Systematic analysis and modeling of the FLASH sparing effect as a function of dose and dose rate

Ultrahigh-dose-rate radiotherapy(FLASH-RT)is a revolutionary radiotherapy technology that can spare normal tissues without compromising tumor control.Although qualitative experimental results have been reported,quantitative and systematic analysis of data is necessary.Particularly,the FLASH effect response model to the dose or dose rate is still unclear.This study investigated the relationships between the FLASH effect and experimental parameters,such as dose,dose rate,and other factors by analyzing published in vivo experimental data from animal models.The data were modeled based on logistic regression analysis using the sigmoid function.The model was evaluated using prediction accuracy,receiver operating characteristic(ROC)curve,and area under the ROC curve.Results showed that the FLASH effect was closely related to the dose,mean dose rate,tissue type,and corresponding biological endpoints.The dose rate corresponding to a 50% probability of triggering cognitive protection in the brain was 45 Gy s^(-1).The dose rate corresponding to a 50% probability of triggering intestinal crypt survival and regeneration was 140 Gy s^(-1).For the skin toxicity effect,the dose corresponding to a 50% probability of triggering the FLASH effect was 24 Gy.This study helps to characterize the conditions underlying the FLASH effect and provides important information for optimizing experiments.

Bending Strength of Glass Materials under Strong Dynamic Impact and Its Strain Rate Effects

Based on the structural characteristics of the high-speed loading tester,a four-point bending test device was designed to carry out the four-point bending strength test of glass under the action of static load and different impact velocities,and the formulae for calculating the maximum dynamic stress and strain rate of glass specimens under the action of impact loads were derived.The experimental results show that the bending strength values of the glass under dynamic impact loading are all higher than those under static loading.With the increase of impact speed,the bending strength value of glass specimens generally tends to increase,and the bending strength value increases more obviously when the impact speed exceeds 0.5 m/s or higher.By increasing the impact velocity,higher tensile strain rate of glass specimens can be obtained because the load action time becomes shorter.The bending strength of the glass material increases with its tensile strain rate,and when the tensile strain rate is between 0 and 2 s^(-1),the bending strength of the glass specimen grows more obviously with the strain rate,indicating that the glass bending strength is particularly sensitive to the tensile strain rate in this interval.As the strain rate increases,the number of cracks formed after glass breakage increases significantly,thus requiring more energy to drive the crack formation and expansion,and showing the strain rate effect of bending strength at the macroscopic level.The results of the study can provide a reference for the load bearing and structural design of glass materials under dynamic loading.

Effect of Health Management in Raising Awareness Rate of Disease Prevention and Treatment in Patients with Prehypertension

Objective: To analyze the effect of health management on improving the awareness rate of disease prevention and treatment in patients with prehypertension, so as to provide guidance for clinical management of patients with prehypertension. Methods: 108 patients diagnosed with prehypertension in our hospital were divided into a control group and an experimental group. The control group was not given management measures, while the experimental group was given health management. The incidence of hypertension and cognition level of hypertension knowledge were compared between the two groups after management. Results: The incidence of hypertension in the experimental group was 7.41% lower than that in the control group 29.63%. The cognitive level of hypertension in the patients (66.54 ± 1.25) was significantly higher than that in the patients without health management (41.45 ± 2.45), and P < 0.05;Conclusion: For patients with prehypertension, the implementation of health management is helpful to improve their cognition of hypertension, master related prevention knowledge, and reduce the incidence of hypertension.

Impact of cooling rate on mechanical properties and failure mechanism of sandstone under thermal-mechanical coupling effect

High geo-temperature is one of the inevitable geological disasters in deep engineering such as resource extraction,space development,and energy utilization.One of the key issues is to understand the mechanical properties and failure mechanism of high-temperature rock disturbed by low-temperature airflow after excavation.Therefore,.the experimental and numerical investigation were carried out to study the impact of cooling rate on mechanical properties and failure mechanism of high temperature sandstone.First,uniaxial compression experiments of high temperature sandstone at different real-time cooling rates were carried out to study the mechanical properties and failure modes.The experimental results indicate that the cooling rate has a significant effect on the mechanical properties and failure modes of sandstone.The peak strain,peak stress,and elastic modulus decrease with an increase in cooling rate,and the fragmentation degree after failure increases gradually.Moreover,the equivalent numerical model of heterogeneous sandstone was established using particle flow code(PFC)to reveal the failure mechanism.The results indicate that the sandstone is dominated by intragrain failure in the cooling stage,the number of microcracks is exponentially related to the cooling rate,and the higher the cooling rate,the more cracks are concentrated in the exterior region.Under axial loading,the tensile stress is mostly distributed along the radial direction,and the damage in the cooling stage is mostly due to the fracture of the radial bond.In addition,axial loading,temperature gradient and thermal stress mismatch between adjacent minerals are the main reasons for the damage of sandstone in the cooling stage.Moreover,the excessive temperature gradient in the exterior region of the sandstone is the main reason for the damage concentration in this region.

