bluuebunny/crossref_metadata_2025_split huggingface dataset:
A personalized, Monte Carlo‐based method for internal dosimetric evaluation of radiopharmaceuticals in children
Authors: Papadimitroulas Panagiotis , Erwin William D. , Iliadou Vasiliki , Kostou Theodora , Loudos George , Kagadis George C. 
Published: June 2018

PurposeHerein, we introduce a methodology for estimating the absorbed dose in organs at risk that is based on specified clinically derived radiopharmaceutical biodistributions and personalized anatomical characteristics.MethodsTo evaluate the proposed methodology, we used realistic Monte Carlo (MC) simulations and computational pediatric models to calculate a parameter called in this work the “specific absorbed dose rate” (SADR). TheSADRis a unique quantitative metric in that it is specific to a particular organ. It is defined as the absorbed dose rate in an organ when the biodistribution of radioactivity over the whole body is considered. Initially, we applied a validation procedure that calculated specific absorbed fractions (SAFs) from mono‐energetic photon sources in the range of 10 keV–2 MeV and compared them with previously published data. We calculated theSADRs for five different radiopharmaceuticals (99mTc‐MDP,123I‐mIBG,131I‐MIBG,131I‐NaI, and153Sm‐EDTMP) based on their biodistributions at four or five different times; the biodistributions were derived from the clinical scintigraphic data of pediatric patients. We used six models representing male and female patients aged 5, 8, and 14 yr to investigate the absorbed dose variability due to anatomical variations. TheGATEMonte Carlo toolkit was used to calculate absorbed doses per organ. Finally, we compared theSADRmethodology to that ofOLINDA/EXM1.1 using rescaled masses according to the studied models. Four target organs were considered for calculating the absorbed doses.ResultsThe ratios ofSAFs calculated withGATEsimulations to those based on previously published data were between 0.9 and 2.2 when the liver was used as a source organ. Subsequently, we usedGATEto calculate a dataset ofSADRs for the six pediatric models. TheSADRs for pediatric models whose total body weights ranged from 20 to 40 kg varied up to approximately 90%, whereas those for models of similar body masses varied less than 15%. Finally, we found absorbed dose discrepancies of approximately 10–150% between theSADRmethodology andOLINDAfor two different radiopharmaceuticals. Absorbed doses fromSADRs and from individualized S‐values in the same pediatric model differed approximately 1–50%.ConclusionsBecause pediatric radiopharmaceutical dosimetric estimates demonstrate large variation due to the patient's anatomical characteristics, personalized data should be considered. Using ourSADRmethod in a larger population of phantoms and for a variety of radiopharmaceuticals could enhance the personalization of dosimetry in pediatric nuclear medicine. The proposed methodology provides the advantage of creating time‐dependent organ dose rate curves.
Climate change exacerbates pest damage through reduced pesticide efficacy
Authors: Matzrafi Maor 
Published: June 2018

AbstractPesticide efficacy is strongly associated with environmental conditions. Conditional resistance defined as a reduction in pesticide sensitivity under changed environmental conditions has been widely detected under climatic changes such as elevated temperatures and CO2 enrichment. Given the effects of environmental conditions on pesticide sensitivity, many of the putative resistance reports made by farmers may be due to pesticide application followed by non‐optimal environmental conditions rather than the evolution of resistance. This type of conditional resistance may be the result of phenotypic plasticity or epigenetic changes in response to environmental changes. Elevated temperatures and CO2 enrichment can directly lead to reduced pesticide efficacy by altering pesticide metabolism and translocation, or indirectly increasing pesticide detoxification in host‐plants thus reducing pesticide availability for the target pest. Stress‐related signal transduction pathways, as well as physiological changes, can both be associated with accelerated pesticide detoxification under climatic changes. The possibility for parallel mechanisms controlling these responses in different pest species should be considered. It is proposed that the same mechanisms leading to non‐target site resistance in pests may also play a role in conditional resistance, suggesting we can predict the pesticides to which pests are likely to be less responsive under changing climatic conditions. Using adjuvants to improve pesticide translocation or reduce pesticide metabolism, alongside with new technologies such as using nanoparticles may result in higher pesticide functionality under the projected climate change. Exploring the physiological, transcriptional and biochemical basis underlying conditional resistance is crucial in maintaining future pest management under changing environmental conditions. © 2018 Society of Chemical Industry
What initiates, what postpones return migration intention? The case of Turkish immigrants residing in Germany
Authors: Tezcan Tolga 
Published: June 2018

