bluuebunny/crossref_metadata_2025 huggingface dataset:
Commissioning of a dedicated commercial Co‐60 total body irradiation unit
Authors: Burmeister Jay , Nalichowski Adrian , Snyder Michael , Halford Robert , Baran Geoff , Loughery Brian , Hammoud Ahmad , Rakowski Joe , Bossenberger Todd
Published: March 2018

We describe the commissioning of the first dedicated commercial total body irradiation (TBI) unit in clinical operation. The Best Theratronics GammaBeam 500 is a Co‐60 teletherapy unit with extended field size and imaging capabilities. Radiation safety, mechanical and imaging systems, and radiation output are characterized. Beam data collection, calibration, and external dosimetric validation are described. All radiation safety and mechanical tests satisfied relevant requirements and measured dose distributions meet recommendations of American Association of Physicists in Medicine (AAPM) Report #17. At a typical treatment distance, the dose rate in free space per unit source activity using the thick flattening filter is 1.53 × 10−3 cGy*min−1*Ci−1. With a 14,000 Ci source, the resulting dose rate at the midplane of a typical patient is approximately 17 and 30 cGy/min using the thick and thin flattening filters, respectively, using the maximum source to couch distance. The maximum useful field size, defined by the 90% isodose line, at this location is 225 × 78 cm with field flatness within 5% over the central 178 × 73 cm. Measured output agreed with external validation within 0.5%. End‐to‐end testing was performed in a modified Rando phantom. In‐house MATLAB software was developed to calculate patient‐specific dose distributions using DOSXYZnrc, and fabricate custom 3D‐printed forms for creating patient‐specific lung blocks. End‐to‐end OSLD and diode measurements both with and without lung blocks agreed with Monte Carlo calculated doses to within 5% and in‐phantom film measurements validated dose distribution uniformity. Custom lung block transmission measurements agree well with design criteria and provide clinically favorable dose distributions within the lungs. Block placement is easily facilitated using the flat panel imaging system with an exposure time of 0.01 min. In conclusion, a novel dedicated TBI unit has been commissioned and clinically implemented. Its mechanical, dosimetric, and imaging capabilities are suitable to provide state‐of‐the‐art TBI for patients as large as 220 cm in height and 78 cm in width.
A Living 3D In Vitro Neuronal Network Cultured inside Hollow Electrospun Microfibers
Authors: Wu Yingjie , Ranjan Vivek Damodar , Zhang Yilei
Published: March 2018

Micro/nanofiber‐based scaffolds are widely used as a physical graft for axon growth in vitro for nerve tissue engineering. In this study, the fabrication of hollow coaxial microfibers with a 3D structure for directional neuronal cell culture is reported. The coaxial microfibers with poly‐ε‐caprolactone (PCL) sheath and polyvinyl alcohol (PVA) mixed with PC 12 cells as core are prepared using a coaxial double cylinder based on the liquid–liquid coflowing electrospinning method. By optimizing the electrospinning conditions, uniform microfibers with an average diameter of 54.6 µm are obtained using a PCL concentration of 20% and a tip‐to‐collector distance of 6 cm with a voltage of 6 kV. After selectively dissolving the PVA core, pheochromocytoma 12 (PC12) cells are successfully cultured inside these fibers. It is experimentally confirmed that such 3D hollow fibers can support and guide PC12 cells to grow, proliferate, and differentiate inside the hollow fibers and form 3D‐connected neuronal networks with axons extended along the hollow fibers. This implies that complex nerve connection could be constructed using the low cost and powerful liquid–liquid coflowing electrospinning method, which open the door to culture well‐controlled nerve connections as in vitro models for neural tissue regeneration, brain disease models, and so on.
Observation of the Dissolution of Topologically Close Packed Phases by an Additional Heat Treatment in Third Generation Nickel‐Based Single Crystal Superalloy Turbine Blades
Authors: Park KeeHyun , Withey Paul
Published: March 2018

Topologically close packed (TCP) phases degrade the superior creep and rupture properties of Ni‐based single crystal superalloys. Initially, small TCP phases are formed in the dendrite core during the early stages of the manufacturing process, such as solution heat treatment, and surrounded by a gamma prime (γ′) phase. Then, TCP phases continue to develop during full heat treatment. However, an additional heat treatment induces diffusion of refractory metals from the TCP phases into the γ′ phase and consequently, the TCP phases clearly disappear. After dissolution, the regions where the TCP phases existed are altered to a normal microstructure composed of γ channels and a normal cubic γ′ phase. Based on the observation result, the mechanism of the dissolution of TCP phases is discussed.
Superior Cryogenic Tensile Strength and Ductility of In Situ Al–Cu Matrix Composite Reinforced with 0.3 wt% Nano‐Sized TiCp
Authors: Geng Run , Tian Wei‐Si , Zhao Qing‐Long , Qiu Feng , Jiang Qi‐Chuan
Published: March 2018

In the present work, the tensile properties at 77 K of the 0.3 wt% nano‐sized TiCp/Al–Cu composite is investigated to explore its potential application at cryogenic temperature. The TiCp/Al–Cu composite exhibits superior ultimate tensile strength (620 MPa), yield strength (531 MPa), and fracture strain (7.2%) at 77 K. The addition of TiCp leads to the refinement of θ′ precipitates and enhanced dislocation strengthening effect, contributing to the improved tensile strength.
Novel Solid‐State Microbial Sensors Based on ZnO Nanorod Arrays
Authors: Landry Cody J. , Burns Fraser P. , Baerlocher Felix , Ghandi Khashayar
Published: March 2018

