88 results on '"Gozin M"'
Search Results
2. Tuning the critical temperature of cuprate superconductor films using self-assembled organic layers
- Author
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Carmeli, I., Lewin, A., Flekser, E., Diamant, I., Zhang, Q., Shen, J., Gozin, M., Richter, S., and Dagan, Y.
- Subjects
Condensed Matter - Superconductivity ,Condensed Matter - Materials Science ,Condensed Matter - Strongly Correlated Electrons - Abstract
Many of the electronic properties of high-temperature cuprate superconductors (HTSC) are strongly dependent on the number of charge carriers put into the CuO$_2$ planes (doping). Superconductivity appears over a dome-shaped region of the doping-temperature phase diagram. The highest critical temperature (Tc) is obtained for the so-called "optimum doping". The doping mechanism is usually chemical; it can be done by cationic substitution. This is the case, for example, in La$_{2-x}$Sr$_x$CuO$_4$ where La3+ is replaced by Sr2+ thus adding a hole to the CuO$_2$ planes. A similar effect is achieved by adding oxygen as in the case of YBa$_2$Cu$_3$O$_{6+\delta}$ where $\delta$ represents the excess oxygen in the sample. In this paper we report on a different mechanism, one that enables the addition or removal of carriers from the surface of the HTSC. This method utilizes a self-assembled monolayer (SAM) of polar molecules adsorbed on the cuprate surface. In the case of optically active molecules, the polarity of the SAM can be modulated by shining light on the coated surface. This results in a light-induced modulation of the superconducting phase transition of the sample. The ability to control the superconducting transition temperature with the use of SAMs makes these surfaces practical for various devices such as switches and detectors based on high-Tc superconductors.
- Published
- 2014
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3. The impact of highly hydrophobic material on the structure of transferrin and its ability to bind iron
- Author
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Drug, E., Fadeev, L., and Gozin, M.
- Published
- 2011
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4. Energetic isomers of 1,2,4,5-tetrazine-bis-1,2,4-triazoles with low toxicity
- Author
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Shlomovich, A., primary, Pechersky, T., additional, Cohen, A., additional, Yan, Q. L., additional, Kosa, M., additional, Petrutik, N., additional, Tal, N., additional, Aizikovich, A., additional, and Gozin, M., additional
- Published
- 2017
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- View/download PDF
5. Hydroxyapatite coatings electrodeposited at near-physiological conditions
- Author
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Metoki, N., Leifenberg-Kuznits, L., Kopelovich, W., Burstein, L., Gozin, M., and Eliaz, N.
- Published
- 2014
- Full Text
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6. The nitration pattern of energetic 3,6-diamino-1,2,4,5-tetrazine derivatives containing azole functional groups
- Author
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Aizikovich, A., primary, Shlomovich, A., additional, Cohen, A., additional, and Gozin, M., additional
- Published
- 2015
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7. Notice of Retraction: Damage tolerance analysis of jet engine compressor disk using FEM
- Author
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Gozin, M. H., primary and Aghaie-Khafri, M., additional
- Published
- 2010
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8. ChemInform Abstract: Palladium‐Catalyzed Vinylation of Aryl Chlorides. Chelate Effect in Catalysis.
- Author
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BEN‐DAVID, Y., primary, PORTNOY, M., additional, GOZIN, M., additional, and MILSTEIN, D., additional
- Published
- 1992
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9. Palladium-catalyzed vinylation of aryl chlorides. Chelate effect in catalysis
- Author
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Ben-David, Y., primary, Portnoy, M., additional, Gozin, M., additional, and Milstein, D., additional
- Published
- 1992
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10. Formation and Characterization of Stable Human Serum Albumin−Tris-malonic Acid [C<INF>60</INF>]Fullerene Complex
- Author
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Belgorodsky, B., Fadeev, L., Ittah, V., Benyamini, H., Zelner, S., Huppert, D., Kotlyar, A. B., and Gozin, M.
- Abstract
The preparation and characterization of the stable human serum albumin (HSA)-C
3 isomer of tris-malonic acid [C60 ]fullerene complex is reported. Other than the anti-fullerene antibody, a stable protein−fullerene complex with a native protein has never been observed. This study may provide valuable answers to the growing concern regarding the effects of carbonaceous nanomaterials on human health on one hand and, on the other, may lead to the development of novel antioxidant therapeutic agents, radiopharmaceuticals, and components for bioelectronic devices.- Published
- 2005
11. Fullerene (ABS-75) treatment reduces disease progression and axonal loss in MOG-induced progressive EAE in NOD mice
- Author
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Alexandre Basso, Frenkel, D., Petrovic-Stojkovic, S., Puckett, L., Monsonego, A., Gozin, M., and Weiner, H. L.
12. Experimental study on aluminum foils use in blast enhancement application
- Author
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Trană, E., Rotariu, A. N., Rotariu, T., Gheorghe Bogdan Pulpea, Moldoveanu, C. E., Bucur, F., Matache, L. C., and Gozin, M.
13. Huge heterotopic brain cyst of the orbit: report of a case and its management.
- Author
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Bagheri A, Gozin M, Veisi A, and Kanavi MR
- Subjects
- Male, Child, Humans, Orbit, Tomography, X-Ray Computed, Brain, Orbital Diseases diagnostic imaging, Orbital Diseases surgery, Cysts diagnostic imaging, Cysts surgery, Choristoma diagnostic imaging, Choristoma surgery
- Abstract
Heterotopic brain tissues are a group of extracerebral neuroglial tissues. Heterotopic brain tissue in the orbit remains a rare clinical entity. This article presents a 7-year-old male child who presented with severe globe displacement, proptosis, and vision loss in the right eye. The orbital imaging showed a huge orbital cystic mass displacing the globe. The cyst was excised entirely from the orbit. The histopathological investigations revealed the presence of a cystic lesion containing brain tissue that was immune reactive for S-100 and glial fibrillary acidic proteins. The diagnosis was confirmed to be heterotopic brain tissue due to the lack of visible bony defect. The relevant literature was also reviewed.
- Published
- 2024
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14. Waste animal fat with hydrothermal liquefaction as a potential route to marine biofuels.
- Author
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Steinbruch E, Singh S, Mosseri M, Epstein M, Kribus A, Gozin M, Drabik D, and Golberg A
- Subjects
- Animals, Cattle, Temperature, Nitrogen, Sulfur, Biofuels, Water chemistry
- Abstract
Unused animal waste rendered fat is a potential feedstock for marine biofuels. In this work, bio-oil was generated using hydrothermal liquefaction (HTL) of nitrogen-free and low sulfur rendered bovine fat. Maximum bio-oil yield of 28 ± 1.5% and high heating value of 38.5 ± 0.16 MJ·kg
‒1 was obtained at 330 °C at 50% animal fat solid load and 20 min retention time. The nitrogen and sulfur content were negligible, making the produced bio-oil useful marine biofuel, taking into account current stringent regulations on NOx and SOx emissions. The economic analysis of the process, where part of the bovine fat waste is converted to the bio-oil and the semi-solid residues can be used to supply the heat demand of the HTL process and alternately generate electricity, showed that our process is likely to generate a positive profit margin on a large scale. We also showed the growing economic importance of electricity in the revenues as commercial production becomes more energy efficient., Competing Interests: The authors declare that they have no competing interests., (© 2023 Steinbruch et al.)- Published
- 2023
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15. Avocado seed waste bioconversion into poly(3-hydroxybutyrate) by using Cobetia amphilecti and ethyl levulinate as a green extractant.
