bluuebunny/crossref_metadata_2025_split huggingface dataset:
Radiographic and fluoroscopic X‐ray systems: Quality control of the X‐ray tube and automatic exposure control using theoretical spectra to determine air kerma and dose to a homogenous phantom
Authors: Konst Bente , Nøtthellen Jacob , Bilet Ellinor , Båth Magnus 
Published: July 2021

AbstractPurposeTo develop a method to perform quality control (QC) of X‐ray tubes and automatic exposure control (AEC) as a part of the QC of the radiographic and fluoroscopic X‐ray system. Our aim is to verify the output from the X‐ray tube by comparing the measured radiation output, or air kerma, to the theoretical output given the applied exposure settings and geometry, in addition to comparing the measured kV to the nominal kV. The AEC system for fluoroscopic and conventional X‐ray systems is assessed by determining the absorbed dose to a homogenous phantom with different thicknesses.MethodThis study presents a model to verify the X‐ray tube measurement results and a method to determine the dose to a homogenous phantom (Dphantom). The following input is needed: a parameterized model of the X‐ray spectrum, the X‐ray tube measurements using a multifunctional X‐ray meter, the exposure parameters recorded via imaging of polymethyl methacrylate (PMMA) slabs of different thickness that simulate the patient using AEC, and a parameterized model for calculating the dose to water from Monte Carlo simulations. The output is the entrance surface dose (ESD) and absorbed dose in the phantom, Dphantom (µGy). In addition, the parameterized X‐ray spectrum is used to compare theoretical and measured air kerma as a part of the QC of the X‐ray tube. To verify the proposed method, the X‐ray spectrum provided in this study, SPECTRUM, was compared to two commercially available spectra, SpekCalc and Institute of Physics and Engineering in Medicine (IPEM) 78. The fraction of energy imparted to the homogenous phantom was compared to the imparted fraction calculated by PCXMC.ResultsThe spectrum provided in this study was in good agreement with two previously published X‐ray spectra. The absolute percentage differences of the spectra varied from 0.05% to 3.9%, with an average of 1.4%, compared to SpekCalc. Similarly, the deviation from IPEM report 78 varied from 0.02% to 2.3%, with an average of 0.74%. The SPECTRUM was parameterized for calculation of the imparted fraction for target angles of 10°, 12°, and 15°, kV (50–150 kV) with the materials Al (2.2–8 mm), Cu (0–1 mm), and any combination of the filters, PMMA and water. The deviation of energy imparted from the results by PCXMC was less than 8% for all measurements across different kV, filtration, and vendors, obtained by using PMMA to record the exposure parameters, while the dose was calculated based on water with same thicknesses as the PMMA.ConclusionThis study presents an accurate and suitable method to perform a part of the QC of fluoroscopic and conventional X‐ray systems with respect to the X‐ray tube and the associated AEC system. The method is suitable for comparing protocols within and between systems via the absorbed dose.
Robust attitude estimation of rotating space debris based on virtual observations of neural network
Authors: Ma Chuan , Zheng Zixuan , Chen Jianlin , Yuan Jianping 
Published: July 2021

SummaryHigh precise estimation and prediction of the target's attitude motion are key technologies for capturing and removing rotating space debris. In this article, a neural‐network‐enhanced Kalman filter (NNEKF) is proposed to improve the precision and robustness of attitude estimation algorithm. The main innovation of the NNEKF is to utilize virtual observations of the inertia characteristics to improve the filter's performances. The virtual observations are obtained using a neural network, which is offline trained using simulation data. In order to decrease the number of nodes of the network, the input data are preprocessed using the discrete Fourier transformation method. Moreover, by involving the characteristic frequencies in the input vector, the neural network can extract information from all the past observations, so as to grasp long‐term characteristics of the dynamical system. Therefore, the NNEKF can provide more precise estimation of the target's moment of inertia, and furthermore improve the accuracy and robustness of attitude estimation and prediction. Simulation results indicate that the NNEKF can reduce the estimation errors by 39% compared with the conventional EKF method when using the same measurement data. And the accumulation errors of prediction using estimates of the NNEKF is just as 24% as the conventional EKF.
Overcoming T Cell Exhaustion via Immune Checkpoint Modulation with a Dendrimer‐Based Hybrid Nanocomplex
Authors: Gao Yue , Ouyang Zhijun , Yang Chao , Song Cong , Jiang Chunjuan , Song Shaoli , Shen Mingwu , Shi Xiangyang 
Published: July 2021

