1,869 research outputs found

    Parental use of the term "Hot Qi" to describe symptoms in their children in Hong Kong: a cross sectional survey "Hot Qi" in children

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    BACKGROUND: The Chinese term "Hot Qi" is often used by parents to describe symptoms in their children. The current study was carried out to estimate the prevalence of using the Chinese term "Hot Qi" to describe symptoms in children by their parents and the symptomatology of "Hot Qi". METHOD: A cross sectional survey by face-to-face interview with a semi-structured questionnaire was carried out in a public hospital and a private clinic in Hong Kong. The parental use of the term "Hot Qi", the symptoms of "Hot Qi" and the remedies used for "Hot Qi" were asked. RESULTS: 1060 pairs of children and parents were interviewed. 903 (85.1%) of parents claimed that they had employed the term "Hot Qi" to describe their children's symptoms. Age of children and place of birth of parents were the predictors of parents using the term "Hot Qi". Eye discharge (37.2%), sore throat (33.9%), halitosis(32.8%), constipation(31.0%), and irritable (21.2%) were the top five symptoms of "Hot Qi" in children. The top five remedies for "Hot Qi" were the increased consumption of water (86.8%), fruit (72.5%), soup (70.5%), and the use of herbal beverages "five-flower- tea" (a combination of several flowers such as Chrysanthemum morifolii, Lonicera japonica, Bombax malabaricum, Sophora japonica, and Plumeria rubra) (57.6%) or selfheal fruit spike (Prunella vulgaris) (42.4%). CONCLUSION: "Hot Qi" is often used by Chinese parents to describe symptoms in their children in Hong Kong. Place of birth of parents and age of the children are main factors for parents to apply the term "Hot Qi" to describe symptoms of their children. The common symptoms of "Hot Qi" suggest infections or allergy

    Enhanced ex vivo expansion of adult mesenchymal stem cells by fetal mesenchymal stem cell ECM

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    Large-scale expansion of highly functional adult human mesenchymal stem cells (aMSCs) remains technologically challenging as aMSCs lose self renewal capacity and multipotency during traditional long-term culture and their quality/quantity declines with donor age and disease. Identification of culture conditions enabling prolonged expansion and rejuvenation would have dramatic impact in regenerative medicine. aMSC-derived decellularized extracellular matrix (ECM) has been shown to provide such microenvironment which promotes MSC self renewal and “stemness”. Since previous studies have demonstrated superior proliferation and osteogenic potential of human fetal MSCs (fMSCs), we hypothesize that their ECM may promote expansion of clinically relevant aMSCs. We demonstrated that aMSCs were more proliferative (∼1.6×) on fMSC-derived ECM than aMSC-derived ECMs and traditional tissue culture wares (TCPS). These aMSCs were smaller and more uniform in size (median ± interquartile range: 15.5 ± 4.1 μm versus 17.2 ± 5.0 μm and 15.5 ± 4.1 μm for aMSC ECM and TCPS respectively), exhibited the necessary biomarker signatures, and stained positive for osteogenic, adipogenic and chondrogenic expressions; indications that they maintained multipotency during culture. Furthermore, fMSC ECM improved the proliferation (∼2.2×), size (19.6 ± 11.9 μm vs 30.2 ± 14.5 μm) and differentiation potential in late-passaged aMSCs compared to TCPS. In conclusion, we have established fMSC ECM as a promising cell culture platform for ex vivo expansion of aMSCs.Singapore-MIT Alliance for Research and Technolog

    Single-walled carbon nanotubes as excitonic optical wires

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    Although metallic nanostructures are useful for nanoscale optics, all of their key optical properties are determined by their geometry. This makes it difficult to adjust these properties independently, and can restrict applications. Here we use the absolute intensity of Rayleigh scattering to show that single-walled carbon nanotubes can form ideal optical wires. The spatial distribution of the radiation scattered by the nanotubes is determined by their shape, but the intensity and spectrum of the scattered radiation are determined by exciton dynamics, quantum-dot-like optical resonances and other intrinsic properties. Moreover, the nanotubes display a uniform peak optical conductivity of ~8 e^2/h, which we derive using an exciton model, suggesting universal behaviour similar to that observed in nanotube conductance. We further demonstrate a radiative coupling between two distant nanotubes, with potential applications in metamaterials and optical antennas

