Jaya Prakash

Micro milling of pure copper

Abstract Unpredictable tool life and premature tool failure are the major concerns in micro machining using micro grain carbide cutters. In this study, the failure mechanism and factors which affect the micro end mill were studied during machining of pure copper workpiece. The machining operation were performed at various cutting speeds, depth of cuts, and feed rates to identify the failure mechanisms using two different helix angles. Chips observed were spiral in shape based on the cutter geometry. The chip size drastically differs from the conventional cutting, but the chip shape remains the same. Both spiral and broken chips were formed. Tool wear increases with the machining time and has a significant effect on the cutting forces. The cutting forces were small compared to conventional cutting. Both feed and radial forces were proportional to the feed rate and depth of cut. Cutting force increases with time as the wear progresses. From this experiment, it is concluded that the helix angle plays an important role. It is also observed that increase in depth of cut increases the tool life, which is quite unique and differs from the mechanics of machining.

Effect of Minimal Quantities of Lubricant in Micro Milling

Environmental, health, and waste disposal problems, which are associated with the conventional cooling technique, leads the interest switched to minimum quantities of lubricant (MQL) in machining. In this study the consumption rate of cutting oil is restricted to 1 mlh −1 against a benchmark flow rate of 42.0 lmin −1 in conventional cooling. The lubricating action of the cutting oil with extremely small amount of cutting fluid provides lower friction coefficient between the chip and tool. The effectiveness of this technique is investigated in terms of tool wear, chip shape, cutting speed and feed rate in micro milling.

Drug Targeting and Delivery

Drug delivery is defined as mechanisms to introduce pharmaceutical compounds to human in order to achieve therapeutic effects. We have come a long way since chewing medicinal plants and inhaling soot from medicinal substance were the only form of drug delivery. These approaches lacked consistency and uniformity of drug delivery. Since then there has been a continuous effort to discover and improve drug delivery routes and drug delivery systems. Conventional drug delivery system includes drug delivery via oral route as solutions, suspensions, emulsions, and tablets. Some are delivered systemically via injections and intravenous application. Medications are applied topically as lotions and gels. Nasal route is used for drug delivery to lungs by inhalers and nebulizers. Apart from antibiotics, vaccines, and chemical compounds, modern medicine includes recombinant DNA, insulin, interferon, interleukin, erythropoietin, tissue plasminogen activator, and other peptides and macromolecules as drugs that require efficient drug delivery systems. Traditional drug delivery systems suffer from various limitations such as low bioavailability, intolerance, toxic side effects, reduced plasma half-life, higher concentration, and low efficacy. The hydrophilic drugs have difficulty in passing through the cell membrane. Systemically delivered drugs reach all the organs irrespective of the affected organ. This causes toxic side effects on the healthy cells. The drugs tend to degrade fast in the plasma so higher doses of drug are required and hence it becomes toxic with reduced efficacy and are expensive. The biological barriers exclude the drug from reaching the affected cells and tissues. Efficient drug targeting can improve drug delivery efficacy, reduce side effects, and lower treatment cost. Hence, much effort is given on the development of novel carriers that would meet the requirement of drug delivery systems. The main areas of research are to increase bioavailability of the drugs, increase plasma half-life, and target to specific organs or cells. This would result in lowering the dose, which would also lower drug-induced toxicity, protect bystander cells and organs from adverse side effects, and reduce medical expenses. In this chapter, we will discuss the biological barriers, advances in drug delivery systems, drug targeting, and their application in diseases.

Effectiveness of methotrexate therapy with occasional corticosteroid in rheumatoid arthritis

Background:Rheumatoid arthritis is an immunologically driven chronic synovitis showing heterogeneity in disease progression, treatment, and variability of response to therapy. This study investigated the effectiveness of methotrexate, folic acid, and vitamin C for treatment of patients with rheumatoid arthritis. Methods:The effects of methotrexate with folic acid, vitamin C, and an occasional steroid were analyzed in 62 patients with rheumatoid arthritis selected on the basis of American College of Rheumatology (ACR) criteria, before and after 24 wk of therapy on (1) lipoprotein profile, (2) Disease Activity Score (DAS)-28, C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR), and (3) oxidative stress. Results:After 24 wk of therapy, the response rates were ACR70 in 72% (45), ACR50 in 21% (13), and ACR20 in 7% (4). The median initial DAS-28-CRP of 5.2 was reduced to 2.5 and median VAS of 7.7 was reduced to 2.4. Assuming normality in the control data, the power of the analysis was 92%. The mean level of low-density lipoprotein-cholesterol (LDL-c), total cholesterol, malondialdehyde, CRP, and triglycerides were significantly (P<0.05) higher, but blood pressure, uric acid, and creatinine were normal in RA patients at baseline. Significant improvements in level of high-density lipoprotein-cholesterol (HDL-c), total cholesterol, CRP, malondialdehyde, and triglycerides were observed in rheumatoid patients treated with methotrexate. At baseline, CRP positively correlated with total lipids (r=0.28, P<0.05) and total cholesterol (r=0.64, P<0.01). Total cholesterol was negatively correlated with HDL-c (r=−0.40, P<0.01). The blood pressure and liver function tests were within normal range at 4 yr follow-up. Conclusions:Methotrexate combination therapy was effective in (1) reducing disease activity, (2) improving rest pain and morning stiffness, and (3) improving lipid profile due to suppression of inflammation. However, whether or not it is capable of lowering or eliminating cardiovascular disease risk requires further investigation as morbidity and mortality are higher in patients with rheumatoid arthritis compared to the general population.

