Potential Interference Effects Research Articles

Short-term interference in learning ballistic motor tasks: Refining the notion of specificity

Introduction Learning of an isometric ballistic force task (BT) can be impaired if it is followed by the learning of a visuomotor accuracy task (VMT) involving isometric contractions of the same muscles (Lundbye-Jensen et al., 2011). This phenomenon, known as retrograde interference, is thought to occur because the memory trace created after learning the BT is affected by the activation of similar neural circuits involved in the VMT (Lundbye-Jensen et al., 2011). However, it remains unclear how the contraction type involved in the two motor tasks influences potential interference effects. The aim of this study was therefore to compare the influence of a VMT involving dynamic position control or isometric force control on short-term retrograde interference in a previously learned isometric BT involving the same muscles. Methods 45 participants were randomly assigned to one of 3 groups. Participants started by learning an isometric BT involving the wrist flexors of the non-dominant hand. Participants in the first two groups then learned a VMT involving dynamic (VMTDynamic group) or isometric (VMTIsometric group) contractions of the same muscles, while participants in the third group took a break (control group). Finally, participants completed the BT retention test. Each BT training consisted of 35 trials in which participants were asked to achieve the highest rate of force development (RFDmax). The VMT training consisted of 50 trials in which participants were asked to follow a curve with a cursor. Position of the cursor was linked to the wrist flexion/extension angle (VMTDynamic) or the isometric force produced (VMTIsometric). Interference was quantified by comparing RFDmax between the end of the initial training (POST) and the start of the retention test (RET). Results A mixed design ANOVA revealed a significant interaction effect (F(2, 40) = 3.87, p = 0.029). Post hoc corrected paired t-tests showed a significant decrease in RFDmax for the VMTIsometric group between POST (2,524 ± 1,144 N/s) and RET (1,960 ± 921 N/s). In contrast, performance of the other two groups did not change (VMTDynamic group: 2,679 ± 1,321 vs. 2,499 ± 1,278 N/s; control group: 2,489 ± 1,005 vs. 2,334 ± 1,013 N/s). Discussion/Conclusion Interference was only observed in the VMTIsometric group, suggesting that the same type of contraction must be involved in the VMT and BT for short-term retrograde interference to occur. It is known that the neural control of isometric contractions is different from dynamic contractions (Duchateau & Enoka, 2016). It can therefore be speculated that the resulting reduction in neural competition between the motor tasks was sufficient to prevent interference in the VMTDynamic group. In conclusion, for retrograde interference to occur, not only must the same muscles be involved in both motor tasks, but they must also perform the same type of contraction.

Maximal and submaximal intended velocity squat sets: Do they selectively impact mechanical performance in paired multijoint upper‐body exercise sets?

AbstractThis study aimed to investigate how squat protocols performed at maximal and submaximal intended velocities during interset periods of paired upper‐body exercises that impact the mechanical performance of these multijoint upper‐body exercises. Twenty‐one young and healthy adults (seven women) completed three experimental sessions, each comprising four sets of five repetitions at 75% of their 1‐repetition maximum, with a 4‐min break between sets using the bench press and bench pull exercises. The experimental sessions differed in the protocol utilized during the interset periods: (i) Passive—no physical exercise was performed; (ii) SQfast—5 repetitions of the squat exercise at maximal intended velocity against the load associated with a mean velocity (MV) of 0.75 m s−1; and (iii) SQslow—5 repetitions of the squat exercise at submaximal velocity (intended MV of 0.50 m s−1) against the load associated with an MV of 0.75 m s−1. Level of significance was p ≤ 0.05. The main findings revealed negligible differences (effect size [ES] < 0.20) among the exercise protocols (passive vs. SQfast vs. SQslow) for all mechanical variables during the bench pull, whereas during the bench press, small differences (ES from 0.23 to 0.31) emerged favoring the passive protocol over SQfast and SQslow in terms of mean set velocity and fastest MV of the set. The absence of significant differences between the SQfast and SQslow protocols, irrespective of the particular upper‐body exercise, implies that the intended lifting velocity does not influence the potential interference effect during paired set training procedures.

Innovations in HbA1c analysis: finding the balance between speed and accuracy. An investigation of a potential new Secondary Reference Measurement Procedure for the IFCC.

