Wigner distribution and entropy of partially coherent light generated by perfect optical vortices.

We developed analytical expressions for the Wigner distribution function of partially coherent fields generated by the scattering of beams with a particular phase structure, namely perfect optical vortex beams. In addition, we provide the modal decomposition of the field correlations and evaluate the evolution of Shannon entropy associated with the partially coherent field.

Systemic Inflammation but not Oxidative Stress Is Associated with Physical Performance in Moderate Chronic Obstructive Pulmonary Disease.

Chronic obstructive pulmonary disease (COPD) patients manifest muscle dysfunction and impaired muscle oxidative capacity, which result in reduced exercise capacity and poor health status. The aim of this study was to compare the physical performance, systemic inflammation, and oxidative stress of patients with moderate COPD, and to associate physical performance with inflammatory and oxidative stress plasma markers. Twenty CONTROL (n = 10) and moderate COPD (n = 10) patients participated in this study. Systematic inflammation and oxidative stress plasma markers, maximal aerobic capacity (VO2peak), and maximal isometric strength (MVIC) of the knee extensor (KE) muscles were measured. VO2peak was 31.3% greater in CONTROL compared to COPD (P = 0.006). The MVIC strength of the KE was 43.9% greater in CONTROL compared to COPD (P = 0.002). Tumor necrosis factor-alpha (TNF-α) was 79.6% greater in COPD compared to CONTROL (P < 0.001). Glutathione peroxidase activity (GPx) activity was 27.5% lesser in COPD compared to CONTROL (P = 0.05). TNF-α concentration was correlated with KE MVC strength (R = -0.48; P = 0.045) and VO2peak (R = -0.58; P = 0.01). Meanwhile, malondialdehyde (MDA) and GPx activity were not associated with KE strength or VO2peak (P = 0.74 and P = 0.14, respectively). COPD patients showed lesser muscle strength and aerobic capacity than healthy control individuals. Furthermore, patients with COPD showed greater systemic inflammation and lesser antioxidant capacity than healthy counterparts. A moderate association was evident between levels of systemic inflammation and physical performance variables.

Propagation of asymmetric optical vortex beams through turbulence and evolution of their OAM spectra.

In the realm of wave propagation through turbulent media, the spectrum of the orbital angular momentum of optical vortex beams is known to undergo symmetric broadening. However, the evolution of beams that are initially azimuthally asymmetric represents a distinct phenomenon. In this work, we have developed an analytical model describing the propagation of asymmetric OAM beams through the so-called Kolmogorov turbulence. Our results describe how the perturbation strength and the initial beam properties lead to a nonsymmetric spectrum of OAM modes. These findings lay the groundwork for further use of asymmetric fields that propagate in inhomogeneous media and their applications such as communications and sensing.

First-order statistics of intensity and phase in Laguerre-Gauss speckles.

Laguerre-Gaussian (LG) beams are characterized by an azimuthal index or topological charge (m), associated with the orbital angular momentum, and by a radial index (p), which represents the number of the rings in the intensity distribution. We present a detailed, systematic study of the first-order phase statistics of the speckle fields created when LG beams of different order interact with random phase screens with different optical roughness. The phase properties of the LG speckle fields are studied in both the Fresnel and the Fraunhofer regimes using the equiprobability density ellipse formalism such that analytical expressions can be derived for the phase statistics.

3D intensity correlations in random fields created by vortex structured beams.

We develop an analytical model for the 3D spatial coherence function of speckle fields generated by scattering of vortex and perfect optical vortex beams. The model is general and describes the spatial coherence along both the transversal and the longitudinal directions. We found that, on propagation, the 3D spatial coherence evolves differently for the different types of initially structured beams, which may affect their use in a variety of sensing applications.

First-order statistics of the phase in optical vortex speckles.

