bluuebunny/crossref_metadata_2025 huggingface dataset:
Fast surface immobilization of native proteins through catalyst-free amino-yne click bioconjugation
Authors: Zhang Yiru , Shen Jianlei , Hu Rong , Shi Xiujuan , Hu Xianglong , He Benzhao , Qin Anjun , Tang Ben Zhong
Published: March 2020

Fast surface immobilization of native bioconjugates through a spontaneous amino-yne click reaction is realized.
Molecular origins of folding rate differences in the thioredoxin family
Authors: Naganathan Athi N.
Published: March 2020

Thioredoxins are a family of conserved oxidoreductases responsible for maintaining redox balance within cells. They have also served as excellent model systems for protein design and engineering studies particularly through ancestral sequence reconstruction methods. The recent work by Gamiz-Arco et al. [Biochem J (2019) 476, 3631–3647] answers fundamental questions on how specific sequence differences can contribute to differences in folding rates between modern and ancient thioredoxins but also among a selected subset of modern thioredoxins. They surprisingly find that rapid unassisted folding, a feature of ancient thioredoxins, is not conserved in the modern descendants suggestive of co-evolution of better folding machinery that likely enabled the accumulation of mutations that slow-down folding. The work thus provides an interesting take on the expected folding-stability-function constraint while arguing for additional factors that contribute to sequence evolution and hence impact folding efficiency.
Autophagy attenuates high glucose-induced oxidative injury to lens epithelial cells
Authors: Liu Xiaomin , Zhao Xiaowen , Cheng Rong , Huang Yusen
Published: March 2020

Purpose: Autophagic dysfunction and abnormal oxidative stress are associated with cataract. The purpose of the present study was to investigate the changes of cellular autophagy and oxidative stress and their association in lens epithelial cells (LECs) upon exposure to high glucose.

Methods: Autophagy and oxidative stress-related changes were detected in streptozotocin-induced Type 1 diabetic mice and normal mouse LECs incubated in high glucose conditions. Rapamycin at a concentration of 100 nm/l or 50 μM chloroquine was combined for analysis of the relationship between autophagy and oxidative stress. The morphology of LECs during autophagy was observed by transmission electron microscopy. The expressions of autophagy markers (LC3B and p62) were identified, as well as the key factors of oxidative stress (SOD2 and CAT) and mitochondrial reactive oxygen species (ROS) generation.

Results: Transmission electron microscopy indicated an altered autophagy activity in diabetic mouse lens tissues with larger autophagosomes and multiple mitochondria. Regarding the expressions, LC3B was elevated, p62 was decreased first and then increased, and SOD2 and CAT were increased before a decrease during 4 months of follow-up in diabetic mice and 72 h of culture under high glucose for mouse LECs. Furthermore, rapamycin promoted the expressions of autophagy markers but alleviated those of oxidative stress markers, whereas chloroquine antagonized autophagy but enhanced oxidative stress by elevating ROS generation in LECs exposed to high glucose.

Conclusions: The changes in autophagy and oxidative stress were fluctuating in the mouse LECs under constant high glucose conditions. Autophagy might attenuate high glucose-induced oxidative injury to LECs.
LHPP suppresses proliferation, migration, and invasion and promotes apoptosis in pancreatic cancer
Authors: Wu Fahong , Chen Yanling , Zhu Jinhai
Published: March 2020

Pancreatic cancer (PaCa) is a common malignant tumor of the digestive system with poor prognosis and no ideal treatment for inoperable patients, which is partly due to delayed diagnoses. It is recently reported that the protein histidine phosphatase LHPP is a tumor suppressor in hepatocellular carcinoma, cervical cancer, and bladder cancer. So far, there is no study on the expression level of LHPP in PaCa, and its mechanism of action on tumors is unclear. In this experiment, LHPP expression was lower in cancer tissues than that in normal pancreatic tissue, and clinicopathological results showed that LHPP expression was correlated with the degree of differentiation and lymphatic metastasis of pancreatic carcinoma. The biological characteristics of LHPP in PaCa cells were examined by the cell counting kit-8 assay, transwell assay, and monoclonal formation test. The inhibitory mechanism of LHPP in PaCa cells was determined using Western blotting and flow cytometry. The results showed that LHPP restrained PaCa cell proliferation, migration, and invasion. Increased LHPP expression promoted the apoptosis of PaCa cells through higher activation of cleaved-PARP and cleaved-Casp3 and lower activation of cIAP1. Importantly, the increase in LHPP enhanced PTEN expression and decreased the phosphorylated AKT level. Moreover, LHPP-induced apoptosis was diminished by SC79 (AKT activator) in PaCa cells. In conclusion, LHPP blocks proliferation, migration, and invasion and enhances apoptosis in PaCa cells through the PTEN/AKT signaling pathway.
Hepatocyte growth factor protects PC12 cells against OGD/R-induced injury by reducing iron
Authors: Li Siyue , Qian Zhong-Ming , Xu Gaojing , Zheng Jie , Wu Yi
Published: March 2020