The escalating prevalence of diabetes worldwide has resulted in a dramatic increase in the number of people who need testing, which in turn necessitates faster HbA1c measurement. The Tosoh GR01 addresses the need for fast turnaround times of whilst offering pragmatic steps to maintain result accuracy in a single instrument by offering two distinct operating modes: Short Mode (SM) and Long Mode (LM). The aim of this study was to evaluate all relevant aspects of the performance of the Tosoh GR01 with a view to accepting the instrument as a future Secondary Reference Measurement Procedure (SRMP) for the IFCC. Certified Clinical & Laboratory Standards Institute (CLSI) Evaluation Protocols (EP) were used to evaluate precision (EP-5), accuracy (EP-9), linearity (EP-6), carry-over (EP-10) and the effect of hemoglobin variants and other potential interferences. Both modes demonstrated CVs <0.6 % in SI units and <0.4 % in NGSP units at 46 mmol/mol (6.4 %) and 75 mmol/mol (9.0 %) and passed both National Glycohemoglobin Standardization Program (NGSP) and International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) certification procedures when compared with 7 IFCC Certified Secondary Reference Measurement Procedures (SRMP). Sigma for both modes was >6 when using the results of EP-5 and EP-9 at an HbA1c concentration of 50 mmol/mol (6.7 %). Neither mode showed any interference with common Hb-variants except for HbAE when HbA1c was >65 mmol/mol. In the SM HbAS, HbAD and HbAC were recognized but no result was reported. There is a good balance between speed and accuracy for determining HbA1c with the Tosoh GR01 in both analytical modes and the device is suitable for use as an IFCC SRMP.

Benchmarking Heterogeneous Photocatalysts for the Nitrogen Reduction Reaction

Ammonia is the key ingredient for living organisms, and artificial catalytic synthesis of ammonia (known as the Haber-Bosch process) is undoubtedly a milestone in scientific research in the 20th century and the cornerstone of today's society.[1] However, the Haber-Bosch process is energy-intensive (2% of the global energy consumption) and is accompanied by large CO2 emissions (1% of global CO2 emission).[2] To catch up with the goal of “Net Zero CO2 Emissions” by 2050, it is imperative to develop a carbon-free and sustainable ammonia production process. The photocatalytic ammonia synthesis method relies only on renewable feedstocks (water and air) and sustainable energy input (light) and can be operated under ambient conditions. The current progress in photocatalytic ammonia synthesis suggests, however, there exists a large gap in performance before commercial use is viable. To replace the Haber-Bosch process and produce commercial fertilizer, the solar-to-ammonia (STA) efficiency needs to be at least 0.1% and the highest reported efficiency carried out in a lab setting is approaching 0.04%[2][3] With advances in measurement techniques, recent studies in the field of electrocatalytic ammonia synthesis have shown that many reported highly active catalysts have later been shown to be inactive toward nitrogen reduction.[4] This false positive result is mainly due to the adventitious ammonia in the environment. A series of discussions were triggered, including identifying and eliminating contaminations, developing robust measurements for low-concentration ammonia detection, and establishing rigorous testing protocols.[4-7] At present, the ammonia yield of electrocatalysis is at least an order of magnitude higher than that of photocatalysis, so the problem of nitrogen contamination will only be more serious in the field of photocatalysis.[7] Unfortunately, such discussions have not received equal attention in this field, and few if any rigorous testing protocols have been employed in existing reports.It is imperative to benchmark and develop a robust testing protocol for the growing field of photocatalytic ammonia synthesis. Here, we developed a rigorous setup to suppress all known ammonia contaminations (e.g., ammonia and NOx), systematically discussed the effect of various gas pretreatment methods, and established the background contamination level in the system. We synthesized three highly active photocatalytic materials (Fe-BiOBr, OVs-TiO2, and Fe2O3/g-C3N4) from the literature and measured their ammonia yield using the setup with strict controls.[8-10] To avoid potential interference effects during the measurements, we cross-compared different ammonia-detecting methods (Indophenol blue method and ion chromatography).[6] In addition, we applied isotope labeling with quantitative NMR to confirm the genuine production of photo-fixed ammonia. Going a step further, we methodically compare the effects of two experimental parameters (temperature and gas flow rate) on the performance of photocatalytic ammonia synthesis. These parameters vary greatly across reports, making it difficult to objectively analyze their impacts on the production of photo-fixed ammonia. Based on our findings, we aim to provide a solid benchmark for this burgeoning field and draw more attention to the importance of rigorous testing. Reference: Smil, Vaclav. Enriching the earth: Fritz Haber, Carl Bosch, and the transformation of world food production. MIT press, 2004.Medford, Andrew J., and Marta C. Hatzell. "Photon-driven nitrogen fixation: current progress, thermodynamic considerations, and future outlook." Acs Catalysis4 (2017): 2624-2643.Yuan, Jili, et al. "Efficient Photocatalytic Nitrogen Fixation: Enhanced Polarization, Activation, and Cleavage by Asymmetrical Electron Donation to N N Bond." Advanced Functional Materials4 (2020): 1906983.Andersen, Suzanne Z., et al. "A rigorous electrochemical ammonia synthesis protocol with quantitative isotope measurements." Nature7762 (2019): 504-508.Choi, Jaecheol, et al. "Identification and elimination of false positives in electrochemical nitrogen reduction studies." Nature communications1 (2020): 1-10.Zhao, Yunxuan, et al. "Ammonia detection methods in photocatalytic and electrocatalytic experiments: how to improve the reliability of NH3 production rates?." Advanced Science8 (2019): 1802109.Iriawan, Haldrian, et al. "Methods for nitrogen activation by reduction and oxidation." Nature Reviews Methods Primers1 (2021): 1-26.Liu, Yang, Zhuofeng Hu, and Jimmy C. Yu. "Fe enhanced visible-light-driven nitrogen fixation on BiOBr nanosheets." Chemistry of Materials4 (2020): 1488-1494.Zhang, Guoqiang, et al. "Constructing a tunable defect structure in TiO 2 for photocatalytic nitrogen fixation." Journal of Materials Chemistry A1 (2020): 334-341.Mou, Hongyu, et al. "A one-step deep eutectic solvent assisted synthesis of carbon nitride/metal oxide composites for photocatalytic nitrogen fixation." Journal of materials chemistry A10 (2019): 5719-5725.

