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Introduction: Treatment of multiple brain metastases by linac‐based stereotactic radiotherapy (SRT) can employ either a multiple‐isocenter (MI) or single‐isocenter (SI) approach. The purposes of this study were to evaluate the dosimetric results of MI and SI approaches and compare the impacts of intra‐fractional setup discrepancies on the robustness of respective approaches using isocenter shifts, whether the same magnitude of translational and rotational effects could lead to a significant difference between the two approaches. Methods: Twenty‐two patients with multiple brain metastases treated by linac‐based SRT were recruited. Treatment plans were computed with both the MI and SI approaches. For the MI approach, the isocenter was located at the geometric center of each planning target volumes (PTVs), whereas the isocenter of the SI approach was located midway between the PTV centroids. To simulate the intra‐fractional errors, isocenter displacements including translational and rotational shifts were hypothetically applied. Apart from the dosimetric outcomes of the two approaches, the impact of the isocenter shifts on PTVs and organs at risk (OARs) were recorded in terms of the differences (δ) in dose parameters relative to the reference plan and was then compared between the MI and SI approaches. Results: Both MI and SI plans met the plan acceptance criteria. The mean Paddick conformity index (Paddick CI) and Dmax of most OARs between MI and SI plans did not show a significant difference, except that higher doses to the left optic nerve and optic chiasm were found in SI plans (p = 0.03). After the application of the isocenter shifts, δCI increased with an increase in the magnitude of the isocenter shift. When comparing between MI and SI plans, the δCIs were similar (p > 0.05) for all extents of translational shifts, but δCIs were significantly higher in SI plans after application of all rotations particularly ±1.5° and ±2.0° shifts. Despite the result that the majority of δDMax of OARs were higher in the SI plans, only the differences in the left optic nerve and chiasm showed generally consistent significance after both translational ≥±1 mm and rotational shifts of ≥±1∘$^\circ $. Conclusion: Both MI and SI approaches could produce clinically acceptable plans. However, isocenter shifts brought dosimetric impacts to both MI and SI approaches and the effects increased with the increase of the shift magnitude. Although similar impacts were shown in plans of both approaches after translational isocenter shift, SI plans were relatively more vulnerable than MI plans to rotational shifts. [ABSTRACT FROM AUTHOR]

The laser induced fluorescence spectrum of palladium dimer (Pd2) in the visible region between 480 and 700 nm has been observed and analyzed. The gas-phase Pd2 molecule was produced by laser ablation of palladium metal rod. Eleven vibrational bands were observed and assigned to the [17.1]3Πg-X3Σu+ transition system. The bond length (ro) and vibrational frequency (ΔG1/2) of the ground X3Σu+ state were determined to be 2.47(4) Å and 211.4(5) cm-1, respectively. A molecular orbital energy level diagram was used to understand the observed ground and excited electronic states. This is the first gas-phase experimental investigation of the electronic transitions of Pd2. [ABSTRACT FROM AUTHOR]

The electronic transition spectrum of platinum monoboride (PtB) radical has been observed for the first time. Using laser vaporization/reaction free jet expansion and laser induced fluorescence spectroscopy, the optical spectrum of PtB in the visible region between 455 and 520 nm has been studied. Gas-phase PtB molecule was produced by the reaction of diborane (B2H6) seeded in argon and laser ablated platinum atom. Seven vibrational bands of the Pt11B radical have been recorded and analyzed. The observation of Pt isotopic molecules and the Pt10B isotope confirmed the carrier of the bands. Two different transition systems, namely: the [20.2]3/2-X2Σ+ and the [21.2]1/2-X2Σ+ systems were identified. PtB was determined to have an X2Σ+ ground state and the bond length, re, was determined to be 1.741 Å. [ABSTRACT FROM AUTHOR]

Electronic transition spectrum of cobalt monoboride (CoB) in the visible region between 495 and 560 nm has been observed and analyzed using laser-induced fluorescence spectroscopy. CoB molecule was produced by the reaction of laser-ablated cobalt atom and diborane (B2H6) seeded in argon. Fifteen vibrational bands with resolved rotational structure have been recorded, which included transitions of both Co10B and Co11B isotopic species. Our analysis showed that the observed transition bands are ΔΩ = 0 transitions with Ω″ = 2 and Ω″ = 3 lower states. Four transition systems have been assigned, namely, the [18.1]3Π2-X3Δ2, the [18.3]3[uppercase_phi_synonym]3-X3Δ3, the [18.6]3- X3Δ3, and the [19.0]2-X3Δ2 systems. The bond length, ro, of the X 3Δ3 state of CoB is determined to be 1.705 Å. The observed rotational lines showed unresolved hyperfine structure arising from the nuclei, which conforms to the Hund's case (aβ) coupling scheme. This work represents the first experimental investigation of the CoB spectrum. [ABSTRACT FROM AUTHOR]

