bluuebunny/crossref_metadata_2025 huggingface dataset:
Electrospray ionization tandem mass spectrometric analysis of ent‐6,7‐seco‐kaurane diterpenoids from the Isodon species
Authors: Zhou Yan , Yang Bin‐Li , Yang Jing , Huang Sheng‐Xiong , Sun Han‐Dong , Xu Hong‐Xi , Ding Li‐Sheng
Published: December 2008

Electrospray ionization tandem mass spectrometry (ESI‐MSn) using an ion trap instrument and accurate mass measurement on a quadrupole time‐of‐flight (Q‐TOF) mass spectrometer has aided the structural characterization and differentiation of the enmein and spiro‐lactone types of ent‐6,7‐seco‐kaurane diterpenoids from Isodon species. The mass spectral fragmentation data from both techniques was compared to obtain the mass spectrometric fragmentation pathways of the ent‐6,7‐seco‐kaurane diterpenoids with high confidence. The analysis revealed that losses of CH2O and CO2 are the predominant process for the enmein type of ent‐kauranes in negative ion mode, and the loss of CO2 is typical for the spiro‐lactone type in positive ion mode. In addition, compounds of the spiro‐lactone type with a conserved core structure but different substituent groups, such as acetyl, hydroxyl, and aldehyde moiety, resulted in diagnostic product ions by means of successive losses of AcOH, H2O, and CO, respectively. The fragmentation knowledge will facilitate the analysis and identification of the ent‐6,7‐seco‐kauranes in future plant research. Copyright © 2008 John Wiley & Sons, Ltd.
FBT: an efficient traceback scheme in hierarchical wireless sensor network
Authors: Cheng Bo‐Chao , Chen Huan , Liao Guo‐Tan
Published: December 2008

With limited resource constraints, wireless sensor networks (WSNs) pose unique technical challenges: WSNs are vulnerable to DoS/DDoS attacks that can easily exhaust rare available resources to prevent execution of their expected functions. Reconstructing the attacking path and locating the attacking source are challenging tasks in the traceback research areas. In conventional IP networks, probabilistic packet marking (PPM) schemes are among the widely used traceback algorithms. However, due to their high convergence times, conventional PPM schemes are not enough for the need for quick and accurate traceback in WSNs. Because marking probability assignment schemes have considerable influence on convergence time and performance, we place a particular emphasis on how to improve both easiness and efficiency for the marking probability assignment of the PPM. In this paper, we propose a novel traceback scheme, called fishbone traceback (FBT), which can be deployed in hierarchical WSN environments. FBT is designed based on the two‐layer labelling technique and a smart marking probability distribution function (MPDF). The use of two‐layer FBT labels is to derive the main branch (‘fish spine’) of the attacking path quickly, while the use of MPDF can greatly reduce the convergence time by integrating witha prioriinformation of hierarchical WSN topology. The FBT path reconstruction procedure is able to rebuild the spine path (for inter‐cluster traceback)viacluster head marking packets. It also reforms the details of the micro fishbone path (for intra‐cluster traceback) on‐demand within a cluster. Both numerical analysis and simulation results show that our solution has better performance in terms of shorter traceback convergence time. In particular, the proposed FBT also includes many salient features (such as the enhanced robustness of the traceback algorithm in case of multi‐attack and reusable spine path), which enable FBT to be a practical solution to the traceback problem in hierarchical WSNs. Copyright © 2008 John Wiley & Sons, Ltd.
Fast convergent key distribution algorithms using a dual quantum channel
Authors: Jin Di , Verma Pramode K. , Kartalopoulos Stamatios V.
Published: December 2008

This paper presents three new algorithms over a dual quantum channel to enhance the convergence speed of the key distribution process. The proposed algorithms effectively use a dual quantum channel between the communicating entities and, when combined with the proposed selection of the basis, improve the efficiency of the key distribution process as well as deter Eve. With the use of an initialization vector (IV), the proposed algorithm does not necessitate information exchange about the bases between Alice and Bob, thus removing the requirement of the availability of a two‐way conventional channel. Simultaneously, it allows the detection of the presence of Eve in real time. Copyright © 2008 John Wiley & Sons, Ltd.
Atomic‐level characterization of materials with core‐ and valence‐level photoemission: basic phenomena and future directions
Authors: Fadley Charles S.
Published: December 2008

In this overview, the basic concepts of core and valence photoelectron spectroscopy (photoemission), photoelectron diffraction, and photoelectron holography are introduced. Then some current developments in these techniques that should enhance their utility for atomic‐level characterization of new materials and surface chemical processes are discussed, including measurements with hard X‐ray excitation, standing‐wave excitation, and ambient pressures in the multi‐torr regime. Copyright © 2008 John Wiley & Sons, Ltd.
Chemical‐state‐resolved in‐depth profiles of gate‐stack structures on Si studied by angular‐dependent photoemission spectroscopy
Authors: Toyoda S. , Okabayashi J. , Oshima M. , Liu G. L. , Liu Z. , Ikeda K. , Usuda K.
Published: December 2008