Laser-assisted Simulation of Dose Rate Effects of Wide Band Gap Semiconductor Devices

Laser-assisted simulation technique has played a crucial role in the investigation of dose rate effects of silicon-based devices and integrated circuits,due to its exceptional advantages in terms of flexibility,safety,convenience,and precision.In recent years,wide band gap materials,known for their strong bonding and high ionization energy,have gained increasing attention from researchers and hold significant promise for extensive applications in specialized environments.Consequently,there is a growing need for comprehensive research on the dose rate effects of wide band gap materials.In response to this need,the use of laser-assisted simulation technology has emerged as a promising approach,offering an effective means to assess the efficacy of investigating these materials and devices.This paper focused on investigating the feasibility of laser-assisted simulation to study the dose rate effects of wide band gap semiconductor devices.Theoretical conversion factors for laser-assisted simulation of dose rate effects of GaN-based and SiC-based devices were been provided.Moreover,to validate the accuracy of the conversion factors,pulsed laser and dose rate experiments were conducted on GaN-based and SiC-based PIN diodes.The results demonstrate that pulsed laser radiation andγ-ray radiation can produce highly similar photocurrent responses in GaN-based and SiC-based PIN diodes,with correlation coefficients of 0.98 and 0.974,respectively.This finding reaffirms the effectiveness of laser-assisted simulation technology,making it a valuable complement in studying the dose rate effects of wide band gap semiconductor devices.

Research on the Intervention Effect of Vibroacoustic Therapy in the Treatment of Patients with Depression

Research purpose:This study implemented somatosensory music therapy on patients with depressive disorders,and explored the effects of somatosensory music therapy on the degree of depression,positive and negative emotions,intuitive stress and autonomic nervous function of patients.Research method:We collected 66 patients diagnosed with depression from the Department of Psychological Medicine of Henan Provincial People’s Hospital,and divided them into a control group and an intervention group according to the random number table,with 33 people in each group.The control group received routine psychiatric treatment and nursing.On the basis of the control group,the intervention group received somatosensory music therapy 3 times a week,30 min each time,for 4 consecutive weeks.The Hamilton Depression Scale,Positive and Negative Emotion Scale,Perceived Stress Scale,and Heart Rate Variability Index were collected and analyzed at baseline(T0),2 weeks after treatment(T1)and 4 weeks after treatment(T2).Research results:After 4 weeks of treatment,the HAMD scores of the two groups decreased to varying degrees,and the difference between the groups was statistically significant(p<0.05).After 4 weeks of treatment,the scores of positive emotions in both groups increased to varying degrees,and the scores of negative emotions increased to varying degrees.The scores decreased to varying degrees,and there were statistically significant differences between the positive and negative emotion groups(p<0.05).After 4 weeks of treatment,the CPSS scores of the two groups decreased to varying degrees,and the difference between the two groups was statistically significant(p<0.05).Analyzing the main effect of intervention factors alone,after 4 weeks of treatment,SDNN and RMSSD indexes all increased to varying degrees,and the degree of increase in the intervention group was greater than that in the control group,and the difference between the groups was statistically significant(p<0.05).Research conclusion:assisting somatosensory music therapy for patients with depressive disorders can improve depressive symptoms,increase positive emotions,reduce negative emotions,and reduce perceived stress.These are beneficial to restore the balance of autonomic nervous system,and are effective for the treatment of depression.

