Characterization of the Polishing‐Induced Contamination of Fused Silica Optics

In this work, the polishing‐induced contamination layer at the fused silica optics surface was studied with various interface analysis techniques: Secondary Ion Mass Spectroscopy (SIMS), Electron Probe Microanalysis (EPMA), X‐Ray Photoelectron Spectroscopy (XPS), and Inductively Coupled Plasma—Optical Emission Spectroscopy (ICP‐OES). Samples were prepared using an MRF polishing machine and cerium‐based slurry. The cerium and iron penetration and concentration were measured in the surface out of defects. Cerium is embedded at the surface in a 60 nm layer and concentrated at 1200 ppmw in this layer while iron concentration falls down at 30 nm. Spatial distribution and homogeneity of the pollution were also studied in the scratches and bevel using SIMS and EPMA techniques. We saw evidence that surface defects, such as scratches, are specific places that hold the pollutants. This overconcentration is also observed in the chamfer. These new insights into the polishing‐induced contamination of fused silica optics and it repartition have been obtained using various characterization methods. Advantages and disadvantages of each one are discussed.     

Effects of urban coarse particles inhalation on oxidative and inflammatory parameters in the mouse lung and colon

Background

Air pollution is a recognized aggravating factor for pulmonary diseases and has notably deleterious effects on asthma, bronchitis and pneumonia. Recent studies suggest that air pollution may also cause adverse effects in the gastrointestinal tract. Accumulating experimental evidence shows that immune responses in the pulmonary and intestinal mucosae are closely interrelated, and that gut-lung crosstalk controls pathophysiological processes such as responses to cigarette smoke and influenza virus infection. Our first aim was to collect urban coarse particulate matter (PM) and to characterize them for elemental content, gastric bioaccessibility, and oxidative potential; our second aim was to determine the short-term effects of urban coarse PM inhalation on pulmonary and colonic mucosae in mice, and to test the hypothesis that the well-known antioxidant N-acetyl-L-cysteine (NAC) reverses the effects of PM inhalation.

Results

The collected PM had classical features of urban particles and possessed oxidative potential partly attributable to their metal fraction. Bioaccessibility study confirmed the high solubility of some metals at the gastric level. Male mice were exposed to urban coarse PM in a ventilated inhalation chamber for 15 days at a concentration relevant to episodic elevation peak of air pollution. Coarse PM inhalation induced systemic oxidative stress, recruited immune cells to the lung, and increased cytokine levels in the lung and colon. Concomitant oral administration of NAC reversed all the observed effects relative to the inhalation of coarse PM.

Conclusions

Coarse PM-induced low-grade inflammation in the lung and colon is mediated by oxidative stress and deserves more investigation as potentiating factor for inflammatory diseases.

     

Mass Spectrometry-Based Proteomics Reveal Alcohol Dehydrogenase 1B as a Blood Biomarker Candidate to Monitor Acetaminophen-Induced Liver Injury

Acute liver injury (ALI) is a severe disorder resulting from excessive hepatocyte cell death, and frequently caused by acetaminophen intoxication. Clinical management of ALI progression is hampered by the dearth of blood biomarkers available. In this study, a bioinformatics workflow was developed to screen omics databases and identify potential biomarkers for hepatocyte cell death. Then, discovery proteomics was harnessed to select from among these candidates those that were specifically detected in the blood of acetaminophen-induced ALI patients. Among these candidates, the isoenzyme alcohol dehydrogenase 1B (ADH1B) was massively leaked into the blood. To evaluate ADH1B, we developed a targeted proteomics assay and quantified ADH1B in serum samples collected at different times from 17 patients admitted for acetaminophen-induced ALI. Serum ADH1B concentrations increased markedly during the acute phase of the disease, and dropped to undetectable levels during recovery. In contrast to alanine aminotransferase activity, the rapid drop in circulating ADH1B concentrations was followed by an improvement in the international normalized ratio (INR) within 10–48 h, and was associated with favorable outcomes. In conclusion, the combination of omics data exploration and proteomics revealed ADH1B as a new blood biomarker candidate that could be useful for the monitoring of acetaminophen-induced ALI.     

Replication of liner collapse phenomenon observed in hyperbaric type IV hydrogen storage vessel by explosive decompression experiments

An experimental design based on representative sample is described in order to reproduce the detachment and deformation of the inner polymer layer (called liner) of hyperbaric hydrogen storage vessels during the emptying step. It is the first step of a better understanding of the mechanisms involved in the creation of a liner collapse. Results showed that a hydraulic testing machine fitted with a pressure hydrogen chamber enables to create a liner collapse on small samples by explosive decompression experiments. Tomographic observations have revealed that the collapse appears at the polymer liner/composite interface in areas that are not sufficiently bonded, nor consistently. Determination of liner collapse amplitudes, assessed by tomography, has underlined that, under some specific conditions, the deformation of the liner is permanent even when hydrogen has completely desorbed from the sample. In addition to liner collapses, composite cracks were also highlighted.     

