bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of high‐flow rate continuous‐flow centrifugation and filtration devices for sampling and concentrating fine‐grained suspended sediment
Authors: Goharrokhi Masoud , Lobb David A. , Owens Philip N.
Published: June 2020

Fine‐grained (<63 μm) suspended sediment is an important vector for transporting contaminants in aquatic systems. Characterization of physical and biogeochemical properties of suspended sediment usually requires bulk samples to assess its quality and to determine its source. Low‐flow rate (~2 to 4 L min−1) continuous‐flow centrifugation (CFC) systems may need a time period from several hours to one day to collect such samples, and thus, due to their low inflow rate, limits application of these devices. A field study was conducted in three different freshwater systems in Manitoba, Canada to examine and compare the performance of two high‐flow rate systems as alternative approaches: the M512 continuous‐flow centrifuge (M512); and continuous filtration using PENTEK 1 μm filtration bags (filtration system). It was determined that the mass collection efficiency (MCE) for the M512 (in absolute terms) was similar to low‐flow rate CFC systems. As with low‐flow rate CFC systems, the M512 preferentially collected particles of a certain size range (i.e., in the case of M512, particles ≥ 0.83 μm) and accordingly this may affect the collection of a truly geochemically and physically representative sample in waters containing a high proportion of finer particles (≤1 μm). Several filtration systems in series improved its MCE performance and, in terms of total collected mass, this configuration appears to be as efficient as the low‐flow rate CFC systems in an equivalent sampling time. The results of this study confirmed that, in nearly all cases, the filtration system collected a representative sample of ambient suspended sediment, in terms of particle size composition, and geochemical and colour properties. In practice, it is suggested that the filtration systems in series have advantages over M512 as the filtration system is more portable and cost‐effective with a lower power demand.
Guidance for gynecologists utilizing telemedicine during COVID‐19 pandemic based on expert consensus and rapid literature reviews
Authors: Grimes Cara L. , Balk Ethan M. , Dieter Alexis A. , Singh Ruchira , Wieslander Cecilia K. , Jeppson Peter C. , Aschkenazi Sarit O. , Kim Jin Hee , Truong Mireille D. , Gupta Ankita S. , Keltz Julia G. , Hobson Deslyn T.G. , Sheyn David , Petruska Sara E. , Adam Gaelen , Meriwether Kate V.
Published: June 2020

Background

COVID‐19 has impacted delivery of outpatient gynecology and shifted care toward use of telemedicine.

Objective

To rapidly review literature and society guidelines and create expert consensus to provide guidance regarding management of outpatient gynecology scenarios via telemedicine.

Search strategy

Searches were conducted in Medline and Cochrane databases from inception through April 15, 2020.

Selection criteria

Literature searches were conducted for articles on telemedicine and abnormal uterine bleeding, chronic pelvic pain, endometriosis, vaginitis, and postoperative care. Searches were restricted to available English language publications.

Data collection and analysis

Expedited literature review methodology was followed and 10 943 citations were single‐screened. Full‐text articles and relevant guidelines were reviewed and narrative summaries developed.

Main results

Fifty‐one studies on the use of telemedicine in gynecology were found. Findings were reported for these studies and combined with society guidelines and expert consensus on four topics (abnormal uterine bleeding, chronic pelvic pain and endometriosis, vaginal discharge, and postoperative care).

Conclusions

Guidance for treating gynecological conditions via telemedicine based on expedited literature review, review of society recommendations, and expert consensus is presented. Due to minimal evidence surrounding telemedicine and gynecology, a final consensus document is presented here that can be efficiently used in a clinical setting.
Calcium sulfate‐containing glass polyalkenoate cement for revision total knee arthroplasty fixation
Authors: Hasandoost Leyla , Alhalawani Adel , Rodriguez Omar , Rahimnejad Yazdi Alireza , Zalzal Paul , Schemitsch Emil H. , Waldman Stephen D. , Papini Marcello , Towler Mark R.
Published: June 2020

Poly(methyl methacrylate) (PMMA) bone cement is used as a minor void filler in revision total knee arthroplasty (rTKA). The application of PMMA is indicated only for peripheral bone defects with less than 5 mm depth and that cover less than 50% of the bone surface. Treating bone defects with PMMA results in complications as a result of volumetric shrinkage, bone necrosis, and aseptic loosening. These concerns have driven the development of alternative bone cements. We report here on novel modified glass polyalkenoate cements (mGPCs) containing 1, 5 and 15 wt% calcium sulfate (CaSO4) and how the modified cements' properties compare to those of PMMA used in rTKA. CaSO4 is incorporated into the mGPC to improve both osteoconductivity and bioresorbability. The results confirm that the incorporation of CaSO4 into mGPCs decreases the setting time and increases release of therapeutic ions such as Ca2+ and Zn2+ over 30 days of maturation in deionized (DI) water. Moreover, the compressive strength for 5 and 15 wt% CaSO4 addition increased to over 30 MPa after 30 day maturation. Although the overall initial compressive strength of the mGPC (~ 30 MPa) is less than PMMA (~ 95 MPa), the compressive strength of mGPC is closer to that of cancellous bone (~ 1.2–7.8 MPa). CaSO4 addition did not affect biaxial flexural strength. Fourier transform infrared analysis indicated no cross‐linking between CaSO4 and the GPC after 30 days. in vivo tests are required to determine the effects the modified GPCs as alternative on PMMA in rTKA.
Sex- and Site-Specific Reference Data for Bone Microarchitecture in Adults Measured Using Second-Generation HR-pQCT
Authors: Whittier Danielle E , Burt Lauren A , Hanley David A , Boyd Steven K
Published: June 2020

