We revisit the issue of whether the effective potential for the conformal factor of the metric,which is generated by quantized matter fields,possesses a non-vanishing vacuum expectation value(VEV)or not.We prove that ...We revisit the issue of whether the effective potential for the conformal factor of the metric,which is generated by quantized matter fields,possesses a non-vanishing vacuum expectation value(VEV)or not.We prove that the effective potential has a vanishing vacuum expectation value on the basis of a global GL(4)symmetry.We also account for why there seems to be two different effective potentials for the conformal factor in a theory,one of which gives rise to a vanishing VEV for the conformal factor,whereas the other has a non-vanishing VEV.展开更多
BACKGROUND Acute appendicitis(AP)is a frequently encountered surgical emergency,and appendectomy is conventionally regarded as the predominant treatment moda-lity.Nevertheless,the therapeutic efficacy of this surgical...BACKGROUND Acute appendicitis(AP)is a frequently encountered surgical emergency,and appendectomy is conventionally regarded as the predominant treatment moda-lity.Nevertheless,the therapeutic efficacy of this surgical approach remains to be improved.Thus,the exploration and implementation of surgical refinements are necessary.AIM To elucidate the therapeutic effectiveness and influencing factors of laparoscopic appendectomy(LA)with mesoappendix dissection in the treatment of AP.METHODS First,150 patients with AP who visited Shangrao Municipal Hospital between January 2022 and June 2024 were enrolled in this study.Among them,72 patients were assigned to the control group to receive conventional LA,whereas 78 cases were included in the observation group for LA with mesoappendix dissection.Subsequently,indicators such as therapeutic effectiveness,surgical indices(ope-ration time,intraoperative blood loss,and hospital stay),postoperative recovery indices(time to ambulation,gastrointestinal function recovery time,and time to food intake),incidence of adverse events(postoperative bleeding,pelvic infection,puncture site infection,and ileus),and serum inflammatory factors[tumor necro-sis factor(TNF)-α,interleukin(IL)-6,and C-reactive protein(CRP)]were collected and comparatively analyzed,and the influencing factors of therapeutic effecti-veness in patients with AP were analyzed.RESULTS Compared with the control group,the observation group had higher clinical the-rapeutic effectiveness,less operation time,intraoperative blood loss,and hospital stay;shorter time to ambulation,gastrointestinal function recovery,and food intake;and a lower total incidence of adverse events,and this difference is statistically significant.In addition,the expression levels of various serum inflammatory factors in the observation group were significantly reduced postoperatively,which were markedly lower than those in the control group.Moreover,sex,age,body mass index,time from acute onset to admission,family medical history,preoperative TNF-α,preoperative IL-6,preoperative CRP,and treatment modality were identified to be not independent factors affecting the therapeutic effectiveness of LA with mesoappendix dissection in patients with AP.CONCLUSION Overall,LA with mesoappendix dissection has a remarkable curative effect in treating patients with AP,which is worthy of clinical promotion.展开更多
The topographic factor(LS factor),derived from the multiplication of the slope length(L)and slope steepness(S)factors,is a vital parameter in soil erosion models.Generated from the digital elevation model(DEM),the LS ...The topographic factor(LS factor),derived from the multiplication of the slope length(L)and slope steepness(S)factors,is a vital parameter in soil erosion models.Generated from the digital elevation model(DEM),the LS factor always varies with the changing DEM resolution,i.e.,the LS factor scale effect.Previous studies have found the phenomenon of the LS factor scale effect,but the underlying causes of this phenomenon has not been well explored.Therefore,how the DEM resolution affects the LS factor and how the scale effect of the L and S factors influence the LS factor scale effect remains unclear.To address these problems,we collected 20 watersheds from the Guangdong Province with different topographic reliefs,and compared the corresponding L,S and LS factors at 10-m and 30-m resolution DEMs.Our results indicate that the S factor,heavily influenced by slope underestimation in coarse-resolution DEMs,makes a difference in the LS factor scale effect.In addition,the LS factor scale effect becomes less significant with increasing reliefs,suggesting the possibility of using 30-m DEM for LS calculation in rugged terrains.Our findings on the underlying mechanisms of the LS factor scale effect help to identify the uncertainty in the LS factor estimation,thereby enhancing the accuracy of soil erosion assessment,particularly in regions with different topographic characteristics and contribute to more effective soil conservation strategies and decision-making.展开更多
Based on the observation data of meteorological observation stations in Jining City during 1970-2024,MK mutation test and principal component analysis(PCA)were used to study the evolution characteristics of urban heat...Based on the observation data of meteorological observation stations in Jining City during 1970-2024,MK mutation test and principal component analysis(PCA)were used to study the evolution characteristics of urban heat island intensity(UHII)and the contribution rate of various influencing factors in Jining City over the past 55 years.The results show that from 1970 to 2024,the UHII in Jining City generally rose at a rate of 0.1℃/10 a.On the interannual scale,the correlation between temperature and UHII was most significantly positive.On the seasonal scale,there was a strong negative correlation between wind speed and UHII.PCA reveals that temperature had a significant positive impact on the increase of UHII in Jining City.展开更多
AIM To analyze the efficacy of laparoscopic radical resection of CRC(LRRCC)in treating older patients with CRC and the effect of this procedure on inflammatory factors.METHODS The study included 104 older patients wit...AIM To analyze the efficacy of laparoscopic radical resection of CRC(LRRCC)in treating older patients with CRC and the effect of this procedure on inflammatory factors.METHODS The study included 104 older patients with CRC admitted from August 2022 to August 2024.Participants undergoing open radical resection of CRC were categorized as the control group(50 patients),whereas those receiving LRRCC were classified as the research group(54 patients).Subsequently,comparative analyses involved data on efficacy,postoperative complications(ileus,incision infection,anastomotic fistula,and pulmonary infection),surgery-related parameters(operation duration and intraoperative bleeding volume),postoperative recoveryrelated indicators(time to first postoperative passage of flatus and defecation and length of hospital stay),and inflammatory factors(tumor necrosis factor-α,highsensitivity C-reactive protein,and interleukin-6).RESULTS Data revealed markedly superior therapeutic efficacy and a lower overall postoperative complication rate in the research group compared to the control group.The research group demonstrated substantially less intraoperative bleeding,less time to first postoperative passage of flatus and defecation,and a shorter length of hospital stay despite a notably longer operation duration compared to the control group.Further,tumor necrosis factor-α,high-sensitivity C-reactive protein,and interleukin-6 levels in the research group were significantly reduced 3 days postoperatively compared to both the preoperative and control group values.CONCLUSION LRRCC for older patients with CRC exhibited superior therapeutic efficacy compared to open radical resection and significantly suppressed postoperative stress-related inflammatory responses,which merits clinical application and promotion.展开更多
