Greater need but reduced access: a population study of planned and elective surgery rates in adult mental health service users.

AIMS: Timely access to surgery is an essential part of healthcare. People living with mental health (MH) conditions may have higher rates of chronic illness requiring surgical care but also face barriers to care. There is limited evidence about whether unequal surgical access contributes to health inequalities in this group. METHODS: We examined 1.22 million surgical procedures in public and private hospitals in New South Wales (NSW), Australia, in 2019. In a cross-sectional study of 76,320 MH service users aged 18 and over, surgical procedure rates per 1,000 population were compared to rates for 6.23 million other NSW residents after direct standardisation for age, sex and socio-economic disadvantage. Rates were calculated for planned and emergency surgery, for major specialty groups, for the top 10 procedure blocks in each specialty group and for 13 access-sensitive procedures. Subgroup analyses were conducted for hospital and insurance type and for people with severe or persistent MH conditions. RESULTS: MH service users had higher rates of surgical procedures (adjusted incidence rate ratio [aIRR]: 1.53, 95% CI: 1.51-1.56), due to slightly higher planned procedure rates (aIRR: 1.22, 95% CI: 1.19-1.24) and substantially higher emergency procedure rates (aIRR: 3.60, 95% CI: 3.51-3.70). Emergency procedure rates were increased in all block groups with sufficient numbers for standardisation. MH service users had very high rates (aIRR > 4.5) of emergency cardiovascular, skin and plastics and respiratory procedures, higher rates of planned coronary artery bypass grafting, coronary angiography and cholecystectomy but lower rates of planned ophthalmic surgery, cataract repair, shoulder reconstruction, knee replacement and some plastic surgery procedures. CONCLUSIONS: Higher rates of surgery in MH service users may reflect a higher prevalence of conditions requiring surgical care, including cardiac, metabolic, alcohol-related or smoking-related conditions. The striking increase in emergency surgery rates suggests that this need may not be being met, particularly for chronic and disabling conditions which are often treated by planned surgery in private hospital settings in the Australian health system. A higher proportion of emergency surgery may have serious personal and health system consequences.

Amplification of pulsed light with arbitrary frequency chirps on nanosecond timescales.

We have developed a system for producing amplified pulses of frequency-chirped light at 780 nm on nanosecond timescales. The system starts with tunable cw laser light and employs a pair of fiber-based phase modulators, a semiconductor optical amplifier, and a tapered amplifier to achieve chirp rates exceeding 3 GHz/10 ns and peak powers greater than 1 W. Driving the modulators with an arbitrary waveform generator enables arbitrary chirp shapes, such as two-frequency linear chirps. We overcome the optical power limitations of the modulators by duty cycling and avoid unseeded operation of the tapered amplifier by multiplexing the chirped pulses with "dummy" light from a separate diode laser.

Biogeographical factors affecting the distribution of stream salamanders on the Cumberland Plateau, USA.

Geophysical and climate conditions play an important role in the distribution of organisms at both fine and broad scales. Headwater streams integrate changes at broad geographical scales and serve as important regions of nutrient processing and support high biodiversity. Stream salamanders are important members of headwater aquatic communities as both predators and prey. Combined with their biphasic life histories and physiological requirements, stream amphibians may serve as indicators for headwater stream conditions. We surveyed 50 streams for salamander occupancy, across eight counties of the southern Cumberland Plateau in Tennessee for which we are unaware of any stream amphibian distribution data. Our objective was to determine what variables best-predicted stream amphibian occupancy among species with variable life histories and habitat needs. Models were generated to determine the effects of elevation, catchment forest cover, and total catchment size as indicators of stream condition. We found species showed no significant responses to forest cover. Though forest cover has previously been the primary predictor of stream amphibian occupancy in streams across the United States, stream amphibian occupancy of the southern Cumberland Plateau was most closely associated with elevation and catchment size. Thus, the unique topography of the southern Cumberland Plateau may instead be the more important factor driving occupancy patterns. Despite limited evidence in this study for negative human impacts on salamander occupancy, low occupancy and abundance relative to other ecoregions suggests either poor quality habitat or large historic impacts. Developing a more comprehensive understanding of regional stream salamander occupancy patterns is necessary to ensure effective management and habitat conservation in a region with limited description of stream ecology.