We have investigated chemical‐state‐resolved in‐depth profiles of SiO2/SiN stack films using angular‐dependent photoemission spectroscopy and maximum‐entropy method (MEM). MEM enables to reproduce the gate‐stack structure from angular‐dependence of core‐level spectra, and it is utilized to determine atomic concentration of the interfacial layer. In‐depth profile of the SiO2/SiN stack film reveals that the SiO2layer is distributed in the surface region and that the SiN layer is partly oxidized, which is well related to nitrogen bonding states analyzed by angular‐dependence of N 1s core‐level spectra. Copyright © 2008 John Wiley & Sons, Ltd.
Characterization of atomic‐level plasmonic structures by low‐energy EELS
Authors: Nagao Tadaaki
Published: December 2008

Plasmonic excitation in atomic‐level one‐dimensional (1D) structure is characterized by use of electron diffraction and electron scattering spectroscopy with highly collimated slow electron beam. The high momentum resolution of the technique unveils the presence of steeply dispersing plasmon dispersion of the atom chains in the infrared region that is usually smeared out as broad feature near the Bragg beams. Two different Au and In chain structures on stepped silicon surfaces are measured to show plasmon dispersion only along the chains, which indicates strong plasmon confinement in each chain. On the other hand, different slope of the plasmon dispersion are found, which is due to the difference in their 1D electronic band and chain width. Copyright © 2008 John Wiley & Sons, Ltd.
Why add anything to nothing? The arcsine difference as a measure of treatment effect in meta‐analysis with zero cells
Authors: Rücker Gerta , Schwarzer Guido , Carpenter James , Olkin Ingram
Published: December 2008

For clinical trials with binary endpoints there are a variety of effect measures, for example risk difference, risk ratio and odds ratio (OR). The choice of metric is not always straightforward and should reflect the clinical question. Additional issues arise if the event of interest is rare. In systematic reviews, trials with zero events in both arms are encountered and often excluded from the meta‐analysis.

The arcsine difference (AS) is a measure which is rarely considered in the medical literature. It appears to have considerable promise, because it handles zeros naturally, and its asymptotic variance does not depend on the event probability.

This paper investigates the pros and cons of using the AS as a measure of intervention effect. We give a pictorial representation of its meaning and explore its properties in relation to other measures. Based on analytical calculation of the variance of the arcsine transformation, a more conservative variance estimate for the rare event setting is proposed. Motivated by a published meta‐analysis in cardiac surgery, we examine the statistical properties of the various metrics in the rare event setting.

We find the variance estimate of the AS to be more stable than that of the log‐OR, even if events are rare. However, parameter estimation is biased if the groups are markedly unbalanced. Though, from a theoretical viewpoint, the AS is a natural choice, its practical use is likely to continue to be limited by its less direct interpretation. Copyright © 2008 John Wiley & Sons, Ltd.
Extending the skill test for disease diagnosis
Authors: Lin Shu‐Chuan , Kvam Paul H. , Lu Jye‐Chyi
Published: December 2008

For diagnostic tests, we present an extension to the skill plot introduced by Briggs and Zaretski (Biometrics2008;64:250–261). The method is motivated by diagnostic measures for osteopetrosis in a study summarized by Hanset al.(The Lancet1996;348:511–514). Diagnostic test accuracy is typically defined using the area (or partial area) under the receiver operator characteristic (ROC) curve. If partial area is used, the resulting statistic can be highly subjective because the focus region of the ROC curve corresponds to a set of low false‐positive rates that are chosen by the experimenter. This paper introduces a more objective diagnostic test for which the focus region depends on a skill score, which in turn depends on the loss functions associated with misdiagnosis. More specifically, the skill‐based diagnostic test serves as a more objective version of the nonparametric test introduced by Dodd and Pepe (Biometrics2003;59:614–623). Copyright © 2008 John Wiley & Sons, Ltd.
Aspect‐oriented component assembly—a case study in parallel software design
Authors: Dangelmayr C. , Blochinger W.
Published: December 2008

