Development and prospect of acoustic reflection imaging logging processing and interpretation method

Acoustic reflection imaging logging technology can detect and evaluate the development of reflection anomalies,such as fractures,caves and faults,within a range of tens of meters from the wellbore,greatly expanding the application scope of well logging technology.This article reviews the development history of the technology and focuses on introducing key methods,software,and on-site applications of acoustic reflection imaging logging technology.Based on the analyses of major challenges faced by existing technologies,and in conjunction with the practical production requirements of oilfields,the further development directions of acoustic reflection imaging logging are proposed.Following the current approach that utilizes the reflection coefficients,derived from the computation of acoustic slowness and density,to perform seismic inversion constrained by well logging,the next frontier is to directly establish the forward and inverse relationships between the downhole measured reflection waves and the surface seismic reflection waves.It is essential to advance research in imaging of fractures within shale reservoirs,the assessment of hydraulic fracturing effectiveness,the study of geosteering while drilling,and the innovation in instruments of acoustic reflection imaging logging technology.

Epidemiological and clinical features,treatment status,and economic burden of traumatic spinal cord injury in China:a hospital-based retrospective study

Traumatic spinal cord injury is potentially catastrophic and can lead to permanent disability or even death.China has the largest population of patients with traumatic spinal cord injury.Previous studies of traumatic spinal cord injury in China have mostly been regional in scope;national-level studies have been rare.To the best of our knowledge,no national-level study of treatment status and economic burden has been performed.This retrospective study aimed to examine the epidemiological and clinical features,treatment status,and economic burden of traumatic spinal cord injury in China at the national level.We included 13,465 traumatic spinal cord injury patients who were injured between January 2013 and December 2018 and treated in 30 hospitals in 11 provinces/municipalities representing all geographical divisions of China.Patient epidemiological and clinical features,treatment status,and total and daily costs were recorded.Trends in the percentage of traumatic spinal cord injuries among all hospitalized patients and among patients hospitalized in the orthopedic department and cost of care were assessed by annual percentage change using the Joinpoint Regression Program.The percentage of traumatic spinal cord injuries among all hospitalized patients and among patients hospitalized in the orthopedic department did not significantly change overall(annual percentage change,-0.5%and 2.1%,respectively).A total of 10,053(74.7%)patients underwent surgery.Only 2.8%of patients who underwent surgery did so within 24 hours of injury.A total of 2005(14.9%)patients were treated with high-dose(≥500 mg)methylprednisolone sodium succinate/methylprednisolone(MPSS/MP);615(4.6%)received it within 8 hours.The total cost for acute traumatic spinal cord injury decreased over the study period(-4.7%),while daily cost did not significantly change(1.0%increase).Our findings indicate that public health initiatives should aim at improving hospitals’ability to complete early surgery within 24 hours,which is associated with improved sensorimotor recovery,increasing the awareness rate of clinical guidelines related to high-dose MPSS/MP to reduce the use of the treatment with insufficient evidence.

The multi-peak point phenomenon of broadband microwave reflection caused by inhomogeneous plasma

During spacecraft re-entry,the challenge of measuring plasma sheath parameters directly contributes to difficulties in addressing communication blackout.In this work,we have discovered a phenomenon of multiple peaks in reflection data caused by the inhomogeneous plasma.Simulation results show that the multi-peak points fade away as the characteristic frequency is approached,resembling a series of gradually decreasing peaks.The positions and quantities of these points are positively correlated with electron density,yet they show no relation to collision frequency.This phenomenon is of significant reference value for future studies on the spatial distribution of plasmas,particularly for using microwave reflection signals in diagnosing the plasma sheath.

