bluuebunny/crossref_metadata_2025 huggingface dataset:
Fine structure of the spermatheca and of the accessory glands inOrchesella villosa(Collembola, Hexapoda)
Authors: Dallai Romano , Zizzari Zaira Valentina , Fanciulli Pietro Paolo
Published: December 2007

The spermatheca and the accessory glands of the collembolanOrchesella villosaare described for the first time. Both organs exhibit ultrastructural differences, according to the time of the intermolt in which the specimens were observed. A thick cuticular layer lines the epithelial cells of the accessory glands. In the reproductive phase, they are involved in secretory activity; a moderately dense secretion found in the apical cell region opens into the gland lumen. Cells with an extracellular cistern are intermingled with the secretory cells. These cells could be involved in fluid secretion, with the secretory product opening into the cistern which is filled with an electron‐transparent material. After the reproductive phase, the gland lumen becomes filled with a dense secretion. The accessory gland secretion may play a protective role towards the eggs. The spermatheca is located between the accessory glands; its epithelium is lined by a thin cuticle forming spine‐like projections into the lumen and consists of cells provided with an extracellular cistern. Secretory cells, similar to those seen in the accessory glands, are missing. Cells with a cistern could be involved in the production of a fluid secretion determining sperm unrolling and sperm motility. J. Morphol., 2008. © 2007 Wiley‐Liss, Inc.
Myogenesis in Aplysia californica (Cooper, 1863) (Mollusca, Gastropoda, Opisthobranchia) with special focus on muscular remodeling during metamorphosis
Authors: Wollesen Tim , Wanninger Andreas , Klussmann‐Kolb Annette
Published: December 2007

To date only few comparative approaches tried to reconstruct the ontogeny of the musculature in invertebrates. This may be due to the difficulties involved in reconstructing three dimensionally arranged muscle systems by means of classical histological techniques combined with light or transmission electron microscopy. Within the scope of the present study we investigated the myogenesis of premetamorphic, metamorphic, and juvenile developmental stages of the anaspidean opisthobranch Aplysia californica using fluorescence F‐actin‐labeling in conjunction with modern confocal laser scanning microscopy. We categorized muscles with respect to their differentiation and degeneration and found three true larval muscles that differentiate during the embryonic and veliger phase and degenerate during or slightly after metamorphosis. These are the larval retractor, the accessory larval retractor, and the metapodial retractor muscle. While the pedal retractor muscle, some transversal mantle fibers and major portions of the cephalopedal musculature are continued and elaborated during juvenile and adult life, the buccal musculature and the anterior retractor muscle constitute juvenile/adult muscles which differentiate during or after metamorphosis. The metapodial retractor muscle has never been reported for any other gastropod taxon. Our findings indicate that the late veliger larva of A. californica shares some common traits with veligers of other gastropods, such as a larval retractor muscle. However, the postmetamorphic stages exhibit only few congruencies with other gastropod taxa investigated to date, which is probably due to common larval but different adult life styles within gastropods. Accordingly, this study provides further evidence for morphological plasticity in gastropod myogenesis and stresses the importance of ontogenetic approaches to understand adult conditions and life history patterns. J. Morphol., 2008. © 2007 Wiley‐Liss, Inc.
Female‐specific increase in primordial germ cells marks sex differentiation in threespine stickleback (Gasterosteus aculeatus)
Authors: Lewis Zachary R. , McClellan Maryanne C. , Postlethwait John H. , Cresko William A. , Kaplan Robert H.
Published: December 2007

Gonadal sex differentiation is increasingly recognized as a remarkably plastic process driven by species‐specific genetic or environmental determinants. Among aquatic vertebrates, gonadal sex differentiation is a frequent endpoint in studies of endocrine disruption with little appreciation of underlying developmental mechanisms. Work in model organisms has highlighted the diversity of master sex‐determining genes rather than uncovering any broad similarities prompting the highly conserved developmental decision of testes versus ovaries. Here we use molecular genetic markers of chromosomal sex combined with traditional histology to examine the transition of the bipotential gonads to ovaries or testes in threespine stickleback (Gasterosteus aculeatus). Serially‐sectioned threespine stickleback fry were analyzed for qualitative and quantitative indications of sexual differentiation, including changes in gonadal morphology, number of germ cells and the incidence of gonadal apoptosis. We show that threespine stickleback sampled from anadromous and lacustrine populations are differentiated gonochorists. The earliest sex‐specific event is a premeiotic increase in primordial germ cell number followed by a female‐specific spike in apoptosis in the undifferentiated gonad of genetic females. The data suggest that an increase in PGC number may direct the undifferentiated gonad toward ovarian differentiation. J. Morphol., 2008. © 2007 Wiley‐Liss, Inc.
Objective evidence of sleep disturbance in women with posttraumatic stress disorder
Authors: Calhoun Patrick S. , Wiley Matt , Dennis Michelle F. , Means Melanie K. , Edinger Jack D. , Beckham Jean C.
Published: December 2007

Although sleep disturbance is considered a hallmark of posttraumatic stress disorder (PTSD), objective evidence for sleep disturbance in patients with PTSD has been equivocal. The goal of the current investigation was to objectively examine sleep disturbance among women with PTSD in their home environment. Women with PTSD (n = 30) and a control group (n = 22) completed three nights of actigraphy monitoring. Results from actigraphy indicated that women with PTSD had poorer sleep efficiency, increased sleep latency, and more restless sleep. Actigraphy measures were moderately correlated with self‐report sleep‐log data, but were unrelated to scores on the Pittsburgh Sleep Quality Index. The current study provides evidence that women with PTSD have objectively measured sleep disturbance in their normal environment at home. Disturbed sleep may have important implications for the health and well‐being of individuals with PTSD.
Psychometric analysis and refinement of the connor–davidson resilience scale (CD‐RISC): Validation of a 10‐item measure of resilience
Authors: Campbell‐Sills Laura , Stein Murray B.
Published: December 2007

