A nonparametric point-by-point method to measure time-dependent frequency in wavelength modulation spectroscopy.

A nonparametric point-by-point (NPP) method is presented for high-accuracy measurement of the time-dependent frequency (laser frequency) in tunable laser absorption spectroscopy, crucial for ensuring ultimate measurement accuracy. In wavelength modulation spectroscopy in particular, the parametric methods in current use for time-dependent frequency measurement are insufficiently accurate and are difficult to apply to complex modulation scenarios. Based on a multi-scale viewpoint, point-by-point measurement of the frequency is realized by linear superposition of the frequency information mapped from the interferometric signal on a unit scale and on a local scale. Validation experiments indicate that the measurement accuracy of the proposed NPP method is three times that of the existing parametric methods, while effectively immunizing against non-ideal tuning effects. Additionally, the NPP method is suitable for use with arbitrarily complex modulations such as square wave modulation, for which parametric methods are inapplicable.

Lens Thickness in Infants and Children with Cataracts.

Purpose: The purpose of this study was to determine the association between lens thickness and cataract in participants aged 0 to 5 years. Design: This was a prospective, multicenter, case-control study. Participants: We enrolled 118 participants (171 eyes) aged 0 to 5 years, mean age 14.6 ± 17.0 months, range 0 to 60 months. Methods: Lens thickness was measured on 342 ultrasound biomicroscopy (UBM) images. Main Outcome Measures: Lens thickness; feasibility of lens thickness measurement from UBM images. Results: The mean lens thickness among noncataracts was 3.60 ± 0.17 mm, compared with 3.16 ± 0.61 mm among cataracts (P < 0.0001). Lens thickness <3.5 mm was significantly associated with increased odds of cataract; adjusted odds ratio = 5.99 (95% confidence interval, 2.41-14.88; P < 0.0003) among participants age 0 to 7 months. Lens thickness was significantly associated with cataract laterality among participants age 0 to 7 months (P < 0.0001). Conclusions: Quantitative UBM can be used to evaluate lens thickness in infants and children with congenital cataracts. The lens in congenital cataract eyes was thinner than that of controls among infants. Abnormal lens thickness was significantly associated with cataract. Future longitudinal studies will examine the association between lens thickness and postcataract surgery outcomes. Financial Disclosures: Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Deep learning-enabled fluorescence imaging for surgical guidance: in silico training for oral cancer depth quantification.

Significance: Oral cancer surgery requires accurate margin delineation to balance complete resection with post-operative functionality. Current in vivo fluorescence imaging systems provide two-dimensional margin assessment yet fail to quantify tumor depth prior to resection. Harnessing structured light in combination with deep learning (DL) may provide near real-time three-dimensional margin detection. Aim: A DL-enabled fluorescence spatial frequency domain imaging (SFDI) system trained with in silico tumor models was developed to quantify the depth of oral tumors. Approach: A convolutional neural network was designed to produce tumor depth and concentration maps from SFDI images. Three in silico representations of oral cancer lesions were developed to train the DL architecture: cylinders, spherical harmonics, and composite spherical harmonics (CSHs). Each model was validated with in silico SFDI images of patient-derived tongue tumors, and the CSH model was further validated with optical phantoms. Results: The performance of the CSH model was superior when presented with patient-derived tumors ( P -value < 0.05 ). The CSH model could predict depth and concentration within 0.4 mm and 0.4 µ g / mL , respectively, for in silico tumors with depths less than 10 mm. Conclusions: A DL-enabled SFDI system trained with in silico CSH demonstrates promise in defining the deep margins of oral tumors.

Prevalence and nature of bullying in schoolchildren aged 10-14 years and its association with malocclusion: A cross-sectional study in the South East of the UK.

OBJECTIVE: To investigate the prevalence of, and relationship between, bullying and malocclusion in schoolchildren aged 10-14 years in the South East of the UK. DESIGN: Cross-sectional cohort study. SETTING: Sixteen primary and secondary schools in South East of the UK. PARTICIPANTS: Schoolchildren aged 10-14 years who were consented to participate. METHODS: The prevalence and nature of bullying were measured using a questionnaire. Traits of malocclusion and the need for orthodontic treatment were assessed by clinical examination and determined by the Index of Orthodontic Treatment Need (IOTN) Dental Health (DHC) and Aesthetic components (AC). RESULTS: Complete data were collected for 698 participants. The number defined as being bullied was 68 (9.7%). There was no difference in the prevalence of bullying between gender, ethnicity or age. Higher rates of bullying were reported in mixed sex schools (P = 0.03). Participants with an increased overjet (P = 0.02) and/or a greater need for treatment, as measured by IOTN DHC (P = 0.01) and AC (P = 0.01), reported higher rates of bullying. While there was no difference in the overall prevalence of bullying between genders, boys were more likely than girls to experience physical bullying (P <0.001) and being called names (P = 0.03). CONCLUSION: A significant relationship was evident between being bullied and certain traits of malocclusion.