Five-blade scratcher for treating severe rhinophyma:A retrospective study

BACKGROUND Rhinophyma,a late-stage subtype of rosacea,is characterized by excessive sebaceous glands and connective tissue proliferation.Patients may experience respiratory disturbances and psychological distress that significantly affect their quality of life when excessive nasal hyperplasia obstructs the external nasal valves.Surgery is the treatment of choice for rhinophyma.However,excessive bleeding,scarring,pigmentation,and high recurrence rates frequently characterize current surgical methods.AIM To evaluate the clinical effectiveness and recurrence rates after treating severe rhinophyma with the five-blade scratcher.METHODS This study retrospectively analyzed the clinical records of 28 patients with severe rhinophyma rosacea.The Global Flushing Severity Score(GFSS),Clinician Erythema Assessment(CEA),Rhinophyma Severity Index(RHISI),Glasgow Benefit Inventory(GBI),and satisfaction scores were used to assess the recovery of patients at 6 months and 5 years,with the recurrence rate calculated at 5 years postoperatively.In addition,the levels of pro-inflammatory factors(TNF-α,IL-1β,and IL-6)in the serum of patients before and after surgery were detected by ELISA.RESULTS The GFSS,CEA,and RHISI scores at 6 months and 5 years postoperatively were significantly lower than those preoperatively(P<0.001 for both periods).Five-blade scratcher treatment greatly benefits patients as demonstrated by the GBI and patient satisfaction.A small number of patients(7/28,25%)reported recurrence after surgical treatment for rhinophyma in our department that was not more serious than before treatment.The expression of pro-inflammatory factors(TNF-α,IL-1β,and IL-6)in the patient's serum was significantly reduced after surgery of five-blade scratcher.CONCLUSION The five-blade scratcher treatment demonstrates notable advantages,including simplicity,safety,efficacy,and cost-effectiveness,coupled with reduced bleeding,minimized scarring,lower recurrence rates,reduced the level of pro-inflammatory factors and improved patient satisfaction.Consequently,this therapeutic modality exhibits a viable option for individuals afflicted with severe rhinophyma.

Retrospective analysis of patients with hepatocellular carcinoma complicated with human immunodeficiency virus infection after hepatectomy

BACKGROUND Hepatocellular carcinoma(HCC)is the third leading cause of cancer death worldwide,with a 5-year relative survival rate of approximately 18%.The similarity between incidence and mortality(830000 deaths per year)underscores the bleak prognosis associated with the disease.HCC is the fourth most common malignancy and the second leading cause of cancer death in China.Most patients with HCC have a history of chronic liver disease such as chronic hepatitis B virus(HBV)or hepatitis C virus(HCV)infection,alcoholism or alcoholic steatohepatitis,nonalcoholic fatty liver disease,or nonalcoholic steatohepatitis.Early diagnosis and effective treatment are the keys to improving the prognosis of patients with HCC.Although the total number of human immunodeficiency virus(HIV)-infected patients is declining globally the incidence of HCC is increasing in HIVinfected patients,especially those who are coinfected with HBV or HCV.As a result,people infected with HIV still face unique challenges in terms of their risk of developing HCC.AIM To investigate the survival prognosis and clinical efficacy of surgical resection in patients with HCC complicated with HIV infection.METHODS The clinical data of 56 patients with HCC complicated with HIV admitted to the Third Affiliated Hospital of Nantong University from January 2013 to December 2023 were retrospectively analyzed.Among these,27 patients underwent hepatectomy(operation group)and 29 patients received conservative treatment(nonoperation group).All patients signed informed consents in line with the provisions of medical ethics.The general data,clinicopathological features and prognoses for the patients in the two groups were analyzed and the risk factors related to the prognoses of the patients in the operation group were identified.RESULTS The median disease-free survival(DFS)and overall survival(OS)of HIV-HCC patients in the surgical group were 13 months and 17 months,respectively,and the median OS of patients in the nonsurgical group was 12 months.The OS of the surgical group was significantly longer than that of the control group(17 months vs 12 months,respectively;P<0.05).The risk factors associated with DFS and OS in the surgical group were initial HIV diagnosis,postoperative microvascular invasion(MVI),a CD4+T-cell count<200/μL,Barcelona stage C-D,and men who have sex with men(MSM;P<0.05).CONCLUSION Hepatectomy can effectively prolong the survival of patients with HIV-HCC but MVI identified during postoperative pathological examination,late tumor detection,late BCLC stage,CD4+T<200/μL and MSM are risk factors affecting the survival and prognosis of patients undergoing hepatectomy.In addition,there were significant differences between the surgical group and the nonsurgical group in terms of the initial diagnosis of HIV,Child-Pugh score,alpha-fetoprotein measurement value,and HART-efficient antiretroviral therapy after the diagnosis of HIV(P<0.05).Therefore,these factors may also affect the survival and prognosis of patients.