AbstractThis study endeavours to identify the determinants of return migration intentions of Turks living in Germany. The decision‐making patterns of potential return migrants are examined by seeking to answer three main research questions: (a) what are the main factors that push Turkish immigrants to consider return migration? (b) What are the main challenges postponing or promoting hesitation in the return decision? (c) what strategies are adopted to overcome those challenges? I conducted in‐depth interviews with 20 Turks living in Germany. Findings show that return migration intentions are associated with economic conditions, stigmatisation in both countries, social networks, commitment to the homeland, and perceived discriminatory attitudes. This study provides evidence that return migration intentions are formed through complex decision‐making processes based on economic and noneconomic factors. Although these factors may cause hesitation or postpone plans to return, all detected challenges were managed through specific coping strategies.
On hierarchical modulation for satellite broadcasting
Authors: Kayhan F. , Montorsi G. , Taricco G. , Alagha N. 
Published: June 2018

SummaryThis paper presents a comparative assessment of 2 multiplexing techniques for providing differentiated classes of services over a realistic broadcasting satellite channel under variable link conditions. A distinctive property of satellite broadcasting channels is the nonlinear characteristics of high power amplifier on‐board of the satellite. Hence, the conventional additive white Gaussian noise channel with average power limitation is no longer an accurate model, and nonlinear characteristics have to be taken into account. In this paper, we compare the performance of time division multiplexing techniques combined with variable coding and modulation with that of hierarchical modulations delivering contents with 2 (or more) differentiated service qualities. The goal is to maximize the throughput over a given transponder while maintaining a target service availability. We design a practical transmitter scheme based on the hierarchical modulation and maximize the throughput by optimizing the achievable mutual information for finite size constellations. This optimization is done for additive white Gaussian noise channel with both average and peak power limit and will provide a lower bound on throughput, which can be achieved by nonorthogonal multiplexing scheme. The results indicate that the gains obtained by nonorthogonal multiplexing is significant only if the required signal to noise threshold for 2 services differ by more than 10 dB. Finally, we provide the bit error ratio simulation results for some selected scenarios.
Condition‐Based Selective Synthesis of 3,4,5‐Trisubstituted Isoxazoline N‐oxides, 4,5‐Dihydroisoxazoles and Isoxazoles
Authors: Chen Xinfei , Peng Yanqing , Yu Weiwei , Zhang Xiao , Shao Xusheng , Xu Xiaoyong , Li Zhong 
Published: June 2018

AbstractFunctionalized isoxazoline N‐oxides, 4,5‐dihydroisoxazoles and isoxazoles have attracted considerable attention because of their wide applications. Starting from 1,1‐dimethoxy‐2‐nitroethene and aldehydes, a cascade approach to these heterocycles was explored to achieve structural diversity controlled by different reaction conditions. Furthermore, this new protocol provided a direct access to 4‐substituted‐3,5‐bis(methoxycarbonyl)‐4,5‐dihydroisoxazoles from aromatic aldehydes for the first time.
Immobilization of Small‐Molecule Ligands Containing Secondary or Tertiary Amine Groups onto TiO2‐Supported Ru Catalysts Driven by the Hydrophobic Effect
Authors: Chen Tianyou , Xu Zushun 
Published: June 2018

AbstractA strategy for effectively immobilizing small‐molecule ligands onto TiO2‐supported Ru catalysts is described. The immobilization was based on a simple two‐phase centrifugation technique and driven by the hydrophobic effect, likely leading to the formation of hydrophobic clusters of small‐molecule ligands. By using this strategy, a library of ligands containing secondary or tertiary amine groups and hydrophobic chains were successfully immobilized onto TiO2‐supported Ru catalysts. Of these ligands, ligands containing 2,2,6,6‐tetramethyl‐1‐piperidine‐N‐oxyl (TEMPO) moieties significantly improved the selectivity for aldehyde at high conversion in aerobic oxidation of alcohols, resulting from the inhibition of auto‐oxidation of aldehydes. This strategy can generate diversity in preparation of organic/inorganic hybrid catalysts.
Mechanical Tuning of Through‐Molecule Conductance in a Conjugated Calix[4]pyrrole
Authors: Stefani Davide , Perrin Mickael , Gutiérrez‐Cerón Cristian , Aragonès Albert C. , Labra‐Muñoz Jacqueline , Carrasco Rodrigo D. C. , Matsushita Yoshitaka , Futera Zdenek , Labuta Jan , Ngo Thien H. , Ariga Katsuhiko , Díez‐Pérez Ismael , van der Zant Herre S. J. , Dulić Diana , Hill Jonathan P. 
Published: June 2018

