Stress Solitary Waves Generated by a Second-Order Polynomial Constitutive Equation

In this paper, a nonlinear constitutive law and a curve fitting, two relationships between the stress-strain and the shear stress-strain for sandstone material were used to obtain a second-order polynomial constitutive equation. Based on the established polynomial constitutive equations and Newton's second law, a mathematical model of the non-homogeneous nonlinear wave equation under an external pressure was derived. The external pressure can be assumed as an impulse function to simulate a real earthquake source. A displacement response under nonlinear two-dimensional wave equation was determined by a numerical method and computer-aided software. The results show that a suit pressure in the sandstone generates the phenomenon of stress solitary waves

Polysulfide Catalytic Materials for Fast-Kinetic Metal–Sulfur Batteries: Principles and Active Centers

Benefiting from the merits of low cost, ultrahigh-energy densities, and environmentally friendliness, metal–sulfur batteries (M–S batteries) have drawn massive attention recently. However, their practical utilization is impeded by the shuttle effect and slow redox process of polysulfide. To solve these problems, enormous creative approaches have been employed to engineer new electrocatalytic materials to relieve the shuttle effect and promote the catalytic kinetics of polysulfides. In this review, recent advances on designing principles and active centers for polysulfide catalytic materials are systematically summarized. At first, the currently reported chemistries and mechanisms for the catalytic conversion of polysulfides are presented in detail. Subsequently, the rational design of polysulfide catalytic materials from catalytic polymers and frameworks to active sites loaded carbons for polysulfide catalysis to accelerate the reaction kinetics is comprehensively discussed. Current breakthroughs are highlighted and directions to guide future primary challenges, perspectives, and innovations are identified. Computational methods serve an ever-increasing part in pushing forward the active center design. In summary, a cutting-edge understanding to engineer different polysulfide catalysts is provided, and both experimental and theoretical guidance for optimizing future M–S batteries and many related battery systems are offered

Density Peaks Clustering Approach for Discovering Demand Hot Spots in City-scale Taxi Fleet Dataset

Abstract—In this paper, we introduce a variant of the density peaks clustering (DPC) approach for discovering demand hot spots from a low-frequency, low-quality taxi fleet operational dataset. From the literature, the DPC approach mainly uses density peaks as features to discover potential cluster centers, and this requires distances between all pairs of data points to be calculated. This implies that the DPC approach can only be applied to cases with relatively small numbers of data points. For the domain of urban taxi operations that we are interested in, we could have millions of demand points per day, and calculating all-pair distances between all demand points would be practically impossible, thus making DPC approach not applicable. To address this issue, we project all points to a density image and execute our variant of the DPC algorithm on the processed image. Experiment results show that our proposed DPC variant could get similar results as original DPC, yet with much shorter execution time and lower memory consumption. By running our DPC variant on a real-world dataset collected in Singapore, we show that there are indeed recurrent demand hot spots within the central business district that are not covered by the current taxi stand design. Our approach could be of use to both taxi fleet operator and traffic planners in guiding drivers and setting up taxi stands. I

Will ocean acidification affect the digestive physiology and gut microbiota of whelk *Brunneifusus ternatanus*?

To understand the physiological responses of the Brunneifusus ternatanus to future ocean acidification (OA), histology, enzyme activity and gut bacterial composition at different pH levels (Control : C group, pH 8.1; Exposure period : EP group, pH 7.3) for 28 days were studied under laboratory conditions. Microbiota composition was analyzed using 16S rRNA gene amplicon sequencing. Enzyme activities of trypsin (TRY), lipase (LPS), amylase (AMS), and lysozyme (LZM) were used as biochemical indicators, as well as weight gain rate (WGR), specific growth rate (SGR) as growth indicators. The stress caused by OA resulted in alterations to the intestine, including partially swollen and degranulated enterocytes and rough endoplasmic reticulum (RER). The relative abundance of the core phylum in the acidified group changed significantly, showing an increase in Tenericutes and a decrease in Proteobacteria. Firmicutes/Bacteroides ratio declined from 4.38 in the control group to 1.25 in the EP group. We found that the enzymes TRY, LPS, and AMS activities were inhibited at reduced pH, which was positively correlated with the dominant genera Mycoplasma and Bacteroides; while LZM activities showed a significant increment, but showing a strong negative correlation. Furthermore, both WG and SRG values showed a depression at low pH lever. These results suggest that if anthropogenic CO2 emissions continue to accelerate, OA could lead to a negative impact on the whelk health, also compromising their growth performance and even survival. These findings will benefit the future risk assessments of OA or other related emerging environmental issue

N-(4-Chloro­phen­yl)-2-de­oxy-α-l-ribo­pyran­osylamine

In the crystal structure of the title compound, C11H14ClNO3, inter­molecular hydrogen bonds link mol­ecules in the ab plane, forming layers that stack along the c axis

Cardiotoxicity Associated with Trastuzumab Therapy in Taiwan: A Single Medical Center's 5-Year Experience

AbstractIntroductionTrastuzumab, a recombinant humanized monoclonal antibody, targets the external domain of HER2 to improve the efficacy of HER2-positive breast cancer treatment and inhibit carcinoma cellular proliferation. The purpose of this study was to identify early changes in cardiac function and dimensional changes in heart size in patients treated with trastuzumab.Materials and MethodsSeventy three female patients with Her2/neu overexpression (IHC 3+/Fish +) in breast cancer underwent echocardiography before and after trastuzumab therapy.ResultsCardiac complications developed in 14 patients (19.2%), including asymptomatic left ventricle systolic dysfunction (n = 12), symptomatic heart failure (n = 2), new asymptomatic left bundle branch block (n = 1), new negative T waves on electrocardiogram (n = 2), pericardial effusion (n = 1), and death (n = 1). No significant deterioration in diastolic function was noted, and right heart diameters and function did not change significantly. Most patients remained in an asymptomatic stage of cardiac disease. A significant decrease in left ventricular ejection fraction (LVEF) was observed in 14 patients (19.2%), and new mitral regurgitation (≥ grade 1) was noted after 3 months of trastuzumab therapy in 7 patients (9.6%).ConclusionsTrastuzumab led to measurable decreases in LVEF (but only 2.7% was symptomatic heart failure) and new mitral regurgitation. Therefore, regular follow-up with echocardiography is essential for early detection and prevention of trastuzumab-induced cardiomyopathy