Combined Resonance Research Articles

Electrocorticographic Activation Patterns of Electroencephalographic Microstates.

Electroencephalography (EEG) microstates are short successive periods of stable scalp field potentials representing spontaneous activation of brain resting-state networks. EEG microstates are assumed to mediate local activity patterns. To test this hypothesis, we correlated momentary global EEG microstate dynamics with the local temporo-spectral evolution of electrocorticography (ECoG) and stereotactic EEG (SEEG) depth electrode recordings. We hypothesized that these correlations involve the gamma band. We also hypothesized that the anatomical locations of these correlations would converge with those of previous studies using either combined functional magnetic resonance imaging (fMRI)-EEG or EEG source localization. We analyzed resting-state data (5min) of simultaneous noninvasive scalp EEG and invasive ECoG and SEEG recordings of two participants. Data were recorded during the presurgical evaluation of pharmacoresistant epilepsy using subdural and intracranial electrodes. After standard preprocessing, we fitted a set of normative microstate template maps to the scalp EEG data. Using covariance mapping with EEG microstate timelines and ECoG/SEEG temporo-spectral evolutions as inputs, we identified systematic changes in the activation of ECoG/SEEG local field potentials in different frequency bands (theta, alpha, beta, and high-gamma) based on the presence of particular microstate classes. We found significant covariation of ECoG/SEEG spectral amplitudes with microstate timelines in all four frequency bands (p = 0.001, permutation test). The covariance patterns of the ECoG/SEEG electrodes during the different microstates of both participants were similar. To our knowledge, this is the first study to demonstrate distinct activation/deactivation patterns of frequency-domain ECoG local field potentials associated with simultaneous EEG microstates.

MRI-based radiomics models for the early prediction of radiation-induced temporal lobe injury in nasopharyngeal carcinoma.

This study was conducted to develop and validate a radiomics-clinics combined model-based magnetic resonance imaging (MRI) radiomics and clinical features for the early prediction of radiation-induced temporal lobe injury (RTLI) in patients with nasopharyngeal carcinoma (NPC). This retrospective study was conducted using data from 130 patients with NPC (80 patients with and 50 patients without RTLI) who received radiotherapy. Cases were assigned randomly to training (n = 91) and testing (n = 39) datasets. Data on 168 medial temporal lobe texture features were extracted from T1WI, T2WI, and T1WI-CE MRI sequences obtained at the end of radiotherapy courses. Clinics, radiomics, and radiomics-clinics combined models (based on selected radiomics signatures and clinical factors) were constructed using machine learning software. Univariate logistic regression analysis was performed to identify independent clinical factors. The area under the ROC curve (AUC) was performed to evaluate the performance of three models. A nomogram, decision curves, and calibration curves were used to assess the performance of the combined model. Six texture features and three independent clinical factors associated significantly with RTLI were used to build the combined model. The AUCs for the combined and radiomics models were 0.962 [95% confidence interval (CI), 0.9306-0.9939] and 0.904 (95% CI, 0.8431-0.9651), respectively, for the training cohort and 0.947 (95% CI, 0.8841-1.0000) and 0.891 (95% CI, 0.7903-0.9930), respectively, for the testing cohort. All of these values exceeded those for the clinics model (AUC = 0.809 and 0.713 for the training and testing cohorts, respectively). Decision curve analysis showed that the combined model had a good corrective effect. The radiomics-clinics combined model developed in this study showed good performance for predicting RTLI in patients with NPC.

Atmospheric nanoparticles hygroscopic growth measurement by a combined surface plasmon resonance microscope and hygroscopic tandem differential mobility analyzer

