Instability identification on large scale underground mined-out area in the metal mine based on the improved FRBFNN

To identify the instability on large scale underground mined-out area in the metal mine effectively,the parameters of radial basis function were determined through clustering method and the improved fuzzy radial basis function neural network(FRBFNN)model of instability identification model about large scale underground mined-out area in the metal mine was built.The improved FRBFNN model was trained and tested.The results show that the improved FRBFNN model has high training accuracy and generalization ability.Parameters such as pillar area ratio,filling level and the value of rock quality designation have strong influence on instability of large scale underground mined-out area.Correctness of analysis about the improved FRBFNN model was proved by the practical application results about instability discrimination of surrounding rock in large-scale underground mined-out area of a metal mine in south China.

Numerical analysis of stability for mined-out area in multi-field coupling

There were differences between real boundary and blast hole controlling boundary of irregular mined-out area in underground metal mines. There were errors in numerical analysis of stability for goaf, if it was analyzed as regular 3D mined-out area and the influence of coupling stress-seepage-disturbance was not considered adequately. Taking a lead zinc mine as the background, the model was built by the coupling of Surpac and Midas-Gts based on the goaf model precisely measured by CMS.According to seepage stress fundamental equations based on the equivalent continuum mechanical and the theory about equivalent load of dynamic disturbance in deep-hole blasting, the stability of mined-out area under multi-field coupling of stress-seepage-dynamic disturbance was numerically analyzed. The results show that it is more consistent between the numerical analysis model based on the real model of irregular 3D shape goaf and the real situation, which could faithfully reappear the change rule of stress–strain about the surrounding rock under synthetic action of blasting dynamic loading and the seepage pressure. The mined-out area multi-field coupling formed by blasting excavation is stable. Based on combination of the advantages of the CMS,Surpac and Midas-Gts, and fully consideration of the effects of multi-field coupling, the accurate and effective way could be provided for numerical analysis of stability for mined-out area.

Numerical simulation for influence of excavation and blasting vibration on stability of mined-out area

Dynamic analysis steps and general flow of fast lagrangian analysis of continua in 3 dimensions(FLAC3D) were discussed. Numerical simulation for influence of excavation and blasting vibration on stability of mined-out area was carried out with FLAC3D. The whole analytical process was divided into two steps, including the static analysis and the dynamic analysis which were used to simulate the influence of excavation process and blasting vibration respectively. The results show that the shape of right upper boundary is extremely irregular after excavation, and stress concentration occurs at many places and higher tensile stress appears. The maximum tensile stress is higher than the tensile strength of rock mass, and surrounding rock of right roof will be damaged with tension fracture. The maximum displacement of surrounding rock is 4.75 mm after excavation. However, the maximum displacement increases to 5.47 mm after the blasting dynamic load is applied. And the covering area of plastic zones expands obviously, especially at the foot of right upper slope. The analytical results are in basic accordance with the observed results on the whole. Damage and disturbance on surrounding rock to some degree are caused by excavation, while blasting dynamic load increases the possibility of occurrence of dynamic instability and destruction further. So the effective supporting and vibration reducing measures should be taken during mining.

Quantitative analysis of biotechnical reinforcement for a steep slope consisting of composite coal-gangue-soil medium adjacent to a mined-out area

The engineering and geological characteristics of a steep slope consisting of coal gangue, rock and soil medium in Huating coal mine have been comprehensively investigated. Owing to humid weather, heavy rainfall, vegetation and porous characteristics of the soil and rock mass, the steep slope will be destabilized and induce mud-rock flow or derive hazard easily. Firstly, based on the classical slope reinforcement theory, some regularity between the shear and displacement in the destabilized zone of the slope with or without root strength contribution is presented. Then, based on the experimental and statistical analysis of root strength, hydrological characteristics and stability status, etc., some possible biotechnical techniques for reinforcement of the steep slope have been suggested. These methods are important for quantitative analysis of destabilization of the slope and design of the biotechnical reinforcement.

