bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of streamflow simulation results of land surface models in GLDAS on the Tibetan plateau
Authors: Bai Peng , Liu Xiaomang , Yang Tiantian , Liang Kang , Liu Changming
Published: October 2016

The Global Land Data Assimilation System (GLDAS) project estimates long‐term runoff based on land surface models (LSMs) and provides a potential way to solve the issue of nonexistent streamflow data in gauge‐sparse regions such as the Tibetan Plateau (TP). However, the reliability of GLDAS runoff data must be validated before being practically applied. In this study, the streamflows simulated by four LSMs (CLM, Noah, VIC, and Mosaic) in GLDAS coupled with a river routing model are evaluated against observed streamflows in five river basins on the TP. The evaluation criteria include four aspects: monthly streamflow value, seasonal cycle of streamflow, annual streamflow trend, and streamflow component partitioning. The four LSMs display varying degrees of biases in monthly streamflow simulations: systematic overestimations are found in the Noah (1.74 ≤ bias ≤ 2.75) and CLM (1.22 ≤ bias ≤ 2.53) models, whereas systematic underestimations are observed in the VIC (0.36 ≤ bias ≤ 0.85) and Mosaic (0.34 ≤ bias ≤ 0.66) models. The Noah model shows the best performance in capturing the temporal variation in monthly streamflow and the seasonal cycle of streamflow, while the VIC model performs the best in terms of bias statistics. The Mosaic model provides the best performance in modeling annual runoff trends and runoff component partitioning. The possible reasons for the different performances of the LSMs are discussed in detail. In order to achieve more accurate streamflow simulations from the LSMs in GLDAS, suggestions are made to further improve the accuracy of the forcing data and parameterization schemes in all models.
Mass spectral determination of phosphopantetheinylation specificity for carrier proteins in Mycobacterium tuberculosis
Authors: Jung James , Bashiri Ghader , Johnston Jodie M. , Baker Edward N.
Published: October 2016

Phosphopantetheinyl transferases (PPTases) are key elements in the modular syntheses performed by multienzyme systems such as polyketide synthases. PPTases transfer phosphopantetheine derivatives from Coenzyme A to carrier proteins (CPs), thus orchestrating substrate supply. We describe an efficient mass spectrometry‐based protocol for determining CP specificity for a particular PPTase in organisms possessing several candidate PPTases. We show that the CPs MbtL and PpsC, both involved in synthesis of essential metabolites in Mycobacterium tuberculosis, are exclusively activated by the type 2 PPTase PptT and not the type 1 AcpS. The assay also enables conclusive identification of the reactive serine on each CP.
Phase Inversion: A Universal Method to Create High‐Performance Porous Electrodes for Nanoparticle‐Based Energy Storage Devices
Authors: Yang Xiaofei , Chen Yuqing , Wang Meiri , Zhang Hongzhang , Li Xianfeng , Zhang Huamin
Published: October 2016

The intrinsic properties of nanoscale active materials are always excellent for energy storage devices. However, the accompanying problems of ion/electron transport limitation and active materials shedding of the whole electrodes, especially for high‐loaded electrode composed of nanoparticles with high specific surface area, bring down their comprehensive performance for practical applications. Here, this problem is solved with the as proposed “phase inversion” method, which allows fabrication of tricontinuous structured electrodes via a simple, convenient, low cost, and scalable process. During this process, the binder networks, electron paths, and ion channels can be separately interconnected, which simultaneously achieves excellent binding strength and ion/electron conductivity. This is verified by constructing electrodes with sulfur/carbon (S/C) and Li3V2(PO4)3/C (LVP/C) nanoparticles, separately delivering 869 mA h g−1 at 1 C in Li–S batteries and 100 mA h g−1 at 30 C in Li–LVP batteries, increasing by 26% and 66% compared with the traditional directly drying ones. Electrodes with 7 mg cm−2 sulfur and 11 mg cm−2 LVP can also be easily coated on aluminum foil, with excellent cycling stability. Phase inversion, as a universal method to achieve high‐performance energy storage devices, might open a new area in the development of nanoparticle‐based active materials.
By‐Product‐Catalyzed Redox‐Neutral Sulfenylation/Deiodination/Aromatization of Cyclic Alkenyl Iodides with Sulfonyl Hydrazides
Authors: Yang Fu‐Lai , Gui Yang , Yu Bang‐Kui , Jin You‐Xiang , Tian Shi‐Kai
Published: October 2016

A by‐product‐catalyzed redox‐neutral process has been established through tandem sulfenylation/deiodination/aromatization of cyclic alkenyl iodides with sulfonyl hydrazides. In the absence of external catalysts and additives a range of 4‐iodo‐1,2‐dihydronaphthalenes reacted with sulfonyl hydrazides to give structurally diverse 2‐naphthyl thioethers in good yields. Mechanistic studies showed that at an early stage sulfonyl hydrazides decomposed completely to thiosulfonates and disulfides and at a late stage the resulting thiosulfonates underwent tandem sulfenylation/deiodination/aromatization with 4‐iodo‐1,2‐dihydronaphthalenes involving a [1,5]‐sigmatropic hydrogen shift. Importantly, iodine was generated as a by‐product from 4‐iodo‐1,2‐dihydronaphthalenes upon heating and served as a catalyst for the decomposition of sulfonyl hydrazides and subsequent formation of 2‐naphthyl thioethers.

