Increase In Frequency Research Articles

Modal analysis of Lamb waves of steel pipeline with calcium deposits

The relevance of the work lies in the study of the effect of calcium deposits of various thicknesses on the inner walls of the pipeline on the parameters of its own vibrations.OBJECTIVE: To construct a mathematical model of a steel pipeline without deposits and with calcium deposits of various thicknesses on its inner walls. To perform a modal analysis of the natural vibrations of the steel pipeline. Theoretically confirm the dependence of the change in the oscillation frequency of the pipeline when exposed to sediments.METHODS. The paper highlights a method for analyzing the natural frequencies of the pipeline using the acoustic method of non-destructive testing, since it can be implemented with one-way access and does not violate the integrity of the object of control. In solving this problem, the method of mathematical analysis in the software package of finite element analysis was used. results. The article describes the relevance of the topic, discusses the main methods of non-destructive testing, and defines Lamb waves. A mathematical model of a steel pipeline section with out internal deposits and with calcium deposits of 5 different thicknesses has been constructed.CONCLUSION. Calculations have shown that the natural vibration frequencies of the pipeline without deposits and with calcium deposits change in the direction of increasing values, the frequency increase occurs in waves. The highest frequency values are obtained when modeling calcium deposits with a thickness of 10 mm on the walls of the pipeline.

Assessing Heatwave-Related Deaths among Older Adults by Diagnosis and Urban/Rural Areas from 1999 to 2020 in Slovenia

Background: The association between mortality and heatwaves is well documented. Heatwaves frequency, intensity, and duration increase with global climate change. The most vulnerable group for dying during heatwaves is older people. Knowing which diseases contribute to a higher number of deaths during heatwaves is important for planning appropriate public health preventive measures. Methods: We assessed the short-term association between the number of deaths for older adults (75+ years) and heatwaves in the years 1999 to 2020 in Slovenia. We estimated the relative risks (RR) with a 95% confidence interval for the number of deaths for the observed diagnosis (all causes, circulatory, respiratory) and urban vs. rural areas associated with heatwaves in Slovenia for each year, comparing the number of deaths during heatwaves with reference days. Results: Most years showed no significant increase in deaths during heatwaves for those aged 75 and older. However, in 2006, 2007, 2014, and 2015, there was a significant increase in deaths during heatwaves. For the general population, heatwaves were associated with an increase in deaths due to all causes: 10% more in 2006 and 26% more in both 2007 and 2014. For those aged 75 and older, heatwaves were associated with an increase in deaths due to all causes: 22% more in 2007, 27% more in 2014, and 28% more in 2015. For those aged 75 and older, heatwaves were associated with an increase in deaths due to circulatory system diseases: 25% more in 2006, 33% more in 2007, 30% more in 2014, and 27% more in 2015. Regarding urban vs. rural areas, in 2006 and 2012, the elderly in urban areas were more affected, with 33% and 26% more deaths, respectively. In contrast, in 2007, 2014, and 2015, old age population in rural areas was more affected, with 29%, 26%, and 31% more deaths, respectively. Conclusions: According to the literature data, older adults are most susceptible to the effects of extreme heat due to physiological changes that occur with aging, chronic diseases, certain medications, a sedentary lifestyle, and social isolation. The results of our study will help in planning appropriate preventive public health measures to better protect older adults during the next heatwaves in Slovenia.

An elevated rate of whole-genome duplications in cancers from Black patients

In the United States, Black individuals have higher rates of cancer mortality than any other racial group. Here, we examine chromosome copy number changes in cancers from more than 1800 self-reported Black patients. We find that tumors from self-reported Black patients are significantly more likely to exhibit whole-genome duplications (WGDs), a genomic event that enhances metastasis and aggressive disease, compared to tumors from self-reported white patients. This increase in WGD frequency is observed across multiple cancer types, including breast, endometrial, and lung cancer, and is associated with shorter patient survival. We further demonstrate that combustion byproducts are capable of inducing WGDs in cell culture, and cancers from self-reported Black patients exhibit mutational signatures consistent with exposure to these carcinogens. In total, these findings identify a type of genomic alteration that is associated with environmental exposures and that may influence racial disparities in cancer outcomes.