Sex and Age Differences in the Effects of Food Frequency on Metabolic Parameters in Japanese Adults.

Owing to differences in dietary preferences between men and women, the associations between dietary intake frequency and metabolic parameters may differ between the sexes. A retrospective observational study of the checkup findings of 3147 Japanese individuals (968 men, 2179 women) aged 20-59 years was conducted to examine differences in dietary habits and associations between food frequency and blood parameters (eGFR, HbA1c, uric acid, and lipids) by sex and age. Males were more likely to consume meat, fish, soft drinks, and alcohol, whereas women were more likely to consume soybeans, dairy products, vegetables, fruits, and snacks. Multivariate linear regression models adjusted for age and BMI revealed that meat intake frequency was positively associated with HbA1c (ß = 0.007, p = 0.03) and negatively associated with eGFR (ß = -0.3, p = 0.01) only in males, whereas fish intake frequency was positively associated with eGFR (ß = 0.4, p = 0.005) only in females. Egg and soy intake frequencies were positively and negatively associated with non-HDL-C (egg: ß = 0.6, p = 0.02; soy: ß = -0.3, p = 0.03) only in females. Alcohol consumption frequency was associated with uric acid (M: ß = 0.06, p < 0.001; F: ß = 0.06, p < 0.001) and HDL-C (M: ß = 1.0, p < 0.001; F: ß = 1.3, p < 0.001) in both sexes. Future research is needed to determine whether varying the emphasis of dietary guidance by sex and age group is effective, since the effects of dietary preferences on metabolic parameters vary by age and sex.

The effect of exposure to radiofrequency electromagnetic fields on cognitive performance in human experimental studies: Systematic review and meta-analyses.

