Split Off Research Articles

Spin-Wave Excitations and Energy Gap in Quasi-One-Dimensional Organic Polymer Ferromagnets11The project supported by National Natural Science Foundation of China

Based on a theory model proposed for organic ferromagnets, the spin configuration and spin-wave excitations in quasi-one-dimensional organic polymer ferromagnets are studied. The results show that: 1) Owing to the unpaired electrons at side free-radicals, the degeneracy of the spin-wave will be removed, the lower branch of the spin-wave excitations will split off into two branches, and it shows ferromagnetic characters; 2) The anisotropic interactions between the unpaired electrons at side free-radicals will make an energy gap appear between the ground state and the lowest excited state.

Color of pure and alkali-doped cerium sulfide: A local-density-functional study.

The electronic structure and mechanisms for the optical excitations of pure and Na-doped \ensuremath{\gamma}-${\mathrm{Ce}}_{2}$${\mathrm{S}}_{3}$ have been investigated using first-principles local-density-functional theory. The energy-band structures from augmented-spherical-wave calculations indicate that the S 3p\ensuremath{\rightarrow}Ce 5d interband transitions give rise to absorptions in the ultraviolet, whereas the observed red color of \ensuremath{\gamma}-${\mathrm{Ce}}_{2}$${\mathrm{S}}_{3}$ is associated with localized Ce 4f\ensuremath{\rightarrow}5d excitations. The cationic vacancies in \ensuremath{\gamma}-${\mathrm{Ce}}_{2}$${\mathrm{S}}_{3}$ (which is derived from the cubic ${\mathrm{Th}}_{3}$${\mathrm{P}}_{4}$ structure) lead to the formation of vacancy bands, which are split off from the top of the S 3p valence band. Na doping removes these vacancy bands and homogenizes the band edges of the valence and conduction bands. As a consequence, the onset of the f\ensuremath{\rightarrow}d transitions is shifted slightly to larger energies and becomes sharper, which is consistent with an observed change in the color of \ensuremath{\gamma}-${\mathrm{Ce}}_{2}$${\mathrm{S}}_{3}$ from maroon to red-orange upon doping with Na. \textcopyright{} 1996 The American Physical Society.

Relationship between interleukin-8 and neutrophil adhesion molecules in rheumatoid arthritis

To evaluate the role of interleukin-8 (IL-8) on the activation of neutrophils in rheumatoid arthritis (RA), we measured IL-8 and the adhesion molecules, L-selectin (CD62L), CD1 1b and CD18, on neutrophils in paired peripheral blood and synovial fluid of RA patients. Synovial fluid IL-8 levels were significantly increased compared to peripheral blood. L-selectin was split off and CD1 1b and CD 18 were upregulated on neutrophils in the synovial fluid. A positive correlation occurred between the IL-8 concentration and CD18 or CD1 1b densities on neutrophils in the synovial fluid (r = 0.75, P < 0.005 and r = 0.60, P < 0.05, respectively). Peripheral blood neutrophils of the patients were desensitised with IL-8 in vivo, as shown by the significantly lower L-selectin shedding after in vitro IL-8 stimulation: 1.6 times decrease for patients vs 3.2 for controls (P < 0.05). In conclusion, these results add further evidence for the role of IL-8 in the activation of neutrophils in RA.

XLVIII. Synthese und struktur der ersten neutralen Tris(allyl) lanthanoid-komplexe La( η3-C 3H5) 3 · 1,5 Dioxan und Nd( η3-C 3H 5) 3 · Dioxan und ihre Eignung als “single site” -Katalysatoren für die stereospezifische Butadienpolymerisation

The title complexes are synthesized from the tetrakis(allyl)lanthanide(III) complexes Li[Ln(C 3H 5) 4] · 1,5 dioxane (Ln = La or Nd) by allyl lithium abstraction with BEt 3 in dioxane. The compounds were characterized by elemental analysis, by IR, 1H and 13C NMR spectroscopy and also by X-ray crystal structure analysis. In both complexes the three allyl anions are η 3 coordinated. By the coordination of dioxane in the case of lanthanum the dimeric structure [{La( η 3-C 3H 5) 3 ( η 1-C 4H 8O 2)} 2( μ-C 4H 8O 2)] ( 1) with neodymium a polymeric structure [Nd( η 3-C 3H 5) 3 ( μ-C 4H 8O 2)] n ] ( 2) is formed. The dioxane can be split off easily at 50°C without further decomposition. Compounds 1 and 2 catalyze the 1,4- trans polymerization of butadiene in toluene with high selectivity. By addition of proper Lewis acids, such as Et 2AlCl, EtAlCl 2 or (MeAlO) x , catalysts for the 1,4- cis polymerization are obtainable. The results allow first conclusions on the mechanism of the lanthanide-complex-catalyzed butadiene polymerization.

