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A. nilotica (L.) leaf extract was subjected to fractional extraction to isolate potential antioxidant compound ethyl gallate. A. nilotica (L.) leaf extract was fractionated with different solvents and was investigated for antioxidant activity. Based on the results, the pure compound obtained from Fr. Y with low IC50 was further characterized by UV–Vis spectra, IR, 1D, 2D-NMR spectra. Pure ethyl gallate showed 75% antioxidant activity. As ethyl gallate is an approved food additive and an emerging anticancer agent, this paper will be of major importance for the food and pharmaceutical industries.

The subtalar joint position during static stance is a crucial determinant of the peak plantar pressures and forms ideal reference point for any intervention in foot-related problems for leprosy-affected patients.The study pursued the hypothesis through a three-dimensional model that stress will be minimal in the distal joints of the foot when the subtalar joint is in neutral static stance position.Finite element model.The computed tomography images of the feet for five patients suffering from Hansen's disease having no muscle weakness and joint restriction were acquired. The gray intensities corresponding to the bones of the foot from the computed tomography images were three-dimensionally reconstructed. The three-dimensional model of the human foot, incorporating the realistic geometry, and the material properties of the hard tissues were then analyzed using a finite element solver for the stress distribution on bones of the foot.The results demonstrate that the position of the calcaneum in the static stance position does contribute to the varying stress in the foot.The stresses in the bones of the foot are minimal while the subtalar is in neutral position; this position will be suitable for foot orthotic fabrication. Clinical relevance The clinicians, therapists, and podiatrists having less engineering skills can quickly assess the patient and get optimal results on the stress associated with the joints of the foot.

This work demonstrates the development of Ag@polyaniline/multi-walled carbon nanotube nanocomposite-based sensor strips and a suitable integrated electronic read-out system for the measurement of trace-level concentrations of ammonia (NH3). The sensor is optimized under various operating conditions and the resulting sensor exhibited an enhanced response (32% for 2 ppm) with excellent selectivity. Stable performance was observed towards NH3 in the presence of high concentrations of CO2 (>40 000 ppm), simulated and real breath samples. A suitable electronic sensor read-out system has also been designed and developed based on multi-scale resistance-to-voltage conversion architecture, processed by a 32-bit microcontroller which is operatable over a wide range of sensor resistance (1 kΩ to 200 MΩ). As a proof of concept, integration of gas-sensing strips with the electronic read-out system was tested with various levels of NH3 ( 2 ppm as critical and 2 ppm as threshold), which is important for clinical breath analyzer applications. The developed prototype device can be readily incorporated into a portable, low-cost and non-invasive point-of-care breath NH3 detection unit for portable pre-diagnostic breath analyzer applications.

Herein we report excellent gas sensor properties of Polyaniline functionalized multiwalled carbon nanotubes (PANI/MWCNTs) based nanocomposite for trace level detection of ammonia (NH3) gas. PANI/MWCNTs nanocomposite was synthesized by in-situ chemical oxidative polymerization of aniline monomer with carboxylated multiwalled carbon nanotubes (C-MWCNTs). The material was structurally characterized by UV–vis Spectroscopy, FT-IR Spectroscopy, Raman Spectroscopy, X-ray Photoelectron Spectroscopy (XPS) and High Resolution Transmission Electron Microscopy (HRTEM). Uniform PANI layer with ∼7 nm thickness was formed on the external walls of the MWCNTs. The gas sensor properties of C-MWCNT and PANI/MWCNTs nanocomposite towards NH3 gas exposure at trace level concentrations (2–10 ppm) under ambient conditions were analyzed and their performances were compared. PANI/MWCNT nanocomposite based sensor exhibited excellent enhancement in sensor response and response/recovery characteristics with good reproducibility towards NH3 gas in comparison with C-MWCNT. The response and recovery time of the PANI/MWCNTs nanocomposite based sensor were found to be significantly improved in the order of a few seconds (6 s) towards NH3 gas. The results reveal the potential application of this sensor in monitoring trace level NH3 gas for varied applications.

Vascular support structures are important devices for treating valve stenosis. Large population of patients is treated for valvular disease and the principal mode of treatment is the use of percutaneous valvuloplasty. Stent devices are proving to be an improved technology in minimal invasive cardiac surgery. This technology now accounts for 20% of treatments in Europe. This new technology provides highly effective results at minimal cost and short duration of hospitalization. During the development process, a number of specific designs and materials have come and gone, and a few have remained. Many design changes were successful, and many were not. This paper discusses the physical behavior of a hooked percutaneous aortic valve stent design using finite element analysis using a new Titanium alloy. The analysis performed in this paper may aid in understanding the stent's displacement ranges when subjected to the physiological pressures exerted by the heart and cardiac blood flow during abnormal cardiovascular conditions. It may also help to evaluate the suitability of a new titanium alloy for fabrication purposes.

