post-synthetic modification

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Synthesis of ZIF 93/11 hybrid nanoparticles via post synthetic modification of ZIF 93 and their use for H2/CO2 separation

Synthesis of ZIF 93/11 hybrid nanoparticles via post synthetic modification of ZIF 93 and their use for H2/CO2 separation

The direct synthesis of hybrid frameworks may not be always possible. Problems arising from limited linker solubility, chemical and thermal stability, or functional group compatibility can make the direct synthesis of hybrid ZIFs difficult. Post-synthetic modification routes are, therefore, a useful alternative approach. Through this technique, materials of high complexity and functionality can be obtained providing the MOF is not destroyed during the chemical reaction. Post-synthetic modification of MOFs can be classified into three types: covalent, dative and post- synthetic deprotection. [11] Covalent post-synthetic modification
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Post synthetic modification of zinc metal organic frameworks through palladium  catalysed carbon carbon bond formation

Post synthetic modification of zinc metal organic frameworks through palladium catalysed carbon carbon bond formation

established ease of undergoing Suzuki coupling reactions for aryl iodides with respect to bromides. While still relatively low, these conversions are high enough to suggest that post- synthetic modification is not completely limited to the crystal surfaces. No further conversion was observed on an increase in reaction time.

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The effect of pressure on the post synthetic modification of a nanoporous metal organic framework

The effect of pressure on the post synthetic modification of a nanoporous metal organic framework

Here we report four post-synthetic modi fi cations, including the fi rst ever example of a high pressure- induced post-synthetic modi fi cation, of a porous copper-based metal – organic framework. Ligand exchange with a water ligand at the axial metal site occurs with methanol, acetonitrile, methylamine and ethylamine within a single-crystal and without the need to expose a free metal site prior to modi fi cation, resulting in signi fi cant changes in the pore size, shape and functionality. Pressure experiments carried out using isopropylalcohol and acetaldehyde, however, results in no ligand exchange. By using these solvents as hydrostatic media for high-pressure single-crystal X-ray di ff raction experiments, we have investigated the e ff ect of ligand exchange on the stability and compressibility of the framework and demonstrate that post-synthetic ligand exchange is very sensitive to both the molecular size and functionality of the exchanged ligand. We also demonstrate the ability to force hydrophilic molecules into hydrophobic pores using high pressures which results in a pressure-induced chemical decomposition of the Cu-framework.
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Alkylating HIV-1 Nef - a potential way of HIV intervention

Alkylating HIV-1 Nef - a potential way of HIV intervention

[27]. It is conceivable that the covalent attachment of a bulky TPCK molecule to Cys55 would interfere with Nef-CD4 interaction and some other Nef functions. Fluorescence titration data indicated that TPCK-modifi- cation indeed dramatically reduced the binding strength of Nef to a CD4 tail peptide (Fig. 5). TPCK-modification may have an additional mechanism against HIV-1 by altering Nef conformation as shown by the CD spec- trum change (Fig. 6) and making it unstable as sug- gested by a shortened half-life of Nef in T cells also (unpublished data). Unfortunately, current cell system is not fit for testing anti HIV-1 activity due to technical difficulty. TPCK only partially (50%, maximum) alkylates wt Nef overexpressed in cultured T cells, leaving more than half of Nef without alkylation (Fig.1). A small frac- tion of unalkylated Nef protein is sufficient to downre- gulate CD4. Moreover, TPCK is toxic to T cells at high concentrations, which compromises the interpretation of an anti HIV-1 activity.
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Post-translational modification of Parkin and its research progress in cancer

