Spleen volume is associated with overt hepatic encephalopathy after transjugular intrahepatic portosystemic shunt in patients with portal hypertension

BACKGROUND Portal shunt and immune status related to the spleen are related to the occurrence of hepatic encephalopathy(HE).It is unknown whether spleen volume before transjugular intrahepatic portosystemic shunt(TIPS)is related to postoperative HE.AIM To investigate the relationship between spleen volume and the occurrence of HE.METHODS This study included 135 patients with liver cirrhosis who underwent TIPS,and liver and spleen volumes were elevated upon computed tomography imaging.The Kaplan-Meier curve was used to compare the difference in the incidence rate of HE among patients with different spleen volumes.Univariate and multivariate Cox regression analyses were performed to identify the factors affecting overt HE(OHE).Restricted cubic spline was used to examine the shapes of the dose-response association between spleen volumes and OHE risk.RESULTS The results showed that 37(27.2%)of 135 patients experienced OHE during a 1-year follow-up period.Compared with preoperative spleen volume(901.30±471.90 cm3),there was a significant decrease in spleen volume after TIPS(697.60±281.0 cm^(3))in OHE patients.As the severity of OHE increased,the spleen volume significantly decreased(P<0.05).Compared with patients with a spleen volume≥782.4 cm^(3),those with a spleen volume<782.4 cm^(3) had a higher incidence of HE(P<0.05).Cox regression analysis showed that spleen volume was an independent risk factor for post-TIPS OHE(hazard ratio=0.494,P<0.05).Restricted cubic spline model showed that with an increasing spleen volume,OHE risk showed an initial increase and then decrease(P<0.05).CONCLUSION Spleen volume is related to the occurrence of OHE after TIPS.Preoperative spleen volume is an independent risk factor for post-TIPS OHE.

Impressive recompensation in transjugular intrahepatic portosystemic shunt-treated individuals with complications of decompensated cirrhosis based on Baveno VII criteria

BACKGROUND Transjugular intrahepatic portosystemic shunt(TIPS)is the standard second-line treatment option for individuals with complications of decompensated cirrhosis,such as variceal bleeding and refractory ascites.AIM To investigate whether recompensation existed in TIPS-treated patients with decompensated cirrhosis according to Baveno VII criteria.METHODS This retrospective analysis was performed on 64 patients who received TIPS for variceal bleeding or refractory ascites.The definition of recompensation referred to Baveno VII criteria and previous study.Clinical events,laboratory tests,and radiological examinations were regularly conducted during a preset follow-up period.The recompensation ratio in this cohort was calculated.Beyond that,univariate and multivariate regression models were conducted to identify the predictors of recompensation.RESULTS Of the 64 patients with a 12-mo follow-up,20(31%)achieved recompensation.Age[odds ratio(OR):1.124;95%confidence interval(CI):1.034-1.222]and postTIPS portal pressure gradient<12 mmHg(OR:0.119;95%CI:0.024-0.584)were identified as independent predictors of recompensation in patients with decompensated cirrhosis after TIPS.CONCLUSION The present study demonstrated that nearly one-third of the TIPS-treated patients achieved recompensation within this cohort.According to our findings,recompensation is more likely to be achieved in younger patients.In addition,postoperative portal pressure gradient reduction below 12 mmHg contributes to the occurrence of recompensation.

