bluuebunny/crossref_metadata_2025 huggingface dataset:
Controlled Reactivity of 1,8‐Diazabicyclo[5.4.0]undec‐7‐ene (DBU) in the Selective Synthesis of 1‐(Bromoethynyl)arenes
Authors: Krishna Moodapelly Shiva , Sharma Gangavaram V. M. , Ramana Doddi Venkata
Published: March 2017

The nucleophilic reactivity of 1,8‐diazabicyclo[5.4.0]undec‐7‐ene (DBU) was completely controlled by the formation of monohydrate (DBU⋅H2O) in the synthesis of 1‐(bromoethynyl)arenes from 1,1‐dibromoalkenes. Differential reactivity of DBU in protic solvents as compared to aprotic solvents has been explored to prevent the formation of mixtures of products in this reaction. Hydrated DBU is found to be superior to dry DBU, both for the selective synthesis and ease of isolation. In addition, use of DBU⋅H2O as a non‐nucleophilic mild base allowed us to synthesise 1‐(bromoethynyl)arenes via a reaction under solvent‐free conditions. Utilization of DBU⋅H2O as sole reagent also allowed us to isolate the products without column chromatographic purifications.

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Copper(II) Acetate‐Catalyzed Hydroxysulfenylation‐Initiated Lactonization of Unsaturated Carboxylic Acids with Oxygen as Oxidant and Oxygenation Reagent
Authors: Du Bingnan , Wang Yang , Mei Haibo , Han Jianlin , Pan Yi
Published: March 2017

A copper(II) acetate‐catalyzed aerobic thiolation of C=C double bonds, oxygenation, and intramolecular cyclization reactions of unsaturated carboxylic acids with thiols has been explored. The reaction proceeds through a new hydroxysulfenylation‐initiated lactonization pathway with carboxyl as electrophilic group, which provides an efficient access to assembly highly valuable thio‐substituted lactone derivatives with good yields under mild conditions. Several control experiments, as well as an isotope labelling experiment disclose that oxygen acts as both oxidant and reactant being transferred into the final product. The mechanistic studies support the discovery of a new strategy through difunctionalization of alkenes based on unsaturated carboxylic acids to construct the diversely substituted lactones.

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(Pentamethylcyclopentadienyl)cobalt(III)‐Catalyzed Direct Trifluoromethylthiolation of Arenes via C−H Activation
Authors: Liu Xu‐Ge , Li Qingjiang , Wang Honggen
Published: March 2017

The direct trifluoromethylthiolation of arenes was realized via (pentamethylcyclopentadienyl)cobalt(III)‐catalyzed C(sp2)‐H activation and coupling with AgSCF3 under the assistance of a directing group. The reaction features redox‐neutrality, mild conditions, broad substrate scope, and good functional group tolerance. Preliminary mechanistic studies have been conducted.

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Highly Sensitive and Bendable Capacitive Pressure Sensor and Its Application to 1 V Operation Pressure‐Sensitive Transistor
Authors: Joo Yunsik , Yoon Jaeyoung , Ha Jewook , Kim Taehoon , Lee Seunghwan , Lee Byeongmoon , Pang Changhyun , Hong Yongtaek
Published: March 2017

Development of highly sensitive pressure sensors that function well even in bending environments and operate at ultralow voltage is desirable for wearable applications. Here, a highly sensitive and bendable capacitive pressure sensor with the ability to distinguish pressure and bending stimuli and a pressure‐sensitive transistor (PST) that can be easily integrated into wearable sensor system due to ultralow voltage (as low as 1 V for stable signal detection) operation is demonstrated. By introducing surface treatment and bonding technique, all components of the pressure sensor are tightly bonded to each other, enabling high bending stability. The sensor shows high pressure sensitivity (9.9 kPa−1) and can detect pressure even in the bending state. Additional bending sensors enables to separately detect signals from the actual pressure and bending deformation. In order to implement low‐power sensor circuitry, the PST is fabricated by integrating the pressure sensor and inkjet‐printing single‐walled carbon nanotube thin film transistor. Such low‐voltage operation of the PST enables to demonstrate the stand‐alone wearable user‐interactive pulse monitoring system by using commercially available electronic devices. The strategy for bendable low‐power sensor may enable realization of wearable sensing system and electronic skins with low power consumption in near future.
Solution‐Processed Neodymium Oxide/ZnO Thin‐Film Transistors with Electron Mobility in Excess of 65 cm V−1 s−1
Authors: Esro Mazran , Kolosov Oleg , Stolojan Vlad , Jones Peter J. , Milne William I. , Adamopoulos George
Published: March 2017

This work reports on solution processed Nd2O3 thin films that are deposited under ambient conditions at moderate temperatures of about 400 °C and their implementation as gate dielectrics in thin film transistors employing solution processed ZnO semiconducting channels is also demonstrated. The optical, dielectric, electric, structural, surface, and interface properties of Nd2O3 films are investigated using a wide range of characterization techniques that reveal smooth Nd2O3 films of cubic structure, wide bandgap (6 eV), high‐k (11), and low leakage currents (<0.5 nA cm−2). Thin film transistors (TFTs) using ZnO channels show excellent characteristics, such as high electron mobility, in excess of 65 cm2 V−1 s−1, high on/off current ratio in the range between 106 and 107, and negligible hysteresis. The devices demonstrate excellent constant bias stress and air stability air, i.e., only a small decrease of the electron mobility and threshold voltage (<12%). In addition, the excellent uniformity and homogeneity that is demonstrated combined with the relatively low deposition temperature (compared with those used with the vast majority of the vacuum based techniques employed) in ambient air on glass substrates indicates the potential for the rapid development of metal oxide‐based TFTs employing gate dielectrics also grown from solutions at low manufacturing cost.
Enantioselective Palladium‐Catalyzed Carbene Insertion into the N−H Bonds of Aromatic Heterocycles
Authors: Arredondo Vanessa , Hiew Stanley C. , Gutman Eugene S. , Premachandra Ilandari Dewage Udara Anulal , Van Vranken David L.
Published: March 2017