REVISION OF THE GENUSACHNANTHES SENSU LATO. PSAMMOTHIDIUM, A NEW GENUS BASED ONA. MARGINULATUM

This paper concerns a revision of some Achnanthes subsection Achnanthidium or genus Achnanthidium species, common on sand grains in freshwaters. The taxonomy of the species required a scanning electronmicroscopy study of new and old material and examination of some type material. The SEM study has provided illustrations of 18 species, some previously unpublished. A new genus Psammothidium is split off Achnanthidium Kutz. and 25 new combinations made for species and infraspecific taxa. One species Psammothidium bristolicum Bukht. is also described from the River Spey, Scotland. Short comments are provided to assist in the identification of each taxon.

‘With healing in her wings…’: Integration and repair in a self-destructive adolescent

Abstract This paper describes certain Jungian concepts related to integration and repair. Fundamental to this is Jung's concept of the self, which Fordham has made the basis of his model of development. To Jung's notion of the self as an integrator and organizer of experience, Fordham has added the idea that the self divides up, or deintegrates. Three corollaries of Fordham's model, pertaining to whole and part objects and the depressive position, are amplified through infant studies. Clinical material from the treatment of a pigeon-phobic adolescent is presented, which attempts to demonstrate that a significant part of what the phobia represented was an infantile state of projective and introjective identification with an anxious mother. Treatment facilitated actions of the self that contributed to the integration of the experiences represented by the pigeons, so that what had been split off became a deintegrate capable of being reintegrated. The focus of this paper is on the developmental as well as the...

The splitting between separate and symbiotic stätes of the self in the psychodynamic of schizophrenia

Abstract We hypothesize that, in the structure of the psychotic self, there is a disintegration between the symbiotic and separate states of the self, of which the patient is painfully aware: to use a metaphor, the light in the schizophrenic self is split: at times it is only in wave form, energy (the patient is living in disintegrated symbiosis), at others it is only matter, corpuscular (the patient is living in disintegrated separation); unfortunately, the wave and the particle are unable to produce a unitary phenomenon: the light becomes two entities. Sometimes we see the psychotic living symbiotically, we feel him to be very close to us, he tells us: “I am the moon, the sun, the universe. I am you”. At other times the patient is in his separate self but, as he is split off from the symbiotic self, his separation is extreme, it is autistic solitude: “nothing exists apart from me: the sun, the moon, the universe, are meaningless shadows which I cannot distinguish …, you are light-years away from me … yo...

Theory of exciton-vibrational dynamics in molecular dimers

Abstract The exciton transfer in a molecular dimer embedded in a condensed medium is investigated theoretically. In order to include coherent vibrational dynamics a single effective mode per monomer is split off from the whole set of vibrational degrees of freedom of the dimer and the environment. The remaining modes are treated as a heat bath. To study the dissipative exciton transfer dynamics the density matrix formalism is applied. Choosing an appropriate exciton-vibrational basis set with respect to the two effective modes the theory is formulated in the related state representation. The general approach is applied to the exciton motion in a chlorophyll a / b dimer of the light-harvesting complex of the photosystem II of higher plants. The complex dynamic behavior following an ultrafast optical excitation in the absorption region of the chlorophyll b monomer is studied in detail.

The role of nickel in Si(001) roughening

The role of Ni impurities on the structure of the Si(001)-(2 × 1) surface has been investigated by statistically comparin STM patterns with Auger spectra. Characteristic reconstructed local structures (“split off dimers” and “vacancy channels”) are observed for different surface concentrations of Ni as measured by Auger electron spectroscopy, and it is shown that the STM image provides a high sensitivity to Ni. For high levels of Ni contamination, long range roughening of the Si(001) surface is observed resulting in more than 50 Å corrugation and loss of atomic structure as detected by the STM. Crystal support cleaning procedures and crystal annealing procedures have been devised permitting Si(001) crystals to be repeatedly heated over long time periods without undergoing surface contamination or macroscopic roughening.

Determining divergence times of the major kingdoms of living organisms with a protein clock.

Amino acid sequence data from 57 different enzymes were used to determine the divergence times of the major biological groupings. Deuterostomes and protostomes split about 670 million years ago and plants, animals, and fungi last shared a common ancestor about a billion years ago. With regard to these protein sequences, plants are slightly more similar to animals than are the fungi. In contrast, phylogenetic analysis of the same sequences indicates that fungi and animals shared a common ancestor more recently than either did with plants, the greater difference resulting from the fungal lineage changing faster than the animal and plant lines over the last 965 million years. The major protist lineages have been changing at a somewhat faster rate than other eukaryotes and split off about 1230 million years ago. If the rate of change has been approximately constant, then prokaryotes and eukaryotes last shared a common ancestor about 2 billion years ago, archaebacterial sequences being measurably more similar to eukaryotic ones than are eubacterial ones.