Tissue Engineering and Artificial Organ

Tissue engineering is an exciting technique, which has the potential to create tissues and organs de novo. Tissue engineering was defined in 1988 as “application of the principles and methods of engineering and life sciences toward fundamental understanding of structure–function relationship in normal and pathological mammalian tissues and the development of biological substitutes for the repair or regeneration of tissue or organ function.” It was later summarized as “an interdisciplinary field which involves fundamentals of life sciences, medical sciences, and principles of material sciences, which can provide a functional substitute for damaged or diseased organ restoring, maintaining, or improving tissue function or a whole organ.” The existence of tissue engineering dates to the sixteenth century, when complex skin flaps were used to replace the nose. Initially, the field was recognized as a subfield of biomaterials. Most definitions of tissue engineering cover a broad range of applications; in practice, the term is closely associated with applications that repair or replace portions of or whole tissues (i.e., bone, cartilage, blood vessels, bladder, skin, and so on). It has the potential to produce a supply of immunologically tolerant “artificial” organ and tissue substitutes that can grow in the patient.

Animal Cell Culture and Cryopreservation

Cell culture is a process by which cells are grown under laboratory conditions outside their natural environment. The historical development of methods of cell culture is closely interrelated with tissue and organ culture. Animal cell culture has a long history of over 100 years, although major advancements have been accomplished in the last 30 years. It has become one of the major tools in life sciences. Almost 50 % of the biological products produced today or planned to be produced in the near future are based on animal cell culture. Therefore, there is an increasing interest in developing technologies for cultivation and maintenance of animal cells. Apart from developing new technologies for culturing and manipulating animal cells for producing biologics, researchers are also interested to look into developmental processes using animal cells as a model system. This chapter is designed to serve as a basic introduction to animal cell culture for the students and the laboratory workers who are interested to understand the key concepts and terminologies in this rapidly growing field.

An Introduction to Biotechnology

Biotechnology is multidisciplinary field which has major impact on our lives. The technology is known since years which involves working with cells or cell-derived molecules for various applications. It has wide range of uses and is termed “technology of hope” which impact human health, well being of other life forms and our environment. It has revolutionized diagnostics and therapeutics; however, the major challenges to the human beings have been threats posed by deadly virus infections as avian flu, Chikungunya, Ebola, Influenza A, SARS, West Nile, and the latest Zika virus. Personalized medicine is increasingly recognized in healthcare system. In this chapter, the readers would understand the applications of biotechnology in human health care system. It has also impacted the environment which is loaded by toxic compounds due to human industrialization and urbanization. Bioremediation process utilizes use of natural or recombinant organisms for the cleanup of environmental toxic pollutants. The development of insect and pest resistant crops and herbicide tolerant crops has greatly reduced the environmental load of toxic insecticides and pesticides. The increase in crop productivity for solving world food and feed problem is addressed in agricultural biotechnology. The technological advancements have focused on development of alternate, renewable, and sustainable energy sources for production of biofuels. Marine biotechnology explores the products which can be obtained from aquatic organisms. As with every research area, the field of biotechnology is associated with many ethical issues and unseen fears. These are important in defining laws governing the feasibility and approval for the conduct of particular research.

Plant Biotechnology and Agriculture

Agricultural biotechnology is the term used in crop and livestock improvement through biotechnology tools. Biotechnology encompasses a number of tools and elements of conventional breeding techniques, bioinformatics, microbiology, molecular genetics, biochemistry, plant physiology, and molecular biology. The biotechnological tools that are important for agricultural biotechnology include conventional plant breeding, tissue culture and micropropagation, molecular breeding or marker-assisted selection, and genetic engineering and GM crops. In this chapter, readers would learn about the role of biotechnology in crop improvement and the major applications of the field.

Antioxidant Enzymes in Rheumatoid Arthritis

Joint destruction in rheumatoid arthritis (RA) is due to tissue injury in the area caused by inflammatory reactions, release of MMPs and free radicals produced by neutrophils and macrophages. The control of free radical production may have therapeutic roles thus the study was done to check the status of lipid peroxidation product malondialdehyde (MDA) and a few antioxidant enzymes in RA patients. 45 RA patients and 40 controls were selected. Controls were asymptomatic and RA patients were selected according to ACR criteria. RA patients had significantly high MDA, SOD and ALP and reduced activity of catalase and GR as compared to controls. SOD showed positive correlation with ALP. GR was positively related with MDA, SOD and ALP. The study shows that MDA is involved in the pathogenesis of RA. The system is trying to quench free radicals by high SOD activity. Higher production of H2O2 or some other mechanism is responsible for inhibition of catalase and GR. However system is trying to reduce the damage by neutralizing superoxide anion. Therapeutic intervention of the oxidative stress may be considered for effective control of inflammation in RA patients.

Pharmacogenomics and Pharmacogenetics

With the information available about human genome and human proteome, it is now well understood that there are a lot of variations between individuals. These minor variations account for many differences like adverse drug reactions, which are responsible for many hospitalizations and casualties. The observed variable effect of drug is due to difference in sensitivity as some people need higher dose and some need lower dose to get similar therapeutic effect, but in some people drug has no therapeutic effects and in some shows strong adverse reactions. Some of these differential effects are due to environmental causes, or the individual’s ability to absorb or metabolize a drug may be altered or multiple drug interaction can occur (in people taking multiple drugs). Pharmacogenetics is the study of the roles of specific genes in these effects, whereas pharmacogenomics is the study of how an individual’s genetic makeup affects the body’s response to drugs or the personalized medicine deals with the concepts that for a particular disease, the rate of progression of the disease for each person is unique and each person responds in a unique way to drugs. In its broadest sense, personalized medicine includes the detection of disease predisposition, screening and early disease diagnosis, assessment of prognosis, pharmacogenomic measurements of drug efficacy and risk of toxic effects, and the monitoring of the illness until the final disease outcome is known.