bluuebunny/crossref_metadata_2025 huggingface dataset:
Lateral Adsorbate Interactions Inhibit HCOO− while Promoting CO Selectivity for CO2 Electrocatalysis on Silver
Authors: Bohra Divya , Ledezma‐Yanez Isis , Li Guanna , de Jong Wiebren , Pidko Evgeny A. , Smith Wilson A.
Published: November 2018

Ag is a promising catalyst for the production of carbon monoxide (CO) via the electrochemical reduction of carbon dioxide (CO2ER). Herein, we study the role of the formate (HCOO−) intermediate *OCHO, aiming to resolve the discrepancy between the theoretical understanding and experimental performance of Ag. We show that the first coupled proton‐electron transfer (CPET) step in the CO pathway competes with the Volmer step for formation of *H, whereas this Volmer step is a prerequisite for the formation of *OCHO. We show that *OCHO should form readily on the Ag surface owing to solvation and favorable binding strength. In situ surface‐enhanced Raman spectroscopy (SERS) experiments give preliminary evidence of the presence of O‐bound bidentate species on polycrystalline Ag during CO2ER which we attribute to *OCHO. Lateral adsorbate interactions in the presence of *OCHO have a significant influence on the surface coverage of *H, resulting in the inhibition of HCOO− and H2 production and a higher selectivity towards CO.
Control of Metal–Organic Framework Crystallization by Metastable Intermediate Pre‐equilibrium Species
Authors: Yeung Hamish H.‐M. , Sapnik Adam F. , Massingberd‐Mundy Felicity , Gaultois Michael W. , Wu Yue , Fraser Duncan A. X. , Henke Sebastian , Pallach Roman , Heidenreich Niclas , Magdysyuk Oxana V. , Vo Nghia T. , Goodwin Andrew L.
Published: November 2018

There is an increasing amount of interest in metal–organic frameworks (MOFs) for a variety of applications, from gas sensing and separations to electronics and catalysis. However, the mechanisms by which they crystallize remain poorly understood. Herein, an important new insight into MOF formation is reported. It is shown that, prior to network assembly, crystallization intermediates in the canonical ZIF‐8 system exist in a dynamic pre‐equilibrium, which depends on the reactant concentrations and the progress of reaction. Concentration can, therefore, be used as a synthetic handle to directly control particle size, with potential implications for industrial scale‐up and gas sorption applications. These findings enable the rationalization of apparent contradictions between previous studies of ZIF‐8 and opens up new opportunities for the control of crystallization in network solids more generally.
Black Phosphorus: Bioactive Nanomaterials with Inherent and Selective Chemotherapeutic Effects
Authors: Zhou Wenhua , Pan Ting , Cui Haodong , Zhao Zhen , Chu Paul K. , Yu Xue‐Feng
Published: November 2018

Black phosphorus nanosheets (BPs) are demonstrated to be highly bioactive anti‐cancer agents because of their inherent and selective chemotherapeutic effects. Fast intracellular biodegradation of BPs and acute elevation of phosphate anions were observed from different types of cancer cells due to the stronger intracellular oxidative stress and accelerated energy metabolism, but normal cells are not affected. Selective biodegradation of BPs induced G2/M phase arrest and subsequent apoptosis‐ and autophagy‐mediated cell death in cancer cells but not normal cells. The selectivity was superior to that of the traditional chemotherapeutic agent, doxorubicin (DOX). In vivo assessment confirmed the efficiency of BPs in suppressing tumor growth. This study provides insights into nanostructured bioactive anti‐cancer agents and reveals a new direction for nanomedicine research.
Catalytic Enantioselective α‐Ketol Rearrangement
Authors: Wu Hua , Andres Rémi , Wang Qian , Zhu Jieping
Published: November 2018

A highly enantioselective α‐ketol rearrangement has been developed. In the presence of a chiral Cu‐bisoxazoline complex, achiral β‐hydroxy‐α‐dicarbonyls were isomerized to chiral α‐hydroxy‐β‐dicarbonyls and their bicyclic derivatives in excellent yields and enantioselectivities. Enantioenriched 2‐acyl‐2‐hydroxy cyclohexan‐1‐ones, dihydroxyhexahydrobenzofuranones, and dihydroxyhexahydro‐cycloheptafuranones, with up to three stereocenters, were readily prepared from achiral starting materials in one operation. The reaction is applicable to the desymmetrization of meso substrates and kinetic resolution of racemic alcohols.
In silico detection of polymorphic microsatellites in the endangered Isis tamarind, Alectryon ramiflorus (Sapindaceae)
Authors: Nichols Joel , Conroy Gabriel C. , Kasinadhuni Naga , Lamont Robert W. , Ogbourne Steven M.
Published: November 2018

Premise of the Study

Alectryon ramiflorus (Sapindaceae) is an endangered rainforest tree known from only two populations. In this study, we identified polymorphic microsatellites, in silico, improving the effectiveness and efficiency of microsatellite development of nonmodel species. The development of genetic markers will support future conservation management of the species.

Methods and Results

We used next‐generation sequencing and bioinformatics to detect polymorphic microsatellites, in silico, reducing both the time and cost of marker development. A panel of 15 microsatellites, 12 of which were polymorphic, were subsequently characterized in 64 adult trees representing the entire species range. Mean observed heterozygosity and expected heterozygosity were 0.471 and 0.425, respectively. The polymorphism information content across loci ranged from 0.152 to 0.875.

