Response of hemocytes profile in the black tiger shrimp (Penaeus monodon) against Vibrio harveyi induced by Xylocarpus granatum leaves extract

Aim: The present study investigated hemocytes profile of black tiger shrimp (Penaeus monodon) induced with Xylocarpus granatum leaves extract to protect against Vibrio harveyi infection. Materials and Methods: X. granatum leaves were chopped into small size, air-dried, and extracted with one of the following solvents: Ethanol, distilled water, and seawater, whereas each solvent was given in three different concentrations (750 ppm, 1.000 ppm, and 1.250 ppm, respectively). Extracts were induced to 60 post-larvae shrimp in each treatment (three replicates, 20 shrimp for each) by immersing method and subsequently challenged with V. harveyi. Results: This study demonstrated different effectiveness among solvents used to extract X. granatum leaves, in which distilled water showed the most effective solvent as can be seen from the lowest percentage on anorexia, lethargic, and weakened reflex of shrimp compared with another solvent, positive and negative controls. Pathological symptoms for shrimp induced by X. granatum leaves extract were minimum with the highest survival rate compared with those of positive and negative control. Total hemocyte cells and its cell constituents such as semi-granular, granular, and hyaline cells on treatment group at 1.250 ppm were higher than controls. Conclusion: Leaves extract of X. granatum extract effectively inhibited V. harveyi infection, increased survival rate, and hemocytes cell of the experimental shrimp. Distilled water extract of X. granatum at 1.250 ppm demonstrated the highest protective effect toward V. harveyi infection on P. monodon.

Methods in Making Steel-Copper Sandwich Laminates Materials

This research is aimed at developing a method to make steel-copper sandwich laminate materials. The research focused on the method of developing the sandwich material. In a method I, the steel plate arrangement is heated up to austenite temperature and subsequently, a molten copper is poured into it. In method II, the steel plate arrangement is immersed into a molten copper in a temperature of 1200 °C. The result shows that in the method I, the diffusion on the interface layer of steel-copper sandwich laminate is unemployed because of an occurrence of oxidation on the steel surface. On the contrary, in method II the diffusion on the interface of steel-copper sandwich laminate is indicated by higher shear stress, which is 231.88 N/mm2. However, the immersing method needs to be improved to give better products, since cavities caused by trapped air still exist and are reducing the quality of the laminates.Penelitian ini ditujukan untuk mengembangkan metode pembuatan laminat baja-tembaga. Penelitian difokuskan pada metode pembuatan laminat. Pada metode I, susunan pelat baja dipanaskan hingga suhu austenit dan kemudian tembaga cair dituangkan. Metode II adalah merendam susunan pelat baja ke dalam tembaga cair bersuhu 1200 0C. Hasil penelitian menunjukkan bahwa pada metode I tidak terjadi difusi pada lapisan antarmuka laminat baja-tembaga karena permukaan baja mengalami oksidasi saat dipanaskan. Sebaliknya, metode II menunjukkan terjadi difusi pada antarmuka laminat baja-tembaga dengan tegangan geser tertinggi 231,88 N/mm2. Namun, metode II harus diperbaiki untuk memberikan produk yang lebih baik karena masih terdapat rongga akibat udara yang terjebak dan mengurangi kualitas laminat.

Kemudahan Biodegradasi Selulosa Bakteri dari Limbah Cucian Beras dengan Penambahan Gliserol, Kitosan, dan Nanopartikel Perak

