Impact Of Branches Research Articles

Controllable Synthesis of Chain Center Dye-Labeled Star Polymers for Quantitative Examination of Interchain Conformation by Time-Resolved Fluorescence Resonance Energy Transfer.

Using a "core-first" approach with atom transfer radical polymerization, fluorescent center-functional star polymers of equivalent molecular weight but with varying numbers of arms (di-, tri-, and tetra-arm) were prepared. The sensitivity of fluorescence, combined with a dye-labeling technique introducing a fluorescent donor (carbazole) and an acceptor (anthracene) at the center of poly(methyl methacrylate) (PMMA) chains, enabled the application of time-resolved fluorescence resonance energy transfer to obtain quantitative insights into the conformation of the star polymer chains in the film state. When the results of star-branched polymers were compared with those of linear polymers of identical type and molecular weight, the impact of branching on polymer behavior was isolated for examination. Although the star topology does not alter the average intercoil distance, it affects the distance dispersity. Star polymers with higher arm numbers display decreased dispersity from distance due to reduced intermolecular aggregation at their geometric centers. This study presents the first spectroscopic evidence regarding the distribution of geometric centers in star polymers, offering a physical understanding of chain interpenetration and entanglement within star polymers.

Strategic Price Competition in Local Retail Deposit Markets: Impact of Branching, Wholesale Funds Access and Liquidity Demand

Strategic Price Competition in Local Retail Deposit Markets: Impact of Branching, Wholesale Funds Access and Liquidity Demand

Strategic Price Competition in Local Retail Deposit Markets: Impact of Branching, Wholesale Funds Access and Liquidity Demand

Strategic Price Competition in Local Retail Deposit Markets: Impact of Branching, Wholesale Funds Access and Liquidity Demand

Vertical Canopy Profile and the Impact of Branches on Soybean Seed Composition.

Soybean [Glycine max (L.) Merr.] seeds are of global importance for human and animal nutrition due to their high protein and oil concentrations, and their complete amino acid (AA) and fatty acid (FA) profiles. However, a detailed description of seed composition at different canopy portions (i.e., main stem and branch nodes) is currently lacking in scientific literature. This study aims to (1) characterize seed yield and composition (protein, oil, AA, and FA) at the main stem (exploring a vertical canopy profile) and stem branches and (2) quantify the impact of canopy yield allocation on seed composition, focusing on branches as a potential contributor for higher yields. Four genotypes were field-grown during the 2018 and 2019 seasons, with seeds manually harvested from all the branches and three main stem segments (lower, middle, and upper). Seed samples were analyzed for seed yield (Mg/ha), seed size (mg/seed), protein and oil content (mg/seed) and their respective concentrations (g/kg), and AA and FA concentrations within protein and oil (g/100 g), herein called abundance. The upper main stem produced greater protein (25%) and oil (15%) content relative to the lower section; however, oil concentration increased from top to bottom while protein concentration followed opposite vertical gradient. Limiting AAs (lysine, cysteine, methionine, threonine, and tryptophan) were more abundant in the lower main stem, while the oleic/(linoleic + linolenic) ratio was greater in the upper segment. Overall, branches produced seeds with inferior nutritional quality than the main stem. However, the contribution of branches to yield (%) was positively related to limiting AA abundance and oil concentration across soybean genotypes. Future research studies should consider the morphological process of stem branching as a critical factor intimately involved with soybean seed composition across environments, genotypes, and management practices.

Effect of Branching on the Delayed Fluorescence and Phosphorescence of Simple Borylated Arylamines.

A donor-π-acceptor strategy is being well exploited in several fields in view of their robust optical properties. However, the impact of branching in quadrupolar [A-(π-D)2] and octupolar [A-(π-D)3] molecules in comparison to parent dipolar (A-π-D) molecules on the delayed fluorescence and phosphorescence properties is seldom explored. We have presented herein the distinct and contrasting optical properties of a tridurylborane core bearing -NH2 (1-3) and -NMe2 (4-6) donor moieties, wherein the number of donors is increased systematically. Because of propeller molecular architecture, the donor and acceptor are weakly coupled, and the frontier molecular orbitals are spatially localized. All of the compounds show delayed fluorescence under ambient conditions and persistent phosphorescence at low temperature. Solvent-dependent studies and temperature-dependent luminescence measurements established that quadrupolar (2 and 5) and octupolar (3 and 6) compounds underwent symmetry breaking in the excited state. Curiously, delayed fluorescence and phosphorescence spectra are found to be blue-shifted and follow the same trend as the fluorescence upon an increase in the branches. The highest quantum yield was observed for dipolar compounds. Besides, the phosphorescence lifetime decreases with an increase in the number of branches. These interesting experimental observations are further supported by quantum-mechanical calculations.

