The Method of Harmonic Balance for the Giesekus Model under Oscillatory Shear

The method of harmonic balance (HB) is a spectrally accurate method used to obtain periodic steady state solutions to dynamical systems subjected to periodic perturbations. We adapt HB to solve for the stress response of the Giesekus model under large amplitude oscillatory shear (LAOS) deformation. HB transforms the system of differential equations to a set of nonlinear algebraic equations in the Fourier coefficients. Convergence studies find that the difference between the HB and true solutions decays exponentially with the number of harmonics ($H$) included in the ansatz as $e^{-m H}$. The decay coefficient $m$ decreases with increasing strain amplitude, and exhibits a "U" shaped dependence on applied frequency. The computational cost of HB increases slightly faster than linearly with $H$. The net result of rapid convergence and modest increase in computational cost with increasing $H$ implies that HB outperforms the conventional method of using numerical integration to solve differential constitutive equations under oscillatory shear. Numerical experiments find that HB is simultaneously about three orders of magnitude cheaper, and several orders of magnitude more accurate than numerical integration. Thus, it offers a compelling value proposition for parameter estimation or model selection.Comment: submitted to JNNF

Origin of cystic artery from hepatic artery proper and its surgical implications

Cystic artery is usually a branch of right hepatic artery given in the Calot’s triangle. Variations in the origin of cystic artery have been reported but there is paucity of literature regarding these in Indian subjects. The present case describes the origin of cystic artery from the hepatic artery proper, with an unusual course, which was detected during routine cadaveric dissection. The development of biliary vasculature is quite complex and it accounts for many variations. Knowledge of cystic artery variability facilitates intraoperative identification of vessels in both classical and laparoscopic surgery of the bile ducts. This emphasises the importance of a thorough knowledge of the cystic arterial variations that often occur and may be encountered during both laparoscopic and open cholecystectomy. Uncontrolled bleeding from the cystic artery and its branches is a serious problem that may increase the risk of intraoperative lesions to vital vascular and biliary structures during hepatobiliary surgery

Characteristics of β-lactamases and their genes (blaA and blaB) in Yersinia intermedia and Y. frederiksenii

BACKGROUND: The presence of β-lactamases in Y. enterocolitica has been reported to vary with serovars, biovars and geographical origin of the isolates. An understanding of the β-lactamases in other related species is important for an overall perception of antibiotic resistance in yersiniae. The objective of this work was to study the characteristics of β-lactamases and their genes in strains of Y. intermedia and Y. frederiksenii, isolated from clinical and non-clinical sources in India. RESULTS: The enzymes, Bla-A (a constitutive class A penicillinase) and Bla-B (an inducible class C cephalosporinase) were found to be present in all the clinical and non-clinical strains of Y. intermedia and Y. frederiksenii by double disc diffusion method. The results showed differential expression of Bla-A as indicated by presence/absence of synergy whereas expression of Bla-B was quite consistent. The presence of these enzymes was also reflected in the high minimum inhibitory concentrations, MIC(50 )(126–1024 mg/L) and MIC(90 )(256–1024 mg/L) of β-lactam antibiotics against these species. Restriction fragment length polymorphism (RFLP) revealed heterogeneity in both blaA and blaB genes of Y. intermedia and Y. frederiksenii. The blaA gene of Y. intermedia shared significant sequence identity (87–96%) with blaA of Y. enterocolitica biovars 1A, 1B and 4. The sequence identity of blaA of Y. frederiksenii with these biovars was 77–79%. The sequence identity of blaB gene of Y. intermedia and Y. frederiksenii was more (85%) with that of Y. enterocolitica biovars 1A, 1B and 2 compared to other species viz., Y. bercovieri, Y. aldovae and Y. ruckeri. Isoelectric focusing data further revealed that both Y. intermedia and Y. frederiksenii produced Bla-A (pI 8.7) and "Bla-B like" (pI 5.5–7.1) enzymes. CONCLUSION: Both Y. intermedia and Y. frederiksenii showed presence of blaA and blaB genes and unequivocal expression of the two β-lactamases. Limited heterogeneity was detected in blaA and blaB genes as judged by PCR-RFLP. Phylogenetic relationships showed that the two species shared a high degree of identity in their bla genes. This is the first study reporting characteristics of β-lactamases and their genes in strains of Y. intermedia and Y. frederiksenii isolated from Asian region

