177 research outputs found
Steganography and Cryptography Techniques Based Secure Data Transferring Through Public Network Channel
من المعلوم انه غالبا ما يتم مهاجمة البيانات المنقولة عبر شبكة الانترنيت ملايين المرات في اليوم الواحد. ولمعالجة هذه المشكلة، تم اقتراح طريقة آمنة تقوم بتأمين البيانات المنقولة عبر الشبكة. الطريقة المقترحة تعتمد تقنيتين لضمان النقل الآمن للرسالة المنقولة. اذ يتم تشفير الرسالة كخطوة أولى، ثم يتم إخفاؤها في غلاف فيديو معين. تقنية التشفير المقترحة هي خوارزمية تشفير انسيابية (RC4) لزيادة سرية الرسالة، وكذلك تحسين خوارزمية تضمين البتات الأقل أهمية (LSB) لتوفير مستوى أمان إضافي. يأتي تحسين طريقة الـ LSB التقليدية من خلال استبدال الاختيار المتسلسل المعتمد سابقا في طريقة الاختيار العشوائي لكل من الإطارات والبكسل من خلال استخدام مفتاحين عشوائيين سريين على التوالي. لذا، تبقى الرسالة المخفية محمية حتى إن تم اختراق الكائن المخفي(stego) لأن المهاجم سيكون غير قادر على معرفة الإطارات والبكسلات الحقيقية التي تتضمن كل جزء من أجزاء الرسالة السرية بالإضافة إلى صعوبة إعادة بناء الرسالة بشكل صحيح. النتائج المتحصلة من البحث تشير إلى أن الطريقة المقترحة توفّر أداءً جيدًا وفقا لمقاييس التقييم المعتمدة عند مقارنتها بعدد كبير من الطرق السابقة ذات الصلة بهذا النوع من الاعمال.Attacking a transferred data over a network is frequently happened millions time a day. To address this problem, a secure scheme is proposed which is securing a transferred data over a network. The proposed scheme uses two techniques to guarantee a secure transferring for a message. The message is encrypted as a first step, and then it is hided in a video cover. The proposed encrypting technique is RC4 stream cipher algorithm in order to increase the message's confidentiality, as well as improving the least significant bit embedding algorithm (LSB) by adding an additional layer of security. The improvement of the LSB method comes by replacing the adopted sequential selection by a random selection manner of the frames and the pixels with two secret random keys. Therefore, the hidden message remains protected even if the stego-object is hacked because the attacker is unable to know the correct frames and pixels that hold each bit of the secret message in addition to difficulty to successfully rebuild the message. The results refer to that the proposed scheme provides a good performance for evaluation metric that is used in this purpose when compared to a large number of related previous methods
Thirteen year retrospective review of the spectrum of inborn errors of metabolism presenting in a tertiary center in Saudi Arabia
Molecular study of hepatitis C viral RNA extracted from local isolates in Pahang, Malaysia: genotyping, subtyping and base sequencing
Hepatitis C virus infection affects approximately 170 million individuals constituting about 3% of the world's population. Most of those infected face the risk of developing liver cirrhosis and/or liver cancer. In Malaysia, hepatitis C prevalence is 1.6% and is still the foremost infection among multiple blood transfusion groups. The current mainstay treatment of HCV is pegylated alpha-interferon in combination with ribavirin, incurring considerable expense on local health services. In fact, less than 50% of treated patients respond favorably to the given therapy. Understanding the characteristics of the RNA genome of the local HCV genotypes can serve as foundation for future development of rapid diagnostic techniques. In addition, it has the potential for helping in designing small interfering RNA (siRNA) to be utilized in studies related to specific silencing of vital viral genes. However, despite the plethora of global HCV studies, there is relative scarcity HCV research in Malaysia. In this present study, HCV isolates from infected haemodialysis patients were studied, focusing on the characterization of their genomes, by genotyping and base-sequencing. The nucleotide sequence of the conserved 5’UTR region of HCV genome revealed several sequence patterns across the 4 main HCV genotypes available in the study panel. Phylogenetic analysis of the NS5B region showed a predominance of HCV genotype 3a. The revealed sequence patterns have the potential for designing probes that could differentiate the predominant HCV genotype 3 from other genotypes. Analysis of the secondary structure of genotype 3a showed conserved loop structures that could be targeted by small interfering RNA molecules. In conclusion, molecular studies of local HCV strains provide a new dimension for the improvement of current HCV detection and genotyping methods, aid in better understanding of the molecular epidemiology of the virus infection and may form the basis for future in-vitro studies on viral molecular pathogenetic mechanis
Synthesis, characterization, antimicrobial activity and molecular docking studies of combined pyrazol-barbituric acid pharmacophores