XGBoost机器学习模型对乙型肝炎肝硬化诊断的应用价值研究

背景 慢性乙型肝炎病毒感染(chronic hepatitis B virus infection,CHBV)进展成肝硬化是缓慢且容易被忽略的,通过临床常规指标来构建肝硬化无创诊断模型成为研究热点.然而,目前有关肝硬化早期诊断的机器学习模型仍是缺乏的.目的 探讨极限梯度提升机(eXtreme gradient boosting,XGBoost)机器学习模型在乙肝肝硬化无创诊断中的效能.方法 回顾性分析2010-2018年首次就诊于安徽医科大学第一附属医院和第二附属医院感染病科的CHBV患者1087例,按照随机原则以3:1的比例分为训练集和验证集.收集所有研究对象的临床资料并利用XGBoost机器学习模型构建预测模型.同时,计算谷草转氨酶与血小板比率指数(aspartate aminotransferase/platelet ratio index,APRI)、纤维蛋白-4(fibrosis-4 index,FIB-4)评分并与XGBoost机器学习模型进行比较.受试者工作特征曲线下面积(area under curve,AUC)以评估模型区分度,校准曲线(calibration curve,CA)及决策曲线(decision curve analysis,DCA)以评估模型校准度及获益度.结果 共纳入CHBV病例1087例,其中训练集817例,验证集270例.训练集与验证集两组间所有预测变量均无统计学差异(P>0.05).训练集中有103例患者发生肝硬化,肝硬化患者APRI和FIB-4评分明显高于非肝硬化患者(P <0.05).在所有预测因子中血小板的相对重要度最高.训练集和验证集的AUC分别为0.95和0.86(P<0.05),两者Kappa值分别为0.78和0.74,提示模型可重复性较好.CA曲线提示模型预测情况与真实情况拟合情况吻合度较高.训练集和验证集的DCA曲线提示所建立模型能够使患者获得较高的获益度.XGBoost机器学习模型对于肝硬化的效能优于APRI评分和FIB-4评分.结论 本研究利用C H B V患者常见的临床信息构建的XGBoost模型对肝硬化的诊断具有良好的性能,值得临床进一步推广.

First report on establishment and characterization of the extrahepatic cholangiocarcinoma sarcoma cell line CBC2T-2

BACKGROUND Extrahepatic cholangiocarcinoma sarcoma is extremely rare in clinical practice.These cells consist of both epithelial and mesenchymal cells.Patient-derived cell lines that maintain tumor characteristics are valuable tools for studying the molecular mechanisms associated with carcinosarcoma.However,cholangiocarcinoma sarcoma cell lines are not available in cell banks.AIM To establish and characterize a new extrahepatic cholangiocarcinoma sarcoma cell line,namely CBC2T-2.METHODS We conducted a short tandem repeat(STR)test to confirm the identity of the CBC2T-2 cell line.Furthermore,we assessed the migratory and invasive properties of the cells and performed clonogenicity assay to evaluate the ability of individual cells to form colonies.The tumorigenic potential of CBC2T-2 cells was tested in vivo using nonobese diabetic/severe combined immunodeficient(NOD/SCID)mice.The cells were injected subcutaneously and tumor formation was observed.In addition,immunohistochemical analysis was carried out to examine the expression of epithelial marker CK19 and mesenchymal marker vimentin in both CBC2T-2 cells and xenografts.The CBC2T-2 cell line was used to screen the potential therapeutic effects of various clinical agents in patients with cholangiocarcinoma sarcoma.Lastly,whole-exome sequencing was performed to identify genetic alterations and screen for somatic mutations in the CBC2T-2 cell line.RESULTS The STR test showed that there was no cross-contamination and the results were identical to those of the original tissue.The cells showed round or oval-shaped epithelioid cells and mesenchymal cells with spindle-shaped or elongated morphology.The cells exhibited a high proliferation ratio with a doubling time of 47.11 h.This cell line has migratory,invasive,and clonogenic abilities.The chromosomes in the CBC2T-2 cells were polyploidy,with numbers ranging from 69 to 79.The subcutaneous tumorigenic assay confirmed the in vivo tumorigenic ability of CBC2T-2 cells in NOD/SCID mice.CBC2T-2 cells and xenografts were positive for both the epithelial marker,CK19,and the mesenchymal marker,vimentin.These results suggest that CBC2T-2 cells may have both epithelial and mesenchymal characteristics.The cells were also used to screen clinical agents in patients with cholangiocarcinoma sarcoma,and a combination of paclitaxel and gemcitabine was found to be the most effective treatment option.CONCLUSION We established the first human cholangiocarcinoma sarcoma cell line,CBC2T-2,with stable biogenetic traits.This cell line,as a research model,has a high clinical value and would facilitate the understanding of the pathogenesis of cholangiocarcinoma sarcoma.

