Zeitschrift für Bioingenieurwesen und biomedizinische Wissenschaft

Image processing algorithms play a key role in the development of visual prosthesis systems. In this study, a new electrode stimulation method for retinal implant systems, “Spatio-Temporal Electrode Mapping and Local Interleaved Stimulation (STEMLIS),” is proposed. In this method, the most meaningful spikes that preserve the spatial discrimination in a temporal frame are selected as stimulation data, and phase shifts are applied to all sub electrode groups to minimize undesired electrode interactions. By using this method, both spatial and temporal resolution of stimulation data can be enhanced, since spatio-temporal mapping is used while selecting the stimulation data from a large number of spike data for stimulation of the low-numbered electrode matrix placed on retina surface. The phase delays between the neighboring electrodes are used to introduce interleaved pulses, which minimize the electrical interactions. To evaluate the contribution of the STEMLIS method to perceived image quality, computer based quantitative simulation studies and visual evaluation tests with normal seeing people were performed. For quantitative evaluation, the outputs for the classical method and the STEMLIS method were compared based on the mean squared error (MSE), the histogram similarity ratio (HSR), and edge discrimination parameters. In visual tests, performance of the method was evaluated in terms of contrast discrimination, pattern recognition, text reading and object counting tasks. The subjects reached higher test scores with proposed method and better scores obtained in quantitative comparison. It is concluded that spatio-temporal enhancement of stimulation data can help to improve perceived image quality on visual prostheses.

Progress in the development of assays for measuring cardiac action potential is crucial for the discovery of drugs for treating cardiac disease and assessing cardiotoxicity. Recently, high-throughput methods for assessing action potential using induced pluripotent stem cell (iPSC) derived cardiomyocytes in both two-dimensional monolayer cultures and three-dimensional tissues have been developed. We describe an improved method for assessing cardiac action potential using an ultra-fast cost-effective plate reader with commercially available dyes. Our methods improve dramatically the detection of the fluorescence signal from these dyes and make way for the development of more high-throughput methods for cardiac drug discovery and cardiotoxicity.

This research work presents the surface thermodynamics approach to M-TB/HIV-Human sputum interactions. This involved the use of the Hamaker coefficient concept as a surface energetics tool in determining the interaction processes, with the surface interfacial energies explained using van der Waals concept of particle interactions. The Lifshitz derivation for van der Waals forces was applied as an alternative to the contact angle approach which has been widely used in other biological systems. The methodology involved taking sputum samples from twenty infected persons and from twenty uninfected persons for absorbance measurement using a digital Ultraviolet visible Spectrophotometer. The variables required for the computations with the Lifshitz formula were derived from the absorbance data. The Matlab software tools were used in the mathematical analysis of the data produced from the experiments (absorbance values). The Hamaker constants and the combined Hamaker coefficients were obtained using the values of the dielectric constant together with the Lifshitz equation. The absolute combined Hamaker coefficients A_132abs and A_131abs on both infected and uninfected sputum samples gave the values of A_132abs = 0.21631×10^-21 Joule for M-TB infected sputum and Ã_132abs = 0.18825×10^-21 Joule for M-TB/HIV infected sputum. The significance of this result is the positive value of the absolute combined Hamaker coefficient which suggests the existence of net positive vanderwaals forces demonstrating an attraction between the bacteria and the macrophage. This however, implies that infection can occur. It was also shown that in the presence of HIV, the interaction energy is reduced by 13% conforming adverse effects observed in HIV patients suffering from tuberculosis.

Energy from biomass has emerged as a promising source of decentralized energy production from developing countries. This paper highlights the importance of solid biofuel or pellets in the context of green energy. These can be used in co-firing with coal and other heating applications. Assessment is done for certain raw materials which do not create food and fodder conflict in the Indian state of Gujarat. Raw material includes agricultural residues available from that region. Pellets manufactured have low sulfur and chlorine content.