BACKGROUND: The objective of this review is to evaluate the associations between short-term exposure to radiofrequency electromagnetic fields (RF-EMF) and cognitive performance in human experimental studies. METHODS: Online databases (PubMed, Embase, Scopus, Web of Science and EMF-Portal) were searched for studies that evaluated effects of exposure to RF-EMF on seven domains of cognitive performance in human experimental studies. The assessment of study quality was based on the Risk of Bias (RoB) tool developed by the Office of Health Assessment and Translation (OHAT). Random effects meta-analyses of Hedges's g were conducted separately for accuracy- and speed-related performance measures of various cognitive domains, for which data from at least two studies were available. Finally, the certainty of evidence for each identified outcome was assessed according to Grading of Recommendations Assessment, Development, and Evaluation (GRADE). RESULTS: 57,543 records were identified and 76 studies (80 reports) met the inclusion criteria. The included 76 studies with 3846 participants, consisting of humans of different age, sex and health status from 19 countries, were conducted between 1989 and 2021. Quantitative data from 50 studies (52 reports) with 2433 participants were included into the meta-analyses. These studies were performed in 15 countries between 2001 and 2021. The majority of the included studies used head exposure with GSM 900 uplink. None of the meta-analyses observed a statistically significant effect of RF-EMF exposure compared to sham on cognitive performance as measured by the confidence interval surrounding the Hedges's g or the significance of the z-statistic. For the domain Orientation and Attention, subclass Attention - Attentional Capacity RF-EMF exposure results in little to no difference in accuracy (Hedges's g 0.024, 95 % CI [-0.10; 0.15], I2 = 28 %, 473 participants). For the domain Orientation and Attention, subclass Attention - Concentration / Focused Attention RF-EMF exposure results in little to no difference in speed (Hedges's g 0.005, 95 % CI [-0.17; 0.18], I2 = 7 %, 132 participants) and probably results in little to no difference in accuracy; it does not reduce accuracy (Hedges's g 0.097, 95 % CI [-0.05; 0.24], I2 = 0 %, 217 participants). For the domain Orientation and Attention, subclass Attention - Vigilance RF-EMF exposure probably results in little to no difference in speed and does not reduce speed (Hedges's g 0.118, 95 % CI [-0.04; 0.28], I2 = 41 %, 247 participants) and results in little to no difference in accuracy (Hedges's g 0.042, 95 % CI, [-0.09; 0.18], I2 = 0 %, 199 participants). For the domain Orientation and Attention, subclass Attention - Selective Attention RF-EMF exposure probably results in little to no difference in speed and does not reduce speed (Hedges's g 0.080, 95 % CI [-0.09; 0.25], I2 = 63 %, 452 participants); it may result in little to no difference in accuracy, but it probably does not reduce accuracy (Hedges's g 0.178, 95 % CI [-0.02; 0.38], I2 = 68 %, 480 participants). For the domain Orientation and Attention, subclass Attention - Divided Attention RF-EMF exposure results in little to no difference in speed (Hedges's g -0.010, 95 % CI [-0.14; 0.12], I2 = 5 %, 307 participants) and may result in little to no difference in accuracy (Hedges's g -0.089, 95 % CI [-0.35; 0.18], I2 = 53 %, 167 participants). For the domain Orientation and Attention, subclass Processing Speed - Simple Reaction Time Task RF-EMF exposure results in little to no difference in speed (Hedges's g 0.069, 95 % CI [-0.02; +0.16], I2 = 29 %, 820 participants). For the domain Orientation and Attention, subclass Processing Speed - 2-Choice Reaction Time Task RF-EMF exposure results in little to no difference in speed (Hedges's g -0.023, 95 % CI [-0.13; 0.08], I2 = 0 %, 401 participants), and may result in little to no difference in accuracy (Hedges's g -0.063, 95 % CI [-0.38; 0.25], I2 = 63 %, 117 participants). For the domain Orientation and Attention, subclass Processing Speed - >2-Choice Reaction Time Task RF-EMF exposure results in little to no difference in speed (Hedges's g -0.054, 95 % CI [-0.14; 0.03], I2 = 0 %, 544 participants) and probably results in little to no difference in accuracy (Hedges's g -0.129, 95 % CI [-0.30; 0.04], I2 = 0 %, 131 participants). For the domain Orientation and Attention, subclass Processing Speed - Other Tasks RF-EMF exposure probably results in little to no difference in speed and does not reduce speed (Hedges's g 0.067, 95 % CI [-0.12; 0.26], I2 = 38 %, 249 participants); it results in little to no difference in accuracy (Hedges's g 0.036, 95 % CI [-0.08; 0.15], I2 = 0 %, 354 participants). For the domain Orientation and Attention, subclass Working Memory - n-back Task (0-3-back) we found Hedges's g ranging from -0.090, 95 % CI [-0.18; 0.01] to 0.060, 95 % CI [-0.06; 0.18], all I2 = 0 %, 237 to 474 participants, and conclude that RF-EMF exposure results in little to no difference in both speed and accuracy. For the domain Orientation and Attention, subclass Working Memory - Mental Tracking RF-EMF exposure results in little to no difference in accuracy (Hedges's g -0.047, 95 % [CI -0.15; 0.05], I2 = 0 %, 438 participants). For the domain Perception, subclass Visual and Auditory Perception RF-EMF exposure may result in little to no difference in speed (Hedges's g -0.015, 95 % CI [-0.23; 0.195], I2 = 0 %, 84 participants) and probably results in little to no difference in accuracy (Hedges's g 0.035, 95 % CI [-0.13; 0.199], I2 = 0 %, 137 participants). For the domain Memory, subclass Verbal and Visual Memory RF-EMF exposure probably results in little to no difference in speed and does not reduce speed (Hedges's g 0.042, 95 % CI [-0.15; 0.23], I2 = 0 %, 102 participants); it may result in little to no difference in accuracy (Hedges's g -0.087, 95 % CI [-0.38; 0.20], I2 = 85 %, 625 participants). For the domain Verbal Functions and Language Skills, subclass Verbal Expression, a meta-analysis was not possible because one of the two included studies did not provide numerical values. Results of both studies did not indicate statistically significant effects of RF-EMF exposure on both speed and accuracy. For the domain Construction and Motor Performance, subclass Motor Skills RF-EMF exposure may reduce speed, but the evidence is very uncertain (Hedges's g -0.919, 95 % CI [-3.09; 1.26], I2 = 96 %, 42 participants); it probably results in little to no difference in accuracy and does not reduce accuracy (Hedges's g 0.228, 95 % CI [-0.01; 0.46], I2 = 0 %, 109 participants). For the domain Concept Formation and Reasoning, subclass Reasoning RF-EMF exposure results in little to no difference in speed (Hedges's g 0.010, 95 % CI [-0.11; 0.13], I2 = 0 %, 263 participants) and probably results in little to no difference in accuracy and does not reduce accuracy (Hedges's g 0.051, 95 % CI [-0.14; 0.25], I2 = 0 %, 100 participants). For the domain Concept Formation and Reasoning, subclass Mathematical Procedures RF-EMF exposure results in little to no difference in speed (Hedges's g 0.033, 95 % CI [-0.12; 0.18], I2 = 0 %, 168 participants) and may result in little to no difference in accuracy but probably does not reduce accuracy (Hedges's g 0.232, 95 % CI [-0.12; +0.59], I2 = 86 %, 253 participants). For the domain Executive Functions there were no studies. DISCUSSION: Overall, the results from all domains and subclasses across their speed- and accuracy-related outcome measures according to GRADE provide high to low certainty of evidence that short-term RF-EMF exposure does not reduce cognitive performance in human experimental studies. For 16 out of 35 subdomains some uncertainty remains, because of limitations in the study quality, inconsistency in the results or imprecision of the combined effect size estimate. Future research should focus on construction and motor performance, elderly, and consideration of both sexes. OTHER: This review was partially funded by the WHO radioprotection programme. The protocol for this review was registered in Prospero reg. no. CRD42021236168 and published in Environment International (Pophof et al. 2021).

