Survival outcomes in early-onset oesophageal adenocarcinoma patients:A systematic review and meta-analyses

BACKGROUND The incidence of oesophageal adenocarcinoma(OAC)has been reported to be increasing in many countries.Alongside this trend,an increase in incidence of early-onset OAC,defined as OAC in adults aged under 50 years,has been observed.It is unclear whether survival outcomes for early-onset OAC patients differ from older age groups.AIM To investigate survival outcomes in early-onset OAC patients.METHODS Ovid Medline and Embase were searched from inception to January 2022 for relevant studies relating to early-onset OAC and survival outcomes.Results regarding the overall five-year survival and risk of death of younger and older patients with OAC were extracted and pooled using meta-analyses to produce pooled estimates and 95%CIs where possible.RESULTS Eleven studies which compared survival of early-onset OAC,defined as age at diagnosis of<50 years,with older patients were included.A narrative review of median and mean survival demonstrated conflicting results,with studies showing early-onset OAC patients having both better and worse outcomes compared to older age groups.A meta-analysis of five-year survival demonstrated similar outcomes across age groups,with 22%-25%of patients in the young,middle and older age groups alive after five years.A meta-analysis of four studies demon-strated that early-onset OAC patients did not have a significantly increased risk of death compared to middle-aged patients(hazard ratio 1.12,95%CI:0.85-1.47).INTRODUCTION There is concern that the incidence of oesophageal adenocarcinoma(OAC)in patients under 50,described as early-onset OAC,is increasing.However,data regarding survival of younger patients with OAC is sparse.Globally,while increasing age remains a major non-modifiable risk factor for cancer,the incidence of early-onset cancers,largely accepted to be in adults aged under 50 years,is increasing[1].This includes an observed increase in the incidence of gastrointestinal malignancies such as colorectal,oesophageal,gastric and hepatobiliary cancers[2-4].Despite oesophageal squamous cell carcinoma(OSCC)being more common globally(88%of cases)[5],a striking increase in oesophageal OAC incidence has been reported in developed countries,such as the United States and Europe[6,7].Worryingly,the United Kingdom has the highest incidence of OAC cases in the world[8].In addition to the increase in OAC,an increase in incidence of early-onset OAC,defined as OAC in adults aged under 50 years,has been observed[9,10].A population-based cohort in the Netherlands,consisting of 59584 patients,demonstrated the incidence of early-onset OAC to have tripled from 1989 to 2018,while OSCC cases declined in this age group[7].OAC usually develops in the lower third of the oesophagus and the gastro-oesophageal junction,with risk factors including obesity and gastro-oesophageal reflux disease[11].A poor prognosis is observed,with the overall five-year survival rate for oesophageal cancer between 15%-20%,even with treatment[12,13].These low survival rates are likely due to a combination of late diagnosis,intrinsic resistance to systemic therapy and the limited efficacy of surgical resection.Younger patients tend to present at a more advanced stage at diagnosis compared to those diagnosed later in life.A single centre,retrospective study found that 33.3%of patients in the younger age category(<50 years old)presented with stage IV OAC,compared to the 20.6%of the oldest age category(>70 years old)[14].Another population-based study in the Netherlands observed that OAC patients under 50 years old also presented with distant metastasis more often in comparison to older patients(50.5%vs 44.7%),and that tumour differentiation also varied between age groups[15].Reports of survival estimates in patients with early-onset OAC compared with older patients have resulted in contrasting findings to date.Some studies report that due to the advanced stage and aggressiveness of the tumours seen that the prognosis of these patients is almost always worse than their older counterparts[16].In contrast,another study found that the overall survival,as well as stage-specific survival was higher in those who were younger[17].A Dutch study which included only resectable cases found no difference in 5-year disease specific survival[18].Given the conflicting evidence to date,the aim of this systematic review was to investigate survival in OAC patients according to age at diagnosis.A protocol was composed,and the reporting of this systematic review designed,using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines[19].The protocol included:The review question,search strategy,inclusion criteria,type of quality assessment,the strategy for data analysis,and the‘population,intervention,comparator,and outcome’criteria.These are expanded below.