AbstractT cell exhaustion, in which dysfunctional T cells are limited in cytokine release and constrained in immune response, leads to immune escape of cancer cells and decreased efficiency of cancer immunotherapy. Direct regulation or blocking of programmed death 1 (PD‐1) represents a promising strategy to overcome T cell exhaustion for reinvigorating anticancer immunity. Here, the construction of a 1,3‐propanesultone (1,3‐PS)‐grafted zwitterionic dendrimer‐entrapped gold nanoparticle platform chelated with Gd(III) (Gd‐Au DENP‐PS) for immune checkpoint modulation is reported. The developed Gd‐Au DENP‐PS possesses good stability, antifouling property, biocompatibility, and dual‐mode computed tomography (CT)/magnetic resonance (MR) imaging functions, and allows for efficient packaging and serum‐enhanced delivery of PD‐1 siRNA to mediate PD‐1 gene silencing in T cells in vitro, and also in vivo in a melanoma‐bearing mouse model and in healthy aging mice. The dendrimer nanocomplexes or T cell‐laden nanocomplexes enable suppression of tumor growth through the generation of significant effector CD8+ and CD4+ T cells, and the tumor immunotherapeutic potency can be further improved by combination with an indoleamine 2,3‐dioxygenase inhibitor. This study identifies a new possibility with a functional dendrimer‐based nanohybrid platform for dual‐mode CT/MR imaging‐guided cancer immunotherapy via the regulation of T cell exhaustion.
Pediatric emergency medicine fellowship point‐of‐care ultrasound training in 2020
Authors: Cramer Natan , Cantwell Lauren , Ong Hilary , Sivasankar Shyam M. , Graff Danielle , Lawson Simone L. , Wilson Paria M. , Noorbakhsh Kathleen A. , Mickley Megan , Zuckerbraun Noel S. , Sobolewski Brad , Soung Jane K. , Azhdam Devora B. , Wagner Neville Desiree N. , Hincapie Mark R. , Marin Jennifer R. 
Published: July 2021

AbstractObjectivesThe primary objective was to survey pediatric emergency medicine (PEM) leaders and fellows regarding point‐of‐care ultrasound (POCUS) training in PEM fellowship programs, including teaching methods, training requirements, and applications taught. Secondary objectives were to compare fellows' and program leaders' perceptions of fellow POCUS competency and training barriers.MethodsThis was a cross‐sectional survey of U.S. PEM fellows and fellowship program leaders of the 78 fellowship programs using two online group‐specific surveys exploring five domains: program demographics; training strategies and requirements; perceived competency; barriers, strengths, and weaknesses of POCUS training; and POCUS satisfaction.ResultsEighty‐three percent (65/78) of programs and 53% (298/558) of fellows responded. All participating PEM fellowship programs included POCUS training in their curriculum. Among the 65 programs, 97% of programs and 92% of programs utilized didactics and supervised scanning shifts as educational techniques, respectively. Sixty percent of programs integrated numerical benchmarks and 49% of programs incorporated real‐time, hands‐on demonstration as training requirements. Of the 19 POCUS applications deemed in the literature as core requirements for fellows, at least 75% of the 298 fellows reported training in 13 of those applications. Although less than half of fellows endorsed competency for identifying intussusception, ultrasound‐guided pericardiocentesis, and transvaginal pregnancy evaluation, a higher proportion of leaders reported fellows as competent for these applications (40% vs. 68%, p ≤ 0.001; 21% vs. 39%, p = 0.003; and 21% vs. 43%, p ≤ 0.001). Forty‐six percent of fellows endorsed a lack of PEM POCUS evidence as a training barrier compared to 31% of leaders (p = 0.02), and 39% of leaders endorsed a lack of local financial support as a training barrier compared to 23% of fellows (p = 0.01).ConclusionsAlthough most PEM fellowship programs provide POCUS training, there is variation in content and requirements. Training does conform to many of the expert recommended guidelines; however, there are some discrepancies and perceived barriers to POCUS training remain.
Contributions of evolutionary anthropology to understanding climate‐induced human migration
Authors: Templon Alannah R. , Kirsch Danielle R. , Towner Mary C. 
Published: July 2021