Time function of surface subsidence based on Harris model in mined-out area

The surface subsidence is a common environmental hazard in mined-out area. Based on careful analysis of the regularity of surface subsidence in mined-out area, we proposed a new time function based on Harris curve model in consideration of the shortage of current surface subsidence time functions. By analyzing the characteristics of the new time function, we found that it could meet the dynamic process, the velocity change process and the acceleration change process during surface subsidence. Then its rationality had been verified through project cases. The results show that the proposed time function model can give a good reflection of the regularity of surface subsidence in mined-out area and can accurately predict surface subsidence. And the prediction data of the model are a little greater than measured data on condition of proper measured data quantity, which is safety in the engineering. This model provides a new method for the analysis of surface subsidence in mined-out area and reference for future prediction, and it is valuable to engineering application.

Study on the Development of Under-forest Economy in Guangdong Mountain Areas

From the origin and connotation of the under-forest economy,this paper analyzed plight of the development of under-forest economy in Guangdong mountain areas. It discussed benefits of under-forest economy,favorable conditions and development path of under-forest economy in Guangdong mountain areas. Results indicate that developing under-forest economy is an essential path for realizing green growth and coordinated development of Guangdong mountain areas. However,due to terrain,market,management and technology reasons,the under-forest economy is still not fully developed in Guangdong mountain areas. The development path of under-forest economy suitable for Guangdong mountain areas should be based on ecological protection and oriented towards maximizing ecological,economic and social benefits. Guangdong mountain areas have in-born natural and resource advantages,economic pull of development mode and market demand change,and favorable condition of policy encouragement for development of under-forest economy. Finally,it came up with recommendations for development of under-forest economy in Guangdong mountain areas from development mode,industrial distribution and development direction.

Determination of Carboplatin Dose by Area Under the Curve in Combination Chemotherapy for Senile Non-small Cell Lung Cancer

To preliminarily determine the appropriate dosage of carboplatin （CBP） at AUC of 5 mg-M1^-1·min^-1 in the combination chemotherapy for Chinese senile patients with non-small cell lung cancer （NSCLC）. Thirty-five Chinese senile patients with NSCLC in advanced stage （Ⅲ/Ⅳ） were given 96 cycles of combination chemotherapy. Chemotherapy schedules included Taxol＋CBP, Gemzar＋CBP and NVB＋CBE The dose of CBP was at 5 mg.mL^-1·min^-1 of area under the concentration-time curve （AUC）. Side effects and quality of life were observed before and after the chemotherapy. Myelosuppression was severe and commonly observed. Grade 3/4 of granulocytopenia was found in 47.9% （46/96） of the patients and grade 3/4 of thrombocytopenia was noted in 28.1% （27/96） of the subjects. However, other side effects were slight. The mean score of quality of life （QOL）, according to the criteria of QOL for Chinese cancer patients had reduced 6.8. At 5 mg.mL^-1·min^-1 by AUC, the hematological toxicity of CBP was severe and it had some negative effects on the QOL. The administration of CBP at 5 mg.mL^-1·min^-1 by AUC may be too high for Chinese senile patients with non-small cell lung cancer.

Compound Planting of Bletilla striata under Forest in the Three Gorges Dam Area

[Objectives] The aim was to study the artificial cultivation of Bletilla striata to realize large scale and standardization planting. [Methods] The comparison tests were conducted on B. striata with different canopy densities of the Magnolia officinalis forests,different compound planting densities and different tending measures and management. [Results] When the stand canopy density was 0. 4-0. 6,the per unit yield of B. striata was 5. 4%,6. 8% higher than that at the canopy density of less than 0. 4 and more than 0. 6,respectively. When the planting density was 30 cm × 30 cm,the per unit yield increased by 16. 1%,12. 0%,13. 1% respectively compared with the planting density of 20 cm × 20 cm,25 cm × 25 cm,35 cm × 35 cm. When B. striata was planted from October to November,the per unit yield was 5. 6% higher than that planted from December to January of the following year,and 21. 3% higher than that from February to March of the second year. When farmyard manure was applied during the cultivation,the per unit yield was 31. 7% and 18. 4% higher than the application of chemical fertilizer and compound fertilizer. When weeding 4 times per year,the per unit yield increased by 240. 1%,137. 0% and 43. 9% respectively from that weeding 1 times,2 times,3 times per year. [Conclusions]When planting B. striata,the stand canopy density of 0. 4-0. 6 could make it receive absolutely shelters and the lighting conditions required for the growth,thereby bringing in high emergence rate,good growth potential and high yield. The best planting effect of B. striata could achieve by planting from October to November with the planting density of 30 cm × 30 cm,which can play the maximum benefit of individual plants. Moreover,weeding 4 times per year combined with the use of farmyard manure can promote the development and growth of tubers,which can greatly improve the yield of B. striata.

