Advanced Materials Research Vol. 749

Abstract: Herein, we proposed a novel, facile method for flocculation of Saccharomyces cerevisiae cells via nanoZnO. According to results, the presence of nanoZnO could significantly facilitate the flocculation of the yeast cells without damage the cellular morphology. Notably, the yeast cells flocculated by using nanoZnO displayed certain antibacterial property. Moreover, the cell activity was almost remained after flocculated by this method.

Abstract: Based on the splicing by overlapping extension (SOE) polymerase chain reaction (PCR),fusion gene mpb83-70 and il-15 were ligated and cloned into pMD18-T,then recombinant plasmid pMD-83-70-15 was constructed. pMD-83-70-15 and pVAX1-BMS were digested by double enzymes HindIII and EcoRI, the purified mpb83-70-il-15 was subcloned into pVAX1-BMS,then recombinant plasmid pVAX1-BMS-83-70-15 was constructed and transient expressed in Mark145 cell. These results laid solid foundations for further studies on mpb83-70-il-15.

Abstract: The purpose of this study was to prepare and characterize guanidinylated chitosan/β-glycerophosphate thermo-sensitive hydrogel system. The primary amine group of chitosan was modified with guanidine group, which was characterized by FT-IR and ¹H NMR. The results showed that the guanidinylations had been successfully carried out in cyanamide and chitosan. Gelation temperature was modulated at 37 °C with the ratio of 50% β-GP solution (weight/volume) and 4% GCS solution (weight/volume) at pH value ranged from 6.9 to 7.2, which could be development a new drug delivery system at body temperature.

Abstract: Phosphodieseterase type 5 inhibitors are safe, efficacy and well tolerated in the treatment of erectile dysfunction and therefore widely used. In this paper, the various synthetic methods and development on the synthesis of sildenafil,vardenafil,tadalafil are evaluated.

Abstract: Objectives: Use quantitative ultrasound technology to determine the bone density of children and adolescents, understand the status and variation of ultrasonic bone density in children and adolescents.Methods: By stratified random cluster sampling, selected 3629 studenes in five schools in Tangshan and measured height and weight,and determined the right foot heel bone density using ultrasonic bone density analyzer.Results: It showed that the average of ultrasonic bone mineral density were 1535.4±20.6(m/s), decreased at the age of 6 to 9 years old and then increased with the age growth; at the age of 9 was the lowest, the SOS value of ultrasonic bone mineral density rebounded slightly from 10 to 13-year-old, after 13-year-old the SOS value increased with the age growth, the highest was at the age of 19. Ultrasonic bone density was associated with height,weight and body mass index.Conclusions: The development of the bone is a dynamic continuous evolutionary process, bone mineral density presented different rules for the different of age, gender, physical development status.

Abstract: Objective: To investigate a better method of inducing hUC-MSCs into chondrocytes in different culture system in vitro. Method: hUC-MSCs were isolated and cultured by tissue block culture, and the cells surface antigens were identified by flow cytometry, hUC-MSCs were cultured with chondrogenic media and stained with Alcian Blue. The production of matrix was estimated from the determination of hydroxyproline content and Alcian Blue method. Expressions of glycosaminoglycan (GAG), type II collagen and Sox-9 were assayed by real-time fluorescence quantitative PCR. Results: The cultured hUC-MSCs phenotype was CD105+/CD29+/CD44+/ CD31-/CD34-/ CD40-/CD45-/HLA-DR-. hUC-MSCs weakly expressed chondrocyte marker, which strongly expressed GAG and type II collagen after chondrogenic induction, and the cells were incubated in pellet culture with higher expression. Real-time PCR results demonstrated that chondrogenic induction cells were expressed GAG, type II collagen and Sox-9, and the cells were incubated in pellet culture with higher expression. Conclusion: hUC-MSCs incubated in pellet culture is more conducive to differentiate into chondrocytes than those cultured in monolayer culture system.

