bluuebunny/crossref_metadata_2025 huggingface dataset:
X‐ray crystallographic structure of BshB, the zinc‐dependent deacetylase involved in bacillithiol biosynthesis
Authors: Woodward Robert L. , Castleman Michaela M. , Meloche Chelsea E. , Karpen Mary E. , Carlson Clare G. , Yobi William H. , Jepsen Jacqueline C. , Lewis Benjamin W. , Zarnosky Brooke N. , Cook Paul D.
Published: December 2019

Many gram‐positive bacteria produce bacillithiol to aid in the maintenance of redox homeostasis and degradation of toxic compounds, including the antibiotic fosfomycin. Bacillithiol is produced via a three‐enzyme pathway that includes the action of the zinc‐dependent deacetylase BshB. Previous studies identified conserved aspartate and histidine residues within the active site that are involved in metal binding and catalysis, but the enzymatic mechanism is not fully understood. Here we report two X‐ray crystallographic structures of BshB from Bacillus subtilis that provide insight into the BshB catalytic mechanism.
A novel androgen receptor antagonist JJ‐450 inhibits enzalutamide‐resistant mutant ARF876L nuclear import and function
Authors: Wu Zeyu , Wang Ke , Yang Zhenyu , Pascal Laura E. , Nelson Joel B. , Takubo Keita , Wipf Peter , Wang Zhou
Published: December 2019

Background

Castration‐resistant prostate cancer can develop resistance to enzalutamide because of androgen receptor (AR) point mutations, AR overexpression, constitutively active AR splice variants, and/or elevated intratumoral androgen synthesis. The point mutation ARF876L was reported to be stimulated, instead of inhibited, by enzalutamide, thus contributing to enzalutamide resistance. We have recently developed JJ‐450 as a novel AR antagonist with the potential to treat enzalutamide‐resistant castration‐resistant prostate cancer (CRPC).

Methods

We employed several assays to determine the impact of JJ‐450 and enzalutamide on prostate cancer cell lines expressing green fluorescent protein (GFP)‐ARF876L. These assays include a prostate‐specific antigen enhancer/promoter‐based luciferase assay to determine AR transcriptional activity, a quantitative real‐time polymerase chain reaction assay, and Western blot analysis to detect expression of AR‐target genes at the messenger RNA and protein level, fluorescence microscopy to show AR subcellular localization, and a 5‐bromo‐2′‐deoxyuridine assay to measure prostate cancer cell proliferation.

Results

As expected, enzalutamide inhibited wild‐type (WT) AR but not ARF876L transcriptional activity in the luciferase assay. In contrast, JJ‐450 inhibited both WT‐AR and ARF876L transcriptional activity to a similar extent. Also, enzalutamide retarded androgen‐induced nuclear import of GFP‐AR, but not GFP‐ARF876L, whereas JJ‐450 retarded nuclear import of both GFP‐AR and GFP‐ARF876L. To further evaluate JJ‐450 inhibition of ARF876L, we stably transfected C4‐2 cells separately with GFP‐AR or GFP‐ARF876L. Enzalutamide inhibited endogenous AR‐target gene expression in C4‐2‐GFP‐ARWT, but not in the C4‐2–GFP‐ARF876L subline, whereas JJ‐450 inhibited AR‐target gene expression in both C4‐2 sublines. More importantly, enzalutamide inhibited proliferation of C4‐2‐GFP‐ARWT, but not of the C4‐2‐GFP‐ARF876L subline, whereas JJ‐450 inhibited proliferation of both C4‐2 sublines.

Conclusion

JJ‐450 inhibits enzalutamide‐resistant ARF876L mutant nuclear translocation and function. Our findings suggest that JJ‐450 and its analogs should be further developed to provide a potential new approach for the treatment of enzalutamide‐resistant CRPC.
SAXSDom: Modeling multidomain protein structures using small‐angle X‐ray scattering data
Authors: Hou Jie , Adhikari Badri , Tanner John J. , Cheng Jianlin
Published: December 2019

Many proteins are composed of several domains that pack together into a complex tertiary structure. Multidomain proteins can be challenging for protein structure modeling, particularly those for which templates can be found for individual domains but not for the entire sequence. In such cases, homology modeling can generate high quality models of the domains but not for the orientations between domains. Small‐angle X‐ray scattering (SAXS) reports the structural properties of entire proteins and has the potential for guiding homology modeling of multidomain proteins. In this article, we describe a novel multidomain protein assembly modeling method, SAXSDom that integrates experimental knowledge from SAXS with probabilistic Input‐Output Hidden Markov model to assemble the structures of individual domains together. Four SAXS‐based scoring functions were developed and tested, and the method was evaluated on multidomain proteins from two public datasets. Incorporation of SAXS information improved the accuracy of domain assembly for 40 out of 46 critical assessment of protein structure prediction multidomain protein targets and 45 out of 73 multidomain protein targets from the ab initio domain assembly dataset. The results demonstrate that SAXS data can provide useful information to improve the accuracy of domain‐domain assembly. The source code and tool packages are available at https://github.com/jianlin-cheng/SAXSDom.
Therapeutic utility of glucocorticoids and antihistamines cotreatment. Rationale and perspectives
Authors: Zappia Carlos D. , Monczor Federico
Published: December 2019

