[en] In the present study, TiO₂ nanotubes were used as containers and were embedded with benzotriazole inhibitor. Later the inhibitor loaded nanocontainer was incorporated in hybrid matrix of silane and titania, which served as a barrier coating

[en] The multifrequency radio continuum and 21 cm H I observations of five blue compact dwarf (BCD) galaxies, Mrk 104, Mrk 108, Mrk 1039, Mrk 1069, and I Zw 97, using the Giant Meterwave Radio Telescope (GMRT) are presented here. Radio continuum emission at 610 MHz and 325 MHz is detected from all the observed galaxies whereas only a few are detected at 240 MHz. In our sample, three galaxies (Mrk 104, Mrk 108, and Mrk 1039) are members of groups and two galaxies (Mrk 1069 and I Zw 97) are isolated galaxies. The radio emission from Mrk 104 and Mrk 108 is seen to encompass the entire optical galaxy whereas the radio emission from Mrk 1039, Mrk 1069, and I Zw 97 is confined to massive H II regions. This, we suggest, indicates that the star formation in the latter group of galaxies has recently been triggered and that the environment in which the galaxy is evolving plays a role. Star formation rates (SFRs) calculated from 610 MHz emission are in the range 0.01-0.1 M_sun yr^-1; this is similar to the SFR obtained for individual star-forming regions in BCDs. The integrated radio spectra of four galaxies are modeled over the frequency range where data is available. We find that two of the galaxies, Mrk 1069 and Mrk 1039, show a turnover at low frequencies, which is well fitted by free-free absorption whereas the other two galaxies, Mrk 104 and Mrk 108, show a power law at the lowest GMRT frequencies. The flatter spectrum, localized star formation, and radio continuum in isolated galaxies lend support to stochastic self-propagating star formation. The H I observations of four galaxies, Mrk 104, Mrk 108, Mrk 1039, and Mrk 1069, show extended disks as large as ∼1.1-6 times the optical size. All the observed BCDs (except Mrk 104) show rotating disk with a half power width of ∼50-124 km s^-1. Solid body rotation is common in our sample. We note that the tidal dwarf origin is possible for two of the BCDs in our sample.

[en] Gram-negative pseudomonas sp. was used as the test organism for the biofilm formation and growth on 316 LN stainless and electrochemical noise (EN) monitoring studies, since this genus has been identified as the major biofilm former on stainless steels. EN studies were conducted for 21 days on the galvanically coupled specimens exposed to the dilute nutrient culture with pseudomonas sp. The visual records of the current potential EN, analysis of statistical and power spectral density (PSD) parameters of current and potential along with shot-noise parameters showed increase in the localized corrosion during initial 2-11 days exposure; thereafter the specimens showed passive behaviour. Raman spectra taken inside the pit for the specimen exposed for 21 days showed the peak corresponding to Cr³⁺ ions signifying repassivation process. Similarly, Raman spectra on the surface outside the pits on the specimens exposed for 7, 10 and 15 days showed steady growth of the peak corresponding to Cr³⁺ ions. This implied steady enrichment of Cr on the surface of the specimen which accounted for the gradual passivation with increased exposure time. (author)

