only causing health concern but also have a significant socio economic impact. In 2012, 4.8 million people died and 471 billion USD were spent due to diabetes . However, the major fact of concern is that around half of the people with diabetes don’t know they have it  and get diagnosed only when serious condition arises. It may be due to the unavailability of technology, lack of consciousness and the invasive natures of the present diagnosis tools ofglucose measurement. But People inherently may show reluctance ofusing invasive tools for diabetes measurement although having consciousness about the complications of diabetes and it can be predicted easily that if the diabetes can be measured in a non invasive manner, the rate ofusing diagnosis tools will be increased which consequently will decrease the no. of undiagnosed people and hence the no. of death by diabetes. Besides, to avoid complexities due to diabetes, frequent glucose monitoring is necessary which is not possible with invasive glucose monitoring devices that requires blood collection at the present state. Moreover, the invasive techniques cause pain, high cost per measurement and potential risk of infection. All these issues inevitably lead to the necessity of a non invasive glucose measurement system.
X-ray diffraction (Shimadzu, XRD 7000, using CuKα radiation, 30 mA and 40 kV) was used to analyze the phase composition and content in the composite. The diffraction pattern, obtained within the angular range of 10-80º (2θ) in step-scanning mode (0.02 º/step, 2 s/step), was analyzed by Rietveld refinement method using Materials Analysis Using Diffraction (MAUD) program. The protocol used to estimate amorphous phase content can be found in a previous work . Microstructural characterizationof the fired sample was assessed using a field-emission gun scanning electron microscopy (FESEM, Carl Zeiss, Supra 35-VP). Apparent density was determined by the Archimedes method. Dielectric and electrical properties were studied by impedancespectroscopy in air. Impedance spectra were acquired at 25 °C and from 300 to 600 °C under open circuit conditions using a Hewlett Packard 4284A LCR meter in a two-probe configuration (frequencies ranging from 20 Hz to 1 MHz with a test signal amplitude of 0.5 V). Au electrodes were painted on the parallel faces of the sample and thermally treated at 700 °C for 15 min. Electrical conductivity (σ), capacitance (C), dielectric constant (ε r ), and dielectric loss (tanδ) were
Dielectric characterization has been applied as a convenient tool for evaluation of transport and polarization mechanisms in soft materials. In this work, we have explored the study of charge transport mechanisms in alginate hydrogel containing neomycin-loaded liposomes. For comparison, drug release kinetic was evaluated by using UV-Vis spectrophotometry and electricalimpedancespectroscopy (EIS) at different external direct current (DC) polarization (100 mV and 1 V). The charge transfer resistance (Rct) was proportional to DC electrical stimulation and inversely to the amount of released neomycin. Optical and electrical measurements confirmed the dependence of neomycin release under influence ofelectrical potentials. The kinetic profile of these systems was described by zero-order model. In addition, the Korsmeyer-Peppas model also suggested a diffusion mechanism based on super case II transport (non-Fickian). These results encouraged the use of EIS as a “dark” spectroscopy technique, since EIS is effective for studies of release kinetics controlled by DC external electrical excitation.
In this study, we have shown by using electrochemical impedancespectroscopy and surface plasmon resonance that peroxidase enzyme adsorbed on the ds-DNA layer on modiied gold electrode. Electrochemical impedancespectroscopy allowed the monitoring of the successful construction of the multicomponent film on the gold surface. And also, continuous monitoring of the SPR signal allowed to obtain the kinetic data of the system desired. The reaction showed that the interaction of the peroxidase on ds-DNA layer is favourable once both kinetic constants and binding energy are comparable to DNA-protein interaction. The interaction constants of our system are as strong as a gold-thiol bond. This procedure employed enables us to monitor the interaction of proteins in real time allowing further applications as a biosensor.
