bluuebunny/crossref_metadata_2025 huggingface dataset:
Programmierter Zelltod bei Bakterien
Authors: Hell Regina , Schumann Wolfgang
Published: December 2017

Die biologische Grundlage des programmierten Zelltodes (programmed cell death, PCD) der Bakterien sind zwei Moleküle, ein stabiles Protein‐Toxin und ein instabiles Antitoxin welches permanent synthetisiert werden muss. Beide Komponenten zusammen werden als TA‐Modul bezeichnet. Wird die Synthese des Antitoxins blockiert oder wird es abgebaut, dann übt das nun freie Toxin entweder eine bakteriostatische oder eine bakterizide Wirkung aus. PCD kann sich auch auf andere Zellen auswirken und dort zu Kannibalismus und Geschwistermord führen. Zum Schluss werden zwei Beispiele der Anwendung von TA‐Modulen in der Biotechnologie beschrieben.
Rückkopplungseffekte zwischen dem Bodenmikrobiom und Pflanzen
Authors: Sander Johannes
Published: December 2017

Die Biodiversität von Pflanzengemeinschaften wird auch von den Mikroorganismen und Kleintieren im Boden beeinflusst: Pathogene und Herbivore können die Etablierung von Jungpflanzen verhindern. Mykorrhizapilze wiederum können sie fördern. Zwei aktuelle Studien haben jetzt die entsprechenden Rückkopplungseffekte im australischen Buschland und in Laubwäldern Nordamerikas untersucht und lieferten dabei neue Erkenntnisse zum Wechselspiel zwischen Bodenmikroorganismen und Pflanzen.
Nachrichten des Verbandes Biologie, Biowissenschaften & Biomedizin in Deutschland
Authors: Lipphardt Veronika , Staubach Fabian
Published: December 2017

Ausbildung & Karriere

Jetzt bewerben: Ars legendi‐Fakultätenpreis Mathematik und Naturwissenschaften 2018

Bündnis TA legt Forderungskatalog vor

Wissenschaft & Gesellschaft

Neue Kooperation mit der Initiative „Tierversuche verstehen“

Digitale Sequenzdaten

Nach der Bundestagswahl

Landesverbände

Nordrhein‐Westfalen
Homoleptic Iridium(III) Compounds Bearing Bulky Bipyridine Ligand for Potential Application to Organic Light‐emitting Diodes
Authors: Kim Myeongbee , Park Joohye , Oh Hoonseok , Ryu Yeonjin , Kang Youngjin
Published: December 2017

Two sky‐blue phosphorescent iridium compounds, fac‐tris(2′,6′‐diisopropoxy‐2,3′‐bipyridinato)‐N,C
4)Ir(III) (1) and fac‐tris(2′,6′‐diisopropoxy‐4‐tert‐butyl‐2,3′‐bipyridinato)‐N,C
4)Ir(III) (2), were synthesized by a one‐pot reaction of a reactive Ir(I) compound with a corresponding bipyridine ligand, to investigate their photophysical and electrochemical properties for potential application to white organic light‐emitting diodes (WOLEDs). Their structures were confirmed by varied spectroscopic methods. Results indicated that both compounds possess facial geometry. The absorption, emission, thermal stability, and electrochemical properties were also investigated systematically. The two compounds showed sky‐blue emission with λmax = 462–463 nm; their photoluminescence quantum efficiencies relative to that of FIrpic were ~0.3–0.4. Compound 2 with a bulky substituent displayed the suppression of concentration quenching at high concentration, and its emission was less shifted to longer wavelengths compared to compound 1. Owing to the bulky substituent, the quantum efficiency of 2 is higher than that of its nonsubstituted counterpart. Therefore, the introduction of the bulky substituent in the ligand framework is an important strategy for developing high‐efficiency blue phosphorescent materials. The two compounds developed in this study show high thermal and electrochemical stability, making them suitable candidates for OLED applications.
Environmental Policy, Sustainable Development, Governance Mechanisms and Environmental Performance
Authors: Haque Faizul , Ntim Collins G
Published: December 2017

We investigate the effects of environmental policy (Climate Change Act – CCA), sustainable development frameworks (Global Reporting Initiative – GRI; UN Global Compact – UNGC) and corporate governance (CG) mechanisms on environmental performance (carbon reduction initiatives – CRIs; actual carbon performance – GHG emissions) of UK listed firms. We use the generalized method of moments (GMM) estimation technique to analyse data consisting of 2245 UK firm‐year observations over the 2002–2014 period. First, we find that the CCA has a positive effect on CRIs, and this effect is stronger in better‐governed firms. Second, we find that the GRI‐based framework is positively associated with CRIs. Third, we find that firms with poor CG structures have lower actual carbon performance compared with their better‐governed counterparts. Overall, our evidence suggests that firms can symbolically conform to environmental policy (CCA) and sustainable development frameworks (GRI, UNGC) by engaging in CRIs without necessarily improving actual environmental performance (GHG emissions) substantively. Copyright © 2017 John Wiley & Sons, Ltd and ERP Environment
Resource Recovery from Low‐Grade Ore Deposits and Mining Residuals by Biohydrometallurgy and Membrane Technology. Potentials and Case Studies
Authors: Werner Arite , Meschke Katja , Bohlke Kevin , Daus Birgit , Haseneder Roland , Repke Jens‐Uwe
Published: December 2017