This study was an attempt to examine the effective factors of the Multiple Sclerosis diseases. The participants of the study were selected from among a total number of 45 men and women who were treated in a health cen...This study was an attempt to examine the effective factors of the Multiple Sclerosis diseases. The participants of the study were selected from among a total number of 45 men and women who were treated in a health center in Azarbayegan and Damavand in Iran. In order to study, the researchers applied various procedures to collect the data of the study. The participants were interviewed and filled out the questionnaires. After categorizing and classifying the collected information and data, it was processed and analyzed and the results are found. To test the research questions, a one-sample T-test was used to analyze the data. The role of hypo vitamin D as a possible risk factor for multiple sclerosis was reviewed. First, it was emphasized that hypo vitamin could be only one of the risk factors for multiple sclerosis and that numerous other environmental and genetic risk factors appear to interact and combine to trigger the disease. The main aim of this study was to examine the effective factors of Multiple Sclerosis diseases. The methodology of this research was to test the research questions;one-sample T-test was used to analyze the data. The findings of this study revealed that the factors of gender, cold weather, vitamin D deficiency, and age (between 30 - 59) were effective on the Multiple Sclerosis diseases.展开更多
The fractal theory was introduced into the gas solid catalytic reaction system to describe the influence of the surface irregularity of catalyst on the gas solid catalytic reaction.A fractal reaction diffusion mode...The fractal theory was introduced into the gas solid catalytic reaction system to describe the influence of the surface irregularity of catalyst on the gas solid catalytic reaction.A fractal reaction diffusion model is proposed for irregular particles.Based on the shape characterization of the irregular particle,the mth order irreversible reactions are theoretically analyzed.A steady state equation of material balance and its solution as the concentration profile of reacting species are given for the reaction diffusion model for irregular particles.Meanwhile,the effectiveness factors are also expressed with fractal dimension.The results indicate that the higher the fractal dimensions,the higher the total reaction rate,and with the increase of the fractal dimension,the utilization factor of the catalyst is deeply increased.展开更多
BACKGROUND Endoscopic retrograde cholangiopancreatography(ERCP)is an accurate diagnostic method for choledocholithiasis and treatment option for stone removal.Additionally,ursodeoxycholic acid(UDCA)can dissolve choles...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.展开更多
BACKGROUND Depression is a common and serious psychological condition,which seriously affects individual well-being and functional ability.Traditional treatment methods include drug therapy and psychological counselin...BACKGROUND Depression is a common and serious psychological condition,which seriously affects individual well-being and functional ability.Traditional treatment methods include drug therapy and psychological counseling;however,these methods have different degrees of side effects and limitations.In recent years,nonconvulsive electrotherapy(NET)has attracted increasing attention as a noninvasive treatment method.However,the clinical efficacy and potential mechanism of NET on depression are still unclear.We hypothesized that NET has a positive clinical effect in the treatment of depression,and may have a regulatory effect on serum inflammatory factors during treatment.AIM To assess the effects of NET on depression and analyze changes in serum inflammatory factors.METHODS This retrospective study enrolled 140 patients undergoing treatment for depression between May 2017 and June 2022,the observation group that received a combination of mindfulness-based stress reduction(MBSR)and NET treatment(n=70)and the control group that only received MBSR therapy(n=70).The clinical effectiveness of the treatment was evaluated by assessing various factors,including the Hamilton Depression Scale(HAMD)-17,self-rating idea of suicide scale(SSIOS),Pittsburgh Sleep Quality Index(PSQI),and levels of serum inflammatory factors before and after 8 wk of treatment.The quality of life scores between the two groups were compared.Comparisons were made using t and χ^(2) tests.RESULTS After 8 wk of treatment,the observation group exhibited a 91.43%overall effectiveness rate which was higher than that of the control group which was 74.29%(64 vs 52,χ^(2)=7.241;P<0.05).The HAMD,SSIOS,and PSQI scores showed a significant decrease in both groups.Moreover,the observation group had lower scores than the control group(10.37±2.04 vs 14.02±2.16,t=10.280;1.67±0.28 vs 0.87±0.12,t=21.970;5.29±1.33 vs 7.94±1.35,t=11.700;P both<0.001).Additionally,there was a notable decrease in the IL-2,IL-1β,and IL-6 in both groups after treatment.Furthermore,the observation group exhibited superior serum inflammatory factors compared to the control group(70.12±10.32 vs 102.24±20.21,t=11.840;19.35±2.46 vs 22.27±2.13,t=7.508;32.25±4.6 vs 39.42±4.23,t=9.565;P both<0.001).Moreover,the observation group exhibited significantly improved quality of life scores compared to the control group(Social function:19.25±2.76 vs 16.23±2.34;Emotions:18.54±2.83 vs 12.28±2.16;Environment:18.49±2.48 vs 16.56±3.44;Physical health:19.53±2.39 vs 16.62±3.46;P both<0.001)after treatment.CONCLUSION MBSR combined with NET effectively alleviates depression,lowers inflammation(IL-2,IL-1β,and IL-6),reduces suicidal thoughts,enhances sleep,and improves the quality of life of individuals with depression.展开更多
Roof disaster has always been an important factor restricting coal mine safety production.Acidic effect can reform the rock mass structure to weaken the macroscopic strength characteristics,which is an effective way t...Roof disaster has always been an important factor restricting coal mine safety production.Acidic effect can reform the rock mass structure to weaken the macroscopic strength characteristics,which is an effective way to control the hard limestone roof.In this study,the effects of various factors on the reaction characteristics and mechanical properties of limestone were analyzed.The results show that the acid with stronger hydrogen production capacity after ionization(pK_(a)<0)has more prominent damage to the mineral grains of limestone.When pKa increases from−8.00 to 15.70,uniaxial compressive strength and elastic modulus of limestone increase by 117.22%and 75.98%.The influence of acid concentration is manifested in the dissolution behavior of mineral crystals,the crystal defects caused by large-scale acid action will lead to the deterioration of limestone strength,and the strength after 15%concentration reformation can be reduced by 59.42%.The effect of acidification time on limestone has stages and is the most obvious in the initial metathesis reaction stage(within 60 min).The key to the strength damage of acidified limestone is the participation of hydrogen ions in the reaction system.Based on the analytic hierarchy process method,the influence weights of acid type,acid concentration and acidification time on strength are 24.30%,59.54% and 16.16%,respectively.The research results provide theoretical support for the acidification control of hard limestone roofs in coal mines.展开更多
