Mass Chain Research Articles

Teaching wave propagation and the emergence of Viète’s**The Latin version of this French name is usually quoted as Vieta. formula

The well-known result for the frequency of a simple spring–masssystem may be combined with elementary concepts like speed = wavelength × frequency to obtain wave propagation speeds for an infinite chain of springs and masses (masses m held apart atequilibrium distance a by springs of stiffness γ). These propagation speeds are dependent on the wavelength of the wave. The dispersionis easily investigated by considering normal modes of increasing wavelength. Thisinvestigation also elegantly highlights how the dispersion physically arises in the form of effective spring constants due to the way in which neighbouring springs contribute tothe propagation of each of the normal modes. The resulting propagation speeds v(λ) are given by an expression , which in the limit of large λ becomes . This of course means that —the serendipitous emergence of what turns out to be Viète’s formula forπ in terms of nested roots of 2.

Nuclear Data Sheets for A = 222

The ENSDF evaluation for A=222 mass chain (1996El01) has been updated on the basis of the experimental results, since September 1995 (literature cutoff date in 1996El01), from various reaction and decay studies for all nuclides in A=222 mass chain (Z=84 to 92). A new nuclide ( 222Po) has since been observed. In addition, new measurements have been reported in Rn, Th and Ra nuclides. The results obtained from various theoretical studies are given as comments. The updated level and decay schemes, and experimental decay and reaction data on which they are based, are summarized and presented for all the nuclides with mass number A=222. The adopted values of level energies, level spins and parities are given, and γ-ray energies, intensities, as well as other nuclear properties are presented. The references, J π arguments, and necessary comments are given in the text. All Q values have been adopted from 2011AuZZ. Theoretical work of 2009Mo27 was consulted.

Energy Transport Through Rare Collisions

We study a one-dimensional hamiltonian chain of masses perturbed by an energy conserving noise. The dynamics is such that, according to its hamiltonian part, particles move freely in cells and interact with their neighbors through collisions, made possible by a small overlap of size $\epsilon > 0$ between near cells. The noise only randomly flips the velocity of the particles. If $\epsilon \rightarrow 0$, and if time is rescaled by a factor $1/{\epsilon}$, we show that energy evolves autonomously according to a stochastic equation, which hydrodynamic limit is known in some cases. In particular, if only two different energies are present, the limiting process coincides with the simple symmetric exclusion process.

Nuclear Data Sheets for A = 161

The experimental results from the various reaction and radioactive decay studies leading to nuclides in the A=161 mass chain have been reviewed. Nuclides ranging from Sm (Z=62) through Os (Z=76) are included, with Os being a new entry based on a recently reported study. These data are summarized and presented, together with adopted level schemes and properties. This work supersedes the previous evaluation (2000Re14) of the data on these nuclides.

Dendritic Carrier Based on PEG: Design and Degradation of Acid-sensitive Dendrimer-like Poly(ethylene oxide)s

Degradable dendrimer-like PEOs were designed using an original ABC-type branching agent featuring a cleavable ketal group, following an iterative divergent approach based on the anionic ring opening polymerization (AROP) of ethylene oxide and arborization of PEO chain ends. A seventh generation dendrimer-like PEO carrying 192 peripheral hydroxyls and exhibiting a molar mass of 446 kg · mol(-1) was obtained in this way. The chemical degradation of these dendritic scaffolds was next successfully accomplished under acidic conditions, forming linear PEO chains of low molar mass (≈2 kg · mol(-1)), as monitored by (1)H NMR, SEC, and MALDI-TOF mass spectrometry as well as by AFM.

Mass Chain Evaluation for A = 95

A full evaluation of the mass chain A = 95 has been done in the ENSDF format taking into account all the available data until June 2009. Excited states populated by in-beam nuclear reactions and by radioactive decay have been considered. The 'evp' editor, developed at the NNDC, has been used for the evaluation. This mass chain was last evaluated in 1993. Many new and improved data were reported since then. A total of 13 nuclei have been evaluated.