C3‐substituted indoles and carbazoles react with α‐aryl‐α‐diazoesters under palladium catalysis to form α‐(N‐indolyl)‐α‐arylesters and α‐(N‐carbazolyl)‐α‐arylesters. The products result from insertion of a palladium‐carbene ligand into the N−H bond of the aromatic N‐heterocycles. Enantioselection was achieved using a chiral bis(oxazoline) ligand, in many cases with high enantioselectivity (up to 99 % ee). The method was applied to synthesize the core of a bioactive carbazole derivative in a concise manner.
Ultrathin Two‐Dimensional Organic–Inorganic Hybrid Perovskite Nanosheets with Bright, Tunable Photoluminescence and High Stability
Authors: Yang Shuang , Niu Wenxin , Wang An‐Liang , Fan Zhanxi , Chen Bo , Tan Chaoliang , Lu Qipeng , Zhang Hua
Published: March 2017

Two‐dimensional (2D) organic–inorganic hybrid perovskite nanosheets (NSs) are attracting increasing research interest due to their unique properties and promising applications. Here, for the first time, we report the facile synthesis of single‐ and few‐layer free‐standing phenylethylammonium lead halide perovskite NSs, that is, (PEA)2PbX4 (PEA=C8H9NH3, X=Cl, Br, I). Importantly, their lateral size can be tuned by changing solvents. Moreover, these ultrathin 2D perovskite NSs exhibit highly efficient and tunable photoluminescence, as well as superior stability. Our study provides a simple and general method for the controlled synthesis of 2D perovskite NSs, which may offer a new avenue for their fundamental studies and optoelectronic applications.
Pelvic Inlet Shape Is Not as Dimorphic as Previously Suggested
Authors: Delprete Hillary
Published: March 2017

It is well known that there are significant differences in the pelves of males and females due, in part, to differing constraints. The male and female pelves must be suitable for upright posture and locomotion, but the female pelvis must also be suitable for reproduction. These differing requirements lead to differences in the shape and size of various pelvic dimensions. These differences are reflected in the pelvic inlet, midplane, and outlet. Current research has documented dimorphisms in the posterior and anterior spaces in all three of these planes. One measure however, that is calculated from the relationship between the length of the anterior–posterior diameter (APD) and the transverse diameter (TD) of the inlet, is not as dimorphic as previously suggested. This computed value is used to describe four main categories of inlet shape: android, gynecoid, anthropoid, and platypelloid. Current textbooks in anatomy and midwifery describe these forms and identify the typical male inlet shape as android and the typical female inlet shape as gynecoid. In this study, however, using skeletonized pelves of 378 adult individuals from three identified skeletal collections, the most common inlet shape for both males and females was android. In addition, when examining shape as a continuous variable, inlet shape is not sexually dimorphic in two of the three populations examined in this study. Based on the results of this study, the inlet shape for males and females is less dimorphic than previously thought, and we need to discontinue using pelvic categories to describe typical inlet shape. Anat Rec, 300:706–715, 2017. © 2017 Wiley Periodicals, Inc.
Survey of pedestrians' crossing time at non‐signalized mid‐block street crossing
Authors: Zhao Yunan , Chen Qun , Qin Jin , Xue Xingjian
Published: March 2017

At non‐signalized mid‐block street crossings in China's cities, pedestrians often weave between motor vehicle flows. This paper investigated the influence patterns of the gender and age of pedestrians, the presence of a pedestrian group, vehicles' interference and the crossing direction on the crossing time at non‐signalized mid‐block street crossings in Changsha, China. The results show that the crossing speed is approximately 1–1.1 m/s; the crossing time increases with increasing age, and the crossing speed of a pedestrian will be quicker when the time gap between the pedestrian and the oncoming vehicle is smaller if he/she decides to cross. This paper also analyzed the crossing time pattern when pedestrians cross lane by lane and found that pedestrians spend the most time crossing the first lane and the least time crossing the middle lane, regardless of whether they are crossing from the curb to the central island or from the central island to the curb. The crossing speed is an important input to the design of pedestrian facilities, so these findings can be applied to the assessment of pedestrian crossing safety in China's cities and can provide a basis for the design of pedestrian crossing facilities. Copyright © 2017 John Wiley & Sons, Ltd.
Learn strategies for managing student travel risks in the BRICs
Authors: Hutton Jim
Published: March 2017

At the turn of the millennium, the BRIC countries — Brazil, Russia, India, and China — started to gain increasing recognition as emerging major players in the global economy. As business boomed, these countries captured both international travelers' and students' interests. Colleges and universities began recognizing the BRICs as key destinations for their students to gain business insights and cultural acuity.
Gangliosides: Structures, Biosynthesis, Analysis, and Roles in Cancer
Authors: Groux‐Degroote Sophie , Guérardel Yann , Delannoy Philippe
Published: March 2017

