Quantile regression and empirical likelihood for the analysis of longitudinal data with monotone missing responses due to dropout,with applications to quality of life measurements from clinical trials

The analysis of quality of life (QoL) data can be challenging due to the skewness of responses and the presence of missing data. In this paper, we propose a new weighted quantile regression method for estimating the conditional quantiles of QoL data with responses missing at random. The proposed method makes use of the correlation information within the same subject from an auxiliary mean regression model to enhance the estimation efficiency and takes into account of missing data mechanism. The asymptotic properties of the proposed estimator have been studied and simulations are also conducted to evaluate the performance of the proposed estimator. The proposed method has also been applied to the analysis of the QoL data from a clinical trial on early breast cancer, which motivated this study.     

Day-level associations of physical activity and sedentary time in mother–child dyads across three years: a multi-wave longitudinal study using accelerometers

Journal of Behavioral Medicine - Understanding associations between mothers’ and children’s physical activity and sedentary behavior on more fine-grained timescales can provide insights...     

F形空心钉与传统3枚平行钉治疗Pauwels Ⅲ型股骨颈骨折的疗效比较

目的:分析比较"F"形空心钉与传统倒三角3枚平行螺钉内固定治疗青壮年Pauwels Ⅲ型股骨颈骨折的临床疗效。方法：2017年1月至2020年1月收治Pauwels Ⅲ型股骨颈骨折患者38例，根据置入钉方式的不同将其分为两组，其中A组18例，采用"F"形空心钉固定，男12例，女6例，年龄37~55岁，受伤至手术时间1~3 d。B组20例，采用传统倒三角3枚平行拉力螺钉固定，男12例，女8例，年龄35~55岁，受伤至手术时间为1~3 d。比较两组患者骨折不愈合，股骨头坏死，股骨颈短缩，空心螺钉退出情况，髋关节功能Harris评分，疼痛视觉模拟评分（visual analogue scale，VAS）。结果：所有患者获得随访，时间为15~31个月。两组患者在骨折不愈合，股骨颈短缩，股骨头坏死方面差异无统计学意义（P>0.05）；两组患者在螺钉退出方面差异有统计学意义（P<0.05）。两组患者术后12个月时髋关节Harris评分及VAS评分差异均无统计学差异（P>0.05）。结论："F"形与传统倒三角3枚平行空心钉内固定治疗青壮年Pauwels Ⅲ型股骨颈骨折中短期疗效相似，但"F"形空心钉退钉率较低。     

RNA sequencing screening of differentially expressed genes after spinal cord injury

In the search for a therapeutic schedule for spinal cord injury, it is necessary to understand key genes and their corresponding regulatory networks involved in the spinal cord injury process. However, ad hoc selection and analysis of one or two genes cannot fully reveal the complex molecular biological mechanisms of spinal cord injury. The emergence of second-generation sequencing technology(RNA sequencing) has provided a better method. In this study, RNA sequencing technology was used to analyze differentially expressed genes at different time points after spinal cord injury in rat models established by contusion of the eighth thoracic segment. The numbers of genes that changed significantly were 944, 1362 and 1421 at 1, 4 and 7 days after spinal cord injury respectively. After gene ontology analysis and temporal expression analysis of the differentially expressed genes, C5ar1, Socs3 and CCL6 genes were then selected and identified by real-time polymerase chain reaction and western blot assay. The mRNA expression trends of C5ar1, Socs3 and CCL6 genes were consistent with the RNA sequencing results. Further verification and analysis of C5ar1 indicate that the level of protein expression of C5ar1 was consistent with its nucleic acid level after spinal cord injury. C5ar1 was mainly expressed in neurons and astrocytes. Finally, the gene Itgb2,which may be related to C5ar1, was found by Chilibot database and literature search. Immunofluorescence histochemical results showed that the expression of Itgb2 was highly consistent with that of C5ar1. Itgb2 was expressed in astrocytes. RNA sequencing technology can screen differentially expressed genes at different time points after spinal cord injury. Through analysis and verification, genes strongly associated with spinal cord injury can be screened. This can provide experimental data for further determining the molecular mechanism of spinal cord injury, and also provide possible targets for the treatment of spinal cord injury. This study was approved ethically by the Laboratory Animal Ethics Committee of Jiangsu Province, China(approval No. 2018-0306-001) on March 6, 2018.     

