bluuebunny/crossref_metadata_2025 huggingface dataset:
Biomimetic fiber‐reinforced composite structures based on natural plant ramifications serving as models
Authors: Schwager H. , Neinhuis C.
Published: November 2016

The increasing demand for material and energy efficient products requires new strategies for designing and developing these products. For this, biomimetics is a promising approach adopting the strategies of living organisms to cope with their environmental conditions as inspiration for solving engineering problems. The evolutionary optimized biological models are often characterized by functional integration, a low environmental impact and high level of sustainability.

In this paper we describe the general approach of such a biomimetic workflow on the example of topology optimization based on the model of natural ramifications. We compare the load adaptations in cactus ramifications to the load‐adaptive growth, which can be found in tree branchings.

Compared to trees, the branches of columnar cacti taper towards the branch base with a pronounced constriction at the attachment point. In addition, the cactus wood features distinct indentations on the upper and lower side of the branch base which can be regarded as relief notches helping to modify the stress distribution in these regions with unfavorable fiber course.

These results of our research point to a cactus specific load adaptation strategy that might be helpful for the design of fiber reinforced composite structures with restricted design space.
Method for efficient determination of material properties for modelling aluminium welding processes
Authors: Striewe B. , Seiderer J. , von Hehl A. , Repenning A. , Khazan P. , Schafstall H.
Published: November 2016

The trend in the automotive and aircraft industry is moving towards customized designs by using compound structures, which provide an enlarged potential for weight and cost savings. Particularly, thermal joined lightweight structures made of aluminium alloys are characterized by moderate material and processing costs. However, the short and locally focused heat input during welding leads to a degradation of material properties, particularly strength in the heat affected zone (HAZ) of the weld. The need of minimizing of rejections and rework leads to high demands on the welding process. This often requires time‐ and cost‐intensive part testing including accurate determination of the mechanical properties after welding. The prediction of the mechanical properties of welded joints, by means of welding simulation, enables a significant reduction of this time‐ and cost‐intensive testing effort. However, the application of such a model requires a sufficient base of material data, which has usually to be generated by an extensive testing procedure for each single alloy. Against this background, a new method for an efficient determination of material properties for the simulation of thermal joining processes of age‐hardenable aluminium alloys was developed within the programme of the research project.
Recipient bone marrow‐derived stromal cells prolong graft survival in a rat hind limb allotransplantation model
Authors: Ikeguchi Ryosuke , Kakinoki Ryosuke , Ohta Souichi , Oda Hiroki , Yurie Hirofumi , Kaizawa Yukitoshi , Mitsui Hiroto , Aoyama Tomoki , Toguchida Junya , Matsuda Shuichi
Published: November 2016

Background

Recent studies have indicated that bone marrow‐derived stromal cells (BMSCs) have immunomodulatory properties that suppress the T cell responses that cause graft rejection. The purpose of this study is to evaluate the effect of recipient BMSCs intravenous infusion for immunomodulation in a rat vascularized composite allotransplantation model.

Methods

A total of nine Wistar (WIS) rats and thirty Lewis (LEW) rats were used. BMSCs were harvested from three LEW rats. Twenty‐four LEW rats were used as recipients and divided randomly into four groups: BMSC group, FK group, UT group, and Iso group. In the BMSC group, orthotopic rat hind limb transplantation was performed between WIS donor and LEW recipient rats. Recipient rats were injected intravenously with 2 × 106 recipient BMSCs on day 6, and with 0.2 mg/kg/day tacrolimus administered over 7 days (n = 6). In the FK group, recipient rats were treated with tacrolimus alone (n = 6). Rats in the UT group received no immunosuppressive treatment (n = 6). In the Iso group, transplantation was performed from three LEW donor rats to six LEW recipient rats without any immunosuppressive treatment (n = 6). Graft survival was assessed by daily inspection and histology. The immunological reactions of recipients were also evaluated.

Results

The graft survival of recipient rats in the BMSC group (24.5 days) was significantly prolonged in comparison with that of the FK group (18 days) (P < .01). Cytokine expression analysis of the skin of grafted limbs showed that BMSCs treatment significantly decreased IFN‐γ mRNA expression of the BMSC group (0.138 ± 0.045) in comparison with that of the FK group (1.049 ± 0.167) (P = .0001). Recipient rats in the BMSC group had significantly reduced serum IFN‐γ cytokine levels (1.571 ± 0.779 pg/ml) in comparison with that of the FK group (7.059 ± 1.522 pg/ml) (P = .001). In in vitro study, BMSCs induce T cell hyporesponsiveness in a mixed lymphocyte reaction.

Conclusion

BMSCs induce T cell hyporesponsiveness and prolong graft survival in the rat vascularized composite allotransplantation model. BMSCs exhibit immunomodulatory properties against acute rejection that can be realized without the need for significant recipient immunosuppression.
Elevated phosphodiester and T2 levels can be measured in the absence of fat infiltration in Duchenne muscular dystrophy patients
Authors: Hooijmans M.T. , Niks E.H. , Burakiewicz J. , Verschuuren J.J.G.M. , Webb A.G. , Kan H.E.
Published: November 2016

