Search

Presently several beta emitting radionuclides are in use as brachytherapy sources, due to their inherent advantages of short-range radiation dose delivery compared to their gamma emitting counterparts. 90Y is one of the well-known hard beta-emitting radioisotopes for the therapeutic application of radioactivity. Among various other modalities, 90Y resin microsphere as a brachytherapy source has its application for liver cancer. In the present study, 90Y was recovered from 235,238U,239Pu(nfast,f)90Sr(β−)90Y using Sr selective crown ether followed by quick purification using the Ion Chromatography technique. The purified 90Y was labelled in strong cation exchange resin to form 90Y resin microsphere. Various quality control parameters, e.g., water solubility, chemical, radionuclidic purity, and half-life, were verified using Gamma spectrometry, Cerenkov, and Liquid Scintillation Counting techniques. The obtained half-life was 64.05 h, which is in excellent agreement with the literature and is indirect evidence of the very high radionuclidic purity of the sample. A rapid method for the synthesis of 90Y resin microsphere brachytherapy source is being reported for the first time after its recovery from irradiated fast reactor fuel dissolver solution. After the separation of 90Sr along with trace level impurities inside the hot cell, simultaneous purification of parent 90Sr and daughter 90Y using single-stage Ion Chromatography step takes 15–25 min only in comparison to 24 h or more time using multistage conventional Ion exchange chromatography column, which saves the separation time and in turn, increase the yield of 90Y per separation campaign. [ABSTRACT FROM AUTHOR]

Identification of a failed fuel subassembly due to the dry rupture of its fuel pin in prototype fast breeder reactor is one of the safety protocols to be standardized for its safe operation for which interaction of fission gases with liquid sodium was studied. This paper reports the studies on the feasibility of detection of fission gases in presence of sodium as well as separation of fission gases out of liquid sodium through Ar purge in a prototypical sodium module with 300 mL of Na. The resultant gases were adsorbed on activated charcoal and determined the activity of fission gases using high resolution gamma spectrometry. Quantitative recovery of fission gases from sodium matrix in the range of sub-picogram levels was established. [ABSTRACT FROM AUTHOR]

A glove box facility was established for the determination of non-metallic F− and Cl− (Halides) impurities in U–6 wt% Zr and U–19 wt%–Pu–6 wt% Zr actinide alloy fuel samples through separation of halides by a pyrohydrolysis procedure after establishing the quantitative conversion of alloy samples to their respective oxides under the experimental conditions. The determination of halides was subsequently accomplished by using ion chromatography. To ensure the complete oxidation and also to accomplish the quantitative recovery of halides out of these metal alloy fuel samples, extended pyrohydrolysis is indispensable. The present pyrohydrolysis procedure was validated by the standard addition method. [ABSTRACT FROM AUTHOR]

Heterodimers of POCl3—CHCl3 were generated in Ne, Ar, and Kr matrixes at low temperatures and were studied using infrared spectroscopy. The remarkable role of co-operative pentavalent phosphorus bonding in the stabilization of the structure dictated by hydrogen bonding is deciphered. The complete potential energy surface of the heterodimer was scanned by ab initio and density functional theory computational methodologies. The hydrogen bond between the phosphoryl oxygen of POCl3 and C—H group of CHCl3 in heterodimers induces a blue-shift in the C—H stretching frequency within the Ne matrix. However, in Ar and Kr matrixes, the C—H stretching frequency is exceptionally red-shifted in stark contrast with Ne. The plausibility of the Fermi resonance by the C—H stretching vibrational mode with higher order modes in the heterodimers has been eliminated as a possible cause within Ar and Kr matrixes by isotopic substitution (CDCl3) experiments. To evaluate the influence of matrixes as a possible cause of red-shift, self-consistent Iso-density polarized continuum reaction field model was applied. This conveyed the important role of the dielectric matrixes in inducing the fascinating vibrational shift from blue (Ne) to red (Ar and Kr) due to the matrix specific transmutation of the POCl3—CHCl3 structure. The heterodimer produced in the Ne matrix possesses a cyclic structure stabilized by hydrogen bonding with co-operative phosphorus bonding, while in Ar and Kr the generation of an acyclic open structure stabilized solely by hydrogen bonding is promoted. Compelling justification regarding the dispersion force based influence of matrix environments in addition to the well-known dielectric influence is presented. [ABSTRACT FROM AUTHOR]

