Capping Mechanism Research Articles

The Optimal Carbon Emission Reduction and Prices with Cap and Trade Mechanism and Competition.

More and more countries employ the Carbon Cap and Trade mechanism (CCT-mechanism) to stimulate the manufacturer to produce much more eco-friendly products. In this paper, we study how the CCT-mechanism affects competitive manufacturers’ product design and pricing strategies. Assume that there are two competitive manufacturers; we give the optimal closed form solutions of the carbon emission reduction rates and retail prices in the Nash game model and the Stackelberg game model with CCT-mechanism, respectively. Additionally, we also discuss the impacts of CCT-mechanism, consumer environmental awareness (CEA), and the sensitivity of switchovers toward price on the optimal carbon emission reduction rates, retail prices, and manufacturers’ profits. We find that (i) when the carbon quota is not enough, there is a trade off between investing in producing much greener product and purchasing carbon quota; when the carbon price is not high, the manufacturer tends to purchase the carbon quota; and when the carbon price is much higher, the manufacturer is more willing to increase the environmental quality of the product; (ii) manufacturer’s size affects product’s emission reduction rate and manufacturer’s optimal profit; larger manufacturer tends to produce much greener product, but it does not mean that he could obtain much more money than the small manufacturer; and (iii) the decision sequence changes manufacturer’s strategies; the optimal emission reduction rate in Nash and Stackelberg game models are almost the same, but the differences of prices and profits between Nash and Stackelberg model’s are much bigger.

131 - Disrupted regulation of Nox1 by protein disulfide isomerase-A1 in colon cancer cells with KRas overactivity

Tumor cells, e.g., colorectal cancer cells (CRC) often upregulate Nox NADPH oxidases, but underlying mechanisms are unclear. Thiol isomerases such as protein disulfide isomerase-A1 (PDIA1) are thioredoxin superfamily redox chaperones overexpressed in cancer and associated with tumoral progression. We previously showed an essential requirement of PDIA1 for agonist-triggered Nox1 activation in vascular smooth muscle . We thus investigated PDIA1/Nox1 crosstalk in CRC, known to highly express Nox1 and mutated overactive KRas. Our analysis of RNAseq databanks and direct validation in CRC cell lines indicated significant positive correlation between PDIA1 expression and Ras activity. We questioned whether Ras activity might influence PDIA1/Nox1 crosstalk and studied CRC with constitutive high (HCT116) vs. moderate (HKE3) or basal (CaCo2) Ras activity. In Caco2 and HKE3, PDIA1 siRNA silencing promoted decreased superoxide generation (HPLC/2OH-ethidium). Unexpectedly, in HCT116, PDIA1 silencing promoted increased superoxide output. Effects of NoxA1ds peptide inhibitor confirmed the Nox1 source. Thus, analogous to vascular cells, PDIA1 supports Nox1 in CRC with basal or moderate Ras activity, while PDIA1 silencing with overactive Ras unleashes Nox1 activity. Since vascular PDIA1 effects involve Rac1 RhoGTPase, a known Nox1 subunit, we hypothesized that direct Ras-mediated Rac1 activation could bypass PDIA1 regulation. Indeed, in HCT116 treated with Rac1 inhibitor, PDIA1 became supportive of superoxide production; conversely, Rac1-G12V active mutant transfection into HKE3 induced PDIA1 to restrict Nox1-dependent superoxide. PDIA1 silencing impaired cell proliferation and migration in HKE3, an effect lost in HCT116. Also, E-cadherin expression enhanced in HKE3 and decreased in HCT116 upon PDIA1 silencing, consistent with PDIA1 supporting epithelial-mesenchymal transition. Thus, PDIA1 may be a servomechanism of Nox1 regulation, supporting it within its operational range but capping its overactivation. Ras upregulation, unleash Nox1 activation possibly via Rac1, inducing PDIA1 capping mechanism switch. PDIA1 may crucially regulate redox-dependent adaptive processes related to cancer progression.

