Interdependent Regulation of Polycystin Expression Influences Starvation-Induced Autophagy and Cell Death

Autosomal dominant polycystic kidney disease (ADPKD) is mainly caused by deficiency of polycystin-1 (PC1) or polycystin-2 (PC2). Altered autophagy has recently been implicated in ADPKD progression, but its exact regulation by PC1 and PC2 remains unclear. We therefore investigated cell death and survival during nutritional stress in mouse inner medullary collecting duct cells (mIMCDs), either wild-type (WT) or lacking PC1 (PC1KO) or PC2 (PC2KO), and human urine-derived proximal tubular epithelial cells (PTEC) from early-stage ADPKD patients with PC1 mutations versus healthy individuals. Basal autophagy was enhanced in PC1-deficient cells. Similarly, following starvation, autophagy was enhanced and cell death reduced when PC1 was reduced. Autophagy inhibition reduced cell death resistance in PC1KO mIMCDs to the WT level, implying that PC1 promotes autophagic cell survival. Although PC2 expression was increased in PC1KO mIMCDs, PC2 knockdown did not result in reduced autophagy. PC2KO mIMCDs displayed lower basal autophagy, but more autophagy and less cell death following chronic starvation. This could be reversed by overexpression of PC1 in PC2KO. Together, these findings indicate that PC1 levels are partially coupled to PC2 expression, and determine the transition from renal cell survival to death, leading to enhanced survival of ADPKD cells during nutritional stress.     

Evaluating demand response opportunities for power systems resilience using MILP and MINLP Formulations

While peak shaving is commonly used to reduce power costs, chemical process facilities that can reduce power consumption on demand during emergencies (e.g., extreme weather events) bring additional value through improved resilience. For process facilities to effectively negotiate demand response (DR) contracts and make investment decisions regarding flexibility, they need to quantify their additional value to the grid. We present a grid-centric mixed-integer stochastic programming framework to determine the value of DR for improving grid resilience in place of capital investments that can be cost prohibitive for system operators. We formulate problems using both a linear approximation and a nonlinear alternating current power flow model. Our numerical results with both models demonstrate that DR can be used to reduce the capital investment necessary for resilience, increasing the value that chemical process facilities bring through DR. However, the linearized model often underestimates the amount of DR needed in our case studies. Published 2018. This article is a U.S. Government work and is in the public domain in the USA. AIChE J, 65: e16508, 2019     

Modelling of solid formation by heterogeneous reactions through a multicomponent transport model of diluted ionic species: Simulation of barite fouling in a geothermal heat exchanger

A general model is proposed in order to describe the growth of a deposit by heterogeneous reactions. The hydrodynamics in the fluid is described by a multicomponent transport model for ionic species diluted in a solvent and heat transfer is taken into account in both liquid and solid domains. The boundary condition at the interface where the reaction takes place is described thoroughly. It involves the reaction kinetics and gives access to the velocity of the interface, ie, the mass rate of the solid deposit. The model is then applied to the case of barite crystallization in a heat exchanger. The liquid phase is therefore composed of two ionic species Ba²⁺ and SO₄²⁻ diluted in water. The solid phase is modelled as a homogeneous barite deposit. The fully dynamic CFD simulation of the model is made using Comsol Multiphysics, in a cylindrical pipe. The solid growth is analyzed over time and space in terms of the relevant variables of the model.     

Conductive-probe atomic force microscopy characterization of silicon nanowire

The electrical conduction properties of lateral and vertical silicon nanowires (SiNWs) were investigated using a conductive-probe atomic force microscopy (AFM). Horizontal SiNWs, which were synthesized by the in-plane solid-liquid-solid technique, are randomly deployed into an undoped hydrogenated amorphous silicon layer. Local current mapping shows that the wires have internal microstructures. The local current-voltage measurements on these horizontal wires reveal a power law behavior indicating several transport regimes based on space-charge limited conduction which can be assisted by traps in the high-bias regime (> 1 V). Vertical phosphorus-doped SiNWs were grown by chemical vapor deposition using a gold catalyst-driving vapor-liquid-solid process on higly n-type silicon substrates. The effect of phosphorus doping on the local contact resistance between the AFM tip and the SiNW was put in evidence, and the SiNWs resistivity was estimated.     

Synthesis and Surface-Active Properties of Uronic Amide Derivatives,Surfactants from Renewable Organic Raw Materials

Short chemical syntheses were developed to produce a new set of surfactants from uronic acids derived from widely available raw materials. Three different strategies were used to synthesize uronic amide derivatives, the structures of which were totally characterized by spectrometric methods (IR, MS, ¹H-RMN and ¹³C-RMN). The best one, using an acid chloride as the synthetic intermediate, furnished the expected amides as a mixture of anomers in 46–58% global yield. Surface-active properties (CMC, γ_cmc, Γ_max, A _min) of homologous series of uronic acid N-alkylamides from C8 to C18 were also assessed. In general, these sugar-based surfactants exhibited good surface-activities, and appeared as valuable nonionic surfactants compared to octylphenol 9–10 ethylene oxide condensate, the most well-known nonionic surfactant. Increasing the alkyl chain length influenced the CMC values for both glucuronic and galacturonic N-alkylamide derivatives. The galacturonic N-alkylamides decreased γ_cmc at slower values than their counterpart’s glucuronic N-alkylamides.     