Quantitative MRI and MRS are increasingly important as non‐invasive outcome measures in therapy development for Duchenne muscular dystrophy (DMD). Many studies have focussed on individual measures such as fat fraction and metabolite levels in relation to age and functionality, but much less attention has been given to how these indices relate to each other. Here, we assessed spatially resolved metabolic changes in leg muscles of DMD patients, and classified muscles according to the degree of fat replacement compared with healthy controls. Quantitative MRI (three‐point Dixon and multi‐spin echo without fat suppression and a tri‐exponential fit) and 2D–CSI 31P MRS scans were obtained from 18 DMD patients and 12 healthy controls using a 3 T and a 7 T MR scanner. Metabolite levels, T2 values and fat fraction were individually assessed for five lower leg muscles. In muscles with extensive fat replacement, phosphodiester over adenosine triphosphate (PDE/ATP), inorganic phosphate over phosphocreatine, intracellular tissue pH and T2 were significantly increased compared with healthy controls. In contrast, in muscles without extensive fat replacement, only PDE/ATP and T2 values were significantly elevated. Overall, our results show that PDE levels and T2 values increase prior to the occurrence of fat replacement and remain elevated in later stages of the disease. This suggests that these individual measures could not only function as early markers for muscle damage but also reflect potentially reversible pathology in the more advanced stages.
Retention marketing tips part 1: Sending the right message
Authors: Talarico Donna
Published: November 2016

You captured her lead. You received her application. Then a deposit. Soon, she shows up for her first class.
Collaboration, effective tools boost recruitment success
Authors: Hope Joan
Published: November 2016

As vice president of enrollment management and marketing for the University College at Southern New Hampshire University, Gregg Mazzola has rich resources to tap into for recruiting students.
Robust open‐loop Nash equilibria in the noncooperative LQ game revisited
Authors: Engwerda Jacob C.
Published: November 2016

This paper reconsiders existence of worst‐case Nash equilibria in noncooperative multi‐player differential games, this, within an open‐loop information structure. We show that these equilibria can be obtained by determining the open‐loop Nash equilibria of an associated differential game with an additional initial state constraint. For the special case of linear‐quadratic differential games, we derive both necessary and sufficient conditions for solvability of the finite planning horizon problem. In particular, we demonstrate that, unlike in the standard linear‐quadratic differential game setting, uniqueness of equilibria may fail to hold. A both necessary and sufficient condition under which there is a unique equilibrium is provided. A sufficient existence condition for a unique equilibrium is derived in terms of a Riccati differential equation. Consequences for control policies are demonstrated in a simple debt stabilization game. ©  2016 The Authors. Optimal Control Applications and Methods published by John Wiley & Sons, Ltd.
Calcium contacts to n‐type crystalline silicon solar cells
Authors: Allen Thomas G. , Bullock James , Zheng Peiting , Vaughan Ben , Barr Matthew , Wan Yimao , Samundsett Christian , Walter Daniel , Javey Ali , Cuevas Andres
Published: November 2016

Direct metallization of lightly doped n‐type crystalline silicon (c‐Si) is known to routinely produce non‐Ohmic (rectifying) contact behaviour. This has inhibited the development of n‐type c‐Si solar cells with partial rear contacts, an increasingly popular cell design for high performance p‐type c‐Si solar cells. In this contribution we demonstrate that low resistance Ohmic contact to n‐type c‐Si wafers can be achieved by incorporating a thin layer of the low work function metal calcium (ϕ ~2.9 eV) between the silicon surface and an overlying aluminium capping layer. Using this approach, contact resistivities of ρc ~ 2 mΩcm2 can be realised on undiffused n‐type silicon, thus enabling partial rear contacts cell designs on n‐type silicon without the need for a phosphorus diffusion. Integrating the Ca/Al stack into a partial rear contact solar cell architecture fabricated on a lightly doped (ND = 4.5 × 1014 cm−3) n‐type wafer resulted in a device efficiency of η = 17.6% where the Ca/Al contact comprised only ~1.26% of the rear surface. We demonstrate an improvement in this cell structure to an efficiency of η = 20.3% by simply increasing the wafer doping by an order of magnitude to ND = 5.4 × 1015 cm−3. Copyright © 2016 John Wiley & Sons, Ltd.
Mercury(II) binds to both of chymotrypsin's histidines, causing inhibition followed by irreversible denaturation/aggregation
Authors: Stratton Amanda , Ericksen Matthew , Harris Travis V. , Symmonds Nick , Silverstein Todd P.
Published: November 2016

The toxicity of mercury is often attributed to its tight binding to cysteine thiolate anions in vital enzymes. To test our hypothesis that Hg(II) binding to histidine could be a significant factor in mercury's toxic effects, we studied the enzyme chymotrypsin, which lacks free cysteine thiols; we found that chymotrypsin is not only inhibited, but also denatured by Hg(II). We followed the aggregation of denatured enzyme by the increase in visible absorbance due to light scattering. Hg(II)‐induced chymotrypsin precipitation increased dramatically above pH 6.5, and free imidazole inhibited this precipitation, implicating histidine‐Hg(II) binding in the process of chymotrypsin denaturation/aggregation. Diethylpyrocarbonate (DEPC) blocked chymotrypsin's two histidines (his40 and his57) quickly and completely, with an IC50 of 35 ± 6 µM. DEPC at 350 µM reduced the hydrolytic activity of chymotrypsin by 90%, suggesting that low concentrations of DEPC react with his57 at the active site catalytic triad; furthermore, DEPC below 400 µM enhanced the Hg(II)‐induced precipitation of chymotrypsin. We conclude that his57 reacts readily with DEPC, causing enzyme inhibition and enhancement of Hg(II)‐induced aggregation. Above 500 µM, DEPC inhibited Hg(II)‐induced precipitation, and [DEPC] >2.5 mM completely protected chymotrypsin against precipitation. This suggests that his40 reacts less readily with DEPC, and that chymotrypsin denaturation is caused by Hg(II) binding specifically to the his40 residue. Finally, we show that Hg(II)‐histidine binding may trigger hemoglobin aggregation as well. Because of results with these two enzymes, we suggest that metal‐histidine binding may be key to understanding all heavy metal‐induced protein aggregation.
Design, synthesis and biological evaluation of novel nicotinamide derivatives bearing a substituted pyrazole moiety as potential SDH inhibitors
Authors: Lv Xian‐Hai , Ren Zi‐Li , Liu Peng , Li Bing‐Xin , Li Qing‐Shan , Chu Ming‐Jie , Cao Hai‐Qun
Published: November 2016