where a is a proportional specific constant of the population and c is an adjustment constant. Several studies (3-6) include anthropomet- ric predictors (i.e., weight, age, gender, race, waist-to-hip ratio, body mass index) in the equation to obtain a better correlation with gold standards, but many of these equations are population specific and no physiological justification for the added terms has been pro- vided. Bioelectrical impedance equations have been developed for newborn infants and tod- dlers, children and adolescents, and for adults of all ages. The most important of these equa- tions is that they show a good correlation with
able to distinguish different high grade atherosclerotic lesions from another at 100 kHz frequency . Although the limited number of available samples might have influenced our data, the results of the present study now demonstrate that not just plaque structure but also qualitative components like inflammatory cells and their proteolytic enzymes influence EIS results, representing a next step when utilizing this new method. However, EIS has to be performed in settings with the lowest achievable environmental influence. It is well known from earlier experiments that EIS requires a close tissue contact [7,16]. Vessel damage might constitute an additional important limitation of the technique itself. Therefore, only spots without visible damage were analyzed in the present study and the tissue contact was kept constant. Perspectively, more has to be learned about the in vivo application of the device. The impact of blood stream and the electric properties of blood surrounding the electrodes during EIS have to be determined. The influence of the pulsatile vessel movement and of electric currents has to be assessed. Furthermore, it has to be evaluated if the method is as sensitive in the coronaries with smaller vessel diameters and lower intimal thicknesses compared to the femoral and aortic arteries under test, although simulations performed before demonstrated that inner vessel diameters did not influence measurement results . However, along with further knowledge and appropriate technical development, EIS could be an additional tool to provide online in vivo information of atherosclerotic lesions in future.
In the present research studies, our efforts were to synthesize and characterize some new compounds from the conventional as well as microwave methods. Microwave method has been considered a green chemical route. These synthesized compounds were characterized by various physicochemical and spectral analyses. In course of microwave assisted synthesis, it was observed that the reaction time decreased from hours to minutes and availability of the product with better yield as compared to the conventional method. Use of solvent is also minimized. The synthesized Schiff base ligands bind with the metal ions in a bidentate manner, with ON donor sites of deprotonated phenolic-O and azomethine-N. The 1 H-NMR data suggest that both the Schiff base ligand deprotonated after complexation. Such metal complexes may be of stereoselective and stereoactive in nature to be applicable for various catalytic reactions. Thermogravimetric studies reflect their thermal stability. The antimicrobial data showed that the metal complexes to be more biologically active compared to those parent Schiff base ligands against all pathogenic species. Such studies may assist to search some novel chemotherapeutics to answer the emerging problem of drug resistance in health sciences.
Figure 3 compares NIR and gravimetric results for the residual acrylamide concentration and con- version for inverse miniemulsion polymerizations that were not used in the calibration model. All reac- tions conducted with the aqueous phase initiator KPS, added to the dispersed phase prior to the miniemul- sification procedure, show an initial conversion around 17%, followed by an induction period during the first minutes of reaction due to the presence of traces of oxygen (polymerization inhibitor). The in- duction period occurred for all reactions (with KPS and AIBN) since oxygen enters the reaction medium during the emulsification and homogenization (with Ultra Turrax) steps. The eventual presence of other impurities may also contribute to this induction pe- riod (Capek, 2010; Qi 2007, Ouyang et al., 2011b). Though, initial induction periods are usually not desired, their presence does not hamper the purpose
Braz. J. of Develop., Curitiba, v. 6, n.4,p.18621-18636 apr. 2020. ISSN 2525-8761 Total cellulose (37.44%), hemicellulose (28.31%) and lignin (22.22%) content in SCB was approximately 88% (Table 1). The acid hydrolysis pretreatment promoted SCB fiber disorganization after a partial removal of the hemicellulose fraction (Figure 1b). The physical structure of the solid residue, which is composed of cellulose (47.25%), lignin (26.47%) and hemicellulose (23.35%), is shown in Table 1. The same acetyl radical proportion in both unpretreated and pretreated SCB indicates that acetyl radicals were released in the same way as acetic acid during hemicellulose depolymerization. There was no change in ash content, which indicates that the acid pretreatment has not altered the mineral composition of SCB. However, a complete removal of extractives during the pretreatment was observed (Table 1).