The recovery of strategic elements from secondary mineral sources and low‐grade ores is of increasing relevance due to a changing global market as well as for reasons of sustainability. The present article shows the potential of biohydrometallurgy as an effective technology for mobilization of metals from secondary sources. Furthermore, the application of membrane separation as a successful technique to recover metals from bioleaching solutions is presented. These issues are discussed within the scope of recent research projects.
Preparation of Keggin‐Type Polyoxometallate/Polypyrrole Composite Microtubes and Their Assist‐Catalytic Properties Towards Methanol Oxidation
Authors: Yuan Yue , Li Guangzhe , Ding Yanhong , Shilf Khan , Zhou Wanli , Peng Jun
Published: December 2017

Polypyrrole@M‐SiW12 (M=Fe3+, Cu2+) composite microtubes were obtained through the in situ chemically oxidative polymerization of pyrrole (Py) to polypyrrole (Ppy) in M‐SiW12 microtubes with oxidants Fe3+ andCu2+ doped into polyoxometallate (POM) microtubes. The biggest oxidation peak current obtained from the Pt/C/PPy@Cu‐SiW12/glassy carbon electrode was 3.5 mA. PPy@M‐SiW12 microtubes provide a new catalyst supporter for the Pt/C catalyst, and present good electrocatalytic activity toward methanol oxidation, perhaps owing to a synergy effect coming from PPy and POM.
Sandwich‐Like Nanosheets of a N‐Doped Porous Carbon/Graphene Composite with Enhanced Electrochemical Properties for Lithium and Sodium Storage
Authors: Qin Weiwei , Teng Yongqiang , Zhang Junke , Xiao Xinfeng , Li Yuan , Li Zhenyu
Published: December 2017

Energy storage systems, including lithium‐/sodium‐ion batteries (LIBs/SIBs), are important for being able to use renewable energies efficiently. The anode material is a vital link in the great industrialization chain. Herein, a sandwich‐like N‐doped porous carbon/graphene (N‐HCG) composite has been successfully achieved by using a facile and low‐temperature liquid‐phase method with melamine as the nitrogen source, followed by a carbonization process. The composite possesses a high specific surface area of 282.4 m2 g−1. As an anode in lithium‐ion batteries, N‐HCG delivers a capacity of 643 mAh g−1 at 100 mA g−1, and a high capacity of 406 mAh g−1 is maintained even at 5 A g−1 after 2700 cycles. For sodium‐ion batteries, the obtained capacities of the N‐HCG electrodes are 208 mAh g−1 (100 mA g−1 for 120 cycles) and 145 mAh g−1 (1000 mA g−1 for 700 cycles). The excellent electrochemical performance including the rate capability and lifespan of N‐HCG can be attributed to the synergistic effects of the 2D sandwich‐like nanosheets with pores and extrinsic nitrogen doping. Thus, the as‐prepared N‐HCG composite is a highly promising anode material for LIB/SIB applications.
Prostate cancer screening with prostate‐specific antigen: Where are we going?
Authors: Albertsen Peter C.
Published: December 2017

Current prostate‐specific antigen screening is not cost‐effective from a public health perspective. A new algorithm using genetic testing and imaging has yet to be developed.

See also pages 507‐13.
Comparative effectiveness of prostate cancer screening between the ages of 55 and 69 years followed by active surveillance
Authors: de Carvalho Tiago M. , Heijnsdijk Eveline A. M. , de Koning Harry J.
Published: December 2017

BACKGROUND

Because of the recent grade C draft recommendation by the US Preventive Services Task Force (USPSTF) for prostate cancer screening between the ages of 55 and 69 years, there is a need to determine whether this could be cost‐effective in a US population setting.

METHODS

This study used a microsimulation model of screening and active surveillance (AS), based on data from the European Randomized Study of Screening for Prostate Cancer and the Surveillance, Epidemiology, and End Results Program, for the natural history of prostate cancer and Johns Hopkins AS cohort data to inform the probabilities of referral to treatment during AS. A cohort of 10 million men, based on US life tables, was simulated. The lifetime costs and effects of screening between the ages of 55 and 69 years with different screening frequencies and AS protocols were projected, and their cost‐effectiveness was determined.

RESULTS

Quadrennial screening between the ages of 55 and 69 years (55, 59, 63, and 67 years) with AS for men with low‐risk cancers (ie, those with a Gleason score of 6 or lower) and yearly biopsies or triennial biopsies resulted in an incremental cost per quality‐adjusted life‐year (QALY) of $51,918 or $69,380, respectively. Most policies in which screening was followed by immediate treatment were dominated. In most sensitivity analyses, this study found a policy with which the cost per QALY remained below $100,000.

CONCLUSIONS

Prostate‐specific antigen–based prostate cancer screening in the United States between the ages of 55 and 69 years, as recommended by the USPSTF, may be cost‐effective at a $100,000 threshold but only with a quadrennial screening frequency and with AS offered to all low‐risk men. Cancer 2018;124:507‐13. © 2017 American Cancer Society.
Dopamine drives left‐hemispheric lateralization of neural networks during human speech
Authors: Fuertinger Stefan , Zinn Joel C. , Sharan Ashwini D. , Hamzei‐Sichani Farid , Simonyan Kristina
Published: December 2017