    On-Chip Rayleigh Imaging and Spectroscopy of Carbon Nanotubes

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    We report a novel on-chip Rayleigh imaging technique using wide-field laser illumination to measure optical scattering from individual single-walled carbon nanotubes (SWNTs) on a solid substrate with high spatial and spectral resolution. This method in conjunction with calibrated AFM measurements accurately measures the resonance energies and diameters for a large number of SWNTs in parallel. We apply this technique for fast mapping of key SWNT parameters, including the electronic-types and chiral indices for individual SWNTs, position and frequency of chirality-changing events, and intertube interactions in both bundled and distant SWNTs

    Uptake and mitochondrial dysfunction of alpha-synuclein in human astrocytes, cortical neurons and fibroblasts

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    © 2013 Braidy et al.; licensee BioMed Central Ltd. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.The accumulation and aggregation of alpha-synuclein (α-syn) in several tissue including the brain is a major pathological hallmark in Parkinson’s disease (PD). In this study, we show that α-syn can be taken up by primary human cortical neurons, astrocytes and skin-derived fibroblasts in vitro. Our findings that brain and peripheral cells exposed to α-syn can lead to impaired mitochondrial function, leading to cellular degeneration and cell death, provides additional evidence for the involvement of mitochondrial dysfunction as a mechanism of toxicity of α-syn in human cells

    Examining Patterns of Adversity in Chinese Young Adults Using the Adverse Childhood Experiences – International Questionnaire (ACE-IQ)

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    Ample evidence supports significant and enduring associations between adverse childhood experiences (ACEs) and negative outcomes later in life. Subsets of ACEs (e.g. childhood maltreatment and household dysfunction) have been examined in Chinese populations, but no known study has comprehensively examined the full constellation of different types of ACEs or patterns of ACE exposure in Chinese samples. As a direct response to the call toestablish a global ACEs surveillance framework, this study provides the first translation and validation of the World Health Organization ACE – International Questionnaire (ACE-IQ).Further, patterns of ACE exposure were identified through latent class analysis. The 29-item ACE-IQ was translated and back-translated from English to traditional Chinese to measure exposure to 13 categories of ACEs. The Chinese ACE-IQ demonstrated good content validity; the ACE-IQ domain subscales also showed satisfactory test-retest reliability and semantic equivalence. In a sample of 433 Chinese young adults, three patterns of ACE exposure were uncovered: Low ACEs (65.82%), Household Violence (24.94%), and Multiple ACEs (9.24%).Concurrent exposure to physical abuse, domestic violence, and emotional abuse (i.e. Household Violence) was a novel pattern found in this study sample, and suggests there may be traditional Chinese norms that potentiate risks for violent household environments in the absence of other household risk factors. Findings underscore the importance of examining ACE exposure within local contexts, as children’s adverse experiences may be idiosyncratic to geographic, social, and cultural norms

    Ferredoxin containing bacteriocins suggest a novel mechanism of iron uptake in <i>Pectobacterium spp</i>