The Dmp8-Dmp18 bicistron messenger RNA enables unusual translation during cellular stress.

Alternatives to the cap mechanism in translation are often used by viruses and cells to allow them to synthesize proteins in events of stress and viral infection. In Drosophila there are hundreds of polycistronic messenger RNA (mRNA), and various mechanisms are known to achieve this. However, proteins in a same mRNA often work in the same cellular mechanism, this is not the case for Drosophila's Swc6/p18Hamlet homolog Dmp18, part of the SWR1 chromatin remodeling complex, who is encoded in a bicistronic mRNA next to Dmp8 (Dmp8-Dmp18 transcript), a structural component of transcription factor TFIIH. The organization of these two genes as a bicistron is conserved in all arthropods, however the length of the intercistronic sequence varies from more than 90 to 2 bases, suggesting an unusual translation mechanism for the second open reading frame. We found that even though translation of Dmp18 occurs independently from that of Dmp8, it is necessary for Dmp18 to be in that conformation to allow its correct translation during cellular stress caused by damage via heat-shock and UV radiation.

Multivalent Crown Ether Receptors Enable Allosteric Regulation of Anion Exchange in an Fe4L6 Tetrahedron

AbstractWe report a strategy for regulating the rate of internally bound anion exchange within an Fe4L6 metal–organic tetrahedron through external coordination of tripodal tris(alkylammonium) cations. The cage features three flexible 18‐crown‐6 receptors at each of its FeII vertices, facilitating strong tritopic interactions with tris(ammonium) cations to “cap” the vertices of the tetrahedron. This capping mechanism restricts the flexibility of the cage framework, thereby reducing the rate of anion exchange within its central cavity by 20‐fold. Thus, we demonstrate the first use of an externally bound multivalent effector to allosterically control internal guest binding in a molecular cage.

Multivalent Crown Ether Receptors Enable Allosteric Regulation of Anion Exchange in an Fe4 L6 Tetrahedron.

We report a strategy for regulating the rate of internally bound anion exchange within an Fe4 L6 metal-organic tetrahedron through external coordination of tripodal tris(alkylammonium) cations. The cage features three flexible 18-crown-6 receptors at each of its FeII vertices, facilitating strong tritopic interactions with tris(ammonium) cations to "cap" the vertices of the tetrahedron. This capping mechanism restricts the flexibility of the cage framework, thereby reducing the rate of anion exchange within its central cavity by 20-fold. Thus, we demonstrate the first use of an externally bound multivalent effector to allosterically control internal guest binding in a molecular cage.

CTD-dependent and -independent mechanisms govern co-transcriptional capping of Pol II transcripts

Co-transcriptional capping of RNA polymerase II (Pol II) transcripts by capping enzyme proceeds orders of magnitude more efficiently than capping of free RNA. Previous studies brought to light a role for the phosphorylated Pol II carboxyl-terminal domain (CTD) in activation of co-transcriptional capping; however, CTD phosphorylation alone could not account for the observed magnitude of activation. Here, we exploit a defined Pol II transcription system that supports both CTD phosphorylation and robust activation of capping to dissect the mechanism of co-transcriptional capping. Taken together, our findings identify a CTD-independent, but Pol II-mediated, mechanism that functions in parallel with CTD-dependent processes to ensure optimal capping, and they support a “tethering” model for the mechanism of activation.

A carbon-constrained EOQ model with uncertain demand for remanufactured products

The classical economic order quantity (EOQ) model is simple and practicable, but it would be invalid without the rigorous assumption that demand is constant. This work breaks through the limitation and develops an extended EOQ model under uncertain demand, in order to derive different optimal acquisition strategies. Under the carbon cap and trade mechanism, the optimal quantities in environmental and economic optimization are usually different, while we deduce the optimal acquisition strategies (III and IIII) to solve multi-objective optimization problems. We rigorously prove the uniqueness of optimal order quantity in each strategy and provide close-form expressions for possible holding and opportunity costs caused by the uncertain supply-demand relationship. Other than conducting an optimization analysis from the perspective of firms, we also analyze the effects of taxation policy on the optimal strategies from the perspective of the government. An interesting phenomenon is that increasing carbon tax will not only reduce profit margins, but will also change the optimal acquisition decisions. Consequently, remanufacturing enterprises can be guided in a sustainable direction, by adopting more energy-efficient strategies to enter the “profitable region”.