BACKGROUND

Succinate dehydrogenase (SDH) plays an important role in the Krebs cycle, which is considered as an attractive target for development of succinate dehydrogenase inhibitors (SDHIs) based on antifungal agents. Thus, in order to discover novel molecules with high antifungal activities, SDH as the target for a series of novel nicotinamide derivatives bearing substituted pyrazole moieties were designed and synthesised via a one‐pot reaction.

RESULTS

The biological assay data showed that compound 3 l displayed the most potent antifungal activity with EC50 values of 33.5 and 21.4 µm against Helminthosporium maydis and Rhizoctonia cerealis, respectively. Moreover, 3 l exhibited the best inhibitory ability against SDH enzymes. The results of docking simulation showed that 3 l was deeply embedded into the SDH binding pocket, and the binding model was stabilised by a cation–π interaction with Arg 43, Tyr 58 and an H‐bond with Trp 173.

CONCLUSION

The study suggests that the pyrazole nicotinamide derivative 3 l may serve as a potential SDHI that can be used as a novel antifungal agent, and provides valuable clues for the further design and optimisation of SDH inhibitors. © 2016 Society of Chemical Industry
Time‐resolved single‐electron wave‐packet detection
Authors: Kataoka Masaya , Fletcher Jonathan D. , Johnson Nathan
Published: November 2016

We discuss a time‐resolved method of detecting single‐electron wave packets traveling in quantum‐Hall edge states. The electron arrival‐time distribution is measured by applying a time‐dependent potential to a detector potential barrier. Using numerical calculations, we show that picosecond time resolutions can be achieved by increasing the rate of change in the barrier potential. We also show comparisons between the calculations and a set of experimental data, to demonstrate that picosecond time resolutions are possible within realistic experimental conditions. We examine the relationship between the full‐width‐at‐half‐maximum of measured temporal distribution and the underlying arrival‐time distribution. As the rate of barrier change increases, we observe the measured width to reach a minimum at 6.4 ps. Our analysis suggests that the arrival‐time distribution can be as small as 1 ps. However, we also find that the presence of energy–time correlations in the probability‐density distribution can distort the measurement results, and the arrival‐time distribution may be actually as broad as 10 ps.

Visualization of the probability density of electron wave packets in the energy–time space used for the analysis of arrival‐time distribution.
Single‐incision robotic cholecystectomy: A special emphasis on utilization of transparent glove ports to overcome limitations of single‐site port
Authors: Lee Hongeun , Lee Doo‐ho , Kim Hongbeom , Han Youngmin , Kim Sun‐Whe , Jang Jin‐Young
Published: November 2016

Background

The current robotic platform overcomes some limitations of single‐incision laparoscopic cholecystectomy (SILC), however, whether robotic surgery is a safe and feasible approach must be investigated.

Methods

Patients referred for elective surgery willing to undergo single‐incision robotic cholecystectomy (SIRC) by consent were enrolled. All procedures were performed by the same team using the same surgical equipment.

Results

Thirty patients underwent SIRC. The mean overall operation time was 53.80 ± 15.20 min (range 32–80) and mean console time was 16.67 ± 5.63 min (range 11–30). The mean postoperative stay was 1.30 ± 0.54 days (range 1–3). There were no perioperative major complications.

Conclusion

SIRC can be rapidly learnt and safely performed while overcoming the ergonomic difficulties encountered during SILC. SIRC can be a viable alternative treatment for gallbladder diseases in selected patients with strong interest in cosmetic outcomes who are willing to pay the higher costs associated with SIRC.
Distributed Systems And Cosmopolitan Localism: An Emerging Design Scenario For Resilient Societies
Authors: Manzini Ezio , M'Rithaa Mugendi K.
Published: November 2016

Until now the discussion on resilience has mainly adopted technical, economic, functional points of view. This paper assumes that, even though these approaches are important and necessary, they are not enough. If resilience must be a characterizing feature of every potential future society, its cultural dimension must be considered too. In order to make a contribution in this direction, the paper introduces the notions of distributed systems and cosmopolitan localism and discusses the possibility of using design tools to connect and reinforce them. It also observes that both distributed systems and cosmopolitan localism can be recognized in the growing wave of social innovations we are witnessing worldwide. Building on them, the paper concludes outlining an emerging design scenario, the SLOC scenario, and the new cultural fabric needed to implement it. Copyright © 2016 John Wiley & Sons, Ltd and ERP Environment
The practice of secure software development in SDLC: an investigation through existing model and a case study
Authors: Karim Nor Shahriza Abdul , Albuolayan Arwa , Saba Tanzila , Rehman Amjad
Published: November 2016