BACKGROUND In patients with liver failure(LF),the high rate of secondary infections,which are associated with poor prognosis,highlights the clinical significance of understanding the underlying risk factors and implem...BACKGROUND In patients with liver failure(LF),the high rate of secondary infections,which are associated with poor prognosis,highlights the clinical significance of understanding the underlying risk factors and implementing targeted intervention programs.AIM To investigate risk factors for secondary infections in patients with LF and evaluate the effectiveness of comprehensive nursing interventions.METHODS This retrospective study included 64 patients with LF,including 32 with and 32 without secondary infections.A questionnaire was used to collect data on age;laboratory parameters,including total and direct bilirubin,prothrombin time,blood ammonia,and other biochemical parameters;invasive procedures;and complications.Patients with secondary infections received comprehensive nursing intervention in addition to routine nursing care,whereas those without secondary infections received only routine nursing care to compare the effect of nursing intervention on outcomes.RESULTS The infection rate,which was not associated with age or complications,was significantly associated with biochemical parameters and invasive procedures(P<0.05).The infection rate was 61.6%in patients who had undergone invasive procedures and 32.1%in those who had not undergone invasive procedures during the hospital stay.The infection rate was also significantly associated with the type of LF(P<0.05),with the lowest rate observed in patients with acute LF and the highest rate observed in those with subacute LF.The nursing satisfaction rate was 58.3%in the uninfected group and 91.7%in the infected group,indicating significantly higher satisfaction in the infected group(P<0.05).CONCLUSION In patients with LF,the rate of secondary infections was high and associated with biochemical parameters and type of LF.Comprehensive nursing intervention can improve patient satisfaction.展开更多
Agricultural intensification has led to an increase in monoculture and the use of chemical pesticides,resulting in a decline in biodiversity and a reduction in ecosystem services,particularly biological pest managemen...Agricultural intensification has led to an increase in monoculture and the use of chemical pesticides,resulting in a decline in biodiversity and a reduction in ecosystem services,particularly biological pest management.However,studies have shown that agroforestry can not only improve land productivity and biodiversity but also regulate some ecosystem services.This study reviews the impacts of physical and biological factors on herbivorous pests,parasites,and predatory natural enemies in fruit-crop agroforestry systems.Fruit-crop agroforestry systems provide high spatial heterogeneity by altering crop layouts,regulating the microclimate and soil quality,and offering food resources and shelter for natural enemies,thus promoting biological pest control.This enhances biological control and makes the agrocomplex system an effective tool for sustainable agriculture.Our research shows that volatile plant substances attract or repel pests and natural enemies based on the characteristics of the insects themselves.When scientifically designed,fruit-crop agroforestry systems provide high spatial heterogeneity and favorable microclimatic conditions,which enhance biological pest control and make the agroforestry system an effective tool for sustainable agriculture.Our research shows that fruit-crop agroforestry systems can provide richer food resources and habitat,enhancing biological pest control and improving pest management.展开更多
China’s growing trade with countries along the“Belt and Road”Initiative is accompanied by a focus on green development.Based on the panel data from 2007 to 2018,this paper establishes a threshold regression model t...China’s growing trade with countries along the“Belt and Road”Initiative is accompanied by a focus on green development.Based on the panel data from 2007 to 2018,this paper establishes a threshold regression model to empirically analyze the institutional quality threshold effect of China’s foreign trade technology spillover on the GTFP of countries along the“Belt and Road.”The results show that China’s foreign trade technology spillover has a significant institutional quality double threshold effect on the green total factor productivity of the countries along the“Belt and Road.”As the institutional quality of the countries along the“Belt and Road”crosses a specific threshold value,the impact of China’s foreign trade technology spillover on the green total factor productivity of the countries along the“Belt and Road”has a significant positive promoting effect,and corresponding suggestions are put forward.展开更多
Approximate analytical expressions of overall effectiveness factors for parallel catalytic reac-tions occurring in a spherical catalyst pellet with both internal and external mass transfer resistancesare obtained afte...Approximate analytical expressions of overall effectiveness factors for parallel catalytic reac-tions occurring in a spherical catalyst pellet with both internal and external mass transfer resistancesare obtained after taking the information given by asymptotic solutions valid for small and largevalues of Thiele moduli.This approximate procedure is feasible for power law as well asLangmuir-Hinshelwood kinetics and the agreement between the approximation and the numerical re-sults is good enough for practical purposes.Moreover,the method does not require any iterative ortrial-and-error computation,and can be conveniently applied in most practical calculations for reac-tors giving reliable results.展开更多
Isothermal effectiveness factors for slab,cylinder and sphere shaped catalysts with uniform or nonuni-form intrinsic activity profiles have been investigated.In the case of zero-,first- and second-order kinetics,the e...Isothermal effectiveness factors for slab,cylinder and sphere shaped catalysts with uniform or nonuni-form intrinsic activity profiles have been investigated.In the case of zero-,first- and second-order kinetics,the effectiveness factors of pellets with increasing activity towards the pellet surface are larger than that ofuniform active catalyst,and they are proportional to the square root of the activity at the pellet surfacewith significant diffusion effect.The effectiveness factor-Thiele modulus curves which are valid for bothuniform and nonuniform catalysts have been obtained with the Thiele modulus modified by equivalent thick-hess of effective layer of the catalyst.Thus,the effectiveness factor for nonuniform active catalyst could bepredicted with a maximun deviation of 5% in the case of significant or insignificant diffusion effect but 10%in general.展开更多
