Automated Three-Dimensional Imaging and Pfirrmann Classification of Intervertebral Disc Using a Graphical Neural Network in Sagittal Magnetic Resonance Imaging of the Lumbar Spine.

This study aimed to develop a graph neural network (GNN) for automated three-dimensional (3D) magnetic resonance imaging (MRI) visualization and Pfirrmann grading of intervertebral discs (IVDs), and benchmark it against manual classifications. Lumbar IVD MRI data from 300 patients were retrospectively analyzed. Two clinicians assessed the manual segmentation and grading for inter-rater reliability using Cohen's kappa.

Impact of Proactive Integrated Care on Chronic Obstructive Pulmonary Disease.

Background: Up to 50% of chronic obstructive pulmonary disease (COPD) patients do not receive recommended care for COPD. To address this issue, we developed Proactive Integrated Care (Proactive iCare), a health care delivery model that couples integrated care with remote monitoring.

Methods: We conducted a prospective, quasi-randomized clinical trial in 511 patients with advanced COPD or a recent COPD exacerbation, to test whether Proactive iCare impacts patient-centered outcomes and health care utilization.

Field-effect transistors based on silicon nanowire arrays: effect of the good and the bad silicon nanowires.

Aligned arrays of silicon nanowires (aa-Si NWs) allow the exploitation of Si NWs in a scalable way. Previous studies explored the influence of the Si NWs' number, doping density, and diameter on the related electrical performance. Nevertheless, the origin of the observed effects still not fully understood.

Spray-coating route for highly aligned and large-scale arrays of nanowires.

Technological implementation of nanowires (NWs) requires these components to be organized with controlled orientation and density on various substrates. Here, we report on a simple and efficient route for the deposition of highly ordered and highly aligned NW arrays on a wide range of receiver substrates, including silicon, glass, metals, and flexible plastics with controlled density. The deposition approach is based on spray-coating of a NW suspension under controlled conditions of the nozzle flow rate, droplet size of the sprayed NWs suspension, spray angle, and the temperature of the receiver substrate.

Molecular gating of silicon nanowire field-effect transistors with nonpolar analytes.

Silicon nanowire field-effect transistors (Si NW FETs) have been used as powerful sensors for chemical and biological species. The detection of polar species has been attributed to variations in the electric field at the conduction channel due to molecular gating with polar molecules. However, the detection of nonpolar analytes with Si NW FETs has not been well understood to date.

Enhanced sensing of nonpolar volatile organic compounds by silicon nanowire field effect transistors.

Silicon nanowire field effect transistors (Si NW FETs) are emerging as powerful sensors for direct detection of biological and chemical species. However, the low sensitivity of the Si NW FET sensors toward nonpolar volatile organic compounds (VOCs) is problematic for many applications. In this study, we show that modifying Si NW FETs with a silane monolayer having a low fraction of Si-O-Si bonds between the adjacent molecules greatly enhances the sensitivity toward nonpolar VOCs.

Catalyst-free functionalization for versatile modification of nonoxidized silicon structures.

Here, we report on a simple, catalyst-free route for obtaining highly versatile subsequent functionalization on Si nanowires and Si(111) substrates. The versatility of this approach allows subsequent functionalization not only for organic species but also for inorganic (nanomaterial) species. The method has the advantage of controlling the density of reactive cross-linkers without affecting the stability of the Si samples and without having metallic (or catalyst) residues on the surface.

Silver coated platinum core-shell nanostructures on etched Si nanowires: atomic layer deposition (ALD) processing and application in SERS.

A new method to prepare plasmonically active noble metal nanostructures on large surface area silicon nanowires (SiNWs) mediated by atomic layer deposition (ALD) technology has successfully been demonstrated for applications of surface-enhanced Raman spectroscopy (SERS)-based sensing. As host material for the plasmonically active nanostructures we use dense single-crystalline SiNWs with diameters of less than 100 nm as obtained by a wet chemical etching method based on silver nitrate and hydrofluoric acid solutions. The SERS active metal nanoparticles/islands are made from silver (Ag) shells as deposited by autometallography on the core nanoislands made from platinum (Pt) that can easily be deposited by ALD in the form of nanoislands covering the SiNW surfaces in a controlled way.

Lithographically patterned silicon nanowire arrays for matrix free LDI-TOF/MS analysis of lipids.

