Kinematic Modeling of a Combined System of Multiple Mecanum-Wheeled Robots with Velocity Compensation.

In industry, combination configurations composed of multiple Mecanum-wheeled mobile robots are adopted to transport large-scale objects. In this paper, a kinematic model with velocity compensation of the combined mobile system is created, aimed to provide a theoretical kinematic basis for accurate motion control. Motion simulations of a single four-Mecanum-wheeled virtual robot prototype on RecurDyn and motion tests of a robot physical prototype are carried out, and the motions of a variety of combined mobile configurations are also simulated. Motion simulation and test results prove that the kinematic models of single- and multiple-robot combination systems are correct, and the inverse kinematic correction model with velocity compensation matrix is feasible. Through simulations or experiments, the velocity compensation coefficients of the robots can be measured and the velocity compensation matrix can be created. This modified inverse kinematic model can effectively reduce the errors of robot motion caused by wheel slippage and improve the motion accuracy of the mobile robot system.

Integration of Zn2+, ATP, and bFGF to Nanodressing with Core-Shell Structure Fabricated by Emulsion Electrospinning for Wound Healing.

Basic fibroblast growth factor (bFGF) plays an important role in active wound repair. However, the existing dosage forms in clinical applications are mainly sprays and freeze-dried powders, which are prone to inactivation and cannot achieve a controlled release. In this study, a bioactive wound dressing named bFGF-ATP-Zn/polycaprolactone (PCL) nanodressing with a "core-shell" structure was fabricated by emulsion electrospinning, enabling the sustained release of bFGF. Based on the coordination and electrostatic interactions among bFGF, ATP, and Zn2+, as well as their synergistic effect on promoting wound healing, a bFGF-ATP-Zn ternary combination system was prepared with higher cell proliferation activity and used as the water phase for emulsion electrospinning. The bFGF-ATP-Zn/PCL nanodressing demonstrated improved mechanical properties, sustained release of bFGF, cytocompatibility, and hemocompatibility. It increased the proliferation activity of human dermal fibroblasts (HDFs) and enhanced collagen secretion by 1.39 and 3.45 times, respectively, while reducing the hemolysis rate to 3.13%. The application of the bFGF-ATP-Zn/PCL nanodressing in mouse full-thickness skin defect repair showed its ability to accelerate wound healing and reduce wound scarring within 14 days. These results provide a research basis for the development and application of this bioactive wound dressing product.

Platinum-based drugs and hydrogel: a promising anti-tumor combination.

Platinum-based drugs are widely used as first-line anti-tumor chemotherapy agents. However, they also have nonnegligible side effects due to the free drugs in circulation. Therefore, it is necessary to develop efficient and safe delivery systems for better tumor cell targeting. Hydrogel is a promising anti-tumor drug carrier that can form a platinum/hydrogel combination system for drug release, which has shown better anti-tumor effects in some studies. However, there is a lack of systematic summary in this field. This review aims to provide a comprehensive overview of the platinum/hydrogel combination system with the following sections: firstly, an introduction of platinum-based drugs; secondly, an analysis of the platinum/hydrogel combination system; and thirdly, a discussion of the advantages of the hydrogel-based delivery system. We hope this review can offer some insights for the development of the platinum/hydrogel combination system for better cancer therapy.

Multigene engineering of medium-chain fatty acid biosynthesis in transgenic Arabidopsis thaliana by a Cre/LoxP multigene expression system.

Medium-chain fatty acids (MCFAs) are an ideal feedstock for biodiesel and a range of oleochemical products. In this study, different combinations of CnFATB3, CnLPAAT-B and CnKASI from coconut (Cocos nucifera L.) were coexpressed in transgenic Arabidopsis thaliana by a Cre/LoxP multigene expression system. Transgenic lines expressing different combinations of these genes were designated FL (FatB3 + LPAAT-B), FK (FatB3 + KASI) and FLK (FatB3 + LPAAT-B + KASI). The homozygous seeds of transgenic Arabidopsis thaliana expressing high levels of these genes were screened, and their fatty acid composition and lipid contents were determined. Compared with its content in wild-type A. thaliana, the lauric acid (C12:0) content was significantly increased by at least 395%, 134% and 124% in FLK, FL and FK seeds, respectively. Meanwhile, the myristic acid (C14:0) content was significantly increased by at least 383%, 106% and 102% in FL, FLK and FK seeds, respectively, compared to its level in wild-type seeds. Therefore, the FLK plants exhibited the best effects to increase the level of C12:0, and FL expressed the optimal combination of genes to increase the level of 14:0 MCFA.

