31 research outputs found
CO2 Promoting Polymorphic Transformation of Clarithromycin: Polymorph Characterization, Pathway Design, and Mechanism Study
No full textCarbon dioxide (CO2) has a wide range of uses such as food additives and raw materials for synthetic chemicals, while its application in the solid-state transformation of pharmaceutical crystals is rare. In this work, we report a case of using 1 atm CO2 as an accelerator to promote the polymorphic transformation of clarithromycin (CLA). Initially, crystal structures of Form 0′ and three solvates were successfully determined by single crystal X-ray diffraction (SCXRD) analysis for the first time and found to be isomorphous. Powder X-ray diffraction (PXRD) and thermal analysis indicated that the solvate desolvates and transforms into the structurally similar non-solvated Form 0′ at room temperature to ~50 °C. Form 0′ and Form II are monotropically related polymorphs with Form II being the most stable. Subsequently, the effect of CO2 on the transformation of CLA solvates to Form II was studied. The results show that CO2 can significantly facilitate the transformation of Form 0′ to Form II, despite no significant effect on the desolvation process. Finally, the molecular mechanism of CO2 promoting the polymorphic transformation was revealed by the combination of the measurement of adsorption capacity, theoretical calculations as well as crystal structure analysis. Based on the above results, a new pathway of preparing CLA Form II was designed: transform CLA solvates into Form 0′ in 1 atm air at 50 °C followed by the transformation of Form 0′ to Form II in 1 atm CO2 at 50 °C. This work provides a new idea for promoting the phase transformation of pharmaceutical crystals as well as a new scenario for the utilization of CO2
Video Fire Detection Algorithm using Multi-Feature Fusion
No full textAt present, the moving target detection and flame characteristics extraction almost become the most important parts in majority of video fire detection systems. Through the above two-part study, a new fire features detection method is presented in precise moving target area. That is, using the improved background difference method and flame features (such as the color and uniformity, Wavelet energy, stroboscopic and contour features) to detect fire. Experiments show that this method can improve theaccuracy and anti-interference ability of fire detection. DOI: http://dx.doi.org/10.11591/telkomnika.v11i10.334
Decentralized Transaction Mechanism Based on Smart Contract in Distributed Data Storage
No full textDistributed data storage has received more attention due to its advantages in reliability, availability and scalability, and it brings both opportunities and challenges for distributed data storage transaction. The traditional transaction system of storage resources, which generally runs in a centralized mode, results in high cost, vendor lock-in and single point failure risk. To overcome the above shortcomings, considering the storage policy with erasure coding, in this paper we propose a decentralized transaction method for cloud storage based on a smart contract, which takes into account the resource cost for distributed data storage. First, to guarantee the availability and decrease the storing cost, a reverse Vickrey-Clarke-Groves (VCG) based auction mechanism is proposed for storage resource selection and transaction. Then we deploy and implement the proposed mechanism by designing a corresponding smart contract. Especially, we address the problem of how to implement a VCG-like mechanism in a blockchain environment. Based on the private chain of Ethereum, we make the simulation for the proposed storage transaction method. The results of simulation show that the proposed transaction model can realize competitive trading of storage resources and ensure the safe and economic operation of resource trading
Video Fire Detection Algorithm using Multi-Feature Fusion
No full textAt present, the moving target detection and flame characteristics extraction almost become the most important parts in majority of video fire detection systems. Through the above two-part study, a new fire features detection method is presented in precise moving target area. That is, using the improved background difference method and flame features (such as the color and uniformity, Wavelet energy, stroboscopic and contour features) to detect fire. Experiments show that this method can improve theaccuracy and anti-interference ability of fire detection. DOI: http://dx.doi.org/10.11591/telkomnika.v11i10.334