Pre-coronavirus disease 2019 brain structure might be associated with social anxiety alterations during the pandemic.

Pre-coronavirus disease 2019 brain structure might be associated with social anxiety alterations during the pandemic.

Effects of gestational inflammation on age-related cognitive decline and hippocampal Gdnf-GFRα1 levels in F1 and F2 generations of CD-1 Mice

BackgroundIt has been reported that age-associated cognitive decline (AACD) accelerated by maternal lipopolysaccharide (LPS) insult during late pregnancy can be transmitted to the second generation in a sex-specificity manner. In turn, recent studies indicated that glial cell line‐derived neurotrophic factor (GDNF) and its cognate receptor (GFRα1) are critical for normal cognitive function. Based on this evidence, we aimed to explore whether Gdnf-GFRα1 expression contributes to cognitive decline in the F1 and F2 generations of mouse dams exposed to lipopolysaccharide (LPS) during late gestation, and to evaluate also the potential interference effect of pro-inflammatory cytokines.MethodsDuring gestational days 15–17, pregnant CD-1 mice (8–10 weeks old) received a daily intraperitoneal injection of LPS (50 μg/kg) or saline (control). In utero LPS-exposed F1 generation mice were selectively mated to produce F2 generation mice. In F1 and F2 mice aged 3 and 15 months, the Morris water maze (MWM) was used to evaluated the spatial learning and memory ability, the western blotting and RT-PCR were used for analyses of hippocampal Gdnf and GFRα1 expression, and ELISA was used to analyse IL-1β, IL-6 and TNF-α levels in serum.ResultsMiddle-aged F1 offspring from LPS-treated mothers exhibited longer swimming latency and distance during the learning phase, lower percentage swimming time and distance in targe quadrant during memory phase, and lower hippocampal levels of Gdnf and GFRα1 gene products compared to age-matched controls. Similarly, the middle-aged F2 offspring from the Parents-LPS group had longer swimming latency and distance in the learning phase, and lower percentage swimming time and distance in memory phase than the F2-CON group. Moreover, the 3-month-old Parents-LPS and 15-month-old Parents- and Father-LPS groups had lower GDNF and GFRα1 protein and mRNAs levels compared to the age-matched F2-CON group. Furthermore, hippocampal levels of Gdnf and GFRα1 were correlated with impaired cognitive performance in the Morris water maze after controlling for circulating pro-inflammatory cytokine levels.ConclusionsOur findings indicate that accelerated AACD by maternal LPS exposure can be transmitted across at least two generations through declined Gdnf and GFRα1 expression, mainly via paternal linage.

Simultaneous and enantiospecific quantification of primaquine and carboxyprimaquine in human plasma using liquid chromatography-tandem mass spectrometry

