VOx Matrix Confinement Approach to Generate Sub-3 nm L10-Pt-Based Intermetallic Catalysts for Fuel Cell Cathode.

Pt-based intermetallic compounds (IMCs) are considered as a class of promising fuel cell electrocatalysts, owing to their outstanding intrinsic activity and durability. However, the synthesis of uniformly dispersed IMCs with small sizes presents a formidable challenge during the essential high-temperature annealing process. Herein, a facile and generally applicable VOx matrix confinement strategy is demonstrated for the controllable synthesis of ordered L10-PtM (M = Fe, Co, and Mn) nanoparticles, which not only enhances the dispersion of intermetallic nanocrystals, even at high loading (40 wt%), but also simplifies the oxide removal and acid-washing procedures. Taking intermetallic PtCo as an example, the as-prepared catalyst displays a high-performance oxygen reduction activity (mass activity of 1.52 A mgPt -1) and excellent stability in the membrane electrode assemblies (MEAs) (the ECSA has just 7% decay after durability test). This strategy provides an economical and scalable route for the controlled synthesis of Pt-based intermetallic catalysts, which can pave a way for the commercialization of fuel cell technologies.

Lipopeptides from Bacillus velezensis induced apoptosis-like cell death in the pathogenic fungus Fusarium concentricum.

AIMS: Stem rot caused by Fusarium concentricum is a new disease of Paris polyphylla reported by our research group. The present study investigates the growth inhibitory and apoptotic effects of Bacillus velezensis FJAT-54560 lipopeptide against F. concentricum. METHODS AND RESULTS: HPLC preparation and LC-MS analysis results show that the crude lipopeptides secreted by Bacillus velezensis FJAT-54560 isolated from Jasminum sambac consist of C14-17 iturin A, C14 fengycin B, C16 fengycin A/A2, C18 fengycin A, C20 fengycin B2, C21 fengycin A2, C22-23 fengycin A, C12-16 surfactin A, and C15 surfactin A derivatives. The mass ratios (g/g) of iturin, fengycin, and surfactin in lipopeptides are 2.40, 67.51, and 30.08%, respectively. Through inhibition zone and inhibition rate experiments, we found that crude lipopeptides and purified fengycin exhibit strong antifungal activity against F. concentricum, including accumulation of reactive oxygen species, loss of mitochondrial membrane potential, DNA fragmentation, Ca2+ accumulation, chromatin condensation, and phosphatidylserine externalization. Transcriptomic analysis indicates that crude lipopeptide-induced apoptosis in F. concentricum cells may be mediated by apoptosis-inducing factors and apoptosis mediators and can serve as a metacaspase-independent model. CONCLUSION: Lipopeptides from Bacillus velezensis FJAT-54560 can control the pathogenic fungus F. concentricum by inducing apoptosis.

Antifungal activities of Bacillus velezensis FJAT-52631 and its lipopeptides against anthracnose pathogen Colletotrichum acutatum.

This study was aim at investigating antifungal activities of Bacillus velezensis FJAT-52631 and its lipopeptides against Colletotrichum acutatum ex situ and in situ. The results showed that the strain FJAT-52631 and its crude lipopeptides (10 mg/ml) exhibited strong inhibitory effects on growth of C. acutatum FJAT-30256 with an inhibition rate of 75.3% and an inhibition zone diameter of 17.66 mm, respectively. Both the viable bacterial cultures and lipopeptides of FJAT-52631 could delay the onset of loquat anthracnose by 1 day and lower the incidence of loquat anthracnose in situ. The whole cultures of B. velezensis FJAT-52631 displayed a 50% biocontrol efficacy on loquat anthracnose at the fourth day after inoculation, but the crude lipopeptides not. The average lesion diameter of the whole-culture treated group was 5.62 mm, which was smaller than that of control group (6.81 mm). All the three types of lipopeptides including iturin A, fengycin, and surfactin A secreted from the strain FJAT-52631 exhibited antifungal activities. Among them, surfactin A displayed higher antifungal activity at a concentration of 1.25 mg/mL than other two lipopeptides even if at a concentration of 60 mg/mL. Thus, the results indicated that surfactin A produced by FJAT-52631 played a major role in the biocontrol of the loquat anthracnose. Scanning electron microscopy (SEM) observation revealed the structural deformities in the mycelia of C. acutatum. The above results suggested that the antifungal lipopeptides from B. velezensis FJAT-52631 would be potential in biocontrol against anthracnose disease of loquat caused by C. acutatum.

