Extrinsic-Riveting Friction Stir Lap Welding of Al/Steel Dissimilar Materials.

To obtain high-quality joints of Al/steel dissimilar materials, a new extrinsic-riveting friction stir lap welding (ERFSLW) method was proposed combining the synthesis advantages of mechanical riveting and metallurgical bonding. SiC-reinforced Al matrix composite bars were placed in the prefabricated holes in Al sheets and steel sheets, arranged in a zigzag array. The bars were stirred and mixed with Al sheets under severe plastic deformation (SPD), forming composite rivets to strengthen the mechanical joining. SiC particles were uniformly dispersed in the lower part of the welding nugget zone (WNZ). The smooth transition between the SiC mixed zone and extrinsic-riveting zone (ERZ) ensured the metallurgical bonding. The maximum tensile shear load of the joints reached 7.8 kN and the maximum load of the weld per unit length was 497 N/mm. The fracture occurred at the interface between the rivets and steel sheets rather than the conventional Al/steel joining interface. Moreover, ERFSLW can prolong the service life of joints due to three fracture stages. This method can be further extended to the welding of other dissimilar materials that conform to the model of "soft/hard".

Fast Li+ Transport Polyurethane-Based Single-Ion Conducting Polymer Electrolyte with Sulfonamide Side chains in the Hard Segment for Lithium Metal Batteries.

Single-ion conducting polymer electrolytes (SICPEs) are considered as one of the most promising candidates for achieving lithium metal batteries (LMBs). However, the application of traditional SICPEs is hindered by their low ionic conductivity and poor mechanical stability. Herein, a self-standing and flexible polyurethane-based single-ion conductor membrane was prepared via covalent tethering of the trifluoromethanesulfonamide anion to polyurethane, which was synthesized using a facile reaction of diisocyanates with poly(ethylene oxide) and 3,5-diaminobenzoic acid (or 3,5-dihydroxybenzoic acid). The polymer electrolyte exhibited excellent ionic conductivity, mechanical properties, lithium-ion transference number, thermal stability, and a broad electrochemical window because of the bulky anions and unique two-phase structures with lithium-ion nanochannels in the hard domains. Consequently, the plasticized electrolyte membrane showed exceptional stability and reliability in a Li||Li symmetric battery. The assembled LiFePO4||Li battery exhibited an outstanding capacity (∼180 mA h g-1), Coulombic efficiency (>96%), and capacity retention. This research provides a promising polymer electrolyte for high-performance LMBs.

[Experimental study on in vitro transdermal absorption of Shangshi Zhitong cataplasm].

OBJECTIVE: To conduct an experimental study on in vitro transdermal absorption of prepared Shangshi Zhitong cataplasm. METHOD: Franz diffusing cells and mice were adopted for the percutaneous penetration study. The accumulative percutaneous permeation of total alkaloids, strychnine and atropine in certain time was determined by acid dye colorimetry and HPLC. RESULT: The accumulative permeation of alkaloids (Q) increased with time (t), with a linear relation between them. CONCLUSION: The in vitro percutaneous penetration of Shangshi Zhitong cataplasm complies with the zero-order kinetics.

[Anaphylactoid reactions induced by polysorbate 80 on Beagle dogs].

OBJECTIVE: To evaluate the sensitization effect of polysorbate 80 from different factories on Beagle dogs. METHOD: Beagles dogs were randomly divided into 5 groups, 3 in each group, received respectively the intravenous infusion of polysorbate 80 made by four factories in the concentration of 0.5%, with the constant infusing speed of 5 mL x min(-1) and volume of 10 mL x kg(-1). Changes were observed before infusion and in the 24 h after infusion, time of symptom appearance and disappearance was recorded, and the grade of response was determined. Moreover, blood pressure and heart rates were tested by the machine of Bp-98E, blood samples of animals were collected before infusion and at 10 min after ending infusion for measuring histamine content in plasma using ELISA. Then the sensitization effect was comprehensively estimated by combined consideration of the responding grade and histamine level. RESULT: Typical symptoms of anaphylactoid reactions were found in sample 3 group, atypical symptoms were found in other polysorbate 80 groups. Different degrees of heart rate speeding and blood pressure downing were found in polysorbate 80 groups. No over 1-fold increase of plasma histamine level was found in all groups. The atypical anaphylactoid reactions and blood pressure of sample 2 group was lighter than other polysorbate 80 groups. Estimation showed that the sample 3 induced the suspicious anaphylactoid reactions, other test solutions did not induce the typical anaphylactoid reactions on Beagle dogs. CONCLUSION: For allergies and other special populations, there is still a certain risk to applicate polysorbate 80 in the concentration of 0.5%. Production process of polysorbate 80 have a certain influence on allergenicity, refined polysorbate 80 increase the security, but further reasearchs are needed to confirmed.

