Assessment of wafer scale MoS atomic layers grown by metal-organic chemical vapor deposition using organo-metal, organo-sulfide, and HS precursors.

Transition Metal Dichalcogenides (TMDs) are a unique class of materials that exhibit attractive electrical and optical properties which have generated significant interest for applications in microelectronics, optoelectronics, energy storage, and sensing. Considering the potential of these materials to impact such applications, it is crucial to develop a reliable and scalable synthesis process that is compatible with modern industrial manufacturing methods. Metal-organic chemical vapor deposition (MOCVD) offers an ideal solution to produce TMDs, due to its compatibility with large-scale production, precise layer control, and high material purity.

Longitudinal genomic surveillance of multidrug-resistant carriage in critical care patients.

Colonization with multidrug-resistant strains causes a substantial health burden in hospitalized patients. We performed a longitudinal genomics study to investigate the colonization of resistant strains in critically ill patients and to identify evolutionary changes and strain replacement events within patients. Patients were admitted to the intensive care unit and hematology wards at a major hospital in Lebanon.

Covalent functionalization of molybdenum disulfide by chemically activated diazonium salts.

Covalent functionalization is one of the most efficient ways to tune the properties of layered materials in a highly controlled manner. However, molecular chemisorption on semiconducting transition metal dichalcogenides remains a delicate task due to the inertness of their surface. Here we perform covalent modification of bulk and single layer molybdenum disulfide (MoS) using chemical activation of diazonium salts.

Early-Onset Neonatal Sepsis 2015 to 2017, the Rise of Escherichia coli, and the Need for Novel Prevention Strategies.

Importance: Early-onset sepsis (EOS) remains a potentially fatal newborn condition. Ongoing surveillance is critical to optimize prevention and treatment strategies.

Objective: To describe the current incidence, microbiology, morbidity, and mortality of EOS among a cohort of term and preterm infants.

Importance of the substrate's surface evolution during the MOVPE growth of 2D-transition metal dichalcogenides.

In this paper, we explore the impact of changing the growth conditions on the substrate surface during the metal-organic vapor phase epitaxy of 2D-transition metal dichalcogenides. We particularly study the growth of molybdenum disulfide (MoS) on sapphire substrates at different temperatures. We show that a high temperature leads to a perfect epitaxial alignment of the MoS layer with respect to the sapphire substrate underneath, whereas a low temperature growth induces a 30° epitaxial alignment.

Material-Selective Doping of 2D TMDC through AlO Encapsulation.

For the integration of two-dimensional (2D) transition metal dichalcogenides (TMDC) with high-performance electronic systems, one of the greatest challenges is the realization of doping and comprehension of its mechanisms. Low-temperature atomic layer deposition of aluminum oxide is found to n-dope MoS and ReS but not WS. Based on electrical, optical, and chemical analyses, we propose and validate a hypothesis to explain the doping mechanism.

Peculiar alignment and strain of 2D WSe grown by van der Waals epitaxy on reconstructed sapphire surfaces.

The increasing scientific and industry interest in 2D MX materials within the field of nanotechnology has made the single crystalline integration of large area van der Waals (vdW) layers on commercial substrates an important topic. The c-plane oriented (3D crystal) sapphire surface is believed to be an interesting substrate candidate for this challenging 2D/3D integration. Despite the many attempts that have been made, the yet incomplete understanding of vdW epitaxy still results in synthetic material that shows a crystallinity far too low compared to natural crystals that can be exfoliated onto commercial substrates.

Weaning of Moderately Preterm Infants from the Incubator to the Crib: A Randomized Clinical Trial.

Objective: To assess whether length of hospital stay is decreased among moderately preterm infants weaned from incubator to crib at a lower vs higher weight.

Study Design: This trial was conducted in the Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network. Infants with gestational ages 29-33 weeks, birthweight <1600 g, and in an incubator were randomly assigned to a weaning weight of 1600 or 1800 g.

Layer-controlled epitaxy of 2D semiconductors: bridging nanoscale phenomena to wafer-scale uniformity.

The rapid cadence of MOSFET scaling is stimulating the development of new technologies and accelerating the introduction of new semiconducting materials as silicon alternative. In this context, 2D materials with a unique layered structure have attracted tremendous interest in recent years, mainly motivated by their ultra-thin body nature and unique optoelectronic and mechanical properties. The development of scalable synthesis techniques is obviously a fundamental step towards the development of a manufacturable technology.