Although the concept of left‐hemispheric lateralization of neural processes during speech production has been known since the times of Broca, its physiological underpinnings still remain elusive. We sought to assess the modulatory influences of a major neurotransmitter, dopamine, on hemispheric lateralization during real‐life speaking using a multimodal analysis of functional MRI, intracranial EEG recordings, and large‐scale neural population simulations based on diffusion‐weighted MRI. We demonstrate that speech‐induced phasic dopamine release into the dorsal striatum and speech motor cortex exerts direct modulation of neuronal activity in these regions and drives left‐hemispheric lateralization of speech production network. Dopamine‐induced lateralization of functional activity and networks during speaking is not dependent on lateralization of structural nigro‐striatal and nigro‐motocortical pathways. Our findings provide the first mechanistic explanation for left‐hemispheric lateralization of human speech that is due to left‐lateralized dopaminergic modulation of brain activity and functional networks.
Tuning the Color Temperature of White‐Light‐Emitting Electrochemical Cells by Laser‐Scanning Perovskite‐Nanocrystal Color Conversion Layers
Authors: Wu Wen‐Kuang , Wang Cheng‐Ming , Chan Ming‐Che , Lien Jiun‐Yi , Su Yong‐Ming , Sarma Monima , Yang Zu‐Po , Su Hai‐Ching , Wong Ken‐Tsung , Wang Sue‐Lein
Published: December 2017

The development of white‐light‐emitting electrochemical cells (LECs) has attracted great attention owing to their numerous advantages. Recently, perovskite materials have also shown many outstanding optoelectronic properties in light absorption and emission, and hence they are suitable for serving as the color conversion layers (CCLs) in solid‐state white‐light‐emitting diodes (LEDs). Here, white LECs were fabricated by integrating non‐doped blue‐green LECs with CCLs made of a single composition of perovskite nanocrystal (NCs). Moreover, the correlated color temperatures (CCTs) of the white LECs can be tuned by modifying the optical properties of the perovskite NCs, in the same way as so as the color conversion properties of CCLs are tuned, through laser scan. By controlling the laser power, scanning number, and duty cycle of the scanned grating patterns on perovskite‐NC CCLs, the CCTs of the white LECs can be tuned from 2502 K to nearly 4300 K. Since this method is much different from that used with conventional CCLs, which use multiple compositions of perovskite NCs to produce white light, the inherent anion‐exchange issue of perovskite NCs can be avoided.
Both canopy and understory traits act as response–effect traits in fire‐managed forests
Authors: Refsland Tyler K. , Fraterrigo Jennifer M.
Published: December 2017

Community‐level shifts in the distributions of plant functional traits associated with environmental change are expected to influence ecosystem functioning. However, few studies have identified traits that both respond to environmental change and affect ecosystem properties, thus limiting potential to scale the effects of environmental change through the community level. We measured canopy and understory plant functional traits, characterizing the most abundant functional trait value (community‐weighted mean; CWM) and the functional diversity (FD), across a soil resource gradient in fire‐managed mixed‐deciduous forests to determine how traits both respond to a disturbance‐resource gradient and affect stocks of active and stable soil organic carbon (SOC) fractions. We expected that understory traits would respond mainly to fire and canopy traits would respond mainly to soil resources. We further hypothesized that fire and resource conditions affect SOC stocks (1) through mass‐ratio, by influencing trait abundance; (2) through non‐additive effects, by influencing the FD of plant communities; or (3) directly, through either combustion or environmental controls on SOC stocks. Understory traits responded to soil resource conditions and fire, whereas only canopy CWM leaf dry matter content (LDMC) varied with resource conditions; no canopy traits varied with fire. Among the response traits, canopy CWM LDMC and diversity in the maximum height of the understory were related to SOC stocks, suggesting they play dual roles as response and effect traits. SOC stocks were primarily associated with mass‐ratio effects from canopy leaf traits and secondarily with non‐additive effects from the canopy and understory. There were also strong, fraction‐dependent patterns in SOC stocks with fire disturbance. Repeatedly burned forests characterized by resource conservative traits (i.e., high canopy CWM LDMC) had a higher relative proportion of active SOC, whereas unburned forests characterized by resource acquisitive traits (i.e., high canopy CWM leaf nitrogen content) had a higher relative proportion of stable SOC. Our results suggest that canopy community‐aggregated leaf traits and diversity in understory size traits can act as both response and effect traits in disturbed forests. Predicting forest SOC stocks using a response–effect trait framework will thus require knowledge of both canopy and understory trait distributions, as well as disturbance history.
Catalytic Activity of Microbially‐formed Palladium Nanoparticles
Authors: Yang Sarah A. , Nordmeier Akira , Chidambaram Dev
Published: December 2017

The catalytic behavior of microbially‐formed palladium nanoparticles using Clostridium pasteurianum BC1 is reported. To our knowledge, this is the first study that evaluates the electrochemical catalytic activity of microbially‐formed palladium nanoparticles. Pd nanoparticles formed using immobilized microbes were found to exhibit an average mass activity of 177 mA mg−1 which was almost twice the activity of the abiotically formed controls (94 mA mg−1). The results of this study aim to support the use of nanoparticles formed using facile and environmentally‐friendly microbial synthesis methods as a suitable alternative as opposed to standard physical and chemical synthesis methods.
Determination of Benzocaine and Tricaine in Fish Fillets Using BIA with Amperometric Detection
Authors: de Lima Rafael Machado Felix , de Oliveira Silva Michele Dorcília , Felix Fabiana Silva , Angnes Lucio , dos Santos Wallans Torres Pio , Saczk Adelir Aparecida
Published: December 2017

A system based on batch injection analysis (BIA) associated with amperometric detection at screen‐printed carbon electrode was used for the precise and rapid quantification of the anesthetics compounds benzocaine and tricaine in fresh fish fillets. Along this study, the best conditions for the BIA‐amperometry system were stablished for the rapid determination of these compounds. The results obtained demonstrate that the proposed method is an interesting alternative to the chromatographic methods, once it allows to perform rapid analysis (more than 300 injections per hour) with low limits of detection (3.02×10−8 mol L−1 for benzocaine and 3.19×10−8 mol L−1 for tricaine), using just 80 μL of sample for each analysis. Furthermore, it was possible to obtain high repeatability for both compounds analyzed, demonstrating good performance. The simple sample preparation developed in this study drastically reduced the amount of fat in the fish extract, favoring precision, as shown by the results of the recovery studies of both anesthetics contained in the fish samples (values above 99 % for both analytes).
Power Generation versus Conventional Potentiostatic Operation of Prussian Blue Based (Bio)Sensors
Authors: Komkova Maria A. , Karyakina Elena E. , Karyakin Arkady A.
Published: December 2017

