Partially buried microcolumns for micro gas analyzers.

This article demonstrates the feasibility of making a partially buried micro gas chromatography (micro-GC) column with a rounded channel wall profile, which enables coating the stationary phase more uniformly and shows better separation characteristics than a square deep reactive ion etched (DRIE) wall profile. A buried structure fabrication method was adapted to fabricate 34 cm long, 165 microm wide, and 65 microm deep partially buried microcolumns, which had a unique rounded microcolumn wall profile similar to that of a flattened circular tube. The separation characteristics were compared to that of a 34 cm long, 100 microm x 100 microm square DRIE microcolumn, which had a similar hydraulic diameter.

Developing dual-beam methodologies for the study of heterogeneous polymer-based systems.

The use of a combined focused ion beam/environmental scanning electron microscope (FIB/ESEM) offers new possibilities for imaging the internal structure of complex heterogeneous polymeric samples. The use of the focused ion beam, using positively charged gallium ions in conjunction with a measured 'defocused' low-energy primary electron beam, has permitted milling through the heterostructure to be achieved in a controlled way, exposing the inner structure, without introducing significant ion beam damage/destruction into the sample. The subsequent use of the environmental scanning electron microscope for imaging the revealed internal structure has then enabled insulating polymer structures to be imaged, without charging problems.

Multidimensional separation of chiral amino acid mixtures in a multilayered three-dimensional hybrid microfluidic/nanofluidic device.

Microscale total analysis systems (microTAS) allow high-throughput analyses by integrating multiple processes, parallelization, and automation. Here we combine unit operations of microTAS to create a device that can perform multidimensional separations using a three-dimensional hybrid microfluidic/nanofluidic device composed of alternating layers of patterned poly(methyl methacrylate) and nanocapillary array membranes constructed from nuclear track-etched polycarbonate. Two consecutive electrophoretic separations are performed, the first being an achiral separation followed by a chiral separation of a selected analyte band.

Glass table-related injuries in children.

Objectives: To investigate the patterns of injury sustained from glass table-related accidents to estimate whether tempered glass would prevent injuries.

Methods: We conducted a retrospective cohort analysis of all patients in an urban pediatric emergency department between October of 1995 and May for 2007 for glass table-related accidents. Data collected included age, sex, injury characteristics, examination findings, radiographic imaging, interventions, and disposition.

The effect of hospital bed occupancy on throughput in the pediatric emergency department.

Study Objective: Although it has been suggested that high hospital occupancy leads to emergency department (ED) overcrowding and impedes ED throughput, there are limited data defining this relationship. The objective of this study is to examine whether high inpatient hospital occupancy negatively affects throughput in a pediatric ED.

Methods: This cross-sectional analysis evaluated patient visits to an urban pediatric ED and hospital occupancy rates.

The transcription repressor, ZEB1, cooperates with CtBP2 and HDAC1 to suppress IL-2 gene activation in T cells.

Activation of T cells leads to the induction of many cytokine genes that are required for appropriate immune responses, including IL-2, a key cytokine for T cell proliferation and homeostasis. The activating transcription factors such as nuclear factor of activated T cells, nuclear factor kappaB/Rel and activated protein-1 family members that regulate inducible IL-2 gene expression have been well documented. However, negative regulation of the IL-2 gene is less studied.

Pathobiology and treatment of hepatitis virus-related thrombocytopenia.

Thrombocytopenia is a well recognized complication of infections, including those from hepatotropic viruses. Thrombocytopenia may actually be the only manifestation of vital hepatitis, which should therefore be considered in the differential diagnosis of primary immune thrombocytopenia (ITP). The mechanisms of thrombocytopenia associated with viral hepatitis vary widely depending on the specific infectious agent and the severity of liver disease.

Development of CD4+CD25+FoxP3+ regulatory T cells from cord blood hematopoietic progenitor cells.

Adult stem cells are capable of generating all of the cells of the hematopoietic system, and this process is orchestrated in part by the interactions between these cells and the stroma. T cell progenitors emerge from the stem cell compartment and migrate to the thymus, where their terminal differentiation and maturation occur, and it is during this phase that selection shapes the immune repertoire. Notch ligands, including Delta-like 1 (DL1), play a critical role in this lymphoid differentiation.

Acute appendicitis is characterized by a uniform and highly selective pattern of inflammatory gene expression.

Acute appendicitis (AA) is the most common life-threatening surgical emergency in pediatrics. To characterize the nature of the inflammatory response in AA, gene expression profiles were generated. We found remarkable uniformity in the genes that were differentially expressed between patients with appendicitis and control groups.

Anticoagulant management of pregnancy following heart valve replacement in the United Kingdom, 1986-2002.

Background And Aim Of The Study: Patients with mechanical heart valves require anticoagulation which is associated with significant maternal mortality (1-4%) and fetal complications (31%) in pregnancy. The study aim was to identify anticoagulant protocols and outcomes for pregnant women undergoing heart valve replacement (HVR) in the United Kingdom.

Methods: Women aged between 18 and 45 years and registered with the United Kingdom Heart Valve Registry (UKHVR) each completed a questionnaire, and their obstetric notes were reviewed.

Assisted reproduction for couples affected by human immunodeficiency virus in California.