Post-translational modification of Parkin and its research progress in cancer

Protein ubiquitination is a fundamental post-transla- tional modification that controls cell fate and function [7]. It has been reported that Parkin mediates its own ubiquitination through K48 protein-dependent ubiqui- tin chain formation, thereby affecting the stability of its own proteins [7, 38]. Durcan and colleagues identified the deubiquitinating enzyme (DUB) Ataxin-3 as a ligand for Parkin, which interacts with Parkin’s UbL and IBR- RING2 domains and promotes Parkin’s β-dimerization [39]. Mutant Ataxin-3, a polyglutamine dilatation associ- ated with the onset of Machado-Joseph neurodegenera- tive disease, promotes Parkin degradation by autophagy and leads to a decrease in Parkin levels in in vivo [40]. In a subsequent study, it was shown that Ataxin-3 binds to the E2 ubiquitin ligase Ubc7 instead of Parkin and promotes Parkin de-ubiquitination only when Parkin itself is ubiq- uitinated [41]. Collectively, these highlight the complex regulation of Parkin ubiquitination, involving the coor- dinated activities of Parkin, DUB and E2 ubiquitin ligase [42, 43]. It is known that when Parkin is ubiquitinated in cells, it degrades in a proteasome-dependent manner, effectively inactivating Parkin [44]. In conclusion, the
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Modification of the Persian version of Hermans Achievement Motivation Questionnaire to develop an adapted scale for measuring motivation of post-stroke survivors in Iran

Modification of the Persian version of Hermans Achievement Motivation Questionnaire to develop an adapted scale for measuring motivation of post-stroke survivors in Iran

devised a 28-item assessment tool, which was adapted from the Sports Motivation Scale (SMS) and re-named the Stroke Rehabilitation Motivation Scale (SRMS). The SRMS, comprised of 7 sets of questions, was tested on 31 Australian participants with acute post-stroke conditions. Based on standardization statistical results such as intra-class correlation coefficients, Cronbach’s alpha, and item-to-total correlation coefficients, a final 7-item SRMS was proved to have good reliability among the rest of 28 items, but validity of the questionnaire was not established. 13
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Synthesis, Modification, Characterisation, And Applications Oflayered Double Hydroxides In Synthetic Organic Chemistry

Synthesis, Modification, Characterisation, And Applications Oflayered Double Hydroxides In Synthetic Organic Chemistry

CHAPTER-1 INTRODUCTION This chapter describes the various catalyst/process options available for an industrial chemist to effect different organic transformations. It includes a brief introduction of homogeneous, heterogeneous, heterogenised homogeneous catalytic systems and basic concepts commonly encountered in catalysis such as selectivity, turnover number, atom economy etc. The importance of selective organic transformations and the need for the design and development of environmentally cleaner catalytic methodologies is also highlighted. This chapter also describes the importance of clays as catalysts for organic synthesis. The clays are divided into anionic clays and cationic clays. The anionic clays otherwise called as hydrotalcites/ layered double hydroxides (LDHs) are a large class of naturally occurring and synthetic clay-like materials with positively charged polymeric mixed-metal hydroxide layers separated by
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ABSTRACTS: July 1986147-152

ABSTRACTS: July 1986147-152

943-947 A highly efficient catalytic modification of synthetic reactions of borane in the presence of 0, is provided by a Rh porphyrin catalyst. The Rh-BH, complex can trans[r]

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ESCAPE: a Large scale Synthetic Corpus for Automatic Post Editing

ESCAPE: a Large scale Synthetic Corpus for Automatic Post Editing

The use of synthetic resources aims to overcome the afore- mentioned problem of “gold” data scarcity with approxi- mate solutions. This can be done in different ways. Sev- eral previous works have shown the viability of mimicking the ideal scenario in which the training triplets include ac- tual human post-edits of machine-translated text by learn- ing, instead, from the weaker connection between the MT output and external references. Though with variable mar- gins, (Oflazer and El-Kahlout, 2007; B´echara et al., 2011; Rubino et al., 2012) report translation quality improve- ments in the PBMT scenario with post-editing components trained on (source, MT, reference) triplets. To the best of our knowledge, though potentially useful to APE research, none of such previous works released reusable datasets. When moving to the data-demanding neural framework, data scarcity becomes a major problem that definitely calls for the external support of artificial corpora that are orders of magnitude larger than the current training sets.
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Oxacycle fused [1]benzothieno[3,2‐b][1]benzothiophene derivatives : synthesis, electronic structure, electrochemical properties, ionisation potential, and crystal structure