In the light of hepatocyte growth factor (HGF) the inhibiting role on the expression of hepcidin, we hypothesized that HGF might be able to reduce cell and tissue iron by increasing ferroportin 1 (Fpn1) content and Fpn1-mediated iron release from cells and tissues. The hypothesized ability of HGF to reduce iron might be one of the mechanisms associated with its neuroprotective action under the conditions of ischemia/reperfusion (I/R). Here, we investigated the effects of HGF on the expression of hepcidin as well as transferrin receptor 1 (TfR1), divalent metal transporter 1 (DMT1), Fpn1, ferritin and iron regulatory proteins (IRPs) in oxygen-glucose deprivation and reoxygenation (OGD/R)-treated PC12 cells by real-time PCR and Western blot analysis. We demonstrated that HGF could completely reverse the OGD/R-induced reduction in Fpn1 and IRP1 expression and increase in ferritin light chain protein and hepcidin mRNA levels in PC12 cells. It was concluded that HGF protects PC12 cells against OGD/R-induced injury mainly by reducing cell iron contents via the up-regulation of Fpn1 and increased Fpn1-mediated iron export from cells. Our findings suggested that HGF may also be able to ameliorate OGD/R or I/R-induced overloading of brain iron by promoting Fpn1 expression.
Age-Related Changes in Speech and Voice: Spectral and Cepstral Measures
Authors: Taylor Sammi , Dromey Christopher , Nissen Shawn L. , Tanner Kristine , Eggett Dennis , Corbin-Lewis Kim
Published: March 2020

Purpose

This study examined differences in selected acoustic measures of speech and voice according to age and sex and across families.

Method

Participants included 169 individuals, 79 men and 90 women, from 18 families, ranging in age from 17 to 87 years. Participants reported no history of articulation disorders, stroke or active neurologic disease, or severe-to-profound hearing loss. They read aloud two passages to facilitate examination of the following speech and voice acoustic parameters: fricative spectral moments (center of gravity, standard deviation, skewness, and kurtosis), the proportion of time spent speaking, mean speaking fundamental frequency, semitone standard deviation (STSD), and cepstral peak prominence smoothed.

Results

The results indicated a significant age effect for fricative spectral center of gravity, spectral skewness, and speaking STSD. There was a significant sex effect for spectral center of gravity, spectral kurtosis, and mean fundamental frequency. Familial relationship was significant for spectral skewness, STSD, and cepstral peak prominence smoothed.

Conclusions

These findings revealed that certain speech and voice features change with age and some change differently for men and women. Additionally, speakers from the same family units may demonstrate similar patterns for prosody, voicing, and articulatory behavior. The results also demonstrated normal differences in speech and voice variation across age, sex, and family unit. Understanding patterns and differences across these demographic variables in healthy speakers is important to distinguishing more confidently between normal and disordered speech and voice patterns clinically.
Interference mitigation and capacity enhancement of cognitive radio networks using modified greedy algorithm/channel assignment and power allocation techniques
Authors: Ranjan Rajeev , Agrawal Navneet , Joshi Sunil
Published: March 2020

Cognitive radio (CR) concept is turning out as a prominent approach used in the wireless communication network for increasing spectrum efficiency by opportunistically and mutually sharing the spectrum of contemporary networks. CR can bear high traffic loads during emergencies and major disasters by overcoming the limitations like lack of network capacity. The fundamental issues pertaining the implementation of CR network (CRN) are the presence of co‐channel interference and adjacent channel interference among CR users; and most importantly interference to primary users. Effective interference mitigation and management in CRN will make it more robust in easing the additional stress because of very high traffic loads during an intense emergency and disaster scenarios. In this study, an approach has been taken to minimise interference among secondary nodes by employing interference index as interference minimisation key which in turn maximises the system capacity. To validate the results, the authors thoroughly used an existing distributed greedy algorithm, which, on the introduction of interference index, furnished a gain of 60% in the CR network capacity. Further, a trade‐off analysis between the interference index and channel leakage ratio is presented with an interference bound of 10 dBm, which may form the basis of interference management in CRN.
Performance off cluster‐based multi‐hop underlay networks with energy harvesting nodes
Authors: Bhatt Madhav , Boddapati Hari Krishna , Prakriya Shankar
Published: March 2020

In this paper, the authors consider an underlay multi‐hop cognitive radio network with energy harvesting secondary nodes, where there is a cluster of secondary decode‐and‐forward relays in each hop. The secondary nodes have no separate energy source available with them, but wake up from idle mode to harvest energy from the primary signal with the time‐switching protocol, and use it for transmitting/relaying using the peak interference constraint. In each cluster, a relay with maximum transmit power is selected except in the last one. In the last cluster, a relay which has a maximum signal‐to‐noise ratio (SNR) at the secondary destination is selected. Though the suggested scheme has low implementation complexity and requires very little channel estimation, its performance is close to that of a scheme in which the link with the best SNR is chosen in each hop (which requires a lot of channel estimation). Analytical expressions are derived for the end‐to‐end outage probability and throughput assuming Rayleigh faded channels. They show that it is important to optimise the time‐switching parameter (fraction of time devoted to energy harvesting) and the number of hops. Simulations confirm the accuracy of the derived expressions.
Distance increasing mapping for variable distance block code
Authors: Talmale Seema , Unnikrishnan Srija , Lande Bhaurao K.
Published: March 2020

