Promoting "Zest for Life": A Systematic Literature Review of Resiliency Factors to Prevent Youth Suicide.

Suicide is a leading cause of death among youth globally. In this critical interpretive synthesis, we examined literature on resiliency factors and suicidality. Systematic searches identified 474 articles, 37 of which were included. Results revealed internal (positive self-appraisal, zest for life, personal traits, and coping skills) and external factors (social support system and inclusive environments) contribute to resilience among youth, with age, sex and gender, and Indigenous identity as important intersecting considerations. Findings validated fostering resilience as primary suicide prevention among youth, with little explanation for how these factors may work to protect youth from suicidality. Continued research in this area requires a focus on how to promote resilience at the community and systems levels.

Longer-range distances by spinning-angle-encoding solid-state NMR spectroscopy.

A new spinning-angle-encoding spin-echo solid-state NMR approach is used to accurately determine the dipolar coupling corresponding to a C-C distance over 4 Å in a fully labelled dipeptide. The dipolar coupling dependent spin-echo modulation was recorded off magic angle, switching back to the magic angle for the acquisition of the free-induction decay, so as to obtain optimum sensitivity. The retention of both ideal resolution and long-range distance sensitivity was achieved by redesigning a 600 MHz HX MAS NMR probe to provide fast angle switching during the NMR experiment: for 1.8 mm rotors, angle changes of up to ∼5° in ∼10 ms were achieved at 12 kHz MAS. A new experimental design that combines a reference and a dipolar-modulated experiment and a master-curve approach to data interpretation is presented.

A 93Nb solid-state NMR and density functional theory study of four- and six-coordinate niobate systems.

A variable B(0) field static (broadline) NMR study of a large suite of niobate materials has enabled the elucidation of high-precision measurement of (93)Nb NMR interaction parameters such as the isotropic chemical shift (delta(iso)), quadrupole coupling constant and asymmetry parameter (C(Q) and eta(Q)), chemical shift span/anisotropy and skew/asymmetry (Omega/Deltadelta and kappa/eta(delta)) and Euler angles (alpha, beta, gamma) describing the relative orientation of the quadrupolar and chemical shift tensorial frames. These measurements have been augmented with ab initio DFT calculations by using WIEN2k and NMR-CASTEP codes, which corroborate these reported values. Unlike previous assertions made about the inability to detect CSA (chemical shift anisotropy) contributions from Nb(V) in most oxo environments, this study emphasises that a thorough variable B(0) approach coupled with the VOCS (variable offset cumulative spectroscopy) technique for the acquisition of undistorted broad (-1/2<-->+1/2) central transition resonances facilitates the unambiguous observation of both quadrupolar and CSA contributions within these (93)Nb broadline data. These measurements reveal that the (93)Nb electric field gradient tensor is a particularly sensitive measure of the immediate and extended environments of the Nb(V) positions, with C(Q) values in the 0 to >80 MHz range being measured; similarly, the delta(iso) (covering an approximately 250 ppm range) and Omega values (covering a 0 to approximately 800 ppm range) characteristic of these niobate systems are also sensitive to structural disposition. However, their systematic rationalisation in terms of the Nb-O bond angles and distances defining the immediate Nb(V) oxo environment is complicated by longer-range influences that usually involve other heavy elements comprising the structure. It has also been established in this study that the best computational method(s) of analysis for the (93)Nb NMR interaction parameters generated here are the all-electron WIEN2k and the gauge included projector augmented wave (GIPAW) NMR-CASTEP DFT approaches, which account for the short- and long-range symmetries, periodicities and interaction-potential characteristics for all elements (and particularly the heavy elements) in comparison with Gaussian 03 methods, which focus on terminated portions of the total structure.

Interaction with and effects on the profile of proteins of Botrytis cinerea by C6 aldehydes.