Silver is widely utilized as antimicrobial agent and wound dressing, where its shape, size, surface area, and surface charge play an important role. The aim of present study was to evaluate the impact of biofield treatment on physicochemical and atomic properties of silver powder. The silver powder was divided into two groups, coded as control and treatment. The treatment group received Mr. Trivedi’s biofield treatment. Subsequently, control and treated samples were characterized using particle size analyzer, X-ray diffraction (XRD) and surface area analyser. Particle size data exhibited that particle sizes d10, d50, d90, and d99 (Size, below which 10, 50, 90, and 99% particle are present, respectively) of treated silver powder were substantially reduced up to 95.8, 89.9, 83.2, and 79.0% on day 84 as compared to control. XRD results showed that lattice parameter, unit cell volume, and atomic weight were reduced, whereas density and nuclear charge per unit volume were found to be increased as compared to control. In addition, the crystallite size was significantly reduced up to 70% after biofield treatment on day 105 as compared to control. Furthermore, the surface area of treated silver powder was substantially enhanced by 49.41% on day 68 as compared to control. These findings suggest that biofield treatment has significantly altered the atomic and physicochemical properties which could make silver more useful in antimicrobial applications.

Salmonella spp., Listeria monocytogenes and viruses constitute major concern for public health. It is known that RTE foods are consumed raw, thus they are often associated with outbreaks of food poisoning. In the present study, the effectiveness of a LAMP fully automated platform able to detect foodborne pathogens in less than an hour, was evaluated. Food samples were inoculated with known pathogens, such as S. enteritidis, L. monocytogenes and hAdV 40/41. With LAMP assays pathogens can be detected shortly and without the need of sophisticated equipment. The results of the present study were then compared to those of the LAMP assays detected by a Light Cycler Roche platform which is a real-time PCR instrument and were in concordance. The developed LAMP platform that is presented in this study could become a valuable, robust, innovative, powerful, cheap and fast monitoring tool which can be extensively used for routine analysis and screening of contaminated foods by the food industry and the Public Health Authorities

Kinematic synergies in human hand movements have shown promising applications in dexterous control of robotic and prosthetic hands. We and others have previously derived kinematic synergies from human hand grasping movements using a widely used linear dimensionality reduction method, Principal Component Analysis (PCA). As the human biomechanical system is inherently nonlinear, using nonlinear dimensionality reduction methods to derive kinematic synergies might be expected to improve the representation of human hand movements in reduced dimensions. In this paper, we derived linear and nonlinear kinematic synergies from linear (PCA), globally nonlinear (Isomap, Stochastic Proximity Embedding (SPE), Sammon Mapping (SaM), and Stochastic Neighbor Embedding (SNE)) and locally nonlinear (Local Linear Embedding (LLE), LaplacianEigenmaps (LaE), and Local Tangent Space Alignment (LTSA)) dimensionality reduction methods. Synergies derived from linear PCA and nonlinear SaMwere able to capture multiple functional postures and physiological patterns. Results from natural hand grasping movements indicated that PCA performed better than all nonlinear dimensionality reduction methods used in the paper. Results from ASL postural movements indicated that PCA, SaM, and SPE better generalized over ASL postural movements when compared to other methods. Overall, our results show that PCA derived synergies offer qualitative and quantitative advantages over nonlinear methods as a limited number of kinematic synergies begin to be implemented in human prosthetics.