- Author
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Gnaim R, Unis R, Gnayem N, Das J, Shamis O, Gozin M, Gnaim J, and Golberg A
- Subjects
- 3-Hydroxybutyric Acid, Hydroxybutyrates chemistry, Polyesters chemistry, Persea
- Abstract
The avocado processing industry produces up to 1.3M tons of agro-waste annually. Chemical analysis of avocado seed waste (ASW) revealed that it is rich in carbohydrates (464.7 ± 21.4 g kg
-1 ) and proteins (37.2 ± 1.5 g kg-1 ). Optimized microbial cultivation of Cobetia amphilecti using an acid hydrolysate of ASW, generated poly(3-hydroxybutyrate) (PHB) in a 2.1 ± 0.1 g L-1 concentration. The PHB productivity of C. amphilecti cultivated on ASW extract was 17.5 mg L-1 h-1 . The process in which a novel ASW substrate was utilized has been further augmented by using ethyl levulinate as a sustainable extractant. This process achieved 97.4 ± 1.9 % recovery yield and 100 ± 1 % purity (measured by TGA, NMR, and FTIR) of the target PHB biopolymer, along with a high and relatively uniform PHB molecular weight (Mw = 1831 kDa, Mn = 1481 kDa, Mw /Mn = 1.24) (measured by gel permeation chromatography), compared to PHB polymer extracted by chloroform (Mw = 389 kDa, Mn = 297 kDa, Mw /Mn = 1.31). This is the first example of ASW utilization as a sustainable and inexpensive substrate for PHB biosynthesis and ethyl levulinate as an efficient and green extractant of PHB from a single bacterial biomass., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier B.V.)- Published
- 2023
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16. Carbon-Nitride Popcorn-A Novel Catalyst Prepared by Self-Propagating Combustion of Nitrogen-Rich Triazenes.
- Author
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Ma J, Das J, Zhang J, Cheng J, Sorcar S, Rosen BA, Shekhter P, Dobrovetsky R, Flaxer E, Yavor Y, Shen R, Kaminker I, Goldbourt A, and Gozin M
- Abstract
The interest in development of non-graphitic polymeric carbon nitrides (PCNs), with various C-to-N ratios, having tunable electronic, optical, and chemical properties is rapidly increasing. Here the first self-propagating combustion synthesis methodology for the facile preparation of novel porous PCN materials (PCN3-PCN7) using new nitrogen-rich triazene-based precursors is reported. This methodology is found to be highly precursor dependent, where variations in the terminal functional groups in the newly designed precursors (compounds 3-7) lead to different combustion behaviors, and morphologies of the resulted PCNs. The foam-type highly porous PCN5, generated from self-propagating combustion of 5 is comprehensively characterized and shows a C-to-N ratio of 0.67 (C
3 N4.45 ). Thermal analyses of PCN5 formulations with ammonium perchlorate (AP) reveal that PCN5 has an excellent catalytic activity in the thermal decomposition of AP. This catalytic activity of PCN5 is further evaluated in a closer-to-application scenario, showing an increase of 18% in the burn rate of AP-Al-HTPB (with 2 wt% of PCN5) solid composite propellant. The newly developed template- and additive-free self-propagating combustion synthetic methodology using specially designed nitrogen-rich precursors should provide a novel platform for the preparation of non-graphitic PCNs with a variety of building block chemistries, morphologies, and properties suitable for a broad range of technologies., (© 2023 The Authors. Small published by Wiley-VCH GmbH.)- Published
- 2023
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17. Insights on hydrogen spillover on carbonaceous supports.
- Author
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Moyal AM, Paz-Tal O, Ben-Yehuda E, Moretto P, Bielewski M, Napolitano E, Gozin M, and Pevzner S
- Abstract
Hydrogen spillover is important in solid-phase catalytic hydrogenation reactions, as well as in hydrogen storage and scavenging. The present study explores the nature of this phenomenon by examining the effects of hydrogen pressure and addition of carbonaceous additives, such as carbon nanotubes (CNT) and C
60 fullerene, on hydrogenation reaction kinetics and its products distribution. For these purposes, a solid-phase hydrogenation reaction was studied, where 1,4-bis-(phenyl-ethynyl)benzene (PEB) was used as a hydrogen acceptor. To the best of our knowledge, this is the first study in which both the reaction kinetics and products distribution of the solid-phase organic hydrogen acceptor were analyzed. A demonstration of hydrogen spillover phenomenon was provided on the basis of the combined interpretation of kinetics and hydrogenated organic products distribution, under different reaction conditions. The results were explained in terms of hydrogen active species availability, distribution and relative migration distance of these species through the carbonaceous media. The insights into the hydrogen spillover chemistry obtained in this research allow for a better understanding of this phenomenon and its implementation in the future hydrogen storage and transportation, and hydrogen-generating devices, including safety aspects of all these applications.- Published
- 2022
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18. Turning mannitol-rich agricultural waste to poly(3-hydroxybutyrate) with Cobetia amphilecti fermentation and recovery with methyl levulinate as a green solvent.
- Author
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Gnaim R, Unis R, Gnayem N, Das J, Gozin M, and Golberg A
- Subjects
- 3-Hydroxybutyric Acid, Fermentation, Halomonadaceae, Levulinic Acids, Polyesters metabolism, Solvents, Hydroxybutyrates chemistry, Mannitol
- Abstract
The present study explored the use of mannitol and mannitol-rich agro-industrial wastes as substrates for PHB production by Cobetia amphilecti isolated from the green Ulva sp. seaweed. Cultivation of C. amphilecti on mannitol, celery, and olive leaves (OLs) waste led to 4.20, 6.00, and 5.16 g L
-1 of cell dry mass (CDM), 76.3, 25.5, and 12.0% of PHB content in CDM and 3.2, 1.53, and 0.62 g L-1 of PHB concentration, respectively; which suggested that they can be exploited as carbon substrates for the production of PHB. Extraction of PHB from C. amphilecti cultures by solubilization in the green solvent methyl levulinate (ML) (2% w/w, 140 °C, 1 h) indicated that the recovery yield and purity of PHB are above 97 and 90% w/w, respectively. The use of ML could be an attractive method for the recovery of PHB when safe and non-toxic solvents are required., (Copyright © 2022 Elsevier Ltd. All rights reserved.)- Published
- 2022
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19. Halophyte biorefinery for polyhydroxyalkanoates production from Ulva sp. Hydrolysate with Haloferax mediterranei in pneumatically agitated bioreactors and ultrasound harvesting.
- Author
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Ghosh S, Coons J, Yeager C, Halley P, Chemodanov A, Belgorodsky B, Gozin M, Chen GQ, and Golberg A
- Subjects
- Bioreactors, Salt-Tolerant Plants, Haloferax mediterranei, Polyhydroxyalkanoates, Ulva
- Abstract
The present study tested the outdoor cultivation of Haloferax mediterranei for PHA production from green macroalgae Ulva sp. in pneumatically agitated bioreactors and applied ultrasonic separation for enhanced settling of archaeal cells. Scaled-up cultivation (40 L) yielded maximum biomass productivity of 50.1 ± 0.11 mg·L
-1 ·h-1 with a PHA productivity of 27 ± 0.01 mg·L-1 ·h-1 and conversion yield of 0.107 g PHA per gram UlvaDW . The maximum mass fraction of PHA achieved in biomass was calculated to be 56% w/w. Ultrasonic harvesting of Hfx. mediterranei cells approached 30% removal at energy inputs around 7.8 kWh·m-3 , and indicated no significant aggregation enhancement by Ca2+ addition. Molecular weight analysis showed an increase in Polydispersity Index (PDI) when the corresponding air velocities were increased suggesting that the polymer was more homogeneous at lower mixing velocities. The current study demonstrated scalable processes for PHA production using Ulva sp. feedstock providing new technologies for halophilic biorefinery., (Copyright © 2021 Elsevier Ltd. All rights reserved.)- Published
- 2022
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20. Nitration of Chitin Monomer: From Glucosamine to Energetic Compound.
