520 research outputs found

    A hospital based study of scenerio of glaucoma patients in upper Assam, India

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    Background: Glaucoma can be defined as a chronic multifactorial optic neuropathy with a characteristic accelerated degeneration of retinal ganglion cells presenting as classical optic nerve head features and correlating visual field changes, which may or may not be associated with angle abnormality in the presence or absence of any cause for the disease.Methods: This was a prospective hospital based study of patients >40years with a suspicion of glaucoma attending the Outpatient Department of Ophthalmology, Assam Medical College, Dibrugarh, Assam, india. Patients were subjected to a comprehensive eye examination to diagnose and classify glaucoma.Results: In this study out of 1000 patients, 22 were diagnosed to have glaucoma (2.2%), most common age group >61years (50%), male patients were 73%, PACG accounted for 11 patients (50%). POAG in 7 cases (32%), LIG in 14%, Neovuscular in 1 cases (5%).Conclusions: Glaucoma prevalence, age and sex distribution was found to be similar to studies conducted in other parts of India. Most common type of glaucoma was PACG followed by POAG

    Optical conductivity study of screening of many-body effects in graphene interfaces

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    Theoretical studies have shown that electron-electron (e-e) and electron-hole (e-h) interactions play important roles in many observed quantum properties of graphene making this an ideal system to study many body effects. In this report we show that spectroscopic ellipsometry can enable us to measure this interactions quantitatively. We present spectroscopic data in two extreme systems of graphene on quartz (GOQ), an insulator, and graphene on copper (GOC), a metal which show that for GOQ, both e-e and e-h interactions dominate while for GOC e-h interactions are screened. The data further enables the estimation of the strength of the many body interaction through the effective fine structure constant, αg\alpha_{g}^{*}. The αg\alpha_{g}^{*} for GOQ indicates a strong correlation with an almost energy independent value of about 1.37. In contrast, αg\alpha_{g}^{*} value of GOC is photon energy dependent, is almost two orders of magnitude lower at low energies indicating very weak correlation.Comment: Main Article (4 pages, 4 figures); Supporting Online Material (12 pages, 9 figures

    Intramammary immunization of pregnant mice with staphylococcal protein a reduces the post-challenge mammary gland bacterial load but not pathology

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    Protein A, encoded by the spa gene, is one of the major immune evading MSCRAMM of S. aureus, demonstrated to be prevalent in a significant percentage of clinical bovine mastitis isolates in Australia. Given its' reported significance in biofilm formation and the superior performance of S. aureus biofilm versus planktonic vaccine in the mouse mastitis model, it was of interest to determine the immunogenicity and protective potential of Protein A as a potential vaccine candidate against bovine mastitis using the mouse mastitis model. Pregnant Balb/c mice were immunised with Protein A emulsified in an alum-based adjuvant by subcutaneous (s/c) or intramammary (i/mam) routes. While humoral immune response of mice post-immunization were determined using indirect ELISA, cell-mediated immune response was assessed by estimation of interferon-gamma (IFN-γ) produced by protein A-stimulated splenocyte supernatants. Protective potential of Protein A against experimental mastitis was determined by challenge of immunized versus sham-vaccinated mice by i/mam route, based upon manifestation of clinical symptoms, total bacterial load and histopathological damage to mammary glands. Significantly (p<0.05) higher levels of IgG1 isotype were produced in mice immunized by the s/c route. In contrast, significantly higher levels of the antibody isotype IgG2a were produced in mice immunized by the i/mam route (p<0.05). There was significant reduction (p<0.05) in bacterial loads of the mammary glands of mice immunized by Protein A regardless of the route of immunization, with medium level of clinical symptoms observed up to day 3 post-challenge. However, Protein A vaccine failed to protect immunized mice post-challenge with biofilm producing encapsulated S. aureus via i/mam route, regardless of the route of immunization, as measured by the level of mammary tissue damage. It was concluded that, Protein A in its' native state was apparently not a suitable candidate for inclusion in a cell-free vaccine formulation against mastitis

    From confined spinons to emergent fermions: Observation of elementary magnetic excitations in a transverse-field Ising chain

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    We report on spectroscopy study of elementary magnetic excitations in an Ising-like antiferromagnetic chain compound SrCo2_2V2_2O8_8 as a function of temperature and applied transverse magnetic field up to 25 T. An optical as well as an acoustic branch of confined spinons, the elementary excitations at zero field, are identified in the antiferromagnetic phase below the N\'{e}el temperature of 5 K and described by a one-dimensional Schr\"{o}dinger equation. The confinement can be suppressed by an applied transverse field and a quantum disordered phase is induced at 7 T. In this disordered paramagnetic phase, we observe three emergent fermionic excitations with different transverse-field dependencies. The nature of these modes is clarified by studying spin dynamic structure factor of a 1D transverse-field Heisenberg-Ising (XXZ) model using the method of infinite time evolving block decimation. Our work reveals emergent quantum phenomena and provides a concrete system for testifying theoretical predications of one-dimension quantum spin models.Comment: 8 pages and 6 figure