Antihistamines and glucocorticoids (GCs) are often used together in the clinic, in several inflammatory‐related situations. Even though there is no clear rationale for this drug association, the clinical practice is based on the assumption that due to their concomitant antiinflammatory effects, there should be an intrinsic benefit in their coadministration. Our group has studied the molecular interaction between the histamine H1 receptor and the glucocorticoid receptor (GR) signaling pathways, showing an enhancing effect on GC‐induced GR transcriptional activity induced by antihistamines. We hypothesize that the existence of this synergistic effect could contribute in reducing the GCs clinical doses, ineffective by itself but effective in combination with an antihistamine. This could result in a therapeutic advantage as the GC‐desired effects may be reinforced by the addition of an antihistamine and, as a consequence of the dose reduction, GC‐related adverse effects could be reduced or at least mitigated. Here we discuss the potential therapeutic applications of this cotreatment seeking to evaluate its usefulness, especially in inflammatory‐related conditions.
Flash point of binary mixtures of chlorinated hydrocarbons with toluene and their predictability with existing mixing rule
Authors: Fayet Guillaume , Tribouilloy Benoit , Rotureau Patricia
Published: December 2019

The flash points of binary mixtures of toluene with two chlorinated hydrocarbons (trichloroethylene and dichloromethane) at different concentrations were investigated to evaluate their predictability by existing mixing rules.

Measurements were performed using both open and closed cup flash point testers highlighting complex ignition phenomena. Beyond a certain level of concentration in chlorinated compound, no proper flash is observed, in our test conditions when the flame is presented, but specific behaviors are observed that did not allow the definitive determination of a flash point. The observed phenomena can be attributed to the formation of halogenated radicals, presenting flame‐retardant behaviors, by decomposition of the chlorinated vapors at the contact of the flame.

Existing mixing rules are based on the consideration of the vapor‐liquid equilibrium defining the amount of flammable vapors above the liquid surface. So, the application of such mixing rule failed predicting this specific phenomenon, more likely related to a specific reactivity problem.

This work also confirms that the sole consideration of the flash point to investigate the flammability of such mixtures may lead to an underestimation of their actual hazard. Additional experimental tests should be conducted to investigate deeper the flammability of such liquid mixtures.
Parental health, informal support, and geographic mobility between parents and adult children
Authors: Vergauwen Jorik , Mortelmans Dimitri
Published: December 2019

Intergenerational solidarity is crucial to address the needs of ageing people. Numerous studies have identified geographic distance between parents and children as an important determinant of intergenerational support. This paper aims to examine to what extent parents' functional disabilities and children's support involvement relate to changing geographic parent–child proximity. We also take a comparative approach to study patterns of geographic mobility of parents and children across Europe. Multilevel multinomial logistic regression analysis is performed on data from the Survey of Health, Ageing and Retirement in Europe for 15 countries. The analysis shows that rapid declines in the functional abilities of parents often lead to intergenerational coresidence. In addition, we find that children start and continue to support most frequently when proceeding to coresidence, although similar results appear for moves leading to a parent–child distance closer than 5 km. Moves bringing parents and children closer together are most prevalent in southern European countries. In contrast to our expectations, the analysis also suggests that parental health declines connect more with moves to coresidence in central and northern European countries compared with the southern region.
Controlled Vortex Formation at Nanostructured Superconductor/Ferromagnetic Junctions
Authors: Niedzielski Björn , Berakdar Jamal
Published: December 2019

Stability and transport properties of superconducting/insulating/ferromagnetic nanostructures are decisively affected by vortex formation in the superconductor. Herein, the emergence of such vortices due to finite size and geometric effects is studied using a Landau–Ginzburg approach coupled to the magnetic layer via its stray field. Numerical simulations based on the finite‐element method evidence that magnetic vortices can be induced and coupled to each others upon appropriate nanostructuring of the magnetic films. These findings are of immediate relevance to transport properties of such structures.
Semi‐idealized simulations of wintertime flows and pollutant transport in an Alpine valley: Origins of local circulations (Part I)
Authors: Sabatier Tiphaine , Paci Alexandre , Lac Christine , Canut Guylaine , Largeron Yann , Masson Valéry
Published: December 2019

Mountainous terrains are known for driving their own dynamics which respond to the local morphological arrangement of the area. Thermally driven flows in particular develop at slope and valley scales and ensure a certain degree of pollutant dispersion under quiescent wintertime synoptic conditions. The present study focuses on a section of the Arve River valley situated close to Mont Blanc which frequently suffers from severe pollution episodes under stable wintertime conditions whilst surrounding valleys appear to be less affected. The particular shape of this basin‐like section and its location at the confluence of several tributary valleys raises the question of the extent to which local circulations participate in pollutant trapping over restricted sectors. A set of high‐resolution numerical simulations are designed in order to improve our understanding of the local flow structure and their sensitivity to thermal stratification, radiative forcing and snow cover. The tributary valleys play a major role in both daytime and night‐time dynamics by deflecting the entering daytime flux and constraining the night‐time flow trajectories. In addition, the basin morphology greatly influences the circulations. During daytime a two‐layer wind structure is developed and driven by spatial variations in sun exposure which is particularly heterogeneous under wintertime forcing. Early spring radiative forcing or the presence of snow allow both of them to develop more homogeneous circulations through the reduction of sun exposure variations, except when snow cover is restricted to shaded basin sidewalls. At night, a three‐layer wind structure is developed. It favours air mass ventilation in the western linear branch of the basin whilst stagnation and recirculation prevail in the curved part of the valley which is also the most polluted. This study therefore highlights spatial variations in circulation patterns consistent with the accumulation of observed pollutants and their heterogeneous distribution.
Ammonia, water, and hydrogen: Can nuclear motion be described classically?
Authors: Frank Irmgard , Genuit Stefanie , Matz Florian , Oschinski Hedda
Published: December 2019

