bluuebunny/crossref_metadata_2025 huggingface dataset:
Platinum(II) Complexes Bearing Triphenylphosphine and Chelating Oximes: Antiproliferative Effect and Biological Profile in Resistant Cells
Authors: Hyeraci Mariafrancesca , Colalillo Marialuigia , Labella Luca , Marchetti Fabio , Samaritani Simona , Scalcon Valeria , Rigobello Maria Pia , Dalla Via Lisa
Published: June 2020

Platinum(II) complexes of the type [Pt(Cl)(PPh3){(κ2‐N,O)‐(1{C(R)=N(OH)‐2(O)C6H4})}] with R=Me, H, (1 and 2) were synthesized and characterized. Single‐crystal X‐ray diffraction confirmed the proposed (SP4‐3) configuration for 1. Study of the antiproliferative activity, performed on a panel of human tumor cell lines and on mesothelial cells, highlighted complex 2 as the more effective. In particular, it showed a remarkable cytotoxicity in ovarian carcinoma cells (A2780) and interestingly, a significant antiproliferative effect on cisplatin resistant cells (A2780cis). Investigation into the intracellular mechanism of action demonstrated that 2 had a lower ability to platinate DNA than did cisplatin, which was taken as reference, and a notably higher uptake in resistant cells. A significant accumulation in mitochondria, along with the ability to induce concentration‐dependent mitochondrial membrane depolarization and intracellular reactive oxygen species production, allowed us to propose a mitochondrion‐mediated pathway as responsible for the interesting cytotoxic profile of complex 2.
Privacy‐aware cloud ecosystems: Architecture and performance
Authors: Barati Masoud , Rana Omer
Published: June 2020

With an increasing number of cloud providers offering services made use of by both individual users and other providers, there is a realization that service provision now involves an “ecosystem” of providers. Some providers may be directly visible to a user, while others may be contributors to composite services and not directly known to the user—as only the provider offering the composite service is visible. Such services may include: domain specific services (eg, simulation), advertising services, or profiling/analytics services. Understanding the impact on data privacy of a user for such a composite service remains a challenge, and providing transparency (and obtaining user consent for data use) remains a key requirement of the European General Data Protection Regulation (GDPR). An architecture that makes use of blockchains and smart contracts is proposed that addresses this requirement. An implementation of the architecture is used to demonstrate how access control can be managed and audited. The scalability and cost of undertaking access control, as the number of actors (both service providers and “voters”) increases, is also described. The proposed approach can be used to support service aggregation across both private and public clouds.
Impact ofCSRand environmental triggers on employee green behavior: The mediating effect of employeewell‐being
Authors: Ahmed Mansoora , Zehou Sun , Raza Syed Ali , Qureshi Muhammad Asif , Yousufi Sara Qamar
Published: June 2020

This article explores the influence of corporate social responsibility (CSR) and three green triggers of environment (awareness, concern, and knowledge) on employee well‐being and green behavior. The study engages the stimulus–organism–responsemodel for testing the association between CSR and well‐being of employees that leads to employee green behavior. Furthermore, social exchange theory has been utilized to describe the association between well‐being and green behavior of employees. Data have been gathered through questionnaire from 509 employees working in guest‐service hotels of Pakistan. Structural equation modeling has been used to test the hypotheses. Findings show that CSR, environmental concern, and knowledge have positive effect on employee well‐being, whereas environmental awareness has positive but insignificant effect on employee well‐being. Furthermore, environmental concern, knowledge, and well‐being have a positive influence on green behavior, whereas CSR and environmental knowledge have a positive but insignificant effect. Moreover, well‐being fully mediates the relationship between CSR and green behavior and between environmental awareness and green behavior of employees. However, a partial mediation was observed between environmental concern and green behavior. The findings also indicate that no mediation was found between environmental knowledge and employee green behavior. The findings suggest that the hotel managers should invest to improve employee's awareness regarding green behavior by conducting environmental training for cultivating environmental knowledge and awareness. Moreover, CSR activities should be performed for attaining competitive edge and maintaining a balance between progress and sustainability of environment.
Genotyping‐in‐Thousands by sequencing reveals marked population structure in Western Rattlesnakes to inform conservation status
Authors: Schmidt Danielle A. , Govindarajulu Purnima , Larsen Karl W. , Russello Michael A.
Published: June 2020

Delineation of units below the species level is critical for prioritizing conservation actions for species at‐risk. Genetic studies play an important role in characterizing patterns of population connectivity and diversity to inform the designation of conservation units, especially for populations that are geographically isolated. The northernmost range margin of Western Rattlesnakes (Crotalus oreganus) occurs in British Columbia, Canada, where it is federally classified as threatened and restricted to five geographic regions. In these areas, Western Rattlesnakes hibernate (den) communally, raising questions about connectivity within and between den complexes. At present, Western Rattlesnake conservation efforts are hindered by a complete lack of information on genetic structure and degree of isolation at multiple scales, from the den to the regional level. To fill this knowledge gap, we used Genotyping‐in‐Thousands by sequencing (GT‐seq) to genotype an optimized panel of 362 single nucleotide polymorphisms (SNPs) from individual samples (n = 461) collected across the snake's distribution in western Canada and neighboring Washington (USA). Hierarchical STRUCTURE analyses found evidence for population structure within and among the five geographic regions in BC, as well as in Washington. Within these regions, 11 genetically distinct complexes of dens were identified, with some regions having multiple complexes. No significant pattern of isolation‐by‐distance and generally low levels of migration were detected among den complexes across regions. Additionally, snakes within dens generally were more related than those among den complexes within a region, indicating limited movement. Overall, our results suggest that the single, recognized designatable unit for Western Rattlesnakes in Canada should be re‐assessed to proactively focus conservation efforts on preserving total genetic variation detected range‐wide. More broadly, our study demonstrates a novel application of GT‐seq for investigating patterns of diversity in wild populations at multiple scales to better inform conservation management.
Ribbonized sap flow: an emerging technology for the integration of sap flow sensor components onto a single platform
Authors: Jones Taylor S. , Winbourne Joy B. , Hutyra Lucy R.
Published: June 2020