Survey results demonstrate that the majority of fertility clinics in California are willing to care for couples affected by human immunodeficiency virus (HIV) if legal restrictions are removed. In response to scientific advances and evolving clinical standards, California reversed the limitations placed on the provision of assisted reproduction for HIV-positive men in 2008.

A double-negative feedback loop between ZEB1-SIP1 and the microRNA-200 family regulates epithelial-mesenchymal transition.

Epithelial to mesenchymal transition occurs during embryologic development to allow tissue remodeling and is proposed to be a key step in the metastasis of epithelial-derived tumors. The miR-200 family of microRNAs plays a major role in specifying the epithelial phenotype by preventing expression of the transcription repressors, ZEB1/deltaEF1 and SIP1/ZEB2. We show here that miR-200a, miR-200b, and the related miR-429 are all encoded on a 7.

Obtundation and seizure following ondansetron overdose in an infant.

Introduction: Ondansetron, an increasingly prescribed 5-HT(3) antagonist used in the management of nausea and vomiting of various etiologies, has a well-established safety profile in therapeutic use. However, little is known about its effects in the setting of an overdose. We describe the first case of severe toxicity in an infant who unintentionally ingested a large quantity of ondansetron.

Effect of solution concentration, surface bias and protonation on the dynamic response of amplitude-modulated atomic force microscopy in water.

The dynamic response of amplitude-modulated atomic force microscopy (AM-AFM) is studied at the solid/water interface with respect to changes in ionic concentration, applied surface potential, and surface protonation. Each affects the electric double layer in the solution, charge on the tip and the sample surface, and thus the forces affecting the dynamic response. A theoretical model is developed to relate the effective stiffness and hydrodynamic damping of the AFM cantilever that is due to the tip/surface interaction with the phase and amplitude signals measured in the AM-AFM experiments.

Adherence to antiretrovirals among US women during and after pregnancy.

Background: Antiretrovirals (ARVs) are recommended for maternal health and to reduce HIV-1 mother-to-child transmission, but suboptimal adherence can counteract its benefits.

Objectives: To describe antepartum and postpartum adherence to ARV regimens and factors associated with adherence.

Methods: We assessed adherence rates among subjects enrolled in Pediatric AIDS Clinical Trials Group Protocol 1,025 from August 2002 to July 2005 on tablet formulations with at least one self-report adherence assessment.

HIV-infected mothers' perceptions of uncertainty, stress, depression and social support during HIV viral testing of their infants.

To explore relationships between mothers' uncertainty about infant HIV serostatus with stress, distress, depressive symptoms, and social support during infant HIV testing. This prospective longitudinal study of 20 HIV-infected mothers involved a prenatal visit and five postpartum visits clustered around infant HIV viral testing. Maternal uncertainty about infant HIV serostatus significantly decreased over time (p < 0.

Complex PTSD, interpersonal trauma and relational consequences: findings from a treatment-receiving Northern Irish sample.

Background: The relationship between PTSD and complex PTSD remains unclear. As well as further addressing this issue, the current study aimed to assess the degree to which DESNOS (complex PTSD) was related to interpersonal trauma and had relational consequences.

Methods: Eighty one treatment-receiving participants with a history of exposure to the 'Troubles' in Northern Ireland, were assessed on various forms of interpersonal trauma, including exposure to the Troubles, and measures of interpersonal and community connectedness.

"Left without being seen": a national profile of children who leave the emergency department before evaluation.

Study Objective: The epidemiology of children who present to the emergency department (ED) and leave without being seen has not been well characterized. We evaluate rates and secular trends of children who leave without being seen, identify factors associated with pediatric leave without being seen cases, and determine whether there are differences in leaving patterns between children and adults seeking emergency care.

Methods: Data were obtained from the National Hospital Ambulatory Medical Care Survey, which collects information on patient visits to EDs throughout the United States.

Micromachined GC columns for fast separation of organophosphonate and organosulfur compounds.

This article demonstrates how to prepare microfabricated columns (microcolumns) for organophosphonate and organosulfur compound separation that rival the performance of commercial capillary columns. Approximately 16,500 theoretical plates were generated with a 3 m long OV-5-coated microcolumn with a 0.25 microm phase thickness using helium as the carrier gas at 20 cm/s.

Immobilization of DNAzyme catalytic beacons on PMMA for Pb2+ detection.

Due to the numerous toxicological effects of lead, its presence in the environment needs to be effectively monitored. Incorporating a biosensing element within a microfluidic platform enables rapid and reliable determinations of lead at trace levels. A microchip-based lead sensor is described here that employs a lead-specific DNAzyme (also called catalytic DNA or deoxyribozyme) as a recognition element that cleaves its complementary substrate DNA strand only in the presence of cationic lead (Pb(2+)).

Mechanical response of a living human epidermal keratinocyte sheet as measured in a composite diaphragm inflation experiment.

Sheets of normal human epidermal keratinocytes (NHEKs) were reconstituted in vitro on tensed but highly compliant, freestanding polydimethylsiloxane (PDMS) membranes, 5.0 mm in diameter and 10 mum thick. NHEK-PDMS composite diaphragm (CD) specimens were then subjected to cyclical axisymmetric inflation tests to investigate epithelial sheet rheology under conditions of physiologically severe deformations (~50% nominal polar biaxial strains).