Are general circulation models obsolete?

Traditional general circulation models, or GCMs—that is, three-dimensional dynamical models with unresolved terms represented in equations with tunable parameters—have been a mainstay of climate research for several decades, and some of the pioneering studies have recently been recognized by a Nobel prize in Physics. Yet, there is considerable debate around their continuing role in the future. Frequently mentioned as limitations of GCMs are the structural error and uncertainty across models with different representations of unresolved scales and the fact that the models are tuned to reproduce certain aspects of the observed Earth. We consider these shortcomings in the context of a future generation of models that may address these issues through substantially higher resolution and detail, or through the use of machine learning techniques to match them better to observations, theory, and process models. It is our contention that calibration, far from being a weakness of models, is an essential element in the simulation of complex systems, and contributes to our understanding of their inner workings. Models can be calibrated to reveal both fine-scale detail and the global response to external perturbations. New methods enable us to articulate and improve the connections between the different levels of abstract representation of climate processes, and our understanding resides in an entire hierarchy of models where GCMs will continue to play a central role for the foreseeable future.     

Durability of Reinforced Concrete with Additions of Natural Pozzolans of Volcanic Origin

In this work, the properties of concrete modified with dosages of natural pozzolans (NP) in substitution of cement or superfine aggregates were evaluated. Proportions of 20/80 pozzolan/cement or pozzolan/superfine aggregates were selected for the additions of quarry and tuff pozzolans. Pozzolanic activity, durability, compressive strength, characteristic resistance, settling consistency, density, electrical resistivity, depth of water penetration, accessible porosity, and carbonation and chloride penetration were determined for the resulting concrete mixtures, and they were subsequently compared to the values obtained for the reference concrete batches without additions. The results of the cementitious mixtures supplemented with tuff (PZT) and quarry (PZQ) pozzolans, expressed in mmol/L, are consistent with the pozzolanism test, with [Ca(OH)₂]/[OH⁻] ratios at 7 days are 6.03/60.19 for PZQ and 1.78/92.78 PZT. In addition to the pozzolanic activity at these dosages, the characteristic resistance and durability parameters required by EHE-08 were verified. Particular attention was given to the determination of the diffusion of chloride ions, introducing an instrumental modification of the accelerated integral method. The modification provides values of diffusion coefficients similar to those obtained by the other methods with the advantage of greater stability and quality of the measurement.     

Experimental Design,Equilibrium Modeling and Kinetic Studies on the Adsorption of Methylene Blue by Adsorbent: Activated Carbon from Durian Shell Waste

For the first time, activated carbon from a durian shell (ACDS) activated by H₂SO₄ was successfully synthesized in the present study. The fabricated ACDS has a porous surface with a specific surface area of 348.0017 m²·g⁻¹, average capillary volume of 0.153518 cm³·g⁻¹, the average pore diameter of 4.3800 nm; ash level of 55.63%; humidity of 4.74%; density of 0.83 g·cm⁻³; an iodine index of 634 mg·g⁻¹; and an isoelectric point of 6.03. Several factors affecting Methylene Blue (MB) adsorption capacity of ACDS activated carbon was investigated by the static adsorption method, revealing that the adsorption equilibrium was achieved after 90 min. The best adsorbent pH for MB is 7 and the mass/volume ratio is equal to 2.5 g·L⁻¹. The MB adsorption process of ACDS activated carbon follows the Langmuir, Freundlich, Tempkin, and Elovich isotherm adsorption model, which has determined the maximum adsorption capacity for MB of ACDS as q_max = 57.47 mg·g⁻¹. The MB adsorption process of ACDS follows the of pseudo-second-order adsorption kinetic equation. The Weber and Morris Internal Diffusion Model, the Hameed and Daud External Diffusion Model of liquids have been studied to see if the surface phase plays any role in the adsorption process. The results of thermodynamic calculation of the adsorption process show that the adsorption process is dominated by chemical adsorption and endothermic. The obtained results provide an insight for potential applications of ACDS in the treatment of water contaminated by dyes.     