Software security is an essential requirement for software systems. However, recent investigation indicates that many software development methodologies do not explicitly include methods for incorporating information security into the software development life cycles (SDLC). This research investigates, using case study, the methodologies being used in software development in Saudi Arabia and describes a model for integrating security into the SDLC. The aim is to identify the appropriate means of introducing security measures much earlier in the SDLC. This model is designed to be an extension to the existing SDLC. For achieving the research objectives and answering the research questions, the research followed a case study research design in an information‐based organization. The research identified various important elements as security standards, policies, processes being practiced, and tools used within SDLC projects. In this regard, recommendations and verification were gathered to elicit the actual activities that are appropriate to be conducted at each phase of SDLC. The non‐functional security requirements were also found, to the use of fortify and hp alm for source code review and web application testing. Copyright © 2016 John Wiley & Sons, Ltd.
Gd(III)‐DO3A‐SBMPP: An Effort to Develop the MRI Contrast Agent with Enhanced Relaxivity
Authors: Rangaswamy Sandhya , Varshney Raunak , Tiwari Anjani K. , Sethi Swarndeep K. , Hemanth kumar B. S. , Ojha Himanshu , Sandeep Kaur‐Ghumaan  , Mishra Anil K.
Published: November 2016

Rational design of a new class of MR (magnetic resonance) contrast agent for enhance relaxivity has been described. The click chemistry was employed to incorporate two moieties of 1‐(2‐methoxyphenyl)piperazine and serinol as a linker to enhance the affinity at the recognition sites. The designed ligand was attached to DO3A to synthesize DO3A‐serinol‐bis‐MPP (SBMPP) in 89 % yield. Gd‐DO3A‐SBMPP showed enhanced relaxivity r1 of 10.85±0.04 mM−1s−1 as compare to known gadolinium based contrast agents in clinics. The potentiometric titration of gadolinium loaded SBMPP exhibited strong selectivity for Gd3+ over physiological metal ions such as Zn2+ and Cu2+. Thus, the synthesis of bis‐conjugate could be observed as novel, instructive and initial proof of concept for the synthesis of MR contrast agent with enhanced relaxivity. The preliminary findings show the good biocompatibility and potential functionalities of MPP analogue to target brain regions through MRI.
Photo Relaxation Change and Emission Quenching in Different Sizes of PbS‐Nanoparticles‐Protein Corona
Authors: Bhunia Amit K. , Kamilya Tapanendu , Saha Satyajit
Published: November 2016

In this study, energy transfer from BSA to different size semiconductor nanoparticles PbS was analyzed by using photo Relaxation change and emission quenching analysis. Structures of thePbS NPs are studied by XRD, TEM, and FT‐IR measurements. The band gap and crystal size of PbS suggest the quantum confinement effect. Photo current of the BSA‐PbS NPs bioconjugate system increased compared to bare PbS nanoparticles from nA to μA. Change in photo relaxation life time of the bare PbS NP and PbS NPs‐BSA bioconjugate system is particle size dependent and interaction dependent. PbS NPs‐BSA bioconjugate were characterized by steady‐state fluorescence spectroscopy to determine the magnitude and mechanism of the energy transfer. It was found that the BSA fluorescence was quenched after the addition of PbS nanoparticles. Quenching of protein is large for larger size PbS nanoparticles. DLS study confirmed that BSA was adsorbed onto the surface of nanoparticles, creating a favourable geometry for quenching. Aggregation of BSA around a single PbS nanoparticle is size dependent. Larger nanoparticles are responsible for hard as well as soft corona due to interaction.Our results, which include photo relaxation times, energy transfer efficiencies showed that energy transferred take place via the Fluorescence Resonance Energy Transfer (FRET) mechanism. These energy transfer processes between protein molecules and PbS nanoparticles, will depend on the size of the particles involved.
Easily Separated a Novel rGO‐MMT Three‐Dimensional Aerogel with Good Adsorption and Recyclable Property
Authors: Yan Xueru , Hu Wei , Guo Junkangn , Cai Xiang , Huang Langhuan , Xiong Yongqiang , Tan Shaozao
Published: November 2016

A novel reduced graphene oxide‐montmorillonite three‐dimensional composite aerogel (rGO‐MMT aerogel) was synthesized successfully. The rGO‐MMT aerogel with good adsorption and recyclable property due to special 3D interconnection porous structure and good mechanical strength. The preparation process was carried out in aqueous solution under atmosphere pressure without any toxic agents or special instruments, which is a facile, green, and low‐cost method. The aerogel was characterized by X‐ray diffraction (XRD), Fourier transform infrared spectroscopy (FT‐IR), Transmission electron microscopy (TEM), Brunner‐Emmet‐Teller (BET) and X‐ray photoelectron spectroscopy (XPS). The adsorptive capacity and recycling of the aerogel were studied, including remove organic dyes (such as Methyl orange and Methylene blue) from wastewater and cycled five runs. The adsorption equilibrium data, adsorption process, and thermodynamic parameters were investigated. Moreover, the rGO‐MMT aerogel absorbent could be easily and directly separated with tweezers. The rGO‐MMT aerogel may find important environmental applications.
Effects of SDS and SDBS on CO2Hydrate Formation, Induction Time, Storage Capacity and Stability at 274.15 K and 5.0 MPa
Authors: Jiang Le‐le , Li Ai‐rong , Xu Jing‐fan , Liu Yan‐jun
Published: November 2016