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Selective Enzymatic Transformation to Aldehydes in vivo by Fungal Carboxylate Reductase from Neurospora crassa
Authors: Schwendenwein Daniel , Fiume Giuseppe , Weber Hansjörg , Rudroff Florian , Winkler Margit
Published: October 2016

The enzymatic reduction of carboxylic acids is in its infancy with only a handful of biocatalysts available to this end. We have increased the spectrum of carboxylate‐reducing enzymes (CARs) with the sequence of a fungal CAR from Neurospora crassa OR74A (NcCAR). NcCAR was efficiently expressed in E. coli using an autoinduction protocol at low temperature. It was purified and characterized in vitro, revealing a broad substrate acceptance, a pH optimum at pH 5.5–6.0, a Tm of 45 °C and inhibition by the co‐product pyrophosphate which can be alleviated by the addition of pyrophosphatase. The synthetic utility of NcCAR was demonstrated in a whole‐cell biotransformation using the Escherichia coli K‐12 MG1655 RARE strain in order to suppress overreduction to undesired alcohol. The fragrance compound piperonal was prepared from piperonylic acid (30 mM) on gram scale in 92 % isolated yield in >98% purity. This corresponds to a productivity of 1.5 g/L/h.

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Study on Vibration Transmission and Interfacial Fusion in Ultrasonic Bonding Process for Thermoplastic Micro Joint
Authors: Sun Yibo , Wang Feng , Li Fang , Yang Xinhua
Published: October 2016

Fusion precision is an important factor to be considered for ultrasonic bonding in thermoplastic MEMS. Vibration transmission in ultrasonic bonding process through polymer workpiece was related to the interfacial fusion, which could be used for in situ monitoring. In this article, experimental platform was established to study the vibration transmission. Experiments were carried out to measure the vibration transmitted from horn onto the high‐frequency dynamic force sensor installed in the anvil. According to the peak‐to‐peak value of dynamic force, the whole bonding process could be divided into rising and falling phases. Interfacial fusion corresponding to ultrasonic transmission was also studied. From experimental results, when the peak‐to‐peak value change rate rose to 130%, some area on the surface starts to melt. When it fell down back to 60%, glass transition occurred with the melt spread gradually over the whole interface. When it fell down to 30%, defects of overflow and bubble began to generate as polymer got into viscous flow state. When the change rate reached 10%, the bubbles burst into smaller ones like floccules as the fluidity of polymer was enhanced further under continuous ultrasonic load. The experimental results gave a deep understanding in the formation of interfacial fusion and the generation of defects.
Bubble/droplet formation and mass transfer during gas–liquid–liquid segmented flow with soluble gas in a microchannel
Authors: Yao Chaoqun , Liu Yanyan , Zhao Shuainan , Dong Zhengya , Chen Guangwen
Published: October 2016

Microchannels have great potential in intensification of gas–liquid–liquid reactions involving reacting gases, such as hydrogenation. This work uses CO2–octane–water system to model the hydrodynamics and mass transfer of such systems in a microchannel with double T‐junctions. Segmented flows are generated with three inlet sequences and the size laws of dispersed phases are obtained. Three generation mechanisms of dispersed gas bubbles/water droplets are identified: squeezing by the oil phase, cutting by the droplet/bubble, cutting by the water–oil/gas–oil interface. Based on the gas dissolution rate, the mass transfer coefficients are calculated. It is found that water droplet can significantly enhance the transfer of CO2 into the oil phase initially. When bubble‐droplet cluster are formed downstream the microchannel, droplet will retard the mass transfer. Other characteristics such as phase hold‐up, bubble velocity and bubble dissolution rate are also discussed. The information is beneficial for microreactor design when applying three‐phase reactions. © 2016 American Institute of Chemical Engineers AIChE J, 63: 1727–1739, 2017
Capturing the non‐spherical shape of granular media and its trickle flow characteristics using fully‐Lagrangian method
Authors: Natsui Shungo , Nashimoto Ryota , Kikuchi Tatsuya , Suzuki Ryosuke O. , Takai Hifumi , Ohno Ko‐ichiro , Sukenaga Sohei
Published: October 2016

We performed a numerical analysis for simulating granular media structures containing non‐spherical elements and the liquid trickle flow characteristics of such structures. Fully‐Lagrangian numerical simulation methods can track all motion information for solid or liquid elements at each point in time. We introduced suitable compressibility to moving particle semi‐implicit (MPS) and performed individual packing behavior calculations for non‐spherical elements, based on discrete element method (DEM) with expanded functions. Rigid bodies‐DEM is a method using a DEM contact force model that is expanded to handle the motion of freely shaped solids. It expresses complex shapes to enable low calculation costs and intuitive mounting. We used the boundary for the granular media configured with non‐spherical elements to implement a trickle flow simulation based on weakly compressible‐MPS. Even for elements of equal volume, different shapes changed the liquid passage velocity and hold‐up amount. The mean downflow velocity of the liquid phase was not always dependent on the void fraction. For the plane of projection, we obtained a good correlation with the mean downflow velocity in each packed structure, and successfully performed arrangements according to the new liquid‐passage shape coefficient. © 2016 American Institute of Chemical Engineers AIChE J, 63: 2257–2271, 2017
Disparities in precarious workers’ health care access in South Korea
Authors: Min Jin‐Young , Park Shin‐Goo , Hwang Sang Hee , Min Kyoung‐Bok
Published: October 2016

Background

This study explored whether precarious workers have difficulties in health care access as compared with non‐precarious workers.

Methods

The 2008 Korean Community Health Survey data were used for this study. Information was obtained on 51,322 participants (40,514 non‐precarious workers and 10,808 precarious workers). Precarious workers were defined as part‐time or contingent workers.

Results

Precarious workers had significantly higher risk of limited access to hospitals (OR = 1.14; 95% CI: 1.06–1.22) and dentists (OR = 1.28; 95% CI: 1.21–1.36) than non‐precarious workers; disparities in doctor contacts among precarious workers were mostly linked to not having enough money. The risk of not receiving preventive care—medical checkups (OR = 0.52; 95% CI: 0.49–0.55) or cancer screenings (OR = 0.82; 95% CI: 0.77–0.86)—was also significantly elevated among precarious workers.