The nitrogen of nitro group is a paradigmatic pnictogen due the presence of a π‐hole and a number of studies have been performed recently on prototypical nitromethane (NM). Homodimers and heterodimers of NM are sustained by π‐hole driven pnictogen bonds hosted by nitrogen. To understand the effect of substitution on this π‐hole and thus the pnictogen bond, heterodimers of nitrobenzene (NB; phenyl substitution in place of methyl) with ammonia (AM) have been probed, as a test case, using matrix isolation infrared spectroscopy and ab initio computations. Of the four structures optimized on the potential energy surface the energetically dominant global minimum, stabilized by π‐hole driven O=N←N pnictogen bonding with co‐operative N−H←O hydrogen bonding, was experimentally identified at low temperatures. A comparison of the pnictogen bonding of NB‐AM dimers with NM counterpart (NM‐AM dimers) divulged the dominance of electrostatic origin of pnictogen bonding in both the class of dimers. The reduced strength of pnictogen bonding in NB‐AM dimers in comparison to NM‐AM dimers was discerned, which has been established to be a consequence of the reduced electrostatic potential at the π‐hole of NB relative to that in NM. The strength of π‐hole driven pnictogen bond was directly correlated with the binding energy and the infrared shifts in the signature vibrational bands of the NB, NM and AM submolecules due to dimerization under matrix isolated conditions at low temperatures. [ABSTRACT FROM AUTHOR]

The existence of unique O＝N⋯π pnicogen bonding in combination with C–H⋯π/C–H⋯O hydrogen bonding interactions has been experimentally affirmed in the heterodimers of nitromethane with aliphatic (acetylene; NMAc) and aromatic (benzene; NMBz) π-electron donors at low temperatures under isolated conditions. The potential energy surfaces of NMAc and NMBz dimers have been probed for stationary points using ab initio and DFT computational methods. Three unique geometries for NMAc dimers were optimized, which were stabilized through mixed O＝N⋯π pnicogen bonding and C–H⋯π/C–H⋯O hydrogen bonding interactions with varying strength. Within the Ar matrix at 12 K, only the C–H⋯π and C–H⋯O bound NMAc dimer was generated, while in N2, two geometries, one stabilized by pnicogen bonded O＝N⋯π and C–H⋯π interactions and the other by C–H⋯π and C–H⋯O interactions, were produced. The NMBz dimer has only one structure stabilized by both O＝N⋯π pnicogen and C–H⋯π hydrogen bonding interactions that appears to be generated preferentially. The binding energies of both the dimers have the greatest contribution from electrostatics in both classes of NMAc and NMBz dimers, which is closely followed by dispersion forces in the case of NMBz. The increased proton affinity of benzene over acetylene appears to enhance the strength of C–H⋯π hydrogen bonds in NMBz while the O＝N⋯π pnicogen bonds remain quite similar in strength in both NMBz and NMAc dimers. [ABSTRACT FROM AUTHOR]

Complex formation between uranyl and carboxylate ligands (benzoate, nicotinate and isonicotinate) has been studied extensively by absorption and luminescence spectroscopy in acetonitrile medium. Experimental data had indicated the existence of stable and enhanced luminescent tris(carboxylato) uranyl(VI) complexes i.e. [UO2(L)3]− with D3h symmetry. The high luminescence of these complexes was due to the sensitization of the Oyl → U ligand to metal charge transfer (LMCT) emission by extremely intense equatorial (carboxylate ligands) LMCT bands. The variation in the experimentally observed parameters such as intensity of equatorial LMCT bands, luminescence lifetimes, quantum yields and structural parameters among tris(carboxylato) uranyl(VI) complexes are affirmed by quantum chemical calculations using density functional theory and the computational results are found to be in good agreement with experimental findings. Interestingly, in a very dilute mixture of [UO2(L)3]− and Eu(III), energy transfer from uranyl to Eu(III) is observed and it leads to the detection of europium at trace levels. This is an intriguing observation as none of the previous studies have reported such a low level of detection limit of Eu(III) by means of energy transfer from any metal. [ABSTRACT FROM AUTHOR]

A spectrophotometric method, circumventing interference from F− ions, during estimation of Zr in U-Zr alloy fuel, has been developed. F− ions from added HF, for quantitative dissolution of metallic fuels, were converted to a strong ionic liquid complex using a cocktail of masking agents. Zr(IV) complexed with Xylenol Orange, displayed enhanced sensitivity below 1 μg/mL, in acetate buffer medium with masking agents, when F−was ≥ 5 μg/mL. Validation and standardization of the method has been accomplished, using arc melted and injection casted samples of U-Zr alloys, respectively. Prevention of interference from F− by masking agents was elucidated using density functional theory. [ABSTRACT FROM AUTHOR]

The paper shows the challenges at teacher-student and technological levels that should face the University to enter virtual education: the teachers' battle to the technology and the teaching method change; the students' resistance to take the responsibility of their learning process in an active way; and the technological challenges that implies the three levels of virtual education (totally virtual, half-virtual and virtual support to face-to-face courses). Virtual education is a teaching-learning process based on the principles of active pedagogy (the student should take the responsibility of a frequent and effective participation), with the characteristics of distance education (during all classes, or most of them, the students and the teacher will not meet personally, although this could happen in a virtual space), and with the possibility of synchronous or asynchronous interaction. In the international arena, virtual education grows every day, offering programs in basic and secondary education, as well as undergraduate and postgraduate degrees. Today it's possible to take virtual courses at some of the most popular universities in the world, which certifies the credits that the student acquires at the end. Many other universities, sensitive about the distance problem of many of their candidates, and of the schedule difficulties in others, have begun to implement virtual programs with the purpose of reaching those students that can't assist to their campus. [ABSTRACT FROM AUTHOR]