and covers approximately 10% of the Brazilian territory. Thus, the Caatinga scrub is the largest dry forest region in South America, characterized by a semi-arid climate, low and irregular rainfall, fertile soils and mostly dry vegetation. The climate of the Caatinga is extremely seasonal and severe droughts are relatively frequent. Rainfall is more intensive in February, March and April. Occasional rain occurs in June and July, whereas the dry season extends from August to January (Machado and Lopes 2004, Roque et al. 2009). In spite of the hard climatic conditions, Caatinga flora is a rich and very important source of food to bees that occur in the region. Santos et al. (2005) prepared a list of thirteen species vital for apiculture in the Northeastern Region of Brazil. These authors reported the importance of the genus Croton, Hytpis and Richardia for honey production in the Brazilian Northeastern region. Recently, Maia- Silva et al. (2012) presented a list of various native plants of the Caatinga visited by honeybees.
The use ofelectricalimpedance to assess cervical ripening has been reported in the literature, e.g., Avis et al. (1997), Etemadi et al. (2013), Gandhi et al. (2006a; 2006b), Hoe et al. (2004) and O’Connell et al. (2000). Avis et al. (1997) presented in-vitro measurements of the electricalimpedanceof cervical tissue from samples taken at caesarean sections, and reported differences between term and preterm samples. In O’Connell et al. (2000) the authors performed measurements ofelectricalimpedanceof pregnant and nonpregnant women, and indicated that the results might be as good as those obtained by BS. Hoe et al. (2004) proposed a bioimpedance probe that might be used to detect preterm labor. Laboratory in-vitro tests were conducted on various collagen concentrations with success. In Gandhi et al. (2006a) the authors observed that the impedance increases significantly only in the third trimester of gestation. The characteristics of the measuring probe (e.g., the distance between electrodes) are considered in Gandhi et al. (2006b). Jokhi et al. (2009) performed EIS measurements on women admitted for induction of labour, using a number of different probes, in conjunction with BS. In their case, only the larger probe (12 mm) was predictive of any labour. Combined results from LIF and EIS were used in (Etemadi et al., 2013) to assess microstructural changes in the cervix. Initial results were presented for a 6-electrode transvaginal probe. Considering the works listed above, and others reported in the open literature, a relationship between electricalimpedance and cervical ripeness seems evident. This is probably intuitive, since expressive changes in the cervical stroma during pregnancy should reflect in changes in its electrical conductance. There is, however, significant influence on the results of the shape of the probes used, which has not been clearly exposed yet. Therefore, it seems that this research topic still deserves further investigation and, in fact, it still attracts considerably interest.
endothermic effects present on heating and accompanying the eutectoid transformation (700 to 800 o C) become exothermic in nature on cooling. Compared with the DSC diagram plotted for ductile iron before austempering , the heating curve reveals a strong exothermic effect at a temperature well above 460°C. The same effect but characterised by lower energy occurs in specimens after austempering at 280 o C and 330 o C. The appearance of the exothermic effect on heating suggests that during austempering of base cast iron a process related with heat absorption by the specimen (the endothermic effect) takes place. To exclude the effect of eutectoid transformation, two experiments were carried out. They consisted in single and double heating of the specimen up to 650 o C followed by cooling. The DSC diagram after double heating cycle and cooling is plotted in Figure 2.