Conclusion

We found that precarious workers had more difficulty accessing health care or receiving health checkups or cancer screenings than their non‐precarious counterparts. Am. J. Ind. Med. 59:1136–1144, 2016. © 2016 Wiley Periodicals, Inc.
Revisiting cancer 15 years later: Exploring mortality among agricultural and non‐agricultural workers in the Serrana Region of Rio de Janeiro
Authors: Krawczyk Noa , de Souza Espíndola Santos Aline , Lima Jaime , Meyer Armando
Published: October 2016

Background Agricultural production has expanded dramatically throughout Brazil. Previous research in the Serrana Region found that from 1979 to 1998, agricultural workers experienced high mortality rates from certain cancers compared to non‐agricultural workers [Meyer et al. (2003): Environ Res 93:264–271].

Methods

New data were obtained for 1999–2013 and Mortality Odds Ratios (MORs) were utilized to compare cancer and other mortality between male agricultural workers in the Serrana Region and non‐agricultural workers in the Serrana Region, Rio de Janeiro, and Porto Alegre, and to compare mortality odds to previous decades.

Results

Respectively, compared to aforementioned reference‐groups, agricultural workers experienced highest MORs for stomach (1.55 [95%CI: 1.13–2.12], 2.30 [95%CI: 1.72–3.08], 2.28 [95%CI: 1.69–3.08]) and esophageal cancers (95%CI: 1.93 [1.38–2.7], 1.93 [95%CI: 1.38–2.71], 3.12 [95%CI: 2.30–4.24]), greater than reported in previous decades. Agricultural workers experienced higher mortality for external‐causes, respiratory, and cardiovascular problems compared to urban reference‐groups.

Conclusion

Agricultural workers may be at increasing risk for cancer and other mortality. Efforts are needed to investigate distinct risk‐factors among this group. Am. J. Ind. Med. 60:77–86, 2017. © 2016 Wiley Periodicals, Inc.
Making extra teeth: Lessons from a TRPS1 mutation
Authors: Kunotai Worawan , Ananpornruedee Panjit , Lubinsky Mark , Pruksametanan Apitchaya , Kantaputra Piranit Nik
Published: October 2016

A Thai mother and her two daughters were affected with tricho‐rhino‐phalangeal syndrome type I. The daughters had 15 and 18 supernumerary teeth, respectively. The mother had normal dentition. Mutation analysis of TRPS1 showed a novel heterozygous c.3809_3811delACTinsCATGTTGTG mutation in all. This mutation is predicted to cause amino acid changes in the Ikaros‐like zinc finger domain near the C‐terminal end of TRPS1, which is important for repressive protein function. The results of our study and the comprehensive review of the literature show that pathways of forming supernumerary teeth appear to involve APC and RUNX2, the genes responsible for familial adenomatous polyposis syndrome and cleidocranial dysplasia, respectively. The final pathway resulting in supernumerary teeth seems to involve Wnt, a morphogen active during many stages of development. © 2016 Wiley Periodicals, Inc.
Visible Light Activation of Boronic Esters Enables Efficient Photoredox C(sp2)–C(sp3) Cross‐Couplings in Flow
Authors: Lima Fabio , Kabeshov Mikhail A. , Tran Duc N. , Battilocchio Claudio , Sedelmeier Joerg , Sedelmeier Gottfried , Schenkel Berthold , Ley Steven V.
Published: October 2016

We report herein a new method for the photoredox activation of boronic esters. Using these reagents, an efficient and high‐throughput continuous flow process was developed to perform a dual iridium‐ and nickel‐catalyzed C(sp2)–C(sp3) coupling by circumventing solubility issues associated with potassium trifluoroborate salts. Formation of an adduct with a pyridine‐derived Lewis base was found to be essential for the photoredox activation of the boronic esters. Based on these results we were able to develop a further simplified visible light mediated C(sp2)–C(sp3) coupling method using boronic esters and cyano heteroarenes under flow conditions.
Deactivation of Mcl‐1 by Dual‐Function Small‐Molecule Inhibitors Targeting the Bcl‐2 Homology 3 Domain and Facilitating Mcl‐1 Ubiquitination
Authors: Song Ting , Wang Ziqian , Ji Fangling , Feng Yingang , Fan Yudan , Chai Gaobo , Li Xiangqian , Li Zhiqiang , Zhang Zhichao
Published: October 2016

By means of limited proteolysis assay, three‐dimensional NMR, X‐ray crystallography and alanine mutations, a dynamic region at the Q221R222N223 motif in the Bcl‐2 homology 3 (BH3) domain of Mcl‐1 has been identified as a conformational switch which controls Mcl‐1 ubiquitination. NoxaBH3 binding biases the QRN motif toward a helical conformation, thus leading to an enhanced in vitro ubiquitination of Mcl‐1. In contrast, BimBH3 binding biases the QRN motif toward a nonhelical conformation, thus leading to the inhibition of ubiquitination. A dual function Mcl‐1 inhibitor, which locates at the BH3 domain of Mcl‐1 and forms hydrogen bond with His224 to drive a helical QRN conformation, so that it not only interferes with the pro‐apoptotic partners, but also facilitates Mcl‐1 ubiquitination in living cells, is described. As a result, this inhibitor manifests a more effective apoptosis induction in Mcl‐1‐dependent cancer cells than other inhibitors exhibiting a similar binding affinity with it.
Mechanism‐Guided Design and Synthesis of a Mitochondria‐Targeting Artemisinin Analogue with Enhanced Anticancer Activity
Authors: Zhang Chong‐Jing , Wang Jigang , Zhang Jianbin , Lee Yew Mun , Feng Guangxue , Lim Teck Kwang , Shen Han‐Ming , Lin Qingsong , Liu Bin
Published: October 2016