A simple spectrofluorimetric method is reported for the estimation of uranium (U) in nitric acid using 0.4 M H2SO4 as an enhancing reagent. The intensity of fluorescence peak of U at 512 nm with excitation at 414 nm shows linearity over 150–6000 µg/mL. Standard addition method is applied to arrive at the estimates of U in simulated dissolver and high active liquid waste solution of nuclear reprocessing plant. The estimate value of U for the sample with high content of other ions is found to be more accurate than the value measured by Davies-Gray method. [ABSTRACT FROM AUTHOR]

In this work, laser induced breakdown spectroscopic (LIBS) technique is utilized to estimate U in presence of large excess of lithium and potassium chloride (LiCl–KCl) or Cd mixtures. Colloidal solution of hydroxides of U, produced by adding NaOH was spread over filter paper and subjected to LIBS analysis after drying in air. Nearly 50 times enhancement in the LIBS signal was found as compared to normal solution. Using Er as an internal standard, emission line of U(II) at 385.957 nm shows linearity from 50 to 600 ppm. The detection limit of U was found to be 21 ppm. The presence of 5% LiCl–KCl salt or 3% Cd does not alter the calibration plot significantly. The estimations of U in synthetic samples agree well with the values measured by spectrophotometric method. [ABSTRACT FROM AUTHOR]

XRF and NAA techniques have been used for the determination of major, minor, and trace elements in Ayurvedic compound formulation Nishakatakadi, a preparation used for the treatment of diabetes mellitus. The concentration of major elements Al, Ca, Cl, K, Mg, P, S, and Si, minor elements Na, Fe, and Ti, and trace elements, Ba, Br, Cr, Co, Cs, Cu, Mn, Pb Rb, Sr, La, Sm, W, and Zn, were determined. The accuracy of the result was evaluated by analyzing NIST certified reference sample. A good correlation between the results of XRF and NAA has been observed for elements detected using both the methods in the individual herbs analyzed. Elemental profile of the herbs and formulations so generated can serve as a fingerprint data of the herbs and formulation that can be used for quality assurance of the formulations [ABSTRACT FROM AUTHOR]

The role of nitrogen, the first member of the pnicogen group, as an electron donor in hypervalent non-covalent interactions has been established long ago, while observation of its electron accepting capability is still elusive experimentally, and remains quite intriguing, conceptually. In the light of minimal computational exploration of this novel class of pnicogen bonding so far, the present work provides experimental proof with unprecedented clarity, for the existence of N(acceptor)⋯N(donor) interaction using the model nitromethane (NM) molecule with ammonia (AM) as a Lewis base in NM–AM aggregates. The NM–AM dimer, in which the nitrogen atom of NM (as a unique pnicogen) accepts electrons from AM (the traditional electron donor), was synthesized at low temperatures under isolated conditions within inert gas matrixes and was characterized using infrared spectroscopy. The experimental generation of the NM–AM dimer stabilized via N⋯N interaction has strong corroboration from ab initio calculations. Furthermore, confirmation regarding the directional prevalence of this N⋯N interaction over C–H⋯N and N–H⋯O hydrogen bonding is elucidated quantitatively by quantum theory of atoms in molecules (QTAIM), electrostatic potential mapping (ESP), natural bond orbital (NBO), non-covalent interaction (NCI) and energy decomposition (ED) analyses. The present study also allows the extension of σ-hole/π-hole driven interactions to the atoms of the second period, in spite of their low polarizability. [ABSTRACT FROM AUTHOR]

The branching of a methyl group in a linear chain has a profound influence on the conformational morphology as it wields a strong control in reducing a large number of conformations. To unravel the effect of branching on the second non-hyperconjugative carbon atom on the conformational landscape, the conformations of tris(2-methylbutyl)phosphate (T2MBP) were studied using Density Functional Theory (DFT) computations and matrix isolation infrared spectroscopy. Experimentally, T2MBP along with N2/Ar/Kr/Xe gases was effusively expanded and deposited at a low temperature of 12 K, which was subsequently probed using infrared spectroscopy. The computations of all the conformations were accomplished using the B3LYP level of theory with the 6-311++G(d,p) basis set. A dimethyl(2-methylbutyl) phosphate (DM2MBP) prototype, a molecule containing a single 2-methylbutyl moiety, was examined for its conformations. Computations predicted 18 and 9 conformations each for the 'gauche' and 'trans' families, respectively, in which the third branched carbon completely influences the orientation of the fourth carbon, which simplifies the conformational problem of DM2MBP. Of the 18 and 9 bunches each in the 'gauche' and 'trans' families, only 7 and 3 conformations, respectively, became energetically important, which when extrapolated to T2MBP resulted in 343 and 147 conformational possibilities. The factor of degeneracy further reduced these numbers and a total of 168 conformations effectively contribute to the conformational composition of T2MBP in the gas phase. The role of stereo electronic and steric factors prevalent in the conformational clusters of T2MBP was unravelled respectively using natural bond orbital and non-covalent interaction analyses. [ABSTRACT FROM AUTHOR]

