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Jin Yu

Publications and source records attributed to Jin Yu.

At least 37 records · Page 2Linked to original sources
PubMed2005

Long-range detection and length estimation of light filaments using extra-attenuation of terawatt femtosecond laser pulses propagating in air.

High-energy femtosecond laser pulses propagating in the atmosphere undergo self-focusing resulting in the appearance of the phenomenon of filamentation. We observed an extra-attenuation of such (terawatt) femtosecond laser pulses propagating in the atmosphere when compared with long pulses (200 ps) with the same energy. This is because, in contrast to the linear propagation of the long pulse, the input femtosecond laser pulse is attenuated owing to either absorption through multiphoton ionization/tunnel ionization or to scattering on the laser-induced plasma; self-phase-modulation and self-steepening further convert partially the energy initially contained in the fundamental bandwidth into the broad side bands of the laser, becoming eventually a white-light laser pulse (supercontinuum). The experimental data allow us to extract an effective extra-attenuation coefficient for an exponential decay of the input pulse energy with the propagation distance. Such a coefficient allows us to estimate an upper bound of the filament length under the experimental conditions used. More generally, our observation leads to a new technique to remotely detect light filaments in the atmosphere.

Journal Article↗
PubMed2005

Establishment of epidermal cell lines derived from the skin of the Atlantic bottlenose dolphin (Tursiops truncatus).

The Atlantic bottlenose dolphin (Tursiops truncatus), a marine mammal found off the Atlantic coast, has become the focus of considerable attention because of an increasing number of mortality events witnessed in this species over the last several years along the southeastern United States. Assessment of the impact of environmental stressors on bottlenose dolphins (BND) has been difficult because of the protected status of these marine mammals. The studies presented herein focused on establishing epidermal cell cultures and cell lines as tools for the in vitro evaluation of environmental stressors on BND skin. Epidermal cell cultures were established from skin samples obtained from Atlantic BND and subjected to karyotype analysis. These cultures were further characterized using immunohistochemical methods demonstrating expression of cytokeratins. By two-dimensional polyacrylamide gel electrophoresis (2D-PAGE), we observed that the proteomic profile of BND skin tissue samples shared distinct similarities with that of skin-derived cultures. Epidermal cell cultures were transfected with a plasmid encoding the SV40 small t- and large T-antigens, as well as the neomycin-resistance gene. Five neomycin-resistant clones were isolated and expanded, and all of them proliferated at a faster rate than nontransfected BND epidermal cultures, which exhibited signs of senescence. Cell lysates prepared from two transfected clones were shown to express, by Western blot analysis, both SV40 tumor antigens. These experimental results are consistent with the concept that transfected clones expressing SV40 tumor antigens represent immortalized BND cell lines. Epidermal cell lines derived from Tursiops truncatus will provide a unique tool for studying key features of the interaction occurring between dolphins and the environment in which they live at their most crucial interface: the skin.

Animals↗
PubMed2005

Physaloside A, an acylated sucrose ester from Physalis viscosa.

Chemical investigations of the crude MeOH extract of Physalis viscosa led to the identification of the novel acylated sucrose ester physaloside A (1). The structure of 1 was determined by 2D NMR analysis, and the absolute configuration was determined by chemical degradation and comparison with authentic standards.

Australia↗
PubMed2005

Cerylimycins [corrected] A and B: antibacterial triterpenes from the new species Tricholoma sp. AU1.

To new triterpenes, trichomycins A (1) and B (2), were purified from the new species Tricholoma sp. AU1 by activity-guided fractionation following their antibacterial activity. The two compounds were found to have a hitherto unreported triterpenoid skeleton. The structures and relative stereochemistry of 1 and 2 were determined through extensive 2D NMR spectroscopy, while the inhibitory activity of 1 and 2 against two Gram-positive and two Gram-negative bacteria and a mammalian cell line was determined.

Anti-Bacterial Agents↗
PubMed2005

Current topics of tinea capitis in China.

Tinea capitis is one type of superficial fungal infection which is found all over the world. The major etiologic agent of tinea capitis varies in different areas. Tinea capitis in China has unique characteristics. The epidemiology, transmission and therapy of child and adult tinea capitis in China are reviewed in this paper.

Adult↗
PubMed2005

Diagnostic support for glaucoma using retinal images: a hybrid image analysis and data mining approach.