Site- and frequency-specific enhancement of visual search performance with online individual alpha frequency (IAF) repetitive transcranial magnetic stimulation (rTMS) to the inferior frontal junction.

In this study, repetitive transcranial magnetic stimulation was applied to either the right inferior frontal junction or the right inferior parietal cortex during a difficult aerial reconnaissance search task to test its capacity to improve search performance. Two stimulation strategies previously found to enhance cognitive performance were tested: The first is called "addition by subtraction," and the second condition utilizes a direct excitatory approach by applying brief trains of high-frequency repetitive transcranial magnetic stimulation immediately before task trials. In a within-subjects design, participants were given active or sham repetitive transcranial magnetic stimulation at either 1 Hz or at 1 Hz above their individual peak alpha frequency (IAF + 1, mean 11.5 Hz), delivered to either the right inferior frontal junction or the right inferior parietal cortex, both defined with individualized peak functional magnetic resonance imaging (fMRI) activation obtained during the visual search task. Results indicated that among the 13 participants who completed the protocol, only active IAF + 1 stimulation to inferior frontal junction resulted in significant speeding of reaction time compared to sham. This site- and frequency-specific enhancement of performance with IAF + 1 repetitive transcranial magnetic stimulation applied immediately prior to task trials provides evidence for the involvement of inferior frontal junction in guiding difficult visual search, and more generally for the use of online repetitive transcranial magnetic stimulation directed at specific functional networks to enhance visual search performance.

Dynamic response of sandwich functionally graded nanoplate under thermal environments and elastic foundations using dynamic stiffness method.

The present paper introduces the development of dynamic stiffness method for analyzing small-scale sandwich functionally graded nanoplates resting on elastic foundation in thermal environments. The mathematical formulation is based on classical plate theory in conjunction with nonlocal elasticity theory. The governing equation is derived using Hamilton's principle. The dynamic stiffness matrix is obtained through the application of the Levy displacement approach and assembled to form the global stiffness matrix. The final matrix is solved for natural frequency of the plates using the Wittrick-Williams algorithm. The proposed methodology is validated against existing literature, demonstrating a strong agreement. Various parametric studies explore the effects of thermal environments, volume fraction index, sandwich configurations, elastic foundation characteristics, nonlocal parameter and boundary conditions. The results show the versatility of the proposed approach in addressing small scaled complex engineering structures. This research significantly contributes to the understanding and analysis of sandwich functionally graded nanoplates, providing valuable insights for applications in aerospace, structural systems, sensors, actuators, and energy harvesting devices.

Sensorless control in full speed domain of interior permanent magnet synchronous motor based on hybrid observer.

Aiming at the problem that an Interior Permanent Magnet Synchronous Motor (IPMSM) cannot be smoothly started in zero-low speed range and smoothly transitioned to medium-high speed range by a single observer. This paper proposes a full-speed range control algorithm based on the fusion of pulsating high-frequency injection and back electromotive force (EMF) position error information. In the low-speed range or at start-up, a square-wave high-frequency signal is injected, and the obtained high-frequency current signal is processed to obtain the rotor position error information. The phase shift due to the introduction of a filter is reduced, which improves the control bandwidth and reduces the noise. To ensure smooth switching of the observer, the observer uses a dual second-order generalized integrator module to output the angular frequency in the low-speed range. A higher-order sliding mode observer based on an inverse EMF model obtains rotor position error information at high speeds. During switching, the rotor position information is processed by a fusion strategy, and the obtained hybrid information is fed into the system to improve the stability of the motor operation. A 0.2 kW IPMSM position sensorless vector control system verifies the algorithm's accuracy.

