Mechanism of droplet-formation in a supersonic microfluidic spray device

Spray drying is an approach employed in automotive, food, and pharmaceutical industries as a robust and cost efficient liquid atomization technique offering direct control over droplet dimensions. The majority of commercially available spray nozzles are designed for large throughput spray drying applications or uniform surface coating, but microfluidic nebulizers have recently been developed as small scale alternatives. Here, we explore the physical parameters that define the droplet size and formation under supersonic flow conditions commonly found in microfluidic spray drying systems. We examined the spray nozzle operation using high speed imaging and laser scattering measurements, which allowed us to describe the spray regimes and droplet size distributions. It was determined that by using this spray nozzle device, droplets with diameters of 4–8 μm could be generated. Moreover, we show that the supersonic de Laval nozzle model can be used to predict the average droplet size. Our approach can be used as a platform for interfacing fluid microprocessing with gas phase detection and characterization

Quantifying Measurement Fluctuations from Stochastic Surface Processes on Sensors with Heterogeneous Sensitivity

Recent advances in micro- and nanotechnology have enabled the development of ultrasensitive sensors capable of detecting small numbers of species. In general, however, the response induced by the random adsorption of a small number of objects onto the surface of such sensors results in significant fluctuations due to the heterogeneous sensitivity inherent to many such sensors coupled to statistical fluctuations in the particle number. At present, this issue is addressed by considering either the limit of very large numbers of analytes, where fluctuations vanish, or the converse limit, where the sensor response is governed by individual analytes. Many cases of practical interest, however, fall between these two limits and remain challenging to analyze. Here, we address this limitation by deriving a general theoretical framework for quantifying measurement variations on mechanical resonators resulting from statistical-number fluctuations of analyte species. Our results provide insights into the stochastic processes in the sensing environment and offer opportunities to improve the performance of mechanical-resonator-based sensors. This metric can be used, among others, to aid in the design of robust sensor platforms to reach ultrahigh-resolution measurements using an array of sensors. These concepts, illustrated here in the context of biosensing, are general and can therefore be adapted and extended to other sensors with heterogeneous sensitivity.We acknowledge funding from the W. D. Armstrong fund, Biotechnology and Biological Sciences Research Council, Newman Foundation, St. John’s College–University of Cambridge, and European Research Council.This is the author accepted manuscript. The final version is available from the American Physical Society via http://dx.doi.org/10.1103/PhysRevApplied.5.06401

Gastric aspiration, epithelial injury and chronic lung allograft rejection

Introduction For patients with a variety of end stage lung diseases, lung transplantation has become an effective therapy. Chronic allograft rejection occurs in over 50% of patients 5 years post transplantation however. Although alloimmune-mediated injury directed against endothelial and epithelial structures were traditionally thought to be the major culprit, non-alloimmunologic inflammation after bile acid aspiration has been implicated in cystic fibrosis (CF) lung injury, after transplantation. Hypothesis Reflux with aspiration of bile acid is present in the lower airways of people with cystic fibrosis associated lung injury before and after transplantation. Bile acid challenge would cause cytoxicity and release of inflammatory mediators from patient derived primary epithelial cells (PBECs), before and after transplantation. Methods PBECs from lung transplantation patients, explanted CF patient cultures and a goblet cell line were used to perform proof of concept experiments. In these experiments the effect of individual primary and secondary bile acids, porcine pepsin, different patient derived gastric juices (whole or filtered and dialysed) samples and an artificial bile acid mixture were evaluated. Cell death, Interleukin 8 (IL-8), Interleukin 6 (IL-6) and Granulocyte Macrophage Colony Stumulating Factor (GMCSF) production were measured by Titer blue and multiplex ELISA. Results Epithelial cells can be cultured successfully from the bronchial brushings of lung transplant recipient, CF patient explanted lungs and a Goblet cell line. In work connected with this study my research group has demonstrated that the lungs of people with advanced CF lung disease removed at the time of transplantation contained significant levels of bile acids higher than expected based on normal serum levels. I therefore tested the effects of bile acids on PBECs from lung transplant and CF patients. Challengesof ≥10mol/l was associated with significant cell death. Potentially physiological challenges with 1, 5 and 10 mol/l bile acids led to a significant release of pro-neutrophilic cytokines from lung transplant PBECs and CF PBECs .The goblet cell line HT-29 MTX was resistant to bile acids. Conclusion Aspiration of bile acids in CF lungs before and after transplantation may cause cell damage and inflammation. This injury may benefit from medical and surgical treatments for reflux, which may benefit the lung allograft generally.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Fracture driven by a Thermal Gradient