Innovation via new ventures as a conversion strategy for the Chinese defense industry

AbstractThe Chinese economic system is undergoing a transformation from a centrally planned to a market economic system. The process is difficult for at least two reasons: civilian producers lack innovative capability; R&amp;D intensive defense firms need to shift some of their production to civilian markets. The latter requires management innovations that are difficult to master under present‐day conditions. Based on the system characteristics of the Chinese defense industry we discuss its problems in managing technological innovation. We conclude that to facilitate the conversion process to civilian markets Chinese defense firms should be encouraged to split off those activities that are aimed at civilian markets.

Preparation of polymer-bound trityl-hydrazines and their application in the solid phase synthesis of partially protected peptide hydrazides

Polymer-bound N-tritylhydrazines 4 were easily prepared by reacting polymeric tritylchlorides 3 with hydrazine. Subsequently, compounds 4 have been successfully applied to the solid phase synthesis of partially protected peptide hydrazides using 1-hydroxybenzotriazolyl esters of Fmoc- or Trt-amino acids. The synthesized peptide hydrazides can be quantitatively split off from the resins by mild acidic treatment, while the benzyl- and tert-butyl protecting groups remain unaffected.

Genetic diversity and phylogenetic relationships among the annual Cicer species as revealed by isozyme polymorphism

There are few estimates of genetic variability within and among populations of the nine annual Cicer species and for the wild species this information is based on few accessions. The present study was undertaken to examine genetic variation within and between annual Cicer species. One hundred and thirty-nine accessions of nine annual Cicer species were used for electrophoretic analysis at ICARDA. High levels of polymorphism in all eight wild annual Cicer species was found. This is in contrast to earlier research which had shown high polymorphism only in C. reticulatum. Cicer reticulatum had the highest proportion of polymorphic loci. However, for the cultigen, among 14 loci assayed, only two were polymorphic, ADH and PGD2. The nine species formed four phylogenetic groups based on the neighbor-joining method. The first group comprised C. arietinum, C. Reticulatum and C. echinospermum, the second C. bijugum, C. judaicum and C. pinnatifidum, the third C. chorassanicum and C. yamashitae; and the fourth group consisted of one species, C. cuneatum. The phylogenetic tree developed from the neighbor-joining technique illustrated that C. reticulatum is the probable progenitor of C. arietinum and that C. echinospermum split off from a common ancestor at an earlier stage in the evolutionary history of Cicer. Genetic diversity data showed that the greatest diversity was within C. reticulatum and the lowest with the cultigen, C. arientinum. With the exception of C. reticulatum, genetic diversity increased with genetic distance from the cultigen. Little geographic variation in genetic diversity was found.

Extracellular Polysaccharides of Candida mucifera Strain CCY 29-170-1

Extracellular polysaccharides produced by Candida mucifera strain CCY 29-170-1 in a liquid medium containing malt extract have been investigated by chemical, enzymic, and NMR spectroscopic methods. Mild acid hydrolysis of the native polysaccharide, followed by enzymic treatments of the polymeric residue, afforded two low-molecular neutral homopolysaccharides. The dominant one was a (1→4)-α-D-glucan with approximately each fifth chain unit branched on O-6. The other polysaccharide was a linear (1→4)-β-D-xylan. The results of linkage analysis evidenced that, originally, some xylan-chain units bore on O-3 substituents, which were split off during the hydrolytic steps.

Chromosome differentiation in the subantarctic Bovichtidae species Cottoperca gobio (Günther, 1861) and Pseudaphritis urvillii (Valenciennes, 1832) (Pisces, Perciformes)

A cytogenetic study on the bovichtid species Cottoperca gobio from the Magellan Strait and Pseudaphritis urvillii from Tasmania showed both species have a plesiomorphic number of chromosomes (2n=48). However, C.gobio has a more conservative karyotype composed entirely of acrocentric chromosomes (Fundamental Number=48); the presence of two metacentric pairs in P. urvilli (FN=52) makes this species karyologically more derived. The differences in the number of chromosomal arms, and the chromosomal location of the nucleolar organizer regions indicate karyological divergence in the two separating stocks from which C.gobio and P.urvillii originated. During the diversification of this notothenioid family, probably coincident with the fragmentation of Gondwana, the stock that split off with the Australian Plate gave rise to the Tasmanian species and experienced more chromosomal modifications than the stock from which C. gobio is derived. The pattern of constitutive heterochromatin suggests a possible homology between a pair of chromosomes in bovichtids and other notothenioids.