Acupuncture for migraine: A systematic review and meta-regression of randomized controlled trials.

OBJECTIVES: This meta-analysis aimed to explore the relationship between the dose of acupuncture sessions, acupuncture frequency, and acupuncture duration and its effects on migraine. METHODS: Eight databases were searched for randomized controlled trials (RCTs) evaluating the efficacy of penetrating manual acupuncture for migraine published in English and Chinese from inception to June 20, 2024. The robust-error meta-regression (REMR) approach and non-linear meta-regression with restricted cubic spline (RCS) were used to investigate the dose-response association between acupuncture sessions, acupuncture frequency, and acupuncture duration and the frequency of migraine attacks. The potential nonlinear relationships was tested by restricting the regression coefficient to zero and a P value＜0.1. The statistical analysis was conducted using Stata 17.0. The risk of bias was independently assessed by two reviewers using the Cochrane tool. The reporting quality for acupuncture procedures was evaluated by STRICTA criteria. RESULTS: Thirty-two RCTs involving 1562 participants were included, and the results showed a J-shaped dose-response association between acupuncture sessions, acupuncture frequency, and acupuncture duration and migraine attack frequency. After 16 acupuncture sessions, the change in the frequency of migraine attacks was 3.95 (95 %CI: 3.13 to 4.77). Three sessions of acupuncture a week resulted in a significant decrease in the frequency of migraine attacks, reaching 4.04 (95 % CI: 2.49 to 5.58). After two months of acupuncture, the frequency of migraine attacks decreased significantly, showing a difference of 4.05 (95 % CI: 3.61 to 4.49). Subsequently, the improvement trend gradually flattened, yielding diminishing benefits to patients. The risk of bias showed that seven studies were rated as "low risk", two were rated as "high risk", and the others were rated as "unclear risk". The reporting quality of RCTs of acupuncture for migraine remain suboptimal. CONCLUSIONS: A non-linear dose-response relationship was found between acupuncture sessions, acupuncture frequency, and acupuncture duration and migraine attack frequency. The results of our study recommend 16 sessions of acupuncture with a frequency of 3 sessions/week and a treatment duration of 1.5 to 2 months. REGISTRATION NUMBER: This meta-analysis has been registered on PROSPERO (CRD42023400493).

Female preference counteracts negative frequency dependent selection for a stable polymorphism in a livebearing fish.

The maintenance of variation within natural populations is key for natural selection to operate. Polymorphism is an intriguing form of variation that involves the persistence of multiple discrete phenotypes called morphs. Polymorphism is often explained by negative frequency dependent selection (NFDS), under which rare morphs have an advantage, such that no one morph takes over. We tested whether mating polymorphism is maintained by NFDS generated by female choice, in the livebearing poeciliid fish, Girardinus metallicus, whose males are either common, plain morphs or rare, black morphs. Females were treated with one morph for several weeks and tested with both, in mate choice and direct competition assays. Contrary to NFDS via female choice, females preferred the morph with which they were treated. This may disrupt the polymorphism given the rarity of black morphs in the wild, unless black morphs have other advantages: we found that black morphs tended to exhibit higher mating activity, and other studies have demonstrated that they are more aggressive. Interestingly, only black morphs display to females prior to copulation; however, there is little evidence for female preference for this morph or the mating display. These results suggest functions for the mating display of black morphs beyond courtship, including aggressive mate guarding, and prompt a discussion of what constitutes courtship behavior.

10 kHz spinal cord stimulation improves metrics of spinal sensory processing in a male STZ rat model of diabetes.