Two new electronic transition systems, namely, the [14.0]2[uppercase_phi_synonym]7/2-Χ 2Δ5/2 and the [15.7]2[uppercase_phi_synonym]5/2-Χ 2Δ5/2 transitions were observed and analyzed using laser vaporization/reaction supersonic free jet expansion and high resolution laser induced fluorescence spectroscopy. In addition, the (v, 0) bands with v=6–10 of the [14.6]2Δ5/2-Χ 2Δ5/2 transition were found to be perturbed by the [15.7]2[uppercase_phi_synonym]5/2 state. The interaction between the [14.6]2Δ5/2 and the [15.7]2[uppercase_phi_synonym]5/2 states is evident in the progressive increase in hyperfine width of rotational lines of the [14.6]2Δ5/2-X 2Δ5/2 transition as the vibrational quantum number increases. Deperturbation procedures were successfully applied to analyze the interaction between these two states. All observed spectra show partially resolved hyperfine structure, and the hyperfine width decreases rapidly as J increases suggested that the hyperfine structure conforms to the Hund’s case aβ coupling scheme. Accurate molecular and hyperfine constants for the [14.0]2[uppercase_phi_synonym]7/2, the [14.6]2Δ5/2 and the [15.7]2[uppercase_phi_synonym]5/2 states were obtained and analyzed. [ABSTRACT FROM AUTHOR]

High resolution laser induced fluorescence spectrum of IrB in the spectral region between 545 and 610 nm has been recorded and analyzed. Reacting laser-ablated iridium atoms with 1% B2H6 seeded in argon produced the IrB molecule. This is the first experimental observation of the IrB molecule. Four vibronic transition bands, (v,0) with v=0–3 of an electronic transition system, have been observed. Spectra of all four isotopic molecules, 191Ir10B, 193Ir10B, 191Ir11B, and 193Ir11B, were recorded. Isotopic relationships confirmed the carrier of the spectra and the vibrational quantum number assignment. Preliminary analysis of rotational lines showed that these vibronic bands are with Ω′=2 and Ω″=3. The electronic transition identified is assigned as the [16.5]3Π2-X 3Δ3 system. Partially resolved hyperfine structure which conforms to the Hund’s case aβ coupling scheme has been observed and analyzed. The bond length r0 of the lower X 3Δ3 state of IrB was determined to be 1.7675 Å. [ABSTRACT FROM AUTHOR]

Laser induced fluorescence spectrum of NiBr in the visible region between 604 and 666 nm has been recorded and analyzed. Fourteen bands belonging to three electronic transition systems, namely, [15.1] 2Δ5/2–X 2Π3/2, [15.1] 2Π3/2–X 2Π3/2, and [14.0] 2Δ5/2–X 2Π3/2 have been observed. Spectra of isotopic molecules were also observed and analyzed. Detailed analysis of the recorded spectra indicated that the two electronic states [15.1] 2Π3/2 and [15.1] 2Δ5/2 lie about 1 cm-1 apart from each other and J-dependent perturbation due to spin-uncoupling interaction has been observed. Least squares fitting procedures involving deperturbation matrix elements were used to fit the observed line positions, which yielded accurate molecular constants for the [15.1] 2Π3/2 and [15.1] 2Δ5/2 states. In addition, the (1,0) band of the [15.1] 2Δ5/2–X 2Π3/2 transition shows partially resolved hyperfine structure that was caused by the interaction of unpaired electron with the magnetic moment of the Br nucleus (nuclear spin of I=3/2) in the excited state. The rapid decrease in hyperfine width as J increases suggests that the hyperfine coupling in the excited state conforms to Hund’s case (aβ) coupling scheme. [ABSTRACT FROM AUTHOR]

Photoabsorption measurements of NO bands have been made by vacuum-ultraviolet Fourier transform spectrometry with a resolution of 0.12 cm-1 in the wavelength region of 166.2–196.2 nm. Accurate line positions are obtained for the δ(υ,0) bands with υ=2, 3, the ε(υ,0) bands with υ=2, 3, and the β(υ,0) bands with υ=10,12,14. Absolute term values are found for the corresponding upper levels C(2,3), D(2,3), and B(10,12,14). Accurate rotational line integrated cross sections have also been obtained for the lines in these bands. Integrated cross sections reported in our earlier papers [J. Chem. Phys. 109, 1751 (1998); 112, 2251 (2000); 115, 3719 (2001); 116, 155 (2002); 117, 10621 (2002); 119, 8373 (2003)] have been revised, and the results reported here comprise the δ(υ,0) bands with υ=0–3, the ε(υ,0) bands with υ=0–3, the β(υ,0) bands with υ=6,7,9–12,14, and the γ(3,0) band. For each band, the band oscillator strength is obtained from the sum of the line strengths of all rotational lines, and these are compared with other published values. [ABSTRACT FROM AUTHOR]