Resilience refers to an individual's ability to thrive despite adversity. The current study examined the psychometric properties of the Connor–Davidson Resilience Scale (CD‐RISC). Three undergraduate samples (ns < 500) were used to determine the factor structure of the CD‐RISC. The first two samples were used to conduct exploratory factor analysis (EFA), and the third was used for confirmatory factor analysis. The EFA showed that the CD‐RISC had an unstable factor structure across two demographically equivalent samples. A series of empirically driven modifications was made, resulting in a 10‐item unidimensional scale that demonstrated good internal consistency and construct validity. Overall, the 10‐item CD‐RISC displays excellent psychometric properties and allows for efficient measurement of resilience.
Posttraumatic stress disorder and smoking relapse: A theoretical model
Authors: Cook Jessica W. , McFall Miles M. , Calhoun Patrick S. , Beckham Jean C.
Published: December 2007

Posttraumatic stress disorder (PTSD) is associated with a high prevalence of cigarette smoking, heavy cigarette consumption, and low cessation rates. To date, little is known about mechanisms impeding smoking cessation among this recalcitrant group of smokers. An important first step in improving smoking cessation treatment efficacy is the assessment of knowledge about mechanisms pertinent to relapse. This theoretical study addresses the gap in the literature regarding factors potentially influencing smoking relapse among individuals with PTSD. Mechanisms reviewed that may be particularly relevant to smoking relapse among PTSD smokers include negative affect, positive affect, attention, anxiety sensitivity, distress tolerance, and self‐efficacy. Treatment implications as well as methodological advances that may be relevant to examining the proposed relapse model are discussed.
Posttraumatic stress and depression symptoms in soldiers returning from combat operations in Iraq and Afghanistan
Authors: Lapierre Coady B. , Schwegler Andria F. , LaBauve Bill J.
Published: December 2007

The purpose of the present research was to identify rates of posttraumatic stress and depressive symptoms in soldiers returning from war. During reintegration training, U.S. Army soldiers, who recently returned from a 12‐month deployment to either Iraq (Operation Iraqi Freedom, n = 2,275) or Afghanistan (Operation Enduring Freedom, n = 1,814), completed study materials. Surveys assessed self‐reported levels of depression, posttraumatic stress, and life satisfaction. Results indicated that approximately 44% of soldiers who volunteered to participate self‐reported clinically significant levels of depressive symptoms, posttraumatic stress symptoms, or both. Although assessing symptoms and not disorders, these results suggest a potentially high rate of mental health concerns in soldiers immediately after returning from a combat zone. Further research should examine the utility of broad scale interventions.
Guilt and giving: A process model of empathy and efficacy
Authors: Basil Debra Z. , Ridgway Nancy M. , Basil Michael D.
Published: December 2007

This research develops a model of consumer response to charity appeals. Using the Extended Parallel Process Model from the fear appeal literature as a foundation, the current model proposes that empathy and self‐efficacy generate guilt and reduce maladaptive responses, which, in turn, shapes donation intention. The results demonstrate that the impact of empathy on charitable donation intention is fully mediated by guilt and maladaptive responses. The impact of self‐efficacy is partially mediated by guilt and maladaptive responses. Therefore, both empathy and self‐efficacy determine whether guilt or maladaptive responses result. This model clarifies the process through which guilt appeals operate, by identifying the roles of empathy and self‐efficacy. © 2008 Wiley Periodicals, Inc.
Activator protein 1‐mediated expression of monocyte chemoattractant protein 1 in cultured rat luteal cells
Authors: Nagaosa Kaz , Aikoshi Izumi , Hasegawa Yuzuru , Nakanishi Yoshinobu
Published: December 2007

We have proposed that luteal cells undergo apoptosis‐dependent phagocytosis by invading monocyte‐derived macrophages in regressive corpora lutea of the rat. Accumulation of monocytes/macrophages seems to be mediated by monocyte chemoattractant protein 1 (MCP‐1) or CCL2, because apoptosis and the production of MCP‐1 mRNA occur simultaneously, but in different luteal cells, in a manner dependent on nuclear factor κB (NF‐κB). In this study, we determined the mechanisms underlying the induction of these two events using primary cultures of rat luteal cells. We found that the activity of the transcription factor activator protein 1 (AP‐1) increased during culturing concomitantly with an increase of MCP‐1 mRNA. The increase of MCP‐1 mRNA was abolished when cultures were maintained in the presence of an inhibitor of either AP‐1 or c‐Jun amino‐terminal kinase (JNK) that phosphorylates and activates c‐Jun, a subunit of AP‐1. Furthermore, the presence of an inhibitor of NF‐κB abrogated an increase in the activity of both AP‐1 and JNK. In contrast, the induction of apoptosis in cultured luteal cells required the action of JNK but appeared to be independent of AP‐1. This may explain why apoptosis and MCP‐1 mRNA production are concomitantly but differentially induced in distinct luteal cells. We therefore suggest the following signaling pathways for the induction of apoptosis and mcp‐1 gene expression during involution of the corpus luteum; NF‐κB's actions lead to the activation of JNK, and the active JNK, at one side, stimulates mcp‐1 gene transcription by activating AP‐1 and, at the other side, induces apoptosis. Mol. Reprod. Dev. 75: 1077–1084, 2007. © 2007 Wiley‐Liss, Inc.
Ethylene polymerization by sterically and electronically modulated Ni(II) α‐diimine complexes
Authors: Bahuleyan Bijal Kottukkal , Son Gi Wan , Park Dae‐Won , Ha Chang‐Sik , Kim Il
Published: December 2007

