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BackgroundMuscle depletion that impairs normal physiological function in elderly patients leads to poor prognosis. This study aimed to evaluate the association between total abdominal muscle area (TAMA), total psoas area (TPA), psoas muscle density (PMD), and short-term postoperative complications in elderly patients with rectal cancer.MethodsAll elderly patients underwent rectal cancer resection with perioperative abdominal computed tomography (CT). Complications were assessed according to the Clavien-Dindo classification. Severe complications were defined as grade III-V following the Clavien-Dindo classification. Univariate and multivariate analyses were performed to evaluate risk factors of short-term severe postoperative complications.ResultsThe cohort consisted of 191 patients with a mean age of 73.60 ± 8.81 years. Among them, 138 (72.25%) patients had Clavien-Dindo 0- II, 53 (27.75%) patients had severe postoperative complications (Clavien-Dindo III-V), and 1(0.52%) patient died within 30 days of surgery. PMD was significantly higher in the Clavien-Dindo 0-II cohort compared to the Clavien-Dindo III-V cohort (p=0.004). Nevertheless, TAMA and TPA failed to exhibit significant differences. Moreover, the multivariate regression analysis implied that advanced age [OR 1.07 95%CI (1.02–1.13) p=0.013], male [OR 5.03 95%CI (1.76-14.41) p=0.003], high charlson comorbidity index (CCI) score [OR 3.60 95%CI (1.44-9.00) p=0.006], and low PMD [OR 0.94 95%CI (0.88-0.99) p=0.04] were independent risk factors of Clavien-Dindo III-V.ConclusionPreoperative assessment of the PMD on CT can be a simple and practical method for identifying elderly patients with rectal cancer at risk for severe postoperative complications.

The objective of this work is to investigate adsorption separation of liquid‐phase xylene isomers using ultramicroporous carbon spheres. The synthesized glucose‐based adsorbent (UMC‐xyl) enabled the challenging separation of liquid‐phase p‐xylene/m‐xylene with an adsorption selectivity of 53 as well as p‐xylene uptake of 91mg/g, outperforming a series of commercial adsorbents including the industrial benchmark KBaX. The micropore diffusion model was used to give the best fit to the adsorption kinetics of UMC‐xyl with a rate achieved higher than KBaX. The xylene isomer separation was facilitated by the narrow ultramicropore size distributed at 5.8–6.8 Å in UMC‐xyl via a synergistic kinetic and size‐sieving separation mechanism. Breakthrough experiments confirmed the effectiveness of UMC‐xyl in the dynamic selective separation of p‐xylene from xylene isomers, together with superior multiple‐cycle eluent regenerability under the synergistic effects of the "like‐dissolve‐like" principle and π–π interaction. The work opens a new direction of using porous carbon adsorbents for continuous liquid‐phase separation of challenging hydrocarbon isomers. [ABSTRACT FROM AUTHOR]

Dynamic working temperature modulation has received considerable attention as a way to enable metal oxide-based gas sensors to recognize the detected gases. Previous reports mainly focused on heating-voltage waveform manipulation and algorithm improvement, not involving the insight of the temperature modulation sensing behavior correlated with fine nanostructures of metal oxide. Here, three types of SnO2 nanoparticles with different percentages of high-energy {221} and low-energy {110} crystal facets were synthesized and assembled as gas sensors. Under a working temperature modulation by applying a square wave pulse heating voltage, their dynamic response behaviors toward volatile organic compounds (VOCs) including alcohols, aldehydes, ketones, amines, and aromatic compounds were systematically explored. The results indicated that they exhibited different characteristic response curves toward different VOCs, presenting the crystal facet-dependent temperature modulation sensing behaviors. This effect was analyzed further and explored in conjunction with the characteristic response curves. Based on their different characteristic response curves that occurred on the three types of SnO2 nanoparticles, the detected gases, and even some congeners, were well discriminated along with a simple PCA recognition algorithm. Additionally, their quantitative analysis was also achieved. [ABSTRACT FROM AUTHOR]

The structure and electrical properties of CaCu3Ti4O12 (CCTO) ceramics doped with xHo2O3 synthesized by solid-phase reaction method were systematically studied. Insights from X-ray diffraction (XRD) measurements indicate the existence of a primary phase of CCTO in all samples. Ho2O3 dopant was found to inhibit grain growth and thus leading to a reduced grain size of ceramics. Moreover, the distribution of resistivity with temperature revealed the manifestation of a negative temperature coefficient (NTC) effect in the samples. More specifically, the resistivity (ρ20) values of obtained ceramics configurations decreased from 8.54 × 106 to 1.76 × 105 Ω cm with increasing Ho2O3 doping content. In addition, thermal constant (B20/75) of all samples was higher than 4000 K. Electrical properties analysis disclosed that electron hopping process is main conduction mechanism within CCTO-based ceramics. In addition, insights from complex impedance spectra revealed the existence of grain boundaries with resistance higher than grains resistance. This effect is strongly connected with the manifestation of electrical relaxation procedures within grain boundaries. Our outcomes verify that both the structural configuration and the electrical performance of the CCTO-based ceramics can be tuned directly and effectively by incorporating Ho2O3 dopant. [ABSTRACT FROM AUTHOR]