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Dynamical time versus system time in quantum mechanics

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Chinese Physics B 2012年第7期21卷 101-107页

作者： Duan Arsenovi Nikola Buri dragomir Davidovi Slobodan Prvanovi Institute of Physics University of Belgrade Vinca Institute of Nuclear Sciences

Properties of an operator representing the dynamical time in the extended parameterization invariant formulation of quantum mechanics are studied. It is shown that this time operator is given by a positive operator measure analogously to the quantities that are known to represent various measurable time operators. The relation between the dynamical time of the extended formulation and the best known example of the system time operator, i.e., for the free one- dimensional particle, is obtained.

关键词： time operators extended state space positive operator valued measure

Signals from the interface:protein nanoclusters stabilize biomolecular condensates

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Signal Transduction and Targeted Therapy 2022年第2期7卷 341-342页

作者： Christian Hoffmann Branislava Rankovic dragomir Milovanovic Laboratory of Molecular Neuroscience German Center for Neurodegenerative Diseases(DZNE)10117 BerlinGermany

In a recent study,Folkmann and colleagues1 show that protein nanoclusters at the surface of biomolecular condensates act as Pickering agents stabilizing these emulsions in *** accumulating evidence suggests that cytosol represents a complex emulsion where multiple membrane-bound organelles and biomolecular condensates co-exist together.2 Each of these condensates is a crucible that can enrich for numerous proteins,RNAs,and even the entire membrane-bound organelles,such as the cluster of synaptic vesicles or the Golgi *** molecules in these condensates remain highly mobile,readily exchange with the surrounding environment and grow/coarsening over time(by coalescence or Ostwald ripening),often towards the round structures to minimize the surface tension.

关键词： clusters molecular readily

Influence of Cr, Mn and Mo Addition on Structure and Properties of V Microalloyed Medium Carbon Steels

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Journal of Materials Science & Technology 2012年第11期28卷 1053-1058页

作者： Abdunnaser Fadel dragomir Glii Nenad Radovi Djordje Drobnjak Department of Metallurgical Engineering Faculty of Technology and Metallurgy University of Belgrade

The effect of austenitizing temperature and Cr, Mo and Mn addition on microstructure and mechanical properties of V microalloyed medium carbon steel has been studied by means of metallography and mechanical testing. The addition of Cr, Mn and Mo leads to a decrease in yield strength （YS） by approximate 100 MPa in comparison to the base steel. It is assumed that Mn and Mo increase hardenability by promoting the formation of bainitic sheaves （BS）, i.e. by suppressing the formation of ferrite-pearlite and acicular ferrite （FP-AF）. Cr at the level used in this work is not that effective. Presence and packet size of bainitic sheaves decrease the Charpy V-notch impact energy at 20 ℃ （CVN20） in comparison to ferrite-pearlite and acicular ferrite microstructures.

关键词： Medium-carbon steels Chromium Molybdenum Manganese addition Bainite Acicular ferrite

Photon pair generation from lithium niobate metasurface with tunable spatial entanglement[Invited]

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Chinese Optics Letters 2023年第1期21卷 25-31页

作者：张吉化马进勇 dragomir N.Neshev Andrey A.Sukhorukov Centre of Excellence for Transformative Meta-Optical Systems(TMOS) Department of Electronic Materials Engineering(EME)Research School of PhysicsThe Australian National UniversityCanberraACT 2601Australia

The two-photon state with spatial entanglement is an essential resource for testing fundamental laws of quantum mechanics and various quantum *** creation typically relies on spontaneous parametric downconversion in bulky nonlinear crystals where the tunability of spatial entanglement is ***,we predict that ultrathin nonlinear lithium niobate metasurfaces can generate and diversely tune spatially entangled photon *** spatial properties of photons including the emission pattern,rate,and degree of spatial entanglement are analyzed theoretically with the coupled mode theory and Schmidt decomposition *** show that by leveraging the strong angular dispersion of the metasurface,the degree of spatial entanglement quantified by the Schmidt number can be decreased or increased by changing the pump laser wavelength and a Gaussian beam *** flexibility can facilitate diverse quantum applications of entangled photon states generated from nonlinear metasurfaces.

关键词： spontaneous parametric downconversion metasurface spatial entanglement

Key questions about the checkpoint blockade-are microRNAs an answer?

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Cancer Biology & Medicine 2018年第2期15卷 103-115页

作者： Mihnea dragomir Baoqing Chen Xiao Fu George A.Calin Department of Experimental Therapeutics The University of Texas MD Anderson Cancer Center Research Center for Functional Genomics Biomedicine and Translational MedicineIuliu Hatieganu University of Medicine and Pharmacy Department of Surgery Fundeni Clinical HospitalCarol Davila University of Medicine and Pharmacy Center for RNA Interference and Non-coding RNAs The University of Texas MD Anderson Cancer Center

The introduction of immune-checkpoint blockade in the cancer therapy led to a paradigm change of the management of late stage cancers. There are already multiple FDA approved checkpoint inhibitors and many other agents are undergoing phase 2 and early phase 3 clinical trials. The therapeutic indication of immune checkpoint inhibitors expanded in the last years, but still remains unclear who can benefit. Micro RNAs are small RNAs with no coding potential. By complementary pairing to the 3' untranslated region of messenger RNA, microRNAs exert posttranscriptional control of protein expression. A network of microRNAs directly and indirectly controls the expression of checkpoint receptors and several microRNAs can target multiple checkpoint molecules,mimicking the therapeutic effect of a combined immune checkpoint blockade. In this review, we will describe the microRNAs that control the expression of immune checkpoints and we will present four specific issues of the immune checkpoint therapy in cancer:(1) imprecise therapeutic indication,(2) difficult response evaluation,(3) numerous immunologic adverse-events, and(4)the absence of response to immune therapy. Finally, we propose microRNAs as possible solutions for these pitfalls. We consider that in the near future microRNAs could become important therapeutic partners of the immune checkpoint therapy.