We report on Prussian Blue based (bio)sensors displaying advantageous analytical performance characteristics when operated both in conventional three‐electrode regime powered by potentiostat and in power generation mode. ‘Self‐powered’ sensors are commonly aimed to produce sufficient energy for signalling and, thus, being energetically autonomous. In order to generate maximum energy output, the electrodes with high potential difference are preferable. In contrast, we propose the systems with the lowest potential difference between the working and the counter electrodes. Short‐circuiting the Prussian Blue modified working and the Ag|AgCl reference electrode, working electrode potential is adjusted to 0.00 V without potentiostat. The efficiency of the (bio)sensors in power generation mode is achieved due to high catalytic activity of Prussian Blue at 0.00 V versus Ag|AgCl reference. Here we discuss the benefits of the Prussian Blue based (bio)sensors operated through power generation in a short‐circuit regime without potentiostat, including an order of magnitude decreased noise and simplified readout. The multimodality of the sensors would provide their versatile functionality for the electroanalysis and elaboration of miniature highly sensitive wearable devices.
Nano‐species Release System Activated by Enzyme‐based XOR Logic Gate
Authors: Filipov Yaroslav , Gamella Maria , Katz Evgeny
Published: December 2017

An enzyme‐based XOR logic gate was realized at interface of an alginate‐modified electrode. The biocatalytic production of H2O2 inside the alginate film was controlled by logically processed input signals. The in situ generated H2O2 was decomposed to yield free radicals in a Fenton‐type reaction catalyzed by iron cations, which were present in the alginate film as cross‐linkers stabilizing the hydrogel. The produced free radicals (•OH, •OOH) resulted in decomposition/dissolution of the alginate film removing it from the electrode surface and stimulating release process of magnetic nanoparticles (MNPs) functionalized with a fluorescent dye and entrapped in the alginate film. The release of the MNPs was analyzed by following fluorescence appearing in the solution. The release process followed the logic features of the XOR gate. The present system is the first realization of the enzyme‐based XOR gate functionally integrated with the downstream actuation process in the form of the signal‐stimulated release.
Direct determination of amino acids in brewery worts produced by different processes by capillary zone electrophoresis
Authors: Corrêa de Carvalho Renata , Rocha dos Santos Mathias Thiago , Duarte Pereira Netto Annibal , Ferreira de Carvalho Marques Flávia
Published: December 2017

The direct and simultaneous determination of cysteine, histidine, phenylalanine, lysine, tryptophan and arginine in brewery worts by capillary zone electrophoresis (CZE) was applied to evaluate the effects of temperature control and protease supplementation during mashing on the changes of these amino acids (AAs) wort composition. A cation exchange resin was used for AAs extraction from wort samples prior to CZE determination. The separation was achieved using a 50 mmol/L phosphate buffer at pH 12.5, containing 0.4 mmol/L cetyltrimethylammonium bromide (CTAB), as background electrolyte (BGE) solution; −20 kV; 20°C and hydrodynamic injection time of 15 s, at 50 mbar. Recovery evaluation using worts led to values between 83.1 and 96.2%, demonstrating the method feasibility, which was successfully applied in the quantification of AAs in wort samples. This study showed that temperature control and addition of exogenous proteases in the mashing may increase the AAs concentration in wort, improving the final product quality (beer). The present method is a good alternative for monitoring specific AAs in worts and their determination can allow the brewing process optimization.
Effect of residual rice husk ash on mechanical‐microstructural properties and thermal conductivity of sodium‐hydroxide‐activated bricks
Authors: Huynh Trong‐Phuoc , Hwang Chao‐Lung , Lin Kae‐Long , Ngo Si‐Huy
Published: December 2017

This research compares the mechanical‐microstructural properties and thermal conductivity of the solid, green construction bricks that contain different percentages of sodium‐hydroxide‐activated residual rice husk ash and class‐F fly ash. The brick specimens were prepared following the guidelines of Vietnamese national standard in term of mixing, forming, and curing. Various percentages of rice husk ash (0%, 10%, 20%, 30%, 40%, and 50%) were added to a standard brick mixture in order to evaluate the influence of rice husk ash content on the strength development, void volume, water absorption capacity, bulk density, and thermal conductivity of the hardened bricks. Moreover, scanning electron microscopy was used to characterize surface morphologies of the brick samples. Further, the suitability of using a binder of rice husk ash and fly ash to produce alkali‐activated construction bricks was investigated. The bricks that were produced demonstrated generally good engineering performance and conformed to the relevant Vietnamese codes. Of particular note, the addition of rice husk ash influenced the properties of the bricks significantly, with brick strength peaking at a rice husk ash content of 10% and decreasing progressively at higher percentages. The findings from the present study support the efficacy of using a binder that contains rice husk ash and fly ash to produce green alkali‐activated construction bricks. © 2017 American Institute of Chemical Engineers Environ Prog, 37: 1647–1656, 2018
Rigorous modeling of gas permeation behavior in facilitated transport membranes (FTMs); evaluation of carrier saturation effects and double‐reaction mechanism
Authors: Ebadi Amooghin Abtin , Moftakhari Sharifzadeh Mohammad Mehdi , Zamani Pedram Mona
Published: December 2017