Gangliosides are acidic glycosphingolipids containing one or more sialic acid residues. They are essential compounds at the outer leaflet of the plasma membrane, where they interact with phospholipids, cholesterol, and transmembrane proteins, forming lipid rafts. They are involved in cell adhesion, proliferation, and recognition processes, as well as in the modulation of signal transduction pathways. These functions are mainly governed by the glycan moiety, and changes in the structures of gangliosides occur under pathological conditions, particularly in neuro‐ectoderm‐derived cancers. With the progress in mass spectrometry analysis of gangliosides, their role in cancer progression can be now investigated in more detail. In this review we summarize the current knowledge on the biosynthesis of gangliosides and their role in cancers, together with the recent development of cancer immunotherapy targeting gangliosides.
Outcome of implantation of a second self‐expanding valve for the treatment of residual significant aortic regurgitation
Authors: Koifman Edward , Patel Nirav , Weissman Gaby , Kiramijyan Sarkis , Didier Romain , Torguson Rebecca , Kumar Sandeep , Tavil‐Shatelyan Arpi , Ben‐Dor Itsik , Satler Lowell F. , Pichard Augusto D. , Waksman Ron
Published: March 2017

Background

Residual aortic regurgitation (AR) following transcatheter aortic valve replacement (TAVR) is associated with adverse outcome. We sought to evaluate the efficacy and safety of second CoreValve (CV) implantation to treat residual AR following the initial CV deployment.

Methods and Results

TAVR patients treated with a second CV due to moderate and above residual AR were compared to single device implantation. Valvular function parameters were compared at baseline, post procedure, and 30 days. Among 172 CV TAVR patients, 11 required a second device (6%) due to significant residual AR. The main differences between the groups were higher rates of low ejection fraction in patients with 2 CV implanted and higher annular diameter (27 [29–25] vs. 25 [26–24] mm, P = 0.03), requiring a larger device. Although two patients in the two CV group had high initial implantation, low implantation was similar between the groups. A second CV achieved adequate reduction in residual AR in six patients (55%), while an additional four patients had moderate residual AR. Only one remained with moderate to severe AR after 30 days follow‐up. There were no cases of peri‐procedural stroke or mortality.

Conclusions

Second implantation of self‐expanding valve can successfully reduce residual significant AR following initial CV implantation and should be considered as therapeutic option for this population. © 2017 Wiley Periodicals, Inc.
Assessment of trans‐aortic pressure gradient using a coronary pressure wire in patients with mechanical aortic and mitral valve prostheses
Authors: Kherada Nisharahmed , Brenes Juan Carlos , Kini Annapoorna S. , Dangas George D.
Published: March 2017

Accurate evaluation of trans‐aortic valvular pressure gradients is challenging in cases where dual mechanical aortic and mitral valve prostheses are present. Non‐invasive Doppler echocardiographic imaging has its limitations due to multiple geometric assumptions. Invasive measurement of trans‐valvular gradients with cardiac catheterization can provide further information in patients with two mechanical valves, where simultaneous pressure measurements in the left ventricle and ascending aorta must be obtained. Obtaining access to the left ventricle via the mitral valve after a trans‐septal puncture is not feasible in the case of a concomitant mechanical mitral valve, whereas left ventricular apical puncture technique is associated with high procedural risks. Retrograde crossing of a bileaflet mechanical aortic prosthesis with standard catheters is associated with the risk of catheter entrapment and acute valvular regurgitation. In these cases, the assessment of trans‐valvular gradients using a 0.014˝ diameter coronary pressure wire technique has been described in a few case reports. We present the case of a 76‐year‐old female with rheumatic valvular heart disease who underwent mechanical aortic and mitral valve replacement in the past. She presented with decompensated heart failure and echocardiographic findings suggestive of elevated pressure gradient across the mechanical aortic valve prosthesis. The use of a high‐fidelity 0.014˝ diameter coronary pressure guidewire resulted in the detection of a normal trans‐valvular pressure gradient across the mechanical aortic valve. This avoided a high‐risk third redo valve surgery in our patient. © 2017 Wiley Periodicals, Inc.
Ischemic postconditioning during primary percutaneous coronary intervention
Authors: Mentias Amgad , Mahmoud Ahmed N. , Elgendy Islam Y. , Elgendy Akram Y. , Barakat Amr F. , Abuzaid A. Sami , Saad Marwan , Kapadia Samir R.
Published: March 2017

Background

Although some studies have shown potential benefit for ischemic postconditioning (IPoC) during primary percutaneous coronary intervention (PCI) in improving surrogate markers of reperfusion and infarction size, the benefit of this approach on clinical outcomes remains unknown.

Methods and Results

Electronic databases were searched for randomized clinical trials that compared IPoC versus conventional treatment during primary PCI. Random effects DerSimonian‐Laird risk ratios (RR) were calculated for different clinical and surrogate outcomes. The main outcome of this analysis was all‐cause mortality. A total of 25 trials involving 3,619 patients were included in the analysis. At a mean follow up of 14 months (95% confidence interval (CI) 8.6–19.4 months), the incidence of all‐cause mortality was 4.9% [95% CI 3.8–6.0%] in the IPoC group versus 3.8% [95% CI 1.9–5.7%] in the control group (RR 0.92, 95% CI 0.68–1.24, P = 0.74). The risk of reinfarction (2.7% [95% CI 1.1–4.3%] vs. 2.3% [0.6–4.0%]; RR 1.29, 95% CI 0.62–2.68, P = 0.72), heart failure (3.6% [95% CI 2.0–5.1%] vs. 5.7% [95% CI 3.3–8.2%]; RR 0.77, 95% CI 0.58–1.06, P = 0.24), target vessel revascularization (3.2% [95% CI 1.7–4.7%] vs. 2.4% [95% CI 1.4–3.3%]; RR 1.40, 95% CI 0.90–2.20, P = 0.20), and stent thrombosis (2.4% [95% CI 1.1–3.8%] vs. 1.8% [95% CI 0.5–3.2%]); RR 1.50, 95% CI 0.60–3.70, P = 0.40) was similar in both groups.