Understanding the mechanism of action (MOA) of bioactive natural products will guide endeavor to improve their cellular activities. Artemisinin and its derivatives inhibit cancer cell proliferation, yet with much lower efficiencies than their roles in killing malaria parasites. To improve their efficacies on cancer cells, we studied the MOA of artemisinin using chemical proteomics and found that free heme could directly activate artemisinin. We then designed and synthesized a derivative, ART‐TPP, which is capable of targeting the drug to mitochondria where free heme is synthesized. Remarkably, ART‐TPP exerted more potent inhibition than its parent compound to cancer cells. A clickable probe ART‐TPP‐Alk was also employed to confirm that the attachment of the TPP group could label more mitochondrial proteins than that for the ART derivative without TPP (AP1). This work shows the importance of MOA study, which enables us to optimize the design of natural drug analogues to improve their biological activities.
Molecular Imaging of Growth, Metabolism, and Antibiotic Inhibition in Bacterial Colonies by Laser Ablation Electrospray Ionization Mass Spectrometry
Authors: Li Hang , Balan Pranav , Vertes Akos
Published: October 2016

Metabolism in microbial colonies responds to competing species, rapidly evolving genetic makeup, and sometimes dramatic environmental changes. Conventional characterization of the existing and emerging microbial strains and their interactions with antimicrobial agents, e.g., the Kirby–Bauer susceptibility test, relies on time consuming methods with limited ability to discern the molecular mechanism and the minimum inhibitory concentration. Assessing the metabolic adaptation of microbial colonies requires their non‐targeted molecular imaging in a native environment. Laser ablation electrospray ionization (LAESI) is an ambient ionization technique that in combination with mass spectrometry (MS) enables the analysis and imaging of numerous metabolites and lipids. In this contribution, we report on the application of LAESI‐MS imaging to gain deeper molecular insight into microbe–antibiotic interactions, and enhance the quantitative nature of antibiotic susceptibility testing while significantly reducing the required incubation time.
[N⋅⋅⋅I+⋅⋅⋅N] Halogen‐Bonded Dimeric Capsules from Tetrakis(3‐pyridyl)ethylene Cavitands
Authors: Turunen Lotta , Warzok Ulrike , Puttreddy Rakesh , Beyeh Ngong Kodiah , Schalley Christoph A. , Rissanen Kari
Published: October 2016

Two [N⋅⋅⋅I+⋅⋅⋅N] halogen‐bonded dimeric capsules using tetrakis(3‐pyridyl)ethylene cavitands with different lower rim alkyl chains are synthesized and analyzed in solution and the gas phase. These first examples of symmetrical dimeric capsules making use of the iodonium ion (I+) as the main connecting module are characterized by 1H NMR spectroscopy, diffusion ordered NMR spectroscopy (DOSY), electrospray ionization mass spectrometry (ESI‐MS), and ion mobility‐mass spectrometry (TW‐IMS) experiments. The synthesis and effective halogen‐bonded dimerization proceeds through analogous dimeric capsules with [N⋅⋅⋅Ag+⋅⋅⋅N] binding motifs as the intermediates as evidenced by the X‐ray structures of (CH2Cl2)2@[3 a2⋅Ag4⋅(H2O)2⋅OTs4] and (CH2Cl2)2@[3 a2⋅Ag4⋅(H2O)4⋅OTs4], two structurally different capsules.
Mesoporous Amorphous Silicon: A Simple Synthesis of a High‐Rate and Long‐Life Anode Material for Lithium‐Ion Batteries
Authors: Lin Liangdong , Xu Xuena , Chu Chenxiao , Majeed Muhammad K. , Yang Jian
Published: October 2016

Amorphous Si (a‐Si) shows potential advantages over crystalline Si (c‐Si) in lithium‐ion batteries, owing to its high lithiation potential and good tolerance to intrinsic strain/stress. Herein, porous a‐Si has been synthesized by a simple process, without the uses of dangerous or expensive reagents, sophisticated equipment, and strong acids that potential cause environment risks. These porous a‐Si particles exhibit excellent electrochemical performances, owing to their porous structure, amorphous nature, and surface modification. They deliver a capacity of 1025 mAh g−1 at 3 A g−1 after 700 cycles. Moreover, the reversible capacity after electrochemical activation, is quite stable throughout the cycling, resulting in a capacity retention about around 88 %. The direct comparison between a‐Si and c‐Si anodes clearly supports the advantages of a‐Si in lithium‐ion batteries.
9‐Silafluorenyl Dichlorides as Chemically Ligating Coupling Agents and Their Application in Peptide Synthesis
Authors: Aspin Samuel J. , Taillemaud Sylvain , Cyr Patrick , Charette André B.
Published: October 2016

A fundamentally simple, mild, and practical procedure for peptide bond formation is reported that employs a stoichiometric amount of easy‐to‐access 9‐silafluorenyl dichlorides as the coupling agent. Without initial preactivation or elaboration of the carboxylic acid or amine termini of the amino acids, the developed reagent is proposed to act through an unprecedented chemical ligation mechanism, bringing the two coupling partners together before being subsequently eliminated. The desired amides or peptide bonds are thus furnished in good yields and with low to no epimerization.
Molecularly Designed Stabilized Asymmetric Hollow Fiber Membranes for Aggressive Natural Gas Separation
Authors: Liu Gongping , Li Nanwen , Miller Stephen J. , Kim Danny , Yi Shouliang , Labreche Ying , Koros William J.
Published: October 2016

New rigid polyimides with bulky CF3 groups were synthesized and engineered into high‐performance hollow fiber membranes. The enhanced rotational barrier provided by properly positioned CF3 side groups prohibited fiber transition layer collapse during cross‐linking, thereby greatly improving CO2/CH4 separation performance compared to conventional materials for aggressive natural gas feeds.
Photoisomerization of Arylazopyrazole Photoswitches: Stereospecific Excited‐State Relaxation
Authors: Wang Ya‐Ting , Liu Xiang‐Yang , Cui Ganglong , Fang Wei‐Hai , Thiel Walter
Published: October 2016