The CO2 hydratetechnology is growing in relative to CO2 capture, storage and transportation processes. An experimental investigation on CO2 hydrate formation in case of SDS (Sodium dodecyl sulfate) and SDBS (Sodium dodecyl benzene sulfonate) with seven concentrationsi. e.0, 0.1, 0.2, 0.3, 0.4, 0.5 and 0.6 g/L was conducted at temperature of 274.15 K and initial pressure of 5.0 MPa. It was found that SDS and SDBS surfactants havelittleinfluence on the total moles of gas consumed in the stirred reactor. The induction time of CO2hydrate formation was approximately 35 minsinboth of 0.5 g/L SDS and 0.3 g/L SDBS solution,while that was 50 minsin pure water. Although the surfactantsreduced the CO2hydrate induction time significantly, they did not show clear influence on the gas storage capacities. The maximum gas storage capacities of CO2 hydrate in pure water, SDS and SDBS aqueous solutions are 89.62, 92.67, 92.62 V/VH, respectively. The difference in decomposition time of CO2 hydrate formed in pure water, SDS and SDBS solutions indicates that SDS and SDBScan greatly enhance the stability of CO2 hydrate.
Organic Solid Acid Catalyst for Efficient Conversion of Furfuryl Alcohol to Biofuels
Authors: Islam Md. Mominul , Bhunia Subhajit , Molla Rostam Ali , Bhaumik Asim , Islam Sk. Manirul
Published: November 2016

We report the synthesis of a highly active microporous sulphonated monolithic catalyst (HCC‐ML‐SO3H) through the Friedel–Crafts alkylation reaction between carbazole and α,α′‐dibromo‐p‐xylene in the presence of a Lewis acid catalyst FeCl3 under refluxing conditions, followed by sulphonation reaction (chlorosulfonic acid treatment under controlled reaction conditions). This sulphonated solid acid catalyst can catalyze the ring opening of furanoid moiety of furfuryl alcohol (FA) and subsequent esterification with various alcohols in one‐pot to produce levulinate esters, which are potential biofuels. Here the porous organic polymer bearing reactive SO3H groups (HCC‐ML‐SO3H) acts as a very reactive solid acid catalyst. Due to large surface area and extensive cross‐linking this porous polymer is very attractive material for the synthesis of levulinate esters from FA under metal free conditions. The catalyst has been characterized by N2 sorption, HR‐TEM, 13C solid state CP MAS NMR, XPS and FT‐IR. The catalyst can be reused for four consecutive reaction cycles without appreciable loss of activity.
A DSSC with an Efficiency of ∼10 %: Fermi Level Manipulation Impacting the Electron Transport at the Photoelectrode‐Electrolyte Interface
Authors: Kushwaha Suman , Mandal Sudip , Subramanian Sundar , Aryasomayajul Subrahmanyam , Ramanujam Kothandaraman
Published: November 2016

In the literature, many studies pertain to gold (Au) nanoparticles, (NPs) incorporated dye‐sensitized solar cells (DSSCs) were reported due to the beneficial effect of the surface plasmon polaritons originating from the Au NPs on the DSSC performance. Thiolated Au quantum dots and dye based DSSCs was explored recently, wherein the Au cluster act both as sensitizer and voltage booster by enhancing the quasi‐Fermi level of TiO2. There is a knowledge gap on effect of thiolated Au NPs on DSSC performance. In this study, we have demonstrated Fermi level equilibration between the TiO2 and thiolated Au NPs. Thiolated Au NPs blocks the back electron transfer at the thiolated Au NPs‐electrolyte interface thereby improving the open circuit voltage and efficiency of DSSCs. We have also shown beneficial effect of WO3–TiO2–thiolated Au NPs interface in enhancing the DSSC performance significantly in comparison to that of sole TiO2 based DSSC. For the DSSC cell: FTO/WO3/TiO2‐Au‐thiolated/N719, an efficiency of 9.9 % is achieved (JSC = 17.4 mA cm−2, VOC = 0.820 V and FF=0.70).
Protein Mimic Hydrophobicity Affects Intracellular Delivery but not Cargo Binding
Authors: Posey Nicholas D. , Caffrey Leah M. , Minter Lisa M. , Tew Gregory N.
Published: November 2016

Protein transduction domain mimics (PTDMs) enable cellular uptake of macromolecular cargo such as proteins and nucleic acids. The presence of hydrophobic domains in PTDMs has been shown to enhance cargo uptake, but the role of hydrophobicity in PTDM‐binding of the desired cargo is not fully understood. Herein, block copolymer PTDMs composed of varying hydrophobic monomers were synthesized via ring‐opening metathesis polymerization (ROMP) to probe the effect that increasingly hydrophobic side chains had on binding enhanced green fluorescent protein (EGFP). PTDM‐facilitated cellular uptake of EGFP into Jurkat T cells was performed to assess the correlation between binding, hydrophobicity, and delivery. Binding studies demonstrated that all PTDMs bound EGFP similarly despite a five log difference in monomer Kow (octanol‐water partition coefficient) and that intermediately hydrophobic PTDMs facilitated higher cellular uptake of EGFP. Taken as a whole, hydrophobicity of the PTDM is a better predictor of effective delivery in Jurkat T cells than cargo binding.
Novel UV–Visible Photodetector in Photovoltaic Mode with Fast Response and Ultrahigh Photosensitivity Employing Se/TiO2 Nanotubes Heterojunction
Authors: Zheng Lingxia , Hu Kai , Teng Feng , Fang Xiaosheng
Published: November 2016