Abstract: Objective: To study the adhesion of streptococcus mutans (S. mutans) to two dental restorative materials and the growth of S. mutans in shaking culture with different frequencies. Methods: The specimen made of acrylic resin and Co-Cr alloy were put into culture medium with S. mutans and incubated respectively in shaking condition with different frequencies for 24h. The amount of S. mutans on the surface of specimen and in the culture media was determined by the clone forming unit (CFU) counting method. Results: When the frequency exceeded 60 rpm in acrylic resin groups and 30 rpm in Co-Cr alloy groups , the adhesive microbial amount declined with the increasing of shaking frequency . When the frequency was between 0¡«90rpm, the amount of in the culture media ascended with the increasing of shaking frequency , but decreased when the frequency increased beyond 90 rpm . Conclusion: When the frequency exceeded a certain level, the adhesion of S. mutans on the surface of two dental materials and the number of bacteria in the culture negatively correlated with the frequency, which implies that oral functional movements may lead to reduced microbes on the surface of dental restorative materials.

Abstract: To evaluate the therapeutic efficacy of calcium hydroxide as an intra canal dressing on controlling postoperative pain and swelling in patients suffering from residual pulpitis. 118 patients with residual pulpitis in their anterior teeth participated in this study. These patients were randomly divided into two groups (group A and group B) of fifty-nine. All teeth were treated with root canal therapy with a two-visit approach. The patients in group A were treated with calcium hydroxide as an intra canal dressing , and in group B using formocresol as an intra canal dressing. All of the patients were followed up for 72 h after each treatment session. The postoperative incidence and severity of pain and swelling were recorded. The data were analyzed by chi-square test and variance analysis. After the first visit, the incidence and severity of pain and swelling showed to be higher in group B and lower in group A. These differences were statistically significant. After the second visit, the incidence and severity of pain and swelling showed to be still higher in group B and lower in group A. But there were no significant difference. Conclusion It is concluded that calcium hydroxide as an intra canal dressing could be effective to decrease the postoperative pain and swelling. It is recommended to use calcium hydroxide as an inter-appointment dressing in teeth with residual pulpitis.

Abstract: ntroduction: This study was to explore the mechanism of exercise induced anti-aging effects on brain at molecular level in mice, which may provide some fundamental evidences for further research in anti-aging in human beings. Methods: 60 male mice (3 month old) were randomly divided into 4 groups: control group (group C), exercise group 1-3 (group E1, E2, and E3) with 15 in each group. Group E1 to E3 had swimming exercise at various load (30, 60, and 90min/day for E1, E2 and E3 respectively) for 8 monthes. The subjects were decapitated immediately and gained brain after the last exercise. The amount of SOD and MDA in gastrocnimius were measured by colorimetric method. The expression of NF-κB P50 mRNA and its protein amount were measured by Western-Blot and RT-PCR. Results and Conclusions: 1) NF-κB was sensitive to exercise stimulation and its actitity level was affected by exercise load. 2) The brain improved their anti-oxidization ability due to the adaptable changes of the antioxidant enzymes after long time moderate load aerobic exercise, which sped up the free radical clearance in the brain to reduce its impairment and meanwhile inhibited the activity of NF-κB. This process could be one of the anti-aging machanisms through aerobic exercises. 3) In long time over-load exercise (90 minutes), the free radicals in the brain accumulated and could not be cleared up timely, which would decrease the anti-oxidization ability. This process would activate NF-κB and enhance its expression, which may result in inflammation reactions and cellular dying, therefore speeding the aging process.

Abstract: By observing the process of hatch chickens, then combined with the modern biological knowledge and computer programming technology the paper proposed a hypothesis--coding sequence of DNA in cell is a set of program code sequence which includes instructions and data. And by making some program model, the paper simulated the two key procedures in life phenomena, namely cell division and cell differentiation. Then we can get some interesting ideas: If we look DNA coding sequence as program code sequence, the life phenomena is fully consistent with the principle of computer process . It is a macroscopic presentation of the life program in running status and whose code sequences were stored in DNA molecule chain. Combined with reflection calculation technology in the computer program model we also can come into an inference that Reflection technology is essential in the life process.