Can carbon cap and trade mechanism be beneficial for remanufacturing?

Remanufacturing is an environmentally friendly and profitable way to conduct production operations. For environmental protection, carbon cap and trade mechanism, which is conventionally considered a burden for manufacturers, is a viable approach to reduce carbon emissions. This paper explores the possibility of a monopolistic manufacturer involved in both manufacturing and remanufacturing to profit under carbon cap and trade mechanism in a single period. We develop a model to derive the favourable conditions under which carbon cap and trade is beneficial for the manufacturer in ordinary markets and green markets and obtain the manufacturer's optimal decisions. Furthermore, we analyse the influence of carbon emissions-related parameters on the manufacturer's optimal decisions and carbon trading quantity. The results show that carbon cap and trade can be valuable for remanufacturing in both the ordinary market and the green market. Policy makers should focus on carbon trading prices to reduce carbon emissions and improve the manufacturers' profits in both markets. In addition, the low carbon emissions characteristics of remanufactured products allow for better profits for manufacturers under carbon cap and trade, and their investments in low carbon production technology should be expanded. Finally, the proportion of green consumers has important performance implications for remanufacturing in green markets. Specifically, excessive green consumers in a monopolistic market are not always a blessing when the carbon trading price is high.

Development of an ELISA assay for screening inhibitors against divalent metal ion dependent alphavirus capping enzyme

Alphavirus non-structural protein, nsP1 has a distinct molecular mechanism of capping the viral RNAs than the conventional capping mechanism of host. Thus, alphavirus capping enzyme nsP1 is a potential drug target. nsP1 catalyzes the methylation of guanosine triphosphate (GTP) by transferring the methyl group from S-adenosylmethionine (SAM) to a GTP molecule at its N7 position with the help of nsP1 methyltransferase (MTase) followed by guanylylation (GT) reaction which involves the formation of m7GMP-nsP1 covalent complex by nsP1 guanylyltransferase (GTase). In subsequent reactions, m7GMP moiety is added to the 5ʹ end of the viral ppRNA by nsP1 GTase resulting in the formation of cap0 structure. In the present study, chikungunya virus (CHIKV) nsP1 MTase and GT reactions were confirmed by an indirect non-radioactive colorimetric assay and western blot assay using an antibody specific for the m7G cap, respectively. The purified recombinant CHIKV nsP1 has been used for the development of a rapid and sensitive non-radioactive enzyme linked immunosorbent assay (ELISA) to identify the inhibitors of CHIKV nsP1. The MTase reaction is followed by GT reaction and resulted in m7GMP-nsP1 covalent complex formation. The developed ELISA nsP1 assay measures this m7GMP-nsP1 complex by utilizing anti-m7G cap monoclonal antibody. The mutation of a conserved residue Asp63 to Ala revealed its role in nsP1 enzyme reaction. Inductively coupled plasma mass spectroscopy (ICP-MS) was used to determine the presence of magnesium ions (Mg2+) in the purified nsP1 protein. The divalent metal ion selectivity and investigation show preference for Mg2+ ion by CHIKV nsP1. Additionally, using the developed ELISA nsP1 assay, the inhibitory effects of sinefungin, aurintricarboxylic acid (ATA) and ribavirin were determined and the IC50 values were estimated to be 2.69 μM, 5.72 μM and 1.18 mM, respectively.