Gravity and magnetism are implemented to change the morphology of zinc oxide nanorod sensors during synthesis. The effects of gravity and magnetism can translate into future application of these nanorods through cost‐effective, environmentally friendly, and easy‐to‐use biosensor technology with the quickest available sensing. The sensors can pave the way toward detection of both bacteria and fungi present on the surface with high sensitivity. This ability to sense microorganisms in a “non‐solution‐based” environment represents a key step forward in the fields of health and food safety, as well as solid‐state nanomaterial biotechnology applications. Hundreds of thousands of people are affected each year by accidental contamination and current protocols are far from preventative. The results of the magnetic field studies when compared with previous results show that the following factors affect the outcome of applying magnetic field during the growth of nanorods on their morphology: the direction of growth with respect to gravity, the method of seeding, and the substrate.
An Integrated Therapeutic Delivery System for Enhanced Treatment of Hepatocellular Carcinoma
Authors: Ye Zhou , Wu Wen‐Rui , Qin Yu‐Fei , Hu Jing , Liu Chao , Seeberger Peter H. , Yin Jian
Published: March 2018

Nanomaterials hold promise for the treatment of human carcinomas but integrating multiple functions into a single drug carrier system remains challenging. Herein, an integrated therapeutic delivery system for human hepatocellular carcinoma (HCC) treatment is reported, which is based on rhodamine B (RhB) end‐labeled cationic poly[2‐(dimethylamino)ethyl methacrylate] (PDMAEMA) and hydrophobic poly(3‐azido‐2‐hydroxypropyl methacrylate) (PGMA‐N3) segments equipped with a covalently bound galactose. This biocompatible and safe platform RhB‐PDMAEMA25‐c‐PGMA50‐Gal micelles (Gal‐micelles) offers four advantages: (1) Galactose ligands enhance cellular uptake by targeting the asialoglycoprotein receptor (ASGPR) that is overexpressed on HCC cell lines surfaces; (2) RhB end‐labeling facilitates real‐time imaging for tracking both in vitro and in vivo; (3) the acidic tumor microenvironment protonates the carrier system for efficient drug release as well as gene transfection, (4) codelivery of anticancer drug doxorubicin (DOX) and B‐cell lymphoma 2 small interfering RNA (Bcl‐2 siRNA) works synergistically against tumor growth in both subcutaneous and orthotopic HCC bearing mouse models. This integrated therapeutic delivery system holds potential for future clinical HCC treatment.
Simultaneous Edge‐on to Face‐on Reorientation and 1D Alignment of Small π‐Conjugated Molecules Using Room‐Temperature Mechanical Rubbing
Authors: Ribierre Jean‐Charles , Tanaka Toshihiko , Zhao Li , Yokota Yuki , Matsumoto Shinya , Hashizume Daisuke , Takaishi Kazuto , Muto Tsuyoshi , Heinrich Benoît , Méry Stéphane , Mathevet Fabrice , Matsushima Toshinori , Uchiyama Masanobu , Adachi Chihaya , Aoyama Tetsuya
Published: March 2018

In this study, room‐temperature mechanical rubbing is used to control the 3D orientation of small π‐conjugated molecular systems in solution‐processed polycrystalline thin films without using any alignment substrate. High absorption dichroic ratio and significant anisotropy in charge carrier mobilities (up to 130) measured in transistor configuration are obtained in rubbed organic films based on the ambipolar quinoidal quaterthiophene (QQT(CN)4). Moreover, a solvent vapor annealing treatment of the rubbed film is found to improve the optical and charge transport anisotropy due to an increased crystallinity. X‐ray diffraction and atomic force microscopy measurements demonstrate that rubbing does not only lead to an excellent 1D orientation of the QQT(CN)4 molecules over large areas but also modifies the orientation of the crystals, moving molecules from an edge‐on to a face‐on configuration. The reasons why a mechanical alignment technique can be used at room temperature for such a polycrystalline film are rationalized, by the plastic characteristics of the QQT(CN)4 layer and the role of the flexible alkyl side chains in the molecular packing. This nearly complete conversion from edge‐on to face‐on orientation by mechanical treatment in polycrystalline small‐molecule‐based thin films opens perspectives in terms of fundamental research and practical applications in organic optoelectronics.
Cactus‐Like NiCoP/NiCo‐OH 3D Architecture with Tunable Composition for High‐Performance Electrochemical Capacitors
Authors: Li Xin , Wu Haijun , Elshahawy Abdelnaby M. , Wang Ling , Pennycook Stephen J. , Guan Cao , Wang John
Published: March 2018

To effectively enhance the energy density and overall performance of electrochemical capacitors (ECs), a new strategy is demonstrated to increase both the intrinsic activity of the reaction sites and their density. Herein, nickel cobalt phosphides (NiCoP) with high activity and nickel cobalt hydroxides (NiCo‐OH) with good stability are purposely combined in a hierarchical cactus‐like structure. The hierarchical electrode integrates the advantages of 1D nanospines for effective charge transport, 2D nanoflakes for mechanical stability, and 3D carbon cloth substrate for flexibility. The NiCoP/NiCo‐OH 3D electrode delivers a high specific capacitance of ≈1100 F g−1, which is around seven times higher than that of bare NiCo‐OH. It also possesses ≈90% capacitance retention after 1000 charge–discharge cycles. An asymmetric supercapacitor composed of NiCoP/NiCo‐OH cathode and metal–organic framework‐derived porous carbon anode achieves a specific capacitance of ≈100 F g−1, high energy density of ≈34 Wh kg−1, and excellent cycling stability. The cactus‐like NiCoP/NiCo‐OH 3D electrode presents a great potential for ECs and is promising for other functional applications such as catalysts and batteries.
Influence of Solvent Additive 1,8‐Octanedithiol on P3HT:PCBM Solar Cells
Authors: Wang Weijia , Song Lin , Magerl David , Moseguí González Daniel , Körstgens Volker , Philipp Martine , Moulin Jean‐François , Müller‐Buschbaum Peter
Published: March 2018