Patients' Experiences During the Long Journey Before Initiating Migraine Prevention with a Calcitonin Gene-Related Peptide (CGRP) Monoclonal Antibody (mAb).

Migraine is under-diagnosed and under-treated. Many people with migraine do not seek medical care, and those who do may initially receive a different diagnosis and/or be dissatisfied with provided care on their journey before treatment with a CGRP-mAb (calcitonin-gene-related-peptide monoclonal antibody). This is a cross-sectional, self-reported, online survey of subjects in Lilly's Emgality® Patient Support Program in 2022. Questionnaires collected insights into subjects' prior experiences with migraine and interactions with healthcare professionals before receiving CGRP-mAbs. Of the 250 participants with episodic and 250 with chronic migraine, 90% were female and white with a mean age of 26.2years (±11.9) at diagnosis and 40.6 (±12.0) years at survey enrollment. Many participants (71%) suspected they had migraine before diagnosis, with 31% reluctant to seek help. Of these, approximately one-third were unaware of treatment, did not think that a physician could do anything more for migraine, would not take them seriously, or were reluctant due to a previous unhelpful experience. Participants mainly received information from friends/family (47%) or the internet (28%). Participants initially sought treatment due to an increase in migraine frequency (77%), attacks interfering with work or school (75%), or increased pain intensity (74%). Subjects saw a mean of 4.1 (±4.3) healthcare providers before migraine diagnosis, and 20% of participants previously received a different diagnosis. Participants reported migraine causes included stress/anxiety/depression (42%), hormonal changes (30%), nutrition (20%), and weather (16%). Acute treatment of migraine included prescription (82%) and over-the-counter (50%) medications, changes in nutrition (62%), adjusting fluid intake (56%), and relaxation techniques (55%). Preventive medications included anticonvulsants (61%), antidepressants (44%), blood pressure-lowering medications (43%), and botulinum toxin A injections (17%). Most discontinuations were due to lack of efficacy or side effects. People with migraine describe reluctance in seeking health care, and misunderstandings seem common especially in the beginning of their migraine journey. Graphical abstract available for this article.

Endomorphin-2 (Endo2) and substance P (SubP) co-application attenuates SubP-induced excitation and alters frequency plasticity in neonatal rat in vitro preparations

Substance P (SubP) and endomorphin-2 (Endo2) are co-localized presynaptically in vesicles of neurons adjacent to inspiratory rhythm-generating pre-Botzinger Complex (preBotC) neurons but the effects of co-released SubP and Endo2 on respiratory motor control are not known. To address this question, SubP alone or a combination of SubP and Endo2 (SubP/Endo2) were bath-applied in a sustained (15-min) or intermittent (5-min application, 5-min washout, x3) pattern at 10–100 nM to neonatal rat brainstem-spinal cord preparations. During neuropeptide application, SubP/Endo2 co-applications generally attenuated SubP-induced increases in burst frequency and decreases in burst amplitude. With respect to frequency plasticity (long-lasting increase in burst frequency 60 min post-neuropeptide application), SubP-induced frequency plasticity was increased with sustained SubP/Endo2 co-applications at 20 and 100 nM. Intermittent SubP/Endo2 co-applications tended to decrease the level of frequency plasticity induced by intermittent SubP alone applications. SubP/Endo2 co-applications revealed potentially new functions for neurokinin-1 (NK1R) and mu-opioid (MOR) receptors on respiratory rhythm-generating medullary neurons.

