bluuebunny/crossref_metadata_2025 huggingface dataset:
Role of nitrogen–oxygen plasma functionalization of carbon nanotubes in epoxy nanocomposites
Authors: Steffen Teresa Tromm , Fontana Luis César , Nahorny Jacimar , Becker Daniela
Published: July 2018

Carbon nanotubes (CNTs) functionalization was carried out with radio frequency plasma in different working gas Ar/O2 and Ar/O2/N2 at different plasma powers to synthesize epoxy nanocomposites. After the CNT's had been treated, the Fourier transform infrared (FTIR) spectroscopy showed an additional peak at 1,740 cm−1, attributed to carboxylic groups, corroborating the X‐ray photoelectron spectroscopy that shows attachment of oxygen groups, which indicates CNTs' functionalization. Raman shows an increase in the ID/IG ratio, attributed to an increased number of defects, in agreement with transmission electron microscope images that show a nanocoating on CNTs' surfaces. Functionalization carried out with low power plasma makes also some C‐N bonds possible, preserving the aromatic carbons of the CNTs' structure. Nanocomposites showed better dispersion and distribution for samples with CNTs treated by Ar/O2/N2 plasma. Furthermore, there was a decrease in Tg when compared with neat epoxy, especially for samples with more nitrogen atoms attached to the CNTs. Mechanical properties presented an improvement, which is specially related to a better phase interaction led by the nitrogen presence on the CNTs' surface. POLYM. COMPOS., 40:E1162–E1171, 2019. © 2018 Society of Plastics Engineers
Volatile compounds in different parts of the fruit Psidium guajava L. cv. “Media China” identified at distinct phenological stages using HS‐SPME‐GC‐QTOF/MS
Authors: Elizalde‐González María P. , Segura‐Rivera Erika J.
Published: July 2018

Introduction

Determination of the volatile organic compounds (VOCs) emitted by immature fruits furthers our understanding of plant–pest interactions and by fruits in a ripe state concerns food quality.

Objectives

To apply headspace solid‐phase microextraction gas chromatography quadrupole time‐of‐flight mass spectrometry (HS‐SPME‐GC‐QTOF/MS) to compare the volatiles emitted by different parts of guava (Psidium guajava L. cv. “Media China”) at different maturation stages.

Methodology

HS‐SPME combined with GC‐QTOF/MS was used to characterise the VOCs of entire guavas in the orchard and under laboratory conditions. For chemical analysis X‐ray fluorescence spectroscopy, refractometry, titration, complexometry, diode array detector high‐performance liquid chromatography (DAD‐HPLC) and refractive index detector (RI)‐HPLC were used.

Results

The guava variety was rich in potassium and poor in sodium. A total of 44 VOCs were identified in different phenological stages and parts of the fruits. Release of VOCs was influenced by the temperature in the plantation, and transformation of innate fruit VOCs started immediately after cutting.

Conclusion

The most abundant VOC released by the immature fruit in the plantation overnight was (S)‐limonene, and it concentrated in the outer skin (pericarp). The esters ethyl benzoate, ethyl octanoate, butyl‐2‐methylbutanoate, ethyl hexanoate, cis‐3‐hexenyl acetate, and ethyl butanoate were emitted by ripe whole fruits. During ripening ethyl benzoate reached a maximum production after three to five days, while the formation of the aldehydes benzaldehyde, hexanal and trans‐2‐hexen‐1‐al started thereafter.
Comparison of privacy‐protecting analytic and data‐sharing methods: A simulation study
Authors: Yoshida Kazuki , Gruber Susan , Fireman Bruce H. , Toh Sengwee
Published: July 2018

Purpose

Privacy‐protecting analytic and data‐sharing methods that minimize the disclosure risk of sensitive information are increasingly important due to the growing interest in utilizing data across multiple sources. We conducted a simulation study to examine how avoiding sharing individual‐level data in a distributed data network can affect analytic results.

Methods

The base scenario had four sites of varying sizes with 5% outcome incidence, 50% treatment prevalence, and seven confounders. We varied treatment prevalence, outcome incidence, treatment effect, site size, number of sites, and covariate distribution. Confounding adjustment was conducted using propensity score or disease risk score. We compared analyses of three types of aggregate‐level data requested from sites: risk‐set, summary‐table, or effect‐estimate data (meta‐analysis) with benchmark results of analysis of pooled individual‐level data. We assessed bias and precision of hazard ratio estimates as well as the accuracy of standard error estimates.

Results

All the aggregate‐level data‐sharing approaches, regardless of confounding adjustment methods, successfully approximated pooled individual‐level data analysis in most simulation scenarios. Meta‐analysis showed minor bias when using inverse probability of treatment weights (IPTW) in infrequent exposure (5%), rare outcome (0.01%), and small site (5,000 patients) settings. SE estimates became less accurate for IPTW risk‐set approach with less frequent exposure and for propensity score‐matching meta‐analysis approach with rare outcomes.

Conclusions

Overall, we found that we can avoid sharing individual‐level data and obtain valid results in many settings, although care must be taken with meta‐analysis approach in infrequent exposure and rare outcome scenarios, particularly when confounding adjustment is performed with IPTW.
Validation studies of claims data in the Asia‐Pacific region: A comprehensive review
Authors: Koram Nana , Delgado Megan , Stark James H. , Setoguchi Soko , de Luise Cynthia
Published: July 2018

Purpose

To describe published validation studies of administrative health care claims data in the Asia‐Pacific region.