Osteopontin-induced lncRNA HOTAIR expression is involved in osteoarthritis by regulating cell proliferation.

BACKGROUND: Osteopontin plays critical roles in osteoarthritis (OA) by regulating the functions of osteoclasts. It is known that osteopontin can induce the expression of lncRNA HOX transcript antisense RNA (HOTAIR), indicating the involvement of HOTAIR in OA. This study was carried out to investigate the role of HOTAIR in OA. METHODS: Synovial fluid was extracted from both OA patients (n = 58) and healthy controls (n = 58). Expression of osteopontin and HOTAIR in synovial fluid was determined by RT-qPCR. Osteopontin was used to treat chondrocytes at dosages of 0, 1, 5 and 10 µg/ml, followed by measurement of HOTAIR expression by RT-qPCR. The role of osteopontin and HOTAIR overexpression, as well as HOTAIR knockdown in regulating the proliferation of chondrocytes was analyzed by cck-8 assay. RESULTS: HOTAIR was upregulated in OA. A positive correlation between HOTAIR and osteopontin was observed. In the primary chondrocytes, osteopontin treatment increased HOTAIR expression, while HOTAIR overexpression and knockdown failed to significantly affect osteopontin expression. In addition, osteopontin and HOTAIR overexpression increased chondrocyte proliferation, while HOTAIRE knockdown decreased chondrocyte proliferation. In addition, HOTAIR knockdown reduced the effects of osteopontin treatment on cell proliferation. CONCLUSIONS: Osteopontin-induced HOTAIR expression is involved in osteoarthritis by regulating cell proliferation.

Comparing the efficacy of pain managements after total hip arthroplasty: A network meta-analysis.

The aim of our current study is to compare efficiency of various interventions implemented for pain management after total hip arthroplasty (THA). PubMed and EMBASE were searched for randomized clinical trials (RCTs) reporting the pain scales for evaluate the efficacy of pain control after THA including at least one pair of direct control groups. Pain scale values and the associated 95% credible interval (CrI) were used to describe efficacy. Surface under the cumulative ranking curve (SUCRA) of each means of pain control was calculated to compare the relative ranking of different interventions. Thirty-five eligible literatures were involved in data analysis. The interventions for postoperative pain management we examined were psoas compartment block (PCB), posterior nerve block (PNB), fascia iliaca block (FIB), periarticular injection (PAI), femoral nerve block (FNB), lumbar plexus block (LPB), spinal anesthesia (SA), epidural analgesia (EPI), intrathecal morphine (IA), intravenous patient-controlled analgesia (IV-PCA), patient-controlled analgesia (PCA), onsteroidal anti-inflammatory drug (NSAID), local infiltration analgaesia (LIA), and reverse LIA (rLIA). In 0 to 6 hours analysis, patients under SA were found to have significantly lower pain score and SA was ranked the best. In 6 to 12 hours analysis, SA was found to be significantly more effective than other interventions and its SUCRA was the highest. No intervention showed a significant effect on reducing pain score for 12 to 24 hours and 24 to 48 hours after THA. SA is the best intervention to reduce THA postoperative pain in the first 24 hours. LPB is a better choice to reduce pain 12 to 48 hours after THA.

Surgical site infection following elective orthopaedic surgeries in geriatric patients: Incidence and associated risk factors.