Deliberate self-harm among pediatric psychiatric inpatients in China:A single-center retrospective study

BACKGROUND For children and adolescents,deliberate self-harm(DSH)is becoming a mental health problem of concern.Despite several studies on the prevalence and factors of DSH in the world,there is little information on DSH among children and adolescents in China.This study explores the prevalence,types,associated risk factors and tendency of DSH in pediatric psychiatric inpatients in China.AIM To understand the situation of DSH among hospitalized children and adolescents and its related factors.METHODS In this study,we retrospectively studied 1414 hospitalized children and adolescents with mental illness at Xiamen Mental Health Center from 2014 to 2019,extracted the demographic and clinical data of all patients,and analyzed clinical risk factors of DSH.RESULTS A total of 239(16.90%)patients engaged in at least one type of DSH in our study.Cutting(n=115,48.12%)was the most common type of DSH.Females(n=171,71.55%)were more likely to engage in DSH than males(n=68,28.45%).DSH was positively associated with depressive disorders[OR=3.845(2.196-6.732);P<0.01],female[OR=2.536(1.815-3.542);P<0.01],parental marital status[OR=5.387(2.254-12.875);P<0.01]and negative family history of psychiatric illness[OR=7.767(2.952-20.433);P<0.01],but not with occupation,substance use and history of physical abuse.CONCLUSION Our findings suggest that for patients with depression,females,an abnormal marriage of parents,and no history of mental illness,attention should be paid to the occurrence of DSH.

Analysis of vascular thrombus and clinicopathological factors in prognosis of gastric cancer:A retrospective cohort study

BACKGROUND Gastric cancer(GC)is one of the most common malignant tumors in the world,and its prognosis is closely related to many factors.In recent years,the incidence of vascular thrombosis in patients with GC has gradually attracted increasing attention,and studies have shown that it may have a significant impact on the survival rate and prognosis of patients.However,the specific mechanism underlying the association between vascular thrombosis and the prognosis of patients with GC remains unclear.AIM To analyze the relationships between vascular cancer support and other clinicopathological factors and their influence on the prognosis of patients with GC.METHODS This study retrospectively analyzed the clinicopathological data of 621 patients with GC and divided them into a positive group and a negative group according to the presence or absence of a vascular thrombus.The difference in the 5-year cumulative survival rate between the two groups was compared,and the relationships between vascular cancer thrombus and other clinicopathological factors and their influence on the prognosis of patients with GC were analyzed.RESULTS Among 621 patients with GC,the incidence of vascular thrombi was 31.7%(197 patients).Binary logistic regression analysis revealed that the degree of tumor differentiation,depth of invasion,and extent of lymph node metastasis were independent influencing factors for the occurrence of vascular thrombi in GC patients(P<0.01).The trend of the χ^(2) test showed that the degree of differentiation,depth of invasion,and extent of lymph node metastasis were linearly correlated with the percentage of vascular thrombi in GC patients(P<0.01),and the correlation between lymph node metastasis and vascular thrombi was more significant(r=0.387).Univariate analysis revealed that the 5-year cumulative survival rate of the positive group was significantly lower than that of the negative group(46.7%vs 73.3%,P<0.01).Multivariate analysis revealed that age,tumor diameter,TNM stage,and vascular thrombus were independent risk factors for the prognosis of GC patients(all P<0.05).Further stratified analysis revealed that the 5-year cumulative survival rate of stage Ⅲ GC patients in the thrombolase-positive group was significantly lower than that in the thrombolase-negative group(36.1%vs 51.4%;P<0.05).CONCLUSION Vascular cancer status is an independent risk factor affecting the prognosis of patients with GC.The combination of vascular cancer suppositories and TNM staging can better judge the prognosis of patients with GC and guide more reasonable treatment.