Albeit the first account of hypervalent⋯π interactions has been reported with halogen⋯π interactions, the feasibility of their extension to other hypervalent atoms as possible Lewis acids is still open. In this work, the role of phosphorus as an acceptor from the π electron cloud (P⋯π pnicogen or phosphorus bonding) in PCl3–C2H2 and PCl3–C2H4 heterodimers is explored, by combining matrix isolation infrared spectroscopy with ab initio and DFT computational methodologies. The respective potential energy surfaces of the PCl3–C2H2 and PCl3–C2H4 heterodimers reveal unique minima stabilized by a concert of reasonably strong to weak interactions, of which P⋯π phosphorus bonding was energetically dominant. Heterodimers, trimers and tetramers bound primarily by this unique phosphorus bond were generated at low temperatures. The dominance of phosphorus bonding in the PCl3–C2H2 and PCl3–C2H4 heterodimers over other interactions (such as H⋯π, H⋯Cl, H⋯P, Cl⋯π and lone pair–π interactions) was confirmed and substantiated using extended quantum theory of atoms in molecules, natural bond orbital, electrostatic potential mapping and energy decomposition analyses. The following inferences in correlation with results from non-covalent-interaction analysis offer a complete understanding of the nature of the P⋯π phosphorus bonding interactions. The significance of electrostatic forces kinetically favoring the formation of phosphorus bonded heterodimers, in addition to thermodynamic stabilization, is demonstrated experimentally. [ABSTRACT FROM AUTHOR]

A simple method has been developed for the estimation of uranium in reactor grade sodium without the removal of sodium using time gated luminescence with pulsed lamp. Samples are prepared after oxidizing the sodium in air followed by dissolution in H2SO4. Luminescence of uranium is measured in 2 M H3PO4 + 1 M H2SO4 medium. Using this method, the concentration of uranium in synthetic sodium sample was determined to be 0.2 µg/g. The limit of detection of uranium in bulk sodium was found to be 0.016 µg/g. [ABSTRACT FROM AUTHOR]

Methyl imidazole (M-Imid)⋯HCl (1 : 1) complexes were studied using matrix isolation infrared spectroscopy and ab initio computations. Computations using the MP2 level of theory with the aug-cc-pVDZ basis set predicted three complexes, where the global minimum had a strong hydrogen-bonded N⋯H⋯Cl interaction with a binding energy of ∼12 kcal mol−1 (complex A). The first local minimum had an H⋯π interaction (complex B) and the second local minimum (complex C) was stabilized through combined hydrogen, halogen and pnicogen bonding (with a nitrogen atom as the pnicogen) interactions. Of the three complexes, the hydrogen-bonded complex A alone possesses experimental significance. Experiments were performed by co-depositing M-Imid and HCl separately in an N2 matrix at a low temperature of ∼12 K. The annealing of the low temperature matrix encouraged the formation of M-Imid–HCl complex A, which was subsequently probed using infrared spectroscopy. Experimentally, the vibrational shift of ∼1720 cm−1 was observed for the N2 matrix, while harmonic frequency calculations indicated a shift of 1063 cm−1 in the H–Cl stretching region of the strong hydrogen-bonded complex A. The inclusion of anharmonicity in the calculations red-shifted the H–Cl stretching frequency further down to 1650 cm−1, which was almost close to the experimental value. It is inferred from this large experimental red-shift of the stretching frequency of the proton donor that proton-shared hydrogen bonding is facilitated in the M-Imid–HCl system experimentally. Using atoms in molecules, energy decomposition and natural bond orbital analyses, the uniqueness of this strong proton-shared hydrogen bonding is established with respect to conventional hydrogen bonding. [ABSTRACT FROM AUTHOR]

A non-destructive and noninvasive technique is preferable for characterization of the spent fuel solutions in the reprocessing plants, especially samples associated with high radiation dose. A hybrid K-edge/KXRF densitometer (HKED) technique has been designed, fabricated, and commissioned indigenously to accomplish the above objective for the spent fuel solutions from compact reprocessing facility for advanced fuels in lead cells (CORAL), Kalpakkam. This paper describes the customized design, development, calibration and validation of the HKED technique using a series of uranium solutions and corroborating the results with potentiometric method. Further, the pure and mixture of thorium and uranium as well as uranium and plutonium solutions were also assayed by HKED technique. [ABSTRACT FROM AUTHOR]

Owing to the fact that σ stacking is as important as π stacking in determining the structural motifs of aliphatic saturated cyclic hydrocarbons, in this work we have provided the first unambiguous spectroscopic evidence for the existence of σ stacking interactions in cyclohexane dimers at low temperatures. Molecular beam experiments performed using effusive nozzle and supersonic jet sources on cyclohexane in an N2 matrix generated cyclohexane dimers stabilized through σ stacking and the dimers were characterized by infrared spectroscopy. The ab initio computations carried out on cyclohexane dimers identified eclipsed (face-to-face), parallel displaced and T-shaped structures, which are predominantly stabilized by σ stacking interactions. While natural bond orbital analysis substantiated a significant amount of σ → σ* interactions involved in the stabilization, the Atoms in Molecules analysis indicated that the stacking is induced by a plausible 'dihydrogen bonding' interaction. Energy decomposition analysis disclosed that a large measure of dispersion interactions effectively contributes for the overall stability of cyclohexane dimers. [ABSTRACT FROM AUTHOR]