In this paper we deal with building parallel programs based on sequential application code and generic components providing specific functionality for parallelization, like load balancing or fault tolerance. We describe an architectural approach employing aspect‐oriented programming to assemble arbitrary object‐oriented components. Several non‐trivial crosscutting concerns arising from parallelization are addressed in the light of different applications, which are representative of the most common types of parallelism. In particular, we demonstrate how aspect‐oriented techniques allow us to leave all existing code untouched. We evaluate and compare our approach with its counterparts in conventional object‐oriented programming. Copyright © 2008 John Wiley & Sons, Ltd.
A study on aggregation of group decisions
Authors: Huang Yeu‐Shiang , Liao Jing‐Tai , Lin Zu‐Liang
Published: December 2008

The analytic hierarchy process (AHP), proposed by Saaty in 1971, has already become a common decision technique in the field of decision science. In attempting to deal with group decision problems, a vast amount of literature has adopted geometric means or arithmetic means to aggregate the multiple opinions of group decision makers with AHP. However, geometric means and arithmetic means are usually subject to the influence of extreme values, and make use of only simple average types of manipulation to combine the judgments of decision makers which may not practically capture the group preferences among alternatives. In this paper, two aspects of consideration are probed into the construction of a group AHP decision model, which are ‘preferential differences’ to denote the differences of preferential weights among alternatives for each decision maker, and ‘preferential ranks’ to denote the ranks of the alternatives for each decision maker. A comparative analysis is performed to investigate the effectiveness of the proposed model, and a ‘satisfaction index’ is suggested to indicate the satisfactory level of the final obtained group decision. Finally, a feedback interview is carried out to collect the post‐model opinions of decision makers in order to understand their acceptance about the proposed model. Copyright © 2008 John Wiley & Sons, Ltd.
Amyloid β‐protein fragments 25–35 and 31–35 potentiate long‐term depression in hippocampal CA1 region of rats in vivo
Authors: Cheng Li , Yin Wen‐Juan , Zhang Jun‐Fang , Qi Jin‐Shun
Published: December 2008

Amyloid β‐protein (Aβ) is thought to be responsible for the deficit of learning and memory in Alzheimer's disease (AD), possibly through interfering with synaptic plasticity in the brain. It has been reported that Aβ fragments suppress the long‐term potentiation (LTP) of synaptic transmission. However, it is unclear whether Aβ fragments can regulate long‐term depression (LTD), an equally important form of synaptic plasticity in the brain. The present study investigates the effects of Aβ fragments on LTD induced by low frequency stimulation (LFS) in the hippocampus in vivo. Our results showed that (1) prolonged 1–10 Hz of LFS all effectively elicited LTD, which could persist for at least 2 h and be reversed by high frequency stimulation (HFS); (2) the effectiveness of LTD induction depended mainly on the number of pulses but not the frequency of LFS; (3) pretreatment with Aβ fragment 25–35 (Aβ25–35, 12.5 and 25 nmol) did not change baseline field excitatory postsynaptic potentials but dose‐dependently potentiated LTD; (4) Aβ fragment 31–35 (Aβ31–35), a shorter Aβ fragment than Aβ25–35, also dose‐dependently strengthened LFS‐induced hippocampal LTD. Thus, the present study demonstrates the enhancement of hippocampal LTD by Aβ in in vivo condition. We propose that Aβ‐induced potentiation of LTD, together with the suppression of LTP, will result in the impairment of cognitive function of the brain. Synapse 63:206–214, 2009. © 2008 Wiley‐Liss, Inc.
Facilitation of glutamate release from rat cerebrocortical glutamatergic nerve terminals (synaptosomes) by phosphatidylserine and phosphatidylcholine
Authors: Yang Tsung‐Tsair , Wang Su‐Jane
Published: December 2008

Phosphatidylserine (PS) and phosphatidylcholine (PC) have been shown to enhance cognitive function. Considering that brain glutamatergic system is thought to participate in cognitive processing, our objective was to determine the effect of PS and PC on glutamate release from the nerve terminal (synaptosome) freshly isolated from rat cerebral cortex. Data showed that both PS and PC potently facilitate 4‐aminopyridine (4‐AP)‐evoked Ca2+‐dependent and Ca2+‐independent glutamate release. Facilitation of glutamate release by PS or PC was associated with an increase of 4‐AP‐evoked depolarization and downstream elevation of cytoplasmic free calcium concentration ([Ca2+]c). In addition, glutamate release elicited by direct Ca2+‐entry with Ca2+‐ionophore (ionomycin) was also facilitated by PS or PC. Furthermore, PS‐ or PC‐mediated facilitation of 4‐AP‐evoked glutamate release was superseded or suppressed by protein kinase C (PKC) activator and inhibitor, respectively. Together, these results suggest that PS or PC effects a facilitation of glutamate exocytosis by increasing nerve terminal excitability and Ca2+influx into cerebrocortical nerve terminals through a signaling cascade involving PKC. Synapse 63:215–223, 2009. © 2008 Wiley‐Liss, Inc.
Changes in the thiamine and riboflavin contents of rice during artisanal parboiling in Ghana
Authors: Manful JT , Swetman AA , Coker RD , Drunis A
Published: December 2008