Vitamin D deficiency and respiratory morbidity among African American very low birth weight infants.

Background: Very low birth weight infants (VLBWI) have unexplained variation in respiratory morbidity, including respiratory distress syndrome (RDS) and bronchopulmonary dysplasia (BPD). We examined a potential association to serum 25-hydroxyvitamin D (s-25OHD) on day one.

Study Design: Prospective, observational study on 89 VLBWI (≤1250 g).

Does vitamin D deficiency affect placental inflammation or infections among very low birth weight infants?

Objective: Examine the association between placental inflammation and neonatal infections, and 25OH vitamin D (25OH D) levels at birth among very low birth weight infants (VLBWI).

Study Design: Serum 25OH D levels were measured in 89 VLBWI (≤1250 g) and 47 mothers on day one, and in 78 infants on day 21. Placentas were examined for maternal and fetal inflammation.

Antimony-mediated control of misfit dislocations and strain at the highly lattice mismatched GaSb/GaAs interface.

Determining the atomic structure of misfit dislocations at highly lattice mismatched interface is essential to optimize the quality of the epitaxial layer. Here, with aberration corrected scanning transmission electron microscopy at sub-Angstrom resolution and molecular dynamics simulation, we investigated the atomic structure of misfit dislocations at GaSb/GaAs interface. New types of Lomer misfit dislocation formed on an Sb wetting monolayer were observed, in contrast to a conventional misfit dislocation whose core is located at interface.

Strain relief and growth optimization of GaSb on GaP by molecular beam epitaxy.

In this paper, the impact of growth parameters on the strain relaxation of highly lattice mismatched (11.8%) GaSb grown on GaP substrate by molecular beam epitaxy has been investigated. The surface morphology, misfit dislocation and strain relaxation of the GaSb islands are shown to be highly related to the initial surface treatment, growth rate and temperature.

Role of spontaneous breathing trial in predicting successful extubation in premature infants.

Background: The ability of clinicians to predict successful extubation in mechanically ventilated premature neonates is limited. Identifying objective criteria for predicting successful extubation may reduce the incidence of failed extubation and the duration of mechanical ventilation.

Objective: To evaluate the validity of objective measures of lung function and spontaneous breathing trial (SBT) in predicting successful extubation among premature neonates with attempted extubations within the first 3 weeks of life.

Role of angiotensin-converting enzyme gene polymorphism in persistent pulmonary hypertension of the newborn.

Aim: To evaluate the association of angiotensin-converting enzyme (ACE) gene polymorphism with risk/severity of persistent pulmonary hypertension of the newborn (PPHN) among at risk infants.

Methods: Infants ≥ 34 weeks with respiratory distress at birth were recruited. PPHN was diagnosed clinically and by cardiac echocardiogram.

Haplotypes of tumor necrosis factor gene and tracheal aspirate fluid levels of tumor necrosis factor-alpha in preterm infants.

Individual variability in the production of tumor necrosis factor-alpha (TNF-alpha) has been attributed to genetic factors. We examined whether alleles of TNF gene (lymphotoxin-alpha+250, TNF-alpha-308, and TNF-alpha-238) affect tracheal aspirate fluid (TAF) levels of TNF-alpha among preterm infants at risk of bronchopulmonary dysplasia. TAF samples were collected within 48 h of birth and 7, 14, 21, and 28 d later.

Auditory brainstem response abnormalities and hearing loss in children with craniosynostosis.

Objectives: Craniosynostosis is a devastating disorder characterized by premature closure of the cranial plates before or shortly after birth. This results in an abnormally shaped skull, face, and brain. Little is known about hearing disorders in such patients, and nothing has been published about their auditory brainstem responses.

A cluster-randomized trial of benchmarking and multimodal quality improvement to improve rates of survival free of bronchopulmonary dysplasia for infants with birth weights of less than 1250 grams.

Objective: We tested whether NICU teams trained in benchmarking and quality improvement would change practices and improve rates of survival without bronchopulmonary dysplasia in inborn neonates with birth weights of <1250 g.

