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To evaluate the association between novel pre- and post-operative biomarker levels and 30-day unplanned readmission or mortality after paediatric congenital heart surgery.
Children aged 18 years or younger undergoing congenital heart surgery (n = 162) at Johns Hopkins Hospital from 2010 to 2014 were enrolled in the prospective cohort. Collected novel pre- and post-operative biomarkers include soluble suppression of tumorgenicity 2, galectin-3, N-terminal prohormone of brain natriuretic peptide, and glial fibrillary acidic protein. A model based on clinical variables from the Society of Thoracic Surgery database was developed and evaluated against two augmented models.
Unplanned readmission or mortality within 30 days of cardiac surgery occurred among 21 (13%) children. The clinical model augmented with pre-operative biomarkers demonstrated a statistically significant improvement over the clinical model alone with a receiver-operating characteristics curve of 0.754 (95% confidence interval: 0.65–0.86) compared to 0.617 (95% confidence interval: 0.47–0.76; p-value: 0.012). The clinical model augmented with pre- and post-operative biomarkers demonstrated a significant improvement over the clinical model alone, with a receiver-operating characteristics curve of 0.802 (95% confidence interval: 0.72–0.89; p-value: 0.003).
Novel biomarkers add significant predictive value when assessing the likelihood of unplanned readmission or mortality after paediatric congenital heart surgery. Further exploration of the utility of these novel biomarkers during the pre- or post-operative period to identify early risk of mortality or readmission will aid in determining the clinical utility and application of these biomarkers into routine risk assessment.
Emergency physicians play an important role in providing care at the end-of-life as well as identifying patients who may benefit from a palliative approach. Several studies have shown that emergency medicine (EM) residents desire further training in palliative care. We performed a national cross-sectional survey of EM program directors. Our primary objective was to describe the number of Canadian postgraduate EM training programs with palliative and end-of-life care curricula.
A 15-question survey in English and French was sent by email to all program directors of both the Canadian College of Family Physicians emergency medicine (CCFP(EM)) and the Royal College of Physicians and Surgeons of Canada emergency medicine (RCPSC-EM) postgraduate training programs countrywide using FluidSurveys™ with a modified Dillman approach.
We received a total of 26 responses from the 36 (response rate = 72.2%) EM postgraduate programs in Canada. Ten out of 26 (38.5%) programs had a structured educational program pertaining to palliative and end-of-life care. Lectures or seminars were the exclusive choice to teach content. Clinical palliative medicine rotations were mandatory in one out of 26 (3.8%) programs. The top two barriers to implementation of palliative and end-of-life care curricula were lack of time (84.6%) and curriculum development concerns (80.8%).
Palliative and end-of-life care training within EM has been identified as an area of need. This cross-sectional survey demonstrates that a minority of Canadian EM programs have palliative and end-of-life care curricula. It will be important for all EM training programs, RCPSC-EM and CCFP(EM), in Canada, to develop an agreed upon set of competencies and to structure their curricula around them.
We review recent chondrule oxygen isotope studies by secondary ion mass spectrometry (SIMS). We discuss primary O-isotope fractionation characteristics of chondrule phases, and how they are used to garner information related to the physicochemical environment from which they formed. This includes high temperature gas–melt interactions, sampling of common precursors among different chondrite types, and how precursor compositions influenced redox states during chondrule formation. We also explore how primary O-isotope ratios of chondrule phases are disturbed by secondary alteration.
