A Novel Method for Linear Systems of Fractional Ordinary Differential Equations with Applications to Time-Fractional PDEs

This paper presents an efficient numerical technique for solving multi-term linear systems of fractional ordinary differential equations(FODEs)which have been widely used in modeling various phenomena in engineering and science.An approximate solution of the system is sought in the formof the finite series over the Müntz polynomials.By using the collocation procedure in the time interval,one gets the linear algebraic system for the coefficient of the expansion which can be easily solved numerically by a standard procedure.This technique also serves as the basis for solving the time-fractional partial differential equations(PDEs).The modified radial basis functions are used for spatial approximation of the solution.The collocation in the solution domain transforms the equation into a system of fractional ordinary differential equations similar to the one mentioned above.Several examples have verified the performance of the proposed novel technique with high accuracy and efficiency.

3D anisotropic modeling and identification for airborne EM systems based on the spectral-element method

The airborne electromagnetic （AEM） method has a high sampling rate and survey flexibility. However, traditional numerical modeling approaches must use high-resolution physical grids to guarantee modeling accuracy, especially for complex geological structures such as anisotropic earth. This can lead to huge computational costs. To solve this problem, we propose a spectral-element （SE） method for 3D AEM anisotropic modeling, which combines the advantages of spectral and finite-element methods. Thus, the SE method has accuracy as high as that of the spectral method and the ability to model complex geology inherited from the finite-element method. The SE method can improve the modeling accuracy within discrete grids and reduce the dependence of modeling results on the grids. This helps achieve high-accuracy anisotropic AEM modeling. We first introduced a rotating tensor of anisotropic conductivity to Maxwell＇s equations and described the electrical field via SE basis functions based on GLL interpolation polynomials. We used the Galerkin weighted residual method to establish the linear equation system for the SE method, and we took a vertical magnetic dipole as the transmission source for our AEM modeling. We then applied fourth-order SE calculations with coarse physical grids to check the accuracy of our modeling results against a 1D semi-analytical solution for an anisotropic half-space model and verified the high accuracy of the SE. Moreover, we conducted AEM modeling for different anisotropic 3D abnormal bodies using two physical grid scales and three orders of SE to obtain the convergence conditions for different anisotropic abnormal bodies. Finally, we studied the identification of anisotropy for single anisotropic abnormal bodies, anisotropic surrounding rock, and single anisotropic abnormal body embedded in an anisotropic surrounding rock. This approach will play a key role in the inversion and interpretation of AEM data collected in regions with anisotropic geology.

血清Th1/Th2、Hmga1、PKM2表达水平及其联合HPV诊断宫颈癌的价值

目的探讨辅助性T细胞1(Th1)/辅助性T细胞2(Th2)、高迁移率族蛋白A1(Hmga1)、丙酮酸激酶M2型(PKM2)水平及联合人乳头状瘤病毒(HPV)对宫颈癌的诊断价值。方法选取2022年3月至2023年3月在河南省中医院就诊的186例宫颈疾病患者作为研究对象,根据疾病类型分为宫颈炎组(n=62)、宫颈癌前病变组(n=58)和宫颈癌组(n=66),另选取60例同期健康体检者作为对照组,比较四组及宫颈癌前病变组和宫颈癌组合并、未合并HPV感染患者入院时Th1/Th2因子[血清干扰素γ(IFN-γ)、白细胞介素-2(IL-2)、白细胞介素-4(IL-4)、白细胞介素-10(IL-10)]、Hmga1、PKM2水平,分析血清Th1/Th2、Hmga1、PKM2水平表达与肿瘤病理特征的关系及联合HPV对宫颈癌合并HPV感染的诊断价值。结果四组受检者入院(体检)时的血清IFN-γ、IL-2、IL-4、IL-10、Hmga1、PKM2水平比较,宫颈癌组>宫颈癌前病变组>宫颈炎组>对照组,差异均有统计学意义(P<0.05);与未合并HPV感染患者比较,宫颈癌前病变组、宫颈癌组合并HPV感染患者入院时的血清IFN-γ、IL-2、IL-4、IL-10、Hmga1、PKM2水平较高,差异均有统计学意义(P<0.05);不同肿瘤分化程度、临床分期、有无淋巴结转移宫颈癌合并HPV感染患者入院时的血清IFN-γ、IL-2、IL-4、IL-10、Hmga1、PKM2水平比较差异均有统计学意义(P<0.05);HPV感染对宫颈癌诊断灵敏度为84.85%(54/66),特异度为72.41%(16/28),准确度为56.45%(70/124);血清IFN-γ、IL-2、IL-4、IL-10、Hmga1、PKM2、HPV感染对宫颈癌、宫颈癌前病变诊断AUC分别为0.761、0.730、0.745、0.806、0.819、0.707、0.786,HPV感染联合各血清指标诊断AUC为0.908,大于单一指标诊断。结论血清Th1/Th2、Hmga1、PKM2水平检测对宫颈癌具有一定的诊断价值,临床可通过其联合HPV感染情况早期辅助诊断宫颈病变,为临床针对性制定干预方案提供参考。