Abstract. The hygroscopic growth of atmospheric aerosols plays an important role in regional radiation, cloud formation, and hence climate. Aerosol hygroscopic growth is often characterized by hygroscopic tandem differential mobility analyzers (HTDMAs), and Xie et al. (2020) recently demonstrated that hygroscopic growth measurements of a single particle are possible using a surface plasmon resonance microscope-azimuthal rotation illumination (SPRM-ARI). The hygroscopic properties of ambient aerosols are not uniform and often exhibit large relative humidity (RH) and size variabilities due to different chemical compositions and mixing states. To better understand the contribution of different aerosol components and establish a link between the apparent hygroscopic properties of single particles and bulk aerosols, we conduct combined hygroscopic growth measurements using a SPRM-ARI and an HTDMA as a case study to prove the concept (experimental information: 100–200 nm, during noontime on 28 September 2021 and 22 March 2022 in Hefei, China). According to the distinct hygroscopic growth behavior from single-particle probing using a SPRM-ARI, the individual particles can be classified into three categories defined as non-hygroscopic (NH), less hygroscopic (LH), and more hygroscopic (MH). The mean growth factor (GF) of the three categories can be utilized to reproduce the GF distribution obtained from the HTDMA measurement. The chemical compositions of individual particles from the three categories are identified to be organic carbon (OC), soot (mainly elemental carbon), fly ash, and secondary aerosols (mainly OC and sulfate), using scanning electron microscopy (SEM) with an energy-dispersive spectrometer (EDS). The coupled SPRM–HTDMA measurement suggests a size-dependent variation of aerosol chemical components, i.e., an increase of OC fraction with increasing particle sizes, which agrees reasonably well with the chemical compositions from collected aerosol samples. This likely links the hygroscopic properties of individual particles to their bulk hygroscopic growth and chemical composition.

Charge Separation in BaTiO3 Nanocrystals: Spontaneous Polarization Versus Point Defect Chemistry.

The fate of photogenerated charges within ferroelectric metal oxides is key for photocatalytic applications. The authors study the contributions of i) tetragonal distortion, responsible for spontaneous polarization, and ii) point defects, on charge separation and recombination within BaTiO3 (BTO) nanocrystals of cubic and tetragonal structure. Electron paramagnetic resonance (EPR) in combination with O2 photoadsorption experiments show that BTO nanocrystals annealed at 600 °C have a charge separation yield enhanced by a factor > 10 compared to TiO2 anatase nanocrystals of similar geometries. This demonstrates for the first time the beneficial effect of the BTO perovskite nanocrystal lattice on charge separation. Strikingly, charge separation is considerably hindered within BTO nanoparticles annealed ≥ 600 °C, due to the formation of Ba-O divacancies that act as charge recombination centers. The opposing interplay between tetragonal distortion and annealing-induced defect formation inside the lattice highlights the importance of defect engineering within perovskite nanoparticles.

Combination resonance and primary resonance characteristics of a dual-rotor system under the condition of the synchronous impact of the inter-shaft bearing

The internal structure of many aero-engines is designed with a dual-rotor system. Up to now, there have been few studies on the influence of aerodynamic excitation on the dual-rotor system. The phenomenon of synchronous impact may occur when the frequency of the aerodynamic excitation force of the fan blade is close to the characteristic frequency of the inter-shaft bearing. This paper investigates the dynamic characteristics of a dual-rotor system under the condition of synchronous impact. The system's motion equations are formulated considering the complex nonlinearities of the inter-shaft bearing, such as Hertz contact force of 10/9 exponential function, clearance, and periodic varying compliance. In addition, the inter-shaft bearing with a local defect is considered. The fan blade’s aerodynamic excitation force is modeled by synthesizing multiple harmonic excitation forces, the amplitudes of which are obtained by the Fourier series expansion. Numerical simulations are employed to get the dynamic responses of the system. The results show that the dynamic characteristic of the dual-rotor system at the primary resonance caused by the high-pressure (H.P.) rotor is not changed by the aerodynamic excitation force, while the primary resonance caused by the low-pressure (L.P.) rotor increases significantly. However, three aerodynamic resonances of the amplitude-frequency response of the dual-rotor system are emerging in the low-frequency region (124, 146 and 186 rad/s). When the synchronous impact phenomenon occurs, the amplitude of the three resonance peaks will increase twice compared to the original status, leading to a doubled increase in the dynamic load of the inter-shaft bearing. The characteristics of the dual-rotor system affected by the parameters such as initial phase difference of local defect, rotor eccentricity of system, clearance of inter-shaft bearing, and the stiffness and damping of supports are discussed in detail. The results obtained provide a deep insight into the mechanism of synchronous impact.

Colorimetric and photothermal dual-mode lateral flow immunoassay based on Au-Fe3O4 multifunctional nanoparticles for detection of Salmonella typhimurium.