The purposes of this study were to investigate the incidence of surgical site infection (SSI) following geriatric elective orthopaedic surgeries and identify the associated risk factors This was a retrospective two-institution study. Between January 2014 and September 2017, patients aged 60 years or older undergoing elective orthopaedic surgeries were included for data collection and analysis. SSI was identified through the review of patients' medical records for the index surgery and through the readmission diagnosis of SSI. Patients' demographics, characteristics of disease, surgery-related variables, and laboratory examination indexes were inquired and documented. Univariate and multivariate logistic analyses were performed to determine independent risk factors for SSI. There were 4818 patients undergoing elective orthopaedic surgeries, and within postoperative 1 year, 74 patients were identified to develop SSIs; therefore, the overall incidence of SSI was 3.64%, with 0.4% for deep and 1.1% for superficial infection. Staphylococcus aureus (25/47, 53.2%) and coagulase-negative staphylococci (11/47, 23.4%) were the most common causative pathogens; half of S. aureus SSIs were caused by Methicillin-resistant Staphylococcus aureus (MRSA) (12/25, 48.0%). Five risk factors were identified to be independently associated with SSI, including diabetes mellitus (odds ratio [OR], 3.7; 95% confidence interval [95% CI], 1.7-5.6), morbid obesity (OR, 2.6; 95% CI, 1.3-3.9), tobacco smoking (OR, 4.2; 95% CI, 2.1-6.4), surgical duration>75th percentile (OR, 1.9; 95% CI, 1.0-2.9), and ALB < 35.0 g/L (OR, 2.3; 95% CI, 1.3-3.4). We recommend the optimisation of modifiable risk factors such as morbid obesity, tobacco smoking, and lower serum albumin level prior to surgeries to reduce the risk of SSI.

Intrathecal injection of lentivirus-mediated glial cell line-derived neurotrophic factor RNA interference relieves bone cancer-induced pain in rats.

Bone cancer pain is a common symptom in cancer patients with bone metastases and the underlying mechanisms are largely unknown. The aim of this study is to explore the endogenous analgesic mechanisms to develop new therapeutic strategies for bone-cancer induced pain (BCIP) as a result of metastases. MRMT-1 tumor cells were injected into bilateral tibia of rats and X-rays showed that the area suffered from bone destruction, accompanied by an increase in osteoclast numbers. In addition, rats with bone cancer showed apparent mechanical and thermal hyperalgesia at day 28 after intratibial MRMT-1 inoculation. However, intrathecal injection of morphine or lentivirus-mediated glial cell line-derived neurotrophic factor RNAi (Lvs-siGDNF) significantly attenuated mechanical and thermal hyperalgesia, as shown by increases in paw withdrawal thresholds and tail-flick latencies, respectively. Furthermore, Lvs-siGDNF interference not only substantially downregulated GDNF protein levels, but also reduced substance P immunoreactivity and downregulated the ratio of pERK/ERK, where its activation is crucial for pain signaling, in the spinal dorsal horn of this model of bone-cancer induced pain. In this study, Lvs-siGDNF gene therapy appeared to be a beneficial method for the treatment of bone cancer pain. As the effect of Lvs-siGDNF to relieve pain was similar to morphine, but it is not a narcotic, the use of GDNF RNA interference may be considered as a new therapeutic strategy for the treatment of bone cancer pain in the future.

Reporting form and content of research priorities identified in knee osteoarthritis clinical practice guidelines: a methodological literature analysis.

