1,329 research outputs found

    Arrays of optical vortices formed by "fork" holograms

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    Singular light beams with optical vortices (OV) are often generated by means of thin binary gratings with groove bifurcation ("fork holograms") that produce a set of diffracted beams with different OV charges. Usually, only single separate beams are used and investigated; here we consider the whole set of diffracted OV beams that, at certain conditions, are involved in efficient mutual interference to form a characteristic pattern where the ring-like structure of separate OV beams is replaced by series of bright and dark lines between adjacent diffraction orders. This pattern, well developed for high diffraction orders, reflects the main spatial properties of the diffracted beams as well as of the fork grating used for their generation. In particular, it confirms the theoretical model for the diffracted beams (Kummer beam model) and enables to determine the sign and the absolute value of the phase singularity embedded in the hologram.Comment: 9 pages, 8 figure

    Chromosomal study in newborn infants with congenital anomalies in Assiut University hospital: Cross-sectional study

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    In 40–60% of congenital malformations, the cause is unknown. Genetic factors account for approximately 15%; environmental factors produce approximately 10%; a combination of genetic and environmental influences produces 20–25%. The study aims to document prevalenceand patterns of congenital malformations detected at birth in Assiut University hospital and clarify underlying chromosomal abnormalities of such malformations. Also possible predisposing factors will be studied.Newborns with apparent congenital anomalies were selected from 5000 newborn infants delivered consecutively at the department of Obstetrics and Gynecology within 7 months. Full maternal history, family history, perinatal history, pedigree construction as well as clinical examinations andinvestigations including karyotype were done. Congenital anomalies were found in 103 cases with a prevalence of 2.06% with male to female ratio of 1.7:1. Skeletal system anomalies had the highestfrequency (37.9%), followed in descending order by chromosomal abnormalities (27.2%), circulatory system anomalies (22.3%), central nervous system (CNS) anomalies (19.4%), genital organs anomalies (16.5%), gastrointestinal tract (GIT) anomalies (14.6%), eye and ear anomalies (8.7%), and lastly urinary system and others anomalies in 3.9% each. Breech presentation, perinatal asphyxia, incubator admission and the need for resuscitation were significantly associated with the presence of congenital anomalies. Higher prevalence of congenital anomalies was observed in neonatesof grand multiparous women, diabetic mothers delivery by CS, cases with oligohydramnios and with positive consanguinity. Chromosomal abnormalities were found in 28 cases (27.18% of malformed cases) (5.6/1000). Numerical abnormalities were found in 22 cases (21.35%) (4.4/1000), Down syndrome in 16 cases, Edward syndrome in two cases, Patau syndrome in one case and Turner syndrome (monosomy) inthree cases. Structural abnormalities were present in six cases (5.83%) (1.2/1000), Down syndrome in two cases, Turner syndrome in two cases, balanced translocation [(12;13)(q15;q34)] with dysmorphic features and undescended testis in one case and deletion 9(q11;q31) with disorder of sex development in one case. To conclude karyotype should not be done routinely for all malformed cases as many of them are due to genetic syndromes. So, it is more useful to consult expert dysmorphologists for proper syndrome identification and for the decision to use more recent molecular techniques for diagnosis

    Magnetic and Optical properties of strained films of multiferroic GdMnO3

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    The effects of strain on a film of mulitferroic GdMnO3 are investigated using both magnetometry and magneto-optic spectroscopy. Optical spectra, in the energy range 1.5eV - 3.5eV, were taken in Faraday geometry in an applied magnetic field and also at remanence. This yielded rich information on the effects of strain on the spin ordering in these films. Epitaxial films of GdMnO3 were grown on SrTiO3 and LaAlO3 substrates. The LaAlO3 was twinned and so produced a highly strained film whereas the strain was less for the film grown on SrTiO3. The Ne\'el temperatures and coercive fields were measured using zero field data and hysteresis loops obtained using a SQUID magnetometer. Optical absorption data agreed with earlier work on bulk materials. The two well known features in the optical spectrum, the charge transfer transition between Mn d states at ~2eV and the band edge transition from the oxygen p band to the d states at ~3eV are observed in the magnetic circular dichroism; however they behaved very differently both as a function of magnetic field and temperature. This is interpreted in terms of the magnetic ordering of the Mn spins.Comment: 9 pages of text including figure

    How much do school teachers know about childhood asthma in Ilesa, Nigeria?