Methods

A comprehensive literature search was conducted in PubMed for English language articles published through 31‐Oct‐2017 in humans from 10 Asian‐Pacific countries or regions (Japan, Australia, New Zealand, China, Hong Kong, India, Singapore, South Korea, Taiwan, and Thailand) that validated claims‐based diagnoses with a gold standard data source. Search terms included the: validation, validity, accuracy, sensitivity, agreement, specificity, positive predictive value, kappa, kappa coefficient, and Cohen's kappa.

Results

Forty‐three studies across six countries were identified: Australia (21); Japan (6); South Korea (6); Taiwan (7); Singapore (2); and New Zealand (1). Gold standard diagnoses were obtained from: medical records (18); registry data (11); self‐reported questionnaires (5); and other data sources (9). Validity measures used included sensitivity, specificity, positive and negative predictive values (12); sensitivity, specificity, and positive predictive value (4); sensitivity and specificity (4); sensitivity and positive predictive value (4); and combinations of other measures (19). Validated outcomes included medical conditions (28); disease‐specific comorbidities (8); death, smoking, and other (ie, injury, hospital outcome measures) (5); medication/transfusion (2). Approximately 72% of the studies were published within the last 5 years.

Conclusions

Validation studies of claims data published in the English language in the Asia‐Pacific region are very limited. Given the increased reliance on administrative health care databases for pharmacoepidemiology and the need for ensuring the credibility of results from such data, additional support for the conduct of validation research of claims data in the Asia‐Pacific region is needed.
Resilient and reproducible processing for CZTSe solar cells in the range of 10%
Authors: Taskesen Teoman , Steininger Vincent , Chen Wenjian , Ohland Jörg , Mikolajczak Ulf , Pareek Devendra , Parisi Jürgen , Gütay Levent
Published: July 2018

In this paper, we present our route to fabricate Cu2ZnSnSe4 (CZTSe) thin films, which allows to achieve reproducible processing of kesterite absorber, that leads to efficiencies in the range of 10%. The article mainly focuses on the annealing process and demonstrates that controlling of the reactor pressure for selenization can be reliably used to tune the losses of volatile constituents in the absorber, enabling adjustments on the properties of the film and solar cell. The findings reveal a noteworthy resilience to small changes of the process parameters in the vicinity of optimum conditions. Interestingly, a certain pressure range for optimum Zn and Sn composition exists, which results in a broad and stable process window and enables reproducible processing of CZTSe with high power conversion efficiencies. The established process also allows simple upscaling of the device area and results in a power conversion efficiency of ≈ 8% on a large area of 2.85 cm2. The highest efficiencies achieved by our process are around 11% for smaller lab scale devices.
Mixed micellization study of dodecyltrimethylammonium chloride and cetyltrimethylammonium bromide mixture in aqueous/urea medium at different temperatures: Theoretical and experimental view
Authors: Mahbub Shamim , Rub Malik Abdul , Hoque Md. Anamul , Khan Mohammed Abdullah
Published: July 2018

The behavior of mixed micelle formation between two cationic surfactants‐dodecyltrimethylammonium chloride (DTAC) and cetyltrimethylammonium bromide (CTAB) in absence/attendance of urea has been investigated by means of conductivity measurements over temperature range of 298.15 to 318.15 K. Lower magnitudes of the critical micelle concentration from their ideal values imply the strong interaction between the studied amphiphiles. The micellar mole fraction (X1) on the basis of the different proposed model (Rubingh, Motomura & Rodenas) and the ideal micellar mole fraction (Xid) were evaluated, and estimated results imply the high contribution of CTAB in the mixed micelle formation that enhances with the augment of the mole fraction of the CTAB. The values of activity coefficients (f1 and f2) (less than unity) and negative values of the interaction parameter (β) in all cases signify the attractive interaction between the amphiphiles studied. Spontaneous mixed micelle formation between the studied amphiphiles (dodecyltrimethylammonium chloride and CTAB) was indicated by the negative magnitudes of free energy of micellization (ΔGm0). The negative values of excess free energy of micellization (ΔGex) indicate the higher stability of the mixed micelle compared with the single micelle. The standard enthalpy change of micellization (ΔHm0) and standard entropy change of micellization (ΔSm0) were also calculated and discussed.
High Hydrostatic Pressure Induces a Lipid Phase Transition and Molecular Rearrangements in Low‐Density Lipoprotein Nanoparticles
Authors: Lehofer Bernhard , Golub Maksym , Kornmueller Karin , Kriechbaum Manfred , Martinez Nicolas , Nagy Gergely , Kohlbrecher Joachim , Amenitsch Heinz , Peters Judith , Prassl Ruth
Published: July 2018

Low‐density lipoproteins (LDL) are natural lipid transporter in human plasma whose chemically modified forms contribute to the progression of atherosclerosis and cardiovascular diseases accounting for a vast majority of deaths in westernized civilizations. For the development of new treatment strategies, it is important to have a detailed picture of LDL nanoparticles on a molecular basis. Through the combination of X‐ray and neutron small‐angle scattering (SAS) techniques with high hydrostatic pressure (HHP) this study describes structural features of normolipidemic, triglyceride‐rich and oxidized forms of LDL. Due to the different scattering contrasts for X‐rays and neutrons, information on the effects of HHP on the internal structure determined by lipid rearrangements and changes in particle shape becomes accessible. Independent pressure and temperature variations provoke a phase transition in the lipid core domain. With increasing pressure an interrelated anisotropic deformation and flattening of the particle are induced. All LDL nanoparticles maintain their structural integrity even at 3000 bar and show a reversible response toward pressure variations. The present work depicts the complementarity of pressure and temperature as independent thermodynamic parameters and introduces HHP as a tool to study molecular assembling and interaction processes in distinct lipoprotein particles in a nondestructive manner.
Bioinspired Nanozymes with pH‐Independent and Metal Ions‐Controllable Activity: Field‐Programmable Logic Conversion of Sole Logic Gate System
Authors: Han Lei , Zhang Haijiao , Li Feng
Published: July 2018

