268 research outputs found

    Usefulness of rifabutin loaded floating beads for the treatment of Helicobacter pylori infection in experimental Mongolian gerbils

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    The objective of the present study was to develop stomach-specific drug delivery system of rifabutin and to evaluate their effectiveness in eradication of Helicobacter pylori in experimental Mongolian gerbil model.Rifabutin loaded floating gellan gum beads prepared by calcium induced ionotropic gelation in acidic medium. The prepared beads were evaluated for in vitro characterization and in vivo Helicobacter pylori clearance efficiency following repeated oral administration to Helicobacter pylori infected Mongolian gerbils. Our results showed that the rifabutin loaded floating beads possess significant anti- Helicobacter pylori effect in the in vivo gerbil model.The findings support that rifabutin floating beads could be a promising gastrointestinal drug delivery system in treatment of Helicobacter pylori.Keywords: Rifabutin, floating beads, gellan gum, Helicobacter pylori

    Image Compression using Gaussian Smoothing Filter and Median Filter

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    Now a day’s we are facing a lots of problem regarding data storage. We have very large amount of data with high resolution quality and it is increasing day by day. Data compression is playing a vital role in modern world, because data compression is a technique by which we can store large amount of data in a limited storage device. Data compression can be used in mass communication, online data storing and real time data storing. This paper is based on data compression using efficient data compression algorithm. In this paper we use Gaussian filter as sharping tool and median filter as compression tool

    Network Based Approaches for Clustering and Location Decisions

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    The objective of this dissertation is to study commonly occurring location and clustering problems on graphs. The dissertation is presented as a collection of results in topics including finding maximum cliques in large graphs, graph clustering in large scale graphs, determining location of facilities for pre-positioning emergency relief supplies, and selecting nodes to form a virtual backbone in a wireless sensor network. To begin with, a new clique relaxation called a k-community is defined as a connected subgraph such that endpoints of every edge have at least k common neighbors within the subgraph. It is used to develop scale reduction techniques to obtain the maximum clique on very large scale real life networks. Analytically, the technique is been shown to be very effective on power-law random graphs. Experimental results on real life graph instances (Collaboration networks, P2P networks, Social networks, etc.) show our procedure to be much more effective than a regular k-core peeling approach. Next, a general purpose network clustering algorithm based on the clique relaxation concept of k-community is presented. A salient feature of this approach is that it does not use any prior information about the structure of the network. By defining a cluster as a k-community, the proposed algorithm aims to provide a clustering of a network into k-communities with varying values of k. Even though the algorithm is not designed to optimize any particular performance measure, the computational results suggest that it performs well on a number of criteria that are used in literature to evaluate the quality of a clustering. The third topic deals with choosing the locations of disaster response facilities for the storage of emergency supplies, which is critical to the quality of service provided in a large scale emergency like an earthquake. In the existing literature, large scale emergency facility location models have either assumed that disaster response facilities will always be functioning and available when required, or that the functioning of a facility is independent of a particular disaster scenario. In this paper new location models are presented that explicitly take into consideration the stochastic nature of the impact a disaster can have on the disaster response facilities and the population centers in surrounding areas. A comparison of the results obtained using our models with those from models available in literature using a case study suggests that the locations suggested by the model in this paper significantly reduce the expected cost of transportation of supplies when we consider the damage a disaster causes to the disaster response facilities and areas near it. Lastly, a distributed approximate algorithm for forming the communication backbone in wireless sensor networks is presented. Some of the most popular routing protocols for wireless sensor networks require a virtual backbone for efficient communication be- tween the sensors. Connected Dominating Sets (CDS) have been studied as a method of choosing nodes to be in the backbone. The traditional approach is to assume that the transmission range of each node is given and then minimize the number of nodes in the CDS representing the backbone. A recently introduced alternative strategy is based on the concept of k-bottleneck connected dominating set (k-BCDS), which, given a positive integer k, minimizes the transmission range of the nodes that ensures a CDS of size k exists in the network. This paper provides a 6-approximate distributed algorithm for the k-BCDS problem. The results of empirical evaluation of the proposed algorithm are also included

    Formulation and evaluation of chitosan containing mucoadhesive buccal patches of metoprolol succinate

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    Mucoadhesive buccal patches containing metoprolol succinate were prepared using the solvent casting method. Chitosan was used as bioadhesive polymer and different ratios of chitosan to PVP K-30 were used. The patches were evaluated for their physical characteristics like mass variation, drug content uniformity, folding endurance, ex vivo mucoadhesion strength, ex vivo mucoadhesion time, surface pH, in vitro drug release, and in vitro buccal permeation study. Patches exhibited controlled release for a period of 8 h. The mechanism of drug release was found to be non-Fickian diffusion and followed the first-order kinetics. Incorporation of PVP K-30 generally enhanced the release rate. Swelling index was proportional to the concentration of PVP K-30. Optimized patches (F4) showed satisfactory bioadhesive strength of 9.6 ± 2.0 g, and ex vivo mucoadhesion time of 272 minutes. The surface pH of all patches was between 5.5 and 6.8 and hence patches should not cause irritation in the buccal cavity. Patches containing 10 mg of drug had higher bioadhesive strength with sustained drug release as compared to patches containing 20 mg of drug. Good correlation was observed between the in vitro drug release and in vitro drug permeation with a correlation coefficient of 0.9364. Stability study of optimized patches was done in human saliva and it was found that both drug and buccal patches were stable