Impact of branching on the conformational heterogeneity of the lipopolysaccharide from Klebsiella pneumoniae: Implications for vaccine design

Resistance of Klebsiella pneumoniae (KP) to antibiotics has motivated the development of an efficacious KP human vaccine that would not be subject to antibiotic resistance. Klebsiella lipopolysaccharide (LPS) associated O polysaccharide (OPS) types have provoked broad interest as a vaccine antigen as there are only 4 that predominate worldwide (O1, O2a, O3, O5). Klebsiella O1 and O2 OPS are polygalactans that share a common D-Gal-I structure, for which a variant D-Gal-III was recently discovered. To understand the potential impact of this variability on antigenicity, a detailed molecular picture of the conformational differences associated with the addition of the D-Gal-III (1 → 4)-α-Galp branch is presented using enhanced-sampling molecular dynamics simulations. In D-Gal-I two major conformational states are observed while the presence of the 1 → 4 branch in D-Gal-III resulted in only a single dominant extended state. Stabilization of the more folded states in D-Gal-I is due to a O4-H⋯O2 hydrogen bond in the linear backbone that cannot occur in D-Gal-III as the O4 is in the Galp(1 → 4)Galp glycosidic linkage. The impact of branching in D-Gal-III also significantly decreases the accessibility of the monosaccharides in the linear backbone region of D-Gal-I, while the accessibility of the terminal D-Gal-II region of the OPS is not substantially altered. The present results suggest that a vaccine that targets both the D-Gal-I and D-Gal-III LPS can be developed by using D-Gal-III as the antigen combined with cross-reactivity experiments using the Gal-II polysaccharide to assure that this region of the LPS is the primary epitope of the antigen.

Impact of Branching on the Conformational Heterogeneity of the Lipopolysaccharide from Klebsiella Pneumonia: Implications for Vaccine Design

Klebsiella pneumonia is a bacterial pathogen for which the development of resistance to antibiotics is a concern. Towards addressing this concern, the development of vaccines offers great potential, with the lipopolysaccharides (LPS) on the surface of K. pneumonia representing a potential antigen. However, variability in the composition of the LPS occurs, a factor that may impact the scope of potential Kleb vaccines. To understand the potential impact of this variability on antigenicity a detailed molecular picture of the conformational differences associated with the addition of a 1-- 4 branch will be presented. Using molecular dynamics simulations in conjunction with enhanced sampling methods the full range of conformations accessible to the unbranched (Kp4) and branched (Kp24) LPS of Klebsiella p. will be determined. The impact of branching will be presented in the context of the accessibility of the monoscaccharide components of the LPS that may impact antigenicity.

Impact of Branching on the Solution Behavior and Serum Stability of Starlike Block Copolymers.

The size control of nanomedicines for tumor diagnosis and therapy is of high importance, since it enables or disables deep and sufficient tumor penetration. Amphiphilic star-shaped block copolypept(o)ides offer substantial promise to precisely adjust the hydrophobic core and the hydrophilic corona, independent of each other, and therefore simultaneously control the size dimension in the interesting size range from 10 to 30 nm. To gain access to core-shell structures of such sizes, 3-arm and 6-arm PeptoStars, based on poly(γ- tert-butyloxycarbonyl-l-glutamate)- b-polysarcosine (pGlu(O tBu)- b-pSar), were prepared via controlled living ring-opening polymerization (ROP) of the corresponding N-carboxyanhydrides. Moreover, size exclusion chromatography (SEC) proves the presence of well-defined star shaped polymers with molecular weights from 38 to 88 kg/mol with low polymer dispersities of 1.16 to 1.23. By varying the α-helical peptide core and maintain a constant polysarcosine corona, hydrodynamic size analyses revealed the importance of using a sufficiently large and dense hydrophilic shielding corona to prevent aggregation of the hydrophobic core and obtain uniform-sized spherical-shaped particles with hydrodynamic diameters below 24 nm. Fluorescence correlation spectroscopy (FCS) additionally demonstrates the absence of protein adsorption in human plasma for 6-arm polypept(o)ide stars and thus confirms polysarcosine as stealthlike material.