[Study on anaphylaxis and hemocytolysis of 6 kinds of tween-80 injection from different souce].

OBJECTIVE: To observe the anaphylaxis and hemocytolysis of 6 kinds of tween-80 injection from different source. METHOD: The Hartley albinism guinea pig was used to carry on the active systematic anaphylaxis (ASA) and the passive cutaneous anaphylaxis (PCA). The in vitro hemolytic experiment and the hemocytolysis was observed by means of spectrophotometry on the domestic rabbit. RESULT: The result of ASA and PLA of 6 kinds of tween-80 injection from different source assumed the negative. In observation time, the temolysis rate of 3 kinds of tween-80 injection are more than 5%, while the others are also more than 5% only in the highly concentrated test tube. CONCLUSION: Six kinds of tween-80 injection from different source have not caused the immune-mediated anaphylaxis, but it may have hematolysis tendency on intravenous injection. The hemocytolysis of tween-80 may not be entirely caused by the impurities. It is worthy of further study that the physical and chemical properties of the product itself and the undeserved concentration is doubtful whether there is also some internal relations with the generation of hemolytic.

[Studies on pharmacokinetics of artemether patch in mice].

OBJECTIVE: To establish a HPLC-MS-MS determination method of artemether (ARM) and active derivatives DHA, and compare the pharmacokinetic parameters of ARM after transdermal and oral administration. METHOD: The mice were divided two groups (transdermal and oral) by parallel design. ARM and active derivatives DHA in plasma of mice at different sampling time were determined. The pharmacokinetic parameters were calculated by DAS 2.0 and by statistic analysis. RESULT: compare oral administration, the pharmacokinetic parameters of ARM after transdermal, Cmax Tmax , AUC(0-t) MRT, had significant difference (P < 0.05). CONCLUSION: The artemether patch has long-releasing property.

A validated stability-indicating HPLC method for the determination of PEGylated puerarin in aqueous solutions.

The aim of this study was to develop a validated specific stability-indicating HPLC method for the quantitative determination of PEGylated puerarin (PEG-PUE) in aqueous solutions. The method was validated by subjecting PEG-PUE to forced degradation under stress conditions of acid, alkali, water hydrolysis, and oxidation. Both PEG-PUE and puerarin (PUE) were simultaneously determined and separated on CAPCELL PAK C18 column by gradient elution with 0.2% aqueous phosphoric acid and acetonitrile as the mobile phase. The flow rate was 1.0 mL min(-1) and detection wavelength was set at 250 nm. Both calibration curves showed good linear regression (r> or =0.9998) within test ranges. The LOD and LOQ of PEG-PUE were determined to be 3 and 9 microg mL(-1) respectively. Degradation of PEG-PUE followed pseudo-first-order kinetics with t(1/2) of 59 min at pH 9.0 and 17.79 h at pH 7.4. However, at pH 5.0 and 2.0, there was no significant degradation of PEG-PUE over time. In conclusion, the method was observed to have the necessary specificity, precision, and accuracy, and to be suitable for quantity monitoring the degradation process of PEG-PUE during stability studies. The degradation studies may give insight into useful information for formulation development of PEG-PUE.

A HPLC-UV method for the determination of puerarin in rat plasma after intravenous administration of PEGylated puerarin conjugate.

A sensitive and reproducible HPLC method for quantitative determination of puerarin (PUE) in rat plasma was developed and validated using 4-hydroxybenzaldehyde as an internal standard. The separation of PUE was performed on a CAPCELL PAK C18 column by gradient elution with 0.2% aqueous phosphoric acid and acetonitrile as the mobile phase. The method was validated and found to be linear in the range of 80-12,000ng/mL. The limit of quantification was 80ng/mL based on 100µL of plasma. The variations for intra- and inter-day precision were less than 8.3%, and the accuracy values were between 98% and 105.2%. The extraction recoveries were more than 85%. The method was successfully applied in the comparative study of pharmacokinetics of PEGylated puerarin (PEG-PUE) versus PUE in rats. Compared with PUE, PEG-PUE showed a 5.2-fold increase in half-life of PUE and a 4.7-fold increase in mean residence time. In addition, this method was also successfully applied to determine the low plasma concentration of PUE regenerated from PEG-PUE in vitro.