奥希替尼联合同步放化疗治疗EGFR T790M突变的晚期非小细胞肺癌患者的临床效果

目的 探讨奥希替尼联合同步放化疗治疗表皮生长因子受体(EGFR)T790M突变的晚期非小细胞肺癌(NSCLC)患者的临床效果。方法 选取2016年3月至2018年9月本院收治的82例EGFR T790M突变的晚期NSCLC患者,采用随机数字表法将其分为对照组(41例)和观察组(41例)。对照组给予同步放化疗治疗,观察组给予奥希替尼联合同步放化疗治疗。比较两组的治疗效果。结果 观察组的疾病控制率、客观缓解率高于对照组,差异具有统计学意义(P<0.05)。观察组的Ⅰ+Ⅱ级皮疹、胃肠道反应、甲沟炎发生率高于对照组,差异具有统计学意义(P<0.05)。随访2年,观察组的无进展生存时间(PFS)为11.32(6.85,12.41)个月,长于对照组的7.29(4.91,9.32)个月(P<0.05);随访1、2年,观察组的生存率为75.61%、39.02%,高于对照组的56.10%、12.20%,差异具有统计学意义(P<0.05)。结论 奥希替尼联合同步放化疗治疗EGFR T790M突变的晚期NSCLC患者可提高近远期治疗效果,延长PFS,提升患者生存率,具有较高的临床应用价值。

经腹入路与经后腹腔入路腹腔镜肾部分切除术治疗T1aN0M0期肾癌的效果分析

目的对比经腹入路与经后腹腔入路腹腔镜肾部分切除术(LPN)治疗T1aN0M0期肾癌的效果,为临床提供参考。方法回顾性分析2021年1月至2024年1月徐州市肿瘤医院收治的100例进行LPN治疗的T1aN0M0肾癌患者的临床资料,根据手术方法的不同分为对照组(50例,接受经腹入路LPN治疗)和观察组(50例,接受经后腹腔入路LPN治疗)。比较两组患者围术期指标水平、应激指标水平和术后并发症发生情况。结果观察组患者手术时间与术后住院时间均短于对照组(均P<0.05);两组患者手术成功率、术中出血量比较,差异均无统计学意义(均P>0.05)。术后1 d,两组患者丙二醛(MDA)、皮质醇(Cor)水平均高于术前,但观察组均低于对照组(均P<0.05)。两组患者术后并发症总发生率比较,差异无统计学意义(P>0.05)。结论与经腹入路相比,经后腹腔入路LPN治疗T1aN0M0期肾癌在缩短手术时间和术后住院时间及减轻应激反应等方面具有优势,值得临床应用。

苹果矮化砧木M9T337组培快繁技术研究

矮化栽培是苹果栽培现代化发展的趋势,应用矮化砧木是实现苹果矮化栽培、标准化管理的主要途径。为完善和优化苹果矮化砧木组培繁殖再生体系,以苹果矮化砧木M9T337为试验材料,分别用75%酒精和1 g/kg升汞进行消毒处理,以筛选外植体最佳消毒方案;以M9T337单芽茎段为材料,研究不同培养基配方组合对组培苗污染率、增殖系数、株高、长势、生根个数和生根率等指标的影响。结果表明,最适合外植体消毒的方法为75%酒精30 s+1 g/kg升汞9 min,最佳M9T337初代培养基、继代培养基和生根培养基配方分别为MS+6-BA 0.8 mg/L+NAA 0.4 mg/L、MS+BA 1.0 mg/L+NAA 0.5 mg/L和1/3MS+IBA 0.1 mg/L。本试验建立了苹果矮化砧木M9T337高效离体快繁技术体系,筛选出了适宜于M9T337最佳扩繁、生根培养基。