Risk factors for recurrence of common bile duct stones after surgical treatment and effect of ursodeoxycholic acid intervention

BACKGROUND Endoscopic retrograde cholangiopancreatography(ERCP)is an accurate diagnostic method for choledocholithiasis and treatment option for stone removal.Additionally,ursodeoxycholic acid(UDCA)can dissolve cholesterol stones and prevent their development and reappearance by lowering the cholesterol concen-tration in bile.Despite these treatment options,there are still patients who experience stone recurrence.The clinical data of 100 patients with choledochal stones who were hospitalized at the Yixing People’s Hospital and underwent ERCP for successful stone extraction between June 2020 and December 2022 were retrospectively collected.According to the post-ERCP treatment plan,100 patients were classified into UDCA(n=47)and control(n=53)groups.We aimed to assess the clinical efficacy and rate of relapse in the two patient populations.We then collected information(basic demographic data,clinical characteristics,and serum biochemical indicators)and determined the factors contributing to relapse using logistic regression analysis.Our secondary goal was to determine the effects of UDCA on liver function after ERCP.Compared to the control group,the UDCA group demonstrated a higher clinical effectiveness rate of 92.45%vs 78.72%(P<0.05).No significant differences were observed in liver function indices,including total bilirubin,direct bilirubin,gamma-glutamyl transpeptidase,alanine aminotransferase,alkaline phosphatase,and aspartate aminotransferase,between the two groups before treatment.After treatment,all liver function indices were significantly reduced.Comparing the control vs UDCA groups,the UDCA group exhibited significantly lower levels of all indices(55.39±6.53 vs 77.31±8.52,32.10±4.62 vs 45.39±5.69,142.32±14.21 vs 189.63±16.87,112.52±14.25 vs 149.36±15.36,122.61±16.00 vs 171.33±22.09,96.98±10.44 vs 121.35±11.57,respectively,all P<0.05).The stone recurrence rate was lower in the UDCA group(13.21%)in contrast with the control group(44.68%).Periampullary diverticula(OR:6.00,95%CI:1.69-21.30),maximum stone diameter(OR:1.69,95%CI:1.01-2.85),stone quantity>3(OR:4.23,95%CI:1.17-15.26),and positive bile culture(OR:7.61,95%CI:2.07-27.91)were independent factors that influenced the relapse of common bile duct stones after ERCP(P<0.05).Furthermore,postoperative UDCA was identified as a preventive factor(OR:0.07;95%CI:0.08-0.09).CONCLUSION The intervention effect of UDCA after ERCP for common bile duct stones is adequate,providing new research directions and references for the prevention and treatment of stone recurrence.

Evaluation of the Effectiveness and Efficiency of the Combination of Levamlodipine Besylate and Valsartan in the Treatment of Hypertension

Objective:To investigate the effectiveness and efficiency of combining levamlodipine besylate and valsartan in the treatment of hypertension.Methods:This study selected 28 patients with hypertension as observation subjects.The treatment duration ranged from January 2020 to June 2023.Using the random number table method,patients were divided into two groups.The control group received treatment with valsartan,while the observation group received a combination of valsartan and levamlodipine besylate.Therapeutic effects and safety were compared between the groups,and changes in the patient’s blood pressure and renal function index levels were assessed.Results:The total clinical effective rate of the observation group was significantly higher than that of the control group(P<0.05).The observation group demonstrated better diastolic blood pressure,systolic blood pressure,and renal function indicators compared to the control group(P<0.05).There was no significant difference in the incidence of adverse reactions between the two groups(P>0.05).Conclusion:The combined treatment of levamlodipine besylate and valsartan in patients with hypertension showed significant clinical efficacy and holds broad application value.

Evaluation of the Effect and Efficiency of Ear Tip Bloodletting Combined with Xianfang Huoming Yin in the Treatment of Early-Stage Wheals

Objective:To evaluate the effect and efficiency of ear tip bloodletting combined with Xianfang Huoming Yin(XFH)in the treatment of early-stage wheals.Methods:70 patients with early-stage wheals admitted from September 2020 to September 2022 were divided into two groups by randomized numerical table method,with 35 cases/group.Both groups received conventional treatment,the control group combined with XFH,and the observation group combined with ear tip bloodletting therapy and XFH.Conscious symptom scores,ocular indexes,therapeutic effects,and sleep quality between the two groups were compared.Results:After the treatment,the patients in the observation group had lower self-awareness symptom scores and sleep quality scores as compared to those in the control group;the diameter of the mass in the observation group was smaller than that of the control group after treatment;the average tear film rupture time and the time taken for the first non-contact tear film to rupture were longer in the observation group than those in the control group;the total effective rate of the treatment in the observation group was higher than that of the control group(P<0.05).Conclusion:Ear tip bloodletting combined with XFH was ideal for the treatment of early-stage wheals and has a high effective rate.

