Comparison of α and β-acid isomerization in hops and beer using HPLC, confocal microscopy, spectrofluorimetry and chemical analysis of metabolites and essential oils in flowers of different hop cultivars produced in Brazil.

We used confocal microscopy and spectrofluorescence to characterize the emission spectra in hop flowers, to follow the isomerization processes in different hop preparations, and beers, to compare with HPLC extracted samples. Flowers of different hop cultivars produced in three regions of Brazil, were quantitated by HPLC and GC-MS. The fluorescence spectra showed two characteristic emission bands evaluated from different preparations.

Doped Carbon Quantum Dots/PVA Nanocomposite as a Platform to Sense Nitrite Ions in Meat.

A sensor device based on doped-carbon quantum dots is proposed herein for detection of nitrite in meat products by fluorescence quenching. For the sensing platform, carbon quantum dots doped with boron and functionalized with nitrogen (B,N-Cdot) were synthesized with an excellent 44.3% quantum yield via a one-step hydrothermal route using citric acid, boric acid, and branched polyethylenimine as carbon, boron, and nitrogen sources, respectively.

The texture of collagen in the microenvironments of Merkel cell carcinoma.

Solid tumors typically contain high levels of fibrillar collagen. The increased stromal collagen deposition usually promotes cancer progression since biochemical and biophysical cues from tumor-associated collagen fibers stimulate neoplastic cells. Few studies have investigated the relationship between Merkel cell carcinoma (MCC) and the extracellular matrix (ECM), but there are no works evaluating collagen.

Effects of the lower energy and pulse stacking in carbon dioxide laser skin treatment: an objective analysis using second harmonic generation.

Purpose: To evaluate the effect of fractional carbon dioxide (CO2) laser treatment using lower power associated with pulse stacking within collagen fibers, using second harmonic generation microscopy and computerized image analysis.

Methods: Twenty male Wistar rats aging eight weeks were used. Each treatment area received a single-pass CO2 fractional laser with different parameters.

Comparison of morphological changes of corneal collagen fibers treated with collagen crosslinking agents using second harmonic generation images.

Corneal cross-linking (CXL) is a common surgical procedure used to modify corneal biomechanics and stabilize keratoconus progression which is still under discussion. Its side effects, which are mostly related to anatomical unpredictability and stromal exposure, are the reason for the search for new CXL agents. In this work we have quantitatively evaluated the porcine corneal stroma architecture treated with collagen crosslinking agents such as riboflavin solutions and açai extract, using second harmonic generation microscopy.

Evaluating viscoelastic properties and membrane electrical charges of red blood cells with optical tweezers and cationic quantum dots - applications to β-thalassemia intermedia hemoglobinopathy.

Biomechanical and electrical properties are important to the performance and survival of red blood cells (RBCs) in the microcirculation. This study proposed and explored methodologies based on optical tweezers and cationic quantum dots (QDs) as biophotonic tools to characterize, in a complementary way, viscoelastic properties and membrane electrical charges of RBCs. The methodologies were applied to normal (HbA) and β-thalassemia intermedia (Hbβ) RBCs.

Exploring Collagen Parameters in Pure Special Types of Invasive Breast Cancer.

One of the promising tools to evaluate collagen in the extracellular matrix is the second-harmonic generation microscopy (SHG). This approach may shed light on the biological behavior of cancers and their taxonomy, but has not yet been applied to characterize collagen fibers in cases diagnosed as invasive breast carcinoma (BC) of histological special types (IBC-ST). Tissue sections from 99 patients with IBC-ST and 21 of invasive breast carcinoma of no special type (IBC-NST) were submitted to evaluation of collagen parameters by SHG.

Castration-induced prostate epithelial cell apoptosis results from targeted oxidative stress attack of M1 -macrophages.

Prostate development and function are regulated by androgens. Epithelial cell apoptosis in response to androgen deprivation is caspase-9-dependent and peaks at Day 3 after castration. However, isolated epithelial cells survive in the absence of androgens.

