Prediction of Compressive Strength of Sustainable Foam Concrete Using Individual and Ensemble Machine Learning Approaches

The entraining and distribution of air voids in the concrete matrix is a complex process that makes the mechanical properties of lightweight foamed concrete (LFC) highly unpredictable. To study the complex nature of aerated concrete, a reliable and robust prediction model is required, employing different machine learning (ML) techniques. This study aims to predict the compressive strength of LFC by using a support vector machine (SVM) as an individual learner along with bagging, boosting, and random forest (RF) as a modified ensemble learner. For that purpose, a database of 191 data points was collected from published literature, where the mix design ingredients, i.e., cement content, sand content, water to cement ratio, and foam volume, were chosen to predict the compressive strength of LFC. The 10-K fold cross-validation method and different statistical error and regression tools, i.e., mean absolute error (MAE), root means square error (RMSE), and coefficient of determinant (R²), were used to evaluate the performance of the developed ML models. The modified ensemble learner (RF) outperforms all models by yielding a strong correlation of R² = 0.96 along with the lowest statistical error values of MAE = 1.84 MPa and RMSE = 2.52 MPa. Overall, the result suggests that the ensemble learners would significantly enhance the performance and robustness of ML models.     

Prediction of the Uric Acid Component in Nephrolithiasis Using Simple Clinical Information about Metabolic Disorder and Obesity: A Machine Learning-Based Model

There is a great need for a diagnostic tool using simple clinical information collected from patients to diagnose uric acid (UA) stones in nephrolithiasis. We built a predictive model making use of machine learning (ML) methodologies entering simple parameters easily obtained at the initial clinical visit. Socio-demographic, health, and clinical data from two cohorts (A and B), both diagnosed with nephrolithiasis, one between 2012 and 2016 and the other between June and December 2020, were collected before nephrolithiasis treatment. A ML-based model for predicting UA stones in nephrolithiasis was developed using eight simple parameters—sex, age, gout, diabetes mellitus, body mass index, estimated glomerular filtration rate, bacteriuria, and urine pH. Data from Cohort A were used for model training and validation (ratio 3:2), while data from Cohort B were used only for validation. One hundred and forty-six (13.3%) out of 1098 patients in Cohort A and 3 (4.23%) out of 71 patients in Cohort B had pure UA stones. For Cohort A, our model achieved a validation AUC (area under ROC curve) of 0.842, with 0.8475 sensitivity and 0.748 specificity. For Cohort B, our model achieved 0.936 AUC, with 1.0 sensitivity, and 0.912 specificity. This ML-based model provides a convenient and reliable method for diagnosing urolithiasis. Using only eight readily available clinical parameters, including information about metabolic disorder and obesity, it distinguished pure uric acid stones from other stones before treatment.     

患者肿瘤组织来源的胶质母细胞瘤类器官的制备方法

目的：探讨胶质母细胞瘤（GBM）患者肿瘤组织来源的GBM类器官（GBO）模型的制备方法。方法：选取2021年广东三九脑科医院新诊断经病理确诊的8例GBM患者的新鲜肿瘤组织标本,将其剪成0.5～1 mm大小的组织碎片并用特制的培养基进行培养,待其成球且直径达到1 mm时剪小传代,同时选取培养2周以上的GBO进行石蜡包埋、切片,后进行H-E染色和免疫组化染色检测,并与亲本GBM组织进行组织学与细胞学的比较。结果：成功培养2例可传代冻存的GBO,并建立GBO生物库。H-E染色结果显示,GBO保留了与亲本GBM组织相似的组织结构和细胞形态;免疫组化实验结果显示,GBO与GBM组织中GFAP、OLIG2、Ki67和ATRX分子的表达情况一致。结论：将患者来源的GBM组织在体外剪小并用特制培养基培养,可构建与GBM患者肿瘤组织在组织和细胞层面一致的GBO。     

Determination of diagnostic threshold in harmonization and comparison of clinical utility for five major antiphospholipid antibody assays used in Japan

BackgroundAnticardiolipin antibodies (aCL) and anti‐β₂‐glycoprotein I antibodies (aβ₂GPI) are essential in diagnosing antiphospholipid syndrome (APS) according to the international APS guideline. Five commercial assays for aCL and aβ₂GPI are available in Japan, but their test results are quite discordant. For harmonization of diagnosing APS, upper reference limit (URL) and diagnostic accuracy of each assay were evaluated and compared by testing common sets of specimens across all assays.MethodsWe evaluated two manual and three automated assays for aCL and aβ₂GPI of IgG‐ and IgM classes. 99%URL (the upper limit of reference interval: as per guideline) together with 97.5%URL were determined by testing sera from 198 to 400 well‐defined healthy subjects. Both URLs were compared with the cutoff values, which were determined based on ROC analysis by testing 50 each of plasma specimens from patients with/without APS. Diagnostic accuracy was evaluated as area under curve (AUC) of the ROC curve.ResultsA variable degree of discrepancy between URLs and the cutoff values was observed, which was partly attributable to between‐year assay variability. 97.5%URLs were set lower and closer to the cutoff values than 99%URLs. For all assays, diagnostic accuracies of both aβ₂GPI‐IgG and aCL‐IgG were generally high (AUC: 0.84−0.93); whereas those for IgM‐class assays were low (AUC: 0.57−0.67), implicating its utility is limited to rare IgG negative APS cases.ConclusionTo ensure harmonized APS diagnosis, the diagnostic thresholds of the five assays were evaluated by common procedures. Contrary to the guideline, 97.5%URL is rather recommended for diagnosing APS, which showed a closer match to the cutoff value.     