Early-onset gastrointestinal cancer:An epidemiological reality with great significance and implications

During the last few years,epidemiological data from many countries suggest that the incidence and prevalence of many cancers of the digestive system are shifting from the older to the younger ages,the so-called“early-onset cancer”.This is particularly evident in colorectal cancer and secondarily in other malignant digestive neoplasms,mainly stomach and in a lesser degree pancreas,and biliary tract.It should be emphasized that data concerning digestive neoplasms,except for those referring to the colon and stomach,could be characterized as rather insufficient.The exact magnitude of the shift in younger ages is expected to become clearer shortly,as long as relevant epidemiological data from many parts of the world would be available.The most important question concerns the etiology of this phenomenon,since its magnitude cannot be explained solely by the better diagnostic methodology and the preventive programs applied in many countries.The existing data support the assumption that a number of environ-mental factors may play a primary role in influencing carcinogenesis,sometimes from childhood.Changes that have appeared in the last decades related mainly to eating habits,consistency of gut microbiome and an increase of obese people interacting with genetic factors,ultimately favor the process of carcinogenesis.Even these factors however,are not entirely sufficient to explain the age-related changes in the frequency of digestive neoplasms.Studies of the individual effect of each of the already known factors or factors likely to be involved in the etiology of this phenomenon and studies using state-of-the-art technologies to accurately determine the degree of the population exposure to these factors are required.In this article,we attempt to describe the epidemiological data supporting the age-shifting of digestive malignancies and their possible pathogenesis.Finally,we propose some measures regarding the attitude of the scientific community to this alarming phenomenon.

Treatment patterns and survival outcomes in patients with nonmetastatic early-onset pancreatic cancer

BACKGROUND The incidence of patients with early-onset pancreatic cancer(EOPC;age≤50 years at diagnosis)is on the rise,placing a heavy burden on individuals,families,and society.The role of combination therapy including surgery,radiotherapy,and chemotherapy in non-metastatic EOPC is not well-defined.AIM To investigate the treatment patterns and survival outcomes in patients with non-metastatic EOPC.METHODS A total of 277 patients with non-metastatic EOPC who were treated at our institution between 2017 and 2021 were investigated retrospectively.Overall survival(OS),disease-free survival,and progression-free survival were estimated using the Kaplan-Meier method.Univariate and multivariate analyses with the Cox proportional hazards model were used to identify prognostic factors.RESULTS With a median follow-up time of 34.6 months,the 1-year,2-year,and 3-year OS rates for the entire cohort were 84.3%,51.5%,and 27.6%,respectively.The median OS of patients with localized disease who received surgery alone and adjuvant therapy(AT)were 21.2 months and 28.8 months,respectively(P=0.007).The median OS of patients with locally advanced disease who received radiotherapy-based combination therapy(RCT),surgery after neoadjuvant therapy(NAT),and chemotherapy were 28.5 months,25.6 months,and 14.0 months,respectively(P=0.002).The median OS after regional recurrence were 16.0 months,13.4 months,and 8.9 months in the RCT,chemotherapy,and supportive therapy groups,respectively(P=0.035).Multivariate analysis demonstrated that carbohydrate antigen 19-9 level,pathological grade,T-stage,N-stage,and resection were independent prognostic factors for non-metastatic EOPC.CONCLUSION AT improves postoperative survival in localized patients.Surgery after NAT and RCT are the preferred therapeutic options for patients with locally advanced EOPC.

Serum ferritin and the risk of early-onset colorectal cancer

BACKGROUND The incidence of early-onset colorectal cancer(EO-CRC)is rising in the United States,and is often diagnosed at advanced stages.Low serum ferritin is often incidentally discovered in young adults,however,the indication for endoscopy in EO-CRC is unclear.AIM To compare serum ferritin between patients with EO-CRC and healthy controls(HCs),and examine the association of serum ferritin in EO-CRC with patient-and disease-specific characteristics.METHODS A retrospective study of patients<50 years with newly-diagnosed EO-CRC was conducted from 1/2013-12/2023.Patients were included if serum ferritin was measured within 2 years prior to 1 year following CRC histologic diagnosis.To supplement the analysis,a cohort of HCs meeting similar inclusion and exclusion criteria were identified for comparison.A sensitivity analysis including only patients with serum ferritin obtained at or before diagnosis was separately performed to minimize risk of confounding.RESULTS Among 85 patients identified with EO-CRC(48 females),the median serum ferritin level was 26 ng/mL(range<1-2759 ng/mL).Compared to HCs(n=80211),there were a higher proportion of individuals with EO-CRC with serum ferritin<20 ng/mL(female 65%,male 40%)versus HCs(female 32.1%,male 7.2%)age 29-39 years(P=0.002 and P<0.00001,respectively).Stage IV disease was associated with significantly higher serum ferritin compared to less advanced stages(P<0.001).Serum ferritin obtained before or at the time of diagnosis was lower than levels obtained after diagnosis.Similar findings were confirmed in the sensitivity analysis.CONCLUSION Severe iron deficiency may indicate an increased risk of EO-CRC,particularly at earlier stages.Further studies defining the optimal serum ferritin threshold and routine incorporation of serum ferritin in screening algorithms is essential to develop more effective screening strategies for EO-CRC.