Laser-induced fluorescence spectrum of NiI in the near infrared region of 714–770 nm has been recorded. Seven bands belonging to three electronic transition systems were observed and analyzed: the (0,0), (1,0), and (2,0) bands of [13.3] 2Σ+-A 2Π3/2 system; the (1,1) and (0,1) bands of [13.9] 2Π3/2-X 2Δ5/2 system; and the (0,0) and (1,0) bands of [13.9] 2Π3/2-A 2Π3/2 system. Spectra of isotopic molecules confirmed the vibrational quantum number assignment of the observed bands. Least-squares fit of rotationally resolved transition lines yielded accurate molecular constants for the v=0–2 levels of the [13.3] 2Σ+ state, the v=0 level of the A 2Π3/2, and the v=1 level of the X 2Δ5/2 state. The vibrational separation, ΔG1/2, of the ground state was measured to be 276.674 cm-1. With the observation of the [13.9] 2Π3/2-A 2Π3/2 and [13.9] 2Π3/2-X 2Δ5/2 transitions, we accurately determined the energy separation between the A 2Π3/2 and the X 2Δ5/2 to be 163.847 cm-1. This confirms that the order of the A 2Π3/2 and X 2Δ5/2 states in NiI is reversed when compared with other nickel monohalides. © 2004 American Institute of Physics. [ABSTRACT FROM AUTHOR]

High-resolution laser-induced fluorescence spectrum of a jet-cooled NiI molecule has been recorded in the near infrared and visible regions. The NiI molecule was produced by reacting laser-ablated nickel atom and methyl iodide (CH[sub 3]I). Three electronic states have been identified that include the X [sup 2]Δ[sub 5/2] and two low-lying [13.9] [sup 2]Π[sub 3/2] and [14.6] [sup 2]Δ[sub 5/2] excited states. Molecular transition bands (v[sup ′],0) of the [13.9] [sup 2]Π[sub 3/2]-X [sup 2]Δ[sub 5/2] system with v[sup ′]=0, 4–9, and the (v[sup ′],0) bands of the [14.6] [sup 2]Δ[sub 5/2]-X [sup 2]Δ[sub 5/2] system with v[sup ′]=0–6 were observed and analyzed. Spectra of isotopic molecules confirmed the assignment of vibrational quantum number of the observed bands. Least squares fit of rotational transition lines yielded accurate molecular constants for the states studied. The bond length r[sub 0] measured for the X [sup 2]Δ[sub 5/2] is 2.3479 Å and the equilibrium bond length, r[sub e], for the [13.9] [sup 2]Π[sub 3/2] and [14.6] [sup 2]Δ[sub 5/2] are, respectively, 2.4834 and 2.5081 Å. With the use of a molecular orbital energy level diagram, we have examined the electronic configurations that give rise to the X [sup 2]Π[sub 3/2] ground state for NiF, NiCl, and NiBr, but the X [sup 2]Δ[sub 5/2] state for NiI. This work represents the first spectroscopic study of the NiI molecule. © 2003 American Institute of Physics. [ABSTRACT FROM AUTHOR]

The ε(0,0) (D [sup 2]Σ[sup +]–X [sup 2]Π[sub r]) band of NO has been recorded by using a vacuum ultraviolet Fourier transform spectrometer from Imperial College, London, with synchrotron radiation at the Photon Factory, KEK, Japan, as a continuum light source. Analysis of the ε(0,0) band provides accurate rotational line positions and term values as well as the photoabsorption cross sections. Molecular constants of the v=0 level of the D [sup 2]Σ state have been determined as T[sub 0]=53 291.10±0.10 cm[sup -1], B[sub 0]=1.991 07±0.000 05 cm[sup -1], and D[sub 0]=(6.6±0.1)×10[sup -6] cm[sup -1]. Accurate rotational line strengths have also been obtained and the sum of the line strengths for all rotational lines is determined as 2.18×10[sup -15] cm[sup 2] cm[sup -1]. The band oscillator strength of the ε(0,0) band is determined to be (2.47±0.12)×10[sup -3]. © 2003 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Electronic transitions of cobalt monochloride and cobalt monoiodide have been studied using laser vaporization-reaction free jet expansion and laser induced fluorescence spectroscopy in the near infrared region. The observed transitions have been identified as the [10.3] 3Φ[SUB4]-X 3Φ[SUB4] transition of CoCl and [11.0] 3Φ[SUB4]-X 3Φ[SUB4] transition of CoI. The magnetic hyperfine structure arising from the cobalt nucleus with I = 7/2 was resolved and analyzed. Accurate rotational and hyperfine parameters for the [10.3] 3Φ[SUB4] and X 3Φ[SUB4] states of CoCl and [11.0] 3Φ[SUB4] and X 3Φ[SUB4] states of CoI have been obtained. Comparison of Fermi contact parameters, b[SUBF], for the upper states indicated that the observed [10.3] 3Φ[SUB4]-X 3Φ[SUB4] transition of CoCl and [11.0] 3Φ[SUB4]-X 3Φ[SUB4] transition of CoI have arisen from the promotion of an electron from the bonding s orbital to a slightly antibonding σ orbital. Observed low-lying 3Φ states of the cobalt monohalides and hydride are also compared and discussed. [ABSTRACT FROM AUTHOR]