Motivated by recent experiments by Yuse and Sano (Nature, 362, 329 (1993)), we propose a discrete model of linear springs for studying fracture in thin and elastically isotropic brittle films. The method enables us to draw a map of the stresses in the material. Cracks generated by the model, imposing a moving thermal gradient in the material, can branch or wiggle depending on the driving parameters. The results may be used to compare with other recent theoretical work, or to design future experiments.Comment: RevTeX file (9 pages) and 5 postscript figure

Coexistence and conviviality in multi-faith, multi-ethnic Burgazadasi, the princes' islands of Istanbul

This thesis aims to provide an understanding of the existing cultural plurality and diversity in Burgazadası, within a post-Ottoman and homogenising context in Turkey. Most of the scholars working on conflict resolution and peace projects in the Balkans and the Middle East have attempted to analyse cultural plurality with the concept of “coexistence”. “Coexistence” as a concept presupposes the pre-existing categories of ethnicity, class and religion (i.e. coexistence between Israelis and Palestinians; Greek and Turkish Cypriots; Serbs, Croats and Bosnians). In this thesis, I demonstrate the inadequacy of the concept of “coexistence” and propose a “conviviality” approach to explore cultural pluralism. In the post-Ottoman, Turkish context in Burgaz, “coexistence” can be used when describing the homogenisation process, the construction and perception of categorisations of differences, the crystallisation of ethnic and religious identities and ruptures to cultural pluralism; but it is deficient in describing the continuity of cultural pluralism and what is shared between the members of the community in Burgaz. By contrast, “conviviality” provides an understanding of the continuity of cultural pluralism in Burgaz, the changes in sociality patterns, shared ways of living, the diversity and differentiations within “different groups”, the islanders' sense of belonging in Burgaz, their appreciation of diversity and acts of solidarity at the times of crisis. I argue that the homogenisation process in Turkey brought ruptures in cultural pluralism in Turkey, and changed the demographics in Burgaz; however the homogenisation process did not rupture the conviviality on the island and Burgazian identity which embraces all types of diversities of its inhabitants. At times of crisis, like in September 1955 riots, Burgaz islanders emphasised their shared Burgaz identity which overrode religious, class and ethnic differencesEThOS - Electronic Theses Online ServiceGBUnited Kingdo

Scalable Synthesis of Few-Layered 2D Tungsten Diselenide (2H-WSe2) Nanosheets Directly Grown on Tungsten (W) Foil Using Ambient-Pressure Chemical Vapor Deposition for Reversible Li-Ion Storage

We report a facile two-furnace APCVD synthesis of 2H-WSe2. A systematic study of the process parameters is performed to show the formation of the phase-pure material. Extensive characterization of the bulk and exfoliated material confirm that 2H-WSe2 is layered (i.e., 2D). X-ray diffraction (XRD) confirms the phase, while high-resolution scanning electron microscopy (HRSEM), high-resolution transmission electron microscopy (HRTEM), and atomic force microscopy (AFM) clarify the morphology of the material. Focused ion beam scanning electron microscopy (FIB-SEM) estimates the depth of the 2H-WSe2 formed on W foil to be around 5-8 μm, and Raman/UV-vis measurements prove the quality of the exfoliated 2H-WSe2. Studies on the redox processes of lithium-ion batteries (LiBs) show an increase in capacity up to 500 cycles. On prolonged cycling, the discharge capacity up to the 50th cycle at 250 mA/g of the material shows a stable value of 550 mAh/g. These observations indicate that exfoliated 2H-WSe2 has promising applications as an LiB electrode material

Resolving protein mixtures using microfluidic diffusional sizing combined with synchrotron radiation circular dichroism

Circular dichroism spectroscopy has become a powerful tool to characterise proteins and other biomolecules. For heterogeneous samples such as those present for interacting proteins, typically only average spectroscopic features can be resolved. Here we overcome this limitation by using free-flow microfluidic size separation in-line with synchrotron radiation circular dichroism to resolve the secondary structure of each component of a model protein mixture containing monomers and fibrils. To enable this objective, we have integrated far-UV compatible measurement chambers into PDMS-based microfluidic devices. Two architectures are proposed so as to accommodate for a wide range of concentrations. The approach, which can be used in combination with other bulk measurement techniques, paves the way to the study of complex mixtures such as the ones associated with protein misfolding and aggregation diseases including Alzheimer’s and Parkinson’s diseases

Evolutionary relationships between Rhynchosporium lolii sp. nov. and other Rhynchosporium species on grass.

