124 research outputs found

    Manufacturing method of an apparatus for the processing of single molecules

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    The invention relates to a method for manufacturing an apparatus for the processing of single molecules. According to this method, a self-assembling resist (155) is deposited on a processing layer (110, PL) and allowed to self-assemble into a pattern of two phases (155a, 155b). One of these phases (155a) is then selectively removed, and at least one aperture is generated in the processing layer (110, PL) through the mask of the remaining resist (155b). Thus apertures of small size can readily be produced that allow for the processing of single molecules (M), for example in DNA sequencing

    Edge Transfer Lithography Using Alkanethiol Inks

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    Edge lithographic patterning techniques are based on the utilization of the edges of micrometer-sized template features for the reproduction of submicrometer structures. Edge transfer lithography (ETL) permits local surface modification in a single step by depositing self-assembled monolayers onto a metal substrate selectively along the feature edges of an elastomeric stamp. In this report two stamp designs are described that now allow for the use of alkanethiol inks in ETL and their use as etch resists to reproduce submicrometer structures in gold. Anisotropically modified stamps are shown to combine the potential for very high-resolution patterning with the versatility and simplicity of microcontact printing

    Differences in gene expression and cytokine production by crystalline vs. amorphous silica in human lung epithelial cells

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    <p>Abstract</p> <p>Background</p> <p>Exposure to respirable crystalline silica particles, as opposed to amorphous silica, is associated with lung inflammation, pulmonary fibrosis (silicosis), and potentially with lung cancer. We used Affymetrix/GeneSifter microarray analysis to determine whether gene expression profiles differed in a human bronchial epithelial cell line (BEAS 2B) exposed to cristobalite vs. amorphous silica particles at non-toxic and equal surface areas (75 and 150 × 10<sup>6</sup>μm<sup>2</sup>/cm<sup>2</sup>). Bio-Plex analysis was also used to determine profiles of secreted cytokines and chemokines in response to both particles. Finally, primary human bronchial epithelial cells (NHBE) were used to comparatively assess silica particle-induced alterations in gene expression.</p> <p>Results</p> <p>Microarray analysis at 24 hours in BEAS 2B revealed 333 and 631 significant alterations in gene expression induced by cristobalite at low (75) and high (150 × 10<sup>6</sup>μm<sup>2</sup>/cm<sup>2</sup>) amounts, respectively (p < 0.05/cut off ≥ 2.0-fold change). Exposure to amorphous silica micro-particles at high amounts (150 × 10<sup>6</sup>μm<sup>2</sup>/cm<sup>2</sup>) induced 108 significant gene changes. Bio-Plex analysis of 27 human cytokines and chemokines revealed 9 secreted mediators (p < 0.05) induced by crystalline silica, but none were induced by amorphous silica. QRT-PCR revealed that cristobalite selectively up-regulated stress-related genes and cytokines (<it>FOS, ATF3, IL6 </it>and <it>IL8</it>) early and over time (2, 4, 8, and 24 h). Patterns of gene expression in NHBE cells were similar overall to BEAS 2B cells. At 75 × 10<sup>6</sup>μm<sup>2</sup>/cm<sup>2</sup>, there were 339 significant alterations in gene expression induced by cristobalite and 42 by amorphous silica. Comparison of genes in response to cristobalite (75 × 10<sup>6</sup>μm<sup>2</sup>/cm<sup>2</sup>) revealed 60 common, significant gene alterations in NHBE and BEAS 2B cells.</p> <p>Conclusions</p> <p>Cristobalite silica, as compared to synthetic amorphous silica particles at equal surface area concentrations, had comparable effects on the viability of human bronchial epithelial cells. However, effects on gene expression, as well as secretion of cytokines and chemokines, drastically differed, as the crystalline silica induced more intense responses. Our studies indicate that toxicological testing of particulates by surveying viability and/or metabolic activity is insufficient to predict their pathogenicity. Moreover, they show that acute responses of the lung epithelium, including up-regulation of genes linked to inflammation, oxidative stress, and proliferation, as well as secretion of inflammatory and proliferative mediators, can be indicative of pathologic potential using either immortalized lines (BEAS 2B) or primary cells (NHBE). Assessment of the degree and magnitude of these responses <it>in vitro </it>are suggested as predictive in determining the pathogenicity of potentially harmful particulates.</p

    Interexaminer Agreement and Reliability of an Internationally Endorsed Screening Framework for Cervical Vascular Risks Following Manual Therapy and Exercise:The Go4Safe Project

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    Objective: Clinicians are recommended to use the clinical reasoning framework developed by the International Federation of Orthopaedic Manipulative Physical Therapists (IFOMPT) to provide guidance regarding assessment of the cervical spine and potential for cervical artery dysfunction prior to manual therapy and exercise. However, the interexaminer agreement and reliability of this framework is unknown. This study aimed to estimate the interexaminer agreement and reliability of the IFOMPT framework among physical therapists in primary care. Methods: Ninety-six patients who consulted a physical therapist for neck pain or headache were included in the study. Each patient was tested independently by 2 physical therapists, from a group of 17 physical therapists (10 pairs) across The Netherlands. Patients and examiners were blinded to the test results. The overall interexaminer agreement, specific agreement per risk category (high-, intermediate-, and low-risk), and interexaminer reliability (weighted κ) were calculated. Results: Overall agreement was 71% (specific agreement in high-risk category = 63%; specific agreement in intermediate-risk category = 38%; specific agreement in low-risk category = 84%). Overall reliability was moderate (weighted κ = 0.39; 95% CI = 0.21-0.57) and varied considerably between pairs of physical therapists (κ = 0.14-1.00). Conclusion: The IFOMPT framework showed an insufficient interexaminer agreement and fair interexaminer reliability among physical therapists when screening the increased risks for vascular complications following manual therapy and exercise prior to treatment. Impact: The IFOMPT framework contributes to the safety of manual therapy and exercise. It is widely adopted in clinical practice and educational programs, but the measurement properties are unknown. This project describes the agreement and reliability of the IFOMPT framework
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