Effect of nitrogen and argon matrices on the C–H asymmetric stretching and bending infrared frequencies of the acetylene molecule, C2H2, has been studied by matrix isolation experiments as well as by calculations at MP2 level of theory. The complexes of C2H2 in nitrogen and argon matrices, viz., C2H2(N2)m (with m=2–8) and C2H2(Ar)n (with n=2–10) are theoretically explored. The computed acetylenic C–H asymmetric stretch in C2H2-nitrogen complexes shows a redshift of 3.0 to 11.9 cm-1 compared with the frequencies of the free acetylene molecule, and a corresponding blueshift of 7.4 to 26.2 cm-1 when C2H2 is complexed with argon atoms. The trends in the computed shifts are in good agreement with the experiments. The molecular electrostatic potential minimum of C2H2 becomes more negative when complexed with nitrogen than on complexation with argon. This observation implies a greater basic character for C2H2 in the nitrogen matrix, favoring the formation of H–π(C2H2–MeOH) complex as compared to that in the Ar matrix. Experimentally the preferential formation of H–π(C2H2-MeOH) complex in the N2 matrix has indeed been observed. [ABSTRACT FROM AUTHOR]

The π electron systems are the conventional electron donors to the hydrogen acceptors in hydrogen bonding. Apart from the hydrogen atom, halogens, chalcogens, pnicogens and triel/tetrel atoms can also be envisaged as electron acceptors involving π clouds. Markedly, in pnicogen…π interactions, the bonding of the hypervalent (predominantly pentavalent) state of the phosphorus atom with π electron donors is elusive and can be thought of as an intuitive extension to trivalent phosphorus…π interactions. In this work, on the one hand, POCl3 was taken as a prototypical molecule to explore these pentavalent phosphorus interactions and on the other hand, acetylene (C2H2), ethylene (C2H4) and benzene (C6H6), in which phosphorus…π bonding can be expected to compete with hydrogen and halogen bonding interactions, were taken as π electron donors. All three POCl3–C2H2, POCl3–C2H4 and POCl3–C6H6 heterodimers were experimentally generated at low temperatures in Ar and N2 matrices and were characterized by both infrared spectroscopy and state-of-the-art quantum chemical computations. Though hydrogen bonding dominates in POCl3–C2H2 and POCl3–C2H4 heterodimers, phosphorus bonding plays a definite and non-trivial role in their overall stabilization. An interesting paradigm transformation was noticed in the POCl3–C6H6 system, where pentavalent phosphorus…π bonding was observed to completely influence the hydrogen bonding interaction. To further shed light on these P…π systems, the interaction characteristics were analyzed with the help of electrostatic potential mapping, natural bond orbital and energy decomposition analyses. [ABSTRACT FROM AUTHOR]

A fast, precise and simple spectrophotometric method was developed for the estimation of uranium in LiCl–KCl salt matrix using phosphoric acid as a complexing agent. The 421 nm absorbance peak of uranium was found to be spectral interference free and area of this peak was used for the quantitative analysis. Linearity over 100–7000 ppm with a detection limit of 25 ppm of uranium in 10% LiCl–KCl matrix was obtained by this method. The present method was successfully applied for the quantitative estimation of uranium in synthetic salt mixtures and the results were found to be more accurate than the values measured by ICP-OES. [ABSTRACT FROM AUTHOR]

Luminescence of uranyl ion (UO22+) complexed with picolinate (PA) has been studied in aqueous and acetonitrile medium. In aqueous medium, for UO22+ to PA ratio of up to 1:20, a 1:1 non-luminescent specie with stability constant of log β = 3.88 was formed. On the contrary, formed specie in acetonitrile medium was luminescent and the enhanced luminescence was due to sensitization by PA and reduction in non-radiative decay channels. UV-Vis absorption spectroscopy studies revealed that the luminescent specie was 1:2 type complex. Density functional theory and DLPNO-CCSD(T) methodologies were applied to arrive at the lowest-energy structures of the 1:1 and 1:2 uranyl-picolinate complexes. [ABSTRACT FROM AUTHOR]

Phosphorus, an important element among the pnicogen group, opens up avenues for experimental and computational explorations of its interaction in a variety of compounds. Although experimental proof of trivalent phosphorus bonding is limited and is growing with time, phosphorus bonding with pentavalent phosphorus has been a long sought after interaction both computationally and experimentally. In the present work, for the first time, we have provided unambiguous experimental evidence for the pentavalent phosphorus bonding interaction by exploiting a phosphoryl chloride (POCl3) prototype under isolated conditions at low temperatures. The POCl3 dimer and higher aggregates can be set as a unique example possessing pentavalent phosphorus bonding with a competing halogen bonding interaction. The POCl3–H2O heterodimer is another interesting system, stabilized through multiple phosphorus and hydrogen bonded interactions. Using matrix isolation infrared spectroscopy, the POCl3 homodimer and POCl3–H2O heterodimer were characterized and the structures were elucidated by employing ab initio and DFT methods. The multifaceted interactions in the POCl3 paradigm were investigated by using Natural Bond Orbital, Energy Decomposition and Electrostatic Potential Mapping analyses. [ABSTRACT FROM AUTHOR]

