2,186 research outputs found

    Quantitative Analysis of the Fate of Gold Nanocages In Vitro and In Vivo after Uptake by U87-MG Tumor Cells

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    Not always equal: When a mother cell that contains Au nanocages divides, the nanoparticles are unequally distributed between the two daughter cells. This unequal distribution of nanoparticles as well as their clearance from the cells (see picture) is quantitatively analyzed both in vitro and in vivo using two-photon microscopy and photoacoustic microscopy, respectively

    A New Theranostic System Based on Gold Nanocages and Phase-Change Materials with Unique Features for Photoacoustic Imaging and Controlled Release

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    This communication reports a new theranostic system with a combination of capabilities to both enhance the contrast of photoacoustic (PA) imaging and control the release of a chemical or biological effector by high-intensity focused ultrasound (HIFU). The fabrication of this system simply involves filling the hollow interiors of gold nanocages with a phase-change material (PCM) such as 1-tetradecanol that has a melting point of 38−39 °C. The PCM can be premixed and thus loaded with a dye, as well as other chemical or biological effectors. When exposed to direct heating or HIFU, the PCM will melt and escape from the interiors of nanocages through small pores on the surface, concurrently releasing the encapsulated molecules into the surrounding medium. We can control the release profile by varying the power of HIFU, the duration of exposure to HIFU, or both

    Measuring the Optical Absorption Cross Sections of Au−Ag Nanocages and Au Nanorods by Photoacoustic Imaging

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    This paper presents a method for measuring the optical absorption cross sections (σ_a) of Au−Ag nanocages and Au nanorods. The method is based on photoacoustic (PA) imaging, where the detected signal is directly proportional to the absorption coefficient (μ_a) of the nanostructure. For each type of nanostructure, we first obtained μ_a from the PA signal by benchmarking against a linear calibration curve (PA signal versus μ_a) derived from a set of methylene blue solutions with different concentrations. We then calculated σ_a by dividing the μ_a by the corresponding concentration of the Au nanostructure. Additionally, we obtained the extinction cross section (σ_e, sum of absorption and scattering) from the extinction spectrum recorded using a conventional UV−vis−NIR spectrometer. From the measurements of σ_a and σ_e, we were able to easily derive both the absorption and scattering cross sections for each type of gold nanostructure. The ratios of absorption to extinction obtained from experimental and theoretical approaches agreed well, demonstrating the potential use of this method in determining the optical absorption and scattering properties of gold nanostructures and other types of nanomaterials

    Depression and suicide risk prediction models using blood-derived multi-omics data

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    More than 300 million people worldwide experience depression; annually, ~800,000 people die by suicide. Unfortunately, conventional interview-based diagnosis is insufficient to accurately predict a psychiatric status. We developed machine learning models to predict depression and suicide risk using blood methylome and transcriptome data from 56 suicide attempters (SAs), 39 patients with major depressive disorder (MDD), and 87 healthy controls. Our random forest classifiers showed accuracies of 92.6% in distinguishing SAs from MDD patients, 87.3% in distinguishing MDD patients from controls, and 86.7% in distinguishing SAs from controls. We also developed regression models for predicting psychiatric scales with R2 values of 0.961 and 0.943 for Hamilton Rating Scale for Depression???17 and Scale for Suicide Ideation, respectively. Multi-omics data were used to construct psychiatric status prediction models for improved mental health treatment

    Photoacoustic quantification of the optical absorption cross-sections of gold nanostructures

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    This study demonstrates a method for measuring the optical absorption cross-sections (σ_a) of Au-Ag nanocages and Au nanorods using photoacoustic (PA) sensing. PA signals are directly proportional to the absorption coefficient (μ_a) of the nanostructure. For each type of nanostructure, we first obtained μa from the PA signal by benchmarking against a linear calibration curve (PA signal vs. μ_a) derived from a set of methylene blue solutions with different concentrations. We then calculated σ_a by dividing the μ_a by the corresponding concentration of the Au nanostructure. Additionally, we obtained the extinction cross-section (σ_e, sum of absorption and scattering cross-sections) from the extinction spectrum recorded using a conventional UV-vis-NIR spectrometer. From the measurements of σ_a and σ_e, we were able to easily derive both the absorption and scattering cross-sections for each type of gold nanostructure. This method can potentially provide the optical absorption and scattering properties of gold nanostructures and other types of nanomaterials