In this work, a general model for the gas permeation behavior of facilitated transport membranes (FTMs) has been developed. The importance of developing a clearer understanding of FTM permeation behavior by introducing a detailed two‐dimensional FTM model was demonstrated. This model accounts for the effects of partial pressure on permeance by considering the carrier saturation‐state phenomenon and reaction‐diffusion portions in FTMs. The model is based on a first order double‐step reaction mechanism with respect to the role of the concentration of zwitterion ions in the facilitated transport of CO2. It is shown here that the individual values of reaction constant rates and diffusion coefficients of components in the chemical reaction, which belong to the FTM condition, have been determined by the FTMs’ permeability and were not guessed or calculated. Overall, this work provides a method for the more reliable use of models to understand and design of FTMs, and to better comprehend the large and growing body of experimental data on these kinds of membranes. © 2017 Society of Chemical Industry and John Wiley & Sons, Ltd.
Migration and accumulation of crude oil in Upper Triassic tight sand reservoirs on the southwest margin of Ordos Basin, Central China: A case study of the Honghe Oilfield
Authors: Jia Jingkun , Yin Wei , Qiu Nansheng , Wang Guangli , Ma Liyuan , Liu Yuchen , Liu Nian
Published: December 2017

The Upper Triassic tight sand oil in the Ordos Basin has gradually become a focus of research; however, compared to the centre of the basin, studies on the margin have been relatively weak. In this study, an integrated approach involving oil–source correlation, charge history, and pressure evolution is used to investigate the migration characteristics of each stage and to establish a migration and accumulation process model of the tight sand oil in the Yanchang Formation of Honghe Oilfield in combination with reservoir densification process. The results show that, based on the fluid inclusion analysis and authigenic illite K–Ar dating technique in combination with burial and thermal modellings, the accumulation periods were 145–130, 120–90, and 90–80 Ma, which corresponds to the Cretaceous. According to the relative content of C30‐diahopane and drimane series compounds, the crude oil from Chang 8(T3ch8) and Chang 9(T3ch9) both originated from the oil shale of Chang 7(T3ch7) in the Upper Triassic Yanchang Formation. The migration characteristics and directions are comprehensively analyzed using the maturity parameters and key elements. In the early stage of the Early Cretaceous, with east‐dipping strata, crude oil migrated from northeast to southwest. During the late Early Cretaceous, the middle‐late Yanshanian movement promoted the development of strike‐slip faults and fractures, and the oil migrated vertically downwards along them. Tectonic inversion changed the strata dip direction to west‐dipping, and lateral migration was also changed to two directions of southwest and northeast. After the Late Cretaceous, the migration dynamics weakened due to strata uplift and cessation of hydrocarbon generation. Only slight adjustments to the crude oil occurred during the Himalayan movement; therefore, the current distribution pattern of the tight sand oil is still affected primarily by the stage of late Early Cretaceous. The migration and accumulation model of the Upper Triassic in the Honghe Oilfield, Ordos Basin, provides a theoretical basis for further exploration and is of general applicability to tight sand reservoirs in the margins of various basins.
Why does repatriate career success vary? An empirical investigation from both traditional and protean career perspectives
Authors: Breitenmoser Anika , Bader Benjamin , Berg Nicola
Published: December 2017

To increase the long‐term benefits of global mobility for multinational corporations, international assignments and intraorganizational careers must be strategically integrated. However, systematic research on former expatriates' career success upon returning to their home organization remains scarce. Hence, this study transfers findings from the career literature to the repatriation context to identify the predictors of objective and subjective repatriate career success. Integrating traditional and protean career theory, we investigate data from 295 repatriates of publicly listed German organizations. Applying partial least squares structural equation modeling, we reveal that objective career success upon repatriation is affected by international assignment characteristics with human capital implications, repatriation support provided by the organization, and the individual's self‐directed career management. Objective career success, organizational repatriation support, and self‐directed career management further affect subjective career success in terms of career satisfaction. Hence, substantiating an impact of both traditional and protean career factors on repatriate careers, our results lay the groundwork for repatriation strategies that combine organizational and individual career management. In this way, multinational corporations can go beyond managing repatriate elites to make better use of all globally experienced employees.
Profiling and characterization of microRNAs responding to sodium butyrate treatment in A549 cells
Authors: Xiao Xiaoqiang , Cao Yingjie , Chen Haoyu
Published: December 2017

Butyrate inhibits growth of lung cancer. However, the molecular mechanism is still unclear. Here we profiled miRNAs that responded to sodium butyrate(NaB) stimulation in A549 cells, a non‐small cell lung cancer cell line, using microarray. We found 33 up‐regulated microRNAs and 22 down‐regulated microRNAs (log2 ≥1.5 folds, P‐value <0.05). The expression of miR‐3935, miR‐574‐3p, and miR‐494‐3p was confirmed by realtime qPCR. Then,we explored their potential targets of miR‐3935 and miR‐494‐3p using long noncoding RNA(LncRNA) microarray. Using cell expressing negative microRNA as control, we found 103 up‐regulated transcripts (including 69 mRNA and 34 LncRNA), and 36 down‐regulated transcripts (including 34 mRNAs and 2 LncRNA), in miR‐3935 over‐expressing A549 cells; 128 up‐regulated transcripts (121 mRNAs, 7 LncRNAs) and 180 down‐regulated transcripts (169 mRNAs, 11 LncRNAs) in mir‐494‐3p, respectively (log2 Fold change ≥ 1 & P < 0.05). The expression of RNF115, NTRK3, SLC39A6, and USB1 was confirmed with qPCR. Immunoblotting was adopted to detect RNF115 expression in miR‐3935 overexpressed A549 cells. Then, using a luciferase reporter assay system, we found that miR‐3935 overexpression significantly decreased 3UTR of RNF115 mediated luciferase expression .In addition, we also observed that the proliferation and migration of A549 cells was obviously prevented by miR‐3935 overexpression. Finally, we showed miR‐3935 and miR‐494‐3p induced interferon stimulated gene 15(ISG15) expression through activating its promoter transcription. Together, we profiled microRNAs that responded to NaB treatment and characterized their biological functions in A549 cells. Those results provided new clue for the future treatment of non small cell lung cancer.
NES1/KLK10 promotes trastuzumab resistance via activation of PI3K/AKT signaling pathway in gastric cancer
Authors: Tang Laiqin , Long Zhiguo , Zhao Na , Feng Guangjia , Guo Xianzhi , Yu Minghua
Published: December 2017