To explore why clinical 10 kHz spinal cord stimulation (10 kHz SCS) might improve neurological function in a model of painful diabetic neuropathy (PDN), the short-term behavioral, electrophysiological, and histological effects of 10 kHz SCS were studied using adult male streptozotocin (STZ)-induced diabetic Sprague-Dawley rats. Four testing groups were established: Naïve controls (N = 8), STZ controls (N = 7), STZ+Sham SCS (N = 9), and STZ+10 kHz SCS (N = 11). After intraperitoneal injection (60 mg/kg) of STZ caused the rats to become hyperglycemic, SCS electrodes were implanted in the dorsal epidural space over the L5-L6 spinal segments in the STZ+Sham SCS and STZ+10 kHz SCS groups and were stimulated for 14 days. The von Frey filament paw withdrawal threshold was measured weekly. At termination, animals were anesthetized and the electrophysiologic response of dorsal horn neurons (receptive field size, vibration, radiant warmth) of the ipsilateral foot was measured. Tissue from the plantar paw surface was obtained post-euthanization for intraepidermal nerve fiber density measurements. In comparison to other control groups, while no significant effect of 10 kHz SCS on peripheral intraepidermal nerve fiber density was observed, 10 kHz SCS 'normalized' the central neural response to vibration, receptive field, and paw withdrawal threshold, and elevated the neural response to tissue recovery from warm stimuli. These results suggest that short-term, low intensity 10 kHz SCS operates in the spinal cord to ameliorate compromised sensory processing, and may compensate for reduced peripheral sensory functionality from chronic hyperglycemia, thereby treating a broader spectrum of the sensory symptoms in diabetic neuropathy.

Enhancing waste sludge solubilization through radio frequency treatment perforating bacterial cells.

Sludge solubilization is known as a rate-limiting step of anaerobic digestion. Although radio frequency (RF) has been applied for sludge pretreatment due to its similar thermal effect as microwave, the potential non-thermal effects of RF treatment remain controversial. In this study, we demonstrate that RF pretreatment enhances the solubilization and lysis of sludge by 8.02%-19.69% through both thermal and non-thermal mechanisms with less energy input. Scanning electron microscope images provide direct evidence that RF-induced microcurrents penetrated bacterial cells, leading to the release of intracellular substances through formed pores. Additionally, the non-thermal effect of RF treatment which could weaken the cell protection and accelerate the lysis rate involves the disruption of binding forces between extracellular polymeric substances and microbial cells. On average, the utilization of RF at a frequency of 27.12 MHz demonstrates its efficacy as a sludge pretreatment technique, as evidenced by a 13.39% reduction in energy consumption and a 16.9% improvement in treatment performance compared to conductive heating (CH). The findings of this study elucidate the possible mechanism of RF treatment of sludge and could establish a theoretical basis for the practical application of RF treatment in sludge management.

Analysis of vibration signals near ground surface during blasting excavation of a tunnel in fractured rock.

This study aims to analyze the vibration signals near the ground surface due to the underneath drilling and blasting activities in a fissured rock tunnel. Blasting induced vibration on the ground surface was continuously monitored in a fissured rock tunnel drilling and blasting excavation project in field. Wavelet packet analysis of the vibration signals using Matlab was carried out for signal denoising, differential blasting delay time interval identification, and three-way time-frequency energy analysis. The results show that within a 30 m range from the palm face, the dominant frequency bands of blasting-induced vibrations on the ground surface were concentrated in the range of 0-130 Hz. Two prominent peak frequency bands were identified at 31.25-39.063 Hz (low-frequency band) and 93.75-101.56 Hz (high-frequency band), accounting for 12% of the total energy. Among the three directions of ground surface vibrations, the energy decay was the most significant in the x-direction (tunnel excavation direction), which amounted to 54.29% of the overall energy decay with increasing distance. The energy decay within the 50-80 Hz range was the most pronounced (more than 90%), when the angle between the vibration propagation direction and the fissure or joint direction was 75°. The conclusions provide the insights in the attenuation of blast-induced vibrations in fissured rock and can potentially assist in the design of blasting vibration control.

Associations of daily eating frequency and nighttime fasting duration with biological aging in National Health and Nutrition Examination Survey (NHANES) 2003-2010 and 2015-2018.

BACKGROUND: Information on the influences of daily eating frequency (DEF) and nighttime fasting duration (NFD) on biological aging is minimal. Our study investigated the potential associations of DEF and NFD with accelerated aging. METHODS: Out of 24212 participants in NHANES 2003-2010 and 2015-2018, 4 predicted age metrics [homeostatic dysregulation (HD), Klemera-Doubal method (KDM), phenoAge (PA), and allostatic load (AL)] were computed based on 12 blood chemistry parameters. Utilizing 24-h dietary recall, DEF was measured by the frequency of eating occurrences, while NFD was determined by assessing the timing of the initial and final meals throughout the day. Weighted multivariate linear regression models and restricted cubic spline (RCS) were utilized to examine the associations. RESULTS: Compared to DEF of ≤ 3.0 times, subjects with DEF ≥ 4.6 times demonstrated lower KDM residual [ß: -0.57, 95% confidence-interval (CI): (-0.97, -0.17)] and PA residual [ß: -0.47, 95% CI: (-0.69, -0.25)]. In comparison to NFD between 10.1 and 12.0 h, individuals with NFD ≤ 10.0 h were at higher HD [ß: 0.03, 95% CI: (0.01, 0.04)], KDM residual [ß: 0.34, 95% CI: (0.05, 0.63)], and PA residual [ß: 0.38, 95% CI: (0.18, 0.57)]. Likewise, those with NFD ≥ 14.1 h also had higher HD [ß: 0.02, 95% CI: (0.01, 0.04)] and KDM residual [ß: 0.33, 95% CI: (0.03, 0.62)]. The results were confirmed by the dose-response relationships of DEF and NFD with predicted age metrics. Lactate dehydrogenase (LDH) and globulin (Glo) were acknowledged as implicated in and mediating the relationships. CONCLUSIONS: DEF below 3.0 times and NFD less than 10.0 or more than 14.1 h were independently associated with higher predicted age metrics.