虚拟筛选和鉴定EGFRL858R/T790M非共价抑制剂

目的:基于计算机虚拟筛选和生物活性评价鉴定新的治疗非小细胞肺癌的EGFR酪氨酸激酶EGFRL858R/T790M非共价抑制剂。方法:基于受体-配体复合物结构(PDB ID:5HCZ)构建药效团模型,选择ROC值为0.849的药效团模型对Specs化合物数据库进行筛选,再经过Libdock对接程序进一步过滤,最终选出20个化合物进行EGFRL858R/T790M酶活测试。结果:当化合物浓度为1μmol·L-1时,有7个化合物能够使EGFRL858R/T790M酶活降至52%以下,且对酶的抑制活性高于对照物吉非替尼[(52.77±0.39)%];当浓度为0.1μmol·L^(-1)时,化合物AN-465/42889633[(65.99±2.94)%]、AG-690/40753617[(68.29±6.18)%]和AN-465/43336751[(78.61±7.23)%]对EGFRL858R/T790M的抑制作用仍优于对照物吉非替尼[(80.42±0.62)%];分子对接结果表明3个分子通过氢键、疏水作用力及静电作用力与EGFRL858R/T790M活性部位相结合。结论:AN-465/42889633、AG-690/40753617和AN-465/43336751可作为非共价EGFRL858R/T790M抑制剂的先导化合物进行研究,同时为新型EG-FR抑制剂的研发奠定基础。

Clinical outcome and prognostic factors of T4N0M0 colon cancer after R0 resection:A retrospective study

BACKGROUND Paradoxically,patients with T4N0M0(stage II,no lymph node metastasis)colon cancer have a worse prognosis than those with T2N1-2M0(stage III).However,no previous report has addressed this issue.AIM To screen prognostic risk factors for T4N0M0 colon cancer and construct a prognostic nomogram model for these patients.METHODS Two hundred patients with T4N0M0 colon cancer were treated at Tianjin Medical University General Hospital between January 2017 and December 2021,of which 112 patients were assigned to the training cohort,and the remaining 88 patients were assigned to the validation cohort.Differences between the training and validation groups were analyzed.The training cohort was subjected to multi-variate analysis to select prognostic risk factors for T4N0M0 colon cancer,followed by the construction of a nomogram model.RESULTS The 3-year overall survival(OS)rates were 86.2%and 74.4%for the training and validation cohorts,respectively.Enterostomy(P=0.000),T stage(P=0.001),right hemicolon(P=0.025),irregular review(P=0.040),and carbohydrate antigen 199(CA199)(P=0.011)were independent risk factors of OS in patients with T4N0M0 colon cancer.A nomogram model with good concordance and accuracy was constructed.CONCLUSION Enterostomy,T stage,right hemicolon,irregular review,and CA199 were independent risk factors for OS in patients with T4N0M0 colon cancer.The nomogram model exhibited good agreement and accuracy.

奥希替尼联合贝伐珠单抗一线治疗EGFR T790M突变晚期NSCLC患者的有效性和安全性

目的探究奥希替尼联合贝伐珠单抗治疗EGFRT 790M突变晚期非小细胞型肺癌(NSCLC)患者的有效性和安全性。方法选取82例EGFR T790M突变晚期NSCLC患者,按单双号分2组。对照组41例采用奥希替尼治疗,研究组41例采用奥希替尼联合贝伐珠单抗治疗。经过4个周期的治疗,对2组治疗的有效性和安全性进行评估。结果治疗后研究组客观缓解率(ORR)、疾病控制率(DCR)和T淋巴细胞亚群(CD3^(+)、CD4^(+)、CD4^(+)/CD8^(+))水平均高于对照组(P<0.05),研究组癌胚抗原(CEA)、人细胞角蛋白21-1(cyfra21-1)、糖类抗原CA125(CA125)水平低于对照组(P<0.05)。2组贫血、皮疹、肝功能损伤、胃肠道反应、蛋白尿和高血压等不良反应分级为1~2级,差异不显著(P>0.05)。结论奥希替尼联合贝伐珠单抗一线治疗EGFR T790M突变晚期NSCLC,可改善患者免疫功能,降低肿瘤标志物水平,临床疗效高,安全性佳。