The hypothesis that nuclear motion can be described classically has been tested for several critical systems. We investigate the inversion of ammonia and the heat capacities of water and hydrogen. We use conventional ab initio molecular dynamics, which describes nuclear motion classically and the electron cloud using density functional theory. Ammonia inversion is described perfectly by the tunneling of the p orbital through the molecular plane. Nuclear tunneling is not needed to describe this phenomenon. While the investigation of heat capacities is hampered by the brief simulation times and limited system sizes, we can nevertheless make some qualitative statements. Indeed, the heat capacity can be frozen out in molecular dynamics simulations of solids, and hence, a quantized description is not required.
Insight into the influence of terminal ligands on magnetic exchange coupling in a series of dimeric copper(II) acetate adducts
Authors: Zueva Ekaterina М. , Petrova Мaria М. , Shamsieva Aliia V. , Trigulova Kamila R. , Musina Elvira I. , Fayzullin Robert R. , Bogomyakov Artem S. , Ovcharenko Victor I. , Karasik Andrey A.
Published: December 2019

A combination of experimental (SQUID magnetometry) and quantum‐chemical (BS‐DFT, CASSCF(n,m)/NEVPT2, DDCI3) methods is used to probe the influence of terminal ligands on magnetic exchange coupling in the series of [Cu2(μ2‐OAc)4L2] complexes with O‐donor terminal ligands extended by two novel complexes containing phosphine oxide ligands. The possibilities and limitations of these approaches are discussed. The influence of terminal ligands on magnetic superexchange interaction was quantified by two contributions—the first contribution is associated with structural changes within the {Cu(μ2‐OAc)4Cu} core, while the second contribution is due to the difference in the electronic influence of different terminal ligands at a given core geometry. Both contributions were found to be approximately of the same order of magnitude. These results indicate that magnetic exchange coupling, known to be highly sensitive to the distortions in core geometry, is not solely determined by the core structure. Our findings are consistent with the fact that various one‐ and multiparameter magnetostructural correlations reported in the literature have only a qualitative predictive capability.
Finite‐time attitude‐tracking control for rigid spacecraft with actuator failures and saturation constraints
Authors: Gao Shihong , Jing Yuanwei , Liu Xiaoping , Zhang Siying
Published: December 2019

In this article, the problem of finite‐time attitude‐tracking control for rigid spacecraft is addressed. Uncertainties caused by external disturbances, unknown inertial matrix, actuator failures, and saturation constraints are tackled simultaneously. First, a smooth function that is more qualified to approximate the standard saturation characteristics is presented to deal with the actuator saturation constraints. Second, a fast nonsingular terminal sliding mode (FNTSM) manifold is constructed as a foundation of controllers design. By incorporating the fuzzy logic system into FNTSM technique, a less demanding solution of coping with model uncertainties is provided because the requirement of a prior knowledge of unknown inertial parameters and external disturbances in many existing achievements is removed. To reduce the number of parameters to be estimated, the norm approximation approach is exploited. Subsequently, an antichattering attitude controller is presented such that all the tracking errors converge into arbitrary small domains around the origin in finite time. The result is further extended to obtain a fault‐tolerant controller against completely failed actuators. Finally, numerical simulation is conducted to verify the effectiveness of the proposed control scheme and comparison with relevant literature demonstrates its high performance. Furthermore, an experiment for the large satellite Hubble Space Telescope is carried out to validate the practical feasibility.
Suspended sediment load estimation in an ungauged river in south‐eastern Australia
Authors: Gibson Abraham , Hancock Greg
Published: December 2019

Soil erosion poses a significant threat to river health as well as the sustainability of soil resources. Management of this issue requires catchment‐specific data to be developed; however, many large catchments are poor in terms of hydrological and sediment transport data. Regional scale (thousands of square kilometres), computer‐based modelling methods are a way to generate such data. This study aims to apply the SedNet model to estimate a sediment budget for a 575 km2, ungauged, agricultural catchment of south‐eastern Australia. The model results are then compared with field measured erosion rates for the catchment, in order to assess the sustainability of soil loss and redistribution across the catchment. SedNet estimated average suspended sediment concentrations between 70 and 120 mg/L, under conditions deemed most representative of the river. These model estimates were comparable with monitoring data, showing suspended sediment concentrations between 30 and 350 mg/L. It was found that soil loss and redistribution across the catchment is low; however, the estimated base sediment loads indicate that river health may be negatively impacted by this. SedNet accurately represented current catchment and river conditions and provided a reliable estimation of sediment yield, demonstrating the ability to estimate sediment loss and redistribution across data‐poor catchments using a multifaceted modelling approach. Methodologies, such as the one presented here, offer the ability to better assess the impacts of erosion on sediment loads to develop strategies to effectively manage excess suspended sediment.
Learn more about best practices for alcohol education on campus
Authors: Rahn Josh
Published: December 2019

Alcohol abuse, and the collateral damage it often causes, is a continuous health and safety challenge on most college campuses. Mitigating alcohol‐related issues requires a comprehensive set of evidence‐based tools and strategies. These strategies often include programs that begin before students attend their first classes.
Was student subjected to unfair disciplinary procedures?
Authors: Gelpi Aileen
Published: December 2019