There are currently no population-based reference data sets available for volumetric bone mineral density and microarchitecture parameters measured using the second-generation high-resolution peripheral quantitative computed tomography (HR-pQCT), yet the technology is rapidly becoming a standard for studies of bone microarchitecture. Although cross-calibrated data sets from the first-generation HR-pQCT have been reported, they are not suitable for second-generation bone microarchitecture properties because of fundamental differences between scanner generations. This study provides site- and sex-specific centile curves across the adult life span for second-generation HR-pQCT properties. A total of 1236 adult participants (768 female and 468 male) from the Calgary area between the ages of 18 and 90 years were scanned at the distal tibia and radius using the second-generation HR-pQCT. Bone densities, microarchitectural properties, and failure load estimated using finite element analysis were determined using standard in vivo protocol. Site- and sex-specific centile curves were generated using the generalized additive models for location, scale, and shape (GAMLSS) method. These data provide reference curves appropriate for predominantly white male and female adults, which can be used as a tool to assess patient- or cohort-specific bone health. © 2020 American Society for Bone and Mineral Research.
Density functional theory studies of effects of boron replacement on the structure and property of RDX and HMX
Authors: Wu Qiong , Yan Gaojie , Li Mingquan , Hu Qinnan , Zhang Zewu , Zhu Weihua
Published: June 2020

In this study, based on two model nitramine compounds hexahydro‐1,3,5‐trinitro‐1,3,5‐triazine (RDX) and octahydro‐1,3,5,7‐tetranitro‐1,3,5, 7‐tetrazocine (HMX), two series of new energetic molecules were designed by replacing carbon atoms in the ring with different amounts of boron atoms, their structures and performances were investigated theoretically by the density functional theory method. The results showed that the boron replacement could affect the molecular shape and electronic structure of RDX and HMX greatly, and then would do harm to the main performance like the heat of formation, density, and sensitivity. However, the compound RDX‐B2 is an exception; it was formed by replacing two boron atoms into the system of RDX and has the symmetric boat‐like structure. Its oxygen balance (4.9%), density (1.91 g/cm3), detonation velocity (8.85 km/s), and detonation pressure (36.9 GPa) are all higher than RDX. Furthermore, RDX‐B2 has shorter and stronger NNO2 bonds than RDX, making it possesses lower sensitivity (45 cm) and better thermal stability (the bond dissociation energy for the NNO2 bond is 204.7 kJ/mol) than RDX. Besides, RDX‐B1 and HMX‐B4 also have good overall performance; these three new molecules may be regarded as a new potential candidate for high energy density compounds.
Bone marrow particle enrichment analysis for the laboratory diagnosis of multiple myeloma: A case study
Authors: Zhang Congming , Zhang Yanan
Published: June 2020

Background

Bone marrow smear and biopsy are the main methods for the diagnosis of multiple myeloma (MM), bone marrow infiltration, and metastasis in lymphoma and cancer. However, several factors, including the focal growth of tumor cells, inappropriate puncture sites, and hemodilution of bone marrow aspirates, lower the rate of target cell detection. To solve this problem, we developed a novel method—bone marrow particle enrichment analysis—and here, we describe this procedure and its use in the diagnosis of a rare case of MM.

Methods

An 88‐year‐old man with primary gastric gamma delta T‐cell lymphoma (γδTCL) was found to have anemia. As the cause of anemia could not be determined, hemodilution was suspected, warranting the re‐examination of the bone marrow aspirate. Re‐puncture could not be performed because of the patient's age and unwillingness to undergo this procedure. Hence, we used a novel approach to enrich bone marrow particles and isolate marrow cells, and subsequently performed morphological and flow cytometric analysis.

Results

Examinations performed after bone marrow particle enrichment revealed the presence of myeloma cells, and the patient was diagnosed with primary gastric γδTCL accompanied by MM.

Conclusions

Bone marrow particle enrichment analysis may be applied to overcome the problems caused by hemodilution of bone marrow aspirates and to improve the rate of tumor cell detection. The application of this method for the diagnosis of hematological disorders should be explored further.
Is aquaporin‐3 involved in water‐permeability changes in the killifish during hypoxia and normoxic recovery, in freshwater or seawater?
Authors: Ruhr Ilan M. , Wood Chris M. , Schauer Kevin L. , Wang Yadong , Mager Edward M. , Stanton Bruce , Grosell Martin
Published: June 2020