A feasible strategy for hybrid photodetector by integrating an array of self‐ordered TiO2 nanotubes (NTs) and selenium is demonstrated to break the compromise between the responsivity and response speed. Novel heterojunction between the TiO2 NTs and Se in combination with the surface trap states at TiO2 help regulate the electron transport and facilitate the separation of photogenerated electron–hole pairs under photovoltaic mode (at zero bias), leading to a high responsivity of ≈100 mA W−1 at 620 nm light illumination and the ultrashort rise/decay time (1.4/7.8 ms). The implanting of intrinsic p‐type Se into TiO2 NTs broadens the detection range to UV–visible (280–700 nm) with a large detectivity of over 1012 Jones and a high linear dynamic range of over 80 dB. In addition, a maximum photocurrent of ≈107 A is achieved at 450 nm light illumination and an ultrahigh photosensitivity (on/off ratio up to 104) under zero bias upon UV and visible light illumination is readily achieved. The concept of employing novel heterojunction geometry holds great potential to pave a new way to realize high performance and energy‐efficient optoelectronic devices for practical applications.
A case for the use of conceptual analysis in science education research
Authors: Kahn Sami , Zeidler Dana L.
Published: November 2016

Imprecise constructs abound in science education research in part due to reliance on stipulative definitions that neglect fine distinctions between closely related constructs and overlook important meanings and hidden values embedded in language. Lack of conceptual clarity threatens construct validity, hampers theory development, and prevents science education researchers from focusing on the precise skills they wish to study and promote. To address these challenges, we argue for the expanded use of conceptual analysis, a traditional form of philosophical inquiry underutilized in science education research. After examining the historical and epistemological bases for this methodology, we introduce a variety of techniques used in this mode of inquiry including generic, differentiation, and conditions‐type analyses using model, borderline, contrary, and invented cases. To further advance our argument, we then conduct an abbreviated differentiation‐type analysis to distinguish “perspectives” from the related terms “orientations” and “positions,” three terms that present conceptual challenges in the research area of Socioscientific Issues (SSI) yet are clarified and contextually situated through this analysis. Finally, in light of our analysis, we suggest future directions for the expanded use of conceptual analysis in science education research. © 2016 Wiley Periodicals, Inc. J Res Sci Teach 54: 538–551, 2017
Neural progenitor cells and their role in the development and evolutionary expansion of the neocortex
Authors: Namba Takashi , Huttner Wieland B.
Published: November 2016

The evolutionary expansion of the mammalian brain, notably the neocortex, provides a platform for the higher cognitive abilities that characterize humans. Cortical expansion is accompanied by increased folding of the pial surface, which gives rise to a gyrencephalic (folded) rather than lissencephalic (unfolded) neocortex. This expansion reflects the prolonged and increased proliferation of neural stem and progenitor cells (NPCs). Distinct classes of NPCs can be distinguished based on either cell biological criteria (apical progenitors [APs], basal progenitors [BPs]) or lineage (primary progenitors and secondary progenitors). Cortical expansion in development and evolution is linked to an increased abundance and proliferative capacity of BPs, notably basal radial glial cells, a recently characterized type of secondary progenitor derived from apical radial glial cells, the primary progenitors. To gain insight into the molecular basis underlying the prolonged and increased proliferation of NPCs and in particular BPs, comparative genomic and transcriptomic approaches, mostly for human versus mouse, have been employed and applied to specific NPC types and subpopulations. These have revealed two principal sets of molecular changes. One concerns differences in the expression of common genes between species with different degrees of cortical expansion. The other comprises human‐specific genes or genomic regulatory sequences. Various systems that allow functional testing of these genomic and gene expression differences between species have emerged, including transient and stable transgenesis, genome editing, cerebral organoids, and organotypic slice cultures. These provide future avenues for uncovering the molecular basis of cortical expansion. WIREs Dev Biol 2017, 6:e256. doi: 10.1002/wdev.256

This article is categorized under:

Nervous System Development > Vertebrates: Regional Development

Comparative Development and Evolution > Organ System Comparisons Between Species

Comparative Development and Evolution > Evolutionary Novelties
Anatomical Variations of the Venous Drainage from the Left Adrenal Gland: An Anatomical Study
Authors: Siebert Matthieu , Robert Yohann , Didier Romain , Minster Antonin , M’sallaoui Wassila , Bellier Alexandre , Chaffanjon Philippe C. J.
Published: November 2016

Background

For radiologists, the venous drainage of adrenal glands is a key to the technique of selective adrenal venous sampling. For endocrine surgeons, it is key to adrenalectomy for carcinoma and pheochromocytoma. This study aims to demonstrate direct anastomosis between the left adrenal vein, the diaphragmatic circulation and the azygos system. Anatomical textbooks only offer very little information concerning the left adrenal vein (LAV) and its potential anastomosis with the reno‐lumbo‐azygo trunk (RLAT) and the diaphragmatic circulation.

Methods

Between November 2014 and October 2015 in the LADAF (French Alps Anatomy Laboratory), we dissected 44 formalin‐fixed adult cadavers.

Results

We found no direct anastomosis between the left adrenal vein and the reno‐azygo‐lumbar trunk and two anastomoses (4.5%) between the adrenal capsular vein and azygos system. A lumbo‐azygo trunk has been found 38 times (86.3%), drained 35 times (79.5%) into the left renal vein and 3 times (6.8%) into the left genital vein. An inferior phrenic vein ending into an adrenal vein was highlighted in all cases, 6 times (13.7%) in a double adrenal vein and 38 times (86.3%) in a single one.