Oxacycle fused [1]benzothieno[3,2‐b][1]benzothiophene derivatives : synthesis, electronic structure, electrochemical properties, ionisation potential, and crystal structure

benzothieno[3,2-b][1]benzothiophene (3) are depicted along with their electrochemical, electronic, and single crystal structure which are compared to the well documented BTBT. To the best of our knowledge this is the first time the depicted strategy has been utilised on BTBT for four fold functionalization. Our synthetic protocol can be considered as a promising starting point, as the tetra-hydroxy BTBT appears to be a prolific intermediate towards a number of interesting chemical transformations on the BTBT core.

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DNA methylation and histone post-translational modification stability in post-mortem brain tissue

DNA methylation and histone post-translational modification stability in post-mortem brain tissue

Where the semiquantitative evaluation indicated changes in the immunohistochemical detection of PTMs, a quantitative evaluation was used to validate the results (Fig. 9). On images of pig neocortex, the intensity of nuclear immunoreactivity was measured (results not shown) and the proportions of immunoreactive cells were counted in two morphologic populations: large round nuclei (neurons) and smaller round to ovoid nuclei (glial cells and small interneurons; elongated nuclei of endothe- lial and smooth muscle cells were excluded). Because DNA cytosine modifications and histone methylation PTMs are stable up to 72 h post-mortem, we did a quantitative validation for only 5mC and H3K27me3. With 5mC and H3K27me3 immunostaining, neither cell population exhibited differences over progressive PMD as determined by ANOVA with Dunnett ’ s post hoc test for multiple comparisons. Among the acetyl marks, only H3K9ac showed a statistically significant decrease in neurons, but not in glial cells. H4K5ac demonstrated decreases in both neurons and glia by 48 h post-mortem. H3K14ac and H4K16ac were expressed at very low levels in neurons to begin with. Statistically significant post-mortem decreases of these two marks were demonstrated in glial nuclei (Fig. 9).
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Journal of Applied Pharmaceutical Science

Journal of Applied Pharmaceutical Science

Screening of synthetic new hetrocyclic derivatives of 3-formyl-4-hydroxy coumarin and evaluated for Anti-Inflammatory activity in albino rats. Structural modification of coumarin [r]

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An one pot multi component synthesis of novel 1,2,4 triazolo[1,5 a]pyrimidines

An one pot multi component synthesis of novel 1,2,4 triazolo[1,5 a]pyrimidines

Several synthetic strategies have been reported for the preparation of triazolopyrimidine derivatives. [5, 13-18] Most of these are based on modification of the classical one-pot Biginelli reaction [5, 14-17] and in some cases on more complex multi-step processes involving harsh reaction conditions and long reaction times. [18-19] One major drawback of the classical Biginelli protocol is the low yield that is frequently encountered when using sterically more demanding aldehydes.

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Ubiquitination of HTLV I Tax in response to DNA damage regulates nuclear complex formation and nuclear export

Ubiquitination of HTLV I Tax in response to DNA damage regulates nuclear complex formation and nuclear export

Tax is ubiquitously expressed in heterogeneous nuclear foci known as Tax Speckled Structures (TSS), as well as more diffusely in the cytoplasm [9,11,15]. Both the nuclear and cytoplasmic activities of Tax are essential for cellular transformation [4,9,16]. Recent reports have indi- cated that the recruitment and/or retention of Tax binding partners within TSS, and elsewhere in the cell, is regulated by the post-translational modification status of Tax [13,17,18]. When fused to a SUMO monomer, Tax is localized predominantly to TSS and sumoylation of Tax is required for the formation of nuclear foci containing both RelA/p300 and Tax [12,13]. Conversely, ubiquitination, or fusion of Tax to a ubiquitin monomer, targets Tax to the cytoplasm and is required for Tax binding to the Ikap- paB kinase complex and nuclear translocation of RelA [12,13]. Further, ubiquitination and sumoylation of Tax occurs on the same C-terminal lysine residues indicating that these modifications are mutually exclusive. Thus, the subcellular localization of Tax, as well as its ability to interact with specific cellular proteins, appear to be regu- lated by these post-translational modifications [12,13]. Despite these findings, it is unclear how the post-transla- tional modification status of Tax is regulated.
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An investigation on using pre treated tyre rubber as a replacement of synthetic polymers for bitumen modification