Claremont McKenna College student John Doe was notified in March 2015 that Scripps College student Jane Roe had accused him of sexually assaulting her in his residence hall room.
Composite Methods and DFT Investigations of the Structures, Vibrational Frequencies and Energies of SF5OOX (X=H, F and Cl) and their Anions
Authors: Lorett‐Velásquez Vaneza , Martínez‐Bernal Jessica Andréa , Pieffet Gilles Paul , Buendía‐Atencio Cristian
Published: December 2019

A complete characterization of the vibrational modes has been performed for neutral and anionic pentafluorosulfur peroxides SF5OOX (X=H, F, and Cl) structures using density functional theory (DFT). The adiabatic electron affinity, bond dissociation energy and heat of formation of neutral pentafluorosulfur peroxides molecules were calculated using several Gn methods, starting from geometries optimized with B3LYP, M06‐2X and MP2 levels of theory. The most accurate enthalpies at 298 K for SF5OOH, SF5OOF, and SF5OOCl are obtained with the G4 level of theory and were used as a reference. S−F and S−Cl bonds present low energy of dissociation compared to the S−H bond. This makes possible a dissociative electron attachment (DEA) of the S−X bond (with X=F, Cl) represented by the SF5OO−X + e‐ → SF5OO− + X− reaction, while a S−H dissociation presents a low probability. This work provides crucial energetic data to improve the chemical information and characterization of these structures previously obtained through experimental studies.
Tetrazolium Nitrate Anion Based Salts as Potential Melt‐Castable Explosives
Authors: Yang Rui , Dong Zhen , Ye Zhiwen
Published: December 2019

In this work, a new family of 1‐(2‐nitratoethyl)‐5‐nitraminotetrazolium and 2‐(2‐nitratoethyl)‐5‐nitraminotetrazolium salts was synthesized and evaluated as potential energetic materials. All compounds were fully characterized by IR, DSC and multinuclear NMR spectroscopy. Four of these compounds were additionally characterized by single crystal X‐ray diffraction. Furthermore, the physical and chemical properties of these salts were thoroughly investigated. The standard enthalpies of formation and detonation properties were calculated using Gaussian 09 and EXPLO5 v6.01 programs. These ionic salts exhibited suitable melting point, good thermal stability, positive heats of formation, and excellent detonation properties, especially compounds 11 and 14 with melting point of 82.13°C and 99.72°C and detonation velocities of 8400 and 8982 m s−1, respectively. Hence, the introduction of nitrate groups into high energy materials may be an effective pathway for the design and synthesis of potential melt‐castable explosives.
Synthesis of CDs from β‐Cyclodextrin for Smart Utilization in Visual Detection of Cholesterol and Cellular Imaging
Authors: Kumar Amit , Kumari Archana , Asu Shwetank , Laha Dipranjan , Kumar Sahu Sumanta
Published: December 2019

In this work, we have synthesized fluorescent carbon dots from β‐cyclodextrin in a single step via the hydrothermal method and abbreviated as (β‐CDs). These synthesized β‐CDs were utilized for the cholesterol detection using fluorometric method. The detection of cholesterol attributable to alcoholic groups of β‐CDs was combined with the phenolic group of the cholesterol due to intermolecular hydrogen bonding and the authentic cavity size of the β‐CDs. The sensing mechanism was characterized by fluorescence lifetime decay, zeta potential, and UV‐visible spectroscopy. These β‐CDs are highly sensitive towards cholesterol with detection of limit is 0.204 μM and relatively wide linear range of 0.5‐40 μM. This assay shows a high sensitivity towards cholesterol even in the presence of interfering biomolecules. These β‐CDs are also used for the detection of cholesterol in the real sample (human blood serum). The small particle size, low cytotoxicity, and excellent fluorescence properties of the synthesized β‐CDs are also used for cellular imaging.
Investigating the Photocatalytic Performances of Nanocomposites Containing Narrow‐band‐gap Copolymers and ZnO†
Authors: Murugan Pachaiyappan , Ramar P. , Mandal Asit Baran , Samanta Debasis
Published: December 2019

Composites of ZnO and conjugated polymers find applications in removal of polluting dyes from industrial wastes. The choice of functionality and repeating unit of polymer is important to improve the efficacy of the process. While heterocyclic diketopyrrolopyrrole (DPP) ‐based polymers are often considered as the most promising donor moiety in traditional bulk heterojunction solar cell devices, benzothiadiazole‐based polymers are reported to show the best performance as photosensitizer for dye degradation. In this paper, we report for the first time the preparation of copolymers containing both the above mentioned heterocyclic repeating units linked directly or by a double bond. We were delighted to observe broad spectrum of substantial light absorption from UV to NIR range and a low band gap for one of the polymers, the main reason behind higher efficacy in dye removal under sunlight. Finally, we studied the efficacy of the polymers as photosensitizer for ZnO promoted dye degradation process which showed almost a complete degradation of a model dye only within two hours, one of the best results reported recently using the conjugated polymers.
Synthesis of Potentially Bioactive Carbohydrate Derivatives by Chemoslective Hydrogenation with PdFe Catalyst
Authors: Rojas Agustín H. , Zendri Lucía Garritano , Lafuente Leticia , Ponzinibbio Agustín , Vetere Virginia
Published: December 2019

