527 research outputs found
إنتاج مادة 17 ألفا هيدروكسي البروجستيرون على مستوى المخمر المعملي بواسطة فطرة كاننجهاميلا إيكينولاتا
The mircrobiological transformation of progesterone by a local isolate of Cunninghamella echiiiulata using a laboratory fermentor was studied. Progresterone (10-50 g/1) wetted by Tween 80 was added to 48-hour old culture and the transformation was left to proceed for 72 hours. Thereafter, the different transformation products were resolved chromatog-raphically. The identity of each product was established through the determination of m.p., mixed m.p., optical rotation and ultraviolet as well as infrared absorption spectra. A comparison of the R{ values of each product with that of the corresponding reference using different solvent systems as well as their colour expressed with two spray reagents, was used as a further proof for the identity of the isolated products. With all concentrations of progesterone tested, maximum yield of 17ot -hydroxyprogesterone was obtained after 48 hours of fermentation Progesterone concentrations of 10 and 20 g/1 were almost quantitatively converted to the different transformation products after 72 hours of fermentation. Using a concentration of 20 g/1 and incubation period of 48 hours, the transformation product mixture consisted of unchanged progesterone (6%), 17 o< -hydroxyprogesterone (54%),llotrhydroxyprogesterone (29%) and llo<;,17<^-dihydroxy-progesterone (2.5%).تم استخدام مخمر صناعي سعة 2 لتر لاختيار مقدرة الفطرة على تكوين هذه المادة في ظروف تشبه تلك المطبقة في الصناعة . وبدراسة تركيزات متعددة فن مادة البروجستيرون تتراوح ما بين 10جرام /لتر إلى 50جرام /لتر ، وجد أن أنسب التركيزات المختبرة هو تركيز 20 جرام من البروجستيرون لكل لترمن الوسط الغذائي ، حيث تم تحويل كل البووجستيرون المضاف إلى المشتقات المختلفة خلال 72 ساعة من بدء الاضافة . ووجد أن أعلى معدل لتكوين مادة 17 ألفا - هيدروكسي البروجستيرون كان بعد 48 ساعة من بدأ إضافة البروجستيرون .
عند فصل المواد الناتجة من تحول البروجستيرون بواسطة الفطرة المستخدمة وذلك بواسطة أعمدة الفصل باستخدام مادة الالومينا وجد أن البروجستيرون يتحول إلى :
17 ألفا - هيدروكسي البروجستيرون ( 54 %)
11 ألفا - هيدروكسي البروجستيرون (29%)
11 ألفا ، 17 ألفا - ثنائي هيدروكسي البروجستيرون (2.5%
GENOTYPE X ENVIRONMENT INTERACTION FOR GRAIN QUALITY CHARACTERS IN RICE (Oryza sativa L.)
Fourteen rice (Oryza sativa L.) varieties and lines were grown at three locations over 2
years. The effect of genotype X environment (G x E) interactions on some grain quality
characters was evaluated. The characters investigated were the following ones: grain
length, grain width, grain shape (L/W ratio), hulling %, milling %, head rice %,elonga-.
tion, gelatinization temperature (G.T.) and amylose content. It was found that the first
order interaction variety x location was significant for hulling %,milling %, head rice %
and G.T. only. On the other hand, the variety X year interaction was insignificant for
all the studied traits except G.T. The second order interaction variety x location X year,
however, was highly significant for all the studied traits.
The best grain shape was recorded for the new promising line Gz 2175-5-6, while
the variety Giza 171 had the highest milling outturn among the short grain varieties and
Giza 181 among the long grain ones.The lowest amylose content values were determined
for Giza 172 (18.04 %) and Giza 171 (18.9%), however, the rice variety IR 28 showed the
highest amylose content (27.21%)
SIMULTANEOUS SPECTROPHOTOMETRIC DETERMINATION OF DICLOFENAC SODIUM, PARACETAMOL, AND CHLORZOXAZONE IN TERNARY MIXTURE USING CHEMOMETRIC AND ARTIFICIAL NEURAL NETWORKS TECHNIQUES
  Objective: The aim of this study is to develop and validate simple, accurate, and precise spectrophotometric methods for the simultaneous determination of diclofenac sodium (DIC), paracetamol (PAR), and chlorzoxazone (CHZ) in ternary mixture using chemometric and artificial neural networks (ANN) techniques.Methods: Three chemometric techniques include classical least squares (CLS), principal component regression (PCR), and partial least squares (PLS) in addition to cascade-forward backpropagation ANN (CFBP-ANN) were prepared using the synthetic mixtures containing the three drugs in methanol. In CLS, PCR, and PLS, the absorbances of the synthetic mixtures in the range 267-295 nm with the intervals Δλ=0.2 nm in their zero-order spectra were selected. Then, calibration or regression was obtained using the absorbance data matrix and concentration data matrix for the prediction of the unknown concentrations of DIC, PAR, and CHZ in their mixtures. In CFBP-ANN, two layers, sigmoid layer with 10 neurons and linear layer were found appropriate for the simultaneous determination of the three drugs in their ternary mixture.Results: The four proposed methods were successfully applied to the analysis of the three drugs in laboratory prepared mixtures and tablets with good percentage recoveries in the range of 98-102%. Relative standard deviation for the precision study was found <1%.Conclusion: The four proposed methods showed simplicity, accuracy, precision, and rapidity making them suitable for quality control and routine analysis of the cited drugs in ternary mixtures and pharmaceutical formulation containing them.Â
Negative effective permeability and left-handed materials at optical frequencies
We present here the design of nano-inclusions made of properly arranged
collections of plasmonic metallic nano-particles that may exhibit a resonant
magnetic dipole collective response in the visible domain. When such inclusions
are embedded in a host medium, they may provide metamaterials with negative
effective permeability at optical frequencies. We also show how the same
inclusions may provide resonant electric dipole response and, when combining
the two effects at the same frequencies, lefthanded materials with both
negative effective permittivity and permeability may be synthesized in the
optical domain with potential applications for imaging and nano-optics
applications.Comment: 11 pages, 6 figures; modified the format, added a figur
EFFECT OF DIFFERENT ALKALI CONCENTRATIONS DURING THE REFINING PROCESS ON THE FATTY ACID COMPOSITION OF SUNFLOWER AND SOYBEAN OILS
The effect of NaOH and KOH at concentrations of 12, 14 and 16 Bé° during the
refining of sunflower and soybean oils on the fatty acid composition was studied using
GLC technique. The quantity of linolenic, linoleic, oleic, palmitic and stearic acid as well
as the USFA (unsaturated fatty acids): SFA (saturated fatty acids) ratio were measured.
Only slight changes in the quantity of individual fatty acids were found particularly
at higher alkali concentrations. The changes in the USFA : SFA ratio compared with
crude or semirefined oil were not significant
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