Rice samples mildly parboiled at various combinations of soaking temperatures and steaming times were analysed for their thiamine and riboflavin contents. The relative parboiling index was calculated and this provided a reliable measure of the overall effects of different conditions on the degree of parboiling. The thiamine content of parboiled rice samples increased gradually as parboiling intensity was increased from initial soaking temperature at 30°C and steaming for 4 min to soaking at 70°C and steaming for 12 min. There was a sharper rise in thiamine when the soaking temperature was increased to 90°C, and the sample that was steamed for 12 min after soaking at 90°C had a thiamine content of 0.612 µg g−1. The level of riboflavin also initially increased with parboiling, but it peaked at 0.278 µg g−1 in the sample that was soaked at 70°C and steamed for 12 min, and then decreased as parboiling intensity was increased further. The commercially parboiled rice sample had a riboflavin content of 0.206 µg g−1. This pattern of change in riboflavin levels with parboiling was probably due to thermal breakdown of the vitamin at higher soaking temperature. Copyright © 2008 John Wiley & Sons, Ltd
Timing of mid‐trimester cervical length shortening in high‐risk women
Authors: Szychowski J. M. , Owen J. , Hankins G. , Iams J. , Sheffield J. , Perez‐Delboy A. , Berghella V. , Wing D. A. , Guzman E. R.
Published: December 2008

Objective

To examine the natural history of cervical length shortening in women who had experienced at least one prior spontaneous preterm birth at between 17 + 0 and 33 + 6 weeks' gestation.

Methods

This was an analysis of prerandomization data from the multicenter Vaginal Ultrasound Cerclage Trial. Serial cervical length was measured by transvaginal sonography in 1014 high‐risk women at 16 + 0 to 22 + 6 weeks. We performed survival analyses in which the outcome was cervical length shortening < 25 mm and data were censored if this did not occur before 22 + 6 weeks' gestation. The incidence of cervical length shortening and the time to shortening were compared for women whose earliest prior preterm birth was in the mid‐trimester, defined as < 24 weeks, vs. those at weeks 24–33. Similar comparisons were performed based on each patient's most recent birth history.

Results

Time to cervical length shortening by survival analysis was significantly shorter (hazard ratio (HR) = 2.2, P < 0.0001) and the relative risk (RR) of shortening significantly higher (RR = 1.8, P < 0.0001) for women whose earliest prior spontaneous preterm birth was at < 24 weeks. A larger effect was observed for women whose most recent birth was at < 24 weeks (HR = 2.8, P < 0.0001; RR = 2.1, P < 0.0001). The observed hazard ratios remained significant after adjusting for confounders in a multivariable Cox proportional hazards model.

Conclusion

Women with a prior spontaneous preterm birth at < 24 weeks are at a higher risk of cervical shortening, and do so at a higher rate and at an earlier gestational age, than do women with a later preterm birth history. Copyright © 2008 ISUOG. Published by John Wiley & Sons, Ltd.
Sonographic features of primary ovarian fibrosarcoma: a report of two cases
Authors: Testa A. C. , Gaurilcikas A. , Licameli A. , Mancari R. , Di Legge A. , Malaggese M. , Mascilini F. , Zannoni G. F. , Scambia G. , Ferrandina G.
Published: December 2008

Two cases of primary cellular fibroblastic tumor of the ovary are described, which presented a challenging clinical and histopathological differential diagnosis of primary ovarian fibrosarcoma and mitotically active cellular fibroma. On sonographic evaluation they both appeared as solid lesions with irregular margins, and on histological analysis both showed a count of 5–7 mitotic figures per 10 high‐power fields. Histopathological examination of the first case was characterized by the presence of hemorrhage, necrosis and severe nuclear atypia, with a metastatic peritoneal lesion, and the eventual diagnosis was primary ovarian fibrosarcoma. The second case, however, was diagnosed as a ‘mitotically active cellular fibroma’ owing to the lack of substantial severe cellular atypia, hemorrhage or necrosis. We speculate that ovarian fibrosarcoma at the preoperative examination might be considered in the differential diagnosis whenever a unilateral, heterogeneous, largely round solid ovarian lesion is detected. Copyright © 2008 ISUOG. Published by John Wiley & Sons, Ltd.
A novel task scheduling algorithm based on dynamic critical path and effective duplication for pervasive computing environment
Authors: Luo Junzhou , Dong Fang , Cao Jiuxin , Song Aibo
Published: December 2008