The electronic structures and spectroscopic parameters of the ground and some low-lying excited states of the first-row transition metal phosphides have been calculated with the density functional theory using the Becke three-parameter hybrid exchange functional with the Lee-Yang-Parr correlation functional (B3LYP). The ground states of the transition metal phosphides are found to be [SUP1]∑[SUP+] (ScP), [SUP2]Δ (TiP), [SUP3]Δ (VP), [SUP4]∑[SUP-] (CrP), [SUP5]Π (MnP), [SUP6]∑[SUP-] (FeP), [SUP5]Δ (CoP), [SUP4]Δ (NiP), and [SUP3]∑[SUP-] (CuP). The B3LYP functional predicts an increase in covalent character in the bonds between the metal and the phosphorus across the transition metal series. The energies of the low-lying excited states relative to the ground state for TiP, FeP, and CoP have been found to be so small that many low-lying states are possible candidates to be the ground state. [ABSTRACT FROM AUTHOR]

The (0,0) band of the B ²Σ[sup +]-X²Σ[sup +] transition of LaS near 726 nm has been studied at high resolution using laser vaporization/reaction supersonic free jet expansion and laser induced fluorescence spectroscopy. Spectra taken at a resolution of about 50 MHz show resolved hyperfine structure which is caused principally by the unpaired 6sσ- electron in the ground state interacting with large magnetic moment of the [sub 57][sup 139]La nucleus with nuclear spin I=7/2. The X²Σ[sup +] state of LaS is in good Hund's case (b[sub βs]) coupling, however, the upper state, B ²Σ[sup +], is close to case (b[sub βJ]) coupling. A total of 1850 rotational-hyperfine transition lines have been assigned and measured. Accurate rotational, spin and hyperfine parameters for the B ²Σ[sup +] and X²Σ[sup +] states have been obtained, which give information about the electron distribution in the molecule. [ABSTRACT FROM AUTHOR]

Four electronic states of NiBr have been studied using the technique of laser vaporization/reaction with supersonic cooling and laser induced fluorescence (LIF) spectroscopy. NiBr molecules were produced by reacting laser ablated nickel atoms and ethyl bromide (C[sub 2]H[sub 5]Br). High resolution LIF spectrum between 724 and 810 nm was recorded, which consists of the (2,0), (1,0), and (0,0) bands of the [13.2] ²Π[sub 3/2-]-X²Π[sub 3/2] system and the [13.2] ²Π[sub 3/2]--A ²Δ[sub 5/2] system, and also the (v,0) with v = 0-4 bands of the [12.6] 2Σ[sup +]-X²Π[sub 3/2] system. Spectra of four isotopic molecules: [sup 58]Ni[sup 79]Br, [sup 58]Ni[sup 81]Br, [sup 60]Ni[sup 79]Br, and [sup 60]Ni[sup 81]Br were observed and analyzed. Least squares fit of rotationally resolved transition lines yielded accurate molecular constants for the X²Π[sub 3/2], A ²Δ[sub 5/2], [12.6] 2Σ[sup +], and [13.2] ²Π[sub 3/2] electronic states of NiBr. The bond length, r[sub 0], measured for the X²Π[sub 3/2] and A ²Δ[sub 5/2] states is 2.19628 and 2.16445 Å, respectively. A molecular orbital diagram has been constructed to explain the four observed electronic states. This work represents the first high-resolution spectroscopic study of NiBr. [ABSTRACT FROM AUTHOR]

The β(6,0) (B [sup 2]Π[sub r]–X [sup 2]Π[sub r]) and γ(3,0) (A [sup 2]Σ[sup +]–X [sup 2]Π[sub r]) bands of NO have been recorded using a vacuum ultraviolet Fourier transform spectrometer with synchrotron radiation as light source. The analysis of the β(6,0) and γ(3,0) bands of NO provides accurate rotational line positions and term values. Molecular constants of the v=6 level of the B [sup 2]Π[sub r] and v=3 level of the A [sup 2]Σ[sup +] have been determined. Accurate rotational line strengths have also been obtained. The band oscillator strength of the β(6,0) and γ(3,0) bands are determined to be 0.48×10[sup -4] and 2.69×10[sup -4], respectively. © 2002 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Natural falcarinol-type (FC-type) polyacetylenes are known to show anticancer activities. We studied the bioactivity of synthetic FC, 1,2-dihydrofalcarinol (FCH) and 3-acetoxyfalcarinol (FCA) and compared them with the natural bioactive polyacetylene [9,17-octadecadiene-12,14-diyne-1,11,16-triol,1-acetate] (DCA) isolated from Devil's club (DC) Oplopanax horridus. Antiproliferation activity of these polyacetylenes, along with DC inner stem bark 70% ethanol and water extracts, was tested on human pancreatic ductal adenocarcinoma cell lines PANC-1 and BxPC-3. Chemically synthesized FC and FCA showed consistent IC50 (50% inhibition concentration) and higher potency than DCA. FC and DCA's mechanism of action investigated by antibody array on apoptosis-associated genes, and cellular features confirmed by microscopy demonstrated that both compounds modulated genes related to pro-apoptosis, antiapoptosis, apoptosis, cell cycle, stress related, and death receptors. FC-type polyacetylenes with a terminal double bond (FC, FCA, and DCA) are potent inhibitors of pancreatic cancer cell proliferation compared to FCH with a terminal single bond. Liquid chromatography mass spectrometry confirmed the presence of FC and FCH in the inner stem bark of DC. For potential applications of FC-type polyacetylenes as anticancer agents, preparing them by chemical synthesis may provide an advantage over the labor intensive extraction process from raw plant material. [ABSTRACT FROM AUTHOR]