Trastuzumab, a humanized antibody targeting human epidermal growth factor receptor 2 (HER2), exhibits remarkable therapeutic efficacy against HER2‐positive gastric cancer. Acquired resistance to trastuzumab remains a barrier to patient survival and the mechanisms underlying this are still not well understood. The normal epithelial cell‐specific‐1 (NES1) gene, also named as KLK10, is recognized as a potential therapeutic target for reversing trastuzumab resistance. The aim of this study was to explore the potential role of KLK10 in trastuzumab resistance (TR) gastric cancer cells. We found that KLK10 was significantly upregulated in trastuzumab‐resistant cell lines, SGC7901‐TR and BGC‐823‐TR. In addition, down regulation of KLK10 reversed the resistance in trastuzumab resistant cells. Overexpression of KLK10 induced trastuzumab resistance, and activated the PI3K/AKT signaling pathway, while downregulation of KLK10 presented the opposite effects. Moreover, when the PI3K/AKT signaling pathway was inhibited, the effect of KLK10 on resistance was diminished. Furthermore, combination of trastuzumab and PI3K/AKT inhibitor XL147 effectively inhibited tumor growth in KLK10‐overexpressing xenografts. Taken together, our findings show that KLK10 promotes trastuzumab resistance, at least in part, through the PI3K/AKT signaling pathway, suggesting that KLK10 is a potentially target to overcome trastuzumab resistance, and the combination might overcome trastuzumab resistance in KLK10‐overexpressed gastric cancer patients.
Molecular mechanisms of tributyltin‐induced alterations in cholesterol homeostasis and steroidogenesis in hamster testis: In vivo and in vitro studies
Authors: Kanimozhi Veerasamy , Palanivel Kandasamy , Akbarsha Mohammad A. , Kadalmani Balamuthu
Published: December 2017

Tributyltins (TBT) are ubiquitous and persistent environmental contaminants that disturb normal endocrine function including gonadal function in humans and marine organisms. TBT was administered through oral route to male Syrian hamsters at daily doses of 50, 100, and 150 ppm/kg for 65 days. Changes in testis morphology, immunohistochemistry of iNOS, 3β‐HSD, and 17β‐HSD, cholesterol transport receptor, nuclear receptors, and transcription factors were analyzed. TBT treatment affected each of these parameters to significant levels in a dose‐dependent manner compared to vehicle treated control. Real‐time PCR and protein analyses revealed that expression levels of ApoE and LDL‐R mRNA were up‐regulated in the testis of TBT‐treated animals while the expression levels of SR‐B1, LXR, PPARs α, β, and γ, SCAP, SREBP 1 and 2, 3β‐HSD, 17β‐HSD, CYP17A1, and P450SCC were down‐regulated. Leydig cells were isolated and separated adopting percoll gradient centrifugation under aseptic condition. The viability of Leydig cell was affected by TBT treatment in a dose‐ and time‐dependent manner. Further, the mechanism of action of TBT was ascertained by siRNA transfection of ApoE, which was upregulated, and SREBP, which was down‐regulated. These observations led us to infer that exposure to TBT hinders intracellular cholesterol transport resulting in abnormal sex steroid biosynthesis and alteration of steroidogenic enzyme activities. Finally, we could recognize ApoE and SREBP as the major factors regulating genes that control cholesterol biosynthesis and steroidogenesis that ultimately inhibit the synthesis of testosterone. Therefore, ApoE is one of the important molecular targets that can be intercepted in context of male infertility/male contraception.
Molecular dynamics insights into the structure, function, and substrate binding mechanism of mucin desulfating sulfatase of gut microbe Bacteroides fragilis
Authors: Praharaj Ardhendu Bhusan , Dehury Budheswar , Mahapatra Namita , Kar Shantanu Kumar , Behera Santosh Kumar
Published: December 2017

