ABSTRACT
Objective A 2-PSU/ RR parallel ankle rehabilitation robot was designed, and the biomechanical properties of human muscles were also analyzed, so as to study rehabilitation strategy of the ankle rehabilitation robot. Methods The actual workspace of the robot was obtained by numerical discrete search method, and the effect of structural parameter changes on the height of robot moving platform was explored. Then the human biomechanical responses such as muscle force and muscle mobility were obtained by human biomechanical simulation software AnyBody, so as to investigate the effect of moving platform height changes on muscle behavior. Results The robot could meet the demand of ankle plantarflexion/ dorsiflexion and inversion/ eversion motion. Appropriately increasing the initial inclination angle and decreasing the length of the fixed-length bar enabled the ankle rehabilitation robot to have a lower overall height. The height of the moving platform was decreased by 10 mm in turn, and the muscle force and muscle activity of the human body involved in the movement were decreased to a certain extent. Conclusions This study provides a new design solution for ankle rehabilitation, offers theoretical guidance for motion analysis of the ankle rehabilitation robot, and accelerates rehabilitation of the patients’ ankles by modifying the mechanism parameters.
ABSTRACT
A microbial fuel cell (MFC)-based microbial electrochemical sensor was developed for real-time on-line monitoring of heavy metals in water environment. The microbial electrochemical sensor was constructed with staggered flow distribution method to optimize the parameters such as external resistance value and external circulation rate. The inhibition of concentration of simulated heavy metal wastewater on voltage under optimal parameters was analyzed. The results showed that the best performance of MFC electrochemical sensor was achieved when the external resistance value was 130 Ω and the external circulation rate was 1.0 mL/min. In this case, the microbial electrochemical sensors were responsive to 1-10 mg/L Cu2+, 0.25-1.25 mg/L Cd2+, 0.25-1.25 mg/L Cr6+ and 0.25-1.00 mg/L Hg2+ within 60 minutes. The maximum rejection rates of the output voltage were 92.95%, 73.11%, 82.76% and 75.80%, respectively, and the linear correlation coefficients were all greater than 0.95. In addition, the microbial electrochemical sensor showed a good biological reproducibility. The good performance for detecting heavy metals by the newly developed microbial electrochemical sensor may facilitate the real-time on-line monitoring of heavy metals in water environment.
Subject(s)
Bioelectric Energy Sources , Electrodes , Metals, Heavy/analysis , Reproducibility of Results , Wastewater , WaterABSTRACT
Polyethylene glycol(PEG) with good hydrophilicity and flexibility can improve pharmacokinetic and pharmacodynamic properties of the nano-preparation,so PEG modification in the surface of nano-preparation can increase the in vivo residence time and concentration of drugs.At present,the targeted nano-preparation with PEG modification has become a research hotspot in the field of pharmaceutics.In this paper,the physical and chemical methods of PEG modification in targeted nano-preparation was summarized,which includes physically inserting PEG-lipid derivatives in nanostructure of targeted nano-preparation or modifying PEG with targeted nano-preparation.In addition,the influence of PEG parameters (molecular mass,modified density and spatial conformation) on properties of targeted nano-preparation was also discussed,which is important to preferably structure PEGylated targeted nano-preparation.
ABSTRACT
Objective The aim of this study was to evaluate the role of multicriteria optimization (MCO) in planning of intensity-modulated radiotherapy (IMRT).Methods Twenty IMRT patients (ten with prostate and ten with lung cancers) were randomly selected.For these patients,the treatment plans were designed with direct machine parameter optimization (DMPO).Based on these plans,new plans were designed with MCO,while keeping the setting conditions unchanged.Comparison was made between the two plans including the dose distribution,the dose volume histogram,the time of optimization and number of monitor unit (MU),but were play by pairing-t test.Results The plan designed in both optimizations satisfied all clinical requirements.For the same or better target coverage,rectum,bladder and small bowel were better with MCO compared with DMPO,MCO reduced 58％ of the time for optimization by average while MU increased 32％ by average for prostate cancer.For lung cancer,the whole lung,heart and spinal cord were better with MCO compared with DMPO,MCO reduced 59％ of the time for optimization by average while MU increased 11％ by average.Conclusions In comparison with DMPO,MCO reduces the dose of organs at risk,shorten the time of optimization.
ABSTRACT
The aim of this work was to study the effect of some nutritional and environmental factors on the production of cellulases, in particular endoglucanase (CMCase) and exoglucanases (FPase) from Bacillus licheniformis MVS1 and Bacillus sp. MVS3 isolated from an Indian hot spring. The characterization study indicated that the optimum pH and temperature value was 6.5 to 7.0 and 50-55°C, respectively. Maximum cellulases production by both the isolates was detected after 60 h incubation period using wheat and rice straw. The combination of inorganic and organic nitrogen source was suitable for cellulases production. Overall, FPase production was much higher than CMCase production by both of the strains. Between the two thermophiles, the cellulolytic activity was more in B.licheniformis MVS1 than Bacillus sp. MVS3 in varying environmental and nutritional conditions.
ABSTRACT
Background and purpose:Indensity modulated radiotherapy(IMRT) is an advanced method in radiotherapy field.Divect machine optimization technique is an good aritmetic for IMRT optimization.The purpose of this study was to compare the dosimetric differences between traditional technique and direct machine parameter optimization(DMPO) technique in the treatment of nasopharyngeal carcinoma(NPC) using step and shoot IMRT.Methods:Eleven patients of(NPC) were treated with step and shoot IMRT in Cancer Hospital,Fudan University from Feb.2005 to May 2006.Their plans(original plan,defined as treat) were archived for comparing with four kinds of IMRT plans(defined as DMPO100,DMPO90,DMPO80,DMPO70) with different predefined maximum number of segments(100,90,80,70,respectively),which were designed to use direct machine parameter optimization(DMPO) technique.We compared the total monitor units(MU),total segments,dose distribution and conformity index among the plans.Results:All the plans showed similar target coverage.Compared with traditional technique,IMRT plans with DMPO technique showed higher conformity index,and had similar uniformity except plan DMPO70.The dose distributions of DMPO100 and DMPO90 were similar or superior to the original plan(treat) in terms of critical organs.Without sacrificing plan quality,the total segments were about half of traditional plan if DMPO technique was used for planning.Moreover,the total monitor units(MUs) and the radiation time were decreased.Conclusions:Compared with traditional technique,plans designed with DMPO technique show sharp decrease in total segments without sacrificing plans quality in the treatment of nasopharyngeal carcinoma(NPC).The DMPO technique can also decrease the total MUs and radiation time.
ABSTRACT
The phosphoprotein gene of vesicular stomatitis virus, a Rhabdovirus, has been inserted into bacterial expression plasmids containing the Escherichia coli tac promoter and ribosome binding site (RBS). A low level of expression of the protein was detected. Sequence analysis showed the presence of 15 nucleotides in the spacer region i.e., between the Shine- Dalgarno sequence and ATG. Alteration of the distance and the sequence in the spacer region by oligonucleotide-directed mutagenesis revealed a correlation among the expression levels, accessibility of the RBS and requirement for a minimum spacing of at least 7 nucleotides between the Shine-Dalgarno sequence and ATG for optimal gene expression.