Analysis of Optical Properties of Off-Axis Reflective Volume Holographic Grating

The coupled wave theory for volume holographic grating with curved interference fringes has been proposed based on the Kogelnik’s coupled wave theory with the plane interference fringes. The formula about the magnitude and directional angle of grating vector in arbitrary position of volume holographic grating with curved grating has been deduced. We found that the wavelength selectivity and angular selectivity may be different in different position of volume holographic curved stripe grating which depend on the angle between the propagation vector of reference beam and signal beam. The larger the angle, the greater the angle and wavelength selectivity, whereas the weaker.

磁耦合谐振式无线能量传输系统的频率特性

磁耦合谐振式无线能量传输具有中等传输距离、高效非辐射能量等优点,本文在阐述磁耦合谐振式无线能量传输工作原理的基础上,研究了谐振的频率对系统性能的影响以及与各个系统参数之间的关系,主要对线圈电感、线圈固有频率、品质因数、传输距离与效率等方面进行了探究,并且研究了中距离条件下频率功率特性曲线,从而在理论上为无线能量传输系统中参数优化与实用工程提供了依据。

Associations between serum uric acid and hepatobiliary-pancreatic cancer:A cohort study

BACKGROUND Uric acid is the end product of purine metabolism.Previous studies have found that serum uric acid(SUA)levels are associated with the total cancer risk.However,due to the dual effect of uric acid on cancer,the relationship between the SUA levels and most specific-site cancer remains unclear.AIM To investigate the associations between the SUA levels and incidence of hepatobiliary-pancreatic cancer.METHODS In this prospective cohort study,444462 participants free of cancer from the UK Biobank were included.The SUA levels were measured at baseline,and the incidence of hepatobiliary-pancreatic cancer was determined by contacting the cancer registry.The hazard ratios(HRs)and 95%confidence intervals(CIs)between the SUA levels and hepatobiliary-pancreatic cancer were investigated using multiple adjusted Cox regression models adjusted for potential confounders.RESULTS In total,920 participants developed liver,gallbladder,biliary tract or pancreatic cancer during a median of 6.6 yrs of follow-up.We found that the HR of pancreatic cancer in the highest SUA group was 1.77(95%CI:1.29-2.42)compared with that in the lowest group.After stratifying by gender,we further found that SUA was associated with an increased risk of pancreatic cancer only among the females(highest quartile vs lowest quartile HR 2.04,95%CI:1.35-3.08).Among the males,the SUA levels were positively associated with the gallbladder cancer risk(highest quartile vs lowest quartile HR 3.09,95%CI:1.28-7.46),but a U-shaped association with the liver cancer risk was observed(P-nonlinear=0.03).CONCLUSION SUA is likely to have gender-specific effects on hepatobiliary-pancreatic cancer.High SUA levels are a risk factor for pancreatic cancer in females and gallbladder cancer in males.A U-shaped association with the liver cancer risk was identified.

Cytokines predict virological response in chronic hepatitis B patients receiving peginterferon alfa-2a therapy