Silicon nanowire arrays were patterned onto silicon chips by a combination of lithography and chemical vapor deposition using the vapor-liquid-solid growth method. Thus, highly reproducible sample deposition zones were obtained that were used for laser desorption ionization (LDI) mass spectrometric analysis of lipidic species with lithium salts as dopants. Using a conventional UV laser (337 nm), hydrocarbons and numerous lipids (triglycerides, diglycerides, wax esters) could be effectively lithiated yielding [M + Li](+) ions.

Silicon nanowires terminated with methyl functionalities exhibit stronger Si-C bonds than equivalent 2D surfaces.

Silicon nanowires (Si NWs) terminated with methyl functionalities exhibit higher oxidation resistance under ambient conditions than equivalent 2D Si(100) and 2D Si(111) surfaces having similar or 10-20% higher initial coverage. The kinetics of methyl adsorption as well as complementary surface analysis by XPS and ToF SIMS attribute this difference to the formation of stronger Si-C bonds on Si NWs, as compared to 2D Si surfaces. This finding offers the possibility of functionalising Si NWs with minimum effect on the conductance of the near-gap channels leading towards more efficient Si NW electronic devices.

Selectively deposited silver coatings on gold-capped silicon nanowires for surface-enhanced Raman spectroscopy.

Gold caps on silicon nanowires are selectively coated with silver by autometallography (electroless deposition). Changing the conditions of silver deposition, a variety of different coating morphologies can be produced [figure: see text]. The different silver coating morphologies are investigated in terms of their capabilities for surface enhanced Raman scattering (SERS) experiments.

Axial p-n junctions realized in silicon nanowires by ion implantation.

The electrical properties of vertically aligned silicon nanowires doped by ion implantation are studied in this paper by a combination of electron beam-induced current imaging and two terminal current-voltage measurements. By varying the implantation parameters in several process steps, uniform p- and n-doping profiles as well as p-n junctions along the nanowire axis are realized. The effective doping is demonstrated by electron beam-induced current imaging on single nanowires, and current-voltage measurements show their well-defined rectifying behavior.

Stable scaffolds for reacting Si nanowires with further organic functionalities while preserving Si-C passivation of surface sites.

We report on Si NWs modified by covalent scaffolds, via SiC bonds, that give nearly full coverage of the Si atop sites and, at the same time, provide a route for subsequent functionalization. The obtained CH(3)CHCHSi NWs exhibit superior oxidation resistance over Si NWs that are modified with CH(3) or CH(3)CC functionalities, which give nearly full coverage of the Si atop site too.

Silicon nanowire-based solar cells.

The fabrication of silicon nanowire-based solar cells on silicon wafers and on multicrystalline silicon thin films on glass is described. The nanowires show a strong broadband optical absorption, which makes them an interesting candidate to serve as an absorber in solar cells. The operation of a solar cell is demonstrated with n-doped nanowires grown on a p-doped silicon wafer.

Nanowires enabling signal-enhanced nanoscale Raman spectroscopy.

Silicon nanowires grown by the vapor-liquid-solid (VLS) mechanism catalyzed by gold show gold caps (droplets) approximately 20-500 nm in diameter with a half spherical towards almost spherical shape. These gold droplets are well suited to exploit the surface-enhanced Raman scattering (SERS) effect and could be used for tip-enhanced Raman spectroscopy (TERS). The gold droplet of a nanowire attached to an atomic force microscopy (AFM) tip could locally enhance the Raman signal and increase the spatial resolution.

Variable expression of endothelial NO synthase in three forms of rat pulmonary hypertension.

Endothelial nitric oxide (NO) synthase (eNOS) mRNA and protein and NO production are increased in hypoxia-induced hypertensive rat lungs, but it is uncertain whether eNOS gene expression and activity are increased in other forms of rat pulmonary hypertension. To investigate these questions, we measured eNOS mRNA and protein, eNOS immunohistochemical localization, perfusate NO product levels, and NO-mediated suppression of resting vascular tone in chronically hypoxic (3-4 wk at barometric pressure of 410 mmHg), monocrotaline-treated (4 wk after 60 mg/kg), and fawn-hooded (6-9 mo old) rats. eNOS mRNA levels (Northern blot) were greater in hypoxic and monocrotaline-treated lungs (130 and 125% of control lungs, respectively; P < 0.

Overexpression of endothelin-1 and enhanced growth of pulmonary artery smooth muscle cells from fawn-hooded rats.

Increased production of endothelin-1 (ET-1) has been detected in lungs of fawn-hooded rats (FHR) with idiopathic pulmonary hypertension. Accelerated pulmonary artery (PA) smooth muscle cell (SMC) proliferation contributes to vascular remodeling in these rats. We hypothesized that PA SMC would be an important site of enhanced ET-1 expression in FHR lung, that these SMC would have increased growth compared with cells from a normotensive strain, and that this locally produced ET-1 would contribute to the increased growth of these cells.