Synthesis of bi(cyclohexasilanyl) derivatives

Starting from 1,3- or 1,4-diphenyldecamethylcyclohexasilane, one phenyl group can be split off selectively by action of trifluoromethanesulfonic acid. The syntheses of some new mixed substituted cyclohexasilanes 1,3- and 1,4-PhSi 6Me 10X (X = CF 3SO 3, H, Cl or Br) are reported. By reaction of 1,3- and 1,4-PhSi 6Me 10Cl with undecamethylcyclohexasilanyl potassium, novel monophenylated bi(cyclohexasilanyl) derivatives are obtained. The preparation of the corresponding monochlorinated derivatives is also reported.

Dehalogenation of 4-chlorobenzoate

Pseudomonas sp. CBS3 is capable of growing with 4-chlorobenzoate as sole source of carbon and energy. The removal of the chlorine of 4-chlorobenzoate is performed in the first degradation step by an enzyme system consisting of three proteins. A 4-halobenzoate-coenzyme A ligase activates 4-chlorobenzoate in a coenzyme A, ATP and Mg2+ dependent reaction to 4-chlorobenzoyl-coenzyme A. This thioester intermediate is dehalogenated by the 4-chlorobenzoyl-coenzyme A dehalogenase. Finally coenzyme A is split off by a 4-hydroxybenzoyl-CoA thioesterase to form 4-hydroxybenzoate. The involved 4-chlorobenzoyl-coenzyme A dehalogenase was purified to apparent homogeneity by a five-step purification procedure. The native enzyme had an apparent molecular mass of 120,000 and was composed of four identical polypeptide subunits of 31 kDa. The enzyme displayed an isoelectric point of 6.7. The maximal initial rate of catalysis was achieved at pH 10 at 60 degrees C. The apparent Km value for 4-chlorobenzoyl-coenzyme A was 2.4-2.7 microM. Vmax was 1.1 x 10(-7) M sec-1 (2.2 mumol min-1 mg-1 of protein). The NH2-terminal amino acid sequence was determined. All 4-halobenzoyl-coenzyme A thioesters, except 4-fluorobenzoyl-coenzyme A, were dehalogenated by the 4-chlorobenzoyl-CoA dehalogenase.

Thermolysis of poly(diaryl diazosulfide)s

AbstractPoly(diaryl diazosulfide)s and model diaryl diazosulfides of the general structure aryl‐NNS‐aryl' are tested for their thermostability. Thermolysis in solution is followed by means of UV spectroscopy. At the beginning of the decay most model diazosulfides follow first‐order kinetics, but show an acceleration of the decay rate in the further course of the thermolysis. In contrast to the models the decomposition of the corresponding polymers cannot be described by first‐order kinetics, except one example (P 1).Thermogravimetry studies show weight losses of 8–12% in the range between 80 and 150°C depending on the structure of the models and polymeric diazosulfides. These values correspond with the content of azo function in these compounds, therefore it is assumed that nitrogen is split off under these reaction conditions.

Influence of the core hole interaction on the dichroism and spin polarization of the 3s angular resolved photoelectron spectra of transition metals in the surface region

Core photoelectron diffraction is considered to investigate the geometrical structure of surface layers. Due to the chemical shift of the core level the spectrum can be split off into a bulk and a surface contribution. Besides this chemical shift there is an additional shift due to the influence of the core hole potential and of the core hole spin. This shift includes an exchange splitting and a configuration interaction which changes the angular momentum character of the final state. The influence of this configuration interaction on the shape of the angular resolved photoelectron spectrum is calculated for the 3s spectrum of Fe. It is shown that the difference is more pronounced in the circular dichroism of the spectrum than in the total spectrum. The dichroism of the spin-up and spin-down spectrum, respectively, is a measure for the strength of the configuration interaction. Thus, it allows to make a distinction between the chemical shift at the surface and the influence of the core hole charge.

H/D exchange reaction at graphitic CH groups by thermal H(D) atoms

Ultrathin C:H films were produced by hydrocarbon ion-beam deposition at Pt(100) single crystal surfaces covered with a monolayer of graphite. Temperature and thermal H(D) impact induced effects were studied with HREELS and AES. C:H film surfaces which exhibit only aromatic sp2 CH groups, HC=CH, get deuterated at a temperature independent rate with an apparent cross section of about 1.3 Å2. After sufficient D exposure at 350 K eventually only sp3 CHD groups cover the surface as deduced from the C-H(D) stretch mode structure in HREEL spectra. At 600 K the radicalic intermediate surface HDC-CH· groups generated by D addition to sp2 groups can split off H or D through thermal activation, thereby transforming the group back to sp2. Thereafter in HREEL spectra both, sp2 and sp3 contributions were measured in the C-H(D) stretch frequency regions. Due to a kinetic isotope effect the surface H is preferentially removed by this reaction. C:H film surfaces under impact of H atoms erode chemically via thermally activated release of hydrocarbon species. As expected, an isotope effect was also observed in the erosion reaction proceeding from the radicalic intermediate.