BACKGROUND Chronic hepatitis B virus infection remains a major global public health problem.Peginterferon-alpha-2a(PEG-IFN)has direct antiviral and immunoregulatory effects,and it has become one of the first choice drugs for the treatment of chronic hepatitis B(CHB).Cytokines play an important role in immunity,and they directly inhibit viral replication and indirectly determine the predominant pattern of the host immune response.AIM To determine the correlation between cytokine/chemokine expression levels and response to PEG-IFN treatment in patients with CHB.METHODS Forty-six kinds of cytokines were analyzed before PEG-IFN therapy and at 24 wk during therapy in 26 CHB patients.RESULTS The monokine induced by INF-γ(CXCL9)and serum interferon-inducible protein 10(IP-10)levels at baseline were higher in virological responders than in nonvirological responders(NRs)and decreased during treatment,whereas the NRs did not exhibit significant changes.The macrophage inflammatory protein 1d(MIP-1d)levels at baseline and during treatment were significantly higher in the virological responders than in the NRs,while thymus and activation-regulated chemokine(TARC)levels at baseline and during treatment were significantly lower in the virological responders than in the NRs.The CXCL9,IP-10,MIP-1d,and TARC baseline levels exhibited the expected effects for interferon treatment.The area under the receiver operating characteristic curve values of CXCL9,IP-10,MIP-1d,and TARC for predicting virological responses were 0.787,0.799,0.787,and 0.77(P=0.01,0.013,0.01,and 0.021),respectively.CONCLUSION We found that cytokine levels before and during treatment may represent potential biomarkers to select CHB patients who can respond to PEG-IFN.Therefore,cytokines can be used as an indicator of antiviral drug selection before CHB treatment.

Absorption,quenching,and enhancement by tracer in acetone/toluene laser-induced fluorescence

To measure the equivalent ratio distribution of the two-stage lean premixed(DLP)flame,we propose using acetone/toluene planar laser-induced fluorescence(PLIF)technology to simultaneously measure the concentrations of the two components.Appropriate excitation laser wavelength and filters are used to assess the influence of acetone and toluene on each other’s fluorescence signal at room temperature.Experimental results show that acetone has a strong absorption effect on toluene’s fluorescence signal,the effective absorption cross-section is 5.77×10-20 cm-2.Acetone has an obvious quenching effect on the toluene fluorescence signal,and the Stern–Volmer coefficient is 0.50 kPa-1.The collisions between the molecules of toluene and acetone will lead to the enhancement of the fluorescence signal of acetone,and the enhancement coefficient is exponential with the acetone’s concentration.The quantitative relationship between the fluorescence intensity and the concentrations of the two tracers is obtained by establishing the photophysical model of toluene and acetone’s fluorescence signals.

A Possible Periodicity in the Radio Light Curves of 3C 454.3

During the period 1966.5-2006.2 the 15 GHz and 8 GHz light curves of 3C 454.3 （z = 0.859） show a quasi-periodicity of ,-12.8 yr （-6.9 yr in the rest frame of the source） with a double-bump structure. This periodic behaviour is interpreted in terms of a rotating double-jet model in which the two jets are created from the black holes of a binary system and rotating with the period of the orbital motion. The periodic variations in the radio fluxes of 3C 454.3 are suggested to be mainly due to the lighthouse effects （or the variation in Doppler boosting） of the precessing jets caused by the orbital motion. In addition, variations in the rate of mass accreting onto the black holes may be also involved.

Smoothness Prior Approach for Spectral Smoothing and Baseline Correction

Smoothness prior approach for spectral smoothing is investigated using Fourier frequency filter analysis.We show that the regularization parameter in penalized least squares could continuously control the bandwidth of low-pass filter.Besides,due to its property of interpolating the missing values automatically and smoothly,a spectral baseline correction algorithm based on the approach is proposed.This algorithm generally comprises spectral peak detection and baseline estimation.First,the spectral peak regions are detected and identified according to the second derivatives.Then,generalized smoothness prior approach combining identification information could estimate the baseline in peak regions.Results with both the simulated and real spectra show accurate baseline-corrected signals with this method.