OBJECTIVES: Clinical practice guideline (CPG) developers conduct systematic summaries of research evidence, providing them great capacity and ability to identify research priorities. We systematically analysed the reporting form and content of research priorities in CPGs related to knee osteoarthritis (KOA) to provide a valuable reference for guideline developers and clinicians. DESIGN: A methodological literature analysis was done and the characteristics of the reporting form and the content of the research priorities identified in KOA CPGs were summarised. DATA SOURCES: Six databases (PubMed, Embase, China National Knowledge Infrastructure, VIP Database for Chinese Technical Periodicals, Wanfang and Chinese Biomedical Literature Database) were searched for CPGs published from 1 January 2017 to 4 December 2022. The official websites of 40 authoritative orthopaedic societies, rheumatology societies and guideline development organisations were additionally searched. ELIGIBILITY CRITERIA: We included all KOA CPGs published in English or Chinese from 1 January 2017 that included at least one recommendation for KOA. We excluded duplicate publications, older versions of CPGs as well as guidance documents for guideline development. DATA EXTRACTION AND SYNTHESIS: Reviewers worked in pairs and independently screened and extracted the data. Descriptive statistics were used, and absolute frequencies and proportions of related items were calculated. RESULTS: 187 research priorities reported in 41 KOA CPGs were identified. 24 CPGs reported research priorities, of which 17 (41.5%) presented overall research priorities for the entire guideline rather than for specific recommendations. 110 (58.8%) research priorities were put forward due to lack of evidence. Meanwhile, more than 70% of the research priorities reflected the P (population) and I (intervention) structural elements, with 135 (72.2%) and 146 (78.1%), respectively. More than half of the research priorities (118, 63.8%) revolved around evaluating the efficacy of interventions. Research priorities primarily focused on physical activity (32, 17.3%), physical therapy (30, 16.2%), surgical therapy (27, 14.6%) and pharmacological treatment (26, 14.1%). CONCLUSIONS: Research priorities reported in KOA CPGs mainly focused on evaluating non-pharmacological interventions. There exists considerable room for improvement for a comprehensive and standardised generation and reporting of research priorities in KOA CPGs.

Construction of an S-scheme electron transfer channel in Cu0/CuFe2O4 magnetic plate column reactor for the LEV degradation: New strategy of visible Photo-Fenton system application.

The complicated loading process and easy falling off of powder catalysts still restrict the wide application of Photo-Fenton technology in practical water treatment. In this study, a magnetic fixed film plate column water treatment equipment is designed as a visible Photo-Fenton reactor to remove levofloxacin (LEV). The effect of magnetic force can ensure that the catalyst is firmly fixed, and the multi-level shallow column plate structure achieves full contact and efficient reaction between the catalyst and wastewater. Simultaneously, the Cu0/CuFe2O4 (STCCF) utilizes Cu0 to construct an S-scheme electron transfer channel, which improves the separation efficiency of photo-generated carriers and provides sufficient photo-generated electrons for the reduction of Fe (Ⅲ) and Cu (Ⅱ). The pseudo-first-order reaction kinetic constant k for the degradation of LEV in the visible Photo-Fenton system is 0.0349 min-1, which is 15.9 times that of the photocatalytic system and 4.8 times that of the Fenton system. After continuous operation for 72 h, the magnetic fixed film plate column reactor can still remove more than 90 % of LEV and 82 % of COD in the secondary effluent of simulated antibiotic pharmaceutical wastewater treatment process, and the effluent is stable and meets the standard. The magnetic fixed film plate column reactor can be used for advanced treatment of antibiotic pharmaceutical wastewater. This study provides a new insight into the application of the Photo-Fenton process.

Lipopeptide C17 Fengycin B Exhibits a Novel Antifungal Mechanism by Triggering Metacaspase-Dependent Apoptosis in Fusarium oxysporum.

Fusarium wilt is a worldwide soil-borne fungal disease caused by Fusarium oxysporum that causes serious damage to agricultural products. Therefore, preventing and treating fusarium wilt is of great significance. In this study, we purified ten single lipopeptide fengycin components from Bacillus subtilis FAJT-4 and found that C17 fengycin B inhibited the growth of F. oxysporum FJAT-31362. We observed early apoptosis hallmarks, including reactive oxygen species accumulation, mitochondrial dysfunction, and phosphatidylserine externalization in C17 fengycin B-treated F. oxysporum cells. Further data showed that C17 fengycin B induces cell apoptosis in a metacaspase-dependent manner. Importantly, we found that the expression of autophagy-related genes in the TOR signaling pathway was significantly upregulated; simultaneously, the accumulation of acidic autophagy vacuoles in F. oxysporum cell indicated that the autophagy pathway was activated during apoptosis induced by C17 fengycin B. Therefore, this study provides new insights into the antifungal mechanism of fengycin.

