This paper presents an implementation of an active battery balancing method using fly-back transformer. The need for balancing the batteries in series is to reduce damage to the battery string and to increase its life span. The proposed charge equalization method utilizes active switches and a multi-input single output fly-back transformer to transfer energy between the batteries. The equalizer achieves voltage and State of Charge (SoC) balance of batteries with same ratings. The method utilizes excess energy from charged cell to charge the other cells making it more efficient and use of single DC-DC boost converter with a fly-back transformer makes it compact and cheaper to implement. The method is proved by MatLab simulation and validated by hardware implementation.

In this work, compact maximum power point tracking method of solar photo voltaic (PV) systems using analog ICs is presented. The analog circuit realizes the maximum power point tracking (MPPT) algorithm which exploits the non-linear characteristics of PV array. This algorithm tracks the maximum power of the solar PV array and maintains the same irrespective of the intensity and the fluctuations in the solar radiation, thus improving the efficiency of the PV system. To implement the proposed algorithm, TI components LM311, LM318 and SN7474 are used. In this work, the simulation of the proposed system has been simulated using Pspice at different operating conditions and results are presented with hardware implementation.

Electrospraying of hydroxyapatite (HA) nanoparticles onto the surface of polymer nanofibers provides a potentially novel substrate for the adhesion, proliferation and differentiation of mesenchymal stem cells (MSCs) into bone tissue regeneration. HA nanoparticles (4%) were electrosprayed on the surface of electrospun polycaprolactone (PCL) nanofibers (420 ± 15 nm) for bone tissue engineering. PCL/HA nanofibers were comparatively characterized with PCL/Collagen (275 ± 56 nm) nanofibers by FT-IR analysis to confirm the presence of HA. Fabricated PCL/HA and PCL/Collagen nanofibers and TCP (control) were used for the differentiation of equine MSC into osteogenic lineages in the presence of DMEM/F12 medium supplemented with β-glycerophosphate, ascorbic acid and dexamethasone. Cell proliferation and differentiation into an osteogenic lineage was evaluated by MTS assay, SEM observation, ALP activity, ARS staining, quantification of mineral deposition and expression of osteocalcin. Proliferation of MSCs increased significantly (P ⩽ 0.05) up to 12% in PCL/Collagen (day 15) compared to PCL/HA nanofibrous substrate. ALP activity was increased 20% in PCL/HA by day 10 confirming the direction of osteogenic lineage from MSCs differentiation. PCL/HA stimulated an increased mineral secretion up to 26% by day 15 on ARS staining compared to PCL/Collagen nanofibers and showing cuboidal morphology by expressing osteocalcin. These results confirmed that the specifically fabricated PCL/HA composite nanofibrous substrate enhanced the differentiation of MSCs into osteogenesis.

This study evaluated the effects of fat and sugar levels on the surface properties of Lactobacillus rhamnosus GG during storage in food model systems, simulating yogurt and ice cream, and related them with the ability of the bacterial cells to adhere to Caco-2 cells. Freeze-dried L. rhamnosus GG cells were added to the model food systems and stored for 7 days. The bacterial cells were analyzed for cell viability, hydrophobicity, ζ potential, and their ability to adhere to Caco-2 cells. The results indicated that the food type and its composition affected the surface and adhesion properties of the bacterial cells during storage, with yogurt being a better delivery vehicle than ice cream in terms of bacterial adhesion to Caco-2 cells. The most important factor influencing bacterial adhesion was the storage time rather than the levels of fats and sugars, indicating that conformational changes were taking place on the surface of the bacterial cells during storage.

The surface properties of lactobacilli are of significant technological importance as they determine the interaction of the bacterial cells with the gastrointestinal mucosa, and therefore influence their location in the gut and their functionality. Studying the surface of the bacteria is critical for understanding the adhesion process better. This review compiles the knowledge from studies on the characterization Lactobacillus surfaces and evaluates the potential relationship between the cells' physicochemical characteristics and their adhesive abilities. It also discusses the effect that the production processes, such as fermentation and drying, can exert on the surface properties and adhesion abilities of lactobacilli.

Aims: To investigate the effects of the medium and cryoprotective agents used on the growth and survival of Lactobacillus plantarum and Lactobacillus rhamnosus GG during freeze drying. Methods and Results: A complex medium was developed consisting primarily of glucose, yeast extract and vegetable-derived peptone. Trehalose, sucrose and sorbitol were examined for their ability to protect the cells during freeze drying. Using standardized amount of cells and the optimized freeze drying media, the effect of the growth medium on cell survival during freeze drying was investigated. The results showed that glucose and yeast extract were the most important growth factors, while sucrose offered better protection than trehalose and sorbitol during freeze drying. When the cells were grown under carbon limiting conditions, their survival during freeze drying was significantly decreased. Conclusions: A clear relationship was observed between cell growth and the ability of the cells to survive during the freeze drying process. Significance and Impact of the Study: The survival of probiotic strains during freeze drying was shown to be dependent on the cryoprotectant used and the growth medium.