We present the theoretical analysis of first-order statistics of the phase in a far-field speckle field, which originates from an optical vortex passing through a random phase screen. By using the concept of the equiprobability density ellipse, we show that the standard deviation of the phase in a speckle field varies non-monotonically in the radial direction and, more interestingly, it exhibits a minimum at a certain radial position determined by the topological charge. In the limit of zero topological charge, the phase statistics naturally converges to the expectation corresponding to the incident Gaussian beam.

The role of phase I and II genetic polymorphisms, smoking, alcohol and cancer family history, in the risk of developing testicular cancer.

BACKGROUND: Testicular cancer (TCa) is a malignant tumor with highest incidence and mortality rates in Chile. The genes coding for cytochrome P450, glutathione-S-transferases (GSTs), and UDP glucuronyl transferases (UGT) participate in the biotransformation and detoxification of xenobiotics. Mutations in these genes have been associated with a high incidence of various types of cancer and an increased risk of presenting adverse reactions to drugs. OBJECTIVE: The aim of this study was to relate the presence of genetic polymorphisms in cytochrome P450 1A1 (CYP1A1), CYP3A4, GSTM1, GSTP1, GSTT1, and UGT1A1 genes and nongenetic factors with the risk of developing TCa. METHODS: A total of 276 volunteers from the Chilean general population and 251 Chilean TCa patients were recruited for the study. Genotypic analyses were performed using qPCR and PCR-RFLP. RESULTS: Variant alleles found to increase the risk of developing TCa were CYP1A1*2C (rs1048943), GSTP1 (rs1695), and GSTT1null, especially when in conjunction with a cancer family history and/or a smoking habit. The results of the multivariate analysis showed that the presence of variant alleles of GSTP1 (rs1695) together with a smoking habit and a family history of cancer accounted for a 15.9% risk of developing TCa in the Chilean population. CYP1A1*2C, GSTM1null, GSTT1null, and GSTP1 (rs1695) are statistically related to the risk of appearance of TCa, alone or associated with nongenetic factors. CONCLUSION: Therefore, phase I and II variant alleles might be useful in evaluating susceptibility to TCa in the studied population.

Spatial intensity correlations of a vortex beam and a perfect optical vortex beam.

We present a model based on the Fresnel diffraction scheme for the spatial coherence function of random fields created by scattering optical vortex and perfect vortex beams. By using the spatial coherence function we showed analytically, numerically, and experimentally the dependence and independence of the speckle size of an optical vortex and perfect optical vortex (POV) with a topological charge, respectively. We also showed in both cases the linear dependence of speckle size on the distance of propagation. Furthermore, we describe a regime in which the spatial coherence function is nonevolving for the optical vortex beam and the POV beam with the propagation distance.

Non-evolving spatial coherence function.

We present a general model for the spatial coherence function of random fields created by scattering elliptical, perfect vortex beams. Remarkably, as opposed to the free-space propagation of typical random fields, there are regimes where the spatial coherence function does not evolve. We demonstrate analytically, numerically, and experimentally that both the size and the shape of spatial correlations can be precisely controlled in a manner that is independent of propagation distance.

Prevalence of seven cardiovascular-related genetic polymorphisms in a Chilean mestizo healthy population.

OBJECTIVE: Among the genetic factors associated with cardiovascular disease (CVD), determining polymorphic genotypes could help to understand the appearance of the illness. Ethnic differences in these polymorphisms could explain population variability in susceptibility to CVD. The main goal of this research is to study the presence of more relevant genetic variants of ApoE, CETP, ACE, PAI-1, MTHFR, FII and FVL of the coagulation cascade, to describe the presence of cardiovascular-related variants in a mestizo group of the Chilean people. METHODS AND RESULTS: The studied population comprised 146 unrelated subjects from the general population, diagnosed as healthy, who were genotyped through conventional and/or real-time PCR. The allele frequencies for the Chilean population were: Apo E, ε2: 0.036, ε3: 0.875 and ε4: 0.089; CETP, B1: 0.51 and B2: 0.49; MTHFR, C: 0.52 and T: 0.48; ACE, I: 0.603 and D: 0.397; PAI-1, 4G: 0.381 and 5G: 0.619; FII, G: 0.97 and A: 0.03, and FV Leiden, G: 0.97 and A: 0.03. CONCLUSIONS: This study contributes to establish a first picture in the Chilean mestizo population about the frequencies of these variants, which could act as single or complementary risk factors to trigger CVD. The obtained allele frequencies show great differences in relation to other South American populations.