Processing solvent additives in polymer:fullerene bulk heterojunction systems are known as a promising method to enhance photovoltaic performance. It is generally agreed that solvent additives enable polymers to have a high degree of molecular order which increases the device performance. However, the understanding of the efficiency enhancement is not complete. There is a lack of insight regarding the quantitative determination of the molecular miscibility between polymer and fullerene as well as the inner morphology changes induced by the additives. In this work, understanding of the influence of the solvent additive 1,8‐octanedithiol (ODT) is provided on the classic system poly(3‐hexylthiophene‐2,5‐diyl):[6,6]‐phenyl‐C61 butyric acid methyl ester (P3HT:PCBM) films. The impact on polymer crystallinity, surface structure, inner morphology, and quantitative molecular miscibility of P3HT and PCBM is studied as a function of ODT volume concentration. The crystallinity is probed with absorption spectroscopy and grazing incidence wide‐angle X‐ray scattering. The morphology and miscibility are characterized via atomic force microscopy and time‐of‐flight grazing incidence small angle neutron scattering. Besides an increased crystallinity and prominent phase separation, ODT increases the solubility of PCBM in P3HT and reduces the size of amorphous P3HT domains. Moreover, solvent processing with a high ODT concentration alters the vertical material composition of the active layer.
Room‐Temperature Ion‐Exchange‐Mediated Self‐Assembly toward Formamidinium Perovskite Nanoplates with Finely Tunable, Ultrapure Green Emissions for Achieving Rec. 2020 Displays
Authors: Yu Dejian , Cao Fei , Gao Yujie , Xiong Yunhai , Zeng Haibo
Published: March 2018

Delicate engineering of chromaticity is required to faithfully reproduce colors in a backlit display, this is extremely difficult for green downconverters because the human eye is highly sensitive to green colors. The central challenge is to achieve finely tunable green emissions in the narrow range of 525–535 nm while keeping the full width at half maximum (FWHM) <25 nm at the same time. Here, a room‐temperature ion‐exchange‐mediated self‐assembly strategy for preparing FAPbBr3 (FA = CH(NH2)2+) nanoplates (NPs) to fulfill this goal is introduced. 2D layered OA2PbBr4 (OA is octadecylamine) NPs are first synthesized by spontaneous reprecipitation, and are then transformed into FAPbBr3 NPs through a OA+‐to‐FA+ exchange induced self‐assembly of HP monolayers. A c‐axis contraction in this process makes a relative large thickness variation in OA2PbBr4 NPs, which can be realized by simply varying the precursor concentration, only result in a small thickness change in subsequent FAPbBr3 NPs, thereby enabling finely tunable emissions in the range of 525–535 nm along with FWHM <25 nm and a quantum yield up to 85%. As a downconverter, the FAPbBr3 NPs realize an ultrapure green backlight that covers ≈95% Rec. 2020 standard in the CIE 1931 color space.
A novel pooled‐sample multiplex luminex assay for high‐throughput measurement of relative telomere length
Authors: Jasmine Farzana , Shinkle Justin , Sabarinathan Mekala , Ahsan Habibul , Pierce Brandon L. , Kibriya Muhammad G.
Published: March 2018

Objectives

Relative telomere length (RTL) is a potential biomarker of aging and risk for chronic disease. Previously, we developed a probe‐based RTL assay on Luminex platform, where probes for Telomere (T) and reference gene (R) for a given DNA sample were tested in a single well. Here, we describe a method of pooling multiple samples in one well to increase the throughput and cost‐effectiveness.

Methods

We used four different microbeads for the same T‐probe and four different microbeads for the same R‐probe. Each pair of probe sets were hybridized to DNA in separate plates and then pooled in a single plate for all the subsequent steps. We used DNA samples from 60 independent individuals and repeated in multiple batches to test the precision.

Results

The precision was good to excellent with Intraclass correlation coefficient (ICC) of 0.908 (95% CI 0.856–0.942). More than 67% of the variation in the RTL could be explained by sample‐to‐sample variation; less than 0.1% variation was due to batch‐to‐batch variation and 0.3% variation was explained by bead‐to‐bead variation. We increased the throughput of RTL Luminex assay from 60 to 240 samples per run. The new assay was validated against the original Luminex assay without pooling (r = 0.79, P = 1.44 × 10−15). In an independent set of samples (n = 550), the new assay showed a negative correlation of RTL with age (r = −0.41), a result providing external validation for the method.