In nature, different environmental factors make organisms to be programmed into different forms. However, it is difficult and significant to realize the field‐programmable logic conversion of sole logic system for molecular logic gates. Here, the concept of pH‐programmable “logic conversion” on the single logic gate based on the peculiar enzyme‐mimicking activity is presented. Inspired by natural enzymes with high pH‐stability and metal ions‐stimulated activity, pH‐independent and metal ions‐controllable catalase mimics (Co3O4 nanozymes) are designed by protein‐directed method. Although pH cannot directly change the activity of nanozymes, pH can change the existence state of metal ions and then the electron transfer rate on nanozymes. So, versatile roles of metal ions for catalase‐like and electrocatalytic activities are discovered on the premise of pH‐independency. For the proof‐of‐concept, OR/INHIBIT‐ and INHIBIT/AND‐switchable logic gates are facilely constructed using pH as the environmental stimulus and metal ions as inputs. Hence, the transformation of logic gate functions is realized without the change of logic gate elements and input molecules. This contribution may not only broaden the species and application area of nanozymes, but also open novel avenues for the molecular logic conversion and the metal ions sensor.
Energy Performance and Aging of RDX‐based TiH2, MgH2 Explosive Composites
Authors: Xue Bing , Lin Moujin , Ma Honghao , Wang Yixin , Shen Zhaowu
Published: July 2018

Two typical binary metal hydrides, TiH2 and MgH2 were introduced into the RDX based explosive composites. Charges with different contents of metal hydride were evaluated through underwater explosion. Composite with 10 % MgH2 exhibited the best shockwave parameters, peak overpressure, specific impulse and specific shock energy of which promoted by 5.7 %, 7.0 % and 8.4 % respectively. Whereas, the specific bubble energy of composite with 10 % TiH2 showed the maximum enhancement of 5.5 %, and density specific energy of which increased significantly attributed to the large density of TiH2. Meanwhile, a 2‐year ambient storage test of metal hydride reactants and RDX‐metal hydride explosive composites was conducted to evaluate the safety and stability. X‐ray diffraction (XRD), thermogravimetry (TG) and differential thermal analysis (DTA) were then conducted to analyze the aged samples. Results revealed that TiH2 and its explosive composites showed an excellent storage stability due to the formation of thin TiO2 film. Whereas, mass fraction of Mg(OH)2 was found increasing with time in both MgH2 and its explosive composite, of which hydrolysis of MgH2 was the main mechanism. Moreover, Mg was found in aged MgH2 powder as a result of decomposition. The mechanical strength of aged charges of RDX based MgH2 explosive composite also degraded significantly ascribed to the released hydrogen.
Monitoring transient events in infrared spectra using local mode analysis
Authors: Massarczyk Matthias , Schlitter Jürgen , Kötting Carsten , Rudack Till , Gerwert Klaus
Published: July 2018

Time‐resolved Fourier transformed infrared (FTIR) spectroscopy of chemical reactions is highly sensitive to minimal spatiotemporal changes. Structural features are decoded and represented in a comprehensible manner by combining FTIR spectroscopy with biomolecular simulations. Local mode analysis (LMA) is a tool to connect molecular motion based on a quantum mechanics simulation with infrared (IR) spectral features and vice versa. Here, we present the python‐based software tool of LMA and demonstrate the novel feature of LMA to extract transient structural details and identify the related IR spectra at the case example of malonaldehyde (MA). Deuterated MA exists in two almost equally populated tautomeric states separated by a low barrier for proton transfer so IR spectra represent a mixture of both states. By state‐dependent LMA, we obtain pure spectra for each tautomeric state occurring within the quantum mechanics trajectory. By time‐resolved LMA, we obtain a clear view of the transition between states in the spectrum. Through local mode decomposition and the band‐pass filter, marker bands for each state are identified. Thus, LMA is beneficial to analyze the experimental spectra based on a mixture of states by determining the individual contributions to the spectrum and motion of each state.
β‐Strand twisting/bending in soluble and transmembrane β‐barrel structures
Authors: Kikuchi Nobuaki , Fujiwara Kazuo , Ikeguchi Masamichi
Published: July 2018

The majority of β‐strands in globular proteins have a right‐handed twist and bend. The dominant driving force for β‐strand twisting is thought to be inter‐strand hydrogen bonds. We previously demonstrated that for water‐soluble proteins, both the twisting and bending of β‐strand are suppressed by the polar side chains of serine, threonine, and asparagine residues. To determine whether this also holds for transmembrane β‐strands, we calculated and statistically analyzed the twist and bend angles of four‐residue frames of β‐strands in both transmembrane and water‐soluble β‐barrel proteins with known three‐dimensional structures. In the case of transmembrane β‐strands, we found that twisting was suppressed even for frames not containing serine, threonine, or asparagine residues. The suppression of twisting in transmembrane β‐strands could be attributed to the propagation of the suppressive effect of serine, threonine, and asparagine residues within a frame to the neighboring, hydrogen‐bonded strands under the restriction that all strands in the closed barrel structure must have similar twist angles. A similar tendency was also observed for water‐soluble β‐barrel proteins. We previously showed that the dominant driving force for β‐strand bending is hydrophobic interactions involving aromatic residues within and outside the strand. Transmembrane β‐barrels have no hydrophobic core; however, rather hydrophilic residues predominate inside the barrel or the β‐strands of transmembrane β‐barrels have larger bend angles than those of water‐soluble β‐barrels. Our results reveal that, in transmembrane β‐barrel proteins, the glycine‐aromatic ring motif is important for generating the β‐strand bending necessary for barrel formation.
Tackling the problem of falsified medicines in the UK
Authors: Houlton Sarah
Published: July 2018

