new synthesis
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Author(s):  
Mustafa Kemal Gümüş ◽  
Sevgi Kansiz ◽  
Gulzhamal Bagitovna Tulemisova ◽  
Necmi Dege ◽  
Eiad Saif

A new synthesis of the title compound, C19H21NO2, was developed with good yield and purity using the reaction of 4-hydroxy-3-methyl-2-butanone, benzaldehyde and ammonium acetate in glacial acetic acid as a solvent. The central piperidine ring adopts a chair conformation, and its least-squares basal plane forms dihedral angles of 85.71 (11) and 77.27 (11)° with the terminal aromatic rings. In the crystal, the molecules are linked by O—H...O and C—H...O hydrogen bonds into double ribbons. The Hirshfeld surface analysis shows that the most important contributions are from H...H (68%), C...H/H...C (19%) and O...H/H...O (12%) interactions.


Surfaces ◽  
2021 ◽  
Vol 5 (1) ◽  
pp. 1-36
Author(s):  
Sayani Biswas ◽  
Prashant S. Alegaonkar

Two-dimensional materials have secured a novel area of research in material science after the emergence of graphene. Now, a new family of 2D material-MXene is gradually growing and making itsmark in this field of study. MXenes since 2011 have been synthesized and experimented on in several ways.The HF treatment although successful poses some serious problems that gradually propelled the ideas of new synthesis methods. This review of the literature covers the major breakthroughs of MXene from the year of its discovery to recent endeavors, highlighting how the synthesis mechanisms have been developed over the years and also the importance of good characterization of data. Results and properties of this class of materials arealso briefly discussed alongwith recent advance in applications.


Polymers ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 4437
Author(s):  
Krystyna Wnuczek ◽  
Andrzej Puszka ◽  
Beata Podkościelna

This paper discusses a new synthesis of bisphenol A-free polycarbonates based on four aliphatic-aromatic systems. In the first stage, different types of monomers (with/without sulfur) derived from diphenylmethane were synthesized. Then, new polycarbonates were prepared in the reactions with diphenyl carbonate (DPC) by transesterification and polycondensation reactions. Three different catalysts (zinc acetate, 4-(dimethylamino)pyridine and benzyltriethylammonium chloride) were tested. The structures of the compounds were confirmed by Nuclear Molecular Resonance spectroscopy (NMR) in each stage. The chemical structures of the obtained polycarbonates were verified by means of Attenuated Total Reflectance Fourier Transform infrared spectroscopy (ATR-FTIR). The presence of a carbonyl group in the infrared spectrum confirmed polycarbonate formation. Thermal studies by differential scanning calorimetry (DSC) were carried out to determine the melting temperatures of the monomers. A gel permeation chromatography analysis (GPC) of the polycarbonates was performed in order to investigate their molar masses. Thermal analysis proved the purity of the obtained monomers; the curves showed a characteristic signal of melting. The obtained polycarbonates were characterized as having high resistance to organic solvents, including tetrahydrofuran. The GPC analysis proved their relatively large molar masses and their low dispersity.


2021 ◽  
pp. 1-18
Author(s):  
Shuguang Huang ◽  
Joseph Schimmels

Abstract In this paper, the realization of any specified planar compliance with two 3R serial elastic mechanisms is addressed. Using the concepts of dual elastic mechanisms, it is shown that the realization of a compliant behavior with 2 serial mechanisms connected in parallel is equivalent to its realization with a 6-spring fully parallel mechanism. Since the spring axes of a 6-spring parallel mechanism indicate the geometry of a dual 3R serial mechanism, a new synthesis procedure for the realization of a stiffness matrix with a 6-spring parallel mechanism is first developed. Then, this result is extended to a geometric construction-based synthesis procedure for two 3-joint serial mechanisms.


2021 ◽  
Vol 23 (2) ◽  
Author(s):  
Daniela Jicman (Stan) ◽  
Elena Niculet ◽  
Mihaela Lungu ◽  
Cristian Onisor ◽  
Laura Rebegea ◽  
...  