Scanning the optical characteristics of lead-free cesium titanium bromide double perovskite nanocrystals

Cs_(2)TiBr_(6) nanocrystals(NCs)are a type of promising optoelectronic materials,owing to their high photoelectric properties and non-toxicity.Here,we synthesize the colloidal Cs_(2)TiBr_(6)NCs using a hot-injection approach.The temperaturedependent absorption data shows that its energy band changes about 30 me V with temperature,reflecting that its energy band structure is much stable.The excitation intensity-dependent transient absorption data confirms its linear absorption cross-sections and carrier recombination rate constants,involving monomolecular and bimolecular recombination,which are all superior to those of conventional perovskite bromide counterparts.In addition,its nonlinear absorption cross-sections are also measured based on femtosecond Z-scan.Our results suggest that Cs_(2)TiBr_(6)NCs can be extensively applied in the field of optoelectronics,owing to its excellent carrier dynamics and nonlinear optical properties.

Refractive Focusing of Interstellar Clouds and Intraday Polarization Angle Swings

Intraday variations of compact extragalactic radio sources in flux density and polarization are generally interpreted in terms of refractive scintillation from the continuous interstellar medium of our Galaxy. However, continuous polarization angle swings of - 180° （for example, the one observed in the QSO 0917＋624） could not be interpreted in this way. Qian et al. have shown that the polarization angle swing observed in the QSO 1150＋812 can be explained in terms of focusing-defocusing effect by an interstellar cloud, which occults two closely-placed polarized components. Here we further show that the polarization angle swing event observed in the QSO 0917＋624 can also be explained in this way. We also found evidence for the cloud eclipsing a non-polarized （core） component during a short period out- side the swing. A particular （and specific） plasma-lens model is proposed to model-fit the polarization swing event of 0917＋624. Some physical parameters related to the plasma-lens and the source components are estimated. The brightness temperatures of the two lensed components are estimated to be -1.6× 10^13 K. Thus bulk relativistic motion with a Lorentz factor less than -20 may be sufficient to avoid the inverse - Compton catastrophe.

A possible precessing nozzle and the Lense-Thirring effect in blazar 3C 454.3

The kinematics of superluminal components in blazar 3C 454.3 are studied.Nine components are included： superluminal knots R1, R2, R3, R4, A, B, C and D（from Britzen et al. 2013） and C4 （from Pauliny-Toth 1998）. We find that their kine-matics derived from VLBI observations can be consistently interpreted in terms of ajet precession scenario with a period of about 14.5 yr. We discuss the model fits oftheir trajectory, distance from the core and apparent velocity. We show that the bulkLorentz factor （in the range 4 to 15） derived for these components does not have anydependence on the phase of the precession （or position angle for ejection）. The Lense-Thirring effect is assumed to interpret the precession of the jet nozzle. The resultsobtained for blazar 3C 454.3 are only suggestive. They are not unique and have yet tobe tested, but they might be useful for understanding the kinematics of superluminalcomponents in blazars and for disentangling different mechanisms and factors.