AbstractHumans are able to thrive in a multitude of ecological and social environments, including varied environments over an individual lifetime. Migration—leaving one place of residence for another—is a central feature of many people's life histories, and environmental change goes hand‐in‐hand with migration, both in terms of cause and consequence. Climate change has amplified this connection between environment and migration, with the potential to profoundly impact millions of lives. Although climate‐induced migration has been at the forefront of other disciplines in the social sciences, evolutionary anthropologists (EAs) have given it little attention. In this paper we draw upon existing literature and contribute our EA perspective to present a framework for analyzing climate‐induced migration that utilizes theoretical approaches from a variety of social science disciplines. We focus on three overlapping dimensions—time, space, and severity—relevant to understanding the impact of climate change on human migration. We apply this framework to case studies from North America of people impacted by climate change and extreme weather events, including hurricanes, droughts, rising sea‐levels, and wildfires. We also consider how access to both economic and social resources influence decisions regarding migration. Research focused on climate‐induced human migration can benefit equally from the addition of EA perspectives and a more interdisciplinary theoretical approach.
Effects of reinforcements and gamma‐irradiation on wear performance of ultra‐high molecular weight polyethylene as acetabular cup liner in hip‐joint arthroplasty: A review
Authors: Nayak Chinmayee , Balani Kantesh 
Published: July 2021

AbstractImproving the wear resistance of ultra‐high molecular weight polyethylene (UHMWPE), the gold standard polymer for acetabular component in hip joint arthroplasty, is the most important challenge in joint arthroplasty. The possible ways that have been approached to this challenge are by: (i) engineering multi‐phase that is, both carbonaceous and noncarbonaceous fillers‐based polyethylene composites, which unite the inherent attributes of each element available in the system. The wear rate of carbonaceous composite is nearly 50% lower (5.11–6.69 × 10−5 mm3/Nm) than that of noncarbonaceous composite (10–12.5 × 10−5 mm3/Nm), thus, recognized as a potential reinforcement, and (ii) coupling gamma‐irradiation, which is a mandated sterilization process, with multi‐phase nanocomposite to understand the free radical‐scavenging effect of fillers and improved interfacial adhesion strength between fillers and matrix. After the exposure of gamma‐rays (50–100 kGy), the free radicals formed by bond breakage in both the reinforcements and the matrix recombine to form covalent/Van der Waals bond in the interface. Thus, dramatical improvement in wear resistance of both types of composites with 2–4 times decreased wear rate is observed compared to that of composites under un‐irradiated condition. However, enhancing the interfacial adhesion between two different phases is a major constraint in the design of UHMWPE composites. Many methods such as functionalization of reinforcements, and irradiation on functionalized UHMWPE composites that can be approached to address this constraint are documented in this review.
Engineering all‐aromatic polyamide surface from hydrophilic to superhydrophobic and the accelerated strategy
Authors: Lv Jing , Guo Longhai , Xie Chunjie , Xu Weitong , Ye Jun , Li Xiaoyu , Qiu Teng , Tuo Xinlin 
Published: July 2021