The problem of falsified medicines entering the supply chain has grown in recent years, including in the UK. However, new initiatives such as the EU Falsified Medicines Directive are attempting to confront the issue.
Power analysis for group supplier selection with multiple production lines
Authors: Pearn W.L. , Tai Y.T. , Wu Yu‐Wen , Wang Yuan‐An
Published: July 2018

Group supplier selection problem is a critical problem because outsourcing is an important issue for supply chain management. For the advanced production processes with extremely low fraction of defectives, typical supplier selection methods no longer work because any sample of reasonable size probably contains no defective items. Thus, process capability indices have been extensively used for advanced production processes to evaluate and measure whether the process meets the specifications and they also provide quality assurance. In the globally competitive production environment, processes involving multiple production lines are quite common due to economies of scale considerations. In this paper, we consider a group supplier selection problem for multi‐supplier and multi‐line, in which a supplier group containing the best suppliers is selected based on a multi‐line yield index
. To avoid the inflation of multiple comparisons, we apply the Bonferroni method and subtraction test statistic to tackle the group supplier selection problem. Critical values for testing procedure and required sample sizes for designated selection powers are obtained and tabulated. In addition, we apply multiple comparisons with the best method and compare the selection powers with the Bonferroni method for various power settings to provide more accurate group supplier decisions for real‐world applications.
The guaranteed adaptive c‐charts with estimated parameter
Authors: Vakilian Fatemeh , Amiri Amirhossein , Faraz Alireza
Published: July 2018

The performance of control charts with estimated parameters in Phase II depends on the accuracy of parameter estimation in Phase I. Estimation accuracy depends on the amount of data. Simulation results show that no realistic number of Phase I samples is available to ensure that the in‐control performance of control charts with estimated parameters is close to cases where the parameters are known. In this paper, the bootstrapping method is applied to adjust the control and warning limits of c‐charts with adaptive sampling schemes, such as variable sample size, variable sampling intervals, and variable parameters. The adjusted charts guarantee that the in‐control average adjusted time to signal is more than a certain amount with a predefined probability. In addition, the performance of the adjusted adaptive c‐charts is compared with the commonly used approach to design adaptive c‐charts.
A surrogate‐based iterative importance sampling method for structural reliability analysis
Authors: Tang Zhang‐Chun , Xia Yanjun
Published: July 2018

In this paper, a surrogate‐based iterative importance sampling (IS) method is proposed to efficiently evaluate failure probability (FP) of engineering structures. The surrogate is constructed by the training points centered at the most probable failure point (MPP), which is estimated by an approximate algorithm without any additional evaluations of the real limit state function (LSF), and the IS method using the estimated MPP is further obtained; and an iterative procedure combined with the surrogate and the IS method is finally proposed to improve the accuracy of the estimated result for the FP. Three numerical examples are employed to demonstrate the accuracy of the proposed method, and further, an inside flap of an aircraft is employed to demonstrate the practical application of the proposed method in engineering problems. The results show that the reasonable estimated result of the FP within the range of 10−3‐10−5 can be evaluated by the proposed method with only hundreds of the evaluations of the real LSF.
Time‐dependent density‐functional study of the photoabsorption spectrum of Au25(SC2H4C6H5)18 anion: Validation of the computational protocol
Authors: Baseggio Oscar , De Vetta Martina , Fronzoni Giovanna , Toffoli Daniele , Stener Mauro , Sementa Luca , Fortunelli Alessandro
Published: July 2018

A validation study of the computational protocol for predicting the optical properties of Monolayer‐Protected metal Clusters (MPCs) using time‐dependent density‐functional theory is presented. The Au25(SC2H4Ph)18− MPC is chosen as a reference, due to the availability of both structural and optical experimental data. The effects of the geometry, the basis set, the exchange‐correlation functionals, and the use of simplified or experimental ligands on the optical properties of Au25(SC2H4Ph)18− are discussed critically. When such options are carefully selected, an almost quantitative matching between theory and experiment is obtained. Noteworthy, the use of a precise geometric structure proves to be both crucial and critical for an accurate prediction of the optical response of MPC systems, a feature which is not easy to achieve using current density‐functional theory approaches.
Rotational grid, PAI‐maximizing crime forecasts
Authors: Mohler George , Porter Michael D.
Published: July 2018

Crime forecasts are sensitive to the spatial discretizations on which they are defined. Furthermore, while the Predictive Accuracy Index (PAI) is a common evaluation metric for crime forecasts, most crime forecasting methods are optimized using maximum likelihood or other smooth optimization techniques. Here we present a novel methodology that jointly (1) selects an optimal grid size and orientation and (2) learns a scoring function with the aim of directly maximizing PAI. Our method was one of the top performing submissions in the 2017 NIJ Crime Forecasting challenge, winning 9 of the 20 PAI categories under the name of team PASDA. We illustrate the model on data provided through the competition from the Portland Police Department.
Examination and analysis of Indian silver punch‐marked coins employing WD‐XRF and other noninvasive techniques
Authors: Mamania Divija , Singh M.R. , Lal U.S.
Published: July 2018