Conclusions

IPoC does not appear to reduce the risk of clinical adverse events in patients with ST‐elevation myocardial infarction undergoing primary PCI. © 2017 Wiley Periodicals, Inc.
A multicenter study of the impella device for mechanical support of the systemic circulation in pediatric and adolescent patients
Authors: Dimas V. Vivian , Morray Brian H. , Kim Dennis W. , Almond Christopher S. , Shahanavaz Shabana , Tume Sebastian C. , Peng Lynn F. , McElhinney Doff B. , Justino Henri
Published: March 2017

Objectives

The objective was to review the use of Impella devices (Abiomed Inc, Danvers, MA) for temporary circulatory support in pediatric and adolescent patients (age ≤ 21 yrs).

Background

Options for minimally invasive circulatory support in children are limited, and published data are confined to case reports and small case series.

Methods

This was a retrospective, multicenter review of Impella implants in pediatric and adolescent patients from 2009‐15, using standardized data collection and INTERMACS definitions.

Results

A total of 39 implants were performed in 38 patients from 16 centers. Median age and weight were 16 yrs (4–21 yrs) and 62 kg (15–134 kg). The primary indication for implant was cardiogenic shock in 28 patients (72%). Cardiac allograft rejection, myocarditis, or cardiomyopathy were the underlying diagnosis in 23 patients (59%); 11 patients had congenital heart disease. The median duration of support was 45 hr (1–1224 hr). Indications for explant included ventricular recovery in 16 patients, transition to another device in 12, death in 5, and transplant in 1. Survival was 85% at 7 days and 68% at 30 days. Major adverse events occurred in 8 patients: hemolysis in 3, bleeding in 2, stroke in 1 (unclear if related to Impella), sepsis in 1, and critical leg ischemia in 1. An increase in aortic regurgitation was noted in three patients, with no evidence of valve injury.

Conclusion

Temporary circulatory support with Impella devices is feasible in pediatric and adolescent patients, with acceptable risk profiles. More experience and follow up is needed to improve technical performance and patient selection. © 2017 Wiley Periodicals, Inc.
Impact of hospital volume on long‐term neurological outcome in patients undergoing carotid artery stenting
Authors: Hung Chi‐Sheng , Yeh Chih‐Fan , Lin Mao‐Shin , Chen Ying‐Hsien , Huang Ching‐Chang , Li Hung‐Yuan , Kao Hsien‐Li
Published: March 2017

Background

The impact of hospital volume on long‐term outcome after carotid artery stenting (CAS) remains unknown.

Objectives

We designed a nationwide cohort study to elucidate the impact of hospital volume on the incidence of stroke after CAS.

Methods

The Taiwan National Health Insurance Research database was used to identify all patients admitted for CAS from 2008 to 2012. We defined high‐volume hospitals as those performing more than 20 CAS per year. The primary outcome was new ischemic stroke after discharging from the index CAS. Propensity score‐matching was performed to create two matched groups for comparison.

Results

A total of 3,248 patients underwent 3,576 CAS procedures were enrolled. There were 56 hospitals performing CAS during the study period. Among these 3,248 patients, 2,226 (68.5%) were performed in high‐volume hospitals. A propensity score‐matching created two groups with 1,000 patients in each group. During a median of 2.06 years follow‐up, 35 (3.5%) and 52 (5.2%) patients in high‐volume hospitals and low‐volume hospitals developed new ischemic stroke 30 days after discharging from the index CAS, respectively (for low‐volume hospitals, HR 1.50, 95%CI 1.06–2.12, P = 0.023). The use of embolic protection device did not result in different periprocedural or postdischarge strokes. The periprocedural (within 30 days after CAS) ischemic stroke or all‐cause mortality rates during follow‐up period were similar between two groups.

Conclusions

CAS performed in high‐volume hospitals was associated with less new ischemic stroke after discharging from the index CAS, compared to those in low‐volume hospitals. © 2017 Wiley Periodicals, Inc.
Measurement of the Influence of the Microstructure of Alumina‐Supported Cobalt Catalysts on their Activity and Selectivity in Fischer–Tropsch Synthesis by using Steady‐State and Transient Kinetics
Authors: Rebmann Edouard , Fongarland Pascal , Lecocq Vincent , Diehl Fabrice , Schuurman Yves
Published: March 2017

Five alumina‐supported Co catalysts with different particle sizes and structures were synthesized. The catalysts showed different activities during long‐term Fischer–Tropsch experiments. Steady‐state isotopic transient kinetic analysis (SSITKA) 12CO/H2→13CO/H2 experiments were performed during these long‐term runs. The number of active sites for CO adsorption and activation was estimated through the summation of all surface intermediates derived from the SSITKA results. Rather than comparing turnover frequencies, a kinetic analysis was performed. A simple kinetic rate equation based on the in situ number of active sites described the steady‐state CO conversion over the five catalysts adequately. Thus the difference in the catalytic performance could not be attributed to a difference in particle size, phase orientation (face‐centered cubic or hexagonal close packed), or Pt‐promotion effect but instead was only because of the number of reduced Co atoms exposed during the reaction. Similarly, the selectivity depended on the CO conversion level and temperature and not on the catalyst structure.
Production of Gasoline Fuel from Alga‐Derived Botryococcene by Hydrogenolysis over Ceria‐Supported Ruthenium Catalyst
Authors: Nakaji Yosuke , Oya Shin‐ichi , Watanabe Hideo , Watanabe Makoto M. , Nakagawa Yoshinao , Tamura Masazumi , Tomishige Keiichi
Published: March 2017