[en] Chrome moly steels are extensively used in chemical industries and power plants for various applications due to their excellent mechanical and corrosion properties. However, in aggressive environments these steels are prone to localized corrosion. An attempt was made to improve the localized corrosion resistance of these steels by mesoporous silica based self healing coatings. Mesoporous silica containers were synthesized by sol- hydrothermal method and it was characterized by low angle XRD, High Resolution TEM and Raman spectroscopy. HRTEM observation suggested that the mesoporous silica materials had a uniform well defined hexagonal mesostructure. Low angle XRD studies further confirmed the hexagonal symmetry structure (P6nm) typical of MCM-41 material. All the characteristic peaks of MCM-41 were observed in Raman spectra. The extraordinary large surface area and narrow mesopore channels are both essential for high inhibitor loading and controlled release was revealed from BET analysis. The surface area was 940 m²/g and mean pore width was 2.5 nm. Later this mesoporous silica was used successfully for loading the inhibitor molecule 2-mercaptobenzothiazole. The loading and controlled release of the inhibitor from mesoporous silica was proved by UV-Visible and Raman spectroscopy studies. These inhibitor loaded nanocontainers were incorporated in zirconia/silane hybrid sol and coated on phosphate pretreated Mod. 9Cr-1Mo alloy specimens by dip coating method. These coatings were characterized by using SEM and Raman spectroscopy. Both coated and uncoated Mod.9Cr - 1Mo steel specimens were subjected to electrochemical impedance spectroscopy (EIS) studies in 0.05M NaCI solution. From EIS studies polarization resistance, capacitance and pore resistance of the coatings were determined. The results obtained in these detailed electrochemical and microscopic studies were correlated with the localized corrosion resistance of coated 9Cr-1Mo steel. Active corrosion protection of Mod. 9Cr-1Mo alloy was proved by EIS studies. (author)

[en] Full text: The aim of this study was to assess the value of (¹⁸F) FDG PET/CT in evaluation of patients with Fever of Unknown Origin (FUO). We retrospectively analysed clinical data and (¹⁸F) FDG PET scan of 48 patients over a period of 1 year. These patients met the revised definition criteria of FUO (febrile illness of greater than 3 weeks duration, temperature greater than 38.3 C and no diagnosis after appropriate in-patient or out-patient evaluation). Most of the patients recruited in this study had normal clinical and radiological examination. (¹⁸F) FDG PET was helpful in making a diagnosis in 24 patients. An infective/inflammatory cause of FUO was found in thirteen (27%) patients, a neoplasm in six (12.5%) patients, autoimmune cause in five (10.4%) patients. A definitive diagnosis could not be made in twenty four (50%) patients. Out of these 24 patients, 15 had normal PET/CT study, 9 had positive PET/CT findings but they lost in follow up and 2 died within 1 month of PET/CT study without any diagnosis. (¹⁸F) FDG PET/CT is a useful tool for evaluation of patients with FUO. It provides important diagnostic clues not suggested by other conventional imaging modalities. Patients with positive PET/CT findings but no definitive diagnosis should be followed up further to improve utility of PET/CT

[en] The aim of this study is to understand the corrosion behaviour and degradation of uncoated high density graphite (HD graphite), and surface protection of partially stabilized zirconia coated high density graphite. Raman microscopy has been used for the surface characterization of PSZ coated high density graphite

[en] Myocardial infarction with non obstructive coronary arteries is defined as acute myocardial infarction (AMI) with angiographically non obstructive coronary artery disease or stenosis ≤50%. MINOCA is reported in 6–15% of patients with AMI and is generally observed in relatively young patients with lower prevalence of traditional cardiovascular risk factors. Cardiac magnetic resonance (CMR) is the gold standard for diagnosis of MINOCA. This is case series of diagnosed cases of MINOCA with cardiac myocardial perfusion imaging. Patient preparation, radioactivity and stress protocol were followed as per standard guidelines. Single photon emission computed tomography (SPECT) images were acquired with a 2-detector gamma camera with SPECT (ECAM SCINTRON). Filtered back-projection (FBP) with a Butterworth filter (order 5, cut off frequency 0.45)/iterative reconstruction will be used for tomographic reconstruction with no attenuation/ scatter correction. Automated quantification of SPECT-MPI using quantitative perfusion software (Cedars Sinai, Los Angeles, California or Corridor 4DM, MiE ) was performed. The second patient showed mild hypoperfusion in apical anterior segment of myocardium, normal motion and wall thickening. All the three patients had non obstructive coronary angiography and still 2 out of 3 showed mild hypoperfusion in MPI. The present case series suggests that myocardial perfusion imaging plays crucial role in early diagnosis of MINOCA. Further more similar studies in larger population could help in delineating the role of MPI in definitive diagnosis and follow up of the patients