An investigation on using pre treated tyre rubber as a replacement of synthetic polymers for bitumen modification

by many researchers (D'Angelo et al. 2006, Tabatabaee and Tabatabaee 2010, Wasage et al. 2011, Gibson, M. et al. 2012, Zoorob et al. 2012) . Non-recoverable creep compliance (Jnr) has been recommended as an alternative to the current SHRP parameter |G*|/sin δ when assessing the permanent deformation performance of different bitumens (D'Angelo et al., 2007). Jnr has the ability to predict the improvement that is imparted by modification, and it is also more sensitive to the stress dependence of modified binders making it suitable for specification purposes for both neat and modified bitumen (D'Angelo 2009, Tabatabaee and Tabatabaee 2010). Also, measuring the Jnr of binders at high stresses and outside the linear viscoelastic region is conceivably more appropriate when considering the rutting behaviour of asphalt mixtures as the strains in binder films on aggregate surfaces can be several hundred times greater than the overall average strain of the mixture. Figure 12 shows the results of Jnr (average value for the 10 creep and recovery cycles) over a wide range of stresses between 0.1 kPa and 25.6 kPa at a test temperature of 60 o C.
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Attenuation of a Pathogenic Mycoplasma Strain by Modification of the obg Gene by Using Synthetic Biology Approaches

Attenuation of a Pathogenic Mycoplasma Strain by Modification of the obg Gene by Using Synthetic Biology Approaches

Until now, the tools from synthetic biology applied to Mycoplasma species have been mostly limited to building a minimal cell (20). However, we have shown that these tools are also useful for the elucidation of gene functions (29) and for the deciphering of host-pathogen interactions (30). The versatility of these approaches that combine in-yeast genome engineering and back-transplantation into a recipient cell is further demonstrated in the present study by showing our ability to generate targeted point mutations within the essential obg gene. Such an achievement was previously impos- sible using the genetic tools available for any Mycoplasma species. Since it is now possible to use synthetic biology tools for most of the ruminant-pathogenic Myco- plasma species that are closely related to M. mycoides subsp. capri (31), new strategies of vaccine design based on precise and multiple targets using genome engineering have become fully realistic. Within this global aim, the TS ⫹ phenotype resulting from
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Exploiting the dynamic properties of covalent modification cycle for the design of synthetic analog biomolecular circuitry

Exploiting the dynamic properties of covalent modification cycle for the design of synthetic analog biomolecular circuitry

We shall now illustrate how the remaining two regimes of the covalent modification cycle, i.e. signal-transducing and threshold-hyperbolic, can be utilised to compute the absolute value of a signal, for which the block diagram is shown in Fig. 4(b). The threshold-hyperbolic regime has a dead-zone, (i.e. a non-responsive region given any input signal) followed by a hyperbolic-like region. To compute the absolute value, the dead-zone range must not respond to input signals, u that are strictly neg- ative and then respond to input signals that are non- negative in a linear manner. To achieve this, note that in the threshold-hyperbolic regime, any hyperbolic response has an “almost linear” region when the input signal is small. By taking advantage of this property, we can ensure that our required threshold-hyperbolic regime has a lin- ear instead of hyperbolic response after the dead-zone region. On the other hand, the signal-transducing regime
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Search | Preprints

