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OBJECTIVES/SPECIFIC AIMS: The objective of this project is to determine whether HRV, collected peri-operatively, is predictive of cognitive decline among older adults who undergo elective surgery/anesthesia. METHODS/STUDY POPULATION: This project is a part of the ongoing INTUIT/PRIME study, which is collecting pre- and post-operative cognitive testing, fMRI imaging, CSF samples, and EEG recordings from 200 older adults (age ≥ 60) undergoing elective non-cardiac/non-neurologic surgery scheduled to last > 2 hours at Duke University Medical Center and Duke Regional Hospital. This project utilizes data from the first 60 INTUIT participants who contributed continuous heart rate data before and during surgery. Participants undergo cognitive testing prior to surgery (baseline) and at 6 weeks after surgery. Our primary dependent variable is the change in the composite score from baseline to 6-weeks. Delirium is assessed in the hospital with the twice daily 3D-CAM tool, so we will report the proportion of individuals with 6-week cognitive decline who exhibited delirium in the days following surgery. Participants’ echocardiogram (ECG) recordings are extracted pre- and intraoperatively from B650/B850 patient monitors with VSCapture software. HRV is defined as the variability between successive R-spikes or inter-beat-intervals on ECG. RESULTS/ANTICIPATED RESULTS: We anticipate that lower intraoperative HRV is associated with worse cognitive decline at 6 weeks after surgery. As secondary objectives, we will determine whether pre-operative HRV or change in HRV (from pre-operative to intra-operative measures) are predictive of cognitive decline after surgery. We expect that in-hospital delirium will be detected in a higher proportion of those with 6-week cognitive decline, compared to those with stable or improved cognition at 6 weeks. DISCUSSION/SIGNIFICANCE OF IMPACT: HRV may address the present need for pre- and intra-operative cognitive risk stratification in the elderly. Physiological indices like HRV have the potential to dramatically change our understanding of CI in older adults undergoing surgery, as they offer an accessible, cost-effective, and non-invasive means whereby clinicians, particularly those unfamiliar with the nuances of geriatric and CI/dementia-related care, can monitor patients and refer those at high-risk of CI after surgery for early intervention.
It is known that the poloidal field is at its maximum during solar minima, and that the behaviour during this time acts as a strong predictor of the strength of the following solar cycle. This relationship relies on the action of differential rotation (the Omega effect) on the poloidal field, which generates the toroidal flux observed in sunspots and active regions. We measure the helicity flux into both the northern and southern hemispheres using a model that takes account of the omega effect, which we find offers a strong quantification of the above relationship. We find that said helicity flux offers a strong prediction of solar activity up to 5 years in advance of the next solar cycle.
Major depressive disorder (MDD) is moderately heritable, however genome-wide association studies (GWAS) for MDD, as well as for related continuous outcomes, have not shown consistent results. Attempts to elucidate the genetic basis of MDD may be hindered by heterogeneity in diagnosis. The Center for Epidemiological Studies Depression (CES-D) scale provides a widely used tool for measuring depressive symptoms clustered in four different domains which can be combined together into a total score but also can be analysed as separate symptom domains.
We performed a meta-analysis of GWAS of the CES-D symptom clusters. We recruited 12 cohorts with the 20- or 10-item CES-D scale (32 528 persons).
One single nucleotide polymorphism (SNP), rs713224, located near the brain-expressed melatonin receptor (MTNR1A) gene, was associated with the somatic complaints domain of depression symptoms, with borderline genome-wide significance (pdiscovery = 3.82 × 10−8). The SNP was analysed in an additional five cohorts comprising the replication sample (6813 persons). However, the association was not consistent among the replication sample (pdiscovery+replication = 1.10 × 10−6) with evidence of heterogeneity.
Despite the effort to harmonize the phenotypes across cohorts and participants, our study is still underpowered to detect consistent association for depression, even by means of symptom classification. On the contrary, the SNP-based heritability and co-heritability estimation results suggest that a very minor part of the variation could be captured by GWAS, explaining the reason of sparse findings.
It is well known that web-based interventions can be effective treatments for depression. However, dropout rates in web-based interventions are typically high, especially in self-guided web-based interventions. Rigorous empirical evidence regarding factors influencing dropout in self-guided web-based interventions is lacking due to small study sample sizes. In this paper we examined predictors of dropout in an individual patient data meta-analysis to gain a better understanding of who may benefit from these interventions.
A comprehensive literature search for all randomized controlled trials (RCTs) of psychotherapy for adults with depression from 2006 to January 2013 was conducted. Next, we approached authors to collect the primary data of the selected studies. Predictors of dropout, such as socio-demographic, clinical, and intervention characteristics were examined.
Data from 2705 participants across ten RCTs of self-guided web-based interventions for depression were analysed. The multivariate analysis indicated that male gender [relative risk (RR) 1.08], lower educational level (primary education, RR 1.26) and co-morbid anxiety symptoms (RR 1.18) significantly increased the risk of dropping out, while for every additional 4 years of age, the risk of dropping out significantly decreased (RR 0.94).
Dropout can be predicted by several variables and is not randomly distributed. This knowledge may inform tailoring of online self-help interventions to prevent dropout in identified groups at risk.
