Increase In Frequency Research Articles

Investigation of mutagenicity of styrene in tumor target and non-target tissues of transgenic Big Blue® mice.

Styrene has been shown to induce lung tumors in mice, but not in rats. The current study investigated the potential role of genotoxicity as an initial key event in the mode of action for styrene-induced lung tumors in mice. Transgenic male B6C3F1 Big Blue® mice were treated by oral gavage for 28 consecutive days with 0 (corn oil), 75, 150, or 300 mg/kg/day of styrene. The 300 mg/kg/day represented the tumorigenic dose in the oral gavage carcinogenicity study conducted in B6C3F1 mice. Following a 28-day expression period, mutant frequencies were assessed at the cII locus of the transgene in the tumor target (lung) and non-target tissues (liver, glandular stomach, and duodenum). Mice treated with N-ethyl-N-nitrosourea (40 mg/kg/day) by oral gavage on Days 1, 2, and 3 of the study and sacrificed on Day 56 served as the positive control group. Genomic DNA was extracted from the selected tissues, processed for the recovery of the transgene into infectious phage, plated onto Escherichia coli strain G1250, and incubated at 37°C for titer determination or at 24°C for the selection of mutant plaques. There were no treatment-related increases in mutant frequency in any of the tissues. The positive control group had a significant increase in the frequency of cII mutants assuring the adequacy of the experimental conditions to detect induced mutations. To conclude, mutagenicity is not considered a plausible initial key event in the mode of action for styrene-induced mouse lung tumors as these data support that styrene is not an in vivo mutagen.

Research on the effect of grinding force on the axial ultrasonic vibration-assisted grinding of Ti-6Al-4V with multi-grain conical grinding head

A multi-grain conical grinding head capable of performing both peripheral and end-face grinding was created in Abaqus to simulate conventional grinding (CG) and axial ultrasonic-assisted vibration grinding (AUVAG) on Ti-6Al-4V alloy. A comparative analysis was conducted to examine the effects of key grinding parameters on the fluctuation amplitude and mean value of grinding forces in CG and AUVAG. The mechanism of ultrasonic vibration’s influence on grinding forces was analyzed, and a theoretical model for normal and tangential grinding forces in peripheral grinding of Ti-6Al-4V was established. Additionally, the surface morphology of CG and AUVAG was analyzed. The study found that the fluctuation amplitude of grinding forces in both AUVAG and CG increases with the axial grinding depth, feed rate, ultrasonic amplitude, and ultrasonic frequency, while it decreases with increasing spindle speed. However, the fluctuation amplitude in AUVAG is greater than that in CG. The average grinding forces in both CG and AUVAG increase with the grinding depth and feed rate, and decrease with the spindle speed. Compared to CG, the mean F x ([Formula: see text]) and F y ([Formula: see text]) are lower in AUVAG, while the mean F z ([Formula: see text]) is higher. Under different axial grinding depths, the maximum reduction in [Formula: see text] and [Formula: see text] for AUVAG is 4.70% and 5.18%, respectively, while the maximum increase in [Formula: see text] is 77.48%. At different feed rates, the maximum reduction in [Formula: see text] and [Formula: see text] for AUVAG is 3.02% and 21.01%, respectively, while the maximum increase in [Formula: see text] is 81.67%. Under different spindle speeds, the maximum reduction in [Formula: see text] and [Formula: see text] is 7.20% and 17.82%, respectively, and the maximum increase in [Formula: see text] is 281%. As the ultrasonic amplitude and frequency increase, [Formula: see text] significantly rises, but the effect on [Formula: see text] and [Formula: see text] is weak. AUVAG improves the surface quality of the specimen.

Processing characteristics of C/C composites with nanosecond pulse laser

This study investigates the effects of the nanosecond pulse laser parameters on the processing characteristics of carbon fiber-reinforced carbon matrix (C/C) composites through a series of laser cutting experiments. It compares the cutting width, depth, heat-affected zone (HAZ) width, processed surface micro-morphology, as well as the oxidation characteristics of the material under different processing parameters. The HAZ width is analyzed in relation to the variations in the oxygen content. The results indicate that both the cutting width and depth initially increase and then decrease with increasing repetition frequency. Moreover, increasing the laser power and pulse width gradually increases the cutting width, depth, and HAZ width, whereas a higher scanning speed tends to reduce the cutting width and depth. Since changes in the processing power, scanning speed, and pulse width affect the HAZ, the oxygen content exhibits a proportional relationship with the HAZ width. In addition, an increase in the repetition frequency can expand the HAZ while reducing the oxygen content. A careful increase in the repetition frequency aids in lowering the ablation threshold of the material, leading to more material removal. Nevertheless, a continuous increase in energy density can trigger a fiber pull-out phenomenon and cause degradation of the matrix.