Clinicians can provide a means to better distribute the pressure around the foot, and can also correct the biomechanics of the foot by using a customized shoe insole. If detected early enough, orthopedic insoles can correct or prevent further complications. In this study the 3 Dimensional (D) model of the foot was used to fabricate a customized orthosis. The Computed Tomography (CT) images of patient’s foot having no muscle weakness and joint restriction were acquired. The gray intensities corresponding to the bones of the foot from the CT images were 3 dimensionally reconstructed. The 3D model of the foot was then imported into the CAD Software. Boolean operations were carried out in between the 3D foot model and a solid rectangular surface to create a customized foot orthosis. The exact contours and shape of the subject’s foot was acquired using the computerized method of fabricating an orthosis. The novel idea described in this study support, automating the process of designing a customized orthosis with the impression got from the 3 dimensionally modeled feet, thereby reducing the modeling time considerably. The simple technique used in this process will help in giving comfort and stability to the patient’s feet while walking.

In the present study, free radical scavenging, cytotoxic, and hemolytic activities of the polyphenolic compound ethyl gallate isolated from ethanol extract of Acacia nilotica Wild. Ex. Del. leaves were determined. The free radical-scavenging activities of the ethyl gallate were demonstrated in several in vitro assays in order to evaluate the possible antioxidant mechanism. The results revealed ethyl gallate as hydrogen donor, metal chelator, and free radical scavenger. Ethyl gallate was effective in scavenging 1,1-Diphenyl-2-picrylhydrazyl (DPPH) radicals and the IC₅₀ value was lower than all the positive controls used in this study. Deoxyribose degradation assay revealed that ethyl gallate had more iron-chelating ability than the direct hydroxyl radical-scavenging ability. The results of the cytotoxic study revealed that the compound was moderately active and IC₅₀ value was found to be100 μg/mL for Vero cell lines and 72 μg/mL for Hela cell lines. The compound possessed no hemolytic activity against rat and human erythrocytes revealing its cytotoxic mechanism and nontoxicity. The results from this work will provide an important information for the food and pharmacological industries with respect to the use of the compound as an antioxidant and a health-related drug.Antioxidant from plant sources is safe to use, as compared to synthetic products. It also can be used as a supplement to alleviate most of the diseases because of its free radical-scavenging activity.

Aseptic loosening is the major cause of failure of hip implants after total hip arthroplasty. Stress shielding of the femur is known to be the principal factor involved in the aseptic loosening of hip implants. Solid stems are found to have a greater rigidity; therefore, they transfer less load proximally, which results in greater stress shielding of the proximal femur. A stem of low stiffness alone would not suffice in achieving a reduced or optimal stress shielding. The femoral stem of the light weight hip implant has a skeletal design with a hexagonal base and neck cross-section. This novel design would ameliorate the implant fixation, aid in optimal rigidity, enhance the medullary revascularization, and offer better mobility to the patient.

Recently, percutaneous valve replacement has emerged as an alternative treatment for stenosis of mitral, aortic, and pulmonary valves, replacing the surgical approach and providing a new perspective on transcatheter placement of cardiac valves. The conventional open heart surgery does not suit most of the cardiothoracic patient population for various reasons. Percutaneous valve replacement has started becoming the first choice for surgical replacement of the cardiac valves. Under such a scenario where good potent porcine valves made from the pericardium of pigs are being made available, the real question is designing and developing cost effective stents to bear these valves. The ones that are imported are highly expensive which cannot be afforded by some of the Indian population. This also has substantial benefits from the standpoints of health, safety, and cost. The manufacturing of a stented aortic valve is an absolutely critical job, which requires proper designs, finite element analysis, and flow dynamics studies. This paper forms the base for an eventual manufacture of stented aortic valves, giving in-depth details pertaining to design and implantation of the bioprosthesis in the aorta with flow pattern analysis postimplantation and its hemodynamic efficacy analysis. Blood flow analysis and associated hemodynamic analysis help to understand the leakage resistance of the stented valve. A valve of this kind will enable minimal invasive cardiac surgeons to perform percutaneous aortic valve replacement with ease. This would also be an economic procedure allaying the high costs that are typically involved in conventional open heart surgery. We believe that this model has great potential for helping to set up a protocol for the growing of a tissue engineered heart valve construct.