Emphasis should be placed on identifying and reporting research priorities to increase research value: An empirical analysis.

OBJECTIVES: To compared the presentation of research priorities in the GRADE (Grading of Recommendations Assessment, Development, and Evaluation) clinical practice guidelines (CPGs) developed under the guidance of the GRADE working group or its two co-chair, and the Chinese CPGs. METHODS: This was a methodological empirical analysis. We searched PubMed, Embase, and four Chinese databases (Wanfang, VIP Database for Chinese Technical Periodicals, China National Knowledge Infrastructure and Chinese Biomedical Literature Database) and retrieved nine Chinese guideline databases or Society websites as well as GRADE Pro websites. We included all eligible GRADE CPGs and a random sample of double number of Chinese CPGs, published 2018 to 2022. The reviewers independently screened and extracted the data, and we summarized and analyzed the reporting on the research priorities in the CPGs. RESULTS: Of the 135 eligible CPGs (45 GRADE CPGs and 90 Chinese CPGs), 668, 138 research priorities were identified respectively. More than 70% of the research priorities in GRADE CPGs and Chinese CPGs had population and intervention (PI) structure. 99 (14.8%) of GRADE CPG research priorities had PIC structures, compared with only 4(2.9%) in Chinese. And 28.4% (190) GRADE CPG research priorities reflected comparisons between PICO elements, approximately double those in Chinese. The types of research priorities among GRADE CPGs and Chinese CPGs were mostly focused on the efficacy of interventions, and the type of comparative effectiveness in the GRADE research priorities was double those in Chinese. CONCLUSIONS: There was still considerable room for improvement in the developing and reporting of research priorities in Chinese CPGs. Key PICO elements were inadequately presented, with more attention on intervention efficacy and insufficient consideration given to values, preferences, health equity, and feasibility. Identifying and reporting of research priorities deserves greater effort in the future.

Medial patellofemoral ligament reconstruction using a digital tensiometer to determine graft tension: Surgical technique and mid-term follow-up.

PURPOSE: The optimal method for achieving proper graft tension during patellofemoral ligament reconstruction is a topic of debate. In the past, a digital tensiometer was used to simulate the knee structure, and a tension of approximately 2N was identified as suitable for restoring the patellofemoral track. However, it is unclear whether this tension level is sufficient during the actual surgery. The objective of this study was to verify the efficacy of graft tension using a digital tensiometer for medial patellofemoral ligament (MPFL) reconstruction and to conduct a mid-term follow-up. METHODS: The study enrolled 39 patients who had experienced recurrent patellar dislocation. Preoperative computed tomography scans and X-rays confirmed patellar instability, patellar tilt angle patellar congruence angle and the history of dislocation and patellar apprehension test. Knee function was evaluated using preoperative and postoperative Lysholm and Kujala scores. RESULTS: The study included 39 knees, comprising 22 females and 17 males, with an average age of 21.10 ± 7.26. The patients were followed up for at least 24 months through telephone or face-to-face questionnaires. All patients had a preoperative history of ≥2 patellar dislocations, none of which were surgically treated. During surgery, all patients underwent isolated MPFL reconstruction and lateral retinacula release. The mean Kujala and Lysholm scores were 91.28 ± 4.90 and 90.67 ± 5.15, respectively. The mean PTA and PCA were 11.5 ± 2.63 and 2.38 ± 3.58, respectively. The study found that a tension of approximately 27.39 ± 5.57N (14.3-33.5N) was required to restore the patellofemoral track in patients with recurrent patellar dislocation. No patients required reoperation during the follow-up period. Overall, 36 out of 39 patients (92.31%) reported no pain when completing daily activities at the last follow-up. CONCLUSION: In conclusion, a tension level of approximately 27.39 ± 5.57N is necessary to restore normal patellofemoral relationships during clinical practice, which indicates that using a tension of 2N is too low. The use of a tensiometer during patellofemoral ligament reconstruction is a more accurate and reliable surgical procedure for treating recurrent patellar dislocation.

[Systematic reviews of mini-invasive surgery versus standard approaches for total knee arthroplasty].