Influence of Ultrasound on the Rheological Properties, Color, Carotenoid Content, and Other Physical Characteristics of Carrot Puree

This study aimed to investigate the effect of ultrasonic frequencies (21 and 35 kHz) on the physical properties of carrot puree at different concentrations (9, 12, and 21 °Brix). The viscosity, total soluble content, density, color, and β-carotene content were tested. It was found that the viscosity of the puree, determined with respect to shear rate, concentration, and the use of ultrasonic treatment, indicates that the purees should be defined as shear thinning fluids. Moreover, a decrease in activation energy was observed with the increase in extract and ultrasonic treatment, which may cause changes in the rate of reactions occurring in the tested material. A significant effect of this may be the observed change in the color of the puree after ultrasonic treatment; the increase in frequency from 21 to 35 kHz caused an increase in redness and yellowness and a decrease in lightness, independently of concentration. The most significant color difference was noted in the puree with a 21 °Brix concentration, where a ΔE value of 21 was recorded. In contrast, the ΔE values for the other purees post-treatment remained below 5. The content of carotenoids did not change after sonication, independently of the concentration of carrot puree.

Comorbidity Pattern and Autonomic Nervous System Dysfunction in Patients with Chronic Vulvar Discomfort

This study examines novel concepts of comorbidity in patients with chronic vulvar discomfort using data from the DATRIV (Diagnostic Accuracy of Three Rings Vulvoscopy) study, which involved 328 participants categorized into four groups: asymptomatic individuals with normal or impaired vulvar skin and patients with chronic vulvar discomfort, classified as either vulvodynia or vulvar dermatosis. Clinical data were collected through a structured questionnaire and analyzed using statistical software, including StatSoft (Dell, Austin, TX, USA), Statistica 12 (TIBCO®, Palo Alto, CA, USA), and SPSS 20 (IBM, Armonk, NY, USA). The study received approval from the Institutional Review Board of Polyclinic Harni, and all participants provided written informed consent. The findings reveal significantly higher comorbidity rates in patients with chronic vulvar discomfort compared to other groups (p = 0.0000). A substantial percentage of asymptomatic participants with both normal (63.4%) and impaired (70.7%) vulvar skin also reported comorbid conditions. Analysis of comorbidity curves revealed distinct patterns of symptom progression, with a gradual increase in frequency from asymptomatic individuals to patients with vulvodynia, followed by a decline in vulvar dermatosis cases. These patterns highlight the central role of autonomic nervous system (ANS) dysfunction, where sympathetic hyperactivity and parasympathetic depression contribute to separate comorbidity chains. These dysfunctions may act independently or concurrently, leading to various health issues. The elevated comorbidity rates and overlapping symptomatology suggest complex pathophysiology driven by ANS dysregulation. Further research on comorbidity clusters may unveil new therapeutic targets and guide the development of multifaceted treatment strategies.

Improved simulation of compound drought and heat extremes in eastern China through CWRF downscaling

Abstract Given their profound socio-economic impact and increasing occurrence, compound drought and heat extremes (CDHEs) have become a focal point of widespread concern. Studies have attempted to reproduce and predict these extremes using general circulation models (GCMs); however, the performance of these models in capturing compound events remains controversial. This study presents an improved simulation of CDHE trends over eastern China by using the regional Climate-Weather Research and Forecasting model (CWRF) to downscale the projections of two GCMs that participated in the Coupled Model Intercomparison Project Phase 6. The results show that CWRF downscaling significantly improved the underestimation of CDHE trends in GCM historical simulations, aligning better with observed trends. Moreover, the improvements of CWRF downscaling in simulating CDHEs are more pronounced than those for univariate events, i.e. extreme drought and extreme heat events. This enhancement largely results from CWRF’s better representation of land-atmosphere interaction processes, as indicated by the more realistic spatial distributions and intensities of the land-atmosphere coupling strength index. Under the SSP245 and SSP585 scenario, CWRF downscaling again predicts a more rapid increase in regional mean CDHE frequency compared to GCMs, with values nearing or exceeding 0.4 by the mid-21st century, suggesting a significant future threat to the study region. This study highlights the important role of land-atmosphere interactions in shaping CDHEs and the efficacy of regional climate models to reduce uncertainty in compound event simulations.

