Publications by authors named "SS Gao"

We propose methods to align interferograms affected by trigger jitter to a reference interferogram based on the information (amplitude/phase) at a fixed-pattern noise location to reduce residual fixed-pattern noise and improve the phase stability of swept source optical coherence tomography (SS-OCT) systems. One proposed method achieved this by introducing a wavenumber shift (k-shift) in the interferograms of interest and searching for the k-shift that minimized the fixed-pattern noise amplitude. The other method calculated the relative k-shift using the phase information at the residual fixed-pattern noise location.

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Retinal vascular diseases are important causes of vision loss. A detailed evaluation of the vascular abnormalities facilitates diagnosis and treatment in these diseases. Optical coherence tomography (OCT) angiography using the highly efficient split-spectrum amplitude decorrelation angiography algorithm offers an alternative to conventional dye-based retinal angiography.

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Article Synopsis
  • A new imaging technique using gold nanorods as contrast agents in optical coherence tomography (OCT) has been developed, showcasing an innovative way to enhance imaging quality.
  • By analyzing the changes in light spectrum from the nanorods, researchers can differentiate signal intensity between short and long wavelengths, which improves detection of these agents.
  • The technique has been proven effective in detecting nanorods in tissue-like samples and successfully labels specific cells in laboratory tests.
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Heat stress stimulates the production of reactive oxygen species (ROS), which cause oxidative damage in the kidney. This study clarifies the mechanism by which saikosaponin-d (SSd), which is extracted from the roots of Bupleurum falcatum L, protects heat-stressed pig kidney proximal tubular (LLC-PK1) cells against oxidative damage. SSd alone is not cytotoxic at concentrations of 1 or 3 μg/mL as demonstrated by a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay.

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The tonotopic map of the mammalian cochlea is commonly thought to be determined by the passive mechanical properties of the basilar membrane. The other tissues and cells that make up the organ of Corti also have passive mechanical properties; however, their roles are less well understood. In addition, active forces produced by outer hair cells (OHCs) enhance the vibration of the basilar membrane, termed cochlear amplification.

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Objective: To develop a detection method for Cryptosporidium parvum oocysts from water samples, which combined immunomagnetic separation (IMS) with Taqman real-time PCR (qPCR).

Methods: Conditions of separation and enrichment of IMS method by using specific streptavidin magnetic beads coated with monoclonal antibodies Cp23 directed against C. parvum oocysts were optimized.

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Objective: To study the correlation between various complications of chronic heart failure (CHF) patients and Chinese medical syndromes, thus indicating distribution laws of Chinese medical syndromes in various complications of CHF patients.

Methods: Chinese medical syndrome typing was performed in 630 CHF patients by cross-sectional study of the demographic data, history of present diseases, related information on Chinese medical four diagnostic methods, and the distribution of complications. Logistic regression analysis was used to determine the correlation of various complications of CHF patients and Chinese medical syndromes.

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Mupirocin, a clinically important antibiotic produced via a trans-AT Type I polyketide synthase (PKS) in Pseudomonas fluorescens, consists of a mixture of mainly pseudomonic acids A, B, and C. Detailed metabolic profiling of mutant strains produced by systematic inactivation of PKS and tailoring genes, along with re-feeding of isolated metabolites to mutant stains, has allowed the isolation of a large number of novel metabolites, identification of the 10,11-epoxidase, and full characterization of the mupirocin biosynthetic pathway, which proceeds via major (10,11-epoxide) and minor (10,11-alkene) parallel pathways.

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The Notch signaling pathway is thought to regulate multiple stages of inner ear development. Mutations in the Notch signaling pathway cause disruptions in the number and arrangement of hair cells and supporting cells in sensory regions of the ear. In this study we identify an insertional mutation in the mouse Sfswap gene, a putative splicing factor, that results in mice with vestibular and cochlear defects that are consistent with disrupted Notch signaling.

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The outer hair cell (OHC) motor protein prestin is necessary for electromotility, which drives cochlear amplification and produces exquisitely sharp frequency tuning. Tecta(C1509G) transgenic mice have hearing loss, and surprisingly have increased OHC prestin levels. We hypothesized, therefore, that prestin up-regulation may represent a generalized response to compensate for a state of hearing loss.

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The study of mouse hearing impairment mutants has led to the identification of a number of human hearing impairment genes and has greatly furthered our understanding of the physiology of hearing. The novel mouse mutant neurological/sensory 5 (nse5) demonstrates a significantly reduced or absent startle response to sound and is therefore a potential murine model of human hearing impairment. Genetic analysis of 500 intercross progeny localized the mutant locus to a 524 kilobase (kb) interval on mouse chromosome 15.

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Five new anthranilic acid derivatives, penipacids A-E (1-5), together with one known analogue (6), which was previously synthesized, were characterized from the ethyl acetate extract of the marine sediment-derived fungus Penicillium paneum SD-44. Their structures were elucidated mainly by extensive NMR spectroscopic and mass spectrometric analysis. The cytotoxicity and antimicrobial activity of the isolated compounds were evaluated.

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Given the frequent use of improvised explosive devices (IEDs) around the world, the study of traumatic blast injuries is of increasing interest. The ear is the most common organ affected by blast injury because it is the body's most sensitive pressure transducer. We fabricated a blast chamber to re-create blast profiles similar to that of IEDs and used it to develop a reproducible mouse model to study blast-induced hearing loss.