Author Correction: Prevalence and associated factors of myopia among adolescents aged 12–15 in Shandong Province, China: a cross-sectional study
No full textA Moving Object Detection Algorithm Based On Multiple Judgments
No full textIn the field of moving object detection, the traditional background subtraction method is used broadly, which seems more sensitive to light and shows poor anti-interference performance. Background modeling is the key step of background subtraction method. The Local Binary Pattern (LBP) algorithm is considered to put texture information into the background model, combining color and texture information and an improved background subtraction method proposed. In addition, a new method is proposed combining the inter-frame difference method with improved background subtraction method in this paper. It can overcome traditional methods only using the pixel gray value changes for moving targets detection. The method makes use of dual-threshold to detect moving targets and makes multiple judgments. It not only uses the change of pixel gray value to detect moving targets, but also takes advantage of the number of changed pixels to detect moving targets which we are interested in. The experiments show that the algorithm proposed is adopted to detect the moving target accurately and can resist interferences brought about by the slow slight movements in the scene with better robustness. DOI: http://dx.doi.org/10.11591/telkomnika.v11i10.333
Association of the ADIPOQ T45G polymorphism with insulin resistance and blood glucose: A meta-analysis
No full textResults of published studies on the association of the ADIPOQ T45G polymorphism with insulin resistance (IR) and blood glucose are conflicting. In this study, we performed a meta-analysis to further investigate such an association. Articles that evaluate the effect of the T45G polymorphism on IR. and blood glucose were identified from the PubMed and Embase databases. Five indices, including fasting blood glucose (FBG), fasting insulin (F-insulin), 2-h blood glucose (2-h BG), 2-h insulin, and homeostasis model assessment insulin resistance index (HOMA-IR), were used to assess the effects of the T45G polymorphism on IR. and blood glucose under a dominant model. 24 articles involving 7630 subjects were included. Twenty-two studies on FBG, 17 on F-insulin, 20 on HOMA-IR, and 3 on 2-h BG were included. No study on 2-h insulin was found. This meta-analysis revealed no significant association between the ADIPOQ T45G polymorphism and IR and blood glucose in the overall population and subgroup subjects under a dominant model, regardless of whether FBG, F-insulin, 2-h BG, or HOMA-IR was used. The present meta-analysis indicated that the mutation allele may have no function in IR development. The ADIPOQ T45G polymorphism is not associated with IR and blood glucose.Endocrinology & MetabolismSCI(E)[email protected]
Seven New Irbesartan Salts: Significantly Improved Dissolution, Excellent Hygrothermal Stability, and Characteristic Supramolecular Synthons
No full textIrbesartan (IRB) is a commonly used BCS Class II antihypertensive drug requiring dissolving capacity enhancement to address oral bioavailability limitations. In this work, seven new IRB salts were successfully synthesized, including one carboxylate (IRB-MAL) and six sulfonate salts (IRB-TOSA, IRB-BSA, IRB-4-CBSA, IRB-2, 5-CBSA, IRB-MSA, and IRB-CPSA). Their vitro dissolution, intrinsic dissolution rates (IDRs), thermal/hygroscopic stability (via thermal analysis, dynamic vapor sorption, and accelerated stability tests), and phase transition process (monitored by in situ Raman spectroscopy) were evaluated. The results revealed that IRB-TOSA, IRB-MAL, IRB-BSA, IRB-4-CBSA, and IRB-MSA salts exhibited IDRs of 0.3194–0.7383 mg/(cm2·min), all significantly higher than IRB, with dissolution concentrations increased by 14.9–113.6%. IRB-TOSA and IRB-4-CBSA salts demonstrated excellent hydrothermal stability. Single crystal structure analysis confirmed proton transfer from coformers’ sulfonic/carboxylic acids (deprotonation site, H-out) to IRB’s diazaheterocycles (protonation site, H-in) in IRB salts. Six sulfonate salts exhibited NH-in–H···OH-out and Nnon-H-in–H···OH-out hydrogen bonds, with the former absent in IRB-MAL. Furthermore, supramolecular synthon studies revealed distinct hydrogen-bonding patterns (e.g., bifurcated bonds in 2,5-CBSA and CPSA salts) that correlate with moisture resistance. Quantitative analysis of IRB salts suggested hydrogen bond strengths may influence their melting points (decomposition temperatures). This study demonstrates that IRB salts hold promise for advanced pharmaceutical applications