Crystal Structure, Microstructure, and Dielectric and Electrical Properties of Ceramic Material Prepared Using Volcanic Ash

In the present work, the electrical and dielectric properties of ceramic samples prepared from volcanic ash were investigated. For this purpose, ceramic samples were prepared using milled volcanic ash with a binder material at a sintering temperature of 950 °C for 2 h. The chemical content of the milled volcanic ash was investigated using XRF. Differential thermal analysis and thermogravimetry were performed to determine the firing conditions. The crystalline phases and microstructures of the ceramic samples were investigated using XRD and SEM, respectively. Finally, the electrical and dielectric properties of the obtained samples were evaluated at a frequency ranging from 1 × 102 to 4 × 106 Hz and temperatures ranging from room temperature to 800 °C. The XRD results revealed that the ceramic samples contained three main phases: albite, hematite, and augite. Moreover, the microstructures of the samples exhibited a large crystal size with a dense surface. The conductivities and dielectric constants of the samples remained stable up to 500 °C. The real and imaginary parts of the dielectric constant decreased with an increase in frequency and increased with an increase in temperature. The results indicated that ceramics based on volcanic ash are promising for use in technological applications such as high-voltage power insulators.

Comparison of Four Body Composition Methods: Circumference Measurements, Eight-Point Bioelectrical Impedance Analysis up to 500 and 1000 kHz to Dual-Energy X-Ray Absorptiometry to Measure Body Fat Percentage

ABSTRACT Introduction A comparison of body composition assessments using military circumferences to bioelectrical impedance analysis (BIA) and the reference standard dual-energy X-ray absorptiometry (DEXA) can gauge effectiveness of assessments. High-frequency (500 KHz) direct segmental multifrequency bioelectrical impedance analysis (DSM-BIA) accurately calculates total water mass and body fat% (BF%), but it is unknown whether higher frequencies (1,000 KHz) increase measurement accuracy. The purpose was to compare DSM-BIA 500, DSM-BIA 1000, the DoD Circumference Method (CM), and the reference-standard DEXA. Materials and Methods Design: Cross sectional, observational study. Participants/Setting: A total of 62 participants from the military healthcare system (n = 25 males, 38.8 ± 11.4 years, n = 37 females 43.7 ± 15.95 years) were measured in an outpatient clinic setting. Statistical Analysis: BF% was estimated via DEXA, DSM-BIA 500, DSM-BIA 1000, and CM to identify the relationship between methods using Pearson correlation, intraclass correlation coefficients (ICCs), and Bland-Altman plots. The study was approved by the IRB from Walter Reed National Military Medical Center at Bethesda and Concordia University Chicago. Results Circumference Method BF% was moderately correlated with DSM-BIA 500 (males r = 0.63, ICC = 0.76; females r = 0.77, ICC = 0.85), DSM-BIA 1000 (males r = 0.59, ICC = 0.74; females r = 0.77, ICC = 0.85), and DEXA (males r = 0.62, ICC = 0.62; females r = 0.73, ICC = 0.82). DSM-BIA 500 BF% was strongly correlated with DSM-BIA 1000 (males r = 0.99, ICC = 0.99; females r = 0.99, ICC = 0.99) and DEXA (males r = 0.93, ICC = 0.94; females r = 0.89, ICC = 0.89). Lastly, DSM-BIA 1000 BF% was also strongly correlated with DEXA (males r = 0.93, ICC = 0.94; females r = 0.84, ICC = 0.90) (P for each reported r < 0.01). Bland-Altman analysis confirmed an overall mean bias of −1.72% CM vs. DEXA in females, indicating the tendency of CM to underestimate BF% compared to DEXA limits of agreement from −14.24 to 10.8. There was an upward slope of the linear relationship between the bias and mean of the measures (Beta = 0.34, P = 0.01). In the full cohort, there was an overall mean bias of 1.14% of CM vs. DSM BIA 1000, with CM tending to overestimate BF% compared to DSM BIA 1000 with limits of agreement −11.13 to 13.41%. There is an upward slope line of the linear relationship between the bias and the mean of the measures (Beta = 0.17, P = .03). Conclusion This study found that CM BF% was moderately correlated with DSM-BIA 500 kHz, DSM-BIA 1,000 kHz BIA, and DEXA. Both DSM-BIA 500 and DSM-BIA 1,000 kHz strongly correlated well with DEXA implying that there was no further increase in correlation with increased frequency. Additionally, there was proportional bias in BF% in the female group between CM and DEXA and in the total group between CM and DSM BIA 1000.