Conclusion

We describe a novel high throughput pooled‐sample multiplex Luminex assay for RTL with good to excellent precision suitable for large‐scale studies.
Entropic Dynamics: Quantum Mechanics from Entropy and Information Geometry
Authors: Caticha Ariel
Published: March 2018

Entropic Dynamics (ED) is a framework in which Quantum Mechanics (QM) is derived as an application of entropic methods of inference. The magnitude of the wave function is manifestly epistemic: its square is a probability distribution. The epistemic nature of the phase of the wave function is also clear: it controls the flow of probability. The dynamics is driven by entropy subject to constraints that capture the relevant physical information. The central concern is to identify those constraints and how they are updated. After reviewing previous work I describe how considerations from information geometry allow us to derive a phase space geometry that combines Riemannian, symplectic, and complex structures. The ED that preserves these structures is QM. The full equivalence between ED and QM is achieved by taking account of how gauge symmetry and charge quantization are intimately related to quantum phases and the single‐valuedness of wave functions.
Optical Switch Based on Dressed Intracavity Dark States
Authors: Guo Miaodi , Su Xuemei
Published: March 2018

We present a scheme to realize two‐direction optical switch by a single‐mode optical cavity containing some four‐level atoms. The high switching efficiency can be obtained through low photon loss and large third‐order nonlinear susceptibility of this N‐type atomic system in cavity. Without the microwave source, it can be reduced to a Λ‐type atomic system where a coupling laser is used to realize single intracavity electromagnetically induced transparency (EIT). Namely, the probe field can be transmitted almost totally at resonance. Thus a two‐direction optical switch is operated and the state for forward (backward) direction is set as “open” (“closed”). When microwave source is introduced, dressed splitting of intracavity dark state happens. The probe field is reflected almost completely at resonance and the state of the optical switch at forward and backward directions (transmitted and reflected channels) is shifted as “closed” and “open”, respectively. Moreover, this scheme is much advantageous to realize splitting of intracavity dark state because weak microwave field () induces the coupling between intracavity dark state and one sublevel of ground state. While a strong pump laser () which couples the intracavity dark state with an excited level is applied to realize this splitting in ref. [Phys. Rev. A 85 013814 (2012)].
Temperature‐Correlated Afterglow of a Semiconducting Polymer Nanococktail for Imaging‐Guided Photothermal Therapy
Authors: Zhen Xu , Xie Chen , Pu Kanyi
Published: March 2018

Nanoparticles for photothermal therapy: Real‐time temperature monitoring is critical to reduce the nonspecific damage during photothermal therapy (PTT); however, PTT agents that can emit temperature‐related signals are rare and limited to few inorganic nanoparticles. We herein synthesize a semiconducting polymer nanococktail (SPNCT) that can not only convert photo‐energy to heat but also emit temperature‐correlated luminescence after cessation of light excitation. Such an afterglow luminescence of the SPNCT detects tumors more sensitively than fluorescence as a result of the elimination of tissue autofluorescence, while its temperature‐dependent nature allows tumor temperature to be optically monitored under near‐infrared (NIR) laser irradiation. Thus, SPNCT represents the first organic optical nanosystem that enables optical‐imaging guided PTT without real‐time light excitation.
Synthesis of C2 Substituted Benzothiophenes via an Interrupted Pummerer/[3,3]‐Sigmatropic/1,2‐Migration Cascade of Benzothiophene S‐Oxides
Authors: He Zhen , Shrives Harry J. , Fernández‐Salas José A. , Abengózar Alberto , Neufeld Jessica , Yang Kevin , Pulis Alexander P. , Procter David J.
Published: March 2018

Functionalized benzothiophenes are important scaffolds found in molecules with wide ranging biological activity and in organic materials. We describe an efficient, metal‐free synthesis of C2 arylated, allylated, and propargylated benzothiophenes. The reaction utilizes synthetically unexplored yet readily accessible benzothiophene S‐oxides and phenols, allyl‐, or propargyl silanes in a unique cascade sequence. An interrupted Pummerer reaction between benzothiophene S‐oxides and the coupling partners yields sulfonium salts that lack aromaticity and therefore allow facile [3,3]‐sigmatropic rearrangement. The subsequently generated benzothiophenium salts undergo a previously unexplored 1,2‐migration to access C2 functionalized benzothiophenes.
Samarium Polystibides Derived from Highly Activated Nanoscale Antimony
Authors: Schoo Christoph , Bestgen Sebastian , Egeberg Alexander , Klementyeva Svetlana , Feldmann Claus , Konchenko Sergey N. , Roesky Peter W.
Published: March 2018

Zintl ions in molecular compounds are of fundamental interest for basic research and application. Two reactive antimony sources are presented that allow direct access to molecular polystibide compounds. These are Sb amalgam (Sb/Hg) and ultrasmall Sb0 nanoparticles (d=6.6±0.8 nm), which were used independently as precursors for the synthesis of the largest f‐element polystibide, [(Cp*2Sm)4Sb8]. Whereas the reaction of the nanoparticles with [Cp*2Sm] directly led to [(Cp*2Sm)4Sb8], Sm/Sb/Hg intermediates were isolated when using Sb/Hg as the precursor. These Sm/Sb/Hg intermediates [{(Cp*2Sm)2Sb}2(μ‐Hg)] and [{(Cp*2Sm)3(μ4,η1:2:2:2‐Sb4)}2Hg] were synthetically trapped and structurally characterized, giving insight in the formation mechanism of polystibide compounds.
Relationship between the interfacial tension and compatibility of polycarbonate and poly(acrylonitrile–butadiene–styrene) blends with reactive compatibilizers
Authors: Ryu Seung Chan , Kim Jae Young , Kim Woo Nyon
Published: March 2018