Patterning single-layer materials by electrical breakdown using atomic force microscopy

The development of nanoelectronics and nanotechnologies has been boosted significantly by the emergence of 2D materials because of their atomic thickness and peculiar properties,and developing a universal,precise patterning technology for single-layer 2D materials is critical for assembling nanodevices.Demonstrated here is a nanomachining technique using electrical breakdown by an AFM tip to fabricate nanopores,nanostrips,and other nanostructures on demand.This can be achieved by voltage scanning or applying a constant voltage while moving the tip.By measuring the electrical current,the formation process on single-layer materials was shown quantitatively.The present results provide evidence of successful pattern fabrication on single-layer MoS2,boron nitride,and graphene,although further confirmation is still needed.The proposed method holds promise as a general nanomachining technology for the future.

Research on batch multielement rapid quantitative analysis based on the standard curve-assisted calibration-free laserinduced breakdown spectroscopy method

This study proposes a batch rapid quantitative analysis method for multiple elements by combining the advantages of standard curve(SC)and calibration-free laser-induced breakdown spectroscopy(CF-LIBS)technology to achieve synchronous,rapid,and accurate measurement of elements in a large number of samples,namely,SC-assisted CF-LIBS.Al alloy standard samples,divided into calibration and test samples,were applied to validate the proposed method.SC was built based on the characteristic line of Pb and Cr in the calibration sample,and the contents of Pb and Cr in the test sample were calculated with relative errors of 6%and 4%,respectively.SC built using Cr with multiple characteristic lines yielded better calculation results.The relative contents of ten elements in the test sample were calculated using CF-LIBS.Subsequently,the SC-assisted CF-LIBS was executed,with the majority of the calculation relative errors falling within the range of 2%-5%.Finally,the Al and Na contents of the Al alloy were predicted.The results demonstrate that it effectively enables the rapid and accurate quantitative analysis of multiple elements after a single-element SC analysis of the tested samples.Furthermore,this quantitative analysis method was successfully applied to soil and Astragalus samples,realizing an accurate calculation of the contents of multiple elements.Thus,it is important to advance the LIBS quantitative analysis and its related applications.

Laser-induced breakdown spectroscopy as a method for millimeter-scale inspection of surface flatness

A non-contact method for millimeter-scale inspection of material surface flatness via Laser-Induced Breakdown Spectroscopy(LIBS)is investigated experimentally.The experiment is performed using a planished surface of an alloy steel sample to simulate its various flatness,ranging from 0 to 4.4 mm,by adjusting the laser focal plane to the surface distance with a step length of 0.2 mm.It is found that LIBS measurements are successful in inspecting the flatness differences among these simulated cases,implying that the method investigated here is feasible.It is also found that,for achieving the inspection of surface flatness within such a wide range,when univariate analysis is applied,a piecewise calibration model must be constructed.This is due to the complex dependence of plasma formation conditions on the surface flatness,which inevitably complicates the inspection procedure.To solve the problem,a multivariate analysis with the help of Back-Propagation Neural Network(BPNN)algorithms is applied to further construct the calibration model.By detailed analysis of the model performance,we demonstrate that a unified calibration model can be well established based on BPNN algorithms for unambiguous millimeter-scale range inspection of surface flatness with a resolution of about 0.2 mm.