BQ123, an ETA-receptor antagonist, attenuates hypoxic pulmonary hypertension in rats.

To investigate the role of endothelin-1 (ET-1) in the pathogenesis of hypoxic pulmonary hypertension, we studied the effects of a recently described endothelin-receptor antagonist (ETA), BQ123, on the development of this process. Intraperitoneal osmotic pumps were placed into 8-wk-old Sprague-Dawley rats that received either saline or BQ123 (0.15 mg/h).

BQ123, an ETA receptor antagonist, inhibits endothelin-1-mediated proliferation of human pulmonary artery smooth muscle cells.

Endothelin (ET-1) has been shown to be co-mitogenic for vascular smooth muscle cells (SMC) from human systemic arteries. A more modest growth-promoting effect has also been described in SMC from the bovine and porcine pulmonary circulation. Whether ET-1 has mitogenic properties in the human pulmonary circulation, and which ET receptor subtype mediates this response, is unknown.

BQ123, an ETA receptor antagonist, attenuates endothelin-1-induced vasoconstriction in rat pulmonary circulation.

Endothelin-1 (ET-1) is a potent endogenous vasoactive peptide whose role in regulation of vascular tone is unclear. BQ123 is a recently described ETA receptor antagonist which may be useful in further investigation of the physiologic and pathophysiologic significance of ET-1. To test its efficacy in the pulmonary circulation, the vascular response to exogenous ET-1 with and without BQ123 was assessed in rat pulmonary artery (PA) rings and salt-perfused lungs.

EDRF suppresses an unidentified vasoconstrictor mechanism in hypertensive rat lungs.

To test whether endothelium-derived relaxing factor (EDRF) plays a role in regulating the hypertensive pulmonary vascular bed, we compared effects of the inhibitor of EDRF production, N omega-nitro-L-arginine (L-NNA), on resting vascular tone in lungs and conduit pulmonary arteries isolated from control and chronically hypoxic rats. In contrast to no effect on normoxic vascular tone in salt solution-perfused normotensive lungs, 100 microM L-NNA caused a marked, L-arginine-sensitive, precapillary vasoconstriction in unstimulated hypertensive lungs. Bioassay of hypertensive lung perfusate did not detect a circulating vasoconstrictor, and L-NNA vasoconstriction was not inhibited by blockers of cyclooxygenase, 5-lipoxygenase, platelet-activating factor receptors, alpha-adrenoceptors, and serotonin 5-HT2 receptors or by scavengers of superoxide anion and H2O2.

Pulmonary function and hypoxic ventilatory response in subjects susceptible to high-altitude pulmonary edema.

To determine if spirometric changes reflect early high-altitude pulmonary edema (HAPE) formation, we measured the FVC, FEV1, and FEF25-75 serially during the short-term period following simulated altitude exposure (4,400 m) in eight male subjects, four with a history of HAPE and four control subjects who had never experienced HAPE. Three of the four HAPE-susceptible subjects developed acute mountain sickness (AMS), based on their positive Environmental Symptom Questionnaire (AMS-C) scores. Clinical signs and symptoms of mild pulmonary edema developed in two of the three subjects with AMS after 4 h of exposure, which prompted their removal from the chamber.

Endothelin-1 increases the pulmonary microvascular pressure and causes pulmonary edema in salt solution but not blood-perfused rat lungs.

Endothelin-1 (ET-1) is a potent vasoactive peptide that has been reported to cause lung edema. This study tested if the edemagenic effect of ET-1 is due to preferential venoconstriction and, if so, whether the site of resistance is similar with salt solution (PSS) and more physiologic blood perfusate. ET-1 caused concentration-dependent contraction of pulmonary arterial and venous rings, with an EC50 of 1.

Increased lung endothelin-1 production in rats with idiopathic pulmonary hypertension.

The role of endogenous circulating or locally produced endothelin-1 (ET-1) in pulmonary hypertensive states is unknown. To investigate this we measured ET-1 levels and preproendothelin-1 (prepro-ET-1) mRNA expression at various ages in control Sprague-Dawley (SDR) rats and in fawn-hooded rats (FHR), a strain which develops idiopathic pulmonary hypertension. Although serum ET-1 levels were similar in SDR and FHR, we found twofold increases in FHR whole lung homogenate ET-1 levels by radioimmunoassay.