Peptide-grafted nanodiamonds: preparation, cytotoxicity and uptake in cells

Nanodiamonds that were prepared by high pressure/high temperature were functionalized with biomolecules for biological applications. Nanodiamonds (NDs, < or =35 nm) that were coated by silanization or with polyelectrolyte layers were grafted with a fluorescent thiolated peptide via a maleimido function; this led to an aqueous colloidal suspension that was stable for months. These substituted NDs were not cytotoxic for CHO cells. Their capacity to enter mammalian cells, and their localisation inside were ascertained after labelling the nucleus and actin, by examining the cells by confocal, reflected light and fluorescence microscopy.     

Possible Role of Circulating Bone Marrow Mesenchymal Progenitors in Modulating Inflammation and Promoting Wound Repair

Circulating bone marrow mesenchymal progenitors (BMMPs) are known to be potent antigen-presenting cells that migrate to damaged tissue to secrete cytokines and growth factors. An altered or dysregulated inflammatory cascade leads to a poor healing outcome. A skin model developed in our previous study was used to observe the immuno-modulatory properties of circulating BMMP cells in inflammatory chronic wounds in a scenario of low skin perfusion. BMMPs were analysed exclusively and in conjunction with recombinant tumour necrosis factor alpha (TNFα) and recombinant hepatocyte growth factor (HGF) supplementation. We analysed the expression levels of interleukin-8 (IL-8) and ecto-5′-nucleotidase (CD73), together with protein levels for IL-8, stem cell factor (SCF), and fibroblast growth factor 1 (FGF-1). The successfully isolated BMMPs were positive for both hemopoietic and mesenchymal markers and showed the ability to differentiate into adipocytes, chondrocytes, and osteocytes. Significant differences were found in IL-8 and CD73 expressions and IL-8 and SCF concentrations, for all conditions studied over the three time points taken into consideration. Our data suggests that BMMPs may modulate the inflammatory response by regulating IL-8 and CD73 and influencing IL-8 and SCF protein secretions. In conclusion, we suggest that BMMPs play a role in wound repair and that their induced application might be suitable for scenarios with a low skin perfusion.     

Characterisation and behaviour of Ti/TiO2/noble metal anodes

The morphology, composition and the electrical and electrochemical behaviour of the anodic microporous layer, prepared by the galvanostatic anodisation of Ti after sparking, followed by galvanostatic deposition of Pt or Ir have been investigated. These electrodes are proposed to function as dimensionally stable anodes (DSAs). For Ti/TiO₂/Pt electrodes, Pt is deposited within some of the micropores of the oxide film. In contrast, for Ti/TiO₂/Ir, the metal is deposited preferentially on the top surface. This difference is thought to result from the position of the metal deposition potential with respect to the flat band potential of n-TiO₂. Optical imaging of both types of DSA suggests that only a few sites on the surface are responsible for electron exchange at the DSA-electrolyte interface. C-AFM measurements of Ti/TiO₂/Pt samples subjected to long-term anodic polarisation, suggest that the Ti-noble metal contact is progressively insulated by thickening of the TiO₂ barrier layer, promoting passivation of the DSA. For Ir coated anodes, catalytic activity is directly related to the presence of Ir and to the stability of the catalytic oxide layer. Under Cu electrowinning conditions, the electrochemically formed hydrated Ir oxide was found to be catalytically less stable, than the iridium oxide film subjected to a heat treatment.     

Functionalized carbon nanotubes are non-cytotoxic and preserve the functionality of primary immune cells

Carbon nanotubes are emerging as innovative tools in nanobiotechnology. However, their toxic effects on environment and health have become an issue of strong concern. In the present study, we address the impact of functionalized carbon nanotubes (f-CNTs) on cells of the immune system. We have prepared two types of f-CNTs, following the 1,3-dipolar cycloaddition reaction (f-CNTs 1 and 2) and the oxidation/amidation treatment (f-CNTs 3 and 4), respectively. We have found that both types of f-CNTs are uptaken by B and T lymphocytes as well as macrophages in vitro, without affecting cell viability. Subsequently, the functionality of the different cells was analyzed carefully. We discovered that f-CNT 1, which is highly water soluble, did not influence the functional activity of immunoregulatory cells. f-CNT 3, which instead possesses reduced solubility and forms mainly stable water suspensions, preserved lymphocytes' functionality while provoking secretion of proinflammatory cytokines by macrophages.     

The autochrome process

Abstract

The autochrome was the first successful commercial colour process. It was invented by Louis and Auguste Lumiere at the tum of the century, patented in 1903 and produced until the 1950s on a sheet film called ‘Filmcolor’. Many articles were published between 1903 when the autochrome process was unveiled to the public, and 1935 when the decline of the screen process began and the first colour films with chromogenic development appeared. There are detailed deseriptions of the plate's range of use, its characteristies and processing, but these publications are very sketchy as to the nature of the components. The most detailed documents, on which this article is based, are the ‘report on the titles and work of Louis Lumiere’ published in 1918, the factory notebooks written by Louis Lumiere or M. Perrigot,¹ and the archives of the Lumiere firm, which are now scattered in various locations.