Association of serum interleukin-6 with negative symptoms in stable early-onset schizophrenia

BACKGROUND Accumulating evidence suggests that the inflammatory cytokine interleukin-6(IL-6)contributes to the pathophysiology of psychiatric disorders.However,there was no study concerning the relationship between IL-6 concentrations and clinical features in the chronic phase of early-onset schizophrenia(EOS).AIM To investigate the relationship between serum IL-6 concentration and the clinical features of EOS.METHODS We measured serum IL-6 Levels from 74 patients with chronic schizophrenia,including 33 with age at onset<21 years(EOS group)and 41 with onset≥21 years in[adult-onset schizophrenia(AOS)group],and from 41 healthy controls.Symptom severities were evaluated using the Positive and Negative Syndrome Scale(PANSS).RESULTS Serum IL-6 concentrations were higher in both EOS and AOS groups than healthy controls(F=22.32,P<0.01),but did not differ significantly between EOS and AOS groups(P>0.05)after controlling for age,body mass index,and other covariates.Negative symptom scores were higher in the EOS group than the AOS group(F=6.199,P=0.015).Serum IL-6 concentrations in the EOS group were negatively correlated with both total PANSS-negative symptom score(r=-0.389,P=0.032)and avolition/asociality subscore(r=-0.387,P=0.026).CONCLUSION Patients with EOS may have more severe negative symptoms than those with adult-onset schizophrenia during the chronic phase of the illness.IL-6 signaling may regulate negative symptoms and its avolition/asociality subsymptoms among the early-onset chronic schizophrenic patients.

Estimating the yield stress of soft materials via laser-induced breakdown spectroscopy

Taking three typical soft samples prepared respectively by loose packings of 77-,95-,and 109-μm copper grains as examples,we perform an experiment to investigate the energy-dependent laser-induced breakdown spectroscopy(LIBS)of soft materials.We discovered a reversal phenomenon in the trend of energy dependence of plasma emission intensity:increasing initially and then decreasing separated by a well-defined critical energy.The trend reversal is attributed to the laser-induced recoil pressure at the critical energy just matching the sample's yield strength.As a result,a one-to-one correspondence can be well established between the samples'yield stress and the critical energy that is easily obtainable from LIBS measurements.This allows us to propose an innovative method for estimating the yield stress of soft materials via LIBS with attractive advantages including in-situ remote detection,real-time data collection,and minimal destructive to sample.

Analysis of risk factors for postpartum depression after cesarean section in women with early-onset preeclampsia

BACKGROUND Early-onset preeclampsia significantly increases maternal and fetal morbidity and mortality.Many pregnant women with early onset preeclampsia choose cesarean section as their delivery method.Although extensive research has explored the association between postpartum depression(PPD)and cesarean section,few studies have investigated the risk factors after cesarean section in women with early-onset preeclampsia.AIM To examine these risk factors through a retrospective,observational analysis of 287 women who underwent a cesarean section for early preeclampsia between June 2014 and March 2024.METHODS Participants were assessed in person during the 32nd week of pregnancy,2 days post-cesarean,and 6 weeks postpartum.According to the Edinburgh Postnatal Depression Scale(EPDS),participants who underwent cesarean section were divided into PPD(n=60)and non-PPD groups(n=227).Furthermore,PPD was diagnosed at 6 weeks postpartum according to depressive symptoms(EPDS score≥11).The demographic and clinical features of PPD were screened.Multivariate logistic regression analysis was used to identify PPD risk factors.RESULTS The prevalence of PPD was 20.9%(60/287)among the 287 women who underwent cesarean section for early-onset preeclampsia.Multivariate logistic regression analyses revealed that advanced age(age>40 years)[odds ratio(OR)=1.93,95%CI:1.31-2.82],previous preeclampsia(OR=7.15,95%CI:5.81-8.85),pre-pregnancy obesity(OR=2.42,95%CI:1.62-3.63),gestational diabetes mellitus(OR=3.52,95%CI:2.51-4.92),preexisting hypertension(OR=1.35,95%CI:1.03-1.89),PPD symptoms(EPDS≥11)at 2 days postpartum(OR=6.15,95%CI:1.32-28.35),high prenatal self-rating anxiety scale score(OR=1.13,95%CI:1.06-1.18),and pain at 6 weeks postpartum(OR=2.16,95%CI:1.28-3.66)were independently associated with PPD.CONCLUSION Risk factors for PPD after cesarean section in women with early-onset preeclampsia include advanced age(age>40 years),pre-pregnancy obesity,previous preeclampsia,gestational diabetes mellitus,preexisting hypertension,PPD symptoms(EPDS≥11)at 2 days postpartum,prenatal anxiety,and pain at 6 weeks postpartum.The early identi-fication of these factors and interventions can mitigate the risk of PPD.