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    In order to kill competing strains of the same or closely related bacterial species, many bacteria produce potent narrow-spectrum protein antibiotics known as bacteriocins. Two sequenced strains of the phytopathogenic bacterium &lt;i&gt;Pectobacterium carotovorum&lt;/i&gt; carry genes encoding putative bacteriocins which have seemingly evolved through a recombination event to encode proteins containing an N-terminal domain with extensive similarity to a [2Fe-2S] plant ferredoxin and a C-terminal colicin M-like catalytic domain. In this work, we show that these genes encode active bacteriocins, pectocin M1 and M2, which target strains of &lt;i&gt;Pectobacterium carotovorum&lt;/i&gt; and &lt;i&gt;Pectobacterium atrosepticum&lt;/i&gt; with increased potency under iron limiting conditions. The activity of pectocin M1 and M2 can be inhibited by the addition of spinach ferredoxin, indicating that the ferredoxin domain of these proteins acts as a receptor binding domain. This effect is not observed with the mammalian ferredoxin protein adrenodoxin, indicating that &lt;i&gt;Pectobacterium spp.&lt;/i&gt; carries a specific receptor for plant ferredoxins and that these plant pathogens may acquire iron from the host through the uptake of ferredoxin. In further support of this hypothesis we show that the growth of strains of &lt;i&gt;Pectobacterium carotovorum&lt;/i&gt; and &lt;i&gt;atrosepticum&lt;/i&gt; that are not sensitive to the cytotoxic effects of pectocin M1 is enhanced in the presence of pectocin M1 and M2 under iron limiting conditions. A similar growth enhancement under iron limiting conditions is observed with spinach ferrodoxin, but not with adrenodoxin. Our data indicate that pectocin M1 and M2 have evolved to parasitise an existing iron uptake pathway by using a ferredoxin-containing receptor binding domain as a Trojan horse to gain entry into susceptible cells

    Ions in mixed dielectric solvents: density profiles and osmotic pressure between charged interfaces

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    The forces between charged macromolecules, usually given in terms of osmotic pressure, are highly affected by the intervening ionic solution. While in most theoretical studies the solution is treated as a homogeneous structureless dielectric medium, recent experimental studies concluded that, for a bathing solution composed of two solvents (binary mixture), the osmotic pressure between charged macromolecules is affected by the binary solvent composition. By adding local solvent composition terms to the free energy, we obtain a general expression for the osmotic pressure, in planar geometry and within the mean-field framework. The added effect is due to the permeability inhomogeneity and nonelectrostatic short-range interactions between the ions and solvents (preferential solvation). This effect is mostly pronounced at small distances and leads to a reduction in the osmotic pressure for macromolecular separations of the order 1--2 nm. Furthermore, it leads to a depletion of one of the two solvents from the charged macromolecules (modeled as planar interfaces). Lastly, by comparing the theoretical results with experimental ones, an explanation based on preferential solvation is offered for recent experiments on the osmotic pressure of DNA solutions.Comment: 13 pages, 8 figure

    Translation and validation of the Chinese ICD-11 International Trauma Questionnaire (ITQ) for the Assessment of Posttraumatic Stress Disorder (PTSD) and Complex PTSD (CPTSD)

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    Two stress related disorders have been proposed for inclusion in the revised ICD11: Posttraumatic Stress Disorder (PTSD) and Complex PTSD (CPTSD). The International Trauma Questionnaire (ITQ) is a bespoke measure of PTSD and CPTSD, and has been widely used in English speaking countries. Objective. The primary aim of this study was to develop a Chinese version of the ITQ and assess its content, construct, and concurrent validity. Methods. Six mental health practitioners and experts rated the Chinese translated and back-translated items to assess content validity. A sample of 423 Chinese young adults completed the ITQ, the WHO Adverse Childhood Experiences International Questionnaire, and the Hospital Anxiety and Depression Scale. Among them, 31 participants also completed the English and Chinese versions of the ITQ administered in random order at retest. Four alternative confirmatory factor analysis models were tested using data from participants who reported at least one adverse childhood experience (ACE; N=314). Results. The Chinese ITQ received excellent ratings on relevance and appropriateness. Test-retest reliability and semantic equivalence across English and Chinese versions were acceptable. The correlated first-order six-factor model and a second-order twofactor (PTSD and DSO) both provided acceptable model fit. The six ITQ symptoms clusters were all significantly correlated with anxiety, depression, and number of ACEs. Conclusions. The Chinese ITQ generates scores with acceptable psychometric properties and provides evidence for including PTSD and CPTSD as separate diagnoses in ICD-11
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