Heat conduction in graphene flakes with inhomogeneous mass interface

Using nonequilibrium molecular dynamics simulations, we study the heat conduction in graphene flakes composed by two regions. One region is mass-loaded and the other one is intact. It is found that the mass interface between the two regions greatly decreases the thermal conductivity, but it would not bring thermal rectification effect. The dependence of thermal conductivity upon the heat flux and the mass difference ratio are studied to confirm the generality of the result. The interfacial scattering of solitons is studied to explain the absence of rectification effect.Comment: 5 pages, 4 figure

Hyperbolic Graph Diffusion Model

Diffusion generative models (DMs) have achieved promising results in image and graph generation. However, real-world graphs, such as social networks, molecular graphs, and traffic graphs, generally share non-Euclidean topologies and hidden hierarchies. For example, the degree distributions of graphs are mostly power-law distributions. The current latent diffusion model embeds the hierarchical data in a Euclidean space, which leads to distortions and interferes with modeling the distribution. Instead, hyperbolic space has been found to be more suitable for capturing complex hierarchical structures due to its exponential growth property. In order to simultaneously utilize the data generation capabilities of diffusion models and the ability of hyperbolic embeddings to extract latent hierarchical distributions, we propose a novel graph generation method called, Hyperbolic Graph Diffusion Model (HGDM), which consists of an auto-encoder to encode nodes into successive hyperbolic embeddings, and a DM that operates in the hyperbolic latent space. HGDM captures the crucial graph structure distributions by constructing a hyperbolic potential node space that incorporates edge information. Extensive experiments show that HGDM achieves better performance in generic graph and molecule generation benchmarks, with a $48\%$ improvement in the quality of graph generation with highly hierarchical structures.Comment: accepted by AAAI 202

Secure Adaptive Topology Control for Wireless Ad-Hoc Sensor Networks

This paper presents a secure decentralized clustering algorithm for wireless ad-hoc sensor networks. The algorithm operates without a centralized controller, operates asynchronously, and does not require that the location of the sensors be known a priori. Based on the cluster-based topology, secure hierarchical communication protocols and dynamic quarantine strategies are introduced to defend against spam attacks, since this type of attacks can exhaust the energy of sensor nodes and will shorten the lifetime of a sensor network drastically. By adjusting the threshold of infected percentage of the cluster coverage, our scheme can dynamically coordinate the proportion of the quarantine region and adaptively achieve the cluster control and the neighborhood control of attacks. Simulation results show that the proposed approach is feasible and cost effective for wireless sensor networks

LncRNA MIR4435-2HG predicts poor prognosis in patients with colorectal cancer

Background LncRNA MIR4435-2HG is observed in a variety of cancers, while its role in colorectal cancer is unknown. We aimed to demonstrate the relationship between MIR4435-2HG and colorectal cancer based on The Cancer Genome Atlas (TCGA) database. Materials and Methods Patients with colorectal cancer were collected from TCGA. We compared the expression of MIR4435-2HG in colorectal cancer and normal tissues with Wilcoxon rank sum test, and logistic regression was used to evaluate the relationship between MIR4435-2HG and clinicopathological characters. Moreover, Kaplan–Meier and Cox regression was performed to evaluate the correlation between MIR4435-2HG and survival rate. Gene set enrichment analysis (GSEA) was also conducted to annotate biological function of MIR4435-2HG. Results MIR4435-2HG level was elevated in colorectal cancer tissues. Increased level of MIR4435-2HG was significantly correlated with TNM stage (OR = 1.66 for T1/T2 vs. T3/T4; OR = 1.68 for N0 vs. N1/N2), stage (OR = 1.66 for stage 1/2 vs. stage 3/4), and carcinoembryonic antigen level before treatment (OR = 1.70 for <5 vs. ≥5) (all P-value <0.05). High MIR4435-2HG expression had a poorer progression-free survival (p = 0.048), and overall survival (OS) (P = 0.028), which were validated in the GSE92921 and GSE29621 datasets. MIR4435-2HG expression (P = 0.040, HR = 1.955 (95% CI [1.031–3.710])) was independently correlated with OS. GSEA demonstrated that the P38/MAPK pathway, the VEGF pathway, the cell adhesion molecules cams, the NOD-like receptor signaling pathway, the cell surface interactions at the vascular wall, and integrin cell surface interactions were differentially enriched in MIR4435-2HG high expression phenotype. Conclusions Increased MIR4435-2HG might be a potential biomarker for the diagnosis and prognosis of colorectal cancer. Moreover, MIR4435-2HG might participate in the development of colorectal cancer via the P38/MAPK and VEGF pathway

Distribution and conservation status of Camellia longzhouensis (Theaceae), a critically endangered plant species endemic to southern China

Camellia longzhouensis (Theaceae) is an endemic evergreen shrub or small tree with a distribution restricted to South China. It is listed as Grade-II in the National Key Protected Wild Plants List. In this study, we surveyed its distribution, examined its population structure, identified factors affecting its survival, and reassessed its extinction risk. We found that C. longzhouensis was only distributed in the Nonggang National Nature Reserve and the surrounding area. Its individuals only grew under the secondary forest canopy in the karst mountain. A total of 58 individuals of C. longzhouensis in three sub-populations were found. Soil fertility and understory light availability were the main habitat factors influencing the survival of C. longzhouensis. Anthropogenic disturbances and reproductive obstacles have caused a low seed-setting rate, poor seedling survival, and a lack of adult plants of C. longzhouensis in the natural habitat. The population structure of C. longzhouensis is spindle-shaped, indicating poor natural regeneration and inhibited seedling recruitment. Cleistanthus petelotii had a significant positive interspecific interaction with C. longzhouensis in the community. Based on the information obtained here and IUCN criterion C2ai, we recommend that C. longzhouensis be categorized in the International Union for Conservation of Nature (IUCN) Red List as Critically Endangered. We also developed a comprehensive protection strategy, consisting of in situ conservation, ex situ conservation, reintroduction, and commercial utilization. This strategy can be readily applied to protect other endangered plants with economic value in karst poor regions