Insertable, dual-density dielectric barrier for acoustic pressure level reduction in a high-performance human head-only MRI system.

We report use of a dual-density dielectric barrier surrounding a detachable high-pass radiofrequency (RF) birdcage coil to achieve an order-of-magnitude reduction of acoustic noise in a high-performance head gradient system. The barrier consisted of a 4.5 mm-thick mass-loaded vinyl and a 6 mm-thick polyurethane foam. It was inserted into the radial gap between the birdcage coil and the RF shield in a prototype head-only gradient system at 3 T. More than 9 dBA reduction of sound pressure level was achieved on the average with representative, high acoustic-noise imaging sequences. Increased acoustic damping was apparent from acoustic impulse response functions. High dielectric constant of the mass-loaded vinyl effectively added distributed capacitance to the birdcage coil, lowering the resonance frequency, but not seriously degrading the RF transmission performance. The barrier occupied the radial space normally used for air cooling of the RF coil and the RF shield. The resulting omission of air cooling was found to be acceptable with efficient gradient thermal management and use of a high-resistivity RF shield for eddy current reduction. The proposed method can improve patient experience while preserving image quality in a high-power head-only gradient system.

On the application of hybrid deep 3D convolutional neural network algorithms for predicting the micromechanics of brain white matter.

BACKGROUND: Material characterization of brain white matter (BWM) is difficult due to the anisotropy inherent to the three-dimensional microstructure and the various interactions between heterogeneous brain-tissue (axon, myelin, and glia). Developing full scale finite element models that accurately represent the relationship between the micro and macroscale BWM is however extremely challenging and computationally expensive. The anisotropic properties of the microstructure of BWM computed by building unit cells under frequency domain viscoelasticity comprises of 36 individual constants each, for the loss and storage moduli. Furthermore, the architecture of each unit cell is arbitrary in an infinite dataset. METHODS: In this study, we extend our previous work on developing representative volume elements (RVE) of the microstructure of the BWM in the frequency domain to develop 3D deep learning algorithms that can predict the anisotropic composite properties. The deep 3D convolutional neural network (CNN) algorithms utilizes a voxelization method to obtain geometry information from 3D RVEs. The architecture information encoded in the voxelized location is employed as input data while cross-referencing the RVEs' material properties (output data). We further develop methods by incorporating parallel pathways, Residual Neural Networks and inception modulus that improve the efficiency of deep learning algorithms. RESULTS: This paper presents different CNN algorithms in predicting the anisotropic composite properties of BWM. A quantitative analysis of the individual algorithms is presented with the view of identifying optimal strategies to interpret the combined measurements of brain MRE and DTI. SIGNIFICANCE: The proposed Multiscale 3D ResNet (M3DR) algorithm demonstrates high learning ability and performance over baseline CNN algorithms in predicting BWM tissue properties. The hybrid M3DR framework also overcomes the significant limitations encountered in modeling brain tissue using finite elements alone including those such as high computational cost, mesh and simulation failure. The proposed framework also provides an efficient and streamlined platform for implementing complex boundary conditions, modeling intrinsic material properties and imparting interfacial architecture information.

Characteristics of lung resistance and elastance associated with tracheal stenosis and intrapulmonary airway narrowing in ex vivo sheep lungs.