In order to effectively utilize massive heterogeneous resources and provide transparent computing capability to upper applications, task scheduling as the key issue of pervasive computing system becomes significantly important. Previous proposed priority and duplication based task scheduling algorithms, which can be applied in pervasive computing environment, usually have following limitations: critical path cannot be calculated accurately while neglecting the effect of resource availability in scheduling; in duplication based resource allocation stage, duplications without restriction would lead to some negative effects on final schedule length (SL). For the purpose of solving these problems, a novel task scheduling algorithm based on dynamic critical path (DCP) and effective duplication, called DCPED, is presented in this paper. In DCPED, a more accurate DCP calculation method which takes resource availability into account is introduced. Meanwhile an effective task duplication strategy is proposed to eliminate ineffective duplications and make an optimized schedule result by using space compression technique and dynamic critical path length (DCPL) based evaluation technique respectively. Finally, simulation results show that DCPED can outperform previous algorithms significantly in NSL and speedup rate metrics. Especially, it is very effective for utilizing computing resources and scheduling the fine‐grain and large‐scale workflow applications in pervasive computing system. Copyright © 2008 John Wiley & Sons, Ltd.
Channel estimation joint DOAs and time delay correlation in TD‐SCDMA mobile radio systems
Authors: Luo Zhinian , Zhang Wenjun , Xu Youyun
Published: December 2008

An improved channel estimation technique based on the Steiner low‐cost channel estimator is proposed, which is widely used in TD‐SCDMA (Time Division‐Synchronous Code Division Multiple Access) cellular mobile radio systems. TD‐SCDMA is also known as third‐generation mobile systems where adaptive antennas are employed. As additive noise has a great adverse effect on the performance of the Steiner estimator, the proposed method employs time‐correlated post‐processing with a threshold filter to reduce channel noise and compensate channel variations. Furthermore, channel estimation combining direction‐of‐arrivals (DOAs) is performed, which can reduce channel interferences without adding computational complexity, for the information of DOAs has been obtained by the inherent adaptive antenna system. The performance of the improved channel estimator is compared with conventional channel estimation approaches, and numerical results show that the new approach can lead to considerable performance enhancement even in high‐speed vehicle propagation environments. Copyright © 2008 John Wiley & Sons, Ltd.
Joint optimization of power scheduling and rate‐distortion performance inone‐helperproblem
Authors: Behroozi Hamid , Soleymani M. Reza
Published: December 2008

We consider themany‐help‐oneproblem, also calledm‐helperproblem, for the special case ofm = 1 where one source provides partial side information to the fusion center (FC) to help reconstruction of the other correlated source. Both correlated sources communicate information about their observations to the FC through an orthogonal multiple access channel (MAC) without cooperating with each other. First, we characterize the optimal tradeoff between the transmission cost, that is, power, and the distortion D. Then, we consider a joint optimization of source coding and power scheduling from an information theory perspective, where the power scheduling is verified using Shannon capacity formula and the source‐coding problem is analyzed using rate‐distortion theory. We show that the joint optimization in the Gaussianone‐helperproblem can be solved analytically. We provide closed‐form expressions for the optimal distortion and the optimal power scheduling in terms of the cost weights. Copyright © 2008 John Wiley & Sons, Ltd.
A New Transition Metal Tetracyanidoborate: Synthesis, Structure and Properties of Co[B(CN)4]2·2H2O
Authors: Nitschke Christian , Köckerling Martin
Published: December 2008

The reaction of tetracyanidoboronic acid, H[B(CN)4], with CoCO3 or Co(OH)2 in aqueous solution leads after slow evaporation of water to single crystals of Co[B(CN)4]2·2H2O. The compound has been characterized by single crystal X‐ray diffraction ($I {\bar 4} \mathit{2}d$, a = 12.2922(9), c = 9.2235(7) Å, Z = 4). The Co2+ ion is octahedrally coordinated by four nitrogen atoms of four different tetracyanidoborate CN groups occupying the four equatorial positions and two molecules of water occupying the remaining corners of the octahedron. The single crystal X‐ray structure, the vibrational spectra, and the thermal properties are compared with other known tetracyanidoborates with divalent cations.
Synthesis and X‐ray Crystal Structure of Bis[oxamide dioximato‐κ2N,N′](oxamide dioxime‐κ2N,N′)cobalt(III) Perchlorate Hexahydrate
Authors: Bélombé Michel M. , Nenwa Justin , Lönnecke Peter , Hey‐Hawkins Evamarie
Published: December 2008