Improvement of biomaterials used in tissue engineering by an ageing treatment.

Biomaterials based on crosslinked sponges of biopolymers have been extensively used as scaffolds to culture mammal cells. It is well known that single biopolymers show significant change over time due to a phenomenon called physical ageing. In this research, it was verified that scaffolds used for skin tissue engineering (based on gelatin, chitosan and hyaluronic acid) express an ageing-like phenomenon. Treatments based on ageing of scaffolds improve the behavior of skin-cells for tissue engineering purposes. Physical ageing of dry scaffolds was studied by differential scanning calorimetry and was modeled with ageing kinetic equations. In addition, the physical properties of wet scaffolds also changed with the ageing treatments. Scaffolds were aged up to 3 weeks, and then skin-cells (fibroblasts) were seeded on them. Results indicated that adhesion, migration, viability, proliferation and spreading of the skin-cells were affected by the scaffold ageing. The best performance was obtained with a 2-week aged scaffold (under cell culture conditions). The cell viability inside the scaffold was increased from 60% (scaffold without ageing treatment) to 80%. It is concluded that biopolymeric scaffolds can be modified by means of an ageing treatment, which changes the behavior of the cells seeded on them. The ageing treatment under cell culture conditions might become a bioprocess to improve the scaffolds used for tissue engineering and regenerative medicine.

Global transcriptome profiles provide insights into muscle cell development and differentiation on microstructured marine biopolymer scaffolds for cultured meat production.

Biomaterial scaffolds play a pivotal role in the advancement of cultured meat technology, facilitating essential processes like cell attachment, growth, specialization, and alignment. Currently, there exists limited knowledge concerning the creation of consumable scaffolds tailored for cultured meat applications. This investigation aimed to produce edible scaffolds featuring both smooth and patterned surfaces, utilizing biomaterials such as salmon gelatin, alginate, agarose and glycerol, pertinent to cultured meat and adhering to food safety protocols. The primary objective of this research was to uncover variations in transcriptomes profiles between flat and microstructured edible scaffolds fabricated from marine-derived biopolymers, leveraging high-throughput sequencing techniques. Expression analysis revealed noteworthy disparities in transcriptome profiles when comparing the flat and microstructured scaffold configurations against a control condition. Employing gene functional enrichment analysis for the microstructured versus flat scaffold conditions yielded substantial enrichment ratios, highlighting pertinent gene modules linked to the development of skeletal muscle. Notable functional aspects included filament sliding, muscle contraction, and the organization of sarcomeres. By shedding light on these intricate processes, this study offers insights into the fundamental mechanisms underpinning the generation of muscle-specific cultured meat.

Improvement of human skin cell growth by radiation-induced modifications of a Ge/Ch/Ha scaffold.

Gelatin-/chitosan-/hyaluronan-based biomaterials are used in tissue engineering as cell scaffolds. Three gamma radiation doses (1, 10 and 25 kGy) were applied to scaffolds for sterilization. Microstructural changes of the irradiated polymers were evaluated by using scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). A dose of 25 kGy produced a rough microstructure with a reduction of the porosity (from 99 to 96 %) and pore size (from 160 to 123 µm). Radiation also modified the glass transition temperature between 31.2 and 42.1 °C (1 and 25 kGy respectively). Human skin cells cultivated on scaffolds irradiated with 10 and 25 kGy proliferated at 48 h and secreted transforming growth factor ß3 (TGF-ß3). Doses of 0 kGy (non-irradiated) or 1 kGy did not stimulate TGF-ß3 secretion or cell proliferation. The specific growth rate and lactate production increased proportionally to radiation dose. The use of an appropriate radiation dose improves the cell scaffold properties of biomaterials.