Trees play an important role in both the water and carbon cycles. Sensors that measure the flow rate of sap in individual trees provide critical insight into water use dynamics, and these data are vital for the understanding of ecosystem functions. Current sap flux sensors typically require the installation of multiple needle‐like probes into the sapwood of the tree. Despite the scientific value of high‐density measurements, the high cost and complexity of existing methods prevents the deployment of large networks of sensors. This study presents a new sap flow sensor design where all sensor components are on a single integrated circuit board (ribbon) thereby reducing cost and complexity. This system also eliminates misalignment errors, which are a problem inherent in some sap flow sensor designs. The new ribbonized sap flow (RSF) sensor was compared to gravimetric measurements of water flow to quantify the accuracy of the method and the tree wounding response. In a pair of field experiments, we tested the general performance of the sensor design over a growing season, and among several tree species. The laboratory calibration showed that the RSF sensor has similar accuracy and wounding response as traditional three‐probe designs. At a flow rate of 15 cm/h, the sensor underreported rates by 68% with a 19‐d wounding response, compared to other sensor designs, which underreport rates by 20–60%. Collectively, our field experiments show that the RSF sensor can produce reliable field data in a variety of species across full growing seasons. The RSF sensor platform is compact, robust, and versatile. Ribbonized sap flow sensors can be quickly and easily manufactured at low cost, which makes them ideal for the dense network of observations needed for the study of complex forest ecosystems and their response to global change.
Utility of routine evaluations for rejection in patients greater than 2 years after heart transplantation
Authors: Golbus Jessica R. , Konerman Matthew C. , Aaronson Keith D.
Published: June 2020

Aims

Guidelines support routine surveillance testing for rejection for at least 5 years after heart transplant (HT). In patients greater than 2 years post‐HT, we examined which clinical characteristics predict continuation of routine surveillance studies, outcomes following discontinuation of routine surveillance, and the cost‐effectiveness of different surveillance strategies.

Methods and results

We retrospectively identified subjects older than 18 who underwent a first HT at our centre from 2007 to 2016 and who survived ≥760 days (n = 217) post‐HT. The clinical context surrounding all endomyocardial biopsies (EMBs) and gene expression profiles (GEPs) was reviewed to determine if studies were performed routinely or were triggered by a change in clinical status. Subjects were categorized as following a test‐based surveillance (n = 159) or a signs/symptoms surveillance (n = 53) strategy based on treating cardiologist intent to continue routine studies after the second post‐transplant year. A Markov model was constructed to compare two test‐based surveillance strategies to a baseline strategy of discontinuing routine studies. One thousand twenty studies were performed; 835 were routine. Significant rejection was absent in 99.0% of routine EMBs and 99.8% of routine GEPs. The treating cardiologist's practice duration, patient age, and immunosuppressive regimen predicted surveillance strategy. There were no differences in outcomes between groups. Routine surveillance EMBs cost more and were marginally less effective than a strategy of discontinuing routine studies after 2 years; surveillance GEPs had an incremental cost‐effectiveness ratio of $1.67 million/quality‐adjusted life‐year.

Conclusions

Acute asymptomatic rejection is rare after the second post‐transplant year. Obtaining surveillance studies beyond the second post‐transplant year is not cost‐effective.
Characterization of pain syndromes in patients with neuromyelitis optica
Authors: Valerio Fernanda , Apostolos‐Pereira Samira L. , Sato Douglas Kazutoshi , Callegaro Dagoberto , Lucato Leandro Tavares , Barboza Victor Rosseto , Silva Valquiria A. , Galhardoni Ricardo , Rodrigues Antonia L. de Lima , Jacobsen Teixeira Manoel , Ciampi de Andrade Daniel
Published: June 2020

Background

Pain is common and refractory in spinal cord injury (SCI). Currently, most studies evaluated pain in male‐predominant traumatic‐SCI. Also, concomitant secondary pain syndromes and its temporal evolution were seldom reported.

Methods

We aimed to prospectively describe the main and secondary pain and its associated factors in inflammatory‐SCI evaluating neuromyelitis optica (NMO) patients. In‐remission NMO patients underwent neurological, imaging and autoantibody evaluations. Questionnaires detailing main and secondary pains, functional state, mood, catastrophizing, quality of life (QoL) and “non‐motor symptoms" were used at two time points.