Increasing exposure of global croplands productivity to growing season heatwaves under climate warming

Abstract Growing season heatwaves that occur simultaneously over global croplands can negatively impact global food baskets. The long-term changes of growing season heatwaves, as well as their impacts on croplands productivity, are crucial to food security, but remain unclear. Here, we investigated changes in the frequency, intensity and magnitude of growing season heatwaves from the past to the future over the global croplands, based on observations and Coupled Model Intercomparison Project Phase 6 models. We introduced an index, gross primary productivity (GPP) exposure, as a proxy of the overall impact of heatwaves on cropland productivity. The results show that the frequency and intensity of growing season heatwaves have increased since 1950 and will continue throughout the 21st century. The increase of the annual accumulated magnitude of growing season heatwaves in the future is mainly contributed by the increase of heatwave frequency. This leads to a global-scale increase in the GPP exposure to growing season heatwaves, with Asia, North America, and Europe being the most affected. The continued increase in GPP exposure is dominated by increases in heatwaves rather than GPP itself. Under the lower emission scenario SSP1-2.6, the global cropland GPP exposure will reduce by 86.11% and 330.47% relative to that under SSP2-4.5 and SSP5-8.5 scenarios, respectively, by the end of 21st century. Our results provide crucial insights into potential impacts of heatwaves on cropland productivity and hence food security.

Assessing the value of harmful algal bloom forecasts in the Pacific Northwest

Abstract Over the past three decades, fisheries and livelihoods on the coasts of Washington and Oregon have been severely impacted by the presence of harmful algal blooms (HABs) that produce domoic acid, a neurotoxin that accumulates in shellfish and endangers public health. Among others, recreational razor clams and commercial Dungeness crab fisheries along the Pacific Northwest (PNW) have been negatively affected, jeopardizing the economies of coastal communities that depend on tourist revenues and income generated through visits of harvesters in the region. The PNW HAB Bulletin, launched in 2008, publishes forecasts on incoming HAB events, which has enabled managers to increase toxin monitoring in high-risk locations and proceed with selected harvesting at safe beaches and delays or closures of fishing seasons, as required. In light of the value of the HAB Bulletin to local managers and communities and the occasional challenges of securing sufficient resources to ensure its continuation, this study attempts to assess the value of information (VOI) for the predictions provided by the Bulletin. Results of the study show that ongoing financial support of the Bulletin is economically justifiable. The value of HAB forecast is positively related to three primary factors: the frequency of HAB events, the precision of forecast, and the number of social and economic sectors benefiting from the forecast. The expected increase in HAB frequency and intensity due to climate change, coupled with advancements in forecasting accuracy through technological development, is anticipated to enhance the value of the forecast program.

Psychological burden of hearing-impaired children and their parents through the COVID-19 pandemic.

Childhood hearing impairment has potential repercussions on the mental well-being of both children and their parents. As a vulnerable population in accessing health care services, they may face specific challenges, especially during the COVID-19 pandemic. This cross-sectional study aims to investigate the association between childhood hearing impairment and the mental health of children and their parents, and to assess health care utilization of hearing-impaired children and its impact on mental outcomes for both during the COVID-19 pandemic. Using the National Health Interview Survey (NHIS) database, we analyzed data for 15,989 children aged 5-17 and their corresponding parents. The correlations between childhood hearing impairment and mental outcomes were examined using logistic regression models. The 2020 (quarter 3 and quarter 4)-2021 NHIS data was singled out and re-analyzed, focusing on the utilization of medical care during the COVID-19 pandemic. After accounting for covariates, hearing-impaired children exhibited a higher frequency of anxiety (OR 2.33, 95% CI 1.79-3.02) or depression (OR 2.14, 95% CI 1.59-2.88). Parents of hearing-impaired children had significantly higher odds of a higher frequency of anxiety (OR 1.55, 95% CI 1.20-2.01) or depression (OR 1.73, 95% CI 1.30-2.29). Interaction effect of hearing impairment with survey year on parents' mental health outcomes was observed (p for interaction <0.1). Children with hearing loss had higher odds of reporting delayed medical care (OR 2.00, 95% CI 1.11-3.59) or canceled medical care (OR 1.96, 95% CI 0.98-3.96, p = 0.059) due to the pandemic. Delayed medical care (OR 12.41, 95% CI 2.78-55.46) or canceled medical care (OR 6.26, 95% CI 1.28-30.75) due to the COVID-19 pandemic significantly contributed to the increase of anxiety frequency in hearing-impaired children. Childhood hearing impairment exhibits a substantial impact on children's and parental mental health, which is further exacerbated by the COVID-19 pandemic. Families of hearing-impaired children appear to be in a vulnerable position during public health emergencies such as the COVID-19 pandemic, which can further exacerbate their mental outcomes.