In this work, two RF magnetron sputtering systems were used to produce undoped and Al-doped ZnO thin films. The systems are similar (AJA, Model ATC ORION 8 (Fig. 3.21 (a)) with the difference being the sputtering targets dimensions that can be deposited on each system. Most of the work was performed in the AJA system existent in CEMOP that is prepared for two inches sputtering targets. The second system used is located at CREST – Loughborough University, and was used to evaluate the performance of several targets manufactured with three inches diameter. The systems are equipped with a load-lock chamber for sample introduction/removal, so very low pressures are achiev ed in the main chamber (≤ 0.05 mPa). Both systems have more than one magnetron (Fig. 3.21 (b)) allowing for co-sputtering and subsequent production of multicomponent materials, although this was not explored in this research work being all the thin films compositions obtained directly from pre-defined ceramic target compositions. The systems can be almost totally computer-controlled and provide the possibility of heating the substrate up to 850 °C. Sputtering of two inches targets was carried out without intentional heating, while three inches targets were sputtered in a range of temperatures between room temperature and 450 ◦C. In both cases was used a base pressure of 3.4 × 10 -4 Pa. Target to substrate (soda-lime
The existence of trace metals in aquatic environments has led to serious concerns about their influence on plant and animal life . Geo-accumulation index is the quantitative measure of the degree of pollution in aquatic sediment. It consists of seven grades ranging from unpolluted to very extremely polluted and the Pollution load index is a quick tool in order to compare the pollution status of different places, the pollution load index is use to determine the pollution severity and its variation along the different sample stations . Heavy metals are chemical elements having atomic weights between 63.546 and 200.590 and a specific gravity that is 5 times greater than that of water. They exist in water in colloidal, particulate and dissolved phases with their occurrence in water bodies being either of natural origin (e.g. eroded minerals within sediments, leaching of ore deposits and volcanism extruded products) or of anthropogenic origin(that is; solid waste disposal, industrial or domestic effluents, harbour channel dredging) . Furthermore, trace toxic metals are not easily removed from the environment nor are readily detoxified or degraded by metabolic activities in the body of the organism, thereby resulting in accumulation [5, 6]. Research has been that, they are no studies on sedimentology and geochemistry of the sediment in Ona River. To provide baseline information and also enlightened the people of the area about the immediate effect of the water body studied, they is need to determine trace metals pollution in sediment using pollution load index and Geo-accumulation Index. This study reports the levels of __________________________
Genomic DNA of D. vulgaris Hildenborough was isolated with a standard cetyltrimethylammonium bromide (CTAB)-DNA precipitation method . The Bfr coding sequence was amplified using two specific oligonucleotide primers homologous to the 5’- and 3’-ends, which also included restriction enzyme recognition sites (NdeI in the forward primer and EcoRI in the reverse primer). The PCR product was purified from 0.8% agarose gels with GFX PCR DNA and a Gel Band Purification kit (GE Healthcare) and then cloned into pET-21c(+) (Novagen). The resulting overexpression vector was used to transform E. coli BL21(DE3) competent cells. Cells were grown in 500 mL 2× YT medium containing 100 µg/mL ampicillin at 37 ºC, at 180 rpm, until reaching an Figure 2.1: Typical calibration curve obtained with a Fe 2+ standard solution. The trend line equation is Abs 510nm =11.251×[Fe 2+ ] (R 2 = 0.9995). Each experimental point represents the mean
In the spectra of undiluted beer, Fig. 1A, measured us- ing the front-face geometry, a relatively intense band with excitation at about 250 nm and emission at 350 nm is ob- served. Additionally, a distinct emission band with excita- tion at 350 nm and emission at 420 nm is present, and a less intense emission band is observed with excitation at 450 nm and emission at 520 nm. Fig. 1B shows the con- tour map for a diluted beer sample (3.2% v/v in water). The short-wavelength fluorescence with excitation at 250 nm and emission at 350 nm is clearly observed, while only a very weak emission band exists with excitation at 350 nm and emission at 420 nm. This spectrum exhibits al- most no fluorescence above 400 nm in excitation and 500 nm in emission. To observe this long-wavelength emis- sion, we recorded the total luminescence of bulk beers using the back-face geometry. In this scheme, the optical path length of the exciting radiation is considerably re- duced, resulting in a reduction of the primary inner-filter effect. The emitted light is still absorbed, as the optical path length for the emission is ca. 0.5 cm. However, the absorption at longer emission wavelengths is considerably lower than that at shorter excitation wavelengths. Fig. 1C shows that the short-wavelength emission is completely removed, while the longer-wavelength emission retains a reasonable intensity.