Conclusions

No connections have been found between left adrenal vein and the RLAT, and frequency of the IPV is discordant with the literature. However, our findings concerning the capsular vessels’ anastomosis with the azygos system, inferior diaphragmatic flow and double adrenal vein could have two clinical applications: Firstly, the ligation of the adrenal vein solely is not enough to entirely interrupt the adrenal vein drainage, and secondly, sampling of hormones in the LAV could be underestimated because of the risk of dilution.
Overexpression of smORF YNR034W-A/EGO4 in Saccharomyces cerevisiae increases the fermentative efficiency of Agave tequilana Weber must
Authors: Vargas-Maya Naurú Idalia , González-Hernández Gloria Angélica , Padilla-Guerrero Israel Enrique , Torres-Guzmán Juan Carlos
Published: November 2016

Fermentative processes are widely used to produce food, beverages and biofuels. Saccharomyces cerevisiae is an efficient ethanol-producing microorganism. However, a concentration of high ethanol and other metabolites can affect yeast viability and decrease the ethanol yield. Many studies have focused on improving the fermentative efficiency, mostly through the genetic engineering of genes that have a direct impact on specific metabolic pathways. In the present study, we characterized a small open reading frame encoding a protein with an unknown function and biological role termed YNR034W-A. We analyzed the expression profile of the YNR034W-A gene during growth and glucose treatment, finding that it is expressed during the diauxic shift and stationary phase and is negatively regulated by glucose. We overexpressed the YNR034W-A gene in the BY4741 laboratory strain and a wild-type yeast strain (AR5) isolated during the Tequila fermentation process. Transformant derivatives of the AR5 strain showed an improved fermentative efficiency during fermentation of Agave tequilana Weber juice. We suggest that the improved fermentative efficiency is the result of a higher stress tolerance response in the YNR034W-A overexpressing transformant.
Proposed recommendations for diagnosing and managing individuals with glutaric aciduria type I: second revision
Authors: Boy Nikolas , Mühlhausen Chris , Maier Esther M. , Heringer Jana , Assmann Birgit , Burgard Peter , Dixon Marjorie , Fleissner Sandra , Greenberg Cheryl R. , Harting Inga , Hoffmann Georg F. , Karall Daniela , Koeller David M. , Krawinkel Michael B. , Okun Jürgen G. , Opladen Thomas , Posset Roland , Sahm Katja , Zschocke Johannes , Kölker Stefan ,   Additional individual contributors
Published: November 2016

Glutaric aciduria type I (GA‐I; synonym, glutaric acidemia type I) is a rare inherited metabolic disease caused by deficiency of glutaryl‐CoA dehydrogenase located in the catabolic pathways of L‐lysine, L‐hydroxylysine, and L‐tryptophan. The enzymatic defect results in elevated concentrations of glutaric acid, 3‐hydroxyglutaric acid, glutaconic acid, and glutaryl carnitine in body tissues, which can be reliably detected by gas chromatography/mass spectrometry (organic acids) and tandem mass spectrometry (acylcarnitines). Most untreated individuals with GA‐I experience acute encephalopathic crises during the first 6 years of life that are triggered by infectious diseases, febrile reaction to vaccinations, and surgery. These crises result in striatal injury and consequent dystonic movement disorder; thus, significant mortality and morbidity results. In some patients, neurologic disease may also develop without clinically apparent crises at any age. Neonatal screening for GA‐I us being used in a growing number of countries worldwide and is cost effective. Metabolic treatment, consisting of low lysine diet, carnitine supplementation, and intensified emergency treatment during catabolism, is effective treatment and improves neurologic outcome in those individuals diagnosed early; treatment after symptom onset, however, is less effective. Dietary treatment is relaxed after age 6 years and should be supervised by specialized metabolic centers. The major aim of this second revision of proposed recommendations is to re‐evaluate the previous recommendations (Kölker et al. J Inherit Metab Dis 30:5‐22, 2007b; J Inherit Metab Dis 34:677‐694, 2011) and add new research findings, relevant clinical aspects, and the perspective of affected individuals.
Factors Influencing the Decision‐Making Process and Long‐Term Interpersonal Outcomes for Parents Who Undergo Preimplantation Genetic Diagnosis for Fanconi Anemia: a Qualitative Investigation
Authors: Haude K. , McCarthy Veach P. , LeRoy B. , Zierhut H.
Published: November 2016

Fanconi anemia (FA) is characterized by congenital malformations, progressive bone marrow failure, and predisposition to malignancy. Hematopoietic stem cell transplantation is used to treat FA, and best results are attained with sibling donors who are human leukocyte antigen (HLA) identical matches. Preimplantation genetic diagnosis (PGD) offers parents of an affected child the opportunity to have an unaffected child who is an HLA match. While some research has investigated parents’ experiences during the PGD process, no published studies specifically address factors influencing their decision‐making process and long‐term interpersonal outcomes. The aims of this study are to: (1) examine parents’ expectations and the influence of media, bioethics, and religion on their decision to undergo PGD; (2) examine parents’ social support and emotional experiences during their PGD process; and (3) characterize long‐term effects of PGD on relationship dynamics (partner, family, friends), others’ attitudes, and parental regret. Nine parents participated in semi‐structured interviews. Thematic analysis revealed their decision to use PGD was variously influenced by media, bioethics, and religion, in particular, affecting parents’ initial confidence levels. Moreover, the PGD process was emotionally complex, with parents desiring varying amounts and types of support from different sources at different times. Parents reported others’ attitudes towards them were similar or no different than before PGD. Parental regret regarding PGD was negligible. Results of this study will promote optimization of long‐term care for FA families.
Modeling Omitted and Not-Reached Items in IRT Models
Authors: Rose Norman , von Davier Matthias , Nagengast Benjamin
Published: November 2016

