A Priori Subcell Limiting Approach for the FR/CPR Method on Unstructured Meshes

A priori subcell limiting approach is developed for high-order flux reconstruction/correction procedure via reconstruction (FR/CPR) methods on two-dimensional unstructured quadrilateral meshes. Firstly, a modified indicator based on modal energy coefficients is proposed to detect troubled cells, where discontinuities exist. Then, troubled cells are decomposed into nonuniform subcells and each subcell has one solution point. A second-order finite difference shock-capturing scheme based on nonuniform nonlinear weighted (NNW) interpolation is constructed to perform the calculation on troubled cells while smooth cells are calculated by the CPR method. Numerical investigations show that the proposed subcell limiting strategy on unstructured quadrilateral meshes is robust in shock-capturing.     

Principles of environmentally-sustainable anaesthesia: a global consensus statement from the World Federation of Societies of Anaesthesiologists

The Earth’s mean surface temperature is already approximately 1.1°C higher than pre-industrial levels. Exceeding a mean 1.5°C rise by 2050 will make global adaptation to the consequences of climate change less possible. To protect public health, anaesthesia providers need to reduce the contribution their practice makes to global warming. We convened a Working Group of 45 anaesthesia providers with a recognised interest in sustainability, and used a three-stage modified Delphi consensus process to agree on principles of environmentally sustainable anaesthesia that are achievable worldwide. The Working Group agreed on the following three important underlying statements: patient safety should not be compromised by sustainable anaesthetic practices; high-, middle- and low-income countries should support each other appropriately in delivering sustainable healthcare (including anaesthesia); and healthcare systems should be mandated to reduce their contribution to global warming. We set out seven fundamental principles to guide anaesthesia providers in the move to environmentally sustainable practice, including: choice of medications and equipment; minimising waste and overuse of resources; and addressing environmental sustainability in anaesthetists’ education, research, quality improvement and local healthcare leadership activities. These changes are achievable with minimal material resource and financial investment, and should undergo re-evaluation and updates as better evidence is published. This paper discusses each principle individually, and directs readers towards further important references.     

菊花总黄酮含药血清对干眼细胞模型AR、NF-κB磷酸化蛋白及TGF-β1表达的影响＊

目的 观察菊花总黄酮在体外条件下对泪腺上皮细胞中雄激素受体（Androgen Receptor，AR）的调控作用及对下游的核因子κB（Nuclear Factor kappa B，NF-κB）、转化生长因子-β1（transforming growth factor-beta1，TGF-β1）的表达影响。方法 以过氧化氢（H₂O₂）诱导泪腺上皮细胞凋亡，建立细胞模型，设立无雄激素培养空白对照组、含雄激素培养对照组、无雄激素培养黄酮治疗组。以MTT法摸索含药血清最佳干预加入量；免疫印迹实验（Western Blot）以及实时荧光定量PCR法（Quantitative Real-Time PCR，qPCR）检测泪腺上皮细胞中AR、NF-κB及TGF-β1的表达情况；并应用雄激素受体阻断剂氟他胺进行AR阻断后再次检测上述指标 。结果 MTT法检测后计算得出含药血清干预细胞的最终浓度为13.2%；无雄激素培养黄酮治疗组及含雄激素培养对照组中AR、NF-κB及TGF-β1的表达增强，与空白对照组对比有显著差异（P<0.01）；无雄激素培养黄酮治疗组中NF-κB表达量比含雄激素培养对照组表达量低，两者间的差异有统计学意义。氟他胺及含药血清干预后，无雄激素培养黄酮治疗组及含雄激素培养对照组中AR及NF-κB的表达未见提高，无统计学意义。结论 菊花总黄酮对泪腺上皮细胞可能存在拟雄激素效应，从而使AR、NF-κB表达增加，并通过上调TGF-β1的表达，可能起到在泪腺局部的抗炎作用。     

Diffusion-weighted magnetic resonance imaging in rat kidney using two-dimensional navigated,interleaved echo-planar imaging at 7.0 T

The purpose of this study was to investigate the feasibility of two-dimensional (2D) navigated, interleaved multishot echo-planar imaging (EPI) to enhance kidney diffusion-weighted imaging (DWI) in rats at 7.0 T. Fully sampled interleaved four-shot EPI with 2D navigators was tailored for kidney DWI (Sprague–Dawley rats, n = 7) on a 7.0-T small bore preclinical scanner. The image quality of four-shot EPI was compared with T₂-weighted rapid acquisition with relaxation enhancement (RARE) (reference) and single-shot EPI (ss-EPI) without and with parallel imaging (PI). The contrast-to-noise ratio (CNR) was examined to assess the image quality for the EPI approaches. The Dice similarity coefficient and the Hausdorff distance were used for evaluation of image distortion. Mean diffusivity (MD) and fractional anisotropy (FA) were calculated for renal cortex and medulla for all DWI approaches. The corticomedullary difference of MD and FA were assessed by Wilcoxon signed-rank test. Four-shot EPI showed the highest CNR among the three EPI variants and lowest geometric distortion versus T₂-weighted RARE (mean Dice: 0.77 for ss-EPI without PI, 0.88 for ss-EPI with twofold undersampling, and 0.92 for four-shot EPI). The FA map derived from four-shot EPI clearly identified a highly anisotropic region corresponding to the inner stripe of the outer medulla. Four-shot EPI successfully discerned differences in both MD and FA between renal cortex and medulla. In conclusion, 2D navigated, interleaved multishot EPI facilitates high-quality rat kidney DWI with clearly depicted intralayer and interlayer structure and substantially reduced image distortion. This approach enables the anatomic integrity of DWI-MRI in small rodents and has the potential to benefit the characterization of renal microstructure in preclinical studies.