The availability of modern imaging techniques such as Confocal Scanning Laser Tomography (CSLT) for capturing high-quality optic nerve images offer the potential for developing automatic and objective methods for diagnosing glaucoma. We present a hybrid approach that features the analysis of CSLT images using moment methods to derive abstract image defining features. The features are then used to train classifers for automatically distinguishing CSLT images of normal and glaucoma patient. As a first, in this paper, we present investigations in feature subset selction methods for reducing the relatively large input space produced by the moment methods. We use neural networks and support vector machines to determine a sub-set of moments that offer high classification accuracy. We demonstratee the efficacy of our methods to discriminate between healthy and glaucomatous optic disks based on shape information automatically derived from optic disk topography and reflectance images.

Data Mining↗
PubMed2004

Vitamin K acupuncture pint injection for severe primary dysmenorrhea: an international pilot study.

CONTEXT: Vitamin K acupuncture point injection, a menstrual pain treatment derived from traditional Chinese medicine, has been a standard treatment in some hospitals in China since the 1980s. OBJECTIVES: To investigate the effects of vitamin K acupuncture point injection on menstrual pain in young women aged 14 to 25 from different countries and cultural backgrounds who have had unmitigated severe primary dysmenorrhea for 6 months or more. DESIGN: Prospective, observational, clinical pilot study SETTINGS: One site in China (a hospital outpatient clinic in Shanghai) and 2 sites in Italy (a hospital clinic in Milan and a private gynecology practice in Verona). INTERVENTIONS: All subjects were treated with bilateral acupuncture point injection of vitamin K on the first or second day of menstrual pain. Vitamin K3 was used in China and vitamin K4 in Italy. MAIN OUTCOME MEASURES: Pain intensity, total duration, and average intensity of menstrual distress, hours in bed, normal daily activity restrictions, and numbers of analgesic tablets taken to relieve pain were recorded before the treatment and for 4 subsequent menstrual cycles. RESULTS: Noticeable pain relief was observed 2 minutes after treatment, and subsequent pain reduction occurred at 30 minutes (P < .001). Subjects reported significantly fewer daily life restrictions, fewer hours in bed, less consumption of analgesic tablets, and lower scores of menstrual pain duration and intensity (P < .001). There were no adverse events. Some women experienced mild, self-limited pain at the injection site. CONCLUSION: Acupuncture point injection with vitamin K alleviated acute menstrual pain, and relief extended through the nontreatment follow-up cycles in this uncontrolled pilot study conducted in 2 countries. Further investigation employing controlled experimental designs is warranted.

Acupuncture Points↗
PubMed2004

Conformational model of the Holliday junction transition deduced from molecular dynamics simulations.

Homologous recombination plays a key role in the restart of stalled replication forks and in the generation of genetic diversity. During this process, two homologous DNA molecules undergo strand exchange to form a four-way DNA (Holliday) junction. In the presence of metal ions, the Holliday junction folds into the stacked-X structure that has two alternative conformers. Experiments have revealed the spontaneous transitions between these conformers, but their detailed pathways are not known. Here, we report a series of molecular dynamics simulations of the Holliday junction at physiological and elevated (400 K) temperatures. The simulations reveal new tetrahedral intermediates and suggest a schematic framework for conformer transitions. The tetrahedral intermediates bear resemblance to the junction conformation in complex with a junction-resolving enzyme, T7 endonuclease I, and indeed, one intermediate forms a stable complex with the enzyme as demonstrated in one simulation. We also describe free energy minima for various states of the Holliday junction system, which arise during conformer transitions. The results show that magnesium ions stabilize the stacked-X form and destabilize the open and tetrahedral intermediates. Overall, our study provides a detailed dynamic model of the Holliday junction undergoing a conformer transition.

Computational Biology↗
PubMed2004

The interferon-inducible p204 protein acts as a transcriptional coactivator of Cbfa1 and enhances osteoblast differentiation.