The predissociation linewidths of vibrational levels v=0 –12 for 16O2, 16O18O, and 18O2 molecules in the B 3Σu- state with rotational quantum numbers N≤20 have been calculated taking into account the spin–orbit interactions of the B 3Σu- state with the 5Πu, 3Σu+, 3Πu, and 1Πu states, and the rotational coupling with the 3Πu state. The predissociation linewidths exhibit systematic variations with rotational quantum number for different vibrational levels. Good agreement between most of the calculated and experimental linewidths has been obtained for all three isotopic molecules, with the exception of the set of linewidths of 16O2 for v=0 and 2. The agreement can be improved by adjustment of the 1Πu potential and the strength of the spin–orbit interaction between the B 3Σu- and 1Πu states. [ABSTRACT FROM AUTHOR]

The predissociation linewidths and level shifts of vibrational levels of three oxygen isotopic molecules 16O2, 16O18O, and 18O2 arising from the interactions of the B 3Σ-u state with the four repulsive states 5Πu, 3Σ+u, 3Πu, and 1Πu, have been calculated. A set of parameters characterizing these interactions has been determined. Good agreement between calculated and experimental predissociation widths and shifts has been obtained for all the three isotopic molecules. [ABSTRACT FROM AUTHOR]

Predissociation linewidths of the (3,0)–(11,0) Schumman–Runge bands of 18O2 and 16O 18O in the wavelength region 180–196 nm have been obtained from the published measurements of the absolute absorption cross sections of Yoshino et al. [Planet. Space Sci. 36, 1201 (1988); 37, 419 (1989)] and spectroscopic constants of these molecules of Cheung et al. [J. Mol. Spectrosc. 131, 96 (1988); 134, 362 (1989)]. The linewidths are determined as parameters in the nonlinear least-squares fitting of calculated to measured cross sections. Predissociation maxima are found at upper vibrational levels with v’=4, 7, and 10 for 18O2 and for 16O 18O. Our predissociation linewidths are mostly greater than previous experimental values for both isotopic molecules. [ABSTRACT FROM AUTHOR]

A nonlinear least-squares method of retrieving predissociation linewidths from the experimental absolute absorption cross sections of Yoshino et al. [Planet. Space Sci. 31, 339 (1983)] has been applied to the (1,0)–(12,0) Schumann–Runge bands of oxygen. Predissociation linewidths deduced for the Schumann–Runge bands are larger than the theoretical predictions of Julienne [J. Mol. Spectrosc. 63, 60 (1976)] and the latest measurements of Lewis et al. [J. Quant. Spectrosc. Radiat. Transfer 36, 187 (1986)]. The larger linewidths found will have an impact on calculations of solar flux penetration into the Earth’s atmosphere and of the photodissociation rates of trace species in the upper atmosphere. Systematic variation of predissociation linewidths with rotational quantum number is observed in the bands (v’,0) with v’=6, 8, 9, 11, and 12. [ABSTRACT FROM AUTHOR]

Objectives To estimate the prevalence of fetal alcohol spectrum disorder (FASD) among young people in youth detention in Australia. Neurodevelopmental impairments due to FASD can predispose young people to engagement with the law. Canadian studies identified FASD in 11%-23% of young people in corrective services, but there are no data for Australia. Design Multidisciplinary assessment of all young people aged 10-17 years 11 months and sentenced to detention in the only youth detention centre in Western Australia, from May 2015 to December 2016. FASD was diagnosed according to the Australian Guide to the Diagnosis of FASD. Participants 99 young people completed a full assessment (88% of those consented; 60% of the 166 approached to participate); 93% were male and 74% were Aboriginal. Findings 88 young people (89%) had at least one domain of severe neurodevelopmental impairment, and 36 were diagnosed with FASD, a prevalence of 36% (95% CI 27% to 46%). Conclusions This study, in a representative sample of young people in detention in Western Australia, has documented a high prevalence of FASD and severe neurodevelopmental impairment, the majority of which had not been previously identified. These findings highlight the vulnerability of young people, particularly Aboriginal youth, within the justice system and their significant need for improved diagnosis to identify their strengths and difficulties, and to guide and improve their rehabilitation. [ABSTRACT FROM AUTHOR]

Presents a correction to the article related to the application of a VUV Fourier transform spectrometer and synchrotron radiation source to measurements of absorption bands of nitrogen oxide, published in previous issues of "Journal of Chemical Physics."