The archaeometallurgical analysis of ancient silver coins provides useful information regarding fabrication methodology, provenance, and trade route and explains large diversification in elementary composition, weight, and physical features. The present investigation deals with the chemical analysis and examination of the processing history of Indian punch‐marked silver coins dating to 400–200 bc. The chemical analysis was carried out by wavelength dispersive X‐ray fluorescence and X‐ray Diffraction (XRD). The microstructural examination was performed using field emission scanning electron microscope (FE‐SEM) and different phases were identified by Scanning Electron Microscopy coupled with Energy Dispersive X‐ray (SEM‐EDX) Spectroscopy. It was observed that all eight coins were manufactured with silver‐copper alloy. The ore used for obtaining silver was argentiferous galena, and cupellation was carried with perfection. The absence of slag inclusions as revealed by SEM examination indicated that coins (numbers 2, 4, 5, and 7) were cast from a molten state. The presence of Cu2O, CuO, and Ag2O on the surfaces of the coins was confirmed by XRD. The formed oxide layers provided protection and saved the coins from bulky corrosion products. The data reveal great divergence of coin surface from the composition of the core with the far better metallurgical process for refining of silver for this hoard.
Computational and Experimental FT‐ IR, NMR, UV‐Vis Spectral Studies of 5,5′‐((4‐chlorophenyl)methylene)bis(1,3‐dimethyl‐6‐(methylamino)pyrimidine‐2,4(1H,3H)‐dione)
Authors: Shukla Shraddha , Bishnoi Abha , Fatma Shaheen , Verma Anil Kumar , Devi Poornima
Published: July 2018

Synthesis of a novel 5,5′‐((4‐chlorophenyl)methylene)bis(1,3‐dimethyl‐6‐(methylamino)pyrimidine‐2,4(1H,3H)‐dione) has been done, followed by respective characterization by various spectroscopic techniques viz FT‐IR, 1H‐NMR, 13C‐NMR, UV‐Vis spectroscopy and computational methods. The study of the structure was done by Density Functional Theory (DFT) at the theory level Becke3–Lee–Yang–Parr (B3LYP) functional and 6–31G (d, p) as basis set. A close examination of various structural and thermodynamic parameters, electrostatic potential, electrophilicity (ω), chemical potential (μ), chemical hardness (η) and max amount of electronic charge transfer (▵Nmax) was done for this compound. Natural bond orbital analysis was employed to study the hyper conjugative interactions occurring within the molecule that are responsible for the stability of the molecule. To study the chemically active sites in the molecule, local reactivity descriptors were also calculated. Electric dipole moment, polarizability and first static hyperpolarizability values have been investigated for the title compound. In addition to it, a discussion about correlation graphs between 1H‐NMR and 13C‐NMR spectroscopic values is also done.
ESIPT‐Based Dual Chemosensor for Sequential Detection of Cd2+/Zn2+ and Nucleoside Triphosphates in Water: Application in Logic Gates
Authors: Singh Harminder , Sharma Rashmi , Bhargava Gaurav , Kumar Subodh , Singh Prabhpreet
Published: July 2018

Here in, novel excited state intramolecular charge transfer (ESIPT)‐modulated fluorophore based on diphenylpyrimidinone DPHQ has been designed and synthesized. DPHQ shows selective 8‐fold ‘turn‐on’ fluorescence response with Cd2+/Zn2+ in buffer (containing 1% CH3CN, pH 7.2) with low detection limits of 55.7/2.7 nM accompanied with a fluorescent colour change from colourless to cyan. DPHQ–Cd2+ ensemble undergo selective fluorescence quenching with nucleoside triphosphates but it is silent to nucleoside di‐and mono‐phosphates. It can detect 58.4 nM concentration of adenosine triphosphate (ATP). The binding mode and sensing mechanism of DPHQ with Cd2+/Zn2+ was supported by the change in optical behaviors, density functional theory (DFT) calculations and Job's plot. DPHQ was successfully used for construction of ‘Set‐Reset’ memorized logic devices and OR, INHIBIT logic gates. As practical applications of DPHQ, we utilized DPHQ for detection of Cd2+/Zn2+ in blood serum and quantification of Zn2+ in tap water samples.
Basicity of Some Pyridinophanes in Gas Phase and Acetonitrile – a DFT Study
Authors: Despotović Ines
Published: July 2018

The gas phase proton affinities and basicities of a [1.1.1]‐(2,6)‐pyridinophane and its derivatives having one ‐CH2‐ bridge replaced by ‐CH=CH‐ and ‐CH2‐CH2‐ are examined by the DFT B3LYP/6‐311+G(2df,p)//B3LYP/6‐31G(d) method. The calculated proton affinities are within the range of 253.8 and 294.8 kcal mol−1. The upper‐scale basicity is consequence of unfavorable steric interactions in neutral bases and diminishing of former in conjugate acids with forming of intramolecular hydrogen bonds (IMHB) being amplified by substitution in theparaposition of pyridine rings by electron‐releasing substituents. The inspection of the nature of IMHBs reveals that IMHB is of a bifurcated type with energy spanning a range between 5.7 and 7.4 kcal mol−1. The basicities of pyridinophanes are examined in acetonitrile. It is found that their pKa values span a range between 18.9 and 31.3 units.
RETRACTED: Shrinkable Nanotubes for Duplex Formation of Short Nucleotides
Authors: Kameta Naohiro , Akiyama Haruhisa
Published: July 2018