The Landé g factors of Ba+are very important in high-precision measurement physics.The wave functions,energy levels,and Landég factors for the 6s ^(2)S_(1/2) and 5d 2D_(3/2,5/2) states of Ba+ions were calcul...The Landé g factors of Ba+are very important in high-precision measurement physics.The wave functions,energy levels,and Landég factors for the 6s ^(2)S_(1/2) and 5d 2D_(3/2,5/2) states of Ba+ions were calculated using the multi-configuration Dirac-Hartree-Fock method and the model-quantum electrodynamics(QED)method.The contributions of the electron correlation effects and QED effects were discussed in detail.The transition energies are in excellent agreement with the experimental results,with differences of approximately 5 cm^(−1).The presently calculated g factor of 2.0024905(16)for the 6S1/2 agrees very well with the available experimental and theoretical results,with a difference at a level of 10^(−6).For the 5D_(3/2,5/2) states,the present results of 0.7993961(126)and 1.2003942(190)agree with the experimental results of 0.7993278(3)[Phys.Rev.A 541199(1996)]and 1.20036739(14)[Phys.Rev.Lett.124193001(2020)]very well,with differences at the level of 10−5.展开更多
In this paper,we study the ρ-meson electromagnetic form factors(EMFFs)within the framework of the light-front quark model.The physical form factors G_(C,M,Q)(Q^(2))of the ρ-meson,as well as the charged square radius...In this paper,we study the ρ-meson electromagnetic form factors(EMFFs)within the framework of the light-front quark model.The physical form factors G_(C,M,Q)(Q^(2))of the ρ-meson,as well as the charged square radius<r^(2)>,the magnetic moment μ,and the quadrupole moment Q,are calculated,which describe the behaviors of EMFFs at zero momentum transfer.Using the type-Ⅱ replacement,we find that the zero-mode does contribute zero to the matrix element S_(00)^(+).It is found that the“M→M_(0)”replacement improves the angular condition remarkably,which permits different prescriptions of ρ-meson EMFFs to give the consistent results.The residual tiny violation of angular condition needs other explanations beyond the zero-mode contributions.Our results indicate that the relativistic effects or interaction internal structure are weaken in the zero-binding limit.This work is also applicable to other spin-1 particles.展开更多
Seagrass beds are crucial coastal ecosystems,functioning as vital blue carbon sinks and natural ecological barriers.However,these ecosystems are increasingly threatened by global climate events,coastal development,and...Seagrass beds are crucial coastal ecosystems,functioning as vital blue carbon sinks and natural ecological barriers.However,these ecosystems are increasingly threatened by global climate events,coastal development,and water eutrophication,making them some of the most endangered ecosystems worldwide.In the Yellow Sea and Bohai Sea regions,seagrass bed assessment and monitoring have been largely overlooked.Thus,strengthening research efforts is necessary to identify current distribution patterns and long-term changes in seagrass bed resources.This study focused on a seagrass bed in Sanggou Bay,Rongcheng,using remote sensing(RS)and geographic information system technologies to analyze multisource satellite data from the US Landsat and Chinese resource satellite series.By combining RS indexes with historical survey data,large-scale temporal and geographic distribution data for seagrass beds were obtained in the study area from 1985 to 2022.The spatial distribution and evolution trends of the seagrass bed were analyzed using a water depth inversion model,and the factors driving its degradation were identified.Results indicated that the seagrass bed area in Sanggou Bay fluctuated between 100 and 140 km^(2) from 1985 to 2010.During 2010–2013,dynamic changes in the seagrass bed area increased,with a considerable decrease in its overall size.After 2014,changes were minimal,indicating a notably stable state.Seagrass bed degradation in Sanggou Bay is influenced by high-intensity human activities,pollution from coastal land sources,raft cultures,underwater terrain conditions,and sedimentary environmental factors.The findings offer essential insights for developing seagrass restoration and protection strategies in Sanggou Bay and contribute to the broader scientific efforts for coastal ecosystem conservation and rehabilitation.展开更多
The ionization chamber produces significant space-charge and ion recombination effects at ultra-high dose rates,posing achallenge for dose monitoring.In addition,there is no generally accepted ion correction model for...The ionization chamber produces significant space-charge and ion recombination effects at ultra-high dose rates,posing achallenge for dose monitoring.In addition,there is no generally accepted ion correction model for dosimetry in FLASHradiotherapy,making it crucial to monitor the dose at ultra-high dose rates accurately and in real time.In this study,the airpressure of the ionization chamber was reduced to perform real-time beam monitoring,and a Faraday cup was used for calibrationfor active dosimetry.To study the saturation effect of the ionization chamber,the drift,attachment,recombination,anddiffusion processes of the electron-ion pairs were modeled using finite-element analysis based on physical phenomenologicalprinciples,and the correction factor was calculated.The experimental results showed that the FLASH ionization chambermeasures good dose linearity at a dose rate of approximately 0.2 Gy/s.When the air pressure of the chamber was adjustedto 10 mbar,the response of the FLASH ionization chamber was linear at a dose rate of approximately 50 Gy/s,with theresiduals within 2%.Furthermore,by using physical phenomenology to resolve the process of electron-ion pair motion inthe sensitive volume of the ionization chamber,the analytical model better describes the saturation effect of carbon ions atultra-high dose rates.The maximum deviation in the calculated correction factor is less than 10%.We studied the saturationeffect in dose measurement,achieving accurate and fast dose and profile position measurement across different dose ratesin a wide range based on the Heavy Ion Research Facility in Lanzhou.展开更多
To the Editor:We read with great interest the recent article by Shi et al.pub-lished in Hepatobiliary Pancreatic Diseases International[1].Shi’s study was based on radiological features and clinical factors to constr...To the Editor:We read with great interest the recent article by Shi et al.pub-lished in Hepatobiliary Pancreatic Diseases International[1].Shi’s study was based on radiological features and clinical factors to construct a model to predict the effectiveness of first transarterial chemoembolization(TACE)treatment for hepatocellular carcinoma(HCC)in prolonging patient survival.The results showed that area under the receiver operating characteristic curve was 0.964 for the training cohort and 0.949 for the validation cohort.展开更多
基金supported in part by the JSPS Kakenhi under Grant No.21K03539。
文摘We revisit the issue of whether the effective potential for the conformal factor of the metric,which is generated by quantized matter fields,possesses a non-vanishing vacuum expectation value(VEV)or not.We prove that the effective potential has a vanishing vacuum expectation value on the basis of a global GL(4)symmetry.We also account for why there seems to be two different effective potentials for the conformal factor in a theory,one of which gives rise to a vanishing VEV for the conformal factor,whereas the other has a non-vanishing VEV.