We studied the morphological, mechanical, and rheological properties of polycarbonate (PC) and poly(acrylonitrile–butadiene–styrene) (PolyABS) blends with different types of compatibilizer. Styrene–acrylonitrile–maleic anhydride terpolymer (SAM) was used as a compatibilizer of the blends. For comparison, styrene–acrylonitrile–glycidyl methacrylate terpolymer (SAG) was also used as a compatibilizer. For the PC–PolyABS (70/30 wt %) blends with SAM, the mechanical strength and complex viscosity reached a maximum when the SAM concentration was 5 phr. The mechanical and rheological results of the blend were consistent with the morphological result that the PolyABS domain size reached a minimum when the SAM content was 5 phr. The interfacial tension (α) of the blend was compared with the compatibilizer type and content, which were calculated by the Palierne emulsion model with the relaxation time of the PC–PolyABS blend. The α is consistent with the morphological and mechanical properties of the PC–PolyABS blend. The results of the morphological, mechanical, and rheological properties of the blend suggest that SAM was a more effective compatibilizer than SAG, and the optimum compatibilizer content of SAM was 5 phr. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46418.
Synthesis, biological evaluation, and docking studies of some 5‐chloro‐2(3H)‐benzoxazolone Mannich bases derivatives as cholinesterase inhibitors
Authors: Uysal Sirin , Parlar Sulunay , Tarikogullari Ayse H. , Aydin Kose Fadime , Alptuzun Vildan , Soyer Zeynep
Published: March 2018

A series of N‐substituted‐5‐chloro‐2(3H)‐benzoxazolone derivatives were synthesized and evaluated for their acetylcholinesterase (AChE), butyrylcholinesterase (BuChE) inhibitory, and antioxidant activities. The structures of the title compounds were confirmed by spectral and elemental analyses. The cholinesterase (ChE) inhibitory activity studies were carried out using Ellman's colorimetric method. The free radical scavenging activity was also determined by in vitro ABTS (2,2‐azinobis(3‐ethylbenzothiazoline‐6‐sulfonic acid)) assay. The biological activity results revealed that all of the title compounds displayed higher AChE inhibitory activity than the reference compound, rivastigmine, and were selective for AChE. Among the tested compounds, compound 7 exhibited the highest inhibition against AChE (IC50 = 7.53 ± 0.17 μM), while compound 11 was found to be the most active compound against BuChE (IC50 = 17.50 ± 0.29 μM). The molecular docking study of compound 7 showed that this compound can interact with the catalytic active site (CAS) of AChE and also has potential metal chelating ability and a proper log P value. On the other hand, compound 2 bearing a methyl substituent at the ortho position on the phenyl ring showed better radical scavenging activity (IC50 = 1.04 ± 0.04 mM) than Trolox (IC50 = 1.50 ± 0.05 mM).
Controlled Assembly of Porphyrin‐MoS2 Composite Nanosheets for Enhanced Photoelectrochemical Performance
Authors: Wu Wenzhuo , Wei Cong , Lin Xiangcheng , Xu Qun
Published: March 2018

As a promising non‐precious metal photoelectrochemical (PEC) catalyst, MoS2 exhibits high electrocatalytic activity and stability, while the weak light absorption efficiency and low photoresponse current limit its practical application. Herein, a facile co‐assembly approach is proposed to construct porphyrin‐MoS2 composite photoelectrocatalysts. The as‐prepared photoelectrocatalysts show a significantly enhanced photocurrent response as high as 16 μA cm−2, which is about 2 times higher than that of bare MoS2. Furthermore, the obtained porphyrin‐MoS2 catalysts exhibit excellent durability when tested for 23000 s, thus providing a useful strategy for the design of highly efficient dye‐sensitized PEC catalysts.
From the basic science of biological effects of ultrashort electrical pulses to medical therapies
Authors: Schoenbach Karl H.
Published: March 2018

This article is based on my presentation at the D'Arsonval Ceremony at the Joint Annual Meeting of the Bioelectromagnetics Society and the European BioElectromagnetics Association in Hangzhou, China, in June of 2017. It describes the pathway from the first studies on the effects of intense, nanosecond pulses on biological cells to the development of medical therapies based on these effects. The motivation for the initial studies of the effects of high voltage, nanosecond pulses on mammalian cells was based on a simple electrical circuit model, which predicted that such pulses allow us to affect not just the plasma membrane but also the subcellular structures. The first experimental study that confirmed this hypothesis was published in 2001 in the Bioelectromagnetics journal. It was followed by a large number of publications that showed that such ultrashort pulses affect cell functions, such as programmed cell death, and, at lower intensity, calcium mobilization from intracellular structures. These basic studies were leading to novel cancer treatments, treatments of cardiac arrhythmia, and advanced wound healing. Further, by reducing the pulse duration into the picosecond range, antenna‐based neural stimulation seems to be possible. This manuscript gives an overview of the progress in this field of research in the decade after the initial bioelectric studies with high‐voltage, nanosecond pulses, particularly the research performed at the Frank Reidy Research Center for Bioelectrics. It also tells you about my journey and that of my colleagues at the Center for Bioelectrics into and through this fascinating bioelectromagnetics research area. Bioelectromagnetics. 39:257–276, 2018. © 2018 Wiley Periodicals, Inc.
Low Protease Content in Medicago truncatula Cell Cultures Facilitates Recombinant Protein Production
Authors: Santos Rita B. , Chandrasekar Balakumaran , Mandal Manoj K. , Kaschani Farnusch , Kaiser Markus , Both Leonard , van der Hoorn Renier A. L. , Schiermeyer Andreas , Abranches Rita
Published: March 2018