The natural volatile compounds cis-3-hexenal (c-3-H) and trans-2-hexenal (t-2-H) have significant antifungal activity with potential for use as postharvest fumigants of fruits and vegetables. However, the nature of their interaction with fungi and impact on fungal growth at the molecular level are largely unknown. The sites of interaction of these six carbon (C6) aldehydes with Botrytis cinerea, a common pathogen of many plant species, was characterized using 3H-labeled c-3-H and t-2-H. Radiolabeled C6 aldehydes were produced with lipoxygenase and hydroperoxide lyase extracts using [9,10,12,13,15,16-3H6]linolenic acid as a substrate. Following exposure of B. cinerea cultures to radiolabeled C6 aldehydes, radiolabel was recovered in protein-enriched but not lipid-enriched fractions. Radiolabel was incorporated at higher levels (6-fold per milligram of fresh weight and 4-fold per microgram of protein) into conidia than mycelia. About 95% of the radiolabeled aldehyde recovered in the protein fraction was from the surface of the fungal tissue, while 5% was from protein in internal tissue (cell wall, membrane, and cytosol). Exposure to t-2-H at both 5.4 and 85.6 micromol affected the protein profile of B. cinerea, changing the intensity of over one-third of all proteins. Both up-regulation and down-regulation of specific proteins were observed by two-dimensional gel electrophoresis, indicating a clear effect of t-2-H on changes in the protein profile of B. cinerea. This is the first evidence that fungal proteins are targets of the volatile C6 aldehydes and that sublethal levels of the aldehydes cause changes in the protein profile of a fungus.

Prosthetic Joint Infections in Patients Undergoing Carpal Tunnel Release.

INTRODUCTION: Little information is available regarding the rate of prosthetic joint infections (PJIs) in patients undergoing carpal tunnel release (CTR) without antibiotic prophylaxis. Hand surgeons should be aware of patients' history of arthroplasty. METHODS: All patients who underwent CTR at our institution between 2012 and 2014 were identified and their charts were reviewed to identify those who had a history of total hip, knee, and/or shoulder arthroplasty. Further chart review consisted of identifying a history of PJI, use of perioperative antibiotics, and surgeon awareness of prior arthroplasty. RESULTS: Two hundred seventy-five CTR surgeries were performed in patients who had previously undergone total joint arthroplasty (TJA). There were no PJIs in any group of patients (P = 0.01). Hand surgeon awareness of the presence of an arthroplasty history had no discernable effect on the choice to use antibiotics. CONCLUSIONS: There was a 0% rate of PJI in our series of patients with a history of TJA who underwent CTR. Overall hand surgeon awareness of TJA status was poor or poorly documented. Routine prophylactic antibiotics may not be indicated in patients undergoing CTR, even with the presence of a prosthetic joint. LEVEL OF EVIDENCE: IV.

Assessment of the longer-term effects of a dietary portfolio of cholesterol-lowering foods in hypercholesterolemia.

BACKGROUND: Cholesterol-lowering foods may be more effective when consumed as combinations rather than as single foods. OBJECTIVES: Our aims were to determine the effectiveness of consuming a combination of cholesterol-lowering foods (dietary portfolio) under real-world conditions and to compare these results with published data from the same participants who had undergone 4-wk metabolic studies to compare the same dietary portfolio with the effects of a statin. DESIGN: For 12 mo, 66 hyperlipidemic participants were prescribed diets high in plant sterols (1.0 g/1000 kcal), soy protein (22.5 g/1000 kcal), viscous fibers (10 g/1000 kcal), and almonds (23 g/1000 kcal). Fifty-five participants completed the 1-y study. The 1-y data were also compared with published results on 29 of the participants who had also undergone separate 1-mo metabolic trials of a diet and a statin. RESULTS: At 3 mo and 1 y, mean (+/-SE) LDL-cholesterol reductions appeared stable at 14.0 +/- 1.6% (P < 0.001) and 12.8 +/- 2.0% (P < 0.001), respectively (n = 66). These reductions were less than those observed after the 1-mo metabolic diet and statin trials. Nevertheless, 31.8% of the participants (n = 21 of 66) had LDL-cholesterol reductions of >20% at 1 y (x +/- SE: -29.7 +/- 1.6%). The LDL-cholesterol reductions in this group were not significantly different from those seen after their respective metabolically controlled portfolio or statin treatments. A correlation was found between total dietary adherence and LDL-cholesterol change (r = -0.42, P < 0.001). Only 2 of the 26 participants with <55% compliance achieved LDL-cholesterol reductions >20% at 1 y. CONCLUSIONS: More than 30% of motivated participants who ate the dietary portfolio of cholesterol-lowering foods under real-world conditions were able to lower LDL-cholesterol concentrations >20%, which was not significantly different from their response to a first-generation statin taken under metabolically controlled conditions.

Biosynthesis of trans-2-hexenal in response to wounding in strawberry fruit.

