303 research outputs found

    Fungal dysbiosis predicts the diagnosis of pediatric Crohn's disease

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    AIM: To investigate the accuracy of fungal dysbiosis in mucosa and stool for predicting the diagnosis of Crohn’s disease (CD). METHODS: Children were prospectively enrolled in two medical centers: one university hospital and one private gastroenterology clinic in the city of Riyadh, Kingdom of Saudi Arabia. The children with confirmed diagnosis of CD by standard guidelines were considered cases, and the others were considered non-inflammatory bowel disease controls. Mucosal and stool samples were sequenced utilizing Illumina MiSeq chemistry following the manufacturer’s protocols, and abundance and diversity of fungal taxa in mucosa and stool were analyzed. Sparse logistic regression was used to predict the diagnosis of CD. The accuracy of the classifier was tested by computing the receiver operating characteristic curves with 5-fold stratified cross-validation under 100 permutations of the training data partition and the mean area under the curve (AUC) was calculated. RESULTS: All the children were Saudi nationals. There were 15 children with CD and 20 controls. The mean age was 13.9 (range: 6.7-17.8) years for CD children and 13.9 (3.25-18.6) years for controls, and 10/15 (67%) of the CD and 13/20 (65%) of the control subjects were boys. CD locations at diagnosis were ileal (L1) in 4 and colonic (L3) in 11 children, while CD behavior was non-stricturing and non-penetrating (B1) in 12 and stricturing (B2) in 3 children. The mean AUC for the fungal dysbiosis classifier was significantly higher in stools (AUC = 0.85 ± 0.057) than in mucosa (AUC = 0.71 ± 0.067) (P < 0.001). Most fungal species were significantly more depleted in stools than mucosal samples, except for Saccharomyces cerevisiae and S. bayanus, which were significantly more abundant. Diversity was significantly more reduced in stools than in mucosa. CONCLUSION: We found high AUC of fungal dysbiosis in fecal samples of children with CD, suggesting high accuracy in predicting diagnosis of CD. Key Words: Fungiome, Mycobiome, Crohn’s disease, Inflammation, Saudi children Core tip: We found high accuracy of fungal dysbiosis in predicting diagnosis of Crohn’s disease (CD), a finding similar to bacterial dysbiosis. However, the higher area under the curve for the fungal dysbiosis classifier in stool (0.85 ± 0.057) than in mucosa (0.71 ± 0.067) (P < 0.001), contrasts with bacterial studies, suggesting higher accuracy of stool samples. Although the clinical application of this finding is limited at present by the high cost of fungal analysis, such information is important from a scientific viewpoint, to increase the understanding of the role of fungal flora in CD and to stimulate further studies.The authors extend their appreciations to the Deanship of Scientific Research at King Saud University in Riyadh, Kingdom of Saudi Arabia for funding this work through Research Group No [RGP-1436-007]. This work was also supported by a grant from the Simons Foundation [No. 409704] to Kirill Korolev) and by the startup fund from Boston University to Kirill Korolev. Simulations were carried out on Shared Computing Cluster at Boston University. Rajita Menon was partially supported by a Hariri Graduate Fellowship from Boston University. Harland Winter, MD received support from Martin Schlaff and the Diane and Dorothy Brooks Foundation. (RGP-1436-007 - King Saud University in Riyadh, Kingdom of Saudi Arabia; 409704 - Simons Foundation; Boston University; Hariri Graduate Fellowship from Boston University; Diane and Dorothy Brooks Foundation)Published versio

    Effect of stabilizer on optical band gap of ZnO and their performance in dye-sensitized solar cells

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    ABSTRACT. In dye-sensitized solar cells, transparent metal oxide working electrodes play a vital role in defining the power conversion efficiency. It was found that the size of nanoparticles influences the electrical, optical properties of these electrodes. Herein, we describe the synthesis of ZnO with zinc acetate dihydrate and different stabilizers (diethylamine and triethylamine) by using a modified solvothermal process. The obtained materials were characterized by XRD, SEM, EDX, TEM, HRTEM, UV-visible, FTIR, and Raman methods. The crystallite sizes for ZnO-1 and ZnO-2 samples were indexed as 39.0 and 40.5 nm for the highest peak intensity with diethylamine and triethylamine stabilizer, respectively. We examine the effect of stabilizers on the morphology, optical band gap, and photovoltaic performance of the prepared ZnO. We found that ZnO prepared using diethylamine stabilizer exhibiting significant efficiency of 1.45%, open-circuit voltage 0.454 V, short-circuit current density 2.128 mA/cm2, and 0.66 fill factor were achieved under 44 mW/cm2 illumination powers with dye-3. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; KEY WORDS: Dye-sensitized solar cells, ZnO, Band gap, Photovoltaic performance &nbsp; Bull. Chem. Soc. Ethiop. 2022, 36(1), 209-222.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; DOI: https://dx.doi.org/10.4314/bcse.v36i1.17 &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp

    Nanocrystalline Na0.1V2O5.nH2Oxerogel Thin Film for Gas Sensing

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    Nanocrystalline thin film of Na0.1V2O5.nH2O xerogel obtained by sol-gel synthesis was used as a gas sensor. Gas sensing properties of different gases such as hydrogen, petroleum and humidity were investigated. Applying XRD and TEM the size of the nanocrystals is found to be 7.5 nm. SEM shows a highly porous structure with submicron meter-sized voids present throughout the sample. FTIR measurement shows different chemical groups identifying the obtained series of gels. The sample was n-type semiconductor according to the thermoelectric power and electrical conductivity. It can be seen that the sensor response curves from 130°C to 150°C show a rapid increase in sensitivity for all types of gas injection, low response values for heating period and the rapid high response values for cooling period. This result may suggest that this material is able to act as gas sensor during the heating and cooling process

    Nanocrystalline Na0.1V2O5.nH2Oxerogel Thin Film for Gas Sensing

    Get PDF
    Nanocrystalline thin film of Na0.1V2O5.nH2O xerogel obtained by sol-gel synthesis was used as a gas sensor. Gas sensing properties of different gases such as hydrogen, petroleum and humidity were investigated. Applying XRD and TEM the size of the nanocrystals is found to be 7.5 nm. SEM shows a highly porous structure with submicron meter-sized voids present throughout the sample. FTIR measurement shows different chemical groups identifying the obtained series of gels. The sample was n-type semiconductor according to the thermoelectric power and electrical conductivity. It can be seen that the sensor response curves from 130°C to 150°C show a rapid increase in sensitivity for all types of gas injection, low response values for heating period and the rapid high response values for cooling period. This result may suggest that this material is able to act as gas sensor during the heating and cooling process

    Neisseria meningitidis nasopharyngeal carriage during the Hajj: A cohort study evaluating the need for ciprofloxacin prophylaxis

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    Background The annual Muslim pilgrimage has the potential of increase risk for acquisition of Neisseria meningitidis. Here, we evaluate the Hajj impact on the prevalence of N. meningitidis carriage in a paired and non-paired cohort of pilgrims. Secondary objectives were to calculate the compliance with recommended vaccination. Methods This is a prospective paired (arriving and departing), non-paired arriving and non-paired departing cohort study with the collection of nasopharyngeal samples at the start and the end of the Hajj. Results The study included unpaired arriving pilgrims at King Abdul Aziz International Airport (N = 1055), unpaired departing cohort (N = 373), and a paired cohort (N = 628) who were tested on arrival and departure. Meningococcal vaccination was received by all pilgrims, 98.2% received quadrivalent polysaccharide vaccine (ACWY), and 1.8% received meningococcal quadrivalent conjugate vaccine (MCV4). Only 1.61% and 23.03% received pneumococcal and influenza vaccines, respectively. Of the 1055 arriving unpaired pilgrim, 36 (3.4%) tested positive for nasopharyngeal carriage of N. meningitidis, and 24 (66.7%) of these were serogroup B, the remainder were non-groupable. Haemophilus influenza was detected among 45 (4.3%), and 11 (1%) carriers were positive for both N. meningitidis and H. influenzae. Out of 373 in the unpaired departing cohort, 6 (1.61%) tested positive for N. meningitidis, and 34 (9.1%) were positive for H. influenzae. Of the 628 paired cohort pilgrims, 36 (5.7%) pilgrims were positive for N. meningitidis at arrival and 16 (2.5%) pilgrims were positive after the hajj. Conclusion This the largest study of the epidemiology of N. meningitidis among pilgrims. The study showed a significant difference in the carriage between pilgrims from high endemicity and other pilgrims with a predominance of serogroup B. The continued use of ciprofloxacin as prophylactic antibiotics should be reconsidered as well as the consideration to add serogroup B as a required vaccination