BACKGROUND: Understanding the characteristics of pulmonary resistance and elastance in relation to the location of airway narrowing, e.g., tracheal stenosis vs. intrapulmonary airway obstruction, will help us understand lung function characteristics and mechanisms related to different airway diseases. METHODS: In this study, we used ex vivo sheep lungs as a model to measure lung resistance and elastance across a range of transpulmonary pressures (5-30 cmH2O) and ventilation frequencies (0.125-2 Hz). We established two tracheal stenosis models by inserting plastic tubes into the tracheas, representing mild (71.8% lumen area reduction) and severe (92.1%) obstructions. For intrapulmonary airway obstruction, we induced airway narrowing by challenging the lung with acetylcholine (ACh). RESULTS: We found a pattern change in the lung resistance and apparent lung elastance as functions of ventilation frequency that depended on the transpulmonary pressure (or lung volume). At a transpulmonary pressure of 10 cmH2O, lung resistance increased with ventilation frequency in severe tracheal stenosis, whereas in ACh-induced airway narrowing the opposite occurred. Furthermore, apparent lung elastance at 10 cmH2O decreased with increasing ventilation frequency in severe tracheal stenosis whereas in ACh-induced airway narrowing the opposite occurred. Flow-volume analysis revealed that the flow amplitude was much sensitive to ventilation frequency in tracheal stenosis than it was in ACh induced airway constriction. CONCLUSIONS: Results from this study suggest that lung resistance and apparent elastance measured at 10 cmH2O over the frequency range of 0.125-2 Hz can differentiate tracheal stenosis vs. intrapulmonary airway narrowing in ex vivo sheep lungs.

A novel hybrid LFC scheme for multi-area interconnected power systems considering coupling attenuation.

In this paper, a hybrid load frequency control (LFC) scheme is proposed for multi-area interconnected power systems to decouple the intricate double control objectives, by dividing all subareas into the responsible areas and the free areas. The LFC in the responsible area has the function of regulating both the local frequency and the tie-line power, while the control objective of the LFC in the free area is thus simplified to regulate the local frequency only. Then, addressing the complex network coupling and uncertain dynamics, an integrated LFC controller is proposed for the free areas, which consists of two parts, namely, the coupling attenuation baseline controller and the disturbance compensation controller. The coupling attenuation baseline controller satisfying the predefined bounded L2-Gain condition is derived based on the solution to a multi-player zero-sum differential game. Additionally, a novel generalized integral observer is designed to estimate the system's integrated disturbance, and the corresponding disturbance compensation controller is derived. After that, the ultimately uniformly bounded (UUB) stability of the integrated LFC controller combining baseline controller and disturbance compensation controller is proven rigorously. Finally, the performance superiority of the proposed hybrid LFC scheme is validated by the simulations in challenging operating modes.

A Pilot Real-World Study of Ultrasonography Findings of Hidradenitis Suppurativa in Indian Patients and Its Diagnostic and Therapeutic Implications.

Introduction Hidradenitis suppurativa (HS) is a multifactorial chronic inflammatory follicular disorder affecting apocrine gland-bearing areas of the body. We conducted an observational study to assess the ultrasonography (USG) findings in suspected HS patients at a tertiary care center in North India over 6 months. Aim The aim of this article was to study the USG findings in HS and correlate clinical and USG findings and scoring systems in HS with stage wise treatments. Materials and Methods All patients with a clinical suspicion of HS underwent an USG examination after clinical examination with a probe of 18 Hz frequency. Hurley's staging of patients was used to stage clinically, and the HS-SOS scoring and Doppler changes were assessed on USG. The treatment was revised in case of a change in the USG grading of severity. Results A total of 23 patients suspected of HS underwent USG evaluation, of which 12 (52%) were male and 9 (48%) were females, with the mean age being 25.3 years (range: 14-40 years). Based on the HS clinical grading, eleven patients (47.8%) were Hurley's stage I, six patients (26%) were stage II, and six patients (26%) were stage III. USG demonstrated that three patients had been misdiagnosed and had folliculitis (8.6%) and Crohn's disease (4.3%). Out of the remaining twenty patients with USG features of HS, based on HS SOS grading, three patients (15%) were grade I, seven (35%) were grade II, and ten (50%) were grade III. Of these, nineteen patients (95%) had axillary involvement, which was bilateral in 84% of cases. The other region affected was the groin in five patients (26.3%), while two had inframammary involvement (10.5%). On further characterization of the type of lesion, nodules (41; 40.6%) were the most common type of lesion by sinuses and thickened hair follicles in 31 (30.6%) patients. Based on USG findings, the management of 26% of patients was changed from medical to surgical intervention. Conclusion USG and Doppler are noninvasive bedside tools for the examination of HS, which helps to rule out differentials and delineate the extent and depth of the disease better by picking up subclinical lesions and help in determining disease activity by Doppler, which in turn helps in planning appropriate medical and surgical management of patients. It also identifies radiological parameters that help identify patients who could fail medical management.