IF07. The Impact of Branches and Fenestrations on Early and Long-Term Visceral Vessel Patency in Complex Aortic Endograft Revascularization

Aortic endograft treatment with fenestrated or branched devices requires a connection between the aortic graft and the visceral vessel (VV); however, data on the perioperative and long-term fate of the VV are still scarce. The aim of our study was to evaluate VV loss (VVL) according to the type of revascularization performed (fenestrations vs branched) and adjunctive visceral procedures (AVPs) necessary. From 2012 to 2017, all fenestrated or branched endovascular repairs of juxtarenal aortic aneurysms (JAAAs), pararenal aortic aneurysms (PAAAs), and thoracoabdominal aortic aneurysms (TAAAs) were considered. Perioperative VVL, AVPs, and graft configuration were considered and evaluated during the follow-up. There were 523 VVs considered, 26% (140) in JAAAs, 32% (165) in PAAAs, and 42% (218) in TAAAs. Branches were used for 114 (52%) vessels in TAAAs, 8 (5%) in PAAAs, and 0 in JAAAs. The overall perioperative VVL was 24 (4.5%), and it was significantly higher in TAAAs compared with JAAAs or PAAAs (8.3% vs 2.4% vs 1.4%; P = .003). Branches had higher perioperative VVL compared with fenestration, 13% (15/123) vs 2% (9/401). This was confirmed selectively in TAAAs (5% [5/96] vs 0% [0/94]; P = .02). A significant VVL difference between branches and fenestrations (21% [11/52] vs 2.5% [(6 /224]; P = .001) was shown only by renal arteries. AVPs were performed in 43 (8.2%) VVs for dissections (0.4%-2%), stenosis (0.6%-3%), bleeding (0.6%-3%), or kinking (7%-35%); a significant difference between branches and fenestrations was seen only for kinking (12% [15/112] vs 5% [20/401]; P = .005). At 5 years, VVL was 2% ± 1%; fenestrations showed significantly higher VVL-free survival compared with branches (100% vs 87% ± 6%; P = .04), and this was confirmed selectively for TAAAs (100% vs 87% ± 6%; P = .04). AVPs did not affect the long-term visceral patency. Early and late VVL is infrequent in complex aortic procedures but seems to occur more frequently in branches compared with fenestrations, specifically in renal arteries. AVPs are often required to correct artery kinking, but this does not affect long-term patency.

Cloud point pressure in the system polyethylene + ethylene – Impact of branching

We propose here a simple theory for polydisperse, branched polyethylene dissolved in ethylene based on a cubic equation, namely the Sako-Wu-Prausnitz-equation of state, in combination with the Lattice Cluster Theory in the incompressible version, which is predictive concerning the branching, while using continuous thermodynamics to account for polydispersity with respect to the molecular mass. The new theory considers polymers to follow the Schulz-Flory distribution and to adopt an average degree of branching. It does not require different parameters for different molar masses, polydispersities or degrees of branching and hence, the number and mass average molar mass as well as average branch content are sufficient. We parameterize this theory for ethylene based on critical data and for polyethylene based on simple arguments and some experimental data of n-alkanes. The binary parameter describing the dispersion energy and its temperature dependence stemming from Lattice Cluster Theory is fit to experimental cloud point data from literature of one specific sample of polyethylene in ethylene. The theory is then used to predict the cloud point curves and critical properties of nine other polyethylene samples in ethylene. The fit and predicted cloud point curves show quantitatively correct temperature dependence. For high polydispersities, the concentration dependence is only qualitatively correct, which is most probably due to the oversimplified Schulz-Flory distribution. The influence of branching on cloud point pressures and critical pressures at constant temperature is predicted quantitatively correct.