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One new lignan (7S,8R,7'R,8'R)-7-(3,4-methylenedioxyphenyl)-8,8'-dimethyl-8'-hydroxyl-7'-methoxyl-7'-(3',4'-methylenedioxyphenyl)-tetrahydrofuran (1), one new sesquiterpene 2-hydroxy-11,12-dehydrocalamenene (2), one new natural product erythro-1-(3,4-dimethoxyphenyl)-4-(3,4-methylenedioxyphenyl)-2,3-dimethyl-butane (3), and two known lignans (+)-anwulignan(erythro-1-(4-hydroxy-3-methoxyphenyl)-4-(3,4-methylenedioxyphenyl)-2,3-dimethyl-butane) (4) and ( - )-zuonin-A (5) were isolated from the stems of Schisandra glaucescens Diels. Their structures were elucidated by spectroscopic methods. The cytotoxicity of compounds 1 and 2 was assayed.

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For visible and infrared color fusion images, objective sharpness assessment model is proposed to measure the clarity of detail and edge definition of the fusion image. Firstly, the contrast sensitivity functions (CSF) of the human visual system is used to reduce insensitive frequency components under certain viewing conditions. Secondly, perceptual contrast model, which takes human luminance masking effect into account, is proposed based on local band-limited contrast model.

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Sound transduction within the auditory portion of the inner ear, the cochlea, is a complex nonlinear process. The study of cochlear mechanics in large rodents has provided important insights into cochlear function. However, technological and experimental limitations have restricted studies in mice due to their smaller cochlea.

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Objective: To study the chemical constituents from Schisandra glaucescens.

Method: The chemical constituents were separated and purifed with silica gel, gel column chromatography preparative HPLC, and their structures were identified by such spectral methods as MS and NMR.

Result: Twelve compounds were separated from petroleum ether fractions, and identified as t-cadinol (1), alpha-cadinol (2), torreyol (3), (+)-ent-epicubenol (4), ent-T-muurolol (5), (-)-15-hydroxycalamenene (6), (-)-cubebol (7), 4-epi-cubebol (8), caryophyllenol-I (9), caryophyllenol-II (10), oxyphyllenodiols A (11), caryolane-1,9/3-diol (12).

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Micromotion and fretting damages at the dental implant/bone interface are neglected for the limitation of check methods, but it is particularly important for the initial success of osseointegration and the life time of dental implant. This review article describes the scientific documentation of micromotion and fretting damages on the dental implant/bone interface. The fretting amplitude is less than 30 µm in vitro and the damage in the interface is acceptable.

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The warm temperature acclimation related 65 kDa protein-2 (Wap65-2), a teleost plasma glycoprotein, plays an important role in immune regulation against bacterial infection. Here, for the first time we determined the full length cDNA sequence of the Japanese sea bass Wap65-2 gene (1 601 bp in length excluding the 3'-polyA tail). The sequence contains an open reading frame that encodes a protein of 436 amino acids with a molecular weight of 4.

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The marine sediment-derived fungus Penicillium commune QSD-17 was re-investigated and cultured on rice solid medium. Two new compounds, isophomenone (1) and 3-deacetylcitreohybridonol (2), together with seven known derivatives (3-9), were identified. Their structures were determined by spectroscopic analysis.

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Bioassay-guided fractionation of the culture extract of Aspergillus wentii EN-48, an endophytic fungus isolated from an unidentified marine brown algal species of the genus Sargassum, led to the isolation of three new tetranorlabdane diterpenoids, asperolides A-C (1-3), and five related derivatives (4-8). The structures of these compounds were established on the basis of spectroscopic interpretation, and compound 1 was confirmed by X-ray crystallographic analysis. The absolute configuration of 1 was determined by application of the modified Mosher's method.

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Typically, chemopreventive agents involve either induction of phase II detoxifying enzymes and/or inhibition of cytochrome P450 enzymes (CYPs) that are required for the activation of procarcinogens. In this study, we investigated the protective effects of phloretin against aflatoxin B1 (AFB1) activation to the ultimate carcinogenic intermediate, AFB(1)-8, 9-epoxide (AFBO), and its subsequent detoxification. Phloretin markedly inhibited formation of the epoxide with human liver microsomes in a dose-dependent manner.

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Vibratory measurements of the structures of the ear are key to understanding much of the pathology in mouse models of hearing loss. Unfortunately the high-speed sampling required to interrogate the high end of the mouse hearing spectrum is beyond the reach of most optical coherence tomography (OCT) systems. To address this issue, we have developed an algorithm that enables phase-sensitive OCT measurements over the full range of the mouse hearing spectrum (4-90 kHz).

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Human hearing loss often occurs as a result of damage or malformations to the functional soft tissues within the cochlea, but these changes are not appreciable with current medical imaging modalities. We sought to determine whether optical coherence tomography (OCT) could assess the soft tissue structures relevant to hearing using mouse models. We imaged excised cochleae with an altered tectorial membrane and during normal development.

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Two new tetracyclic diterpenes of the rarely reported cyclopiane class, conidiogenones H and I (1 and 2, resp.), along with five related congeners, conidiogenones B - D and F (3-5 and 6, resp.) and conidiogenol (7), were characterized from the culture extracts of Penicillium chrysogenum QEN-24S, an endophytic fungus derived from an unidentified marine red algal species of the genus Laurencia.

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