Wounded strawberry fruit produces a diverse group of volatile compounds including aldehydes, alcohols, and esters derived from the lipoxygenase (LOX) and hydroperoxide lyase (HPL) pathways. Because the wound volatiles may play an important role in plant-fungal interaction, the goal of this study was to develop a greater understanding about the biosynthesis of the major wound volatile, trans-2-hexenal (t-2-H), produced by strawberry fruit upon wounding. To that end, composition and quantity of total and free fatty acids of control and wounded strawberry fruit were analyzed. In addition, activities of the key enzymes, LOX and HPL, and production of C6 aldehydes were determined. Intact strawberry fruit did not produce detectable t-2-H which is derived from alpha-linolenic acid (18:3). However, in response to wounding by bruising, strawberry fruit emitted t-2-H and its precursor cis-3-hexenal (c-3-H). The level of total lipid 18:3 in the fruit increased 2-fold in response to wounding, whereas free 18:3 declined slightly ( approximately 30%). At 10 min following wounding, fruit exhibited a 25% increase in LOX activity, which leads to the production of 13-hydroperoxyoctadecatrienoic acid (13-HPOT) from 18:3. The activity of HPL, which catalyzes formation of cis-3-hexenal from 13-HPOT, increased 2-fold by 10 min after wounding. Thus, during a 15 min period after wounding, free 18:3 substrate availability and the activity of two key enzymes, LOX and HPL, changed in a manner consistent with increased c-3-H and t-2-H biosynthesis.

EEG-based usability assessment of 3D shutter glasses.

OBJECTIVE: Neurotechnology can contribute to the usability assessment of products by providing objective measures of neural workload and can uncover usability impediments that are not consciously perceived by test persons. In this study, the neural processing effort imposed on the viewer of 3D television by shutter glasses was quantified as a function of shutter frequency. In particular, we sought to determine the critical shutter frequency at which the 'neural flicker' vanishes, such that visual fatigue due to this additional neural effort can be prevented by increasing the frequency of the system. APPROACH: Twenty-three participants viewed an image through 3D shutter glasses, while multichannel electroencephalogram (EEG) was recorded. In total ten shutter frequencies were employed, selected individually for each participant to cover the range below, at and above the threshold of flicker perception. The source of the neural flicker correlate was extracted using independent component analysis and the flicker impact on the visual cortex was quantified by decoding the state of the shutter from the EEG. MAIN RESULT: Effects of the shutter glasses were traced in the EEG up to around 67 Hz-about 20 Hz over the flicker perception threshold-and vanished at the subsequent frequency level of 77 Hz. SIGNIFICANCE: The impact of the shutter glasses on the visual cortex can be detected by neurotechnology even when a flicker is not reported by the participants. Potential impact. Increasing the shutter frequency from the usual 50 Hz or 60 Hz to 77 Hz reduces the risk of visual fatigue and thus improves shutter-glass-based 3D usability.

Dynamic Nuclear Polarization enhanced NMR at 187 GHz/284 MHz using an Extended Interaction Klystron amplifier.

A Dynamic Nuclear Polarisation (DNP) enhanced solid-state Magic Angle Spinning (MAS) NMR spectrometer which uses a 187 GHz (corresponding to (1)H NMR frequency of 284 MHz) Extended Interaction Klystron (EIK) amplifier as the microwave source is briefly described. Its performance is demonstrated for a biomolecule (bacteriorhodopsin), a pharmaceutical, and surface functionalised silica. The EIK is very compact and easily incorporated into an existing spectrometer. The bandwidth of the amplifier is sufficient that it obviates the need for a sweepable magnetic field, once set, for all commonly used radicals. The variable power (CW or pulsed) output from the EIK is transmitted to the DNP-NMR probe using a quasi-optic system with a high power isolator and a corrugated waveguide which feeds the microwaves into the DNP-NMR probe. Curved mirrors inside the probe project the microwaves down the axis of the MAS rotor, giving a very efficient system such that maximum DNP enhancement is achieved with less than 3 W output from the microwave source. The DNP-NMR probe operates with a sample temperature down to 90K whilst spinning at 8 kHz. Significant enhancements, in excess of 100 for bacteriorhodopsin in purple membrane (bR in PM), are shown along with spectra which are enhanced by ≈25 with respect to room temperature, for both the pharmaceutical furosemide and surface functionalised silica. These enhancements allow hitherto prohibitively time consuming experiments to be undertaken. The power at which the DNP enhancement in bR in PM saturates does not change significantly between 90K and 170 K even though the enhancement drops by a factor of ≈11. As the DNP build up time decreases by a factor 3 over this temperature range, the reduction in T1n is presumably a significant contribution to the drop in enhancement.