A series of highly active ethylene polymerization catalysts based on bidendate α‐diimine ligands coordinated to nickel are reported. The ligands are prepared via the condensation of bulky ortho‐substituted anilines bearing remote push–pull substituents with acenaphthenequinone, and the precatalysts are prepared via coordination of these ligands to (DME)NiBr2 (DME = 1,2‐dimethoxyethane) to form complexes having general formula [ZN = C(An)‐C(An) = NZ]NiBr2 [Z = (4‐NH2‐3,5‐C6H2R2)2CH(4‐C6H4Y); An, acenaphthene quinone; R, Me, Et, iPr; Y = H, NO2, OCH3]. When activated with methylaluminoxane (MAO) or common alkyl aluminiums such as ethyl aluminium sesquichloride (EAS) all catalysts polymerize ethylene with activities exceeding 107 g‐PE/ mol‐Ni h atm at 30 °C and atmospheric pressure. Among the cocatalysts used EAS records the best activity. Effects of remote substituents on ethylene polymerization activity are also investigated. The change in potential of metal center induced by remote substituents, as evidenced by cyclic voltammetric measurements, influences the polymerization activity. UV–visible spectroscopic data have specified the important role of cocatalyst in the stabilization of nickel‐based active species. A tentative interpretation based on the formation of active and dormant species has been discussed. The resulting polyethylene was characterized by high molecular weight and relatively broad molecular weight distribution, and their microstructure varied with the structure of catalyst and cocatalyst. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 1066–1082, 2008
Synthesis of semitelechelic POSS‐polymethacrylate hybrids by thiol‐mediated controlled radical polymerization with unusual thermal behaviors
Authors: Kotal Atanu , Si Satyabrata , Paira Tapas K. , Mandal Tarun K.
Published: December 2007

We have developed an efficient and versatile method for the synthesis of polyhedral oligomeric silsesquioxanes (POSS)‐polymethacrylate hybrids, such as POSS‐poly(methyl methacrylate) (POSS‐PMMA), POSS‐poly(ethyl methacrylate) (POSS‐PEMA), and POSS‐poly(benzyl methacrylate) (POSS‐PBzMA) of controllable molecular weights and low polydispersities by thiol‐mediated radical polymerization at elevated temperature (100 °C). By tuning the reactant concentrations and degree of polymerization of the grafted polymethacrylate chains, POSS content in these hybrid materials could be varied. MALDI‐TOF‐MS analysis of the hybrid molecule shows that the nanoscale POSS moiety is connected to the end of polymethacrylate chain through the sulfur atom bridge. These hybrid materials were further characterized using various techniques such as FTIR, XRD, NMR, TGA, and DSC. In all synthesized hybrids, the incorporation of POSS moiety at the end of polymethacrylate chain resulted in the decrease of glass transition temperature (Tg) compared to that of neat polymethacrylates of comparable molecular weights. Surprisingly, POSS‐PMMA hybrids only with relatively high POSS content (∼ 10 and 16 wt %) showed physical aging behavior as reveled by DSC study. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 1111–1123, 2008
Ranking the affinity of aromatic residues for carbon nanotubes by using designed surfactant peptides
Authors: Xie Hui , Becraft Eric J. , Baughman Ray H. , Dalton Alan B. , Dieckmann Gregg R.
Published: December 2007

A series of surfactant peptides were created to evaluate the affinity of aromatic AAs for single‐walled carbon nanotubes in the absence of complications from peptide folding or self‐association. Each surfactant peptide has a lipidlike architecture, with two Lys residues at the C‐terminus as a hydrophilic head, five Val residues to form a hydrophobic tail, and the testing AA at the N‐terminus. Raman and CD spectroscopic studies reveal that the surfactant peptides have a large unordered structural component which is independent of peptide concentration, suggesting that the peptides undergo minimal association under experimental conditions, thus removing this interference from interpretation of the peptide/carbon nanotube interactions. A lack of peptide self‐association is also indicated by sedimentation equilibrium ultracentrifugation results. Optical spectroscopy of the peptide/carbon nanotube dispersions indicate that among the three aromatic AAs, tryptophan has the highest affinity for carbon nanotubes (both bundled and individual states) when incorporated into a surfactant peptide, while the Tyr‐containing peptide is more selective for individual carbon nanotubes. Phe has the lowest overall affinity for carbon nanotubes. Raman spectra of dispersions made with SPF, SPY and SPW display similar types of nanotubes dispersed, although differences in the relative nanotube populations are observed by optical spectroscopy. Copyright © 2007 European Peptide Society and John Wiley & Sons, Ltd.
Case study using the Los Angeles tall buildings structural design council guidelines: 40‐storey concrete core wall building
Authors: Zekioglu Atila , Willford Michael , Jin Limin , Melek Murat
Published: December 2007

Los Angeles Tall Building Design Council (LATBDC) 2005 guidelines for analysis and design of tall buildings are utilized for the design of a 40 storey tall reinforced concrete building located in downtown Los Angeles. The case study structure is a 415 feet tall reinforced concrete residential building with 118 feet by 96 feet plan area. Lateral load carrying system of the building is bearing walls coupled with 32 to 60 inches deep spandrel beams. Gravity system consists of 8″ thick post‐tensioned concrete flat slabs resting on reinforced concrete gravity columns and bearing walls. Linear and nonlinear dynamic analysis procedures were followed using 475 and 2,475 year return period seismic events respectively. Design of core wall segments and spandrel beams connecting the segments together were controlled by both of these seismic hazard levels and analysis procedures. Nonlinear dynamic analysis of the 40 storey building showed inelastic flexural response at the spandrel beams over the building height in addition to the first few levels of the core wall segments. As intended, recorded component deformations were within the collapse prevention performance limits set by FEMA 356. The case study results highlight a significant limitation for Step 2 (Life Safety for DBE) to demonstrate achievement of ‘life safety’. Copyright © 2007 John Wiley & Sons, Ltd.
Prediction of birth weight by fetal crown–rump length and maternal serum levels of pregnancy‐associated plasma protein‐A in the first trimester
Authors: Leung T. Y. , Sahota D. S. , Chan L. W. , Law L. W. , Fung T. Y. , Leung T. N. , Lau T. K.
Published: December 2007

Objective

To determine whether the first trimester crown–rump length (CRL), maternal serum levels of pregnancy‐associated plasma protein A (PAPP‐A) and free beta‐human chorionic gonadotropin (fβ‐hCG) are independent predictors of birth weight.