文摘BACKGROUND Acute appendicitis(AP)is a frequently encountered surgical emergency,and appendectomy is conventionally regarded as the predominant treatment moda-lity.Nevertheless,the therapeutic efficacy of this surgical approach remains to be improved.Thus,the exploration and implementation of surgical refinements are necessary.AIM To elucidate the therapeutic effectiveness and influencing factors of laparoscopic appendectomy(LA)with mesoappendix dissection in the treatment of AP.METHODS First,150 patients with AP who visited Shangrao Municipal Hospital between January 2022 and June 2024 were enrolled in this study.Among them,72 patients were assigned to the control group to receive conventional LA,whereas 78 cases were included in the observation group for LA with mesoappendix dissection.Subsequently,indicators such as therapeutic effectiveness,surgical indices(ope-ration time,intraoperative blood loss,and hospital stay),postoperative recovery indices(time to ambulation,gastrointestinal function recovery time,and time to food intake),incidence of adverse events(postoperative bleeding,pelvic infection,puncture site infection,and ileus),and serum inflammatory factors[tumor necro-sis factor(TNF)-α,interleukin(IL)-6,and C-reactive protein(CRP)]were collected and comparatively analyzed,and the influencing factors of therapeutic effecti-veness in patients with AP were analyzed.RESULTS Compared with the control group,the observation group had higher clinical the-rapeutic effectiveness,less operation time,intraoperative blood loss,and hospital stay;shorter time to ambulation,gastrointestinal function recovery,and food intake;and a lower total incidence of adverse events,and this difference is statistically significant.In addition,the expression levels of various serum inflammatory factors in the observation group were significantly reduced postoperatively,which were markedly lower than those in the control group.Moreover,sex,age,body mass index,time from acute onset to admission,family medical history,preoperative TNF-α,preoperative IL-6,preoperative CRP,and treatment modality were identified to be not independent factors affecting the therapeutic effectiveness of LA with mesoappendix dissection in patients with AP.CONCLUSION Overall,LA with mesoappendix dissection has a remarkable curative effect in treating patients with AP,which is worthy of clinical promotion.
基金funded by the Guangdong Major Project of Basic and Applied Basic Research(2021B0301030007)the Supplemental Funds for Major Scientific Research Projects of Beijing Normal University,Zhuhai(ZHPT2023013)+1 种基金the National Natural Science Foundation of China(42301387)the Science and Technology Program of Guangdong(No.2024B1212070012)。
文摘The topographic factor(LS factor),derived from the multiplication of the slope length(L)and slope steepness(S)factors,is a vital parameter in soil erosion models.Generated from the digital elevation model(DEM),the LS factor always varies with the changing DEM resolution,i.e.,the LS factor scale effect.Previous studies have found the phenomenon of the LS factor scale effect,but the underlying causes of this phenomenon has not been well explored.Therefore,how the DEM resolution affects the LS factor and how the scale effect of the L and S factors influence the LS factor scale effect remains unclear.To address these problems,we collected 20 watersheds from the Guangdong Province with different topographic reliefs,and compared the corresponding L,S and LS factors at 10-m and 30-m resolution DEMs.Our results indicate that the S factor,heavily influenced by slope underestimation in coarse-resolution DEMs,makes a difference in the LS factor scale effect.In addition,the LS factor scale effect becomes less significant with increasing reliefs,suggesting the possibility of using 30-m DEM for LS calculation in rugged terrains.Our findings on the underlying mechanisms of the LS factor scale effect help to identify the uncertainty in the LS factor estimation,thereby enhancing the accuracy of soil erosion assessment,particularly in regions with different topographic characteristics and contribute to more effective soil conservation strategies and decision-making.
基金Supported by the Project of Jining Meteorological Bureau(2024JNZL08).
文摘Based on the observation data of meteorological observation stations in Jining City during 1970-2024,MK mutation test and principal component analysis(PCA)were used to study the evolution characteristics of urban heat island intensity(UHII)and the contribution rate of various influencing factors in Jining City over the past 55 years.The results show that from 1970 to 2024,the UHII in Jining City generally rose at a rate of 0.1℃/10 a.On the interannual scale,the correlation between temperature and UHII was most significantly positive.On the seasonal scale,there was a strong negative correlation between wind speed and UHII.PCA reveals that temperature had a significant positive impact on the increase of UHII in Jining City.
基金Supported by the Medical Research Project of Jiangsu Health Commission,No.Z2021010.