A highly efficient and chemoselective hydrogenation method was developed using a bimetallic PdFe catalyst. Pd and Ni catalysts failed in the tests performed. However, PdFe supported on carbon catalyst (10% w/w Pd and a molar ratio Fe/Pd=0.5) achieved interesting results. The selective nitro and aldehyde group reductions on the aromatic aglycone moiety were satisfactory. The desired products were obtained with high conversion and selectivity. A set of aryl O‐glycosides, such as bioactive Gastrodin, were prepared in very good yields and high β‐anomeric selectivity.
Solar Mineralization of Hard‐Degradable Amphetamine Using TiO2/RGO Nanocomposite
Authors: Karimi‐Nazarabad Mahdi , Goharshadi Elaheh K. , Aziznezhad Mohammad
Published: December 2019

Illicit drugs have attracted much extensive scientific interest as a class of environmental contaminants due to their frequent occurrence, hard degradability, and potential risk to aquatic life and human. In this work, TiO2/reduced graphene oxide (RGO) nanocomposites were used to degrade amphetamine under solar light. Among the prepared photocatalysts, nanocomposite with 30 mg RGO (TiO2/RGO30) possessed the best photocatalytic activity in the photodegradation of hard‐degradable amphetamine under solar light irradiation. The mineralization efficiency of 91% were achieved after 180 min solar light irradiation. The enhanced photocatalytic degradation of TiO2/RGO30 nanocomposite could be attributed to the increased optical absorption, effective separation, and migration of photogenerated charge carriers as the results of introducing RGO in the nanostructure. Several intermediates were identified during the degradation process using liquid chromatography tandem mass spectrometry (HPLC/MS‐MS) technique. Based on the identified intermediates, the repeated hydroxylation of the amphetamine and its fragmentation are proposed for the degradation pathway.
Acid and 1, 2‐Dichloroethane Co‐Promoted Substitution of the Amino Groups in Gramine and its Analogues with Trialkyl Phosphites
Authors: Guo Shengmei , Zhang Zhebin , Xu Jianxin , Li Sen , Fu Zhengjiang , Cai Hu
Published: December 2019

The transformation of gramine and its analogues represents an important strategy in organic chemistry. Here, we report an acid and DCE co‐promoted phosphonation of gramine and its analogues using trialkyl phosphites as nucleophilic reagents. This reaction avoided the use of stoichiometric alkylation reagents, PBu3 (Tributyl phosphine) and noble metal catalyst. Except for the tertiary amino group in indoles, the primary amino and secondary amino groups, which the previous work did not mentioned were explored.
Fabrication of CS/SA Double‐Network Hydrogel and Application in pH‐Controllable Drug Release
Authors: Li Yuanze , Wang Haili , Niu Yuzhong , Ma Songmei , Xue Zhongxin , Song Aixin , Zhang Shaohua , Xu Wenlong , Ren Chunguang
Published: December 2019

In order to promote the application range, double‐network hydrogels are usually fabricated to improve the mechanical properties. In this work, chitosan (CS) single‐network hydrogels were prepared firstly and sodium alginate (SA) was introduced as the second network. According to scanning electron microscopy (SEM), the microstructures of the CS and SA single‐network were identified as three‐dimensional network of pore and fiber structure, respectively. The microstructure maintained the pore structure after the formation of CS/SA double‐network due to the small amount of SA. The size of the pores was reduced, indicating the cross‐linking of the double‐network. The rheological results indicated that CS/SA double‐network with small amount of SA could enhance the mechanical strength of the hydrogel effectively. Finally, the in vitro release was operated, verifying the sustained release ability of the double‐network hydrogel. In addition, only small amount of the drug could be release in physiological environment (pH 7.4), while a quickly release was obtained in pathological tissue (pH 5.5), decreasing the side effect of the drug.
Reversible Polymorphic Transition and Hysteresis‐Driven Phase Selectivity in Single‐Crystalline C8‐BTBT Rods
Authors: Kim Min‐Woo , Kwon Sooncheol , Kim Jehan , Lee Changhoon , Park Ina , Shim Ji Hoon , Jeong Il‐Seok , Jo Yong‐Ryun , Park Byoungwook , Lee Joo‐Hyung , Lee Kwanghee , Kim Bong‐Joong
Published: December 2019

Organic semiconductors (OSCs) are highly susceptible to the formation of metastable polymorphs that are often transformed by external stimuli. However, thermally reversible transformations in OSCs with stability have not been achieved due to weak van der Waals forces, and poor phase homogeneity and crystallinity. Here, a polymorph of a single crystalline 2,7‐dioctyl[1] benzothieno[3,2‐b][1]benzothio‐phene rod on a low molecular weight poly(methyl methacrylate) (≈120k) that limits crystal coarsening during solvent vapor annealing is fabricated. Molecules in the polymorph lie down slightly toward the substrate compared to the equilibrium state, inducing an order of greater resistivity. During thermal cycling, the polymorph exhibits a reversible change in resistivity by 5.5 orders with hysteresis; this transition is stable toward bias and thermal cycling. Remarkably, varying cycling temperatures leads to diverse resistivities near room temperature, important for nonvolatile multivalue memories. These trends persist in the carrier mobility and on/off ratio of the polymorph field‐effect transistor. A combination of in situ grazing incident wide angle X‐ray scattering analyses, visualization for electronic and structural analysis simulations, and density functional theory calculations reveals that molecular tilt governs the charge transport characteristics; the polymorph transforms as molecules tilt, and thereby, only a homogeneous single‐crystalline phase appears at each temperature.
Widespread morphological parallelism in Korthalsella (Santalaceae, tribe Visceae): A molecular phylogenetic perspective
Authors: Sultan Amir , Robertson Alastair W. , Callmander Martin W. , Phillipson Peter B. , Meyer Jean‐Yves , Tate Jennifer A.
Published: December 2019