AbstractBeing a new kind of nanomaterials, aromatic polyamide nanofibers (ANF) have been much highlighted in recent studies. We here demonstrate an isopropyl alcohol (IPA) accelerated chemical cleavage on poly (p‐phenylene terephthalamide) chopped fibers, which provides an efficient preparation method of ANF. The comprehensive study on the processes accelerated by different alcohols revealed that the preparation time of ANF in the mixed medium of dimethyl sulfoxide (DMSO)‐alcohol (20:1 in volume) was shorten to 45 min and 75 min for methanol (ethanol) and isopropanol, respectively. However, the nanofibers prepared in DMSO‐IPA exhibited the minimum in axial and radial dimensions, providing the finest and most uniform diameter of 16 nm. The corresponding ANF films through vacuum assisted filtration also showed the highest tensile strength of 150 MPa, in comparison with those of the ANF films prepared using other alcohols, which were about 110 MPa. Furthermore, ANF/silicon hybrid films were prepared by the ionic ring‐opening reaction followed by the alkoxysilane condensation and nanoparticle fabrication. By changing the organo functional groups in the alkoxysilane, the surface of the films were adjustable in a wide contact angle range from 56° (hydrophilic) to 150° (superhydrophobic), suggesting the amendable interfacial properties potential applicable to composite fabrication with most of the resin matrix.
Alteration of unfolded protein responses and autophagy signaling represented the molecular basis underlying saccharin toxicity to Drosophila (Diptera: Drosophilidae)
Authors: Osabutey Angelina F. , Kim A‐Young , Seo Bo Yoon , Mai Linh Xuan , Koh Young Ho 
Published: July 2021

AbstractThe purpose of this study was to develop a new control method for Drosophila using saccharin sodium dihydrate (saccharin), an artificial sweetener that is safe for humans and the environment, and to elucidate its mode of action. In this study, we confirmed that saccharin can dose‐dependently inhibit the development of or kill vinegar flies (VFs) and spotted wing Drosophila (SWDs). In addition, we found that low concentrations of saccharin induced a similar effect as starvation in Drosophila, whereas high concentrations of saccharin induced changes in the unfolded protein response (UPR) and autophagy signaling that were unlike starvation and inhibited development or killed the VF and the SWD by performing real‐time quantitative polymerase chain reaction analyses. Spinosad is a widely used plant protection agent for SWD control. When saccharin was cotreated with 0.25–1.0 ppm spinosad, an additive insecticidal activity was observed only at high concentrations of saccharin. However, when saccharin was cotreated with 2.0 ppm spinosad, an additive insecticidal activity was observed at low concentrations of saccharin. Taken together, alteration of UPR and autophagy signaling represented the molecular basis underlying saccharin toxicity to Drosophila and concurrent spraying of an insecticide with saccharin could enhance the insecticidal activities.
New results on finite‐time stability of fractional‐order Cohen–Grossberg neural networks with time delays
Authors: Du Feifei , Lu Jun‐Guo 
Published: July 2021

AbstractThe finite‐time stability (FTS) of fractional‐order delayed Cohen–Grossberg neural networks (FODCGNNs) with the order ℘ ∈ (1, 2) is investigated in this study. Based on the fractional‐order delayed Gronwall inequality (FODGI), a new sufficient condition to guarantee the FTS of FODCGNNs is established, which reduces the conservation of the existing criterion. Finally, one numerical example is exhibited to illustrate the effectiveness and less conservativeness of the obtained results.
Understanding Community Water System Disinfection Practices in the United States
Authors: Gibson Mark C. , Bartrand Timothy A. 
Published: July 2021

Key TakeawaysA novel analysis was conducted of utility‐provided and US Environmental Protection Agency–collected data on disinfection practices for small, medium, large, and very large community water systems.The analysis includes a total of 3,823 systems across four size categories that collectively serve more than 217 million US customers.In the United States, chlorine‐based disinfectants are by far the most widely used for both centralized (primary) and residual (secondary) disinfection in the distribution system.
The effects of trait social anxiety on affective and behavioral reactions to others' resource allocations
Authors: Anderl Christine , Dorrough Angela R. , Rohrbeck Mariví , Glöckner Andreas 
Published: July 2021

AbstractMost studies investigating interindividual differences in the context of social decision making have focused on the decision maker. Considerably less empirical attention has been paid to interindividual differences in how recipients react both affectively and behaviorally. In two preregistered studies (total N = 667), we examined whether heightened levels of trait social anxiety are associated with higher levels of forecasted and experienced negative affective reactions in response to uneven resource allocations by an interaction partner in a dictator game and an ultimatum game as well as corresponding hypothetical and actual behavioral reactions. In accordance with our predictions, social anxiety levels correlated with negative affective reactions; these correlations were stronger the more unevenly the resources were allocated by the other individual. The observed effects remained robust when controlling for expectations and basic personality traits and across two different economic social decision‐making tasks. This suggests that social anxiety level is an important contributor to interpersonal differences in affective reactions to another individual's uneven resource allocations.
Determination of amoxicillin and cotrimoxazole concentrations in sputum of patients with cystic fibrosis
Authors: Tron Camille , Belleguic Chantal , Piau Caroline , Brinchault Graziella , Deneuville Eric , Ricordel Charles , Kayal Samer , Bellissant Eric , Verdier Marie‐Clémence , Lemaitre Florian 
Published: July 2021