To design against mechanical failure, most implants such as valve stents are assessed on the basis of survival on a long term. However, accurate investigation of the stress/strain distributions in such valve stents, which govern their deformation and fracture behavior, is essential for their prolonged, and safe use. With this background, an S–N type fatigue analysis was done on three stents with Von Mises stress component having the infinite life at 1.e + 006. The results of this study may aid a biomedical scientist to zero in on the material that could be used to analyze and fabricate percutaneous valve stents.

One of the main constituents of total hip replacement (THR) is the design reconstruction of femoral stem component. The major causes of the debonding of the stem–bone interfaces include the aseptic loosening of the femoral stem, dislocation, wear, fatigue, micromotions, design factors, and certain biological responses generated due to the interaction of the implants with the body environment. The usage of cemented stems result in the generation of the high cement mantle stresses thereby results in the loosening of the implants. The porous stems developed by various manufactures are of solid stems with indentations, with collars, collarless, tapered stems; tear dropped polished stems without indentations offer greater rigidity, results in the transfer less load proximally, which results in greater stress shielding of the proximal femur. Stress shielding is found to be the major cause for the failure of the hip implants and revision surgeries. A stem of low stiffness alone would not suffice in achieving a reduced or optimal stress shielding. The biomaterials such as 316L stainless steel (SS), cobalt–chromium alloys (CoCrMo) , and titanium alloys (Ti–6Al–4V) used in THRs provide high strength to weight ratio and have an excellent biocompatibility. Skeletal femoral stems with varying cross sections were designed. The materials used for the design were 316L stainless steel and Ti–6Al–4V . The femoral stem with hexagonal cross section was optimized based on the design that has low weight and better load-bearing capacity. This novel design would ameliorate the implant fixation, aid in optimal rigidity, enhance the medullary revascularization, and offer better motility to the patient.

Dietary intake of phytochemicals having antioxidant activity is associated with a lower risk of mortality from many diseases. Therefore, the aim of this study was to determine the free radical scavenging, cytotoxic and hemolytic activities of leaves ofAcacia niloticaby using various methods. The results of the present study revealed that ethanol extract was the most effective and IC50value was found to be 53.6 μg mL−1for Vero cell lines and 28.9 μg mL−1for Hela cell lines in cytotoxicity assays. The zone of color retention was 14.2 mm in -carotene bleaching assay, which was as significant as positive control, butylated hydroxy toluene. None of the tested extracts possessed any hemolytic activity against rat and human erythrocytes revealing their cytotoxic mechanism and non-toxicity. Thus, only the ethanol extract could be considered as a potential source of anticancer and antioxidant compounds. Further phytochemical studies will be performed for specification of the biologically active principles.

Objective: To design a new trileaflet aortic valve and investigate its mechanical behavior using finite ele- ment methods. Background: Quantification of aortic valve deformation during cardiac cycle is essential in understanding normal and pathological valvular function and eventually in the design of valves. We have designed and analyzed a new tissue valve model to investigate the mechanics of the valve and its components. Methods: Steps involves in 3D CAD based geometric modeling of a trileaflet aortic valve and the effects of different component dimensions on the mechanical behavior of valve is presented in this paper. Conceptual designing of individual components was used to build the total geometric model. Different physiological pressures were applied on the valve model and its deformation patterns were studied. Results: A new geometric model of a trileaflet aortic valve was designed. Its mechanical behavior was studied. Geometric analysis and simulation of these models enhanced the designer to optimize the geometry suitable for performance during and after implantation. Conclusion: The geometry-based model presented here allows determining quickly if the new set of valve component dimensions results in a functional valve. This is of great interest to designers of new prosthetic heart valve models, as well as to surgeons involved in valve- sparing surgery.

Our objective was to design a new trileaflet aortic valve using computer-aided design (CAD). Quantification of aortic valve geometries is essential in understanding normal and pathological valvular function and eventually in the design of valves. We have designed a new tissue valve model to investigate its suitability in aortic valve replacement. Steps involved in three-dimensional CAD-based geometric modeling of a trileaflet aortic valve and the effects of different component dimensions on the mechanical behavior of valve are presented in this article. Conceptual designing of individual components was used to build the total geometric model. A new geometric model of a trileaflet aortic valve was designed. This may be of great interest to designers of new prosthetic heart valve models, as well as to surgeons involved in valve-sparing surgery.

Valve stents are small cylindrical structures introduced in stenosed valves to replace them and restore blood flow. High radial force has become an essential feature of these stents. The primary aim of this investigation was to investigate the effects of varying stent "design parameters" on its radial force by using the finite element method (FEM). The improved model design was carried out to meet the functional and surgical requirements. The finite element model to evaluate radial force of stent was dependant on various design parameters. The results show that amplitude was the dominant parameter in this study. Increasing either strut circumference or thickness generally improved radial force of stent. However, increasing either amplitude or radius of curvature generally weakened it. In conclusion, FEM can quantify the compressive mechanical property of stent and help designers to optimize stent systems.