Interfacial Friction and Adhesion of Polymer Brushes

A bead-probe lateral force microscopy (LFM) technique is used to characterize the interfacial friction and adhesion properties of polymer brushes. Our measurements attempt to relate the physical structure and chemical characteristics of the brush to their properties as thin-film, tethered lubricants. Brushes are synthesized at several chain lengths and surface coverages from polymer chains of polydimethylsiloxane (PDMS), polystyrene (PS), and a poly(propylene glycol)-poly(ethylene glycol) block copolymer (PPG/PEG). At high surface coverage, PDMS brushes manifest friction coefficients (COFs) that are among the lowest recorded for a dry lubricant film (μ ≈ 0.0024) and close to 1 order of magnitude lower than the COF of a bare silicon surface. Brushes synthesized from higher molar mass chains exhibit higher friction forces than those created using lower molar mass polymers. Increased grafting density of chains in the brush significantly reduces the COF by creating a uniform surface of stretched chains with a decreased surface viscosity. Brushes with lower surface tension and interfacial shear stresses manifest the lowest COF. In particular, PDMS chains exhibit COFs lower than PS by a factor of 3.7 and lower than PPG/PEG by a factor of 4.7. A scaling analysis conducted on the surface coverage (σ) in relation to the fraction (ε) of the friction force developing from adhesion predicts a universal relation ε ~ σ(4/3), which is supported by our experimental data.

Nuclear Data Sheets for A = 127

The 1996 evaluation for the A=127 mass chain (1996Ki01) has been revised. The experimental results from various decays and reactions for the A=127 mass chain have been compiled and evaluated. The nuclides covered in this evaluation are from 127Ag to 127Nd. The data are summarized and presented, together with adopted level schemes.

Nuclear Data Sheets for A = 133

Evaluated nuclear structure and decay data for all nuclei within the A=133 mass chain are presented. The experimental data are evaluated and best values for level and gamma-ray energies, quantum numbers, lifetimes, gamma-ray intensities, and other nuclear properties are recommended. Inconsistencies and discrepancies that exist in the literature are noted. This work supersedes the earlier evaluation by S. Raab (1995Ra12), published in Nuclear Data Sheets 75, 491 (1995).

Role of Maltose Enzymes in Glycogen Synthesis by Escherichia coli

Mutants with deletion mutations in the glg and mal gene clusters of Escherichia coli MC4100 were used to gain insight into glycogen and maltodextrin metabolism. Glycogen content, molecular mass, and branch chain distribution were analyzed in the wild type and in ΔmalP (encoding maltodextrin phosphorylase), ΔmalQ (encoding amylomaltase), ΔglgA (encoding glycogen synthase), and ΔglgA ΔmalP derivatives. The wild type showed increasing amounts of glycogen when grown on glucose, maltose, or maltodextrin. When strains were grown on maltose, the glycogen content was 20 times higher in the ΔmalP strain (0.97 mg/mg protein) than in the wild type (0.05 mg/mg protein). When strains were grown on glucose, the ΔmalP strain and the wild type had similar glycogen contents (0.04 mg/mg and 0.03 mg/mg protein, respectively). The ΔmalQ mutant did not grow on maltose but showed wild-type amounts of glycogen when grown on glucose, demonstrating the exclusive function of GlgA for glycogen synthesis in the absence of maltose metabolism. No glycogen was found in the ΔglgA and ΔglgA ΔmalP strains grown on glucose, but substantial amounts (0.18 and 1.0 mg/mg protein, respectively) were found when they were grown on maltodextrin. This demonstrates that the action of MalQ on maltose or maltodextrin can lead to the formation of glycogen and that MalP controls (inhibits) this pathway. In vitro, MalQ in the presence of GlgB (a branching enzyme) was able to form glycogen from maltose or linear maltodextrins. We propose a model of maltodextrin utilization for the formation of glycogen in the absence of glycogen synthase.

Nuclear Data Sheets for A = 125

The 1999 evaluation for A = 125 mass chain (1999Ka26) has been revised using experimental results from decays and reactions. Adopted values for the level and decay properties are tabulated. Inconsistencies and discrepancies are noted.