Transcription regulators are transiently expressed during the prostate gland adaptation to the hypoandrogenic environment.

The high incidence of prostatic diseases, including malignant tumors, makes the understanding of prostate biology very important. Androgen deprivation, blockade by orchiectomy, or chemical castration causes prostate and tumor shrinkage. The gene networks involved in a cell type-specific fashion are rather unknown.

Enhanced mobility and controlled transparency in multilayered reduced graphene oxide quantum dots: a charge transport study.

Reduced graphene oxide (rGO) layers are known to be significantly conductive along the basal plane throughout delocalized sp domains. Defects present in rGO implies in disordered systems with numerous localized sites, resulting in a charge transport governed mainly by a 2D variable range hopping (VRH) mechanism. These characteristics are observed even in multilayered rGO since the through-plane conduction is expected to be insubstantial.

Hydrophilic Quantum Dots Functionalized with Gd(III)-DO3A Monoamide Chelates as Bright and Effective T-weighted Bimodal Nanoprobes.

Magnetic resonance imaging (MRI) is a powerful non-invasive diagnostic tool that enables distinguishing healthy from pathological tissues, with high anatomical detail. Nevertheless, MRI is quite limited in the investigation of molecular/cellular biochemical events, which can be reached by fluorescence-based techniques. Thus, we developed bimodal nanosystems consisting in hydrophilic quantum dots (QDs) directly conjugated to Gd(III)-DO3A monoamide chelates, a Gd(III)-DOTA derivative, allowing for the combination of the advantages of both MRI and fluorescence-based tools.

Topical essential fatty acid oil on wounds: Local and systemic effects.

Background: The use of medicinal plants and their derivatives is increasing, and approximately one-third of all traditional herbal medicines are intended for wound treatment. Natural products used in these treatments include vegetable oils, which are rich in essential fatty acids. Once in contact with an ulcerative surface, the oil reaches the blood and lymphatic vessels, thus eliciting systemic effects.

Second-harmonic generation imaging analysis can help distinguish sarcoidosis from tuberculoid leprosy.

Sarcoidosis and tuberculoid leprosy (TL) are prototypes of granulomatous inflammation in dermatology, which embody one of the histopathology limitations in distinguishing some diseases. Recent advances in the use of nonlinear optical microscopy in skin have enabled techniques, such as second-harmonic generation (SHG), to become powerful tools to study the physical and biochemical properties of skin. We use SHG images to analyze the collagen network, to distinguish differences between sarcoidosis and TL granulomas.

Peri/epicellular protein disulfide isomerase-A1 acts as an upstream organizer of cytoskeletal mechanoadaptation in vascular smooth muscle cells.

Although redox processes closely interplay with mechanoresponses to control vascular remodeling, redox pathways coupling mechanostimulation to cellular cytoskeletal organization remain unclear. The peri/epicellular pool of protein disulfide isomerase-A1 (pecPDIA1) supports postinjury vessel remodeling. Using distinct models, we investigated whether pecPDIA1 could work as a redox-dependent organizer of cytoskeletal mechanoresponses.

Six-wave mixing coherent anti-Stokes Raman scattering microscopy.

Acquiring images of biological tissues and cells without the assistance of exogenous labels with a fast repetition rate and chemical specificity is what coherent anti-Stokes Raman Scattering (CARS) imaging offers. Nonresonant background (NRB) is one of the main drawbacks of the CARS microscopy technique because it limits the detection of weak Raman lines and the detection of low-concentration molecules. We show that a six-wave mixing process with two beams, which is a cascade effect of CARS, show better signal/NRB ratio and can be utilized for biological tissues imaging.

Collagen analysis by second-harmonic generation microscopy predicts outcome of luminal breast cancer.

Second-harmonic generation microscopy represents an important tool to evaluate extracellular matrix collagen structure, which undergoes changes during cancer progression. Thus, it is potentially relevant to assess breast cancer development. We propose the use of second-harmonic generation images of tumor stroma selected on hematoxylin and eosin-stained slides to evaluate the prognostic value of collagen fibers analyses in peri and intratumoral areas in patients diagnosed with invasive ductal breast carcinoma.