Electronic structure calculations and nonadiabatic dynamics simulations (more than 2000 trajectories) are used to explore the Z–E photoisomerization mechanism and excited‐state decay dynamics of two arylazopyrazole photoswitches. Two chiral S1/S0 conical intersections with associated enantiomeric S1 relaxation paths that are barrierless and efficient (timescale of ca. 50 fs) were found. For the parent arylazopyrazole (Z8) both paths contribute evenly to the S1 excited‐state decay, whereas for the dimethyl derivative (Z11) each of the two chiral cis minima decays almost exclusively through one specific enantiomeric S1 relaxation path. To our knowledge, the Z11 arylazopyrazole is thus the first example for nearly stereospecific unidirectional excited‐state relaxation.
Reaction of Pentelidene Complexes with Diazoalkanes: Stabilization of Parent 2,3‐Dipnictabutadienes
Authors: Seidl Michael , Stubenhofer Markus , Timoshkin Alexey Y. , Scheer Manfred
Published: October 2016

The reaction of the phosphinidene complex [Cp*P{W(CO)5}2] (1 a) with diphenyldiazomethane leads to [{W(CO)5}Cp*P=NN{W(CO)5}=CPh2] (2). Compound 2 is a rare example of a phosphadiazadiene ligand (R‐P=N−N=CR′R′′) complex. At temperatures above 0 °C, 2 decomposes into the complex [{W(CO)5}PCp*{N(H)N=CPh2)2] (3), among other species. The reaction of the pentelidene complexes [Cp*E{W(CO)5}2] (E=P, As) with diazomethane (CH2NN) proceeds differently. For the arsinidene complex (1 b), only the arsaalkene complex 4 b [{W(CO)5}2{η1:2‐(Cp*)As=CH2}] is formed. The reaction with the phosphinidene complex (1 a) results in three products, the two phosphaalkene complexes [{W(CO)5}2{η1:2‐(R)P=CH2}] (4 a: R=Cp*, 5: R=H) and the triazaphosphole derivative [{W(CO)5}P(Cp*)‐CH2‐N{W(CO)5}=N‐N(N=CH2)] (6 a). The phosphaalkene complex (4 a) and the arsaalkene complex (4 b) are not stable at room temperature and decompose to the complexes [{W(CO)5}4(CH2=E−E=CH2)] (7 a: E=P, 7 b: E=As), which are the first examples of complexes with parent 2,3‐diphospha‐1,3‐butadiene and 2,3‐diarsa‐1,3‐butadiene ligands.
Design, Synthesis, and Application of an Optimized Monofluorinated Aliphatic Label for Peptide Studies by Solid‐State 19F NMR Spectroscopy
Authors: Kokhan Serhii O. , Tymtsunik Andriy V. , Grage Stephan L. , Afonin Sergii , Babii Oleg , Berditsch Marina , Strizhak Alexander V. , Bandak Dmytro , Platonov Maxim O. , Komarov Igor V. , Ulrich Anne S. , Mykhailiuk Pavel K.
Published: October 2016

A conformationally restricted monofluorinated α‐amino acid, (3‐fluorobicyclo[1.1.1]pentyl)glycine (F‐Bpg), was designed as a label for the structural analysis of membrane‐bound peptides by solid‐state 19F NMR spectroscopy. The compound was synthesized and validated as a 19F label for replacing natural aliphatic α‐amino acids. Calculations suggested that F‐Bpg is similar to Leu/Ile in terms of size and lipophilicity. The 19F NMR label was incorporated into the membrane‐active antimicrobial peptide PGLa and provided information on the structure of the peptide in a lipid bilayer.
Graphene oxide‐bound electron‐deficient tin(IV) porphyrin: a highly efficient and selective catalyst for trimethylsilylation of alcohols and phenols with hexamethyldisilazane
Authors: Zarrinjahan Alireza , Moghadam Majid , Mirkhani Valiollah , Tangestaninejad Shahram , Mohammadpoor‐Baltork Iraj
Published: October 2016

The catalytic activity of graphene oxide‐bound tetrakis(p‐aminophenyl)porphyrinatotin(IV) trifluoromethanesulfonate, [SnIV(TNH2PP)(OTf)2], in the trimethylsilylation of alcohols and phenols with hexamethyldisilazane (HMDS) is reported. The prepared catalyst was characterized using inductively coupled plasma analysis, scanning electron microscopy, transmission electron microscopy, and Fourier transform infrared and diffuse reflectance UV–visible spectroscopies. This heterogeneous catalyst was used for selective trimethylsilylation of various alcohols and phenols with HMDS in short reaction times and high yields. Also, the catalyst is of high reusability and stability, in that it was recovered several times without loss of its initial activity. The chemoselectivity of this catalytic system in the silylation of primary alcohols in the presence of secondary and tertiary alcohols and also phenols was investigated.
Heteroleptic Schiff base complexes containing terpyridine as chemical nucleases and their biological potential: A study of DNA binding and cleaving, antimicrobial and cytotoxic tendencies
Authors: Ponya Utthra Ponnukalai , Kumaravel Ganesan , Senthilkumar Raju , Raman Natarajan
Published: October 2016

Amidst the very many metallodrugs for the treatment of cancer regularly reported, the development of the next generation of compounds with an aim of overcoming the shortcomings by enhancing biological activity and cytotoxicity but exhibiting low toxicity is essential. Herein we report such octahedral metal(II) complexes (1–12) containing triazole‐derived Schiff base as the scaffold. The complexes were synthesized and characterized by means of elemental analysis and various spectroscopic techniques. The complexes were subjected to various investigations that involved their interaction with calf thymus DNA and supercoiled pBR322 DNA. In vitro antimicrobial studies were also conducted in addition to the use of spectrophotometric, spectrofluorometric, cyclic voltammetric and hydrodynamic techniques. Although all complexes showed activity, complex 9 revealed excellent DNA proclivity, DNA cleaving tendencies and antimicrobial efficacy. All copper(II) complexes were evaluated for their antiproliferative activity against a panel of human cancer cell lines (HeLa, Hep‐2, MCF‐7 and NHDF). Complexes 1–12 showed activity against all the cell lines with low toxicity towards normal cell line, and the activity of complex 9 towards Hep‐2 was prominent. The effect of the ligand system on the complexes is also discussed along with the importance of tuning the ligand system.
Fabrication of PMMA/zeolite nanofibrous membrane through electrospinning and its adsorption behavior
Authors: Lee Jacky Jia Li , Ang Bee Chin , Andriyana Andri , Shariful Md Islam , Amalina M. A.
Published: October 2016