文摘AIM To analyze the efficacy of laparoscopic radical resection of CRC(LRRCC)in treating older patients with CRC and the effect of this procedure on inflammatory factors.METHODS The study included 104 older patients with CRC admitted from August 2022 to August 2024.Participants undergoing open radical resection of CRC were categorized as the control group(50 patients),whereas those receiving LRRCC were classified as the research group(54 patients).Subsequently,comparative analyses involved data on efficacy,postoperative complications(ileus,incision infection,anastomotic fistula,and pulmonary infection),surgery-related parameters(operation duration and intraoperative bleeding volume),postoperative recoveryrelated indicators(time to first postoperative passage of flatus and defecation and length of hospital stay),and inflammatory factors(tumor necrosis factor-α,highsensitivity C-reactive protein,and interleukin-6).RESULTS Data revealed markedly superior therapeutic efficacy and a lower overall postoperative complication rate in the research group compared to the control group.The research group demonstrated substantially less intraoperative bleeding,less time to first postoperative passage of flatus and defecation,and a shorter length of hospital stay despite a notably longer operation duration compared to the control group.Further,tumor necrosis factor-α,high-sensitivity C-reactive protein,and interleukin-6 levels in the research group were significantly reduced 3 days postoperatively compared to both the preoperative and control group values.CONCLUSION LRRCC for older patients with CRC exhibited superior therapeutic efficacy compared to open radical resection and significantly suppressed postoperative stress-related inflammatory responses,which merits clinical application and promotion.
文摘This study was an attempt to examine the effective factors of the Multiple Sclerosis diseases. The participants of the study were selected from among a total number of 45 men and women who were treated in a health center in Azarbayegan and Damavand in Iran. In order to study, the researchers applied various procedures to collect the data of the study. The participants were interviewed and filled out the questionnaires. After categorizing and classifying the collected information and data, it was processed and analyzed and the results are found. To test the research questions, a one-sample T-test was used to analyze the data. The role of hypo vitamin D as a possible risk factor for multiple sclerosis was reviewed. First, it was emphasized that hypo vitamin could be only one of the risk factors for multiple sclerosis and that numerous other environmental and genetic risk factors appear to interact and combine to trigger the disease. The main aim of this study was to examine the effective factors of Multiple Sclerosis diseases. The methodology of this research was to test the research questions;one-sample T-test was used to analyze the data. The findings of this study revealed that the factors of gender, cold weather, vitamin D deficiency, and age (between 30 - 59) were effective on the Multiple Sclerosis diseases.
文摘The fractal theory was introduced into the gas solid catalytic reaction system to describe the influence of the surface irregularity of catalyst on the gas solid catalytic reaction.A fractal reaction diffusion model is proposed for irregular particles.Based on the shape characterization of the irregular particle,the mth order irreversible reactions are theoretically analyzed.A steady state equation of material balance and its solution as the concentration profile of reacting species are given for the reaction diffusion model for irregular particles.Meanwhile,the effectiveness factors are also expressed with fractal dimension.The results indicate that the higher the fractal dimensions,the higher the total reaction rate,and with the increase of the fractal dimension,the utilization factor of the catalyst is deeply increased.
文摘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.
基金Supported by Guangdong Provincial Medical Scientific Research Fund Project,No.B2016109.
文摘BACKGROUND Depression is a common and serious psychological condition,which seriously affects individual well-being and functional ability.Traditional treatment methods include drug therapy and psychological counseling;however,these methods have different degrees of side effects and limitations.In recent years,nonconvulsive electrotherapy(NET)has attracted increasing attention as a noninvasive treatment method.However,the clinical efficacy and potential mechanism of NET on depression are still unclear.We hypothesized that NET has a positive clinical effect in the treatment of depression,and may have a regulatory effect on serum inflammatory factors during treatment.AIM To assess the effects of NET on depression and analyze changes in serum inflammatory factors.METHODS This retrospective study enrolled 140 patients undergoing treatment for depression between May 2017 and June 2022,the observation group that received a combination of mindfulness-based stress reduction(MBSR)and NET treatment(n=70)and the control group that only received MBSR therapy(n=70).The clinical effectiveness of the treatment was evaluated by assessing various factors,including the Hamilton Depression Scale(HAMD)-17,self-rating idea of suicide scale(SSIOS),Pittsburgh Sleep Quality Index(PSQI),and levels of serum inflammatory factors before and after 8 wk of treatment.The quality of life scores between the two groups were compared.Comparisons were made using t and χ^(2) tests.RESULTS After 8 wk of treatment,the observation group exhibited a 91.43%overall effectiveness rate which was higher than that of the control group which was 74.29%(64 vs 52,χ^(2)=7.241;P<0.05).The HAMD,SSIOS,and PSQI scores showed a significant decrease in both groups.Moreover,the observation group had lower scores than the control group(10.37±2.04 vs 14.02±2.16,t=10.280;1.67±0.28 vs 0.87±0.12,t=21.970;5.29±1.33 vs 7.94±1.35,t=11.700;P both<0.001).Additionally,there was a notable decrease in the IL-2,IL-1β,and IL-6 in both groups after treatment.Furthermore,the observation group exhibited superior serum inflammatory factors compared to the control group(70.12±10.32 vs 102.24±20.21,t=11.840;19.35±2.46 vs 22.27±2.13,t=7.508;32.25±4.6 vs 39.42±4.23,t=9.565;P both<0.001).Moreover,the observation group exhibited significantly improved quality of life scores compared to the control group(Social function:19.25±2.76 vs 16.23±2.34;Emotions:18.54±2.83 vs 12.28±2.16;Environment:18.49±2.48 vs 16.56±3.44;Physical health:19.53±2.39 vs 16.62±3.46;P both<0.001)after treatment.CONCLUSION MBSR combined with NET effectively alleviates depression,lowers inflammation(IL-2,IL-1β,and IL-6),reduces suicidal thoughts,enhances sleep,and improves the quality of life of individuals with depression.