Hydrogenolysis of hydrogenated botryococcene (Hy‐Bot) was conducted over various supported Ru catalysts, Ir/SiO2, and Pt/SiO2–Al2O3. Ru/CeO2 with very high dispersion showed the highest yield (70 %) of gasoline‐range (C5–C12) alkanes at 513 K. The main gasoline‐range products were dimethylalkanes. This yield is comparable to or higher than the gasoline yields from botryococcene in the literature, which were obtained at much higher temperature. Ir/SiO2 also showed a high fuel yield, but the activity was much lower than that with the Ru catalysts. The reaction over Pt/SiO2–Al2O3 slowed down before total conversion of Hy‐Bot was achieved. Ru/CeO2 was stable in the hydrogenolysis of Hy‐Bot without loss of activity and selectivity during reuses. The carbon balance was low for the hydrogenolysis of Hy‐Bot over all catalysts if the main products are heavy hydrocarbons, whereas for the hydrogenolysis of squalane the carbon balance was kept near 100 %. 1H NMR spectra of the product mixture and thermogravimetric analyses of the product mixture and the recovered catalyst revealed that the formation of aromatic compounds, polymeric products, and coke was negligible for the carbon balance. In a model reaction using substrate compounds with a substructure of Hy‐Bot, only 2,5‐dimethylhexane, which has a C6 chain with two Cprimary−Ctertiary bonds, produced a cyclic product, 1,4‐dimethylcyclohexane, which has a higher boiling point than the substrate. This dehydrocyclization reaction makes the product distribution in the hydrogenolysis of Hy‐Bot more complex.
Direct Synthesis of Ultrasmall Ruthenium Nanoparticles on Porous Supports Using Natural Sources for Highly Efficient and Selective Furfural Hydrogenation
Authors: Zhang Zhanrong , Song Jinliang , Jiang Zhiwei , Meng Qinglei , Zhang Pei , Han Buxing
Published: March 2017

The synthesis of noble‐metal nanoparticles (NPs) with ultrasmall particle sizes (<2 nm) is crucially important but challenging. Making use of the unique structure of natural sources for the preparation of functional materials is an attractive topic. By taking advantage of the coordination effect between polyphenols and metal ions, we report a straightforward strategy for the synthesis of porous heterogeneous catalysts containing ultrasmall Ru NPs. These catalysts exhibit excellent catalytic activity for the selective hydrogenation of furfural. We envisage that this strategy will find a broad range of applications in the near future.
Membrane‐Supported Multichannel Microfluidic Solvent Extraction System
Authors: Prechtl Carolin , Kraut Manfred , Franzreb Matthias , Brenner-Weiß Gerald , Dittmeyer Roland
Published: March 2017

Although microfluidic solvent extraction (µSX) is a recent field in separation, its application is still limited to single‐channel microfluidic devices. However, the industrial application of microheat exchangers has already proven that parallelization of microchannels is an important tool to increase the specific device efficiency. Hence, in this study, a multichannel system for µSX is introduced. As a model process, D,L‐5‐phenylhydantoin was extracted from ethyl acetate into aqueous buffer. By means of different experimental setups, the potential and limitations of membrane‐supported multichannel µSX were investigated. The reactor dimensions perpendicular to flow and transmembrane mass transport are the most challenging factors for the introduced device.
Sulfur‐Doped Porphyrinic Carbon Nanostructures Synthesized with Amorphous MoS2 for the Oxygen Reduction Reaction in an Acidic Medium
Authors: Park Hyun‐Suk , Han Sang‐Beom , Kwak Da‐Hee , Lee Gyu‐Ho , Choi In‐Ae , Kim Do‐Hyoung , Ma Kyeng‐Bae , Kim Min‐Cheol , Kwon Hye‐Jin , Park Kyung‐Won
Published: March 2017

To develop doped carbon nanostructures as non‐precious metal cathode catalysts, nanocomposites were synthesized by using SBA‐15 and 5,10,15,20‐tetrakis(4‐methoxyphenyl)porphyrin–iron(III) chloride with different ratios of amorphous MoS2 precursor. From various analyses, it was found that, during pyrolysis at 900 °C under an N2 atmosphere, the amorphous MoS2 precursor decomposed into Mo and S, facilitating the formation of graphene sheet‐like carbon with MoC and doping of sulfur in the carbon. In the nanocomposite formed from 10 wt % MoS2 precursor (denoted as Mo/S/PC‐10), most of the MoS2 was decomposed, thus forming S‐doped carbon, which was grown on the MoC phase without crystalline MoS2. Furthermore, Mo/S/PC‐10 exhibited better performance in the oxygen reduction reaction (specific activity of 1.23 mA cm−2 at 0.9 V and half‐wave potential of 0.864 V) than a commercial Pt catalyst, owing to a heteroatom‐doped carbon nanostructure with a fairly high specific surface area. In the polarization curve of the unit‐cell performance measured at 80 °C under ambient pressure, Mo/S/PC‐10 as a cathode catalyst exhibited an optimal power density of 314 mW cm−2 and a current density of 280 mA cm−2 at 0.6 V.
Design and FPGA implementation of an efficient security mechanism for mobile pay‐TV systems
Authors: Arshad Hamed , Nikooghadam Morteza , Avezverdi Sara , Nazari Mahboubeh
Published: March 2017