A new idea regarding the generation of a block code for a code rate of 1/2 and less than 1/2 is developed here. The minimum distance between the codewords can be maximised using a suitable transformation of the P matrix in the generator matrix G of the block code. This study gives the construction of distance increasing mapping (DIM) such that the proposed code is a variable distance modified block code with a code rate equal to 1/2. An algorithm for such DIM is developed here. The construction for distance preserving mapping (DPM) is also generalised in an algorithmic way. Further, to achieve DIM from the proposed DPM, for the established codes with a code rate less than 1/2, transformation is developed with the help of permutation arrays. The performance of the codes has also been evaluated. Decoding of this code is also simple and can be carried out using the existing techniques of decoding of block codes. The probability of undetected error is found to be better than the existing block codes.
Joint resource allocation for dynamic cellular‐enabled UAVs communication
Authors: Fan Chaoqiong , Bao Shijian , Li Bin , Zhao Chenglin
Published: March 2020

Emerging cellular‐enabled unmanned aerial vehicles (UAVs) communication poses both opportunities and challenges to the current research of UAV applications. On the one hand, the advanced cellular technologies and authentication mechanisms make significant performance improvements of reliability, security, coverage, and throughput of UAVs possible. On the other hand, the considerably dynamic characteristics of the new aerial users bring some complicated and open issues to the future heterogeneous network. To throw some light on this field, the authors study the joint power allocation and channel reuse problem of uplink transmission in a cellular‐enabled UAVs network with full consideration of the rapid channel variations resulting from high mobility of UAVs. Given the diverse requirements of terrestrial cellular users (CUs) and UAVs, i.e. large capacity for CU links and ultra‐reliability for UAV links, they formulate the problem as optimising the uplink capacities of CUs with reliable transmission constraint of UAVs. By decoupling the intricate problem into two sub‐problems, a joint resource allocation algorithm is proposed, which relies only on the statistical information of dynamic channels to implement, hence is robust. Finally, numerical results are provided to corroborate the anticipated performances of the proposed scheme.
Vision‐based tip position tracking control of two‐link flexible manipulator
Authors: Sahu Umesh Kumar , Patra Dipti , Subudhi Bidyadhar
Published: March 2020

Owing to the non‐collocation of actuators and sensors in a flexible‐link manipulator (FLM) it becomes difficult to achieve accurate tip position tracking. To resolve this issue, a vision sensor is used for direct measurement of the tip position instead of employing the traditional mechanical sensors. Among the different visual servoing (VS) control schemes, image‐based VS (IBVS) is more effective. However, there are many challenges in the IBVS scheme such as singularities in the interaction matrix and local minima in trajectories that affect the system performance in real‐time applications. In this study, the moment‐based new visual feature is selected to address the aforesaid issues that arise in the IBVS scheme. Furthermore, a new two‐time scale IBVS controller is developed for addressing the tip‐tracking control problem of the two‐link flexible manipulator (TLFM). In the proposed control scheme, the dynamics of the FLM is decomposed into two‐time scale models, namely a slow subsystem and a fast subsystem. The performance and robustness of the proposed new two‐time scale IBVS controller for TLFM are verified by pursuing simulation studies. It is observed from the obtained results that the proposed controller effectively stabilises the oscillatory dynamics and tracks the reference trajectory accurately.
Modelling of axial‐flux eddy‐current couplers
Authors: Mohammadi Sajjad , Kirtley James , Niaz Azari Milad
Published: March 2020

Analytical models are widely employed in the design of electromagnetic devices. This study presents a flux‐tube model for axial‐flux eddy‐current couplers with surface magnets. Thanks to the developed three‐dimensional magnetic equivalent circuit, the proposed model is able to handle complex geometries and take into account all dimensional parameters and material properties such as iron saturation and permanent magnet (PM) characteristics. In addition, the associated practical design considerations including iron saturation, demagnetisation criteria, actual current paths, and heating conditions are analytically presented. Also, a three‐dimensional finite‐element analysis is utilised in the assessment of the model. Finally, a prototype is made to experimentally analyse the design and confirm analytical and numerical results.
Computationally efficient steady‐state finite element simulation of multiphase PM AC machines
Authors: Lekić Đorđe M. , Vukosavić Slobodan N.
Published: March 2020

In this study the authors propose a generalised procedure for computationally efficient steady‐state finite element (FE) simulation of symmetrical multiphase permanent magnet (PM) AC machines with an arbitrary number of phases. The procedure is based on newly derived general equations for phase waveform reconstruction that fully exploit the phase symmetry of multiphase electrical machines. This result can be used to reconstruct the full electrical period of any phase waveform from the smallest possible number of magnetostatic FE simulations executed within the minimum angular displacement of the rotor. Reconstruction of phase waveforms is done during post‐processing and does not contribute to the execution time of FE simulations. The applicability of the proposed method is demonstrated by deriving specific equations for two‐phase, three‐phase, five‐phase and six‐phase machines. Results of classical time‐stepping and newly proposed computationally efficient FE simulation are presented for four rotor PM flux switching machines with the different number of phases. Obtained results show that the relative reduction of simulation time increases with the number of machine phases.
Expanding vision‐based ADAS for non‐structured environments
Authors: Antony Joseph , Manikandan Suchetha
Published: March 2020

