59 research outputs found

    A Breathing Stabilization System

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    Breathing Stabilization System is a new idea and method. The purpose of this system is to produce a device to control a patient’s breathing for gated radiotherapy. This thesis focuses on building a simple Breathing Stabilization System that includes five solenoids, a power supply and five force sensors to build up the whole system. Significantly, this thesis will introduce the modeling of solenoids in detail that include how to build a mathematical model of the solenoids. The simulation of the electromagnetic in professional multi-physics software COMSOL will also be explained. To drive the solenoid system, a voltage-to-current converter is used. This part will be introduced as well as the operational amplifier circuit used by the force sensors

    Variational Learning for the Inverted Beta-Liouville Mixture Model and Its Application to Text Categorization

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    he finite invert Beta-Liouville mixture model (IBLMM) has recently gained some attention due to its positive data modeling capability. Under the conventional variational inference (VI) framework, the analytically tractable solution to the optimization of the variational posterior distribution cannot be obtained, since the variational object function involves evaluation of intractable moments. With the recently proposed extended variational inference (EVI) framework, a new function is proposed to replace the original variational object function in order to avoid intractable moment computation, so that the analytically tractable solution of the IBLMM can be derived in an effective way. The good performance of the proposed approach is demonstrated by experiments with both synthesized data and a real-world application namely text categorization

    Induction of CCL8/MCP-2 by mycobacteria through the activation of TLR2/PI3K/Akt signaling pathway.

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    Pleural tuberculosis (TB), together with lymphatic TB, constitutes more than half of all extrapulmonary cases. Pleural effusions (PEs) in TB are representative of lymphocytic PEs which are dominated by T cells. However, the mechanism underlying T lymphocytes homing and accumulation in PEs is still incompletely understood. Here we performed a comparative analysis of cytokine abundance in PEs from TB patients and non-TB patients by protein array analysis and observed that MCP-2/CCL8 is highly expressed in the TB-PEs as compared to peripheral blood. Meanwhile, we observed that CCR5, the primary receptor used by MCP-2/CCL8, is mostly expressed on pleural CD4(+) T lymphocytes. Furthermore, we found that infection with either Mycobacterium bovis Bacillus Calmette-Guérin (BCG) or Mycobacterium tuberculosis H37Rv induced production of MCP-2/CCL8 at both transcriptional and protein level in Raw264.7 and THP-1 macrophage cells, mouse peritoneal macrophages as well as human PBMC monocyte-derived macrophages (MDMs). The induction of MCP-2/CCL8 by mycobacteria is dependent on the activation of TLR2/PI3K/Akt and p38 signaling pathway. We conclude that accumulation of MCP-2/CCL8 in TB-PEs may function as a biomarker for TB diagnosis

    Intraocular complement activation is related to retinal vascular and neuronal degeneration in myopic retinopathy

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    PurposeTo investigate the relationship between the intraocular levels of complement proteins and myopia-related retinal neuronal and vascular degeneration.MethodsAqueous humour from 147 myopic patients, including 60 low-myopia and 87 high-myopia were collected during Implantable Collamer Lens implantation surgery. All participants received comprehensive ophthalmic examinations, including logMAR best corrected visual acuity, axial length measurement, fundus photography and ocular B-scan ultrasonography. The myopic eyes were further classified into simple myopia (SM, n = 78), myopic posterior staphyloma (PS, n = 39) and PS with myopic chorioretinal atrophy (PS + CA, n = 30). Retinal thickness and vascular density in the macula (6 mm × 6 mm) and optic nerve head (4.5 mm × 4.5 mm) were measured using Optical Coherence Tomography (OCT) and OCT angiography (OCTA). The levels of complement proteins including C1q, C3, C3b/iC3b, C4, CFB, CFH, C2, C4b, C5, C5a, CFD, MBL and CFI in the aqueous humour were measured using the Luminex Multiplexing system. The real-time RT-PCR was conducted to examine the expression of complement genes (C1q, C2, C3, C4, CFI and CFD) in the guinea pig model of long-term form deprivation-induced myopic retinal degeneration.ResultsOCTA showed that retinal neuronal thickness and vascular density in superficial and deep layers of the macular zone as well as vascular density in the optic nerve head were progressively decreased from SM to PS and PS + CA (p < 0.05). The aqueous humour levels of C1q, C3, C3b/iC3b, C4, CFB, CFH, C2, C4b, C5 and CFI were significantly higher in high-myopic eyes compared to those in low-myopic eyes. Further subgroup analysis revealed the highest levels of complement components/fragments in the PS + CA group. The intraocular levels of complement factors particularly C3b/iC3b and C4 were negatively correlated with macular zone deep layer retinal thickness and vascular density and optic nerve head vascular density. The expression of C2, C3 and C4 genes was significantly higher in guinea pig eyes with myopic retinal degeneration compared to control eyes.ConclusionsThe intraocular classical pathway and alternative pathway of the complement system are partially activated in pathological myopia. Their activation is related to the degeneration of retinal neurons and the vasculature in the macula and the vasculature in the optic nerve head

    Condom use social norms and self-efficacy with different kinds of male partners among Chinese men who have sex with men: results from an online survey