布鲁氏菌病患者外周血白细胞及血小板参数的变化及临床意义

目的 研究布鲁氏菌病患者外周血白细胞及血小板参数的变化及其特点,探讨其临床应用价值。方法 纳入确诊布鲁氏菌病的患者90例,其中急性期59例,慢性期31例,另外选取同期40例健康人群为健康对照组。收集患者的临床症状等基本资料;采用全自动血液分析仪检测各组外周血白细胞计数、淋巴细胞计数、中性粒细胞计数、单核细胞计数、血小板计数、平均血小板体积(MPV)、血小板分布宽度(PDW);采用流式细胞仪检测外周血CD3^(+)T、CD4^(+)T及CD8^(+)T细胞计数,计算患者的中性粒细胞/淋巴细胞比值(NLR)及血小板/淋巴细胞比值(PLR),分析各细胞参数的变化特点并分析各参数对布鲁氏菌病的临床诊断价值。结果 慢性期组的关节痛和脊柱炎占比高于急性期组(P<0.05);与健康对照组相比,急性期组的白细胞计数、中性粒细胞计数、血小板计数及NLR均降低,慢性期组MPV和PDW降低,而CD3^(+)T细胞计数和单核细胞计数升高(P<0.05)。有关节炎症状的急性期布病患者白细胞计数、淋巴细胞计数、CD3^(+)T细胞计数和CD8^(+)T细胞计数低于无关节炎的急性期布病患者,而PLR则升高(P<0.05)。受试者工作特征(ROC)曲线分析结果显示中性粒细胞计数和NLR水平对于急性期布鲁氏菌病的ROC曲线下面积(AUC)分别为0.780和0.717,而CD3^(+)T细胞计数对于诊断慢性期布鲁氏菌病的AUC为0.748。在急性期患者中,CD3^(+)T、CD8^(+)T细胞计数及PLR水平对诊断关节炎的AUC分别为0.779、0.768、0.722。结论 急性期和慢性期布鲁氏菌病患者外周血白细胞和血小板参数均有不同程度的改变,对于布鲁氏菌病的诊断以及急性期布病患者关节炎的诊断有一定的临床应用价值。

比较浓度-时间曲线下面积与谷浓度指导万古霉素治疗重症患者的临床随机对照研究

目的探讨浓度-时间曲线下面积和谷浓度指导万古霉素治疗重症患者的临床安全性和疗效差异。方法入选2021年1月至2023年12月收住兰州大学第二医院重症医学科因革兰阳性菌感染且经医师确认需使用万古霉素治疗的患者,经纳排标准筛选后,采用随机数字表法将入选患者分为两组进行前瞻性、随机、单盲对照研究,对照组以万古霉素谷浓度10~20 mg/L为目标靶值,观察组以万古霉素浓度-时间曲线下面积400~600 mg·h/L为目标靶值。经过监测,最终对照组77例、观察组79例符合目标靶值范围并进行相关统计学分析与比较。结果观察组万古霉素相关急性肾损伤(AKI)发生率明显低于对照组(P=0.002),两组临床疗效及总治疗时间差异无统计学意义。根据多因素Logistic回归分析显示,谷浓度(OR=1.021,95%CI 1.019~1.577,P=0.033)及急性生理学和慢性健康状况评价Ⅱ(APACHEⅡ)评分(OR=1.189,95%CI 1.055~1.339,P=0.004)是万古霉素相关AKI独立危险因素,采样总数量(OR=0.476,95%CI 0.247~0.917,P=0.000)是临床转归独立危险因素。对谷浓度与万古霉素相关AKI进行受试者工作特征(ROC)曲线分析,谷浓度预测万古霉素相关AKI临界值为15.65 mg/L,敏感度为0.786,特异度为0.697,ROC曲线下面积为0.727。结论基于浓度-时间曲线下面积为目标靶值的药物监测方法,可以减少万古霉素相关AKI发生,但临床疗效无差别。