A series of catalytic reactions has been performed in our laboratory using olivine-type silicates (OTS) and SiC as catalysts for the conversion of carbon-containing molecules (such as acetylene, CO and methanol) to small organic molecules (C2H4, C3H3, CH3O) and also polycyclic aromatic hydrocarbons (PAHs). Experimentally, small-to-medium-sized gas-phase compounds such as PAHs, reaction intermediates and hydrocarbon compounds were detected in situ using the time-of-light mass-spectrometry technique. Solid deposition on the catalyst surface was examined by high-resolution transmission electron microscopy and thermo-gravimetric analysis techniques. Our laboratory results show that the conversion of acetylene to PAHs, the CO disproportionation reaction for producing CO2 and carbon deposition (graphitic and carbon nanostructures), and also the transformation of methanol to hydrocarbon compounds can easily be achieved with OTS as a catalyst. Furthermore, the conversion of acetylene to PAHs could also be achieved by SiC as the catalyst. It is proposed that these catalytic reactions mimic similar chemical processes in circumstellar envelopes (CSEs). [ABSTRACT FROM AUTHOR]

It is demonstrated that, according to semi-classical theory, the isotopic dependence of the predissociation linewidths in the Schumann-Runge bands of oxygen cannot be removed by simple scaling of the reduced mass. This is in contrast to the isotopic dependence of the predissociated vibrational energy levels. © 1995 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Comments on an study on the predissociation of oxygen in the B state. Distinction which confirms that the simulated spectra are excitation spectra and not absorption spectra; Criticism on the conclusions concerning the predissociation.

Catalytic conversion reactions of acetylene on a solid SiC grain surface lead to the formation of polycyclic aromatic hydrocarbons (PAHs) and are expected to mimic chemical processes in certain astrophysical environments. Gas-phase PAHs and intermediates were detected in situ using time-of-flight mass spectrometry, and their formation was confirmed using GC-MS in a separate experiment by flowing acetylene gas through a fixed-bed reactor. Activation of acetylene correlated closely with the dangling bonds on the SiC surface which interact with and break the C–C π bond. The addition of acetylene to the resulting radical site forms a surface ring structure which desorbs from the surface. The results of HRTEM and TG indicate that soot and graphene formation on the SiC surface depends strongly on reaction temperature. We propose that PAHs as seen through the ‘UIR’ emission bands can be formed through decomposition of a graphene-like material, formed on the surface of SiC grains in carbon-rich circumstellar envelopes. [ABSTRACT FROM AUTHOR]

Devil's clubOplopanax horridus(DC) is a close relative of ginseng; its inner root and stem bark extract showed antiproliferation activity on human leukemia, ovarian, breast and colon cancer cells. We study here the effects of DC 70% ethanol extract alone, or in combination with cisplatin, gemcitabine, and paclitaxel on pancreatic endocrine HP62 and pancreatic ductal carcinoma PANC-1 and BxPC-3 cells. Antiproliferation activity assay, cell cycle analysis by flow cytometry, apoptosis-related markers by antibody array, and RT-PCR assay were used for this study. DC extract inhibited proliferation of HP62 with IC50(50% inhibition concentration) at 0.037±0.002% (v/v), PANC-1 at 0.0058 ± 0.0004% and BxPC-3 at 0.021 ± 0.003%. DC at 0.0033% combined with 1 nM of paclitaxel showed inhibition synergy on PANC-1 cells with a combination index of 0.44. Apoptosis focused antibody array profile indicated upregulation of cytochrome C, claspin, cIAP-2 and HTRA2/Omi apoptosis-related markers in DC-treated HP62 and PANC-1. Our data suggest that DC acts through targeting the intrinsic mitochondrial apoptosis pathway in the pancreatic cancer cells. The high antiproliferation potency of DC on PANC-1 is potentially useful as an adjunct therapy for treating pancreatic cancer, which is known for developing resistance to conventional chemotherapeutics. [ABSTRACT FROM PUBLISHER]

MicroRNAs (miRs) play a pivotal role in a variety of biological processes including stem cell differentiation and function. Human foetal femur derived skeletal stem cells (SSCs) display enhanced proliferation and multipotential capacity indicating excellent potential as candidates for tissue engineering applications. This study has examined the expression and role of miRs in human foetal femur derived SSC differentiation along chondrogenic and osteogenic lineages. Cells isolated from the epiphyseal region of the foetal femur expressed higher levels of genes associated with chondrogenesis while cells from the foetal femur diaphyseal region expressed higher levels of genes associated with osteogenic differentiation. In addition to the difference in osteogenic and chondrogenic gene expression, epiphyseal and diaphyseal cells displayed distinct miRs expression profiles. miR-146a was found to be expressed by human foetal femur diaphyseal cells at a significantly enhanced level compared to epiphyseal populations and was predicted to target various components of the TGF-β pathway. Examination of miR-146a function in foetal femur cells confirmed regulation of protein translation of SMAD2 and SMAD3, important TGF-β and activin ligands signal transducers following transient overexpression in epiphyseal cells. The down-regulation of SMAD2 and SMAD3 following overexpression of miR-146a resulted in an up-regulation of the osteogenesis related gene RUNX2 and down-regulation of the chondrogenesis related gene SOX9. The current findings indicate miR-146a plays an important role in skeletogenesis through attenuation of SMAD2 and SMAD3 function and provide further insight into the role of miRs in human skeletal stem cell differentiation modulation with implications therein for bone reparation. [ABSTRACT FROM AUTHOR]