基于E81T8-Ni2填充盖面的L415M管线钢的焊接工艺评定

L415M管线钢环向焊接接头焊接工艺填充盖面焊丝采用E81T8-Ni2代替E71T8-Ni1,替代原则不符合GB/T 31032—2014《钢质管道焊接及验收》的覆盖原则,需要重新进行焊接工艺评定。基于施工单位焊接工艺需求,为了验证E81T8-Ni2能否用于L415M对接焊缝的填充盖面焊接,采用焊条电弧焊打底,自保护药芯焊丝半自动焊填充盖面组合焊接方法,根焊焊接材料为E6010,填充盖面为E81T8-Ni2,依据GB/T31032—2014进行焊接工艺评定。对评定试样进行外观检查、无损检测、拉伸试验、弯曲试验、刻槽锤断试验以及冲击试验。试验结果表明,L415M管线钢环向焊接接头各项指标合格,拉伸试样断在母材上,焊接接头满足高强匹配要求。焊接工艺评定试验研究成果可为长输管道用L415M管线钢焊接工艺以及焊材选择提供参考。

梓醇干预PKM2/LDHA表达调控Th17细胞分化的机制研究

目的研究梓醇通过干预丙酮酸激酶M2(PKM2)、乳酸脱氢酶A(LDHA)表达进而影响辅助性T细胞17(Th17)分化的机制。方法从C57BL/6小鼠脾脏中分选出naive CD4^(+)T细胞,通过加入定向分化刺激剂诱导72 h使naive CD4^(+)T细胞向Th17细胞分化。在诱导分化的同时,分别用0(定向对照)、20、40、80μg/mL梓醇对细胞进行处理。采用流式细胞术检测细胞中Th17细胞分化比例,采用比色法检测细胞培养上清液中丙酮酸、乳酸水平,采用实时荧光定量-逆转录聚合酶链式反应(qRT-PCR)法检测细胞中视黄酸相关孤儿受体γt(RORγt)、PKM2、LDHA mRNA表达情况,采用Western blot法检测细胞中PKM2、LDHA、信号转导和转录激活因子3(STAT3)、磷酸化STAT3(p-STAT3)蛋白表达情况。结果与定向对照组比较,经20、40、80μg/mL梓醇作用72 h后,细胞中Th17细胞分化比例分别降低了6.74%、8.41%、9.24%;细胞培养上清液中丙酮酸、乳酸水平,细胞中PKM2、LDHA、RORγt mRNA表达水平以及细胞中PKM2、LDHA蛋白表达水平和STAT3磷酸化水平均显著降低(P<0.05)。结论梓醇可通过下调PKM2、LDHA表达来降低糖酵解水平,进而抑制Th17细胞分化。

奥西替尼二线治疗EGFR T790M突变非小细胞肺癌脑转移临床研究

目的:研究奥西替尼二线治疗EGFR T790M突变非小细胞肺癌(NSCLC)脑转移的临床疗效。方法:前瞻性选择一线治疗失败的EGFR T790M突变非小细胞肺癌脑转移患者100例。采用随机数字表法分为两组,各50例,观察组采用奥西替尼方案治疗,对照组采用培美曲塞+顺铂方案治疗。比较两组的治疗效果﹑脑转移肿瘤直径变化﹑血清肿瘤标志物及血管内皮生长因子(VEGF)水平及不良反应。结果:与对照组比较,观察组客观缓解率(68.0%与30.0%)及疾病控制率(88.0%与70.0%)明显较高(均P<0.05);治疗后与对照组比较,观察组患者脑部肿瘤直径明显缩小,血清癌胚抗原(CEA)、神经特异性烯醇化酶(NSE)、VEGF水平明显降低,无进展生存期明显延长(均P<0.05);两组腹泻、皮疹、骨髓抑制、恶心呕吐等不良反应发生率比较差异有统计学意义(均P<0.05)。结论:奥西替尼二线治疗EGFR T790M突变NSCLC脑转移可有效控制肿瘤进展,安全可行。

