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1.
Micromachines (Basel) ; 12(9)2021 Sep 18.
Article in English | MEDLINE | ID: mdl-34577767

ABSTRACT

In the field of robotic hand design, soft body and anthropomorphic design are two trends with a promising future. Designing soft body anthropomorphic robotic hands with human-like grasping ability, but with a simple and reliable structure, is a challenge that still has not been not fully solved. In this paper, we present an anatomically correct robotic hand 3D model that aims to realize the human hand's functionality using a single type of 3D-printable material. Our robotic hand 3D model is combined with bones, ligaments, tendons, pulley systems, and tissue. We also describe the fabrication method to rapidly produce our robotic hand in 3D printing, wherein all parts are made by elastic 50 A (shore durometer) resin. In the experimental section, we show that our robotic hand has a similar motion range to a human hand with substantial grasping strength and compare it with the latest other designs of anthropomorphic robotic hands. Our new design greatly reduces the fabrication cost and assembly time. Compared with other robotic hand designs, we think our robotic hand may induce a new approach to the design and production of robotic hands as well as other related mechanical structures.

2.
J Environ Sci (China) ; 100: 340-352, 2021 Feb.
Article in English | MEDLINE | ID: mdl-33279048

ABSTRACT

This study aimed to explore the adsorption performance of sludge-based activated carbon (SBC) towards dissolved organic matters (DOMs) removal from sewage, and investigated the modification effect of different types of chemicals on the structure of synthesized SBC. Waste activated sludge (WAS) was used as a carbon source, and HCl, HNO3, and NaOH were used as different types of chemicals to modify the SBC. With the aid of chemical activation, the modified SBC showed higher adsorption performances on DOMs removal with maximum adsorption of 29.05 mg/g and second-order constant (k) of 0.1367 (L/mol/sec) due to the surface elution of ash and minerals by chemicals. The surface elemental composition of MSBC suggested that the content of C-C and C-O functional groups on the surface of modified sludge-based activated carbon (MSBC) played an important role on the adsorption capacities of MSBC towards DOMs removal in sewage. Additionally, the residual molecular weight of DOMs in sewage was investigated using a 3-dimension fluorescence excitation-emission matrix (3D-EEM) and high-performance size exclusion chromatography (HP-SEC). Results showed that the chemical modification significantly improved the adsorption capacity of MSBC on humic acids (HA) and aromatic proteins (APN), and both of NaOH-MSBC and HCl-MSBC were effective for a wide range of different AMW DOMs removal from sewage, while the HNO3-MSBC exhibited poorly on AMW organics of 2,617 Da and 409 Da due to the reducing content of macropore. In brief, this study provides reference values for the impact of the chemicals of the activation stage before the SBCs application.


Subject(s)
Sewage , Water Pollutants, Chemical , Adsorption , Charcoal , Humic Substances
3.
Am J Chin Med ; 33(6): 935-43, 2005.
Article in English | MEDLINE | ID: mdl-16355450

ABSTRACT

A rapid and simple high-performance liquid chromatographic method for determination of berberine in rat thalamus was described in this study. Thalamus samples were pretreated by protein precipitation with methanol and acetonitrile. Berberine was determined using a Hypersil C(18) column with an isocratic mobile phase of acetonitrile--0.05 M potassium dihydrogen phosphate (containing 0.5% triethylamine, pH 3.0) (30:70 v/v) and with UV detection at 265 nm. The lower limit of quantification for berberine in thalamus was 24 ng/ml, and the lowest concentration of berberine determined in rat thalamus samples was 47.5 ng/ml at 48 hours. The calibration curve for berberine was linear (r(2) = 0.9994) over the concentration range 24-6000 ng/ml. At this concentration range, the overall recoveries (91.20%-93.24%) for berberine were determined and the accuracy of the intra- and inter-day assays from rat thalamus were less than 6% RSD. Following intravenous administration of 10.2 mg/kg of Coptidis Rhizoma (CR) extract containing 3 mg/kg berberine into rats, the thalamus level of berberine increased rapidly (t(1/2alpha) = 1.93 hours), peaked at 2.48 hours with a concentration of 271 ng/g, and had a slow elimination rate (t(1/2beta) = 14.6 hours), which suggested that berberine might directly act on certain regions of the thalamus, have pharmacological effects on some cerebral dysfunctions, and be an active ingredient of huang lian jie du tang for the treatment of cerebral disease.


Subject(s)
Berberine/pharmacokinetics , Drugs, Chinese Herbal/pharmacokinetics , Thalamus/metabolism , Animals , Chromatography, High Pressure Liquid , Coptis chinensis , Half-Life , Injections, Intravenous , Male , Molecular Structure , Rats , Rats, Wistar
4.
J Pharm Biomed Anal ; 37(2): 297-301, 2005 Feb 23.
Article in English | MEDLINE | ID: mdl-15708670

ABSTRACT

A new HPLC method for the determination of puerarin in cerebral ischemia reperfusion rat plasma is introduced. Puerarin, the principal bioactive component of puerariae radix isoflavone, was extracted from plasma by methanol. The HPLC separation was then performed on a reversed-phase C18 column using water-acetonitrile (89:11, v/v) as eluting solvent system, and UV detection at 252 nm to measure the analyte with a limit of quantitation about 9.44 ng ml(-1). The calibration curve for puerarin was linear (r=0.9998) in the concentration range of 9.44-1208.00 ng ml(-1), both intra- and inter-day precision of the puerarin were determined and their coefficient of variation did not exceed 10%. The validated method has been successfully applied for pharmacokinetic studies of puerarin from rat plasma after intravenous administration of puerariae radix isoflavone. Another novel finding of this study was that the elimination rate of puerarin was significantly slower in the cerebral ischemia reperfusion rat than in the normal rat, judging by the pharmacokinetic parameters obtained. Since puerariae radix isoflavone was mainly administrated to the patients suffering from cerebralvascular diseases, the pharmacokinetic studies performed on the pathological animal models were suitable references for clinical application.


Subject(s)
Brain Ischemia/blood , Drugs, Chinese Herbal/pharmacokinetics , Pueraria/chemistry , Reperfusion Injury/blood , Animals , Chromatography, High Pressure Liquid , Disease Models, Animal , Injections, Intravenous , Male , Metabolic Clearance Rate , Rats , Rats, Wistar , Reproducibility of Results , Sensitivity and Specificity
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