骨科术后患者万古霉素AUC_(0~24h)影响因素分析及预测模型研究

目的探讨万古霉素在骨科术后患者中的24 h曲线下面积(AUC_(0~24h))的影响因素,并预测分析AUC_(0~24h)较好的药代动力学模型。方法纳入新疆医科大学第六附属医院2018年1月至2022年12月进行骨科手术并使用万古霉素的患者,收集患者的基本信息、用药情况、血常规和血生化指标,分析影响骨科术后患者万古霉素AUC_(0~24h)的因素。采用一级药代动力学公式、个体化给药辅助决策系统(JPKD)和万古霉素日剂量消除率公式计算AUC_(0~24h)。结果最终纳入91例患者,结果发现胱抑素C(OR=189.168,P=0.005)和单次剂量(OR=19.160,P<0.001)是骨科术后患者万古霉素AUC_(0~24h)的独立保护因素,视黄醇结合蛋白是万古霉素AUC_(0~24h)的独立危险因素(OR=0.910,P<0.05)。通过对骨科术后患者万古霉素AUC_(0~24h)模型预测分析,JPKD软件和万古霉素日剂量消除率公式的绝对权重偏差均低于30%,JPKD软件和万古霉素日剂量消除率公式的AUC_(0~24h)与一级药代动力学公式的AUC_(0~24h)组内相关系数分别为0.781和0.524。结论胱抑素C是影响骨科术后患者万古霉素AUC_(0~24h)的重要因素,JPKD软件较万古霉素日剂量消除率公式方法更适用于预测骨科术后万古霉素AUC_(0~24h)。

肾小管及肾小球标志物在2型糖尿病患者不同肾损伤阶段诊断价值的研究

目的探讨肾小管及肾小球相关标志物在2型糖尿病(type 2 diabetes mellitus,T2DM)患者不同肾损伤阶段的诊断价值。方法选取于2018年4月1日至2019年10月31日入住首都医科大学附属北京同仁医院内分泌科的T2DM患者272例,完善临床生化指标及尿蛋白四项:尿微量白蛋白/肌酐(urinary albumin to creatinine ratio,ACR)、α1-微球蛋白/肌酐(urinary α1-microglobulin to creatinine ratio,UA1CR)、免疫球蛋白G/肌酐(urinary immunoglobulin G to creatinine ratio,UIGG)、转铁蛋白/肌酐(urinary transferrin to creatinine ratio,UTRF);进行眼底照相、核医学99mTc-EC检测肾有效血浆流量(effective renal plasma flow,ERPF)和99mTc-DTPA检测肾小球滤过率(glomerular filtration rate,GFR)。根据ACR和眼底检查结果分为4组:正常蛋白尿无糖尿病视网膜病变(diabetic retinopathy,DR)132例,即对照组(ACR≤30 mg/g);正常蛋白尿合并DR 32例,为糖尿病肾病(diabetic kidney disease,DKD)前期组;微量蛋白尿组78例(30<ACR≤300 mg/g)和大量蛋白尿组30例(ACR>300 mg/g)。比较四组间尿蛋白四项和ERPF、GFR的水平,通过受试者工作特征(receiver operating characteristic,ROC)曲线评价上述各指标在不同肾损伤阶段的诊断价值。结果尿蛋白四项和ERPF、GFR的水平在不同组间差异有统计学意义(P<0.05)。在尿蛋白正常组中,DR组中肾小管功能标志物UA1CR较对照组明显升高(P<0.01);肾小球功能标志物ACR、UTRF和GFR在两组间差异无统计学意义(P>0.05),DR组UIGG较对照组升高(P<0.01)。在微量蛋白尿组和大量蛋白尿组,尿蛋白四项随肾损伤程度增加而增加,而ERPF和GFR随肾损伤程度增加而降低。ROC曲线分析显示,在尿蛋白排出正常的T2DM患者中合并DR组中肾小管功能标志物UA1CR和ERPF的曲线下面积(area under the curve,AUC)分别为68.2%(P<0.01)和60.5%(P<0.05),而肾小球功能标志物ACR和GFR的AUC均小于60%,差异无统计学意义(P>0.05)。尿蛋白四项及GFR在微量和大量蛋白尿组的AUC均大于60%(P<0.05),ERPF在大量蛋白尿组AUC为67.2%(P<0.05)。结论T2DM极早期微血管改变即ACR正常仅有DR时,肾小管标志物UA1CR先于肾小球标志物ACR和GFR发生变化。肾损伤早期,肾小管标志物诊断效能优于肾小球;肾损伤后期,肾小球标志物诊断效能优于肾小管。提示DKD肾小管功能的改变可能早于肾小球。