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    Abstract Background Social norms and self-efficacy play important roles in promoting consistent condom use among men who have sex with men (MSM). Few studies have investigated the association between social norms, self-efficacy and consistent condom use with different kinds of male partners among MSM. We conducted an online survey of MSM to evaluate this in China. Methods A cross-sectional online survey was conducted in 2015. Participants completed a validated questionnaire covering socio-demographic information, consistent condom use, condom use social norms and self-efficacy. Eligible participants were 16 or older, born biologically as a male, engaged in anal sex with a man at least once during their lifetime, engaged in condomless anal or vaginal sex in the last three months. In this study, we further restricted to people who had sex with male partners in the last three months. Participants were classified into three groups: engaged in sex only with regular partners, engaged in sex only with casual partners and engaged in sex with both regular partners and casual partners. Results Participants were recruited from 32 provinces in China. Among 1057 participants, 451(42.7%), 217(20.5%), and 389(36.8%) engaged in sex with regular partners only, casual partners only and both types in the last three months, respectively. Men engaged in sex only with regular partners in the last three months had a higher condom use self-efficacy than with other two types of partners (P  0.05). Conclusions Both social norms and self-efficacy were positively correlated with consistent condom use with any types of partners among Chinese MSM. Tailored interventions that aimed to improve social norms and self-efficacy has the potential to improve overall condom use among Chinese MSM. Trial registration ClinicalTrials.gov: NCT02516930 . August 6, 2015

    Condom use social norms and self-efficacy with different kinds of male partners among Chinese men who have sex with men: results from an online survey.

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    BACKGROUND: Social norms and self-efficacy play important roles in promoting consistent condom use among men who have sex with men (MSM). Few studies have investigated the association between social norms, self-efficacy and consistent condom use with different kinds of male partners among MSM. We conducted an online survey of MSM to evaluate this in China. METHODS: A cross-sectional online survey was conducted in 2015. Participants completed a validated questionnaire covering socio-demographic information, consistent condom use, condom use social norms and self-efficacy. Eligible participants were 16 or older, born biologically as a male, engaged in anal sex with a man at least once during their lifetime, engaged in condomless anal or vaginal sex in the last three months. In this study, we further restricted to people who had sex with male partners in the last three months. Participants were classified into three groups: engaged in sex only with regular partners, engaged in sex only with casual partners and engaged in sex with both regular partners and casual partners. RESULTS: Participants were recruited from 32 provinces in China. Among 1057 participants, 451(42.7%), 217(20.5%), and 389(36.8%) engaged in sex with regular partners only, casual partners only and both types in the last three months, respectively. Men engaged in sex only with regular partners in the last three months had a higher condom use self-efficacy than with other two types of partners (P  0.05). CONCLUSIONS: Both social norms and self-efficacy were positively correlated with consistent condom use with any types of partners among Chinese MSM. Tailored interventions that aimed to improve social norms and self-efficacy has the potential to improve overall condom use among Chinese MSM. TRIAL REGISTRATION: ClinicalTrials.gov: NCT02516930 . August 6, 2015

    Progress in biological and medical research in the deep underground: an update

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    As the growing population of individuals residing or working in deep underground spaces for prolonged periods, it has become imperative to understand the influence of factors in the deep underground environment (DUGE) on living systems. Heping Xie has conceptualized the concept of deep underground medicine to identify factors in the DUGE that can have either detrimental or beneficial effects on human health. Over the past few years, an increasing number of studies have explored the molecular mechanisms that underlie the biological impacts of factors in the DUGE on model organisms and humans. Here, we present a summary of the present landscape of biological and medical research conducted in deep underground laboratories and propose promising avenues for future investigations in this field. Most research demonstrates that low background radiation can trigger a stress response and affect the growth, organelles, oxidative stress, defense capacity, and metabolism of cells. Studies show that residing and/or working in the DUGE has detrimental effects on human health. Employees working in deep mines suffer from intense discomfort caused by high temperature and humidity, which increase with depth, and experience fatigue and sleep disturbance. The negative impacts of the DUGE on human health may be induced by changes in the metabolism of specific amino acids; however, the cellular pathways remain to be elucidated. Biological and medical research must continue in deep underground laboratories and mines to guarantee the safe probing of uncharted depths as humans utilize the deep underground space

    Dysregulation in Retinal Para-Inflammation and Age-Related Retinal Degeneration in CCL2 or CCR2 Deficient Mice

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    We have shown previously that a para-inflammatory response exists at the retinal/choroidal interface in the aging eye; and this response plays an important role in maintaining retinal homeostasis under chronic stress conditions. We hypothesized that dysregulation of the para-inflammatory response may result in an overt pro-inflammatory response inducing retinal degeneration. In this study, we examined this hypothesis in mice deficient in chemokine CCL2 or its cognate receptor CCR2. CCL2- or CCR2-deficient mice developed retinal degenerative changes with age, characterized as retinal pigment epithelial (RPE) cell and photoreceptor cell death. Retinal cell death was associated with significantly more subretinal microglial accumulation and increased complement activation. In addition, monocytes from CCL2- or CCR2-deficient mice had reduced capacity for phagocytosis and chemotaxis, expressed less IL-10 but more iNOS, IL-12 and TNF-α when compared to monocytes from WT mice. Complement activation at the site of RPE cell death resulted in C3b/C3d but not C5b-9 deposition, indicating only partial activation of the complement pathway. Our results suggest that altered monocyte functions may convert the protective para-inflammatory response into an overtly harmful inflammation at the retina/choroidal interface in CCL2- or CCR2-deficient mice, leading to RPE and photoreceptor degeneration. These data support a concept whereby a protective para-inflammatory response relies upon a normally functioning innate immune system. If the innate immune system is deficient chronic stress may tip the balance towards an overt inflammatory response causing cell/tissue damage
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