Results

Pain was present in 53 (73.6%) of the 72 patients included. At‐level neuropathic pain was the most common main pain syndrome, affecting 32 subjects (60.4% of those with pain). Over 70% (n = 38) of this cohort reported two pain syndromes. Those without pain were significantly younger (26.1 ± 12.7 y.o. in those without pain and 40.1 ± 12.5, 37.2 ± 11.4 y.o. in those whose main pain was neuropathic and non‐neuropathic, respectively,p = .001), and no differences in the inflammatory status were observed between groups. On follow‐up, one‐fifth (n = 11) had a different main pain syndrome from the first visit. Pain impacted QoL as much as disability and motor strength.

Conclusion

Pain is a prevalent and disabling non‐motor symptom in NMO‐SCI. Most patients experience more than one pain syndrome which can change in time even in the absence of clinical relapse. Age of the inflammatory‐SCI was a major determinant of pain. Acknowledging temporal changes and multiplicity of pain syndromes in NMO‐SCI may give insights into more precise designs of clinical trials and general management of pain in SCI.

Significance

In this longitudinal study with NMO‐related SCI, pain affected almost three‐quarters of patients with NMO. Over 70% have more than one pain syndrome and at‐level neuropathic pain is the most common type of pain syndrome. Patients without pain were significantly younger but had the same burden of inflammatory lesions than those with pain. During follow‐up, up to one fifth of patients presented with changes in the main pain syndromes, which can occur even in the absence of clinical activity of the inflammatory disease. In this cohort, Pain affected quality of life as much as disability or motor strength.
Clinoptilolite‐based Conductometric Sensors for Detection of Ammonium in Aqueous Solutions
Authors: Saiapina Olga , Vronska Yelyzaveta , Dzyadevych Sergei , Jaffrezic‐Renault Nicole
Published: June 2020

New clinoptilolite‐based conductometric sensors were developed and optimized for selective detection of ammonium in the buffered aqueous solutions. The sensors’ selective elements were prepared by subsequent drop‐casting of zeolite and Nafion on the gold electrode surface. Electrochemical impedance spectroscopy and differential conductometry were used to investigate the sensor performance. As determined in the phosphate buffer solution, the detection limit of the sensors was 30 μM and the linear range 0–1.5 mM. The developed sensors were featured with a simple preparation procedure, high selectivity to
, and storage stability for not less than 126 days.
Voltammetric Determination of 5‐Aminoquinoline at Carbon Film Electrode and Carbon and Gold Screen Printed Electrodes – A Comparative Study
Authors: Jiránek Ivan , Barek Jiří , Matysik Frank‐Michael
Published: June 2020

Aminoquinolines are widely used as antimalarial drugs and thus there is an ever increasing demand for their determination. In this paper, non‐traditional carbon film electrode developed in our laboratory (CFE) with easily replaceable carbon film was used for the determination of 5‐aminoquinoline (5‐AQ) and compared with well‐established commercially available carbon screen printed electrode (CSPE) and gold screen printed electrode (AuSPE). Electrochemical behavior of 5‐AQ was characterized by cyclic and differential pulse voltammetry. Differences in electrochemical behavior of 5‐AQ at different electrodes were evaluated. Determination of 5‐AQ was carried out by differential pulse, square wave, and direct current voltammetry. Practical applicability of the method was verified by direct determination of 5‐AQ in model samples of drinking and river water. Achieved limits of quantitation were in submicromolar concentrations. It was found out that novel CFE in terms of overall performance is in most aspects superior to routinely used commercially available CSPE and AuSPE.
Selection of aptamers targeted to food‐borne pathogenic bacteria Vibrio parahaemolyticus
Authors: Wang Lan , Lyu Shuxia , Gu Ganyu , Bolten Samantha
Published: June 2020

Vibrio parahaemolyticus (Vp) is a common marine halophilic food‐borne pathogen, mainly found in seafood and food with a high salt content. Gastrointestinal reactions such as diarrhea, headache, vomiting, nausea, and abdominal cramps may occur after eating food infected with Vp. This study aimed to screen for high‐affinity aptamers that specifically recognize Vp. A high‐affinity modified aptamer screening kit was used to rapidly screen aptamers of the food‐borne Vp. The first round of screening involved release of target aptamers from the microspheres. The "false‐positive" aptamers were eliminated after specific binding to and elution of Vp in the second round. The second round of screening of the aptamers involved polymerase chain reaction (PCR), and the abundance of a sequence was determined using next‐generation sequencing. Nine high‐affinity aptamer sequences were obtained, and the first eight modified aptamer sequences were derived using a cloud‐based intelligent software of the American AM Biotech Co. Escherichia coli (E. coli) was used as a control, and aptamer ID 12 with the highest affinity for Vp was selected using real‐time PCR. According to the principle of color change caused by nano‐gold condensing under salt induction, Salmonella, Listeria monocytogenes (L. monocytogenes), and E. coli were used as counter‐screening bacteria, and the aptamer ID12 was combined with nano‐gold. The results showed that aptamer ID12 has strong specificity for Vp. Based on these findings, this study developed a simple, innovative, and rapid method for screening Vp aptamers.
Oil jump risk
Authors: Ebrahimi Nima , Pirrong Craig
Published: June 2020

