233 research outputs found

    Interfacial Reactions of Ozone with Surfactant Protein B in a Model Lung Surfactant System

    Get PDF
    Oxidative stresses from irritants such as hydrogen peroxide and ozone (O_3) can cause dysfunction of the pulmonary surfactant (PS) layer in the human lung, resulting in chronic diseases of the respiratory tract. For identification of structural changes of pulmonary surfactant protein B (SP-B) due to the heterogeneous reaction with O_3, field-induced droplet ionization (FIDI) mass spectrometry has been utilized. FIDI is a soft ionization method in which ions are extracted from the surface of microliter-volume droplets. We report structurally specific oxidative changes of SP-B_(1−25) (a shortened version of human SP-B) at the air−liquid interface. We also present studies of the interfacial oxidation of SP-B_(1−25) in a nonionizable 1-palmitoyl-2-oleoyl-sn-glycerol (POG) surfactant layer as a model PS system, where competitive oxidation of the two components is observed. Our results indicate that the heterogeneous reaction of SP-B_(1−25) at the interface is quite different from that in the solution phase. In comparison with the nearly complete homogeneous oxidation of SP-B_(1−25), only a subset of the amino acids known to react with ozone are oxidized by direct ozonolysis in the hydrophobic interfacial environment, both with and without the lipid surfactant layer. Combining these experimental observations with the results of molecular dynamics simulations provides an improved understanding of the interfacial structure and chemistry of a model lung surfactant system subjected to oxidative stress

    Dietary supplementation of young broiler chickens with Capsicum and turmeric oleoresins increases resistance to necrotic enteritis

    Get PDF
    The Clostridium-related poultry disease, necrotic enteritis (NE), causes substantial economic losses on a global scale. In the present study, a mixture of two plant-derived phytonutrients, Capsicum oleoresin and turmeric oleoresin (XT), was evaluated for its effects on local and systemic immune responses using a co-infection model of experimental NE in commercial broilers. Chickens were fed from hatch with a diet supplemented with XT, or with a non-supplemented control diet, and either uninfected or orally challenged with virulent Eimeria maxima oocysts at 14d and Clostridium perfringens at 18d of age. Parameters of protective immunity were as follows: (1) body weight; (2) gut lesions; (3) serum levels of C. perfringens α-toxin and NE B-like (NetB) toxin; (4) serum levels of antibodies to α-toxin and NetB toxin; (5) levels of gene transcripts encoding pro-inflammatory cytokines and chemokines in the intestine and spleen. Infected chickens fed the XT-supplemented diet had increased body weight and reduced gut lesion scores compared with infected birds given the non-supplemented diet. The XT-fed group also displayed decreased serum α-toxin levels and reduced intestinal IL-8, lipopolysaccharide-induced TNF-α factor (LITAF), IL-17A and IL-17F mRNA levels, while cytokine/chemokine levels in splenocytes increased in the XT-fed group, compared with the animals fed the control diet. In conclusion, the present study documents the molecular and cellular immune changes following dietary supplementation with extracts of Capsicum and turmeric that may be relevant to protective immunity against avian N

    Cinnamaldehyde enhances in vitro parameters of immunity and reduces in vivo infection against avian coccidiosis

    Get PDF
    The effects of cinnamaldehyde (CINN) on in vitro parameters of immunity and in vivo protection against avian coccidiosis were evaluated. In vitro stimulation of chicken spleen lymphocytes with CINN (25-400ng/ml) induced greater cell proliferation compared with the medium control (P<0·001). CINN activated cultured macrophages to produce higher levels of NO at 1·2-5·0ÎŒg/ml (P<0·001), inhibited the growth of chicken tumour cells at 0·6-2·5ÎŒg/ml (P<0·001) and reduced the viability of Eimeria tenella parasites at 10 and 100ÎŒg/ml (P<0·05 and P<0·001, respectively), compared with media controls. In chickens fed a diet supplemented with CINN at 14·4mg/kg, the levels of IL-1ÎČ, IL-6, IL-15 and interferon-Îł transcripts in intestinal lymphocytes were 2- to 47-fold higher (P<0·001) compared with chickens given a non-supplemented diet. To determine the effect of CINN diets on avian coccidiosis, chickens were fed diets supplemented with CINN at 14·4mg/kg (E. maxima or E. tenella) or 125mg/kg (E. acervulina) from hatch for 24d, and orally infected with 2·0×104 sporulated oocysts at age 14d. CINN-fed chickens showed 16·5 and 41·6% increased body-weight gains between 0-9d post-infection (DPI) with E. acervulina or E. maxima, reduced E. acervulina oocyst shedding between 5-9 DPI and increased E. tenella-stimulated parasite antibody responses at 9 DPI compared with control