Morphological Map of ZIF-8 Crystals with Five Distinctive Shapes: Feature of Filler in Mixed-Matrix Membranes on C3H6/C3H8 Separation

Morphology-tailoring of metal–organic frameworks (MOFs) is essential for their specific application in molecular-separation, catalysis, and drug-delivery. However, precision syntheses of uniform MOFs crystals with anisotropic shape are still challenging. Herein, a morphological map for monodisperse ZIF-8 crystals with five distinctive shapes was constructed in terms of the synthetic conditions. It was revealed that the formation mechanism for ZIF-8 crystals with various shapes is strongly dependent on the concentration of cetyltrimethylammonium bromide (CTAB) added, not limited to the traditional capping mechanism for MOFs and metal nanocrystals. The generality of this strategy was also verified through the successful morphology-controllable synthesis of ZIF-67 crystals. The effect of ZIF-8 morphology on separation performance of resulting cross-linked poly(ethylene oxide) (XLPEO)-based mixed-matrix membranes for C3H6/C3H8 mixtures was also evaluated.

Cooperativity and Flexible Domains Participation in PIP Aquaporin Gating

From structural data two distinct mechanisms have been proposed to describe how aquaporins are gated (Frick et al. FEBSLett. 2013). Gating of some aquaporins -AQP0 or AQPZ- is mediated by the displacement of a single residue inside the pore (pinching), while for others -e.g. PIP- the blocking of the pore occurs as the result of loopD rearrangement (capping). Regarding PIP capping mechanism, it has been suggested that the open-closed transition not only involves loopD but also N and C-terminal movements. The PIP subfamily consists of two paralogs, PIP1 and PIP2, which can form heterotetramers. Heterotetramerization occurs with random stoichiometry and all formed heterotetramers have different water transport capability and pH0,5 than PIP2 homotetramers (Jozefkowicz et al. Biophys J. 2016). Since there is no structural information available for PIP1, many of the molecular events that explain changes in the pH sensing in heterotetramers are still unknown. We investigate the cooperative gating of homo and heterotetramers. In particular, we study the participation of flexible domains in this process. Our results show that all homo and heterotetrameric species share the same degree of cooperativity for proton sensing. However the cooperativity is apparently lower when PIP1-PIP2 heterotetramers and PIP2 homotetramers are both present in the membrane due to their different pH0,5. In addition, we detected loopD participation in PIP2 gating is more efficient than C-term, since mutation of Leu202 keep the channel open even at low pH, while truncation of C-term do not modify pH sensing. The elucidation of the peculiarities of PIP gating sheds light on the regulatory mechanisms that control water transport trough membranes and extends the knowledge about the participation of flexible domains in the control of the biological activity of oligomeric channels.

The evolution of China’s emission trading mechanisms: From international offset market to domestic Emission Trading Scheme

With the decline of the international market under the Clean Development Mechanism, China is establishing a national Emission Trading Scheme by setting up emission cap and trade rules for high emission industries in seven pilot areas. The shift from the international to domestic market and from an offset program to a true cap and trade mechanism requires several significant changes. This paper reviews the development and evolution of China’s carbon trading market policy instruments. We find that there are substantial changes in both structure and policy. First, Emission Trading Scheme is a broad cap-and-trade mechanism with many new stakeholders added to those already involved in China’s Clean Development Mechanism. Second, the administrative structure is decentralized compared to that of the Clean Development Mechanism. Third, while the Emission Trading Scheme is best thought of as a new policy, China’s experience with the Clean Development Mechanism influences that policy. A large number of Clean Development Mechanism projects are being converted into offsets for the national Emission Trading Scheme market, and many institutional stakeholders that emerged during the Clean Development Mechanism are now involved in the Emission Trading Scheme. The combination of new policies and stakeholders, a decentralization of structure and the conversion of Clean Development Mechanism projects raise questions regarding the integrity of the cap and the enforcement of compliance as the Emission Trading Scheme is expanded into a nationwide system.