Strand breaks occur naturally in the deoxyribonucleic acid (DNA) chain. Studies have shown that the amount of breaks increases with exposure to ultraviolet (UV) light. Additionally, it has been shown that low energy electrons, with energies below DNA’s ionization energy, are capable of also inducing strand breaks on DNA. These breaks alter the length of the DNA molecule which in turn alters its electricalimpedance. As such, the amount of strand breaks can be indirectly measured through an impedancespectroscopy (IS). This work presents the construction of a cryogenic unit capable to hold an interdigitated sensor, with a sample of DNA or DNA with gold nanoparticles (AuNPs), allowing IS measurements to occur. This cryogenic unit is able to withstand temperatures in the range of 77 to 300 K, while monitoring the temperature at which its sample is. Liquid nitrogen was used as the cold source, allowing the low temperatures mentioned above to be reached. Since the heating process lasts around 8 h, depending on the amount of liquid nitrogen used, it becomes hard to manually start a measurement at the appropriate time. To counter this, a user interface was developed that monitors the temperature, automatically starting a measurement when a temperature defined by the user is reached. Overall, a cryogenic system was built which can be applied in the future for the study of DNA and DNA+AuNPs thin films.
Peaks were observed in the UV-visible spectrum for media where PA14 was grown, either alone or as part of the polymicrobial infection model (figure 5). These changes were observed at 315 nm, 368 nm and 698 nm, and correspond to the absorbance peaks of pyocyanin found at 238 nm, 316 nm, 347 nm, 368 nm and 690 nm . It is clear therefore from the UV-visible spectrum that pyocyanin is present within the ASM media following the growth of P. aeruginosa at 69 hours. We investigated the impact that pyocyanin had on the measured impedance by firstly measuring the impedanceof pyocyanin alone in ASM at different concentrations, from 1000 m M to 10 m M. Only a slight change in the impedance was seen at low frequencies and high concentrations of pyocyanin (1000 m M to approximately 500 m M), which was unrepresentative of the changes observed when the impedanceof a culture containing PA14 (alone or polymicrobial) was measured (data not shown). We reasoned that this could be because the pyocyanin existed in its oxidised form and therefore no reduced pyocyanin was available to balance the redox reaction at each electrode. Alternatively, pyocyanin could have been just one of multiple electroactive compounds that transferred electrons in a chain, with the compounds at an appropriate redox potential compared to the electrode causing the change in impedance. An alternative situation was explored, were pyocyanin was added directly to a late log culture of P. aeruginosa and S. aureus in order to assess the effect it had on the impedance. Cultures of P. aeruginosa (PA14) and S. aureus (RN4220) were grown in ASM microaerophilically overnight to late log phase in 24 well plates. After measuring the impedanceof the media, and the impedanceof the late log phase cultures, pyocyanin was added to the cultures at concentrations of 100 m M and 300 m M and a further impedance measurement was immediately carried out. The results indicated a clear change in the impedance for each of the electrode chambers (figure 6), similar to the changes in phase observed through the growth of PA14 and the polymicrobial infection model. It was noticed when similar experiments were carried out in LB media that the blue pigment resulting from the addition of pyocyanin changed from blue to clear in all but the top layer of each of the cultures. On shaking, the pyocyanin was rapidly oxidised and returned to its original blue pigment, before gradually being reduced again. This was apparent after five minutes for the culture of S. aureus while P. aeruginosa took longer to lose its pigment and did so to a lesser degree.
We are investigating the possibility of better sensitiv- ity analysis by utilising the simulation software CFS++ (Kaltenbacher, 2010) being developed at the TU Vienna. Modifications in the software for this purpose are ongoing. Besides sensitivities, these changes can be used to compute adjoints and thus solve optimisation problems, including pa- rameter estimation problems. Simulations with CFS++ will also shed light on the dampening influence of the external circuit if we increase the number of electrodes, thereby in- creasing the complexity of the external circuit, in particular the number of external impedances.