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    Background: Childhood asthma is affected by events and conditions of the school environment. Teachers as de-facto caregivers of children with asthma have a major role to play in ensuring good asthma control in school. This study set out to determine the level of knowledge of school teacher about childhood asthma and factors influencing this knowledge.Methods: Four secondary schools (two private and two public) in Ilesa, South West Nigeria were selected by multistage sampling method. All the teachers in these schools were required to fill a self -administered questionnaire incorporating a validated 40-item asthma knowledge questions. Factors associated with the level of knowledge were determined appropriately.Results: A total of 132 teacher (M: F = 1:2) participated in the study with 85 (64.4%) from private school. The mean (SD) age of the teachers was 38.0 (9.1) years and median (IQR) years in teaching service was 7.0 (5.0 to 15.0) years. Majority (56.1%) of the teachers had university education while only 7 (5.3%) had a post graduate degree. The mean (SD) score of the 40 item questions was 21.5 (7.2) and majority (51.5%) had poor asthma knowledge (score < 22). Poorer knowledge was observed in questions related to the nature and management of childhood asthma than triggers and manifestations. No significant correlation was found between knowledge and age, teaching experience and qualifications (p > 0.05). However, teachers with previous training about childhood asthma had relatively good knowledge about the condition. (p <0.05)Conclusion: The level of knowledge about childhood asthma among school teachers in Ilesa is poor particularly as regards to nature and management of the disease. We advocate for training of school teachers about common childhood conditions including asthma to ensure optimal symptoms control in school.Keywords: Childhood asthma, Knowledge, School teacher

    Presenting features, treatment patterns and outcomes of patients with breast cancer in Pakistan: Experience at a university hospital

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    BACKGROUND: Breast cancer is the most common cancer in Pakistani women. We report the presenting features, treatment patterns and survival of breast cancer from a University Hospital in Southern Pakistan and compare the data with international population based studies. MATERIALS AND METHODS: Medical records of patients diagnosed to have breast cancer between January 1999 and November 2008 were reviewed retrospectively. RESULTS: A total of 845 patients were identified. Median age of diagnosis was 48 years (range 18-92). Clinical stage was as follows: Stage I 9.9%; Stage II 48.5%; Stage III 26.2%; Stage IV 13.8%; data not available 1.5%. Approximately, half (51.6%) were estrogen receptor (ER) positive and 17.5% over-expressed Her2/neu. Nearly 23% patients received neo-adjuvant chemotherapy while 68.9% received adjuvant chemotherapy. Anthracycline based treatment was the most common treatment until 2003 while later on, patients also received taxanes and trastuzumab based therapy. Age, stage, tumor size, lymph node status, tumor grade, ER status, treatment with hormonal therapy and radiation were the major predictive factors for overall survival (OS). We report an impressive 5 year OS of 75%, stage specific survival was 100%, 88% and 58% for Stages I, II and III respectively. CONCLUSION: The majority of patients present at a younger age and with locally advanced disease. However, short term follow-up reveals that the outcomes are comparable with the published literature from developed countries. Long-term follow-up and inclusion of data from population-based registries are required for accurate comparison

    Fluorinated Templates for Energy-Related Nanomaterials and Applications

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    Fluorinated ionomer membranes, as represented by the commercially available Nafion films, are macroscopically homogeneous and optically transparent but microscopically inhomogeneous with the presence of nanoscale hydrophilic cavities. These cavities serve as nanoscale reactors for the synthesis of nanoparticles from a variety of materials. The membranes with embedded nanoscale semiconductors, still optically transparent, have been used as sheet-photocatalysts for energy conversion applications, while those with embedded reactive metals used as nano-energetic materials for hydrogen generation and beyond. This chapter provides an overview on the templated synthesis of nanomaterials in fluorinated ionomer membranes and the various energy-related applications of this unique class of nanocomposite materials

    Fluorinated Templates for Energy-Related Nanomaterials and Applications

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    Fluorinated ionomer membranes, as represented by the commercially available Nafion films, are macroscopically homogeneous and optically transparent but microscopically inhomogeneous with the presence of nanoscale hydrophilic cavities. These cavities serve as nanoscale reactors for the synthesis of nanoparticles from a variety of materials. The membranes with embedded nanoscale semiconductors, still optically transparent, have been used as sheet-photocatalysts for energy conversion applications, while those with embedded reactive metals used as nano-energetic materials for hydrogen generation and beyond. This chapter provides an overview on the templated synthesis of nanomaterials in fluorinated ionomer membranes and the various energy-related applications of this unique class of nanocomposite materials

    Molecular Detection of Leishmania spp. in Skin and Blood of Stray Dogs from Endemic Areas of Cutaneous Leishmaniasis in Saudi Arabia