Studying the inner regions of protoplanetary disks (1-10 AU) is of importance to understand the formation of planets and the accretion process feeding the forming central star. Herbig AeBe stars are bright enough to be routinely observed by Near IR interferometers. The data for the fainter T Tauri stars is much more sparse. In this contribution we present the results of our ongoing survey at the VLTI. We used the PIONIER combiner that allows the simultaneous use of 4 telescopes, yielding 6 baselines and 3 independent closure phases at once. PIONIER's integrated optics technology makes it a sensitive instrument. We have observed 22 T Tauri stars so far, the largest survey for T Tauri stars to this date.
Our results demonstrate the very significant contribution of an extended component to the interferometric signal. The extended component is different from source to source and the data, with several baselines, offer a way to improve our knowledge of the disk geometry and/or composition. These results validate an earlier study by Pinte et al. 2008 and show that the dust inner radii of T Tauri disks now appear to be in better agreement with the expected position of the dust sublimation radius, contrary to previous claims.
The close environment of Herbig stars starts to be revealed step by step and it appears to be quite complex. Many physical phenomena interplay: the dust sublimation causing a puffed-up inner rim, a dusty halo, a dusty wind or an inner gaseous component. To investigate more deeply these regions, getting images at the first Astronomical Unit scale is necessary. This has become possible with near infrared instruments on the VLTI. We have developed a new imaging method adapted to young stellar objects where we process separately the stellar component from the rest of the image to reveal the environment by using the spectral differences between these two components. We present the result of this method on the first imaging survey of Herbig stars carried out by PIONIER on the VLTI.
Co/Pt thin film multilayers with strong perpendicular anisotropy and out-of-plane coercivities of 5-11 kOe were magnetically altered in areas of local ion beam interaction. The ion irradiations were performed by ion projection through silicon stencil masks fabricated by silicon on insulator (SOI) membrane technology. The ion projector at the Fraunhofer Institute for Silicon Technology (ISiT) was operated at 73 keV ion energy and with a 8.7- fold demagnification. After exposure to 3 × 1014Ar+/ cm2 magnetic islands smaller than 100 nm in diameter were resolved in the Co/Pt multilayersby means of magnetic force microscopy. The impact of different ion species (He+, Ar+ and Xe+) and ion energies (10 – 200 keV) on the multilayer structure was evaluated using Monte Carlo simulations. The ballistic interface intermixing was used to predict magnetic coercivity changes for various irradiation conditions. The simulations revealed that with 73 keV Ar+ and Xe+ ions the irradiation dose could be reduced by a factor of 100 and 400 respectively in comparison to 73 keV He+which was verified in the experiments. X-ray reflectivity measurements confirmed that the Co/Pt superlattice structure is slightly weakened during the irradiation and that the surface smoothness of the media is preserved. Using the Ion Projection Process Development Tool (PDT) at IMS-Vienna concentric data tracks including head positioning servo informations were patterned onto a 1” IBM microdrive™ glass disk which was coated with Co/Pt multilayers. In a single exposure step several tracks within an exposure field of 17 mm in diameter were structured by 2 × 1015He+/ cm2 at 45 keV using a 4- fold demagnification set-up.
Porous Si Alms formed on different p-doped substrates are studied by Raman spectroscopy, photoluminescence, and spectroscopic ellipsometry. Due to a thermal treatment the morphology is changed. A reduction in the number of nanocrystals with diameters below 30Å is found. It is shown that the photoluminescence is caused by the formation of small nanocrystals and that the effect of amorphous Si as a basic mechanism can be ruled out. The strain which must be taken into account for the interpretation of the Raman spectra decreases with increasing heating temperature.
The results of our recent research on the ohmic contact formation mechanism in furnace alloyed Au/Te/Au/GaAs contacts are summarized, and preliminary Raman measurements on annealed Ge/Pd/GaAs structures are presented. The data and those reported in literature on the AuGe- and Ge/Pd- GaAs systems are argued to be more in agreement with the graded crystalline heterojunction concept (the formation of n+-Ge/GaAs, n+Ga2Te3/GaAs junctions) than with the doping model (the formation of n+-GaAs).
For the formation of single layers and layer systems the depth homogeneity of porous silicon (PS) plays a key role. We have measured qualitatively and quantitatively structural gradients in p-PS layers with increasing layer thicknesses by fitting reflectance spectra in the infrared and by measuring thickness oscillations in the reflectance during the formation of PS layers. These results allow us to give recipes for the formation of PS layers with a homogenous optical thickness in depth.
Recently passive optical devices like filter structures or waveguides based on porous silicon have attracted high interest due to their easy and cheap fabrication. We have formed interference filters using porous silicon by changing the current density during formation. For the specific design of these filter structures a calibration of the etch rate and the refractive indices is required. Therefore we have determined the effective dielectric function for different substrate doping levels and anodization current densities by fitting reflectance spectra. Based on these results different kinds of reflectance filters consisting of discrete layers (Bragg reflectors, Fabry-Perot filters) as well as filters with a continuous change of the refractive indices with depth (rugate-filters) can be realised. Furthermore we present applications of these filter structures such as anti-reflectance coatings and high quality mirrors.