The risk premium associated with large upside jumps in oil market is a significant driver of the cross‐section of stock returns from 1986 to 2014. In contrast to previous research, variance risk is priced only when we do not control for jumps. Upward jumps are priced in tight supply‐demand conditions but not in more abundant supply periods. There is some evidence that downward jumps are priced in abundant supply conditions but not in tight conditions. Innovations in risk neutral jumps have predictive power for important economic indicators, including notably consumption growth. This helps explain the pricing of jump risks.
Phytogeographic implications of a fossil endocarp of Diploclisia (Menispermaceae) from the Miocene of eastern China
Authors: Jia Hui , Ferguson David K. , Sun Bainian , Meng Xiangning , Hua Yifan
Published: June 2020

Based on a detailed morphologic and tomologic investigation of a fossil endocarp, a new species of Diploclisia (Menispermaceae) is described from the Late Miocene of Jiahu, Zhejiang Province, eastern China. This represents the first record of the genus in the Neogene. The fossil endocarp closely resembles that of the Chinese endemic, Diploclisia affinis. The past and present distribution of Diploclisia shows that the genus probably originated in north‐east China in the Palaeocene (66–56 Ma) at the latest, which has undergone various phases of expansion and contraction. The more advanced Diploclisia glaucescens probably expanded into south and south‐east Asia in the Pleistocene, when global sea‐levels were lower.
Numerical thermal‐hydraulic performance investigations in turbulent curved channel flow with horseshoe baffles
Authors: AL‐Juhaishi Lafta F. M. , Mohd Ali Mas F. , Mohammad Hafidh H. , Ajeel Raheem K.
Published: June 2020

A numerical work is performed to investigate the thermal‐hydraulic performance in a curved channel of a journal bearing equipped with oblique horseshoe baffles. Water, a working fluid, is passed through the curved channel at a constant temperature condition of 358 K. The effects of different parameters of baffles, that is, attack angle (α = 45°, 60°, and 90°) and the number of baffles (NB = 9 and 13 baffles), are examined. Influences of design parameters on heat transfer and friction performances are studied and displayed in terms of the Nusselt number, the friction factor, the Nusselt number enhancement ratio, and the thermal‐hydraulic performance factor (THPF). The numerical simulations present the flow structures of the tested channel in terms of velocity, isotherms, turbulent kinetic energy, and vorticity contours. The numerical results reveal that the adopted geometry of the curved channel with baffles yields a significant enhancement of heat transfer rate over the plain channel (without baffles), which is approximately 2.5 to 3.8 times. Also, the results show that the best condition to achieve maximum heat transfer is at angle α = 90°, NB = 13, and Re = 5000, compared with other conditions. Furthermore, the maximum THPF of the curved channel using baffles is 4.4 at the same condition. The results confirmed that the geometry of the baffles inside the curved channel has a remarkable impact on heat transfer improvement, accompanied by a reasonable increase in friction losses.
Outdoor light at night and postmenopausal breast cancer risk in the NIH‐AARP diet and health study
Authors: Xiao Qian , James Peter , Breheny Patrick , Jia Peng , Park Yikyung , Zhang Dong , Fisher Jared A. , Ward Mary H. , Jones Rena R.
Published: June 2020

Circadian disruption may play a role in breast carcinogenesis. Previous studies reported relationships between outdoor light at night (LAN) and the breast cancer risk, but their findings are mixed. There is also a need to examine LAN and breast cancer incidence according to different individual and environmental characteristics to identify subpopulations at greater risk associated with LAN exposure. We studied residential outdoor LAN estimated from satellite imagery at baseline (1996) in relation to postmenopausal breast cancer incidence over ~16 years of follow‐up in 186 981 postmenopausal women including 12 318 incident postmenopausal breast cancer cases in the NIH‐AARP Diet and Health Study. We used Cox proportional hazards models to estimate hazard ratios (HR) and two‐sided 95% confidence intervals (CI) of the relationship between quintiles of LAN and postmenopausal breast cancer risk, overall and by hormone receptor status and cancer stage. We found that when compared to women in the lowest quintile of baseline LAN, those in the highest quintile had a 10% increase in postmenopausal breast cancer risk (HR (95% CI), 1.10 (1.02, 1.18), P‐trend, .002). The association appeared to be stronger for estrogen receptor (ER) positive breast cancer (1.12 [1.02, 1.24], .007) than for ER‐negative cancer (1.07 [0.85, 1.34], .66). Our findings also suggested that the relationship between LAN and breast cancer risk may differ by individual characteristics, such as smoking, alcohol drinking, sleep duration and BMI, and neighborhood environment. In conclusion, our study suggests that higher outdoor LAN exposure may be a risk factor for postmenopausal breast cancer.
In vitro evaluation of the metabolic stability of nine fragrance chemicals in trout and human hepatocytes
Authors: Weeks John , Li Albert P. , Doshi Utkarsh , Johanning Karla , Guiney Patrick D.
Published: June 2020