Korthalsella (Santalaceae, tribe Visceae) mistletoes are hemiparasitic plants that are widespread on islands and continental regions around the Indian and Pacific Oceans. In this study, we add key taxa to a previously generated dataset to produce a more inclusive phylogenetic analysis of the genus. The resulting nuclear ITS and plastid trnL‐F phylogenies reveal that the historical sectional classifications based on morphology are not supported. Instead, it appears that widespread morphological parallelism has occurred throughout Korthalsella. Geographical distribution seems to be a better indicator of phylogenetic relatedness as species found in the same geographic region, island or island group generally are more closely related to one another than species sharing similar morphological characters in other areas. We find greater support for recognition of species as local endemics rather than wide‐ranging taxa. Given these results, taxonomic changes that recognise previously described taxa are proposed, but other changes will require further study of broadly distributed taxa.
Unraveling the influence of atmospheric evaporative demand on drought and its response to climate change
Authors: Vicente‐Serrano Sergio M. , McVicar Tim R. , Miralles Diego G. , Yang Yuting , Tomas‐Burguera Miquel
Published: December 2019

This review examines the role of the atmospheric evaporative demand (AED) in drought. AED is a complex concept and here we discuss possible AED definitions, the subsequent metrics to measure and estimate AED, and the different physical drivers that control it. The complex influence of AED on meteorological, environmental/agricultural and hydrological droughts is discussed, stressing the important spatial differences related to the climatological conditions. Likewise, AED influence on drought has implications regarding how different drought metrics consider AED in their attempts to quantify drought severity. Throughout the article, we assess literature findings with respect to: (a) recent drought trends and future projections; (b) the several uncertainties related to data availability; (c) the sensitivity of current drought metrics to AED; and (d) possible roles that both the radiative and physiological effects of increasing atmospheric CO2 concentrations may play as we progress into the future. All these issues preclude identifying a simple effect of the AED on drought severity. Rather it calls for different evaluations of drought impacts and trends under future climate scenarios, considering the complex feedbacks governing the climate system.

This article is categorized under:

Paleoclimates and Current Trends > Earth System Behavior
Publisher Correction to: Heparin treatment mitigates radiation-induced oral mucositis in mice by interplaying with repopulation processes
Authors:   Springer Berlin Heidelberg
Published: December 2019

Correction to:

Strahlenther Onkol 2018

10.1007/s00066-018-01423-4

The article was initially published with incorrect copyright information or changed later to incorrect copyright information.

Upon publication of this Correction, the copyright of the article changed to “The Author(s)”.

Th
Temporal Responses of Microbial Communities to Anaerobic Soil Disinfestation
Authors: Poret-Peterson Amisha T. , Sayed Nada , Glyzewski Nathaniel , Forbes Holly , González-Orta Enid T. , Kluepfel Daniel A.
Published: December 2019

Anaerobic soil disinfestation (ASD) is an organic amendment-based management tool for controlling soil-borne plant diseases and is increasingly used in a variety of crops. ASD results in a marked decrease in soil redox potential and other physicochemical changes, and a turnover in the composition of the soil microbiome. Mechanisms of ASD-mediated pathogen control are not fully understood, but appear to depend on the carbon source used to initiate the process and involve a combination of biological (i.e., release of volatile organic compounds) and abiotic (i.e., lowered pH, release of metal ions) factors. In this study, we examined how the soil microbiome changes over time in response to ASD initiated with rice bran, tomato pomace, or red grape pomace as amendments using growth chamber mesocosms that replicate ASD-induced field soil redox conditions. Within 2 days, the soil microbiome rapidly shifted from a diverse assemblage of taxa to being dominated by members of the Firmicutes for all ASD treatments, whereas control mesocosms maintained diverse and more evenly distributed communities. Rice bran and tomato pomace amendments resulted in microbial communities with similar compositions and trajectories that were different from red grape pomace communities. Quantitative PCR showed nitrogenase gene abundances were higher in ASD communities and tended to increase over time, suggesting the potential for altering soil nitrogen availability. These results highlight the need for temporal and functional studies to understand how pathogen suppressive microbial communities assemble and function in ASD-treated soils.
Cell shape determines gene expression: cardiomyocyte morphotypic transcriptomes
Authors: Haftbaradaran Esfahani Payam , ElBeck Zaher , Sagasser Sven , Li Xidan , Hossain Mohammad Bakhtiar , Talukdar Husain Ahammad , Sandberg Rickard , Knöll Ralph
Published: December 2019