BackgroundThe enantiomers of the 8-aminoquinoline anti-malarial primaquine have different pharmacological properties. Development of an analytical method for simultaneous quantification of the enantiomers of primaquine and its metabolite, carboxyprimaquine, will support clinical pharmacometric assessments.MethodsA simple and sensitive method consisting of liquid chromatography coupled with tandem mass spectrometry (LC–MS/MS) was developed for simultaneous and enantiospecific determination of primaquine and its metabolite, carboxyprimaquine, in human plasma. Stable isotopes were used as internal standards to compensate for potential interference and matrix effects. Plasma samples (100 µL) were precipitated with 1% formic acid in acetonitrile followed by phospholipid removal solid phase extraction. Primaquine and carboxyprimaquine enantiomers were separated on a Chiralcel OD-3R (150 mm × 4.6 mm; I.D. 3 μm) column using a LC gradient mode. For separation of racemic primaquine and carboxyprimaquine, the LC method was modified and validated using a reverse phase column (Hypersil Gold 100 mm × 4.6 mm; I.D. 3 µm) and a mobile phase composed of 10 mM ammonium acetate buffer, pH 3.5 and acetonitrile in the isocratic mode. Method validation was performed according to regulatory guidelines.ResultsThe calibration range was set to 0.571–260 ng/mL and 2.44–2,500 ng/mL for primaquine and carboxyprimaquine enantiomers, respectively, resulting in a correlation coefficient (r2) ≥ 0.0998 for all calibration curves. The intra- and inter-day assay precisions were < 10% and the accuracy was between 94.7 to 103% for all enantiomers of primaquine and carboxyprimaquine. The enantiospecific method was also modified and validated to quantify racemic primaquine and carboxyprimaquine, reducing the total run time from 30 to 8 min. The inter-, intra-day assay precision of the racemic quantification method was < 15%. The absolute recoveries of primaquine and carboxyprimaquine were between 70 and 80%. Stability was demonstrated for up to 2 years in − 80 °C. Both the enantiomeric and racemic LC–MS/MS methods were successfully implemented in pharmacokinetic studies in healthy volunteers.ConclusionsSimple, sensitive and accurate LC–MS/MS methods for the quantification of enantiomeric and racemic primaquine and carboxyprimaquine in human plasma were validated successfully and implemented in clinical routine drug analysis.

Multiprobe study of excited states in C12 : Disentangling the sources of monopole strength between the energy of the Hoyle state and Ex=13 MeV

Background: The Hoyle state is the archetypal α-cluster state which mediates the 3α reaction to produce C12 and is of great interest for both nuclear structure and astrophysics. Recent theoretical calculations predict a breathing-mode excitation of the Hoyle state at Ex≈9 MeV. Its observation is hindered by the presence of multiple broad states and potential interference effects. An analysis with Gaussian line shapes of measurements at the Research Center for Nuclear Physics (Osaka University) with the Grand Raiden spectrometer suggested that additional strength was needed at Ex≈9 MeV to reproduce the data; this analysis did not account for the well-known threshold effects observed in C12. Nevertheless, various theoretical studies have since concluded that this additional strength corresponds to the predicted breathing-mode excitation of the Hoyle state. To meaningfully identify a new source of monopole strength in this astrophysically significant region, a more appropriate phenomenological analysis which accounts for penetrability and interference effects must be used to determine whether the data can be explained with previously established states. Purpose: We aim to investigate the monopole strength in the astrophysically important excitation-energy region of C12 between Ex=7 and 13 MeV to determine whether the previously established sources of monopole strength are able to reproduce the data. Method: The C12(α,α′)C12 and C14(p,t)C12 reactions, which are expected to exhibit contrasting selectivity towards different monopole excitations, were employed at various detection angles and beam energies to populate states in C12. The inclusive excitation-energy spectra were simultaneously analyzed with multilevel, multichannel line shapes. Various scenarios with different sources of monopole strength and interference effects were considered to determine whether the ghost of the Hoyle state and the previously established broad 03+ state at Ex≈10 MeV are able to reproduce the observed monopole strength. Results: Clear evidence was found for excess monopole strength at Ex≈9 MeV, particularly in the C12(α,α′)C12 reaction at 0∘. This additional strength cannot be reproduced by the previously established monopole states between Ex=7 and 13 MeV. Coincident charged-particle decay data suggest that the strength at Ex≈9 MeV is dominantly monopole, with no evidence of a J>0 contribution. Conclusions: The data support a new source of monopole strength at Ex≈9 MeV, which cannot be described with a phenomenological parametrization of all previously established states. An additional 0+ state at Ex≈9 MeV yielded a significantly improved fit of the data and is a clear candidate for the predicted breathing-mode excitation of the Hoyle state. Alternatively, the results may suggest that a more sophisticated, physically motivated parametrization of the astrophysically important monopole strengths in C12 is required.17 MoreReceived 19 November 2020Revised 21 May 2021Accepted 16 June 2021DOI:https://doi.org/10.1103/PhysRevC.105.024308©2022 American Physical SocietyPhysics Subject Headings (PhySH)Research AreasAlpha decayCollective levelsDirect reactionsNuclear astrophysicsNuclear reactionsNuclear structure & decaysProperties6 ≤ A ≤ 19TechniquesCluster modelsNuclear PhysicsGravitation, Cosmology & Astrophysics