Conclusions

The microsatellite markers developed in this study will be useful in gaining an understanding of A. ramiflorus’ genetic diversity, level of inbreeding, and population structure and for guiding future restoration and management efforts.
Quality, impact, and quantification: Indicators and metrics use by social scientists
Authors: Haddow Gaby , Hammarfelt Björn
Published: November 2018

The use of indicators and metrics for research evaluation purposes is well‐documented; however, less is known about their use by individual scholars. With a focus on the social sciences, this article contributes to the existing literature on indicators and metrics use in fields with diverse publication practices. Scholars in Australia and Sweden were asked about their use and reasons for using metrics. A total of 581 completed surveys were analyzed to generate descriptive statistics, with textual analysis performed on comments provided to open questions. While just under half of the participant group had used metrics, the Australians reported use in twice the proportion of their Swedish peers. Institutional policies and processes were frequently associated with use, and the scholars' comments suggest a high level of awareness of some metrics as well as strategic behavior in demonstrating research performance. There is also evidence of tensions between scholars' research evaluation environment and their disciplinary values and publication practices.
Alkyl Sulfides as Promising Sulfur Sources: Metal‐Free Synthesis of Aryl Alkyl Sulfides and Dialkyl Sulfides by Transalkylation of Simple Sulfides with Alkyl Halides
Authors: Liu Ting , Qiu Renhua , Zhu Longzhi , Yin Shuang‐Feng , Au Chak‐Tong , Kambe Nobuaki
Published: November 2018

A site‐selective metal‐free dealkylative approach to synthesize aryl alkyl and symmetrical dialkyl sulfides has been developed. This procedure is convenient and has wide functional group tolerance giving rise to sulfides carrying various alkyl chains from simple alkyl sulfides and alkyl halides in good to excellent yields. This transalkylation proceeds by an ionic mechanism via sulfonium intermediates and it was proposed that dimethylacetamide (DMAC) may participate in part to promote the reaction.
Adaptive Fault‐Tolerant Control of Uncertain MIMO Systems with Reduced Requirement on Desired Trajectory Under Unknown Control Direction
Authors: Jiang Qiqi , Xian Xiaodong , Zhang Zhirong
Published: November 2018

This paper aims at investigating the tracking control problem for a class of multi‐input multi‐output (MIMO) nonlinear systems with non‐square control gain matrix subject to unknown control direction and uncertain desired trajectory. By using the artificial neural network (NN) reconstructs the target trajectory with actual disguised trajectory, we are able to design a practical and stable tracking control scheme without the need for the unavailable desired trajectory. Nussbaum‐type function is incorporated in the control law to handle the unknown control direction. The remarkable feature of the proposed scheme is that it is robust against modeling uncertainties and tolerant to actuation faults, yet guarantees that the closed‐loop system is stable in the sense of ultimately uniformly bounded (UUB). The effectiveness of the proposed control schemes are illustrated through simulation results.
Intervention, stimulus control, and generalization effects of response interruption and redirection on motor stereotypy
Authors: Gould Kaitlin M. , Harper Jill M. , Gillich Emily , Luiselli James K.
Published: November 2018

This study evaluated the effects of response interruption and redirection (RIRD) on motor stereotypy (hand and body movements) in a child with neurodevelopmental disorders. We also assessed whether a stimulus paired with RIRD could acquire inhibitory control when tested during nonintervention conditions. Compared with baseline phases in a reversal design, RIRD decreased both hand and motor stereotypies, and there was evidence of stimulus control. Extending RIRD to a second setting was also effective. The care providers responsible for intervention implemented RIRD with fidelity, and they rated the procedure positively. Clinical and research implications from these findings are discussed.
Development of a micelle‐enhanced high‐throughput fluorometric method for determination of niclosamide using a microplate reader
Authors: Abd El‐Hay Soad S. , Belal Fathalla F.
Published: November 2018

The present paper describes the development and validation of a simple and sensitive micelle‐enhanced high‐throughput fluorometric method for the determination of niclosamide (NIC) in 96‐microwell plates. The proposed method is based on the reduction of the nitro group of niclosamide to an amino group using Zn/HCl to give a highly fluorescent derivative that was developed simultaneously and measured at λem 444 nm after excitation at λex 275 nm. Tween‐80 and carboxymethylcellulose (CMC) have been used as fluorescence enhancers and greatly enhanced the fluorescence by factors of 100–150%. The different experimental conditions affecting the fluorescence reaction were carefully investigated and optimized. The proposed method showed good linearity (r2≥ 0.9997) over the concentration ranges of 1–5 and 0.5–5 μg/ml with lower detection limits of 0.01 and 0.008 μg/ml and lower quantification limits of 0.04 and 0.03 μg/ml on using Tween‐80 and or CMC, respectively. The developed high‐throughput method was successfully applied for the determination of niclosamide in both tablets and spiked plasma. The capability of the method for measuring microvolume samples made it convenient for handling a very large number of samples simultaneously. In addition, it is considered an environmentally friendly method with lower consumption of chemicals and solvents.
A multi‐site metastasis‐on‐a‐chip microphysiological system for assessing metastatic preference of cancer cells
Authors: Aleman Julio , Skardal Aleksander
Published: November 2018