Aquaporins are the predominant water‐transporting proteins in vertebrates, but only a handful of studies have investigated aquaporin function in fish, particularly in mediating water permeability during salinity challenges. Even less is known about aquaporin function in hypoxia (low oxygen), which can profoundly affect gill function. Fish deprived of oxygen typically enlarge gill surface area and shrink the water‐to‐blood diffusion distance, to facilitate oxygen uptake into the bloodstream. However, these alterations to gill morphology can result in unfavorable water and ion fluxes. Thus, there exists an osmorespiratory compromise, whereby fish must try to balance high branchial gas exchange with low ion and water permeability. Furthermore, the gills of seawater and freshwater teleosts have substantially different functions with respect to osmotic and ion fluxes; consequently, hypoxia can have very different effects according to the salinity of the environment. The purpose of this study was to determine what role aquaporins play in water permeability in the hypoxia‐tolerant euryhaline common killifish (Fundulus heteroclitus), in two important osmoregulatory organs—the gills and intestine. Using immunofluorescence, we localized aquaporin‐3 (AQP3) protein to the basolateral and apical membranes of ionocytes and enterocytes, respectively. Although hypoxia increased branchial AQP3 messenger‐RNA expression in seawater and freshwater, protein abundance did not correlate. Indeed, hypoxia did not alter AQP3 protein abundance in seawater and reduced it in the cell membranes of freshwater gills. Together, these observations suggest killifish AQP3 contributes to reduced diffusive water flux during hypoxia and normoxic recovery in freshwater and facilitates intestinal permeability in seawater and freshwater.
Associations between Posttraumatic Stress Symptoms, Creative Thinking, and Trait Resilience among Chinese Adolescents Exposed to the Lushan Earthquake
Authors: Liang Yiming , Zheng Hao , Cheng Jin , Zhou Yueyue , Liu Zhengkui
Published: June 2020

Trauma has been shown to have a detrimental impact on individuals; however, it may also provide an opportunity for individual growth. The present study investigated the relationship between post‐traumatic stress symptoms (PTSS) and creative thinking and examined the role of trait resilience as a potential moderator of the relationship. A longitudinal study was conducted 1.5 months after the Lushan earthquake (T1: June 2013), and 102 students who experienced the earthquake were surveyed. PTSS were measured at T1 (June 2013), trait resilience was measured at T2 (October 2013), and creative thinking was measured at T3 (April 2014). PTSS and trait resilience were measured by self‐reported questionnaires, and creative thinking was assessed by the Practical Creative Thinking Test. Overall, PTSS were negatively associated with creative thinking, and trait resilience moderated this relationship. Further analysis revealed a significant positive relationship between PTSS and creative thinking for individuals with high trait resilience. The current study highlights the moderating effect of trait resilience on the relationship between PTSS and creative thinking and identifies a positive association between PTSS and creative thinking among early adolescents with high trait resilience. Our findings suggest that increased creative thinking may be a manifestation of post‐traumatic growth in the cognitive process.
Ultrasound Surveillance of Abnormal Cervical Lymph Nodes in Patients With Papillary Thyroid Carcinoma After Surgery
Authors: Hu Minxia , Xia Chunxia , Zhou Yajing , Yu Fengxia , Zhu Qiang , Zhao Hanxue
Published: June 2020

Objectives

To document the changing trends of abnormal cervical lymph nodes (LNs) in patients with papillary thyroid carcinoma (PTC) who had serial follow‐up ultrasound (US) scans after surgery and to determine how these node abnormalities progress in real time.

Methods

Ultrasound findings from 568 consecutive patients with PTC who were monitored postoperatively were reviewed. Abnormal LNs were classified as either suspicious or indeterminate according to the European Thyroid Association guidelines. Outcomes from US monitoring of the LNs were recorded and analyzed.

Results

Seventy‐six (13.4%) of 568 patients were identified with abnormal LNs. Among them, 55 (72.4%) were initially found to have suspicious LNs, and the other 21 (27.6%) had indeterminate lesions. Of the 55 suspicious LNs, final scans showed that 38 (69.1%) lesions were still suspicious, whereas the remaining 17 (30.9%) nodes were shown to have resolved after a median follow‐up of 36 months. Of the 21 indeterminate node abnormalities, final scans showed that 16 (76.2%) LNs remained indeterminate, whereas the other 5 (23.8%) nodes had developed into suspicious LNs after a median follow‐up of 44 months. Loss of the fatty hilum and peripheral or diffusedly increased vascularity were more likely to be linked to persistent suspicious LNs (P = .02 and .04, respectively). Suspicious LNs with echogenic foci but a lack of other abnormal features were more frequently found to have resolved thereafter (P = .03).

Conclusions

Abnormal LNs detected after PTC surgery can often remain indolent during US surveillance, and a small portion of the nodes would have resolved over time.
Superfast Self‐Healing and Photothermal Active Hydrogel with Nondefective Graphene as Effective Additive
Authors: Du Lina , Cao Shuai , Zheng Xiaoli , Jiang Lei , Ren Zhiyong , Chen Jun , Xu Qun
Published: June 2020

2D graphene with high quality holds great promise in improving the performance of the hydrogels owing to its exceptional electronic, thermal, and mechanical properties. However, the structure defects existed in graphene restrict its further applications. Herein, a simple and green method of fabricating defect‐free graphene nanosheets with the assistance of supercritical carbon dioxide (SC CO2) is designed. The graphene nanosheets directly assemble with acrylic acid monomer and clay, and a flexible semitransparent hydrogel is fabricated. Benefiting from the excellent properties of the defect‐free graphene, the hydrogel exhibits the high mechanical performance, superfast self‐healing capability, excellent conductivity, and super photothermal conversion efficiency. According to the advantages above, the graphene/poly(acrylic acid)/clay hydrogels can be used for intelligent sensors for disease diagnosis, artificial electronic skin, and military stealth materials in the near future.
Laser‐made 3D Auxetic Metamaterial Scaffolds for Tissue Engineering Applications
Authors: Flamourakis George , Spanos Ioannis , Vangelatos Zacharias , Manganas Phanee , Papadimitriou Lina , Grigoropoulos Costas , Ranella Anthi , Farsari Maria
Published: June 2020