Methods

This was an observational study over 1.5 years in Chinese patients who underwent first‐trimester combined screening for Down syndrome in a University fetal medicine unit. After excluding cases with multiple pregnancies, congenital malformations and in‐utero deaths, the relationship between fetal CRL (expressed as standardized Z‐score (Z‐CRL)), maternal PAPP‐A and fβ‐hCG levels (expressed as log10 of multiples of the median) and birth weight (Z‐BW) were analyzed by Pearson's correlation test followed by multiple regression to check for their independency. The predictive power of the independent predictors for small‐for‐gestational age (SGA, defined as birth weight < 10th centile) was then assessed using receiver–operating characteristics (ROC) curves, and the likelihood ratios were derived.

Results

A total of 2760 cases were included. Z‐CRL, log10 PAPP‐AMoM, and log10 fβ‐hCG were positively correlated with Z‐BW (P < 0.0001), but only Z‐CRL and log10 PAPP‐AMoM were independent predictors (P < 0.0001). The areas under the ROC curves of PAPP‐AMoM and Z‐CRL were 0.608 and 0.593, respectively (P < 0.0001). Likelihood ratios increased with decreasing PAPP‐AMoM and Z‐CRL, but were around 1 when the markers were at or above the mean.

Conclusion

First‐trimester CRL and PAPP‐A are independent factors that influence final birth weight. The lower the PAPP‐A and the smaller the CRL, the higher the risk of a fetus becoming SGA. However, their predictive powers are not sufficiently good for them to be used alone for SGA screening. Copyright © 2007 ISUOG. Published by John Wiley & Sons, Ltd.
Fetal aberrant right subclavian artery in normal and Down syndrome fetuses
Authors: Zalel Y. , Achiron R. , Yagel S. , Kivilevitch Z.
Published: December 2007

Objectives

To evaluate the prevalence of fetal aberrant right subclavian artery (ARSA) in a low‐risk population and compare it with that among Down syndrome fetuses, in order to estimate its potential as a marker in Down syndrome screening.

Methods

Women undergoing routine fetal sonographic examination between 13 and 26 weeks of gestation were evaluated once for the presence of ARSA using either a transvaginal multifrequency 5–9‐MHz probe or a transabdominal 4–8‐MHz probe as appropriate. Early pregnancy outcome was obtained in all cases.

Results

Nine hundred and twenty‐four fetuses were recruited. An ARSA was detected in 13 fetuses (1.4%) with normal karyotype. During the study period, eight fetuses with Down syndrome referred either with known karyotype or with signs suspicious for Down syndrome were evaluated by the same protocol. Three of eight fetuses (37.5%) were found to have an ARSA. In none of these cases was ARSA an isolated finding. The odds ratio for ARSA in Down syndrome compared with normal fetuses was 42.04 (95% CI, 9.08–194.6).

Conclusions

An ARSA was found in 1.4% of the normal population. In the small group of Down syndrome fetuses we observed a trend towards a higher rate of ARSA than in normal fetuses. In none of the Down syndrome fetuses was ARSA an isolated finding. Larger prospective studies are needed to examine the significance of ARSA as an isolated finding and the potential of ARSA as a marker in Down syndrome screening. Copyright © 2007 ISUOG. Published by John Wiley & Sons, Ltd.
Maternal and fetal hemodynamic effects induced by nitric oxide donors and plasma volume expansion in pregnancies with gestational hypertension complicated by intrauterine growth restriction with absent end‐diastolic flow in the umbilical artery
Authors: Valensise H. , Vasapollo B. , Novelli G. P. , Giorgi G. , Verallo P. , Galante A. , Arduini D.
Published: December 2007

Objective

To evaluate the effect of plasma volume expansion (PVE) and nitric oxide (NO) donors, in addition to antihypertensive therapy for gestational hypertensive pregnancies complicated by intrauterine growth restriction (IUGR) with absent end‐diastolic flow (AEDF) in the umbilical artery (UA).

Methods

This was a case–control study into which 32 gestational hypertensive pregnancies with IUGR and AEDF were enrolled. Sixteen of these were treated with antihypertensive drugs, NO donors and PVE (Group A), and 16, matched for maternal age, gestational age and fetal conditions, were treated with antihypertensive drugs only (Group B). All patients underwent fetal and uteroplacental assessment and maternal echocardiography to evaluate total vascular resistance (TVR) and cardiac output before and 5–14 days after initiation of treatment.

Results

After 5–14 days of treatment, the maternal TVR in Group A fell from 2170 ± 248 to 1377 ± 110 dynes·s·cm−5 (P < 0.01), and that in Group B fell from 2090 ± 260 to 1824 ± 126 dynes·s·cm−5 (P < 0.01), with the reduction being greater in Group A than in Group B (P < 0.01). There was a significant increase in cardiac output in Group A after 5–14 days of treatment vs. baseline (6.19 ± 0.77 vs. 4.32 ± 0.66, P < 0.001), and, after treatment, cardiac output was significantly greater in Group A than it was in Group B (6.19 ± 0.77 vs. 4.70 ± 0.44, P < 0.001). Reappearance of end‐diastolic flow in the UA occurred in 14/16 patients in Group A but in no patients in Group B (87.5% vs. 0%, P < 0.05). The interval between detection of UA‐AEDF and delivery was 28 ± 16 days in Group A and 11 ± 6 days in Group B (P < 0.05).