Analysis of lymph node metastasis and survival prognosis in early gastric cancer patients: A retrospective study

BACKGROUND Early gastric cancer(EGC)is a common malignant tumor of the digestive system,and its lymph node metastasis and survival prognosis have been concerning.By retrospectively analyzing the clinical data of EGC patients,we can better under-stand the status of lymph node metastasis and its impact on survival and prog-nosis.AIM To evaluate the prognosis of EGC patients and the factors that affect lymph node METHODS The clinicopathological data of 1011 patients with EGC admitted to our hospital between January 2015 and December 2023 were collected in a retrospective cohort study.There were 561 males and 450 females.The mean age was 58±11 years.The patient underwent radical gastrectomy.The status of lymph node metastasis in each group was determined according to the pathological examination results of surgical specimens.The outcomes were as follows:(1)Lymph node metastasis in EGC patients;(2)Analysis of influencing factors of lymph node metastasis in EGC;and(3)Analysis of prognostic factors in patients with EGC.Normally distributed measurement data are expressed as mean±SD,and a t test was used for comparisons between groups.The data are expressed as absolute numbers or percentages,and the chi-square test was used for comparisons between groups.Rank data were compared using a nonparametric rank sum test.A log-rank test and a logistic regression model were used for univariate analysis.A logistic stepwise regression model and a Cox stepwise regression model were used for multivariate analysis.The Kaplan-Meier method was used to calculate the survival rate and construct survival curves.A log-rank test was used for survival analysis.RESULTS Analysis of influencing factors of lymph node metastasis in EGC.The results of the multifactor analysis showed that tumor length and diameter,tumor site,tumor invasion depth,vascular thrombus,and tumor differentiation degree were independent influencing factors for lymph node metastasis in patients with EGC(odds ratios=1.80,1.49,2.65,5.76,and 0.60;95%CI:1.29–2.50,1.11–2.00,1.81–3.88,3.87-8.59,and 0.48-0.76,respectively;P<0.05).Analysis of prognostic factors in patients with EGC.All 1011 patients with EGC were followed up for 43(0–13)months.The 3-year overall survival rate was 97.32%.Multivariate analysis revealed that age>60 years and lymph node metastasis were independent risk factors for prognosis in patients with EGC(hazard ratio=9.50,2.20;95%CI:3.31-27.29,1.00-4.87;P<0.05).Further analysis revealed that the 3-year overall survival rates of gastric cancer patients aged>60 years and≤60 years were 99.37%and 94.66%,respectively,and the difference was statistically significant(P<0.05).The 3-year overall survival rates of patients with and without lymph node metastasis were 95.42%and 97.92%,respectively,and the difference was statistically significant(P<0.05).CONCLUSION The lymph node metastasis rate of EGC patients was 23.64%.Tumor length,tumor site,tumor infiltration depth,vascular cancer thrombin,and tumor differentiation degree were found to be independent factors affecting lymph node metastasis in EGC patients.Age>60 years and lymph node metastasis are independent risk factors for EGC prognosis.

Adherence to Advisory Committee on Immunization Practices in diabetes mellitus patients in Saudi Arabia:A multicenter retrospective study

BACKGROUND Patients with diabetes mellitus(DM)are predisposed to an increased risk of infection signifying the importance of vaccination to protect against its potentially severe complications.The Centers for Disease Control and Prevention/Advisory Committee on Immunization Practices(CDC/ACIP)issued immunization recommendations to protect this patient population.AIM To assess the adherence of patients with DM to the CDC/ACIP immunization recommendations in Saudi Arabia and to identify the factors associated with the vaccine adherence rate.METHODS An observational retrospective study conducted in 2023 was used to collect data on the vaccination records from 13 diabetes care centers in Saudi Arabia with 1000 eligible patients in phase I with data collected through chart review and 709 patients in phase II through online survey.RESULTS Among participants,10.01%(n=71)had never received any vaccine,while 85.89%(n=609)received at least one dose of the coronavirus disease 2019(COVID-19)vaccine,and 34.83%(n=247)had received the annual influenza vaccine.Only 2.96%(n=21),2.11%(n=15),and 1.12%(n=8)received herpes zoster,tetanus,diphtheria,and pertussis(Tdap),and human papillomavirus(HPV)vaccines,respectively.For patients with DM in Saudi Arabia,the rate of vaccination for annual influenza and COVID-19 vaccines was higher compared to other vaccinations such as herpes zoster,Tdap,pneumococcal,and HPV.Factors such as vaccine recommendations provided by family physicians or specialists,site of care,income level,DM-related hospitalization history,residency site,hemoglobin A1c(HbA1c)level,and health sector type can significantly influence the vaccination rate in patients with DM.Among non-vaccinated patients with DM,the most reported barriers were lack of knowledge and fear of side effects.This signifies the need for large-scale research in this area to identify additional factors that might facilitate adherence to CDC/ACIP vaccine recommendations in patients with DM.CONCLUSION In Saudi Arabia,patients with DM showed higher vaccination rates for annual influenza and COVID-19 vaccines compared to other vaccinations such as herpes zoster,Tdap,pneumococcal,and HPV.Factors such as vaccine recommendations provided by family physicians or specialists,the site of care,income level,DM-related hospitalization history,residency site,HbA1c level,and health sector type can significantly influence the vaccination rate in patients with DM.