The complex and dynamic consortia of microbiota that harbors the human gastrointestinal tract contributes ominously to the maintenance of health, the onset and progression of diverse spectrum of disorders. The capability of these enteric microbes to bloom within the gut mucosal milieu is often associated to the glycan metabolism of mucin‐degrading bacteria. Accruing evidences suggests that the desulfation of mucin is a rate‐limiting step in mucin degradation mechanism by colonic bacterial mucin‐desulfating sulfatase enzymes (MDS) enzymes. Till date no experimental evidence is available on how conformational flexibility influences structure and substrate specificity by MDS of gut microbe Bacteroides fragilis. Henceforth, to gain deep insights into the missing but very imperative mechanism, we performed a comprehensive molecular dynamics study, principal component analysis and MM/PBSA binding free energies to gain insights into (i) the domain architecture and mode of substrate binding (ii) conformational dynamics and flexibility that influence the orientation of substrate, (iii) energetic contribution that plays very decisive role to the overall negative binding free energy and stabilities of the complexes (iv) critical residues of active site which influence binding and aid in substrate recognition. This is the first ever report, depicting the molecular basis of recognition of substrates and provides insights into the mode of catalysis by mucin desulfating sulfatase enzymes in gut microbiota. Overall, our study shed new insights into the unmapped molecular mechanisms underlying the recognition of various substrates by mucin desulfating sulfatase, which could be of great relevance in therapeutic implications in human gut microbiota associated disorders.
GANT‐61 and GDC‐0449 induce apoptosis of prostate cancer stem cells through a GLI‐dependent mechanism
Authors: Tong Wangxia , Qiu Lei , Qi Meng , Liu Jianbing , Hu Kaihui , Lin Wenxiong , Huang Yan , Fu Junsheng
Published: December 2017

Aberrant reactivation of the Sonic Hedgehog (SHH) signaling pathway promotes prostate cancer (PC) growth and progression by regulating cancer‐related genes through its downstream effectors GLI1 and GLI2. Therefore, targeting the SHH‐GLI pathway provides an alternative approach to avoid cancer progression. The aim of this study was to delineate the underlying molecular mechanisms by which GDC‐0449 (a SMO receptor inhibitor) and GANT‐61 (a GLI transcription factor inhibitor) regulate cellular proliferation and self‐renewal in human PC stem cells (ProCSCs). Inhibition of the SHH signaling pathway by GANT‐61 induced apoptosis with more efficacy than by GDC‐0449 in ProCSCs and PC cell lines. GLI1 and GLI2 expression, promoter‐binding activity and GLI‐responsive luciferase reporter activity were all decreased with either GDC‐0449 or GANT‐61 treatment. Expression of Fas, DR4, DR5, and cleavage of caspase‐3 and PARP were increased, whereas levels of PDGFR‐α and Bcl‐2 were reduced. Double knockout of GLI1 and GLI2 using shRNA abolished the effects observed with either GDC‐0449 or GANT‐61 treatment. Collectively, our results showed that GANT‐61 and GDC‐0449 induced ProCSC apoptosis by directly or indirectly inhibiting the activities of the GLI family transcription factors, may enhance the efficacy of PC treatment.
SIRT7 depletion inhibits cell proliferation, migration, and increases drug sensitivity by activating p38MAPK in breast cancer cells
Authors: Chen Kun‐Lin , Li Lian , Yang Fang‐Xiao , Li Cheng‐Min , Wang Yi‐Ru , Wang Gen‐Lin
Published: December 2017

SIRT7 is a member of the sirtuin family of proteins that are known to be associated with tumor development. However, the functional roles and molecular mechanisms underlying the function of SIRT7 in breast cancer cell survival and tumor development remain unclear. Recent studies demonstrated that SIRT7 is upregulated in breast cancer cells and tissues. In the present study, we systematically explored the roles of SIRT7 in the growth of breast cancer cells and tumors both in vitro and in vivo. Our results showed that SIRT7 plays a major role in facilitating cell survival by promoting cell proliferation and inhibiting apoptosis. SIRT7 depletion significantly inhibited cell invasion and wound healing by blocking cell cycle progression and inducing cell apoptosis. Meanwhile, SIRT7 depletion can increase the sensitivity of breast cancer cells to doxorubicin (DOX). Xenograft model studies showed that stable silencing of SIRT7 inhibited tumor growth and enhanced tumor sensitivity to DOX. Further research revealed that p38MAPK is involved in SIRT7‐mediated regulation of breast cancer cell proliferation and tumor growth. Taken together, our results showed that SIRT7 plays a critical role in breast cancer cell survival, migration, and tumor growth, and increased the efficiency of DOX treatment both in vitro and in vivo. Therefore, SIRT7 is a promising therapeutic target in breast cancer treatment.
Chemical aspects of metal ion chelation in the synthesis and application antibody‐based radiotracers
Authors: Boros Eszter , Holland Jason P.
Published: December 2017

Radiometals are becoming increasingly accessible and are utilized frequently in the design of radiotracers for imaging and therapy. Nuclear properties ranging from the emission of γ‐rays and β+‐particles (imaging) to Auger electron and β− and α‐particles (therapy) in combination with long half‐lives are ideally matched with the relatively long biological half‐life of monoclonal antibodies in vivo. Radiometal labeling of antibodies requires the incorporation of a metal chelate onto the monoclonal antibody. This chelate must coordinate the metal under mild conditions required for the handling of antibodies, as well as provide high kinetic, thermodynamic, and metabolic stability once the metal ion is coordinated to prevent release of the radionuclide before the target site is reached in vivo. Herein, we review the role of different radiometals that have found applications of the design of radiolabeled antibodies for imaging and radioimmunotherapy. Each radionuclide is described regarding its nuclear synthesis, coordinative preference, and radiolabeling properties with commonly used and novel chelates, as well as examples of their preclinical and clinical applications. An overview of recent trends in antibody‐based radiopharmaceuticals is provided to spur continued development of the chemistry and application of radiometals for imaging and therapy.
Integration of molecular dynamics simulation and hotspot residues grafting for de novo scFv design against Salmonella Typhi TolC protein
Authors: Leong Siew Wen , Lim Theam Soon , Ismail Asma , Choong Yee Siew
Published: December 2017