BACKGROUND: Meningiomas are the most common primary benign brain tumors in adults. Given the extended life expectancy of most meningiomas, consideration of quality of life (QOL) is important when selecting the optimal management strategy. There is currently a dearth of meningioma-specific QOL tools in the literature. OBJECTIVE: In this systematic review, we analyze the prevailing themes and propose toward building a meningioma-specific QOL assessment tool. METHODS: A systematic search was conducted, and only original studies based on adult patients were considered. QOL tools used in the various studies were analyzed for identification of prevailing themes in the qualitative analysis. The quality of the studies was also assessed. RESULTS: Sixteen articles met all inclusion criteria. Fifteen different QOL assessment tools assessed social and physical functioning, psychological, and emotional well-being. Patient perceptions and support networks had a major impact on QOL scores. Surgery negatively affected social functioning in younger patients, while radiation therapy had a variable impact. Any intervention appeared to have a greater negative impact on physical functioning compared to observation. CONCLUSION: Younger patients with meningiomas appear to be more vulnerable within social and physical functioning domains. All of these findings must be interpreted with great caution due to great clinical heterogeneity, limited generalizability, and risk of bias. For meningioma patients, the ideal QOL questionnaire would present outcomes that can be easily measured, presented, and compared across studies. Existing scales can be the foundation upon which a comprehensive, standard, and simple meningioma-specific survey can be prospectively developed and validated.
Stress in thin films is one of the mayor technological problems of silicon micromachining. Therefore stress reduction by a compensation method increases the technological use of a material. Three methods to obtain stress free films are investigated:
1. Stress in SiO2 and Si3N4 can be compensated by ion implantation.
2. Sandwich layers of SiO2 and Si3N4 can be made internally stress compensated by variation of the thickness ratio.
3. Polysilicon is stress reduced by appropriate doping and annealing.
The film stress is evaluated by the measurement of the bending of the substrate. Examples of processed membranes, bridges and cantilevers made of stress compensated films are given.
Thin SiO2 films grown on silicon substrates were exposed to electron beam irradiation at energies from 100 eV to 2.5 KeV. Then, thermally stimulated exoelectron emission (TSEE) spectra were taken by heating the sample linearly to a maximum temperature of 600°C. We have compared the emission behavior from oxides grown on both n-typeand p-type, (100) and (111) silicon wafers. The TSEE spectra show emission peaks whichcan be categorized by their behavior into two groups. The β emission peaks are characteristic of emission from localized electron traps while the γ emission peaks result from the annealing of beam-induced defects. We have observed changes in the β peaks which appear to be associated with the concentration of dopants in the substrate material. In addition, we have identified a beam energy threshold near the oxygen Is binding energy for the creation of defects. This suggests that defect creation results froman electronic transition similar to electron stimulated desorption.
In order to fill high quality insulators into narrower spaces in advanced metallizationthe digital CVD (Chemical Vapor Deposition) of multilayer stacked Si oxide and nitride films was studied. Reaction of TES (triethylsilane) with hydrogen (H) atoms was also found to lead to conformal CVD of Si film involving organic species. This reaction took place only on the surface reaction. In-situ FTIR studies reveal that H atoms react with Si-C2H5 bonds in TES and thus generate strong Si-CH3 bonds and weak Si-H bonds, thereby liberating H2 and forming the organic Si film on the surface, and the surface reaction is dominated by the thermal effect from the substrate. Then Si oxide or nitride films were formed by the digitaCVD which repeated a cycle of deposition of this film with subsequent oxidation or nitridation. Oxide film integrity was improved greatly by removing included organic bonds in the TES/H reaction film by exposing the film to H atoms before the oxidation step. Thus electrically excellent multilayer stacked oxide and nitride films were obtained in a deep trench.
Thin films of (BaxSrj-x)TiO3 (BST) deposited by RF sputtering have been studied for the application to the capacitor material of dynamic random access memory (DRAM). The effects of film structures on the dielectric constant and the leakage current were investigated. The films deposited at 550–600°C consist of granular grains, and the films deposited above 650°C contain columnar grains. The dielectric constant is related to the grain size in the direction of thickness. The leakage current increases as the film structure changes from granular to columnar. The low leakage current (less than 10−8 A/cm2 at +2 and -2 V) and the small value of equivalent SiO2 thickness (0.9 nm) were attained in the (Ba065Sr035) TiO3 thin films.