Exploiting the unique properties of three‐dimensional (3D) auxetic scaffolds in tissue engineering and regenerative medicine applications provides new impetus to these fields. Herein, the results on the fabrication and characterization of 3D auxetic scaffolds for tissue engineering applications are presented. The scaffolds are based on the well‐known re‐entrant hexagonal geometry (bowtie) and they are fabricated by multiphoton lithography using the organic−inorganic photopolymer SZ2080. In situ scanning electron microscopy–microindentations and nanoindention experiments are employed to characterize the photocurable resin SZ2080 and the scaffolds fabricated with it. Despite SZ2080 being a stiff material with a positive Poisson’s ratio, the scaffolds exhibit a negative Poisson’s ratio and high elasticity due to their architecture. Next, mouse fibroblasts are used to seed the scaffolds, showing that they can readily penetrate them and proliferate in them, adapting the scaffold shape to suit the cells’ requirements. Moreover, the scaffold architecture provides the cells with a predilection to specific directions, an imperative parameter for regenerative medicine in many cell‐based applications. This research paves the way for the utility of 3D auxetic metamaterials as the next‐generation adaptable scaffolds for tissue engineering.
Facile Synthesis and In‐Depth Characterization of Polymethacrylimides with Tunable Properties
Authors: Jovic Kristina , De Bruycker Kevin , Richter Thomas , Barner‐Kowollik Christopher , Blinco James P.
Published: June 2020

High‐performance polymers such as polymethacrylimides have outstanding properties, for example, a unique strength‐to‐weight ratio and a high thermal stability, usually coupled to a high glass transition temperature. However, the requirement of high processing temperatures caused by these high glass‐transition temperatures is often not desired for melt extrusion processes. Herein, a novel and straightforward imidization process of poly(methacrylic anhydrides) is presented with different ratios of ammonia and N‐isopropylamine that is induced by thermal treatment. Therefore, polymethacrylimides with a varying degree of N‐substitution, and thus a varying number of hydrogen‐bond‐donating moieties, are synthesized under facile reaction conditions. An in‐depth investigation into the structures obtained with this new methodology is undertaken via a combination of nuclear magnetic resonance spectroscopy (NMR), Fourier‐transform infrared spectroscopy (FT‐IR), and high‐resolution electrospray ionization mass spectrometry (ESI‐MS). Additionally, thermal properties of the materials are investigated using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) analyses. These latter measurements highlight the key opportunity available with this novel synthesis to tailor the thermal properties of the polymer by providing a clear correlation between hydrogen bond formation, as observed by FT‐IR, and the glass transition temperature.
Preparation of Poly(Ionic Liquid) Particles with Anionic Side Chain by Dispersion Polymerization
Authors: Nakano Takanori , Yamane Mitsuyoshi , Kurozuka Aya , Suzuki Toyoko , Minami Hideto
Published: June 2020

Micrometer‐sized poly(ionic liquid) (PIL) particles with an anionic side chain, poly(1‐butyl‐3‐methylimidazolium 3‐sulfopropyl methacrylate) (poly([Bmim][SPMT])), are successfully prepared by dispersion polymerization at 60 °C in ethanol/ethyl acetate (2/8, w/w) with poly(vinylpyrrolidone) as a stabilizer. However, the obtained particles do not maintain the particulate state during drying at room temperature due to poly([Bmim][SPMT])’s low glass‐transition temperature, below room temperature. In order to prevent coalescence and maintain particle shape, a cross‐linking monomer is added after the nucleation stage of dispersion polymerization. Moreover, Fourier‐transform infrared spectroscopy (FT‐IR) demonstrates cation exchange between the obtained particles and metal cations (Ag+).
A generalization of the 2D Slepian functions
Authors: Bouzeffour Fethi , Garayev Mubariz
Published: June 2020

The paper is devoted to the study of 2D version special functions generalizing the famous Slepian functions. As a consequence, many desirable spectral properties of the corresponding weighted finite Fourier transform are deduced from the rich literature. In particular, a similar aspect related to Slepian's seminal papers is the investigation of differential operators that commute with appropriate integral operators. Finally, we provide some analytic expressions for the finite Fourier transforms of the disk polynomials and the two variables Gegenbauer polynomials.
A 3 dB E‐plane waveguide directional coupler employing micromachining technique for terahertz application
Authors: Deng Jiang‐Yu , Duan Jun‐Ping , Liu Rui , Zhang Bin‐Zhen
Published: June 2020

In this work, 3 dB branch‐line waveguide in the range of 335‐415 GHz directional coupler is proposed, where the insertion loss is less than 0.9 dB and the directionality is better than 20 dB. The coupler is composed of three “crossing”‐shaped structures, which can effectively enhance the directionality and coupling, based on a certain broad bandwidth. The designed coupler has been modeled and optimized, using commercial full‐wave simulation software HFSS, fabricated by the UV‐LIGA process. In addition, its deformation was theoretically analyzed at different pressures by ANSYS software to test its practicability. Both of the test and simulated results have a nice correlation. We conclude that our proposed coupler has excellent performance and can be used for the investigation of submillimeter wave components in terahertz applications.
Characterizing a PTW microDiamond detector in kilovoltage radiation beams
Authors: Khan Ahtesham Ullah , Culberson Wesley S. , DeWerd Larry A.
Published: June 2020

Purpose

The aim of this work was to characterize the dosimetric properties of the PTW microDiamond (60019) single crystal synthetic diamond detector (DD) in kilovoltage x‐ray beams. The following characteristics were addressed in this study: required preirradiation dose, dose‐rate linearity, energy dependence, and percent depth dose response of the DD.