Weaning methods affect ruminal methanogenic archaea composition and diversity in Holstein calves

The objective of the present study was to examine the effect of different weaning methods on the ruminal methanogenic archaea composition and diversity in Holstein calves.Thirty-six newborn Holstein bull calves were assigned to 1 of 3 treatments:(1)conventional weaning(d 56)and fed a high proportion of solid feed(CWS);(2)conventional weaning(d 56)and fed a high proportion of liquid feed(CWL);(3)early weaning(d 42)and fed with a high proportion of solid feed(EWS).High-throughput sequencing of the methyl coenzyme M reductase(mcr A)gene,which encodes theα-subunit of methyl coenzyme M reductase-the enzyme that catalyzes the final step in methanogenesis was used to determine the composition and diversity of rumen methanogens.No significant difference(P>0.05)was observed for operational taxonomic units(OTUs)or richness indices,but diversity indices increased(P<0.05)for calves fed high dietary solids.Predominant families across the three treatments were Methanobacteriaceae,Thermoplasmataceae and Methanomassiliicoccaceae.Calves in the EWS treatment had a higher(P<0.05)relative abundance of Methanobrevibacter sp.strain AbM4 and Methanosphaera stadtmanae,while calves in the CWL treatment had a higher(P<0.05)abundance of Methanosphaera sp.strain SM9.A positive(P<0.05)relationship was identified between butyrate and Methanobrevibacter sp.strain AbM4.In conclusion,the composition and diversity of methanogens in the rumen of Holstein calves varied under the different weaning methods.This study identified a positive relationship between butyrate and Methanobrevibacter sp.strain AbM4,potentially reflecting correlations between ruminal fermentation variables and methanogenesis function.These in-depth analyses provide further understanding of weaning methods for intensified production systems.

叶酸受体1在肺腺癌组织中的表达及其与T790M基因突变的相关性研究

目的探讨叶酸受体1(FOLR1)在肺腺癌组织中的表达以及T790M基因突变后FOLR1蛋白在癌组织中的表达变化。方法收集2017年1月至2022年12月在河南省人民医院接受治疗的94例肺腺癌患者的临床资料。根据T790M基因突变情况分为突变组44例和未突变组50例。采用免疫组织化学法检测94例肺腺癌组织中FOLR1的蛋白水平,分析腺癌组织中FOLR1蛋白表达与T790M基因突变的相关性。分析不同临床病理特征与FOLR1蛋白表达的关系。结果比较T790M基因突变和未突变肺腺癌组织中FOLR1蛋白的表达率差异有统计学意义(P=0.047)。结论FOLR1蛋白的表达与T790M耐药基因的突变之间有相关性,且FOLR1将是肺腺癌T790M耐药基因的诊断和治疗的潜在靶点。

M-矩阵Sylvester方程的一类交替方向迭代法

Sylvester方程广泛出现在科学计算和工程应用的许多领域中,本文研究了M-矩阵Sylvester方程的数值解法.基于M-矩阵的性质和交替方向迭代的思想,提出了一类交替方向迭代法以求解M-矩阵Sylvester方程,并给出了新方法的收敛性分析.数值实验表明,新方法是可行的,而且在一定条件下也是较为有效的.

Method of reverberation ray matrix for static analysis of planar framed structures composed of anisotropic Timoshenko beam members

Based on the method of reverberation ray matrix（MRRM）, a reverberation matrix for planar framed structures composed of anisotropic Timoshenko（T） beam members containing completely hinged joints is developed for static analysis of such structures.In the MRRM for dynamic analysis, amplitudes of arriving and departing waves for joints are chosen as unknown quantities. However, for the present case of static analysis, displacements and rotational angles at the ends of each beam member are directly considered as unknown quantities. The expressions for stiffness matrices for anisotropic beam members are developed. A corresponding reverberation matrix is derived analytically for exact and unified determination on the displacements and internal forces at both ends of each member and arbitrary cross sectional locations in the structure. Numerical examples are given and compared with the finite element method（FEM） results to validate the present model. The characteristic parameter analysis is performed to demonstrate accuracy of the present model with the T beam theory in contrast with errors in the usual model based on the Euler-Bernoulli（EB） beam theory. The resulting reverberation matrix can be used for exact calculation of anisotropic framed structures as well as for parameter analysis of geometrical and material properties of the framed structures.