肠道分节丝状菌与儿童轮状病毒感染关系分析

目的探讨肠道分节丝状菌(SFB)定植与轮状病毒感染风险的关系及SFB抵御轮状病毒感染的可能机制。方法病例对照研究。选择在浙江大学医学院附属儿童医院门诊因腹泻经粪便检测轮状病毒阳性的0~5岁患儿50例为研究对象,即轮状病毒性肠炎组,并以非胃肠道疾病、非感染性疾病的外科疾病患儿55例为对照组,年龄、性别组成与轮状病毒性肠炎组相匹配。提取粪便菌群的DNA,通过实时荧光定量PCR分析测定SFB,将轮状病毒性肠炎组及对照组患儿分别按照年龄和性别分组,分析SFB的阳性率在不同组间的差异,并进一步比较分析这两组患儿在≤2岁组及>2~5岁年龄组SFB阳性率的差异。通过p3340蛋白与轮状病毒进行中和试验,确定Vero细胞轮状病毒感染率与p3340浓度之间的关系。组间比较采用χ^(2)检验或Fisher确切概率法。结果轮状病毒性肠炎组患儿50例,年龄(1.7±0.9)岁,对照组患儿55例,年龄(1.8±1.1)岁。轮状病毒性肠炎组患儿SFB的阳性率在各个年龄中呈递减分布,其中≤1岁组最高,为10/14,>1~2岁组为67%(14/21),>2~5岁组为9/15,差异无统计学意义(P=0.867);对照组患儿≤1岁组SFB阳性率为12/15,>1~2岁组为95%(19/20),>2~5岁组为50%(10/20),差异有统计学意义(P=0.004)。轮状病毒性肠炎组患儿男童SFB阳性率为74%(20/27),女童为56%(13/23),差异无统计学意义(χ^(2)=1.71,P=0.192);对照组患儿男童SFB阳性率为79%(22/28),女童为70%(19/27),差异无统计学意义(χ^(2)=0.49,P=0.485)。轮状病毒性肠炎组SFB阳性率66%(33/50),对照组为75%(41/55),差异无统计学意义(χ^(2)=0.56,P=0.454)。在≤2岁患儿中,轮状病毒性肠炎组SFB阳性率69%(24/35),对照组为89%(31/35),差异有统计学意义(χ^(2)=4.16,P=0.041);在>2~5岁患儿中,轮状病毒性肠炎组SFB阳性率为9/15,对照组为50%(10/20),差异无统计学意义(P=0.734)。经Pearson相关性分析,随着SFB阳性率的增加,轮状病毒的感染率呈下降趋势(r=-0.87,P<0.001)。随着p3340特异蛋白浓度的增加,适合培养轮状病毒的Vero细胞荧光素酶的发光强度呈下降趋势(F=4.17,P=0.001)。结论2岁以内婴幼儿肠道SFB定植与降低轮状病毒感染风险相关;克隆特定SFB功能蛋白p3340可以中和轮状病毒感染Vero细胞,且这种针对轮状病毒感染的机制可能不同于常见的抗病毒机制。

Beyond ribosomal function:RPS6 deficiency suppresses cholangiocarcinoma cell growth by disrupting alternative splicing

Cholangiocarcinoma(CCA)is a bile duct malignancy with a dismal prognosis.This study systematically investigated the role of the ribosomal protein S6(RPS6)gene,which is dependent in CCA.We found that RPS6 upregulation in CCA tissues was correlated with a poor prognosis.Functional investigations have shown that alterations in RPS6 expression,both gain-and loss-of function could affect the proliferation of CCA cells.In xenograft tumor models,RPS6 overexpression enhances tumorigenicity,whereas RPS6 silencing reduces it.Integration analysis using RNA-seq and proteomics elucidated downstream signaling pathways of RPS6 depletion by affecting the cell cycle,especially DNA replication.Immunoprecipitation followed by mass spectrometry has identified numerous spliceosome complex proteins associated with RPS6.Transcriptomic profiling revealed that RPS6 affects numerous alternative splicing(AS)events,and combined with RNA immunoprecipitation sequencing,revealed that minichromosome maintenance complex component 7(MCM7)binds to RPS6,which regulates its AS and increases oncogenic activity in CCA.Targeting RPS6 with vivo phosphorodiamidate morpholino oligomer(V-PMO)significantly inhibited the growth of CCA cells,patient-derived organoids,and subcutaneous xenograft tumor.Taken together,the data demonstrate that RPS6 is an oncogenic regulator in CCA and that RPS6-V-PMO could be repositioned as a promising strategy for treating CCA.