Co(OAc)2 reacts with oxamide dioxime (H2oxado) in water in the presence of ClO4– ions to produce [Co(Hoxado)2(H2oxado)]ClO4·6H2O (1), where Hoxado– is the anion of H2oxado, derived from the deprotonation of one of the two hydroximinic groups, and in which oxidation of CoII to CoIII (in air) had occurred. 1 is the first example of a salt in which the cation, [Co(H2oxado)3]3+, is doubly deprotonated to generate the chiral cation, [Co(Hoxado)2(H2oxado)]+. The central cobalt cation is pseudo‐octahedrally coordinated by six nitrogen atoms. In the solid state, the complex cations form centro‐symmetric dimers via O–H···O bridges. The bulk structure is consolidated by an extended three‐dimensional network of O–H···O and N–H···O bridges that interconnect the ionic constituents and the water molecules.
Structural Variety in the Pseudo‐ternary System M/Ge/I:;alpha;‐[NMe(nBu)3](GeI4)I, β‐[NMe(nBu)3](GeI4)I and [ImMe(nBu)][N(nBu)4](GeI4)3I2
Authors: Wolff Michael , Feldmann Claus
Published: December 2008

By reaction of GeI4, [N(nBu)4]I as iodide donor, and [NMe(nBu)3][N(Tf)2] as ionic liquid, reddish‐black, plate‐like shaped crystals are obtained. X‐ray diffraction analysis of single crystals resulted in the compositions ;alpha;‐[NMe(nBu)3](GeI4)I (Pbca; a = 1495.4(3) pm; b = 1940.6(4) pm; c = 3643.2(7) pm; Z = 16) and β‐[NMe(nBu)3](GeI4)I (Pn; a = 1141.5(2) pm; b = 953.6(2) pm; c = 1208.9(2) pm; β = 100.8(1)°; Z = 2). Depending on the reaction temperature, the one or other compound is formed selectively. In addition, the reaction of GeI4 and [N(nBu)4]I, using [ImMe(nBu)][BF4] (Im = imidazole) as ionic liquid, resulted in the crystallization of [ImMe(nBu)][N(nBu)4](GeI4)3I2 (P21/c; a = 1641.2(3) pm; b = 1903.0(4) pm; c = 1867.7(4) pm; β = 92.0(1)°; Z = 4). The anionic network of all three compounds is established by molecular germanium(IV)iodide, which is bridged by iodide anions. The different connectivity of (GeI4–I–) networks is attributed to the flexibility of I– regarding its coordination and bond length. Here, a [3+1]‐, 4‐ and 5‐fold coordination is first observed in the pseudo‐ternary system M/Ge/I (M: cation).
Pb5I2P28, $^{1}_{\infty}\rm [PbP_{14}]{\rm ^{2-}}$ Strands Coordinated to a Unique [Pb3I2]4+ Unit
Authors: Bawohl Melanie , Nilges Tom
Published: December 2008

Pb5I2P28 is the first compound containing a former unseen [P3I2]4+ unit, connecting two crystallographically independent adjacent [PbP14]2− polyphosphide strands. The polyanion substructure is closely related to the one realized in the HgPbP14 structure type, with a homo‐nuclear coordination of the cations to the polyanions. It has been prepared by using the mineralizator concept for polyphosphides from the elements and PbI2 as the mineralizator species. The new polyphosphide has a pronounced tendency to form easy cleavable, needle shaped crystals featuring massive stacking vaults. Nevertheless, a single crystal structure determination was possible from inter‐grown crystals. Pb5I2P28 crystallizes monoclinically in the space group P21/n (No. 14) with lattice parameters of a = 9.792(2), b = 17.717(2), c = 19.191(3) Å, β = 96.39(1)°, V = 3308.6(8) Å3. Depending on the preparation route, the aspect ratio of the needle shaped crystals can be varied.
Functionalised Tris(pyrazolyl)methane Ligands and Re(CO)3 Complexes Thereof
Authors: Kunz Peter C. , Berghahn Michael , Brückmann Nadine E. , Dickmeis Marcus , Kettel Markus , Spingler Bernhard
Published: December 2008