In vitro metabolic stability of nine fragrance chemicals: p‐tolyl acetate, cashmeran, ethylene brassylate, celestolide, galaxolide, traseolide, ambretone, tonalide and pentadecanolide, was evaluated in trout and human hepatocytes. The compounds were incubated with trout hepatocytes at 12°C and human hepatocytes at 37°C. Quantification of compound disappearance with time was performed using gas chromatography/mass spectrometry. in vivo hepatic intrinsic clearance values were calculated from the in vitro data. Significant metabolism was observed with trout hepatocytes for five of the nine fragrance chemicals, while all nine were metabolized significantly with human hepatocytes. Previously published models were used to examine expected bioaccumulation and persistence in whole organisms. Calculated half‐lives due to metabolism of the nine chemicals are significantly shorter for humans than trout: <1 hour and <1 day, respectively. For all chemicals with demonstrated hepatic metabolism, the models indicate a lack of accumulation. For those where metabolism was demonstrated in trout, calculated bioconcentration factors would not be classified as bioaccumulative under prevailing regulatory systems.
Biomaterials functionalized with nanoclusters of integrin‐ and syndecan‐binding ligands improve cell adhesion and mechanosensing under shear flow conditions
Authors: Karimi Fatemeh , Thombare Varsha Jagannath , Hutton Craig A. , O'Connor Andrea J. , Qiao Greg G. , Heath Daniel E.
Published: June 2020

We have engineered biomaterials that display nanoclusters of ligands that bind both integrin and syndecan‐4 cell receptors. These surfaces regulate cell behaviors under static conditions including adhesion, spreading, actin stress fiber formation, and migration. The syndecan‐4 receptors are also critical mediators of cellular mechanotransduction. In this contribution we assess whether this novel class of materials can regulate the response of cells to applied mechanical stimulation, using the shear stress imparted by laminar fluid flow as a model stimulus. Specifically, we assess endothelial cell detachment due to flow, cell alignment due to flow, and cell adhesion from the flowing fluid. A high degree of cell retention was observed on surfaces containing integrin‐binding ligands or a mixed population of integrin‐ and syndecan‐binding ligands. However, the presence of both ligand types was necessary for the cells to align in the direction of flow. These results imply that integrin engagement is necessary for adhesion strength, but engagement of both receptor types aids in appropriate mechanotransduction. Additionally, it was found that surfaces functionalized with both ligand types were able to scavenge a larger number of cells from flow, and to do so at a faster rate, compared to surfaces functionalized with only integrin‐ or syndecan‐binding ligands. These results show that interfaces functionalized with both integrin‐ and syndecan‐binding ligands regulate a significant range of biophysical cell behaviors in response to shear stress.
Molecular and biochemical mechanisms of human iris color: A comprehensive review
Authors: Dorgaleleh Saeed , Naghipoor Karim , Barahouie Ahmad , Dastaviz Farzad , Oladnabi Morteza
Published: June 2020

Eye color is determined as a polymorphism and polygenic trait. Brown is the most common eye color in the world, accounting for about 79%, blue eye color for about 8–10%, hazel for 5%, and green for 2%. Rare‐colored eyes include gray and red/violet. Different factors are involved in determining eye color. The two most important factors are the iris pigment and the way light is scattered from the iris. Gene expression determines the iris pigmentation and how much melanin is present in the eye, which is the number of melanin subunits that identify eye color. The genes involved in the pigmentation of single‐nucleotide polymorphism (SNP) have a significant role; and even some genes are included only in the eye color through SNP. MicroRNAs also affect melanocyte synthesis, which is usually affected by the downregulation of essential genes involved in pigmentation. In this study, we assess the biochemical pathways of melanin synthesis, and the role of each gene in this pathway also has been examined in the signaling pathway that stimulates melanin synthesis.
COVID‐19 patients benefit from early antiviral treatment: A comparative, retrospective study
Authors: Yu Ting , Tian Chunxia , Chu Si , Zhou Haifeng , Zhang Zili , Luo Shanshan , Hu Desheng , Fan Heng
Published: June 2020

The outbreak of COVID‐19, caused by severe acute respiratory syndrome coronavirus 2, started in December 2019, Wuhan, China. We aimed to figure out the time‐point and duration of using antiviral drugs for receiving the maximal effects in patients with COVID‐19. In this study, we enrolled 129 confirmed COVID‐19 mild to moderate patients who had been treated with antiviral drugs during their hospitalization in Wuhan Union Hospital China. The patients were divided into an early antiviral treatment group and late antiviral treatment group. The demographic data, laboratory tests, the virus clearance time, chest computed tomography scans, and so forth were extracted, calculated, and compared between two groups. Our data showed that the median time from illness onset to initiation of antiviral treatment was 6 days in all patients. The group with early antiviral treatment demonstrated 7 days shorter in the virus clearance time when compared to the group with late antiviral treatment. After virus clearance, the group with early antiviral treatment showed milder illness than the group with late antiviral treatment. Early antiviral treatment could effectively shorten the virus clearance time, and prevent the rapid progression of COVID‐19. Therefore, the COVID‐19 patients should receive combined therapies with antiviral treatment at an early stage.
Large‐signal behavioral model for radio frequency power transistors based on modified canonical sectionwise piecewise‐linear functions
Authors: Cai Jialin , King Justin , Liu Jun , Wang Jianhua , Sun Lingling
Published: June 2020