Porous silicon multilayers are easily produced by a variation of the current density during the electrochemical etching process. The obtained porosity profile in depth is equivalent to a refractive index profile. Preparing appropriate multilayer systems one can design optical filters with sharp reflectivity peaks from the infrared through the whole visible spectral range (dielectric mirrors). Stability in time is achieved applying a suitable oxidation process. In many cases of optical process and material control the required spectral decomposition of the probing light can be done with sufficient accuracy by a set of porous silicon optical filters whose spectral characteristics can lbe adapted easily to the given problem. In this work we present the prototype of an optical sensor that is a low-cost alternative to ‘real’ (and expensive) spectrometers. Application examples in the infrared and visible are given to demonstrate the sensor performance;.
Porous silicon (PS) layers can easily be formed by an electrochemical etch process using a mixture of hydrofluoric acid (HF) and ethanol. The microstructure and porosity of the layers depend on the HF concentration, the doping level of the substrate and the current density applied during the etch process. Changing the current density during the etch process will result in a well defined layer structure consisting of layers with different porosities. Each single layer can be treated as an effective medium exhibiting a refractive index depending mainly on the porosity of the layer. Using reflectance measurements we have investigated the dependence of the refractive index of PS layers on the formation current density for different substrates. In addition the etch rate was determined by thickness measurements with an electron microscope. Based on these results various kinds of optical interference filters were studied. We have formed samples consisting of discrete single layers with different porosities (e.g. Bragg reflectors) as well as samples with continuous variation of the refractive index (rugate filters). Combining these PS filters with standard photolithography steps, microoptical devices such as spectral sensitive photodiodes can be realized.
The use of nanotechnology based materials for chemical sensing has been of great interest since nanocrystalline materials have been shown to offer improved sensor sensitivity, stability, and response time. Several groups are successfully integrating nanostructures such as nanowires into operational sensors. The typical procedure may include random placement (e.g., dispersion, with fine-line patterning techniques used to create functional sensors) or time consuming precise fabrication (e.g., mechanical placement using an atomic force microscope or laser tweezer techniques). Dielectrophoresis has also been utilized, however it can be challenging to achieve good electrical contact of the nanostructures to the underlying electrodes. In this paper we report on a sensor platform that incorporates nanorods in a controlled, efficient, and effective manner. Semiconducting SnO2 nanorods are used as the sensing element for detection of hydrogen (H2) and propylene (C3H6) up to 600oC. Using a novel approach of combining dielectrophoresis with standard microfabrication processing techniques, we have achieved reproducible, time-efficient fabrication of gas sensors with reliable contacts to the SnO2 nanorods used for the detection of gases. The sensor layout is designed to assist in the alignment of the nanorods by selectively enhancing the electric field strength and allowing for the quick production of sensor arrays. The SnO2 nanorods are produced using a thermal evaporation-condensation approach. After growth, nanorods are separated from the resulting material using gravimetric separation. The rods vary in length from 3μm to greater than 10μm, with diameters ranging from 50 to 300nm. Dielectrophoresis is used to align multiple nanorods between electrodes. A second layer of metal is incorporated using standard microfabrication methods immediately after alignment to bury the ends of the rods making contact with the underlying electrodes within another layer of metal. Electrical contact was verified during testing by the response to H2 and C3H6 gases at a range of temperatures. Testing was performed on a stage with temperature control and probes were used for electrical contact. Gas flows into the testing chamber at a flow rate of 4000sccm. Sensor response of normalized current shift, |Igas-Iair|/Iair, was measured at a constant voltage bias. Sensors showed response to both H2 and C3H6. Detection of H2 was achieved at 100oC and response levels improved approximately 12000-fold at 600oC. Detection of C3H6 started at 100oC and improved approximately 10000-fold at 600oC. Detection of at least 200ppm for both gases was achieved at 600oC. Using this novel microfabrication approach, semiconducting SnO2 nanorods integrated into a microsensor platform have been demonstrated and sensing response showed dramatic increases at higher temperatures.
A sensitive antigen suspension is described for use with a simple slide agglutination method which makes possible a serological diagnosis or exclusion of typhoid fever without recourse to a laboratory. The method has been tested on 414 sera sent to our laboratory; it detected all cases with a titre of 1: 80 or more, and most of those with a titre of 1: 40. The method was further tested on 130 clinically observed cases, in which it gave satisfactory results. The S. A. method gave a positive result with 98 out of 100 sera from patients with typhoid fever, whereas the classical Widal reaction gave a positive result with 68 of them only.
The intensity and rapidity of the slide agglutination reaction provide a rough measure of the titre of a serum. A quick and distinct agglutination indicates a titre of 1: 80 or more and is diagnostic of typhoid fever. A slow and indistinct result is obtained when the titre of the serum is about 1: 40. A negative test indicates with great probablity that a diagnosis of typhoid fever may be excluded.
We think the method succeeds because the nature of the suspension employed and the peculiar behaviour of slide agglutinations permit the detection of O agglutinins as well as H agglutinins.