Search | Preprints

AAB- Amino acid biosynthesis; ATP-ATP synthase; CarMet-Carbohydrate metabolism; CGD-Cell growth and division; COB- Cell organization; COD-Cellular organization and development; DevPro-Developmental process; DRM-DNA and RNA metabolism; EnMet- Energy metabolism; EnStr-Environmental stress; EnvDevs-Environmental and developmental signals; GG-Glycolysis and gluconeogenesis; Gly-Glycolysis; NitMet-Nitrogen metabolism; Oxi- Oxidative stress; OxiRed-Oxidation-reduction process; Photo- Photosynthesis; ProtF-Protein folding; ProtMet-Protein metabolism; ProtS-Protein synthesis; PTR-Post-transcriptional regulations; ROSsca-ROS scavenging; SigTran-Signal transduction; STP- Storage proteins; StrRes-Stress response; TCA- Calvin cycle; Tranp- Transport, Trans-Translation; Chlo-Chloroplast; Mem-Membrane; Cyto-Cytoplasm; Nucl-Nucleus; Mito-Mitochondria; Plast-Plastid; Vacu-Vacuole; HS-Hoagland solutin
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Synthetic Interactions of the Post-Golgi sec Mutations of Saccharomyces cerevisiae

Synthetic Interactions of the Post-Golgi sec Mutations of Saccharomyces cerevisiae

Figure 1.—Crosses of post-Golgi sec mutants to mutants in members of the tethering complex. White boxes indicate no interaction, black boxes indicate syn- thetic lethality at 25⬚, and gray boxes indicate that the restrictive temperature of the double mutant was at least 3⬚ lower than that of either single mutant. AL, the mutations are allelic; ND, not deter- mined. Data for some crosses were previously published: sec2-41 ⫻ sec3-2, sec5-24, sec6-4, and sec10-2 (Nair et al. 1990); sec4-8 ⫻ sec3-2, sec5-24, sec10-2, and sec15-1 (Salminen and Novick 1987); sec6-4 ⫻ sec1-1 and sec3-2 (Po- tenza et al. 1992); sec8-9 ⫻ sec1-1, sec3-2, sec6-24, and sec10-2 (Bowser et al. 1992); sec15-1 ⫻ sec3-2, sec5-24, and sec10-2 (Sal- minen and Novick 1987); sec2-41 ⫻ sec15-1 (Salminen and Novick 1987; Nair et al. 1990); sec2-41 ⫻ sec8-9 (Nair et al. 1990; Bowser et al. 1992); sec6-4 ⫻ sec8-9 (Bowser et al. 1992; Potenza et al. 1992); sec8-9 ⫻ sec15-1 (Salminen and Novick 1987; Bowser et al. 1992).
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Epigenetic mechanisms in cancer: push and pull between kneaded erasers and fate writers

Epigenetic mechanisms in cancer: push and pull between kneaded erasers and fate writers

Abstract: Research concerning the epigenome over the years has systematically and sequentially shown substantial development and we have moved from global inhibition of modifications of the epigenome toward identification and targeted therapy against tumor-specific epigenetic mechanisms. In accordance with this approach, several drugs with epigenetically modulating activity have received considerable attention and appreciation, and recently emerging scientific evidence is uncovering details of their mode of action. High-throughput technologies have con- siderably improved our existing understanding of tumor suppressors, oncogenes, and signaling pathways that are key drivers of cancer. In this review, we summarize the general epigenetic mechanisms in cancer, including: the post-translational modification of DNA methyltransferase and its mediated inactivation of Ras association domain family 1 isoform A, Sonic hedgehog signaling, Wnt signaling, Notch signaling, transforming growth factor signaling, and natural products with epigenetic modification ability. Moreover, we introduce the importance of nano- medicine for delivery of natural products with modulating ability to epigenetic machinery in cancer cells. Such in-depth and comprehensive knowledge regarding epigenetic dysregulation will be helpful in the upcoming era of molecular genomic pathology for both detection and treatment of cancer. Epigenetic information will also be helpful when nanotherapy is used for epigenetic modification.
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