Path loss modelling of mmwave outdoor propagation for 5G mobile systems at 28, 38, 60, and 73 GHz in four Nigerian cities

Millimetre-waves (mmWaves), a critical part of 5G, have not been extensively studied in the sub-Saharan tropical environment. This study was conducted to model the outdoor propagation path loss of mmWaves in four Nigerian cities at 28, 38, 60, and 73 GHz for 5G mobile systems: Abuja, Lagos, Ibadan, and Port Harcourt. The study utilised simulation data from a Composite Raytracing-Image-Method propagation model in MATLAB 2023a with OpenStreetMap 3D building maps to formulate the Close-In free-space Reference Distance (CI), Floating Intercept (FI), and Alpha–Beta-Gamma (ABG) large-scale path loss models. This model considered the specific atmospheric conditions, terrain, building materials and structures, and geographical layouts of each site. The study found that the path loss exponent ranged from 2.712 to 3.819 in line-of-sight scenarios, with shadow fading standard deviation (σCI) ranging from 11.778 to 37.199. In non-line-of-sight scenarios, the path loss exponent ranged from 3.375 to 5.033, with σCI ranging from 12.441 to 44.181 across the four frequencies studied. The ABG model consistently provided the most accurate predictions compared to CI and FI, particularly the mean absolute error and root mean square error values. However, performance varied across cities, frequencies, and scenarios, with Port Harcourt exhibiting the highest path loss values across all frequencies and scenarios, followed by Lagos. Furthermore, the omnidirectional large-scale path loss increases marginally as the frequency increases, except at 60 GHz, which had a higher path loss per distance than 73 GHz. Finally, the findings showed that the propagation characteristics of mmWaves for 5G networks in sub-Saharan tropical environments, such as Nigeria, exhibit significant variability based on factors such as atmospheric conditions, terrain, building materials, and geographical layouts. The formulated path loss models can be used to predict the coverage area and signal quality of millimetre-wave communication systems at these frequencies and locations.

Ultra‐Thin 3.5%Si Steel with Both Magnetic Properties and Mechanical Properties Produced by Different Process Routes of Large‐Scale Production

The microstructural and textural evolution, as well as the recrystallization kinetics under different cold‐rolling methods and their influencing mechanism on the properties of the thin‐gauge 3.5%Si nonoriented silicon steel, are investigated by electron backscattering diffraction, X‐ray diffractometer, tensile, and magnetic properties test. The results indicate that compared with the primary cold‐rolling process, the reduction rate of secondary cold‐rolling process is lower (58.3%), and many shear bands are formed in the coarse cold‐rolled sheet, which leads to the formation of strong Goss and cube texture after recrystallization annealing. Owing to the high annealing temperature, the average grain size of finished annealed sheet is little different under different cold‐rolling processes, so the mechanical properties and high‐frequency iron loss are basically the same. The iron loss of the secondary cold‐rolled products decreases with an increase in frequency, and the improvement in the iron loss of the high field (1.5 T) becomes larger than that of the low field (1.0 T). Given the high anisotropy index of the Goss texture, the iron loss anisotropy of the secondary cold‐rolled sheet is higher. Considering the magnetic and mechanical properties, the optimum process is the secondary cold rolling with the intermediate annealing temperature of 900 °C.