Nuclear Data Sheets for A = 207

Evaluated nuclear structure and decay data for all nuclei within the A=207 mass chain are presented. The experimental data are evaluated and best values for level and gamma-ray energies, quantum numbers, lifetimes, gamma-ray intensities, and other nuclear properties are recommended. Inconsistencies and discrepancies that exist in the literature are noted. This work supersedes the earlier evaluation by M.J. Martin (1993Ma73), published in Nuclear Data Sheets 70, 315 (1993).

Twinkling Phenomena in Snap-Through Oscillators

Oscillatory behavior in a chain of masses connected by springs with continuous but nonmonotonic spring forces can be induced under quasistatic loading. An insight into the birth of this behavior is obtained from a single mass system. A bifurcation study shows the potential for equilibrium jumps between multiple equilibria. As such, the transients occurring under quasistatic loading do not converge to the static loading case. Transients during dynamic loading show sensitivity to the loading parameters.

Electrospray ionization Fourier transform mass spectrometric analysis of intact bikunin glycosaminoglycan from normal human plasma

A mixture of glycosaminoglycan (GAG) chains from a plasma proteoglycan bikunin was fractionated using native, continuous-elution polyacrylamide gel electrophoresis, and the resulting fractions were analyzed by electrospray ionization Fourier transform mass spectrometry (ESI FTMS). Molecular mass analysis of the intact GAG afforded information about the length and composition of GAG chains in the mixture. Ambiguity in the interpretation of the intact GAG mass spectra was eliminated by conducting an additional experiment in which the GAG chains of known molecular mass were treated with a GAG-degrading enzyme, chondroitinase ABC, and the digestion products were analyzed by ESI FTMS. The plasma bikunin GAG chains consisted predominantly of odd number of saccharides, although few chains consisting of even number of saccharides were also detected. Majority of the analyzed chains were tetrasulfated or pentasulfated and comprised by 29–41 monosaccharides.

Dietary fish oil alleviates soleus atrophy during immobilization in association with Akt signaling to p70s6k and E3 ubiquitin ligases in rats

Reduced muscle activity leads to impaired insulin signaling, which leads to loss of contractile proteins and muscle mass via the Akt pathway. Dietary fish oil rich in long chain n-3 polyunsaturated fatty acids has been shown to prevent insulin signaling resistance in skeletal muscle. This study was conducted to elucidate the protective effect of dietary fish oil on disuse-induced perturbations in insulin signaling and soleus muscle atrophy. To accomplish this, rats were fed a corn-oil- (control) or fish-oil-based diet for 2 weeks, and then subjected to hindlimb immobilization while still receiving the same diets. After 10 days of immobilization, the soleus muscle mass and myosin heavy chain level had markedly decreased; however, these losses were significantly suppressed in rats fed dietary fish oil, compared with the control group. Dietary fish oil nearly completely attenuated the disturbances in activation of the Akt and p70 S6 kinase proteins, as well as the gene expression of muscle-specific E3 ubiquitin ligases (muscle atrophy F-box and muscle RING finger 1). However, insulin receptor substrate 1 associated with the p85 subunit of phosphoinositide 3-kinase was not altered during immobilization. Dietary fish oil also inhibited alterations in the gene expression of cyclooxygenase-2 and inducible nitric oxide synthase, with no additional observation of oxidative stress. Collectively, these findings indicate that dietary fish oil prior to and during immobilization may alleviate the immobilization-induced soleus muscle atrophy, at least in part, via the Akt pathway through E3 ubiquitin ligases and p70s6k.

Nuclear Data Sheets for A = 121

The 2000 Nuclear Data Sheets for A = 121 by T. Tamura, with literature cutoff date of July 1,1999 has been updated. The experimental results from various decays and reactions for A=121 mass chain have been compiled and evaluated. The nuclides covered in this evaluation are from 121Rh to 121Pr. The data are summarized and presented, together with adopted level schemes.

Nuclear Data Sheets for A = 163

The available data from the various reaction and decay studies leading to nuclides having mass number A=163 have been reviewed. These data are summarized and presented, together with adopted level schemes and properties, for nuclides from Eu (Z=63) through Os (Z=76). 163Eu represents a new addition to these nuclides. Level structures are now known for 163Ta and 163W through high-spin studies and recoil-decay tagging techniques. Several radioactive decays in this mass chain are not known at all or poorly established. No β or γ-ray data are available for 163Re– 163W– 163Ta– 163Hf ε decay chain. Those for 163Hf– 163Lu– 163Yb ɛ decay chain and 163Eu– 163Gd– 163Tb β − decay chain are very sketchy. This evaluation is an update and revision of the previous one (2000Si01).