Au-Fe3O4 multifunctional nanoparticles (NPs) were synthesizedand integrated with lateral flow immunoassay (LFIA) for dual-mode detection of Salmonella typhimurium. The Au-Fe3O4 NPs not only combined excellent local surface plasmon resonance characteristics and superparamagnetic properties, but also exhibited good photothermal effect. In the detection, antibody-conjugated Au-Fe3O4 NPs first captured S. typhimurium from complex matrix, which was then loaded on the LFIA strip and trapped by the T-line. By observing the color bands with the naked eyes, qualitative detection was performed free of instrument. Bymeasuring the photothermal signal, quantification was achieved with a portable infrared thermal camera. The introduction of magnetic separation achieved the enrichment and purification of target bacteria, thus enhancing the detection sensitivity and reducing interference. This dual-mode LFIA achieved a visual detection limit of 5 × 105CFU/mL and a photothermal detection limit of 5 × 104CFU/mL. Compared with traditional Au-based LFIA, this dual-mode LFIA increased the detection sensitivity by 2 orders of magnitude and could be directly applied to unprocessed milk sample. Besides, this dual-mode LFIA showed good reproducibility and specificity. The intra-assay and inter-assay variation coefficients were 3.0% and 7.9%, and with this dual-mode LFIA, other bacteria hardly produced distinguishable signals. Thus, the Au-Fe3O4 NPs-based LFIA has potential to increase the efficiency of pandemic prevention and control. Au-Fe3O4 nanoparticle proved to be a promising alternative reporter for LFIA, achieving multifunctions: target purification, target enrichment, visual qualitation, and instrumental quantification, which improved the limitations of traditional LFIA.

Imaging oxidative stress in brains of chronic methamphetamine users: A combined 1H-magnetic resonance spectroscopy and peripheral blood biomarker study.

Preclinical data suggest methamphetamine (MA), a widely used stimulant drug, can harm the brain by causing oxidative stress and inflammation, but only limited information is available in humans. We tested the hypothesis that levels of glutathione (GSH), a major antioxidant, would be lower in the brains of chronic human MA preferring polysubstance users. We also explored if concentrations of peripheral immunoinflammatory blood biomarkers were related with brain GSH concentrations. 20 healthy controls (HC) (33 years; 11 M) and 14 MA users (40 years; 9 M) completed a magnetic resonance spectroscopy (MRS) scan, with GSH spectra obtained by the interleaved J-difference editing MEGA-PRESS method in anterior cingulate cortex (ACC) and left dorsolateral prefrontal cortex (DLPFC). Peripheral blood samples were drawn for measurements of immunoinflammatory biomarkers. Independent samples t-tests evaluated MA vs. HC differences in GSH. GSH levels did not differ between HC and MA users (ACC p = 0.30; DLPFC p = 0.85). A total of 17 of 25 immunoinflammatory biomarkers were significantly elevated in MA users and matrix metalloproteinase (MMP)-2 (r = 0.577, p = 0.039), myeloperoxidase (MPO) (r = -0.556, p = 0.049), and MMP-9 (r = 0.660, p = 0.038) were correlated with brain levels of GSH. Normal brain GSH in living brain of chronic MA users is consistent with our previous postmortem brain finding and suggests that any oxidative stress caused by MA, at the doses used by our participants, might not be sufficient to cause either a compensatory increase in, or substantial overutilization of, this antioxidant. Additionally, more research is required to understand how oxidative stress and inflammatory processes are related and potentially dysregulated in MA use.

Radicals from tributyl phosphate decomposition: a combined electron paramagnetic resonance spectroscopic and computational chemistry investigation.

The radiation- and chemically-induced radicals from tributyl phosphate (TBP) have been characterized by EPR spectroscopy and theoretical calculations. The yield of X-ray-generated TBP radicals measured by a PBN spin trap is 0.22 μmol J-1 (2.1 radicals/100 eV) at room temperature (298 K). The EPR spectra obtained by irradiating TBP with an electron beam at 77 K are in close agreement with literature data for samples irradiated with gamma- and X-rays [https://doi.org/10.1007/BF02165504, https://doi.org/10.1016/1359-0197(89)90319-6]. Possible conformers of alkyl-type, TBP-derived radicals were analyzed by Density Functional Theory calculations. The main contribution to the experimental spectrum at 77 K is shown to be made by a conformer of the CH3˙CHCH2-radical, which contains all carbon atoms of the butyl group in the same plane. The EPR spectra of TBP radicals induced by the OH radical in aqueous solution were measured for the first time using a continuous flow system. The formation of the alkyl-type TBP radicals CH3˙CHCH2-, ˙CH2CH2-, and -CH2˙CHO- in the ratio of 5/4/1 was detected; their spectral assignment was based on quantum chemical calculations with rotational averaging of HFC constants for the corresponding beta- and alpha-protons.