Voltammetric Determination of Ascorbic Acid in Pharmaceutical Formulations Using Modified Iodine-Coated Platinum Electrode

Background: Despite the high reactivity of the platinum electrode, the iodine-coated platinum electrode shows obvious inertness toward adsorption and surface processes. For that, iodine-coated platinum electrodes accommodate themselves to interesting voltammetric applications. Objectives: This study reports using the modified iodine-coated polycrystalline platinum electrode as a voltammetric sensor for ascorbic acid determination in pharmaceutical formulations. Methods: The developed voltammetric method based on recording cyclic voltammograms of ascorbic acid at iodine-coated electrode The optimized experimental parameters for the determination of ascorbic acid were using 0.1 M KCl as a supporting electrolyte with a scan rate of 50mV/s. Results: The anodic peak related to ascorbic acid oxidation was centered at nearly 0.28V. An excellent and extended linear dependence of the oxidative peak current on the concentration of ascorbic acid was observed in the range 2.84x10-3 - 5.68 mM. The limit of detection (LOD) and limit of quantitation (LOQ) were 1.0 µM and 3.01 µM, respectively, attesting to the method’s sensitivity. The investigation for the effect of potential interference from multivitamin tablet ingredients (vitamins B1, B6, B12, folic acid, citric acid, sucrose, glucose, and zinc) indicated specific selectivity toward ascorbic acid and the absence of any electrochemical response toward these components. Recovery results in the range 98.93±2.78 - 99.98±5.20 for spiked standard ascorbic acid in pharmaceutical formulations further confirmed the potential applicability of the developed method for the determination of ascorbic acid in real samples. Conclusions: The developed method was successfully applied to the analysis of ascorbic acid (vitamin C), and the obtained results were in good agreement with the labeled values; besides, the statistical tests indicated no significant difference at p=0.05 with a 95% confidence level.

Anodic Stripping Voltammetric Determination Of Copper In Multivitamin-Mineral Formulations Using Iodine-Coated Platinum Electrode

In this work, the utilization of the modified iodine-coated polycrystalline platinum electrode as a voltammetric sensor for copper determination in pharmaceutical formulations was reported. The optimized experimental parameters for the determination of copper were using 0.1M KCl as a supporting electrolyte with a scan rate of 50 mV/s, deposition potential of - 0.2 V, and a deposition time of 2 minutes. The anodic peak related to Copper oxidation is centered at about + 0.05 V. The extended detected linear range for the developed method was between 1 ppm and 100 ppm. The anodic current showed excellent linearity with R2 = 0.9986. The limit of detection (LOD) and limit of quantitation (LOQ) were 0.115 ppm and 0.346 ppm, respectively, which attests to the sensitivity of the method. The investigation for the effect of potential interferences from multivitamins tablet ingredients indicated a specific selectivity toward copper and the absence of any electrochemical response toward these components. The developed method was successfully applied to analyze copper and the obtained results were in good agreement with the labeled values, besides that, the statistical tests indicated no significant difference at p = 0.05 with 95 % confidence level.

Voltammetric Determination of Paracetamol in Pharmaceutical Formulations at Iodine-Coated Polycrystalline Platinum Electrode

In this work the modified iodine-coated polycrystalline platinum electrode was used to develope a voltammetric sensor for paracetamol determination in pharmaceutical formulations. The optimized experimental parameters for the determination of paracetamol were using 0.5 M H2SO4 as a supporting electrolyte with a scan rate of 50 mV/s. The anodic peak related to paracetamol oxidation was centered at about +0.60 V. The extended calibration graph was constructed between 1 ppm and 500 ppm. The anodic current showed excellent linearity with R2 = 0.9985. The limit of detection (LOD) and limit of quantitation (LOQ) were 0.046 and 0.139 ppm, respectively, which attests to the sensitivity of the method. The investigation for the effect of potential interferences from the content of tablet matrices indicated a specific selectivity toward paracetamol and the absence of any electrochemical response toward these components. The developed method was successfully applied to analysis paracetamol in three brands of pharmaceutical formulations and the obtained results were in good agreement with the labeled values, besides that, the statistical tests indicated no significant difference at p = 0.05 with a 95 % confidence level.