Metastatic disease remains one of the primary reasons for cancer‐related deaths, yet the majority of in vitro cancer models focus on the primary tumor sites. Here, we describe a metastasis‐on‐a‐chip device that houses multiple bioengineered three‐dimensional (3D) organoids, established by a 3D photopatterning technique employing extracellular matrix‐derived hydrogel biomaterials. Specifically, cancer cells begin in colorectal cancer (CRC) organoid, which resides in a single microfluidic chamber connected to multiple downstream chambers in which liver, lung, and endothelial constructs are housed. Under recirculating fluid flow, tumor cells grow in the primary site, eventually enter circulation, and can be tracked via fluorescent imaging. Importantly, we describe that in the current version of this platform, HCT116 CRC cells preferentially home to the liver and lung constructs; the corresponding organs of which CRC metastases arise the most in human patients. We believe that in subsequent studies this platform can be implemented to better understand the mechanisms underlying metastasis, perhaps resulting in the identification of targets for intervention.
Metabolite identification of tanshinol borneol ester in rats by high‐performance liquid chromatography combined with electrospray ionization quadrupole time‐of‐flight mass spectrometry
Authors: Wang Jie , Ma Cuicui , Li Qiannan , Wang Xing , Yang Yang , Yang Lingjian , Jiang Wei , Liao Sha , Wang Shixiang , Jia Pu , Zhao Ye , Zheng Xiaohui
Published: November 2018

Tanshinol borneol ester (DBZ) is a potential drug candidate composed of danshensu and borneol. It shows anti‐ischemic and anti‐atherosclerosis activity. However, little is known about its metabolism in vivo. This research aimed to elucidate the metabolic profile of DBZ through analyzing its metabolites using high‐performance liquid chromatography combined with electrospray ionization quadrupole time‐of‐flight mass spectrometry. Chromatographic separation was performed on an Agilent TC‐C18 column (150 × 4.6 mm, 5.0 μm) with gradient elution using methanol and water containing 0.2% (v/v) formic acid as the mobile phase. Metabolite identification involved analyzing the retention behaviors, changes in molecular weights and MS/MS fragment patterns of DBZ and its metabolites. As a result, 20 potential metabolites were detected and tentatively identified in rat plasma, urine and feces after administration of DBZ. DBZ could be metabolized to O‐methylated DBZ, DBZ‐O‐glucuronide, O‐methylated DBZ‐O‐glucuronide, hydroxylated DBZ and danshensu. Danshensu, a hydrolysis product of DBZ, could further be transformed into 12 metabolites. The proposed method was confirmed to be a reliable and sensitive alternative for characterizing metabolic pathways of DBZ and providing valuable information on its druggability.
Drivers and barriers of eco‐innovation types for sustainable transitions: A quantitative perspective
Authors: Kiefer Christoph P. , Del Río González Pablo , Carrillo‐Hermosilla Javier
Published: November 2018

Firms are influenced by internal factors (resources and capabilities) and external factors (e.g., regulation) when taking the decision to eco‐innovate. However, the analysis of the internal factors has received much less attention than the external ones. This paper aims to fill this gap in the literature by analyzing the role of resources, competences, and dynamic capabilities (RCCs) as determinants (drivers and barriers) of different eco‐innovation (EI) types. Those EI types contribute differently to the sustainable transition of the economy and society, that is, towards the circular economy. The statistical analyses reveal that RCCs are quite relevant as determinants of EIs, and that different RCCs are more or less relevant for different EI types. In particular, the determinants of systemic and radical EIs substantially differ from those for continuous improvements. Our results suggest that physical RCCs, involvement in green supply chains, an EI‐friendly corporate culture, technology‐push and market‐pull, and internal financing resources represent drivers to these EIs, whereas cooperation, organizational learning, an ISO (International Organization for Standardization) ecological certification, and technological path dependency are barriers. The results may guide firms to pursue competitive and sustainable advantage by innovating through certain EI types corresponding to available and dedicated RCCs. They may also be useful to policy makers who are willing to promote specific EI types.
Extraction and Antioxidant Activities of Magnolia kwangsiensisFiglar & Noot. Leaf Polyphenols
Authors: Zheng Yan‐Fei , Liu Xiong‐Min , Lai Fang
Published: November 2018

Microwave‐assisted extraction was employed to extract polyphenols from the leaf of Magnolia kwangsiensis Figlar & Noot. The yield of polyphenols was 2.44±0.02 % under the optimal conditions of RSM: acetone concentration of 70 %, ratio of solvent to material of 21 mL⋅g−1 and extraction time of 16 min. The antioxidant activities were evaluated in terms of total antioxidant ability, reducing power, DPPH⋅ and ⋅OH scavenging activity. Results showed the polyphenols presented potential antioxidant activities, especially the stronger scavenging activity on ⋅OH. In term of ⋅OH scavenging activity, the IC50 value of NKA‐9 purification was 0.335 mg mL−1, equivalent to 35.23 % of VC. The IC50 values of crude extract and ethyl acetate extract were 0.580 and 0.828 mg mL−1, equivalent to 60.99 % and 87.07 % of VC. Results indicated that M. kwangsiensis leaf polyphenols present potential antioxidant activities that make it beneficial for human health by preventing or reducing oxidative damage.
Reactivity of the Major Product of C5′‐Oxidative DNA Damage in Nucleosome Core Particles
Authors: Rana Anup , Yang Kun , Greenberg Marc M.
Published: November 2018

The major pathway for DNA damage following hydrogen atom abstraction from the C5′‐position results in direct strand scission and concomitant formation of a 5′‐aldehyde‐containing nucleotide (e.g., T‐al). We determined that the half‐life of alkali‐labile T‐al in free DNA under physiological conditions varies from 5–12 days. T‐al reactivity was examined at three positions within nucleosome core particles (NCPs). β‐Elimination increased >2.5‐fold when T‐al was proximal to the lysine‐rich histone H4 tail. No difference in reactivity between free DNA and NCPs was observed when T‐al was distal from the histone tails. The position‐dependent involvement of histone tails in T‐al elimination was gleaned from experiments with sodium cyanoborohydride and histone protein variants. The enhancement of T‐al elimination in NCPs is significantly smaller than previously observed for abasic sites. Computational studies comparing elimination from T‐al and abasic sites indicate that the barrier for the rate‐determining step in the latter is 2.6 kcal mol−1 lower and is stabilized by a hydrogen bond between the C4‐hydroxy group and phosphate leaving group. The long lifetime for T‐al in NCPs, combined with what is known about its repair suggests that this DNA lesion might pose significant challenges within cells.
Efficient Cytoplasmic Delivery of Antisense Probes Assisted by Cyclized‐Peptide‐Mediated Photoinduced Endosomal Escape
Authors: Tan Xiaohong , Bruchez Marcel P. , Armitage Bruce A.
Published: November 2018