The synthesis of new tripodal nitrogen ligands derived from tris(pyrazolyl)methane (TpmR, R = H, tBu, Ph in 3‐position) is described. After deprotonation of the parent tris(pyrazolyl)methane TpmR, the carbanion reacts readily with ethylene oxide to yield the 3,3,3‐tris(3′‐substituted pyrazolyl)propanol ligands[(3‐Rpz)3CCH2CH2OH, R = H, tBu, Ph, 1a–c]. These ligands can be easily derivatised at the alcohol function. Microwave‐assisted reactions of these ligands and [Re(CO)5Br] yields the complex [(1a)Re(CO)3]Br (4) in the case of ligand 1a, whereas in the case of the substituted ligands 1b and 1c degradation was observed. The degradation products are identified as [(HpzR)2Re(CO)3Br] [R = tBu (7b), Ph (7c)]. These complexes were also prepared directly from [Re(CO)5Br] and the corresponding pyrazoles by microwave‐assisted synthesis. The Re(CO)3 complexes 4 and [(1a)Re(CO)3]OTf (5) are water‐soluble. The structures of 5·H2O and [{(pz)3CCH2CH3}Re(CO)3]OTf·1.5H2O·1/2CH3CN (6·1.5H2O·1/2CH3CN) as well as the structure of 7b have been elucidated by X‐ray crystallography.
Crystal Structure and Magnetic Properties of Copper(II) and Nickel(II) Binuclear Complexes with Bisacylhydrazones Based on 2,6‐Diformyl‐4‐methylphenol
Authors: Tupolova Yuliya P. , Popov Leonid D. , Lukov Vladimir V. , Shcherbakov Igor N. , Levchenkov Sergey I. , Kogan Victor A. , Maevskiy Oleg V. , Vlasenko Valeriy G. , Zubenko Alexander A.
Published: December 2008

The series of binuclear Cu(II) and Ni(II) complexes with an asymmetrical exchange fragment based on 2,6‐diformyl‐4‐methylphenol bishydrazone has been synthesized for the first time. The compositions and structures of both ligands and its complexes have been established with the data of IR, 1H NMR, and extended X‐ray absorption fine structure (EXAFS) spectroscopical studies as well as magnetic measurements. The structure of [Ni2L3(μ‐Pz)]·2CH3OH (L = triply deprotonated form of bishydrazone, Pz = pyrazol) was confirmed by X‐ray crystallographic analysis. In this complex, the coordination environment of two nickel ions is quite different, one nickel atom is square‐planar and the other is distorted octahedral coordinated. The values of exchange parameter calculated in terms of HDVV theory have been compared with the features of an asymmetrical exchange fragment's electronic and geometrical structure.
Crystal Structure and Spectroscopic Characterization of Zinc(II) and Mercury(II) Complexes of N‐(Pyridin‐2‐ylmethylene)benzene‐1,4‐diamine
Authors: Marjani Katayoun , Asgarian Jafar , Mousavi Mohsen , Amani Vahid
Published: December 2008

The behavior of N,N′‐bis(pyridin‐2‐ylmethylene)benzene‐1,4‐diamine (L) towards zinc(II), cadmium(II), and mercury(II) chlorides was studied in methanol solutions. In the presence of metal ions, the organic molecule was decomposed to N‐(pyridin‐2‐ylmethylene)benzene‐1,4‐diamine (L′), and complexes of general formula M(L′)Cl2 were isolated from the mixture. The complexes were identified by elemental analysis, IR, 1H NMR, and 13C NMR spectra, and their structures were further confirmed by single‐crystal X‐ray diffraction analysis of Zn(L′)Cl2 and Hg(L′)Cl2. In the solid state of both complexes, the molecules are stabilized by N–H···Cl hydrogen bonds and aromatic π–π stacking interactions.
Separation of 1,3‐Cyclohexanebis(methylamine) Isomers by Template Synthesis of Open‐Framework Bimetallic Phosphites
Authors: Chen Guangyan , Su Hao , Yu Jianguo , Yang Yang , Zhao Yongnan , Fu Zhifeng
Published: December 2008

Two three‐dimensional open‐framework bimetallic phosphites have been hydrothermally synthesized by using 1,3‐cyclohexanebis(methylamine), CHBMA, as template. Compound TJPU‐3Mn crystallizes in the monoclinic space group C2/c with a = 33.929(7) Å, b = 13.045(3) Å, c = 8.9713(18) Å, β = 104.37(3)°, V = 3846.5(13) Å3, Z = 4. The extended structure of TJPU‐3Mn is constructed by MO4, PO4, and HPO3 blocks that form a macroanionic framework with extra‐large 20‐ring channels running along the [001] direction. The CHBMA cations and water molecules are located in the channel spaces and are involved in complex H‐bonding to the framework. It is a rare structural analogue of the well‐known aluminophosphate JDF‐20. Replacing Mn by Fe in the starting mixture leads to formation of TJPU‐6Fe, which crystallizes in the orthorhombic space group Pna21 with a = 14.0720(5), b = 14.5227(5), c = 10.4461(3) Å, V = 2134.80(12) Å3, Z = 2. The connection of MO4 and HPO3 produces a new 6‐1 secondary building unit (SBU). Interconnection of these SBUs generates a layer in the bc plane with 12‐ring windows and a chain along the a direction with the SBUs alternately oriented up and down. Pillaring of the layers by the chains produces a three‐dimensional architecture with zigzag 12‐ring channels due to the upwardly and downwardly arranged SBUs in the chain. While CHBMA cations exist in cis form in TJPU‐3Mn, they have trans configuration in TJPU‐6Fe. The present results show potential for separating CHBMA isomers by means of hydrothermal reactions.
Chelation of CeIII and PrIII by N,N′‐Bis(pyridoxylideneiminato)ethylene, a Schiff Base Ligand Derived from Vitamin B6: Synthesis, Structural Features and TGA Evaluations of [M(Hpyr2en)(pyr2en)]·nH2O (M = CeIII, n = 2; PrIII, n = 8)
Authors: Manzoni de Oliveira Gelson , Bortolotto Ricardo , Ribas Douglas G. , Faoro Eliandro , Schulz Lang Ernesto , Burrow Robert A.
Published: December 2008