    Crystal Structure, Electronic Structure, and Optical Properties of the Novel Li4cdge2s7, a Wide-Bandgap Quaternary Sulfide with a Polar Structure Derived from Lonsdaleite

    Get PDF
    The novel quaternary thiogermanate Li4CdGe2S7 (tetralithium cadmium digermanium heptasulfide) was discovered from a solid-state reaction at 750 °C. Single-crystal X-ray diffraction data were collected and used to solve and refine the structure. Li4CdGe2S7 is a member of the small, but growing, class of I4-II-IV2-VI7 diamond-like materials. The compound adopts the Cu5Si2S7 structure type, which is a derivative of lonsdaleite. Crystallizing in the polar space group Cc, Li4CdGe2S7 contains 14 crystallographically unique ions, all residing on general positions. Like all diamond-like structures, the compound is built of corner-sharing tetrahedral units that create a relatively dense three-dimensional assembly. The title compound is the major phase of the reaction product, as evidenced by powder X-ray diffraction and optical diffuse reflectance spectroscopy. While the compound exhibits a second-harmonic generation (SHG) response comparable to that of the AgGaS2 (AGS) reference material in the IR region, its laser-induced damage threshold (LIDT) is over an order of magnitude greater than AGS for λ = 1.064 ÎŒm and τ = 30 ps. Bond valence sums, global instability index, minimum bounding ellipsoid (MBE) analysis, and electronic structure calculations using density functional theory (DFT) were used to further evaluate the crystal structure and electronic structure of the compound and provide a comparison with the analogous I2-II-IV-VI4 diamond-like compound Li2CdGeS4. Li4CdGe2S7 appears to be a better IR nonlinear optical (NLO) candidate than Li2CdGeS4 and one of the most promising contenders to date. The exceptional LIDT is likely due, at least in part, to the wider optical bandgap of ∌3.6 eV

    Small anisotropy of the lower critical field and s±s_\pm-wave two-gap feature in single crystal LiFeAs

    Full text link
    The in- and out-of-plane lower critical fields and magnetic penetration depths for LiFeAs were examined. The anisotropy ratio ÎłHc1(0)\gamma_{H_{c1}}(0) is smaller than the expected theoretical value, and increased slightly with increasing temperature from 0.6TcT_c to TcT_c. This small degree of anisotropy was numerically confirmed by considering electron correlation effect. The temperature dependence of the penetration depths followed a power law(∌\simTnT^n) below 0.3TcT_c, with nn>>3.5 for both λab\lambda_{ab} and λc\lambda_c. Based on theoretical studies of iron-based superconductors, these results suggest that the superconductivity of LiFeAs can be represented by an extended s±s_\pm-wave due to weak impurity scattering effect. And the magnitudes of the two gaps were also evaluted by fitting the superfluid density for both the in- and out-of-plane to the two-gap model. The estimated values for the two gaps are consistent with the results of angle resolved photoemission spectroscopy and specific heat experiments.Comment: 10 pages, 5 figure

    Solitary osteochondroma of the twelfth rib with intraspinal extension and cord compression in a middle-aged patient

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Osteochondroma is a disease of growing bone and thus typically presents in younger patients. It has rarely been described in middle-aged and elderly patients. Data on the occurrence of osteochondroma show that the reported incidence of costal osteochondroma is very low. Moreover, costal osteochondroma arising at the costovertebral junction with neural foraminal extension and spinal cord compression is extremely rare.</p> <p>Case presentation</p> <p>This study reports the case of a 58-year-old patient with a solitary osteochondroma of the 12th rib with intraspinal extension and spinal cord compression. The clinical history, plain radiographs, computed tomography (CT), magnetic resonance imaging, and pathologic findings of the reported patient have been reviewed. The relevant medical literature has also been reviewed. The patient was treated with surgery for complete tumour excision to avoid tumour recurrence. After surgery, the patient's symptoms improved. An additional CT scan obtained at 1 year after surgery did not show any evidence of recurrence.</p> <p>Conclusions</p> <p>This patient is the oldest patient reported to have this rare form of costal osteochondroma. The age of the patient and the erosion of the adjacent bones raised clinical suspicion of malignancy; therefore, surgical management involved complete tumour excision with thoracolumbar fixation and fusion.</p