An experimental set‐up for studying photophysics and photochemistry of molecules in an inert gas medium (matrix‐isolated) and in the ice phase at low temperatures has been developed and commissioned at the Photophysics beamline, Indus‐1 synchrotron radiation source. This end‐station uses an in‐house‐developed closed‐cycle cryostat for achieving cryo‐temperatures (∼10 K). Synchrotron radiation from the Photophysics beamline is used as the source of UV–VUV photons and the system is equipped with a Fourier transform infrared spectrometer for characterization of the molecular species formed at low temperature. Various individual components of the end‐station like closed‐cycle cryostat, experimental chamber, gas mixing and deposition systems are tested to ascertain that the desired performance criteria are satisfied. The performance of the composite system after integration with the Photophysics beamline is evaluated by recording IR and UV–VUV photoabsorption spectra of sulfur dioxide at low temperatures (10 K), both in the ice phase as well as isolated in argon matrices. Results obtained are in good agreement with earlier literature, thus validating the satisfactory performance of the system. As an off‐shoot of the study, the VUV absorption spectrum of matrix‐isolated SO2 in argon matrix up to 10.2 eV is reported here for the first time. This experimental end‐station will provide new opportunities to study photon‐induced reactions in molecules of environmental, astrochemical and industrial importance. Details of the design, development and initial experimental results obtained are presented. [ABSTRACT FROM AUTHOR]

Abstract: Uranyl tris nitrato i.e. [UO2(NO3)3]– was formed by adding tetramethylammonium nitrate to uranyl nitrate in acetonitrile medium. The luminescence features of this complex in acetonitrile are very sensitive to water content, which could lead to the use of it as a luminescent probe for water present in acetonitrile. The luminescence intensity ratio of 507 to 467 nm peak of uranyl tris nitrato showed a linear response in the range 0–5% (v/v) water content in acetonitrile. The present method was applied for three synthetic samples of acetonitrile for water detection and the results obtained were compared using Karl Fischer titration. There was a good agreement in the values obtained by both the methods. [ABSTRACT FROM AUTHOR]

Quantitative analysis of Pr, Nd, Ce, La and Sm were carried out simultaneously in LiF-KCl matrix using laser induced breakdown spectroscopic technique. Two non-interfering analytical emission lines have been identified for each lanthanide and using the internal standard method, the calibration curve is constructed from 0.3 to 5% for Pr, Nd, Ce and La and from 0.3 to 3% for Sm. Both the emission lines showed good regression coefficient ( R ) ranging from 0.9953 to 0.9996. The analytical capability of this method is studied through the correlation uncertainty of measured values with its known value in synthetic samples containing all the lanthanides in equal amount (0.5, 1 and 2%). Low value of correlation uncertainty (less than 10%) confirms that LIBS has a great potential for quantitative analysis of lanthanides in LiF-KCl matrix. [ABSTRACT FROM AUTHOR]

A phosphorous trichloride (PCl3)–benzene (C6H6) heterodimer was generated in a low temperature N2 matrix and was characterized using infrared spectroscopy. The structure of the heterodimer produced in the matrix isolation experiment was discerned through ab initio computations. Computations disclosed that the experimentally detected dimer is stabilized through strong non-covalent phosphorus bonded P…π interaction, considered as a class of pnicogen bonding. This experimentally unmapped P…π interaction so far has been reconnoitered using atoms in molecules and natural bond orbital and energy decomposition analyses. The influence of substitutions on both the PCl3 and C6H6 monomeric units of the heterodimer was subsequently examined to understand the strength of P…π interaction as a result of these substitutions. [ABSTRACT FROM AUTHOR]

The objectives of this prospective observational study were to determine the proportion of patients with traumatic brain injury who received effective anti-seizure prophylaxis. The study was conducted in a tertiary level ICU of a major trauma referral centre between February 2012 and August 2013. A total of 2361 patients were admitted to the ICU in this study period, of whom 125 patients (index) with traumatic head injury were included in this study. The patients had a mean age of 45 years (SD=19), a mean score on the Glasgow Coma Scale of 9 (SD=4), a mean injury severity score of 27 (SD=13) and a mean APACHE III score of 55 (SD=27). Only 13.6 % (17 of 125) of patients were given anti-seizure prophylaxis and phenytoin levels were measured in 9.6% (12 of 125). Although all 12 patients achieved an effective concentration for phenytoin therapy (>40 µmol/l) after the loading dose, no patient had their target concentration consistently maintained in the recommended therapeutic range (40 to 80 µmol/l) throughout the seven-day monitoring period. There was wide fluctuation in phenytoin levels in the patients in this study. Twenty-two (18%) of the index patients had post-traumatic seizures, indicating a high prevalence for this study. Poor compliance with guidelines could possibly explain this phenomenon. Future studies are needed to look at the dosing and monitoring of phenytoin and/or alternative anti-seizure prophylaxis in patients with traumatic brain injury. [ABSTRACT FROM AUTHOR]

