Heat transfer in a swirling fluidized bed with Geldart type-D particles

A relatively new variant in fluidized bed technology, designated as the swirling fluidized bed (SFB), was investigated for its heat transfer characteristics when operating with Geldart type D particles. Unlike conventional fluidized beds, the SFB imparts secondary swirling motion to the bed to enhance lateral mixing. Despite its excellent hydrodynamics, its heat transfer characteristics have not been reported in the published literature. Hence, two different sizes of spherical PVC particles (2.61mm and 3.65mm) with the presence of a center body in the bed have been studied at different velocities of the fluidizing gas. The wall-to-bed heat transfer coefficients were measured by affixing a thin constant foil heater on the bed wall. Thermocouples located at different heights on the foil show a decrease in the wall heat transfer coefficient with bed height. It was seen that only a discrete particle model which accounts for the conduction between the particle and the heat transfer surface and the gas-convective augmentation can adequately represent the mechanism of heat transfer in the swirling fluidized bed

The therapeutic potential of regulatory T cells for the treatment of autoimmune disease

IntroductionImmune tolerance remains the holy grail of therapeutic immunology in the fields of organ and tissue transplant rejection, autoimmune diseases, and allergy and asthma. We have learned that FoxP3(+)CD4(+) regulatory T cells play a vital role in both the induction and maintenance of self-tolerance.Areas coveredIn this opinion piece, we highlight regulatory T cells (Treg) cell biology and novel immune treatments to take advantage of these cells as potent therapeutics. We discuss the potential to utilize Treg and Treg-friendly therapies to replace current general immunosuppressives and induce tolerance as a path towards a drug-free existence without associated toxicities.Expert opinionFinally, we opine on the fact that biomedicine sits on the cusp of a new revolution: the use of human cells as versatile therapeutic engines. We highlight the challenges and opportunities associated with the development of a foundational cellular engineering science that provides a systematic framework for safely and predictably regulating cellular behaviors. Although Treg therapy has become a legitimate clinical treatment, development of the therapy will require a better understanding of the underlying Treg biology, manufacturing advances to promote cost effectiveness and combinations with other drugs to alter the pathogenicity/regulatory balance

Octogenarians on hemodialysis: a prospective study

Octogenarians represent the fastest growing group of patients on hemodialysis. These patients were previously treated with conservative measures, while they were believed to have too poor prognosis on renal replacement therapy. We investigated clinical characteristics and outcome of patients prospectively after at least 2 years of follow-up. Six male and six female patients who were older than 80 years at the start of hemodialysis were followed up. Their clinical characteristics, comorbidities, etiology of renal disease, nutritional status, complications, vascular access, hospitalizations, compliance and outcome were recorded. The primary renal disease was unknown in 42.8% of patients. All patients had one or more comorbid conditions. Dialysis was initiated in an emergency situation in 64.3%. Vascular access was long-term hemodialysis catheter in 71.4%. Only 14.2% of them received erythropoietin. There were no major bleedings with reduced doses of heparin. The most common complications were catheter-related ones (infections, ruptures). All patients together required seven hospitalizations per year (0.58 per patient). The octogenarians tended to be underdialyzed with the mean adequacy of dialysis (Kt/V) 0.92. The 1-year survival was 71.4%, and 2-year survival was 50%, i.e., they had good survival on hemodialysis. Most of them died from causes that were not related to the uremia. Their treatment requires a careful planning of renal service expansion while more octogenarians who need renal replacement treatment may be expected

Using proprioceptive sensors for categorizing interactions

t.salter | f.michaud | d.letournea

Genome sequencing and functional characterization of a Dictyopanus pusillus fungal enzymatic extract offers a promising alternative for lignocellulose pretreatment of oil palm residues.

The pretreatment of biomass remains a critical requirement for bio-renewable fuel production from lignocellulose. Although current processes primarily involve chemical and physical approaches, the biological breakdown of lignin using enzymes and microorganisms is quickly becoming an interesting eco-friendly alternative to classical processes. As a result, bioprospection of wild fungi from naturally occurring lignin-rich sources remains a suitable method to uncover and isolate new species exhibiting ligninolytic activity. In this study, wild species of white rot fungi were collected from Colombian forests based on their natural wood decay ability and high capacity to secrete oxidoreductases with high affinity for phenolic polymers such as lignin. Based on high activity obtained from solid-state fermentation using a lignocellulose source from oil palm as matrix, we describe the isolation and whole-genome sequencing of Dictyopanus pusillus, a wild basidiomycete fungus exhibiting ABTS oxidation as an indication of laccase activity. Functional characterization of a crude enzymatic extract identified laccase activity as the main enzymatic contributor to fungal extracts, an observation supported by the identification of 13 putative genes encoding for homologous laccases in the genome. To the best of our knowledge, this represents the first report of an enzymatic extract exhibiting laccase activity in the Dictyopanus genera, offering means to exploit this species and its enzymes for the delignification process of lignocellulosic by-products from oil palm