203 research outputs found
An examination of the Nihayat Al-Talab and the determination of its place and value in the history of Islamic chemistry
In 1923 there was published the Arabic text of
K. al-Muktasab an alchemical work of the thirteenth
century written by al-'Iraqi, with a translation and
introduction by Dr. E. J. Holmyard. Jildaki, an alchemist
of the fourteenth. century, wrote his great work, Nihayat
al-Talab as a voluminous commentary on K. al-Muktasab.
The present thesis is an attempt to examine the contents
of the Nihayat and determine its place and value in the
history of Islamic chemistry. The importance of the
Nihayat lies in the main in its lengthy quotations from
earlier authors whose works are not now extant. It is
valuable also because it gives a clear account of the
more important alchemical theories and tenets prevalent
among the Muslim writers of the Middle Ages.
The copy of the Nihayat which I have used consists
of three quarto volumes amounting altogether to 1067 pages. The account given of each volume in the present
thesis is not in proportion to its size, which is almost
the same for all the three volumes; an attempt has been
made to exclude, as far as possible, any unnecessary
repetitions, and thus the account given of the third
volume is only half the size of that of the first.
In the course of the Introduction a summary has been
given of the theoretical and philosophical views of
Jildaki; and an extensive Index has been prepared to
facilitate detailed reference to the very large number of
subjects mentioned in the thesis
Singularity Avoidance of Charged Black Holes in Loop Quantum Gravity
Based on spherically symmetric reduction of loop quantum gravity,
quantization of the portion interior to the horizon of a Reissner-Nordstr\"{o}m
black hole is studied. Classical phase space variables of all regions of such a
black hole are calculated for the physical case . This calculation
suggests a candidate for a classically unbounded function of which all
divergent components of the curvature scalar are composed. The corresponding
quantum operator is constructed and is shown explicitly to possess a bounded
operator. Comparison of the obtained result with the one for the Swcharzschild
case shows that the upper bound of the curvature operator of a charged black
hole reduces to that of Schwarzschild at the limit . This
local avoidance of singularity together with non-singular evolution equation
indicates the role quantum geometry can play in treating classical singularity
of such black holes.Comment: To be appeared in International Journal of Theoretical Physic
Yield performance estimation of corn hybrids using machine learning algorithms
Abstract Estimation of yield performance for crop products is a topic of interest in agriculture. In breeding programs, we cannot test all possible hybrids created by crossing two parents (inbred and tester) since it would be too time consuming and costly. In this paper, we exploit different machine learning algorithms including decision tree, gradient boosting machine, random forest, adaptive boosting, XGBoost and neural network to predict the yield of corn hybrids using data provided in the 2020 Syngenta Crop Challenge. The participants were asked to predict the yield of missing hybrids which were not tested before. Our results show that the prediction obtained by XGBoost is more accurate than other models with a root mean square error equal to 0.0524. Therefore, we use XGBoost model to estimate the yield performance for untested combinations of inbreds and testers. Using this approach, we identify hybrids with high predicted yield that can be bred to increase corn production
Introduction à l’étude des Salmonella et des salmonelloses en Iran
Néel R., Kaweh M., Jorgensen K., Taslimi H. Introduction à l’étude des Salmonella et des salmonelloses en Iran. In: Bulletin de l'Académie Vétérinaire de France tome 106 n°10, 1953. pp. 547-554
Bacterial flora-typing with targeted, chip-based Pyrosequencing