- Author
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Dou H, Zheng Y, Qu M, Chen P, He C, Gozin M, and Pang S
- Abstract
The nitration of chitin monomer in a mixture of nitric acid and acetic anhydride was conducted and a highly nitrated (3R,4R,6R)-3-acetamido-6-((nitrooxy)methyl)tetrahydro-2 H -pyran-2,4,5-triyl trinitrate ( 1 ) was obtained. Its structure was fully characterized using infrared spectroscopy, NMR spectroscopy, elemental analysis, and X-ray diffraction. Compound 1 possesses good density (ρ: 1.721 g·cm
-3 ) and has comparable detonation performance (Vd : 7717 m·s-1 ; P: 25.6 GPa) to that of nitrocellulose (NC: Vd : 7456 m·s-1 ; P: 23 GPa; Isp = 239 s) and microcrystalline nitrocellulose (MCNC; Vd : 7683 m·s-1 ; P: 25 GPa; Isp = 250 s). However, Compound 1 has much lower impact sensitivity (IS: 15 J) than the regular nitrocellulose (NC; IS: 3.2 J) and MCNC (IS: 2.8 J). Compound 1 was calculated to exhibit a good specific impulse (Isp : 240 s), which is comparable with NC (Isp : 239 s) and MCNC (Isp : 250 s). By replacing the nitrocellulose with Compound 1 in typical propellants JA2, M30, and M9, the specific impulse was improved by up to 4 s. These promising properties indicate that Compound 1 has a significant potential as an energetic component in solid propellants.- Published
- 2021
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21. Fighting SARS-CoV-2 with green seaweed Ulva sp. extract: extraction protocol predetermines crude ulvan extract anti-SARS-CoV-2 inhibition properties in in vitro Vero-E6 cells assay.
- Author
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Shefer S, Robin A, Chemodanov A, Lebendiker M, Bostwick R, Rasmussen L, Lishner M, Gozin M, and Golberg A
- Abstract
Due to the global COVID-19 pandemic, there is a need to screen for novel compounds with antiviral activity against SARS-COV-2. Here we compared chemical composition and the in vitro anti- SARS-COV-2 activity of two different Ulva sp. crude ulvan extracts: one obtained by an HCl-based and another one by ammonium oxalate-based (AOx) extraction protocols. The composition of the crude extracts was analyzed and their antiviral activity was assessed in a cytopathic effect reduction assay using Vero E6 cells. We show that the extraction protocols have a significant impact on the chemical composition, anti- SARS-COV-2 activity, and cytotoxicity of these ulvan extracts. The ulvan extract based on the AOx protocol had a higher average molecular weight, higher charge, and 11.3-fold higher antiviral activity than HCl-based extract. Our results strongly suggest that further bioassay-guided investigation into bioactivity of compounds found in Ulva sp. ulvan extracts could lead to the discovery of novel anti-SARS-CoV-2 antivirals., Competing Interests: Robert Bostwick and Lynn Rasmussen are employed by Sothern Research., (©2021 Shefer et al.)
- Published
- 2021
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22. Polyhydroxyalkanoates and biochar from green macroalgal Ulva sp. biomass subcritical hydrolysates: Process optimization and a priori economic and greenhouse emissions break-even analysis.
- Author
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Ghosh S, Greiserman S, Chemodanov A, Slegers PM, Belgorodsky B, Epstein M, Kribus A, Gozin M, Chen GQ, and Golberg A
- Subjects
- Biomass, Charcoal, Polyhydroxyalkanoates, Ulva
- Abstract
Although macroalgae biomass is an emerging sustainable feedstock for biorefineries, the optimum process parameters for their hydrolysis and fermentation are still not known. In the present study, the simultaneous production of polyhydroxyalkanoates (PHA) and biochar from green macroalgae Ulva sp. is examined, applying subcritical water hydrolysis and Haloferax mediterranei fermentation. First, the effects of temperature, treatment time, salinity, and solid load on the biomass and PHA productivity were optimized following the Taguchi method. Hydrolysis at 170 °C, 20 min residence time, 38 g L
-1 salinity with a seaweed solid load of 5% led to the maximum PHA yield of 0.104 g g-1 Ulva and a biochar yield of 0.194 ± 1.23 g g-1 Ulva. Second, the effect of different initial culture densities on the biomass and PHA productivity was studied. An initial culture density of 50 g L-1 led to the maximum volumetric PHA productivity of 0.024 ± 0.002 g L-1 h-1 with a maximum PHA content of 49.38 ± 0.3% w/w Sensitivity analysis shows that within 90% confidence, the annual PHA production from Ulva sp. is 148.14 g PHA m-2 year-1 with an annual biochar production of 42.6 g m-2 year-1 . Priori economic and greenhouse gas break-even analyses of the process were done to estimate annual revenues and allowable greenhouse gas emissions. The study illustrates that PHA production from seaweed hydrolysate using extreme halophiles coupled to biochar production could become a benign and promising step in a marine biorefinery., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier B.V. All rights reserved.)- Published
- 2021
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23. Marine bacteria associated with the green seaweed Ulva sp. for the production of polyhydroxyalkanoates.
- Author
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Gnaim R, Polikovsky M, Unis R, Sheviryov J, Gozin M, and Golberg A
- Subjects
- Bacteria, RNA, Ribosomal, 16S genetics, Polyhydroxyalkanoates, Seaweed, Ulva
- Abstract
This work aimed to isolate a series of bacterial strains associated with the green seaweed Ulva sp. and evaluate their capability to manufacture PHA. The effect of the type of supplemented sugars found to be in macroalgae, on the growth and PHA productivity of the strains was studied. Analysis of the 16S rRNA gene sequence of the isolated strains revealed that the PHA-producing bacteria were phylogenetically related to the genus Cobetia, Bacillus, Pseudoaltermonas and Sulfitobacter, which showed high PHA contents among the isolates. The highest PHA content was observed in the case of Cobetia strain, with up to 61% w/w in the presence of mannitol and 12% w/w on Ulva sp. acid hydrolysate as a substrate., (Copyright © 2021 Elsevier Ltd. All rights reserved.)
- Published
- 2021
- Full Text
- View/download PDF
24. Applying machine learning to balance performance and stability of high energy density materials.
- Author
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Huang X, Li C, Tan K, Wen Y, Guo F, Li M, Huang Y, Sun CQ, Gozin M, and Zhang L
- Abstract
The long-standing performance-stability contradiction issue of high energy density materials (HEDMs) is of extremely complex and multi-parameter nature. Herein, machine learning was employed to handle 28 feature descriptors and 5 properties of detonation and stability of 153 HEDMs, wherein all 21,648 data used were obtained through high-throughput crystal-level quantum mechanics calculations on supercomputers. Among five models, namely, extreme gradient boosting regression tree (XGBoost), adaptive boosting, random forest, multi-layer perceptron, and kernel ridge regression, were respectively trained and evaluated by stratified sampling and 5-fold cross-validation method. Among them, XGBoost model produced the best scoring metrics in predicting the detonation velocity, detonation pressure, heat of explosion, decomposition temperature, and lattice energy of HEDMs, and XGBoost predictions agreed best with the 1,383 experimental data collected from massive literatures. Feature importance analysis was conducted to obtain data-driven insight into the causality of the performance-stability contradiction and delivered the optimal range of key features for more efficient rational design of advanced HEDMs., Competing Interests: The authors declare no competing interests., (© 2021 The Author(s).)
- Published
- 2021
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25. Hydrothermal processing of a green seaweed Ulva sp. for the production of monosaccharides, polyhydroxyalkanoates, and hydrochar.