With the development of de novo binders for protein targets from non‐related scaffolds, many possibilities for therapeutics and diagnostics have been created. In this study, we described the use of de novo design approach to create single‐chain fragment variable (scFv) for Salmonella enterica subspecies enterica serovar Typhi TolC protein. Typhoid fever is a global health concern in developing and underdeveloped countries. Rapid typhoid diagnostics will improve disease management and therapy. In this work, molecular dynamics simulation was first performed on a homology model of TolC protein in POPE membrane bilayer to obtain the central structure that was subsequently used as the target for scFv design. Potential hotspot residues capable of anchoring the binders to the target were identified by docking “disembodied” amino acid residues against TolC surface. Next, scFv scaffolds were selected from Protein Data Bank to harbor the computed hotspot residues. The hotspot residues were then incorporated into the scFv scaffold complementarity determining regions. The designs recapitulated binding energy, shape complementarity, and interface surface area of natural protein‐antibody interfaces. This approach has yielded 5 designs with high binding affinity against TolC that may be beneficial for the future development of antigen‐based detection agents for typhoid diagnostics.
Myocardial Perfusion Reserve Index in Children With Kawasaki Disease
Authors: Friesen Richard M. , Schäfer Michal , Jone Pei‐Ni , Appiawiah Nana , Vargas Daniel , Fonseca Brian , DiMaria Michael V. , Truong Uyen , Malone LaDonna , Browne Lorna P.
Published: December 2017

Background

Coronary artery lesions in patients with Kawasaki disease (KD) can impair myocardial perfusion, yet evaluation of perfusion defects by cardiac magnetic resonance (MR) in children is often qualitative.

Purpose

In this study we aimed to use a quantitative method of myocardial perfusion using stress cardiac MR‐derived myocardial perfusion reserve index (MPRI) in children with KD and compare MPRI with ventricular mechanical performance evaluated by cardiac MR strain analysis.

Study Type

This study was a retrospective review.

Subjects

Twenty‐one children with a diagnosis of KD who underwent stress perfusion cardiac MR were compared with nine controls.

Field Strength/Sequence

First‐pass perfusion imaging using a T1‐weighted gradient echo sequence was performed at rest and stress after administration of adenosine with 1.5T or 3T magnets.

Assessment

The MPRI was calculated as the ratio of maximum slope of myocardial enhancement during stress compared to rest and was evaluated with the American Heart Association 17 segment model.

Statistical Tests

Demographic and clinical characteristics among KD patients and controls were compared using Student's t‐test for normally distributed continuous variables, Wilcoxon‐rank sum test for nonnormally distributed variables, and χ2 for categorical variables.

Results

There was a significant decrease in MPRI in Segment 7 (1.53 vs. 2.23, P = 0.0058) in KD patients compared with controls. The reduction in MPRI in Segment 12 approached statistical significance (1.58 vs. 2.31, P = 0.0636). Three patients who underwent serial studies had decreased MPRI longitudinally. No differences were seen in circumferential or radial strain.

Data Conclusion

MPRI shows impaired myocardial perfusion in patients with KD. MPRI can change over time, suggestive of progressive coronary artery changes, which may precede fibrosis and mechanical decline. MPRI can assess segmental and global perfusion defects in patients with KD and should be a part of routine cardiac MR evaluation in KD.

Level of Evidence: 3

Technical Efficacy Stage 3

J. Magn. Reson. Imaging 2017.
A role for autophagy in long‐term spatial memory formation in male rodents
Authors: Hylin Michael J. , Zhao Jing , Tangavelou Karthikeyan , Rozas Natalia S. , Hood Kimberly N. , MacGowan Jacalyn S. , Moore Anthony N. , Dash Pramod K.
Published: December 2017

A hallmark of long‐term memory formation is the requirement for protein synthesis. Administration of protein synthesis inhibitors impairs long‐term memory formation without influencing short‐term memory. Rapamycin is a specific inhibitor of target of rapamycin complex 1 (TORC1) that has been shown to block protein synthesis and impair long‐term memory. In addition to regulating protein synthesis, TORC1 also phosphorylates Unc‐51‐like autophagy activating kinase‐1 (Ulk‐1) to suppress autophagy. As autophagy can be activated by rapamycin (and rapamycin inhibits long‐term memory), our aim was to test the hypothesis that autophagy inhibitors would enhance long‐term memory. To examine if learning alters autophagosome number, we used male reporter mice carrying the GFP‐LC3 transgene. Using these mice, we observed that training in the Morris water maze task increases the number of autophagosomes, a finding contrary to our expectations. For learning and memory studies, male Long Evans rats were used due to their relatively larger size (compared to mice), making it easier to perform intrahippocampal infusions in awake, moving animals. When the autophagy inhibitors 3‐methyladenine (3‐MA) or Spautin‐1 were administered bilaterally into the hippocampii prior to training in the Morris water maze task, the drugs did not alter learning. In contrast, when memory was tested 24 hours later by a probe trial, significant impairments were observed. In addition, intrahippocampal infusion of an autophagy activator peptide (TAT‐Beclin‐1) improved long‐term memory. These results indicate that autophagy is not necessary for learning, but is required for long‐term memory formation.
The Devil Is in the Details: Why the Answer to Most Questions About Creativity Will Always Be “It Depends”
Authors: Baer John
Published: December 2017

“Creativity” is an abstract concept. To make progress, creativity research needs to think about creativity in more concrete ways.
Toward a Science of Creativity: Considerable Progress but Much Work to be Done
Authors: Plucker Jonathan A.
Published: December 2017

The past 50 years have seen a tremendous strengthening of the field of creativity studies. Developments over the past couple decades, in particular, have led to a burgeoning science of creativity. But major methodological and substantive issues remain and must be addressed in order for the science of creativity to reach its potential to improve the well‐being of people around the globe.