OBJECTIVE: To conduct a systematic review to compare the early efficacies of minimally invasive surgery (MIS) versus conventional approaches in TKA (total knee arthroplasty). METHODS: Randomized controlled trials (RCTs) and clinical controlled trials (CCTs) were retrieved from the databases of MEDLINE (1996.6 - 2010.12), EMBASE (1996.6 - 2010.12), PubMed (1996 - 2010.12) and Cochrane Library (Issue 2, 2012). Journal of Orthopedics (from establishment to December 2010) and Orthopedic Journal of China (from establishment to December 2010) were manually searched. Both RCTs and CCTs were included. The data were extracted by two reviewers with designed extraction form RevMan 4.2.8 software for data analysis. The criteria were as follows: (1) operative duration and reduced blood loss; (2) VAS (visual analog scale) score; (3) faster recovery of ROM (range of movement); (4) quadriceps muscle strength; (5) component positioning malalignment; (6) tibiofemoral angle; (7) rate of complications. RESULTS: A total of 18 RCTs were included. Compared with the standard TKA procedure, the MIS group had a longer operative duration (WMD (weighted mean difference) 14.16, 95%CI (confidence interval) (12.61, 15.71)); reduced blood loss (WMD 8.31, 95%CI (6.16, 10.46)); lower VAS score at Days 3-5 post-operation (WMD 4.99, 95%CI (4.19, 5.78)); better Mean Knee Society scores at Week 6 post-operation (WMD 4.99, 95%CI (4.19, 5.78)), improvement in ROM occurred more rapidly at Month 3 post-TKA (WMD 14.59, 95%CI (8.39, 20.80)). Although the differences were not statistically significant, tibiofemoral angle was more precise in the standard group and the rate of component malalignment occurred more frequently in the MIS group (WMD 0.20, 95%CI (-0.12, 0.52)) (RR 1.57, 95%CI (0.88, 2.83)). CONCLUSION: MIS leads to a faster recovery than conventional surgery with a shorter operative duration, a reduced blood loss, a lower VAS score and a faster recovery of ROM and quadriceps muscle strength. However, the rates of component malalignment and complications occur more frequently in the MIS group. Potential benefits in long-term survival rate and functional improvement require further investigations.

Boosting the activity and stability via synergistic catalysis of Co nanoparticles and MoC to construct a bifunctional electrocatalyst for high-performance and long-life rechargeable zinc-air batteries.

The high overpotential of the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER) leading to slow air cathode kinetics is still a major challenge for zinc-air batteries (ZABs), hindering the commercialization of ZABs. With the advantages of cost-effectiveness and feasibility of synthesis at room temperature, zeolite imidazole frameworks (ZIFs) are regarded as advanced precursors. But a majority of ZIF-derived catalysts show only one catalytic activity, which limits their performance in ZABs as well as the cycling stability. In addition, molybdenum carbide (MoC) is recognized as an excellent candidate for renewable energy conversion due to its good chemical resistance and thermal stability. Herein, we report a ZIF-67-derived Co/MoC-NC multiphase doped carbon bifunctional ORR/OER catalyst with multiple active sites for the cathode of ZABs. The synergistic catalysis of Co nanoparticles and MoC nanoparticles in Co/MoC-NC which are embedded in a thin layer of N-doped graphitic carbon and immobilized on N-doped graphitic carbon, respectively, demonstrates superior ORR catalytic performance and durability both under alkaline and acidic conditions (E1/2 = 0.87 V in 1.0 M KOH and E1/2 = 0.76 V in 0.5 M H2SO4). Simultaneously, Co/MoC-NC also exhibits favorable OER performance (10 mA cm-2, η = 320 mV) in 1 M KOH. Furthermore, a remarkable peak-power density of 215.36 mW cm-2 and great cycling stability could be achieved while applying Co/MoC-NC in the cathode of ZABs (over 300 h). This work will provide a viable design concept for designing and synthesizing multifunctional catalysts to construct rechargeable ZABs.