Conclusion

Administration of NO donors and PVE in gestational hypertensive pregnancies affected by IUGR and UA‐AEDF appears to improve both maternal and fetal hemodynamics, inducing prolongation of gestation. Copyright © 2007 ISUOG. Published by John Wiley & Sons, Ltd.
The mer‐Triaquatrichloroiron(III) Molecule in Triethylenediammonium and Piperazinium Chloride Matrices
Authors: James Bruce D. , Skelton Brian W. , White Allan H.
Published: December 2007

The neutral mer‐triaquatrichloroiron(III) molecule, mer‐[(H2O)3FeCl3], has been structurally defined, co‐crystallized with a pair of organic‐cation/chloride salts, from hydrochloric acid solution in each case. The array {[HN(CH2CH2)3NH]Cl2}{mer‐[(H2O)3FeCl3]}, (1) has been previously described in a room‐temperature study in terms of orthorhombic Pnma symmetry; here, at low‐temperature (ca. 153 K), the description is in terms of P212121, with the complex of quasi‐m symmetry. Full m symmetry is achieved in the second complex, {[H2N(CH2CH2)2NH2]Cl2}{mer‐[(H2O)3FeCl3]}, (2) which crystallizes in space group P21/m. Fe–Cl and Fe–O(H2) are very tightly ranged in 1, < > 2.3359(6), 2.051(5) Å, respectively, less so in 2 (2.326(1), 2.340(1); 2.049(2)–2.080(2) Å), despite strong hydrogen‐bonding in the lattice between the hydrogen atoms of the coordinated water molecules and the uncoordinated chloride ions. A redetermination of the structure of FeCl3·6H2O (3), trans‐tetraquadichloroiron(III) chloride dihydrate, is also recorded; at 100 K,Fe–Cl,O are 2.2830(4), 2.0543(9) Å.
Chirale Halbsandwich‐Pentamethylcyclopentadienyl‐Rhodium(III)‐ und Iridium(III)‐Komplexe mit Schiff‐Basen aus Salicylaldehyd und α‐Aminosäureestern [1]
Authors: Böhm Andreas , Brunner Henri , Beck Wolfgang
Published: December 2007

Chiral Half‐sandwich Pentamethylcyclopentadienyl Rhodium(III) and Iridium(III) Complexes with Schiff Bases from Salicylaldehyde and α‐Amino Acid Esters [1]

A series of diastereoisomeric half‐sandwich complexes with Schiff bases from salicylaldehyde and L‐α‐amino acid esters including chiral metal atoms, [(η5‐C5H5)(Cl)M(N,O‐Schiff base)], has been obtained from chloro bridged complexes [(η5‐C5Me5)(Cl)M(μ‐Cl)]2 (M = Rh, Ir). Abstraction of chloride from these complexes with Ag[BF4] or Ag[SO3CF3] affords the highly sensitive compounds [(η5‐C5Me5)M(N,O‐Schiff base]+X− (M = Rh, Ir; X = BF4, CF3SO3) to which PPh3 can be added under formation of [(η5‐C5Me5)M(PPh3)(N,O‐Schiff base)]+X−. The diastereoisomeric ratio of the complexes (1‐7 and 11‐12) has been determined from NMR spectra.
Synthesis and Characterization of Gd2[Pt2(SO4)4(HSO4)2](HSO4)2
Authors: Arndt Annika , Wickleder Mathias S.
Published: December 2007

Red single crystals of Gd2[Pt2(SO4)4(HSO4)2](HSO4)2 (triclinic, $P{\bar 1}$, Z = 1, a = 844.02(9), b = 908.50(9), c = 939.49(8) pm, α = 107.73(1)°, β = 112.10(1)°, γ = 103.53(1)°) were obtained by the reaction of [Gd(NO3)(H2O)7][PtCl6]·4H2O with sulfuric acid at 320 °C in a sealed glass ampoule. In the crystal structure, Pt2 dumbbells are coordinated by four chelating sulfate groups and two monodentate hydrogensulfate ions. Two further HSO4− ions are not bonded to the Pt2 dumbbell. The Gd3+ ions are eightfold coordinated by oxygen atoms. The IR data of Gd2[Pt2(SO4)4(HSO4)2](HSO4)2 are typical for these type of compounds. The thermal decomposition of the compound leads to elemental platinum and Gd2O3.
Synthesis, Crystal Structures and Luminescent Properties of Terbium, Neodymium and Yttrium Complexes with a New Amide Type Ligand
Authors: Tang Zheng‐Hua , Liu Dian‐Yi , Tang Yu , Cao Xiao‐Ping
Published: December 2007

Solid complexes of terbium, neodymium and yttrium nitrates with an amide type ligand, N‐benzyl‐2‐(benzyloxy)benzamide (L) have been prepared in ethyl acetate and characterized by elemental analysis and IR spectroscopy. The crystal and molecular structures of the complexes TbL3(NO3)3, NdL3(NO3)3 and YL3(NO3)3 have been determined by single crystal X‐ray diffraction. The crystal structures of the complexes are similar. The structures show that the crystal consists of two similar but independent molecules in the asymmetric unit and the metal ion is coordinated toward nine donor atoms, three of which belong to the oxygen atoms of three monodentate ligands and six oxygen atoms from three bidentate nitrates. Furthermore, the REL3(NO)3 complex units are linked by the intermolecular hydrogen bonds to form a three‐dimensional net. At the same time, the luminescent properties of the ligand and the complex TbL3(NO3)3 were studied as well.
Syntheses, Structures, and Polymorphism of β‐Diketonato Complexes – Co(thd)3
Authors: Ahmed M. A. K. , Fjellvåg Helmer , Kjekshus Arne , Dietzel Pascal D. C.
Published: December 2007