煤层底板含水层区域注浆改造浆液扩散范围现场示踪试验

近年来,为解放底板高承压灰岩水上煤炭资源,华北煤田普遍采用地面定向钻技术,对太原组薄层灰岩进行区域性注浆加固改造(习称“底板区域治理”),以全面封堵灰岩岩溶裂隙并阻断垂向导水通道。该技术中,与浆液扩散范围(半径)密切相关的“水平分支孔”孔间距设计问题,一直备受学界和业界的广泛关注。皖北矿区底板区域注浆工程量大,特别是深部资源开采,将有数十亿元的注浆工程,有必要查清浆液扩散范围真实数据。为此,以皖北矿区恒源煤矿为研究基地,依托Ⅱ63采区底板区域治理工程,设计并实施浆液扩散范围示踪试验,在中间的水平分支孔(Z8-7)投放荧光剂(示踪剂),在两侧的水平分支孔(Z8-6、Z8-8)以及交叉分支检测孔(Z8JC)取岩屑样鉴别荧光水泥,以获得浆液扩散范围,进而在浆液扩散影响因素分析基础上,构建恒源煤矿底板区域注浆治理浆液扩散范围计算公式。结果表明:①综合岩屑现场及室内鉴别结果分析,获得恒源煤矿Ⅱ63采区底板区域注浆浆液扩散范围为38.3~44.0 m,且水泥分布密集区在水平分支孔浆液扩散范围30 m以内,该区域内注浆效果最佳。②通过现场岩屑快速鉴别与室内岩屑精准鉴别,取得的浆液扩散范围基本一致,证明了荧光示踪浆液扩散范围的有效性。③通过对比分析,认为在计算参数、边界约束等符合实际注浆工况条件下,浆液扩散范围理论计算和数值模拟结果,与现场示踪试验实测结果较为接近。④利用示踪试验过程中的压水试验及注浆参数、钻遇构造及水文地质响应等数据,考虑重力、构造、地下水径流等因素影响,借助SPSS非线性拟合软件,得到恒源煤矿Ⅱ63采区底板区域注浆浆液扩散范围计算公式。⑤基于恒源煤矿受注层实际地质、水文地质条件,利用拟合的浆液扩散范围计算公式得出Ⅱ63采区Z8场地浆液扩散范围为37.8~42.9 m,与浆液扩散范围示踪试验实测结果相近,计算公式可在类似条件下推广应用。本次煤矿底板区域注浆浆液扩散范围现场示踪工程试验,不仅取得了浆液扩散范围的真实数据,而且阐明了浆液扩散与多种地质、水文地质因素之间的内在联系,揭示了超深、超长定向钻注浆浆液扩散机理,构建了浆液扩散范围计算公式,为类似条件下底板区域治理工程水平分支孔孔间距的合理设计提供了参考依据。

