Triplet-triplet annihilation upconversion in polymeric systems and model membranes

Triplet-triplet annihilation upconversion (TTAUC) is gaining prominence in the field of optical spectroscopy and holds the potential to revolutionize various emerging technologies such as solar cells, bioimaging and light-activated drug release. This is attributed to its capability of converting long-wavelength photons to higher energy photons, even at low excitation power densities (~5 mW cm-2). The low excitation power density can activate the drug release without damaging the tissue by excitation radiation. The implementation of TTAUC in light-activated drug release necessitates the transfer of the upconversion system comprising sensitizer and annihilator, from solution to solid phase. However, TTAUC is most efficient in solutions and needs inert conditions. The challenge lies in the fact that diffusion plays a crucial role in molecular processes for triplet-triplet energy transfer (TTET) and triplet-triplet annihilation (TTA). In this work, liposomes with sensitizer, annihilator and drug molecules have been synthesized. Time-resolved studies of sensitizer and annihilator in lipid bilayer membranes reveal the triplet lifetime properties, the triplet lifetime of sensitizer and annihilator molecules play a vital role in determining the efficiency of energy transfer processes. The study reveals sensitizer and annihilator molecules localize within the lipid bilayer. Therefore, increasing the local concentration leads to the self-quenching of sensitizer triplets, but localization enhances the energy transfer rates. The observations made using time-resolved study of TTAUC in LUVs indicate despite the higher viscosity of the medium, energy transfer is faster in the lipid bilayer system. Long triplet lifetimes of the sensitizer and annihilators are advantageous in getting high upconversion yield, this study will be crucial in designing efficient light-activated drug delivery systems using liposomes

Delayed mesh erosion after rectopexy: A rare surprise diagnosis

Mesh rectopexy is a frequently performed surgery for the treatment of rectal prolapse. Mesh rectopexy may be complicated by mesh infection, mesh erosion/migration into bowel wall, and extrusion of mesh. Erosion of the mesh into the rectum is very rare. Delayed erosion of mesh into rectosigmoid can present after many years of mesh rectopexy and poses diagnostic dilemma. We report a case of delayed mesh erosion into the rectum diagnosed during sigmoidoscopy

Progress in Understanding Metabolic Syndrome and Knowledge of Its Complex Pathophysiology

The metabolic syndrome (MetS), first introduced by Haller in 1975, was sometimes also known as insulin resistance syndrome, syndrome X, and plurimetabolic syndrome. In 1989, it was rechristened by Kaplan as the “Deadly Quartet” based on a consolidation of central obesity, impaired glucose tolerance, dyslipidemia, and systemic hypertension. MetS is positively associated with a pro-inflammatory and pro-thrombotic state, attributed to increased pro-thrombotic and inflammatory marker activity. Moreover, MetS is frequently associated with increased atherosclerotic cardiovascular disease, impaired glucose tolerance, hyperuricemia, obstructive sleep apnea, and chronic kidney disease. Despite concerted endeavors worldwide, the complexity of the pathophysiology of metabolic syndrome still needs to be clearly understood. Currently, therapeutic possibilities are confined to individual therapy for hyperglycemia, hypertension, hypertriglyceridemia, hyperuricemia, regular physical exercise, and a restricted diet. In this review, progress regarding the understanding and pathophysiology of MetS; recent emerging technologies, such as metabolomics and proteomics; the relation of MetS with obesity, diabetes, and cardiovascular diseases; and the association of MetS with COVID-19 are discussed

A Review on Data-Driven Quality Prediction in the Production Process with Machine Learning for Industry 4.0

The quality-control process in manufacturing must ensure the product is free of defects and performs according to the customer’s expectations. Maintaining the quality of a firm’s products at the highest level is very important for keeping an edge over the competition. To maintain and enhance the quality of their products, manufacturers invest a lot of resources in quality control and quality assurance. During the assembly line, parts will arrive at a constant interval for assembly. The quality criteria must first be met before the parts are sent to the assembly line where the parts and subparts are assembled to get the final product. Once the product has been assembled, it is again inspected and tested before it is delivered to the customer. Because manufacturers are mostly focused on visual quality inspection, there can be bottlenecks before and after assembly. The manufacturer may suffer a loss if the assembly line is slowed down by this bottleneck. To improve quality, state-of-the-art sensors are being used to replace visual inspections and machine learning is used to help determine which part will fail. Using machine learning techniques, a review of quality assessment in various production processes is presented, along with a summary of the four industrial revolutions that have occurred in manufacturing, highlighting the need to detect anomalies in assembly lines, the need to detect the features of the assembly line, the use of machine learning algorithms in manufacturing, the research challenges, the computing paradigms, and the use of state-of-the-art sensors in Industry 4.0