Impact of Branches on the Volume of RTGS and NEFT Transactions in the Indian Public Sector Banks

Indian banking system is exceptionally technology oriented at par with the global banking standards. Technology has enabled banks to deliver effectively, momentously and most importantly in a secure manner. It has enhanced the overall growth of the Indian banking sector. As technology is the order of the day, Reserve Bank of India has implemented a new range of electronic products like RTGS, NEFT, IMPS, ECS, mobile banking, MICR and CTS etc., that offers a wide range of services to the customers. The major driving force behind the technological up gradation and transformation in the Indian banking sector has been the financial sector reforms of the nineties i.e., opening up of the economy and globalization. A sea change happened with the arrival of foreign and private banks backed with state-of-the-art technology leading to effective competition in the entire gamut of banking operations. The structure of the scheduled Commercial banks in India is classified as public sector, private sector, foreign banks and Regional Rural Banks. The authors have attempted to expound the branch impact on the volume of RTGS and NEFT payment methods in the Indian Public Sector banks. The authors have taken the volume of RTGS and NEFT transactions for the last five years (2011–2015) for the entire public sector banks. Descriptive statistics and Simple Linear Regression has been used to expound the branch impact on volume. It is evident that new strategy changes the focus to have a relook at the conventional delivery system in the Indian Banking model.

The effect of branching in a semiconducting polymer on the efficiency of organic photovoltaic cells

The impact of branching in a diketopyrrolopyrrole polymer on the performance of polymer-fullerene photovoltaic cells is investigated. Compared to the linear polymer, the branched polymer affords a more finely dispersed fibrillar network in the photoactive layer and as a result a large enhancement of the photocurrent and power conversion efficiency.

Impact of branching on the supramolecular assembly of thioethers on Au(111).

Alkanethiolate monolayers are one of the most comprehensively studied self-assembled systems due to their ease of preparation, their ability to be functionalized, and the opportunity to control their thickness perpendicular to the surface. However, these systems suffer from degradation due to oxidation and defects caused by surface etching and adsorbate rotational boundaries. Thioethers offer a potential alternative to thiols that overcome some of these issues and allow dimensional control of self-assembly parallel to the surface. Thioethers have found uses in surface modification of nanoparticles, and chiral thioethers tethered to catalytically active surfaces have been shown to enable enantioselective hydrogenation. However, the effect of structural, chemical, and chiral modifications of the alkyl chains of thioethers on their self-assembly has remained largely unstudied. To elucidate how molecular structure, particularly alkyl branching and chirality, affects molecular self-assembly, we compare four related thioethers, including two pairs of structural isomers. The self-assembly of structural isomers N-butyl methyl sulfide and tert-butyl methyl sulfide was studied with high resolution scanning tunneling microscopy (STM); our results indicate that both molecules form highly ordered arrays despite the bulky tert-butyl group. We also investigated the effect of intrinsic chirality in the alkyl tails on the adsorption and self-assembly of butyl sec-butyl sulfide (BSBS) with STM and density functional theory and contrast our results to its structural isomer, dibutyl sulfide. Calculations provide the relative stability of the four stereoisomers of BSBS and STM imaging reveals two prominent monomer forms. Interestingly, the racemic mixture of BSBS is the only thioether we have examined to date that does not form highly ordered arrays; we postulate that this is due to weak enantiospecific intermolecular interactions that lead to the formation of energetically similar but structurally different assemblies. Furthermore, we studied all of the molecules in their monomeric molecular rotor form, and the surface-adsorbed chirality of the three asymmetric thioethers is distinguishable in STM images.