- Author
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Steinbruch E, Drabik D, Epstein M, Ghosh S, Prabhu MS, Gozin M, Kribus A, and Golberg A
- Subjects
- Biomass, Monosaccharides, Polyhydroxyalkanoates, Seaweed, Ulva
- Abstract
In the fermentation and bioenergy industry, terrestrial biomass is usually fractionated and the collected components, such as starch, are processed separately. Such a separation has not been reported for seaweeds. In this work, the direct hydrothermal processing of the whole green seaweed Ulva sp. biomass is compared to processing of separated starch and cellulose, to find the preferable route for monosaccharide, hydrochar, and polyhydroxyalkanoates (PHA) production. Glucose was the major released monosaccharide. A significant share of the glucose yield comes from the starch fraction. The highest hydrochar yield with the lowest ash content was obtained from the separated cellulose fraction. The highest PHA yield was obtained using a whole Ulva sp. hydrolysate fermentation with Haloferaxmediterranei. Economic analysis shows the advantage of direct Ulva sp. biomass fermentation to PHA. The co-production of glucose and hydrochar does not add significant economic benefits to the process under plausible prices of the two outputs., (Copyright © 2020 Elsevier Ltd. All rights reserved.)
- Published
- 2020
- Full Text
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26. Strategies for Achieving Balance between Detonation Performance and Crystal Stability of High-Energy-Density Materials.
- Author
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Li C, Li H, Zong HH, Huang Y, Gozin M, Sun CQ, and Zhang L
- Abstract
Performance-stability contradiction of high-energy-density materials (HEDMs) is a long-standing puzzle in the field of chemistry and material science. Bridging the gap that exists between detonation performance of new HEDMs and their stability remains a formidable challenge. Achieving optimal balance between the two contradictory factors is of a significant demand for deep-well oil and gas drilling, space exploration, and other civil and defense applications. Herein, supercomputers and latest quantitative computational strategies were employed and high-throughput quantum calculations were conducted for 67 reported HEDMs. Based on statistical analysis of large amounts of physico-chemical data, in-crystal interspecies interactions were identified to be the one that provokes the performance-stability contradiction of HEDMs. To design new HEDMs with both good detonation performance and high stability, the proposed systematic and comprehensive strategies must be satisfied, which could promote the development of crystal engineering of HEDMs to an era of theory-guided rational design of materials., Competing Interests: Declaration of Interests The authors declare no competing interests., (Copyright © 2020 The Author(s). Published by Elsevier Inc. All rights reserved.)
- Published
- 2020
- Full Text
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27. Molecular and Crystal Features of Thermostable Energetic Materials: Guidelines for Architecture of "Bridged" Compounds.
- Author
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Li H, Zhang L, Petrutik N, Wang K, Ma Q, Shem-Tov D, Zhao F, and Gozin M
- Abstract
Extensive density functional theory (DFT) calculation and data analysis on molecular and crystal level features of 60 reported energetic materials (EMs) allowed us to define key descriptors that are characteristics of these compounds' thermostability. We see these descriptors as reminiscent of "Lipinski's rule of 5", which revolutionized the design of new orally active pharmaceutical molecules. The proposed descriptors for thermostable EMs are of a type of molecular design, location and type of the weakest bond in the energetic molecule, as well as specific ranges of oxygen balance, crystal packing coefficient, Hirshfeld surface hydrogen bonding, and crystal lattice energy. On this basis, we designed three new thermostable EMs containing bridged, 3,5-dinitropyrazole moieties, HL3 , HL7 , and HL9 , which were synthesized, characterized, and evaluated in small-scale field detonation experiments. The best overall performing compound HL7 exhibited an onset decomposition temperature of 341 °C and has a density of 1.865 g cm
-3 , and the calculated velocity of detonation and maximum detonation pressure were 8517 m s-1 and 30.6 GPa, respectively. Considering HL7 's impressive safety parameters [impact sensitivity (IS) = 22 J; friction sensitivity (FS) = 352; and electrostatic discharge sensitivity (ESD) = 1.05 J] and the results of small-scale field detonation experiments, the proposed guidelines should further promote the rational design of novel thermostable EMs, suitable for deep well drilling, space exploration, and other high-value defense and civil applications., (Copyright © 2019 American Chemical Society.)- Published
- 2020
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28. Energetic Butterfly: Heat-Resistant Diaminodinitro trans-Bimane.
- Author
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Zhang P, Kumar D, Zhang L, Shem-Tov D, Petrutik N, Chinnam AK, Yao C, Pang S, and Gozin M
- Subjects
- Explosive Agents chemistry, Hot Temperature, Pyrazoles chemistry, Software, Solvents chemistry, Thermodynamics, Bridged Bicyclo Compounds, Heterocyclic chemistry
- Abstract
Due to a significant and prolific activity in the field of design and synthesis of new energetic molecules, it becomes increasingly difficult to introduce new explosophore structures with attractive properties. In this work, we synthesized a trans-bimane-based energetic material-3,7-diamino-2,6-dinitro-1 H ,5 H -pyrazolo-[1,2-a]pyrazole-1,5-dione (4), the structure of which was comprehensively analyzed by a variety of advanced spectroscopic methods and by X-ray crystallo-graphy (with density of 1.845 g·cm
-3 at 173 K). Although obtained crystals of 4 contained solvent molecules in their structure, state-of-the-art density functional theory (DFT) computational techniques allowed us to predict that solvent-free crystals of this explosive would preserve a similar tightly packed planar layered molecular arrangement, with the same number of molecules of 4 per unit cell, but with a smaller unit cell volume and therefore higher energy density. Explosive 4 was found to be heat resistant, with an onset decomposition temperature of 328.8 °C, and was calculated to exhibit velocity of detonation in a range of 6.88-7.14 km·s-1 and detonation pressure in the range of 19.14-22.04 GPa, using for comparison both HASEM and the EXPLO 5 software. Our results indicate that the trans -bimane explosophore could be a viable platform for the development of new thermostable energetic materials., Competing Interests: The authors declare no conflict of interest.- Published
- 2019
- Full Text
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29. Macroalgal biomass subcritical hydrolysates for the production of polyhydroxyalkanoate (PHA) by Haloferax mediterranei.
- Author
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Ghosh S, Gnaim R, Greiserman S, Fadeev L, Gozin M, and Golberg A
- Subjects
- Carbon metabolism, Hydrolysis, Hydroxybutyrates metabolism, Pentanoic Acids metabolism, Ulva, Biomass, Haloferax mediterranei metabolism, Polyhydroxyalkanoates biosynthesis
- Abstract
Non-conventional carbon sources, such as macroalgae, are sustainable alternatives for large-scale production of biopolymers. The present study examined macroalgae-derived carbohydrates, as carbon sources for the production of polyhydroxyalkanoates (PHAs) by Haloferax mediterranei. Simulants of the hydrolysates of seven different macroalgal biomasses were prepared and the PHA production was studied. A maximum biomass concentration with maximum PHA content was detected in medium prepared from green macroalgae. The highest cell dry weight and PHA concentrations were 3.8 ± 0.2 g·L
-1 and 2.2 ± 0.12 g·L-1 respectively when Haloferax mediterranei was grown in 25% (w/w) of Ulva sp. hydrolysate, at 42 °C temperature and initial pH of 7.2. Poly(3-hydroxy-butyrate-co-3-hydroxyvalerate was the major PHA constituent. The present study demonstrated that Ulva sp. is a promising feedstock for PHA production., (Copyright © 2018 Elsevier Ltd. All rights reserved.)- Published
- 2019
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30. Alkaline and Earth Alkaline Energetic Materials Based on a Versatile and Multifunctional 1-Aminotetrazol-5-one Ligand.