Item nonresponse is a common problem in educational and psychological assessments. The probability of unplanned missing responses due to omitted and not-reached items may stochastically depend on unobserved variables such as missing responses or latent variables. In such cases, missingness cannot be ignored and needs to be considered in the model. Specifically, multidimensional IRT models, latent regression models, and multiple-group IRT models have been suggested for handling nonignorable missing responses in latent trait models. However, the suitability of the particular models with respect to omitted and not-reached items has rarely been addressed. Missingness is formalized by response indicators that are modeled jointly with the researcher’s target model. We will demonstrate that response indicators have different statistical properties depending on whether the items were omitted or not reached. The implications of these differences are used to derive a joint model for nonignorable missing responses with ability to appropriately account for both omitted and not-reached items. The performance of the model is demonstrated by means of a small simulation study.
Comparison of Revision Rates of Non-modular Constrained Versus Posterior Stabilized Total Knee Arthroplasty: A Propensity Score Matched Cohort Study
Authors: Moussa Mohamed E. , Lee Yuo-yu , Westrich Geoffrey H. , Mehta Nabil , Lyman Stephen , Marx Robert G.
Published: November 2016

Background

Attaining stability during total knee arthroplasty (TKA) is essential for a successful outcome. Although traditional constrained total knee prostheses have generally been used in conjunction with intramedullary stems, some devices have been widely used without the use of stems, referred to as non-modular constrained condylar total knee arthroplasty (NMCCK).

Questions/Purposes

The aim of this study was to compare revisions rates after total knee replacement with a non-modular constrained condylar total knee (NMCCK) compared to a posterior-stabilized (PS) design.

Methods

Between 2007 and 2012, primary PS total knees were compared with NMCCK implants from the same manufacturer. Propensity score matching was performed, and implant survivorship was examined using a Cox proportional hazards model. The cohort consisted of 817 PS knees and 817 NMCCKs matched for patient demographics, surgeon volume, and pre-operative diagnosis.

Results

All cause revisions occurred in 11 of 817 (1.35%) in the PS group compared to 28 of 817 (3.43%) in the NMCCK group ( p = 0.0168). Excluding revisions for infection and fracture, 8 of 817 (0.98%) PS knees required revision for mechanical failure compared to 18 of 817 (2.20%) NMCCK knees ( p = 0.0193).

Conclusions

While revisions rates in both cohorts were low, there was a significantly higher revision rate with NMCCKs. Given that cases requiring the use of NMCCK implants are likely more complex than those in which PS implants are used, our findings support the judicious use of NMCCK prostheses.
The roles of ebolavirus glycoproteins in viral
pathogenesis
Authors: Ning Yun-Jia , Deng Fei , Hu Zhihong , Wang Hualin
Published: November 2016

Ebolaviruses are highly dangerous pathogens exhibiting extreme virulence in humans
and nonhuman primates. The majority of ebolavirus species, most notably Zaire ebolavirus, can cause Ebola virus disease (EVD),
formerly known as Ebola hemorrhagic fever, in humans. EVD is associated with
case-fatality rates as high as 90%, and there is currently no specific treatment or
licensed vaccine available against EVD. Understanding the molecular biology and
pathogenesis of ebolaviruses is important for the development of antiviral
therapeutics. Ebolavirus encodes several forms of glycoproteins (GPs), which have
some interesting characteristics, including the transcriptional editing coding
strategy and extensive O-glycosylation modification, clustered in the mucin-like
domain of GP1, full-length GP (GP1,2), and shed GP. In
addition to the canonical role of the spike protein, GP1,2,
in viral entry, ebolavirus GPs appear to have multiple additional functions, likely
contributing to the complex pathogenesis of the virus. Here, we review the roles of
ebolavirus GPs in viral pathogenesis.
Hierarchical model-based inference for forest inventory utilizing three sources of information
Authors: Saarela Svetlana , Holm Sören , Grafström Anton , Schnell Sebastian , Næsset Erik , Gregoire Timothy G. , Nelson Ross F. , Ståhl Göran
Published: November 2016

∙ Key message

The study presents novel model-based estimators for growing stock volume and its uncertainty estimation, combining a sparse sample of field plots, a sample of laser data, and wall-to-wall Landsat data. On the basis of our detailed simulation, we show that when the uncertainty of estimating mean growing stock volume on the basis of an intermediate ALS model is not accounted for, the estimated variance of the estimator can be biased by as much as a factor of three or more, depending on the sample size at the various stages of the design.

∙ Context

This study concerns model-based inference for estimating growing stock volume in large-area forest inventories, combining wall-to-wall Landsat data, a sample of laser data, and a sparse subsample of field data.

∙ Aims

We develop and evaluate novel estimators and variance estimators for the population mean volume, taking into account the uncertainty in two model steps.

∙ Methods

Estimators and variance estimators were derived for two main methodological approaches and evaluated through Monte Carlo simulation. The first approach is known as two-stage least squares regression, where Landsat data were used to predict laser predictor variables, thus emulating the use of wall-to-wall laser data. In the second approach laser data were used to predict field-recorded volumes, which were subsequently used as response variables in modeling the relationship between Landsat and field data.

Results

∙ The estimators and variance estimators are shown to be at least approximately unbiased. Under certain assumptions the two methods provide identical results with regard to estimators and similar results with regard to estimated variances.

∙ Conclusion

We show that ignoring the uncertainty due to one of the models leads to substantial underestimation of the variance, when two models are involved in the estimation procedure.