基金Project(2021YFC2902102)supported by the National Key Research and Development Program of ChinaProject(52374142)supported by the National Natural Science Foundation of ChinaProject(JSTU-2022-066)supported by the Young Talent Support Project of Jiangsu Association for Science and Technology,China。
文摘Roof disaster has always been an important factor restricting coal mine safety production.Acidic effect can reform the rock mass structure to weaken the macroscopic strength characteristics,which is an effective way to control the hard limestone roof.In this study,the effects of various factors on the reaction characteristics and mechanical properties of limestone were analyzed.The results show that the acid with stronger hydrogen production capacity after ionization(pK_(a)<0)has more prominent damage to the mineral grains of limestone.When pKa increases from−8.00 to 15.70,uniaxial compressive strength and elastic modulus of limestone increase by 117.22%and 75.98%.The influence of acid concentration is manifested in the dissolution behavior of mineral crystals,the crystal defects caused by large-scale acid action will lead to the deterioration of limestone strength,and the strength after 15%concentration reformation can be reduced by 59.42%.The effect of acidification time on limestone has stages and is the most obvious in the initial metathesis reaction stage(within 60 min).The key to the strength damage of acidified limestone is the participation of hydrogen ions in the reaction system.Based on the analytic hierarchy process method,the influence weights of acid type,acid concentration and acidification time on strength are 24.30%,59.54% and 16.16%,respectively.The research results provide theoretical support for the acidification control of hard limestone roofs in coal mines.
文摘BACKGROUND In patients with liver failure(LF),the high rate of secondary infections,which are associated with poor prognosis,highlights the clinical significance of understanding the underlying risk factors and implementing targeted intervention programs.AIM To investigate risk factors for secondary infections in patients with LF and evaluate the effectiveness of comprehensive nursing interventions.METHODS This retrospective study included 64 patients with LF,including 32 with and 32 without secondary infections.A questionnaire was used to collect data on age;laboratory parameters,including total and direct bilirubin,prothrombin time,blood ammonia,and other biochemical parameters;invasive procedures;and complications.Patients with secondary infections received comprehensive nursing intervention in addition to routine nursing care,whereas those without secondary infections received only routine nursing care to compare the effect of nursing intervention on outcomes.RESULTS The infection rate,which was not associated with age or complications,was significantly associated with biochemical parameters and invasive procedures(P<0.05).The infection rate was 61.6%in patients who had undergone invasive procedures and 32.1%in those who had not undergone invasive procedures during the hospital stay.The infection rate was also significantly associated with the type of LF(P<0.05),with the lowest rate observed in patients with acute LF and the highest rate observed in those with subacute LF.The nursing satisfaction rate was 58.3%in the uninfected group and 91.7%in the infected group,indicating significantly higher satisfaction in the infected group(P<0.05).CONCLUSION In patients with LF,the rate of secondary infections was high and associated with biochemical parameters and type of LF.Comprehensive nursing intervention can improve patient satisfaction.
文摘Agricultural intensification has led to an increase in monoculture and the use of chemical pesticides,resulting in a decline in biodiversity and a reduction in ecosystem services,particularly biological pest management.However,studies have shown that agroforestry can not only improve land productivity and biodiversity but also regulate some ecosystem services.This study reviews the impacts of physical and biological factors on herbivorous pests,parasites,and predatory natural enemies in fruit-crop agroforestry systems.Fruit-crop agroforestry systems provide high spatial heterogeneity by altering crop layouts,regulating the microclimate and soil quality,and offering food resources and shelter for natural enemies,thus promoting biological pest control.This enhances biological control and makes the agrocomplex system an effective tool for sustainable agriculture.Our research shows that volatile plant substances attract or repel pests and natural enemies based on the characteristics of the insects themselves.When scientifically designed,fruit-crop agroforestry systems provide high spatial heterogeneity and favorable microclimatic conditions,which enhance biological pest control and make the agroforestry system an effective tool for sustainable agriculture.Our research shows that fruit-crop agroforestry systems can provide richer food resources and habitat,enhancing biological pest control and improving pest management.
文摘China’s growing trade with countries along the“Belt and Road”Initiative is accompanied by a focus on green development.Based on the panel data from 2007 to 2018,this paper establishes a threshold regression model to empirically analyze the institutional quality threshold effect of China’s foreign trade technology spillover on the GTFP of countries along the“Belt and Road.”The results show that China’s foreign trade technology spillover has a significant institutional quality double threshold effect on the green total factor productivity of the countries along the“Belt and Road.”As the institutional quality of the countries along the“Belt and Road”crosses a specific threshold value,the impact of China’s foreign trade technology spillover on the green total factor productivity of the countries along the“Belt and Road”has a significant positive promoting effect,and corresponding suggestions are put forward.
文摘Approximate analytical expressions of overall effectiveness factors for parallel catalytic reac-tions occurring in a spherical catalyst pellet with both internal and external mass transfer resistancesare obtained after taking the information given by asymptotic solutions valid for small and largevalues of Thiele moduli.This approximate procedure is feasible for power law as well asLangmuir-Hinshelwood kinetics and the agreement between the approximation and the numerical re-sults is good enough for practical purposes.Moreover,the method does not require any iterative ortrial-and-error computation,and can be conveniently applied in most practical calculations for reac-tors giving reliable results.
文摘Isothermal effectiveness factors for slab,cylinder and sphere shaped catalysts with uniform or nonuni-form intrinsic activity profiles have been investigated.In the case of zero-,first- and second-order kinetics,the effectiveness factors of pellets with increasing activity towards the pellet surface are larger than that ofuniform active catalyst,and they are proportional to the square root of the activity at the pellet surfacewith significant diffusion effect.The effectiveness factor-Thiele modulus curves which are valid for bothuniform and nonuniform catalysts have been obtained with the Thiele modulus modified by equivalent thick-hess of effective layer of the catalyst.Thus,the effectiveness factor for nonuniform active catalyst could bepredicted with a maximun deviation of 5% in the case of significant or insignificant diffusion effect but 10%in general.