- Author
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Yang J, Yin X, Wu L, Wu J, Zhang J, and Gozin M
- Abstract
In our effort to seek for the "green" energetic coordination polymers (CPs), a versatile and multifunctional 1-amino-tetrazol-5-one ligand was synthesized and its complexes with a series of alkaline and earth alkaline metals were prepared and comprehensively characterized. A broad range of differently shaped 1D, 2D, and 3D supramolecular structures for the prepared energetic compounds were found, where each metal was bound in a specific and characteristic fashion. All prepared CPs show very good thermostability, with decomposition temperatures above 236 °C and remarkable insensitivity to mechanical impact and friction (impact sensitivity > 40 J, friction sensitivity > 360 N). In terms of detonation performance, our CPs were calculated to have detonation velocities in the range of 6.8-8.1 km·s
-1 and detonation pressures in the range of 16.5-24.5 GPa. Upon their combustion, new materials show a range of characteristic flame colors (from yellow to blue), making these compounds as promising components for various "green" pyrotechnic formulations.- Published
- 2018
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31. Design of Zero Oxygen Balance Energetic Materials on the Basis of Diels-Alder Chemistry.
- Author
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Yang J, Gong X, Mei H, Li T, Zhang J, and Gozin M
- Abstract
Herein, a novel zero oxygen balance polycyclic energetic compound trans-3,3,4,4,7,7,8,8-octanitro-9,10-dioxatricyclo[4.2.1.1
2,5 ]-decane ( trans-BIT) was designed and expected to exhibit high crystal density (ρ = 2.06 g/cm3 ), outstanding detonation performance ( D = 9.473 km/s, P = 42.2 GPa), and promising thermostability and sensitivity. We proposed that the synthesis of this compound could be achieved via a facile Diels-Alder reaction, using tetranitroethylene and oxadiazole as starting materials. We also predicted that the crystal structure of trans-BIT would have P21 / C space group symmetry.- Published
- 2018
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32. Microbial Degradation of Epoxy.
- Author
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Eliaz N, Ron EZ, Gozin M, Younger S, Biran D, and Tal N
- Abstract
Epoxy resins have a wide range of applications, including in corrosion protection of metals, electronics, structural adhesives, and composites. The consumption of epoxy resins is predicted to keep growing in the coming years. Unfortunately, thermoset resins cannot be recycled, and are typically not biodegradable. Hence, they pose environmental pollution risk. Here, we report degradation of epoxy resin by two bacteria that are capable of using epoxy resin as a sole carbon source. These bacteria were isolated from soil samples collected from areas around an epoxy and polyurethanes manufacturing plant. Using an array of molecular, biochemical, analytical, and microscopic techniques, they were identified as Rhodococcus rhodochrous and Ochrobactrum anthropi . As epoxy was the only carbon source available for these bacteria, their measured growth rate reflected their ability to degrade epoxy resin. Bacterial growth took place only when the two bacteria were grown together, indicating a synergistic effect. The surface morphology of the epoxy droplets changed significantly due to the biodegradation process. The metabolic pathway of epoxy by these two microbes was investigated by liquid chromatography mass spectrometry. Bisphenol A, 3,3'-((propane-2,2-diylbis(4,1-phenylene))bis(oxy))bis(propane-1,2-diol) and some other constituents were identified as being consumed by the bacteria.
- Published
- 2018
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33. Highly Reactive Metastable Intermixed Composites (MICs): Preparation and Characterization.
- Author
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He W, Liu PJ, He GQ, Gozin M, and Yan QL
- Abstract
Highly reactive metastable intermixed composites (MICs) have attracted much attention in the past decades. The MIC family of materials mainly includes traditional metal-based nanothermites, novel core-shell-structured, 3D ordered macroporous-structured, and ternary nanocomposites. By applying special fabrication approaches, highly reactive MICs with uniformly dispersed reactants, "layer-by-layer" or "core-shell" structures, can be prepared. Thus, the combustion performance can be greatly improved, and the ignition characteristics and safety can be precisely controlled by using a certain preparation strategy. Here, the preparation and characterization of the MICs that have been developed during the past few decades are summarized. Traditional preparation methods for MICs generally include physical mixing, high-energy ball milling, sol-gel synthesis, and vapor deposition, while the novel methods include self-assembly, electrophoretic deposition, and electrospinning. Various preparation procedures and the ignition and combustion performance of different MIC reactive systems are compared and discussed. In particular, the advantages of novel structured MICs in terms of safety and combustion efficiency are clarified, based on which suggestions regarding the possible future research directions are proposed., (© 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)
- Published
- 2018
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34. Stabilizing Metastable Polymorphs of Metal-Organic Frameworks via Encapsulation of Graphene Oxide and Mechanistic Studies.
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Su H, Du Y, Zhang J, Peng P, Li S, Chen P, Gozin M, and Pang S
- Abstract
Polymorphic transition from a metastable phase to a stable phase often occurs in metal-organic frameworks (MOFs) under the action of external stimuli. However, these transitions sometimes result in deteriorating their special performances and can even lead to serious safety problems. Therefore, developing a simple and efficient strategy for enhancing the stabilities of metastable MOF polymorphs is very imperative and meaningful. Herein, we propose a simple graphene oxide (GO)-encapsulating strategy for improving the stabilities of metastable MOF polymorphs. To illustrate this strategy, we designed and synthesized two polymorphic MOFs [MOF(ATA-a) and MOF(ATA-b)] as examples, which are based on energetic 5-amino-1 H-tetrazole as ligands. Single-crystal X-ray diffraction showed that these two polymorphs have a same chemical composition [Zn
2 (ATA)3 (ATA)2/2 ]n , but different space groups, space systems, and different stacking modes of the neighboring ligands. As expected, the metastable polymorph [MOF(ATA-a)] underwent a complete polymorphic transition at room temperature to form its stable polymorph [MOF(ATA-b)]. Using the proposed strategy, we successfully encapsulated a small amount of GO in the metastable polymorph [GO⊂MOF(ATA-a)]. The resultant composite exhibited better chemical stability, extremely higher thermal stability, and larger Brunauer-Emmett-Teller surface area compared to both its precursor and the physically mixed analogue. Remarkably, its onset decomposition temperature ( Td ) was as high as 377.4 °C, which is even higher than that of 1,3,5-triamino-2,4,6-trinitrobenzene ( Td = 321 °C), making it a potential heat-resistant explosive. The mechanism of stabilization was investigated in detail using various analytical techniques. This work may not only provide new insights into the stabilization of functional MOF polymorphs but also open up a new field for the application of GO.- Published
- 2018
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35. Polymorphism, phase transformation and energetic properties of 3-nitro-1,2,4-triazole.
- Author
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Zhang P, Zhao X, Du Y, Gozin M, Li S, and Pang S
- Abstract
We report the preparation, analysis, and phase transformation behavior of polymorphs of 3-nitro-1,2,4-triazole. The compound crystallizes in two different polymorphic forms, Form I (tetragonal, P 4
1 21 2) and Form II (monoclinic, P 21 / c ). Analysis of the polymorphs has been investigated using microscopy, differential scanning calorimetry, in situ variable-temperature powder X-ray diffraction, and single-crystal X-ray diffraction. On heating, Form II converts into Form I irreversibly, and on further heating, decomposition is observed. In situ powder X-ray diffraction studies revealed that Form II transforms to Form I above 98 °C, indicating that Form I is more stable than Form II at high temperature. Form II of 3-nitro-1,2,4-triazole has good detonation properties ( V = 8213 m sdet = 8213 m s-1 , PC-J = 27.45 GPa), and low sensitivity (IS > 40 J, FS = 360 N, ESD = 29 J), which make it a competitive candidate for use as a new insensitive explosive., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)- Published
- 2018
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36. Reoperation in Horizontal Strabismus and its Related Risk Factors.
