Carbon dioxide as carbon source: Activation via electrogenerated O2 in ionic liquids

The activation of carbon dioxide has been obtained in O₂/CO₂ saturated ionic liquids, via electrochemically generated O₂⁻, at a less negative potential than the one of the direct cathodic reduction of CO₂. This electrochemical activation has been applied to the C–N bond formation from amines and carbon dioxide in the synthesis of organic carbamates. A competitive reaction between electrogenerated superoxide ion and imidazolium cations yielding 2-imidazolones has been pointed out. This procedure allows to avoid the utilization of volatile and toxic organic solvents, supporting electrolytes and catalysts.     

Hetero-azeotropic distillation: combining fungal dehydration and lipid extraction

A low-cost single-stage laboratory process combining fungal dehydration and lipid extraction was compared with a traditional two-stage method employing freeze-drying and subsequent mechanical disruption in the presence of solvent. The ability of a number of organic solvents to form hetero-azeotropes with water was exploited. Chloroform, cyclohexane and hexane were assessed in their abilities to both dry and extract lipid from the oleaginous phycomycete Mortierella alpina (ATCC 32222). Drying rate and lipid extraction were maximised under conditions that prevented fungal agglomeration. The total processing time was limited by the rate of dehydration rather than by the rate of lipid extraction. In all cases azeotropic distillation facilitated a greater rate of dehydration than was possible with freeze-drying. A consequent reduction in overall processing time was observed. Uniquely, both the solvent used and the mode of mixing employed controlled the morphology of the aggregates formed during distillation. In combination with mild mixing chloroform discouraged agglomeration whereas cyclohexane and hexane promoted aggregation. Successful lipid extraction was dependent on the use of dry biomass rather than on the application of heat to effect distillation. Neither the application of heat nor the solvent employed had any significant effect on the lipid composition of the extracted oil.     

Spray Chilling Microencapsulation of <Emphasis Type="Italic">Lactobacillus acidophilus</Emphasis> and <Emphasis Type="Italic">Bifidobacterium animalis</Emphasis> subsp. <Emphasis Type="Italic">lactis</Emphasis> and Its Use in the Preparation of Savory Probiotic Cereal Bars

The use of probiotic microorganisms has been limited by the difficulty of maintaining their viability during processing and throughout the product’s shelf life. This study evaluated the viability of microencapsulating Lactobacillus acidophilus (LA) and Bifidobacterium animalis subsp. lactis (BL) using the spray chilling technique to add them to savory cereal bars. The results showed that spray chilling generated a powder that was composed of smooth and continuous spheres with low moisture content and low water activity. The microencapsulated microorganisms exhibited a storage viability at least of 90 days as microparticles and in savory cereal bars, and their counts were superior to those resulting from other methods of adding activated and lyophilized probiotics to savory cereal bars. Thus, microparticles prepared by spray chilling are good vehicles for incorporating probiotics into cereal bars and have the potential to release the probiotics in the consumers’ intestines by means of fat digestion. Savory cereal bars that did and did not contain probiotics exhibited no differences in sensorial acceptance or commercial potential.     

Nonlinear dynamic behavior of saddle-form cable nets under uniform harmonic load

The dynamic response of saddle-form cable nets is investigated in this paper. Even though they consist of cables, which are well known for their geometric nonlinearity, such systems could be characterized as weakly nonlinear due to the high levels of pretensioning of their cables and to their hyperbolic paraboloid surface, having opposite curvatures at all points and thus increased stiffness. Nevertheless, resonance phenomena that are typical of highly nonlinear systems are detected here, for common geometries and levels of pretension, even for low levels of load amplitude. First, a single-degree-of-freedom (SDOF) cable net is studied analytically and numerically, and nonlinear resonances are confirmed. Then, the response of multi-degree-of-freedom (MDOF) cable nets, subjected to harmonic dynamic excitation, is investigated. Although the static response is proved to be almost linear, the dynamic nonlinearity is intense, as verified by jump phenomena, bending of the response curve, superharmonic resonances, and dependence on the initial conditions.     