    Hybrid Spectral-IRDx: Near-IR and Ultrasound Attenuation System for Differentiating Breast Cancer from Adjacent Normal Tissue

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    OBJECTIVE: While performing surgical excision for breast cancer (lumpectomy), it is important to ensure a clear margin of normal tissue around the cancer to achieve complete resection. The current standard is histopathology; however, it is time-consuming and labour-intensive requiring skilled personnel. METHOD: We describe a Hybrid Spectral-IRDx - a combination of the previously reported Spectral-IRDx tool with multimodal ultrasound and NIR spectroscopy techniques. We show how this portable, cost-effective, minimal-contact tool could provide rapid diagnosis of cancer using formalin-fixed (FF) and deparaffinized (DP) breast biopsy tissues. RESULTS: Using this new tool, measurements were performed on cancerous/fibroadenoma and its adjacent normal tissues from the same patients (N=14). The acoustic attenuation coefficient () and reduced scattering coefficient (s) (at 850, 940, and 1060 nm) for the cancerous/fibroadenoma tissues were reported to be higher compared to adjacent normal tissues, a basis of delineation. Comparing FF cancerous and adjacent normal tissue, the difference in s at 850 nm and 940 nm were statistically significant (p=3.17e-2 and 7.94e-3 respectively). The difference in between the cancerous and adjacent normal tissues for DP and FF tissues were also statistically significant (p=2.85e-2 and 7.94e-3 respectively). Combining multimodal parameters and s (at 940 nm) show highest statistical significance (p=6.72e-4) between FF cancerous/fibroadenoma and adjacent normal tissues. CONCLUSION: We show that Hybrid Spectral-IRDx can accurately delineate between cancerous and adjacent normal breast biopsy tissue. SIGNIFICANCE: The results obtained establish the proof-of-principle and large-scale testing of this multimodal breast cancer diagnostic platform for core biopsy diagnosis

    Diversity of virulence factors associated with West Australian methicillin-sensitive staphylococcus aureus isolates of human origin

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    An extensive array of virulence factors associated with S. aureus has contributed significantly to its success as a major nosocomial pathogen in hospitals and community causing variety of infections in affected patients. Virulence factors include immune evading capsular polysaccharides, poly-N-acetyl glucosamine, and teichoic acid in addition to damaging toxins including hemolytic toxins, enterotoxins, cytotoxins, exfoliative toxin, and microbial surface components recognizing adhesive matrix molecules (MSCRAMM). In this investigation, 31 West Australian S. aureus isolates of human origin and 6 controls were analyzed for relative distribution of virulence-associated genes using PCR and/or an immunoassay kit and MSCRAMM by PCR-based typing. Genes encoding MSCRAMM, namely, Spa, ClfA, ClfB, SdrE, SdrD, IsdA, and IsdB, were detected in >90% of isolates. Gene encoding a-toxin was detected in >90% isolates whereas genes encoding ß-toxin and SEG were detectable in 50-60% of isolates. Genes encoding toxin proteins, namely, SEA, SEB, SEC, SED, SEE, SEH, SEI, SEJ, TSST, PVL, ETA, and ETB, were detectable in >50% of isolates. Use of RAPD-PCR for determining the virulence factor-based genetic relatedness among the isolates revealed five cluster groups confirming genetic diversity among the MSSA isolates, with the greatest majority of the clinical S. aureus (84%) isolates clustering in group IIIa

    Twórczość plastyczna jako forma wspierania rozwoju osób niewidomych i głuchoniewidomych

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    Twórczość plastyczna wydaje się być niedocenianym przez tyflopedagogów obszarem aktywności dzieci, młodzieży oraz dorosłych osób niewidomych i głuchoniewidomych. Tymczasem osoby te warto angażować w wiele form plastycznej kreacji, dodatkowo kierując się zasadą „im wcześniej, tym lepiej”. Tego typu doświadczenia mogą wspierać rozwój poznawczy, emocjonalny i społeczny osób z poważną dysfunkcją wzroku. Zostanie to wykazane na podstawie analizy literatury przedmiotu oraz poprzez przytoczenie studiów przypadków głuchoniewidomych uczestników plenerów rzeźbiarskich w Orońsku.Udostępnienie publikacji Wydawnictwa Uniwersytetu Łódzkiego finansowane w ramach projektu „Doskonałość naukowa kluczem do doskonałości kształcenia”. Projekt realizowany jest ze środków Europejskiego Funduszu Społecznego w ramach Programu Operacyjnego Wiedza Edukacja Rozwój; nr umowy: POWER.03.05.00-00-Z092/17-00
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