Intracellular delivery and endosomal release of antisense oligonucleotides remain a significant challenge in the development of gene‐targeted therapeutics. Previously, noncovalently cyclized TAT peptide (Cyc‐TAT), in which the final ring‐closing step is accomplished by hybridization of two short complementary γPNA segments, has been proven more efficient than its linear analogues at entering cells. As Cyc‐TAT also readily accommodates a binding site, that is, an overhanging γPNA sequence, for codelivery of functional nucleic acid probes into cells, we were able to demonstrate that the overhang‐Cyc‐TAT penetrated into A549 cells when carrying an anti‐telomerase γPNA that specifically reduced telomerase activity by over 97 %. Herein, we report that the cyclized TAT(FAM) can escape endosomes much more efficiently than the linear TAT(FAM) after LED illumination (490 nm). Based on this observation, the endosomal release of overhang‐Cyc‐TAT(FAM)/anti‐telomerase γPNA complex can be greatly enhanced by photoactivation, thus shortening cell treatment time from 60 to 3 h, while keeping the same high efficiency in inhibiting telomerase activity inside A549 cells.
miR‐381 overcomes cisplatin resistance in breast cancer by targeting MDR1
Authors: Yi Dandan , Xu Lei , Wang Ru , Lu Xingyi , Sang Jianfeng
Published: November 2018

Increasing evidence suggests the involvement of microRNA‐381 (miR‐381) in chemoresistance of cancer treatment. However, its function and molecular mechanisms in breast cancer chemoresistance are still not well elucidated. In the present study, we aimed to investigate the functional role of miR‐381 in cisplatin (DDP) resistance of breast cancer and discover the underlying molecular mechanism. The expression levels of miR‐381 and MDR1 were detected by quantitative real‐time PCR (qRT‐PCR) and Western blot analysis in breast cancer tissues and cell lines. The DDP sensitivity and cell apoptosis of breast cancer cells were determined by MTT assay and flow cytometric analysis, respectively. The relationship between miR‐381 and MDR1 was explored by target prediction and luciferase reporter analysis. miR‐381 was decreased in DDP‐resistant breast cancer tissues and cell lines. Low miR‐381 expression was correlated with poor prognosis of breast cancer patients. miR‐381 overexpression improved DDP sensitivity of MCF‐7/DDP and MDA‐MB‐231/DDP cells. Conversely, miR‐381 inhibition lowered the response of MCF‐7 and MDA‐MB‐231 to DPP. Moreover, miR‐381 could directly suppress multidrug resistance 1 (MDR1) expression. MDR1 knockdown could overcome DDP resistance in MCF‐7/DDP and MDA‐MB‐231/DDP cells, while MDR1 overexpression led to DDP resistance in MCF‐7 and MDA‐MB‐231 cells. Notably, MDR1 overexpression counteracted the inductive effect of miR‐381 mimics on DDP sensitivity of MCF‐7/DDP and MDA‐MB‐231/DDP cells. On the contrary, miR‐381 inhibition‐mediated DDP resistance in MCF‐7 and MDA‐MB‐231 cells was reversed by MDR1 knockdown. In summary, miR‐381 could overcome DDP resistance of breast cancer by directly targeting MDR1, providing a novel therapeutic target for breast cancer chemoresistance.
A novel user‐friendly transcatheter edge‐to‐edge mitral valve repair device in a porcine model
Authors: Pan Wenzhi , Pan Cuizhen , Jilaihawi Hasan , Wei Lai , Tang Yue , Zhou Daxin , Ge Junbo
Published: November 2018

Objectives

The present study was performed to evaluate the feasibility and safety of the ValveClamp system for transcatheter edge‐to‐edge mitral valve repair in a porcine model.

Background

The ValveClamp system is a novel, transapically delivered edge‐to‐edge mitral valve repair system designed for ease of operation.

Methods

Thirteen young adult swine were enrolled in the study. The procedure was performed via the transapical approach under epicardial echocardiography guidance.

Results

The acute procedure success rate was 92.3% (12/13). The catheter manipulation time was just 18.5 ± 8.2 min. Four pigs were explanted on the 14th day after the procedure. One pig died at the 20th day because of pneumonia. The other eight pigs lived to the study endpoint (140 days). No pig had severe mitral valve dysfunction. The gross observation showed that the clamp device was securely attached and created a double‐orifice mitral valve in all pigs except the failed one. In the eight pigs living to the endpoint, the clamp device was noted to be completely endothelialized. None of the 13 pigs developed infective endocarditis, thrombosis, thromboembolism, or valve impairment. In two pigs for which mitral regurgitation (MR) was created, the degree of MR was reduced from severe to trace after the device implantation.