Medicago truncatula is an established model for studying legume biology. More recently, it has also been exploited as a Molecular Farming platform for the production of recombinant proteins, with the successful expression of fungal and human proteins in plants and cell suspension cultures of this species. One of the challenges that now must be overcome is the degradation of final products during production and downstream processing stages. In the M. truncatula genome, there are more than 400 putative protease‐encoding genes, but to date, the proteolytic content of Medicago cell cultures has not been studied. In this report, the proteolytic activities that can potentially hamper the successful production of recombinant proteins in this system are evaluated. The potential proteases responsible for the degradation of target proteins are identified. Interestingly, the number of proteases found in Medicago spent medium is considerably lower than that of the well‐established tobacco bright yellow 2 (BY‐2) system. Papain‐like cysteine proteases are found to be the major contributors to recombinant protein degradation in Medicago. This knowledge is used to engineer a cell line with reduced endogenous protease activity by expressing a selective protease inhibitor, further improving this expression platform.
Understanding and designing head‐to‐tail cyclic peptides
Authors: Slough Diana P. , McHugh Sean M. , Lin Yu‐Shan
Published: March 2018

Cyclic peptides (CPs) are an exciting class of molecules with a variety of applications. However, design strategies for CP therapeutics, for example, are generally limited by a poor understanding of their sequence–structure relationships. This knowledge gap often leads to a trial‐and‐error approach for designing CPs for a specific purpose, which is both costly and time‐consuming. Herein, we describe the current experimental and computational efforts in understanding and designing head‐to‐tail CPs along with their respective challenges. In addition, we provide several future directions in the field of computational CP design to improve its accuracy, efficiency and applicability. These advances, combined with experimental techniques, shall ultimately provide a better understanding of these interesting molecules and a reliable working platform to rationally design CPs with desired characteristics.
Exploring Equity in Early Postsecondary Education
Authors: Fox Heather L. , Zamani‐Gallaher Eboni M.
Published: March 2018

This chapter examines how postsecondary practitioners are encouraged to work collaboratively with child welfare agencies and other community‐based organizations to identify and implement culturally responsive supports for former foster youth to promote early academic achievement.
Electrochemical Biosensor for MicroRNA Detection Based on Cascade Hybridization Chain Reaction
Authors: Liang Meijuan , Pan Min , Hu Jialing , Wang Fuan , Liu Xiaoqing
Published: March 2018

The development of effective strategies for sensitive and specific detection of microRNAs will facilitate clinical diagnostics. Here, we utilize cascade hybridization chain reaction as an enzyme‐free isothermal amplified strategy, and construct label‐free electrochemical biosensors for microRNAassay. MicroRNA initiated autonomous assembly of DNA nanostructures through the toehold‐mediated strand displacement reaction. The assembly behavior was examined by gel electrophoresis and morphology of branched DNA nanostructure was verified by atomic force microscope. This cascade hybridization chain reaction leads to extended growth of DNA chains and higher amplification efficiency compared with the regular hybridization chain reaction. The performance of the sensors was characterized by electrochemical impedance spectroscopy, differential pulse voltammetry, and chronocoulometric analysis. The prepared biosensor exhibits high sensitivity and a lower detection limit of 11 pM for the determination of microRNA‐21. This electrochemical assay based on cascade hybridization chain reaction is specific and can distinguish between highly homologous targets such as fully complementary target microRNA‐21, single, or two‐base mismatched sequences and other family members. These findings open the possibility of using cascade hybridization chain reaction as possible amplified electrochemical sensing platforms.
Dibenzo[a,e]pentalenophanes: Bending a Non‐Alternant Hydrocarbon
Authors: Hermann Mathias , Wassy Daniel , Kratzert Daniel , Esser Birgit
Published: March 2018

In cyclophanes, an aromatic moiety is incorporated into a (strained) cyclic structure. Of particular interest as model systems for bent carbon nanostructures are those containing polycyclic aromatic hydrocarbons. Dibenzo[a,e]pentalene (DBP) is a non‐alternant polycyclic hydrocarbon with small band gap and tunable optoelectronic properties. However, changing these properties by bending of the DBP structure has yet to be investigated. Herein, we report the synthesis, optoelectronic, and structural properties of (2,7)dibenzo[a,e]pentalenophanes with four different bridge sizes and bending angles of the DBP unit, accompanied by (TD)DFT calculations. The last, strain‐inducing dehydration reaction was accomplished by using Burgess’ reagent. The HOMO and LUMO levels and the magnetic shielding of protons pointing inside the cyclophane cavity grew stepwise with increasing ring strain. Single‐crystal X‐ray structures of the smallest three derivatives revealed a near semi‐circle and a bend angle of the DBP unit of almost 88° for the smallest derivative. We demonstrated the synthetic versatility of our approach by varying the substituents at the DBP unit, allowing for further tuning of optoelectronic properties. The synthetic strategy presented herein may pave the way for the synthesis of conjugated DBP nanorings.
Towards the Next Generation of Lochmann–Schlosser Superbases: A Potassium Neopentyl/Alkoxy Aggregate used in the Tetra‐Functionalization of Ferrocene
Authors: Jennewein Bianca , Kimpel Sascha , Thalheim Daniel , Klett Jan
Published: March 2018

Lochmann–Schlosser superbases are formed by mixing alkyllithium with potassium alkoxides. These reagents could prove their synthetic usefulness and reliability in many reactions over five decades. However, despite many efforts, the real source of the exceptional reactivity remained a secret. The seemingly manageable system of four components (lithium, potassium atoms, alkyl groups, and alkoxy groups) and their interaction is obscured by poor solubility and fierce reactivity. Recent progress was achieved by using neopentyllithium, leading to alkane‐soluble aggregates with varying lithium/potassium content and a flexible alkyl/alkoxy ratio. Herein, we isolated two new alkane‐soluble alkyl/alkoxy mixed aggregates, [Li4KNp2(OtBu)3] and [K4Np(OtAm)3]. The latter compound is a thermally stable three‐component potassium alkyl/alkoxy base with well‐defined stoichiometry, in contrast to lithium‐containing Lochmann–Schlosser bases with variable metal and alkyl/alkoxy content. In a simple protocol, this potassium‐base gave tetrametalated ferrocene, which was converted into 1,1′,3,3′‐ferrocenetetracarboxylic acid by reaction with CO2. A subsequent conversion into the methyl ester allowed its separation from accompanying di‐ and tri‐substituted ferrocenes.
Synthesis and Immunological Studies of Oligosaccharides that Consist of the Repeating Unit of Streptococcus pneumoniae Serotype 3 Capsular Polysaccharide
Authors: Xiong Chenghe , Feng Shaojie , Qiao Yin , Guo Zhongwu , Gu Guofeng
Published: March 2018