Previous studies have shown that elderly patients (age ≥65 years) are less likely to be admitted to the intensive care unit following a rapid response team call and have high hospital mortality rates. This study has shown that elderly patients have a significantly higher probability of being admitted to an intensive care unit following a rapid response team call at night than during the day. However, at no time are they at greater risk than younger patients of incomplete vital sign recording, a failure to escalate care for acute deterioration or mortality. [ABSTRACT FROM AUTHOR]

The objectives were to describe the incidence of accidental vascular catheter removal (AVCR) in an Australian Intensive Care Unit (ICU) and evaluate whether the fixation method or patient delirium increased the risk of AVCR. This prospective observational study was based in a tertiary level ICU between April 2011 and October 2012. All vascular catheters were secured either by sutures or by a suture-less securement device (STATLOCK(™), Bard Medical, Covington, GA, USA) as per the treating clinician. Data were obtained from bedside nursing staff, with daily screening for delirium completed by the ICU medical team using the Confusion Assessment Method-ICU. 2361 patients were admitted during this period with 1032 patients screened and data available for 322 patients (452 vascular catheters). AVCR occurred in 15 patients (16 vascular catheters) (5.0%) with an incidence of AVCR of 2.77 per 100 catheter-days. Delirious patients were 13-fold more likely to have an AVCR event (odds ratio=13.3; 95% confidence interval 4.36, 40.52; P <0.0001). There was a non-significant trend to an increase in AVCR when using the suture-less securement device (odds ratio=2.6; 95% confidence interval 0.87, 7.8; P=0.09) but delirious patients were no more likely to have an AVCR episode when a suture-less securement device was used (P=0.95). In this study the use of suture-less securement did not seem to increase the risk of AVCR. However, there was a non-significant trend towards increased AVCR when using suture-less securement devices, which may reflect a ß error. [ABSTRACT FROM AUTHOR]

The objectives were to describe the incidence of accidental vascular catheter removal (AVCR) in an Australian Intensive Care Unit (ICU) and evaluate whether the fixation method or patient delirium increased the risk of AVCR. This prospective observational study was based in a tertiary level ICU between April 2011 and October 2012. All vascular catheters were secured either by sutures or by a suture-less securement device (STATLOCK™, Bard Medical, Covington, GA, USA) as per the treating clinician. Data were obtained from bedside nursing staff, with daily screening for delirium completed by the ICU medical team using the Confusion Assessment Method-ICU. 2361 patients were admitted during this period with 1032 patients screened and data available for 322 patients (452 vascular catheters). AVCR occurred in 15 patients (16 vascular catheters) (5.0%) with an incidence of AVCR of 2.77 per 100 catheter-days. Delirious patients were 13-fold more likely to have an AVCR event (odds ratio=13.3; 95% confidence interval 4.36, 40.52; P <0.0001). There was a non-significant trend to an increase in AVCR when using the suture-less securement device (odds ratio = 2.6; 95% confidence interval 0.87, 7.8; P=0.09) but delirious patients were no more likely to have an AVCR episode when a suture-less securement device was used (P=0.95). In this study the use of suture-less securement did not seem to increase the risk of AVCR. However, there was a non-significant trend towards increased AVCR when using suture-less securement devices, which may reflect a B error. [ABSTRACT FROM AUTHOR]

Objectives. The aims of the present study were to: (1) describe the documentation process of limitation of medical therapy (LMT) orders at the time of a rapid response team (RRT) call; and (2) compare documented LMT orders not associated with an RRT call (control, Group 1) with LMT orders documented at the time of an RRT call (Group 2). Methods. A descriptive study, over a 6-month period (February-August 2011), involving the review of the medical records of patients prospectively identified as either Group 1 or Group 2. Results. There were 994 RRT calls; of these, 50 patients (5%) had an LMT order documented by the RRT. A cardiac arrest was the trigger for the RRT for six patients (12%). Patients in Group 1 (n = 50) and Group 2 were of similar median age (80.5 vs 78.5 years; P = 0.30), LMTs were recorded at a similar time of day (15 : 30 vs 15 : 55 hours; P = 0.52) and day of the week (weekend: 32% vs 35%; P = 0.72). Comparing group 2 with Group 1, the RRT was less likely to document a not-for-resuscitation (NFR; 31 (62%) vs 49 (98%); P < 0.01) or a not-for-ICU (NFICU; 18 (36%) vs 41 (82%); P < 0.01) order, but more likely to document a not-for-RRT call (NFRRT; 31 (62%) vs 22 (44%); P = 0.04) and modified RRT calling criteria (MRRT; 4 (8%) vs 0 (0%); P = 0.04) orders. For Group 2 compared with Group 1 orders, involvement of the patient in the decision making process (9 (18%) vs 25 (50%); P < 0.01) or the next of kin (29 (58%) vs 45 (90%); P < 0.01) was documented less often. Conclusions. Documentation of LMT orders at the time of an RRT call is less likely to include documented involvement of patients or their next of kin, and is more likely to be an NFRRT or MRRT order. These findings have implications for overall clinical governance. [ABSTRACT FROM AUTHOR]