Biliary fibrosis is an important but neglected pathological feature in hepatobiliary disorders:from molecular mechanisms to clinical implications

Fibrosis resulting from pathological repair secondary to recurrent or persistent tissue damage often leads to organ failure and mortality.Biliary fibrosis is a crucial but easily neglected pathological feature in hepatobiliary disorders,which may promote the development and progression of benign and malignant biliary diseases through pathological healing mechanisms secondary to biliary tract injuries.Elucidating the etiology and pathogenesis of biliary fibrosis is beneficial to the prevention and treatment of biliary diseases.In this review,we emphasized the importance of biliary fibrosis in cholangiopathies and summarized the clinical manifestations,epidemiology,and aberrant cellular composition involving the biliary ductules,cholangiocytes,immune system,fibroblasts,and the microbiome.We also focused on pivotal signaling pathways and offered insights into ongoing clinical trials and proposing a strategic approach for managing biliary fibrosis-related cholangiopathies.This review will offer a comprehensive perspective on biliary fibrosis and provide an important reference for future mechanism research and innovative therapy to prevent or reverse fibrosis.

CYP2C19基因多态性与儿童幽门螺杆菌根除治疗效果的关系

目的探讨CYP2C19基因多态性与儿童幽门螺杆菌(Hp)根治效果的关系。方法回顾性队列研究。研究对象为2016年9月至2018年12月因"恶心、呕吐、腹痛、腹胀、反酸、烧心、胸痛、呕血、黑便"等消化道症状就诊于浙江大学医学院附属儿童医院,且已进行胃镜检查的125例患儿。患儿快速尿素酶试验(RUT)阳性,治疗前胃窦黏膜进行Hp培养和药敏试验,经过2周规范Hp根除治疗,且1个月后查13C尿素呼气试验结果判断疗效。利用胃镜检查中常规进行RUT检测过的胃窦黏膜,提取组织DNA,进行CYP2C19基因多态性检测并根据代谢型分组,结合Hp培养和药敏结果,分析CYP2C19基因多态性与儿童Hp根除治疗效果的关系。行列分析采用χ^(2)检验,组间比较采用Fisher确切概率法。结果125例患儿中男76例、女49例,CYP2C19基因多态性分布频率为弱或慢代谢(PM)型30.4%(38/125),中间代谢(IM)型20.8%(26/125),正常代谢(NM)型47.2%(59/125),快代谢(RM)型1.6%(2/125),超快代谢(UM)型为0,不同基因型阳性率间差异有统计学意义(χ^(2)=124.00,P<0.001)。PM、IM、NM、RM型患儿Hp根除治疗成功率分别为84.2%(32/38)、53.8%(14/26)、67.8%(40/59)、0,各基因型Hp根除治疗成功率的差异有统计学意义(χ^(2)=11.35,P=0.010),IM型Hp根除治疗成功率低于PM型(P=0.011)。在相同标准三联Hp根除治疗方案前提下,IM型Hp根除治疗成功率为8/19,低于PM(80.0%,24/30)和NM型(77.3%,34/44)(P=0.007、0.007)。各基因型Hp标准三联方案根除治疗效果差异有统计学意义(χ^(2)=9.72,P=0.008)。结合克拉霉素药敏结果分析Hp根除治疗成功率,IM型敏感组为4/15,耐药组为4/4,差异有统计学意义(χ^(2)=6.97,P=0.018)。结论CYP2C19基因在儿童中存在多态性分布,且与儿童Hp根治疗效存在密切关系,PM型根除治疗成功率较高。