A highly convergent and efficient strategy was developed for the chemical synthesis of complex oligosaccharides of Streptococcus pneumoniae type 3 capsular polysaccharides that contain multiple glucuronic acid units. Once the oligoglucosides were efficiently and stereoselectively assembled, the designated glucose units were regioselectively oxidized to glucuronic acid in one step at the final synthetic stage, which helped avoid difficult glycosylations that involved glucuronic acid. The target oligosaccharides had a free amino group at the reducing terminus and varied caps at the non‐reducing terminus to enable further modification and structure–activity relationship studies. Immunological evaluations of the oligosaccharide–tetanus toxoid conjugates showed that they elicited robust T‐cell‐dependent immunoglobulin G antibody responses and that the sugar chain length had a major impact on their immunological properties. In particular, the penta‐ and hexasaccharides were identified as promising antigens for vaccine development.
Superconductivity in the 2‐Dimensional Homologous Series AMmBi3Q5+m (m=1, 2) (A=Rb, Cs; M=Pb, Sn; Q=Se, Te)
Authors: Malliakas Christos D. , Chung Duck Young , Claus Helmut , Kanatzidis Mercouri G.
Published: March 2018

Superconductivity in the two‐dimensional AMmBi3Q5+m family of semimetals is reported. The AMBi3Te6 (m=1) and AM2Bi3Te7 (m=2) members of the homologous series with A=Rb, Cs and M=Pb, Sn undergo a bulk superconducting transition ranging from 2.7 to 1.4 K depending on the composition. The estimated superconducting volume fraction is about 90 %. Superconducting phase diagrams as a function of chemical pressure are constructed for the solid solution products of each member of the homologous series, AMBi3−xSbxTe6−ySey and AM2Bi3−xSbxTe7−ySey (0≤x≤3 or 0≤y≤2). The structural flexibility of the ternary AMmM′3Te5+m semiconducting homology to form isostructural analogues with a variety of metals, M=Pb, Sn; M′=Bi, Sb, gives access to a large number of electronic configurations and superconductivity due to chemical pressure effects.
Enantioselective behaviour of tetraconazole during strawberry wine‐making process
Authors: Liu Na , Pan Xinglu , Zhang Shuang , Ji Mingshan , Zhang Zhihong
Published: March 2018

The fate of tetraconazole enantiomers in strawberries during wine‐making process was studied. The residues were determined by ultra‐performance convergence chromatography tandem triple quadrupole mass spectrometry after each process steps. Results indicated that there was significant enantioselective dissipation of tetraconazole enantiomers during the fermentation process. And (−)‐tetraconazole degraded faster than (+)‐tetraconazole. The half‐lives of (−)‐tetraconazole and (+)‐tetraconazole were 3.12, 3.76 days with washing procedure and 3.18, 4.05 days without washing procedure. The processing factors of strawberry wine samples after each step were generally less than 1. In particular, the processing factors of the fermentation process were the lowest. The results could help facilitate more accurate risk assessments of tetraconazole during wine‐making process.
DR3TBDTT Based Ternary Blends Containing Conjugated Polymers: Crystallization Determines Morphology and Performance
Authors: Yin Jingping , Zhou Weihua , Ai Qingyun , Meng Xiangchuan , Liu Siqi , Yu Zoukangning , Zeng Jianrong , Chen Yiwang
Published: March 2018

How the conjugated polymers affect the crystallization of DR3TBDTT, in addition to the corresponding morphology and performance, is not well understood. In this work, the weakly crystalline polymer PTB7‐Th and highly crystalline polymers of PCDTBT and P3HT were incorporated into DR3TBDTT:PC71BM system to investigate the variation of crystallization, morphology and performance. It is demonstrated that PTB7‐Th is the most effective additive to improve the PCE value of DR3TBDTT:PC71BM to 5.7%, showing the nucleating agent reducing the crystallization correlation length (CCL) value of DR3TBDTT from 18.7 nm to 17.0 nm, in addition to the optimized morphology. In contrast, the PCDTBT and P3HT could induce the crystallization of DR3TBDTT, leading to much higher CCL value as well as obvious phase separation. Despite of energy level alignment, the crystallization of DR3TBDTT influenced by polymers determines the corresponding morphology of active layers and photovoltaic performance.
Impact of socioeconomic status on survival for patients with anal cancer
Authors: Lin Daniel , Gold Heather T. , Schreiber David , Leichman Lawrence P. , Sherman Scott E. , Becker Daniel J.
Published: March 2018

BACKGROUND

Although outcomes for patients with squamous cell carcinoma of the anus (SCCA) have improved, the gains in benefit may not be shared uniformly among patients of disparate socioeconomic status. In the current study, the authors investigated whether area‐based median household income (MHI) is predictive of survival among patients with SCCA.