Effects of improved amino acid balance diet on lysine mammary utilization, whole body protein turnover and muscle protein breakdown on lactating sows

Background The study objective was to test the hypothesis that low crude protein(CP)diet with crystalline amino acids(CAA)supplementation improves Lys utilization efficiency for milk production and reduces protein turnover and muscle protein breakdown.Eighteen lactating multiparous Yorkshire sows were allotted to 1 of 2 isocaloric diets(10.80 MJ/kg net energy):control(CON;19.24%CP)and reduced CP with“optimal”AA profile(OPT;14.00%CP).Sow body weight and backfat were recorded on d 1 and 21 of lactation and piglets were weighed on d 1,14,18,and 21 of lactation.Between d 14 and 18,a subset of 9 sows(CON=4,OPT=5)was infused with a mixed solution of 3-[methyl-2H3]histidine(bolus injection)and[13C]bicarbonate(priming dose)first,then a constant 2-h[13C]bicarbonate infusion followed by a 6-h primed constant[1-13C]lysine infusion.Serial blood and milk sampling were performed to determine plasma and milk Lys enrichment,Lys oxidation rate,whole body protein turnover,and muscle protein breakdown.Results Over the 21-d lactation period,compared to CON,sows fed OPT had greater litter growth rate(P<0.05).Compared to CON,sows fed OPT had greater efficiency of Lys(P<0.05),Lys mammary flux(P<0.01)and whole-body protein turnover efficiency(P<0.05).Compared to CON,sows fed OPT tended to have lower whole body protein breakdown rate(P=0.069).Muscle protein breakdown rate did not differ between OPT and CON(P=0.197).Conclusion Feeding an improved AA balance diet increased efficiency of Lys and reduced whole-body protein turnover and protein breakdown.These results imply that the lower maternal N retention observed in lactating sows fed improved AA balance diets in previous studies may be a result of greater partitioning of AA towards milk rather than greater body protein breakdown.

Estimating the grain size of microgranular material using laser-induced breakdown spectroscopy combined with machine learning algorithms

Recent work has validated a new method for estimating the grain size of microgranular materials in the range of tens to hundreds of micrometers using laser-induced breakdown spectroscopy(LIBS).In this situation,a piecewise univariate model must be constructed to estimate grain size due to the complex dependence of the plasma formation environment on grain size.In the present work,we tentatively construct a unified calibration model suitable for LIBS-based estimation of those grain sizes.Specifically,two unified multivariate calibration models are constructed based on back-propagation neural network(BPNN)algorithms using feature selection strategies with and without considering prior information.By detailed analysis of the performances of the two multivariate models,it was found that a unified calibration model can be successfully constructed based on BPNN algorithms for estimating the grain size in the range of tens to hundreds of micrometers.It was also found that the model constructed with a priorguided feature selection strategy had better prediction performance.This study has practical significance in developing the technology for material analysis using LIBS,especially when the LIBS signal exhibits a complex dependence on the material parameter to be estimated.

Phase field model for electric-thermal coupled discharge breakdown of polyimide nanocomposites under high frequency electrical stress

In contrast to conventional transformers, power electronic transformers, as an integral component of new energy power system, are often subjected to high-frequency and transient electrical stresses, leading to heightened concerns regarding insulation failures. Meanwhile, the underlying mechanism behind discharge breakdown failure and nanofiller enhancement under high-frequency electrical stress remains unclear. An electric-thermal coupled discharge breakdown phase field model was constructed to study the evolution of the breakdown path in polyimide nanocomposite insulation subjected to high-frequency stress. The investigation focused on analyzing the effect of various factors, including frequency, temperature, and nanofiller shape, on the breakdown path of Polyimide(PI) composites. Additionally, it elucidated the enhancement mechanism of nano-modified composite insulation at the mesoscopic scale. The results indicated that with increasing frequency and temperature, the discharge breakdown path demonstrates accelerated development, accompanied by a gradual dominance of Joule heat energy. This enhancement is attributed to the dispersed electric field distribution and the hindering effect of the nanosheets. The research findings offer a theoretical foundation and methodological framework to inform the optimal design and performance management of new insulating materials utilized in high-frequency power equipment.