    Identification of a novel angiogenic peptide from periostin

    Get PDF
    Angiogenic peptides have therapeutic potential for the treatment of chronic ischemic diseases. Periostin, an extracellular matrix protein expressed in injured tissues, promotes angiogenesis and tissue repair. We previously reported that in vivo administration of both recombinant full-length protein and the first FAS I domain of periostin alleviated peripheral artery occlusive disease by stimulating the migration of humane endothelial colony forming cells (ECFCs) and subsequent angiogenesis. In the present study, we ascertained the peptide sequence responsible for the periostin-induced angiogenesis. By serial deletion mapping of the first FAS I domain, we identified a peptide sequence (amino acids 142-151) of periostin for stimulation of chemotactic migration, adhesion, proliferation and endothelial tube formation of human ECFCs in vitro. Chemotactic migration of ECFCs induced by the periostin peptide was blocked by pre-incubation with an anti-??5 integrin neutralizing antibody. Treatment of ECFCs with the periostin peptide led to phosphorylation of both AKT and ERK, and pretreatment of ECFCs with the MEK-ERK pathway inhibitor U0126 or the PI3K-AKT pathway inhibitors, LY294002 or Wortmannin, blocked the periostin peptide-stimulated migration of ECFCs. These results suggest that the synthetic periostin peptide can be applied for stimulating angiogenic and therapeutic potentials of ECFCs

    Association between Interpersonal Trust, Reciprocity, and Depression in South Korea: A Prospective Analysis

    Get PDF
    Background: A growing body of empirical evidence indicates that low-level social capital is related to poor mental health outcomes. However, the prospective association between social capital and depression remains unclear, and no published studies have investigated the association with longitudinal data in East-Asian countries. Methods: We analyzed data from the ongoing Korean Welfare Panel Study to prospectively investigate association between social capital and depression. Social capital was measured at the individual level by two items specific to interpersonal trust and reciprocity. Depression was annually assessed as a dichotomous variable using the Center for Epidemiologic Studies Depression Scale. After excluding participants who had depression in 2006, logistic regression models were applied to estimate the association between each social capital indicator and new-onset depression developed in 2007 or long-term depression in both 2007 and 2008. We also examined the association in a subpopulation restricted to healthy participants after excluding individuals with any pre-existing disability, chronic disease, or poor self-rated health condition. Results: Compared to the high interpersonal trust group, the odds ratios of developing new-onset and long-term depression among the low interpersonal trust group were 1.22 (95% CI: 1.08∌1.38) and 1.23 (95% CI: 1.03∌1.50), respectively, and increased to 1.32 (95% CI: 1.10∌1.57) and 1.47 (95% CI: 1.05∌2.08) in the subpopulation analyses restricted to healthy individuals. Although the low and intermediate reciprocity group also had significantly higher odds of developing new-onset depression compared to the high reciprocity group, the effects were attenuated and statistically non-significant in the subpopulation analyses. Conclusion: Low interpersonal trust appears to be an independent risk factor for new-onset and long-term depression in South Korea

    Percutaneous Coronary Intervention Versus Medical Therapy for Chronic Total Occlusion of Coronary Arteries:A Systematic Review and Meta-Analysis

    Get PDF
    PURPOSE OF REVIEW: Chronic total occlusion (CTO) of the coronary arteries is a significant clinical problem and has traditionally been treated by medical therapy or coronary artery bypass grafting. Recent studies have examined percutaneous coronary intervention (PCI) as an alternative option. RECENT FINDINGS: This systematic review and meta-analysis compared medical therapy to PCI for treating CTOs. PubMed and Embase were searched from their inception to March 2019 for studies that compared medical therapy and PCI for clinical outcomes in patients with CTOs. Quality of the included studies was assessed by Newcastle-Ottawa scale. The results were pooled by DerSimonian and Laird random- or fixed-effect models as appropriate. Heterogeneity between studies and publication bias was evaluated by I2 index and Egger's regression, respectively. Of the 703 entries screened, 17 studies were included in the final analysis. This comprised 11,493 participants. Compared to PCI, medical therapy including randomized and observational studies was significantly associated with higher risk of all-cause mortality (risk ratio (RR) 1.99, 95% CI 1.38-2.86), cardiac mortality (RR 2.36 (1.97-2.84)), and major adverse cardiac event (RR 1.25 (1.03-1.51)). However, no difference in the rate of myocardial infarction and repeat revascularization procedures was observed between the two groups. Univariate meta-regression demonstrated multiple covariates as independent moderating factors for myocardial infarction and repeat revascularization but not cardiac death and all-cause mortality. However, when only randomized studies were included, there was no difference in overall mortality or cardiac death. In CTO, when considering randomized and observational studies, medical therapy might be associated with a higher risk of mortality and myocardial infarction compared to PCI treatment

    El Conocimiento DidĂĄctico del Contenido en ciencias: estado de la cuestiĂłn

    Get PDF
    This paper gives a descriptive overview of the literature related to Pedagogical Content Knowledge - PCK - in the sciences. It is expected that this review can contribute to a better understanding of PCK, pointing out what has been investigated about this concept. Specifically, we analyze: a) how PCK is defined, what are its main features and how it has been appropriated by teachers; b) the relationship between PCK, knowledge of the contents to be taught and students learning; c) how PCK was actually used in teachers' training and teachers' evaluation; and, d) the scientific areas in which PCK has been studied. It concludes that PCK is an essential tool for improving the quality of teacher training
    • 

    corecore