Gel Electrophoresis Chip Using Joule Heat Self-Dissipation, Short Run Time, and Online Dynamic Imaging.

Gel electrophoresis (GE) is one of the most general tools in biomedicine. However, it suffers from low resolution, and its mechanism has not been fully revealed yet. Herein, we presented the dispersion model of w2 (t) ∝ Tt, showing the band dispersion (w) via temperature (T) and running time (t) control. Second, we designed an efficient GE chip via the time control and rapid Joule heat self-dissipation by thermal conductive plastic (TCP) and electrode buffer. Third, we conducted the simulations on TCP and polymethylmethacrylate (PMMA) chips, unveiling that (i) the temperature of TCP was lower than the PMMA one, (ii) the temperature uniformity of TCP was better than the PMMA one, and (iii) the resolution of TCP was superior to the PMMA one. Fourth, we designed both TCP and PMMA chips for experimentally validating the dispersion model, TCP chip, and simulations. Finally, we applied the TCP chip to thalassemia and model urine protein assays. The TCP chip has merits of high resolution, rapid run of 6-10 min, and low cost. This work paves the way for greatly improving electrophoretic techniques in gel, chip, and capillary via temperature and time control for biologic study, biopharma quality control, clinical diagnosis, and so on.

Observation of the clinical effect of immediate implantation and delayed implantation in the maxillary and maxillary molars.

Objective: To study the clinical application effect of two kinds of implants in the upper and lower molars. Methods: A selection of 120 patients (134 teeth) who underwent implant treatment in the upper and lower molars in the army hospital of the Chinese people's liberation army from January 2018 to June 2019 were divided into an immediate group (using immediate implantation) and a delayed group (using delayed implantation) using a random number table 60 cases (60 teeth) in each group; differences in implant success rate, buccal keratinized gingival width before and after treatment, alveolar bone absorption, periodontal pocket depth, and gingival aesthetic indicators were compared between the two groups. Results: The gingival aesthetics effect of the immediate group was better than that of the delayed group on the whole and the difference was statistically significant (P<0.05); after 12 months of restoration, the implantation success rate of the immediate group was 96.67%. The deferred group was 93.33%, and the difference between the two groups was not statistically significant (P>0.05). Conclusion: Both delayed restoration and immediate implant restoration can achieve good results in implant restoration treatment in the maxillary and maxillary molars. However, immediate implantation has certain advantages in reducing the amount of alveolar bone absorption and maintaining the aesthetic effect of the gums.

Effect of polystyrene microplastics on tetracycline photoconversion under simulated sunlight: Vital role of aged polystyrene.

Photoconversion of tetracycline (TC) has been widely reported. However, the effect of microplastics (MPs) on TC conversion kinetics and mechanism has rarely been discussed. In this study, we investigated the effect of (aged) MPs on TC degradation under simulated sunlight and elucidated the underlying mechanism. Our findings demonstrated that the physical and chemical properties of polystyrene (PS), such as particle size, surface groups, and morphology, were significantly altered after aging. Moreover, photoconversion efficiency of TC was suppressed with the spiking of aged PS, while virgin PS showed an opposite tendency. The photodegradation reaction for photosensitization of PS involved 1O2 and HO·. The light-screening effect of aged PS occupied predominance, weakening the direct UV-light absorption of TC and resulting in lower TC degradation efficiency. Additionally, triplet-excited state PS was generated after photon acceptance by aged PS, which could transfer energy to O2, leading to the production of 1O2. The toxicity test manifested that the direct impact of TC products on fathead minnow was ignorable, but long-term negative effects on growth deserved observation. This study enhances our understanding of the environmental fate of PS and TC under sunlight, and provides crucial reference information for better evaluating the potential risk of MPs and chemicals.

[The pharmacokinetics of long-circulating beta-elemene liposomes].

OBJECTIVE: To study the pharmacokinetics of long-circulating beta-elemene liposomes. METHODS: Gas chromatography was established to determine the concentration of beta-elemene in plasma of rats. RESULTS: The alpha, T(1/2beta), K12 and AUC of long-circulating beta-elemene liposomes groups were higher compared with those of the conventional liposomes,and the T(1/2alpha), Vc, CL, K10 of the latter were lower. CONCLUSION: Long-circulating beta-elemene liposomes can prolong the duration of beta-elemene in the body and improve the efficacy of drugs.