Molecular monolayer nanotubes produced by self‐assembly of an amphiphile modified with a 2‐nitrobenzyl group as a photoresponsive unit are able to encapsulate dinucleotides via electrostatic attraction. Upon photoirradiation, the 18 nm inner diameter of the nanotubes shrinks to less than 2 nm as a result of photochemical cleavage of the 2‐nitrobenzyl group in the amphiphile. This shrinking of the nanotube channels leads to a propulsive release of the dinucleotides into the bulk solution and simultaneously accelerates formation of the dinucleotide duplexes. The larger nanotube channels without photoirradiation merely release each dinucleotide into the bulk solution, indicating that the squeezing via transportation in the narrow nanotube channels is necessary for duplex formation. In addition to the size effect, water with a lower polarity confined within the narrow nanotube channels helps to stabilize the energetically unfavorable hydrogen‐bonded base pair between the dinucleotides. This system should enable researchers to perform biological reactions that occur only in specific environments and conditions in living organisms.
Presynaptic cannabinoid CB2 receptors modulate [3H]‐Glutamate release at subthalamo‐nigral terminals of the rat
Authors: Sánchez‐Zavaleta Rodolfo , Cortés Hernán , Avalos‐Fuentes José Arturo , García Ubaldo , Segovia Vila José , Erlij David , Florán Benjamín
Published: July 2018

Recent studies suggested the expression of CB2 receptors in neurons of the CNS, however, most of these studies have only explored one aspect of the receptors, i.e., expression of protein, messenger RNA, or functional response, and more complete studies appear to be needed to establish adequately their role in the neuronal function. Electron microscopy studies showed the presence of CB2r in asymmetric terminals of the substantia nigra pars reticulata (SNr), and its mRNA appeared is expressed in the subthalamic nucleus. Here, we explore the expression, source, and functional effects of such receptors by different experimental approaches. Through PCR and immunochemistry, we showed mRNA and protein for CB2rs in slices and primary neuronal cultures from subthalamus. GW833972A, GW405833, and JHW 133, three CB2r agonists dose‐dependent inhibited K+‐induced [3H]‐Glutamate release in slices of SNr, and the two antagonist/inverse agonists, JTE‐907 and AM630, but not AM281, a CB1r antagonist, prevented GW833972A effect. Subthalamus lesions with kainic acid prevented GW833972A inhibition on release and decreased CB2r protein in nigral synaptosomes, thus nigral CB2rs originate in subthalamus. Inhibition of [3H]‐Glutamate release was PTX‐ and gallein‐sensitive, suggesting a Giβγ‐mediated effect. P/Q Ca2+‐type channel blocker, ω‐Agatoxin‐TK, also inhibited the [3H]‐Glutamate release, this effect was occluded with GW833972A inhibition, indicating that the βγ subunit effect is exerted on Ca2+channel activity. Finally, microinjections of GW833972A in SNr induced contralateral turning. Our data showed that presynaptic CB2rs inhibit [3H]‐Glutamate release in subthalamo‐nigral terminals by P/Q‐channels modulation through the Giβγ subunit and suggested their participation in motor behavior.
Antitumor activity of RT2 peptide derived from crocodile leukocyte peptide on human colon cancer xenografts in nude mice
Authors: Maraming Pornsuda , Klaynongsruang Sompong , Boonsiri Patcharee , Maijaroen Surachai , Daduang Sakda , Chung Jing‐Gung , Daduang Jureerut
Published: July 2018

RT2, derived from the leukocyte peptide of Crocodylus siamensis, can kill human cervical cancer cells via apoptosis induction, but no evidence has shown in vivo. In this study, we investigated the antitumor effect of RT2 on human colon cancer xenografts in nude mice. Twenty‐four mice were injected subcutaneously with human colon cancer HCT 116 cells. Eleven days after cancer cell implantation, the mice were treated with intratumoral injections of phosphate buffered saline (PBS) or RT2 (0.01, 0.1, and 1 mg/mouse) once every 2 days for a total of 5 times. The effect of a 10‐day intratumoral injection of RT2 on body weight, biochemical, and hematological parameters in BALB/c mice showed no significant difference between the groups. Tumor volume showed a significant decrease only in the treatment group with RT2 (1 mg/mouse) at day 6 (P < .05), day 8 (P < .01), and day 10 (P < .01) after the first treatment. The protein expression levels of cleaved poly (ADP‐ribose) polymerase (PARP), apoptosis‐inducing factor (AIF), and the p53 tumor suppressor protein (p53) in xenograft tumors increased after treatment with RT2 (1 mg/mouse) compared to those in the PBS‐injected group. Moreover, RT2 increased the expression of Endo G and Bcl‐2 family proteins. Therefore, the peptide RT2 can inhibit tumor growth via the induction of apoptosis in an in vivo xenograft model.
Documenting the state of adaptation for the global stocktake of the Paris Agreement
Authors: Tompkins Emma L. , Vincent Katharine , Nicholls Robert J. , Suckall Natalie
Published: July 2018

Article 7, paragraph 14 of the Paris Agreement to the United Nations Framework Convention on Climate Change commits Parties to create a five yearly assessment of observed adaptation to track progress and enable appropriate future commitments through the Nationally Determined Contributions and National Adaptation Plans. No large‐scale study exists that shows the types of adaptation, the spatial distribution of types of adaptation, and the numbers of people engaging in that adaptation. To address this gap, and to feed into debates about the modalities for the global stocktake, in this paper we propose a new “stocktaking” approach to document the spectrum and prevalence of observed adaptation over large scales. The four‐step stocktaking approach focuses on: (a) obtaining consensus on the objectives of adaptation; (b) agreeing the sources of evidence; (c) agreeing the search method; and (d) categorizing the adaptations. By focusing on documenting rather than evaluating adaptation, the simple approach avoids some of the adaptation heuristic traps. With guidance to countries on how to operationalize, this approach could improve the transparency of adaptation data collection and analysis, ensure comparability of findings across space and time, and inform the Adaptation Communications (Article 7.10)—a prerequisite to strengthening future ambition commitments within the Paris Agreement.