Nanosecond pulse shaping at 780 nm with fiber-based electro-optical modulators and a double-pass tapered amplifier.

We describe a system for generating frequency-chirped and amplitude-shaped pulses on time scales from sub-nanosecond to ten nanoseconds. The system starts with cw diode-laser light at 780 nm and utilizes fiber-based electro-optical phase and intensity modulators, driven by an arbitrary waveform generator, to generate the shaped pulses. These pulses are subsequently amplified to several hundred mW with a tapered amplifier in a delayed double-pass configuration. Frequency chirps up to 5 GHz in 2 ns and pulse widths as short as 0.15 ns have been realized.

Efficient Formation of Ultracold Molecules with Chirped Nanosecond Pulses.

We describe experiments and associated quantum simulations involving the production of ultracold (87)Rb2 molecules with nanosecond pulses of frequency-chirped light. With appropriate chirp parameters, the formation is dominated by coherent processes. For a positive chirp, excited molecules are produced by photoassociation early in the chirp, and then transferred into high vibrational levels of the lowest triplet state by stimulated emission later in the chirp. Generally good agreement is seen between the data and the simulations. Shaping of the chirp can lead to a significant enhancement of the formation rate. Further improvements using higher intensities and different intermediate states are predicted.

Enhancement of Ultracold Molecule Formation Using Shaped Nanosecond Frequency Chirps.

We demonstrate that judicious shaping of a nanosecond-time-scale frequency chirp can dramatically enhance the formation rate of ultracold (87)Rb(2) molecules. Starting with ultracold (87)Rb atoms, we apply pulses of frequency-chirped light to first photoassociate the atoms into excited molecules and then, later in the chirp, deexcite these molecules into a high vibrational level of the lowest triplet state a (3)Σ(u)(+). The enhancing chirp shape passes through the absorption and stimulated emission transitions relatively slowly, thus increasing their adiabaticity, but jumps quickly between them to minimize the effects of spontaneous emission. Comparisons with quantum simulations for various chirp shapes support this enhancement mechanism.

Excitation of weakly bound molecules to trilobitelike Rydberg states.

We observe "trilobitelike" states of ultracold (85)Rb(2) molecules, in which a ground-state atom is bound by the electronic wave function of its Rydberg-atom partner. We populate these states through the ultraviolet excitation of weakly bound molecules, and access a regime of trilobitelike states at low principal quantum numbers and with vibrational turning points around 35 Bohr radii. This demonstrates that, unlike previous studies that used free-to-bound transitions, trilobitelike states can also be excited through bound-to-bound transitions. This approach provides high excitation probabilities without requiring high-density samples, and affords the ability to control the excitation radius by selection of the initial-state vibrational level.

Copper and silver complexes bearing flexible hybrid scorpionate ligand mpBm.

The addition of flexible scorpionate ligand, [mpBm]⁻{i.e. HB(mt)2(mp), where mt = methyl-2-mercaptoimidazole and mp = 2-mercaptopyridine} to group eleven centres is reported for the first time. The coordination of this hybrid ligand to copper(I) and silver(I) centres in the presence of triphenylphosphine and trialkylphosphine co-ligands has been investigated. The trialkylphosphines coordinates to both copper and silver centres while the less basic triarylphosphine only successfully coordinates to the copper centre. Structural characterisation of [Cu{HB(mt)2(mp)}(PPh3)], [Cu{HB(mt)2(mp)}(PCy3)] and [Ag{HB(mt)2(mp)}(PCy3)] confirm κ³-SSH coordination modes for ligand where one of the mt 'arms' and the mp 'arm' of the scorpionate ligand are coordinated to the metal centre. The second mt 'arm' remains uncoordinated in all three complexes. A comparison has been made with the parent sulfur based scorpionate ligand, [Tm]⁻{HB(mt)3}.

Observation of a resonant four-body interaction in cold cesium Rydberg atoms.