Cellulose being an excellent biopolymer has cemented its place firmly in many industries as a coating material, textile, composites, and biomaterial applications. In the present study, we have investigated the effect of biofield treatment on physicochemical properties of cellulose and cellulose acetate. The cellulose and cellulose acetate were exposed to biofield and further the chemical and thermal properties were investigated. X-ray diffraction study asserted that the biofield treatment did affect the crystalline nature of cellulose. The percentage of crystallite size was found increased significantly in treated cellulose by 159.83%, as compared to control sample. This showed that biofield treatment was changing the crystalline nature of treated cellulose. However treated cellulose acetate showed a reduction in crystallite size (-17.38%) as compared to control sample. Differential Scanning Calorimetry (DSC) of treated cellulose showed no improvement in melting temperature as compared to control sample. Contrarily cellulose acetate showed significant improvement in melting temperature peak at 351.91ºC as compared to control (344ºC) polymer. Moreover percentage change in latent heat of fusion (ΔH) was calculated from the DSC thermogram of both treated and control polymers. A significant increase in percentage ΔH of both treated cellulose (59.09%) and cellulose acetate (105.79%) polymers indicated that biofield treatment enhanced the thermal stability of the treated polymers. CHNSO analysis revealed a significant change in percentage hydrogen and oxygen of treated cellulose (%H-17.77, %O-16.89) and cellulose acetate (%H-5.67, %O-13.41). Though minimal change was observed in carbon percentage of both treated cellulose (0.29%) and cellulose acetate (0.39%) polymers as compared to their respective control samples. Thermo gravimetric analysis and Differential thermo gravimetric (TGA-DTG) analysis of treated cellulose acetate (353ºC) showed increased maximum thermal decomposition temperature as compared to control polymer (351ºC). This showed the higher thermal stability of the treated cellulose acetate polymer; although the maximum thermal decomposition temperature of treated cellulose (248ºC) was decreased as compared to control cellulose (321ºC). These outcomes confirmed that biofield treatment has changed the physicochemical properties of the cellulose polymers.

The objective of presented study was to evaluate in vitro effects of extracorporeal shockwave therapy (ESWT) on the keratinocyte morphology, cytoskeleton and mitotic activity. To determine in vitro effects of ESWT on keratinocytes, we applied 100 pulses with an energy flux density 0.1 mJ/mm2 and a frequency of 1 Hz at a distance of 5 cm between therapy head and culture flask. The treatment parameters were determined in a pilot study. Haematoxylin and Eosin staining, as well as immunohistochemistry for Ki-67, CK5, CK14 and CK10 was performed on the cultured keratinocytes and results were compared between ESW treated group and Controls. No pathomorphological abnormalities or alterations in the cells monolayer could be observed. When assessing histological images of all HE-stained sections of ESW-treated and untreated keratinocytes (control group), no morphological differences could be seen between or within the groups. The proliferation marker Ki-67 was found at a frequency of 14% for ESW-treated and 10% for untreated keratinocytes. There were also figures of 95% (CK5 staining) and 90% (CK14 staining) for ESW-treated, as well as 85% (CK5 staining) and 85% (CK14 staining) for untreated keratinocytes. CK10-positive cells showed a frequency of 24% in the ESWtreated and 33% in the untreated cell cultures. Immunohistochemical observations indicated an increased proliferation behaviour following treatment with extracorporeal shockwaves in vitro and maturation of the exposed keratinocytes. Our results suggest an increase in proliferation activity of keratinocytes after in vitro treatment with ESWT. Further investigations of the effects of ESWT on the keratinocyte expression of the chemokines and cytokines are underway.

Background: H. pylori infection is strongly related with chronic gastritis of the antrum of the stomach, which causes impairment in gastric acid and pepsin secretion, and is thus linked to malabsorption of food-vitamin B12. H. pylori can cause an individual to have a vitamin B12 deficiency. It is also a known contributor to gastritis ulcers and it can prevent to the stomach from being able to absorb the vitamin B12 you consume and leads to a deficiency of vitamin B12. The purpose of this study is to determine the frequency of vitamin B12 deficiency in Helicobacter pylori infected patients.

Methods: All patients above 13 years of age, of either gender with Helicobacter pylori infection were evaluated for urine vitamin B12 level by human vitamin B12 ElSA kit. The data was analyzed in statistical software (SPSS) and the P-value=0.05 was considered as statistically significant.

Results: One hundred and twenty nine (129) Helicobacter pylori infected patients with means age 44.3176 ± 15.9114 (males) and 49.6308 ± 15.1612 (females) were enrolled and evaluated. Sixty seven (52%) H. pylori infected patients had normal vitamin B12 level, 31 (47%) were males and 36 (53%) were females. Whereas sixty tow (48%) H. pylori infected patient had low vitamin B12 level, 42 (67%) were males and 20 (33%) were females with (p-value 0.02).

Conclusions: The frequency of vitamin B12 deficiency observed in H. pylori infected patients in this study (48%). However, there is a significant difference between H. pylori infected male patients and female patients who had deficient in vitamin B12 (68%, 32% respectively) with p value (0.01*).