Time-restricted feeding’s effect on overweight and obese patients with chronic kidney disease stages 3-4: A prospective non-randomized control pilot study

BackgroundTime-restricted feeding (TRF) has become a popular weight loss method in recent years. It is widely used in the nutritional treatment of normal obese people and obese people with chronic diseases such as diabetes mellitus and hypertension, and has shown many benefits. However, most TRF studies have excluded chronic kidney disease (CKD) patients, resulting in a lack of sufficient evidence-based practice for the efficacy and safety of TRF therapy for CKD. Therefore, we explore the efficacy and safety of TRF in overweight and obese patients with moderate-to-severe stage CKD through this pilot study, and observe patient compliance to assess the feasibility of the therapy.MethodsThis is a prospective, non-randomized controlled short-term clinical trial. We recruited overweight and obese patients with CKD stages 3-4 from an outpatient clinic and assigned them to either a TRF group or a control diet (CD) group according to their preferences. Changes in renal function, other biochemical data, anthropometric parameters, gut microbiota, and adverse events were measured before the intervention and after 12 weeks.ResultsThe change in estimated glomerular filtration rate (eGFR) before and after intervention in the TRF group (Δ = 3.1 ± 5.3 ml/min/1.73m2) showed significant improvement compared with the CD group (Δ = -0.8 ± 4.4 ml/min/1.73m2). Furthermore, the TRF group had a significant decrease in uric acid (Δ = -70.8 ± 124.2 μmol/L), but an increase in total protein (Δ = 1.7 ± 2.5 g/L), while the changes were inconsistent for inflammatory factors. In addition, the TRF group showed a significant decrease in body weight (Δ = -2.8 ± 2.9 kg) compared to the CD group, and body composition indicated the same decrease in body fat mass, fat free mass and body water. Additionally, TRF shifted the gut microbiota in a positive direction.ConclusionPreliminary studies suggest that overweight and obese patients with moderate-to-severe CKD with weight loss needs, and who were under strict medical supervision by healthcare professionals, performed TRF with good compliance. They did so without apparent adverse events, and showed efficacy in protecting renal function. These results may be due to changes in body composition and alterations in gut microbiota

A New Benzofuran Glucoside from Ficus Tikoua Bur

From the water-soluble portion of the methanol extract of stems of Ficus tikoua Bur., a new benzofuran glucoside, named 6-carboxyethyl-5-hydroxybenzofuran 5-O-β-d-glucopyranoside (1), together with one known benzofuran glucoside (2) were isolated. Their structures were elucidated by 1D and 2D (1H-1H COSY, HMQC, and HMBC) NMR spectroscopy and HRMS techniques. The antioxidant activities of the isolated compounds were assayed based on the scavenging activities of DPPH free radical. Compounds 1 and 2 exhibited moderate antioxidant activities, and the IC50 values were 242.8 μg·mL−1 and 324.9 μg·mL−1, respectively

Caffeine protects against experimental acute pancreatitis by inhibition of inositol 1,4,5-trisphosphate receptor-mediated Ca 2+ release

Objective Caffeine reduces toxic Ca2+ signals in pancreatic acinar cells via inhibition of inositol 1,4,5-trisphosphate receptor (IP3R)-mediated signalling, but effects of other xanthines have not been evaluated, nor effects of xanthines on experimental acute pancreatitis (AP). We have determined effects of caffeine and its xanthine metabolites on pancreatic acinar IP3R-mediated Ca2+ signalling and experimental AP. Design Isolated pancreatic acinar cells were exposed to secretagogues, uncaged IP3 or toxins that induce AP and effects of xanthines, non-xanthine phosphodiesterase (PDE) inhibitors and cyclic adenosine monophosphate and cyclic guanosine monophosphate (cAMP/cGMP) determined. The intracellular cytosolic calcium concentration ([Ca2+]C), mitochondrial depolarisation and necrosis were assessed by confocal microscopy. Effects of xanthines were evaluated in caerulein-induced AP (CER-AP), taurolithocholic acid 3-sulfate-induced AP (TLCS-AP) or palmitoleic acid plus ethanol-induced AP (fatty acid ethyl ester AP (FAEE-AP)). Serum xanthines were measured by liquid chromatography-mass spectrometry. Results Caffeine, dimethylxanthines and non-xanthine PDE inhibitors blocked IP3-mediated Ca2+ oscillations, while monomethylxanthines had little effect. Caffeine and dimethylxanthines inhibited uncaged IP3-induced Ca2+ rises, toxin-induced Ca2+ release, mitochondrial depolarisation and necrotic cell death pathway activation; cAMP/cGMP did not inhibit toxin-induced Ca2+ rises. Caffeine significantly ameliorated CER-AP with most effect at 25 mg/kg (seven injections hourly); paraxanthine or theophylline did not. Caffeine at 25 mg/kg significantly ameliorated TLCS-AP and FAEE-AP. Mean total serum levels of dimethylxanthines and trimethylxanthines peaked at >2 mM with 25 mg/kg caffeine but at <100 µM with 25 mg/kg paraxanthine or theophylline. Conclusions Caffeine and its dimethylxanthine metabolites reduced pathological IP3R-mediated pancreatic acinar Ca2+ signals but only caffeine ameliorated experimental AP. Caffeine is a suitable starting point for medicinal chemistr