Objective: To design a novel percutaneous stented valve and model its implantation in the aorta.Background: The dimensions of stented aortic valve components govern its ability to prevent backflow of blood into the left ventricle. Whilst the theoretical parameters for the best stent performance have already been established, an effective valve model and its suitability along with the stent are lacking.Methods: This article discusses the design of a stented valve suitable for percutaneous aortic valve replacement. Steps involved in 3D CAD-based geometric modeling of the stented aortic valve and its implantation in the aorta are presented. Conceptual designing of individual components was used to build the total geometric model.Results: A novel geometric model of percutaneous stented aortic valve was generated. The improved design enhances its performance during and after implantation.Conclusion: The blunt hooks in the stent model prevent its migration in either direction by getting embedded in the aortic endothelium. This novel stent aortic valve may be of great interest to designers of future bioprosthetic heart valve models, as well as to surgeons involved in minimally invasive valve surgeries.

The artifi cial knee is used in the bone resurfacing of the arthritis-affected knee using a procedure called Total Knee Arthroplasty or Total Knee Replacement. The article discusses the existing artifi cial knees that are in the Indian market and the market share analysis of different players in this market. The article also forecasts the expected sales of this orthopaedic implant until the year 2010. The article compares the international artifi cial knee implant technology scenario with that of the Indian market. The international artifi cial knee market is compared with the Indian knee implants market. The article concludes with the requirements of an ideal artifi cial knee that would suit not only the Indian market, but also the Eastern world. Journal of Medical Marketing (2010) 10, 115 – 121. doi: 10.1057/jmm.2009.29; published online 19 February 2010 Keywords: Indian orthopaedic market ; artifi cial knee ; market share analysis ; market estimate ; total knee replacement Downloaded from mmj.sagepub.com

Total Knee Arthroplasty (TKA) using standard artificial knee implant has a limitation in restriction in the range of motion and freedom of movements'. This study was worked out to compare the kinematics of a reconstructed 3D knee with standard and high flexion artificial knee designs. A CT bone model reconstructed with MIMICS for a 3D normal knee joint and the simulation was done for normal knee, standard version of artificial knee as well as the high flexion knee designs. The results of the analyses, provides us an insight that high flexion designs were most suited and gives increased range of motion and also provides an additional degree of freedom so that it almost mimics the normal knee movement. The high flexion design when tested under simulated environment provided a better functionality and increased movements. It was concluded that the normal knee has 6 degrees of freedom (DOF); the standard version has 1 rotation and 1 translation. The high flexion design provides 2 rotations and 1 translation.

The present study compares the two extraction methods and evaluates the free radical scavenging activity of Acacia nilotica. Results indicated that the sequential extraction method was effective in concentrating the active principles in the ethanol extract as compared to the maceration method in DPPH assay. Based on the results, free radical scavenging property of the extracts obtained from sequential extraction method was analyzed in different assays to find out the possible antioxidant mechanism. Our results indicate that ethanol extract rich in phenolic and flavonoid contents had potent antioxidant activity and were significant in comparison with all the positive controls used in this study. The possible antioxidant mechanism of the ethanol extract can be due to its hydrogen or electron donating and direct free radical scavenging properties. Hence, the ethanol extract represents a source of potential antioxidants that could be used in pharmaceutical and food preparations.

Cr(VI) (hexavalent) is a very strong oxidant which causes high cytotoxicity through oxidative stress in tissue systems. Its abundance in groundwater and drinking water in several parts of the world has been noted to cause severe toxicity to both flora and fauna. This study evaluated the effects of aqueous extract of Phyllanthus amarus Schum. & Thon. against Cr(VI)-induced oxidative toxicity in vitro in MDA-MB-435S human breast carcinoma cells, along with an estimation of its antioxidant potential, inhibition of lipid peroxidation and determination of its polyphenolic composition. The extract showed significant (P