动态增强磁共振成像定量参数联合表观扩散系数值对外周带前列腺癌的诊断价值研究

目的探究动态增强磁共振成像(DCE-MRI)定量参数联合表观扩散系数(ADC)值诊断外周带早期前列腺癌的价值。方法选取2019年2月至2021年12月经穿刺病理学检查确诊为外周带早期前列腺癌31例和前列腺炎27例为研究对象。患者均进行DCE-MRI定量参数检查,以病理学检查结果为金标准,分析不同患者的DCE-MRI特征。并采用受试者工作特征曲线下面积(AUC)分析基于DCE-MRI定量参数与扩散加权成像(DWI)序列对外周带早期前列腺癌与前列腺炎的诊断价值。结果31例前列腺癌患者中,T2加权成像(T2WI)以外周带结节状低信号为主,占58.06%;DWI以结节状、弥漫性高信号,ADC值下降为主,占51.61%;DCE-MRI可见病灶早期强化,以延迟后病灶造影剂退出,强化曲线呈流出型为主,占64.52%。27例前列腺炎患者中,T2WI以外周带单侧或双侧弥漫性不均匀低信号为主,占51.85%;DWI可见外周带单侧或双侧不规则高信号,ADC值降低为主,占59.26%;DCE-MRI可见病灶早期强化,以延迟后造影剂退出不明显,强化曲线呈流入型为主,占81.48%。外周带早期前列腺癌患者ADC值低于前列腺炎,速率常数(Kep)值、转移常数(K^(trans))高于前列腺炎(P<0.05)。DCE-MRI定量参数联合ADC值诊断外周带早期前列腺癌的AUC为0.862(95%CI:0.659,0.865)、敏感度为87.10%,特异度为81.48%,准确度为84.48%,阳性预测值为84.38%,阴性预测值为84.62%。结论DCE-MRI定量参数联合ADC值对外周带早期前列腺癌的诊断效能良好,能显著提高临床检出率,为疾病的诊断与治疗提供依据。

万古霉素在重症感染中的治疗药物监测现状及前景

万古霉素被誉为治疗革兰阳性菌感染的最后一道防线,也是推荐的一线用药。因其治疗窗窄,重症患者需监测药物浓度以指导临床安全用药。传统上基于万古霉素谷浓度的治疗药物监测已被临床广泛接受。2009年美国传染病学会(IDSA)指南建议,对于重症患者目标谷浓度为15~20 mg/L。近十余年国内外学者对于该治疗浓度的安全性及有效性评价不一。2020年更新指南提出,肾损伤风险最小、最准确且最佳的给药方法是通过曲线下面积(AUC)指导给药剂量和监测,提倡个体化目标AUC/最低抑菌浓度(MIC)比值为400~600 mg/(h·L)。由此可见目前就万古霉素临床监测指标存在争议。因此,本文就万古霉素治疗重症感染过程中进行治疗浓度监测的手段及策略进行综述,对指导临床合理用药具有重要意义,有助于临床医师制定个体化给药方案,最大程度减少或避免药物毒性。

汉藏文化交融背景下的安多地区藏族建筑檐下装饰构件做法研究

安多地区是我国三大藏区之一,处于青藏高原向黄土高原、河西走廊、四川盆地过渡的关键地带。在汉、藏建筑文化交流与碰撞的背景下,安多地区藏族建筑基于自身地域特点发展出了“摞活”“挑头檩”“挂牌”“花板代栱”等类型多样、兼具汉藏融合特点的檐下装饰构件做法,极大丰富了藏族建筑异彩纷呈的整体面貌。以往安多地区受到了地理尺度巨大、科研力量欠缺等研究限制,而如今成为“一带一路”沿线的热点区域后,其地域性营造特征又面临着特色丧失的显著趋同化威胁,亟需对安多地区藏族建筑具有代表性和多样化的檐下装饰构件做法开展深入研究。

新疆灌区农业节水发展现状与对策建议

水是新疆可持续发展的生命线,也是新疆农业发展的瓶颈。农业是新疆用水大户,占经济社会总用水量的90%以上,南疆农业用水占比更高。新疆节水潜力重点在农业,农业节水是新疆经济社会可持续发展的根本出路。为提高新疆农业水资源利用效率,促进农业高质量发展,本文梳理回顾了新疆灌区农业节水发展历程,分析了农业节水发展现状及存在问题,结合新时期国家对新疆农业发展的新定位、新要求,提出了大力发展适水型现代农业、加大高效节水工程建设、持续推进降盐节水、加强数字化灌区建设、加强农业节水宣传培训、健全农业节水服务体系等对策建议,以期为新疆现代农业可持续发展和保障国家粮棉油安全提供有力支撑。