Polycyclic aromatic hydrocarbons (PAHs) are known to be present in many astrophysical objects and environments, but our understanding of their formation mechanism(s) is far from satisfactory. In this paper, we describe an investigation of the catalytic conversion reaction of acetylene gas to PAHs over pyroxene and alumina. Crystalline silicates such as pyroxenes (with general formula [Mg, Fe]SiO3) and alumina (Al2O3) are observed astrophysically through their infrared spectra and are likely to promote grain surface chemical reactions. In the experiments reported here, gas-phase PAHs were produced by the catalytic reaction of acetylene over crystalline silicates and alumina using a pulsed jet expansion technique and the gaseous products detected using time-of-flight mass spectrometry. In a separate experiment, the catalytic formation of PAHs from acetylene was further confirmed with acetylene gas at atmospheric pressure flowing continuously through a fixed-bed reactor. The gas effluent and carbonaceous compounds deposited on the catalysts were dissolved separately in dichloromethane and analysed using gas chromatography-mass spectrometry. Among the samples studied, alumina showed higher activity than the pyroxene-type grains for the acetylene reaction. It is proposed that formation of the PAHs relies on the Mg[sup 2+] ions in the pyroxenes and Al[sup 3+] ions in alumina, where these ions act as Lewis acid sites. X-ray diffraction, Fourier transform infrared and high-resolution transmission electron microscopy techniques were used to characterize the structure and physical properties of the pyroxene and alumina samples. [ABSTRACT FROM AUTHOR]

RATIONALE We implemented, for the first time, laser-induced dissociation (LID) within a modified hybrid linear ion trap mass spectrometer, QTrap, while preserving the original scanning capabilities and routine performance of the instrument. METHODS Precursor ions of interest were mass-selected in the first quadrupole (Q1), trapped in the radiofrequency-only quadrupole (q2), photodissociated under irradiation with a 193- or 266-nm laser beam in the third quadrupole (q3), and mass-analyzed using the linear ion trap. RESULTS LID of singly charged protonated peptides revealed, in addition to conventional amide-bond cleavages, preferential fragmentation at Cα-C/N-Cα bonds of the backbone as well as at the Cα-Cβ/Cβ-Cγ bonds of the side-chains. The LID spectra of [M+H]+ featured product ions that were very similar to the observed radical-induced fragmentations in the CID spectra of analogous odd-electron radical cations generated through dissociative electron-transfer in metal-ligand-peptide complexes or through laser photolysis of iodopeptides. CONCLUSIONS LID of [M+H]+ ions results in fragmentation channels that are comparable with those observed upon the CID of M•+ ions, with a range of fascinating radical-induced fragmentations. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The influence of water in the CH feed on the performance of 3%Mo/ZSM-5 catalyst during methane direct aromatization under supersonic jet expansion (SJE) condition was investigated. We observed that both surface MoOC and β-MoC species are catalytically active for methane aromatization under SJE condition. The presence of water can promote the removal of surface carbon before the generation of aromatic-type and/or graphitic carbon. In appropriate amount, water can improve the stability of surface MoOC, and hence resulting in better catalytic performance. The study provided valuable information relevant to the direct utilization of methane hydrate. © 2010 American Institute of Chemical Engineers AIChE J, 2011 [ABSTRACT FROM AUTHOR]

The possibility that the non-adiabatic correction to the scattering length of a pair of hydrogen atoms interacting via the ground state molecular potential, X1Σg +, of H2 could be made by replacing the mass of each nucleus by a different effective mass is explored. The Born-Oppenheimer potential with adiabatic, relativistic and radiative corrections is used in calculations of the scattering lengths and the mass-dependent shifts of the rotationless vibrational levels with fixed and varying effective masses. The shifts are compared with established values and it is demonstrated that the semi-classical formula for the scattering length accounts well for the effect of changing the mass. A perturbing potential that is equivalent to a change in mass is derived and it is compared to a published local non-adiabatic potential. [ABSTRACT FROM AUTHOR]

The two major aggrecanases involved in osteoarthritis (OA) are ADAMTS-4 and ADAMTS-5. Knock-out studies suggested that ADAMTS-5, but not ADAMTS-4, is the major aggrecanase in murine OA. However, studies of human articular cartilage suggest that ADAMTS-4 also contributes to aggrecan degradation in human OA. This study investigated ADAMTS-4 in human OA. While ADAMTS-4 was virtually absent in control cartilage, numerous ADAMTS-4 immuno-positive chondrocytes were present in OA cartilage and their numbers increased with disease severity. RT-PCR confirmed expression, especially in the surface zone. DNA methylation was lost at specific CpG sites in the ADAMTS-4 promoter in OA chondrocytes, suggesting that the increased gene expression was more than a simple up-regulation, but involved loss of DNA methylation at specific CpG sites, resulting in a heritable and permanent expression of ADAMTS-4 in OA chondrocytes. These results suggest that ADAMTS-4 is epigenetically regulated and plays a role in aggrecan degradation in human OA. [ABSTRACT FROM AUTHOR]