Cold Rydberg atoms subject to long-range dipole-dipole interactions represent a particularly interesting system for exploring few-body interactions and probing the transition from 2-body physics to the many-body regime. In this work we report the direct observation of a resonant 4-body Rydberg interaction. We exploit the occurrence of an accidental quasicoincidence of a 2-body and a 4-body resonant Stark-tuned Förster process in cesium to observe a resonant energy transfer requiring the simultaneous interaction of at least four neighboring atoms. These results are relevant for the implementation of quantum gates with Rydberg atoms and for further studies of many-body physics.

Formation of ultracold Rb2 molecules in the v'' = 0 level of the a(3)Σ+(u) state via blue-detuned photoassociation to the 1(3)Π(g) state.

We report on the observation of blue-detuned photoassociation in Rb(2), in which vibrational levels are energetically above the corresponding excited atomic asymptote. (85)Rb atoms in a MOT were photoassociated at short internuclear distance to levels of the 1(3)Π(g) state at a rate of approximately 5 × 10(4) molecules s(-1). We have observed most of the predicted vibrational levels for all four spin-orbit components; 0(+)(g), 0(-)(g), 1(g), and 2(g), including levels of the 0(+)(g) outer well. These molecules decay to the metastable a(3)Σ(+)(u) state, some preferentially to the v'' = 0 level, as we have observed for photoassociation to the v' = 8 level of the 1(g) component.

Creation of arbitrary time-sequenced line spectra with an electro-optic phase modulator.

We use a waveguide-based electro-optic phase modulator, driven by a nanosecond-timescale arbitrary waveform generator, to produce an optical spectrum with an arbitrary pattern of peaks. A programmed sequence of linear voltage ramps, with various slopes, is applied to the modulator. The resulting phase ramps give rise to peaks whose frequency offsets relative to the carrier are equal to the slopes of the corresponding linear phase ramps. This simple extension of the serrodyne technique provides multi-line spectra with peak spacings in the 100 MHz range.

Gap junctions in human glioblastomas: implications for suicide gene therapy.

Glioblastoma is a very aggressive astrocytic tumor and most patients have 1-year survival time after diagnosis. A promising therapeutic strategy is the local delivery of the herpes simplex virus thymidine kinase gene in the tumor bed followed by ganciclovir treatment. The presence of functional gap junctions is highly relevant for the success of suicide gene therapy. Connexins are expressed in practically all tissues and form gap junctions that allow intercellular communication. Connexin 43 (Cx43) is the major connexin member being expressed in astrocytes but its status in glioblastoma is not well defined. We have investigated by immunofluorescence the presence of Cx43 in 74 human glioblastoma samples; its expression was detected in 77% of the samples analyzed. We report here that glioblastoma is a heterogenous disease as regards Cx43 expression with presentations, in which Cx43 expression is unaltered, reduced or totally lost. A predominant Cx43 cytoplasmic localization was observed in four out of eight primary glioblastoma cultures that we have established. This aberrant localization reduced gap junctionnal intercellular communication by 50 to 75% as compared with primary cell cultures displaying gap junctional plaques. However, the bystander effect evaluated after lentiviral delivery of the herpes simplex virus thymidine kinase gene and ganciclovir treatment was detected in all Cx43-positive primary cell cultures, and it was independant of the Cx43 localization. These findings may have important clinical implications for the design of anticancer cytotoxic therapies that rely on the gap junction-mediated bystander effect for their success.

Immunohistochemical analyses of NPAS3 expression in the developing human fetal brain.

The NPAS3 gene encodes a transcription factor with disease roles in neurodevelopment, neoplasia and neurobehaviour. We report the first immunohistochemical findings on NPAS3 protein expression in the developing human fetal brain during the three trimesters (10-41 weeks) of gestational development. In the first trimester, NPAS3 expression is largely confined in the nucleus of cells of the ventricular zone. Similarly, strong nuclear expression in the hippocampus is noted as early as the first trimester, but with progressive increases in expression becoming more apparent in the molecular layer and layer III of the maturing neocortex during the second and third trimesters. In the cerebellum, nuclear expression is seen in basket cells and in Bergmann glia, but some cytoplasmic staining present in the internal granule layer of neurons. Findings from this study will assist in understanding the role of NPAS3 in human gestational brain development and consequently the pathological involvement in human diseases.