A novel, large‐signal behavioral modeling methodology for radio frequency power transistors, based on the modified canonical sectionwise piecewise‐linear (CSWPL) functions, is presented in this article. The basic theory of the proposed model is provided. Compared with the existing standard CSWPL model, the proposed model provides superior prediction capabilities for a reasonable increase in model complexity. Model verification is performed through comparisons with simulated and experimental data of a 10 W GaN HEMT device at mild and severe mismatch conditions, across a wide range of input power levels. The models can predict, more accurately, both the fundamental and the second harmonic scattered waves compared with the standard CSWPL model.
T2* mapping in an equine articular groove model: Visualizing changes in collagen orientation
Authors: Brinkhof Sander , te Moller Nikae , Froeling Martijn , Brommer Harold , van Weeren René , Ito Keita , Klomp Dennis
Published: June 2020

T2* mapping is promising for the evaluation of articular cartilage collagen. In this work, a groove model in a large animal is used as a model for posttraumatic arthritis. We hypothesized that T2* mapping could be employed to differentiate between healthy and (subtly) damaged cartilage. Eight carpal joints were obtained from four adult Shetland ponies that had been included in the groove study. In this model, grooves were surgically created on the proximal articular surface of the intermediate carpal bone (radiocarpal joint) and the radial facet of the third carpal bone (middle carpal joint) by either coarse disruption or sharp incision. After 9 months, T2* mapping of the entire carpal joint was carried out on a 7.0‐T whole‐body magnetic resonance imaging (MRI) scanner by means of a gradient echo multi‐echo sequence. Afterwards, assessment of collagen orientation was carried out based on Picrosirius Red‐stained histological sections, visualized by polarized light microscopy (PLM). The average T2* relaxation time in grooved samples was lower than in contralateral control sites. Opposite to the grooved areas, the “kissing sites” had a higher average T2* relaxation time than the grooved sites. PLM showed mild changes in orientation of the collagen fibers, particularly around blunt grooves. This work shows that T2* relaxation times are different in healthy cartilage vs (early) damaged cartilage, as induced by the equine groove model. Additionally, the average T2* relaxation times are different in kissing lesions vs the grooved sites.
Flattening the curve in oncologic surgery: Impact of Covid‐19 on surgery at tertiary care cancer center
Authors: Chang Edward I. , Liu Jesse Jun
Published: June 2020

Introduction

Covid‐19 has ushered in drastic changes to the healthcare system in order to “flatten the curve”; in particular, surgical operations that can consume vital, limited resources, not to mention the risk to staff, anesthesiologists, and surgeons. However, under unique circumstances with diligent preparation, vital oncologic operations can be performed safely.

Methods

Prospective comparison of surgical cases during the pandemic from December 2019 to May 2020 to the correlating time frame from December 2018 to May 2019.

Results

A significant decline in case volume was not appreciated until the United States declared a national state of emergency, allowing patients with cancer to continue to undergo curative tumor resection until then (428.3 ± 51.5 vs 166.6 ± 59.8 cases/week; P < .001). The decrease was consistent with the mean case volume during the holidays (213.8 ± 76.8 vs 166.6 ± 59.8 case/week; P = .648). Evaluation of surgical subspecialties demonstrated a significant decrease for all subspecialties with the greatest decline in sarcoma (P = .002) and endocrine (P = .001) surgeries, while vascular (P = .004) and thoracic (P = .011) surgeries had the least.

Conclusions

The novel coronavirus has drastically reduced oncologic operations, but with proper evaluation of patients and allocation of resources, surgery can be performed safely without compromising the aim to flatten the curve and control the coronavirus pandemic.
An unfitted mesh semi‐implicit coupling scheme for fluid‐structure interaction with immersed solids
Authors: Fernández Miguel A. , Gerosa Fannie M.
Published: June 2020

Unfitted mesh finite element approximations of immersed incompressible fluid‐structure interaction problems which efficiently avoid strong coupling without compromising stability and accuracy are rare in the literature. Moreover, most of the existing approaches introduce additional unknowns or are limited by penalty terms which yield ill‐conditioning issues. In this paper, we introduce a new unfitted mesh semi‐implicit coupling scheme which avoids these issues. To this purpose, we provide a consistent generalization of the projection based semi‐implicit coupling paradigm of (Int. J. Num. Meth. Engg., 69(4):794‐821, 2007) to the unfitted mesh Nitsche‐extended‐FEM framework.
The million dollar donor journey: Stages of development for high‐net‐worth women donors
Authors: Dale Elizabeth J. , O'Connor Heather A.
Published: June 2020

Most charitable giving research focuses on individual donors at a specific point in time and uses quantitative surveys with limited data about donors' experiences. This study uses reflective interviews to examine the life trajectories of a cohort of women donors who have made gifts of $1 million or more to causes that benefit women and girls. By drawing from developmental psychology, we illustrate the iterative process of learning about giving—shaped by life experiences—that comprise the journey to becoming a million‐dollar donor. We find that, in their journeys toward making their million‐dollar commitment, women donors followed a shared trajectory with distinct stages and prompts for progression. Our findings provide guidance for fundraising professionals to recognize the stages of a potential donor's readiness to give and to facilitate progression in the journey, thus increasing the potential for more large‐scale gift commitments in the future and deepening the donor–fundraiser relationship.
Use a Hold Study and a Web‐Based App to Assess Chloramine Demand
Authors: Alexander Matthew T. , Dugan Alison G. , Wahman David G.
Published: June 2020