Characteristics of laser-induced breakdown spectroscopy of liquid slag

Rapid online analysis of liquid slag is essential for optimizing the quality and energy efficiency of steel production. To investigate the key factors that affect the online measurement of refined slag using laser-induced breakdown spectroscopy(LIBS), this study examined the effects of slag composition and temperature on the intensity and stability of the LIBS spectra. The experimental temperature was controlled at three levels: 1350℃, 1400℃, and 1450℃. The results showed that slag composition and temperature significantly affected the intensity and stability of the LIBS spectra. Increasing the Fe content and temperature in the slag reduces its viscosity, resulting in an enhanced intensity and stability of the LIBS spectra. Additionally, 42 refined slag samples were quantitatively analyzed for Fe, Si, Ca, Mg, Al, and Mn at 1350℃, 1400℃, and 1450℃.The normalized full spectrum combined with partial least squares(PLS) quantification modeling was used, using the Ca Ⅱ 317.91 nm spectral line as an internal standard. The results show that using the internal standard normalization method can significantly reduce the influence of spectral fluctuations. Meanwhile, a temperature of 1450℃ has been found to yield superior results compared to both 1350℃ and 1400℃, and it is advantageous to conduct a quantitative analysis of the slag when it is in a “water-like” state with low viscosity.

Incorporating empirical knowledge into data-driven variable selection for quantitative analysis of coal ash content by laser-induced breakdown spectroscopy

Laser-induced breakdown spectroscopy(LIBS)has become a widely used atomic spectroscopic technique for rapid coal analysis.However,the vast amount of spectral information in LIBS contains signal uncertainty,which can affect its quantification performance.In this work,we propose a hybrid variable selection method to improve the performance of LIBS quantification.Important variables are first identified using Pearson's correlation coefficient,mutual information,least absolute shrinkage and selection operator(LASSO)and random forest,and then filtered and combined with empirical variables related to fingerprint elements of coal ash content.Subsequently,these variables are fed into a partial least squares regression(PLSR).Additionally,in some models,certain variables unrelated to ash content are removed manually to study the impact of variable deselection on model performance.The proposed hybrid strategy was tested on three LIBS datasets for quantitative analysis of coal ash content and compared with the corresponding data-driven baseline method.It is significantly better than the variable selection only method based on empirical knowledge and in most cases outperforms the baseline method.The results showed that on all three datasets the hybrid strategy for variable selection combining empirical knowledge and data-driven algorithms achieved the lowest root mean square error of prediction(RMSEP)values of 1.605,3.478 and 1.647,respectively,which were significantly lower than those obtained from multiple linear regression using only 12 empirical variables,which are 1.959,3.718 and 2.181,respectively.The LASSO-PLSR model with empirical support and 20 selected variables exhibited a significantly improved performance after variable deselection,with RMSEP values dropping from 1.635,3.962 and 1.647 to 1.483,3.086 and 1.567,respectively.Such results demonstrate that using empirical knowledge as a support for datadriven variable selection can be a viable approach to improve the accuracy and reliability of LIBS quantification.

Research Progress in Early-onset Colorectal Cancer

Colorectal cancer used to be a common disease among middle-aged and elderly people.In recent years,the incidence of colorectal cancer(Early-onset colorectal cancer,EOCRC)under 50 years old has increased year by year.Different from the traditional late-onset colon cancer(LOCRC),the diagnosis stage of EOCRC is mostly in the late stage,with poor cell differentiation and poor diagnosis,and there is a layer of consensus and guidance on the diagnosis,treatment or screening of EOCRC at presentation.Therefore,fully understanding the disease characteristics and risk exposure factors of EOCRC is helpful to guide early screening and treatment,which ultimately reduces the mortality of EOCRC.In this review article,we summarized the epidemiology,physiology,risk exposure factors and pathological diagnosis of EOCRC,and discussed the diagnosis and treatment prospect of EOCRC.

Integrated Experimental and Simulation Investigation of Breakdown Voltage Characteristics Across Electrode Configurations in SF_(6) Circuit Breakers

This study investigates the breakdown voltage characteristics in sulfur hexafluoride(SF6)circuit breakers,employing a novel approach that integrates both experimental investigations and finite element simulations.Utilizing a sphere-sphere electrode configuration,we meticulously measured the relationship between breakdown voltage and electrode gap distances ranging from 1 cm to 4.5 cm.Subsequent simulations,conducted using COMSOL Multiphysics,mirrored the experimental setup to validate the model’s accuracy through a comparison of the breakdown voltage-electrode gap distance curves.The simulation results not only aligned closely with the experimental data but also allowed the extraction of detailed electric field strength,electric potential contours,and electric current flow curves at the breakdown voltage for gap distances extending from 1 to 4.5 cm.Extending the analysis,the study explored the electric field and potential distribution at a constant voltage of 72.5 kV for gap distances between 1 to 10 cm,identifying the maximum electric field strength.A comprehensive comparison of five different electrode configurations(sphere-sphere,sphere-rod,sphere-plane,rod-plane,rod-rod)at 72.5 kV and a gap distance of 1.84 cm underscored the significant influence of electrode geometry on the breakdown process.Moreover,the research contrasts the breakdown voltage in SF6 with that in air,emphasizing SF6’s superior insulating properties.This investigation not only elucidates the intricate dynamics of electrical breakdown in SF6 circuit breakers but also contributes valuable insights into the optimal electrode configurations and the potential for alternative insulating gases,steering future advancements in high-voltage circuit breaker technology.