Conclusions

It was feasible and safe to use ValveClamp to perform a catheter‐mediated edge‐to‐edge mitral valve repair in a porcine model. This system is potentially applicable as a novel user‐friendly system for the treatment of MR.
Mn3O4@C Nanoparticles Supported on Porous Carbon as Bifunctional Oxygen Electrodes and their Electrocatalytic Mechanism
Authors: Li Ms. Wanqing , Fu Mr. Hongquan , Cao Yonghai , Wang Hongjuan , Yu Hao , Qiao Zhiwei , Liang Hong , Peng Feng
Published: November 2018

Mn3O4 nanoparticles encapsulated inside carbon nanospheres supported on a carbon plate (Mn3O4@CS/CP) were designed, their bifunctional electrocatalytic performance for both, the oxygen evolution reaction (OER) at the anode and the oxygen reduction reaction (ORR) at the cathode were studied in alkaline solution. The prepared Mn3O4@CS/CP catalyst exhibits excellent electrocatalytic performance towards ORR, with less negative onset potential and long durability. Combining the results of in‐situ Fourier transform infrared spectroscopy (FTIR) and density functional theory (DFT) calculations, it is revealed that Mn3O4 acts as active site for ORR to promote the transformation of OH* into OH−. In addition, Mn3O4@CS/CP possesses an excellent electrochemical OER performances with the lower overpotential along with prosper Tafel slope and robust durability. DFT calculations show the transformation from O* to OOH* is the rate determining step for OER, and Mn3O4@CS/CP shows the minimum barrier, indicating that graphene sheet on the outer of Mn3O4 improves the transformation from O* to OOH*. The oxygen electrode activity parameter (potential difference between OER at current density of 10 mA/cm2 and ORR at current density of −2 mA/cm2) on Mn3O4@CS/CP is 0.72 V, which is superior to those of most bifunctional electrocatalysts reported to date, predicting a promising application in metal‐air batteries and fuel cells.
Turn On of a Ruthenium(II) Photocatalyst by DNA‐Templated Ligation
Authors: Anzola Marcello , Winssinger Nicolas
Published: November 2018

Here, the synthesis of a RuII photocatalyst by light‐directed oligonucleotide‐templated ligation reaction is described. The photocatalyst was found to have tremendous potential for signal amplification with >15000 turnovers measured in 9 hours. A templated reaction was used to turn on the activity of this ruthenium(II) photocatalyst in response to a specific DNA sequence. The photocatalysis of the ruthenium(II) complex was harnessed to uncage a new precipitating dye that is highly fluorescent and photostable in the solid state. This reaction was used to discriminate between different DNA analytes based on localization of the precipitate as well as for in cellulo miRNA detection. Finally, a bipyridine ligand functionalized with two different peptide nucleic acid (PNA) sequences was shown to enable template‐mediated ligation (turn on of the ruthenium(II) photocatalysis) and recruitment of substrate for templated photocatalysis.
Synthesis and Ring Strain of a Benzoborirene‐N‐Heterocyclic Carbene Adduct
Authors: Hahn Jennifer , Keck Constanze , Maichle‐Mössmer Cäcilia , von Grotthuss Esther , Ruth Paul Niklas , Paesch Alexander , Stalke Dietmar , Bettinger Holger F.
Published: November 2018

The reduction of an N‐heterocyclic carbene (1,3‐diisopropyl‐4,5‐dimethylimidazolin‐2‐ylidene, IiPr
) adduct of dichloro(ortho‐bromophenyl)borane by tert‐butyl lithium at low temperature yields the IiPr
adduct A of parent benzoborirene, a highly strained boron‐containing bicyclic compound. A is unstable at room temperature and dimerizes at low temperature to the bis‐IiPr
adduct of 9,10‐dihydro‐9,10‐diboraanthracene, characterized by single‐crystal X‐ray crystallography.
Incarceration of Iodine in a Pyrene‐Based Metal–Organic Framework
Authors: Gładysiak Andrzej , Nguyen Tu N. , Spodaryk Mariana , Lee Jung‐Hoon , Neaton Jeffrey B. , Züttel Andreas , Stylianou Kyriakos C.
Published: November 2018

A pyrene‐based metal‐organic framework (MOF) SION‐8 captured iodine (I2) vapor with a capacity of 460 and 250 mg g−1MOF at room temperature and 75 °C, respectively. Single‐crystal X‐ray diffraction analysis and van‐der‐Waals‐corrected density functional theory calculations confirmed the presence of I2 molecules within the pores of SION‐8 and their interaction with the pyrene‐based ligands. The I2–pyrene interactions in the I2‐loaded SION‐8 led to a 104‐fold increase of its electrical conductivity compared to the bare SION‐8. Upon adsorption, ≥95 % of I2 molecules were incarcerated and could not be washed out, signifying the potential of SION‐8 towards the permanent capture of radioactive I2 at room temperature.
Resurrection and Reactivation of Acetylcholinesterase and Butyrylcholinesterase
Authors: Franjesevic Andrew J. , Sillart Sydney B. , Beck Jeremy M. , Vyas Shubham , Callam Christopher S. , Hadad Christopher M.
Published: November 2018