Designing a gelatin/chitosan/hyaluronic acid biopolymer using a thermophysical approach for use in tissue engineering.

Cell culture on biopolymeric scaffolds has provided treatments for tissue engineering. Biopolymeric mixtures based on gelatin (Ge), chitosan (Ch) and hyaluronic acid (Ha) have been used to make scaffolds for wound healing. Thermal and physical properties of scaffolds prepared with Ge, Ch and Ha were characterized. Thermal characterization was made by using differential scanning calorimetry (DSC), and physical characterization by gas pycnometry and scanning electron microscopy. The effects of Ge content and cross-linking on thermophysical properties were evaluated by means of a factorial experiment design (central composite face centered). Gelatin content was the main factor that affects the thermophysical properties (microstructure and thermal transitions) of the scaffold. The effect of Ge content of the scaffolds for tissue engineering was studied by seeding skin cells on the biopolymers. The cell attachment was not significantly modified at different Ge contents; however, the cell growth rate increased linearly with the decrease of the Ge content. This relationship together with the thermophysical characterization may be used to design scaffolds for tissue engineering.

Use of Chitosan from Southern King Crab to Develop Films Functionalized with RGD Peptides for Potential Tissue Engineering Applications.

Southern King Crab (SKC) represents an important fishery resource that has the potential to be a natural source of chitosan (CS) production. In tissue engineering, CS is very useful to generate biomaterials. However, CS has a lack of signaling molecules that facilitate cell-substrate interaction. Therefore, RGD (arginine-glycine-aspartic acid) peptides corresponding to the main integrin recognition site in extracellular matrix proteins have been used to improve the CS surface. The aim of this study was to evaluate in vitro cell adhesion and proliferation of CS films synthesized from SKC shell wastes functionalized with RGD peptides. The FTIR spectrum of CS isolated from SKC shells (SKC-CS) was comparable to commercial CS. Thermal properties of films showed similar endothermic peaks at 53.4 and 53.0 °C in commercial CS and SKC-CS, respectively. The purification and molecular masses of the synthesized RGD peptides were confirmed using HPLC and ESI-MS mass spectrometry, respectively. Mouse embryonic fibroblast cells showed higher adhesion on SKC-CS (1% w/v) film when it was functionalized with linear RGD peptides. In contrast, a cyclic RGD peptide showed similar adhesion to control peptide (RDG), but the highest cell proliferation was after 48 h of culture. This study shows that functionalization of SKC-CS films with linear or cyclic RGD peptides are useful to improve effects on cell adhesion or cell proliferation. Furthermore, our work contributes to knowledge of a new source of CS to synthesize constructs for tissue engineering applications.

Effect of Electrical Stimulation on PC12 Cells Cultured in Different Hydrogels: Basis for the Development of Biomaterials in Peripheral Nerve Tissue Engineering.

Extensive damage to peripheral nerves is a health problem with few therapeutic alternatives. In this context, the development of tissue engineering seeks to obtain materials that can help recreate environments conducive to cellular development and functional repair of peripheral nerves. Different hydrogels have been studied and presented as alternatives for future treatments to emulate the morphological characteristics of nerves. Along with this, other research proposes the need to incorporate electrical stimuli into treatments as agents that promote cell growth and differentiation; however, no precedent correlates the simultaneous effects of the types of hydrogel and electrical stimuli. This research evaluates the neural differentiation of PC12 cells, relating the effect of collagen, alginate, GelMA, and PEGDA hydrogels with electrical stimulation modulated in four different ways. Our results show significant correlations for different cultivation conditions. Electrical stimuli significantly increase neural differentiation for specific experimental conditions dependent on electrical frequency, not voltage. These backgrounds allow new material treatment schemes to be formulated through electrical stimulation in peripheral nerve tissue engineering.

Micropatterned Nanofiber Scaffolds of Salmon Gelatin, Chitosan, and Poly(vinyl alcohol) for Muscle Tissue Engineering.