Early-onset colorectal cancer:A review of current knowledge

Colorectal cancer(CRC)is one of the most prevalent malignancies worldwide.Although most prevalent among older people,its incidence above 50 years old has been decreasing globally in the last decades,probably as a result of better screening.Paradoxically,its incidence in patients below 50 years old[early-onset CRC(EO-CRC)]has been increasing,for reasons not yet fully understood.EOCRC’s increasing incidence is genre independent but shows racial disparities and has been described to occur worldwide.It follows a birth-cohort effect which probably reflects a change in exposure to CRC risk factors.Its incidence is predicted to double until 2030,which makes EO-CRC a serious public health issue.Both modifiable and non-modifiable risk factors have been identified-some are potential targets for preventive measures.EO-CRC is often diagnosed at advanced stages and histological features associated with poor prognosis have been described.EO-CRC presents some distinctive features:Microsatellite instability is common,but another subtype of tumours,both microsatellite and chromosome stable also seems relevant.There are no age-specific treatment protocols and studies on EO-CRC survival rates have shown conflicting data.Due to the higher germline pathological mutations found in EO-CRC patients,an accurate genetic risk evaluation should be performed.In this review,we summarize the current evidence on epidemiological,clinical,histopathological and molecular features of EO-CRC and discuss the contribution of genetics and lifestyle risk factors.We further comment on screening strategies and specific dimensions to consider when dealing with a younger cancer patient.

Self-absorption effects of laser-induced breakdown spectroscopy under different gases and gas pressures

The self-absorption effect is one of the main factors affecting the quantitative analysis accuracy of laser-induced breakdown spectroscopy.In this paper,the self-absorption effects of laserinduced 7050 Al alloy plasma under different pressures in air,Ar,and N2have been studied.Compared with air and N2,Ar significantly enhances the spectral signal.Furthermore,the spectral self-absorption coefficient is calculated to quantify the degree of self-absorption,and the influences of gas species and gas pressure on self-absorption are analyzed.In addition,it is found that the spectral intensity fluctuates with the change of pressure of three gases.It can also be seen that the fluctuation of spectral intensity with pressure is eliminated after correcting,which indicates that the self-absorption leads to the fluctuation of spectral intensity under different pressures.The analysis shows that the evolution of optical thin spectral lines with pressure in different gases is mainly determined by the gas properties and the competition between plasma confinement and Rayleigh–Taylor instability.

A data selection method for matrix effects and uncertainty reduction for laser-induced breakdown spectroscopy

Severe matrix effects and high signal uncertainty are two key bottlenecks for the quantitative performance and wide applications of laser-induced breakdown spectroscopy(LIBS).Based on the understanding that the superposition of both matrix effects and signal uncertainty directly affects plasma parameters and further influences spectral intensity and LIBS quantification performance,a data selection method based on plasma temperature matching(DSPTM)was proposed to reduce both matrix effects and signal uncertainty.By selecting spectra with smaller plasma temperature differences for all samples,the proposed method was able to build up the quantification model to rely more on spectra with smaller matrix effects and signal uncertainty,therefore improving final quantification performance.When applied to quantitative analysis of the zinc content in brass alloys,it was found that both accuracy and precision were improved using either a univariate model or multiple linear regression(MLR).More specifically,for the univariate model,the root-mean-square error of prediction(RMSEP),the determination coefficients(R^(2))and relative standard derivation(RSD)were improved from 3.30%,0.864 and 18.8%to 1.06%,0.986 and 13.5%,respectively;while for MLR,RMSEP,R^(2)and RSD were improved from 3.22%,0.871 and 26.2%to 1.07%,0.986 and 17.4%,respectively.These results prove that DSPTM can be used as an effective method to reduce matrix effects and improve repeatability by selecting reliable data.