The present work investigates the effect of various solution parameters and electrospinning parameters on the characteristics of electrospun nanofibrous membranes. Scanning electron microscopy was used to analyze the surface morphology of the nanofibrous membrane. Adsorption test on methyl orange was also carried out and analyzed using the UV–vis. Results showed that increasing voltage decreased mean nanofiber diameter. Meanwhile, increasing PMMA concentration, feed rate, distance between collector‐and‐needle tip increased mean nanofiber diameter. Zeolite concentration and needle size did not affect the surface morphology significantly. The UV–vis spectra of the adsorption test showed that ∼93%, 85.5%, and 78% of methyl orange were adsorbed for 30, 50, and 100 mg L−1 initial dye concentration, respectively, within 11 min. The maximum adsorption capacity was found to be 95.33 mg g−1. Therefore, PMMA/zeolite nanofibrous membranes possess the adsorption capability toward effective dye removal. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44450.
Development and characterization of multilayer films based on polyhydroxyalkanoates and hydrocolloids
Authors: de Andrade Camila Souza , Fonseca Gustavo Graciano , Innocentini Mei Lucia Helena , Fakhouri Farayde Matta
Published: October 2016

New biodegradable polymeric materials have been developed in order to minimize the environmental impact caused by the traditional packaging found in the market. Polyhydroxyalkanoates (PHAs) are biopolymers with important features such as biodegradability and biocompatibility; however, the costs associated with PHAs production and the limited mechanical properties reduce their application. Whey is a residual product from dairy industry and gelatin is a biopolymer with good processing characteristics. In this context, a filmogenic solution based on these two biopolymers was incorporated into pure PHA films to improve their optical, mechanical, and structural properties. The filmogenic solution was prepared from gelatin, cheese whey and PHAs, using glycerol as plasticizer agent. The multilayers films (gelatin concentrations at 3 and 5%, w/v) showed higher values for all properties when compared with the PHA standard film. In this sense, the addition of this solution was responsible for the improvement of the film properties. The 5% gelatin multilayers films added of cheese whey and PHAs showed better results when compared with the multilayers films with gelatin at 3%. The film composed of gelatin 5% and cheese whey showed a water vapor permeability ranging from 0.45 g mm/m2/d/kPa, elongation of 2.18%, and opacity of 14.5%. However, the results of the morphological analysis showed that both films presented a homogeneous surface without cracks. Moreover, the results of the thermal analysis of both films indicate polymeric miscibility. Thus, the choice of the best film will depend on its applicability. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44458.
Antioxidant and physicochemical properties of blended films based on gelatin‐sodium caseinate activated with natural extracts
Authors: Bonilla Jeannine , Sobral Paulo J. A.
Published: October 2016

Blend films of pigskin gelatin (GEL) and sodium caseinate (SCas) with boldo (B), guarana (G), cinnamon (C), or rosemary (R) extracts added were studied. SCas and extracts addition in blend films significantly increased the gloss and better UV barrier of GEL100 films. Extracts incorporation significantly decreased the rigidity and elongation of GEL100 films, which were significantly improved in GEL75:SCas25 blend films with extracts (EM = 295.69 ± 21.75 MPa and EB = 11.60 ± 3.43%). SCas addition not affected the TS parameter. The water vapor permeability of GEL100 films was reduced in blended films with extracts, showing the lowest value for GEL75:SCas25 + R (0.99 ± 0.07 × 1010 g s−1 m−1 Pa−1). FTIR and microstructure analyses showed good compatibility for all components. The antioxidant activity of GEL100 was significantly increased with SCas and extracts addition (GEL50:SCas50 + R = 4.31 ± 0.11 mM), suggesting the application of these films as an active food packaging material. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44467.
Engineering of Poly Lactic Acids (PLAs) for melt processing: Material structure and thermal properties
Authors: Barletta M. , Moretti P. , Pizzi E. , Puopolo M. , Tagliaferri V. , Vesco S.
Published: October 2016

Bottles and other packaging account for approximately 70% of the global market of biopolymers, which include both biodegradable and durable materials. Durable materials account for the vast majority of the market, especially the bottles. Degradable polymers are instead refrained by the often‐insufficient mechanical and thermal properties, which limit their usage to single‐use packaging items at ambient temperature and in dry conditions. In this respect, the present work deals with the development and manufacturing of innovative and custom‐built Poly Lactic Acids (PLAs) for injection and compression molding, which are designed to be compostable, suitable for food contact and characterized by a good compromise of mechanical properties and thermal stability. A commercial grade PLA was, therefore, compounded in a twin‐screw co‐rotating extruder by the addition of maleated and glycidyl methacrylate PLAs as chain extenders and micro‐lamellar talc as mineral filler and nucleation promoter. Compatibilization between PLA, chain extenders and mineral filler was, therefore, investigated. Differential Scanning Calorimetry (DSC) and Fourier Transform Infrared Spectroscopy (FTIR) were performed to evaluate the material structure and thermal response of the pellets after reactive compounding extrusion. The experimental findings show that material structure and, especially, crystallization of the PLA can be controlled by fine‐tuning the compound formulation as well as by setting of the operational parameters. In addition, achievement of the appropriate crystallization degree in the polymer is found to lead to composite materials, which can boast very good thermal stability. Accordingly, the custom‐built PLA formulations feature the potential to expand significantly the fields of application of non‐durable polymers, thus posing a valid alternative to both durable biopolymers and conventional plastics in injection and compression molding process. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44504.
Different perspectives: Spatial ability influences where individuals look on a timed spatial test
Authors: Roach Victoria A. , Fraser Graham M. , Kryklywy James H. , Mitchell Derek G.V. , Wilson Timothy D.
Published: October 2016