Characterization and compensation of the residual chirp in a Mach-Zehnder-type electro-optical intensity modulator.

We utilize various techniques to characterize the residual phase modulation of a waveguide-based Mach-Zehnder electro-optical intensity modulator. A heterodyne technique is used to directly measure the phase change due to a given change in intensity, thereby determining the chirp parameter of the device. This chirp parameter is also measured by examining the ratio of sidebands for sinusoidal amplitude modulation. Finally, the frequency chirp caused by an intensity pulse on the nanosecond time scale is measured via the heterodyne signal. We show that this chirp can be largely compensated with a separate phase modulator. The various measurements of the chirp parameter are in reasonable agreement.

Unexpected pincer-type coordination (kappa3-SBS) within a zerovalent platinum metallaboratrane complex.

The first structurally characterised zerovalent platinum complex to contain a tridentate pincer-type coordination mode (kappa(3)-SBS) is presented, raising further questions concerning the geometries and trans influence of Z-type ligands.

A new hybrid scorpionate ligand: a study of the metal-boron bond within metallaboratrane complexes.

A new boron-based hybrid scorpionate ligand based upon one 2-mercaptopyridine (mp) and two 1-methyl-imidazoyl-2-thione (mt) units, Na[HB(mt)(2)(mp)] has been prepared. This new ligand together with the recently reported ligand K[HB(mp)(3)] have been used to prepare analogues of the original metallaboratrane complex [Ru(CO)(PPh(3)){kappa(4)-SSBS-B(mt)(3)}]. The effect of tautomerisation of the ligand arms upon the electronic properties of the boron and metal centres is examined in an attempt to probe further the nature of the metal-boron bond within metallaboratrane complexes.

Cardiac resynchronisation therapy for heart failure.

Heart failure (HF) is increasingly common and, despite advances in pharmacotherapeutic management, often progresses. Progression is marked by structural and electrical changes-remodelling. In approximately one-third of patients, ventricular dilatation is accompanied by intraventricular conduction delays, most commonly the left bundle branch block (LBBB). The presence of LBBB is associated with mechanical dyssynchrony of the heart. Cardiac resynchronisation therapy (CRT), the use of special pacemakers with or without implantable cardioverter defibrillators, aims to resynchronise the failing heart, improving myocardial contraction without increased energetics. Several, large, randomised clinical trials have now established the benefit of CRT in a select group of HF patients, providing functional and, recently shown, mortality benefits. However, a substantial proportion of patients are considered non-responders to CRT, and studies are now underway to identify the patients most likely to respond to CRT.

Influence of atrial fibrillation on cardiac brain natriuretic peptide release during haemodynamic stress in heart failure.

BACKGROUND: The determinants of release of brain natriuretic peptide (BNP) in heart failure (HF) are incompletely understood, particularly, the effect of heart rhythm and haemodynamic stress. AIMS: To investigate the effect of haemodynamic stress on cardiac BNP release in HF and differentiate this response for atrial fibrillation (AF) and sinus rhythm (SR). METHODS: In 18 HF patients (ejection fraction<40%, 9 in AF and 9 in SR) haemodynamics and BNP levels were measured from arterial and coronary sinus samples at baseline, after 10 min of 20 degrees passive head up tilt (HUT) and after 10 min of isometric handgrip (IHG) exercise. From these data, we calculated a transcardiac BNP gradient and compared results between the AF and SR cohort. RESULTS: During haemodynamic stress in both groups, there were no significance differences in left sided filling pressures. At baseline, there were no differences in BNP measurements between the SR and AF group. The transcardiac BNP gradient increased significantly in the SR (p=0.02) but not the AF cohort, after HUT. During IHG exercise, there was a significant decrease in cardiac BNP release in the AF cohort (p=0.03) but not the SR cohort. CONCLUSION: These data imply in HF, cardiac rhythm influences cardiac BNP release in response to haemodynamic stress.