Advanced driver assistance systems (ADAS) become an integral part of almost all modern automotive systems. ADAS have been evolving over a decade and the expansion of vision‐based ADAS is quite rapid mainly due to the recent advancements in camera technologies. Most of the vision‐based ADAS applications have been developed focusing on structured environment parameters and being tested adequately for those environments whereas they cannot be applied with their current framework as such for non‐structured environments due to various limitations. This study presents a comprehensive overview of challenges in expanding the vision‐based ADAS for non‐structured environments. The authors have proposed a segmentation detection method for pedestrians and cyclists in a non‐structured road environment to improve the accuracy of the popular deep learning networks. This method uses upper body detection and a pairing technique that improves the average precision significantly without consuming much computational resources. This approach would help to transform the structured environment ADAS to non‐structured environments with minimal modifications. With the proposed approach, they are able to increase the accuracy of certain object classes up to 49% for various popular deep learning networks.
Multiple object tracking using a dual‐attention network for autonomous driving
Authors: Gao Ming , Jin Lisheng , Jiang Yuying , Bie Jing
Published: March 2020

Multiple object tracking (MOT) remains an open and challenging problem for autonomous vehicles. Existing methods mainly ignore prior information from real traffic scenes. Here, the authors propose a novel MOT algorithm that considers traffic safety for vulnerable road users. The proposed method integrates two attention modules with a novel detection refinement strategy. Since skilled drivers pay more attention to pedestrians and cyclists, the authors employ a saliency detection method to extract scene attention region. Then, a detection refinement strategy achieved a good trade‐off between parallel single object trackers and detection results. Channel attention can mine the most useful feature channel for traffic road users. In the end, the authors operate their method on the popular MOT 17 benchmark in comparison with other high‐level MOT algorithms. The tracking results show that the proposed dual‐attention network achieves the state‐of‐the‐art performance.
Experimental study of the effect of surface groove micro‐texturing on lubrication characteristics
Authors: Gao Huichao , Chen Xinyuan
Published: March 2020

This study investigated the effect of surface groove micro‐texturing on hydrodynamic lubrication characteristics. All textured samples were processed by laser; non‐textured reference samples were also created for comparison. Four types of surface groove patterns with different groove angles and groove depths were utilised. Different rotational speeds and gaps were used in the experiment to explain the relationship between the load‐carrying capacity and the groove texture parameters under different conditions. The results suggested that the load‐carrying capacity was greatly influenced by the operational conditions and that the samples with surface groove textures generated a larger hydrodynamic lift force than the non‐textured samples.
Rapid hydrothermal method for the preparation of carbon quantum dots in the presence of hydrogen peroxide
Authors: Qin Jin‐Lan , Li Shan‐Ji , Yuan Ning‐Ning , Chen Ying , Lei Bing‐Fu , Hu Chao‐Fan , Liu Ying‐Liang
Published: March 2020

Carbon quantum dots (CQDs) have been studied for years as one of the most promising fluorescent nanomaterials. Herein, CQDs were prepared rapidly by a simple, eco‐friendly one‐pot hydrothermal method in the presence of hydrogen peroxide. Different sizes of CQDs are obtained by changing the reaction time. X‐ray photoelectron spectroscopy and Fourier transform infrared spectrometry demonstrated the existence of a large number of oxygen‐containing groups on the surface of CQDs. The as‐prepared CQDs exhibited bright yellow luminescence under UV light, they are applied for bioimaging of HeLa cells, and showed bright luminescence and excellent biocompatibility.
Low‐temperature oxidation of metal nanoparticles obtained by chemical dispersion
Authors: Dzidziguri Ella L. , Sidorova Elena N. , Yahiyaeva Jansaya E. , Ozherelkov Dmitriy Yu. , Gromov Alexander A. , Nalivaiko Anton Yu.
Published: March 2020

Oxidation of cobalt, nickel, molybdenum and tungsten nanoparticles under prolonged exposure in the air was studied. Nanoparticles were obtained by chemical dispersion with the following reduction temperatures: 200–400°C for cobalt; 200–400°C for nickel; 700–800°C for molybdenum and 750–850°C for tungsten. Scanning electron microscopy, transmission electron microscopy, XRD and thermogravimetric analysis were used for nanoparticles characterisation. The average size of nanoparticles, specific surface area and the coherent scattering area were determined. The method for oxide film thickness calculation on the surface of the nanoparticles was proposed and confirmed its adequacy. Based on experimental data, the growth law of the oxide film on the studied nanoparticles was determined. The obtained results can be used in the certification of nanoparticles and evaluation of a highly dispersed metal powders shelf life.
“TNOs are Cool”: A survey of the trans-Neptunian region
Authors: Farkas-Takács A. , Kiss Cs. , Vilenius E. , Marton G. , Müller T. G. , Mommert M. , Stansberry J. , Lellouch E. , Lacerda P. , Pál A.
Published: March 2020