Cardiomyocytes undergo considerable changes in cell shape. These can be due to hemodynamic constraints, including changes in preload and afterload conditions, or to mutations in genes important for cardiac function. These changes instigate significant changes in cellular architecture and lead to the addition of sarcomeres, at the same time or at a later stage. However, it is currently unknown whether changes in cell shape on their own affect gene expression and the aim of this study was to fill that gap in our knowledge. We developed a single-cell morphotyping strategy, followed by single-cell RNA sequencing, to determine the effects of altered cell shape in gene expression. This enabled us to profile the transcriptomes of individual cardiomyocytes of defined geometrical morphotypes and characterize them as either normal or pathological conditions. We observed that deviations from normal cell shapes were associated with significant downregulation of gene expression and deactivation of specific pathways, like oxidative phosphorylation, protein kinase A, and cardiac beta-adrenergic signaling pathways. In addition, we observed that genes involved in apoptosis of cardiomyocytes and necrosis were upregulated in square-like pathological shapes. Mechano-sensory pathways, including integrin and Src kinase mediated signaling, appear to be involved in the regulation of shape-dependent gene expression. Our study demonstrates that cell shape per se affects the regulation of the transcriptome in cardiac myocytes, an effect with possible implications for cardiovascular disease.
Coupling of CSF and sagittal sinus pressure in adult patients with pseudotumour cerebri
Authors: Lalou Afroditi-Despina , Czosnyka Marek , Czosnyka Zofia H. , Krishnakumar Deepa , Pickard John D. , Higgins Nick J.
Published: December 2019

Objective

Pseudotumour cerebri syndrome (PTCS including idiopathic intracranial hypertension) is characterised by the symptoms and signs of raised cerebrospinal fluid pressure (CSFp) in the absence of ventricular dilatation or an intracranial mass lesion. Its aetiology is unknown in the majority of cases but there is much evidence for impaired CSF absorption. Traditionally, sagittal sinus pressure has been considered to be independent of CSF pressure in adults. However, the discovery of stenoses of intracranial venous sinuses and introduction of venous sinus stenting has highlighted the importance of the venous drainage in PTCS. In this study, we have explored the relationship between CSFp and SSp before and during a CSF infusion test and during CSF drainage.

Materials and methods

Ten patients (9 females:1 male) with PTCS underwent infusion studies in parallel with direct retrograde cerebral venography. Both SSp and CSFp were recorded at a baseline and during CSFp elevation in a course of a CSF infusion test. The drainage of CSF after the CSF infusion was performed in 7 patients. In 5 cases, jugular venous pressure was also measured.

Results

CSFp and SSp including their amplitudes correlated significantly and strongly both at baseline (R = 0.96; p = 0.001) and during infusion (R = 0.92; p = 0.0026). During drainage, this correlation was maintained until SSp reached a stable value, whereas CSFp continued to decrease.

Conclusions

In this series of ten patients with PTCS, CSFp and SSp were coupled, both at baseline and during infusion. The implications of such coupling for the calculation of CSF outflow resistance are discussed.
A phase 3 study of nivolumab in previously treated advanced gastric or gastroesophageal junction cancer (ATTRACTION-2): 2-year update data
Authors: Chen Li-Tzong , Satoh Taroh , Ryu Min-Hee , Chao Yee , Kato Ken , Chung Hyun Cheol , Chen Jen-Shi , Muro Kei , Kang Won Ki , Yeh Kun-Huei , Yoshikawa Takaki , Oh Sang Cheul , Bai Li-Yuan , Tamura Takao , Lee Keun-Wook , Hamamoto Yasuo , Kim Jong Gwang , Chin Keisho , Oh Do-Youn , Minashi Keiko , Cho Jae Yong , Tsuda Masahiro , Sameshima Hiroki , Kang Yoon-Koo , Boku Narikazu
Published: December 2019

Background

Nivolumab showed improvement in overall survival (OS) in ATTRACTION-2, the first phase 3 study in patients with gastric/gastroesophageal junction (G/GEJ) cancer treated with ≥ 2 chemotherapy regimens. The 2-year follow-up results of ATTRACTION-2 are presented herein.

Methods

ATTRACTION-2 was a randomized, double-blind, placebo-controlled, phase 3 trial (49 sites; Japan, South Korea, and Taiwan). The median (min–max) follow-up period was 27.3 (24.1–36.3) months. The primary endpoint was OS. A subanalysis of OS was performed based on best overall response and tumor-programmed death ligand-1 (PD-L1) expression status.

Results

Overall, 493 of 601 screened patients were randomized (2:1) to receive nivolumab (330) or placebo (163). OS (median [95% confidence interval; CI]) was significantly longer in the nivolumab group (5.26 [4.60–6.37] vs 4.14 [3.42–4.86] months in placebo group) at the 2-year follow-up (hazard ratio [95% CI], 0.62 [0.51–0.76]; P < 0.0001). A higher OS rate was observed in the nivolumab vs placebo group at 1 (27.3% vs 11.6%) and 2 years (10.6% vs 3.2%). The OS benefit was observed regardless of tumor PD-L1 expression. Among patients with a complete or partial response (CR or PR) in the nivolumab group, the median OS (95% CI) was 26.6 (21.65—not applicable) months; the OS rates at 1 and 2 years were 87.1% and 61.3%, respectively. No new safety signals were identified.