Correction to "Three-Dimensional Superlattice of PbS Quantum Dots in Flakes".

[This corrects the article DOI: 10.1021/acsomega.7b01791.

Three-Dimensional Superlattice of PbS Quantum Dots in Flakes.

In the last two decades, many experiments were conducted in self-organization of nanocrystals into two- and three-dimensional (3D) superlattices and the superlattices were synthesized and characterized by different techniques, revealing their unusual properties. Among all characterization techniques, X-ray diffraction (XRD) is the one that has allowed the confirmation of the 3D superlattice formation due to the presence of sharp and intense diffraction peaks. In this work, we study self-organized superlattices of quantum dots of PbS prepared by dropping a monodispersed colloidal solution on a glass substrate at different temperatures.

Topical use and systemic action of green and roasted coffee oils and ground oils in a cutaneous incision model in rats (Rattus norvegicus albinus).

Introduction: Wounds are a common health problem. Coffee is widely consumed and its oil contains essential fatty acids. We evaluated the local (skin) and systemic effects associated with the topical use of coffee oils in rats.

InP Nanowire Biosensor with Tailored Biofunctionalization: Ultrasensitive and Highly Selective Disease Biomarker Detection.

Electrically active field-effect transistors (FET) based biosensors are of paramount importance in life science applications, as they offer direct, fast, and highly sensitive label-free detection capabilities of several biomolecules of specific interest. In this work, we report a detailed investigation on surface functionalization and covalent immobilization of biomarkers using biocompatible ethanolamine and poly(ethylene glycol) derivate coatings, as compared to the conventional approaches using silica monoliths, in order to substantially increase both the sensitivity and molecular selectivity of nanowire-based FET biosensor platforms. Quantitative fluorescence, atomic and Kelvin probe force microscopy allowed detailed investigation of the homogeneity and density of immobilized biomarkers on different biofunctionalized surfaces.

Stiffness signatures along early stages of Xylella fastidiosa biofilm formation.

The pathogenicity of Xylella fastidiosa is associated with its systematic colonization of the plant xylem, forming bacterial biofilms. Mechanisms of bacterial transport among different xylem vessels, however, are not completely understood yet, but are strongly influenced by the presence of extracellular polymeric substances (EPS), which surrounds the assembly of cells forming the biofilm. In this work, we show quantitative measurements on the elastic properties of the system composed by EPS and bacterial cell.

Multimodal evaluation of ultra-short laser pulses treatment for skin burn injuries.

Thousands of people die every year from burn injuries. The aim of this study is to evaluate the feasibility of high intensity femtosecond lasers as an auxiliary treatment of skin burns. We used an animal model and monitored the healing process using 4 different imaging modalities: histology, Optical Coherence Tomography (OCT), Second Harmonic Generation (SHG), and Fourier Transform Infrared (FTIR) spectroscopy.

Epithelial Ovarian Cancer Diagnosis of Second-Harmonic Generation Images: A Semiautomatic Collagen Fibers Quantification Protocol.

A vast number of human pathologic conditions are directly or indirectly related to tissular collagen structure remodeling. The nonlinear optical microscopy second-harmonic generation has become a powerful tool for imaging biological tissues with anisotropic hyperpolarized structures, such as collagen. During the past years, several quantification methods to analyze and evaluate these images have been developed.

Idiopathic atrophoderma of Pasini and Pierini: A case study of collagen and elastin texture by multiphoton microscopy.

Background: The diagnosis of idiopathic atrophoderma of Pasini and Pierini (IAPP) relies on typical clinical features, particularly distinctive pigmented ovular/round depressed plaques. Histologic examination often reveals no obvious changes, but patterns of collagen distribution, using multiphoton imaging and second harmonic generation can help track hidden details of tissue organization contributing to atrophy.

Objective: To identify histologic features that distinguish IAPP from unaffected skin.