scholarly journals The Influence of Disorder in the Synthesis, Characterization and Applications of a Modifiable Two-Dimensional Covalent Organic Framework

Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 71
Author(s):  
Jordan Brophy ◽  
Kyle Summerfield ◽  
Jiashi Yin ◽  
Jon Kephart ◽  
Joshua T. Stecher ◽  
...  

Two-dimensional covalent organic frameworks (2D-COFs) have been of increasing interest in the past decade due to their porous structures that ideally can be highly ordered. One of the most common routes to these polymers relies on Schiff-base chemistry, i.e., the condensation reaction between a carbonyl and an amine. In this report, we elaborate on the condensation of 3,6-dibromobenzene-1,2,4,5-tetraamine with hexaketocyclohexane (HKH) and the subsequent carbonylation of the resulting COF, along with the possibility that the condensation reaction on HKH can result in a trans configuration resulting in the formation of a disordered 2D-COF. This strategy enables modification of COFs via bromine substitution reactions to place functional groups within the pores of the materials. Ion-sieving measurements using membranes from this COF, reaction of small molecules with unreacted keto groups along with modeling studies indicate disorder in the COF polymerization process. We also present a Monte Carlo simulation that demonstrates the influence of even small amounts of disorder upon both the 2D and 3D structure of the resulting COF.

Molecules ◽  
2021 ◽  
Vol 26 (24) ◽  
pp. 7581
Author(s):  
Fang Li ◽  
Jingqin Xu ◽  
Yajie Wang ◽  
Haiyan Zheng ◽  
Kuo Li

Under pressure of 1–100 GPa, unsaturated organic molecules tend to form covalent bond to each other for a negative enthalpy change, which often produces polymeric materials with extended carbon skeleton. The polymerization reactions typically happen in crystal, which promotes the topochemical process. This review summarized the topochemical polymerization processes of several alkynes, aromatics, and alkynylphenyl compounds, including the critical crystal structures before the reaction, bonding process, and the structure of the products. Secondly, this review also summarized the condensation reaction identified in the polymerization process, including the elimination of small molecules such as NH3, etc.


2019 ◽  
Author(s):  
Kristina Eriksen ◽  
Bjarne Nielsen ◽  
Michael Pittelkow

<p>We present a simple procedure to make an augmented reality app to visualize any 3D chemical model. The molecular structure may be based on data from crystallographic data or from computer modelling. This guide is made in such a way, that no programming skills are needed and the procedure uses free software and is a way to visualize 3D structures that are normally difficult to comprehend in the 2D space of paper. The process can be applied to make 3D representation of any 2D object, and we envisage the app to be useful when visualizing simple stereochemical problems, when presenting a complex 3D structure on a poster presentation or even in audio-visual presentations. The method works for all molecules including small molecules, supramolecular structures, MOFs and biomacromolecules.</p>


2019 ◽  
Vol 26 (8) ◽  
pp. 1351-1365 ◽  
Author(s):  
Zhentao Huang ◽  
Qingxin Yao ◽  
Simin Wei ◽  
Jiali Chen ◽  
Yuan Gao

Precision medicine is in an urgent need for public healthcare. Among the past several decades, the flourishing development in nanotechnology significantly advances the realization of precision nanomedicine. Comparing to well-documented nanoparticlebased strategy, in this review, we focus on the strategy using enzyme instructed selfassembly (EISA) in biological milieu for theranostics purpose. In principle, the design of small molecules for EISA requires two aspects: (1) the substrate of enzyme of interest; and (2) self-assembly potency after enzymatic conversion. This strategy has shown its irreplaceable advantages in nanomedicne, specifically for cancer treatments and Vaccine Adjuvants. Interestingly, all the reported examples rely on only one kind of enzymehydrolase. Therefore, we envision that the application of EISA strategy just begins and will lead to a new paradigm in nanomedicine.


2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Chen Wang ◽  
Jiawei Zhang ◽  
Jie Yin ◽  
Yichao Gan ◽  
Senlin Xu ◽  
...  

AbstractThe Myc proto-oncogene family consists of three members, C-MYC, MYCN, and MYCL, which encodes the transcription factor c-Myc (hereafter Myc), N-Myc, and L-Myc, respectively. Myc protein orchestrates diverse physiological processes, including cell proliferation, differentiation, survival, and apoptosis. Myc modulates about 15% of the global transcriptome, and its deregulation rewires the cellular signaling modules inside tumor cells, thereby acquiring selective advantages. The deregulation of Myc occurs in >70% of human cancers, and is related to poor prognosis; hence, hyperactivated Myc oncoprotein has been proposed as an ideal drug target for decades. Nevertheless, no specific drug is currently available to directly target Myc, mainly because of its “undruggable” properties: lack of enzymatic pocket for conventional small molecules to bind; inaccessibility for antibody due to the predominant nucleus localization of Myc. Although the topic of targeting Myc has actively been reviewed in the past decades, exciting new progresses in this field keep emerging. In this review, after a comprehensive summarization of valuable sources for potential druggable targets of Myc-driven cancer, we also peer into the promising future of utilizing macropinocytosis to deliver peptides like Omomyc or antibody agents to intracellular compartment for cancer treatment.


Crystals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 117
Author(s):  
Yousef Hijji ◽  
Rajeesha Rajan ◽  
Hamdi Ben Yahia ◽  
Said Mansour ◽  
Abdelkader Zarrouk ◽  
...  