Plant-derived extracts have been used as folk remedies for Type 2 diabetes mellitus (T2DM) for many centuries, and offer the potential of cheap and readily available alternatives to conventional pharmaceuticals in developing countries. Extracts of Costus pictus (CP), a plant belonging to the Costaceae family, are reported to have antidiabetic activity in vivo. The exact molecular mode of action(s) of CP is unclear but the antihyperglycemic effect seen in animal studies was associated with dramatic increases in insulin secretion so in our study we have measured the effect of aqueous CP extract on insulin secretion in vitro from the MIN6 β-cell line and isolated mouse and human islets. Our data demonstrate that CP has a direct stimulatory effect on insulin secretion at basal but not stimulatory glucose concentrations which was not associated with compromised membrane integrity or decrease β-cell viability. Single cell calcium microfluorimetry measurements showed that CP caused elevations in β-cell intracellular Ca(2+) concentrations ([Ca(2+)](i)), an effect which was completely abolished by the removal of extracellular Ca(2+) or blockade of voltage-gated Ca(2+) channels (VGCC). These in vitro observations suggest that one mode of action of CP is through stimulating insulin secretion which may be mediated, in part, by the ability of CP to increase [Ca(2+)](i) levels through VGCC. CP extracts may provide an affordable and inexpensive alternative for treating patients with T2DM.

Gout is a rheumatic disease that is manifestated by an intense inflammation secondary to monosodium urate crystal deposition in joints. In the present study, we assessed the effect of 6-shogaol (isolated active principle from ginger) on monosodium urate crystal-induced inflammation in mice; an experimental model for gouty arthritis and compared it with that of the non-steroidal anti-inflammatory drug, indomethacin. Paw volume and levels/activities of lysosomal enzymes, lipid peroxidation, anti-oxidant status and inflammatory mediator TNF-alpha were determined in control and monosodium urate crystal-induced mice. The levels of beta-glucuronidase and lactate dehydrogenase were also measured in monosodium urate crystal-incubated polymorphonuclear leucocytes (PMNL) in vitro. The levels of lysosomal enzymes, lipid peroxidation, and inflammatory mediator tumour necrosis factor-alpha and paw volume were increased significantly and the activities of anti-oxidant status were in turn decreased in monosodium urate crystal-induced mice, whereas these changes were reverted to near normal levels upon 6-shogaol administration. In vitro, 6-shogaol reduced the level of beta-glucuronidase and lactate dehydrogenase in monosodium urate crystal-incubated polymorphonuclear leucocytes in concentration dependent manner when compared to control cells. The present results clearly indicated that 6-shogaol exerted a strong anti-inflammatory effect and can be regarded as useful tool for the treatment of acute gouty arthritis.

Background Vascular support structures are important devices for treating valve stenosis. Large population of patients are treated for valvular disease and the principal mode of treatment is the use of percutaneous valvuloplasty. Stent devices are proving to be an improved technology in minimal invasive cardiac surgery. This technology now accounts for 20% of treatments in Europe. This new technology provides highly effective results at minimal cost and short duration of hospitalization. Methods This paper discusses the design and finite element analysis (FEA) of a percutaneous aortic valve stent. The stent design was modeled and subjected to FEA. The improved model design was carried out to meet the functional and surgical requirements. Analysis was done with different materials with loads ranging from 50 to 73 kgf/mm 2 . These forces were selected because these values are far greater than the normal human blood pressure which ranges from 10 to 16 kPa. It was also to understand the mechanical behavior of different stent materials under such high pressures. Results A stent model was generated and its physical, mechanical, and behavioral properties were studied. Finite element analysis and simulation of the model help the designer to optimize the geometry suitable for performance during and after implantation. The design objective for the stent is to have long-term durability, low thrombogenicity, and resistance to migration and paravalvular leak. Conclusion The analysis performed in this paper may aid in understanding the stent's tolerable pressure ranges in comparison with the physiological pressures exerted by the heart and cardiac blood flow during abnormal cardiovascular conditions. It may also help in finding the material that will best suit the stent.

Total knee arthroplasty (TKA) has been the end-time surgical procedure for pain relief and movement restoration in cases of severe arthritis. The knee implant design plays a vital role in deciding the activity levels of a patient after total knee replacement (TKR). In about 90% of younger patients undergoing the knee replacement surgeries, the restriction is not from the subject but from the implant design. This paper discusses parameters affecting the activity levels after TKR. It also briefs the design aspects of a novel knee design that allows the normal high flexion activity even after TKR. The application of finite element modeling in medical applications has been evolving as the field of high importance especially in the development of medical devices. The TKA has been in existence for over six decades till now. The generic artificial knee implants used in the TKA have the restriction in its range of motion of about 90°. A new design allowing flexion extension range of over 120° was designed with a view to facilitate partial squatting and the same is used for the analysis purpose. The loading conditions of 10 times the body weight are considered. The finite element analyses of the designs were carried out based on standard biomaterial used in orthopedic implants. In this paper, we have discussed the results of analyses of an artificial knee with titanium (Ti) alloy. The results of the analyses were used in identifying areas of extreme stresses within the design and the spot prone for higher deformation. Based on these results, slight modification on the designs was carried out. The results are also verified whether the body is within the linear deformation levels. As the results obtained were very satisfactory, the models have been recommended for prototyping.