<p>Abstract</p> <p>Background</p> <p>The metagenomic analysis of microbial communities holds the potential to improve our understanding of the role of microbes in clinical conditions. Recent, dramatic improvements in DNA sequencing throughput and cost will enable such analyses on individuals. However, such advances in throughput generally come at the cost of shorter read-lengths, limiting the discriminatory power of each read. In particular, classifying the microbial content of samples by sequencing the < 1,600 bp 16S rRNA gene will be affected by such limitations.</p> <p>Results</p> <p>We describe a method for identifying the phylogenetic content of bacterial samples using high-throughput Pyrosequencing targeted at the 16S rRNA gene. Our analysis is adapted to the shorter read-lengths of such technology and uses a database of 16S rDNA to determine the most specific phylogenetic classification for reads, resulting in a weighted phylogenetic tree characterizing the content of the sample. We present results for six samples obtained from the human vagina during pregnancy that corroborates previous studies using conventional techniques.</p> <p>Next, we analyze the power of our method to classify reads at each level of the phylogeny using simulation experiments. We assess the impacts of read-length and database completeness on our method, and predict how we do as technology improves and more bacteria are sequenced. Finally, we study the utility of targeting specific 16S variable regions and show that such an approach considerably improves results for certain types of microbial samples. Using simulation, our method can be used to determine the most informative variable region.</p> <p>Conclusion</p> <p>This study provides positive validation of the effectiveness of targeting 16S metagenomes using short-read sequencing technology. Our methodology allows us to infer the most specific assignment of the sequence reads within the phylogeny, and to identify the most discriminative variable region to target. The analysis of high-throughput Pyrosequencing on human flora samples will accelerate the study of the relationship between the microbial world and ourselves.</p
First report on the validity of a continuous Metabolic Syndrome score as an indicator for Metabolic Syndrome in a national sample of paediatric population - The CASPIAN-III study
Introduction: The aim of this study was to assess the validity of a continuous Metabolic Syndrome score (cMetS) in a nationally representative sample of Iranian children and to identify sex and age-specific optimal cut-off points of cMetS that are associated with MetS. Material and methods: This study was conducted among 3,254 schoolchildren aged 10-18 years. cMetS was derived by aggregating age and sex-standardised residuals of waist circumference (WC), mean arterial pressure (MAP), glucose, high density lipoprotein-cholesterol (HDL-C) and triglycerides (TG). To determine the optimal cut-off points of cMetS for predicting MetS, receiver operator characteristic (ROC) curve analysis was used with an estimation of the variables' sensitivity and specificity. Results: A graded relationship was documented between cMetS and the number of risk factors. Increasing mean values of cMetS with increasing numbers of components were apparent for both genders. The overall optimal cMetS cut-off point for predicting the presence of MetS was 2.93 sensitivity = 92%, specificity = 91%, area of the curve = 0.96 (0.95-0.97). The values for boys and girls were 2.97 and 3.26 respectively in the total study. Conclusion: This nationwide study confirmed the validity of the cMetS score in a population-based sample of Iranian children. cMetS appears to be an appropriate index for investigating the association between potential risk factors and MetS in epidemiological research in Iran
Association of anthropometric measures with cardiovascular risk factors and metabolic syndrome in normal-weight children and adolescents: The CASPIAN III study
Objective: This nationwide study was conducted to determine the association of anthropometric measures with cardiovascular risk factors and metabolic syndrome (MetS) in Iranian normal-weight children and adolescents. Methods: We analyzed the data of 3,565 children and adolescents (50.3 boys), aged 10-18 years, with a normal BMI (5th-84th percentile) obtained from the third survey of 'Childhood and Adolescence Surveillance and Prevention of Adult Non-communicable Disease' (CASPIAN III) study. The diagnostic criteria for MetS were defined by the International Diabetes Federation consensus. Results: The prevalence of MetS for 10- to 13.9-year-old boys, 14- to 18-year-old boys, 10- to 13.9-year-old girls, and 14- to 18-year-old girls were 1.4, 2.8, 2.3, and 3.3, respectively. After adjustment for age and sex, each unit increase in BMI (within normal range) and waist circumference increased the odds of MetS from 6 to 72 and from 1 to 20, respectively. The dominant pattern of dyslipidemia among the participants was high triglycerides and low high-density lipoprotein cholesterol. Conclusion: This study complements recent research about the high frequency of metabolic risk factors among normal-weight individuals in the pediatric age group. © 2013 S. Karger GmbH, Freiburg