The goal of this work is to determine the physical characteristics of resonant, detached and scattered disk objects in the trans-Neptunian region, observed mainly in the framework of the “TNOs are Cool” Herschel open time key programme. Based on thermal emission measurements with the Herschel/PACS and Spitzer/MIPS instruments, we determine size, albedo, and surface thermal properties for 23 objects using radiometric modeling techniques. This is the first analysis in which the physical properties of objects in the outer resonances are determined for a notable sample. In addition to the results for individual objects, we compared these characteristics with the bulk properties of other populations of the trans-Neptunian region. The newly analyzed objects show a large variety of beaming factors, indicating a diversity of thermal properties, and in general they follow the albedo-color clustering identified earlier for Kuiper belt objects and Centaurs, further strengthening the evidence for a compositional discontinuity in the young Solar System.
H II regions and high-mass starless clump candidates
Authors: Zhang S. , Zavagno A. , Yuan J. , Liu H. , Figueira M. , Russeil D. , Schuller F. , Marsh K. A. , Wu Y.
Published: March 2020

Context. The role of ionization feedback on high-mass (>8 M⊙) star formation is still highly debated. Questions remain concerning the presence of nearby H II regions changes the properties of early high-mass star formation and whether H II regions promote or inhibit the formation of high-mass stars.

Aims. To characterize the role of H II regions on the formation of high-mass stars, we study the properties of a sample of candidates high-mass starless clumps (HMSCs), of which about 90% have masses larger than 100 M⊙. These high-mass objects probably represent the earliest stages of high-mass star formation; we search if (and how) their properties are modified by the presence of an H II region.

Methods. We took advantage of the recently published catalog of HMSC candidates. By cross matching the HMSCs and H II regions, we classified HMSCs into three categories: (1) the HMSCs associated with H II regions both in the position in the projected plane of the sky and in velocity; (2) HMSCs associated in the plane of the sky, but not in velocity; and (3) HMSCs far away from any H II regions in the projected sky plane. We carried out comparisons between associated and nonassociated HMSCs based on statistical analyses of multiwavelength data from infrared to radio.

Results. We show that there are systematic differences of the properties of HMSCs in different environments. Statistical analyses suggest that HMSCs associated with H II regions are warmer, more luminous, more centrally-peaked and turbulent. We also clearly show, for the first time, that the ratio of bolometric luminosity to envelope mass of HMSCs (L∕M) could not be a reliable evolutionary probe for early massive star formation due to the external heating effects of the H II regions.

Conclusions. We show HMSCs associated with H II regions present statistically significant differences from HMSCs far away from H II regions, especially for dust temperature and L∕M. More centrally peaked and turbulent properties of HMSCs associated with H II regions may promote the formation of high-mass stars by limiting fragmentation. High-resolution interferometric surveys toward HMSCs are crucial to reveal how H II regions impact the star formation process inside HMSCs.
Strong surface outflows on accretion discs
Authors: Nixon C. J. , Pringle J. E.
Published: March 2020

In order to provide an explanation for the unexpected radial brightness distribution of the steady accretion discs seen in nova-like variables, we have recently proposed that the accretion energy is redistributed outwards by means of strong, magnetically driven surface flows. In this paper we note that the “powerful, rotating disc winds” observed in the soft states of black hole X-ray binaries, and also in the disc around a magnetised neutron star in Her X–1, have the properties of the outflows we recently postulated to exist in the nova-like variable accretion discs around white dwarfs. The relevant properties are that the flows are not winds, but are instead bound flows (travelling at less than the escape velocity) and that the mass fluxes in the flows are a substantial fraction of the accretion rate in the disc.
CO-driven activity constrains the origin of comets
Authors: Fulle M. , Blum J. , Rotundi A.
Published: March 2020

Context.An open question in the study of comets is the so-called cohesion bottleneck, that is, how dust particles detach from the nucleus.

Aims.We test whether the CO pressure buildup inside the pebbles of which cometary nuclei consist can overcome this cohesion bottleneck.

Methods.A recently developed pebble-diffusion model was applied here to comet C/2017K2 PANSTARRS, assuming a CO-driven activity.

Results.(i) The CO-gas pressure inside the pebbles erodes the nucleus into the observed dust, which is composed of refractories, H2O ice and CO2ice. (ii) The CO-driven activity onset occurs up to heliocentric distances of 85 au, depending on the spin orientation of the comet nucleus. (iii) The activity onset observed at ≈26 au suggests a low obliquity of the nucleus spin axis with activity in a polar summer. (iv) At 14 au, the smallest size of the ejected dust is ≈0.1 mm, consistent with observations. (v) The observed dust-loss rate of ≈200 kg s−1implies a fallout ≥30%, a nucleus surface active area ≥10 km2, a CO-gas loss rate ≥10 kg s−1, and a dust-to-gas ratio ≤20. (vi) The CO-driven activity never stops if the average refractory-to-all-ices mass ratio in the nucleus is ≤4.5 for a nucleus all-ices-to-CO mass ratio ≈4, as observed in comets Hale–Bopp and Hyakutake. These results make comet C/2017K2 similar to the Rosetta target comet 67P/Churyumov–Gerasimenko. (vii) The erosion lifetime of cometary planetesimals is a factor 103shorter than the timescale of catastrophic collisions. This means that the comets we observe today cannot be products of catastrophic collisions.
Antikoagulation bei über 80-jährigen Patienten mit Vorhofflimmern
Authors: Zeymer Uwe , Zahn Ralf
Published: March 2020