The aim of this study was to explore the degree and determinants of satisfaction of family members of patients being cared for in an Australasian intensive care unit. This was a prospective observational study that took place within a mixed medical/surgical, level three intensive care unit. One hundred and eight family members of patients staying in the intensive care for more than 48 hours were identified. Eight were excluded because next of kin contact details were unavailable. A questionnaire was posted to next of kin four weeks after intensive care unit discharge. Subjects who had not responded after four weeks were contacted by telephone and, if consent was given, a phone questionnaire was performed. Evidence of family meetings with the social worker or medical staff was sought in the patients' case notes retrospectively. Family satisfaction was measured using a 10-item questionnaire incorporating visual analogue scales. Seven subjects refused to participate. Fifty-nine responded by post and a further 25 agreed to a phone interview. Nine subjects were unable to be contacted. Eighty-four family members were included, 73 of patients who survived. Overall family satisfaction was a high 8.0 (interquartile range 6.5 to 9.5). Highest scores recorded were for communications with nursing staff (9.0), while lowest scores were for frequency of doctors' communication (7.0). Families who had meetings with the social worker or medical staff were less likely to report dissatisfaction (relative risk 0.14; confidence interval 0.03 to 0.59; P=0.08; relative risk 0.23; confidence interval 0.07 to 0.81; P=0.02). Our study found that the majority of families are happy with their care in the intensive care unit. Social work and medical meetings with the family reduce dissatisfaction. [ABSTRACT FROM AUTHOR]

This essay highlights a form of love mysticism, known as bridal mysticism, that includes "erotic" forms of human love and the transformation of human love into a spiritual love of God. This is a comparative study based on the writings of Bernard of Clairvaux (twelfth century) from medieval Christianity and Nammajvar, a Hindu mystic of the fifth and sixth centuries. Both mystics saw themselves as lovers or brides of God and modeled their yearning for union with God in terms of human love of female for male. For both, their love intensified after periods of abandonment and rejection by their beloved. However, these mystics differed in their narrations of personal and social responsibilities once their union with God was achieved. [ABSTRACT FROM AUTHOR]

Rice seedlings maintained under uncontrolled glasshouse conditions were inoculated with conidial suspensions of a fungal pathogen, Helminthosporium oryzae, at various times during the 24 h. Significant increase in the percent germination and germ tube length of conidia were observed in the rice samples inoculated at 02:00 and 06:00h. The 24 h temporal variation in leaf temperature was positively correlated with variation in stomatal movements. The results indicate a 24 h rhythm in the behavior of the fungal pathogen on the host in relation to the conditions of the growing environment. In all the inoculated seedlings, the appearance of a large number of brown leaf spots was confined to the light span. Among the plants inoculated, earlier initiation of brown leaf spot appearance, maximum number of leaf spots, and highest disease severity were observed when plants were inoculated at 02:00h. There was a positive correlation between disease severity of the host and in vivo values of percent germination of conidia and germ tube length of the pathogen in plants inoculated between 02:00 and 06:00h. The findings of this study implicate that light intensity and temperature could play a predominant role in controlling disease susceptibility rhythms in plants. [ABSTRACT FROM AUTHOR]

The article discusses a study which examined the use of inferior vena cava (IVC) filters in critically ill patients. Particular focus is given to clinical indications for IVC filter placement in venous thromboembolism management. Also discussed are risks associated with IVC filter placement, IVC filter retrieval, and complications associated with IVC filter placement.

The article discusses a study which examined the clinical features, predisposing factors, complications and mortality of patients with submandibular space infections (SMSI). Particular focus is given to pathogenic microorganisms responsible for SMSI. Topics discussed include the risk of intensive care unit (ICU) readmission in patients with non-odontogenic SMSI, importance of dental care in preventing SMSI, and inadequacy of primary dental care in South Australia.

The cotton plant, Gossypium hirsutum L. (cv. Lakshmi) exhibits circadian leaf movements. Fusaric acid (5-n butyl pyridine 2-carboxylic acid), an in vivo toxin shown to be produced during the pathogenesis of the wilt disease in cotton, causes phase shifts of the leaf movement rhythm that varied in degree and magnitude as a function of the treated phases. The data support the hypothesis that membranes play a vital role as a pacemaker in circadian rhythms. [ABSTRACT FROM AUTHOR]

The article looks at the Six Sigma quality control standard, specifically on tools the program offers for high-level product innovation. The define, measure, analyze, improve and control (DMAIC) method and the define, measure, analyze, design and verify (DMADV) method are mentioned. Particular focus is given to the ideate, define, design and validate (IDDV) method, describing how to use brainstorming to develop ideas, evaluating processes using risk analysis, and implementing pilot programs.