Test and Microstructural Analysis of a Steel Slag Cement-Based Material Using the Response Surface Method

In this study, the silica fume replacement rate, fly ash replacement rate, and curing temperature were regarded as the independent variables, and the compressive and flexural strengths were regarded as the response values. The response surface method was used to construct the response surface polynomial regression model and obtain the optimal preparation parameters of a steel slag cement-based gel slurry (SCGS). The univariate and multivariate effects on the SCGS’s strength were investigated via analysis of variance and a three-dimensional surface model, and the hydration products and strength development law were characterized via scanning electron microscopy and X-ray diffraction. The actual compressive strengths at 3 and 28 d of age were 31.78 and 53.94 MPa, respectively, which were close to the predicted values (32.59 and 55.81 MPa, respectively), demonstrating that the optimized strengths were accurate and reliable. Further, the hydration reaction rate of SiO₂ in the silica fume and the physical filling effect of the inert components of fly ash and steel slag under the optimal parameters were the key factors for the early strength of the material. Moreover, continuous C₃S hydration in steel slag and the continuous excitation of the volcanic ash properties of fly ash were important factors for the later strength.     

运用甘油磷酸氧化酶法测定冰冻红细胞解冻后残留甘油的含量

目的 建立测定冰冻红细胞解冻洗涤后残留甘油含量的酶学方法测定工艺.方法 进行甘油磷酸氧化酶法的线性范围测定、重复性、准确性(回收试验)、游离血红蛋白干扰试验,并比较不同样本处理方法(钨酸钠裂解法、三氯醋酸裂解法及制备后2h直接取上清液法)对酶法检测甘油的影响;进行系列浓度甘油红细胞酶法测定结果与传统过碘酸钠滴定法测定结果比对.结果 用GPO-PAP法检测甘油浓度在0.05～2.0 g/L时有较好的线性关系,,=0.9994,Y=0.942 X+0.0239;甘油含量为0.2 g/L、1.0 g/L的样本,批内CV值分别为2.68％、0.81％(n=20),日间CV值分别为4.59％、4.37％(n=20);甘油浓度从0.29～2.09 g/L间其回收率97.1％～100.8％,样本的平均回收率为99.0％;10g/L游离血红蛋白对GPO-PAP法检测结果无干扰;3种样本处理方法所测得的系列浓度甘油红细胞样品及解冻去甘油红细胞制品(n=18)酶法测定结果一致(P＞0.05);系列浓度甘油红细胞测定结果显示酶法测定比滴定法更准确,滴定法测定值偏高.结论 甘油磷酸氧化酶法可用于冰冻解冻去甘油红细胞制品中残留甘油含量的测定,方法简便、快速、准确、重复性好.3种样本处理方法对GPO-PAP法检测甘油含量无影响.     

案例教学在职业卫生学教学中的应用效果评价

目的 探讨案例教学在七年制临床医学专业职业卫生学教学中的应用,并对之进行效果评价。方法 选择本校2010级临床医学专业七年制学生为教学对象,并将之分为案例教学组（55人）和传统教学组（56人）;分别实施案例教学（理论课采用“故事化案例”教学、实验课采用“现患案例”教学）和传统教学（理论课采用传统讲授形式、实验课主要为观看教学录像片）。分别以t检验祀Y2检验对两组学生的课后考评成绩和问卷调查结果进行分析比较。结果 案例教学组学生的课后考评总分[（11．84±2．86）VS．（9．80±3．39）,t=-3．419]、基本认知能力分[（4．80±1．08）vs（4．05±1．43）,f=-3．097]、分析解决能力分[（7．04±2．21）VS（5．75±2．59）,t=-2．813）]44高于传统教学组（P〈0．05）。问卷调查显示,案例教学组学生对所用教学方法在提高分析问题能力（x^2=4．757）、增进学习兴趣（x^2=4．371）、促进知识融会贯通（x^2=4．276）等方面持肯定态度的人数和比例高于传统教学组（P〈0．05）。结论 案例教学可通过激发学生的学习能动性,提高其创造性运用知识、分析和解决实际问题的能力,从而提升课程成绩。     

补肾化毒法治疗SLE的理论机制探讨

用补肾化毒中药“狼疮静颗粒”治疗活动性SLE取得较好疗效,动物实验明确了该药对狼疮动物模型的部分免疫机理。本文着重探讨了补肾化毒法治疗SLE的理论机制。通过1967例SLE临床证型分析,探讨了SLE病变机理;通过理论分析,认为本病肾虚为本,毒瘀为标,基于病机,方附法出;最后指出补肾化毒法不是活动性SLE唯一治法,临症应重视辨证。     

内标多控法测定枳实中黄酮类成分及其不确定度评定研究

目的 建立HPLC内标多控法测定枳实药材中黄酮类成分的方法,并对测定结果进行不确定度评定。方法 以柚皮苷为内标,建立柚皮苷与橙皮苷、新橙皮苷的相对校正因子,计算枳实中黄酮类成分的含量,再根据数学模型,对测定过程中引入的不确定度进行评估,由此计算测定结果不确定度。结果 采用本方法测定枳实中柚皮苷与橙皮苷、新橙皮苷含量的扩展不确定度分别为W×2.94%、W×3.49%、W×3.34%。结论 建立的不确定度评定法可为内标多控法测定中药有效成分的不确定度分析提供参考。     

上海医学院博士研究生招生制度改革的调查研究

2007年和2008年,复旦大学上海医学院实行了博士研究生招生考试一申请制.为了总结2年来博士研究生招生制度改革的实践,上海医学院对2008年博士研究生考生和导师进行了随机和匿名问卷调查.结果 显示,大部分受访者对招生制度改革给予了充分的肯定,同时对博士研究生招生工作提出了一些建设性的建议.