A Numerical Study of Dynamic Behaviors of Graphene-Platelet-Reinforced ETFE Tensile Membrane Structures Subjected to Harmonic Excitation

This study presents a numerical investigation of the dynamic behavior of graphene platelet (GPL)-reinforced ethylene tetrafluoroethylene (ETFE) tensile membrane structures subjected to harmonic excitation. Modal and harmonic response analyses were performed to assess both the natural frequencies and the dynamic responses of the ETFE membrane. GPLs were employed as the reinforcements to enhance the mechanical properties of the membrane materials, whose Young’s modulus was predicted through the effective medium theory (EMT). Parametric studies were conducted to examine the impact of pre-strain and the attributes of the GPL reinforcements, including weight fraction and aspect ratio, on the natural frequencies and amplitude–frequency response curves of the membrane structure. The first natural frequency substantially increased from 5.46 Hz without initial strain to 31.0 Hz with the application of 0.1% initial strain, resulting in a frequency shift that moved the natural frequency out of the range of typical wind-induced pulsations. Embedding GPL fillers into ETFE membrane was another potential solution to enhance the dynamic stability of the membrane structure, with a 1% addition of GPLs resulting in a 48.6% increase in the natural frequency and a 45.1% reduction in resonance amplitude. GPLs with larger aspect ratios provided better reinforcement, offering a means to fine-tune the membrane’s dynamic response. These results underscore that by strategically adjusting both pre-strain levels and GPL characteristics, the membrane’s dynamic behavior can be optimized, offering a promising approach for improving the stability of structures subjected to wind-induced loads.

RBIO-10. RADIATION FRACTION SIZE DIFFERENTIALLY AFFECTS MYELOID-DERIVED SUPPRESSOR CELL (MDSC) SUBSETS IN WHO GRADE 1 MENINGIOMA

Abstract Meningiomas are often cured after focal therapy with surgical resection and/or radiotherapy (RT); however, a small proportion still recur. RT dose can be used to modulate anti-tumor immune responses, potentially through regulating immunosuppressive MDSCs. Here, we investigate the effect of a single fraction of RT (2Gy vs. 15Gy) on frequency and activation status of MDSC subsets in patients with WHO grade 1 meningioma. We hypothesize that 2Gy will promote immunosuppressive MDSC activity more than 15Gy. Fresh tumor cells from patients with a presumed diagnosis of meningioma were digested into primary cell cultures and treated with a single fraction of 2 or 15 Gy or were sham irradiated using a XRAD 320 Biological Irradiator. Cells were incubated for 18hrs prior to flow cytometric analysis. MDSC populations were identified as Live/Dead-CD11b+CD33+HLA-DR-. MDSC subsets were then divided into M-MDSC (CD14+CD15-) or G-MDSC (CD15+CD14-). Five WHO grade 1 meningiomas were analyzed. The total frequency of MDSCs in tumors increased from 3% with sham RT to 4% after irradiation with 2Gy (p=0.03). This was driven by a 2-fold increase in frequency of total M-MDSCs, as G-MDSCs decreased by half after 2Gy (p=0.03). After irradiation with 15Gy, M-MDSC frequency was nearly half that of 2Gy. The frequency of TGF-β+MDSCs increased after 15 Gy (p=0.02). The frequency of IL-10+G-MDSCs increased in response to 2Gy (p =0.03) but decreased 4-fold after 15Gy. 18hrs after 2Gy, IFN-γ+M-MDSCs increased compared to sham (p=0.01). In this small cohort of grade 1 meningiomas, a 2Gy fraction of RT appeared to support expansion of the M-MDSC subset. RT at both fraction sizes increased immunosuppressive cytokine producing-MDSCs: M-MDSC-IL-10; G-MDSC-TGF-β. These findings indicate the need for further studies to understand the subset-specific impact of RT on MDSC, a key immune cell type in brain cancers.