Oxidation of Co(thd)2 dissolved in different solvents has been investigated in air and oxygen atmosphere. In oxygen atmosphere and at the boiling point of the solvents this treatment leads to oxidation of CoII to CoIII, but also to degradation of some of the thd ligands and formation of a new mixed‐ligand complex. Three pure‐cultivated crystalline Co(thd)3 phases are reported: 1 (room‐temperature phase), 2 (low‐temperature phase), and 3 (metastable phase) and in addition there exists an amorphous Co(thd)3 phase (4) with approximate composition Co(thd)3·xH(thd); x = 0.06. Reaction of metal(II) oxides (MO, M = Mn, Fe, and Co) with H(thd) under air or O2 atmosphere is an easy direct route to M(thd)3 complexes. Structure determinations are reported for Co(thd)3 (1–3) based on single‐crystal X‐ray diffraction data. Modification 1 crystallizes in space group $P{\bar 3}c \rm 1$ with a = b = 18.8100(10), c = 18.815(2) Å at 295 K; R(wR2) = 0.180, modification 2 in space group C2/c with a = 28.007(12), b = 18.482(8), c = 21.356(9) Å, β = 97.999(5)° at 100 K; R(wR2) =0.211, and modification 3 in space group Pnma with a = 19.2394(15), b = 18.8795(15), c = 10.7808(8) Å at 100 K; R(wR2) = 0.193. The molecular structures of 1–3 all comprise a central Co atom octahedrally co‐ordinated by the ketonato O atoms of three thd ligands. The transformation between modifications 1 and 2 is of a fully reversible second‐order character. Modifications 1 and 3 are, on the other hand, related by a quasi‐reversible cycle. Heat treatment (specifically sublimation) of 1 leads to 3 whereas re‐crystallization or prolonged storage at room temperature is required to regenerate 1. Co(thd)3 has sufficient thermal stability to permit sublimation without degradation. The various forms of Co(thd)3 are all diamagnetic, viz. a confirmation of the CoIII valence state.
Prenatal antibiotic treatment does not decrease group B streptococcus colonization at delivery
Authors: Baecher Laura , Grobman William
Published: December 2007

Objective

To evaluate whether an outpatient antibiotic regimen decreased group B streptococcal (GBS) colonization to preclude the use of intrapartum antibiotics.

Methods

A double‐blind randomized controlled trial evaluating prenatal oral amoxicillin versus placebo with the primary outcome of GBS colonization at the time of labor.

Results

Of those patients receiving both amoxicillin and a repeat culture at the time of labor, 6 of the 14 (43%) tested positive for GBS colonization. Given persistent GBS colonization of 67% (10/15) in the placebo group, treatment with amoxicillin did not significantly impact colonization at the time of delivery (P = 0.20).

Conclusion

A regimen of outpatient amoxicillin was associated with persistent GBS colonization in 43% of women at the time of labor. Oral prenatal antibiotic prophylaxis against GBS does not sufficiently reduce colonization to preclude intrapartum intravenous antibiotics.
An investigation of predictors of renal insufficiency following treatment of hyperthyroidism in cats
Authors: Riensche Melissa R. , Graves Thomas K. , Schaeffer David J.
Published: December 2007

To determine if routine pre-treatment clinical data can be used to predict the development of overt renal insufficiency following treatment of feline hyperthyroidism, we studied retrospectively all non-azotemic cats undergoing treatment for hyperthyroidism at our hospital. Medical records were reviewed for signalment, clinical signs, and serum biochemical, hematologic and urinalysis parameters before and after treatment for hyperthyroidism. Two groups – cats that developed post-treatment renal insufficiency, and those that did not – were compared. No significant differences could be detected between the groups with respect to the parameters measured. Our study suggests that the results of routine pre-treatment clinical data cannot be used to reliably predict renal function after treatment for hyperthyroidism, validating the necessity of a methimazole trial prior to definitive therapy. The widely held belief that cats with pre-treatment urine specific gravity>1.035 are at less risk for development of renal azotemia after treatment of hyperthyroidism seems unwarranted.
Relationship between women's occupational work and bone health: a study from India
Authors: Shatrugna Veena , Kulkarni Bharati , Kumar P. Ajay , Balakrishna N. , Rani K. Usha , Reddy G. Chennakrishna , Rao G. V. Narasimha
Published: December 2007

Physical activity is known to influence the bone mass of an individual. Few studies have examined the effect of occupational activities on bone health. The present study investigated the relationship between occupational activities and the bone parameters measured by dual-energy X-ray absorptiometry in 158 women from a low-income group in India. Women involved in three occupations with different bone-loading patterns (beedi (cigarette) makers, sweepers and construction workers) were included in the study. Anthropometric parameters, parity and percentage of menopausal women did not differ significantly between the three groups and dietary intake of Ca was low in all the groups. Bone mineral density (BMD) values of the overall group at all the sites were much lower than those reported from developed countries, possibly due to different body sizes in these regions. Femoral neck and hip BMD were not different in the three groups in spite of marked differences in activity patterns. However, bone area in the femoral neck was higher in the beedi makers compared with sweepers probably due to the squatting position adopted by beedi makers. Lumbar spine BMD was significantly lower among the sweepers when compared with the beedi makers and the groups performing walking and weight-bearing activities (sweepers and construction workers) had a higher prevalence of osteoporosis in the lumbar spine. However, weight-bearing effects of the upper body due to a squatting position were associated with better lumbar spine BMD in the beedi makers. The present study thus indicates that undernutrition might affect the relationship between occupational activities and bone parameters.
Concentrations of resveratrol and derivatives in foods and estimation of dietary intake in a Spanish population: European Prospective Investigation into Cancer and Nutrition (EPIC)-Spain cohort
Authors: Zamora-Ros Raul , Andres-Lacueva Cristina , Lamuela-Raventós Rosa M. , Berenguer Toni , Jakszyn Paula , Martínez Carmen , Sánchez María J. , Navarro Carmen , Chirlaque María D. , Tormo María-José , Quirós Jose R. , Amiano Pilar , Dorronsoro Miren , Larrañaga Nerea , Barricarte Aurelio , Ardanaz Eva , González Carlos A.
Published: December 2007