Learning in anatomy can be both spatially and visually complex. Pedagogical investigations have begun exploration as to how spatial ability may mitigate learning. Emerging hypotheses suggests individuals with higher spatial reasoning may attend to images differently than those who are lacking. To elucidate attentional patterns associated with different spatial ability, eye movements were measured in individuals completing a timed electronic mental rotation test (EMRT). The EMRT was based on the line drawings of Shepherd and Metzler. Individuals deduced whether image pairs were rotations (same) or mirror images (different). It was hypothesized that individuals with high spatial ability (HSA) would demonstrate shorter average fixation durations during problem solving and attend to different features of the EMRT than low spatial ability (LSA) counterparts. Moreover, question response accuracy would be associated with fewer fixations and shorter average response times, regardless of spatial reasoning ability. Average fixation duration in the HSA group was shorter than LSA (F(1,8) = 7.99; P = 0.022). Importantly, HSA and LSA individuals looked to different regions of the EMRT images (Fisher Exact Test: 12.47; P = 0.018); attending to the same locations only 34% of the time. Correctly answered questions were characterized by fewer fixations per question (F(1, 8) = 18.12; P = 0.003) and shorter average response times (F(1, 8) = 23.89; P = 0.001). The results indicate that spatial ability may influence visual attention to salient areas of images and this may be key to problem solving processes for low spatial individuals. Anat Sci Educ 10: 224–234. © 2016 American Association of Anatomists.
Longitudinal retention of anatomical knowledge in second‐year medical students
Authors: Doomernik Denise E. , van Goor Harry , Kooloos Jan G.M. , ten Broek Richard P.
Published: October 2016

The Radboud University Medical Center has a problem‐based, learner‐oriented, horizontally, and vertically integrated medical curriculum. Anatomists and clinicians have noticed students’ decreasing anatomical knowledge and the disability to apply knowledge in diagnostic reasoning and problem solving. In a longitudinal cohort, the retention of anatomical knowledge gained during the first year of medical school among second‐year medical students was assessed. In May 2011, 346 medical students applied for the second‐year gastro‐intestinal (GI) tract course. The students were asked to participate in a reexamination of a selection of anatomical questions of an examination from October 2009. The examination consisted of a clinical anatomy case scenario and two computed tomography (CT) images of thorax and abdomen in an extended matching format. A total of 165 students were included for analysis. In 2011, students scored significantly lower for the anatomy examination compared to 2009 with a decline in overall examination score of 14.7% (±11.7%). Decrease in knowledge was higher in the radiological questions, compared to the clinical anatomy cases 17.5% (±13.6%) vs. 7.9% (±10.0%), respectively, d = 5.17. In both years, male students scored slightly better compared to female students, and decline of knowledge seems somewhat lower in male students (13.1% (±11.1%) vs. 15.5% (±12.0%), respectively), d = −0.21. Anatomical knowledge in the problem‐oriented horizontal and vertical integrated medical curriculum, declined by approximately 15% 1.5 year after the initial anatomy course. The loss of knowledge in the present study is relative small compared to previous studies. Anat Sci Educ 10: 242–248. © 2016 American Association of Anatomists.
A Surfactant‐Encapsulating Polyoxometalate Nanowire Assembly as a New Carrier for Nanoscale Noble‐Metal Catalysts
Authors: Zhou Wen‐Zhe , Feng Xiao‐Jia , Tan Hua‐Qiao , Shi Hong‐Fei , Wang Yong‐Hui , Gao Shan , Li Yang‐Guang
Published: October 2016

The loading of noble‐metal nanoparticles (NMNPs) onto various carriers to obtain stable and highly efficient catalysts is currently an important strategy in the development of noble metal (NM)‐based catalytic reactions and their applications. We herein report a nanowire supramolecular assembly constructed from the surfactant‐encapsulating polyoxometalates (SEPs) CTAB‐PW12, which can act as new carriers for NMNPs. In this case, the Ag NPs are loaded onto the SEP nanowire assembly with a narrow size distribution from 5 to 20 nm in diameter; the average size is approximately 10 nm. The Ag NPs on the nanowire assemblies are well stabilized and the over agglomeration of Ag NPs is avoided owing to the existence of well‐arranged polyoxometalate (POM) units in the SEP assembly and the hydrophobic surfactant on the surface of the nanowire assembly. Furthermore, the loading amount of the Ag NPs can be adjusted by controlling the concentration of the AgNO3 aqueous solution. The resultant Ag/CTAB‐PW12 composite materials exhibit high activity and good stability for the catalytic reduction of 4‐nitrophenol (4‐NP) with NaBH4 in isopropanol/H2O solution. The NMNPs‐loaded SEP nanoassembly may represent a new composite catalyst system for application in NM‐based catalysis.
Zustandsuntersuchung und Instandsetzung am Hauptdach des Hauses der Kulturen der Welt in Berlin
Authors: Hornig Ute , Rudolph Matthias
Published: October 2016