Th17/Treg balance and macrophage polarization ratio in lower extremity arteriosclerosis obliterans

Objective:To explore the balance of peripheral blood T helper 17 cells/regulatory T cell(Th17/Treg)ratio and the polarization ratio of M1 and M2 macrophages in lower extremity arteriosclerosis obliterans(ASO).Methods:A rat model of lower extremity ASO was established,and blood samples from patients with lower extremity ASO before and after surgery were obtained.ELISA was used to detect interleukin 6(IL-6),IL-10,and IL-17.Real-time RCR and Western blot analyses were used to detect Foxp3,IL-6,IL-10,and IL-17 expression.Moreover,flow cytometry was applied to detect the Th17/Treg ratio and M1/M2 ratio.Results:Compared with the control group,the iliac artery wall of ASO rats showed significant hyperplasia,and the concentrations of cholesterol and triglyceride were significantly increased(P<0.01),indicating the successful establishment of ASO.Moreover,the levels of IL-6 and IL-17 in ASO rats were pronouncedly increased(P<0.05),while the IL-10 level was significantly decreased(P<0.05).In addition to increased IL-6 and IL-17 levels,the mRNA and protein levels of Foxp3 and IL-10 in ASO rats were significantly decreased compared with the control group.The Th17/Treg and M1/M2 ratios in the ASO group were markedly increased(P<0.05).These alternations were also observed in ASO patients.After endovascular surgery(such as percutaneous transluminal angioplasty and arterial stenting),all these changes were significantly improved(P<0.05).Conclusions:The Th17/Treg and M1/M2 ratios were significantly increased in ASO,and surgery can effectively improve the balance of Th17/Treg,and reduce the ratio of M1/M2,and the expression of inflammatory factors.

EGFR T790M突变非小细胞肺癌患者的临床病理学、免疫微环境特征及对预后预测的意义

背景与目的:表皮生长因子受体20号外显子T790M突变(epidermal growth factor receptor exon 20 threonine-tomethionine substitution mutation at position 790,EGFR T790M)是非小细胞肺癌(non-small cell lung cancer,NSCLC)对第一/二代EGFR酪氨酸激酶抑制剂(EGFR tyrosine kinase inhibitor,EGFR TKI)的获得性耐药机制之一,EGFR T790M突变也可见于未经EGFR TKI治疗的NSCLC,本研究旨在比较原发性和获得性EGFR T790M突变NSCLC中的临床病理学特征和预后差异,进一步探讨NSCLC中获得性T790M突变的免疫微环境特征。方法:本研究回顾性分析复旦大学附属肿瘤医院从2020年4月—2022年9月诊断的3762例NSCLC,其中2070例(55.02%)存在EGFR突变,556例(14.77%)接受EGFR TKI治疗。其中EGFR T790M突变的NSCLC 119例(3.16%),51例(1.35%)为原发性EGFR T790M突变,68例(1.81%)为获得性EGFR T790M突变。收集患者的临床资料,对原发性和获得性T790M突变NSCLC进行比较,采用多重免疫荧光组织化学(multiple immunofluorescence histochemistry,mIHC)探讨获得性T790M突变NSCLC免疫微环境特征。结果:原发性和获得性T790M突变在女性患者中的比例均高于男性;原发性T790M突变患者更为年轻;原发性和获得性T790M突变均更容易出现在差分化癌中;原发性T790M突变NSCLC患者中,程序性死亡受体配体1(programmed death-ligand 1,PD-L1)表达阳性率较高(60.00%);获得性T790M突变NSCLC患者中,PD-L1表达阳性率较低(22.39%)。获得性T790M突变NSCLC往往伴随着TP53改变(39.7%)。单因素Cox回归分析结果显示,间质表皮转化因子(mesenchymal to epithelial transition factor,MET)改变是出现获得性T790M突变的危险因素(P=0.0005)。原发性和获得性T790M突变的平均总生存期(overall survival,OS)差异无统计学意义(分别为35.4和37.3个月)。然而,获得性T790M突变患者复发和转移的比例较高。获得性T790M突变中,间质区域存在更多的免疫细胞浸润,如CD20^(+)B淋巴细胞、CD23^(+)B淋巴细胞、CD8^(+)T淋巴细胞、CD8^(+)程序性死亡受体1(programmed death 1,PD-1)^(-/+)细胞、CD20^(+)PD-1^(-/+)细胞及CD23^(+)PD-1^(-/+)细胞等。此外,研究发现EGFR伴有抑癌基因(tumor suppressor gene,TSG)改变时,肿瘤细胞与CD8+T淋巴细胞、CD20+B淋巴细胞、CD8^(+)PD-1^(+)细胞、CD20^(+)PD-1^(+)细胞和CD23^(+)PD-1^(+)细胞的平均距离较仅有EGFR突变更近。结论:相较于原发性T790M突变,获得性T790M突变的病例中,PD-L1阳性率较低。获得性T790M突变常伴有TP53改变,而MET改变则是引发获得性T790M突变的一个危险因素。虽然获得性T790M突变患者的复发和转移风险较高,但其平均OS与原发性T790M突变患者并无显著差异。获得性T790M突变患者中,伴有TSG突变时可改变免疫细胞的空间分布,有望从免疫治疗中获益。