Conclusions

Nivolumab treatment resulted in clinically meaningful long-term improvements in OS in patients with previously treated G/GEJ cancer. The long-term survival benefit of nivolumab was most evident in patients with a CR or PR.
Recent developments in cognitive fMRI for temporal lobe epilepsy
Authors: Schmidbauer Victor , Bonelli Silvia
Published: December 2019

Epilepsy is frequently accompanied by severe cognitive side effects. Temporal lobe epilepsy (TLE), and even successful surgical treatment, may affect cognitive function, in particular language as well as verbal and visual memory function. Epilepsy arising from the temporal lobe can be controlled surgically in up to 70% of patients. The goals of epilepsy surgery are to remove the brain areas generating the seizures without causing or aggravating neuropsychological deficits. This requires accurate localization of the brain areas generating the seizures (“epileptogenic zone”) and the areas responsible for motor and cognitive functions, such as language and memory (“essential brain regions”) during presurgical evaluation. In the past decades, functional magnetic resonance imaging (fMRI) has been increasingly used to noninvasively lateralize and localize not only primary motor and somatosensory areas, but also brain areas that are involved in everyday language and memory processes. The imaging modality also shows potential for predicting the effects of temporal lobe resection on language and memory function. Together with other MRI modalities, cognitive fMRI is a promising tool to improve surgical strategies tailored to individual patients with regard to functional outcome, by virtue of definition of epileptic cerebral areas that need to be resected and eloquent areas that need to be spared.

The aim of this review is to provide an overview of recent developments and practical recommendations for the clinical use of cognitive fMRI in TLE.
Supporting Students in Using Energy Ideas to Interpret Phenomena: The Role of an Energy Representation
Authors: Kubsch Marcus , Nordine Jeffrey , Fortus David , Krajcik Joseph , Neumann Knut
Published: December 2019

In the sciences, energy is an important idea to get insight into phenomena, as energy can help to reveal hidden systems and processes. However, students commonly struggle to use energy ideas to interpret and explain phenomena. To support students in using energy ideas to interpret and explain phenomena, a range of different graphical representations are commonly used. However, there is little empirical research regarding whether and how these representations actually support students’ ability to use energy ideas. Building on common ways of representing energy transfer, we address this issue by exploring whether, and if so how, a specific representation called the energy transfer model (ETM) supports middle school students’ interpretation of phenomena using the idea of energy transfer. We conducted an interview study with N = 30 8th grade students in a quasi-experimental setting and used qualitative content analysis to investigate student answers. We found evidence that students who construct an ETM when making sense of phenomena consider the role of energy transfers between systems more comprehensively, i.e., they reason about hidden processes and systems to a larger extent than students who do not construct an ETM.
Whither the University? Universities of Technology and the Problem of Institutional Purpose
Authors: Miller Seumas
Published: December 2019

There is a need to provide an appropriate normative conception of the modern university: a conception which identifies its unifying purposes and values and, thereby, gives direction to institutional role occupants, governments, public policymakers and other would-be institutional designers. Such a conception could admit differences between modern universities; differences, for example, between so-called universities of technology and other universities. Indeed, it is preferable to frame the issue at the level of higher education or university systems rather than at the level of individual universities. According to the teleological normative theory of social institutions, social institutions are organizations or systems of organizations that provide collective goods by means of joint activity; universities are no exception. So what are the fundamental collective good(s) that universities of technology, or the larger systems of which they are a part, ought to be providing and how are they travelling in this regard? This is the question addressed in this paper.
A synopsis of Stenostephanus Nees (Acanthaceae) in Bolivia
Authors: Wood John R. I.
Published: December 2019

12 species of Stenostephanus Nees occur in Bolivia, two of which, S. madidiensis J.R.I.Wood and S. sehuencasii J.R.I.Wood are described as new. Ten species are endemic to the country with all growing on the humid eastern slopes of the Andes. The distribution of all Bolivian species is described and mapped and implications for conservation are discussed. A key to the species found in Bolivia and a table of their principal distinguishing characteristics are provided. The new species are illustrated with line drawings and photographs.
Genetic characterization of cassava (Manihot esculenta Crantz) genotypes using agro-morphological and single nucleotide polymorphism markers
Authors: Karim Kumba Y. , Ifie Beatrice , Dzidzienyo Daniel , Danquah Eric Y. , Blay Essie T. , Whyte Jim B. A. , Kulakow Peter , Rabbi Ismail , Parkes Elizabeth , Omoigui Lucky , Norman Prince E. , Iluebbey Peter
Published: December 2019

Dearth of information on extent of genetic variability in cassava limits the genetic improvement of cassava genotypes in Sierra Leone. The aim of this study was to assess the genetic diversity and relationships within 102 cassava genotypes using agro-morphological and single nucleotide polymorphism markers. Morphological classification based on qualitative traits categorized the germplasm into five different groups, whereas the quantitative trait set had four groups. The SNP markers classified the germplasm into three main cluster groups. A total of seven principal components (PCs) in the qualitative and four PCs in the quantitative trait sets accounted for 79.03% and 72.30% of the total genetic variation, respectively. Significant and positive correlations were observed between average yield per plant and harvest index (r = 0.76***), number of storage roots per plant and harvest index (r = 0.33*), height at first branching and harvest index (0.26*), number of storage roots per plant and average yield per plant (r = 0.58*), height at first branching and average yield per plant (r = 0.24*), length of leaf lobe and petiole length (r = 0.38*), number of leaf lobe and petiole length (r = 0.31*), width of leaf lobe and length of leaf lobe (r = 0.36*), number of leaf lobe and length of leaf lobe (r = 0.43*), starch content and dry matter content (r = 0.99***), number of leaf lobe and root dry matter (r = 0.30*), number of leaf lobe and starch content (r = 0.28*), and height at first branching and plant height (r = 0.45**). Findings are useful for conservation, management, short term recommendation for release and genetic improvement of the crop.