The ([sup v],0) bands, for v = 0-5, of the B[sup 1]Pi-X [sup 1]Σ transition of YBr between 806.2-891.2nm have been studied using the technique of laser vaporization/reaction with supersonic cooling and laser-induced fluorescence spectroscopy. Spectra of both the Y[sup 79]Br and Y[sup 81]Br isotopic molecules were observed and analysed. A least-squares fit of all the measured line positions yielded vibrational and rotational constants for the B[sup 1]Pi state. The equilibrium bond length of the B[sup 1]Pi state is determined to be 2.6225(2)Å. [ABSTRACT FROM AUTHOR]

The hyperfine spectra of the Na[sub 2] 1 [sup 3]Δ[sub g] state have been recorded with sub-Doppler continuous wave (CW) perturbation facilitated optical–optical double resonance (PFOODR) spectroscopy via A [sup 1]∑[sub u][sup +]∼b [sup 3]∏[sub u] mixed intermediate levels. The rotational lines into the N=14–51 levels of the 1 [sup 3]Δ[sub g] state observed previously [J. Mol. Spectrosc. 134, 50 (1989)] have four components for transitions between symmetric rotational levels or five components for transitions between antisymmetric rotational levels and the hyperfine coupling belongs to Hund’s case b[sub βS]. For the low-N levels observed later, however, the hyperfine spectra are much more complicated. We have worked out the matrix elements of the molecular Hamiltonian in the case b[sub βS] basis. After taking into consideration spin–orbit, spin–spin, and spin–rotation interactions, we obtained a set of molecular constants for the Na[sub 2] 1 [sup 3]Δ[sub g] state, with which we can reproduce the hyperfine spectra of both high- and low-N rotational levels. © 2001 American Institute of Physics. [ABSTRACT FROM AUTHOR]

We derive and use new parameters to quantify the semiempirical expressions of Julienne and Krauss [J. Mol. Spectrosc. 56, 270 (1975)] for the [sup 5]Π[sub u], [sup 3]Σ[sub u][sup +], [sup 3]Π[sub u], and [sup 1]Π[sub u] potentials that predissociate the rovibrational levels of the B [sup 3]Σ[sub u][sup -] state of O[sub 2]. Using the new parameters in the model of Julienne and Krauss we evaluate fine-structure predissociation linewidths for the Schumann-Runge bands that terminate on the v=13,14 rovibrational levels of the B [sup 3]Σ[sub u][sup -] state. We compare these linewidths and those calculated with several existing sets of parameters with the measurements of Dooley et al. [J. Chem. Phys. 109, 3856 (1998)]. We also show the deperturbing effect of the level shifts, calculated with the new parameters, on the energies of the rotationless v=0-17 vibrational levels of the B [sup 3]Σ[sub u][sup -] state. © 2001 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Fourier transform spectroscopic measurements of the absorption bands of the Herzberg III (A[sup ′] [sup 3]Δ[sub u]-X [sup 3]Σ[sub g][sup -]) of O[sub 2] at 295 K have been made with a resolution of 0.06 cm[sup -1] in the wavelength region 240 to 275 nm. Rotational line positions are determined with an accuracy of 0.005 cm[sup -1], and rotational term values are presented for the vibrational levels, v[sup ′]=4-11. Precise band oscillator strengths of the (4,0)-(11,0) bands are obtained for the first time by direct measurement by summing the cross sections of individual rotational lines of the bands. The rotational line strengths and the branching ratios are also presented for the same bands. The continuity relationship for the band oscillator strengths to photodissociation continuum cross sections has been applied to the three-band systems. © 2000 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Line-by-line photoabsorption cross-sections of the NO δ(1,0) band were measured with the VUV Fourier transform spectrometer from Imperial College, London, using synchrotron radiation at Photon Factory, KEK, Japan, as a continuum light source. The analysis of the NO δ(1,0) band provides accurate rotational line positions and term values as well as the photoabsorption cross-sections. The molecular constants of the C(1) [sup 2]Π level are found to be T[sub 0]=54 690.155±0.03 cm[sup -1], B[sub v]=1.944 06±0.000 62 cm[sup -1], D[sub v]=(5.91±0.42)x10[sup -5] cm[sup -1], A[sub D]=-0.0187±0.0050 cm[sup -1], p=-0.0189±0.0037 cm[sup -1], and q=-0.015 21±0.000 20 cm[sup -1]. The sum of the line strengths for all rotational transitions of the NO δ(1,0) band is determined as 4.80x10[sup -15] cm[sup 2] cm[sup -1], corresponding to a band oscillator strength of 0.0054±0.0003. © 2000 American Institute of Physics. [ABSTRACT FROM AUTHOR]