Effects of photobiomodulation with blue light during and after adipocyte differentiation

Phototherapy was applied to treat medical conditions since 3,500 years, when the ancient Egyptians and Indians used sunlight to treat various diseases. It was only with the invention of electric light in the late 19th century that an alternative emerged. From that time on, the use of phototherapy in the medical field grew, techniques were perfected and developed and eventually gained widespread acceptance. To date, over 2000 scientific articles have been published in PubMed focusing on the various physiological effects of red and NIR radiation. These wavelengths of light have been shown to penetrate through human tissues and to locally and systematically influence cell metabolism, cell signalling, inflammatory processes and growth. This treatment is now called "photobiomodulation" (PBM) therapy. Despite the numerous studies reported, variability in irradiation settings and parameters has led to inconsistent outcomes. The greatest lack of knowledge is related to the effects of low wavelengths of blue/green light. Compared to red/NIR light, blue light is used for a limited range of medical applications because of its inhibitory and cytotoxic effects. However blue light effects have rarely been reported in adipogenesis or lipogenesis studies on adipose tissue. Hence, the biomodulatory potential of blue light at 453 nm wavelength was tested on 3T3-L1 cells during and after the differentiation process with respect to adipogenesis/lipogenesis, metabolic processes, cell proliferation and transcriptome changes. PBM using blue light revealed dose dependent effects during preadipocytes 3T3-L1 differentiation. A single irradiation performed at the first day of induction (Day0) led to a slight effect with a reduced lipid accumulation and changes in the expression of adipogenic markers that appeared down-regulated already after one exposure. Also metabolism, reflecting mitochondria activity, was negatively affected by blue light since oxidative phosphorylation and ATP contents were decreased with effects that were long lasting until 24h. Tests with repeated irradiations for all differentiation period showed an enhanced inhibition in lipid accumulation and metabolism. This chronic exposure was supposed to rise the ROS amount leading to DNA damages that have had as consequence a cell cycle delay, reduced proliferation rate and cell death processes. Gene expression analysis supported this hypothesis by an up-regulation of the p53 pathway and for all the other genes involved in repair systems such as ATM, Chk1 and Claspin. The blue light spectrum, being close to the harmful UVs wavelength, seems to induce cell death mediated by oxidative stress and damages accumulation in differentiating preadipocytes. On the other hand mature adipocytes treated with 21.6 j/cm2 or 43.2 j/cm2 of blue light have proven to be less responsive. No significant differences were reported in metabolism, growth and lipid storage. Similarly apoptosis has not been deregulated and no changes in ROS levels or cellular damages have been observed. In conclusion adipocytes seem to be more sensitive to blue light exposure during early rather than in late differentiation phases. Furthermore, the high doses of irradiation chosen led to inhibitory effects on metabolism and differentiation promoting cell death in preadipocytes subjected to chronic exposure while no effects were recorded in irradiated mature adipocytes. The results indicated that an optimal choice of irradiation parameters, particularly the dose or irradiation time, is important. Too high doses can lead to expected inhibitory but also deleterious effects on cells. Though inhibitory effects in adipogenesis or proliferation are requested relating to the treatment of hyperplastic obesity or dysregulation of lipid accumulation during childhood, the formation of aberrant cells has to be avoided. Therefore additional studies are needed to promote or reject blue light application in these fields. If tetraploid or aneuploid cells formation is not observed, blue light could be a possible alternative to pharmacological or surgical solutions in some obese subjects. However, there is currently no evidence of a possible application in hypertrophic obesity condition

An infrared spectroscopy study of the conformational evolution of the Bis(trifluoromethanesulfonyl)imide ion in the liquid and in the glass state

We measure the far-infrared spectrum of N,N-Dimethyl-N-ethyl-N-benzylammonium (DEBA) bis(trifluoromethanesulfonyl) imide (TFSI) ionic liquid (IL) in the temperature range between 160 and 307 K. Differential scanning calorimetry measurements indicate that such IL undergoes a glass transition around 210K. DFT calculations allow us to assign all the experimental absorptions to specific vibrations of the DEBA cation or of the two conformers of the TFSI anion. We find that the vibration frequencies calculated by means of the PBE0 functional are in better agreement with the experimental ones than those calculated at the B3LYP level, largely used for the attribution of vibration lines of ionic liquids. Experimentally we show that, in the liquid state, the relative concentrations of the two conformers of TFSI depend on temperature through the Boltzmann factor and the energy separation, ΔH, is found to be ≈2 kJ/mol, in agreement with previous calculations and literature. However, in the glassy state, the concentrations of the cis-TFSI and trans-TFSI remain fixed, witnessing the frozen state of this phase