- Author
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Rajavi Z, Gozin M, Sabbaghi H, Behradfar N, Kheiri B, and Faghihi M
- Abstract
This study was performed to determine the surgical outcomes and the related risk factors of second operation in patients with residual horizontal deviations. In this interventional case series study, a total of 119 patients with a history of reoperation were included (39 exotropia and 80 esotropia). Cases with consecutive strabismus, muscular palsy, systemic disease, lack of ocular fixation, and those, who had vertical deviation and Dissociated Vertical Deviation (DVD)>5 Prism Diopters (pd) were excluded. Medial Rectus (MR) resection in residual Exotropia (XT) and Lateral Rectus (LR) resection in residual Esotropia (ET) were performed. Unilateral or bilateral operations were considered if the preoperative residual deviation was < 20 pd or > 20 pd, respectively. Success of the reoperation was considered if the postoperative angle of deviation was ≤ 10 pd. Unilateral and bilateral MR resection was performed in 26% and 74% of patients with XT, respectively, with greater dose response in unilateral cases (2.8 versus 2.6 mm/pd). Successful surgical outcomes were observed in 94.9% of patients with XT. Unilateral and bilateral LR resection was also performed in patients with residual ET, each in 50% of patients. Unilateral cases showed greater dose-response compared to bilateral ones (2.6 versus 2 mm/pd) and successful surgical outcomes were observed in 83.8% of patients with ET. No variable was found as a risk factor of reoperation in both groups. In conclusion, both LR and MR resection are easy and predictable surgical approaches with high success rate in patients with residual ET and XT. Generally, MR resection is more effective than LR resection. Unilateral operation is less recommended in the residual exotropic group, due to its lower success compared to the bilateral operation. Unfortunately, none of the mentioned variables were found to be the risk factor of reoperation in the sampled patients., Competing Interests: Ethical issues have been completely observed by the authors. All named authors meet the International Committee of Medical Journal Editors (ICMJE) criteria for authorship for this manuscript, take responsibility for the integrity of the work as a whole, and have given final approval for the version to be published. No conflict of interest has been presented.
- Published
- 2018
37. Design of New Bridge-Ring Energetic Compounds Obtained by Diels-Alder Reactions of Tetranitroethylene Dienophile.
- Author
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He P, Mei HZ, Wu L, Yang JQ, Zhang JG, Cohen A, and Gozin M
- Abstract
The density functional theory method was employed to calculate three-dimensional structures for a series of novel explosophores. The design of new molecules (DA1-DA12) was based on the bridge-ring structures that could be formed via Diels-Alder (DA) reaction of selected nitrogen-rich dienes and tetranitroethylene dienophile. The feasibility of the proposed DA reactions was predicted on the basis of the molecular orbital theory. The strong interactions between the HOMO of dienes, with electron-donating groups (Diene2, Diene6, and Diene8), and the LUMO of tetranitroethylene dienophile suggested thermodynamically favorable formation of the desired DA reaction products. In addition to molecular structures of the explored DA compounds, their physicochemical and energetic properties were also calculated in detail. Due to compact bridge-ring structures, new energetic molecules have highly positive heats of formation (up to 1124.90 kJ·mol
-1 ) and high densities (up to 2.04 g·cm-3 ). Also, as a result of all-right ratios of nitrogen and oxygen, most of the new compounds possess high detonation velocities (8.28-10.02 km·s-1 ) and high detonation pressures (30.87-47.83 GPa). Energetic compounds DA1, DA4, and DA12 exhibit a superior detonation performance over widely used HMX explosive, and DA5, DA7, and DA10 could be comparable to the state-of-the-art CL-20 and ONC explosives. Our proposed designs and synthetic methodology should provide a platform for the development of novel energetic materials with superior performance.- Published
- 2018
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38. Silver Nanoparticles Complexed with Bovine Submaxillary Mucin Possess Strong Antibacterial Activity and Protect against Seedling Infection.
- Author
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Makarovsky D, Fadeev L, Salam BB, Zelinger E, Matan O, Inbar J, Jurkevitch E, Gozin M, and Burdman S
- Subjects
- Animals, Cattle, Comamonadaceae pathogenicity, Microbial Sensitivity Tests, Mucins chemistry, Proof of Concept Study, Seedlings microbiology, Seeds microbiology, Silver chemistry, Anti-Bacterial Agents pharmacology, Comamonadaceae drug effects, Metal Nanoparticles chemistry, Mucins pharmacology, Seedlings drug effects, Silver pharmacology
- Abstract
A simple method for the synthesis of nanoparticles (NPs) of silver (Ag) in a matrix of bovine submaxillary mucin (BSM) was reported previously by some of the authors of this study. Based on mucin characteristics such as long-lasting stability, water solubility, and surfactant and adhesive characteristics, we hypothesized that these compounds, named BSM-Ag NPs, may possess favorable properties as potent antimicrobial agents. The goal of this study was to assess whether BSM-Ag NPs possess antibacterial activity, focusing on important plant-pathogenic bacterial strains representing both Gram-negative ( Acidovorax and Xanthomonas ) and Gram-positive ( Clavibacter ) genera. Growth inhibition and bactericidal assays, as well as electron microscopic observations, demonstrate that BSM-Ag NPs, at relatively low concentrations of silver, exert strong antimicrobial effects. Moreover, we show that treatment of melon seeds with BSM-Ag NPs effectively prevents seed-to-seedling transmission of Acidovorax citrulli , one of the most threatening pathogens of cucurbit production worldwide. Overall, our findings demonstrate strong antimicrobial activity of BSM-Ag NPs and their potential application for reducing the spread and establishment of devastating bacterial plant diseases in agriculture. IMPORTANCE Bacterial plant diseases challenge agricultural production, and the means available to manage them are limited. Importantly, many plant-pathogenic bacteria have the ability to colonize seeds, and seed-to-seedling transmission is a critical route by which bacterial plant diseases spread to new regions and countries. The significance of our study resides in the following aspects: (i) the simplicity of the method of BSM-Ag NP synthesis, (ii) the advantageous chemical properties of BSM-Ag NPs, (iii) the strong antibacterial activity of BSM-Ag NPs at relatively low concentrations of silver, and (iv) the fact that, in contrast to most studies on the effects of metal NPs on plant pathogens, the proof of concept for the novel compound is supported by in planta assays. Application of this technology is not limited to agriculture; BSM-Ag NPs potentially could be exploited as a potent antimicrobial agent in a wide range of industrial areas, including medicine, veterinary medicine, cosmetics, textiles, and household products., (Copyright © 2018 American Society for Microbiology.)
- Published
- 2018
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39. Synthesis of Denser Energetic Metal-Organic Frameworks via a Tandem Anion-Ligand Exchange Strategy.
- Author
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Zhang J, Su H, Dong Y, Zhang P, Du Y, Li S, Gozin M, and Pang S
- Abstract
High-density materials have attracted extensive attention because of their broad applications. However, strategies for improving the densities of MOFs and preparing denser MOFs remain almost unexplored. Herein, we propose a tandem anion-ligand exchange strategy for synthesizing denser MOFs by using three-dimensional cationic MOFs (3D CMOFs) with pillared layered structures as precursors and high-density anions and small monotopic ligands as exogenous guests. By means of this strategy, we choose the high-density nitroformate ion [C(NO
2 )3 - ] as an exogenous anion and water as an exogenous ligand to successfully synthesize two layered CMOFs. Single-crystal X-ray diffraction showed that after this transformation, the extra-framework anions are replaced with the C(NO2 )3 - anions, and the distances between adjacent layers in the two-dimensional (2D) networks are more than 3.70 Å shorter than those of their 3D precursors. The resultant materials exhibit higher densities, higher heats of detonation, higher nitrogen and oxygen contents, and lower metal contents. In particular, the density of {Cu(atrz)2 [C(NO2 )3 ]2 (H2 O)2 ·atrz·2H2 O}n (2b, ρ = 1.76 g cm-3 , atrz = 4,4'-azo-1,2,4-triazole) is increased by 0.12 g cm-3 compared to its 3D precursor {2a, [Cu(atrz)3 (NO3 )2 ·2H2 O]n , ρ = 1.64 g cm-3 }, and its heat of detonation is also enhanced to more than 1900 kJ kg-1 . The resultant 2D layered CMOFs are also new potential high-energy density materials. This work may provide new insights into the design and synthesis of high-density MOFs. Moreover, we anticipate that the approach reported here would be useful for the preparation of new MOFs, in particular, which are otherwise difficult or unfeasible through traditional synthetic routes.- Published
- 2017
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40. Green Energetic Nitrogen-Rich Salts of 1,1'-Dinitramino-5,5'-bistetrazolate.