Rising Extreme Meltwater Trends in Greenland Ice Sheet (1950–2022): Surface Energy Balance and Large-Scale Circulation Changes

Abstract The Greenland Ice Sheet (GrIS) meltwater runoff has increased considerably since the 1990s, leading to implications for the ice sheet mass balance and ecosystem dynamics in ice-free areas. Extreme weather events will likely continue to occur in the coming decades. Therefore, a more thorough understanding of the spatiotemporal patterns of extreme melting events is of interest. This study aims to analyze the evolution of extreme melting events across the GrIS and determine the climatic factors that drive them. Specifically, we have analyzed extreme melting events (90th percentile) across the GrIS from 1950 to 2022 and examined their links to the surface energy balance (SEB) and large-scale atmospheric circulation. Extreme melting days account for approximately 35%–40% of the total accumulated melting per season. We found that extreme melting frequency, intensity, and contribution to the total accumulated June–August (summer) melting show a statistically significant upward trend at a 95% confidence level. The largest trends are detected across the northern GrIS. The trends are independent of the extreme melting percentile rank (90th, 97th, or 99th) analyzed and are consistent with average melting trends that exhibit an increase in similar magnitude and spatial configuration. Radiation plays a dominant role in controlling the SEB during extreme melting days. The increase in extreme melting frequency and intensity is driven by the increase in anticyclonic weather types during summer and more energy available for melting. Our results help to enhance the understanding of extreme events in the Arctic.

Analysis and Identification of Eccentricity of Axial-Flow Impeller by Variational Mode Decomposition

The axial-flow impellers are widely applied to industry due to their excellent hydraulic performance and simple structure, but they may be affected by their eccentricity during operation. This study compared and studied the effects of the axial-flow eccentricity of an impeller on hydraulic performance, impeller radial force, and downstream pressure pulsation of the unit. The research results indicate that impeller eccentricity has a small effect on hydraulic performance. Compared with the design conditions, the efficiency, power, and head changes caused by impeller eccentricity are all less than 1%, but the impeller eccentricity leads to a sharp increase in the radial force of the impeller. Under the design conditions, the average value of the radial force of the impeller is 31.38 N; under eccentric conditions, the average value of the radial force of the impeller increased by nine times, reaching 316.30 N. By analyzing the pressure pulsation signals decomposed by the VMD method, it is shown that the influence of eccentricity on pressure pulsation is mainly reflected in the increase in impeller frequency on pressure pulsation. Under design conditions, the corresponding amplitude of the impeller frequency is 2.6; under eccentric conditions, the amplitude corresponding to the impeller frequency increased by 100 times, reaching 274.4. This study elucidates the specific effects of axial impeller eccentricity, providing theoretical guidance for the safe and stable operation of axial-flow units, and has important engineering significance.

Investigating the effect of MXene reinforcement on the mechanical and vibrational behaviour of honeycomb core sandwich composite structures

Honeycomb core sandwich composite panels are now being employed in various industries and possess huge potential owing to the fact that they provide almost similar properties as that of traditional metallic materials with substantial reduction in weight and are extremely corrosion resistant. MXene nanosheets have caught attention of the scientific community owing their extraordinary physical, chemical and mechanical properties. In the present work, the effect MXene reinforcement on the bending and vibrational behaviour of honeycomb cored sandwich composite structures has been investigated using experimentation and finite element (FE) modeling. The honeycomb cored sandwich plates were fabricated and samples were tested via three-point bending and vibration test under various testing conditions. The SEM images revealed that the MXene nanosheets were well dispersed within the epoxy matrix when their mixture was prepared and the homogenous dispersion was also maintained in the fabricated honeycomb core. Also, the MXene and glass fibres were found to be well bonded with the matrix. As far as bending behaviour is concerned, the sandwich structure containing MXene reinforced honeycomb core displayed superior load bearing capacity and exhibited higher values of core shear strength and face sheet bending strength at all testing temperatures. Furthermore, the reinforcement of MXene resulted in an increase in the natural frequency for all the considered modes irrespective of the end conditions. For instance, the natural frequency of the honeycomb core sandwich composite plate at first mode increased by 5.5 % and 10.2 % under CFFF and CFCF boundary conditions, respectively, upon addition of MXene.