Application of Ortho-Bridge Combination System in the treatment of ulnar impaction syndrome with ulna-shortening osteotomy / 中华创伤骨科杂志

Objective:To investigate the clinical outcomes of Ortho-Bridge Combination System (OBCS) to achieve precise ulna-shortening osteotomy (USO) in the treatment of ulnar impaction syndrome.Methods:A retrospective study was conducted to analyze the 25 patients with ulnar impaction syndrome who had been treated at Institute of Orthopedic Trauma Research, The 920th Hospital of Joint Logistic Support Force of Chinese People's Liberation Army between January 2020 to March 2022. The patients all underwent USO using OBCS. They were 14 females and 11 males with an age of (43.2 ± 10.1) years. Their CT scans were retrieved for preoperative planning and design of a personalized USO. Intraoperatively, OBCS was fixated to the ulna before USO. After the bone was resected according to preoperative planning, the gap between the osteotomy sites was closed with compression, and OBCS was finally fixated with locking screws. The time for bone union after resection, complications, range of motion and grip strength were recorded. The clinical outcomes were evaluated by visual analogue scale (VAS) and Mayo wrist score.Results:All patients completed their operations successfully using OBCS. Their follow-up time was (13.5 ± 1.2) months. The ulnar variation was corrected and osteotomy ends got united in all patients, without nonunion, angulation, or rotation. The wrist VAS significantly decreased from 6.0 (5.0, 6.5) points before operation to 2.0 (1.0, 2.0) points at the last follow-up ( P<0.05). At the last follow-up, the Mayo wrist score [(85.4 ± 8.9) points], grip strength [(39.4 ± 1.2) kg], wrist flexion-extension (111.9° ± 12.6°), wrist pronation-supination (133.2° ± 15.7°), and ulnar radial deviation (35.3° ± 2.8°) were significantly increased compared with the preoperative values [(69.2 ± 13.3) points, (31.3 ± 5.2) kg, 102.0° ± 16.0°, 128.0° ± 15.5°, and 32.2° ± 2.8°] ( P<0.05). Conclusion:In the treatment of ulnar impaction syndrome, OBCS can facilitate the process of USO, correct ulnar variance, and avoid complications like rotation and angulation to improve functions of the wrist.

Enhanced anti-cancer efficacy to cancer cells by doxorubicin loaded water-soluble amino acid-modified ß-cyclodextrin platinum complexes.

The effective targeted delivery of insoluble anticancer drugs to increase the intracellular drug concentration has become a focus in cancer therapy. In this system, two water-soluble amino acid-modified ß-cyclodextrin (ß-CD) platinum complexes were reported. They showed preferable binding ability to DNA and effective inhibition to cancer cells, and they could bind and unwind pBR322 DNA in a manner which was similar to cisplatin. Besides, our platinum complexes could effectively deliver the anticancer drug doxorubicin (Dox) into cells and had higher cell inhibition ratio, but less toxicity on the normal cells, compared with cancer cells. In this combination system, Dox was encapsulated into the hydrophobic cavities of ß-CD at the optimum molar ratio of 1:1, which were validated by UV-visible (UV-vis) absorption spectroscopy, fluorescence spectroscopy and MTT experiments. Moreover, the combination system had higher cell inhibition ratio than free Dox and amino acid-modified ß-CD platinum complexes, and the results of high content screening (HCS) showed that Dox-loaded amino acid-modified ß-CD platinum complexes could permeate the cell membrane and enter cells, suggesting the efficient transport of Dox across the membranes with the aid of the ß-CD. We expect that the amino acid-modified ß-CD platinum complexes will deliver the antitumor drug Dox to enhance intracellular drug accumulation and such combination system showed great potential as an antitumor drug.

Growth of Listeria monocytogenes and Pseudomonas fragi on Cooked Pork in a Modified Atmosphere Packaging/Nisin Combination System.

The influence of carbon dioxide (CO2) atmospheres combined with various nisin concentrations on the growth of Listeria monocytogenes Scott A and Pseudomonas fragi CCRC 10939 on cooked tenderloin pork stored at 4 and 20°C was investigated. Atmospheres employed were 100 and 80% CO2; and an air control. Pork tenderloins were steamed, cooled, and coinoculated with L. monocytogenes and P. fragi . Headspace composition of sample bags determined throughout storage at 4°C indicated that greater growth occurred on air-stored tenderloins than on modified atmosphere-stored (MA-stored) samples. Colony counts of P. fragi were appreciably reduced by the MA storage; however, the same pattern was not found in L. monocytogenes . Although P. fragi on cooked tenderloin was unaffected by nisin, the growth of L. monocytogenes was prevented when samples were treated with 1 × 104 nisin IU/ml. In addition, the modified atmosphere packaging (MAP) (100% CO2, 80% CO2 + 20% air)/nisin (103, 104 IU/ml) combination system used in this study decreased growth of both organisms, and this inhibitory effect for MAP/nisin combination system was more pronounced at 4°C than at 20°C. The concept of a Safety Index, which compares numbers of spoilage and pathogenic organisms, was also used as a measure of the relative safety of this MAP/nisin combination system.