scholarly journals Synthesis, Drug Release, and Antibacterial Properties of Novel Dendritic CHX-SrCl2 and CHX-ZnCl2 Particles

Pharmaceutics ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1799
Author(s):  
Rui Sun ◽  
Jiaxin Zhang ◽  
Robert A. Whiley ◽  
Gleb B. Sukhorukov ◽  
Michael J. Cattell

This work demonstrated for the first time the synthesis of novel chlorhexidine particles containing strontium and zinc, to provide an effective, affordable, and safe intervention in the treatment of recurrent infections found in Medicine and Dentistry. The CHX-SrCl2 and CHX-ZnCl2 particles were synthesized by co-precipitation of chlorhexidine diacetate (CHXD) and zinc chloride or strontium chloride, where particle size was manipulated by controlling processing time and temperature. The CHX-ZnCl2 and CHX-SrCl2 particles were characterized using SEM, FTIR, and XRD. UV-Vis using artificial saliva (pH 4 and pH 7) was used to measure the drug release and ICP-OES ion release. The antibacterial properties were examined against P. gingivalis, A. actinomycetemcomitans, and F. nucleatum subsp. Polymorphum, and cytotoxicity was evaluated using mouse fibroblast L929 cells. The novel particles were as safe as commercial CHXD, with antibacterial activity against a range of oral pathogens. UV-Vis results run in artificial saliva (pH 4 and pH 7) indicated a higher release rate in acidic rather than neutral conditions. The CHX-ZnCl2 particles provided the functionality of a smart Zinc and CHX release, with respect to environmental pH, allowing responsive antibacterial applications in the field of medicine and dentistry.

2020 ◽  
Vol 21 (17) ◽  
pp. 6369
Author(s):  
Wen Zhou ◽  
Xinyu Peng ◽  
Xuedong Zhou ◽  
Andrea Bonavente ◽  
Michael D. Weir ◽  
...  

Secondary caries often occurs at the tooth-composite margins. This study developed a novel bioactive composite containing DMAHDM (dimethylaminohexadecyl methacrylate) and NACP (nanoparticles of amorphous calcium phosphate), inhibiting caries at the enamel restoration margins in an in vitro saliva-derived biofilm secondary caries model for the first time. Four composites were tested: (1) Heliomolar nanocomposite, (2) 0% DMAHDM + 0% NACP, (3) 3% DMAHDM + 0% NACP, (D) 3% DMAHDM + 30% NACP. Saliva-derived biofilms were tested for antibacterial effects of the composites. Bovine enamel restorations were cultured with biofilms, Ca and P ion release of nanocomposite and enamel hardness at the enamel restoration margins was measured. Incorporation of DMAHDM and NACP into composite did not affect the mechanical properties (p > 0.05). The biofilms’ CFU (colony-forming units) were reduced by 2 logs via DMAHDM (p < 0.05). Ca and P ion release of the nanocomposite was increased at cariogenic low pH. Enamel hardness at the margins for DMAHDM group was 25% higher than control (p < 0.05). With DMAHDM + NACP, the enamel hardness was the greatest and about 50% higher than control (p < 0.05). Therefore, the novel composite containing DMAHDM and NACP was strongly antibacterial and inhibited enamel demineralization, resulting in enamel hardness at the margins under biofilms that approached the hardness of healthy enamel.


2018 ◽  
Vol 8 (3) ◽  
pp. 247-266
Author(s):  
Michelle L. Wilson

Initially, Oliver Twist (1839) might seem representative of the archetypal male social plot, following an orphan and finding him a place by discovering the father and settling the boy within his inheritance. But Agnes Fleming haunts this narrative, undoing its neat, linear transmission. This reconsideration of maternal inheritance and plot in the novel occurs against the backdrop of legal and social change. I extend the critical consideration of the novel's relationship to the New Poor Law by thinking about its reflection on the bastardy clauses. And here, of course, is where the mother enters. Under the bastardy clauses, the responsibility for economic maintenance of bastard children was, for the first time, legally assigned to the mother, relieving the father of any and all obligation. Oliver Twist manages to critique the bastardy clauses for their release of the father, while simultaneously embracing the placement of the mother at the head of the family line. Both Oliver and the novel thus suggest that it is the mother's story that matters, her name through which we find our own. And by containing both plots – that of the father and the mother – Oliver Twist reveals the violence implicit in traditional modes of inheritance in the novel and under the law.


2018 ◽  
Author(s):  
Satish Kodali ◽  
Liangshan Chen ◽  
Yuting Wei ◽  
Tanya Schaeffer ◽  
Chong Khiam Oh

Abstract Optical beam induced resistance change (OBIRCH) is a very well-adapted technique for static fault isolation in the semiconductor industry. Novel low current OBIRCH amplifier is used to facilitate safe test condition requirements for advanced nodes. This paper shows the differences between the earlier and novel generation OBIRCH amplifiers. Ring oscillator high standby leakage samples are analyzed using the novel generation amplifier. High signal to noise ratio at applied low bias and current levels on device under test are shown on various samples. Further, a metric to demonstrate the SNR to device performance is also discussed. OBIRCH analysis is performed on all the three samples for nanoprobing of, and physical characterization on, the leakage. The resulting spots were calibrated and classified. It is noted that the calibration metric can be successfully used for the first time to estimate the relative threshold voltage of individual transistors in advanced process nodes.