TENSILE INTEGRITY ACROSS THE SCALES OF THE LIVING MATTER: A STRUCTURAL PICTURE OF THE HUMAN CELL

Tensile integrity principle governs the existence of stable constructs in which sets of pre-tensed cables and pre-compressed struts mutually interconnect according to specific topological rules and exchange forces in a way to guarantee the structure’s overall self-equilibrium. Starting from the simplest form of 2-element bow-like system, several structural components can be arranged together to assemble increasingly intricate tensegrity architectures where bars levitate sustained by a precise interplay with tensed cables, whose peculiar organization balances the vector field of axial forces. Modulation of the internal pre-stress tunes tensegrity systems towards disparate forms with different rigidities and stored elastic energies, while the floating arrangement of the compressed elements and the possible chirality confer to the whole structure pronounced deployability. This makes tensile integrity a persuasive structural paradigm for explaining and reproducing some underlying mechanisms at the basis of several dynamics experimentally observed in single cells as well as at different scales of biological architectures. In particular, by deeply exploring the intra-cellular environment, one discovers that the cytoskeleton mechanically sustains the cell’s membrane, structurally integrates cellular sub-constituents and steers migration, adhesion and division activities by behaving as a dynamic tensegrity lattice, hierarchically assembled by protein filaments, in turn made of continuously reacting polymeric tensegrity-chains at the lower nano-scale

Fall Risk Assessment Tools for Elderly Living in the Community: Can We Do Better?

Background Falls are a common, serious threat to the health and self-confidence of the elderly. Assessment of fall risk is an important aspect of effective fall prevention programs. Objectives and methods In order to test whether it is possible to outperform current prognostic tools for falls, we analyzed 1010 variables pertaining to mobility collected from 976 elderly subjects (InCHIANTI study). We trained and validated a data-driven model that issues probabilistic predictions about future falls. We benchmarked the model against other fall risk indicators: history of falls, gait speed, Short Physical Performance Battery (Guralnik et al. 1994), and the literature-based fall risk assessment tool FRAT-up (Cattelani et al. 2015). Parsimony in the number of variables included in a tool is often considered a proxy for ease of administration. We studied how constraints on the number of variables affect predictive accuracy. Results The proposed model and FRAT-up both attained the same discriminative ability; the area under the Receiver Operating Characteristic (ROC) curve (AUC) for multiple falls was 0.71. They outperformed the other risk scores, which reported AUCs for multiple falls between 0.64 and 0.65. Thus, it appears that both data-driven and literature-based approaches are better at estimating fall risk than commonly used fall risk indicators. The accuracy–parsimony analysis revealed that tools with a small number of predictors (~1-5) were suboptimal. Increasing the number of variables improved the predictive accuracy, reaching a plateau at ~20-30, which we can consider as the best trade-off between accuracy and parsimony. Obtaining the values of these ~20-30 variables does not compromise usability, since they are usually available in comprehensive geriatric assessments

Hybrid Light-Emitting Diodes from Microcontact-Printing Double-Transfer of Colloidal Semiconductor CdSe/ZnS Quantum Dots onto Organic Layers

We have developed a totally dry technique for the deposition of colloidal semiconductor nanocrystals on organic substrates. This approach is fully compatible with current organic LED technology. It appears that the slow evaporation of drop-cast QD films is critical for the success of the transfer process. This novel approach has been utilized to fabricate a hybrid organic–inorganic red LE

Stacking sequences in composite laminates through design optimization

AbstractComposites are experiencing a new era. The spatial resolution at which is to date possible to build up complex architectured microstructures through additive manufacturing-based and sintering of powder metals 3D printing techniques, as well as the recent improvements in both filament winding and automated fiber deposition processes, are opening new unforeseeable scenarios for applying optimization strategies to the design of high-performance structures and metamaterials that could previously be only theoretically conceived. Motivated by these new possibilities, the present work, by combining computational methods, analytical approaches and experimental analysis, shows how finite element Design Optimization algorithms can be ad hoc rewritten by identifying as design variables the orientation of the reinforcing fibers in each ply of a layered structure for redesigning fiber-reinforced composites exhibiting at the same time high stiffness and toughening, two features generally in competition each other. To highlight the flexibility and the effectiveness of the proposed strategy, after a brief recalling of the essential theoretical remarks and the implemented procedure, selected example applications are finally illustrated on laminated plates under different boundary conditions, cylindrical layered shells with varying curvature subjected to point loads and composite tubes made of carbon fiber-reinforced polymers, recently employed as structural components in advanced aerospace engineering applications

Adaptation to Complex Pictures: Exposure to Emotional Valence Induces Assimilative Aftereffects

Aftereffects have been documented for a variety of perceptual categories spanning from body gender to facial emotion, thus becoming an important tool in the study of high-level vision and its neural bases. We examined whether the perceived valence of a complex scene is subject to aftereffects, by observing the participants’ evaluation of the valence of a test picture preceded by a different picture. For this study, we employed an adaptation paradigm with positive and negative images used as adapters, and positive, negative, and neutral images used as tests. Our results show that adaptation to complex emotional pictures induces assimilative aftereffects: participants judged neutral tests more positively following positive adapters and more negatively following negative adapters. This depended on the prolonged adaptation phase (10 s), as the results of a second experiment, in which adapters lasted for 500 ms, did not show aftereffects. In addition, the results show that assimilative aftereffects of negative and positive adapters also manifested themselves on non-neutral (negative and positive) targets, providing evidence that the global emotional content of complex pictures is suitable to induce assimilative aftereffects