Effect of the Belt and Road Initiative on Agricultural Value Chain Linkages: Evidence from Eora 26 Input-Output Data

The Belt and Road Initiative（BRI）aims to create a new paradigm of China’s opening-up. Using the input-output data from Eora 26 database from 1995 to 2015, this paper measures the agricultural value chain linkages（AVCL）by fun-tuning the cross-border times indicator, examines the policy effect of the BRI on AVCL, and analyzes the potential mechanism and heterogeneity of the policy effect. We find that the implementation of the BRI has significantly promoted the AVCL between China and economies along the Belt and Road from the perspectives of both value-added outflow and inflow, which is confirmed by a series of effectiveness checks. The heterogeneous effect analysis suggests that economies along the overland Silk Road and in areas adjacent to China get stronger AVCL promotion, and the policy effect is significant for economies with low political and investment risks, but not in those with high political and investment risks. We also explore the potential interference effect of free trade agreements（FTA）using triple difference models, which indicates that the AVCL promotion effect of the BRI is robustly significant, but FTA partner countries get stronger AVCL promotion. Also, we find that the policy effect of the BRI on AVCL is mainly achieved by reducing agricultural trade costs and extending agricultural production lengths. The above results have important policy implications: First, under the existing cooperation mechanism, it is necessary to formulate advanced agricultural cooperation agreements, and the quasi-public goods role of BRI should be fully utilized in the field of international food security and high-quality agricultural development. Second, China can take advantage of its own agricultural production capacity, identify the heterogeneity of the target market, distinguish the comparative advantages of different markets in the cooperation of primary agricultural products, agricultural semi-finished products, and agricultural capital products, take into account the political environment and business operations of different markets, and formulate differentiated agricultural cooperation policies. Third, countries along the Belt and Road should promote cooperation in the fields of cross-border e-commerce, agricultural product inspection, and construction of agricultural industrial parks, so as to reduce the cost of cross-border agricultural trade and extend the cross-border agricultural value chains.

Electrochemical Biosensor for the Detection of Amygdalin in Apple Seeds with a Hybrid of f-MWCNTs/CoFe2O4 Nanocomposite

Background: Amygdalin is a natural compound known for curing cancer. It is seen in several plants including in bitter almonds, apricots, peaches, apples, and plum seeds (kernels). Amygdalin is a toxic molecule containing a nitrile group, due to which toxic cyanide anion releases by the action of a β-glucosidase. The consumption of amygdalin may lead to cyanide poisoning in the human body. Therefore, for the first time, this work is aimed at developing a novel electrochemical biosensor for the detection of Amygdalin (AMG) in apple seed samples. Methods: The proposed electrochemical biosensor was fabricated by immobilizing cytochrome c (Cyt c) on a Glassy Carbon Electrode (GCE) with nanocomposite of cobalt ferrite nanoparticles (CoFe2O4 NPs) and functionalised multiwalled carbon nanotubes (f-MWCNTs). The characterization of the synthesized nanocomposite was performed with FTIR, TEM, TGA/DSC, and XRD techniques. Moreover, various experimental parameters such as the effect of pH, deposition time, sweep rate, potential, and enzyme incubation time and interference were also studied. Results: The fabricated biosensor enhanced the peak current by 10-folds compared to unmodified GCE. Under optimized experimental conditions, the biosensor exhibited linear response from 2 to 20 μM, with a linear regression equation Ipa (μA) = 8.4989 c + 6.6307 (R² = 0.9927). The LOD’s and LOQ’s were found to be 0.0112 μM and 0.2213 μM, respectively. Conclusion: The designed biosensor was successfully applied for the analysis of AMG content in the apple seed samples. The outcomes of this study identify the efficient electrocatalytic activity of the fabricated nanocomposite as significant electronic factors as major contributors to the electron transfer mechanism, with promising scope for the design of biosensor to sense toxic molecules.

Neural Correlates of Strategy Switching in the Macaque Orbital Prefrontal Cortex.

We can adapt flexibly to environment changes and search for the most appropriate rule to a context. The orbital prefrontal cortex (PFo) has been associated with decision making, rule generation and maintenance, and more generally has been considered important for behavioral flexibility. To better understand the neural mechanisms underlying the flexible behavior, we studied the ability to generate a switching signal in monkey PFo when a strategy is changed. In the strategy task, we used a visual cue to instruct two male rhesus monkeys either to repeat their most recent choice (i.e., stay strategy) or to change it (i.e., shift strategy). To identify the strategy switching-related signal, we compared nonswitch and switch trials, which cued the same or a different strategy from the previous trial, respectively. We found that the switching-related signal emerged during the cue presentation and it was combined with the strategy signal in a subpopulation of cells. Moreover, the error analysis showed that the activity of the switch-related cells reflected whether the monkeys erroneously switched or not the strategy, rather than what was required for that trial. The function of the switching signal could be to prompt the use of different strategies when older strategies are no longer appropriate, conferring the ability to adapt flexibly to environmental changes. In our task, the switching signal might contribute to the implementation of the strategy cued, overcoming potential interference effects from the strategy previously cued. Our results support the idea that ascribes to PFo an important role for behavioral flexibility.SIGNIFICANCE STATEMENT We can flexibly adapt our behavior to a changing environment. One of the prefrontal areas traditionally associated with the ability to adapt to new contingencies is the orbital prefrontal cortex (PFo). We analyzed the switching related activity using a strategy task in which two rhesus monkeys were instructed by a visual cue either to repeat or change their most recent choice, respectively using a stay or a shift strategy. We found that PFo neurons were modulated by the strategy switching signal, pointing to the importance of PFo in behavioral flexibility by generating control over the switching of strategies.