PATH-51. CENTRAL NERVOUS SYSTEM METASTASES ARE GENOMICALLY DIVERGENT FROM THEIR RESPECTIVE EXTRACRANIAL SITES

Abstract INTRODUCTION Next-generation sequencing (NGS) has become standard of care in establishing the diagnosis and guiding treatment of cancers. Our understanding of genomic evolution of brain metastases (BM) and leptomeningeal disease (LMD) from solid tumor malignancies remains limited. Here we present updated data from our pilot study. METHODS We prospectively collected clinical data and NGS of seventeen patients undergoing craniotomy for symptomatic BM from solid tumor malignancies or cerebrospinal fluid (CSF) sampling for LMD. Matched systemic and CNS analyses were performed using a research-based NGS assay. When extracranial disease tissue was unavailable, liquid NGS served as a surrogate. RESULTS CNS metastases were present at initial diagnosis in 10/17 and 11/17 patients had not received systemic therapy prior to CNS tissue sampling. The predominant cancer type was NSCLC (n=11), followed by breast cancer (n=3), ovarian high grade serous carcinoma (n=1), GEJ adenocarcinoma (n=1), and basosquamous carcinoma of skin (n=1). The mean tumor mutational burden in extracranial samples was 3.65 (SD 3.34; SEM 0.97), in contrast to CNS samples 21.63 (SD 26.47; SEM 7.64). Concordant mutations in matched sampling had an increase in CNS variant allele frequency (VAF) (27.8% vs 17.3%; arithmetic difference = 10.5, p=0.054) and CNS gene copy number alterations (CNA) (2.4 copies vs 0.8 copies; arithmetic difference = 1.6, p=0.171). Known driver alterations in EGFR, KRAS and PIK3CA were retained. LMD was present in 4/17 patients, with two present at enrollment and two developing during the study. CONCLUSIONS Matched sequencing reveals CNS metastases to harbor a significantly higher TMB, retention of primary driver alterations with a trend towards higher VAF and CNA of concordant mutations. While limited by small sample size, these data indicate genetic evolution in CNS metastases regardless of prior treatment status.

Characteristics and clinical course of myoclonus in Cavalier King Charles Spaniels.

Myoclonus has been described in aging Cavalier King Charles Spaniels (CKCS), but the natural course of the disease and response to treatment have not been described. Report the clinical features and course of myoclonus in CKCS. Twenty-seven caregivers provided questionnaire responses at a median of 24 months after the onset of myoclonus in their CKCS. Fifteen caregivers completed a second follow-up questionnaire at a median of 17 months after submission of the first questionnaire. The caregivers of affected CKCS were invited to provide video footage for review. Owners of CKCS with videos demonstrating myoclonus then completed the online questionnaire for further evaluation. A second shortened questionnaire was sent to participants at least 6 months after completion of the first. Most CKCS displayed spontaneous myoclonus affecting predominantly the head (25/27). Overall, the majority had episodes that increased in frequency (20/27) and severity (17/27). Eighteen dogs had developed changes in behavior since the onset of myoclonus. These dogs were typically older and had experienced myoclonic episodes for longer than dogs without behavioral changes. Generalized epileptic seizures were reported in 4/27 dogs. Ten dogs received medical treatment. Eight were prescribed levetiracetam; all had an initial decrease in episode frequency, but a subsequent increase in both frequency and severity of episodes was common. Myoclonus in CKCS tends to progress in frequency and severity regardless of treatment. Progressive behavioral changes suggestive of cognitive decline are common. These findings support the possibility of an underlying neurodegenerative process.

Study on the Effect of Lignin Removal Rate on the Dielectric Properties of Delignified Materials

To investigate the relationship between the lignin removal rate change of wood and its dielectric properties, this study employed Mongolian Scotch Pine and Paulownia as the test materials. The acidic sodium chlorite method was used to delignify the treated material, and the lignin removal rate was determined at a specified reaction time interval to ascertain the dielectric constant and the tangent of the dielectric loss angle. The findings revealed that: As the delignification process progresses, the lignin content declines, accompanied by a reduction in the dielectric constant at elevated frequencies. This decline reaches a plateau near 10 MHz. The results demonstrated that the dielectric constant of the samples decreased with an increase in frequency and exhibited a stabilizing effect near 10 MHz. However, the dielectric constant of delignified wood was significantly higher than that of untreated wood. Additionally, the dielectric constant exhibited a linear relationship with the increase in lignin removal rate, while the tangent of the dielectric loss angle demonstrated a tendency to increase and then decrease. An investigation into the dielectric properties of delignified wood can yield valuable data and a theoretical foundation for the development of wood-based dielectric materials.