Motion Detection in Low Resolution Grayscale Videos Using Fast Normalized Cross Correrelation on GP-GPU

Motion estimation (ME) has been widely used in many computer vision applications, such as object tracking, object detection, pattern recognition and video compression. The most popular block based similarity measures are the sum of absolute differences (SAD), the sum of squared differences (SSD) and the normalized cross correlation (NCC). Similarity measure obtained using NCC is more robust under varying illumination changes as compared to SAD and SSD. However NCC is computationally expensive and application of NCC using full or exhaustive search method further increases required computational time. Relatively efficient way of calculating the NCC is to pre-compute sum-tables to perform the normalization referred to as fast NCC (FCC). In this paper we propose real time implementation of full search FCC algorithm applied to gray scale videos using NVIDIA’s Compute Unified Device Architecture (CUDA). We present fine-grained optimization techniques for fully exploiting computational capacity of CUDA. Novel parallelization strategies adopted for extracting data parallelism substantially reduce computational time of exhaustive FCC. We show that by efficient utilization of global, shared and texture memories available on CUDA, we can obtain the speedup of the order of 10x as compared to the sequential implementation of FCC

Syntheses, spectral, thermal and pH-metric studies on bivalent metal ion complexes of N,N’-bis(3-carboxy-1-oxo-z-prop-2-elenyl)ethylenediamine

A novel carboxyamide ligand has been synthesized using maleic anhydride and ethylenediamine. Co(II), Ni(II), Cu(II) and Pd(II) complexes of the ligand, i.e., N,N’-bis(3-carboxy-1-oxo-z-prop-2-elenyl)ethylenediamine [H2L] have been prepared and characterized by elemental analyses,  IR, electronic, 1H NMR, EPR spectral and thermal studies. It is revealed by IR and 1H NMR spectral studies that the ligand coordinated to the metal ions through deprotonated carboxylate oxygen and non-deprotonated amide nitrogen in all the complexes. It is suggested by electronic spectral and magnetic moment studies that N2O2 coordination is around each metal center with a strong field square planar chromophore. All the complexes have been studied by TGA and DTA studies done simultaneously. The complex formation between ligand and metal ions [Mn(II), Co(II), Ni(II), Cu(II) and Zn(II)] has also been studied pH metrically in 75% aqueous DMF solution at 298 K in 0.1 M NaClO4. The probable structures of the complexes have also been proposed

DISCRIMINATORY POTENTIAL OF BIPHASIC MEDIUM OVER COMPENDIAL AND BIORELEVANT MEDIUM FOR ASSESSMENT OF DISSOLUTION BEHAVIOR OF TABLETS CONTAINING MELOXICAM NANOPARTICLES

ABSTRACTObjective: Dissolution test serves as a quality control tool for assessment of drug release from dosage form as well as a research tool to optimize newformulations. The existing guidelines by FDA, EMA, ICH, USP, etc., describe specifications for the dissolution of immediate release as well as modifiedrelease oral dosage form. However, none of them have discussed about the discriminatory potential of the medium to differentiate release profile of twoor more products that are pharmaceutically equivalent. It is pertinent to add here that the pharmaceutical equivalents are not always bioequivalent.Hence, a discriminatory dissolution procedure is a must requirement to differentiate the release behavior of drug from a pharmaceutically equivalentproduct that contains different types and amount of excipient in the formulation. This also becomes more cumbersome when it is desirable forprediction of in vivo behavior of a drug when it is converted into a novel delivery system like nanoparticles. The reason could be the presence ofexcipients used to formulate drug nanoparticles into solid oral dosage form, may change the drug disintegration as well as dissolution behavior, whichultimately may lead to altered bioavailability.Methods: In this study, the nanoparticles of meloxicam were prepared using wet media milling and the milled samples were dried using spray drier.The dried nanoparticles were converted into tablet dosage form by varying the type of diluent. To one batch lactose was used and another one wascontaining dicalcium phosphate (DCP). The assessment of release of meloxicam from these two batches was evaluated in various dissolution media.Results: The study revealed that in all the cases the nanoparticulate tablets of Batch 1 have given increased dissolution profile as compared tomarketed formulation (Muvera), Batch 2 and controlled tablets of meloxicam. This proved that the excipients also play a major role in the releasebehavior of drug otherwise if it was not so, the nanoparticulate tablets of Batch 1 and Batch 2 would have given the same dissolution profile in all thetried media. Batch 1 containing lactose with a higher surface area provided more and rapid wetting of the drug by the dissolution media compared toBatch 2 that contained DCP as a major diluent.®Conclusion: Among all the dissolution media tried to evaluate the discriminatory power and simulation with a biorelevant medium, the biphasicmedium of pH 1.8, 4.8 and 6.8 has promised to simulate with biorelevant media. However, the medium of pH 6.8 has shown the best dissolution profile.Keywords: Solubility, Compendial media, Biphasic media, Dissolution, Meloxicam