The differentiation of uncommitted mesenchymal cells into osteoblasts is a fundamental molecular event governing both embryonic development and bone repair. The bone morphogenetic proteins (BMPs) are important regulators of this process; they function by binding to cell surface receptors and signaling by means of Smad proteins. Core binding factor alpha-1 (Cbfa1), a member of the runt family of transcription factors, is an essential transcriptional regulator of osteoblast differentiation and bone formation, and this process is positively or negatively regulated by a variety of coactivators and corepressors. We report that p204, an interferon-inducible protein that was previously shown to inhibit cell proliferation and promote the differentiation of myoblasts to myotubes, is a novel regulator in the course of osteogenesis. p204 is expressed in embryonic osteoblasts and hypertrophic chondrocytes in the growth plate as well as in the calvaria osteoblasts of neonatal mice. Its level is increased in the course of the BMP-2-triggered osteoblast differentiation of pluripotent C2C12 cells. This increase is probably due to the activation of the gene encoding 204 (Ifi204) by Smad transcription factor, including Smad1, -4, and -5. Overexpression of p204 enhances the BMP-2-induced osteoblast differentiation in vitro, as revealed by elevated alkaline phosphatase activity and osteocalcin production. p204 acts as a cofactor of Cbfa1: 1) high levels of p204 augment, whereas the lowering of p204 level decreases, the Cbfa1-dependent transcription, and 2) p204 associates with Cbfa1 both in vitro and in vivo. Two nonoverlapping segments in p204 bind to Cbfa1, and the N-terminal 88-amino acid segment of Cbfa1 is required for binding to p204. p204, which is the first interferon-inducible protein found to associate with Cbfa1, functions as a novel regulator of osteoblast differentiation.

Alkaline Phosphatase↗
PubMed2004

Cyclooxygenase-2 parallels invasive depth and increased MVD in transitional cell carcinoma.

To investigate the relationship between the expression of cyclooxygenase-2 (COX-2), and invasive depth and angiogenesis in human transitional cell carcinoma (TCC), the expression of COX-2 and von Willebrand factor (vWF) was detected in paraffin-embedded transitional cell carcinoma specimens from 50 patients with histologically confirmed bladder transitional cell carcinoma. Microvessels were counted and microvessel density (MVD) was calculated. The correlation between COX-2 and invasive depth, MVD and invasive depth, COX-2 and MVD were analyzed. COX-2 expression was significantly related to the invasive depth of tumors; it solely expressed in invasive TCC. The ratio of COX-2 positively stained samples in each stage correlated to the invasive stages; so did the proportion of COX-2 (+) cells in whole tumor cells. Also, MVD increased with the invasive stages of tumors and positively correlated to the invasive depth. The COX-2-positive TCC samples were highly vascular, their microvessel density was significantly higher than that of the COX-2-negative TCC samples. There was a positive correlation between MVD and COX-2 (+) cells proportion. Our findings suggested that COX-2 was positively correlated with the invasive depth and involved in the process of angiogenesis in human transitional cell carcinoma.

Carcinoma, Transitional Cell↗
PubMed2004

Kilometer-range nonlinear propagation of femtosecond laser pulses.

Ultrashort, high-power laser pulses propagating vertically in the atmosphere have been observed over more than 20 km using an imaging 2-m astronomical telescope. This direct observation in several wavelength bands shows indications for filament formation at distances as far as 2 km in the atmosphere. Moreover, the beam divergence at 5 km altitude is smaller than expected, bearing evidence for whole-beam parallelization about the nonlinear focus. We discuss implications for white-light Lidar applications.

Journal Article↗
PubMed2004

Globoidnan A: a lignan from Eucalyptus globoidea inhibits HIV integrase.

An HTS campaign aimed at the identification of inhibitors of HIV integrase showed that the methanol extract from the buds of a Eucalyptus globoidea was active. Bioassay guided fractionation of this extract resulted in the purification and structural elucidation of the lignan, globoidnan A (1) as the only compound in the extract responsible for the inhibition of HIV integrase. The compound was found to inhibit the combined 3' processing and strand transfer activity of HIV integrase with an IC50=0.64 microM.

Eucalyptus↗
PubMed2004

Adult tinea capitis due to Trichophyton violaceum in China.

Tinea capitis is rare in adults. We report a case of adult tinea capitis due to Trichophyton violaceum in China. The female patient was immunosuppressed with prednisone due to the underlying disease of vulgaris pemphigus and was treated successfully with terbinafine. We also reviewed published cases of adult tinea capitis in China and compared these data with the characteristics of published cases in other regions in the world.

Antifungal Agents↗
PubMed2004

Molecular typing study of the Microsporum canis strains isolated from an outbreak of tinea capitis in a school.