Adaptive neural tracking control of strict-feedback nonlinear systems with event-triggered state measurement.

This paper investigates the adaptive neural tracking control of the strict-feedback nonlinear systems, where the states are measured in an event-triggered manner so as to save the communication resources. As the neural networks (NNs) account for the unknown dynamics of the system, the minimum learning parameters (MLPs) are extracted from the weights of the NNs and the upper bounds of the disturbances. The estimates of the MLPs are updated in an event-triggered manner to ensure the approximation ability of the NNs and the stability of the closed-loop system. An adaptive neural model is established to substitute for the original strict-feedback system and direct the design of the backstepping-based control laws. The states of this adaptive model are reset to the measured states of the original system when the triggering condition is violated. The triggering condition is constructed in the compound form and with the adaptive threshold. The dead-zone operator is involved to avoid the accumulation of triggering instants. In this paper, we notice the problem of "jumps of virtual control laws" for the event-triggered control (ETC) in the backstepping frame, and a detailed formulaic definition is given in section 2.2. To solve this problem, the first-order filters are fabricated to provide the continuous substitutes for virtual control laws. In addition, the "complexity explosion" generated by direct differentiating of virtual control laws can be averted. Through the proposed scheme, the closed-loop system can be viewed as an impulsive dynamic system, and the semi-globally uniformly ultimate boundedness (SGUUB) of all the errors is proved. Finally, two examples validate the feasibility of the proposed control scheme.

Adaptive fuzzy tracking control for underactuated surface vessels with unmodeled dynamics and input saturation.

This paper investigates the tracking control of the underactuated surface vessel (USV) with the off-diagonal inertial matrix, and under the influence of unmodeled dynamics as well as the constraint of input saturation. With the fuzzy logic systems (FLSs) accounting for the uncertainties, we present an adaptive fuzzy state-feedback control scheme with the minimum learning parameters (MLPs) of the FLSs. Based on the conventional USV model described in three degrees of freedom (DOF), an improved model is established at first, which involves the terms of dynamic disturbances generated by the unmodeled dynamics of the indecisive motions. Then, the off-diagonal inertial matrix is released by restructuring the kinematic loop of the improved model, and the backstepping approach is employed through the control design. To solve the underactuated problem, the tracking error in the sway motion is restructured by adding an adaptive compensating variable and further allocated to the actuated motions. The K∞ functions are structured in the control laws to offset the dynamic disturbances. The Gauss error functions are employed to approximate the uncertainties of the input saturation, which are described by the continuous control inputs with the bounded multiplicative gains. Via the small-gain theorem, the resulting closed-loop system is proved to be ultimately bounded. Finally, a simulation example is carried out to validate the effectiveness of the developed scheme.

Model-Based Event-Triggered Tracking Control of Underactuated Surface Vessels With Minimum Learning Parameters.

This article studies the model-based event-triggered control (ETC) for the tracking activity of the underactuated surface vessel (USV). Following this ideology, the continuous acquisition of states is no longer needed, and the communication traffic is reduced in the channel of sensor to controller. The control laws are fabricated in the frame of an adaptive model, which is renewed with the states of the original system whenever the triggering condition is violated. In the scheme, both internal and external uncertainties are approximated by the neural networks (NNs). To decrease the computing complexity, the minimum learning parameters (MLPs) are involved both in the adaptive model and the derived controller. The adaptive laws of only two MLPs are devised, and their updating only happens at triggering instants. Using the MLPs, an adaptive triggering condition is further derived. To avoid the "Zeno" phenomenon in small tracking errors, a dead-zone operator is designed for the triggering condition. Furthermore, we incorporate the dynamic surface control (DSC) into the controller design, such that the jumping of virtual control laws at triggering instants is smoothed and the problem of "complexity explosion" is circumvented. Through the techniques of the impulsive dynamic system and the direct Lyapunov function, the parameter setting for the DSC is derived to guarantee the semiglobal uniformly ultimate boundedness (SGUUB) of all the error signals in the closed-loop system. Finally, the effectiveness of the proposed scheme is validated through the simulation.