Organophosphorus (OP) nerve agents and pesticides present significant threats to civilian and military populations. OP compounds include the nefarious G and V chemical nerve agents, but more commonly, civilians are exposed to less toxic OP pesticides, resulting in the same negative toxicological effects and thousands of deaths on an annual basis. After decades of research, no new therapeutics have been realized since the mid‐1900s. Upon phosphylation of the catalytic serine residue, a process known as inhibition, there is an accumulation of acetylcholine (ACh) in the brain synapses and neuromuscular junctions, leading to a cholinergic crisis and eventually death. Oxime nucleophiles can reactivate select OP‐inhibited acetylcholinesterase (AChE). Yet, the fields of reactivation of AChE and butyrylcholinesterase encounter additional challenges as broad‐spectrum reactivation of either enzyme is difficult. Additional problems include the ability to cross the blood brain barrier (BBB) and to provide therapy in the central nervous system. Yet another complication arises in a competitive reaction, known as aging, whereby OP‐inhibited AChE is converted to an inactive form, which until very recently, had been impossible to reverse to an active, functional form. Evaluations of uncharged oximes and other neutral nucleophiles have been made. Non‐oxime reactivators, such as aromatic general bases and Mannich bases, have been developed. The issue of aging, which generates an anionic phosphylated serine residue, has been historically recalcitrant to recovery by any therapeutic approach—that is, until earlier this year. Mannich bases not only serve as reactivators of OP‐inhibited AChE, but this class of compounds can also recover activity from the aged form of AChE, a process referred to as resurrection. This review covers the modern efforts to address all of these issues and notes the complexities of therapeutic development along these different lines of research.
Simply Structured Near‐Infrared Emitters with a Multicyano Linear Acceptor for Solution‐Processed Organic Light‐Emitting Diodes
Authors: Zhao Bingjie , Xie Guohua , Wang Huiqin , Han Chunmiao , Xu Hui
Published: November 2018

Near‐infrared (NIR) organic light‐emitting diodes (OLEDs) show great potential in a variety of applications including sensors, night vision, and information security. Despite the superiority of thermally activated delayed fluorescence (TADF) in 100 % exciton harvesting, the development of NIR TADF OLEDs is still a great challenge, especially in terms of solution‐processing technology. In this work, a multicyano acceptor of 2‐dicyanomethylene‐3‐cyano‐4,5,5‐trimethyl‐2,5‐dihydrofurance (TCF) with strong electron‐withdrawing ability was employed to construct solution‐processible NIR emitters, CzTCF and tBCzTCF, with the feature of donor–π–acceptor (D–π–A) structure. The significantly enhanced intermolecular charge transfer effects not only render the deep‐red and NIR emissions of CzTCF and tBCzTCF films, respectively, but also lead to their typical TADF characteristics. Consequently, the nondoped solution‐processed NIR OLED based on tBCzTCF was successfully demonstrated with the peak wavelength of 715 nm, which paves the way for developing NIR emitters without polycyclic aromatic cores and heavy‐metal ions.
H2 Activation by Non‐Transition‐Metal Systems: Hydrogenation of Aldimines and Ketimines with LiN(SiMe3)2
Authors: Elliott Daniel C. , Marti Alex , Mauleón Pablo , Pfaltz Andreas
Published: November 2018

In recent years, H2 activation at non‐transition‐metal centers has met with increasing attention. Here, a system in which H2 is activated and transferred to aldimines and ketimines using substoichiometric amounts of lithium bis(trimethylsilyl)amide is reported. Notably, the reaction tolerates the presence of acidic protons in the α‐position. Mechanistic investigations indicated that the reaction proceeds via a lithium hydride intermediate as the actual reductant.
The Quest for Stable Silaaldehydes: Synthesis and Reactivity of a Masked Silacarbonyl
Authors: Sarkar Debotra , Nesterov Vitaly , Szilvási Tibor , Altmann Philipp J. , Inoue Shigeyoshi
Published: November 2018

The first donor–acceptor complex of a silaaldehyde, with the general formula (NHC)(Ar)Si(H)OGaCl3(NHC=N‐heterocyclic carbene), was synthesized using the reaction of silyliumylidene–NHC complex [(NHC)2(Ar)Si]Cl with water in the presence of GaCl3. Conversion of this complex to the corresponding silacarboxylate dimer [(NHC)(Ar)SiO2GaCl2]2, free silaacetal ArSi(H)(OR)2, silaacyl chloride (NHC)(Ar)Si(Cl)OGaCl3, and phosphasilene–NHC adduct (NHC)(Ar)Si(H)PTMS unveil its true potential as a synthon in silacarbonyl chemistry.
Are aromatase inhibitors associated with higher myocardial infarction risk in breast cancer patients? A Medicare population‐based study
Authors: Kamaraju Sailaja , Shi Yushu , Smith Elizabeth , Nattinger Ann B. , Laud Purushottam , Neuner Joan
Published: November 2018

Background

Theoretically, the estrogen deprivation induced by aromatase inhibitors (AIs) might cause ischemic heart disease, but empiric studies have shown mixed results. We aimed to compare AIs and tamoxifen with regard to cardiovascular events among older breast cancer patients outside of clinical trials. We hypothesized that AIs increase the risk of myocardial infarction.

Methods

We identified women age ≥67 years diagnosed with breast cancer from June 30, 2006 to June 1, 2008 in the surveillance, epidemiology, and end results (SEER)‐Medicare database, treated with either tamoxifen or an AI, and followed through December 31, 2012. To compare myocardial infarction (MI) risk for the treatment groups of AIs vs tamoxifen, we developed and assigned stabilized probability of treatment weights and used the Fine and Gray model for time to MI with death not related to MI as a competing risk.

Results

Of the cohort of 5648 women, 4690 were treated with AIs and 958 with tamoxifen; a total of 251 patients developed MI, and 22 patients died of MI during the study period while 476 died of other causes. The hazard for MI was not significantly different between AI vs tamoxifen groups (HR = 1.01, 95% CI 0.72‐1.42), after adjusting for the following known MI risk factors at the start of adjuvant therapy: diabetes, ischemic heart disease, congestive heart failure, MI, and peripheral vascular disease.