A mobile pay‐TV service is one of the ongoing services of multimedia systems. Designing an efficient mechanism for authentication and key distribution is an important security requirement in mobile pay‐TV systems. Until now, many security protocols have been proposed for mobile pay‐TV systems. However, the existing protocols for mobile pay‐TV systems are vulnerable to various security attacks. Recently, Wang and Qin proposed an authentication scheme for mobile pay‐TV systems using bilinear pairing on elliptic curve cryptography. They claimed that their scheme could withstand various attacks. In this paper, we demonstrate that Wang and Qin's scheme is vulnerable to replay attacks and impersonation attacks. Furthermore, we propose a novel security protocol for mobile pay‐TV systems using the elliptic curve cryptosystem to overcome the weaknesses of Wang and Qin's scheme. In order to improve the efficiency, the proposed scheme is designed in such a way that needs fewer scalar multiplication operations and does not use bilinear pairing, which is an expensive cryptographic operation. Detailed analyses, including verification using the Automated Validation of Internet Security Protocols and Applications tool and implementation on FPGA, demonstrate that the proposed scheme not only withstands active and passive attacks and provides user anonymity but also has a better performance than Wang and Qin's scheme.
An Internet‐based platform for the estimation of outcrossing potential between cultivated and Chilean vascular plants
Authors: Cid Pablo , Aguirre Carlos , Sánchez Miguel Ángel , Zamorano Daniel , Mihoc Maritza , Salazar Erika , Chacón Gustavo , Navarrete Humberto , Rosas Marcelo , Prieto Humberto
Published: March 2017

A national‐scale study of outcrossing potential within Chilean vascular flora was conducted using an upgraded algorithm, which adds parameters such as pollinator agents, climate, and geographic conditions. Datasets were organized and linked in a Web platform (www.flujogenico.cl), in which the development of a total outcrossing potential (TOP) predictor was formulated. The TOP predictor is the engine in the Web platform, which models the effect of a type of agricultural practice on others (coexistence calculation mode) and on the environment (biodiversity calculation mode). The scale for TOP results uses quintiles in order to define outcrossing potential between species as “very low,” “low,” “medium,” “high,” or “very high.” In a coexistence analysis considering 256 species (207 genera), the 10 highest TOP values were for genera Citrus, Prunus, Trifolium, Brassica, Allium, Eucalyptus, Cucurbita, Solanum, Lollium, and Lotus. The highest TOP for species in this analysis fell at “high” potential, 4.9% of the determined values. In biodiversity mode, seven out of 256 cultivated species (2.7%) were native, and 249 (97.3%) corresponded to introduced species. The highest TOP was obtained in the genera Senecio, Calceolaria, Viola, Solanum, Poa, Alstroemeria, Valeriana, Vicia, Atriplex, and Campanula, showing “high” potential in 4.9% of the values. On the other hand, 137 genetically modified species, including the commercial and pre‐commercial developments, were included and represented 100 genera. Among these, 22 genera had relatives (i.e., members of the same genus) in the native/introduced group. The genera with the highest number of native/introduced relatives ranged from one (Ipomea, Limonium, Carica, Potentilla, Lotus, Castanea, and Daucus) to 66 species (Solanum). The highest TOP was obtained when the same species were coincident in both groups, such as for Carica chilensis, Prosopis tamarugo, and Solanum tuberosum. Results are discussed from the perspective of assessing the possible impact of cultivated species on Chilean flora biodiversity. The TOP predictor (http://epc.agroinformatica.cl/) is useful in the context of environmental risk assessment.
Stable isotope analyses—A method to distinguish intensively farmed from wild frogs
Authors: Dittrich Carolin , Struck Ulrich , Rödel Mark‐Oliver
Published: March 2017

Consumption of frog legs is increasing worldwide, with potentially dramatic effects for ecosystems. More and more functioning frog farms are reported to exist. However, due to the lack of reliable methods to distinguish farmed from wild‐caught individuals, the origin of frogs in the international trade is often uncertain. Here, we present a new methodological approach to this problem. We investigated the isotopic composition of legally traded frog legs from suppliers in Vietnam and Indonesia. Muscle and bone tissue samples were examined for δ15N, δ13C, and δ18O stable isotope compositions, to elucidate the conditions under which the frogs grew up. We used DNA barcoding (16S rRNA) to verify species identities. We identified three traded species (Hoplobatrachus rugulosus, Fejervarya cancrivora and Limnonectes macrodon); species identities were partly deviating from package labeling. Isotopic values of δ15N and δ18O showed significant differences between species and country of origin. Based on low δ15N composition and generally little variation in stable isotope values, our results imply that frogs from Vietnam were indeed farmed. In contrast, the frogs from the Indonesian supplier likely grew up under natural conditions, indicated by higher δ15N values and stronger variability in the stable isotope composition. Our results indicate that stable isotope analyses seem to be a useful tool to distinguish between naturally growing and intensively farmed frogs. We believe that this method can be used to improve the control in the international trade of frog legs, as well as for other biological products, thus supporting farming activities and decreasing pressure on wild populations. However, we examined different species from different countries and had no access to samples of individuals with confirmed origin and living conditions. Therefore, we suggest improving this method further with individuals of known origin and history, preferably including samples of the respective nutritive bases.
Single‐Ion Magnetic Behavior in CoII–CoIII Mixed‐Valence Dinuclear and Pseudodinuclear Complexes
Authors: Manna Soumen , Bhunia Apurba , Mistri Soumen , Vallejo Julia , Zangrando Ennio , Puschmann Horst , Cano Joan , Manna Subal Chandra
Published: March 2017