2021 ◽  
Vol 16 (2) ◽  
pp. 262-281
Author(s):  
Tomás Antonio Freire de Pinho
Keyword(s):  

O conceito de natureza humana é alvo de discussão entre especialistas das ciências humanas e naturais. Um marco incontornável do debate é o livro Sociobiology: the new synthesis de Edward Wilson e sua interpretação darwinista do comportamento humano. O presente artigo investiga os principais instrumentos teóricos e conhecimentos científicos usados pelo autor para realizar esse tipo de interpretação. Defendemos que, ao fazê-lo, Wilson almeja dialogar com especialistas de outras áreas e “biologizar” as humanidades. Exploraremos em particular como o autor explica a natureza humana a partir do dilema altruísmo-egoísmo. Identificamos que a análise de Wilson sobre o comportamento humano assume a forma de premissas e inferências envolvendo a ubiquidade, a origem genética, a adaptação e o tratamento matemático.


Molecules ◽  
2021 ◽  
Vol 26 (24) ◽  
pp. 7507
Author(s):  
Montassar Khalil ◽  
Alexis Hocquigny ◽  
Mathieu Berchel ◽  
Tristan Montier ◽  
Paul-Alain Jaffrès

A convergent synthesis of cationic amphiphilic compounds is reported here with the use of the phosphonodithioester–amine coupling (PAC) reaction. This versatile reaction occurs at room temperature without any catalyst, allowing binding of the lipid moiety to a polar head group. This strategy is illustrated with the use of two lipid units featuring either two oleyl chains or two-branched saturated lipid chains. The final cationic amphiphiles were evaluated as carriers for plasmid DNA delivery in four cell lines (A549, Calu3, CFBE and 16HBE) and were compared to standards (BSV36 and KLN47). These new amphiphilic derivatives, which were formulated with DOPE or DOPE-cholesterol as helper lipids, feature high transfection efficacies when associated with DOPE. The highest transfection efficacies were observed in the four cell lines at low charge ratios (CR = 0.7, 1 or 2). At these CRs, no toxic effects were detected. Altogether, this new synthesis scheme using the PAC reaction opens up new possibilities for investigating the effects of lipid or polar head groups on transfection efficacies.


2021 ◽  
Vol 25 (12) ◽  
pp. 88-97
Author(s):  
H.A. Al-Ghulikah ◽  
A.S. El-Azab ◽  
M.S. AL-Saleem ◽  
M.S. AL-Towayan ◽  
S.A. Al-Issa

Green and classical techniques have been utilized for preparing of a variety of aryl - substituted pyrazoline and pyrimidine derivatives (2-8). Reactions of chalcones 1 with semicarbazide and thiosemicarbazide, nicotinic acid hydrazide and amino guanidine hydrochloride afforded the corresponding N-substituted pyrazoline derivatives 2-5. Pyrimidine derivatives 6-8 were achieved via reaction of chalcone derivatives 1 with several reagents namely: guanidine nitrate, thiourea and 6-amino-2-thioxo-2,3- dihydropyrimidin-4(1H)-one under conventional and ultrasonic conditions. Ultrasonic method was found to be an easy work-up procedure and it gave high yield in comparison with conventional method. The structures of new synthesis compounds were characterized by elemental and spectral analyses. Some of newly compounds were tested in vitro antibacterial activity against some gram–positive and gram–negative. The antimicrobial results displayed favorable antimicrobial activity. Molecular docking has been perfomed for compound 5b using MOE 2008.10, The data results obtained are quite promising.


ACS Omega ◽  
2021 ◽  
Author(s):  
Victor V. Dotsenko ◽  
Alexander V. Bespalov ◽  
Arthur S. Vashurin ◽  
Nicolai A. Aksenov ◽  
Inna V. Aksenova ◽  
...  

2021 ◽  
Author(s):  
Prasad Sankaravel ◽  
M. Meenakshi ◽  
P. Hanumantha Rao

Shaped and multiple beams using planar phased arrays. This paper presents a new synthesis and computation method to generate user-specified multiple beams and shaped beams in any arbitrary 3D space. The computation method can generate independently controllable simultaneous multiple beams with arbitrary peak powers. This method is extended to generate arbitrarily shaped beams, using a combination of optimally placed multiple beams at appropriate locations with specific power ratios.<br>


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