A study of the intermolecular branch frequency dependence of tie-chain concentration in single-site linear low-density polyethylene blown films by a new FTIR method

The relative concentrations of tie chains (TCs) in six single-site linear low-density polyethylene blown films (LLDPE) were measured using a polarized Fourier transform infrared (FTIR) technique along with a newly developed sample preparation strategy. Before the FTIR measurements, the films were first subjected to a tensile strain of 20% using a homemade appliance and then annealed at a temperature of 60 °C over a time period of 24 h to relax all nonTCs in the amorphous phase. The relative TC concentrations were inferred from the FTIR measurement of the orientation order of the amorphous chains in the stretched films. It is believed that a greater concentration of TCs leads to a higher orientation order for the amorphous chains. The results showed that the quantity of TCs is essentially determined by the chains with the appropriate branch frequency (∼12 branches per 1000 backbone carbons based upon the films used in this work), especially those of the high molar mass chains as formation of TCs requires suitable ethylene sequence lengths between branches. The dart impact strength of the films appeared to be positively related to the relative concentration of TCs; films with greater concentrations showed higher dart impact strength. No clear correlations were observed between the relative concentration of TCs and the tear resistance of the films. However, the TC concentration seems to be related to the magnitude of the difference between the transverse direction and machine direction tear resistance.

Effect of network structure on the stress–strain behaviour of endlinked PDMS elastomers

Endlinked poly(dimethylsiloxane) (PDMS) networks synthesized from telechelic precursor chains of different molar mass were prepared with varying volume fractions of non-reactive chains acting as solvent. Uniaxial extension and compression measurements were performed on these networks to investigate their stress–strain behaviour. The effect of the network structure and of solvent on the stress–strain behaviour is examined by controlling the extent of crosslinks and entanglements during the network synthesis. The master curve of the Rubinstein and Panyukov non-affine slip-tube (NAST) model provide an adequate fit to most of the extension and compression data. Furthermore, the crosslink and entanglement parameters of the NAST model ( G c and G e) are found to be in general in reasonable agreement with the 2 C 1 and 2 C 2 parameters of the Mooney–Rivlin continuum model applied to the extension data. For high molar mass precursor chains, the entanglement contribution to the modulus surpasses the crosslink contribution.

Microalbuminuria versus brain natriuretic peptide in cardiac hypertrophy of hypertensive rats

The objective of this study was to assess a possible link between microalbuminuria (MA), a major risk factor of the cardiorenal syndrome and the brain natriuretic peptide (BNP), a marker of cardiac hypertrophy. Two kidney-one clip (2K-1C) renovascular hypertension was induced in 24 male Wistar rats (weighing 220-250 g). Rats were randomized into four groups for 8 weeks: Sham, not treated; Bos, treated with bosentan; Cap, treated with captopril; Bos/Cap, treated with both drugs. Blood pressure, plasma BNP and transforming growth factor beta1 (TGF-β1) concentrations, microalbuminuria and creatininemia as well as cardiac mass, BNP, alpha- and beta-myosin heavy chain (MHC) gene expression and kidney histology were determined. Following stenosis, Sham rats developed hypertension (p < 0.001), an increase in BNP (p < 0.05) and TGF-β1 (p < 0.005) concentrations, creatinine levels (p < 0.001), and urinary albumin (p < 0.001). Under drug treatment, decreases in blood pressure (p < 0.001), creatinine levels (p < 0.05), plasma TGF-β1 (p < 0.005) and BNP (p < 0.05) concentrations, were concomitant with the absence of MA which was significantly correlated with reductions in cardiac mass (p < 0.05) and hypertrophy markers (BNP and β-MHC gene expression) (p < 0.005) as well as in renal fibrosis. These findings suggest a potential link between microalbuminuria evolution and BNP as well as a possible effect of microalbuminuria-lowering therapy on halting the progression, or even inducing the regression of cardiac hypertrophy.