Methods: A cluster-randomized trial enrolled 4093 inborn neonates with birth weights of <1250 g at 17 centers of the National Institute of Child Health and Human Development Neonatal Research Network. Three centers were selected as best performers, and the remaining 14 centers were randomized to intervention or control.

Cumulative index of exposure to hypocarbia and hyperoxia as risk factors for periventricular leukomalacia in low birth weight infants.

Background: Hypocarbia and hyperoxia are risk factors for periventricular leukomalacia in low birth weight infants. The association of a cumulative index of exposure to hypocarbia and hyperoxia and periventricular leukomalacia has not been evaluated.

Objective: Our goal was to examine the relationship between cumulative index of exposure to hypocarbia and hyperoxia and periventricular leukomalacia during the first 7 days of life in low birth weight infants.

Deletion allele of angiotensin-converting enzyme is associated with increased risk and severity of bronchopulmonary dysplasia.

Objective: To explore whether the deletion (D) allele of angiotensin-converting enzyme (ACE) is associated with the risk or severity of bronchopulmonary dysplasia (BPD) among very low birth weight (BW) infants.

Study Design: Infants with a BW < or = 1250 g were prospectively recruited. The D and I (insertion) alleles of ACE were determined using a polymerase chain reaction followed by restriction fragment length polymorphism analysis.

Oxygen delivery through nasal cannulae to preterm infants: can practice be improved?

Objective: Oxygen delivery through nasal cannulae to convalescent preterm infants is a common but largely unstudied practice. To learn more about current nasal cannula oxygen delivery practices, we examined the variations in oxygen delivery through nasal cannulae among the centers of the Neonatal Research Network, the frequency of prescription of low levels of oxygen, and the success of weaning to room air. We hypothesized that some infants treated with oxygen through nasal cannulae were receiving oxygen levels equivalent to those of room air.

Polymorphism of tumor necrosis factor-alpha and risk and severity of bronchopulmonary dysplasia among very low birth weight infants.

Background: Preterm infants with bronchopulmonary dysplasia (BPD) exhibit prolonged elevation of inflammatory indices in their tracheal aspirates. Tumor necrosis factor-alpha (TNF-alpha) is a central mediator of the inflammatory response. The adenine-containing alleles of TNF-alpha-308 and lymphotoxin-alpha+250 have been associated with increased levels of TNF-alpha, whereas the adenine allele of TNF-alpha-238 produces lower levels of TNF-alpha after stimulation.

Tumor necrosis factor-alpha allele lymphotoxin-alpha+250 is associated with the presence and severity of placental inflammation among preterm births.

Histologic inflammation of placenta has been associated with increased risk for bronchopulmonary dysplasia and periventricular leukomalacia among preterm infants. Tumor necrosis factor-alpha (TNF-alpha) plays a central role in the regulation of inflammation. Some alleles of TNF (LT-alpha+250, TNF-alpha-308, and TNF-alpha-238) have been associated with susceptibility and/or severity of many diseases characterized by inflammation and/or involving the immune system.

Serial changes in levels of IL-6 and IL-1beta in premature infants at risk for bronchopulmonary dysplasia.

The aim of this study was to define the inflammatory changes occurring in the lungs of infants at risk for bronchopulmonary dysplasia (BPD) over the first 28 days of life, and to define an optimal strategy for steroids therapy in the prevention of BPD. We measured levels of interleukin-6 (IL-6) and interleukin-1 beta (IL-1beta) in tracheal aspirate (TA) samples and blood of premature infants with severe respiratory distress syndrome RDS (n = 45) on the first day of life prior to initiation of surfactant therapy and on days 5-7, 12-14, 19-21, and 26-28. Levels of IL-6 and IL-1beta were determined with a commercially available enzyme-linked immunoassay.

Surfactant phospholipids and surface activity among preterm infants with respiratory distress syndrome who develop bronchopulmonary dysplasia.

Our objective was to determine if preterm infants with respiratory distress syndrome who develop bronchopulmonary dysplasia have abnormalities in surfactant phospholipids and/or function. Tracheal aspirate samples obtained from preterm infants with respiratory distress syndrome on days 1, 3-5, 7-10, 14-17, 21-24 and 27-30 were analyzed for total phospholipids and phospholipids fractions by determination of total phospholipid phosphorus and thin layer chromatography, respectively. Surfactant properties were assessed with captive bubble surfactometer.