This article is categorized under:

Policy and Governance > International Policy Framework

Vulnerability and Adaptation to Climate Change > Institutions for Adaptation
Eukaryotic cell dynamics from crawlers to swimmers
Authors: Othmer H. G.
Published: July 2018

Movement requires force transmission to the environment, and motile cells are robustly, though not elegantly, designed nanomachines that often can cope with a variety of environmental conditions by altering the mode of force transmission used.a As with humans, the available modes range from momentary attachment to a substrate when crawling, to shape deformations when swimming, and at the cellular level this involves sensing the mechanical properties of the environment and altering the mode appropriately. While many types of cells can adapt their mode of movement to their microenvironment (ME), our understanding of how they detect, transduce and process information from the ME to determine the optimal mode is still rudimentary. The shape and integrity of a cell is determined by its cytoskeleton (CSK), and thus the shape changes that may be required to move involve controlled remodeling of the CSK. Motion in vivo is often in response to extracellular signals, which requires the ability to detect such signals and transduce them into the shape changes and force generation needed for movement. Thus the nanomachine is complex, and while much is known about individual components involved in movement, an integrated understanding of motility in even simple cells such as bacteria is not at hand. In this review we discuss recent advances in our understanding of cell motility and some of the problems remaining to be solved.

This article is categorized under

Structure and Mechanism > Computational Materials Science

Structure and Mechanism > Computational Biochemistry and Biophysics
Sir William Crookes and his radiometer
Authors: Stanhill Gerald
Published: July 2018

William Crookes started his remarkable scientific career as a weather observer. A brief description of his many achievements is followed by a more detailed account of the past, present and possible future of the radiometer he invented.
Computational methods for analyzing and modeling genome structure and organization
Authors: Lin Dejun , Bonora Giancarlo , Yardımcı Galip Gürkan , Noble William S.
Published: July 2018

Recent advances in chromosome conformation capture technologies have led to the discovery of previously unappreciated structural features of chromatin. Computational analysis has been critical in detecting these features and thereby helping to uncover the building blocks of genome architecture. Algorithms are being developed to integrate these architectural features to construct better three‐dimensional (3D) models of the genome. These computational methods have revealed the importance of 3D genome organization to essential biological processes. In this article, we review the state of the art in analytic and modeling techniques with a focus on their application to answering various biological questions related to chromatin structure. We summarize the limitations of these computational techniques and suggest future directions, including the importance of incorporating multiple sources of experimental data in building a more comprehensive model of the genome.

This article is categorized under:

Analytical and Computational Methods > Computational Methods

Laboratory Methods and Technologies > Genetic/Genomic Methods

Models of Systems Properties and Processes > Mechanistic Models
Revisiting the non-resonant Higgs pair production at the HL-LHC
Authors: Adhikary Amit , Banerjee Shankha , Barman Rahool Kumar , Bhattacherjee Biplob , Niyogi Saurabh
Published: July 2018

Abstract

We study the prospects of observing the non-resonant di-Higgs pair production in the Standard Model (SM) at the high luminosity run of the 14 TeV LHC (HL-LHC), upon combining multiple final states chosen on the basis of their yield and cleanliness. In particular, we consider the

$$ b\overline{b}\gamma \gamma,\ b\overline{b}{\tau}^{+}{\tau}^{-},\ b\overline{b}W\ {W}^{\ast },\ W\ {W}^{\ast}\gamma \gamma $$

b

b
¯

γ
γ
,

b

b
¯

τ
+

τ
−

,

b

b
¯

W

W
∗

,

W

W
∗

γ
γ

and 4W channels mostly focusing on final states with photons and/or leptons and study 11 final states. We employ multivariate analyses to optimise the discrimination between signal and backgrounds and find it performing better than simple cut-based analyses. The various differential distributions for the Higgs pair production have non-trivial dependencies on the Higgs self-coupling (λ

hhh
). We thus explore the implications of varying λ

hhh
for the most sensitive search channel for the double Higgs production, viz.,

$$ b\overline{b}\gamma \gamma $$

b

b
¯

γ
γ

. The number of signal events originating from SM di-Higgs production in each final state is small and for this reason measurement of differential distributions may not be possible. In order to extract the Higgs quartic coupling, we have to rely on the total number of events in each final state and these channels can be contaminated by various new physics scenarios. Furthermore, we consider various physics beyond the standard model scenarios to quantify the effects of contamination while trying to measure the SM di-Higgs signals in detail. In particular, we study generic resonant heavy Higgs decays to a pair of SM-like Higgs bosons or to a pair of top quarks, heavy pseudoscalar decaying to an SM-like Higgs and a Z-boson, charged Higgs production in association with a top and a bottom quark and also various well-motivated supersymmetric channels. We set limits on the cross-sections for the aforementioned new physics scenarios, above which these can be seen as excesses over the SM background and affect the measurement of Higgs quartic coupling. We also discuss the correlations among various channels which can be useful to identify the new physics model.
Onset of random matrix behavior in scrambling systems
Authors: Gharibyan Hrant , Hanada Masanori , Shenker Stephen H. , Tezuka Masaki
Published: July 2018