Role of polymorphisms of the endothelial nitric oxide synthase gene in predicting slow-flow phenomenon after primary percutaneous coronary intervention
Objective: The aim of the present study was to examine the association between 2 polymorphisms of the endothelial nitric oxide (eNOS) gene (-786T>C and +894G>T) and the no-reflow/slow-flow phenomenon in post-primary percutaneous coronary intervention (PPCI) patients. Methods: A total of 103 post-PPCI patients were enrolled. Coronary no-reflow phenomenon was defined as a Thrombolysis in Myocardial Infarction (TIMI) flow grade 0-1 and coronary slow-flow phenomenon (CSFP) was defined as a TIMI flow grade �2. Results: Due to the small number of post-PPCI patients with the no-reflow phenomenon (n=4), the primary comparison was made between CSFP (n=20) and normal flow (n=83) groups. There was a greater frequency of CSFP among carriers of the-786C allele of the eNOS-786T>C polymorphism (odds ratio OR: 3.90; 95% confidence interval CI: 0.87-17.45; p=0.07). However, no such association was detected between the +894T allele of the eNOS +894G>T and CSFP (OR: 0.92; 95% CI: 0.21-3.98; p=0.91). In the adjusted analysis, the-786T>C polymorphism did not reach statistical significance. Conclusion: There was no significant association between CSFP and 2 of the most common polymorphisms of the eNOS gene in post-PPCI patients. © 2020 Turkish Society of Cardiology
C-Terminal Domain Deletion Enhances the Protective Activity of cpa/cpb Loaded Solid Lipid Nanoparticles against Leishmania major in BALB/c Mice
Cutaneous leishmaniasis (CL) is the most common form of leishmaniasis with an annual incidence of approximately 2 million cases and is endemic in 88 countries, including Iran. CL's continued spread, along with rather ineffectual treatments and drug-resistant variants emergence has increased the need for advanced preventive strategies. We studied Type II cysteine proteinase (CPA) and Type I (CPB) with its C-terminal extension (CTE) as cocktail DNA vaccine against murine and canine leishmaniasis. However, adjuvants' success in enhancing immune responses to selected antigens led us to refocus our vaccine development programs. Herein, we discuss cationic solid lipid nanoparticles' (cSLN) ability to improve vaccine-induced protective efficacy against CL and subsequent lesion size and parasite load reduction in BALB/c mice. For this work, we evaluated five different conventional as well as novel parasite detection techniques, i.e., footpad imaging, footpad flowcytometry and lymph node flowcytometry for disease progression assessments. Vaccination with cSLN-cpa/cpb-CTE formulation showed highest parasite inhibition at 3-month post vaccination. Immunized mice showed reduced IL-5 level and significant IFN-ã increase, compared to control groups. We think our study represents a potential future and a major step forward in vaccine development against leishmaniasis
Nutrition and lung cancer: a case control study in Iran
Background: Despite many prospective and retrospective studies about the association of dietary habit and lung
cancer, the topic still remains controversial. So, this study aims to investigate the association of lung cancer with
dietary factors.
Method: In this study 242 lung cancer patients and their 484 matched controls on age, sex, and place of residence
were enrolled between October 2002 to 2005. Trained physicians interviewed all participants with standardized
questionnaires. The middle and upper third consumer groups were compared to the lower third according to the
distribution in controls unless the linear trend was significant across exposure groups.
Result: Conditional logistic regression was used to evaluate the association with lung cancer. In a multivariate
analysis fruit (Ptrend < 0.0001), vegetable (P = 0.001) and sunflower oil (P = 0.006) remained as protective factors and
rice (P = 0.008), bread (Ptrend = 0.04), liver (P = 0.004), butter (Ptrend = 0.04), white cheese (Ptrend < 0.0001), beef
(Ptrend = 0.005), vegetable ghee (P < 0.0001) and, animal ghee (P = 0.015) remained as risk factors of lung cancer.
Generally, we found positive trend between consumption of beef (P = 0.002), bread (P < 0.0001), and dairy
products (P < 0.0001) with lung cancer. In contrast, only fruits were inversely related to lung cancer (P < 0.0001).
Conclusion: It seems that vegetables, fruits, and sunflower oil could be protective factors and bread, rice, beef,
liver, dairy products, vegetable ghee, and animal ghee found to be possible risk factors for the development of
lung cancer in Iran
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