Investigation of the synergistic effects of ICRF + NBI heating in EAST plasma discharges

Following an upgrade of the neutral beam injection (NBI) system, obvious synergy between combined NBI and ion cyclotron resonance frequency (ICRF) heating was observed in recent experiments conducted at EAST. To investigate the effects of beam-ions accelerated by radiofrequency (RF) wave, analyses are performed by using TRANSP code based on the experimental results. The calculated results argue that only a small fraction of the ICRF power is absorbed by the beam ions in the ICRF + NBI synergistic heating of the (H)D plasma. To enhance the beam–RF interactions in synergistic heating and achieve high plasma performance of EAST, different experimental conditions, including multiple injection powers and diverse beam injection options, were explored. Beam injected fast ions are passing particles, trapped particles observed when synergy heating between ICRF and NBI. In particular, by varying the injection direction of the beam ions it was observed that more tangential beam yields better synergy in comparison with more perpendicular beam. The neutron emission rate of D–D fusion in tokamaks is improved and less fast ion loss is produced with tangential NBI + ICRF heating. Also, the effect of the ratio P ICRF/P NBI on ICRF + NBI combined heating is demonstrated, the higher power boosts the fusion enhancement. The study of the performed synergistic heating provides an important reference for the subsequent combined NBI + ICRF heating experiments on EAST.

Accuracy of combined physical examination, transvaginal ultrasonography, and magnetic resonance imaging to diagnose deep endometriosis

To assess the ability of Physical Examination (PE), Transvaginal Ultrasonography (TVUS), and Magnetic Resonance Imaging (MRI) alone and combined to diagnose Deep Infiltrating Endometriosis (DIE). We retrospectively queried our pelvic MRI database to identify women who underwent PE, TVUS, and pelvic MRI for DIE up to 12 months prior to surgery between January 1, 2016 and August 31, 2020. The presence of uterosacral ligaments (USL), vaginal, rectosigmoid (RS), parametrial or sacrorectogenital septum (lateral) DIE shown by PE, TVUS and MRI were correlated with surgical and histological findings. We included 178 patients. The sensitivity, specificity, positive and negative predictive values, and accuracy of each technique separately and combined were assessed for each location. When the three techniques were combined, two models were tested: A) all three techniques positive and concordant, and B) at least two techniques positive and concordant. The prevalence of USL, vaginal, RS, and lateral DIE were 94.4%, 20.2%, 34.3% and 32.6%, respectively. MRI was more sensitive than PE, TVUS or any combination to detect DIE. MRI and model B were the most accurate for detecting USL and RS locations with an accuracy of 90.4% and 82.6%, a sensitivity of 91.1% and 50%, and a specificity of 77.8% and 90.9%, respectively. Model B was the most accurate for the vaginal location with an accuracy of 82.6%, a sensitivity of 50%, and a specificity of 90.9%. Finally, MRI was more accurate than any combination for identifying a lateral location with an accuracy of 75.1%, a sensitivity of 36%, and a specificity of 93.8%. A combination of PE, TVUS and MRI more accurate than each technique separately to diagnose DIE due to the equally high sensitivity of each, and the high specificity of PE and TVUS.

Combination resonances of a dual-rotor system with inter-shaft bearing

Combination resonances of a dual-rotor system with inter-shaft bearing

Update on diverse vascular cognitive impairment (VCID)