Two CoII–CoIII mixed‐valance complexes of molecular formulas [Co2(H2L)2(H2O)2][Co2(H2L)2(H2O)(m‐phth)]·8(H2O) {1; H2L2– = 2‐[(2‐hydroxy‐3‐methoxybenzylidene)amino]‐2‐(hydroxymethyl)propane‐1,3‐diolato, m‐phth = 1,3‐benzenedicarboxylate} and [Co4(H2L)4(H2O)2(ppda)]·2(dmf)·3.2(H2O) {2; ppda = 1,4‐phenylenediacrylate; dmf = N,N‐dimethylformamide} were synthesized and characterized by single‐crystal X‐ray diffraction and magnetic studies at low temperature. The structural determination reveals that 1 is composed of dinuclear ion pairs, namely, a cationic [Co2(H2L)2(H2O)2]+ (1+) and an anionic [Co2(H2L)2(H2O)(m‐phth)]– (1–) unit. In each of these ions, the CoII and CoIII centers present distorted octahedral geometries. Compound 2 is a centrosymmetric tetranuclear complex comprising two symmetry‐related dinuclear CoII–CoIII units bridged by ppda anions. Alternating current/direct current (ac/dc) magnetic studies revealed that the individual CoII–CoIII unit exhibits field‐induced slow magnetic relaxation consistent with single‐ion magnet (SIM) behavior. Ab initio NEVPT2 calculations confirm large zero‐field splitting (zfs) from a first‐order spin–orbit coupling (SOC) in both complexes (D = –62.4, –95.8, and –101.9 cm–1 and E/D = 0.219, 0.216, and 0.234 for 1+, 1–, and 2, respectively).
Smart Design of Small Pd Nanoparticles Confined in Hollow Carbon Nanospheres with Large Center‐Radial Mesopores
Authors: Du Xin , Zhao Caixia , Li Xiaoyu , Huang Hongwei , He Junhui , Wen Yongqiang , Zhang Xueji
Published: March 2017

Although considerable progress has been made with carbon‐based heterogeneous nanocatalysts, great effort is still needed to regulate their structural parameters to further improve their catalytic activities and stabilities. Herein, we have successfully designed and synthesized new composite nanocatalysts composed of porous hollow carbon nanospheres (PHCNs) containing many small Pd nanoparticles (NPs) on their inner surfaces (PHCNs@Pd NPs). Notably, the PHCNs have disordered micropores and large center‐radial mesopores in the shell and craterlike inner surface, and a high density of small Pd NPs are partially confined on the inner surfaces of the PHCNs. Dendrimer‐like mesoporous silica nanospheres (DMSNs) as hard templates play a critical role in the formation of these unique structures. The resulting PHCNs@Pd NP catalyst exhibits high catalytic activity and selectivity as well as good recyclability in the catalytic oxidation of benzyl alcohol to benzaldehyde, and this catalytic performance is attributed to the unique structure of the support coupled with ultradispersed Pd NPs. Moreover, this synthesis strategy may provide some inspiration for the synthesis of advanced composites with complicated nanostructures for various applications.
Electrofiltration improves dead‐end filtration of hyaluronic acid and presents an alternative downstream processing step that overcomes technological challenges of conventional methods
Authors: Gözke Gözde , Kirschhöfer Frank , Prechtl Carolin , Brenner‐Weiss Gerald , Krumov Nikolay Venelinov , Obst Ursula , Posten Clemens
Published: March 2017

Hyaluronic acid (HA) dispersion obtained from the bacteria Streptococcus equi was concentrated by electrofiltration. In the conventional downstream processing of HA, extraction and precipitation lead to increase in environmental issues, structural changes, and time and energy related costs. Using electrofiltration as an alternative technology delivers solutions to these limitations. Experiments were conducted in order to test the applicability of electrofiltration to downstream processing of the negatively charged HA. The structural changes and molecular weight distributions, often a consequence of the employed separation method, were tested by analysis of the initial dispersions and final products. In comparison to the conventional filtration, concentration factors were increased up to almost four times without any detectable structural change in the final product.
Enhanced growth and total fatty acid production of microalgae under various lighting conditions induced by flashing light
Authors: Choi Yong‐Keun , Kim Hyun‐Joong , Kumaran Rangarajulu Senthil , Song Hak‐Jin , Song Kyung‐Guen , Kim Kwang Jin , Lee Sang Hyun , Yang Yung‐Hun , Kim Hyung Joo
Published: March 2017

Microalgae are gaining importance as a source of high‐value bioproducts. However, data regarding optimization of algal productivity via variation of environmental factors are lacking. Here, we evaluated a novel lighting method for the enhancement of biomass and total fatty acid (TFA) productivities during algal cultivation. We cultivated six different algal strains (Chlorella vulgaris KCTC AG10002, Acutodesmus obliquus KGE18, Uronema sp. KGE03, Micractinium reisseri KGE19, Fragilaria sp., and Spirogyra sp.) under various lighting conditions—continuous light (CL), light‐dark cycle (LD), and continuous dark (CD)—with or without additional flashing light. We monitored dry cell weight (DCW) and TFA concentrations during cultivation. For each algal strain, the growth rate showed markedly different responses to the various lighting modes. The growth rates of C. vulgaris KCTC AG10002 (1.34‐fold DCW increase, LD with flash), A. obliquus KGE18 (5.16‐fold DCW increase, LD with flash), Uronema sp. KGE03 (2.77‐fold DCW increase, CL with flash), and M. reisseri KGE19 (1.52‐fold DCW increase, CL with flash) markedly increased in response to flashing light. Additionally, in some algal strains cultivated under the LD mode, the flashing light treatment induced increased TFA concentrations (C. vulgaris, 1.19‐fold increase; A. obliquus, 2.59‐fold increase; and M. reisseri, 3.31‐fold increase). Phytohormone analysis of M. reisseri revealed increases in growth rate and TFA concentrations, associated with phytohormone induction via flashing light (e.g. 2.93‐fold increase in gibberellic acid); hence, flashing light can promote substantial alterations in algal metabolism.
Value and Opportunity for Improvement Science in Evaluation
Authors: Inkelas Moira , Christie Christina A. , Lemire Sebastian
Published: March 2017