Methods

UWADCL x‐ray beams, characterized by NIST‐traceable ionization chambers, were used in this study. Preirradiation dose required by the DD, in order to stabilize the detector’s response to within 0.1%, was quantitated. Dose‐rate dependence was also investigated using the UW250‐M and UW50‐M beams, where the dose rate was varied by changing the tube current.

and

calibration coefficients for all the available M series beams at UWADCL were obtained to determine the energy dependence of the DD, Diode E, Diode P, and P11 parallel‐plate ionization chamber. A custom‐built water tank was utilized to measure the percent depth dose (PDD) response of the DD, Diode E, Diode P, and P11 chamber in UW250‐M, UW100‐M, and UW50‐M beams. The measured PDD response of the detectors was compared with the simulated PDD data using EGSnrc Monte Carlo code.

Results

A 1.5 Gy dose‐to‐water or air‐kerma was found to be sufficient for the given DD’s response to stabilize to within 0.1% in all of the beams used in this study. The dose‐rate dependence parameter, Δ, was found to be 1.00 ± 0.02 and 1.016 ± 0.05 for the UW250‐M and UW50‐M beams, respectively. Relative to the

Co calibration coefficients, the DD was found to under‐respond relative to calculated absorbed dose to water response and over‐respond relative to the calculated air‐kerma response in the M‐series beams. Agreement of 1.5% was found between the measured PDD values and Monte Carlo simulated PDD values for UW250‐M, UW100‐M, and UW50‐M beams.

Conclusions

In order to stabilize the response, the DD needs a preirradiation dose, which is unique to every DD. A linear relationship between detector response and dose rate was found within the evaluated uncertainty. An energy dependence of the DD was studied, which is more pronounced in the low‐energy beams and can be partially attributed to the metal contact material around the sensitive volume of the DD. Overall, the DD was found to be suitable for kilovoltage x‐ray dosimetry.
A biological effect‐guided optimization approach using beam distal‐edge avoidance for intensity‐modulated proton therapy
Authors: Bai Xuemin , Lim Gino , Grosshans David , Mohan Radhe , Cao Wenhua
Published: June 2020

Purpose

Linear energy transfer (LET)‐guided methods have been applied to intensity‐modulated proton therapy (IMPT) to improve its biological effect. However, using LET as a surrogate for biological effect ignores the topological relationship of the scanning spot to different structures of interest. In this study, we developed an optimization method that takes advantage of the continuing increase in LET beyond the physical dose Bragg peak. This method avoids placing high biological effect values in critical structures and increases biological effect in the tumor area without compromising target coverage.

Methods

We selected the cases of two patients with brain tumors and two patients with head and neck tumors who had been treated with proton therapy at our institution. Three plans were created for each case: a plan based on conventional dose‐based optimization (DoseOpt), one based on LET‐incorporating optimization (LETOpt), and one based on the proposed distal‐edge avoidance‐guided optimization method (DEAOpt). In DEAOpt, an L1‐norm sparsity term, in which the penalty of each scanning spot was set according to the topological relationship between the organ positions and the location of the peak scaled LET‐weighted dose (c LETxD) was added to a conventional dose‐based optimization objective function. All plans were normalized to give the same target dose coverage. Dose (assuming a constant relative biological effectiveness value of 1.1, as in clinical practice), biological effect (c LETxD), and computing time consumption were evaluated and compared among the three optimization approaches for each patient case.

Results

For all four cases, all three optimization methods generated comparable dose coverage in both target and critical structures. The LETOpt plans and DEAOpt plans reduced biological effect hot spots in critical structures and increased biological effect in the target volumes to a similar extent. For the target, the c LETxD98% and c LETxD2% in the DEAOpt plans were on average 7.2% and 11.74% higher than in the DoseOpt plans, respectively. For the brainstem, the c LETxDmean in the DEAOpt plans was on average 33.38% lower than in the DoseOpt plans. In addition, the DEAOpt method saved 30.37% of the computation cost over the LETOpt method.

Conclusions

DEAOpt is an alternative IMPT optimization approach that correlates the location of scanning spots with biological effect distribution. IMPT could benefit from the use of DEAOpt because this method not only delivers comparable biological effects to LETOpt plans, but also is faster.
Exchange rate and the economic growth in India: An empirical analysis
Authors: Shaik Khulsum , Gona Babu Rao
Published: June 2020