Background. As the US population becomes increasingly older and more diverse, the number of Americans with dementia is expected to rise substantially, particularly the number of those with concomitant vascular disease. Moreover, the impact of vascular disease on dementia risk may be exacerbated in African Americans and Hispanics, who are at greater risk for vascular disease and for whom vascular disease may play a larger role in clinical dementia. As public health awareness of dementia increases, it is becoming common to see individuals presenting for clinical assessment with minor cognitive complaints. Neuroimaging studies of these individuals frequently identify “incidental” white matter hyperintensities (WMH), usually ascribed to “microvascular disease” by radiologists, raising concerns in patients about their brain health and future risk for dementia.
 Methods. To date, however, we are not aware of any studies designed to examine the baseline and future impact of white matter (WM) injury in the clinical setting, particularly among diverse populations where age-related WMH volumes are known to be higher1 or comprehensively examined the impact of individual and combined magnetic resonance imaging (MRI) measures of white matter injury on cognitive performance among a diverse, non-demented, stroke-free population with cognitive complaints over an extended period of observation. For this presentation, I summarized the available evidence of the impact of WMH and cognition and reviewed the design of a new study to prospectively assess this outcome in a diverse population and develop a risk factor profile to assist in the diagnosis of those at risk for dementia.
 Results. There is substantial evidence that WMH are common, increase in amount and prevalence with age,2 impact cognition and dementia,3 and are a measure of vascular brain injury. The significance of studying WM injury is buoyed by the fact that dementia risk scales emphasize the role of vascular risk in dementia prediction4 and that institution of effective treatment could lessen the burden of dementia on population.5 Yet, a complete understanding of WMH as markers of vascular brain injury contributing to cognitive complaints and possibly vascular cognitive impairment (VCI) requires a comprehensive determination of the full spectrum of WM injury associated with vascular risk, potential mechanisms of WMH formation and progression, ethnoracial, other genetic influences and how WMH interact with neurodegenerative pathologies, in particular Alzheimer’s disease (AD). Evidence of the importance of “asymptomatic” vascular brain injury on present cognition and future cognitive decline led to the design of a new multi-site study of diverse individuals with cognitive complaints and WMH, that aims to develop a predictive risk factor score that can be widely used in future treatment trials called diverse VCID. Diverse VCID is a multi-site study of 2250 individuals of non-Hispanic Whites, Hispanic/Latinos, and Black African Americans who will be followed for approximately 3 years to deliver a clinical risk score that predicts dementia based on neuroimaging, plasma biomarkers, genetic and clinical data.
 Conclusions. Vascular diseases are now recognized to be a major contributor to cognitive impairment and dementia disproportionately affecting individuals from diverse backgrounds. Diverse VCID is designed to address this critical issue and to facilitate future treatment studies of vascular cognitive impairment.

Analysis on parametric vibration of hydraulic opposing cylinders controlled by a servo valve considering pressure pulsation

During the working process of the system of hydraulic opposing cylinders controlled by a servo valve, the fluid equivalent stiffness changes dynamically due to the pressure pulsation of the pump source. Therefore, the transmission system has obvious nonlinear effects, and its dynamic performance is difficult to improve further. Thus, a nonlinear dynamic model of the system of hydraulic opposing cylinders controlled by a servo valve was established. By using the multiscale method, the steady-state approximate solutions of the primary resonance and the combination resonance of the system were derived to reveal their characteristic laws. The results showed that the dominant frequency of the system's primary resonance is the frequency of the external excitation source, and the dominant frequency of the system's combination resonance is the sum of the natural frequency of each order and the fluctuation frequency of the fluid equivalent stiffness. The amplitude of the combination resonance was smaller than that of the primary resonance. The maximum error between the theoretical natural frequency and the experimental modal frequency was 3.77%, which verified the correctness of the system's nonlinear dynamic model. The research can provide a theoretical reference for the dynamics optimization design of the hydraulic transmission system.

Combined Underdamped Bistatic Stochastic Resonance for Weak Signal Detection and Fault Diagnosis under Wavelet Transform

A novel combined underdamped bistable stochastic resonance (CUBSR) is proposed in this paper. Under the noise-free condition, the output amplitude is used as a measurement index of classical bistable stochastic resonance (CBSR) and CUBSR, which demonstrate CUBSR does not have output saturation characteristics and has a more prominent signal enhancement capability. Then, the expressions of mean first-pass time (MFPT), steady-state probability density (SPD) and signal-to-noise ratio (SNR) are derived. Combined with the fourth-order Runge–Kutta algorithm and genetic algorithm (GA) for numerical simulations, the comparison of the theoretical derivation and numerical simulation of CUBSR can be verified. Then, the two systems are applied to the engineering application of bearing fault diagnosis. Finally, the multi-scale noise-modulated SR method based on wavelet packet transform is studied to overcome the limitation of traditional parameter modulation and to achieve SR detection at multiple frequencies. Simulation analysis and bearing fault diagnosis show that the method can effectively detect the multi-frequency weak signal submerged in noise, resulting in a significant enhancement in signal amplitude.