Role of branching of hydrophilic domain on physicochemical properties of amphiphilic macromolecules

A novel series of amphiphilic macromolecules (AMs) composed of a sugar backbone, aliphatic chains, and branched, hydrophilic poly(oligoethylene glycol) methyl ether methacrylate (POEGMA)were developed for drug delivery applications. The branched, hydrophilic domains (POEGMA homopolymers with one hydroxyl group) were prepared via atom transfer radical polymerization (ATRP) of oligo(ethylene glycol) methyl ether methacrylate (OEGMA) monomers using 2-hydroxyethyl-2-bromoisobutyrate (HEBiB) as an initiator and copper bromide/bipyridine (CuBr/Bpy) as the catalyst system. To form the amphiphilic structures, the branched POEGMAs were coupled to hydrophobic domains that were formed via acylation of a sugar backbone. The impact of branching in the hydrophilic domain was investigated by comparing the AMs' solution and thermal properties with those of the linear counterparts. Although these highly branched AMs showed similar critical micelle concentration (CMC) values as compared to linear analogues, they possessed quite low glass transition (Tg ) temperatures. Consequently, these novel AMs with branched hydrophilic domain combine the desirable thermal properties of POEGMA with favorable solution properties of amphiphilic architectures, which make them suitable for injectable drug delivery systems.

The Role of Entropy and Enthalpy of Actin Filaments in Cellular Actin-Based Processes: Two Examples

Actin filaments play a fundamental role in cell migration and cell mechanics. Assembled by different Actin-Binding Proteins into different structures -cortex, stress fibers, filipodia, lamellipodium- actin filament is the basic unit available for the cell to apply forces or carry tensions. Actin filament is a semi-flexible polymer at the scale of the cell, which means that it is able to bend and to be bent by thermal fluctuations but it is mostly straight. This leads to a large contribution of the entropy to the dynamics of actin filaments and the networks they form. Here will be discussed our recent results regarding the link between these individual actin filament properties, semi-flexible fluctuating filaments, and their role in two examples: the actin-based force generation and the mechanics of the lamellipodium. We have recently shown that the polymerization of actin filaments that experience orientational fluctuations generates forces in a mechanism associated to the reduction of their entropy (1). In another experiments we have investigated the link between the elastic response of dense Arp2/3 branched actin networks and their microscopic architecture -in terms of branching and capping concentrations. Our results indicate that the elasticity of such dense branched networks originates more in the “enthalpic” deformations of the filaments themselves than in the “entropic” response usually probed in more diluted actin gels (2).(1) Brangbour et al (2011) Force-Velocity Measurements of a Few Growing Actin Filaments. PLoS Biology 9 e1000613.(2) Pujol et (2012) Impact of branching on the elasticity of actin networks. PNAS 109, p10364-9.

Impact of branching on the elasticity of actin networks.

Actin filaments play a fundamental role in cell mechanics: assembled into networks by a large number of partners, they ensure cell integrity, deformability, and migration. Here we focus on the mechanics of the dense branched network found at the leading edge of a crawling cell. We develop a new technique based on the dipolar attraction between magnetic colloids to measure mechanical properties of branched actin gels assembled around the colloids. This technique allows us to probe a large number of gels and, through the study of different networks, to access fundamental relationships between their microscopic structure and their mechanical properties. We show that the architecture does regulate the elasticity of the network: increasing both capping and branching concentrations strongly stiffens the networks. These effects occur at protein concentrations that can be regulated by the cell. In addition, the dependence of the elastic modulus on the filaments' flexibility and on increasing internal stress has been studied. Our overall results point toward an elastic regime dominated by enthalpic rather than entropic deformations. This result strongly differs from the elasticity of diluted cross-linked actin networks and can be explained by the dense dendritic structure of lamellipodium-like networks.

Impact of branching on the viscoelasticity of wormlike reverse micelles

We present an investigation on the effect of inter-micellar connections (branches) on the rheology of wormlike micelles. The system chosen is made of lecithin, minute amounts of water and organic solvents. Lecithin and water self-assemble into wormlike reverse micelles that can be branched or unbranched depending on the oil composition (and on the water content). In this respect, cyclohexane favours disconnected reverse micelles while isooctane promotes the formation of branches. By using mixtures of cyclohexane and isooctane as the oil phase and different water/lecithin ratios, the branch density of the system can be finely tuned. PGSE-NMR experiments allowed us to distinguish between branch-free (unbranched) and branched systems and the response of the very same samples to mechanical stress was measured by rheology. This allows, for the first time, an experimental correlation between rheological properties and the presence of branches. It turned out that the presence of a few inter-micellar connections sensibly decreases the zero-shear viscosity measured in steady state flow curves. Comparison with oscillatory rheology experiments indicates that the main effect of branches is to shorten the terminal relaxation time by speeding-up the reptation.