Tinea capitis is a dermatophyte infection of the scalp that occurs most often in prepubescent children. Tinea capitis may be transmitted by shared use of contaminated hairbrush, by contact with fomites or by direct physical contact with an infected person. Occasionally, outbreak of tinea capitis would happen under some special conditions. Last year, we found an outbreak of tinea capitis in a school due to Microsporum canis. In epidemiological study, we performed the prevalence survey to all of the exposed persons by physical examinations and mycological laboratory tests, including KOH preparation and fungal cultures. We also investigated the environment in the school. In molecular typing study of the M. canis isolated from patients and the environment, random primer amplification polymorphic DNA (RAPD) method, the specific amplification of subrepeat element in the ribosomal DNA nontranscribed spacer (NTS), and the analysis of DNA sequence in the intertranscribed spacer (ITS) of rDNA were performed. The total number of exposed children was seventy-one, among them forty-two were attacked by tinea capitis. The ratio between boy and girl was 13:1. The ages of the patients was ranged from 3.5 years old to 10 years old. Four patients bred cat or dog as pet. Most patients appeared noninflammatory type of tinea capitis and several patients were inflammatory type. Under microscopic examination the invaded hair were all ectothrix. The pathogens isolated from these patients were M. canis. And we also isolated M. canis from the carpet and the pillowcase in the school. The patterns of total strains of M. canis in the RAPD method and PCR amplification of the rDNA NTS region study were identical, and the isolates from patients and the environment contained the same DNA sequences in the ITS region. The outbreak of tinea capitis was caused by M. canis. The M. canis isolated from patients and from the environment were probably the same origin.

Child↗
PubMed2004

Time window of fibroblast growth factor-18-mediated neuroprotection after occlusion of the middle cerebral artery in rats.

To assess the time window for fibroblast growth factor-18 (FGF18)-mediated neuroprotection, FGF18 was administered by intravenous infusion at various times after transient occlusion of the middle cerebral artery (MCAO) in rats. Vehicle or FGF18 (100 microg x kg(-1) x h(-1)) was infused at 0.25, 0.5, 1.0, 2.0, 4.0, or 8.0 hours after MCAO with infarct volumes and behavioral deficits measured at 24.0 hours after MCAO. A separate group of animals received the infusions 24 hours after MCAO with endpoints measured at 48 hours after MCAO. Infusion of FGF18 reduced infarct volumes and improved scores in tests of reference and working memory, motor ability, and exploratory behavior. FGF18 was most efficacious when infused within 2 hours after MCAO. Significant reductions in infarct volumes and reductions in deficits of reference memory and motor activity were also observed with FGF18 infused 24 hours after MCAO. Measurements taken at infusion times before 2 hours after MCAO showed that regional cerebral blood flow was increased by FGF18. Administration of vehicle or FGF18 had no significant effect on mean arterial blood pressure, heart rate, brain temperature, blood pH, Pco2, or Po2. These results demonstrate that FGF18 is an effective neuroprotective agent when administered early after transient MCAO in rats. Efficacy observed with infusions at later times suggests an expanded time window for FGF18-mediated neuroprotection.

Animals↗
PubMed2004

[Integrated traditional Chinese and western medicine should make new contribution to the reproductive health of women].

The Obstectrics and Gynecology Hospital attached to Fudan University has made great achievements in the clinical and experimental study of integrated traditional Chinese and western medicine in the past 45 years. Study on induction of ovulation with acupuncture revealed the relationship between circulating estrogen and central beta-endorphin, and suggested that the depletion of central beta-endorphin resulted in the release of GnRH and ovulation, and the main indication for acupuncture treatment was pubertal dysfunctional uterine bleeding. Acupuncture was also successfully used to treat anorexia nervosa. The successful treatment of polycystic ovary syndrome (PCOS) with Yu's Tonifying Recipe for tonifying the kidney and resolving phlegm was found to be related to the elevation of serum FSH which resulted in ovulation. Good result was obtained in hyperinsulinemia pattern of PCOS treated with Tiangui Recipe for replenishing the kidney and activating blood. In studies on patients and animal model, Tiangui Recipe was found to decrease peripheral androgen and insulin levels and lead to central regulation of proopiomelanocortin, neuropeptide Y and leptin receptor, as well as regulation of neuro-endocrine-metabolic network. Thus it can promote ovulation and reduce body weight. In the studies, a new way to classify PCOS was suggested. Gengnianchun Recipe for women with postmenopausal syndrome was found to be effective in increasing estrogen receptors (ERs) and ER mRNA in hypothalamus and peripheral organs and regulating neuro-endocrine-immune-metabolic network in patients and aging rats. Gongtai was effective for controlling menorrhagia under the mechanism of regulating endometrial prostaglandins. The researches mentioned above indicate that illness is the disorder of some key-links in the life network of the patient which may be affected by factors from the environment. And this idea is different from the ideas in traditional Chinese medicine and biomedicine. It indicates that woman in subclinical health state has already got something incontrollable in her life network, and it also gives a new impact on the treatment and prevention of women's diseases as well as the prevention and treatment of women's reproductive health.