In the present globalization economic world, exchange rate plays a major role in every country's economic activity. Here, exchange rate policy has been identified as one of the endogenous factors that can affect the economic performance of a nation. Exchange rate plays a key role in international economic transactions because no nation can remain in isolation due to varying factor endowment. Movements in the exchange rate have ripple effects on other economic growth. The study used secondary data that were collected from the World Development Indicators data base and analysed. The study used the ordinary least square and VECM Granger Causality method of estimation for data covered the period from 1990 to 2017. The results from the econometric analyses show that there is a short‐run relationship between exchange rate, inflation rate, interest rate and GDP. The result obtained from the unit root analysis indicates that least one time series variable property is stationary. The study concludes that in India, the factors that influence the level of growth rate are extent of exchange rate and its variables. Based on the findings, from the Granger causality investigation procedure at 5% critical value are EXCH, INT, INF, IMP and EXP among other variables that affect economic growth. The study recommends the need to be technologically inclined in all sectors of Indian economy; excess and over budgetary inflation and implementation should be cut to barest minimal level to avert the ideal of external borrowing which most consequently result in external debt and services. The Indian government should show the path of redirecting its investment profile by channelling it towards capital projects of the government.
Short‐ and long‐term outcomes of gestational diabetes and its treatment on fetal development
Authors: Murray Sarah R. , Reynolds Rebecca M.
Published: June 2020

Globally the prevalence of gestational diabetes mellitus (GDM) is rising mainly due to the increase in maternal obesity. A number of different methods to screen for and diagnose GDM have been described although consensus on the preferred methods does not yet exist. GDM has significant short‐ and long‐term health risks for the mother, developing fetus and the children born to mothers with GDM. Short‐term risks for the fetus include macrosomia (excessive birthweight), shoulder dystocia, birth trauma, and hypoglycaemia in the immediate postpartum period. Long‐term risks for offspring born to mothers with GDM include increased rates of childhood and adulthood obesity and an increased cardiometabolic risk. A number of pharmacological treatments for GDM have been identified, these include insulin and oral glucose‐lowering drugs metformin and glibenclamide. Whilst these oral glucose‐lowering drugs show similar short‐term childhood outcomes to insulin there is increasing evidence that these drugs may have adverse long‐term outcomes on children and adults exposed to the drugs in utero. Future research on treatments for GDM should include long‐term follow‐ up of children exposed to glucose lowering medication in utero to determine the long‐term cardiometabolic risk in the offspring born to mothers with GDM.
Design of ethylene‐propylene‐diene monomer foam and its double‐layer composite for improving sound absorption properties via experimental method and theoretical verification
Authors: Wang Xiting , Wang Yansong , Ma Lifeng , Guo Hui , Yang Chao , Liu Ningning , Wang Jincheng
Published: June 2020

In this work, the ethylene‐propylene‐diene monomer (EPDM) foam was fabricated via 4‐4′‐oxobisbenzenesulfonyl hydrazide (OBSH) and phenolic resin (PF) in an effort to prepare the sound‐absorbing composite which has excellent sound absorption at the medium and low frequency. For single‐layer EPDM foams, cell morphology showed a certain pattern, causing the peak of the sound absorption coefficient move to a higher frequency and the peak value reached a maximum of about 0.75 as the OBSH content increased. In addition, with the foaming temperature increasing, the cell morphology had a different tendency and the peak of the sound absorption coefficient moved first to the higher frequency and then to the lower frequency due to the vulcanization reaction. Compared with the single‐layer EPDM foams, the sound absorption curve of the double‐layer composite made of the single‐layer EPDM foam and pure EPDM sheet with cavities moved to a lower frequency by about 400 Hz. The theoretical calculation method was used to verify the accuracy of the experimental results. This work provided a simple approach to control the sound absorption property of EPDM foamed material and its double‐layer composite through from an experimental and theoretical perspective.
Chain conformation and dynamics in ultrahigh molecular weight polyethylene melts undergoing extensional–shear coupled flow: insight from dissipative particle dynamics simulation
Authors: Wang Junxia , Chen Xiaochuan , Cao Changlin , Yu Dingshan
Published: June 2020

A first attempt is made to present a detailed mesoscopic‐level description of the conformation and equilibrium dynamic properties of macromolecular chains in ultrahigh molecular weight polyethylene/polypropylene blends driven by extension‐dominated coupled flow, in comparison with shear‐dominated coupled flow. Extension‐dominated coupled flow can be defined as = 0.005, ≥ 0.1 and shear‐dominated coupled flow as = 0.1, ≥ 1, as verified by the time‐dependent evolution tendency of cell parameters and velocity profiles along the x, y, z directions. In the case of extension‐dominated coupled flow, the chains are greatly elongated and prefer to align along the flow direction, where the polypropylene chains appear to form a somewhat uniform layer. By comparison, the macromolecular chains assume a highly collapsed conformation and have a greater preference to align themselves perpendicular to the flow direction under shear‐dominated coupled flow, which can be ascribed to the rapid diffusion of polymer chains and a minor role of the weak van de Waals interaction in structural transitions. Analyses of conformational behavior derived from dissipative particle dynamics trajectories can, in general, serve as a useful guideline for experimental investigations of ultrahigh molecular weight polyethylene based materials prepared by eccentric rotor extrusion. © 2020 Society of Chemical Industry
Thermomagnetic Properties of Dy0.9Ho0.1MnO3 Multiferroics
Authors: Naini Pavan Kumar , Satapathy Jyotirmayee , Abhinav Etyala Meher , Srinivas Adiraj , Raja Muthuvel Manivel
Published: June 2020