Analysis of alkaline phosphatase and γ-glutamyltransferase after radiofrequency ablation of primary liver cancer: A retrospective study

BACKGROUND Changes in alkaline phosphatase(ALP)andγ-glutamyltransferase(GGT)levels in patients with primary liver cancer(PLC)after radiofrequency ablation(RFA).Hepatocellular carcinoma is a malignant tumor with high incidence worldwide.As a common local treatment,RFA has attracted much attention for its efficacy and influence on liver function.AIM To investigate the effect of serum ALP and GGT levels on the prognosis of patients with PLC treated by RFA.METHODS The preoperative clinical data of 165 patients who were pathologically or clinically diagnosed with PLC and who received RFA in our hospital between October 2018 and June 2023 were collected.The chi-square test was used to compare the data between groups.The Kaplan-Meier method and Cox regression were used to analyze the associ-ations between serum ALP and GGT levels and overall survival,progression-free survival(PFS)and clinical characteristics of patients before treatment.RESULTS The 1-year survival rates of patients with normal(≤135 U/L)and abnormal(>135 U/L)serum ALP before treatment were 91%and 79%,respectively;the 2-year survival rates were 90%and 68%,respectively;and the 5-year survival rates were 35%and 18%,respectively.The difference between the two groups was statistically significant(P=0.01).Before treatment,the 1-year survival rates of patients with normal serum GGT levels(≤45 U/L)and abnormal serum GGT levels(>45 U/L)were 95%and 87%,the 2-year survival rates were 85%and 71%,and the 5-year survival rates were 37%and 21%,respectively.The difference between the two groups was statist-ically significant(P<0.001).Serum ALP[hazard ratio(HR)=1.766,95%confidence interval(95%CI):1.068-2.921,P=0.027]and GGT(HR=2.312,95%CI:1.367-3.912,P=0.002)is closely related to the overall survival of PLC patients after RF ablation and is an independent prognostic factor.The 1-year PFS rates were 72%and 50%,the 2-year PFS rates were 52%and 21%,and the 5-year PFS rates were 14%and 3%,respectively.The difference between the two groups was statistically significant(P<0001).The 1-year PFS rates were 81%and 56%in patients with normal and abnormal serum GGT levels before treatment,respectively;the 2-year PFS rates were 62%and 35%,respectively;and the 5-year PFS rates were 18%and 7%,respectively,with statistical significance between the two groups(P<0.001).The serum ALP concentration(HR=1.653,95%CI:1.001-2.729,P=0.049)and GGT(HR=1.949,95%CI:1.296-2.930,P=0.001)was closely associated with PFS after RFA in patients with PLC.The proportion of male patients with abnormal ALP levels is high,the Child-Pugh grade of liver function is poor,and the incidence of ascites is high.Among GGT-abnormal patients,the Child-Pugh grade of liver function was poor,the tumor stage was late,the proportion of patients with tumors≥5 cm was high,and the incidence of hepatic encephalopathy was high.CONCLUSION Serum ALP and GGT levels before treatment can be used to predict the prognosis of patients with PLC after RFA,and they have certain guiding significance for the long-term survival of patients with PLC after radiofrequency therapy.