    Secondary renal amyloidosis in a 13-year-old girl with bronchiectasis

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    A 13-year-old girl was diagnosed with non-cystic fibrosis (CF)-related multifocal bronchiectasis accompanied by nephrotic-range proteinuria of unknown cause. On renal biopsy, there were many segmental homogeneous deposits of amyloid tissue with positive Congo red staining in the glomeruli and interstitium. On electron microscopy, relatively straight, non-branching, randomly arranged amyloid fibrils were showed in the mesangium of the glomeruli. These fibrils were approximately 10 nm in diameter, compatible with secondary amyloidosis. Her level of serum amyloid A was remarkably elevated. To our knowledge, this girl is the first case of secondary renal amyloidosis induced by bronchiectasis in Korean children

    Grading system for periodontitis by analyzing levels of periodontal pathogens in saliva

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    Periodontitis is an infectious disease that is associated with microorganisms that colonize the tooth surface. Clinically, periodontal condition stability reflects dynamic equilibrium between bacterial challenge and host response. Therefore, periodontal pathogen assessment can assist in the early detection of periodontitis. Here we developed a grading system called the periodontal pathogen index (PPI) by analyzing the copy numbers of multiple pathogens both in healthy and chronic periodontitis patients. We collected 170 mouthwash samples (64 periodontally healthy controls and 106 chronic periodontitis patients) and analyzed the salivary 16S rRNA levels of nine pathogens using multiplex, quantitative real-time polymerase chain reaction. Except for Aggregatibacter actinomycetemcomitans, copy numbers of all pathogens were significantly higher in chronic periodontitis patients. We classified the samples based on optimal cut-off values with maximum sensitivity and specificity from receiver operating characteristic curve analyses (AUC = 0.91, 95% CI: 0.87-0.96) into four categories of PPI: Healthy (1-40), Moderate (41-60), At Risk (61-80), and Severe (81-100). PPI scores were significantly higher in all chronic periodontitis patients than in the controls (odds ratio: 31.7, 95% CI: 13.41-61.61) and were associated with age, scaling as well as clinical characteristics including clinical attachment level and plaque index. Our PPI grading system can be clinically useful for the early assessment of pathogenic bacterial burden and follow-up monitoring after periodontitis treatment

    Role of Staphylococcal Superantigen in Atopic Dermatitis: Influence on Keratinocytes

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    Staphylococcus aureus may perform an crucial function in atopic dermatitis (AD), via the secretion of superantigens, including staphylococcal enterotoxins (SE) A or B, and toxic shock syndrome toxin-1 (TSST-1). Dysregulated cytokine production by keratinocytes (KCs) upon exposure to staphylococcal superantigens (SsAgs) may be principally involved in the pathophysiology of AD. We hypothesized that lesional KCs from AD may react differently to SsAgs compared to nonlesional skin or normal skin from nonatopics. We conducted a comparison of HLA-DR or CD1a expression in lesional skin as opposed to that in nonlesional or normal skin by immunohistochemistry (IHC). We also compared, using ELISA, the levels of IL-1α, IL-1β, and TNF-α secreted by cultured KCs from lesional, nonlesional, and normal skin, after the addition of SEA, SEB and TSST-1. IHC revealed that both HLA-DR and CD1a expression increased significantly in the epidermis of lesional skin versus nonlesional or normal skin in quite a similar manner. IL-1α, IL-1β, and TNF-α secretion was also significantly elevated in the cultured KCs from lesional skin after the addition of SsAgs. Our results indicated that KCs from lesional skin appear to react differently to SsAgs and increased proinflammatory cytokine production in response to SsAgs may contribute to the pathogenesis of AD
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