Interference into radio broadcast satellite uplinks

Radio frequency interference into satellite transmission channels is a matter of concern. There have been many studies of this subject by the ITU (International Telecommunications Union) particularly to mobile user receivers in the satellite radio broadcasting services by IMT (International Mobile Telecommunications) transmitters, since such receivers have high sensitivities (e.g., downlink channel system noise temperatures of under 100 deg. Kelvin) and provide Satellite Digital Audio Radio Service (SDARS) quality using relatively low satellite signal levels on the ground. Recently, proposals have been made by future low orbit satellite constellations, IMT and terrestrial interconnection systems to share radio frequency bands used by the transmission uplinks to radio broadcasting satellites. The broadcasting satellite uplink transmission channel at 7 GHz has typical system noise temperatures of 900 deg. Kelvin followed by very high electronic and antenna amplification. The overall system transmission design is generally set so the satellite broadcast uplink C/N does not appreciably degrade the downlink C/N, since the downlink simultaneously serves than 35 million mobile users with satellite radio service in North America. This paper describes the effect of potential interference into a satellite radio broadcast service from in-band and adjacent band transmissions and from associated intermodulation products by sharing uplink frequency spectrum transmitters. The analysis shows that such sharing services should be carefully arranged in the radio frequencies utilized and limited in flux densities impinging the geostationary orbital arc so harmful interference to radio broadcast satellite services does not occur.

Sensitive Simultaneous Determination of Rutin and Folic Acid with the Use of a Solid Lead Electrode by Means of Adsorptive Stripping Voltammetry

AbstractIn this article a solid lead electrode (PbE) was utilized for the first time for determination of organic substances by means of adsorptive stripping voltammetry. A new procedure of simultaneous determination of rutin and folic acid was developed. Two well shaped and well separated reduction signals of rutin and folic acid were obtained with the use of PbE. The optimization of analytical procedure was presented. The calibration graphs for rutin and folic acid for an accumulation time of 120 s were linear in the ranges from 2×10−9 to 1×10−7 mol L−1 and from 2×10−9 to 5×10−8 mol L−1, respectively. The obtained detection limits for rutin and folic acid determination following accumulation time of 120 s were 7.9×10−10 and 8.4×10−10 mol L−1. Potential interference effects were investigated. The proposed procedure was used for analysis of pharmaceutical preparations with satisfactory results showing practical applications. The analytical parameters of the proposed procedure were compared with other voltammetric procedures of mentioned substances determination.

Early initiation of home-based sensori-motor training improves muscle strength, activation and size in patients after knee replacement: a secondary analysis of a controlled clinical trial

BackgroundThere is accumulating evidence for the advantages of rehabilitation involving sensori-motor training (SMT) following total knee replacement (TKR). However, the best way in which to deliver SMT remains elusive because of potential interference effects amongst concurrent exercise stimuli for optimal neuromuscular and morphological adaptations. The aim of this study was to use additional outcomes (i.e. muscle strength, activation and size) from a published parent study to compare the effects of early-initiated home-based rehabilitative SMT with functional exercise training (usual care) in patients undergoing TKR.MethodsA controlled clinical trial was conducted at the Orthopedic University Hospital of Rion, Greece involving allocation concealment to patients. Fifty-two patients electing to undergo TKR were randomised to either early-initiated SMT [experimental] or functional exercise training [control] in a home-based environment. Groups were prescribed equivalent duration of exercise during 12-weeks, 3–5 sessions of ~ 40 min per week of home-based programmes. Muscle strength and activation (peak force [PF]; peak amplitude [Peak Amp.] and root mean square of integrated electromyography [RMS iEMG]), muscular size (including rectus femoris muscle cross-sectional area [CSARF]), and knee ROM were assessed on three separate occasions (pre-surgery [0 weeks]; 8 weeks post-surgery; 14 weeks post-surgery).ResultsPatients undertaking SMT rehabilitation showed significantly greater improvements over the 14 weeks compared to control in outcomes including quadriceps PF (25.1 ± 18.5 N vs 12.4 ± 20.8 N); iPeak Amp. (188 ± 109.5% vs 25 ± 105.8%); CSARF (252.0 ± 101.0 mm2 vs 156.7 ± 76.2 mm2), respectively (p < 0.005); Knee ROM did not offer clinically relevant changes (p: ns) between groups over time. At 14 weeks post-surgery, the SMT group’s and control group’s performances differed by relative effect sizes (Cohen’s d) ranging between 0.64 and 1.06.ConclusionA prescribed equivalent time spent in SMT compared to usual practice, delivered within a home-based environment, elicited superior restoration of muscle strength, activation and size in patients following TKR.Trial registrationISRCTN12101643, December 2017 (retrospective registration).