经鼻高流量氧气湿化治疗老年慢性阻塞性肺疾病急性加重合并呼吸衰竭的可行性研究

ObjectiveTo investigate the feasibility of transnasal heated humidified high flow nasal cannula oxygen therapy (HFNC) in the treatment of acute exacerbation of chronic obstructive pulmonary disease (AECOPD) with respiratory failure in elderly patients. MethodsA total of 176 elderly patients with AECOPD complicated with respiratory failure who were hospitalized at Peking University Shougang Hospital from December 2016 to January 2022 were enrolled, including 82 patients in an HFNC group and 94 patients in an NPPV group. After treatment, pulse oxygen saturation (SPO₂), arterial partial pressure of carbon dioxide (PaCO₂), oxygenation index (OI), respiratory rate (RR), heart rate (HR), mean arterial pressure (MAP), comfort score, discharge rate, rate of endotracheal intubation, rate of transfer to intensive care unit (ICU), and mortality were compared between the two groups. The independent sample t-test was used for comparison between the two groups. Statistical data are expressed in percentage or number of cases and the χ² test was used for their comparisons. ResultsThe SPO₂ values at 30 min, 1 h, and 6 h were significantly higher in the HFNC group than in the NPPV group (t=-2.049,-2.618, and -3.314, P=0.043, 0.010, and 0.001, respectively). SPO₂ before discharge was significantly lower than that of the NPPV group (t=2.162, P=0.033), but OI at each time point and before discharge had no statistical significance (P＞0.05). MAP at 6 h was significantly higher in the HFNC group than in the NPPV group (t=-2.209, P=0.029), but within the normal range. HRs at 2 h and 3 h in the HFNC group were significantly higher than those of the NPPV group (t=-2.199 and -2.336, P=0.030 and 0.021, respectively). There were no significant differences in RR, HR, or MAP between the two groups at other time points and before discharge (P＞0.05). There was no significant difference in PaCO2 between the two groups (P＞0.05). Comfort score in the HFNC group was significantly higher than that of the NPPV group (t=-46.807, P＜0.001). There were no significant differences in discharge rate, ICU transfer rate, endotracheal intubation rate, and mortality between the two groups (P＞0.05). ConclusionHFNC is as effective as NPPV in treating elderly patients with AECOPD complicated with type Ⅰ or mild type Ⅱ respiratory failure, and HFNC is more comfortable than NPPV.     

刺果甘草全基因组Survey及叶绿体基因组特征分析＊

目的 基于基因组Survey分析对刺果甘草Glycyrrhiza pallidiflora Maxim.基因组大小和杂合率进行估计，并通过叶绿体基因组序列特征对其在甘草属Glycyrrhiza L.中的系统发育位置进行研究。方法 使用二代测序技术对刺果甘草进行测序，采用K-mer方法对测序reads进行分析，估算刺果甘草基因组大小和杂合率，使用生物信息学方法进行叶绿体基因组组装、注释和系统发育分析。结果 Survey分析结果显示其基因组大小约为577.82 Mb，杂合度约为0.31%，重复序列比例约为53.72%。叶绿体基因组长度为127，267 bp，不具有典型的四分体结构，总GC含量为34.32%，包含110个基因，其中76个蛋白质编码基因，30个tRNA基因和4个rRNA基因。系统发育分析表明，刺果甘草与圆果甘草G. squamulosa Franch.亲缘较接近。结论 刺果甘草存在低杂合和重复序列较多的特点，为了更好地对全基因组进行序列拼接和组装，可尝试采用三代测序结合二代测序的分析策略进行基因组组装；刺果甘草叶绿体全基因组比对和系统发育分析，为后续开展甘草属遗传多样性研究和分子鉴定标记筛选提供了重要依据。     

髌周去神经化预防全膝关节置换术后膝前疼痛

目的　依据髌周解剖学特点，探讨全膝关节置换术（total knee arthroplasty，TKA）中应用髌周电灼去神经化的临床效果。 方法　纳入82名诊断为骨性关节炎的患者（91膝），予行双侧或单侧不置换髌骨的TKA，按随机对照原则将病人分为两组，共有41名实验组患者（45膝）在TKA中接受了髌周去神经化处理，41名对照组患者（46膝）未做该处理。手术主刀为同一骨科医师，均使用相同的膝关节假体系统。主要评价项目包括膝关节KSS评分、Western Ontario and McMaster Universities（WOMAC）、Feller髌骨评分及VAS评分。 结果　82名患者术后均获随访，平均随访时间为12个月，两组病人的膝关节KSS评分、WOMAC、Feller髌骨评分及VAS评分均无显著统计学差异（P>0.05）。 结论　在TKA中行髌周电灼去神经化，不能显著改善病人的预后。