Die Zahl von Patienten über 80-Jahre mit Vorhofflimmern wird durch den demografischen Wandel über die nächsten Jahre ständig zunehmen. Da all diese Patienten einen CHADS-VASc-Score von > 2 haben, empfehlen die derzeitigen Leitlinien eine orale Antikoagulation. Auch wegen des erhöhten Schlaganfall-Risikos bei über 80-Jährigen führt die orale Antikoagulation mit Vitamin-K-Antagonisten zu einer signifikanten Verringerung der Rate ischämischer Schlaganfälle. In den randomisierten Zulassungsstudien führten die NOAKs im direkten Vergleich zu den Vitamin-K-Antagonisten zu einer Verringerung der Gesamtschlaganfallrate, im Wesentlichen bedingt durch eine drastische Reduktion der hämorrhagischen Schlaganfälle. Dieser Effekt war bei den über 75-jährigen Patienten sogar ausgeprägter als bei den jüngeren Patienten. Probleme bei den > 80-Jährigen stellen die Adhärenz zur oralen Antikoagulation, Verschlechterungen der Nierenfunktion und eine häufig beobachtete Polypharmazie sowie das damit verbundene Risiko für Blutungskomplikationen dar.
Transoral incisionless fundoplication with an ultrasonic surgical endostapler for the treatment of gastroesophageal reflux disease: 12-month outcomes
Authors: Testoni Pier Alberto , Testoni Sabrina , Mazzoleni Giorgia , Pantaleo Giuseppe , Cilona Maria Bernadette , Distefano Giovanni , Fanti Lorella , Antonelli Mario , Passaretti Sandro
Published: March 2020

Background Transoral incisionless fundoplication (TIF) with the Medigus ultrasonic surgical endostapler (MUSE) is a new intervention for the treatment of the gastroesophageal reflux disease (GERD). The aim of this study was to assess the 12-month clinical, functional, and endoscopic effects of TIF by MUSE.

Methods Patients undergoing MUSE completed the GERD-Health Related Quality of Life (GERD-HRQL) and Reflux Symptom Index (RSI) questionnaires, and underwent endoscopy, esophageal 24-hour pH-impedance recording, and high resolution manometry (HRM) before the TIF procedure and 12 months later, or after 6 months for HRM.

Results Among the 37 patients treated, esophageal intubation was not possible in one and esophageal perforation occurred in another. Clinical and endoscopic follow-up at 12 months was completed in 20 patients, with significant improvements in GERD-HRQL, RSI, heartburn, regurgitation scores, and proton pump inhibitor (PPI) consumption observed. One patient required surgery for persisting symptoms. Functional follow-up was possible in 13 patients and showed no significant improvements in the analyzed parameters.

Conclusions TIF with MUSE significantly improved symptoms at 1-year follow-up, allowing the consumption of PPIs to be stopped or halved in 90 % of patients.
Nickel-Catalysed Allylboration of Aldehydes
Authors: Partridge Benjamin M. , Dennis Francesca M. , Robertson Craig C.
Published: March 2020

A nickel catalyst for the allylboration of aldehydes is reported, facilitating the preparation of homoallylic alcohols in high diastereoselectivity. The observed diastereoselectivities and NMR experiments suggest that allylation occurs through a well-defined six-membered transition state, with nickel acting as a Lewis acid.
Short-Form New Knee Society Score: What Is Its Responsiveness and Convergent Validity with Other Scores?
Authors: Maniar Rajesh Navin , Maniar Parul Rajesh , Chanda Debashish , Gajbhare Dnyaneshwar , Chouhan Toral
Published: March 2020

The short-form version of New Knee Society Score (SF-NKSS) was designed with a purpose to reduce respondent burden. Literature review revealed only one report by Scuderi et al on responsiveness of derived SF-NKSS, but it was evaluated in two separate patient cohorts pre- and postsurgery. Our study had evaluated responsiveness and convergent validity of derived SF-NKSS in a single, large patient cohort followed longitudinally from preoperative status to over 1 year. Our database of 148 knee arthroplasty patients operated by the same surgeon, whose NKSS, Western Ontario and McMaster Universities Arthritis Index (WOMAC), and 12-item Short-Form Survey (SF-12) scores were prospectively collected preoperatively and postoperatively at 3 and 12 months for a study published earlier, was analyzed for derived SF-NKSS. Responsiveness was evaluated by determining the effect size, standardized response mean (SRM), and ceiling and floor effects. For convergent validity, Pearson's correlation coefficient was used. SF-NKSS was found to be most responsive with the largest effect size and SRM at 3 months (3.02 and 2.50, respectively) and at 12 months (3.58 and 2.92, respectively) with no ceiling or floor effect. SF-NKSS was followed in responsiveness by original NKSS, WOMAC, and SF-12 in a descending order. Convergent validity showed a strong correlation (r = 0.8–1.0; p < 0.001) of SF-NKSS with NKSS and a moderate to strong correlation (r = 0.5–0.6; p < 0.001) with WOMAC and SF-12. We concluded that SF-NKSS is a reliable, highly responsive tool for post-total knee replacement evaluation. It also has the ability to register improvement in the patient's recovery, which can continue even after 1 year. We found that the SF-NKSS can be used interchangeably with the original NKSS.
Stigma for Mental Disorders among Nursing Staff in a Tertiary Care Hospital
Authors: Grover Sandeep , Sharma Neha , Mehra Aseem
Published: March 2020

Objective This study aimed to evaluate the prevalence of stigma for mental disorders among nursing staff in a tertiary care hospital, and the secondary objective of the study was to assess the correlation of stigma with the socio-demographic profile and previous experience with mentally ill patients.