- Author
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He P, Wu L, Wu J, Wang Q, Li Z, Gozin M, and Zhang J
- Abstract
A series of nitrogen-rich energetic salts of 1,1'-dinitramino-5,5'-bistetrazolate (DNABT) guanidinium (1), aminoguanidinium (2), diaminoguanidinium (3), triaminoguanidinium (4), diaminouronium (5), 3,4-diamino-1,2,4-triazolium (6), and ethylenediammonium (7) was synthesized by a metathesis strategy and characterized by elemental analysis, mass spectrometry, and IR spectroscopy as well as single-crystal X-ray diffraction and differential scanning calorimetry (DSC). The natural bond orbitals (NBOs) and electrostatic potentials (ESPs) were further computed for a better understanding of the structures of the DNABT molecule. The heats of formation were calculated based on the Born-Haber energy cycle. The detonation parameters were evaluated by using the EXPLO5 program, and the sensitivities were measured according to BAM standers. These new salts exhibit highly positive heats of formation (407.0-1377.9 kJ mol
-1 ) and good thermal stabilities (180-211 °C). Most of these compounds possess detonation velocities comparable to RDX and acceptable detonation pressures. The high volumes of explosion gases of the salts 3 and 4 (921 and 933 L kg-1 , respectively) further support their power as explosives. The enhancing performances, the fact of being free of metals, and the more moderate sensitivities than K2 DNABT, suggest that the salts 4 (D=8851 m s-1 , P=29.0 GPa), 5 (D=9053 m s-1 , P=32.3 GPa), and 6 (D=8835 m s-1 , P=30.2 GPa) might be potential environmentally friendly energetic materials., (© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)- Published
- 2017
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41. Alkali and alkaline earth metal salts of tetrazolone: structurally interesting and excellently thermostable.
- Author
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He P, Wu L, Wu JT, Yin X, Gozin M, and Zhang JG
- Abstract
Tetrazolone (5-oxotetrazole) was synthesized by a moderate strategy through three steps (addition, cyclization and catalytic hydrogenation) avoiding the unstable intermediate diazonium, as reported during the previous preparation. Alkali and alkaline earth metal salts with lithium (1), sodium (2), potassium (3), rubidium (4) caesium (5), magnesium (6), calcium (7), strontium (8) and barium (9) were prepared and fully characterized using elemental analysis, IR and NMR spectroscopy, DSC and TG analysis. All metal salts were characterized via single-crystal X-ray diffraction. They crystallize in common space groups with high densities ranging from 1.479 (1) to 3.060 g cm
-3 (5). Furthermore, the crystal structures of 7, 8 and 9 reveal interesting porous energetic coordination polymers with strong hydrogen bond interactions. All new salts have good thermal stabilities with decomposition temperature between 215.0 °C (4) and 328.2 °C (7), significantly higher than that of the reported nitrogen-rich salt neutral tetrazolone. The sensitivities towards impact and friction were tested using standard methods, and all the tetrazolone-based compounds investigated can be classified into insensitive. The flame test of these metal salts supports their potential use as perchlorate-free pyrotechnics or eco-friendly insensitive energetic materials.- Published
- 2017
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42. Formation of Highly Thermostable Copper-Containing Energetic Coordination Polymers Based on Oxidized Triaminoguanidine.
- Author
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Yan QL, Cohen A, Petrutik N, Shlomovich A, Zhang JG, and Gozin M
- Abstract
A series of novel highly thermostable energetic coordination polymers (ECPs), with promising mechanical sensitivity properties, were prepared by an in situ oxidation-coordination reaction of triaminoguanidine hydrochloride with copper nitrate in aqueous solution. The molecular structures and properties of these ECPs could be tuned, by varying the ratios and concentrations of the starting materials. Our ECPs exhibit remarkable thermostability (>390 °C) and very low sensitivity to impact (Im > 98 J). The best-performing material (ECP-5) has a calculated detonation velocity of 8969 m·s(-1) and a decomposition peak temperature of 396.9 °C, demonstrating an outstanding balance between two inherently contradicting properties: high detonation performance and very low sensitivity.
- Published
- 2016
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43. Highly energetic compositions based on functionalized carbon nanomaterials.
- Author
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Yan QL, Gozin M, Zhao FQ, Cohen A, and Pang SP
- Abstract
In recent years, research in the field of carbon nanomaterials (CNMs), such as fullerenes, expanded graphite (EG), carbon nanotubes (CNTs), graphene, and graphene oxide (GO), has been widely used in energy storage, electronics, catalysts, and biomaterials, as well as medical applications. Regarding energy storage, one of the most important research directions is the development of CNMs as carriers of energetic components by coating or encapsulation, thus forming safer advanced nanostructures with better performances. Moreover, some CNMs can also be functionalized to become energetic additives. This review article covers updated preparation methods for the aforementioned CNMs, with a more specific orientation towards the use of these nanomaterials in energetic compositions. The effects of these functionalized CNMs on thermal decomposition, ignition, combustion and the reactivity properties of energetic compositions are significant and are discussed in detail. It has been shown that the use of functionalized CNMs in energetic compositions greatly improves their combustion performances, thermal stability and sensitivity. In particular, functionalized fullerenes, CNTs and GO are the most appropriate candidate components in nanothermites, solid propellants and gas generators, due to their superior catalytic properties as well as facile preparation methods.
- Published
- 2016
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44. Systemic Gene Silencing in Primary T Lymphocytes Using Targeted Lipid Nanoparticles.
- Author
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Ramishetti S, Kedmi R, Goldsmith M, Leonard F, Sprague AG, Godin B, Gozin M, Cullis PR, Dykxhoorn DM, and Peer D
- Subjects
- Animals, CD4-Positive T-Lymphocytes transplantation, Cells, Cultured, Lipids chemistry, Mice, Mice, Inbred C57BL, Nanoparticles chemistry, RNAi Therapeutics methods, CD4-Positive T-Lymphocytes metabolism, Gene Silencing, Nanoparticles metabolism, RNA, Small Interfering administration & dosage
- Abstract
Modulating T cell function by down-regulating specific genes using RNA interference (RNAi) holds tremendous potential in advancing targeted therapies in many immune-related disorders including cancer, inflammation, autoimmunity, and viral infections. Hematopoietic cells, in general, and primary T lymphocytes, in particular, are notoriously hard to transfect with small interfering RNAs (siRNAs). Herein, we describe a novel strategy to specifically deliver siRNAs to murine CD4(+) T cells using targeted lipid nanoparticles (tLNPs). To increase the efficacy of siRNA delivery, these tLNPs have been formulated with several lipids designed to improve the stability and efficacy of siRNA delivery. The tLNPs were surface-functionalized with anti-CD4 monoclonal antibody to permit delivery of the siRNAs specifically to CD4(+) T lymphocytes. Ex vivo, tLNPs demonstrated specificity by targeting only primary CD4(+) T lymphocytes and no other cell types. Systemic intravenous administration of these particles led to efficient binding and uptake into CD4(+) T lymphocytes in several anatomical sites including the spleen, inguinal lymph nodes, blood, and the bone marrow. Silencing by tLNPs occurs in a subset of circulating and resting CD4(+) T lymphocytes. Interestingly, we show that tLNP internalization and not endosome escape is a fundamental event that takes place as early as 1 h after systemic administration and determines tLNPs' efficacy. Taken together, these results suggest that tLNPs may open new avenues for the manipulation of T cell functionality and may help to establish RNAi as a therapeutic modality in leukocyte-associated diseases.