Selectively Promoting or Preventing Osteoblast Growth on Titanium Functionalized with Polyelectrolyte Multilayers

Titanium plays an important role in medical applications, such as hip joint implants or fixation plates. These implants must perform differently depending on their clinical application. In particular, the osseointegrative properties required of the implant vary with clinical application. The present work is aimed at the functionalization of titanium surface using polyelectrolyte multilayers consisting of natural biopolymers and testing their cell adhesive properties with respect to the osseointegration capacity. Multilayered coatings were created from chitosan (Chi), hyaluronic acid (HA), and gelatine (Gel) through layer‐by‐layer deposition. Cell adhesion, proliferation, and viability were tested in vitro with the human osteoblast cell line CAL‐72 at timescales up to 7 d. Two multilayer coatings consisting of alternated chitosan/gelatin or chitosan/hyaluronic acid layers with the outmost layer of gelatin (Chi/Gel) or hyaluronic acid (Chi/HA), respectively, were tested. The experimental results showed that surfaces functionalized with Chi/Gel and Chi/HA multilayers demonstrated a good initial adhesion of osteoblasts. After 4 d culturing, osteoblast cells were almost completely detached from the substrates functionalized with Chi/HA multilayers. In contrast to Chi/HA, the proliferation of osteoblasts on substrates with Chi/Gel multilayer coatings was statistically significantly higher compared to the control titanium. We have shown that the growth of osteoblasts can be enhanced or completely prevented on a titanium surface functionalized with polyelectrolyte multilayers consisting of natural biopolymers, as desired. Both multilayer coatings, Chi/Gel and Chi/HA, have potential for applications in the field of titanium implants, where rapid osseointegration is essential, and/or where no ingrowth of the implant is desired, respectively.     

Fruit load or fruit position alters response to temperature and subsequently cherry tomato quality

Changes in fruit–source ratio during the growth and maturation of cherry tomato fruits were studied in combination with increased fruit temperature. Six treatments were compared: the presence or absence of local heating combined with different fruit origins (7P, fruit from trusses pruned to seven flowers; 14P, proximal fruits; 14D, distal fruits from trusses pruned to 14 flowers). 7P were less sensitive to heating whereas 14P and 14D showed greater reduction in water and dry matter (DM) content. Distal fruits had the lowest structural DM (sDM), which could be due to a lower fruit cell number. Heating further decreased the sDM, so that fruit sink size was the lowest for distal fruits subjected to heating. Under low competition (7P), heating had a beneficial effect on sugar and lycopene content, whereas acids, β‐carotene and vitamin C content were reduced. Under high competition (14P, 14D), heating increased the ratio sDM–DM. This was mainly due to the reduced content of sugars and acids, but also to the reduced accumulation of secondary metabolites such as vitamin C, β‐carotene and lycopene. This study underlines the interactions between fruit temperature and the fruit–source ratio and the consequences for fruit composition and nutritional quality. Copyright © 2005 Society of Chemical Industry     

Nanoporous materials from stable and metastable structures of 1,2-PB-b-PDMS block copolymers

Experimental procedures used at the preparation and characterization stages of nanoporous materials (NPM) from 1,2-polybutadiene-b-polydimethylsiloxane (1,2-PB-b-PDMS) block copolymers are presented. The NPM were obtained from self-assembled block copolymers after firstly cross-linking 1,2-PB (the matrix component) and secondly degrading PDMS (the expendable component). Depending on the temperature of the cross-linking reaction different morphologies can be ‘frozen’ from the same block copolymer. Starting with a block copolymer precursor of lamellar morphology at room temperature, the gyroid structure or a metastable structure showing hexagonal symmetry (probably HPL) were permanently captured by cross-linking the precursor at 140 °C or at 85 °C, respectively. PDMS was degraded by reaction with tetrabutylamonium fluoride; considerations on the mechanism of cleaving reaction are presented. The characterization of the materials at different stages of preparation includes gravimetry, infrared spectroscopy, small angle x-ray scattering, electron microscopy and isothermal nitrogen adsorption experiments.     

Short‐Wave Infrared Sensor by the Photothermal Effect of Colloidal Gold Nanorods

Photodetection in the short‐wave infrared (SWIR) spectrum is a challenging task achieved often by costly low bandgap compound semiconductors involving highly toxic elements. In this work, an alternative low‐cost approach is reported for SWIR sensors that rely on the plasmonic‐induced photothermal effect of solution‐processed colloidal gold nanorods (Au NRs). A series of uniform solution‐processed Au NRs of various aspect ratios are prepared exhibiting a strong and well‐defined longitudinal localized surface plasmon resonance (L‐LSPR) maximum from 900 nm to 1.3 µm. A hybrid device structure is fabricated by applying Au NRs on the surface of a thermistor. Under a monochromatic illumination, hybrid Au‐NR/thermistor devices exhibit a clear photoresponse in the form of photoinduced resistance drop in the wavelength window from 1.0 to 1.8 µm. The photoresponsivity of such hybrid devices reaches a maximum value of 4.44 × 10⁷ Ω W^?1 at λ = 1.4 µm (intensity = 0.28 mW cm^?2), a wavelength in agreement with the L‐LSPR of the Au NRs applied. Colloidal Au NRs, capable to perform fast conversion between photon absorption and thermal energy, thus open an interesting avenue for alternative low‐cost SWIR photodetection.     

Design,Synthesis and Evaluation of a Series of 1,5-Diaryl-1,2,3-triazole-4-carbohydrazones as Inhibitors of the YAP-TAZ/TEAD Complex

Starting from our previously reported hit, a series of 1,5-diaryl-1,2,3-triazole-4-carbohydrazones were synthesized and evaluated as inhibitors of the YAP/TAZ-TEAD complex. Their binding to hTEAD2 was confirmed by nanodifferential scanning fluorimetry, and some of the compounds were also found to moderately disrupt the YAP-TEAD interaction, as assessed by a fluorescence polarization assay. A TEAD luciferase gene reporter assay performed in HEK293T cells and RTqPCR measurements in MDA-MB231 cells showed that these compounds inhibit YAP/TAZ-TEAD activity to cells in the micromolar range. In spite of the cytotoxic effects displayed by some of the compounds of this series, they are still good starting points and can be suitably modified into an effective and viable YAP-TEAD disruptor in the future.