AbstractIn the management of cystic fibrosis, treatments against Staphylococcus aureus and Haemophilus influenzae such as amoxicillin or cotrimoxazole have to be prescribed and the antibiotherapy's efficacy may be linked to the concentration that reaches the infected site. As cystic fibrosis patients present disturbed pharmacokinetics parameters, drug monitoring would be relevant to assess the lung distribution of antibiotics and to optimize dosing regimens. In this context, the aim of the study was to develop and validate HPLC‐based methods for the determination of both antibiotics in bronchial sputum from cystic fibrosis patients, in order to assess the distribution of the drugs into the lungs. Plasma proteins were precipitated by acetonitrile and amoxicillin concentrations in sputum were determined by HPLC coupled with tandem‐mass spectrometry. Following liquid extraction with ethyl acetate, cotrimoxazole was quantified by HPLC using ultraviolet detection. Both methods were rapid, specific, accurate and reproducible. The method was applied to patient samples. In three treated patients, concentrations of amoxicillin in sputum were similar and below the lower limit of quantification (0.1 μg/g) and in six patients, sputum concentrations up to 11.1 and 6.4 μg/g were measured for sulfamethoxazole and trimethoprim, respectively.
Activity of Fluorinated Curcuminoids against Leishmania major and Toxoplasma gondii Parasites
Authors: Khan Tariq A. , Koko Waleed S. , Al Nasr Ibrahim S. , Schobert Rainer , Biersack Bernhard 
Published: July 2021

AbstractA new 3,4‐difluorobenzylidene analog of curcumin, CDF, was recently reported, which demonstrated significantly enhanced bioavailability and in vivo anticancer activity compared with curcumin. For highlighting the antiparasitic behavior of CDF, we tested this compound together with its new O‐methylated analog MeCDF against Leishmania major and Toxoplasma gondii parasites. Both CDF and MeCDF were tested in vitro against L. major and T. gondii. In addition, the in vitro cytotoxicity against Vero cells and macrophages was determined and selectivity indices were calculated. The DPPH radical scavenging activity assay was carried out in order to determine the antioxidant activity of the test compounds. Both compounds showed high activities against both parasite forms with EC50 values in the (sub‐)micromolar range (0.35 to 0.8 μM for CDF, 0.31 to 1.2 μM for MeCDF). The higher activity of CDF against L. major amastigotes when compared with MeCDF can in parts be attributed to the antioxidant activity of CDF while MeCDF lacking any antioxidant activity was more active than CDF against T. gondii parasites. In conclusion, CDF and MeCDF are promising antiparasitic drug candidates due to their high activities against L. major and T. gondii parasites.
Membrane Functionalization in Pilot Scale: Roll‐to‐Roll Electron Beam System with Inline Contact Angle Determination
Authors: Schulze Agnes , Drößler Lutz , Weiß Steffen , Went Marco , Abdul Latif Amira , Breite Daniel , Fischer Kristina 
Published: July 2021

AbstractZur Steigerung von Permeationsleistung und Antifouling‐Eigenschaften von Polymermembranen wurde eine einstufige Reaktion mittels Elektronenbestrahlung entwickelt. Dieses Verfahren kombiniert die Oberflächenaktivierung des Membranpolymers und die simultane permanente Immobilisierung von hydrophilen Molekülen. Die Technologie kann auf verschiedene Polymere, Flachfilter‐/Hohlfaser‐Membranen sowie auf alle Porenbereiche angewendet werden. Das dafür entwickelte Rolle‐zu‐Rolle‐System ermöglicht alle Prozess‐Schritte inkl. Inline‐Analytik zur Qualitätskontrolle der Membranoberfläche in einer kontinuierlich betriebenen Anlage.