Optimal time delayed control of the combination resonances of viscoelastic graphene sheets under dual-frequency excitation

In this study, the nonlinear combination vibration of a single-layer graphene sheet (SLGS) resting on a visco-Pasternak foundation and exposed to dual-frequency excitation was investigated. The time delayed feedback proportional-derivative (PD) controller was applied to an SLGS for the first time, and three combination resonances with two different time delays were examined. The approximate analytical solutions of nonlinear vibration equations were obtained using the multiple scales perturbation method, and their stability under the condition of combination resonance was investigated. The optimal time delay for the controller of the system was analyzed and calculated. Finally, the results of this study were compared with those of other studies. The results showed that the dual-frequency excitation intensifies the nonlinear behavior of the system. Further, the influence of the feedback gain coefficients and time delays on the combination resonance of the system was examined, and the results showed that the efficiency of vibration control can be improved by adjusting the feedback gain and time delay parameters. This study aims to provide theoretical guidance for the application of viscoelastic graphene sheets.

Development and External Validation of a Prediction Model to Identify Candidates for Prostate Biopsy.

Prostate biopsies are associated with infectious complications and approximately 80% are either benign or clinically insignificant prostate cancer. Our aim is to develop and independently validate prediction model to avoid unnecessary prostate biopsies by predicting clinically significant prostate cancer (csPCa) Materials and Methods: Retrospective analysis of single-center cohort (Mount Sinai Hospital, NY) of 1632 men who underwent systematic or combined systematic and Magnetic Resonance Imaging (MRI)/ultrasound fusion targeted prostate biopsy between 2014-2020. External cohort (University of Miami) included 622 men that underwent biopsy. Outcome for predicting csPCa was defined as International Society of Urologic Pathology (ISUP) Gleason grade ≥ 2 on biopsy. Multivariable logistic regression analysis was performed to build nomogram using coefficients of logit function. Nomogram validation was performed in external cohort by plotting receiver operating characteristics (ROC). We also plotted decision curve analysis (DCA) and compared nomogram-predicted probabilities with actual rates of csPCa probabilities in external cohort. Of 1632 men, 43% showed csPCa on biopsy. PSA density, prior negative biopsy, and Prostate Imaging and Reporting Data System (PI-RADS) scores 3, 4, and 5 were significant predictors for csPCa. ROC for prediction of csPCa was 0.88 in external cohort. There was agreement between predicted and actual rate of csPCa in external cohort. DCA demonstrated net benefit using the model. Using the prediction model at threshold of 30, 35% of biopsies and 46% of diagnosed indolent PCa could be avoided, while missing 5% of csPCa. Using our prediction model can help reduce unnecessary prostate biopsies with minimal impact on csPCa detection rates.

MRI-based analysis of different clinically significant prostate cancer detection rate of prostate imaging reporting and data system score 4 in the peripheral zone.

To compare the clinically significant prostate cancer (csPCa) detection rate between diffusion-weighted imaging (DWI) 4 and DWI 3 with positive dynamic contrast-enhanced (DCE) (hereinafter called 'DWI 3/DCE+') lesions in the peripheral zone (PZ) and to explore the diagnostic performance of targeted biopsy (TB) or systematic biopsy (SB) in patients with Prostate Imaging Reporting and Data System (PI-RADS) 4 lesions. We retrospectively enrolled 206 patients who underwent multiparametric magnetic resonance imaging and had at least one PI-RADS 4 lesion in the PZ. All patients subsequently underwent combined magnetic resonance imaging/ultrasound fusion-guided TB and ultrasound-guided 12-core SB. The chi-square test was used to compare the csPCa detection rates between DWI 4 and DWI 3/DCE+ lesions. Based on the TB + SB results as a standard reference, we analyzed the sensitivity, negative predictive value, and diagnostic accuracy of TB alone or SB alone. Patients with DWI 4 lesions had higher csPCa detection rate than those with DWI 3/DCE+ lesions when using TB + SB, TB, and SB, and the differences were significant for TB + SB (72.22 vs. 54.84%, p = 0.015) or SB (65.97 vs. 46.77%, p = 0.010). For DWI 3/DCE+ patients whose prostate-specific antigen levels ranged from 4 to 10ng/mL, TB alone showed the highest negative predictive value (95% Cl 78.12-100). DWI 4 tends to have worse results than DWI 3/DCE+. TB has great diagnostic performances in DWI 3/DCE+ patients, especially for those prostate-specific antigen ranging from 4 to 10ng/mL.