Nanotechnology is the creation and utilization of materials, devices and systems through the control of substance in a nanometer scale. Nanobiotechnology creates a better understanding of cell biology because molecules in the cells are organized in nanoscale dimensions and they function as nanomachines. Nanomedicine is the process of diagnosing, treating and preventing diseases and traumatic injuries, relieving pain and improving human health. The high cost, together with a limited space for significant economies in the mass scale production of tissue engineered products has hindered widespread clinical application. In addition, presently available tissue engineered products still share some of the concepts of substitution medicine, where a laboratory grown 'spare part' is implanted in the body to compensate for lost tissue. Several of these recent developments in electrospun nanofibers are already at advanced phases of commercialization or clinical trials. By building pioneering achievements in tissue engineering, advanced therapies in the regeneration of pathological tissues to treat, modify and prevent disabling chronic disorders such as diabetes, osteoarthritis, diseases of cardiovascular and central nervous system are achievable. The vision for nano-assisted regenerative medicine ideally involves the development of cost-effective disease modifying therapies that will allow for in situ tissue regeneration. This article summarises the recent developments in electrospun nanofibers for healthcare applications.

The annual world wide market for controlled release of polymer systems which extends beyond drug delivery is now estimated to $60 billion and these systems are used by over 100 million people each year. It was estimated that drug delivery will play a pivotal role in approximately 40% of all pharmaceutical sales in near future. Novel methods of drug delivery will not only result in more effective and efficacious treatments but also generates new niche markets to provide greater intellectual property protection to already existing drug formulations. Recently, biodegradable electrospun polymer nanofibrous substrate as drug carrier seems to be a promising method for delivering anticancer drugs, especially in postoperative local chemotherapy. Alternatively drug release can be triggered by the environment or other external events such as changes in pH, temperature, or the presence of analyte such as glucose. In general, controlled release of polymer systems delivering drugs in the optimum dosage for long periods is to increase the efficacy of drug, reducing patient compliance. Recent research for the use of nanotechnology (nanoparticle and nanofibers) in drug delivery suggests that the technology might solve problems in the areas such as controlled release, various topical administration, gut absorption and targeted systemic delivery. This review article described the applications of polymer nanoparticles and nanofibers for loading potential drugs for the controlled release to target incurable diseases.

Chitosan, a naturally available biopolymer which is now increasingly being used as a functional finish on textile substrates to impart antimicrobial characteristics and increase dye uptake of fabrics was applied on wool fabrics. Henna a natural dye with proven bactericidal properties was applied on wool fabrics along with chitosan to impart antimicrobial characteristics. The effect of chitosan application on the dyeing properties of wool fabrics was studied by measuring the K/S values of the treated substrates at various concentrations of chitosan and the dye. The antimicrobial properties of chitosan and natural dyes both when applied independently and collectively on fabrics were assessed. The results proved that the chitosan treated wool fabrics showed increase dye uptake of fabrics. The treated fabrics were found to be antimicrobial and the chitosan treatment enhances the antimicrobial characteristics of the dyes. Fastness properties of the applied finish to washing, rubbing and perspiration have also been discussed.

AIMS:To investigate the changes in the surface properties of Lactobacillus rhamnosus GG during growth, and relate them with the ability of the Lactobacillus cells to adhere to Caco-2 cells. METHODS AND RESULTS:Lactobacillus rhamnosus GG was grown in complex medium, and cell samples taken at four time points and freeze dried. Untreated and trypsin treated freeze dried samples were analysed for their composition using SDS-PAGE analysis and Fourier transform infrared spectroscopy (FTIR), hydrophobicity and zeta potential, and for their ability to adhere to Caco-2 cells. The results suggested that in the case of early exponential phase samples (4 and 8 h), the net surface properties, i.e. hydrophobicity and charge, were determined to a large extent by anionic hydrophilic components, whereas in the case of stationary phase samples (13 and 26 h), hydrophobic proteins seemed to play the biggest role. Considerable differences were also observed between the ability of the different samples to adhere to Caco-2 cells; maximum adhesion was observed for the early stationary phase sample (13 h). The results suggested that the adhesion to Caco-2 cells was influenced by both proteins and non-proteinaceous compounds present on the surface of the Lactobacillus cells. CONCLUSION:The surface properties of Lact. rhamnosus GG changed during growth, which in return affected the ability of the Lactobacillus cells to adhere to Caco-2 cells. SIGNIFICANCE AND IMPACT OF THE STUDY:The levels of adhesion of Lactobacillus cells to Caco-2 cells were influenced by the growth time and reflected changes on the bacterial surface. This study provides critical information on the physicochemical factors that influence bacterial adhesion to intestinal cells.

Nanotechnology is an emerging technology seeking to exploit distinct technological advances controlling the structure of materials at a reduced dimensional scale approaching individual molecules and their aggregates or supramolecular structures. The manipulation and utilization of materials at nanoscale are expected to be critical drivers of economic growth and development in this century. In recent years, nanoscale sciences and engineering have provided new avenues for engineering materials down to molecular scale precision. The resultant materials have been demonstrated to have enhanced properties and applicability; and these materials are expected to be enabling technologies in the successful development and application of nanomedicine. Nanomedicine is defined as the monitoring, repair, construction, and control of human biological systems at the molecular level using engineered nanodevices and nanostructures. Electrospinning is a simple and cost-effective technique, capable of producing continuous fibers of various materials from polymers to ceramics. The electrospinning technique is used for the preparation of nanofibers and macroporous scaffolds intended for drug delivery and tissue engineering. These have special characteristics in terms of fabrication, porosity, variable diameters, topology and mechanical properties. This review summarizes the recent developments in utilizing nanofibers for drug delivery and tissue engineering applications.