AbstractA conformationally flexible calix[4]pyrrole possessing a conjugated electronic structure (an N‐substituted oxoporphyrinogen (OxP) related to porphyrin) was used to investigate the influence of mechanical stretching on the single‐molecule conductance of these molecules using the mechanically‐controlled break junction (MCBJ) technique. The results show that the molecule can be immobilized in a single‐molecule break junction configuration, giving rise to different behaviours. These include step‐like features in the conductance vs. displacement traces as well as conductance traces that exhibit a slower decay (‘downhill’ traces) than measured for direct tunneling. The latter class of traces can be associated with the mechanical manipulation (i. e., stretching) of the molecule with inter‐electrode distances as long as 2 nm. Density functional theory (DFT) calculations reveal that OxP molecules are stable under stretching in the length regime studied.
Mesoporous Sn‐TiO2 Catalysts by Molecular Protection Strategy for the Baeyer‐Villiger Oxidation of Cyclohexanone with Molecular Oxygen
Authors: Liu Zhirui , Zhou Zhiwei , Qin Juan , Liu Guang , Huang Hao , Wu Wenliang 
Published: June 2018

AbstractIn order to improve the catalytic performance of tin‐doped samples in the Baeyer‐Villiger oxidation of cyclohexanone with molecular oxygen as oxidant, the mesoporous Sn‐TiO2 catalysts with more incorporation of tin species were successfully prepared via a simple vapor‐phase self‐assembly method followed by molecular protection strategy treated with ethylenediamine solution. The physical and chemical properties of these prepared samples can be characterized by different methods including XRD, N2 sorption, Raman, ICP, UV‐vis DRS, pyridine‐adsorbed IR, SEM and TEM. The characterization results indicated that the ethylenediamine can protect the ordered mesopores of anatase TiO2, which would be beneficial to the more tetrahedrally homogeneous incorporation of tin species resulting in the promotion of Lewis acidity. The ordered mesoporous 18Sn‐TiO2‐EN catalyst with highest surface areas, pore volume and appropriate Lewis acidity showed the highest catalytic performance, whose cyclohexanone conversion, caprolactone selectivity and TON value were up to 94.1%, 95.2% and 3.7, respectively, and it showed good catalytic stability.
Effect of Molecular Crowding Agents on the Activity and Stability of Immunosuppressive Enzyme Indoleamine 2,3‐Dioxygenase 1
Authors: Roy Ashalata , Das Sreeparna , Manna Debasis 
Published: June 2018

AbstractIndoleamine 2,3‐dioxygenase 1 (IDO1) plays pivotal role in regulating the metabolism of L‐tryptophan (L‐Trp) through kynurenine pathway, which is a well‐established therapeutic target for the treatment of diseases associated with immunosuppression. Disproportionate expression of the enzyme and poor prediction of various types of malignancies make the development and clinical trials of IDO1 inhibitors extremely relevant. However, IDO1‐based drug development has been hindered due to the use of idealized dilute buffer solution media during the screening and optimization of inhibitors, which do not reflect the highly crowded intracellular environment. In this report, IDO1 enzyme activity and its inhibitory activity against few potent compounds of N′‐hydroxyamidine and aryl‐substituted pyran scaffolds were investigated under macromolecularly crowded environment. The synthetic crowding agents were used to generate a cellular mimetic condition where IDO1 enzyme was found to retain its activity. A non‐linear relationship between the size and volume of the crowding agent with enzyme kinetic parameters was observed. The results suggest that judicious use of size and volume of the crowding agent could provide cellular mimetic environment. A very similar catalytic efficiency, inhibitory activity along with preservation of secondary structural content of IDO1 enzyme under the selected crowded media makes these crowding agents appropriate for further therapeutic application.
Design and Integration of Molecular‐Type Catalysts in Fuel‐Cell Technology
Authors: Jose Vishal , Elouarzaki Kamal , Fisher Adrian C. , Lee Jong‐Min 
Published: June 2018