Performance analysis of a high-frequency two-stage proportional valve piloted by two high-speed on/off valve arrays

Two-stage proportional valves (TSPV) have been used extensively for electro-hydraulic control systems with large-flow applications. Due to the inherent characteristics of the pilot spool, such as hysteresis, motion quality, and dead zone, the dynamic performance of the traditional TSPV cannot be further improved. To solve this issue, this paper proposes a high-frequency two-stage proportional valve (HFTSPV) piloted by two high-speed on/off valve arrays, which integrates the advantages of dual nozzle flapper mechanism and parallel-connected valve technology. First, an entire mathematical model is established, in which some key parameters are estimated by experiments, such as the actual diameters and flow coefficients of orifices, and flow coefficient of pilot valve. Then, the influences of fixed orifices with different diameters on the dynamic characteristics of main spool are explored. Subsequently, the optimal diameter of fixed orifice is calculated theoretically by using the maximum pressure sensitivity and flow linearity, aiming to realize the high dynamic and small displacement fluctuation. Finally, step and sinusoidal tracking experiments show that the delay time of the HFTSPV is close to 3.3 ms, and the displacement fluctuation decreases with the increase of tracking frequency. Amplitude–frequency results indicate that −3 dB frequency of the HFTSPV reaches 16 Hz under ±50% full scale and 30 Hz under 0% –50% full scale.

Salivary DNA methylation derived estimates of biological aging, cellular frequency and protein expression as predictors of oral mucositis severity and survival in head and neck cancer patients

BackgroundOral mucositis is a painful and debilitating condition that occurs in the majority of head and neck cancer patients receiving radiation and/or chemotherapy. While some patient and treatment related factors are known to contribute to the incidence and severity of disease, reliable biomarkers remain elusive. In the following study, we investigated the association of salivary DNA methylation derived biological aging, cellular frequency and protein concentration measures with the severity of oral mucositis and overall survival in a cohort of head and neck cancer (HNC) patients (n = 103). MethodsDNA methylation profiling was performed on saliva samples obtained prior to treatment. Biological aging measures included Horvath2, PhenoAge, FitAge and GrimAge, and cellular frequency included epithelial and specific immune cell populations. ResultsSevere mucositis (i.e. grade 3 or 4) occurred in nearly half of patients. For malignant HNC patients (n = 84), every 1-SD increase in GrimAge was associated with 2.62-times risk of severe mucositis (95 % CI: 1.38, 5.57), while a 1-SD increase in monocyte frequency was associated with a decreased risk (OR [95 %CI]: 0.40 [0.18, 0.80]). Over a median follow-up of 53 months, 39 of 103 participants died. Six protein scores (TNFSF14, GCSF, MATN3, GDF8, nCDase, TNF-β) were associated with survival at q < 0.15. ConclusionWe provide evidence that the risk-related biological aging measure GrimAge may be a useful predictor of mucositis severity in HNC patients. Salivary monocyte frequency may be protective against mucositis, and this measure could be used as a predictive biomarker while also providing clues into the pathobiology of the disease.

Picosecond photoacoustic generation of ultrasounds with composites of graphene-decorated gold nanoparticles