Female↗
PubMed2004

[Brain volumetric MRI study in healthy elderly persons using statistical parametric mapping].

PURPOSE: To investigate the age-related changes in the brains of healthy elderly subjects, a volumetric MRI was performed using Statistical Parametric Mapping (SPM) and Region of Interest (ROI) methods. We determined the volumes of the whole brain, the gray matter, the prefrontal cortex, the hippocampus and the entorhinal cortex. SUBJECTS AND METHODS: We examined 61 subjects (29 males and 32 females) aged 61 to 91 years (mean +/- SD = 72.4 +/- 7.85) who were residents of Okinawa prefecture, living at home and highly active as demonstrated by sustained participation in senior citizens clubs and/or group activities at senior citizen welfare centers. They had no history of psychiatric disorders, neurological or significant physical illness. They had Mini-Mental State Examination scores of 24 or above (mean +/- SD = 28.3 +/- 1.57), Japanese version of the Geriatric Depression Scale scores of 9 or below, and Tokyo Metropolitan Institute of Gerontology scores of 11 or above. All subjects were dextral. This study received prior approval by the participating medical institution. Informed consent was obtained from the individual subjects. Volumetric MRI was performed using a 1.5 Tesla MRI scanner (Magnetom Vision, Siemens). T1-weighted images were acquired in the coronal plane (perpendicular to anterior commissure-posterior commissure line) using a 3D-FLASH (fast low angle shot) sequence. Imaging parameters were: TR = 35 ms, TE = 5 ms, Flip angle = 45 deg., Field of View = 240 mm, Matrix 256 x 256, Pixel 0.9375 x 0.9375, Slice thickness 1.5 mm, Gapless. MR image data were analyzed by SPM using an imaging analysis software MEDx (Sensor Systems Inc.) running on UNIX workstation (Sun SPARC Solaris 7, Sun Microsystems, Inc.). Volumetry was performed by automatic segmentation technique using SPM for the whole brain and the gray matter, and manual tracing using ROI based quantitative methods for the prefrontal cortex, the hippocampus and the entorhinal cortex. Local volumes were normalized by the intracranial volume and the gray matter volume. Correlation to age was determined by Pearson's correlation coefficient. Volumetric MRI was performed under blinded conditions. RESULTS: Volumetric MRI of normal brain in healthy elderly subjects showed age-related changes. The whole brain (r = -0.568, p < 0.01), the gray matter (r = -0.406, p < 0.01), the prefrontal cortex (r = -0.470, p < 0.01), the hippocampus (r = -0.305, p < 0.05), and the entorhinal cortex (r = -0.455, p < 0.01) volume significantly decreased with age. The age-related hippocampal volume reduction was similar to the gray matter reduction, but the age-related prefrontal cortex and entorhinal cortex volume reductions were greater than the gray matter volume reduction. The prefrontal cortex and the hippocampal volumes differed by sex, being greater in females (p < 0.05). The hippocampal volume was lateralized: right side was greater than the left (p < 0.01). The entorhinal cortex volume was lateralized so that the left side was greater than the right (p < 0.01). CONCLUSION: As a result of volumetric MRI using SPM, age-related changes of normal brain in healthy elderly persons did not always show unified atrophy. The ratio of atrophy was different by a local area. Our findings suggested that the most marked age-related brain volume reductions were seen in the prefrontal cortex and the entorhinal cortex. The age-related hippocampal volume reduction was similar to the gray matter reduction.

Aged↗