Resveratrol has been shown to have beneficial effects on diseases related to oxidant and/or inflammatory processes and extends the lifespan of simple organisms including rodents. The objective of the present study was to estimate the dietary intake of resveratrol and piceid (R&P) present in foods, and to identify the principal dietary sources of these compounds in the Spanish adult population. For this purpose, a food composition database (FCDB) of R&P in Spanish foods was compiled. The study included 40 685 subjects aged 35–64 years from northern and southern regions of Spain who were included in the European Prospective Investigation into Cancer and Nutrition (EPIC)-Spain cohort. Usual food intake was assessed by personal interviews using a computerised version of a validated diet history method. An FCDB with 160 items was compiled. The estimated median and mean of R&P intake were 100 and 933 μg/d respectively. Approximately, 32 % of the population did not consume R&P. The most abundant of the four stilbenes studied wastrans-piceid (53·6 %), followed bytrans-resveratrol (20·9 %),cis-piceid (19·3 %) andcis-resveratrol (6·2 %). The most important source of R&P was wines (98·4 %) and grape and grape juices (1·6 %), whereas peanuts, pistachios and berries contributed to less than 0·01 %. For this reason the pattern of intake of R&P was similar to the wine pattern. This is the first time that R&P intake has been estimated in a Mediterranean country.
Modeling Atomic-Resolution Scanning Transmission Electron Microscopy Images
Authors: Findlay Scott D. , Oxley Mark P. , Allen Leslie J.
Published: December 2007

A real-space description of inelastic scattering in scanning transmission electron microscopy is derived with particular attention given to the implementation of the projected potential approximation. A hierarchy of approximations to expressions for inelastic images is presented. Emphasis is placed on the conditions that must hold in each case. The expressions that justify the most direct, visual interpretation of experimental data are also the most approximate. Therefore, caution must be exercised in selecting experimental parameters that validate the approximations needed for the analysis technique used. To make the most direct, visual interpretation of electron-energy-loss spectroscopic images from core-shell excitations requires detector improvements commensurate with those that aberration correction provides for the probe-forming lens. Such conditions can be relaxed when detailed simulations are performed as part of the analysis of experimental data.
Oxygen isotope and salinity variations in the Indian sector of the Southern Ocean
Authors: Srivastava Rohit , Ramesh R. , Prakash Satya , Anilkumar N. , Sudhakar M.
Published: December 2007

A combined study of stable oxygen isotopes (δ18O) and salinity of surface ocean waters collected from the Southern Indian Ocean during the late austral summer and early fall (25th January to 1st April, 2006) helped to trace atmospheric and oceanic processes: near the equator, a very clear signature of the domination of evaporation‐precipitation process was seen, while a precipitation dominated zone was located between two evaporation dominated zones south of the equator. The signature of the Agulhas Front (AF) and the Subtropical Front (STF, recognizable by the sharp decrease in salinity and δ18O) in the surface waters were identified at 41°S and 44°S in February; during the return journey (March) these two fronts had merged and were located at 41°S. South of 45°S, the slope of the δ18O‐salinity relationship was close to zero; while north of 62°S could have some precipitation/evaporation effect, south of 63°S was clearly dominated by freezing/melting.
Numerical modeling of the magnetic topology near Mars auroral observations
Authors: Liemohn M. W. , Ma Y. , Nagy A. F. , Kozyra J. U. , Winningham J. D. , Frahm R. A. , Sharber J. R. , Barabash S. , Lundin R.
Published: December 2007

Magnetohydrodynamic (MHD) simulations of the Mars magnetic field topology are presented for the auroral observations reported from the Mars Express SPICAM instrument. It is found that the field lines closest to the assumed emission location are open. That is, they are connected to the interplanetary magnetic field, thus allowing access for solar wind electrons to bombard the upper atmosphere and create a auroral‐like emission. The most likely population responsible for the creation of the emissions recorded by SPICAM is magnetosheath electrons. It is found that numerous closed magnetic field lines, connected to two strong crustal field regions, can straddle the terminator, leaving open the speculation that atmospheric photoelectrons could be responsible for nightside auroral‐like emissions. However, for the particular case of the initially reported SPICAM auroral observations, the MHD results do not produce such terminator‐crossing field lines near the emission region.
Latitudinal dependence of diapycnal diffusivity in the thermocline observed using a microstructure profiler
Authors: Hibiya Toshiyuki , Nagasawa Maki , Niwa Yoshihiro
Published: December 2007