High-precision reconstruction of a heat flux boundary via a programmable scanning electron beam controlled by the voltage waveform design method

A scanning electron beam can be used to construct heat flux boundaries (HFBs). However, the long current response time in the deflection coil using a current control method (CCM) cause the deviation of the current waveform, potentially reducing the accuracy of the reconstructed HFB relative to the target HFB. The impact of the current response time on the reconstruction accuracy increases as the field frequency increases, and the accuracy can be reduced from 0.89 to 0.69. To shorten the current response time and improve the reconstruction accuracy, a voltage waveform design method (VWDM) is introduced as a replacement for the CCM. The result indicates that the accuracy of the HFB reconstructed by a scanning electron beam controlled by the VWDM can reach 0.91. Additionally, increasing the maximum output voltage of the power amplifier used to generate the voltage can further improve the reconstruction accuracy of the HFB with the VWDM. This study provides a new approach for the accurate construction of HFBs for rapid thermal processing, additive manufacturing and thermal assessment of hypersonic vehicles.

Estimating Rainfall Anomalies with IMERG Satellite Data: Access via the IPE Web Application

This study assesses the possibilities of the Integrated Multi-satellite Retrievals for Global Precipitation Measurement (IMERG-GPM) to estimate extreme rainfall anomalies. A web application, the IMERG Precipitation Extractor (IPE), was developed which allows for the querying, visualization, and downloading of time-series satellite precipitation data for points, watersheds, country extents, and digitized areas. The tool supports different temporal resolutions ranging from 30 min to 1 week and facilitates advanced analyses such as anomaly detection and storm tracking, an important component for climate change study. To validate the IMERG precipitation data for anomaly estimation over a 22-year period (2001 to 2022), the Rainfall Anomaly Index (RAI) was calculated and compared with RAI data from 2360 NOAA stations across the conterminous United States (CONUS), considering both dry and wet climate regions. In the dry region, the results showed an average correlation coefficient (CC) of 0.94, a percentage relative bias (PRB) of −22.32%, a root mean square error (RMSE) of 0.96, a mean bias ratio (MBR) of 0.74, a Nash–Sutcliffe Efficiency (NSE) of 0.80, and a Kling–Gupta Efficiency (KGE) of 0.52. In the wet region, the average CC of 0.93, PRB of 24.82%, RMSE of 0.96, MBR of 0.79, NSE of 0.80, and KGE of 0.18 were computed. Median RAI indices from both the IMERG and NOAA indicated an increase in rainfall intensity and frequency since 2010, highlighting growing concerns about climate change. The study suggests that IMERG data can serve as a valuable alternative for modeling extreme rainfall anomalies in data-scarce areas, noting its possibilities, limitations, and uncertainties. The IPE web application also offers a platform for extending research beyond CONUS and advocating for further global climate change studies.

Fine-scale genetic structure and rare variant frequencies.

In response to the current challenge in genetic studies to make new associations, we advocate for a shift toward leveraging population fine-scale structure. Our exploration brings to light distinct fine-structure within populations having undergone a founder effect such as the Ashkenazi Jews and the population of the Quebec' province. We leverage the fine-scale population structure to explore its impact on the frequency of rare variants. Notably, we observed an 8-fold increase in frequency for a variant associated with the Usher syndrome in one Quebec subpopulation. Our study underscores that smaller cohorts with greater genetic similarity demonstrate an important increase in rare variant frequencies, offering a promising avenue for new genetic variants' discovery.