慢性阻塞性肺疾病急性加重期患者血浆miR-205、miR-21表达水平及临床意义

目的 探讨血浆miR-205、miR-21在慢性阻塞性肺疾病急性加重期(AECOPD)患者中的表达水平及临床意义。方法 选取2022年1—12月收治的COPD 140例,另选取同期体检的健康人群70例作为健康组。根据COPD是否进入急性加重期将患者分为急性加重组63例与稳定组77例。采用荧光定量PCR法检测3组血浆miR-205、miR-21水平,采用受试者工作特征曲线评估血浆miR-205、miR-21对AECOPD发生的预测价值,采用多因素Logistic逐步回归分析探讨AECOPD预后的影响因素。结果 稳定组和急性加重组COPD患者血浆miR-205、miR-21水平均高于健康组,且急性加重组高于稳定组(P<0.05)。血浆miR-205、miR-21联合预测AECOPD发生的曲线下面积大于二者单独预测。死亡组AECOPD患者血浆miR-205、miR-21水平高于生存组(P<0.05)。血浆miR-205、miR-21高表达及急性生理与慢性健康状况Ⅱ系统评分≥2分是AECOPD患者入院后28 d死亡的危险因素(P<0.01)。结论 AECOPD患者血浆miR-205、miR-21表达水平明显升高,可作为早期诊断和预后的生物学指标,且二者联合预测AECOPD患者发生的效能更高。

血压升高与我国中年人群生存时间关系的前瞻性研究

目的 基于前瞻性队列探讨血压升高对我国中年人群生存时间的影响。方法 1982-1985年在全国10组35~59岁人群中进行心血管病危险因素调查并对死亡结局进行随访。采用生存曲线下面积法计算血压升高人群及非血压升高人群的平均生存时间并进行比较。将收缩压超过115 mmHg定义为血压升高。结果 纳入分析的研究对象共24096人,其中男性12161人,女性11935人,平均随访19.7年。血压升高人群与非血压升高人群相比,在总人群中,生存时间减少0.50岁;在男性人群中,生存时间减少0.46岁;在女性人群中,生存时间减少0.94岁;在城市人群中,生存时间减少0.63岁;在农村人群中,生存时间减少0.61岁;在35~44岁人群中,生存时间减少0.27岁;在45~54岁人群中,生存时间减少0.50岁;在55岁及以上的人群中,生存时间减少0.67岁。结论 血压升高对我国中年人群生存时间的影响女性大于男性,城市大于农村,年龄越大,影响越大。

依据MRI影像组学数据构建颈椎失稳诊断分类模型的可行性

背景:既往颈椎失稳相关研究在传统影像学检查下对其病变发展过程中的动静力交互作用关系和病理特征变化阐释不明,近年来逐渐兴起的MRI影像组学可为颈椎失稳的深入研究提供新的途径。目的:探讨MRI影像组学在颈椎失稳研究中的应用价值。方法:通过招募广告和中国中医科学院望京医院脊柱二科门诊,纳入18-45岁青年颈椎失稳受试者和非失稳受试者进行颈椎MRI采集,在椎间盘所在的横断面图层,对椎间盘区、关节突区、椎前肌区、颈后肌群深层区及颈后肌群浅层区等5个特定感兴趣区域进行手动分割,以提取并筛选影像组学特征,最终进行颈椎失稳诊断分类模型的构建,并使用曲线下面积评价模型的效能。结果与结论:①共纳入56例颈椎失稳受试者和55例非失稳受试者,每个感兴趣区域提取影像组学特征各1688个;经过筛选最终获得300组具有特异性的影像组学特征组合,每个感兴趣区域各60组;②初步建立了5个感兴趣区域的颈椎失稳诊断分类模型,其中关节突区的支持向量机模型和颈后肌群深层区的支持向量机模型对于失稳和非失稳的分类具有一定的准确性,十折交叉验证平均曲线下面积分别为0.7197和0.7033;③椎间盘区的Logistic模型、椎前肌区的LightGBM模型及颈后肌群浅层区的Logistic模型对于失稳和非失稳的分类准确性一般,十折交叉验证平均曲线下面积分别为0.6504,0.6207和0.6442;④证明了MRI影像组学在颈椎失稳研究中应用的可行性,进一步深化了对颈椎失稳发病机制的认识,同时也为颈椎失稳的精准诊断提供了客观依据来源。