AbstractThe field of molecular electrocatalysis research includes a wide range of emerging technologies that utilize molecular catalysts to catalyze anodic and/or cathodic reactions within a fuel‐cell setup, and has developed greatly in the last 10 years. Although the vast majority of fuel cells utilize noble metals as catalysts, several systems have been recently developed that are based on molecular catalysts. The focus here is on the integration of molecular catalysts in a fuel‐cell setup, which is contextualized, and which is named as “fuel‐cell‐based molecular‐type catalysts” here. The latter utilize a wide variety of chemical compounds, such as organometallics and organic or bioinspired compounds, to harvest chemical energy to generate current. Here, the state‐of‐the‐art for all molecular catalysts that convert chemical energy in a fuel‐cell setup is discussed and a novel classification system is presented to illustrate how molecular catalysts integrate into the broad field of fuel cells. The current performance of molecular catalysts in systems that use different fuels is summarized, and finally, for the first time, the achievable power outputs of fuel cells using uniquely molecular catalysts are presented.
Reproductive Performance and Energy Balance in Consecutive and Skip Repeat Spawning Female Steelhead Reconditioned in Captivity
Authors: Jenkins Laura E. , Pierce Andrew L. , Graham Neil , Branstetter Ryan , Hatch Douglas R. , Nagler James J. 
Published: June 2018

AbstractSteelhead Oncorhynchus mykiss are known for their life history diversity, displaying a range of freshwater residence ages, maturation ages, and spawning intervals. Female maturation is thought to be condition dependent at critical periods, during which individuals falling below energetic thresholds remain reproductively inactive for the subsequent annual cycle. After their initial, or maiden, spawning, females may enter into another maturation cycle and spawn after 1 year (consecutive spawners) or 2 years (skip spawners). The purpose of this study was to quantify reproductive performance in maiden, consecutive, and skip spawning female steelhead, which differ in their energy availability schedules during ovarian development, in order to quantify the benefits that can be expected from kelt reconditioning programs. Hatchery origin female steelhead returning to Dworshak National Fish Hatchery for their maiden spawning (Clearwater River, Idaho, 2013–2016) were manually spawned, placed in tanks, and reconditioned. Size (somatic mass, FL) and reproductive performance (total, individual, and dry egg mass, fecundity, and fertilization success) were measured, and spawn date fidelity was determined. Repeat spawners had greater mass, length, and mass at length than did maiden spawners. In absolute terms, skip spawners had greater total, individual, and dry egg mass than maiden and consecutive spawners, and both consecutive and skip spawners had greater fecundity than did maiden spawners. When standardized for size, skip spawners had greater total, individual, and dry egg mass than maiden and consecutive spawners; size‐standardized consecutive spawners had lower individual egg mass than maiden spawners but higher fecundity. Our results suggest that egg size and reproductive investment are determined early in oogenesis based on an assessment of energy reserves, and do not increase when excess energy is available during the vitellogenic period of oogenesis. Instead, excess energy during the vitellogenic period is allocated to somatic growth. Increases in fecundity and egg size suggest that reconditioned kelts released to spawn naturally will be more productive than maiden spawners.
Predictive accuracy of cerebroplacental ratio for adverse perinatal and neurodevelopmental outcomes in suspected fetal growth restriction: systematic review and meta‐analysis
Authors: Conde‐Agudelo A. , Villar J. , Kennedy S. H. , Papageorghiou A. T. 
Published: June 2018