LRRC4 inhibits the proliferation of human glioma cells by modulating the expression of STMN1 and microtubule polymerization.

LRRC4 is a tumor suppressor of glioma, and it is epigenetically inactivated commonly in glioma. Our previous study has shown that induction of LRRC4 expression inhibits the proliferation of glioma cells. However, little is known about the mechanisms underlying the action of LRRC4 in glioma cells. We employed two-dimensional fluorescence differential gel electrophoresis (2-D DIGE) and MALDI -TOF/TOF-MS/MS to identify 11 differentially expressed proteins, including the significantly down-regulated STMN1 expression in the LRRC4-expressing U251 glioma cells. The levels of STMN1 expression appeared to be positively associated with the pathogenic degrees of human glioma. Furthermore, induction of LRRC4 over-expression inhibited the STMN1 expression and U251 cell proliferation in vitro, and the glioma growth in vivo. In addition, induction of LRRC4 or knockdown of STMN1 expression induced cell cycle arrest in U251 cells, which was associated with modulating the p21, cyclin D1, and cyclin B expression, and the ERK phosphorylation, and inhibiting the CDK5 and cdc2 kinase activities, but increasing the microtubulin polymerization in U251 cells. LRRC4, at least partially by down-regulating the STMN1expression, acts as a major glioma suppressor, induces cell cycle arrest and modulates the dynamic process of microtubulin, leading to the inhibition of glioma cell proliferation and growth. Potentially, modulation of LRRC4 or STMN1 expression may be useful for design of new therapies for the intervention of glioma.

Application of carbon fiber composite minielectrodes for measurement of kinetic constants of nitric oxide decay in solution.

Carbon fiber microelectrodes and carbon fiber composite minielectrodes (CFM/CFCM) have been generally used for measurements of nitric oxide (NO) concentration in chemical and biological systems. The response time of a CFM/CFCM is usually from milliseconds to seconds depending on the electrode size, the thickness of coating layers on the electrode, and NO diffusion coefficients of the coating layers. As a result, the time course of recoded current changes (I-t curves) by the CFM/CFCM may be different from the actual time course of NO concentration changes (c-t curves) if the half-life of NO decay is close to or shorter than the response time of the electrode used. This adds complexity to the process for determining rate constants of NO decay kinetics from the recorded current curves (I-t curves). By computer simulations based on a mathematical model, an approximation method was developed for determining rate constants of NO decay from the recorded current curves. This method was first tested and valuated using a commercial CFCM in several simple reaction systems with known rate constants. The response time of the CFCM was measured as 4.7±0.7 s (n=5). The determined rate constants of NO volatilization and NO autoxidation in our measurement system at 37 °C are (1.9±0.1)×10(-3) s(-1) (n=4) and (2.0±0.3)×10(3) M(-1) s(-1) (n=7), which are close to the reported rate constants. The method was then applied to determine the rate of NO decay in blood samples from control and smoking exposed mice. It was observed that the NO decay rate in the smoking group is >20% higher than that in control group, and the increased NO decay rate in the smoking group was reversed by 10 µM diphenyleneiodonium chloride (DPI), an inhibitor of flavin enzymes such as leukocyte NADPH oxidase.

The tissue distribution in mice and pharmacokinetics in rabbits of oxaliplatin liposome.

A rapid, sensitive, and simple high-performance liquid chromatographic (HPLC) method with an ultraviolet detector (UV) has been developed for the determination of oxaliplatin in the plasma of rabbits and tissues of mice. The sample preparation was carried out by complexation with 0.5 mL of DETC (diethyl-dithiocarbamate) solution and extracted by ether and chloroform. Then, 20 microL of supernatant was injected into the HPLC system with 0.25 mol/L of sodium chloride solution and methanol (30:70 v/v) as the mobile phase at a flow rate of 1.0 mL/min. Separation was performed with a C(18) column at 25 degrees C. The peak was detected at 254 nm. The calibration curve was linear (R(2) > or = 0.9995) in the concentration range of 0.1 approximately 200 microg/mL in plasma and tissues. The intra- and interday variation coefficients were not more than 2.61 and 3.83%, respectively. The limit of detection was 20 ng/mL. The mean recoveries of oxaliplatin were ranged from 97.83 to 104.17% in plasma and tissues. The present method has been successfully applied to the pharmacokinetic study of oxaliplatin liposome in mice and rabbits.