关键词： MicroRNA PD-1 PD-L1 CTLA-4 checkpoint inhibitors

Multiple Integral Inequalities for Schur Convex Functions on Symmetric and Convex Bodies

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Analysis in Theory and Applications 2023年第1期39卷 1-15页

作者： Silvestru Sever dragomir Mathematics College of Engineering&ScienceVictoria UniversityMelbourne CityMC 8001Australia DST-NRF Centre of Excellence in the Mathematical and Statistical SciencesSchool of Computer Science&Applied MathematicsUniversity of the WitwatersrandPrivate Bag 3Johannesburg 2050South Africa

In this paper,by making use of Divergence theorem for multiple integrals,we establish some integral inequalities for Schur convex functions defined on bodies B⊂R^(n)that are symmetric,convex and have nonempty *** for ... 详细信息

关键词： Schur convex functions multiple integral inequalities

Application of the Principles of “Green Chemistry” for the Synthesis of 10-Undecylenic Aliphatic Esters with Antimicrobial Activity

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Journal of Renewable Materials 2020年第6期8卷 675-686页

作者： dragomir Vassilev Nadezhda Petkova Yulian Tumbarski Milena Koleva Panteley Denev Department of Physics Chemistry and EcologyTechnical University of GabrovoGabrovo5300Bulgaria Department of Inorganic and Organic Chemistry University of Food TechnologiesPlovdiv4002Bulgaria Department of Microbiology University of Food TechnologiesPlovdiv4002Bulgaria

Undenicylic acid(10:1)is known as an antifungal agent and an active ingredient of many topical medicines[1–6].The present research investigates the preparation of aliphatic esters of 10-undecylic acid with butanol and i-amyl alcohol by the conventional and ultrasound-assisted syntheses as well as the structural elucidation of the resulting compounds,by FTIR and NMR *** antimicrobial properties of the obtained 10-undecylenic esters were tested against Gram-positive bacteria(Staphylococcus aureus;Enterococcus faecalis;Listeria monocytogenes),Gram-negative bacteria(Escherichia coli;Salmonella sp.)and filamentous fungi(Penicillium sp.;Aspergillus niger;Fusarium moniliforme)using the conventional agar-well diffusion *** results demonstrated that all esters had insignificant antibacterial activity.i-Amyl-10-undecylenate and t-butyl-10-undecylenate showed activity against both Gram-positive and Gram-negative bacteria,while i-butyl-10-undecylenate and n-butyl-10-undecylenate were effective only against Gram-positive bacteria *** contrast,all 10-undecylenic esters demonstrated high antifungal activity,which was most pronounced in ***,the obtained products can be successfully used as promising antifungal agents for various pharmaceutical formulations as well as biocontrol means against plant pathogens.

关键词： 10-undecylenate alkyl esters FTIR and NMR spectroscopy antimicrobial activity

THE HADAMARD INEQUALITY FOR CONVEX FUNCTION VIA FRACTIONAL INTEGRALS

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Acta Mathematica Scientia 2013年第5期33卷 1293-1299页

作者： M.E.ZDEMR S.S.dragomir C.YILDIZ Department of Mathematics K.K.Education Faculty Atatürk University School of Engineering & Science Victoria University

In this paper, we establish several inequalities for some differantiable mappings that are connected with the Riemann-Liouville fractional integrals. The analysis used in the proofs is fairly elementary.

关键词： Hadamard's inequality convex functions power-mean inequality Riemann-Liouville fractional integration

Microwave-Assisted Isolation and Acetylation of Inulin from Helianthus Tuberosus L Tubers

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Journal of Renewable Materials 2018年第7期6卷 671-679页

作者： Nadezhda Petkova Gergana Gencheva dragomir Vassilev Milena Koleva Albert Krastanov Panteley Denev Department of Organic Chemistry and Inorganic Chemistry University of Food Technologies26 Maritza Blvd.Plovdiv4002Bulgaria Department Physics Chemistry and EcologyTechnical University of GabrovoGabrovo5300Bulgaria Department of Biotechnology University of Food Technologies26 Maritza Blvd.Plovdiv4002Bulgaria

Jerusalem artichoke (Helianthus tuberosus L.) tubers are industrial crop considered as a promising source forinulin production. “Green” method was performed for accelerated inulin extraction from Helianthus tuberosus *** by the application of microwave irradiation. Further pretreatment of the water extract with acetone andethanol yielded inulin (20%) with purity 89% and degree of polymerization 18. Jerusalem artichoke inulin wascharacterized by FTIR and NMR spectroscopy. For the first time eco-friendly synthesis of acetylated Jerusalemartichoke inulin was performed by the reaction with acetic anhydride, without toxic solvent, but only withsodium acetate as catalyst under microwave irradiation for 60 s. The degree of acetylation (DA=2.1) and thestructure of inulin esters were confirmed by 1H and 13C NMR. The suggested microwave acetylation shortenssignificantly the esterification reaction.

关键词： Jerusalem artichoke inulin inulin acetates microwave irradiation