Induction of Au-methotrexate conjugates by sugar molecules: production, assembly mechanism, and bioassay studies

Au-methotrexate (Au-MTX) conjugates induced by sugar molecules were produced by a simple, one-pot, hydrothermal growth method. Herein, the Au(III)-MTX complexes were used as the precursors to form Au-MTX conjugates. Addition of different types of sugar molecules with abundant hydroxyl groups resulted in the formation of Au-MTX conjugates featuring distinct characteristics that could be explained by the diverse capping mechanisms of sugar molecules. That is, the instant-capping mechanism of glucose favored the generation of peanut-like Au-MTX conjugates with high colloidal stability while the post-capping mechanism of dextran and sucrose resulted in the production of Au-MTX conjugates featuring excellent near-infrared (NIR) optical properties with a long-wavelength plasmon resonance near 630–760 nm. Moreover, in vitro bioassays showed that cancer cell viabilities upon incubation with free MTX, Au-MTX conjugates doped with glucose, dextran and sucrose for 48 h were 74.6%, 55.0%, 62.0%, and 63.1%, respectively. Glucose-doped Au-MTX conjugates exhibited a higher anticancer activity than those doped with dextran and sucrose, therefore potentially presenting a promising treatment platform for anticancer therapy. Based on the present study, this work may provide the first example of using biocompatible sugars as regulating agents to effectively guide the shape and assembly behavior of Au-MTX conjugates. Potentially, the synergistic strategy of drug molecules and sugar molecules may offer the possibility to create more gold-based nanocarriers with new shapes and beneficial features for advanced anticancer therapy.

Probleme de datare a armelor balcanice din sec. XVIII-XIX aflate pe teritoriul actual al Romaniei / Issues Relating to the Dating of the Balkan Arms from the 18th–19th Centuries on the Current Territory of Romania

Probleme de datare a armelor balcanice din sec. XVIII-XIX aflate pe teritoriul actual al Romaniei / Issues Relating to the Dating of the Balkan Arms from the 18th–19th Centuries on the Current Territory of Romania

A General Approach to Synthesize Metal Nanostructures by Using Cucurbit[7]uril

Various metal (iron, copper, zinc, platinum)-based nanostructures were synthesized by a simple, green, and one-pot reaction of respective metal precursor and a cucurbit[7]uril (CB7) in an aqueous alkaline mixture at room temperature. The metal nanostructures (MNS) were obtained without adding any additional traditional reducing or protecting agents and/or external energy sources. Further, we could be able to tune the size and shape of the MNS just by varying the experimental conditions such as reaction concentration. Depending on the metal salts and reaction conditions, we could be able to produce different sizes and shapes of nanostructures. For example, the diameter of the CuO and iron nanoparticles (NP) was observed as [Formula: see text][Formula: see text]nm (even [Formula: see text][Formula: see text]nm) which suggests the inclusion mechanism. However, the particle size of zinc and platinum was over 2[Formula: see text]nm which suggests the capping mechanism for the well-dispersed nanoparticles. It is worth mentioning that the CB7 acts as both reducing and protecting agent for the preparation of various MNS at ambient conditions. This one-pot and green approach for the preparation of MNS in aqueous solution has various advantages due to its mild synthesis condition and no toxic materials were used or produced, which is an important aspect for the exploration of biomedical applications and environmental influence of several metal nanoparticles that are presently prepared in organic solvents.

Two-period Production Decisions in a Hybrid Manufacturing/Remanufacturing System with Consume Preferences under Carbon Cap and Trade Mechanism

We develop a two-period profit-maximization nonlinear programming model to research the impact of carbon cap and trade mechanism as well as the consumer preferences on the enterprises remanufacturing decision and pricing decision. The results illustrate that: with the greater consumer's preference for remanufacturing products, the enterprise will be more positive to conduct remanufacturing, and the profit will be greater as well. The enterprises’ manufacturing/remanufacturing decision and pricing decision is related to carbon trading price but which is not influenced by the initially allocated carbon emission quotas from government.

The structure of the binary methyltransferase-SAH complex from Zika virus reveals a novel conformation for the mechanism of mRNA capping.