    RecXplainer: Post-Hoc Attribute-Based Explanations for Recommender Systems

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    Recommender systems are ubiquitous in most of our interactions in the current digital world. Whether shopping for clothes, scrolling YouTube for exciting videos, or searching for restaurants in a new city, the recommender systems at the back-end power these services. Most large-scale recommender systems are huge models trained on extensive datasets and are black-boxes to both their developers and end-users. Prior research has shown that providing recommendations along with their reason enhances trust, scrutability, and persuasiveness of the recommender systems. Recent literature in explainability has been inundated with works proposing several algorithms to this end. Most of these works provide item-style explanations, i.e., `We recommend item A because you bought item B.' We propose a novel approach, RecXplainer, to generate more fine-grained explanations based on the user's preference over the attributes of the recommended items. We perform experiments using real-world datasets and demonstrate the efficacy of RecXplainer in capturing users' preferences and using them to explain recommendations. We also propose ten new evaluation metrics and compare RecXplainer to six baseline methods.Comment: Awarded the Best Student Paper at TEA Workshop at NeurIPS 2022. 13 page

    Kitozan male molekulske mase kao nosač hidrodinamički uravnoteženog sustava za usporenu isporuku ciprofloksacin hidroklorida

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    Chitosan has become a focus of major interest in recent years due to its excellent biocompatibility, biodegradability and non-toxicity. Although this material has already been extensively investigated in the design of different types of drug delivery systems, it is still little explored for stomach specific drug delivery systems. The objective of the present investigation was to explore the potential of low molecular mass chitosan (LMCH) as carrier for a hydrodynamically balanced system (HBS) for sustained delivery of water soluble drug ciprofloxacin hydrochloride (CP). Various formulations were prepared by physical blending of drug and polymer(s) in varying ratios followed by encapsulation into hard gelatin capsules. All the formulations remained buoyant in 0.1mol L1 HCl (pH 1.2) throughout the experiment. Effect of addition of xanthan gum (XG) or ethyl cellulose (EC) on drug release was also investigated. Zero order drug release was obtained from the formulations containing LMCH alone or in combination with XG, and in one instance also with EC. Our results suggest that LMCH alone or in combination with XG is an excellent material for stomach specific sustained delivery of CP from hydrodynamically balanced single unit capsules.Zbog svoje biokompatibilnosti, biorazgradljivosti i netoksičnosti kitozan je vrlo interesantan istraživačima u području farmaceutske tehnologije. Najviše se upotrebljavao u dizajniranju različitih sustava za isporuku lijekova ali vrlo malo za sustave za specifičnu isporuku u želucu. Cilj ovog rada bio je ispitati mogućnost upotrebe kitozana male molekulske mase (LMCH) kao nosača u hidrodinamički balansiranom sustavu (HBS) za usporenu isporuku vodotopljivog lijeka ciprofloksacin hidroklorida (CP). Pripravljene su različite formulacije stvaranjem fizičke smjese lijeka i polimera u različitim omjerima, koje su potom kapsulirane u želatinske kapsule. Svi su pripravci za vrijeme cijelog eksperimenta ostali plutati u 0,01mol L1 HCl (pH 1,2). Ispitivan je i učinak ksantan gume (XG) ili etilceluloze (EC) na oslobađanje lijeka. Oslobađanje lijeka nultog reda postignuto je iz formulacija koje sadrže samo LMCH ili LMCH u kombinaciji sa XG i u jednom slučaju s EC. Dobiveni rezultati pokazuju da je LMCH, sam ili u kombinaciji sa XG, izvrstan materijal za sustave za specifičnu isporuku CP iz hidrodinamički balansiranih kapsula

    Di-n-butyltin(IV) Complexes Derived from Heterocyclic β-diketones and N-Phthaloyl Amino Acids: Preparation, Biological Evaluation, Structural Elucidation Based upon Spectral [IR, NMR (1H, 13C, 19F and 119Sn)] Studies

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    Stable, six coordinated Bu2SnLA type complexes have been prepared [where LH = RCOC:C(OH)N(C6 H5)N:CCH3; R = -4-F-C6H4-(L1H), R = -4-Cl-C6H4-(L2H), R= -4-Br-C6H4-(L3H), R=-CF3(L4H) and AH = C(O)C6 H4 C(O)NCHR'COOH; R'= -H(A1H), -CH3(A2H), -CH(CH3)2(A3H)] by the interaction of 1:1:1 molar ratios of di-n-butyltin(IV) dichloride with corresponding organic moieties in refluxing benzene using two moles of Et3N as a base. In these complexes LH and AH behave as bidentate and coordination is taking place through oxygen, this is inferred from IR and 13C NMR studies. These complexes possess tin atoms in skew trapezoidal bipyramidal geometry with the C-Sn-C angles ranging from 149.88° to 156.84°. Some of these complexes with their corresponding organic moieties (LH, AH) were tested for their antimicrobial activities
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