The application of finite element modeling in medical applications has been evolving as the field of high importance especially in the development of medical. The generic artificial knee implants used in the total knee arthroplasty have the restriction in its range of motion with around 90 degrees. A new design allowing flexion extension range of over 120 degrees has been designed with a view to facilitate partial squatting and the same is used for the analysis purpose. The loading conditions of 10 times the body weight are considered. Finite element analyses of this design have been carried out based on standard biomaterial used in orthopaedic implants. In this paper we discuss the results of analyses of an artificial knee with stainless steel alloy. The results of the analyses were used in identifying areas of extreme stresses within the design and the spot prone for higher deformation. Based on these results slight modification on the designs was carried out. The results are also verified whether the body is within the linear deformation levels. As the results obtained were very satisfactory the models have been recommended for prototyping. It is verified from the results that the new models respond positive till a load of 300 kg and then they enter into the maximum yield stress levels. However, in reality, the loading on an artificial knee is less than 300 kg. So the results are inferred positive and the models were sent for prototyping.

Vascular support structures are an important tool for treating valve stenosis. A large population of patients are treated for valvular disease and the principal mode of treatment is the use of percutaneous valvuloplasty. Stent devices are proving to be an improved treatment method; these devices now account for 20% of treatments in Europe. This new technology provides highly effective results at minimal cost and with reduced hospital stays. Accurate and reliable structural analysis provides essential information to the design team in an environment where in vivo experimentation is extremely expensive or impossible. This paper describes the design of a new vascular support structure (stent), to provide designers with estimates of the critical parameters which are essential. Stainless steel stents are preferred to be used as balloon-expanded prostheses as they are cost-effective.

Aim: This paper discusses the design and Finite Element Analysis (FEA) of a Percutaneous Aor-tic Valve Stent. The aim of this study was to model a percutaneous aortic valve stent and subject it to finite element analysis. The design process was carried out to meet the functional and surgical requirements. Methods and Results: Analysis was done with different materials with loads ranging from 50 kgf/mm² to 73 kgf/mm². These forces were selected because these val-ues are far greater than the normal human blood pressure which ranges from 10kPa to 16kPa. It was also to understand the mechanical behavior of different stent materials under such high pressures. A stent model was generated and its physical, mechanical and behavioral properties were studied. Finite element analysis and simulation of the model enhanced the designer to optimize the geometry suitable for perform-ance during and after implantation. The design objective for the stent is to have long term du-rability, low thrombogenicity, resistance to mi-gration and paravalvular leak. Conclusion: The analysis performed in this paper may aid in understanding the stent’s tolerable pressures ranges in comparison with the physiological pressures exerted by the heart and cardiac blood flow during abnormal cardiovascular conditions.

Vascular support structures are an important tool for treating valve stenosis. A large population of patients are treated for valvular disease and the principal mode of treatment is the use of percutaneous valvuloplasty. Stent devices are proving to be an improved treatment method; these devices now account for 20% of treatments in Europe. This new technology provides highly effective results at minimal cost and short duration of hospitalization. Accurate and reliable structural analysis provides essential information to the design team in an environment where in vivo experimentation is extremely expensive, or impossible. This paper describes the design of vascular support structure (stents), to provide designers with estimates of the critical parameters which are essential to restore the functions of the endothelium of the Aorta during and after implantation without injuring it.

The application of finite-element modelling in medical applications has been evolving as a field of high importance in recent times. Total knee arthroplasty (TKA) has been in existence for over 6 decades. The generic artificial knee implants used in the TKA have a restricted range of motion of around 90 degrees. A new design allowing a flexion extension range of over 120 degrees was designed and is used for analysis. Loading conditions of 10 times the body weight are considered. The finite-element analyses of the designs were carried out based on standard biomaterials used in orthopaedic implants. The results of the analyses were used in identifying areas of extreme stress within the design and the spots prone to higher deformation. On the basis of these results slight modification of the designs was carried out. The results are also verified whether the body is within the linear deformation levels. The results obtained were very satisfactory and based on these results the models have been recommended for prototyping.

The energy contribution due to cation-pi interactions has been computed for 37 RNA binding proteins. The contribution of these cation-pi interacting residues in sequential separation, secondary structure involvement, solvent accessibility, and stabilization centers has been evaluated. Sequential separation of the cation-pi involving residues show that, long range contacts predominates in all the proteins studied. Lys and Arg prefers to be in helical structures. Of the cation-pi interacting residues, Arg and Lys were in the exposed regions and the aromatic residues (Phe, Tyr and Trp) were in the buried and partially buried regions in the protein structures. Stabilization centers for these proteins showed that all the five residues found in cation-pi interactions are important in locating one or more of such centers. On the whole, the results presented in this work will be very useful for further investigations on the specificity and selectivity of RNA binding proteins and also for their structural studies.