A decomposition method of nuclear magnetic resonance T2 spectrum for identifying fluid properties

Based on analysis of NMR T2 spectral characteristics,a new method for identifying fluid properties by decomposing T2 spectrum through signal analysis has been proposed.Because T2 spectrum satisfies lognormal distribution on transverse relaxation time axis,the T2 spectrum can be decomposed into 2 to 5 independent component spectra by fitting the T2 spectrum with Gauss functions.By analyzing the free relaxation response characteristics of crude oil and formation water,the dynamic response characteristics of the core mutual drive between oil and water,the petrophysical significance of each component spectrum is clarified.T2 spectrum can be decomposed into clay bound water component spectrum,capillary bound fluid component spectrum,micropores fluid component spectrum and macropores fluid component spectrum.According to the nature of crude oil in the target area,the distribution range of T2 component spectral peaks of oil-bearing reservoir is 165-500 ms on T2 time axis.This range can be used to accurately identify fluid properties.This method has high adaptability in identifying complex oil and water layers in low porosity and permeability reservoirs.

Determination of Fe^(2+)/Fe^(3+)Ratios of Magnetite using Different Methods:A Case Study from the Qimantag Metallogenic Belt

Determination of Fe^(2+)/Fe^(3+) ratios from metallogenic belts to explore controlling physical and chemical conditions of rock formation is of great significance.In order to explore magnetite Fe^(2+)/Fe^(3+) ratios of the Qimantag metallogenic belt,part of the Eastern Kunlun orogenic belt in the northeastern margin of the Qinghai–Tibetan plateau,western Central Orogenic Belt of China,and overcome the limitation of the traditional electronic probe,five different measurement methods are proposed and their respective advantages and disadvantages evaluated,with the composition data of the magnetite obtained using electron probe microanalysis(EPMA).The direct oxygen measurement method has a significant impact on the determination results of FeO and Fe2O3,but the accuracy and uniformity of the results are low.The valence method(Flank method)based on the spectral intensity ratio of Lαto Lβfor iron is also unreliable for FeO and Fe_(2)O^(3) measurements because it is difficult to establish a relationship between Lβ/Lα,the spectral intensity ratio,and the Fe^(2+)/Fe^(3+) content ratio.In comparison,the charge difference method,the surplus-oxygen method and the Mössbauer spectrum method are still the most favorable.Mössbauer spectroscopy,with its isomer movement particularly sensitive to the oxidation state of iron,yields results closer to 0.5,which is relatively reliable.Earlier magnetite deposits are located in intrusions or contact zones and formed by magmatic fluids with high Fe2+/Fe3+ratios,whereas later magnetite deposits are farther away from intrusions and have low Fe^(2+)/Fe^(3+) ratios.The transformation mechanism of hematite and magnetite in the Qimantage metallogenic belt is also studied.No large volume changes,such as pore filling and shrinkage fracture,were detected in the metallogenic belt,and the transformation mechanism is more similar to a reoxidation and reduction mechanism.