Strain-rate effect on initial crush stress of irregular honeycomb under dynamic loading and its deformation mechanism

The seemingly contradictory understandings of the initial crush stress of cellular materials under dynamic loadings exist in the literature, and a comprehensive analysis of this issue is carried out with using direct information of local stress and strain. Local stress/strain calculation methods are applied to determine the initial crush stresses and the strain rates at initial crush from a cell-based finite element model of irregular honeycomb under dynamic loadings. The initial crush stress under constant-velocity compression is identical to the quasi-static one, but less than the one under direct impact, i.e. the initial crush stresses under different dynamic loadings could be very different even though there is no strain-rate effect of matrix material. A power-law relation between the initial crush stress and the strain rate is explored to describe the strain-rate effect on the initial crush stress of irregular honeycomb when the local strain rate exceeds a critical value, below which there is no strain-rate effect of irregular honeycomb. Deformation mechanisms of the initial crush behavior under dynamic loadings are also explored.The deformation modes of the initial crush region in the front of plastic compaction wave are different under different dynamic loadings.

Model Building of the Initial Crown Effect Rate in 4-High Mill

The code for calculating the crown effect rate of hot strip steel Was developed using the effect function method. The effect of the initial crown on the crown of the product in hot strip rolling was investigated. The coefficients of a polynomial of degree six for calculating the base value of initial crown effect rate in 4-high mill were determined and the compensation factors of per unit width rolling force, bending force, work roll crown and draft on the initial crown effect rate were given. The difference between the calculation result by established model and theoretical value obtained by effect function method was 4.88 μm when the strip width was 1.85 m.

Effect of montmorillonite on hydrate-based methane separation from mine gas

Three types of mine gas samples were used in the solutions of tetrahydrofuran(THF),sodium dodecyl sulfate(SDS)and THF-SDS with/without MMT respectively to investigate the effect of montmorillonite(MMT)on separation characteristics of methane recovered from mine gas based on hydrate method.The partition coefficient,separation factor and recovery rate were used to evaluate the effects of MMT,and the selection factor was primarily proposed to define the selectivity of mine gas hydrate in the relative target gases.The experimental results indicate that MMT could improve the following factors including hydration separation factor,the selection factor,the partition coefficient,and the recovery rate.Furthermore,the effect of SDS on the function of MMT is analyzed in the process of hydration separation.Finally,due to the results of the experiment,it is concluded that MMT hydration mechanism explores the effect of MMT enrichment methane from mine gas.

Mechanical properties of deep sandstones under loading rate effect

The advance speed of the working face in coal mines can significantly affect the fluctuation frequency of abutment pressure in front of the coal body.Moreover,it has a certain correlation with the change of axial loading rate in coal and rock mechanics test.Therefore,uniaxial compression tests under various loading rates of 0.05,0.1,0.15,0.25,0.5 MPa/s were conducted using 2000 kN triaxial testing machine and PCI-2 acoustic emission test system to study the loading rate effect on the mechanical properties of deep sandstones.The results show that 1)the peak strength and elastic modulus of the deep sandstone increase with the loading rate increasing;2)with the loading rate increasing,the deep sandstone transforms from plastic-elastic-plastic to plastic-elastic and moreover,the failure mode gradually transfers from type I to type III;3)With the loading rate increasing,the total input strain energy,elastic strain energy,and dissipated strain energy generally increase;4)the damage variable presents the evolution characteristics of inverted“S”shape with time,and with the loading rate increasing,the damage degree of the deep sandstone is aggravated.The conclusion obtained can provide the theoretical basis for the stability control of the surrounding rock in deep engineering.

Asymmetric Effects on Escape Rates of Bistable System

The asymmetric effects on the escape rates from the stable states x±in the bistable system are analyzed. The results indicate that the multiplicative noise and the additive noise always enhance the particle escape from stable states x±of bistable.However,the asymmetric parameter r enhances the particle escape from stable state x_+,and holds back the particle escape from stable state x_-.

Effects of time lag and stress loading rate on permeability in low permeability reservoirs

In order to study the effect of time lag and stress loading rates on rock deformation,the conventional stepped stress loading mode was changed into a continuous mode to investigate the effect of effective pressure on permeability and porosity.The time lag effect of rock deformation illustrating the relationship between changes in permeability and steady time was studied.Permeability reduction ratios were measured under different stress loading rates which were achieved by different pump rate settings.The results show that permeability and porosity gradually decrease with increases in effective pressure.Permeability at high effective pressure attains stability quickly.Steady times at low effective pressure are very long.Reduction in permeability at lower stress loading rates is small,while,in contrast,it is large at high stress loading rates.