Dynamic analysis of an axially moving underwater pipe conveying pulsating fluid

In this paper, both linear and non-linear dynamics of a slender and uniform pipe conveying pulsating fluid, which is axially moving in an incompressible fluid, are comprehensively studied. The vibration equations of the system are established by considering various factors, including a coordinate conversion system, an “axial added mass coefficient” describing the additional inertia forces caused by the external fluid, the Kelvin–Voigt viscoelastic damping, a kind of non-linear additional axial tension, and the pulsating internal fluid. The vibration equations are discretized by the Galerkin procedure and solved by the Runge–Kutta approach, and the validity of the solution procedure is carefully checked. After that, the linear and non-linear responses of the system are studied when the internal flow velocity and the axially moving speed of the pipe are small. For linear responses, the Kelvin–Voigt viscoelastic damping has great influences on the second and third modes of the system. For the non-linear dynamic, the results are rich and changeful, including the first and second principal parametric resonances, the secondary resonance, the combination resonance, period-1 motion, quasi-periodic motion, and chaotic motion. Finally, the influence of several key system parameters on the non-linear responses is analyzed.

Neural Reactivity to Social Punishment Predicts Future Engagement in Nonsuicidal Self-injury Among Peer-Rejected Adolescents

BackgroundRates of nonsuicidal self-injury (NSSI) increase dramatically in adolescence. Affective reactivity and adverse social experiences have been linked to NSSI, but less is known about whether these factors may separately or interactively predict NSSI, especially longitudinally. This study combined functional magnetic resonance imaging and a sociometric measure to test whether a combination of neural (e.g., amygdala) reactivity to social punishment and peer-nominated peer acceptance/rejection predicts NSSI longitudinally in adolescence. Amygdala reactivity was examined as a potential neural marker of affective reactivity to social punishment, which may heighten NSSI risk in contexts of social adversity. MethodsOne hundred twenty-five adolescents (63 female) completed a social incentive delay task during neuroimaging and school-based peer nominations to measure peer acceptance/rejection. NSSI engagement was assessed at baseline and 1-year follow-up. ResultsGreater amygdala reactivity to social punishment predicted greater NSSI engagement 1 year later among adolescents with high peer rejection. This effect for the amygdala was specific to social punishment (vs. reward) and held when controlling for biological sex and pubertal development. Exploratory analyses found that ventral striatum reactivity to social reward and punishment similarly interacted with peer rejection to predict NSSI but that amygdala connectivity with salience network regions did not. ConclusionsAmygdala reactivity to social punishment, in combination with high peer rejection, may increase NSSI risk in adolescence, possibly via heightened affective reactivity to adverse social experiences. Objective measures of neurobiological and social risk factors may improve prediction of NSSI, while therapeutic approaches that target affective reactivity and increase prosocial skills may protect against NSSI in adolescence.

Combined internal resonances at crossover of slacked micromachined resonators

The dynamics of micro-/nanoelectromechanical systems (M/NEMS) curved beams have been thoroughly investigated in the literature, commonly for curved arch beams actuated with electrodes facing their concave surface. Except for few works on slacked carbon nanotubes, the literature lacks a deep understanding of the dynamics of slacked curved resonators, where the electrode is placed in front of the convex beam surface. This paper investigates the dynamics of slacked curved resonators as experiencing combined internal resonances. The curved slacked resonator is excited using an antisymmetric partial electrode while the electrostatic voltage load is driven to elevated excitations, which breaks the symmetry of the system and affects natural frequencies and corresponding mode shapes. The axial load is tuned to monitor the ratios between the natural frequencies of different vibration modes, which induces simultaneous 1:1 and 2:1 internal resonances between the first and second mode with the third. We observe the interaction of hardening and softening bending of the fundamental backbone curves triggering various patterns of the response scenario and the appearance of coexisting regions of irregular dynamics.