METHODS

Patients diagnosed with SCCA from 2004 through 2013 in the Surveillance, Epidemiology, and End Results registry were included. Socioeconomic status was defined by census‐tract MHI level and divided into quintiles. Multivariable Cox proportional hazards models and logistic regression were used to study predictors of survival and radiotherapy receipt.

RESULTS

A total of 9550 cases of SCCA were included. The median age of the patients was 58 years, 63% were female, 85% were white, and 38% were married. In multivariable analyses, patients living in areas with lower MHI were found to have worse overall survival and cancer‐specific survival (CSS) compared with those in the highest income areas. Mortality hazard ratios for lowest to highest income were 1.32 (95% confidence interval [95% CI], 1.18‐1.49), 1.31 (95% CI, 1.16‐1.48), 1.19 (95% CI, 1.06‐1.34), and 1.16 (95% CI, 1.03‐1.30). The hazard ratios for CSS similarly ranged from 1.34 to 1.22 for lowest to highest income. Older age, black race, male sex, unmarried marital status, an earlier year of diagnosis, higher tumor grade, and later American Joint Committee on Cancer stage of disease also were associated with worse CSS. Income was not found to be associated with the odds of initiating radiotherapy in multivariable analysis (odds ratio of 0.87 for lowest to highest income level; 95% CI, 0.63‐1.20).

CONCLUSIONS

MHI appears to independently predict CSS and overall survival in patients with SCCA. Black race was found to remain a predictor of SCCA survival despite controlling for income. Further study is needed to understand the mechanisms by which socioeconomic inequalities affect cancer care and outcomes. Cancer 2018;124:1791‐7. © 2018 American Cancer Society
Adaptive precision in block‐Jacobi preconditioning for iterative sparse linear system solvers
Authors: Anzt Hartwig , Dongarra Jack , Flegar Goran , Higham Nicholas J. , Quintana‐Ortí Enrique S.
Published: March 2018

We propose an adaptive scheme to reduce communication overhead caused by data movement by selectively storing the diagonal blocks of a block‐Jacobi preconditioner in different precision formats (half, single, or double). This specialized preconditioner can then be combined with any Krylov subspace method for the solution of sparse linear systems to perform all arithmetic in double precision. We assess the effects of the adaptive precision preconditioner on the iteration count and data transfer cost of a preconditioned conjugate gradient solver. A preconditioned conjugate gradient method is, in general, a memory bandwidth‐bound algorithm, and therefore its execution time and energy consumption are largely dominated by the costs of accessing the problem's data in memory. Given this observation, we propose a model that quantifies the time and energy savings of our approach based on the assumption that these two costs depend linearly on the bit length of a floating point number. Furthermore, we use a number of test problems from the SuiteSparse matrix collection to estimate the potential benefits of the adaptive block‐Jacobi preconditioning scheme.
Accelerating explicit ODE methods on GPUs by kernel fusion
Authors: Korch Matthias , Werner Tim
Published: March 2018

Graphics processing units (GPUs) have a promising architecture for implementing highly parallel solution methods for systems of ordinary differential equations (ODEs). However, their high performance comes at the price of caveats such as small caches or wide SIMD. For ODE methods, optimizing the memory access pattern is often crucial. In this article, instead of considering only one specific method, we generalize the description of explicit ODE methods by using data flow graphs consisting of basic operations that are suitable to cover the types of computations occurring in all common explicit methods. After showing that the straightforward approach for processing the data flow graph by calling one kernel per basic operation is memory bound, we explain how the number of memory accesses can be reduced by the kernel fusion technique, which fuses several basic operations into one kernel. Moreover, we will present enabling transformations that allow additional fusions and thus can reduce the number of memory accesses even further. We apply these optimizations to three different classes of explicit ODE methods: embedded Runge–Kutta (RK) methods, parallel iterated RK (PIRK) methods, and peer methods. A detailed experimental evaluation on three modern GPUs showed speedups between 1.86 and 3.51 compared to unfused implementations.
Growth of Bulk GaN from Gas Phase
Authors: Siche Dietmar , Zwierz Radoslaw
Published: March 2018

The present status of the GaN bulk growth by vapor growth methods is reviewed and is shortly classified into all methods with bulk growth potential. The hydride vapor phase epitaxy (HVPE) as the most developed and already commercialized method using chlorine as transport agent was frequently reviewed before. However, it does not yield true bulk GaN, suffers from perfection limiting heteroepitaxy, direction depending growth rate, parasitic growth and by‐product formation, the latter both limiting the process duration. Therefore, in this review other methods are considered. Alternative transport agents are pronounced, like iodine, hydrogen, oxygen, water and the pseudo halide CN− ‐ ion, which are not able to reveal potential for bulk growth. These mostly less successful approaches, are sometimes repeated, because not adequately published.
Identifying the Mechanism of Continued Growth of the Solid–Electrolyte Interphase
Authors: Single Fabian , Latz Arnulf , Horstmann Birger
Published: March 2018

Continued growth of the solid–electrolyte interphase (SEI) is the major reason for capacity fade in modern lithium‐ion batteries. This growth is made possible by a yet unidentified transport mechanism that limits the passivating ability of the SEI towards electrolyte reduction. We, for the first time, differentiate the proposed mechanisms by analyzing their dependence on the electrode potential. Our calculations are compared to recent experimental capacity‐fade data. We show that the potential dependence of SEI growth facilitated by solvent diffusion, electron conduction, or electron tunneling qualitatively disagrees with the experimental observations. Only diffusion of Li interstitials results in a potential dependence matching the experiments. Therefore, we identify the diffusion of neutral radicals, such as Li interstitials, as the cause of long‐term SEI growth.