Iduronate-2-Sulfatase-Regulated Dermatan Sulfate Levels Potentiate the Invasion of Breast Cancer Epithelia through Collagen Matrix

Cancer epithelia show elevation in levels of sulfated proteoglycans including dermatan sulfates (DS). The effect of increased DS on cancer cell behavior is still unclear. We hypothesized that decreased expression of the enzyme Iduronate-2-sulfatase (IDS) can lead to increased DS levels, which would enhance the invasion of cancer cells. Breast cancer sections shows depleted IDS levels in tumor epithelia, when compared with adjacent untransformed breast tissues. IDS signals showed a progressive decrease in the non-transformed HMLE, transformed but non-invasive MCF-7 and transformed and invasive MDA-MB-231 cells, respectively, when cultured on Type 1 collagen scaffolds. DS levels measured by ELISA increased in an inverse-association with IDS levels. Knockdown of IDS in MCF-7 epithelia also increased the levels of DS. MCF-7 cells with depleted IDS expression, when imaged using two photon-excited fluorescence and second harmonic generation microscopy, exhibited a mesenchymal morphology with multiple cytoplasmic projections compared with epithelioid control cells, interacted with their surrounding matrix, and showed increased invasion through Type 1 collagen matrices. Both these traits were phenocopied when control MCF-7 cells were cultivated on Type 1 collagen gels polymerized in the presence of DS. In monolayer cultures, DS had no effect on MCF-7 migration. In the context of our demonstration that DS enhances the elastic modulus of Type 1 collagen gels, we propose that a decrease of IDS expression leads to accumulation within cancer epithelia of DS: the latter remodels the collagen around cancer cells leading to changes in cell shape and invasiveness through fibrillar matrix milieu

Microscopic study of resonant third-harmonic generation from amorphous silicon nanodisk arrays

A detailed microscopic study of third-harmonic generation (THG) from two-dimensional arrays of sub-wavelength spaced amorphous silicon nanodisks is reported. The arrays are designed to support broadband, minimally angle-sensitive resonances for the fundamental excitation wavelength in the 1500 nm region. This results in resonantly enhanced visible THG in the green spectral range with similar to 500-fold enhancement on-resonance, compared to the un-patterned a-Si thin-film. THG multispectral microscopic imaging reveals individual nanodisks with enhanced non-linear signal on-resonance. For increasing pump intensities, spatially dependent saturation effects are observed for the first time, to the best of our knowledge, in such dielectric nanostructure arrays with THG images showing a reversal of contrast. (C) 2018 Optical Society of Americ

Intensity and spatial dependence of saturation effects in Resonant Third harmonic generation from amorphous silicon nanodisk arrays

Third harmonic generation microscopy of hexagonal arrays of amorphous silicon nanodisks with resonance at fundamental wavelength is presented. The onset and progression of intensity and spatially dependent saturation effects are clearly observed through the contrast reversal of third harmonic generation signal generated at the nanodisks

Recent Advances in Chronotherapy Targeting Respiratory Diseases

Respiratory diseases contribute to a significant percentage of mortality and morbidity worldwide. The circadian rhythm is a natural biological process where our bodily functions align with the 24 h oscillation (sleep-wake cycle) process and are controlled by the circadian clock protein/gene. Disruption of the circadian rhythm could alter normal lung function. Chronotherapy is a type of therapy provided at specific time intervals based on an individual's circadian rhythm. This would allow the drug to show optimum action, and thereby modulate its pharmacokinetics to lessen unwanted or unintended effects. In this review, we deliberated on the recent advances employed in chrono-targeted therapeutics for chronic respiratory diseases