Understanding the interaction of single-walled carbon nanotube (SWCNT) on estrogen receptor: A combined molecular dynamics and experimental study

Considering the large-scale production of diversified nanomaterials, it is paramount importance to unravel the structural details of interactions between nanoparticles and biological systems, and thus to explore the potential adverse impacts of nanoparticles. Estrogen receptors (ER) is one of the most important receptor of human reproductive system and the binding of carbon nanotubes to estrogen receptors was the possible trigger leading to the reproductive toxicity of carbon nanotubes. Thus, with single-walled carbon nanotube (SWCNT) treated as model nanomaterials, a combination of in vivo experiments, spectroscopy assay and molecular dynamic modeling was applied to help us unravel some important issues on the binding characterization between SWCNT and the ligand binding domain (LBD) of ER alpha (ERα). The fluorescence assay and molecular dynamics simulations together validated the binding of SWCNT to ERα, suggesting the possible molecular initiating event. As a consequence, SWCNT binding led to a conformational change on tertiary structure levels and hydrophobic interaction was recognized as the driving force governing the binding behavior between SWCNT and LBD of ERα. A in vivo process presented that the exposure of SWCNT increased ERα expression from 26.43 pg/ml to 259.01 pg/ml, suggesting a potential estrogen interference effects of SWCNT. Our study offers insight on the binding of SWCNT and ERα LBD at atomic level, helpful to accurately evaluate the potential health risks of SWCNT.

Block periodization of strength and endurance training is superior to traditional periodization in ice hockey players.

Team sports like ice hockey require high levels of performance in numerous physical characteristics such as strength, power, and endurance. As such, training is associated with a potential interference effect. The present study randomized well-trained ice hockey players into a block periodization group (BP; n=8), focusing on the development of either strength and power or endurance on a weekly, undulating basis, and a traditional group (TRAD; n=8), performing a mixed training model, with simultaneous focus of strength, power, and endurance training every week. During the 6-week intervention, the two groups performed equal volumes and intensities of both strength, power, and endurance training. BP led to larger improvements than TRAD in knee extension peak torque at 180°s-1 (6.6±8.7 vs -4.2%±6.3%, respectively; P<0.05) and maximal oxygen uptake (5.1±3.3 vs 1.1%±3.5%, respectively; P<0.05). There was also a trend toward larger improvements in BP than TRAD in peak torque in knee extension at 60°s-1 (2.1±2.5 vs -0.1%±2.5%, respectively; P<0.1, effect size=0.83) and mean power output during a 30-s cycling sprint (4.1±2.5 vs -0.3%±5.9%, respectively; P<0.1, effect size=0.89). Overall, BP exhibited a moderate to large effect size for all these variables compared to TRAD. The present study suggests that block periodization of strength and endurance training induces superior adaptations in both strength and endurance capacities in well-trained ice hockey players compared to traditional mixed organization, despite similar training volume and intensity.

Colorimetric zearalenone assay based on the use of anaptamer and of gold nanoparticles withperoxidase-like activity.

An aptamer based colorimetric assay is described for the determination of zearalenone (ZEN). It is based on the inhibition of the peroxidase-mimicking activity of gold nanoparticles (AuNPs) by the ZEN aptamer. However, in the presence of ZEN, the aptamer is bound by ZEN and can no longer inhibit the peroxidase-mimicking activity of AuNPs. The color change of solution is related to ZEN concentration and observed with bare eyes. Under optimal conditions, the absorbance (at 630nm) increases linearly in the ZEN concentration range of 10-250ng·mL-1, and the limit of detection is 10ng·mL-1. The specificity of the assay was verified by studying the effect of potential interferents. The recoveries from ZEN spiked corn and corn oil range from 92 to 110%, and the relative standard deviations are between 2.4 and 6.4%. The results are in good agreement with those obtained by an ELISA. Graphical abstract Schematic presentation of colorimetric assay for rapid and sensitive determination of zearalenone (ZEN) based on the inhibition of ZEN aptamer on the the peroxidase-like activity of gold nanoparticle (AuNPs).