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    Dogs can act as reservoirs of canine leishmaniasis, caused by Leishmania species. The aims of this study were to determine the prevalence of canine leishmaniasis using a PCR technique among stray dogs living in three provinces of Saudi Arabia, Riyadh, Al-Ahsa Oasis and Al-Qaseem, here the disease is endemic; and to identify and document different Leishmania to species levels Methods: This cross-sectional investigation was conducted, from Mar 2016 to Apr 2018, in three parts of Saudi Arabia: Central province (Riyadh), Eastern province (Al-Ahsa Oasis) and Al-Qaseem province. Blood samples were collected from 526 dogs; 40 presented cutaneous nodules so were suspected clinically of cutaneous leishmaniasis. Biopsy tissue collections and parasite cultures were performed. A generic kDNA was performed using different primers for Leishmania differentiation. Results: All blood samples were negative for Leishmania infantum infection by molecular analysis, though forty dogs had thick cutaneous lesions in different parts of their body. Four dogs’ skin lesions were associated with dermatitis, splenomegaly and lymphadenomegaly. Parasite culture was used to diagnose cutaneous leishmaniasis, identifying 31/40 (77.5%) positive samples. Overall, of 526 samples, the prevalence of L. major and L. tropica was found to be 4% and 1.9%, respectively. Gender and age had a significant effect on Leishmania prevalence: (P=0.0212 and0.0357), respectively. Conclusion: This was the first molecular study of dog leishmaniasis from Saudi Arabia of dogs confirmed to have cutaneous leishmaniasis. Further epidemiological and molecular investigations of domestic and wild canine infections with L. major, L. tropica and L. infantum in endemic and nonendemic areas of Saudi Arabia are required, for leishmaniasis control

    Racial, Ethnic, and Sex Disparities in Patients With STEMI and Cardiogenic Shock

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    OBJECTIVES: The aim of this study was to evaluate the combined impact of race, ethnicity, and sex on in-hospital outcomes using data from the National Inpatient Sample. BACKGROUND: Cardiogenic shock (CS) is a major cause of mortality following ST-segment elevation myocardial infarction (STEMI). Early revascularization reduces mortality in such patients. Mechanical circulatory support (MCS) devices are increasingly used to hemodynamically support patients during revascularization. Little is known about racial, ethnic, and sex disparities in patients with STEMI and CS. METHODS: The National Inpatient Sample was queried from January 2006 to September 2015 for hospitalizations with STEMI and CS. The associations between sex, race, ethnicity, and outcomes were examined using complex-samples multivariate logistic or generalized linear model regressions. RESULTS: Of 159,339 patients with STEMI and CS, 57,839 (36.3%) were women. In-hospital mortality was higher for all women (range 40% to 45.4%) compared with men (range 30.4% to 34.7%). Women (adjusted odds ratio [aOR]: 1.11; 95% confidence interval [CI]: 1.06 to 1.16; p \u3c 0.001) as well as Black (aOR: 1.18; 95% CI: 1.04 to 1.34; p = 0.011) and Hispanic (aOR: 1.19; 95% CI: 1.06 to 1.33; p = 0.003) men had higher odds of in-hospital mortality compared with White men, with Hispanic women having the highest odds of in-hospital mortality (aOR: 1.46; 95% CI: 1.26 to 1.70; p \u3c 0.001). Women were older (age: 69.8 years vs. 63.2 years), had more comorbidities, and underwent fewer invasive cardiac procedures, including revascularization, right heart catheterization, and MCS. CONCLUSIONS: There are significant racial, ethnic, and sex differences in procedural utilization and clinical outcomes in patients with STEMI and CS. Women are less likely to undergo invasive cardiac procedures, including revascularization and MCS. Women as well as Black and Hispanic patients have a higher likelihood of death compared with White men

    Polyclonal epitope mapping reveals temporal dynamics and diversity of human antibody responses to H5N1 vaccination

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    Novel influenza A virus (IAV) strains elicit recall immune responses to conserved epitopes, making them favorable antigenic choices for universal influenza virus vaccines. Evaluating these immunogens requires a thorough understanding of the antigenic sites targeted by the polyclonal antibody (pAb) response, which single-particle electron microscopy (EM) can sensitively detect. In this study, we employ EM polyclonal epitope mapping (EMPEM) to extensively characterize the pAb response to hemagglutinin (HA) after H5N1 immunization in humans. Cross-reactive pAbs originating from memory B cells immediately bound the stem of HA and persisted for more than a year after vaccination. In contrast, de novo pAb responses to multiple sites on the head of HA, targeting previously determined key neutralizing sites on H5 HA, expanded after the second immunization and waned quickly. Thus, EMPEM provides a robust tool for comprehensively tracking the specificity and durability of immune responses elicited by novel universal influenza vaccine candidates
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