The development of scaffolds that mimic the aligned fibrous texture of the extracellular matrix has become an important requirement in muscle tissue engineering. Electrospinning is a widely used technique to fabricate biomimetic scaffolds. Therefore, a biopolymer blend composed of salmon gelatin (SG), chitosan (Ch), and poly(vinyl alcohol) (PVA) was developed by electrospinning onto a micropatterned (MP) collector, resulting in a biomimetic scaffold for seeding muscle cells. Rheology and surface tension studies were performed to determine the optimum solution concentration and viscosity for electrospinning. The scaffold microstructure was analyzed using SEM to determine the nanofiber's diameter and orientation. Blends of SG/Ch/PVA exhibited better electrospinnability and handling properties than pure PVA. The resulting scaffolds consist of a porous surface (∼46%), composed of a random fiber distribution, for a flat collector and scaffolds with regions of aligned nanofibers for the MP collector. The nanofiber diameters are 141 ± 2 and 151 ± 2 nm for the flat and MP collector, respectively. In vitro studies showed that myoblasts cultured on scaffold SG/Ch/PVA presented a high rate of cell growth. Furthermore, the aligned nanofibers on the SG/Ch/PVA scaffold provide a suitable platform for myoblast alignment.

Phase memory of optical vortex beams.

Optical vortex beams are under considerable scrutiny due to their demonstrated potential for applications ranging from quantum optics to optical communications and from material processing to particle trapping. However, upon interaction with inhomogeneous material systems, their deterministic properties are altered. The way these structured beams are affected by different levels of disturbances is critical for their uses. Here, for the first time, we quantify the degradation of perfect optical vortex beams after their interaction with localized random media. We developed an analytical model that (1) describes how the spatial correlation and the phase variance of disturbance affect the phase distribution across the vortex beams and (2) establishes the regimes of randomness for which the beams maintain the memory of their initial vorticity. Systematic numerical simulations and controlled experiments demonstrate the extent of this memory effect for beams with different vorticity indices.

Osteoconductive Effect of a Nanocomposite Membrane Treated with UV Radiation.

Modulation of the bio-regenerative characteristics of materials is an indispensable requirement in tissue engineering. Particularly, in bone tissue engineering, the promotion of the osteoconductive phenomenon determines the elemental property of a material be used therapeutically. In addition to the chemical qualities of the constituent materials, the three-dimensional surface structure plays a fundamental role that various methods are expected to modulate in a number of ways, one most promising of which is the use of different types of radiation. In the present manuscript, we demonstrate in a calvarial defect model, that treatment with ultraviolet irradiation allows modification of the osteoconductive characteristics in a biomaterial formed by gelatin and chitosan, together with the inclusion of hydroxyapatite and titanium oxide nanoparticles.

Enhanced recombinant protein production in CHO cell continuous cultures under growth-inhibiting conditions is associated with an arrested cell cycle in G1/G0 phase.

Low temperature and sodium butyrate (NaBu) are two of the most used productivity-enhancing strategies in CHO cell cultures during biopharmaceutical manufacturing. While these two approaches alter the balance in the reciprocal relationship between cell growth and productivity, we do not fully understand their mechanisms of action beyond a gross cell growth inhibition. Here, we used continuous culture to evaluate the differential effect of low temperature and NaBu supplementation on CHO cell performance and gene expression profile. We found that an increase in cell-productivity under growth-inhibiting conditions was associated with the arrest of cells in the G1/G0 phase. A transcriptome analysis revealed that the molecular mechanisms by which low temperature and NaBu arrested cell cycle in G1/G0 differed from each other through the deregulation of different cell cycle checkpoints and regulators. The individual transcriptome changes in pattern observed in response to low temperature and NaBu were retained when these two strategies were combined, leading to an additive effect in arresting the cell cycle in G1/G0 phase. The findings presented here offer novel molecular insights about the cell cycle regulation during the CHO cell bioprocessing and its implications for increased recombinant protein production. This data provides a background for engineering productivity-enhanced CHO cell lines for continuous manufacturing.