Optical assessment of gel-like mechanical and structural properties of surface layers: single particle tracking and molecular rotors

This paper was presented at the 4th Micro and Nano Flows Conference (MNF2014), which was held at University College, London, UK. The conference was organised by Brunel University and supported by the Italian Union of Thermofluiddynamics, IPEM, the Process Intensification Network, the Institution of Mechanical Engineers, the Heat Transfer Society, HEXAG - the Heat Exchange Action Group, and the Energy Institute, ASME Press, LCN London Centre for Nanotechnology, UCL University College London, UCL Engineering, the International NanoScience Community, www.nanopaprika.eu.Thin gel-like layers form at many surfaces of natural or artificial origin. Important properties of such layers include thickness, viscosity and density. Here we discuss two optical approaches which allow assessment of these properties with high resolution. The first approach relies on centroid calculation and defocus imaging based 3D tracking of fluorescent tracer particles, which is based on standard fluorescent microscopy and allows a precision of particle detection in the range of 10nm. The size of the particle and its surface charge and polarity will determine the particle invasion into the layer. Thus simultaneous application of different colored beads with different size and properties can reveal the thickness and nature of the layer. Via tracking the thermal vibration of particles invading the layer the bulk viscosity of the layer can be calculated. The second approach uses “molecular rotor” fluorophores (MR). Due to their molecular structure, the MR’s fluorescence quantum yield increases as their internal rotation is hampered by e.g. high viscosity of the embedding medium. The MRs are several orders of magnitude smaller than the structural (macro) molecules of a gel-like layer and therefore the MRs are not necessarily directly sensitive toward the bulk viscosity of the layer. In contrast, the MRs internal rotation will be attenuated by the MRs interaction with the structural elements of the layer or the solvent included in it. Depending on their molecular structure MRs exhibit different sensitivity to the mechanical properties of the large macromolecules or the solvent in a layer. Thus, they may be used to assess the microdomain’s viscosity or density in a surface layer. Using a ratiometric imaging approach, they can be used for continuous measurements in very different experimental settings

Conformity Between Ileoscopy Appearance with Terminal Ileum Histopathology Appearance in Normal Colonoscopy Chronic Diarrhea Patients

Background: Chronic diarrhea is one of the most common problem in gastroenterology cases. Ileoscopy is one of the modalities to determine the etiology of chronic diarrhea by normal colonoscopy appearance. Recently, there is still controversy in the need of this examination in normal macroscopic appearance. The aim of this study is to study the conformity of histopathology abnormalities with ileoscopy appearance in chronic diarrhea patients with normal colonoscopy.Methods: This study uses cross sectional study design by collecting 60 medical record data in several hospitals in Jakarta in the period of 1 January 2005 to 31 December 2011. Diagnostic test between ileoscopy and histopathology is performed by histopathology examination as a gold standard.Results: Study results revealed conformity between both examinations for 93.33%. Sensitivity value of ileoscopy examination compared to histopathology as a gold standard was 94%, specificity 90%, positive predictive value 97.9%, and negative predictive value 75%.Conclusion: Ileoscopy examination in chronic diarrhea patients and normal colonoscopy showed similar results with histopathology examination

National Consensus on the Use of Sedation Drugs in the Gastrointestinal Endoscopic Procedures

Gastrointestinal endoscopy is rapidly developing and several gastrointestinal endoscopy equipment are available for both diagnostic and therapeutic purposes. Proper sedation is critical in performing endoscopic procedures, both for patients and physicians. This consensus is used as a guideline and not as a legal standard in performing endoscopic services. This consensus explained the definition, indication, contraindication, and complication prevention during sedation. Factors affecting the need of sedation is patient factors, procedure factors, and sedation level. Diagnostic or therapeutic upper gastrointestinal tract endoscopy which not complicated can be performed with minimal sedation or moderate sedation, while deep sedation can be considered for longer and more complex procedures. Furthermore, assessment and selection of sedation was explained, followed by the guide to choose pharmacological sedation and analgesics. Currently, diazepam, midazolam, propofol, fentanyl, and pethidine is the most likely used sedation during gastrointestinal endoscopy, with midazolam as the preferred medication of choice. This consensus also explained the antidote of each drug and the recovery after procedure. This consensus aimed to improve gastrointestinal endoscopic procedure services in Indonesia