Higher rates of glucose utilization and glycolysis generally correlate with poor prognosis in several types of malignant tumors. Own earlier studies on model systems demonstrated that the nonmetabolizable glucose analog 2-deoxy-D-glucose (2-DG) could enhance the efficacy of radiotherapy in a dose-dependent manner by selectively sensitizing cancer cells while protecting normal cells. Phase I/II clinical trials indicated that the combination of 2-DG, at an oral dose of 200 mg/kg body weight (BW), with large fractions of gamma-radiation was well tolerated in cerebral glioma patients. Since higher 2-DG doses are expected to improve the therapeutic gain, present studies were undertaken to examine the tolerance and safety of escalating 2-DG dose during combined treatment (2-DG + radiotherapy) in glioblastoma multiforme patients.Untreated patients with histologically proven glioblastoma multiforme (WHO criteria) were included in the study. Seven weekly fractions of (60)Co gamma-rays (5 Gy/fraction) were delivered to the tumor volume (presurgical CT/MRI evaluation) plus 3 cm margin. Escalating 2-DG doses (200-250-300 mg/kg BW) were administered orally 30 min before irradiation after overnight fasting. Acute toxicity and tolerance were studied by monitoring the vital parameters and side effects. Late radiation damage and treatment responses were studied radiologically and clinically in surviving patients.Transient side effects similar to hypoglycemia were observed in most of the patients. Tolerance and patient compliance to the combined treatment were very good up to a 2-DG dose of 250 mg/kg BW. However, at the higher dose of 300 mg/kg BW, two out of six patients were very restless and could not complete treatment, though significant changes in the vital parameters were not observed even at this dose. No significant damage to the normal brain tissue was observed during follow-up in seven out of ten patients who received complete treatment and survived between 11 and 46 months after treatment.Oral administration of 2-DG combined with large fractions of radiation (5 Gy/fraction/week) is safe and could be tolerated in glioblastoma patients without any acute toxicity and late radiation damage to the normal brain. Further clinical studies to evaluate the efficacy of the combined treatment are warranted.

The use of soft computing techniques for medical image analysis is reviewed in this paper. These techniques involve application of fuzzy logic, neural network and evolutionary algorithms. We introduce the different imaging modalities and motivation for using soft computing techniques for medical image analysis. We review different soft computing based approaches for image processing and segmentation, which can improve the diagnostic value of the images. We also present some results with MRI images. Based on these approaches we suggest an architectural framework for soft computing based application development.

Retinoblastoma (RB) is an eye cancer found in children. Early diagnosis of RB is very crucial for the treatment to be effective. miRNA 18a is highly expressed in the serum of RB patients which can be used as a diagnostic marker to detect RB. A pillar based micro mixer is designed and fabricated on PMMA platform to hybridize the target miRNA 18a with its complementary quenched probe throughout the flow. The fluorescence can be measured in the monitoring well by the fluorescent reader at a particular wavelength and compared with the controls. The RB serums showed high fluorescence than the controls. The results were validated with the contemporary technique, Real-Time PCR and the results were concurring. Another advantage of the device is that the effort required for the immobilization of the probe on a platform is not needed, at the same time cost and time required for diagnosis is reduced.

The hyper-radiosensitivity at low doses recently observed in vitro in a number of cell lines is thought to have important implications for improving tumor radiotherapy. However, cell-cell contact and the cellular environment influence cellular radiosensitivity at higher doses, and they may alter hyper-radiosensitivity in vivo. To confirm this supposition, we investigated the effects of cell density, multiplicity and nutritional deprivation on low-dose hypersensitivity in vitro. Cell survival in the low-dose range (3 cGy to 2 Gy) was studied in cells of two human glioma (BMG-1 and U-87) and two human oral squamous carcinoma (PECA-4451 and PECA-4197) lines using a conventional macrocolony assay. The effects of cell density, multiplicity and nutritional deprivation on hyper-radiosensitivity/induced radioresistance were studied in cells of the BMG-1 cell line, which showed prominent hypersensitivity and induced radioresistance. The induction of growth inhibition, cell cycle delay, micronuclei and apoptosis was also studied at the hyper-radiosensitivity-inducing low doses. Hyper-radiosensitivity/induced radioresistance was evident in the cells of all four cell lines to varying extents, with maximum sensitivity at 10-30 cGy, followed by an increase in survival up to 50 cGy-1 Gy. Both the glioma cell lines had more prominent hyper-radiosensitivity than the two squamous carcinoma cell lines. Low doses inducing maximum hyper-radiosensitivity did not cause significant growth inhibition, micronucleation or apoptosis in BMG-1 cells, but a transient G(1)/S-phase block was evident. Irradiating and incubating BMG-1 cells at high density for 0 or 4 h before plating, as well as irradiating cells as microcolonies, reduced hyper-radiosensitivity significantly, indicating the role of cell-cell contact-mediated processes. Liquid holding of BMG-1 cells in HBSS + 1% serum during and after irradiation for 4 h significantly reduced hyper-radiosensitivity, suggesting that hyper-radiosensitivity may be due partly to active damage fixation processes at low doses. Therefore, our findings suggest that the damage-induced signaling mechanisms influenced by (or mediated through) cell-cell contact or the cellular environment, as well as the lesion fixation processes, play an important role in hyper-radiosensitivity. Further studies are required to determine the exact nature of the damage that triggers these responses as well as for evaluating the potential of low-dose therapy.