Comparison of QT Correction Methods in the Pediatric Population of a Community Hospital: A Retrospective Study

Objective:Accurate measurement of QT interval,the ventricular action potential from depolarization to repolarization,is important for the early detection of Long QT syndrome.The most effective QT correction(QTc)formula has yet to be determined in the pediatric population,although it has intrinsically greater extremes in heart rate(HR)and is more susceptible to errors in measurement.The authors of this study compare six dif-ferent QTc methods(Bazett,Fridericia,Framingham,Hodges,Rautaharju,and a computer algorithm utilizing the Bazett formula)for consistency against variations in HR and RR interval.Methods:Descriptive Retrospective Study.We included participants from a pediatric cardiology practice of a community hospital who had an ECG performed in 2017.All participants were healthy patients with no past medical history and no regular med-ications.Results:ECGs from 95 participants from one month to 21 years of age(mean 9.7 years)were included with a mean HR of 91 beats per minute(bpm).The two-sample paired t-test or Wilcoxon signed-rank test assessed for any difference between QTc methods.A statistically significant difference was observed between every combination of two QTc formulae.The Spearman’s rank correlation analysis explored the QTc/HR and QTc/RR relationships for each formula.Fridericia method was most independent of HR and RR with the lowest absolute value of correlation coefficients.Bazett and Computer had moderate correlations,while Framingham and Rautaharju exhibited strong correlations.Correlations were positive for Bazett and Computer,reflecting results from prior studies demonstrating an over-correction of Bazett at higher HRs.In the linear QTc/HR regression analysis,Bazett had the slope closest to zero,although Computer,Hodges,and Fridericia had comparable values.Alternatively,Fridericia had the linear QTc/RR regression coefficient closest to zero.The Bland-Altman method assessed for bias and the limits of agreement between correction formulae.Bazett and Computer exhibited good agreement with minimal bias along with Framingham and Rautaharju.To account for a possible skewed distri-bution of QT,all the above analyses were also performed excluding the top and bottom 2%of data as sorted by heart rate ranges(N=90).Results from this data set were consistent with those derived from all participants(N=95).Conclusions:Overall,the Fridericia correction method provided the best rate correction in our pedia-tric study cohort.

Readmission rate and early complications in patients undergoing total knee arthroplasty:A retrospective study

BACKGROUND Total knee arthroplasty(TKA)can improve pain,quality of life,and functional outcomes.Although uncommon,postoperative complications are extremely consequential and thus must be carefully tracked and communicated to patients to assist their decision-making before surgery.Identification of the risk factors for complications and readmissions after TKA,taking into account common causes,temporal trends,and risk variables that can be changed or left unmodified,will benefit this process.AIM To assess readmission rates,early complications and their causes after TKA at 30 days and 90 days post-surgery.METHODS This was a prospective and retrospective study of 633 patients who underwent TKA at our hospital between January 1,2017,and February 28,2022.Of the 633 patients,28 were not contactable,leaving 609 who met the inclusion criteria.Both inpatient and outpatient hospital records were retrieved,and observations were noted in the data collection forms.RESULTS Following TKA,the 30-day and 90-day readmission rates were determined to be 1.1%(n=7)and 1.8%(n=11),respectively.The unplanned visit rate at 30 days following TKA was 2.6%(n=16)and at 90 days was 4.6%(n=28).At 90 days,the unplanned readmission rate was 1.4%(n=9).Reasons for readmissions included medical(27.2%,n=3)and surgical(72.7%,n=8).Unplanned readmissions and visits within 90 days of follow-up did not substantially differ by age group(P=0.922),body mass index(BMI)(P=0.633),unilateral vs bilateral TKA(P=0.696),or patient comorbidity status(30-day P=0.171 and 90-day P=0.813).Reoperation rates after TKA were 0.66%(n=4)at 30 days and 1.15%(n=8)at 90 days.The average length of stay was 6.53 days.CONCLUSION In this study,there was a low readmission rate following TKA.There was no significant correlation between readmission rate and patient factors such as age,BMI,and co-morbidity status.