Purpose: To synthesize, and determine the antibacterial activity and binding mode of new pyrazolbarbituric acid derivatives in a search for new antimicrobial agents.Methods: One-pot multi-component reaction of aldehyde derivatives, barbituric acid and 3-methyl-1- phenyl-1H-pyrazol-5(4H)-one in the presence of NHEt2 to afford Michael adduct was carried out. The reaction was carried out in water and afforded new heterocycles in a one-step fashion, with expedient work-up and high yield without extraction and purification steps. The synthesized compounds were evaluated for antimicrobial activity using agar disc diffusion. Molecular docking approach via MOE-Dock program was applied to predict the binding interactions of some of the new pyrazol-barbituric acid derivatives against six different target proteins downloaded from Protein Data Bank.Results: A series of pyrazole-barbituric acid derivatives were successfully synthesized and characterized. The synthesized compounds showed moderate to very good antibacterial activity against S. aureus ATCC 29213 and E. faecalis ATCC29212, as well as also antifungal activity against Candida albicans ATCC 10400Conclusion: A series of pyrazole-barbituric acid derivatives has been synthesized and some of them display antimicrobial activities.Keywords: Pyrazole, Barbituric acid, Pyrazole-barbituric acid derivatives, Antimicrobial activity, Molecular dockin
Tandem Aldol-Michael reactions in aqueous diethylamine medium: a greener and efficient approach to dimedone-barbituric acid derivatives
BACKGROUND: Green chemistry is a rapidly developing new field that provides us with a proactive avenue for the sustainable development of future science and technologies. Green chemistry uses highly efficient and environmentally benign synthetic protocols to deliver lifesaving medicines, accelerating lead optimization processes in drug discovery, with reduced unnecessary environmental impact. From this view point, it is desirable to use water instead of organic solvents as a reaction medium, since water is safe, abundant and an environmentally benign solvent. RESULTS: A convenient one-pot method for the efficient synthesis of the novel Zwitterion derivatives 4a-pvia a three-component condensation reaction of barbituric acid derivatives 1a,b, dimedone 2, and various aldehydes 3 in the presence of aqueous diethylamine media is described. This new approach is environmentally benign, with clean synthetic procedure, short reaction times and easy work-up procedure which proceeded smoothly to provide excellent yield (88-98%). The synthesized products were characterized by elemental analysis, IR, MS, NMR and CHN analysis. The structure of 4a was further confirmed by single crystal X-ray diffraction. The compound crystallizes in the orthorhombic space group Pbca with α = 14.6669 (5) Å, b = 18.3084 (6) Å, c = 19.0294 (6) Å, α = 90°, β = 90°, = 90°, V = 5109.9 (3) Å(3), and Z = 8. The molecules are packed in crystal structure by weak intermolecular C–H⋅ ⋅ ⋅O hydrogen bonding interactions. CONCLUSIONS: An environmentally benign Aldol-Michael protocol for the synthesis of dimedone-barbituric derivatives using aqueous diethylamine medium is achieved
Catalytic effectiveness of azobisisobutyronitrile/[SiMes)Ru(PPH3)(Ind)Cl2 initiating system in the polymerization of methyl methacrylate and other vinylic monomers
The catalytic system of azo-bis-isobutyronitrile (AIBN) combined with (SiMes)Ru(PPH3)(Ind)Cl-2 [M-20] was investigated for the controlled radical polymerization of methyl methacrylate (MMA) in solution. Various factors that may influence the catalytic polymerization process, such as the aging time of the initiating system, AIBN/M-20 ratio, concentration of monomer, polymerization time, temperature, and the nature of solvent were examined. The results showed that the yield, molecular weight, and molecular distribution are practically unaffected by these parameters; however, the syndiotactic stereo-structure tendency that characterizes the produced poly(methyl methacrylate) (PMMA) varied with temperature. The optimum conditions for PMMA synthesis were determined to produce an essentially syndiotactic material with uniformly high molecular weights. It was also revealed that the kinetics of MMA polymerization is of first order with respect to the concentration of monomer. A comparison was also made for some vinylic polymers synthesized either with the AIBN alone or with the AIBN/M-20 initiating system under the same conditions
Corrigendum to “Novel spirooxindole based benzimidazole scaffold: In vitro, nanoformulation and in vivo studies on anticancer and antimetastatic activity of breast adenocarcinoma”
This is a critical needed correction. In Fig. 15, the image corresponding to the lung from mouse treated with 25 mg/kg was taken from the same section of the mouse that was treated with 10 mg/kg. The corrected Fig. 15 [Formula presented] Fig. 15. Microscopic pictures of H&E stained lung sections from groups received (A) 4*106 cells/200 μL showing congested blood vessels (red arrows), peribronchial and interstitial aggregation (black arrows) of tumour cells admixed with MNCs. Microscopic pictures of H&E stained lungs sections from treated groups (B) 10 or (c) 25 mg/kg) showing disappeared congestion with decreased numbers of perivascular and interstitial infiltration of tumour cells. Increasing dose of treatment 25 mg/kg was more efficient than 10 mg/kg. Low magnification X: 100 with 100 μm scale bar.</p
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