Methods This cross-sectional study was performed among the 210 nurses working in a tertiary care multispecialty teaching public sector hospital in north India. They were evaluated on community attitudes toward the mentally ill (CAMI) scale.

Results About two-thirds of the participants (67.1%) were females and had done graduation (64.2%) in nursing. Nearly 50% of the study participants had an experience of working with mentally ill patients. Female had a more significant positive attitude on the domain of social restrictiveness. Authoritarianism had a significant positive correlation with benevolence and social restrictiveness domains. The benevolence domain had a significant correlation with all other domains. Social restrictiveness domain also had a significant correlation with other domains.

Conclusion Nurses have a positive attitude toward mentally ill patients.
Advances in the Treatment of Drug-Resistant Pediatric Epilepsy
Authors: Gonzalez-Giraldo Ernesto , Sullivan Joseph E.
Published: March 2020

Epilepsy is a common disorder in children and adults that causes significant morbidity and affects many aspects of a patient's lives. Two-thirds of patients with epilepsy are controlled with established antiseizure medications, leaving a significant number of patients searching for other options. The purpose of this review is to provide an overview of recent advancements in the management of treatment-resistant epilepsy in pediatric patients. Recent publications have shown the efficacy of new pharmaceutical options such as fenfluramine and cannabidiol, some of which have been tested specifically in patients with childhood-onset epilepsy syndromes such as Dravet's syndrome and Lennox–Gastaut's syndrome. Furthermore, recent approval by the U.S. Food and Drug Administration of stiripentol has made available a previously difficult-to-obtain option for patients with Dravet's syndrome. Finally, implanted responsive neurostimulation devices for direct cortical stimulation and deep brain stimulation have shown efficacy in adult patients and may represent a thrilling new horizon for pediatric patients.
Platelet and Red Blood Cell Indices in Patients with Panic Disorder: A Receiver Operating Characteristic Analysis
Authors: Ransing Ramdas S. , Gupta Neha , Agrawal Girish , Mahapatro Nilima
Published: March 2020

Objective Panic disorder (PD) is associated with changes in platelet and red blood cell (RBC) indices. However, the diagnostic or predictive value of these indices is unknown. This study assessed the diagnostic and discriminating value of platelet and RBC indices in patients with PD.

Materials and Methods In this cross-sectional study including patients with PD (n = 98) and healthy controls (n = 102), we compared the following blood indices: mean platelet volume (MPV), platelet distribution width (PDW), and RBC distribution width (RDW). The receiver operating characteristic (ROC) curve was used to calculate the area under the ROC curve (AUC), sensitivity, specificity, and likelihood ratio for the platelet and RBC indices.

Results Statistically significant increase in PDW (17.01 ± 0.91 vs. 14.8 ± 2.06; p < 0.0001) and RDW (16.56 ± 2.32 vs. 15.12 ± 2.43; p < 0.0001) levels were observed in patients with PD. PDW and mean corpuscular hemoglobin concentration had larger AUC (0.89 and 0.74, respectively) and Youden’s index (0.65 and 0.39, respectively), indicating their higher predictive capacity as well as higher sensitivity in discriminating patients with PD from healthy controls.

Conclusion PDW can be considered a “good” diagnostic or predictive marker in patients with PD.
Adoption of an Electronic Medical Record Tool for Childhood Obesity by Primary Care Providers
Authors: Williams Amy , Turer Christy , Smith Jamie , Nievera Isabelle , McCulloch Laura , Wareg Nuha , Clary Megan , Rajagopalan Anuradha , Brownson Ross C. , Koopman Richelle J. , Hampl Sarah
Published: March 2020

Background Primary care providers are tasked with the increasingly difficult job of addressing childhood obesity during clinic visits. Electronic medical record (EMR)-enabled decision-support tools may aid providers in this task; however, information is needed regarding whether providers perceive such tools to be useful for addressing nutrition and physical activity lifestyle behaviors.

Objectives This study aimed to evaluate the usefulness and usability of FitTastic, an EMR-enabled tool to support prevention and management of childhood obesity in primary care.

Methods In this mixed-method study, we implemented the FitTastic tool in two primary-care clinics, then surveyed and conducted focused interviews with providers. Validated Technology Acceptance Model perceived usefulness and National Aeronautics and Space Administration (NASA) perceived usability survey questions were e-mailed to 60 providers. In-depth provider interviews with family medicine and pediatric physicians (n = 12) were used to further probe adoption of FitTastic.

Results Surveys were completed by 73% of providers (n = 44). The mean score for FitTastic's usefulness was 3.3 (standard deviation [SD] = 0.54, scale 1–5, where 5 is strongly agree) and usability, 4.8 (SD = 0.86, scale 1–7, where 7 is strongly agree). Usefulness and usability scores were associated with intention to use FitTastic (correlation for both, p < 0.05). Data from provider interviews indicated that useful features of FitTastic included: standardizing the approach to childhood obesity, and facilitating conversations about weight management, without increasing cognitive workload. However, use of FitTastic required more time from nurses to input lifestyle data.