The influence of reflections from the train body and the ground on the sound radiation from a railway rail

Purpose – The vibration of the rails is a significant source of railway rolling noise, often forming the dominantcomponent of noise in the important frequency region between 400 and 2000 Hz. The purpose of the paper is toinvestigate the influence of the ground profile and the presence of the train body on the sound radiation fromthe rail.Design/methodology/approach – Two-dimensional boundary element calculations are used, in which therail vibration is the source. The ground profile and various different shapes of train body are introduced in themodel, and results are observed in terms of sound power and sound pressure. Comparisons are also made withvibro-acoustic measurements performed with and without a train present.Findings – The sound radiated by the rail in the absence of the train body is strongly attenuated by shieldingdue to the ballast shoulder. When the train body is present, the sound from the vertical rail motion is reflectedback down toward the track where it is partly absorbed by the ballast. Nevertheless, the sound pressure at thetrackside is increased by typically 0–5 dB. For the lateral vibration of the rail, the effects are much smaller. Oncethe sound power is known, the sound pressure with the train present can be approximated reasonably well withsimple line source directivities.Originality/value – Numerical models used to predict the sound radiation from railway rails have generallyneglected the influence of the ground profile and reflections from the underside of the train body on the soundpower and directivity of the rail. These effects are studied in a systematic way including comparisons with measurements.

Quantifying the natural growth rate of hepatocellular carcinoma:A real-world retrospective study in southwestern China

BACKGROUND In recent years,approximately half of the newly diagnosed cases and mortalities attributed to hepatocellular carcinoma(HCC)have been reported in China.Despite the high incidence of HCC,there remains a paucity of data regarding the natural growth pattern and the determination of optimal surveillance intervals specific to the Chinese population.AIM To quantify the natural tumor growth pattern of HCC in regional China.METHODS A retrospective analysis was performed on patients from a single institution in Southwest China who had undergone two or more serial dynamic computed tomography or magnetic resonance imaging scans between 2014 and 2020,without having received any anti-cancer therapy.Tumor growth was assessed using tumor volume doubling time(TVDT)and tumor growth rate(TGR),with volumes measured manually by experienced radiologists.Simple univariate linear regression and descriptive analysis were applied to explore associations between growth rates and clinical factors.RESULTS This study identifies the median TVDT for HCC as 163.4 d,interquartile range(IQR)72.1 to 302.3 d,with a daily TGR of 0.42%(IQR 0.206%-0.97%).HCC growth patterns reveal that about one-third of tumors grow indolently with TVDT exceeding 270 d,another one-third of tumors exhibit rapid growth with TVDT under 90 d,and the remaining tumors show intermediate growth rates,with TVDT ranging between 3 to 9 months.CONCLUSION The identified TGRs support biannual surveillance and follow-up for HCC patients in certain regions of China.Given the observed heterogeneity in HCC growth,further investigation is warranted.

Conversion hip arthroplasty for failed nailing of intertrochanteric fracture: Reflections on some important aspects

In this editorial,I present my comments on the article by Solarino et al.Conversion hip arthroplasty,which is an optional salvage procedure performed following unsuccessful fixation of intertrochanteric femur fractures in elderly pati-ents,entails more complex processes and higher rates of operative complications than primary arthroplasty.Hence,it is important to consider the appropriateness of the primary treatment choice,as well as the adequacy of nailing fixation for intertrochanteric fractures.This article briefly analyzes the possible factors contributing to the nailing failure of intertrochanteric fractures and attempts to find corresponding countermeasures to prevent fixation failures.It also analyzes the choice of treatment between nailing fixation and primary arthroplasty for intertrochanteric fractures.