Conclusions

In this SEER‐Medicare‐based population study, there were no significant differences in the risk of MI between AI and tamoxifen users after adjustment for known risk factors.
Predictors of all‐cause mortality and ischemic events within and beyond 1 year after an acute coronary syndrome: Results from the EPICOR registry
Authors: Rossello Xavier , Bueno Héctor , Pocock Stuart J , Van de Werf Frans , Danchin Nicolas , Annemans Lieven , Medina Jesús , Zeymer Uwe
Published: November 2018

Background

Patients discharged after an acute coronary syndrome (ACS) have substantial risk of recurrent ischemic events or dying.

Hypothesis

A difference may exist in risk predictors for all‐cause mortality and ischemic events between year 1 and 2 of follow‐up post‐ACS.

Methods

EPICOR (NCT01171404) was a prospective, international, real‐world cohort study of consecutive patients hospitalized for ACS within 24 hours of symptom onset and surviving to discharge. Total of 10 568 patients were enrolled (555 hospitals; 20 countries) and followed‐up for 2 years. From these, 4943 were admitted with ST‐elevation myocardial infarction (STEMI) and 5625 with non‐ST‐elevation ACS (NSTE‐ACS). Potential baseline predictors of major adverse cardiac and cerebrovascular events (MACCE; death, non‐fatal myocardial infarction [MI], non‐fatal stroke) were evaluated in year 1 and 2 post‐discharge.

Results

MACCE incidence per 100 person‐years at risk within and after 1 year was 5.3 vs 3.6, primarily death (4.1 vs 2.3), with no significant differences for MI or stroke. Older age, lack of coronary revascularization, raised creatinine, low hemoglobin, previous cardiac disease, previous chronic obstructive pulmonary disease, raised glucose, male sex, and geographic region were risk factors for MACCE in both year 1 and 2. By contrast, low ejection fraction, poorer quality of life, low body mass index (BMI) <20 kg/m2, in‐hospital cardiac complications, and Killip class lost predictive power after 1 year.

Conclusion

We observed continuous MACCE risk during 2 years of follow‐up after discharge for ACS, with greater mortality within the first year. Specific predictors at discharge for events after 1 year could not be identified.
Prevalence of comorbidities and effect on survival in survivors of human papillomavirus–related and human papillomavirus–unrelated head and neck cancer in the United States
Authors: Eytan Danielle F. , Blackford Amanda L. , Eisele David W. , Fakhry Carole
Published: November 2018

Background

The increasing incidence of human papillomavirus (HPV)–related head and neck cancer (HNC) has led to the increasing prevalence of survivors, yet to the best of the authors’ knowledge the prevalence of comorbidities during the survivorship period and their effects on survival are relatively unknown.

Methods

In this retrospective cross‐sectional study, individuals with a first incident primary diagnosis of HNC from 2004 through 2011 from the Surveillance, Epidemiology, and End Results (SEER)–Medicare‐linked databases were included in the analysis and classified as patients with HPV‐related or HPV‐unrelated HNC. The presence of 30 comorbid conditions of interest was identified. Associations between comorbidity and treatment group as well as overall survival were evaluated.

Results

The study population consisted of 8025 patients with HPV‐unrelated HNC and 2499 patients with HPV‐related HNC. Hypertension, congestive heart failure, cerebrovascular disease, and chronic obstructive pulmonary disease all were found to be highly prevalent at the time of the cancer diagnosis and increased over time for both groups. These comorbidities were found at significantly lower rates in the HPV‐related HNC population, yet were associated with an increased risk of death in both groups. The probabilities of developing cancer‐related comorbidities such as pneumonia, dysphagia, weight loss, malnutrition, and dental issues rose significantly in both groups after treatment but were more likely in patients with HPV‐related HNC. In both groups of patients, the presence of each comorbidity either at the time of diagnosis or during survivorship was associated with a significantly increased risk of death.

Conclusions

There is a large burden of comorbidities in both patients with HPV‐related and HPV‐unrelated HNC, both of which are associated with decreased survival. Oncologic surveillance should not be limited to the evaluation of disease status, but also should include screening for the highly prevalent conditions associated with the risk of death.
Medulloblastoma: Challenges and advances in treatment and research
Authors: Martirosian Vahan , Neman Josh
Published: November 2018

Background

Medulloblastoma (MB) is a pediatric brain tumor occurring in the posterior fossa. MB is a highly heterogeneous tumor, which can be grouped into four main subgroups: WNT, SHH, Group 3, and Group 4. Each subgroup is different both in its implicated pathways and pathology, as well as how they are treated in the clinic.

Recent Findings

Standard protocol for MB treatment consists of maximal safe resection, followed by craniospinal radiation (in patients 3 years and older) and adjuvant chemotherapy. Advances in clinical stratification of this tumor have allowed establishment of treatment de‐escalation trials aimed at reducing long‐term side effects. However, there have been few advances in identifying novel therapeutic strategies for MB patients due to difficulties in creating chemotherapeutics that can bypass the blood‐brain‐barrier—among other factors. On the other hand, with the help of whole genome sequencing technologies, molecular pathways involved in MB pathogenesis have become clearer and have helped drive MB research. Regardless, this advance in research has yet to translate to the clinic, which may be due to the inability of current in vivo and in vitro models to accurately recapitulate this heterogeneous tumor in humans.