Optimize your water treatment or distribution system by undertaking a chloramine hold study. In tandem with a web‐based app, the tool can help prioritize efforts to improve monochloramine stability and prevent nitrification
Evolution of monetary policy approaches: A case study of Indian economy
Authors: Adil Masudul Hasan , Rajadhyaksha Niranjan
Published: June 2020

The monetary policy framework of India has undergone several transformations reflecting underlying macroeconomic and financial conditions as also the dominant socio‐politico‐economic paradigm. The present study makes pertinent commentary notes on different monetary policy approaches, including, for instance, the era of development planning, the era of monetarism, the era of multiple indicator approach, and the era of inflation targeting in India along with their respective advantages and disadvantages.
Improved efficacy of bio‐mineralization of human mesenchymal stem cells on modified PLLA nanofibers coated with bioactive materials via enhanced expression of integrin α2β1
Authors: Andalib Nazanin , Kehtari Mousa , Seyedjafari Ehsan , Motamed Nassrin , Matin Maryam M.
Published: June 2020

Current therapeutic interventions in bone defects are mainly focused on finding the best bioactive materials for inducing bone regeneration via activating the related intracellular signaling pathways. Integrins are trans‐membrane receptors that facilitate cell‐extracellular matrix (ECM) interactions and activate signal transduction. To develop a suitable platform for supporting human bone marrow mesenchymal stem cells (hBM‐MSCs) differentiation into bone tissue, electrospun poly L‐lactide (PLLA) nanofiber scaffolds were coated with nano‐hydroxyapatite (PLLA/nHa group), gelatin nanoparticles (PLLA/Gel group), and nHa/Gel nanoparticles (PLLA/nHa/Gel group) and their impacts on cell proliferation, expression of osteoblastic biomarkers, and bone differentiation were examined and compared. MTT data showed that proliferation of hBM‐MSCs on PLLA/nHa/Gel scaffolds was significantly higher than other groups (P < .05). Alkaline phosphatase activity was also more increased in hBM‐MSCs cultured under osteogenic media on PLLA/nHa/Gel scaffolds compared to others. Gene expression evaluation confirmed up‐regulation of integrin α2β1 as well as the osteogenic genes BGLAP, COL1A1, and RUNX2. Following use of integrin α2β1 blocker antibody, the protein level of integrin α2β1 in cells seeded on PLLA/nHa/Gel scaffolds was decreased compared to control, which confirmed that most of the integrin receptors were bound to gelatin molecules on scaffolds and could activate the integrin α2β1/ERK axis. Collectively, PLLA/nHa/Gel scaffold is a suitable platform for hBM‐MSCs adhesion, proliferation, and osteogenic differentiation in less time via activating integrin α2β1/ERK axis, and thus it might be applicable in bone tissue engineering.
Qualitative and quantitative determination of steroidal saponins in Trillium govanianum by UHPLC‐QTOF‐MS/MS and UHPLC‐ELSD
Authors: Singh Prithvi Pal , Bora Prateek Singh , Suresh Patil Shivprasad , Bhatt Vinod , Sharma Upendra
Published: June 2020

Introduction

Trillium govanianum (Nag Chhatri and Teen Patra) is traditionally used for curing joint pains, wounds, and sexual disorders. Steroidal saponins are the main active components of this species. However, only a small amount of information is available about steroidal saponins of this plant.

Objective

To develop an ultra‐high‐performance liquid chromatography‐quadrupole time of flight tandem mass spectrometry (UHPLC‐QTOF‐MS/MS) and ultra‐high‐performance liquid chromatography‐evaporative light scattering detector (UHPLC‐ELSD) methods for the qualitative and quantitative determination of steroidal saponins in T. govanianum.

Method

The dried rhizomes of T. govanianum (100 mg) were extracted with ethanol–water (80:20, 10 mL) by ultrasonic treatment for 30 min at 40°C. The prepared sample was analysed by UHPLC‐QTOF‐MS/MS and UHPLC‐ELSD for the qualitative and quantitative determination of steroidal saponins.

Result

A total of 24 saponins were identified using UHPLC‐QTOF‐MS/MS; seven of them were characterised by comparing with standards. Furthermore, five saponins [govanoside B (2), protodioscin (6), pennogenin tetraglycosides (11), borassoside E (21) and borassoside D (24)] were quantified using UHPLC‐ELSD method in different extracts and fractions of T. govanianum. The method showed good linearity (R2 ≥ 0.993), limit of detection (0.92–4.09 μg/mL), limit of quantification (3.1–13.5 μg/mL), precision [intra‐day relative standard deviations (RSDs) < 4.3% and inter‐day RSDs < 5.5%], and accuracy (84.0–110.3%). This is the first report on the quantification of 2, 6, 11, 21 and 24 in T. govanianum.

