a qualitative approach and draws on the perspectives and experiences of people with TB. The results demonstrate emergence of a syndemic of stress, substance abuse, TB and HIV that is sustained by poverty, occupational insecurity, marginalization and isolation. Frictions between the narrow focus of the health care system on TB and the wider syndemic processes in which the lives of many persons with TB are embedded, contribute to poorer health outcomes and increase the risks of developing drug resistance. Finally, the article argues that the large-scale and impersonal forces become embodied as individual pathology through the crucial interface of the ways in which persons experience and make sense of these forces and pathologies. Qualitative research is needed for the adequate analysis of this biosocial complexity in order to provide a solid basis for responses to TB-centred syndemics in various settings.