The objectives of this research were to study the effect of glycerol and chitosan addition toward biodegradability of cellulose based rice waste water, the effect of biodegradation time toward mass lost and biodegradability, and determine functional group and crystalinity of the highest biodegradability composite. Bacterial celluloses were prepared from 100 mL rice waste water that fermented by Acetobacter xylinum for 7 days with addition of glycerol (for Cellulose-Glycerol and Cellulose-Glycerol-Chitosan). Then, bacterial celluloses were immersed in chitosan solution (for Cellulose-Chitosan and Cellulose-Glycerol-Chitosan). The water in bacterial cellulose and its composites was removed by heating, then deposited silver nanoparticle on the bacterial cellulose and its composite. The silver nanoparticles were prepared by chemical reduction with using AgNO3 solution, trisodium citric as reducing agent, and gelatin as stabilizer. The silver nanoparticle was deposited into bacterial cellulose and its composites film by immersing method. After that, the bacterial cellulose and its composites were biodegradated by soil burrial test method for 14 days. Then, cellulose with the highest biodegradability was characterized by ATR-FTIR and XRD. The silver nanoparticle formation was showed by UV-Vis spectrum with peak in the 418.8 nm area. The glycerol addition can increase biodegradability, whereas the chitosan addition can decrease biodegradability. The increasing of biodegradation time, mass lost increased but the biodegradability decreased. After biodegradation, intensity of pyran cyclic in cellulose-glycerol which is deposited Ag (SG + Ag) decreased, but crystallinity of it increased. Keywords : Biodegradation, glycerol, chitosan, silver nanoparticle, bacterial cellulose. DOI: http://dx.doi.org/10.15408/jkv.v2i1.3111

Evaluation of Contamination Reduction on Gypsum Casts from Alginate Impressions Disinfected with Four Different Materials

<p><strong>INTRODUCTION:</strong> Infection control is one of the most important aspects in dentistry. According to the special features of dentistry, this profession can have a very important role in transmission of infection. This study was conducted by comparing the effects of four common disinfectants on the microbial contamination of alginate impressions and corresponding gypsum casts.</p><p><strong>METHODS &amp; MATERIAL:</strong> In this experimental study, eleven patients aged 20-30 years old were selected by convenience sampling method. Six alginate impressions for each patient were formed by 24-hour intervals. These sixty six alginate impressions were divided in six groups (control-no wash, wash with water, Micro10, 2% Glutaraldehyde, 5.25% Sodium hypochlorite and Deconex). Disinfection methods were done by spraying (except for glutaraldehyde group that was done by immersing method) and then the alginate impressions were placed in plastic bags for 10 minutes to prevent the evaporation of disinfectants. Sixty six gypsum casts were made from alginate impressions. Microbial swabs were collected from mid palatal region of alginate impressions and gypsum casts for all groups by dried sterile cotton. The swabs were cultured for bacteria by inoculation on Blood Agar at 37°C for 3 days. The positive cultures were counted and the data was analyzed by software SPSS21.</p><p><strong>RESULTS:</strong> The counting colonies of gypsum casts and alginate impressions which were disinfected by Micro10, 2% Glutaraldehyde, 5.25% Sodium hypochlorite and Deconex were not statistically significant and meaningful.</p><p><strong>CONCLUSION:</strong> All disinfectants used in this study, had the same and acceptable effect.</p>

A Photochromic Copolymer Hydrogel Contact Lens: From Synthesis to Application

A photochromic poly(2-hydroxyl-ethyl methacrylate-N-vinylpyrrolidone-spironaphthoxazine) hydrogel (p(HEMA-NVP-SPO)) has been designed and synthesized by free radical polymerization in this work. The chemical and structural information of hydrogels was investigated by IR spectra, equilibrium water content (EWC), and SEM. The IR spectra confirmed successful synthesis of copolymer. The domain of NVP contributed to not only EWC but also inner structure of hydrogel, while SPO had little influence on these properties of hydrogel. The photochromic behaviors of hydrogel including photochromic properties and thermal fading kinetics were systematically studied and compared with hydrogel made by immersing method. Results showed that when SPO was incorporated in hydrogel by polymerization, maximum absorbance wavelength got shorter, and the relaxation half-life became longer. In addition, salicylic acid as a drug model could be loaded into hydrogel by immersing method, and its sustained drug release in a given period was dependent on the characteristics of solution and loading time.

Preparation of Superhydrophobic Surface on Copper Foils by a Facile Method

In the paper, we prepared superhydrophobic surfaces on copper foils via a facile solution-immersing method. The influence of experiment conditions, such as solution concentration, immersing time and temperature, on the surface structure is investigated in detail. When the concentration of stearic acid-ethanol solution, the immersing time and the temperature are 2 g/L, 120 min and 40°,respectively, the resulting copper surface possesses great superhydrophobicity with a water contact angle of up to 159° and a sliding angle of only 3°.