Modern biomedical advances have propelled percutaneous valve replacement into an effective and powerful therapy for many heart valve diseases, especially aortic valve stenosis. Experiences so far suggest that outcomes for new percutaneous valve replacement surgery compare favorably with that of traditional valve surgery in selected patients with severe symptomatic aortic stenosis. The inception of percutaneous aortic valve replacement (PAVR) began in 1992 when the potential for treating valve diseases was demonstrated through a modern technique of endoluminal deployment of a catheter-mounted crimped stented heart valve in an animal model. The first successful demonstration of such novel technique of surgical replacement of a heart valve was performed in 2002, when valve implantation in a patient with aortic stenosis was reported. Despite initial stumbles and a perception of being an uphill task, PAVR has emerged as one of the breakthroughs in surgical procedures. More than 1500 citations were found in PubMed, half of which were available after 2011. This is primarily because more than 50,000 procedures are being performed in more than 40 countries worldwide, with encouraging outcomes, and several stented valves have been launched in the market. This review provides a detailed analysis of the current state of the art of PAVR. Moreover, a competitive landscape of various devices available in the market and their design considerations, biomaterial selections, and overall hemodynamic performance are presented.

Prevention and treatment of various degenerative diseases using traditional medicines is increasingly generating interest, especially in geriatric clinical research. This study aimed to evaluate the free-radical scavenging properties and potential to prevent DNA damage (from oxidative stress) of 56 extracts (polar and non-polar) from 14 medicinal plants (from 12 families) used by diverse Indian tribes and ethnic groups. Although widely known for traditional uses, these plants have not been extensively used for clinical purposes. Scavenging of DPPH\bullet radical by all the extracts was evaluated to estimate their antioxidant potential and rank them accordingly. Extracts occupying the top 10 ranks were further evaluated and extensively screened for their antioxidant potential by estimation of their ABTS\bullet+-scavenging and Fe+3-reducing properties. A cumulative ranking system was designed for these 10 plant extracts based on the results of the 3 antioxidant assays. Simultaneously, protection of DNA against photolyzed H2O2-induced oxidative damage by all 56 extracts was studied in pBR322. Considerable anti-genotoxic potential was exhibited by the top 3 extracts on the cumulative rank table, thereby proving the results of all the experiments were congruent. This is a preliminary report, which may yield a roadmap for isolating the active components from these extracts and designing geriatric medicines.

Biotechnology, in its present perspective, encompasses activities, such as recombination of genes; cloning, or making genetically identical copies of a living thing; and splicing of genes from DNA of one organism into the genome of unrelated species, to create new, self-reproducing forms of life. The vast potential of biotechnology is being increasingly realised, and efforts are in progress to harness it for improving quality and quantity of bio-weapons, The bio-weapons, as such, are highly attractive because of their non-detection by routine security systems, ease of access, low production cost and easy transportation, A wide range of genetically manipulated organisms and their by-products are considered to have an added advantage, because these genetically manipulated biologics not only accentuate the existing properties of bio-weapons, but also could be made target-specific. Biotechnology, if used prudently, can play a significant role to counter such threats of biologics, viz., by producing (i) bio-armoury comprising powerful antibiotics, antisera toxoids and vaccines to neutralise and eliminate a wide range of diseases, and (ii) bio-sensors for rapid detection, identification and neutralisation of biological warfare agents. This article elucidates some facets of biological warfare, legal protective strategies emphasised through international consultation, cooperation and adherence to the Biological and Toxin Weapons Convention, and discusses how biotechnology could be effectively used to strengthen countries' defence and combat the threat of biological warfare.