ABSTRACTObjectiveThe cerebroplacental ratio (CPR) has been proposed for the routine surveillance of pregnancies with suspected fetal growth restriction (FGR), but the predictive performance of this test is unclear. The aim of this study was to determine the accuracy of CPR for predicting adverse perinatal and neurodevelopmental outcomes in suspected FGR.MethodsPubMed, EMBASE, CINAHL and Lilacs were searched from inception to 31 July 2017 for cohort or cross‐sectional studies reporting on the accuracy of CPR for predicting adverse perinatal and/or neurodevelopmental outcomes in singleton pregnancies with FGR suspected antenatally based on sonographic parameters. Summary receiver–operating characteristics (ROC) curves, pooled sensitivities and specificities, and summary likelihood ratios (LRs) were generated.ResultsTwenty‐two studies (including 4301 women) met the inclusion criteria. Summary ROC curves showed that the best predictive accuracy of CPR was for perinatal death and the worst was for neonatal acidosis, with areas under the summary ROC curves of 0.83 and 0.57, respectively. The predictive accuracy of CPR was moderate to high for perinatal death (pooled sensitivity and specificity of 93% and 76%, respectively, and summary positive and negative LRs of 3.9 and 0.09, respectively) and low for composite of adverse perinatal outcomes, Cesarean section for non‐reassuring fetal status, 5‐min Apgar score < 7, admission to the neonatal intensive care unit, neonatal acidosis and neonatal morbidity, with summary positive and negative LRs ranging from 1.1 to 2.5 and 0.3 to 0.9, respectively. An abnormal CPR result had moderate accuracy for predicting small‐for‐gestational age at birth (summary positive LR of 7.4). CPR had a higher predictive accuracy in pregnancies with suspected early‐onset FGR. No study provided data for assessing the predictive accuracy of CPR for adverse neurodevelopmental outcome.ConclusionCPR appears to be useful in predicting perinatal death in pregnancies with suspected FGR. Nevertheless, before incorporating CPR into the routine clinical management of suspected FGR, randomized controlled trials should assess whether the use of CPR reduces perinatal death or other adverse perinatal outcomes. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.
Prediction of preterm delivery in symptomatic women using PAMG‐1, fetal fibronectin and phIGFBP‐1 tests: systematic review and meta‐analysis
Authors: Melchor J. C. , Khalil A. , Wing D. , Schleussner E. , Surbek D. 
Published: June 2018

ABSTRACTObjectiveTo assess the accuracy of placental alpha microglobulin‐1 (PAMG‐1), fetal fibronectin (fFN) and phosphorylated insulin‐like growth factor‐binding protein‐1 (phIGFBP‐1) tests in predicting spontaneous preterm birth (sPTB) within 7 days of testing in women with symptoms of preterm labor, through a systematic review and meta‐analysis of the literature. The test performance of each biomarker was also assessed according to pretest probability of sPTB ≤ 7 days.MethodsThe Cochrane, MEDLINE, PubMed and ResearchGate bibliographic databases were searched from inception until October 2017. Cohort studies that reported on the predictive accuracy of PAMG‐1, fFN and phIGFBP‐1 for the prediction of sPTB within 7 days of testing in women with symptoms of preterm labor were included. Summary receiver–operating characteristics (ROC) curves and sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and positive (LR+) and negative (LR–) likelihood ratios were generated using indirect methods for the calculation of pooled effect sizes with a bivariate linear mixed model for the logit of sensitivity and specificity, with each diagnostic test as a covariate, as described by the Cochrane Handbook for Systematic Reviews of Diagnostic Test Accuracy.ResultsBivariate mixed model pooled sensitivity of PAMG‐1, fFN and phIGFBP‐1 for the prediction of sPTB ≤ 7 days was 76% (95% CI, 57–89%), 58% (95% CI, 47–68%) and 93% (95% CI, 88–96%), respectively; pooled specificity was 97% (95% CI, 95–98%), 84% (95% CI, 81–87%) and 76% (95% CI, 70–80%) respectively; pooled PPV was 76.3% (95% CI, 69–84%) (P < 0.05), 34.1% (95% CI, 29–39%) and 35.2% (95% CI, 31–40%), respectively; pooled NPV was 96.6% (95% CI, 94–99%), 93.3% (95% CI, 92–95%) and 98.7% (95% CI, 98–99%), respectively; pooled LR+ was 22.51 (95% CI, 15.09–33.60) (P < 0.05), 3.63 (95% CI, 2.93–4.50) and 3.80 (95% CI, 3.11–4.66), respectively; and pooled LR– was 0.24 (95% CI, 0.12–0.48) (P < 0.05), 0.50 (95% CI, 0.39–0.64) and 0.09 (95% CI, 0.05–0.16), respectively. The areas under the ROC curves for PAMG‐1, fFN and phIGFBP‐1 for sPTB ≤ 7 days were 0.961, 0.874 and 0.801, respectively.ConclusionsIn the prediction of sPTB within 7 days of testing in women with signs and symptoms of preterm labor, the PPV of PAMG‐1 was significantly higher than that of phIGFBP‐1 or fFN. Other diagnostic accuracy measures did not differ between the three biomarker tests. As prevalence affects the predictive performance of a diagnostic test, use of a highly specific assay for a lower‐prevalence syndrome such as sPTB may optimize management. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.