Conclusion

The present study provides an efficient analytical method for the identification and quantification of steroidal saponins and will be helpful for the quality evaluation of T. govanianum.
Vanishing Hysteresis in Carbon Nanotube Transistors Embedded in Boron Nitride/Polytetrafluoroethylene Heterolayers
Authors: Kumar Sandeep , Dagli Daghan , Dehm Simone , Das Chittaranjan , Wei Li , Chen Yuan , Hennrich Frank , Krupke Ralph
Published: June 2020

Carbon nanotube field‐effect transistors fabricated on silicon wafers with thermal oxide often suffer from large gate‐voltage hysteresis, induced by charge trapping sites in oxides, surface hydroxyl groups, and the presence of water molecules. Surface functionalization and passivation, as well as vacuum annealing and reduced operating temperature, have shown to diminish or even eliminate hysteresis. Herein, the fabrication of nearly hysteresis‐free transistors on Si/SiO2 by embedding carbon nanotubes and the connecting electrodes in a hexagonal boron nitride (h‐BN) bottom layer and a polytetrafluoroethylene (PTFE) top layer is demonstrated. The conditions at which catalyst‐free synthesis of h‐BN on SiO2/Si with borazine is obtained, and the subsequent liquid‐phase deposition of PTFE, are discussed. Device transfer curves are measured before and after PTFE deposition. It is found that the hysteresis is reduced after PTFE deposition, but vanishes only after a waiting period of several days. Simultaneously, the on‐state current increases with time. The results give evidence for the absence of trap states in h‐BN/PTFE heterolayers and a high breakthrough field strength in those wafer‐scalable materials.
Resolving governance disputes in communities: A study of software license decisions
Authors: He Vivianna Fang , Puranam Phanish , Shrestha Yash Raj , von Krogh Georg
Published: June 2020

Research summary

Resolving governance disputes is of vital importance for communities. Gathering data from GitHub communities, we employ hybrid inductive methods to study discussions around initiation and change of software licenses—a fundamental and potentially contentious governance issue. First, we apply machine learning algorithms toidentifyrobust patterns in data: resolution is more likely in larger discussion groups and in projects without a license compared to those with a license. Second, we analyze textual data toexplainthe causal mechanisms underpinning these patterns. The resulting theory highlights the group process (reflective agency switches disputes from bargaining to problem solving) and group property (preference alignment over attributes) that are both necessary for the resolution of governance disputes, contributing to the literature on community governance.

Managerial summary

Online communities play an increasingly important role in how companies innovate across organizational boundaries and attract talent across geographic locations. However, online communities are no Utopia; disputes abound even (more) when we collaborate virtually. In particular, governance disputes can threaten the functioning and existence of online communities. Our study suggests that governance disputes in online communities either unfold as bargaining over which solution is better or searching for a satisfactory solution. The latter is more likely to reach a resolution, when there is common ground. Companies interested in leveraging the power of online communities should (a) identify or train certain participants to transform endless bargaining into collective problem solving and (b) foster shared knowledge and value basis among participants through recruitment and strong organizational culture.
Stakeholder engagement strategies, national institutions, and firm performance: A configurational perspective
Authors: Gupta Kamini , Crilly Donal , Greckhamer Thomas
Published: June 2020

Research summary

Research documents the performance effects of attending to shareholders and treating employees well but underplays national differences in the relative power of labor and capital. We advance a configurational perspective that acknowledges the fit between stakeholder engagement, context, firm attributes and performance. As a cornerstone of this perspective, we develop a typology of stakeholder engagement strategies expressing how firms navigate the tension between conforming with local expectations—by prioritizing shareholders or employees, according to context—and being distinctive—by diverging from their peers. Analyzing a cross‐national sample of firms from 2004 to 2011, we identify combinations of engagement strategies, firm attributes, and contexts linked to high performance. Our findings highlight the multiple context‐dependent paths, which link stakeholder engagement to high firm performance.

Managerial summary

How do firms navigate pressures from shareholders and employees across different institutional environments? We develop a typology of stakeholder engagement strategies based on how firms in different countries strike a balance between conformity (i.e., prioritizing locally important stakeholders) and differentiation (i.e., prioritizing stakeholders that their local peers might neglect). Our findings show that the engagement strategies associated with high performance vary according to local institutional context and firm characteristics. In particular, by not merely prioritizing stakeholders who are already locally important, firms can use stakeholder engagement to differentiate themselves from their peers, and such engagement strategies are often linked to high performance.
Thermal, Morphological, and Functional Characterization of Gros Michel Banana Starch Modified with Octenyl Succinic Anhydride
Authors: Quintero‐Castaño Víctor D. , Bello‐Pérez Luis A. , Álvarez‐Barreto Cristina I. , Castellanos‐Galeano Francisco J. , Rodríguez‐García Mario E.
Published: June 2020

Banana is a food crop produced extensively in Colombia for fresh consumption. This fruit in the green state has a large amount of starch, which—unlike other Musaceae—has a small granule size that makes it attractive for use in the food industry. This work characterizes physicochemically, morphologically, structurally, and functionally isolated and modified starches from Gros Michel banana. This characterization uses techniques like SEM, XRD, FTIR, DSC, RVA, and HPLC. The results show a morphological change, given that the granules display superficial adherence of small masses. The IR spectra shows molecular vibrations in the modified starch at 1578 and 1745 cm−1; the X‐ray diffraction patterns show alteration of the 3D starch structure, given that it changes in large proportion from a hexagonal to a monoclinic conformation after the modification. The maximum viscosities obtained via RVA change from 1380 cP for the isolated starch to 1247 cP for the modified starch. The amylopectin/amylose ratio is altered after the modification, going from 75/25 to 87/13. Modified starches are a viable alternative for use in the food industry as additives to stabilize emulsions that do not need high processing temperatures.