Ferroelectric BaTiO3 thin film capacitors were fabricated using different designs. Silicon wafers with an oxide layer were used as the substrates. Conductive metallic oxide of RuO2 was reactively sputtered on SiO2/Si as a bottom electrode. The BaTiO3 thin films with a thickness in the range of 150–300nm were deposited by RF magnetron sputtering. Different capacitor structures, including single layer amorphous, single layer polycrys-talline, and bi-layer amorphous on polycrystalline, were investigated in this study. The clear interface between BaTiO3 and RuO2 as demonstrated by cross-sectional scanning electron microscopy implies little interdiffusion. The DC conducticity of a film with a thickness of around 200nm was as low as 1×10−13OHgr-cm at 4V. The dielectric constant of the composite structure was controlled in a range from 30 to 130. Breakdown voltage varied from 5×105V/cm to 1×106V/cm.
This work describes process development of various kinds of compound sidewall spacer in submicron CMOS technology to improve gate oxide (GOX) leakage characteristics. This is attained by minimizing the impact of gate-level defects (GLDs) caused by in-process particle incorporation. Transistor characteristics did not suffer from this new sidewall spacer process.
Low temperature electron spin resonance (ESR) measurements were carried out on a broad range of separation by implantation of oxygen (SIMOX) substrates. The post-implantation forming anneal (T 1325°C) was observed to induce a donor in the SIMOX structure, more specifically, a shallow effective mass donor in Si of axial symmetry and preferential alignment along , likely an oxygen-related heat-treatment donor. Controlled etching back experiments revealed that the donor defects reside in an interfacial Si layer of at least 600$$A thick at both sides of the buried oxide layer reaching a local volume density of about 1018 cm−3. In the flat band situation, the donor was observed to be in a diamagnetic, ESR non-active state. Downward sweeping of the Si energy bands near the buried oxide interfaces, relative to the Fermi level, either by in situ positive ate biasing of large area metal-oxide-silicon capacitors fabricated on the buried oxide or γ7-irradiation induced positive charging of the buried oxide, was observed to alter the ionization state of part of the donors into an ESR-active state.
The electrical characteristics of n- and p-channel poly-Si thin film transistors having a double layer gate dielectric structure are reported. The gate dielectric consists of a silicon dioxide layer and a nitrogen-rich silicon nitride layer, both deposited by PECVD at low temperatures (≥400° C). When the silicon nitride was in contact with the poly-Si film, the effective carrier mobility (μeff), threshold voltage (Vth and subthreshold swing (St) for n-channel devices were 36 cm2/Vsec, -1.8 V and 1.65 V/decade, respectively, while for p-channel devices were 6 cm2/Vsec, -37 and 2.47 V/decade, respectively. These devices were not stable under negative gate bias stress, due to the injection of holes into the silicon nitride. When silicon dioxide was in contact with the poly-Si film, the μeff, Vth and St for n-channel devices were 26 cm2/Vsec, 3 V and 1.63 V/decade, respectively, while for p-channel devices were 10 cm2/Vsec, -22 V and 1.52 V/decade, respectively. These devices were stable under d.c. bias stress.
The asymmetric amorphous silicon thin film transistors are fabricated and exposed to various stress environments. A visible light illumination of 200,000 Ix and gate bias of 30 V are applied to both asymmetric and widely used symmetric a-Si TFT's. It is observed that the leakage current of asymmetric structure, where only one electrode is fully overlapped by gate electrode, is much less than that of symmetric one. The visible light illumination as well as gate bias stress do not degrade the leakage current of the asymmetric a-Si TFT's, while the leakage current in die symmetric TFT's are increased considerably due to the stress. Also, the degree of degradation in the threshold voltage, the field effect mobility and the subthreshold slope of asymmetric TFT's are relatively much less than that of conventional symmetric TFT's.
Current-voltage and conductance-voltage characterization is used to study high bias related “positive charge” in MOS tunnel diodes fabricated on p-type substrates. This charge effect appears to be associated with interface state levels that are located both throughout the band gap, and at a well-defined energy level roughly 0.3 eV above the silicon valence band edge. The well-defined state apparently acts as a tunnelingcenter communicating with the gate electrode and the silicon valence band. In addition, the first observation of high bias related charge is reported for tunnel diodes built on n-type substrates. This charge has positive character at low bias levels, transforming to net negative charge at high gate voltages.