Novel Multifaceted Roles for RNF213 Protein

Ring Finger Protein 213 (RNF213), also known as Mysterin, is the major susceptibility factor for Moyamoya Arteriopathy (MA), a progressive cerebrovascular disorder that often leads to brain stroke in adults and children. Although several rare RNF213 polymorphisms have been reported, no major susceptibility variant has been identified to date in Caucasian patients, thus frustrating the attempts to identify putative therapeutic targets for MA treatment. For these reasons, the investigation of novel biochemical functions, substrates and unknown partners of RNF213 will help to unravel the pathogenic mechanisms of MA and will facilitate variant interpretations in a diagnostic context in the future. The aim of the present review is to discuss novel perspectives regarding emerging RNF213 roles in light of recent literature updates and dissect their relevance for understanding MA and for the design of future research studies. Since its identification, RNF213 involvement in angiogenesis and vasculogenesis has strengthened, together with its role in inflammatory signals and proliferation pathways. Most recent studies have been increasingly focused on its relevance in antimicrobial activity and lipid metabolism, highlighting new intriguing perspectives. The last area could suggest the main role of RNF213 in the proteasome pathway, thus reinforcing the hypotheses already previously formulated that depict the protein as an important regulator of the stability of client proteins involved in angiogenesis. We believe that the novel evidence reviewed here may contribute to untangling the complex and still obscure pathogenesis of MA that is reflected in the lack of therapies able to slow down or halt disease progression and severity.     

Adipose Tissue Secretion Pattern Influences β-Cell Wellness in the Transition from Obesity to Type 2 Diabetes

The dysregulation of the β-cell functional mass, which is a reduction in the number of β-cells and their ability to secure adequate insulin secretion, represents a key mechanistic factor leading to the onset of type 2 diabetes (T2D). Obesity is recognised as a leading cause of β-cell loss and dysfunction and a risk factor for T2D. The natural history of β-cell failure in obesity-induced T2D can be divided into three steps: (1) β-cell compensatory hyperplasia and insulin hypersecretion, (2) insulin secretory dysfunction, and (3) loss of β-cell mass. Adipose tissue (AT) secretes many hormones/cytokines (adipokines) and fatty acids that can directly influence β-cell function and viability. As this secretory pattern is altered in obese and diabetic patients, it is expected that the cross-talk between AT and pancreatic β-cells could drive the maintenance of the β-cell integrity under physiological conditions and contribute to the reduction in the β-cell functional mass in a dysmetabolic state. In the current review, we summarise the evidence of the ability of the AT secretome to influence each step of β-cell failure, and attempt to draw a timeline of the alterations in the adipokine secretion pattern in the transition from obesity to T2D that reflects the progressive deterioration of the β-cell functional mass.     

Molecular Mechanisms of Diabetic Kidney Disease

The inflammatory component of diabetic kidney disease has become of great interest in recent years, with genetic and epigenetic variants playing a fundamental role in the initiation and progression of the disease. Cells of the innate immune system play a major role in the pathogenesis of diabetic kidney disease, with a lesser contribution from the adaptive immune cells. Other components such as the complement system also play a role, as well as specific cytokines and chemokines. The inflammatory component of diabetic kidney disease is of great interest and is an active research field, with the hope to find potential innovative therapeutic targets.     

11β-Hydroxysteroid Dehydrogenase Type 1 within Osteoclasts Mediates the Bone Protective Properties of Therapeutic Corticosteroids in Chronic Inflammation

Therapeutic glucocorticoids (GCs) are powerful anti-inflammatory tools in the management of chronic inflammatory diseases such as rheumatoid arthritis (RA). However, their actions on bone in this context are complex. The enzyme 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) is a mediator of the anti-inflammatory actions of therapeutic glucocorticoids (GCs) in vivo. In this study we delineate the role of 11β-HSD1 in the effects of GC on bone during inflammatory polyarthritis. Its function was assessed in bone biopsies from patients with RA and osteoarthritis, and in primary osteoblasts and osteoclasts. Bone metabolism was assessed in the TNF-tg model of polyarthritis treated with oral GC (corticosterone), in animals with global (TNF-tg^11βKO), mesenchymal (including osteoblast) (TNF-tg^{11βflx/tw2cre}) and myeloid (including osteoclast) (TNF-tg^{11βflx/LysMcre}) deletion. Bone parameters were assessed by micro-CT, static histomorphometry and serum metabolism markers. We observed a marked increase in 11β-HSD1 activity in bone in RA relative to osteoarthritis bone, whilst the pro-inflammatory cytokine TNFα upregulated 11β-HSD1 within osteoblasts and osteoclasts. In osteoclasts, 11β-HSD1 mediated the suppression of bone resorption by GCs. Whilst corticosterone prevented the inflammatory loss of trabecular bone in TNF-tg animals, counterparts with global deletion of 11β-HSD1 were resistant to these protective actions, characterised by increased osteoclastic bone resorption. Targeted deletion of 11β-HSD1 within osteoclasts and myeloid derived cells partially reproduced the GC resistant phenotype. These data reveal the critical role of 11β-HSD1 within bone and osteoclasts in mediating the suppression of inflammatory bone loss in response to therapeutic GCs in chronic inflammatory disease.