Conclusion FitTastic is perceived as a useful and usable EMR-based lifestyle behavior tool that standardizes, facilitates, and streamlines healthy lifestyle conversations with families. Perceived usability and usefulness scores correlated with provider intention-to-use the technology. These data suggest that EMR-based child obesity prevention and management tools can be feasible to use in the clinic setting, with potential for scalability. Usefulness can be optimized by limiting amount of time needed by staff to input data.
Experimental investigation on improving the efficiency of power coupling from the incident microwave to the discharge in a plasma torch
Authors: Zhang Wencong , Wu Li , Liu Zhuang , Tao Junwu , Huang Kama
Published: March 2020

A high efficiency of power coupling from the incident microwave to the discharge is a general demand for large-scale and high-power applications of microwave plasma torches. This paper aims to experimentally explore the possibility of improving the power coupling efficiency by choosing a proper glass tube in a microwave plasma torch with a metallic enclosure, rather than using additional tuning measures such as a movable short-circuited ending plunger or a three-stub tuner. The power coupling efficiencies for the glass tubes with different wall thicknesses were experimentally measured under different incident microwave powers and different pressures. The results showed that the power coupling efficiency was improved with the increase in the glass tube wall thickness in a wide range of operating conditions for the microwave plasma torch with specific dimensions. An efficiency higher than 85% can be achieved once the wall thickness of the glass tube is in a particular range. This indicates that external tuning measures can be reduced for the microwave plasma torch with a proper glass tube, which helps to save the cost of tuning devices and enhance the flexibility in different working environments.
Multistate ring polymer instantons and nonadiabatic reaction rates
Authors: Ranya Srinath , Ananth Nandini
Published: March 2020

We present two multistate ring polymer instanton (RPI) formulations, both obtained from an exact path integral representation of the quantum canonical partition function for multistate systems. The two RPIs differ in their treatment of the electronic degrees of freedom; while the Mean-Field (MF)-RPI averages over the electronic state contributions, the Mapping Variable (MV)-RPI employs explicit continuous Cartesian variables to represent the electronic states. We compute both RPIs for a series of model two-state systems coupled to a single nuclear mode with electronic coupling values chosen to describe dynamics in both adiabatic and nonadiabatic regimes. We show that the MF-RPIs for symmetric systems are in good agreement with the previous literature, and we show that our numerical techniques are robust for systems with non-zero driving force. The nuclear MF-RPI and the nuclear MV-RPI are similar, but the MV-RPI uniquely reports on the changes in the electronic state populations along the instanton path. In both cases, we analytically demonstrate the existence of a zero-mode, and we numerically find that these solutions are true instantons with a single unstable mode as expected for a first order saddle point. Finally, we use the MF-RPI to accurately calculate rate constants for adiabatic and nonadiabatic model systems with the coupling strength varying over three orders of magnitude.
Glass formation in amorphous ZnO films revealed by chip calorimetry
Authors: Zeumault Andre
Published: March 2020

In this work, we utilize the high heating/cooling rates of chip calorimetry to perform in situ annealing of an inkjet-printed zinc oxide solgel ink consisting of zinc acetate, 2-methoxyethanol, and monoethanolamine and directly observe the thermodynamic signatures of its corresponding structural phase transformations. We find that rapid solvent removal achieved by annealing above the boiling point of the solvent, similar to an industrial drying technique known as flash drying, induces the formation of ≈98% amorphous zinc oxide films having an unprecedented, largely pronounced glass transition while retaining its semiconductor properties evidenced by field-effect transistor measurements. Thin-films produced at comparable heating rates to those used for calorimetry experiments are used to corroborate these findings using independent measurements. Prepared films exhibit a clear amorphous halo centered about the three most prominent Bragg positions of the wurtzite phase of ZnO and remain thermally stable against crystallization until 250°C have a room temperature thermal conductivity of ≈1.03–1.4Wm−1K−1 (consistent with recent ab initio estimates) with supporting evidence of a structural relaxation near TG consistently observed in both electronic and thermal conductivity.
Discrimination between strain and temperature effects of a single fiber Bragg grating sensor using sidelobe power
Authors: Sarkar Sanjib , Tarhani Mehdi , Khosravi Eghbal Morad , Shadaram Mehdi
Published: March 2020

A fiber Bragg grating (FBG) is one of the most common and widely used fiber optic sensors. One main issue when using a FBG-based sensor is that it is simultaneously sensitive to both the strain and the temperature, and compensation for the temperature and strain effects is necessary to measure these parameters. The available compensation techniques mean that the interrogation of FBG sensor systems is complex and make sensor networks bulky by increasing the number of sensors. Several of these compensation techniques are not feasible in in situ applications. In this paper, we propose a method for discriminating between the strain and the temperature by measuring the change in the single Bragg wavelength. Our proposed technique is based on measuring the sidelobe power, which appears adjacent to the main Bragg peak due to the strength of the interference between the forward and backward propagating waves of the Bragg grating sensor. We demonstrate by experiments that the proposed methodology can discriminate between the strain and temperature effects, making the interrogation system less complex with a very reasonable hardware cost.