Author(s):  
G. O. Hutchinson

The chapter looks at the division between poetry and prose in ancient and other literatures, and shows the importance of rhythmic patterning in ancient prose. The development of rhythmic prose in Greek and Latin is sketched, the system explained and illustrated (from Latin). It is firmly established, for the first time, which of the main Greek non-Christian authors 31 BC–AD 300 write rhythmically. The method takes a substantial sample of random sentence-endings (usually 400) from each of a large number of Imperial authors; it compares that sample with one sample of the same size (400) drawn randomly from a range of authors earlier than the invention of this rhythmic system. A particular sort of X2-test is applied. Many Imperial authors, it emerges, write rhythmically; many do not. The genres most likely to offer rhythmic writing are, unexpectedly, narrative: historiography and the novel.


Author(s):  
Robert Louis Stevenson ◽  
Ian Duncan

Your bed shall be the moorcock’s, and your life shall be like the hunted deer’s, and ye shall sleep with your hand upon your weapons.’ Tricked out of his inheritance, shanghaied, shipwrecked off the west coast of Scotland, David Balfour finds himself fleeing for his life in the dangerous company of Jacobite outlaw and suspected assassin Alan Breck Stewart. Their unlikely friendship is put to the test as they dodge government troops across the Scottish Highlands. Set in the aftermath of the 1745 rebellion, Kidnapped transforms the Romantic historical novel into the modern thriller. Its heart-stopping scenes of cross-country pursuit, distilled to a pure intensity in Stevenson’s prose, have become a staple of adventure stories from John Buchan to Alfred Hitchcock and Ian Fleming. Kidnapped remains as exhilarating today as when it was first published in 1886. This new edition is based on the 1895 text, incorporating Stevenson’s last thoughts about the novel before his death. It includes Stevenson’s ‘Note to Kidnapped’, reprinted for the first time since 1922.


Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 256
Author(s):  
Florentina Golgovici ◽  
Mariana Prodana ◽  
Florentina Gina Ionascu ◽  
Ioana Demetrescu

The purpose of our study is to compare the behavior of two reprocessed dental alloys (NiCr and CoCr) at different temperatures considering the idea that food and drinks in the oral cavity create various compositions at different pH levels; the novelty is the investigation of temperature effect on corrosion parameters and ion release of dental alloys. Electrochemical stability was studied together with morphology, elemental composition and ions release determination. The results obtained are in good concordance: electrochemistry studies reveal that the corrosion rate is increasing by increasing the temperature. From SEM coupled with EDS, the oxide film formed on the surface of the alloys is stable at low temperatures and a trend to break after 310K. ICP-MS results evidence that in accordance with increasing temperature, the quantities of ions released from the alloys immersed in artificial saliva also increase, though they still remain small, less than 20 ppm.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Diana P. Pires ◽  
Rodrigo Monteiro ◽  
Dalila Mil-Homens ◽  
Arsénio Fialho ◽  
Timothy K. Lu ◽  
...  

AbstractIn the era where antibiotic resistance is considered one of the major worldwide concerns, bacteriophages have emerged as a promising therapeutic approach to deal with this problem. Genetically engineered bacteriophages can enable enhanced anti-bacterial functionalities, but require cloning additional genes into the phage genomes, which might be challenging due to the DNA encapsulation capacity of a phage. To tackle this issue, we designed and assembled for the first time synthetic phages with smaller genomes by knocking out up to 48% of the genes encoding hypothetical proteins from the genome of the newly isolated Pseudomonas aeruginosa phage vB_PaeP_PE3. The antibacterial efficacy of the wild-type and the synthetic phages was assessed in vitro as well as in vivo using a Galleria mellonella infection model. Overall, both in vitro and in vivo studies revealed that the knock-outs made in phage genome do not impair the antibacterial properties of the synthetic phages, indicating that this could be a good strategy to clear space from phage genomes in order to enable the introduction of other genes of interest that can potentiate the future treatment of P. aeruginosa infections.


1997 ◽  
Vol 75 (6) ◽  
pp. 773-789 ◽  
Author(s):  
Eric J. Dumdei ◽  
Julia Kubanek ◽  
John E. Coleman ◽  
Jana Pika ◽  
Raymond J. Andersen ◽  
...  

Chemical investigations of Cadlinaluteomarginata skin extracts, egg masses, and dietary sponges have led to the identification of the novel terpenoids cadlinaldehyde (30), spongian 32, seco-spongian 35, 20-acetoxy-12-marginatone (38), and lutenolide (39) from the nudibranch skin extracts, the new drimane sesquiterpenoid 1α,2α-diacetoxyalbicanyl acetate (40) from the nudibranch's egg mass, and the new sesquiterpenoids O-methyl-9-oxofurodysininlactone (47), 2-oxomicro-cionin-2-lactone (48), and O-methyl-2-oxomicrocionin-2-lactone (49), from the dietary sponge Pleraplysilla sp. The known terpenoids furodysinin (1), furodysin (16), marginatafuran (21), and 9,11-dihydrogracillin A (37), which have been frequently isolated from C. luteomarginata skin extracts, were found for the first time in extracts of the dietary sponges Pleraplysilla sp. and Aplysilla sp. One of the new terpenoids, cadlinaldehyde (30), has an unprecedented degraded sesterterpenoid skeleton. Keywords: nudibranch, sponge, terpenoids, structure elucidation.


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