- Published
- 2015
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45. Diameter-selective dispersion of carbon nanotubes by β-lactoglobulin whey protein.
- Author
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Karchemsky F, Drug E, Mashiach-Farkash E, Fadeev L, Wolfson HJ, Gozin M, and Regev O
- Subjects
- Animals, Binding Sites, Cattle, Circular Dichroism, Cryoelectron Microscopy, Microscopy, Electron, Transmission, Models, Molecular, Particle Size, Protein Structure, Quaternary, Spectrophotometry, Whey Proteins, Lactoglobulins chemistry, Milk Proteins chemistry, Nanotubes, Carbon chemistry, Nanotubes, Carbon ultrastructure
- Abstract
The β-lactoglobulin (β-LG) protein was discovered to be an efficient and selective dispersant for carbon nanotubes (CTNs) with certain diameters. A dispersion process of CTNs by the β-LG was studied, focusing on the relationships between the surface curvature of the CNT and the β-LG's efficiency in dispersing them, using cryogenic-transmission electron microscopy (cryo-TEM) and optical spectroscopy. Plausible binding sites of the β-LG, responsible for the interaction of the protein with CNTs of various diameters (surface curvatures) were also investigated and were found to be in good agreement with corresponding docking calculations., (Copyright © 2013 Elsevier B.V. All rights reserved.)
- Published
- 2013
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46. New biodegradable organic-soluble chelating agents for simultaneous removal of heavy metals and organic pollutants from contaminated media.
- Author
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Ullmann A, Brauner N, Vazana S, Katz Z, Goikhman R, Seemann B, Marom H, and Gozin M
- Subjects
- Biological Assay, Cadmium chemistry, Environmental Pollution, Environmental Restoration and Remediation methods, Escherichia coli drug effects, Hydrogen-Ion Concentration, Ions, Lead chemistry, Ligands, Metals chemistry, Metals, Heavy chemistry, Nitrogen chemistry, Organic Chemicals chemistry, Sewage, Soil Pollutants chemistry, Solvents chemistry, Water Pollutants, Chemical chemistry, Water Pollution, Chelating Agents chemistry, Metals, Heavy analysis, Organic Chemicals analysis, Water Pollutants, Chemical analysis
- Abstract
Advanced biodegradable and non-toxic organic chelators, which are soluble in organic media, were synthesized on the basis of the S,S-ethylenediamine-disuccinate (S,S-EDDS) ligand. The modifications suggested in this work include attachment of a lipophilic hydrocarbon chain ("tail") to one or both nitrogen atoms of the S,S-EDDS. The new ligands were designed and evaluated for application in the Sediments Remediation Phase Transition Extraction (SR-PTE) process. This novel process is being developed for the simultaneous removal of both heavy metals and organic pollutants from contaminated soils, sediments or sludge. The new chelators were designed to bind various target metal ions, to promote extraction of these ions into organic solvents. Several variations of attached tails were synthesized and tested. The results for one of them, N,N'-bis-dodecyl-S,S-EDDS (C24-EDDS), showed that the metal-ligand complexes are concentrated in the organic-rich phase in the Phase Transition Extraction process (more than 80%). Preliminary applications of the SR-PTE process with the C24-EDDS ligand were conducted also on actually contaminated sludge (field samples). The extraction of five toxic metals, namely, Cd, Cu, Ni, Pb and Zn was examined. In general, the extraction performance of the new ligand was not less than that of S,S-EDDS when a sufficient ligand-to-extracted ion ratio (about 4:1 was applied., (Copyright © 2013 Elsevier B.V. All rights reserved.)
- Published
- 2013
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47. Citrate-capped gold nanoparticle electrophoretic heat production in response to a time-varying radiofrequency electric-field.
- Author
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Corr SJ, Raoof M, Mackeyev Y, Phounsavath S, Cheney MA, Cisneros BT, Shur M, Gozin M, McNally PJ, Wilson LJ, and Curley SA
- Abstract
The evaluation of heat production from gold nanoparticles (AuNPs) irradiated with radiofrequency (RF) energy has been problematic due to Joule heating of their background ionic buffer suspensions. Insights into the physical heating mechanism of nanomaterials under RF excitations must be obtained if they are to have applications in fields such as nanoparticle-targeted hyperthermia for cancer therapy. By developing a purification protocol which allows for highly-stable and concentrated solutions of citrate-capped AuNPs to be suspended in high-resistivity water, we show herein, for the first time, that heat production is only evident for AuNPs of diameters ≤ 10 nm, indicating a unique size-dependent heating behavior not previously observed. Heat production has also shown to be linearly dependent on both AuNP concentration and total surface area, and severely attenuated upon AuNP aggregation. These relationships have been further validated using permittivity analysis across a frequency range of 10 MHz to 3 GHz, as well as static conductivity measurements. Theoretical evaluations suggest that the heating mechanism can be modeled by the electrophoretic oscillation of charged AuNPs across finite length scales in response to a time-varying electric field. It is anticipated these results will assist future development of nanoparticle-assisted heat production by RF fields for applications such as targeted cancer hyperthermia.
- Published
- 2012
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48. Tuning the critical temperature of cuprate superconductor films with self-assembled organic layers.
- Author
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Carmeli I, Lewin A, Flekser E, Diamant I, Zhang Q, Shen J, Gozin M, Richter S, and Dagan Y
- Abstract
Control over the T(c) value of high-T(c) superconductors by self-assembled monolayers is demonstrated (T(c) = critical temperature). Molecular control was achieved by adsorption of polar molecules on the superconductor surface (see scheme) that change its carrier concentration through charge transport or light-induced polarization., (Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)
- Published
- 2012
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49. Doped biomolecules in miniaturized electric junctions.
- Author
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Mentovich E, Belgorodsky B, Gozin M, Richter S, and Cohen H
- Subjects
- Animals, Cattle, Electric Conductivity, Electron Transport, Models, Molecular, Surface Properties, Fullerenes chemistry, Serum Albumin, Bovine chemistry, Transistors, Electronic
- Abstract
Control over molecular scale electrical properties within nano junctions is demonstrated, utilizing site-directed C(60) targeting into protein macromolecules as a doping means. The protein molecules, self-assembled in a miniaturized transistor device, yield robust and reproducible operation. Their device signal is dominated by an active center that inverts affinity upon guest incorporation and thus controls the properties of the entire macromolecule. We show how the leading routes of electron transport can be drawn, spatially and energetically, on the molecular level and, in particular, how the dopant effect is dictated by its "strategic" binding site. Our findings propose the extension of microelectronic methodologies to the nanometer scale and further present a promising platform for ex situ studies of biochemical processes.
- Published
- 2012
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50. Toward the development of the direct and selective detection of nitrates by a bioinspired Mo-Cu system.
- Author
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Marom H, Popowski Y, Antonov S, and Gozin M
- Subjects
- Hydrogen Peroxide chemistry, Molecular Structure, Spectrometry, Fluorescence, Sulfides chemical synthesis, Sulfides chemistry, Sulfones chemical synthesis, Sulfones chemistry, Sulfoxides chemical synthesis, Sulfoxides chemistry, Copper chemistry, Models, Chemical, Molybdenum chemistry, Nitrates analysis
- Abstract
The development of a new platform for the direct and selective detection of nitrates is described. Two thioether-based chemosensors and the corresponding sulfoxides and sulfones were prepared, and their photophysical properties were evaluated. Upon selective sulfoxidation of these thioethers with nitrates via an oxygen-transfer reaction promoted by a bioinspired Mo-Cu system, significant fluorescence shifts were measured. A selective response of these systems, discriminating between nitrate salts and H(2)O(2), was also shown., (© 2011 American Chemical Society)
- Published
- 2011
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