The(3R,4R,6R)-3-(((E)-2-hydroxybenzylidene)amino)-6-(hydroxymethyl)tetrahydro-2H-pyran-2,4,5-triol water-soluble Glucose amine Schiff base (GASB-1) product was made available by condensation of 2-hydroxybenzaldehyde with (3R,6R)-3-amino-6-(hydroxymethyl)-tetra-hydro-2H-pyran-2,4,5-triol under mono-mode microwave heating. A one-pot 5-minute microwave-assisted reaction was required to complete the condensation reaction with 90% yield and without having byproducts. The 3D structure of GASB-1 was solved from single crystal X-ray diffraction data and computed by DFT/6-311G(d,p). The Hirshfeld surface analysis (HSA), molecular electronic potential (MEP), Mulliken atomic charge (MAC), and natural population analysis (NPA) were performed. The IR and UV-Vis spectra were matched to their density functional theory (DFT) relatives and the thermal behavior was resolved in an open-room condition via thermogravimetry/Derivative thermogravimetry (TG/DTG) and differential scanning calorimetry (DSC). The highest occupied molecular orbital/lowest unoccupied molecular orbital (HOMO/LUMO), density of state (DOS), and time-dependence TD-DFT computations were correlated to the experimental electron transfer in water and acrylonitrile solvents.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kiyoshi Masuyama ◽  
Tomoaki Higo ◽  
Jong-Kook Lee ◽  
Ryohei Matsuura ◽  
Ian Jones ◽  
...  

AbstractIn contrast to hypertrophic cardiomyopathy, there has been reported no specific pattern of cardiomyocyte array in dilated cardiomyopathy (DCM), partially because lack of alignment assessment in a three-dimensional (3D) manner. Here we have established a novel method to evaluate cardiomyocyte alignment in 3D using intravital heart imaging and demonstrated homogeneous alignment in DCM mice. Whilst cardiomyocytes of control mice changed their alignment by every layer in 3D and position twistedly even in a single layer, termed myocyte twist, cardiomyocytes of DCM mice aligned homogeneously both in two-dimensional (2D) and in 3D and lost myocyte twist. Manipulation of cultured cardiomyocyte toward homogeneously aligned increased their contractility, suggesting that homogeneous alignment in DCM mice is due to a sort of alignment remodelling as a way to compensate cardiac dysfunction. Our findings provide the first intravital evidence of cardiomyocyte alignment and will bring new insights into understanding the mechanism of heart failure.


2021 ◽  
Vol 7 (3) ◽  
pp. 209-219
Author(s):  
Iris J Holzleitner ◽  
Alex L Jones ◽  
Kieran J O’Shea ◽  
Rachel Cassar ◽  
Vanessa Fasolt ◽  
...  

Abstract Objectives A large literature exists investigating the extent to which physical characteristics (e.g., strength, weight, and height) can be accurately assessed from face images. While most of these studies have employed two-dimensional (2D) face images as stimuli, some recent studies have used three-dimensional (3D) face images because they may contain cues not visible in 2D face images. As equipment required for 3D face images is considerably more expensive than that required for 2D face images, we here investigated how perceptual ratings of physical characteristics from 2D and 3D face images compare. Methods We tested whether 3D face images capture cues of strength, weight, and height better than 2D face images do by directly comparing the accuracy of strength, weight, and height ratings of 182 2D and 3D face images taken simultaneously. Strength, height and weight were rated by 66, 59 and 52 raters respectively, who viewed both 2D and 3D images. Results In line with previous studies, we found that weight and height can be judged somewhat accurately from faces; contrary to previous research, we found that people were relatively inaccurate at assessing strength. We found no evidence that physical characteristics could be judged more accurately from 3D than 2D images. Conclusion Our results suggest physical characteristics are perceived with similar accuracy from 2D and 3D face images. They also suggest that the substantial costs associated with collecting 3D face scans may not be justified for research on the accuracy of facial judgments of physical characteristics.


2021 ◽  
Vol 22 (4) ◽  
pp. 2008
Author(s):  
Jinsha Liu ◽  
Priyanka Pandya ◽  
Sepideh Afshar

Around 77 new oncology drugs were approved by the FDA in the past five years; however, most cancers remain untreated. Small molecules and antibodies are dominant therapeutic modalities in oncology. Antibody-drug conjugates, bispecific antibodies, peptides, cell, and gene-therapies are emerging to address the unmet patient need. Advancement in the discovery and development platforms, identification of novel targets, and emergence of new technologies have greatly expanded the treatment options for patients. Here, we provide an overview of various therapeutic modalities and the current treatment options in oncology, and an in-depth discussion of the therapeutics in the preclinical stage for the treatment of breast cancer, lung cancer, and multiple myeloma.


2020 ◽  
Vol 53 (03) ◽  
pp. 324-334
Author(s):  
Gautam Biswas

Abstract Reconstruction of the complex anatomy and aesthetics of the midface is often a challenge. A careful understanding of this three-dimensional (3D) structure is necessary. Anticipating the extent of excision and its planning following oncological resections is critical.In the past over two decades, with the advances in microsurgical procedures, contributions toward the reconstruction of this area have generated interest. Planning using digital imaging, 3D printed models, osseointegrated implants, and low-profile plates, has favorably impacted the outcome. However, there are still controversies in the management: to use single composite tissues versus multiple tissues; implants versus autografts; vascularized versus nonvascularized bone; prosthesis versus reconstruction.This article explores the present available options in maxillary reconstruction and outlines the approach in the management garnered from past publications and experiences.


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