Numerical Derivation of Strain Rate Effects on Material Properties of Masonry with Solid Clay Bricks

In this paper, numerical method is used als. A typical unit of masonry is selected to serve merical model of RVE is established with detailed to study the strain rate effect on masonry materias a representative volume element （RVE）. Nudistinctive modeling of brick and mortar with their respective dynamic material properties obtained from laboratory tests. The behavior of brick and mortar are characterized by a dynamic damage model that accounts for rate-sensitive and pressuredependent properties of masonry materials. Dynamic loads of different loading rates are applied to RVE. The equivalent homogenized uniaxial compressive strength, threshold strain and elastic modulus in three directions of the masonry are derived from the simulated responses of the RVE. The strain rate effect on the masonry material with clay brick and mortar, such as the dynamic increase factor （DIF） of the ultimate strength and elastic modulus as a function of strain rate are derived from the numerical results.

Model Building of Backup Roller Diameter Effect Rate in 4-High Mill

Software for calculating the strip profile in 4-high hot rolling mill was developed using influence coefficient method. Regularity of backup roller diameter effect rate was studied systematically using the software. The results show that backup roller diameter effect rates decrease versus the increase of strip width, increase significantly versus the increase of backup roller diameter and obscurely increase versus the increase of reduction. The difference between backup roller diameter effect rate and it is reference value increases versus strip width increasing. When backup rollers diameter is set to be 1.64 m and strip width is 1.85 m, the error of strip profile calculated using the model of backup roller diameter effect rate reference value will be 3.55μm. Based on the results, reference values of roller diameter effect rate and six power polynomial fitting coefficients of modification coefficients were determined considering coherent parameters. The high precision model of backup roller diameter effect rate was established. When the model is used to predict strip profile, the accuracy is less than 5.0 μm.

Effects of Temperature and Strain Rate on Dynamic Properties of Concrete

To study the dynamic properties of the concrete subjected to impulsive loading, stress-time curves of concrete in different velocities were measured using split Hopkinson pressure bar (SHPB).Effects of temperature and strain rate on the dynamic yield strength and constitutive relation of the con-crete were analyzed. The dynamic mechanical properties of the reinforced concrete are subjected to high strain rates when it is at a relatively low temperature. But with temperature increasing, the temperature softening effect makes the strength of the concrete weaken and the impact toughness of the concrete is saliently relative to strain rate effect. So, strain rate effect, strain hardening and temperature softening work together on the dynamic mechanical capability of concrete and the relation between them is relatively complex.

Particle Size Distribution,Powder Agglomerates and Their Effects on Sinterability of Ultrafine Alumina Powders

An intensive study of the particle size distribution of four commercial ultrafine alumina powders to obtain information about the powder agglomeration and relate them to the compactibility and the sinterability has been made.

CLOUD RADIATIVE AND MICROPHYSICAL EFFECTS ON THE RELATION BETWEEN SPATIAL MEAN RAIN RATE, RAIN INTENSITY AND FRACTIONAL RAINFALL COVERAGE

Cloud radiative and microphysical effects on the relation between spatial mean rain rate, rain intensity and fractional rainfall coverage are investigated in this study by conducting and analyzing a series of two-dimensional cloud resolving model sensitivity experiments of pre-summer torrential rainfall in June 2008. The analysis of time-mean data shows that the exclusion of radiative effects of liquid clouds reduces domain mean rain rate by decreasing convective rain rate mainly through the reduced convective-rainfall area associated with the strengthened hydrometeor gain in the presence of radiative effects of ice clouds, whereas it increases domain mean rain rate by enhancing convective rain rate mainly via the intensified convective rain intensity associated with the enhanced net condensation in the absence of radiative effects of ice clouds. The removal of radiative effects of ice clouds decreases domain mean rain rate by reducing stratiform rain rate through the suppressed stratiform rain intensity related to the suppressed net condensation in the presence of radiative effects of liquid clouds, whereas it increases domain mean rain rate by strengthening convective rain rate mainly via the enhanced convective rain intensity in response to the enhanced net condensation in the absence of radiative effects of liquid clouds. The elimination of microphysical effects of ice clouds suppresses domain mean rain rate by reducing stratiform rain rate through the reduced stratiform-rainfall area associated with severely reduced hydrometeor loss.