Copyright: 2013 King et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are creditedThe fungal genus Rhynchosporium (causative agent of leaf blotch) contains several host-specialised species, including R. commune (colonising barley and brome-grass), R. agropyri (couch-grass), R. secalis (rye and triticale) and the more distantly related R. orthosporum (cocksfoot). This study used molecular fingerprinting, multilocus DNA sequence data, conidial morphology, host range tests and scanning electron microscopy to investigate the relationship between Rhynchosporium species on ryegrasses, both economically important forage grasses and common wild grasses in many cereal growing areas, and other plant species. Two different types of Rhynchosporium were found on ryegrasses in the UK. Firstly, there were isolates of R. commune that were pathogenic to both barley and Italian ryegrass. Secondly, there were isolates of a new species, here named R. lolii, that were pathogenic only to ryegrass species. R. lolii was most closely related to R. orthosporum, but exhibited clear molecular, morphological and host range differences. The species was estimated to have diverged from R. orthosporum ca. 5735 years before the present. The colonisation strategy of all of the different Rhynchosporium species involved extensive hyphal growth in the sub-cuticular regions of the leaves. Finally, new species-specific PCR diagnostic tests were developed that could distinguish between these five closely related Rhynchosporium species.Peer reviewedFinal Published versio

Genome-wide association study on coronary artery disease in type 1 diabetes suggests beta-defensin 127 as a risk locus

Aims Diabetes is a known risk factor for coronary artery disease (CAD). There is accumulating evidence that CAD pathogenesis differs for individuals with type 1 diabetes (T1D). However, the genetic background has not been extensively studied. We aimed to discover genetic loci increasing CAD susceptibility, especially in T1D, to examine the function of these discoveries and to study the role of the known risk loci in T1D. Methods and results We performed the largest genome-wide association study to date for CAD in T1D, comprising 4869 individuals with T1D (cases/controls: 941/3928). Two loci reached genome-wide significance, rs1970112 in CDKN2B-AS1 [odds ratio (OR) =1.32, P = 1.50 x 10(-8)], and rs6055069 on DEFB127 promoter (OR= 4.17, P= 2.35 x 10(-9)), with consistent results in survival analysis. The CDKN2B-AS1 variant replicated (P = 0.04) when adjusted for diabetic kidney disease in three additional T1D cohorts (cases/controls: 434/3123). Furthermore, we explored the function of the lead discoveries with a cardio-phenome-wide analysis. Among the eight suggestive loci (P <1 x 10(-6)), rs70962766 near B3GNT2 associated with central blood pressure, rs1344228 near CNTNAP5 with intima media thickness, and rs2112481 on GRAMD2B promoter with serum leucocyte concentration. Finally, we calculated genetic risk scores for individuals with T1D with the known susceptibility loci. General population risk variants were modestly but significantly associated with CAD also in T1D (P=4.21 x 10(-7)). Conclusion While general population CAD risk loci had limited effect on the risk in T1D, for the first time, variants at the CDKN2B-AS1 locus were robustly associated with CAD in individuals with T1D. The novel finding on beta-defensin DEFB127 promoter provides a link between diabetes, infection susceptibility, and CAD, although pending on future confirmation. [GRAPHICS] .Peer reviewe

Structure and expression analysis of rice paleo duplications

Having a well-known history of genome duplication, rice is a good model for studying structural and functional evolution of paleo duplications. Improved sequence alignment criteria were used to characterize 10 major chromosome-to-chromosome duplication relationships associated with 1440 paralogous pairs, covering 47.8% of the rice genome, with 12.6% of genes that are conserved within sister blocks. Using a micro-array experiment, a genome-wide expression map has been produced, in which 2382 genes show significant differences of expression in root, leaf and grain. By integrating both structural (1440 paralogous pairs) and functional information (2382 differentially expressed genes), we identified 115 paralogous gene pairs for which at least one copy is differentially expressed in one of the three tissues. A vast majority of the 115 paralogous gene pairs have been neofunctionalized or subfunctionalized as 88%, 89% and 96% of duplicates, respectively, expressed in grain, leaf and root show distinct expression patterns. On the basis of a Gene Ontology analysis, we have identified and characterized the gene families that have been structurally and functionally preferentially retained in the duplication showing that the vast majority (>85%) of duplicated have been either lost or have been subfunctionalized or neofunctionalized during 50–70 million years of evolution