Conclusions

There have been significant advances in knowledge and treatment of medulloblastoma over the last few decades. Whole genome sequencing has helped elucidate clear differences between the subgroups of MB, allowing physicians to better tailor treatments to each patient in an effort to reduce long‐term sequelae. However, there are still many more obstacles to overcome, including less cytotoxic therapies in the clinic and better modeling systems to accurately replicate this disease in the laboratory. Scientists and physicians must work in a more cohesive manner to create translatable results from the laboratory to the clinic—helping improve therapies for medulloblastoma patients.
Flow Cytometry Instrumentation – An Overview
Authors: Büscher Martin
Published: November 2018

The term flow cytometry, used since the seventies, describes a technology employed mainly in biology and medicine to measure and classify suspended particles, e.g., cells or microspheres. Measurable cell parameters include: geometric properties, such as cell size (diameter, surface area, volume); physiological properties (membrane potential, integrity, vitality); and quantities of DNA, RNA, cytokines, surface antigens, nuclear antigens, enzymes, and proteins. © 2018 by John Wiley & Sons, Inc.
High‐performance SIMD implementation of the lattice‐Boltzmann method on the Xeon Phi processor
Authors: Robertsén Fredrik , Mattila Keijo , Westerholm Jan
Published: November 2018

We present a high‐performance implementation of the lattice‐Boltzmann method (LBM) on the Knights Landing generation of Xeon Phi. The Knights Landing architecture includes 16GB of high‐speed memory (MCDRAM) with a reported bandwidth of over 400 GB/s, and a subset of the AVX‐512 single instruction multiple data (SIMD) instruction set. We explain five critical implementation aspects for high performance on this architecture: (1) the choice of appropriate LBM algorithm, (2) suitable data layout, (3) vectorization of the computation, (4) data prefetching, and (5) running our LBM simulations exclusively from the MCDRAM. The effects of these implementation aspects on the computational performance are demonstrated with the lattice‐Boltzmann scheme involving the D3Q19 discrete velocity set and the TRT collision operator. In our benchmark simulations of fluid flow through porous media, using double‐precision floating‐point arithmetic, the observed performance exceeds 960 million fluid lattice site updates per second.
Computational Prediction of 1H and 13C NMR Chemical Shifts for Protonated Alkylpyrroles: Electron Correlation and Not Solvation is the Salvation
Authors: Lacerda Evanildo G. , Kamounah Fadhil S. , Coutinho Kaline , Sauer Stephan P. A. , Hansen Poul Erik , Hammerich Ole
Published: November 2018

Prediction of chemical shifts in organic cations is known to be a challenge. In this article we meet this challenge for α‐protonated alkylpyrroles, a class of compounds not yet studied in this context, and present a combined experimental and theoretical study of the 13C and 1H chemical shifts in three selected pyrroles. We have investigated the importance of the solvation model, basis set, and quantum chemical method with the goal of developing a simple computational protocol, which allows prediction of 13C and 1H chemical shifts with sufficient accuracy for identifying such compounds in mixtures. We find that density functional theory with the B3LYP functional is not sufficient for reproducing all 13C chemical shifts, whereas already the simplest correlated wave function model, Møller–Plesset perturbation theory (MP2), leads to almost perfect agreement with the experimental data. Treatment of solvent effects generally improves the agreement with experiment to some extent and can in most cases be accomplished by a simple polarizable continuum model. The only exception is the NH proton, which requires inclusion of explicit solvent molecules in the calculation.
Secure and efficient protection for HTTP cookies with self‐verification
Authors: Lee Wei‐Bin , Chen Hsing‐Bai , Chang Shun‐Shyan , Chen Tzung‐Her
Published: November 2018

Hypertext transfer protocol (HTTP) cookies are used to store user‐related information sent by a website, and they can be read again later to maintain a link between a user's computer and the website and to remember the user's previous state on the website. In cloud services, cookies are used by service providers to maintain smooth operation for users. As cookies are sent in a public networking environment and saved on users' browsers, two problems are encountered when using cookies: (a) how to protect sensitive information on a cookie from disclosure and (b) how to determine whether cookies have been modified maliciously. Several studies have been conducted on web security to assess problems that occur when cookies are injected and hijacked. In the present study, a secure and efficient cookie protection scheme is proposed. The scheme is designed with the following principles: (a) a key is hidden within a cookie, (b) the integrity of the cookie is verified by both the web server and the web browser, and (c) the key and sensitive information in the cookie can only be read by the website. The proposed method was analyzed for its security and efficiency. Moreover, the methods from related studies and the proposed method were compared. The results revealed that the proposed cookie scheme is effective at improving cookie security.
Range‐wide genomic data synthesis reveals transatlantic vicariance and secondary contact in Atlantic cod
Authors: Fairweather Robert , Bradbury Ian R. , Helyar Sarah J. , de Bruyn Mark , Therkildsen Nina O. , Bentzen Paul , Hemmer‐Hansen Jakob , Carvalho Gary R.
Published: November 2018

Recent advances in genetic and genomic analysis have greatly improved our understanding of spatial population structure in marine species. However, studies addressing phylogeographic patterns at oceanic spatial scales remain rare. In Atlantic cod (Gadus morhua), existing range‐wide examinations suggest significant transatlantic divergence, although the fine‐scale contemporary distribution of populations and potential for secondary contact are largely unresolved. Here, we explore transatlantic phylogeography in Atlantic cod using a data‐synthesis approach, integrating multiple genome‐wide single‐nucleotide polymorphism (SNP) datasets representative of different regions to create a single range‐wide dataset containing 1,494 individuals from 54 locations and genotyped at 796 common loci. Our analysis highlights significant transatlantic divergence and supports the hypothesis of westward post‐glacial colonization of Greenland from the East Atlantic. Accordingly, our analysis suggests the presence of transatlantic secondary contact off eastern North America and supports existing perspectives on the phylogeographic history of Atlantic cod with an unprecedented combination of genetic and geographic resolution. Moreover, we demonstrate the utility of integrating distinct SNP databases of high comparability.