Abstract

The fine grained energy spectrum of quantum chaotic systems is widely believed to be described by random matrix statistics. A basic scale in such a system is the energy range over which this behavior persists. We define the corresponding time scale by the time at which the linearly growing ramp region in the spectral form factor begins. We call this time t
ramp. The purpose of this paper is to study this scale in many-body quantum systems that display strong chaos, sometimes called scrambling systems. We focus on randomly coupled qubit systems, both local and k-local (all-to-all interactions) and the Sachdev-Ye-Kitaev (SYK) model. Using numerical results, analytic estimates for random quantum circuits, and a heuristic analysis of Hamiltonian systems we find the following results. For geometrically local systems with a conservation law we find t
ramp is determined by the diffusion time across the system, order N
2 for a 1D chain of N qubits. This is analogous to the behavior found for local one-body chaotic systems. For a k-local system like SYK the time is order log N but with a different prefactor and a different mechanism than the scrambling time. In the absence of any conservation laws, as in a generic random quantum circuit, we find t
ramp ∼ log N, independent of connectivity.
Neurodegenerative Erkrankungen des Kindesalters
Authors: Schulz Angela , Nickel Miriam
Published: July 2018

Das Verständnis der neurodegenerativen Erkrankungen im Kindesalter hat sich in jüngster Zeit rasant verändert: Nicht nur die Anzahl unterschiedlicher Krankheiten und zugrunde liegender Gendefekte nimmt stetig zu, auch die Ansätze für Diagnostik und Therapie haben sich aufgrund neuerer technologischer und therapeutischer Fortschritte in dieser Krankheitsgruppe weiterentwickelt. Es wurden neue Gendefekte identifiziert, die eine Grundlage für das Verständnis der molekularen Mechanismen, die dieser Krankheitsgruppe zugrunde liegen, sowie für die Entwicklung gezielter Therapien bieten. Diese Übersichtsarbeit konzentriert sich hauptsächlich auf eine der häufigsten Krankheitsgruppen, die zu einer Degeneration des zentralen Nervensystems führen, die neuronalen Ceroid-Lipofuszinosen (NCL). Die Anzahl der NCL-verursachenden Gene und das Wissen über Genotyp-Phänotyp-Korrelationen sind in den letzten Jahren gewachsen und erste Therapien wurden entwickelt. Damit stellt diese Krankheitsgruppe die schnelle wissenschaftliche Entwicklung auf dem Gebiet der seltenen, neurodegenerativen Erkrankungen im Kindesalter sehr gut dar.
Linking the gut and liver: crosstalk between regulatory T cells and mucosa-associated invariant T cells
Authors: Atif Muhammad , Warner Suz , Oo Ye H.
Published: July 2018

The gut–liver axis is increasingly considered to play a vital part in the progression of chronic inflammatory gut and liver diseases. Hence, a detailed understanding of the local and systemic regulatory mechanisms is crucial to develop novel therapeutic approaches. In this review, we discuss in-depth the roles of regulatory T cells (Tregs) and mucosal-associated invariant T cells (MAITs) within the context of inflammatory bowel disease, primary sclerosing cholangitis, and non-alcoholic steatohepatitis. Tregs are crucial in maintaining peripheral tolerance and preventing autoimmunity. MAIT cells have a unique ability to rapidly recognize microbial metabolites and mount a local immune response and act as a ‘biliary firewall’ at the gut and biliary epithelial barrier. We also outline how current knowledge can be exploited to develop novel therapies to control the propagation of chronic gut- and liver-related inflammatory and autoimmune conditions. We specifically focus on the nature of the Tregs’ cell therapy product and outline an adjunctive role for low-dose IL-2. All in all, it is clear that translational immunology is at crucial crossroads. The success of ongoing clinical trials in cellular therapies for inflammatory gut and liver conditions could revolutionize the treatment of these conditions and the lives of our patients in the coming years.
Subjektiver Überkonsum von Wohnraum: Empirische Evidenz für die Schweiz
Authors: Delbiaggio Katia , Wanzenried Gabrielle
Published: July 2018

In Switzerland, living space consumption per person has been increasing for years. Besides structural causes, the overconsumption of living space is one of the determinants. After theoretical considerations, we first use an empirical model to explain the subjective overconsumption of living space of households, and we include household-, dwelling- and residence-specific determinants in our model. The sample is based on the Swiss Household Panel. Our analyses show that nearly 10 % of the Swiss households live in a dwelling that they consider as too large. These households exhibit statistically significant differences with regard to most determinants of subjective overconsumption of living space in comparison to the rest of the sample. The logit estimations show that mainly older households and single-person households are characterised by the largest subjective overconsumption of living space. In a second step, we propose a method based on conditional probabilities to estimate the subjective overconsumption of living space on the neighbourhood level in a city in case there are no information available on the subjective overconsumption of living space. We use a dataset from the Federal Office of Statistics. Their analyses show that about 6 % of the households in Lucerne consider their dwelling as too large. Furthermore, the different neighbourhoods are characterised by a large heterogeneity. Accordingly, effective measures to address the subjective overconsumption should be implemented on a local level.