The un‐tethered free‐fall microstructure profiler “TurboMAP‐D” collected 53 velocity microstructure profiles in the interior Pacific Ocean. The data between ∼1000 m and ∼1600 m depth was used to infer diapycnal diffusivity in the main thermocline. We found diapycnal diffusivity at 20°–30°N was roughly proportional to the logarithm of locally available energy density of the semidiurnal internal tide and reached more than 10−4 m2 s−1 near the Izu‐Ogasawara Ridge. In contrast, diapycnal diffusivity was found to remain at ∼10−5 m2 s−1 equatorward of 20°N and poleward of 30°N, irrespective of the amount of locally available semidiurnal internal tide energy. The observed mixing hotspots were a factor of 2–3 less intense than predicted based on fine‐scale parameterizations, although further microstructure measurements are needed to better quantify them. The present study has confirmed the existence of a latitudinal dependence of diapycnal diffusivity which must be taken into account in global circulation models.
TES carbon monoxide validation with DACOM aircraft measurements during INTEX‐B 2006
Authors: Luo M. , Rinsland C. , Fisher B. , Sachse G. , Diskin G. , Logan J. , Worden H. , Kulawik S. , Osterman G. , Eldering A. , Herman R. , Shephard M.
Published: December 2007

Validation of Tropospheric Emission Spectrometer (TES) tropospheric CO profiles with in situ CO measurements from the Differential Absorption CO Measurement (DACOM) instrument during the Intercontinental Chemical Transport Experiment (INTEX)‐B campaigns in March to May 2006 are presented. For each identified DACOM CO profile, one to three TES CO profiles are selected closest in location to the small area that the DACOM profile covers. The time differences between the comparison profiles are within 2 hours. The DACOM CO vertical profiles are adjusted by applying nearest coincident TES averaging kernels and the a priori profiles. This step accounts for the effect of the vertical resolution of the TES CO retrievals and removes the influence of the a priori assumptions in the comparisons. Comparison statistics for data taken near Houston in March 2006 show good agreement between TES and the adjusted DACOM CO profiles in the lower and middle troposphere with a correlation coefficient of 0.87. On average, the TES CO volume mixing ratio profile is 0–10% lower than the adjusted DACOM CO profile from the lower to middle troposphere. This is within the 10–20% standard deviations of the TES or DACOM CO profiles taken in the Houston area. The comparisons of TES and DACOM CO profiles near Hawaii and Anchorage in April to May 2006 are not as good. In these regions the aircraft DACOM CO profiles are characterized by plumes or enhanced CO layers, consistent with known features in the tracer fields due to transpacific transport of polluted air parcels originating from East Asia. Although TES observations over the Pacific region also show localized regions of enhanced CO, the coincidence criteria for obtaining good comparisons with aircraft measurements are challenging. The meaning of validation comparisons in profile portions where TES retrievals have little sensitivity is addressed. Examinations of characteristic parameters in TES retrievals are important in data applications.
Raman scattering of light by low-energy electronic excitations of the Tb3+ ion in the crystal KTb(WO4)2
Authors: Eremenko V. V. , Kurnosov V. S. , Peschanskiĭ A. V. , Fomin V. I. , Khats’ko E. N.
Published: December 2007

The Raman scattering spectrum in a KTb(WO4)2 crystal is investigated in the frequency range 3–950cm−1 at temperatures 5, 80, and 300K. The symmetry of all 36 vibrational excitations predicted by group-theoretical analysis is determined. The temperature behavior of the scattering spectra indicates that there is no phase transition in the temperature interval studied. Low-energy electronic transitions are found between the levels of the ground-state multiplet F67 of Tb3+ split in a crystal field with symmetry C2. It is determined that the first excited electronic quasidoublet consists of two singlet levels with different symmetry and is separated by a quite high (∼75 cm−1) energy from the ground-state quasidoublet. The behavior of all experimentally observed levels in external magnetic fields H⊥C2 and H∥C2 is investigated. The results confirm that a virtually pure case of Ising anisotropy is realized at low temperatures and the magnet studied in the present work can be regarded as a system of two-level magnetic ions.
Exchange broadening of EPR line in ZnO:Co
Authors: Sati P. , Stepanov A. , Pashchenko V.
Published: December 2007

We study the X-band EPR spectra of Co2+ in single-crystalline Zn1−xCoxO (x=0.001–0.075) thin films grown by plasma-assisted molecular beam epitaxy. By analyzing the EPR linewidth behavior we argue that the exchange-narrowing model, usually applied to Mn-based II-VI DMS, fails here and that a combined effect of exchange and dipolar broadening can explain the linewidth variation with Co content and temperature.
Redistribution (condensation) of magnons in a ferromagnet under pumping
Authors: Zvyagin A. A.
Published: December 2007

In recent years several experiments have been performed to study the Bose-Einstein condensation of quasiparticles, in particular, magnons in magnetically ordered systems. Recently the Bose-Einstein condensation of magnons was observed at room temperatures in a ferromagnetic film. A theory of the condensation (redistribution) of magnons under the conditions of pumping, which explains many features of that experiment, is presented. The use of the term “Bose-Einstein condensation of magnons” is discussed.
Mass of an Abrikosov vortex
Authors: Fil V. D. , Ignatova T. V. , Burma N. G. , Petrishin A. I. , Fil D. V. , Shitsevalova N. Yu.
Published: December 2007

In the excitation of a vortex lattice in the mixed phase of Yb6 single crystals by an elastic wave, the dynamic response is found to have a negative component quadratic in the frequency; we associate this component with the vortex mass. The value of the effect is in catastrophic contradiction with the existing theoretical estimates.
Heat transfer in the “plastic” phase of hexafluoroethane
Authors: Konstantinov V. A. , Revyakin V. P. , Sagan V. V.
Published: December 2007

The thermal conductivity of solid hexafluoroethane C2F6 is investigated in three samples of different density in the temperature interval from 90K up to the onset of melting. The isochroic thermal conductivity in the β phase is practically constant immediately after the α→β transition, and as the temperature is increased further it grows weakly on up to the onset of melting. This behavior is due to weakening of the translation-orientation interaction as the rotational motion of the C2F6 molecules around the C–C axis becomes less hindered.