Efficient RRT*-based Safety-Constrained Motion Planning for Continuum Robots in Dynamic Environments

Continuum robots, characterized by their high flexibility and infinite degrees of freedom (DoFs), have gained prominence in applications such as minimally invasive surgery and hazardous environment exploration. However, the intrinsic complexity of continuum robots requires a significant amount of time for their motion planning, posing a hurdle to their practical implementation. To tackle these challenges, efficient motion planning methods such as Rapidly Exploring Random Trees (RRT) and its variant, RRT*, have been employed. This paper introduces a unique RRT*-based motion control method tailored for continuum robots. Our approach embeds safety constraints derived from the robots' posture states, facilitating autonomous navigation and obstacle avoidance in rapidly changing environments. Simulation results show efficient trajectory planning amidst multiple dynamic obstacles and provide a robust performance evaluation based on the generated postures. Finally, preliminary tests were conducted on a two-segment cable-driven continuum robot prototype, confirming the effectiveness of the proposed planning approach. This method is versatile and can be adapted and deployed for various types of continuum robots through parameter adjustments

E3 ubiquitinase RNF138 inhibits the development of ulcerative colitis

Objective To explore the role of RNF138 (ring finger protein 138) in the ulcerative colitis (UC). Methods The expression of RNF138 in active, remission and ulcerative colitis upon immunosuppressive treatment was analyzed by GEO database. The UC model was constructed by RNF138-deficient mice. The pathological observation, histological analysis and colon measurement were performed by the model mice. The transcriptome analysis was employed by using mouse colon tissue samples. The expression levels of RNF138 and p-p65 in colon tissue of model mice were detected by immunohistochemistry and Western blots. The expression of target gene of NF-кB pathway was detected by qPCR. Immunohistochemistry was used to evaluate the expression of RNF138 and NF-кB p65 in clinical samples of UC. Results GEO database and clinical samples showed that the expression of RNF138 decreased in the samples of active UC as compared to that in the remission stage(P＜0.05). Knocking out RNF138 promoted the occurrence and progression of DSS induced UC (P＜0.05). Knocking out RNF138 promoted upregulation of p-p65 and its target gene expression(P＜0.05), indicating NF-кB signal pathway activation. Conclusions RNF138 inhibits the development of UC through suppressing the NF-кB genetic pathway

Folate-Functionalized Magnetic-Mesoporous Silica Nanoparticles for Drug/Gene Codelivery To Potentiate the Antitumor Efficacy

An appropriate codelivery system for chemotherapeutic agents and nucleic acid drugs will provide a more efficacious approach for the treatment of cancer. Combining gene therapy with chemotherapeutics in a single delivery system is more effective than individual delivery systems carrying either gene or drug. In this work, we developed folate (FA) receptor targeted magnetic-mesoporous silica nanoparticles for the codelivery of VEGF shRNA and doxorubicin (DOX) (denoted as M-MSN­(DOX)/PEI-FA/VEGF shRNA). Our data showed that M-MSN­(DOX)/PEI-FA could strongly condense VEGF shRNA at weight ratios of 30:1, and possesses higher stability against DNase I digestion and sodium heparin. <i>In vitro</i> antitumor activity assays revealed that HeLa cell growth was significantly inhibited. The intracellular accumulation of DOX by confocal microscopy and fluorescence spectrophotometry showed that M-MSN­(DOX)/PEI-FA were more easily taken up than nontargeted M-MSN­(DOX). Quantitative PCR and ELISA data revealed that M-MSN/PEI-FA/VEGF shRNA induced a significant decrease in VEGF expression as compared to cells treated with either the control or other complexes. The invasion and migration phenotypes of the HUVECs were significantly decrease after coculture with MSN/PEI-FA/VEGF shRNA nanocomplexes-treated HeLa cells. The approach provides a potential strategy to treat cancer by a singular nanoparticle delivery system

Combined Effect of Dynapenia and Abdominal Obesity on the Prevalence of Peripheral Artery Disease in Older Adults Over 75 Years Old in China

The objective is to examine the separate and joint effects of dynapenia and abdominal obesity on the prevalence of peripheral artery disease (PAD) in older adults of different ages (60-74 and over 75 years old). This study comprised 1293 community-dwelling Chinese participants recruited from Shanghai, China, who were aged at least 60 years (753 women; mean age: 72.0 ± 5.9 years). Dynapenia was defined as low-grip strength (<28.0 kg for males and <18.0 kg for females) but normal skeletal muscle index (≥7.0 kg/m 2 for males and ≥5.7 kg/m 2 for females). Abdominal obesity was determined according to waist circumference (≥90 cm for males and ≥85 cm for females), and PAD was diagnosed by an ankle-brachial index  ≤ 0.9. Binary logistic regression models were performed to determine associations between dynapenia, abdominal obesity, and the combination of dynapenia and abdominal obesity and PAD. According to dynapenia and abdominal obesity status stratified by age (60-74 or over 75), the patients were divided into 4 groups: normal, dynapenia alone, abdominal obesity alone, and co-occurring groups. A logistic regression showed that the co-occurring groups (odds ratio = 4.63, 95% confidence interval = 1.41-15.21) had a higher prevalence of PAD than the normal group after adjusting for the covariates in older adults over 75 years of age. The combination of dynapenia and abdominal obesity increase the prevalence of PAD in older adults over 75 years. The present findings have important implications for the early identification of older adults with PAD and appropriate interventions should be implemented

Hard nanocrystalline gold materials prepared via high-pressure phase transformation

As one of the important materials, nanocrystalline Au (n-Au) has gained numerous interests in recent decades owing to its unique properties and promising applications. However, most of the current n-Au thin films are supported on substrates, limiting the study on their mechanical properties and applications. Therefore, it is urgently desired to develop a new strategy to prepare nAu materials with superior mechanical strength and hardness. Here, a hard n-Au material with an average grain size of - 40 nm is prepared by cold-forging of the unique Au nanoribbons (NRBs) with unconventional 4H phase under high pressure. Systematic characterizations reveal the phase transformation from 4H to face-centered cubic (fcc) phase during the cold compression. Impressively, the compressive yield strength and Vickers hardness (H-v) of the prepared n-Au material reach similar to 140.2 MPa and similar to 1.0 GPa, which are 4.2 and 2.2 times of the microcrystalline Au foil, respectively. This work demonstrates that the combination of high-pressure cold-forging and the in-situ 4H-to-fcc phase transformation can effectively inhibit the grain growth in the obtained n-Au materials, leading to the formation of novel hard n-Au materials. Our strategy opens up a new avenue for the preparation of nanocrystalline metals with superior mechanical property