    Spread, circulation, and evolution of the Middle East respiratory syndrome coronavirus

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    The Middle East respiratory syndrome coronavirus (MERS-CoV) was first documented in the Kingdom of Saudi Arabia (KSA) in 2012 and, to date, has been identified in 180 cases with 43% mortality. In this study, we have determined the MERS-CoV evolutionary rate, documented genetic variants of the virus and their distribution throughout the Arabian peninsula, and identified the genome positions under positive selection, important features for monitoring adaptation of MERS-CoV to human transmission and for identifying the source of infections. Respiratory samples from confirmed KSA MERS cases from May to September 2013 were subjected to whole-genome deep sequencing, and 32 complete or partial sequences (20 were ≥99% complete, 7 were 50 to 94% complete, and 5 were 27 to 50% complete) were obtained, bringing the total available MERS-CoV genomic sequences to 65. An evolutionary rate of 1.12 × 10−3 substitutions per site per year (95% credible interval [95% CI], 8.76 × 10−4; 1.37 × 10−3) was estimated, bringing the time to most recent common ancestor to March 2012 (95% CI, December 2011; June 2012). Only one MERS-CoV codon, spike 1020, located in a domain required for cell entry, is under strong positive selection. Four KSA MERS-CoV phylogenetic clades were found, with 3 clades apparently no longer contributing to current cases. The size of the population infected with MERS-CoV showed a gradual increase to June 2013, followed by a decline, possibly due to increased surveillance and infection control measures combined with a basic reproduction number (R0) for the virus that is less than 1

    Metabolomics: a promising tool for deciphering metabolic impairment in heavy metal toxicities

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    Heavy metals are the metal compounds found in earth’s crust and have densities higher than that of water. Common heavy metals include the lead, arsenic, mercury, cadmium, copper, manganese, chromium, nickel, and aluminum. Their environmental levels are consistently rising above the permissible limits and they are highly toxic as enter living systems via inhalation, ingestion, or inoculation. Prolonged exposures cause the disruption of metabolism, altered gene and/or protein expression, and dysregulated metabolite profiles. Metabolomics is a state of the art analytical tool widely used for pathomolecular inv22estigations, biomarkers, drug discovery and validation of biotransformation pathways in the fields of biomedicine, nutrition, agriculture, and industry. Here, we overview studies using metabolomics as a dynamic tool to decipher the mechanisms of metabolic impairment related to heavy metal toxicities caused by the environmental or experimental exposures in different living systems. These investigations highlight the key role of metabolomics in identifying perturbations in pathways of lipid and amino acid metabolism, with a critical role of oxidative stress in metabolic impairment. We present the conclusions with future perspectives on metabolomics applications in meeting emerging needs

    Community case clusters of Middle East respiratory syndrome coronavirus in Hafr Al-Batin, Kingdom of Saudi Arabia: A descriptive genomic study

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    The Middle East respiratory syndrome coronavirus (MERS-CoV) was first described in September 2012 and to date 86 deaths from a total of 206 cases of MERS-CoV infection have been reported to the WHO. Camels have been implicated as the reservoir of MERS-CoV, but the exact source and mode of transmission for most patients remain unknown. During a 3 month period, June to August 2013, there were 12 positive MERS-CoV cases reported from the Hafr Al-Batin region district in the north east region of the Kingdom of Saudi Arabia. In addition to the different regional camel festivals in neighboring countries, Hafr Al-Batin has the biggest camel market in the entire Kingdom and hosts an annual camel festival. Thus, we conducted a detailed epidemiological, clinical and genomic study to ascertain common exposure and transmission patterns of all cases of MERS-CoV reported from Hafr Al-Batin. Analysis of previously reported genetic data indicated that at least two of the infected contacts could not have been directly infected from the index patient and alternate source should be considered. While camels appear as the likely source, other sources have not been ruled out. More detailed case control studies with detailed case histories, epidemiological information and genomic analysis are being conducted to delineate the missing pieces in the transmission dynamics of MERS-CoV outbreak
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