INFLUENCE OF FORMULATION PARAMETERS ON DISSOLUTION RATE ENHANCEMENT OF PIROXICAM USING LIQUISOLID TECHNIQUE

ABSTRACTObjective: This study revealed formulation of a liquisolid system of poorly soluble piroxicam to enhance its dissolution rate. To formulate a liquisolidsystem loaded with piroxicam, solubility study was carried out in various non-volatile liquids.Methods: In 1 ml of polyethylene glycol (PEG) 600, 100 mg piroxicam was added and stirred with gentle heating. To the above liquid medication, 1 gmicrocrystalline cellulose (MCC) 102 (as MCC has given better results), 1 g Syloid 244 FP, 2 g PEG 4000, 500 mg aerosil 200, and 0.255 g sodium starchglycolate (SSG) (5%) were added and mixed properly. The blend was compressed and subjected for quality control parameters.Results: Among all the non-volatile liquids evaluated, piroxicam was most soluble in PEG 600. Using this as liquid medication, several liquisolid compactswere prepared by varying the ratios of MCC PH 102 as carrier and Syloid 244FP as coating material and evaluated for precompression studies. To furtheraccelerate the release of drug, various additives were added in the formulation. Among them, PEG 4000 has shown better flow as well as compressionproperties. Hence, the final formulation (LS-16B) was prepared using a combination of MCC PH 102, Syloid 244 FP, PEG 4000 and SSG as superdisintegrant.The dissolution studies revealed that about 92.18% drug got released from liquisolid compacts in 120 minutes, whereas only 68.16% release wasobserved for pure piroxicam. X-ray diffraction and scanning electron microscopy images revealed the successful formation of liquisolid system.Conclusion: It was concluded that dissolution rate of poorly soluble piroxicam could be enhanced using liquisolid technique.Keywords: Piroxicam, Polyethylene glycol 600, Microcrystalline cellulose PH 102, Syloid 244 FP, Polyethylene glycol 4000

IN VITRO ANTI-INFLAMMATORY AND ANTIOXIDANT ACTIVITIES OF HINGULESWARA RASABASED HERBOMINERAL FORMULATIONS

Objective: The aims of the present investigation were to develop the herbal and/or herbomineral formulations of Hinguleswara rasa and to compare their anti-inflammatory and antioxidant activities, in vitro, with that of standard drug samples.Methods: This study was an interventional investigation in three samples: In the first sample, Hinguleswara rasa (HR1) was prepared as per methodology described in Rasatarangini using Shuddha Hingula (10 g), Shuddha Vatsanabha (10 g), and Pippali (10 g). In the second and third sample, respectively, Hinguleswara rasa was prepared by replacing Shuddha Hingula with Kajjali where Kajjali made from Hingulotha parada and Sodhita parada constitutes two varieties of Hinguleswara rasa, i.e. HR2 and HR3. In vitro antioxidant activity was studied using 2,2-diphenyl-1-picrylhydrazyl, and the absorbance was recorded at 517 nm. For evaluating the in vitro anti-inflammatory studies, the inhibition of albumin denaturation technique was performed.Results: The results showed that the formulation of Hinguleswara rasa has shown dose-dependent activity which was observed in 100 μg concentration. HR1, HR2, and HR3 showed 36.11, 17.22, and 16.11% radical scavenging activity.Conclusion: It could be concluded that the changes made in the formulations did not affect the in vitro anti-inflammatory and antioxidant effects of the herbomineral formulations