N-trimethyl chitosan-coated multivesicular liposomes for oxymatrine oral delivery.

BACKGROUND: Multivesicular liposomes (MVLs), uncoated and coated with N-trimethyl chitosan (TMC), have been studied for their potential use for drug delivery by the oral route. METHOD: Synthesized TMC was characterized by infrared spectroscopy, revealing the presence of trimethyl groups, and by proton nuclear magnetic resonance spectroscopy, allowing the calculation of the degree of substitution quaternization (70.2%). Oxymatrine (OM), a natural quinolizidine alkaloid used clinically for treating hepatitis B, was chosen as a model drug. The surface-modified MVLs and uncoated MVLs were characterized in vitro in terms of their shape, size, zeta potential, entrapment efficiency, coating efficiency, the stability of MVLs in polymer suspension, and the stability in simulated gastric and intestinal fluids. RESULTS: In vivo, the area under the plasma concentration-time curve obtained from the pharmacokinetics study of TMC-coated MVLs was found to be about 3.26- and 1.96-fold higher than that of OM solution and uncoated MVLs, respectively. CONCLUSION: TMC-coated MVLs can be considered as a potential carrier for oral drug administration.

Effect of emodin on chondrocyte viability in an in vitro model of osteoarthritis.

Emodin is an anthraquinone isolated from the Chinese herb Radix et Rhizoma Rhei and has been used to treat various diseases for centuries. The aim of the present study was to investigate the effect of emodin on the inflammatory mediators in rat chondrocytes. In the present study, chondrocytes were isolated from rats, cultured and harvested when they reached generation P3. Cells were treated with different doses of emodin (10, 20, and 30 µg/ml) followed by interleukin 1ß (IL-1ß, 10 ng/ml). Control cells were either untreated or treated with IL-1ß alone. An enzyme-linked immunosorbent assay was used to measure levels of nitric oxide (NO) and prostaglandin E2 (PGE2). Reverse transcription-quantitative polymerase chain was performed to measure levels of matrix metallopeptidase (MMP)-3 and -13 mRNA. The expression of MMP-3, MMP-13, extracellular-signal regulatory kinase (ERK)1/2, phosphorylated ERK1/2 and ß-catenin proteins were detected by western-blot analysis. The results demonstrated that treatment with emodin treatment reduced the cytotoxicity of IL-1ß and inhibited the expression of NO and PGE2 in rat chondrocytes. Furthermore, emodin inhibited the expression of MMP3 and MMP13, and the phosphorylation of various proteins involved in the ERK and Wnt/ß-catenin pathway. Therefore, emodin is able to promote the proliferation of chondrocytes by inhibiting the ERK and Wnt/ß-catenin pathway and downregulating the expression of a series of inflammatory mediators in chondrocytes.

Preparation of submicron unilamellar liposomes by freeze-drying double emulsions.

A novel method is described for the preparation of sterile submicron unilamellar liposomes. The method is based on the lyophilization of double emulsions containing disaccharides as lyoprotectants in both the inner and outer aqueous phase. Using various phospholipids or mixtures of lipids as emulsifiers, the double emulsions can be prepared by a two-step emulsification, including hydrophilic agents in the inner aqueous phase or lipophilic agents in the oil phase. Then, the double emulsions are lyophilized after sterilization by passing them through a 0.22-microm pore filter. Rehydration of the lyophilized products results in liposomes with a relatively high encapsulation efficiency (for calcein, 87%; 5-fluorouracil, 19%; flurbiprofen, 93%) and a size below 200 nm measured by the dynamic light scattering technique (DLS) and the atomic force microscopy (AFM). The liposomes were found to be unilamellar from freeze-fracture electron micrographs and X-ray diffraction patterns. In addition, the liposomes can be reconstituted just before use by rehydration of the lyophilized products which are relatively stable. Thus, this reproducible and simple technique can be used to prepare sterilized, submicron unilamellar liposomes with a relatively high encapsulation efficiency, and excellent stability during long-term storage.