Graded and Quantitative Technology and Application of Coal-Bearing Reservoir Based on Seismic Reflection Characteristics

Taiyuan formation is the main exploration strata in Ordos Basin, and coals are widely developed. Due to the interference of strong reflection of coals, we cannot completely identify the effective reservoir information of coal-bearing reservoir on seismic data. Previous researchers have studied the reservoir by stripping or weakening the strong reflection, but it is difficult to determine the effectiveness of the remaining reflection seismic data. In this paper, through the establishment of 2D forward model of coal-bearing strata, the corresponding geophysical characteristics of different reflection types of coal-bearing strata are analyzed, and then the favorable sedimentary facies zones for reservoir development are predicted. On this basis, combined with seismic properties, the coal-bearing reservoir is quantitatively characterized by seismic inversion. The above research shows that the Taiyuan formation in LS block of Ordos Basin is affected by coals and forms three or two peaks in different locations. The reservoir plane sedimentary facies zone is effectively characterized by seismic reflection structure. Based on the characteristics of sedimentary facies belt and petrophysical analysis, the reservoir is semi quantitatively characterized by attribute analysis and waveform indication, and quantitatively characterized by pre stack geostatistical inversion. Based on the forward analysis of coal measure strata, this technology characterizes the reservoir facies belt through seismic reflection characteristics, and describes coal measure reservoirs step by step. It effectively guides the exploration of LS block in Ordos Basin, and has achieved good practical application effect.

MECHANISM FOR THE TRANSITION FROM A REGULAR REFLECTION TO A MACH REFLECTION OR A VON NEUMANN REFLECTION

In this paper, by taking into account the thickness of the incident shock as well as the influence of the boundary layer, we point out that even in a regular reflection there should be present a contact discontinuity. By using the smallest energy criterion, the inclined angle of this contact discontinuity can be determined for differen incident angle. Then, with this inclined contact discontinuity, together with the law of conservation of mass, the mechanism for the transition from a regular reflection to a Mach reflection or a von Neumann reflection becomes clear. The important roles played by the leftest point in the reflected shock polar are identified.

Investigation of reflection anisotropy induced by micropipe defects on the surface of a 4H-SiC single crystal using scanning anisotropy microscopy

Optical reflection anisotropy microscopy mappings of micropipe defects on the surface of a 4H-SiC single crystal are studied by the scanning anisotropy microscopy(SAM)system.The reflection anisotropy(RA)image with a'butterfly pattern'is obtained around the micropipes by SAM.The RA image of the edge dislocations is theoretically simulated based on dislocation theory and the photoelastic principle.By comparing with the Raman spectrum,it is verified that the micropipes consist of edge dislocations.The different patterns of the RA images are due to the different orientations of the Burgers vectors.Besides,the strain distribution of the micropipes is also deduced.One can identify the dislocation type,the direction of the Burgers vector and the optical anisotropy from the RA image by using SAM.Therefore,SAM is an ideal tool to measure the optical anisotropy induced by the strain field around a defect.

Correction of microwave pulse reflection by digital filters in superconducting quantum circuits

Reducing the control error is vital for high-fidelity digital and analog quantum operations.In superconducting circuits,one disagreeable error arises from the reflection of microwave signals due to impedance mismatch in the control chain.Here,we demonstrate a reflection cancelation method when considering that there are two reflection nodes on the control line.We propose to generate the pre-distortion pulse by passing the envelopes of the microwave signal through digital filters,which enables real-time reflection correction when integrated into the field-programmable gate array(FPGA).We achieve a reduction of single-qubit gate infidelity from 0.67%to 0.11%after eliminating microwave reflection.Real-time correction of microwave reflection paves the way for precise control and manipulation of the qubit state and would ultimately enhance the performance of algorithms and simulations executed on quantum processors.

Wave Reflection by Rectangular Breakwaters for Coastal Protection

In this study,we focus on the numerical modelling of the interaction between waves and submerged structures in the presence of a uniform flow current.Both the same and opposite senses of wave propagation are considered.The main objective is an understanding of the effect of the current and various geometrical parameters on the reflection coefficient.The wave used in the study is based on potential theory,and the submerged structures consist of two rectangular breakwaters positioned at a fixed distance from each other and attached to the bottom of a wave flume.The numerical modeling approach employed in this work relies on the Boundary Element Method(BEM).The results are compared with experimental data to validate the approach.The findings of the study demonstrate that the double rectangular breakwater configuration exhibits superior wave attenuation abilities if compared to a single rectangular breakwater,particularly at low wavenumbers.Furthermore,the study reveals that wave mitigation is more pronounced when the current and wave propagation are coplanar,whereas it is less effective in the case of opposing current.