A novel life-cycle analysis framework to assess the performances of tall buildings considering the climate change

Structural performance against wind hazards is necessary in modern tall building design, especially for structures in the region prone to tropical cyclones. In fact, wind-related failures and building life-cycle analysis (LCA) may be impacted by climate change on the increase of frequency and intensity of tropical cyclones. In this study, a novel LCA framework considering the climate change is proposed, which includes taking into account the climate change via the serviceability failure cost for the cases where the building vibrates exceeding the corresponding thresholds. In detail, the non-stationary Poisson process is used to model the occurrence and intensity of tropical cyclones, which in turn leads to the financial loss of the coastal building. Specifically, the vulnerability of the building is derived considering both the uncertainty of the extreme wind speeds in the tropical cyclone boundary layer and the fragility curve which includes the uncertainty from the structural damping ratio. To estimate the maintenance cost, the financial values associated with maintenance-related operations and the emission of greenhouse gas are combined. In order to illustrate the proposed LCA framework, a case study targeting a 240 m high benchmark building located close to the coast of Hong Kong is conducted. In addition, the sensitivity of the damping ratio, limit threshold, and climate change are assessed via the LCA results of the benchmark building.

Computational and experimental studies of vibration-protective properties of a pneumatic wheel of the MTZ-82 BELARUS tractor with external spring-hydraulic mini-suspension

BACKGROUND: Currently used in various sectors of the national economy, numerous wheeled suspensionless vehicles on pneumatic tires have a low level of vibration protection of the frame and limited cross-country ability. Therefore, the development and study of the design characteristics of a pneumatic wheel with increased elastic-damping properties and cross-country ability is a relevant technical problem. AIM: Development of the design and study the vibration-protective properties of a pneumatic wheel with an external spring-hydraulic mini-suspension to improve the ride smoothness and cross-country ability of large-sized suspensionless vehicles. METHODS: A description of the design of a wheel with mini-suspension and a support roller is presented. The wheel modeling was carried out in the PascalABC software, which takes into account the nonlinearity of the total force of the pneumatic tire and the spring-hydraulic mini-suspension, which is installed parallel to the tire at an angle to the vertical axis of the wheel. The test method consisted of comparison of free and forced vibrations of the rear pneumatic wheel of the MTZ-82 BELARUS tractor with a 400-965/15.5-38 tire, which operated without and with mini-suspension at a vertical load of 0.6 tons and various excessive pressure in the tire. RESULTS: The results of computational and experimental studies show that if the tire is radially compressed by 75 mm, the excess pressure inside the pneumatic wheel almost does not change, and if the pressure in the tire decreases from 1.6 to 0.4 bar, the resonant vibration frequency of the standard wheel axle decreases by 25%, while the dynamic coefficient remains unacceptably high (more than 5), leading to the tire breakaway from the supporting surface. Installing a mini-suspension parallel to the wheel in the form of a spring-hydraulic shock-absorbing strut leads to an increase in the resonant frequency by 1 Hz, however, the resonant peaks are reduced by almost 3 times to a dynamic coefficient of 2.5...2, which significantly increases the ride smoothness of suspensionless vehicles and reduces the likelihood of wheel breakaway from the supporting surface. CONCLUSION: It was found with the studies that the proposed wheel with a mini-suspension as a spring-hydraulic strut and a support roller has a relatively simple design, ensures high vibration-protective properties with small amplitudes of kinematic disturbance and can be used to improve the ride smoothness and cross-country ability of wheeled suspensionless vehicles.

Diverging Projections of Future Droughts in High‐End Climate Scenarios for Different Potential Evapotranspiration Methods: A National‐Scale Assessment for Poland

ABSTRACTIt has been broadly reported that future climate change will most likely affect the spatio‐temporal distribution of water resources and consequently droughts. There is a prevailing notion that an increase in temperature and frequency of heat waves are expected to result in more intense droughts in the coming years. In this study, we aimed to evaluate the effect of the potential evapotranspiration (PET) method selection on future drought projections over Poland. In our study, simulations of the Soil and Water Assessment Tool (SWAT) model were conducted, utilising an ensemble of six EURO‐CORDEX projections, spanning the period from 2006 to 2100 under the RCP8.5 scenario. Two model setups with two different PET methods (Penman‐Monteith—PM and Hargreaves—HAR) were used. For drought conditions evaluation we selected the Standardized Precipitation Index (SPI) and Standardized Precipitation‐Evapotranspiration Index (SPEI) for meteorological drought, Standardized Streamflow Index (SSI) for hydrological drought, and Standardized Soil Moisture Index (SMI) for agricultural drought. The meteorological and hydrological droughts were calculated using a 12‐month time aggregation window, while agricultural drought was calculated using a 3‐month window. Climate projections revealed that by 2080s annual mean temperature and precipitation increase is expected by up to +3.4°C and +10.3% respectively. Under future climate conditions duration and severity of meteorological droughts are projected to decrease. PM method leads to a higher PET increases (1.35 mm year−1) than the HAR method (1.1 mm year−1) throughout the century which entail diverging signal of change for agricultural and hydrological droughts. PM‐ and HAR‐based simulations indicate increase in the total duration and cumulative severity of agricultural droughts, buthowever, for HAR‐based projections, the increase is much less. For hydrological droughts the signal of change is similar for both PET methods, but considerably distinct in magnitude. Considering the entire simulation period, by the end of the century cumulative severity of hydrological droughts is projected to decrease, with a much more pronounced decline for HAR (70% reduction) than for the PM method (35% reduction). Our study demonstrated that methodological choices are crucial to the assessment of future drought risk under climate change.