Holmium (Ho)‐doped DyMnO3 multiferroic compound is prepared using conventional solid‐state reaction route, and X‐ray powder diffraction analysis is conducted to confirm the single‐phase structure. Coexistence of magnetic and electric behavior in case of multiferroics is analyzed by heat capacity measurements from low temperature (2 K) to room temperature (300 K) under different magnetic fields. Herein, the existence antiferromagnetic and ferroelectric phase transitions in this compound at <10, 18, and 40 K, respectively, is revealed, which are attributed to the structural ordering or alignment of Mn3+ ions and R3+ ions. The magnetocaloric effect of this sample is also studied from heat capacity measurements. A maximum magnetic entropy change (ΔS)M of ≈6.3 J kg−1 K−1 and adiabatic temperature change (ΔT)ad of 3–4 K is achieved in 0.1Ho‐doped compound for a magnetic field change of 5 T and useful for low‐temperature magnetic refrigeration applications.
Elementary Laser‐Less Quantum Logic Operations with (Anti‐)Protons in Penning Traps
Authors: Nitzschke Diana , Schulte Marius , Niemann Malte , Cornejo Juan M. , Ulmer Stefan , Lehnert Ralf , Ospelkaus Christian , Hammerer Klemens
Published: June 2020

Static magnetic field gradients superimposed on the electromagnetic trapping potential of a Penning trap can be used to implement laser‐less spin–motion couplings that allow the realization of elementary quantum logic operations in the radio‐frequency regime. An important scenario of practical interest is the application to g‐factor measurements with single (anti‐)protons to test the fundamental charge, parity, time reversal (CPT) invariance as pursued in the Baryon Antibaryon Symmetry Experiment (BASE) collaboration. The classical and quantum behavior of a charged particle in a Penning trap with a superimposed magnetic field gradient is discussed. Using analytic and numerical calculations, it is found that it is possible to carry out a SWAP gate between the spin and the motional qubit of a single (anti‐)proton with high fidelity, provided the particle has been initialized in the motional ground state. The implications of the findings for the realization of quantum logic spectroscopy in this system are discussed.
Isotropic Scalar Quantum Sensing of Magnetic Fields for Industrial Application
Authors: Staacke Robert , John Roger , Wunderlich Ralf , Horsthemke Ludwig , Knolle Wolfgang , Laube Christian , Glösekötter Peter , Burchard Bernd , Abel Bernd , Meijer Jan
Published: June 2020

Magnetic field sensors based on quantum mechanic effects are often susceptible to misalignments of the magnetic field or need advanced procedures to compensate for these. Also, the record breaking sensitivities reported for superconducting quantum interference devices and alkali vapor magnetometers come along with large and complex experimental setups. The nitrogen vacancy center in diamond can be used to design a simple, small, and robust sensor without employing microwave radiation. By using compressed nanodiamond particles, it is possible to eliminate the need of an alignment of the magnetic field and still obtain the absolute magnetic flux density in a single measurement. In order to demonstrate the capabilities of this approach, a centimeter‐sized modified automotive demo board is employed as a complete sensor with a sensitivity of 78 T/.
Stability analysis and saturation control for nonlinear positive Markovian jump systems with randomly occurring actuator faults
Authors: Zhang Junfeng , Yang Haoyue , Raïssi Tarek
Published: June 2020

This article investigates the stability analysis and control design of a class of nonlinear positive Markovian jump systems with randomly occurring actuator faults and saturation. It is assumed that the actuator faults of each subsystem are varying and governed by a Markovian process. The nonlinear term is located in a sector. First, sufficient conditions for stochastic stability of the underlying systems are established using a stochastic copositive Lyapunov function. Then, a family of reliableL1‐gain controller is proposed for nonlinear positive Markovian jump systems with actuator faults and saturation in terms of a matrix decomposition technique. Under the designed controllers, the closed‐loop systems are positive and stochastically stable with anL1‐gain performance. An optimization method is presented to estimate the maximum domain of attraction. Furthermore, the obtained results are developed for general Markovian jump systems. Finally, numerical examples are given to illustrate the effectiveness of the proposed techniques.
How do oil prices and investments impact the dynamics of firm value?
Authors: Khan Aima , Qureshi Muhammad Azeem , Davidsen Pål Ingebrigt
Published: June 2020

Abstract

The purpose of this study is twofold: (i) to analyze the impact of investment policy decision on the firm value given the uncertain oil and gas prices and (ii) to propose policies that enhance firm value. The study develops a system dynamics model that integrates the financial and operational activities of oil firms. The simulation results reveal that, when oil and gas prices increase, positive future expectations lead to increased investments and reduced cash flows. Greater volume of investments over the firm's current investment policy decreases its future cash flows and the total firm value over the first 20 years of the simulation period; it increases thereafter. To support higher investments, the firm would issue a higher number of shares, and consequently the market price per share would be lower, and vice versa. The simulation results suggest a relatively lower volume of investments to increase the market price per share.