Explainable machine learning model for predicting furosemide responsiveness in patients with oliguric acute kidney injury

BackgroundAlthough current guidelines didn’t support the routine use of furosemide in oliguric acute kidney injury (AKI) management, some patients may benefit from furosemide administration at an early stage. We aimed to develop an explainable machine learning (ML) model to differentiate between furosemide-responsive (FR) and furosemide-unresponsive (FU) oliguric AKI.MethodsFrom Medical Information Mart for Intensive Care-IV (MIMIC-IV) and eICU Collaborative Research Database (eICU-CRD), oliguric AKI patients with urine output (UO) < 0.5 ml/kg/h for the first 6 h after ICU admission and furosemide infusion ≥ 40 mg in the following 6 h were retrospectively selected. The MIMIC-IV cohort was used in training a XGBoost model to predict UO > 0.65 ml/kg/h during 6–24 h succeeding the initial 6 h for assessing oliguria, and it was validated in the eICU-CRD cohort. We compared the predictive performance of the XGBoost model with the traditional logistic regression and other ML models.Results6897 patients were included in the MIMIC-IV training cohort, with 2235 patients in the eICU-CRD validation cohort. The XGBoost model showed an AUC of 0.97 (95% CI: 0.96–0.98) for differentiating FR and FU oliguric AKI. It outperformed the logistic regression and other ML models in correctly predicting furosemide diuretic response, achieved 92.43% sensitivity (95% CI: 90.88–93.73%) and 95.12% specificity (95% CI: 93.51–96.3%).ConclusionA boosted ensemble algorithm can be used to accurately differentiate between patients who would and would not respond to furosemide in oliguric AKI. By making the model explainable, clinicians would be able to better understand the reasoning behind the prediction outcome and make individualized treatment.     

Improvement of the Thermal Conductivity and Mechanical Properties of 3D-Printed Polyurethane Composites by Incorporating Hydroxylated Boron Nitride Functional Fillers

Recently, the use of fused deposition modeling (FDM) in the three-dimensional (3D) printing of thermal interface materials (TIMs) has garnered increasing attention. Because fillers orient themselves along the direction of the melt flow during printing, this method could effectively enhance the thermal conductivity of existing composite materials. However, the poor compatibility and intensive aggregation of h-BN fillers in polymer composites are still detrimental to their practical application in thermally conductive materials. In this study, hydroxyl-functionalized boron nitride (OH-BN) particles were prepared by chemical modification and ultrasonic-assisted liquid-phase exfoliation to explore their impact on the surface compatibility, mechanical properties and the final anisotropic thermal conductivity of thermoplastic polyurethane (TPU) composites fabricated by FDM printing. The results show that the surface-functionalized OH-BN fillers are homogeneously dispersed in the TPU matrix via hydrogen bonding interactions, which improve the interfacial adhesion between the filler and matrix. For the same concentration of loaded filler, the OH-BN/TPU composites exhibit better mechanical properties and thermal conductivities than composites incorporating non-modified h-BN. These composites also show higher heat conduction along the stand-vertical direction, while simultaneously exhibiting a low dielectric constant and dielectric loss. This work therefore provides a possible strategy for the fabrication of thermal management polymers using 3D-printing methods.     

Numerical Estimation of SAR and Temperature Distributions inside Differently Shaped Female Breast Tumors during Radio-Frequency Ablation

Radio-frequency (RF) ablation is a reliable technique for the treatment of deep-seated malignant tumors, including breast carcinoma, using high ablative temperatures. The paper aims at a comparative analysis of the specific absorption rate and temperature distribution during RF ablation with regard to different female breast tumors. In the study, four tumor models equivalent to an irregular tumor were considered, i.e., an equivalent sphere and ellipsoid with the same surfaces and volumes as the irregular tumor and an equivalent sphere and ellipsoid inscribed in the irregular tumor. An RF applicator with a specific voltage, operating at 100 kHz inserted into the anatomically correct female breast, was applied as a source of electromagnetically induced heat. A conjugated Laplace equation with the modified Pennes equation was used to obtain the appropriate temperature gradient in the treated area. The levels of power dissipation in terms of the specific absorption rate (SAR) inside the naturalistically shaped tumor, together with the temperature profiles of the four simplified tumor models equivalent to the irregular one, were determined. It was suggested that the equivalent tumor models might successfully replace a real, irregularly shaped tumor, and the presented numeric methodology may play an important role in the complex therapeutic RF ablation process of irregularly shaped female breast tumors.     