A multinuclear 1H, 13C and 11B solid-state MAS NMR study of 16- and 18-electron organometallic ruthenium and osmium carborane complexes.

The first (1)H, (13)C, (31)P and (11)B solid state MAS NMR studies of electron-deficient carborane-containing ruthenium and osmium complexes [Ru/Os(p-cym)(1,2-dicarba-closo-dodecaborane-1,2-dithiolate)] are reported. The MAS NMR data from these 16-electron complexes are compared to those of free carborane-ligand and an 18-electron triphenylphosphine ruthenium adduct, and reveal clear spectral differences between 16- and 18-electron organometallic carborane systems in the solid state.

Investigation into the effect of Si doping on the performance of Sr(1-y)Ca(y)MnO(3-δ) SOFC cathode materials.

In this paper we report the successful incorporation of silicon into Sr1-yCayMnO3-δ perovskite materials for potential applications in cathodes for solid oxide fuel cells. The Si substitution onto the B site of a (29)Si enriched Sr1-yCayMn1-xSixO3-δ perovskite system is confirmed by (29)Si MAS NMR measurements at low B0 field. The very large paramagnetic shift (~3000-3500 ppm) and anisotropy (span ~4000 ppm) suggests that the Si(4+) species experiences both Fermi contact and electron-nuclear dipolar contributions to the paramagnetic interaction with the Mn(3+/4+) centres. An improvement in the conductivity is observed for low level Si doping, which can be attributed to two factors. The first of these is attributed to the tetrahedral coordination preference of Si leading to the introduction of oxide ion vacancies, and hence a partial reduction of Mn(4+) to give mixed valence Mn. Secondly, for samples with high Sr levels, the undoped systems adopt a hexagonal perovskite structure containing face sharing of MnO6 octahedra, while Si doping is shown to help to stabilise the more highly conducting cubic perovskite containing corner linked octahedra. The level of Si, x, required to stabilise the cubic Sr1-yCayMn1-xSixO3-δ perovskite in these cases is shown to decrease with increasing Ca content; thus cubic symmetry is achieved at x = 0.05 for the Sr0.5Ca0.5Mn1-xSixO3-δ series; x = 0.075 for Sr0.7Ca0.3Mn1-xSixO3-δ; x = 0.10 for Sr0.8Ca0.2Mn1-xSixO3-δ; and x = 0.15 for SrMn1-xSixO3-δ. Composites with 50% Ce0.9Gd0.1O1.95 were examined on dense Ce0.9Gd0.1O1.95 pellets. For all series an improvement in the area specific resistances (ASR) values is observed for the Si-doped samples. Thus these preliminary results show that silicon can be incorporated into perovskite cathode materials and can have a beneficial effect on the performance.

A spectrometer designed for 6.7 and 14.1 T DNP-enhanced solid-state MAS NMR using quasi-optical microwave transmission.

A Dynamic Nuclear Polarisation (DNP) enhanced solid-state Magic Angle Spinning (MAS) NMR spectrometer operating at 6.7 T is described and demonstrated. The 187 GHz TE(13) fundamental mode of the FU CW VII gyrotron is used as the microwave source for this magnetic field strength and 284 MHz (1)H DNP-NMR. The spectrometer is designed for use with microwave frequencies up to 395 GHz (the TE(16) second-harmonic mode of the gyrotron) for DNP at 14.1T (600 MHz (1)H NMR). The pulsed microwave output from the gyrotron is converted to a quasi-optical Gaussian beam using a Vlasov antenna and transmitted to the NMR probe via an optical bench, with beam splitters for monitoring and adjusting the microwave power, a ferrite rotator to isolate the gyrotron from the reflected power and a Martin-Puplett interferometer for adjusting the polarisation. The Gaussian beam is reflected by curved mirrors inside the DNP-MAS-NMR probe to be incident at the sample along the MAS rotation axis. The beam is focussed to a ~1 mm waist at the top of the rotor and then gradually diverges to give much more efficient coupling throughout the sample than designs using direct waveguide irradiation. The probe can be used in triple channel HXY mode for 600 MHz (1)H and double channel HX mode for 284 MHz (1)H, with MAS sample temperatures ≥85 K. Initial data at 6.7 T and ~1 W pulsed microwave power are presented with (13)C enhancements of 60 for a frozen urea solution ((1)H-(13)C CP), 16 for bacteriorhodopsin in purple membrane ((1)H-(13)C CP) and 22 for (15)N in a frozen glycine solution ((1)H-(15)N CP) being obtained. In comparison with designs which irradiate perpendicular to the rotation axis the approach used here provides a highly efficient use of the incident microwave beam and an NMR-optimised coil design.