幽门螺杆菌毒力因子基因型和儿童胃十二指肠疾病的关系

目的探讨幽门螺杆菌(Hp)毒力因子基因型与儿童胃十二指肠疾病、胃黏膜病理学改变程度的关系。方法回顾性队列研究。研究时间为2020年5至10月,研究对象为2012年4月至2014年12月因消化道不适症状就诊于浙江大学医学院附属儿童医院,胃镜检查确诊为胃十二指肠疾病、胃黏膜Hp培养阳性的68例患儿的冻存菌株。复苏Hp菌株提取DNA后进行PCR扩增和琼脂糖凝胶电泳,确定细胞毒素相关蛋白A(cagA)、空泡细胞毒素A(vacA)(s1a、s1b/s2,m1/m2)、外膜炎性蛋白A(oipA)、血型抗原结合黏附素(babA2)、十二指肠溃疡促进因子A(dupA)基因的检出率,对oipA基因进行测序,判定基因状态。根据胃镜诊断结果、胃黏膜病理结果进行分组,分析各毒力因子基因型的检出率在不同组患儿之间的差异,组间比较采用χ^(2)检验或Fisher确切概率法。结果完成基因测定的68株Hp菌株来自68例Hp感染的胃十二指肠疾病患儿,根据胃镜诊断结果分为浅表性胃炎47例和消化性溃疡21例。根据胃黏膜病理炎症程度分为轻度8例和中重度60例;按胃黏膜病理炎症活动性分为活动性组61例和无活动性组7例。cagA、vacA、vacA s1/m2、功能性oipA、babA2和dupA 6种毒力因子基因的检出率分别为100%(68/68)、100%(68/68)、94%(64/68)、99%(67/68)、82%(56/68)、71%(48/68);6种毒力因子基因在浅表性胃炎组检出率分别为100%(47/47)、100%(47/47)、96%(45/47)、98%(46/47)、81%(38/47)、70%(33/47),在消化性溃疡组分别为100%(21/21)、100%(21/21)、90%(19/21)、100%(21/21)、86%(18/21)、71%(15/21),各基因型检出率在两组患儿间差异均无统计学意义(均P>0.05);6种毒力因子基因在胃黏膜炎症程度轻度组分别为8/8、8/8、8/8、7/8、7/8、5/8,在胃黏膜炎症程度中重度组分别为100%(60/60)、100%(60/60)、93%(56/60)、100%(60/60)、82%(49/60)、72%(43/60),各基因型检出率在两组患儿间差异均无统计学意义(均P>0.05);6种毒力因子基因在胃黏膜炎症活动性组分别为100%(61/61)、100%(61/61)、93%(57/61)、98%(60/61)、82%(50/61)、72%(44/61),在无活动性组分别为7/7、7/7、7/7、7/7、6/7、4/7,各基因型检出率在两组患儿间差异均无统计学意义(均P>0.05)。4种或5种毒力因子基因阳性组合检出率在不同组患儿之间的差异均无统计学意义(均P>0.05)。结论cagA、vacA、vacA s1/m2、功能性oipA、babA2、dupA基因与儿童浅表性胃炎和消化性溃疡及胃黏膜病理炎症程度和活动性的关系均不明显;cagA、vacA、oipA、babA2、dupA的不同基因组合对于预测儿童Hp感染的临床结局没有显著作用。

Flame features and oscillation characteristics in near-blowout swirl-stabilized flames using high-speed OH-PLIF and mode decomposition methods

Flame features and dynamics are important to the explanation and prediction of a lean blowout(LBO)phenomenon.In this paper,recognition of near-LBO flame features and oscillation characterization methods were proposed based on flame spectroscopic images.High-speed planar laser-induced fluorescence measurements of OH were used to capture unique dynamic features such as the local extinction and reignition feature and entrained reactant pockets.The Zernike moment demonstrated a good performance in recognition of stability and near-LBO conditions,though the geometric moment had more advantages to characterize frequency characteristics.Low-frequency oscillations,especially at the obvious self-excited oscillation frequency around 200 Hz,were found when approaching an LBO condition,which can be expected to be used as a novel prediction characteristic parameter of the flameout limit.Proper orthogonal decomposition(POD)and dynamic mode decomposition(DMD)were used to conduct dynamic analysis of near-LBO flames.POD modes spectra showed the unique frequency characteristics of stable and near-LBO flames,which were basically in line with those at the heat-release frequency.The primary POD modes demonstrated that the radial vibration mode dominated in a stable flame,while the rotation mode was found to exist in a near-LBO flame.Analysis of modal decomposition showed that flame shedding and agminated entrained reactant pockets were responsible for generating self-excited flame oscillations.