Zika virus, a flavivirus like Dengue and West Nile viruses, poses a significant risk as a pathogen in the category of emerging infectious diseases. Zika infections typically cause nonspecific, mild symptoms, but can also manifest as a neurological disorder like Guillain-Barré syndrome. Infection in pregnant women is linked to microcephaly in newborn infants. The methyltransferase domain of the non-structural protein 5 is responsible for two sequential methylations of the 5′-RNA cap. This is crucial for genome stability, efficient translation, and escape from the host immune response. Here we present the crystal structures of the Zika methyltransferase domain in complex with the methyl-donor SAM and its by-product SAH. The methyltransferase-SAH binary complex presents a new conformation of a “closed” or “obstructed” state that would restrict the binding of new RNA for capping. The combination and comparison of our new structures with recently published Zika methyltransferase structures provide a first glimpse into the structural mechanism of Zika virus mRNA capping.

The CAP as a Job Stabiliser

SummaryThe CAP's impact upon farm structures, farm incomes and rural development has attracted significant interest among researchers and policymakers. However, its impact upon employment levels has been studied only indirectly, and valuable inferences have been missed. Taking account of the CAP's role in and impacts on employment requires a broader approach to policy evaluation as employment changes are closely related to changes in sector activity. Besides fulfilling agro‐food production and other rural objectives, the CAP should also be seen as a dynamic job‐generating and maintenance tool. CAP measures, besides directly creating jobs in Pillars I and II, keep alive several farming activities which, without their support, would probably cease, with significant job losses in many regions. Moreover, the CAP, via the multiplier effect (sectoral and fiscal), creates and secures jobs in non‐agro‐food sectors that are crucial for regional and national economies. Furthermore, under the current dismal economic and social conditions in several EU countries not least in terms of employment levels, the CAP's mechanisms are vital. Certainly, a further careful overhaul of the CAP could enhance its power as a job‐stabilising programme.

Synthesis and characterization of binaphthalene-2,2′-diamine-functionalized gold nanoparticles

Gold nanoparticles 1.7 and 54 nm in diameters have been synthesized and functionalized successfully with their surfaces engineered using two atropisomeric capping ligands, 2,2′-bis(diphenylphosphino)-1,1′-binaphthalene (BINAP) and 1,1′-binaphthalene-2,2′-diamine (DABN), respectively. A systematic study to compare the two different gold nanoparticles is presented using multiple material characterization techniques. It was found that the two systems show different capping mechanism and hence differ in their intrinsic core and surface properties. The compound BINAP plays only surface capping agent and stabilizes the gold nanoparticles, resulting in small particle size and suppressed surface plasmon resonance absorption at 520 nm. The DABN capping ligand is different from BINAP and acts as both reducing and capping agent, causing the reduction of Au (III) to Au (0). The nucleation growth of the gold core occurs in accordance with the polymerization-passivation process by DABN, resulting in a big particle size of 20 nm. A strong surface plasmon resonance band shows a maximum peak at 564 nm, consistent with the Au core size. The simultaneous oxidative polymerization of DABN and the induced metal reduction process lead to the formation of gold nanoparticles encapsulated by a mixture of DABN oligomers or polymers.

Shear strength of pharmaceutical tablets: Theoretical considerations, evaluation and relation with the capping tendency of biconvex tablets

Capping is a major industrial issue during pharmaceutical powder compression, especially in the case of biconvex tablets. Several articles proposed that capping was in fact a failure in shear. Shear strength should thus be interesting to study the capping tendency of a formulation. In this work, the ratio between the shear strength and the tensile strength obtained by diametral compression was first studied from a theoretical point of view considering different failure criteria. Then, a shear test usually performed on bilayer tablets was adapted to monolayer tablets. The shear strength obtained for 5 products, 2 of them having a known capping tendency, were compared with the strengths obtained during diametral compression test and uniaxial compression test.The results indicated that, for the formulations with a capping tendency, the ratio between the shear strength and diametral compression strength was lower than for the other products. Considering the mechanism of capping, the weakness in shear of these formulations explained their capping tendency. This was also linked with the mechanical anisotropy of the same formulations which was shown in the literature. In the cases studied in this article, the fundamental reason for the capping tendency was the anisotropic strength of the tablets.