Evaluation of the potential cytotoxicity of metals associated with implanted biomaterials (I).

The present assessments of potential toxicity of metal ions (Al, Ni, Cr, V, and Ag) that construct the metallic biomaterials were carried out in vitro. By measurements of cell alkaline phosphatase (ALP) activity and reduction ability of cell methyl tetrazolium (MTT), the cytotoxicity of prevalence metallic biomaterials has been investigated. Furthermore, the poison and erosion of metal ions and atoms on human tissue are discussed. Research results indicated that trace Cr(VI) showed serious cytotoxicity and Ni as well as V are cytotoxic if the ion concentration in culture medium is over 100 micromol x L(-1) and 1 micromol x L(-1), respectively. A strange phenomenon is that Ag also is cytotoxic if the ion concentration is higher than 500 micromol x L(-1). Al ion is biphasic in cytotoxicity. At low ion concentration (< 10 micromol x L(-1)), Al ions can stimulate cell proliferation, whereas at concentrations over 1,000 micromol x L(-1), cytotoxicity increases.

[Study on preparation technology of aconitine liposomes].

OBJECTIVE: To optimize the prescription and preparation of aconitine liposomes. METHODS: Aconitine liposomes were prepared by ethanol injection method. The encapsulation efficiency was taken as inspection target and the preparation of liposomes were optimized by orthogonal design. HPLC was used to measure the encapsulation efficiency. RESULTS: The best prescription was aconitine/ lecithin/cholesterol( 1: 15: 5)with phosphate buffer solution (pH 7. 4) as hydration media. The hydration temperature was 60 degrees C. CONCLUSION: The optimized formulation of aconitine liposomes is reasonable in prescription, practicable in technology, high in encapsulation efficiency and good in stability.

[HPCE determination of matrine in matrine liposome].

OBJECTIVE: To establish an HPCE method for the determination of matrine in Matrine Liposome. METHODS: HPCE was used. The best condition was achieved with a fused silica capillary tube( 150 cm x 75 microm), 0.25 mol/L phosphate buffer (pH 6.8), at constant voltage of 20 kV and temperature at 25 degrees C. The UV detection wavelength was 206 nm. RESULTS: The calibration curve was linear in the range of 0.3-6.025 mg/ml for matrine (0.9995). The average recovery of matrine was 97.3%. CONCLUSION: This methods is simple, quick, accurate and suitable for the quality control for Matrine Liposome.

Direct production of cellulose laurate by mechanical activation-strengthened solid phase synthesis.

This work reports that cellulose laurate could be directly produced by mechanical activation-strengthened solid phase synthesis (MASPS) in a customized stirring mill with using bagasse pulp and lauric acid as materials in an environmentally friendly way. Cellulose laurates with different degree of substitution were obtained under different synthesis conditions without the use of organic co-reagents and solvents. The characterization results showed that cellulose laurates had great changes in surface morphologies and crystal structures compared with bagasse pulp because of the intense milling and introduction of laurate groups, but still retained the cellulose I crystalline form of the native cellulose. MASPS could be considered as a simple, efficient and green method for the production of long chain cellulose esters.

Evaluation of the potential cytotoxicity of metals associated with implanted biomaterials (II).

The effects of metal ions on the cell DNA and RNA synthetic functions and the destruction of cell defensive system caused by metal ions were studied on the investigation of the effects of metal ions on cell alkaline phosphatase (ALP) activity and cell metabolism ability. The poisonous behaviours of metal ions [Cr (VI), Ni, V, Cr (III), Ag, and Al] on living tissue were both quantitatively and qualitatively measured. It was shown that Cr (VI) has a notable action on both cellular DNA and RNA synthetic functions, and following that, were Ni, V. The limitation action of Cr (III) on the synthetic abilities of DNA and RNA increased with the increase of Cr (III) concentration. Different to other five metal ions, the limitation of Al ion on RNA was greater than that on DNA. The limitation of V, Ag ions on DNA was same to that on RNA. Trace Cr (VI), in culture medium resulted in the decreasing of GSH in living tissue. Similar to that, a little higher Ni ion concentration seriously reduced the GSH content in living tissue. It was suggested that Cr (VI), Ni, might destroy and/or disturb the orientation of the microtubulin in cell skeleton. For other four metal ions, together with increasing the concentration in culture medium, the osmotic pressure increased. Consequently, more metal ions entered cell membrane, more GSH were lost in cell.