Impact of branching on the UV degradation of metallocene LLDPE

The effect of UV degradation on metallocene linear low density polyethylenes (LLDPEs) of different branching characteristics was studied. The samples were exposed to natural weather condition. The extent of the degradation on these LLDPEs was measured by Mechanical, FTIR and GPC testings. This paper addressed the structural modifications due to UV degradation of metallocene LLDPE (m-LLDPE). The results suggested that Z-N HDPE is very stable. Carbonyl absorbance and degradation of mechanical properties of m-LLDPEs increased with increasing branch content of the polymers. For short exposure times, the results suggested increase in the degree of cross-linking of m-PEs with the increase in BC leading to brittle behavior. However, at high exposure times chain scission dominates and it is branch content dependent. Most of the mechanical properties show a sharp rate of drop at branch contents less than 20 branches/1000 C followed by a slow drop rate. The results of the mechanical properties correlate very well with the carbonyl absorbance. GPC results confirmed that chain scission leading to a broader MWD is dominant at high exposure times and for LLDPEs with high branch contents. Branch type did not show any influence on mechanical properties.

Pharmacophore mapping, molecular docking and QSAR studies of structurally diverse compounds as CYP2B6 inhibitors

Pharmacophore mapping, molecular docking and quantitative structure–activity relationship (QSAR) studies were carried out for a structurally diverse set of 48 compounds as CYP2B6 inhibitors. The generated best pharmacophore hypotheses from the three methods of conformer generation (FAST, BEST and conformer algorithm based on energy screening and recursive buildup) indicate the importance of two features, namely, hydrogen bond acceptor [electron-rich centre] and ring aromaticity. The distance between the two centres of the important features for ideal inhibitors varied from 5.82 to 6.03 Å. The chemometric tools used for the QSAR analysis were genetic function approximation (GFA) and genetic partial least squares. The developed QSAR models indicate the importance of an electron-rich centre, size of molecule, impact of branching and ring system and distribution of charges in the molecular surface. The docking study confirms the importance of an electron-rich centre for binding with the iron atom of the cytochrome enzyme. A GFA model with spline option was found to be the best model based on internal validation as well as the r 2 m (overall) criterion (Q 2 = 0.772, r 2 m (overall) = 0.774). According to the external prediction statistics (R 2 pred = 0.876), another GFA-derived model with spline option outperforms the remaining models.

Pt(II) Uptake by Dendrimer Outer Pockets: 1. Solventless Ligand Exchange Reaction

Density functional theory is used to elucidate molecular-level details of the complexation of Pt(II) metal compounds with PAMAM dendrimers. Particular attention is given to the ligand exchange reaction (LER). Binding of Pt(II) complexes to one dendrimer atom site (monodentate binding) is found to be thermodynamically feasible. Tertiary amine nitrogen (N3) is found to be the most favorable binding site in agreement with previous experimental work. Comparing the binding of Pt(II) species to atom sites in simple molecules with those to similar sites in dendrimer outer pockets allowed us to assess the impact of dendrimer branches on the binding. The impact of branches is manifested in more complex reaction profiles for complexation of Pt(II) species, because of the numerous ways in which a single molecule could be hosted by an outer dendrimer pocket. It is found that branches slightly improve the binding strength to all sites, particularly to N3. However, they could also be responsible for the increase of the activation energy for direct LER of PtCl(4)(2-) and PtCl(3)(H(2)O)- at the N3 site. Considering the thermodynamics of both complexation steps, namely noncovalent binding (NCB) and LER, it is found that to have a PtCl(3)(-) moiety bound to N3, as a result of NCB + LER operating on PtCl(4)(2-), is more likely than to have any other ion hosted in the outer pockets. However, the activation energy for direct LER of PtCl(4)(2-) at the N3 site is found to be the largest among all Pt(II) metal complexes and even larger than the barrier to its own aquation yielding PtCl(3)(H(2)O)(-).