ELM induced divertor heat loads on TCV

Results are presented for heat loads at the TCV outer divertor target during ELMing H-mode using a fast IR camera. Benefitting from a recent surface cleaning of the entire first wall graphite armour, a comparison of the transient thermal response of freshly cleaned and untreated tile surfaces (coated with thick co-deposited layers) has been performed. The latter routinely exhibit temperature transients exceeding those of the clean ones by a factor ~3, even if co-deposition throughout the first days of operation following the cleaning process leads to the steady regrowth of thin layers. Filaments are occasionally observed during the ELM heat flux rise phase, showing a spatial structure consistent with energy release at discrete toroidal locations in the outer midplane vicinity and with individual filaments carrying ~1% of the total ELM energy. The temporal waveform of the ELM heat load is found to be in good agreement with the collisionless free streaming particle model

"Snowflake" H Mode in a Tokamak Plasma

An edge-localized mode (ELM) H-mode regime, supported by electron cyclotron heating, has been successfully established in a snowflake (second-order null) divertor configuration for the first time in the TCV tokamak. This regime exhibits 2 to 3 times lower ELM frequency and 20%30% increased normalized ELM energy ($Delta W_{ELM}/W_p$) compared to an identically shaped, conventional single-null diverted H mode. Enhanced stability of mid- to high-toroidal-mode-number ideal modes is consistent with the different snowflake ELM phenomenology. The capability of the snowflake to redistribute the edge power on the additional strike points has been confirmed experimentally

The rs13388259 Intergenic Polymorphism in the Genomic Context of the BCYRN1 Gene Is Associated with Parkinson’s Disease in the Hungarian Population

Parkinson's disease (PD) is a common neurodegenerative disorder characterized by bradykinesia, resting tremor, and muscle rigidity. To date, approximately 50 genes have been implicated in PD pathogenesis, including both Mendelian genes with rare mutations and low-penetrance genes with common polymorphisms. Previous studies of low-penetrance genes focused on protein-coding genes, and less attention was given to long noncoding RNAs (lncRNAs). In this study, we aimed to investigate the susceptibility roles of lncRNA gene polymorphisms in the development of PD. Therefore, polymorphisms (n = 15) of the PINK1-AS, UCHL1-AS, BCYRN1, SOX2-OT, ANRIL and HAR1A lncRNAs genes were genotyped in Hungarian PD patients (n = 160) and age- and sex-matched controls (n = 167). The rare allele of the rs13388259 intergenic polymorphism, located downstream of the BCYRN1 gene, was significantly more frequent among PD patients than control individuals (OR = 2.31; p = 0.0015). In silico prediction suggested that this polymorphism is located in a noncoding region close to the binding site of the transcription factor HNF4A, which is a central regulatory hub gene that has been shown to be upregulated in the peripheral blood of PD patients. The rs13388259 polymorphism may interfere with the binding affinity of transcription factor HNF4A, potentially resulting in abnormal expression of target genes, such as BCYRN1

Measurement of the CKM angle γ from a combination of B±→Dh± analyses

A combination of three LHCb measurements of the CKM angle γ is presented. The decays B±→D K± and B±→Dπ± are used, where D denotes an admixture of D0 and D0 mesons, decaying into K+K−, π+π−, K±π∓, K±π∓π±π∓, K0Sπ+π−, or K0S K+K− final states. All measurements use a dataset corresponding to 1.0 fb−1 of integrated luminosity. Combining results from B±→D K± decays alone a best-fit value of γ =72.0◦ is found, and confidence intervals are set γ ∈ [56.4,86.7]◦ at 68% CL, γ ∈ [42.6,99.6]◦ at 95% CL. The best-fit value of γ found from a combination of results from B±→Dπ± decays alone, is γ =18.9◦, and the confidence intervals γ ∈ [7.4,99.2]◦ ∪ [167.9,176.4]◦ at 68% CL are set, without constraint at 95% CL. The combination of results from B± → D K± and B± → Dπ± decays gives a best-fit value of γ =72.6◦ and the confidence intervals γ ∈ [55.4,82.3]◦ at 68% CL, γ ∈ [40.2,92.7]◦ at 95% CL are set. All values are expressed modulo 180◦, and are obtained taking into account the effect of D0–D0 mixing