Application of narrow-band CE-Chirp NB ASSR in hearing threshold assessment of hearing-impaired children

Objective:To investigate the application value of NB CE-Chirp ASSR in the assessment of hearing threshold in children with hearing impairment. Methods:The hearing test results of 44 children with sensorineural hearing loss（88 ears） diagnosed in Shanghai Children's Hospital from January 2023 to December 2023 were retrospectively studied, including 19 ears in mild hearing loss group, 26 ears in moderate group, 20 ears in severe group and 23 ears in extremely severe group. Correlations between auditory brainstem response（ABR） thresholds, pure tone audiometry（PTA） thresholds and NB CE-Chirp ASSR response thresholds in different hearing loss groups were analyzed. Results:The threshold difference between ABR and NB CE-Chirp ASSR（2 000-4 000 Hz） was between 0.50-4.08 dB in different degrees of hearing loss group. There was a significant correlation between NB CE-Chirp ASSR and ABR response threshold in each group（P<0.001）, and the correlation coefficients of mild, severe and extremely severe groups were all greater than 0.8, showing a strong correlation. The average threshold difference between PTA and NB CE-Chirp ASSR in each group was between 1.88-3.91 dB. The correlation coefficients were all greater than 0.8, showing a strong correlation. The difference between PTA and NB CE-Chirp ASSR response threshold at 500, 1 000, 2 000 and 4 000 Hz in each groupwas between 0.25-3.84 dB. With the increase of frequency, the correlation coefficient between PTA and NB CE-Chirp ASSR response threshold showed an upward trend. The frequency with the highest coefficient was 4 000 Hz, and the r values were all greater than 0.9, followed by 2 000 Hz, and the correlation coefficient was relatively low at 500 Hz. In the extremely severe group, each frequency coefficient was greater than 0.7, showing a strong correlation. Conclusion:NB CE-Chirp ASSR has good frequency specificity and can reliably assess hearing thresholds in hearing-impaired children.

Deep water characteristics of electrodynamic transducers based on distributed-parameter equivalent circuit of acoustic cavity

The source level of the electrodynamic transducer with a passive pressure compensation airbag in ultra-low frequencies (bands below 100 Hz) decreases sharply with the increase in working depth. A theoretical model with a distributed-parameter equivalent circuit of the acoustic cavity was proposed to explore the mechanism of this phenomenon and find a way to improve the ultra-low frequency source level in deep water (over 200 m). The results indicate that the decrease in acoustic compliance of the cavity in deep water leads to an increase in resonant frequency, resulting in a decrease in source level in the ultra-low frequency band. The resonance frequency in deep water shows differences based on distributed and lumped parameter models. The resonance frequency test results of the prototype show that the theoretical results based on a distributed-parameter model proposed in this study are more consistent with the test values. The effects of the acoustic cavity's structural size, the acoustic parameters of the gas in the cavity, and the active pressure compensation method on the source level at different depths were analyzed. Results reveal that the acoustic performance in ultra-low frequency bands at large depths can be markedly improved using the active pressure compensation method.

Magnitude of antigen-specific T-cell immunity the month after completing vaccination series predicts the development of long-term persistence of antitumor immune response

BackgroundFor best efficacy, vaccines must provide long-lasting immunity. To measure longevity, memory from B and T cells are surrogate endpoints for vaccine efficacy. When antibodies are insufficient for protection, the...