Photoacoustic or light-to-pressure transducer materials exhibit tremendous potential across various disciplines and applications, embracing theragnostic ultrasounds and permeabilization of biological barriers for drug delivery or for gene transfection. Here, we report the photoacoustic response in the picosecond excitation regime of graphene and gold nanoparticles decorated graphene dispersed in a polydimethylsiloxane polymer matrix. A novel decoration method was developed to nucleate Au nanoparticles of 25 nm on the graphene surface without reducing agent. We observed that the picosecond excitation enforced by the stress confinement generates high-frequency waves, with bandwidths of −6 dB and −20 dB of around 70 MHz and 130 MHz respectively, and peak pressure > 5 MPa. Further, the presence of gold surface decoration leads to a better dispersibility of the flake into the polymer matrix and to an increasing bandwidth at −6 dB up to 85 MHz. The decrease in source thickness leads to an increase in ultrasound frequency, which retains its value even when the laser fluence is increased up to 150 mJ cm –2. This enables the generation of high pressures while keeping the same bandwidth. We experimentally show that the photoacoustic waveform can be tailored by changing the temporal duration of the laser light, the geometry of the acoustic source, and the nature of the graphene absorber. Flexible decoration and fabrication methods of thin films, along with the generation of high-frequency and high-pressure ultrasound waves, offer new perspectives for the use of physical methods to permeabilize biological barriers and develop high-resolution photoacoustic imaging systems.

Gestational and postnatal exposure to wildfire smoke and prolonged use of respiratory medications in early life

As wildfire frequency and severity increases, smoke exposures will cause increasingly more adverse respiratory effects. While acute respiratory effects of smoke exposure have been documented in children, longer term sequelae are largely unstudied. Our objective here was to examine the association between gestational and postnatal exposure to wildfire smoke and prolonged use of prescription medication for respiratory conditions in early childhood. Using Merative MarketScan claims data, we created cohorts of term children born in western states between 1 January 2010-31 December 2014 followed for at least three years. Using NOAA Hazard Mapping System data, we determined the average number of days a week that >25% of the population in a metropolitan statistical area (MSA) was covered by smoke within each exposure period. The exposure periods were defined by trimester and two 12 week postnatal periods. Medication use was based on respiratory indication (upper respiratory, lower respiratory, or any respiratory condition) and categorized into outcomes of prolonged use (⩾30 d use) (PU) and multiple prolonged uses (at least two prolonged uses) (MPU). We used logistic regression models with random intercepts for MSAs adjusted for child sex, birth season, and birth year. Associations differed by exposure period and respiratory outcome, with elevated risk of MPU of lower respiratory medications following exposure in the third trimester and the first 12 postnatal weeks (RR 1.15, 95% CI 0.98, 1.35; RR 1.21, 95% CI 1.05, 1.40, respectively). Exposure in the third trimester was associated with an increase in MPU of any respiratory among males infants only (male RR 1.22, 95% CI 1.00, 1.50; female RR 0.93, 95% CI 0.66, 1.31). Through novel use of prescription claims data, this work identifies critical developmental windows in the 3rd trimester and first 12 postnatal weeks during which environmental inhalational disaster events may impact longer-term respiratory health.

Detection of adulteration in Iranian grape molasses added glucose/fructose/sugar beet syrups with 13C/12C isotope ratio analysis method.

Grape molasses (GM), produced from grapes, is a traditional Iranian food and is widely consumed in Iran. However, GM adulteration is among the most widespread illegitimate procedures involving contamination of food with foreign materials, such as adding sugar-water solution, date syrup, sugar beet syrup, and grape sauce. This study used stable carbon 13C/12C isotope ratio analysis method to detect adulteration of GM samples with glucose syrups (GS), fructose syrups (FS), and beet sugar syrups (BS) at the ratio of 0%, 10%, 30%, and 50% (by weight). Physicochemical properties of GM including °Brix, conductivity, specific gravity, pH, moisture content, ash content, hydroxymethyl furfural, sugar content, and rheological properties of samples were investigated. The δ13C isotope ratio of the GM was determined as -26.61%, that of the GS as -13.23%, that of the FS as -13.42%, and that of the BS as -16.58%. The δ13C isotope ratio increased by the addition of adulterant syrups to GM. The addition of each adulterant syrup had a different effect on the physicochemical parameters; however, the °Brix and specific gravity had a positive correlation with the δ13C isotope ratio results. The magnitudes of G' and G" increase with an increase in frequency representing the viscoelastic behavior of samples. The obtained results of this study suggest the use of δ13C isotope ratio method as a fast and accurate method to investigate the adulteration of grape molasses.