A variable temperature solid-state nuclear magnetic resonance, electron paramagnetic resonance and Raman scattering study of molecular dynamics in ferroelectric fluorides.

The local nuclear and electronic structures and molecular dynamics of the ferroelectric lattice in selected geometric fluorides (BaMgF(4), BaZnF(4), BaMg(1 - x)Mn(x)F(4) and BaMg(1 - x)Ni(x)F(4); x = 0.001 and 0.005) have been investigated. The (19)F and (25)Mg isotropic chemical shift δ(iso), (25)Mg quadrupolar coupling constants (C(q)) and asymmetry parameters (η) reflect the geometry of the coordination spheres. The zero-field splitting parameters |D| and |E| are consistent with distorted axial symmetry (low temperatures) and nearly rhombic symmetry (high temperatures) of octahedral Mn(2+) coordination. The high resolution of the nuclear magnetic resonance, electron paramagnetic resonance and phonon spectra are consistent with the highly ordered crystallographic structure. Combined multi-technique data evidence the subtle discontinuous changes in the temperature dependences of |D| and |E|, isotropic chemical shifts δ(iso) and signature parameters of Raman bands and suggest a discontinuous structural distortion of the fluoride octahedra. The temperature at which this change occurs depends on the ionic radius of the central ion of the octahedral site and is estimated to be ∼ 300 K for Zn(2+) fluorides and ∼ 240 K for Mg(2+) fluorides. This geometrical distortion modifies the lattice dynamics and originates from the rotation of the fluoride octahedra around a new direction approximately perpendicular to that related to the paraelectric-ferroelectric phase transition.

New insights into the fundamental chemical nature of ionic liquid film formation on magnesium alloy surfaces.

Ionic liquids (ILs) based on trihexyltetradecylphosphonium coupled with either diphenylphosphate or bis(trifluoromethanesulfonyl)amide have been shown to react with magnesium alloy surfaces, leading to the formation a surface film that can improve the corrosion resistance of the alloy. The morphology and microstructure of the magnesium surface seems critical in determining the nature of the interphase, with grain boundary phases and intermetallics within the grain, rich in zirconium and zinc, showing almost no interaction with the IL and thereby resulting in a heterogeneous surface film. This has been explained, on the basis of solid-state NMR evidence, as being due to the extremely low reactivity of the native oxide films on the intermetallics (ZrO2 and ZnO) with the IL as compared with the magnesium-rich matrix where a magnesium hydroxide and/or carbonate inorganic surface is likely. Solid-state NMR characterization of the ZE41 alloy surface treated with the IL based on (Tf)2N(-) indicates that this anion reacts to form a metal fluoride rich surface in addition to an organic component. The diphenylphosphate anion also seems to undergo an additional chemical process on the metal surface, indicating that film formation on the metal is not a simple chemical interaction between the components of the IL and the substrate but may involve electrochemical processes.

Production of the long-chain alcohols octanol, decanol, and dodecanol by Escherichia coli.

As a follow-up to earlier studies on the emission of long-chain alcohols from broth cultures of Gram-negative enteric bacteria, E. coli was examined for the production of 1-octanol, 1-decanol, and 1-dodecanol. Ten strains of E. coli cultured in tryptic soy broth were assayed for volatile metabolites using solid-phase microextraction. Long-chain alcohols were produced by all strains with 1-decanol predominating with production ranging from 23.6 ng mL(-1) to 148 ng mL(-1). The production of long-chain alcohols followed the onset of the exponential growth phase of the broth culture. Doubling the concentration of glucose (5 g L(-1)) in the broth had no effect on the concentration of long-chain alcohols produced. Addition of octanoic, decanoic, or dodecanoic acids (as K(+) salts) to the broth (100 mg L(-1)) markedly increased the production of the corresponding alcohols by E. coli, ranging from a 13-fold increase for decanol to a 51-fold increase for dodecanol. However, decanol remained the predominant alcohol detected in all assays. These neutral volatile alcohols may have application as vapor-phase indicators for certain classes of bacteria, particularly, Gram-negative enteric bacteria.