© 2020 The Authors. System Dynamics Review published by John Wiley & Sons Ltd on behalf of System Dynamics Society
Proposal of frequency‐based decomposition approach for minimization of errors in surface texture parameter calculation
Authors: Podulka Przemysław
Published: June 2020

In this paper, the frequency‐based decomposition approach (FBDA) for preprocessing of surface texture parameters calculation/assessment was proposed. Two types of textures were analysed: turned or grinded details. They were measured with interferometric method. For detection/minimization of high‐frequency measuring errors (HFME) the wavelets, Haar, Daubechies, Coiflet, biorthogonal or reverse‐biorthogonal approaches were proposed. Moreover, in some cases, the power spectrum density and/or autocorrelation function analysis provided an additional and/or valuable information about surface texture/features as well. It was assumed that application of various extraction methods (such as FBDA) can provide reasonable results for noise extraction in accordance to the commonly used algorithms, such as median filter, moving average (arithmetic mean) filter or other denoising procedures (e.g., Gaussian denoising filter) proposed in commercial software. The influence of proposed procedure on calculation (error minimization) of surface topography parameters (from ISO 25178 standard) was also presented. Some errors (especially those caused by false estimation of noise‐removal procedure) in surface topography parameter calculation were comprehensively studied with profile analysis; for areal HFME decomposition, the noise surface was defined. For some turned details, the HFME was observed in profiles analysis mostly. The biggest high frequencies from removed noise surface (created by noise extraction with FBDA) contained, the better results (of proposed approach) were obtained. It was also assumed that FBDA for preprocessing of both grinded and turned surfaces with various decomposition filters (in some cases the RBW) gave more ‘direct results’ that commonly used denoising approaches.
Graphical approaches for the control of generalized error rates
Authors: Robertson David S. , Wason James M. S. , Bretz Frank
Published: June 2020

When simultaneously testing multiple hypotheses, the usual approach in the context of confirmatory clinical trials is to control the familywise error rate (FWER), which bounds the probability of making at least one false rejection. In many trial settings, these hypotheses will additionally have a hierarchical structure that reflects the relative importance and links between different clinical objectives. The graphical approach of Bretz et al (2009) is a flexible and easily communicable way of controlling the FWER while respecting complex trial objectives and multiple structured hypotheses. However, the FWER can be a very stringent criterion that leads to procedures with low power, and may not be appropriate in exploratory trial settings. This motivates controlling generalized error rates, particularly when the number of hypotheses tested is no longer small. We consider the generalized familywise error rate (k‐FWER), which is the probability of making kor more false rejections, as well as the tail probability of the false discovery proportion (FDP), which is the probability that the proportion of false rejections is greater than some threshold. We also consider asymptotic control of the false discovery rate, which is the expectation of the FDP. In this article, we show how to control these generalized error rates when using the graphical approach and its extensions. We demonstrate the utility of the resulting graphical procedures on three clinical trial case studies.
The contemplated average success probability for normally distributed models with an application to optimal sample sizes selection
Authors: Zhang Ying‐Ying , Rong Teng‐Zhong , Li Man‐Man
Published: June 2020

We analytically obtain the average success probability (ASP) and the contemplated average success probability (CASP) for normally distributed observed differences in the treatment group and the placebo group means of the early trial and the confirmatory trial, assuming a uniform noninformative prior for the population treatment effect and a common known variance of the observations from both groups. For the CASP optimization problem with a fixed subtotal sample size of the early trial and the confirmatory trial of one arm larger than a threshold, we obtain the optimal plan of the sample sizes in a theorem. Moreover, in the theorem, we obtain the analytical formula of the optimal CASP as an increasing function of the subtotal sample size. After that, we calculate and compare the numerical values of the ASP with those in Table 1 of Chuang‐Stein (2006). Finally, we investigate the numerical features of the CASP and find the optimal plan of the sample sizes for a given subtotal sample
size.
Recent Advances in the Protection of Amine Functionality: A Review
Authors: Omprakash Rathi Jyoti , Subray Shankarling Ganapati
Published: June 2020

Selective protection of −NH2 functionality has enormous utility and significance in organic synthesis. Amines are nucleophile and basic in nature thus vulnerable to react with an extensive range of reagents, especially oxidizing, alkylating, and carbonyl compounds and therefore can require protection to mask these properties in the multifunctional molecule during chemical reactions. Protection of amine functionality finds important application in peptide synthesis, thus several methodologies have been developed for N‐Protection reaction. Herein, we have reviewed recent advances in the protection of amines (from 2012 till present) in the hope that this will update the current body of knowledge and aid researchers working in this area.
Synthesis of Ag2O‐SnO2 and SnO2‐Ag2O Nanocomposites and Investigation on Photocatalytic Performance under Direct Sun Light
Authors: Kumar M. Rajesh , Murugadoss G. , Venkatesh N. , Sakthivel P.
Published: June 2020

Ag2O‐SnO2 and SnO2‐Ag2O nanocomposites were successfully synthesized by a facile one‐step chemical precipitation method. The microstructural features of nanocomposites were characterized by X‐Ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high‐resolution transmission electron microscopy (HR‐TEM), Fourier transform infrared spectroscopy (FT‐IR), UV‐visible (UV‐vis) and Photoluminescence (PL) spectroscopy. The SnO2‐Ag2O showed enhanced PL emission than the Ag2O‐SnO2 nanocomposite. Photocatalytic activity of the nanocomposites was studied for methylene blue (MB) and methyl orange (MO) dyes under sun light. The Ag2O‐SnO2 nanocomposite showed excellent photocatalytic activity for the degradation of both dyes. The high photocatalytic activity of Ag2O‐SnO2 could be ascribed to the enhanced charge separation derived from the coupling of Ag2O with SnO2 due to the potential energy differences between Ag2O and SnO2, which would promote interfacial charge‐transfer relative to that of charge carrier recombination.