[en] Graphical abstract: Display Omitted Highlights: ► TiO₂ nanotube powders were synthesized by rapid breakdown anodization method. ► Benzotriazole was loaded into the TiO₂ nanotube powders. ► Low pH induced release of benzotriazole from TiO₂ nanotube powders was proved. -- Abstract: Titanium dioxide (TiO₂) is one of the most studied substances in material science due to its versatile properties and diverse applications. In this study titanium dioxide nanotube powder were synthesized by rapid breakdown anodization (RBA) method. The synthesis involved potentiostatic anodization of titanium foil in 0.1 M HClO₄ electrolyte under an applied voltage of 20 V and rapid stirring. The morphology and the phase of titanium dioxide nanotube powder were studied using field emission scanning electron microscopy, laser Raman spectroscopy and high resolution transmission electron microscopy. Benzotriazole was chosen as model inhibitor to evaluate TiO₂ nanotube powder's corrosion inhibitor loading and releasing properties. The storage and release properties of TiO₂ nanotube powder were studied using UV–visible spectroscopy and thermogravimetric analysis.

[en] Full text: NETs are heterogeneous group of tumors which take up amino acids, transform them into biogenic amines and store the amines in vesicles, this forms the basis of uptake of ¹⁸F-DOPA in these tumors. These tumors can be small and situated almost throughout the body and may also present as advanced disease with multiple metastatic sites. Like in management of any other tumor it is imperative to stage the status of disease in NETs for the effective management of these patients and ¹⁸F-DOPA PET/CT is one such imaging modality used in the evaluation of neuroendocrine tumors (NETs). Here is our initial experience using ¹⁸F-DOPA PET/CT imaging in these patients. Twenty-seven patients with NETs (carcinoids, medullary thyroid carcinomas, phaeochromocytomas Insulinoma) were prospectively enrolled and scheduled for ¹⁸F-DOPA PET/CT. Wherever possible, tissue diagnosis was attempted. Results obtained were compared with other conventional diagnostic procedures (mainly ¹⁸F-FDG PET/CT, and 68Ga-DOTANOC PET/CT, and with ultrasound, CT, etc) and with follow-up. ¹⁸F-DOPA PET/CT identified 17/24 positive cases in either the primary/metastatic/recurrent tumor. In case of Insulinoma ¹⁸F-DOPA was found to be most superior than other imaging modalities in localizing the disease and staging of disease

[en] Highlights: • Laser Raman analysis was carried out on native and pitted surfaces of mod.9Cr-1Mo steel. • Chemical composition of the native films upon pitting was studied by in situ Raman spectroscopy. • Findings of XPS experiments were in good agreement with the results from Raman spectroscopy. In-situ Raman and X-ray photoelectron spectroscopic studies were performed for the identification of native and corroded surface oxide layers of modified 9Cr-1Mo steel. The Raman data obtained for native oxide layer of modified 9Cr-1Mo steel revealed that it was mainly composed of oxides of Fe and Cr. The presence of alloying element Mo was found to be less significant in the native oxide film. The oxides of Cr were dominant at the surface and were found to be decreasing closer to metal/oxide layer interface. The changes in the chemical composition of the native films upon in-situ pitting during potentiostatic polarization experiment were characterized by in-situ Raman analysis. The corrosion products of potentiostatically polarized modified 9Cr-1Mo steel was composed of dominant Fe (III) phases viz., γ- Fe₂O_3, α and γ − FeOOH along with the oxides of chromium. The results from Raman analysis were corroborated with the XPS experiments on as received and pitted samples of modified 9Cr-1Mo steel specimens. It was observed that the oxides of Cr and Mo contributed for the stability of the surface layer by forming Cr₂O₃ and MoO₃. Also, the study attempted to find out the intermediate corrosion products inside the metastable pits to account for the pseudo passive behavior of modified 9Cr-1Mo steel in 0.1 M NaCl solution.