Das Hauptdach eines wegen seiner Historie und auffälligen Baukonstruktion bekannten Bauwerks – des Hauses der Kulturen der Welt in Berlin – war hinsichtlich seines Zustands zu begutachten und in Bezug auf die Dauerhaftigkeit der vorhandenen Flüssigkunststoffabdichtung zu bewerten. Die Dachkon struktion besteht aus einem zweiachsig gekrümmten Flächentragwerk mit umlaufendem Randbalken aus vorgespanntem Leichtbeton. Sie ist das Ergebnis des Wiederaufbaus von 1984 bis 1987 nach einem Teileinsturz der damaligen Berliner Kongresshalle im Jahr 1980. Die sehr dünne Dachschale besteht ebenfalls aus Leichtbeton und besitzt, wie der Randbalken auch, zum Schutz vor Feuchtezutritt eine eigens für diesen Zweck entwickelte Spritzabdichtung auf Polyurethanbasis. Die Auswahl der zum damaligen Zeitpunkt neuartigen Abdichtung sollte der Tatsache Rechnung tragen, dass die Bauweise des Daches zwingend einen Feuchtigkeitsschutz erfordert, der die erwarteten Formänderungen und Rissbewegungen des Daches schadlos kompensieren muss. Der folgende Beitrag berichtet über Art, Umfang und wesentliche Ergebnisse der Zustands untersuchungen an der Dachabdichtung, den Randbalken und den Widerlagern. Im Weiteren werden die aus den Unter suchungen resultierenden Instandsetzungsempfehlungen, die zum gegenwärtigen Zeitpunkt Grundlage der Bauausführung sind, beschrieben. Neben der Darstellung der technischen Grundlagen und Besonderheiten des Bauwerks, die bei der Instandsetzung berücksichtigt werden müssen, wird auf Besonderheiten der Ausführung eingegangen.
Wirklichkeitsnahe Brandeinwirkungen für die Planung und Nachrechnung von Tunnelschalen
Authors: Burghard Stefan , Fischer Oliver
Published: October 2016

Die verfügbaren numerischen Systeme zur Abbildung von Strömungsprozessen haben mittlerweile einen Entwicklungsstand erreicht, der es erlaubt, auch komplexe Vorgänge, wie z.B. Tunnelbrände, mit einigermaßen vertretbarem Rechenaufwand bereits sehr realistisch abzubilden. Damit besteht einerseits die Möglichkeit, die für den allgemeinen Fall entwickelten Temperatur‐Zeit‐Verläufe der Regelwerke unter tunnelspezifischen individuellen Randbedingungen kritisch zu hinterfragen. Andererseits lassen sich die im Brandfall zu erwartende Temperatur‐ und Rauchentwicklung sowie die Beanspruchung und Schädigung der Tunnelschale ohne die Erfordernis aufwendiger Großbrandversuche relativ wirklichkeitsnah beurteilen. Neben den bei Gewölbetunneln allgemein bestehenden Möglichkeiten einer nichtlinearen Berechnung (Nutzung von Umlagerungsmöglichkeiten) [1] bietet die simulationsgestützte Ermittlung von Brandeinwirkungen insbesondere bei der Nachrechnung bestehender Tunnel in vielen Fällen ein großes Potenzial – vor allem dann, wenn die Berechnung mit Regelbrandkurven umfangreiche Ertüchtigungsmaßnahmen nach sich ziehen würde, obwohl aufgrund der vorliegenden Randbedingungen deutlich geringere Bauteiltemperaturen zu erwarten sind. Im vorliegenden Beitrag werden zunächst Brandereignisse in Tunneln und wesentliche Grundlagen der Herleitung von Temperatur‐Zeit‐Verläufen für die heiße Bemessung von Tunnelschalen diskutiert. Es werden dann die Möglichkeiten, Hintergründe und Grenzen einer Simulation von Brandszenarien mit numerischen CFD‐Modellen erläutert und schließlich über Parameterstudien aufgezeigt, welchen Einfluss die projektspezifischen Randbedingungen (insbesondere die Größe des Tunnelquerschnitts) auf die sich einstellenden Oberflächentemperaturen besitzen können.
Systematic review of active surveillance versus surgical management of asymptomatic small non-functioning pancreatic neuroendocrine neoplasms
Authors: Partelli S , Cirocchi R , Crippa S , Cardinali L , Fendrich V , Bartsch D K , Falconi M
Published: October 2016

Background

The incidence of asymptomatic, sporadic, small non-functioning pancreatic neuroendocrine neoplasms (NF-PNENs) has increased in recent decades. Conservative treatment has been advocated for these tumours. The aim of this study was systematically to evaluate the literature on active surveillance and to compare this with surgical management for asymptomatic sporadic small NF-PNENs.

Methods

PubMed, Embase and the Cochrane Library were searched systematically for studies that compared the active surveillance of asymptomatic, sporadic, small NF-PNENs with surgical management. PRISMA guidelines for systematic reviews were followed.

Results

After screening 3915 records, five retrospective studies with a total of 540 patients were included. Of these, 327 patients (60·6 per cent) underwent active surveillance and 213 (39·4 per cent) had surgery. There was wide variation in the tumour diameter threshold considered as inclusion criterion (2 cm to any size). The median length of follow-up ranged from 28 to 45 months. Measurable tumour growth was observed in 0–51·0 per cent of patients. Overall, 46 patients (14·1 per cent) underwent pancreatic resection after initial conservative treatment. In most patients the reason was an increase in tumour size (19 of 46). There were no disease-related deaths in the active surveillance group in any of the studies.

Conclusion

This systematic review suggests that active surveillance of patients affected by sporadic, small, asymptomatic NF-PNENs may be a good alternative to surgical treatment.
A parsimonious model for locomotor in virtual agents based on dynamical coupling with the environment
Authors: Zaldivar Pino Angel , Gonzalez Bedia Manuel , Seron Arbeloa Francisco José
Published: October 2016

In the domain of virtual agents modeling, computationalist approaches tend to predominate. The lack of plausibility of the rules in nature provides models with a low capacity to generalize and a very limited insight into behavioral phenomena. An alternative view is that behavior could emerge as a whole from the basic principles of non‐linear dynamics that underlie such behavior in the environment. This paper presents a dynamic agent endowed with a sensing device, a controller and actuators to interact with the environment. The control architecture is based on ordinary differential equations with the function of modulating the stimulus signals to action signals under a sensory‐motor flow. The parameter values are defined in an evolutionary process depending on the task to be performed. A series of experiments are presented to illustrate certain qualities of our model such as the adaptability to change, a highly intuitive and flexible design methodology, and a high degree of individual autonomy, among others. We think this kind of modeling is useful in the animation world for modeling flocks, crowds, and swarms as a valid alternative to other less parsimonious techniques.