基金supported by the National key Research and Development Program of China under Grant No.2022YFA1602500the National Natural Science Foundation of China under Grant Nos.12174316 and 1236040286,and 12404306。
文摘The Landé g factors of Ba+are very important in high-precision measurement physics.The wave functions,energy levels,and Landég factors for the 6s ^(2)S_(1/2) and 5d 2D_(3/2,5/2) states of Ba+ions were calculated using the multi-configuration Dirac-Hartree-Fock method and the model-quantum electrodynamics(QED)method.The contributions of the electron correlation effects and QED effects were discussed in detail.The transition energies are in excellent agreement with the experimental results,with differences of approximately 5 cm^(−1).The presently calculated g factor of 2.0024905(16)for the 6S1/2 agrees very well with the available experimental and theoretical results,with a difference at a level of 10^(−6).For the 5D_(3/2,5/2) states,the present results of 0.7993961(126)and 1.2003942(190)agree with the experimental results of 0.7993278(3)[Phys.Rev.A 541199(1996)]and 1.20036739(14)[Phys.Rev.Lett.124193001(2020)]very well,with differences at the level of 10−5.
基金supported by the National Natural Science Foundation of China(Grant Nos.11875122,12175025,and 12147102)Tongling University Talent Program(Grant No.R23100)。
文摘In this paper,we study the ρ-meson electromagnetic form factors(EMFFs)within the framework of the light-front quark model.The physical form factors G_(C,M,Q)(Q^(2))of the ρ-meson,as well as the charged square radius<r^(2)>,the magnetic moment μ,and the quadrupole moment Q,are calculated,which describe the behaviors of EMFFs at zero momentum transfer.Using the type-Ⅱ replacement,we find that the zero-mode does contribute zero to the matrix element S_(00)^(+).It is found that the“M→M_(0)”replacement improves the angular condition remarkably,which permits different prescriptions of ρ-meson EMFFs to give the consistent results.The residual tiny violation of angular condition needs other explanations beyond the zero-mode contributions.Our results indicate that the relativistic effects or interaction internal structure are weaken in the zero-binding limit.This work is also applicable to other spin-1 particles.
基金supported by the Marine S&T Fund of Shandong Province for Pilot National Laboratory for Marine Science and Technology(Qingdao)(No.2022QNLM 050302-4)the Geological Survey Project of the China Geological Survey(No.DD20230071)+1 种基金the China Geological Survey Project‘Investigation and Monitoring of the Coastal Geological Environment of the Yangtze River Estuary’(No.DD20242714)the cooperation fund of Collaborative Research on Marine Geological Environment and Hazards in the Yangtze River Delta and Red River Delta.
文摘Seagrass beds are crucial coastal ecosystems,functioning as vital blue carbon sinks and natural ecological barriers.However,these ecosystems are increasingly threatened by global climate events,coastal development,and water eutrophication,making them some of the most endangered ecosystems worldwide.In the Yellow Sea and Bohai Sea regions,seagrass bed assessment and monitoring have been largely overlooked.Thus,strengthening research efforts is necessary to identify current distribution patterns and long-term changes in seagrass bed resources.This study focused on a seagrass bed in Sanggou Bay,Rongcheng,using remote sensing(RS)and geographic information system technologies to analyze multisource satellite data from the US Landsat and Chinese resource satellite series.By combining RS indexes with historical survey data,large-scale temporal and geographic distribution data for seagrass beds were obtained in the study area from 1985 to 2022.The spatial distribution and evolution trends of the seagrass bed were analyzed using a water depth inversion model,and the factors driving its degradation were identified.Results indicated that the seagrass bed area in Sanggou Bay fluctuated between 100 and 140 km^(2) from 1985 to 2010.During 2010–2013,dynamic changes in the seagrass bed area increased,with a considerable decrease in its overall size.After 2014,changes were minimal,indicating a notably stable state.Seagrass bed degradation in Sanggou Bay is influenced by high-intensity human activities,pollution from coastal land sources,raft cultures,underwater terrain conditions,and sedimentary environmental factors.The findings offer essential insights for developing seagrass restoration and protection strategies in Sanggou Bay and contribute to the broader scientific efforts for coastal ecosystem conservation and rehabilitation.
文摘The ionization chamber produces significant space-charge and ion recombination effects at ultra-high dose rates,posing achallenge for dose monitoring.In addition,there is no generally accepted ion correction model for dosimetry in FLASHradiotherapy,making it crucial to monitor the dose at ultra-high dose rates accurately and in real time.In this study,the airpressure of the ionization chamber was reduced to perform real-time beam monitoring,and a Faraday cup was used for calibrationfor active dosimetry.To study the saturation effect of the ionization chamber,the drift,attachment,recombination,anddiffusion processes of the electron-ion pairs were modeled using finite-element analysis based on physical phenomenologicalprinciples,and the correction factor was calculated.The experimental results showed that the FLASH ionization chambermeasures good dose linearity at a dose rate of approximately 0.2 Gy/s.When the air pressure of the chamber was adjustedto 10 mbar,the response of the FLASH ionization chamber was linear at a dose rate of approximately 50 Gy/s,with theresiduals within 2%.Furthermore,by using physical phenomenology to resolve the process of electron-ion pair motion inthe sensitive volume of the ionization chamber,the analytical model better describes the saturation effect of carbon ions atultra-high dose rates.The maximum deviation in the calculated correction factor is less than 10%.We studied the saturationeffect in dose measurement,achieving accurate and fast dose and profile position measurement across different dose ratesin a wide range based on the Heavy Ion Research Facility in Lanzhou.
基金supported by a grant from the Nursing Re-search Program of the First Affiliated Hospital of Zhejiang Univer-sity School of Medicine(No.2022ZYHL045).
文摘To the Editor:We read with great interest the recent article by Shi et al.pub-lished in Hepatobiliary Pancreatic Diseases International[1].Shi’s study was based on radiological features and clinical factors to construct a model to predict the effectiveness of first transarterial chemoembolization(TACE)treatment for hepatocellular carcinoma(HCC)in prolonging patient survival.The results showed that area under the receiver operating characteristic curve was 0.964 for the training cohort and 0.949 for the validation cohort.