This chapter focuses on features of improvement science that the evaluation field could benefit from, drawing from case examples. Themes addressed include learning from error, learning from and reducing variation, systems thinking, and learning for scale. We also consider opportunities for professional development, whereby evaluation professionals and people in practice can successfully apply improvement science techniques and methods within and across fields and in the complex systems that shape health, social, and educational outcomes. Finally, we describe resource and management challenges of building improvement science into the evaluation repertoire.
Online Learning as a Wind Tunnel for Improving Teaching
Authors: Stigler James W. , Givvin Karen B.
Published: March 2017

Attempts to improve teaching through research have met with limited success. This is, in part, due to the fact that teaching is a complex cultural system that has evolved over long periods of time—multiply determined and inherently resistant to change. But it is also true that research on teaching is difficult to carry out. Using traditional educational research methodologies, testing new methods of teaching requires, first, that teachers be able to implement the method at a scale sufficient for study, that random assignment of teachers to conditions can be feasibly carried out, and that ecological validity of the treatment can be preserved. In this chapter, we propose an alternative approach that combines the affordances of online learning with the methodologies of systems improvement. Using an analogy from the development of the airplane, we discuss how online learning might be a wind tunnel for the study and improvement of teaching.
Timely and Appropriate Healthcare Access for Newborns: A Neighborhood‐Based, Improvement Science Approach
Authors: Brown Courtney M. , Kahn Robert S. , Goyal Neera K.
Published: March 2017

Newborns in low‐income families often experience delays between birth hospital discharge and the first primary care visit. Delays in primary care can result in inadequate support and education for families and may lead to emergency department (ED) visits for nonurgent conditions. Our intervention sought to reduce average age at first primary care visit to ≤ 9 days of life and reduce nonurgent ED visits by 20% among infants < 6 months old from one low‐income neighborhood in Cincinnati, Ohio. We applied improvement science to iteratively address the many family‐ and system‐level barriers to primary care. Improvement science is a structured approach to improving outcomes through ongoing data collection and examination of how specific practices affect performance. Advantages of this approach include the ability to detect incremental changes in outcomes and continuously adapt interventions over time. This chapter discusses the successes and challenges of applying improvement science to our goals.
Understanding the Similarities and Distinctions Between Improvement Science and Evaluation
Authors: Christie Christina A. , Lemire Sebastian , Inkelas Moira
Published: March 2017

In this chapter, we discuss the similarities and points of departure between improvement science and evaluation, according to use, valuing, and methods—three dimensions of evaluation theory to which all theorists attend (Christie & Alkin, ). Using these three dimensions as a framework for discussion, we show some of the ways in which improvement science and evaluation are similar and how they are different in terms of purposes, goals, and processes. By doing so we frame the illustrative cases of improvement science that follow in this issue.
Compromised hippocampus‐striatum pathway as a potential imaging biomarker of mild‐traumatic brain injury and posttraumatic stress disorder
Authors: Rangaprakash D. , Deshpande Gopikrishna , Daniel Thomas A. , Goodman Adam M. , Robinson Jennifer L. , Salibi Nouha , Katz Jeffrey S. , Denney Thomas S. , Dretsch Michael N.
Published: March 2017

Objectives

Military service members risk acquiring posttraumatic stress disorder (PTSD) and mild‐traumatic brain injury (mTBI), with high comorbidity. Owing to overlapping symptomatology in chronic mTBI or postconcussion syndrome (PCS) and PTSD, it is difficult to assess the etiology of a patient's condition without objective measures. Using resting‐state functional MRI in a novel framework, we tested the hypothesis that their neural signatures are characterized by functionally hyperconnected brain regions which are less variable over time. Additionally, we predicted that such connectivities possessed the highest ability in predicting the diagnostic membership of a novel subject (top‐predictors) in addition to being statistically significant.

Methods

U.S. Army Soldiers (N = 87) with PTSD and comorbid PCS + PTSD were recruited along with combat controls. Static and dynamic functional connectivities were evaluated. Group differences were obtained in accordance with our hypothesis. Machine learning classification (MLC) was employed to determine top predictors.

Results

From whole‐brain connectivity, we identified the hippocampus‐striatum connectivity to be significantly altered in accordance with our hypothesis. Diffusion tractography revealed compromised white‐matter integrity between aforementioned regions only in the PCS + PTSD group, suggesting a structural etiology for the PCS + PTSD group rather than being an extreme subset of PTSD. Employing MLC, connectivities provided worst‐case accuracy of 84% (9% more than psychological measures). Additionally, the hippocampus‐striatum connectivities were found to be top predictors and thus a potential biomarker of PTSD/mTBI.

Conclusions

PTSD/mTBI are associated with hippocampal‐striatal hyperconnectivity from which it is difficult to disengage, leading to a habit‐like response toward episodic traumatic memories, which fits well with behavioral manifestations of combat‐related PTSD/mTBI. Hum Brain Mapp 38:2843–2864, 2017. © 2017 The Authors Human Brain Mapping Published by Wiley Periodicals, Inc.