Effect of an Adaptive-Density Filling Structure on the Mechanical Properties of FDM Parts with a Variable Cross-Section

Fused deposition modeling (FDM) technique is one of the most popular additive manufacturing techniques. Infill density is a critical factor influencing the mechanical properties of 3D-printed components using the FDM technique. For irregular components with variable cross-sections, to increase their overall mechanical properties while maintaining a lightweight, it is necessary to enhance the local infill density of the thin part while decreasing the infill density of the thick part. However, most current slicing software can only generate a uniform infill throughout one model to be printed and cannot adaptively create a filling structure with a varying infill density according to the dimensional variation of the cross-section. In the present study, to improve the mechanical properties of irregular components with variable cross-sections, an adaptive-density filling structure was proposed, in which Hilbert curve with the same order was used to fill each slice, i.e., the level of the Hilbert curves in each slice is the same, but the side length of the Hilbert curve decreases with the decreasing size of each slice; hence, the infill density of the smaller cross-section is greater than that of the larger cross-section. The ultimate bearing capacity of printed specimens with the adaptive-density filling structure was evaluated by quasi-static compression, three-point bending, and dynamic compression tests, and the printed specimens with uniform filling structure and the same overall infill density were tested for comparison. The results show that the maximum flexural load, the ultimate compression load, and the maximum impact resistance of the printed specimens with the adaptive-density filling structure were increased by 140%, 47%, and 82%, respectively, compared with their counterparts using the uniform filling structure.     

新型FGG基因突变导致遗传性纤维蛋白原缺陷症的研究

目的:对临床发现的1例遗传性纤维蛋白原缺陷症患者及其家属进行凝血相关指标检测和基因型分析,并探讨可能的分子发病机制.方法:采集先证者及其家属共4人的外周血,检测凝血酶原时间(PT)、活化部分凝血活酶时间(APTT)、凝血酶时间(TT)、纤维蛋白原(Fg)、D-二聚体及8项凝血因子指标.对编码纤维蛋白原3条肽链的FGA、...     

健康老龄化: 理念、体系、能力与评估

分析2008 — 2018年中国老年人社区为老服务需求发展轨迹及影响因素,为发展多层次养老服务体系及促进健康老龄化的实现提供参考依据。

收集中国老年健康影响因素跟踪调查（CLHLS）2008、2011、2014和2018年相关数据,应用Mplus 8.3构建潜变量增长模型（LGM）,采用无条件最小二乘法测量不包含协变量的社区为老服务需求的变化轨迹,并构建有条件的LGM分析2008 — 2018年中国老年人社区为老服务需求变化轨迹及影响因素。

中国老年人2008、2011、2014和2018年社区为老服务需求得分分别为（4.89 ± 2.27）、（5.49 ± 1.94）、（5.38 ± 2.06）和（5.21 ± 2.05）分,不同年份老年人社区为老服务需求得分差异无统计学意义（P > 0.05）。无条件LGM分析结果显示,二次函数无条件LGM为中国老年人社区为老服务需求发展轨迹的最优模型,且社区为老服务需求的初始水平显著 > 0（截距 = 4.91,P < 0.01）,在2008 — 2011年呈上升趋势（斜率 = 0.38,P < 0.01）,而2011 — 2018年则呈下降趋势（斜率 = – 0.12,P < 0.01）。有条件LGM分析结果显示,年龄（β = 0.026）、婚姻状况的截距（β = 0.260）、居住地（β = – 0.567）和教育年限（β = 0.224）对中国老年人社区为老服务需求的截距均有显著影响（均P < 0.05）;其中年龄和教育年限对斜率1均呈正向预测（β₁ = 0.021,0.018,均P < 0.05）,对斜率2的预测均不显著（均P > 0.05）;婚姻状况截距和斜率对斜率1均呈正向预测（β₁ = 0.118,0.021,均P < 0.05）,对斜率2亦均呈正向预测（β₂ = 0.146,0.049,均P < 0.05）;居住地对斜率1和斜率2均呈正向预测（β₁ = 0.707,β₂ = 0.046,均P < 0.05）。

中国老年人2008 — 2018年社区为老服务需求呈曲线增长的变化轨迹,初始水平及增长速度均存在个体差异,年龄、婚姻状况、居住地和教育年限是中国老年人社区为老服务需求水平及增长速度的主要影响因素。

     

Primary Gastric Carcinoma Cells Frequently Lose Heterozygosity at the APC and MCC Genetic Loci

Loss of heterozygosity (LOH) at APC and MCC gene loci (both mapped to 5q21) was investigated in 24 surgical specimens of primary gastric carcinomas using the polymerase chain reaction after tumor cell enrichment by cell sorting based on differences in DNA content. LOH at APC and/or MCC was detected in 87% (13/15) of the cases; at the APC in 86% (12/14) and at the MCC locus in 100% (7/7). LOH at the APC locus was always accompanied by LOH at the MCC locus. LOH at the APC and/or MCC was found in both differentiated and undifferentiated types in both early and advanced stages of gastric carcinoma. Thus, LOH at APC and/or MCC is considered to be one of the most prevalent genetic alterations in human gastric carcinoma and occurs at an early stage of the carcinogenesis.