The neutral Schiff base N,N′‐bis(pyridoxylideneiminato)ethylene (H2pyr2en) reacts with CeCl3·4H2O and PrCl3·4H2O to give [Ce(Hpyr2en)(pyr2en)]·2H2O (1) and [Pr(Hpyr2en)‐(pyr2en)]·8H2O (2). In the two bimolecular chelate systems, the endo hydroxyl groups of the rings undergo deprotonation by transferring one proton to the pyridinic nitrogen atoms. This confirms the ability of the pyridoxal containing ligand H2pyr2en to form stable heavy metal chelates with unusual coordination polyhedra. Complexes 1 and 2 show coordination number 8, and represent a distorted quadratic antiprismatic arrangement. To date no other references have been made to the complexation of Ce and Pr by any vitamin B6 derivative. The synthesis and the structure elucidation of 1 and 2 represent a contribution to the research on prevention and therapy of damages caused by heavy elements.
Population dynamics of two rodent species in agro‐ecosystems of central Argentina: intra‐specific competition, land‐use, and climate effects
Authors: Andreo Verónica , Lima Mauricio , Provensal Cecilia , Priotto José , Polop Jaime
Published: December 2008

Understanding the role of feedback structure (endogenous processes) and exogenous (climatic and environmental) factors in shaping the dynamics of natural populations is a central challenge within the field of population ecology. We attempted to explain the numerical fluctuations of two sympatric rodent species in agro‐ecosystems of central Argentina using Royama's theoretical framework for analyzing the dynamics of populations influenced by exogenous climatic forces. We found that both rodent species show a first‐order negative feedback structure, suggesting that these populations are regulated by intra‐specific competition (limited by food, space, or enemy‐free space). In Akodon azarae endogenous structure seems to be very strongly influenced by human land‐use represented by annual minimum normalized difference vegetation index (NDVI), with spring and summer rainfall having little influence upon carrying capacity. Calomys venustus’ population dynamics, on the other hand, seem to be more affected by local climate, also with spring and summer rainfall influencing the carrying capacity of the environment, but combined with spring mean temperature.
Factors influencing the distribution and growth of dwarf bamboo, Fargesia nitida, in a subalpine forest in Wolong Nature Reserve, southwest China
Authors: Wang Yong Jian , Tao Jian Ping , Zhong Zhang Cheng
Published: December 2008

Dwarf bamboos impose intense resource competition in subalpine coniferous forests, and their exclusive densities have crucial impacts on tree regeneration and understory species diversity. We studied the factors influencing the distribution and growth of dwarf bamboo, Fargesia nitida, in a subalpine forest in southwest China. TWINSPAN, based on an attribute matrix, could divide the subalpine forest into 11 sub‐associations, and more clearly reflected ecological functional features of the subalpine forest than analysis based on a species matrix. TWINSPAN was also generally consistent with DCA ordination based on the attribute matrix. DCA and DCCA ordination showed relationships between the distribution of F. nitida population and environment factor. The first DCCA axis showed topography and disturbance gradients (except fallen trees and broken branches); the second DCCA axis showed canopy density and composition gradients. Stepwise multiple regression analyses showed that distribution (culm density and coverage) of F. nitida decreased significantly with landslide and slope aspect, and increased significantly with soil status. The light condition had positive effects on growth and size of bamboo. A stable environment in the northern slope and more broadleaved species dominating in canopy would increase the dwarf bamboo biomass. Thus, the disturbance regimes, the slope aspect and the BA of evergreen conifer trees can provide useful guidelines for the control and management of F. nitida populations, and in helping to understand the succession and regeneration of subalpine forest in this region.
T1 Radiculopathy: Electrodiagnostic Evaluation
Authors: Radecki Jeffrey , Feinberg Joseph H. , Zimmer Zachary R.
Published: December 2008

Electromyography (EMG) studies are useful in the anatomical localization of nerve injuries and, in most cases, isolating lesions to a single nerve root level. Their utility is important in identifying specific nerve-root-level injuries where surgical or interventional procedures may be warranted. In this case report, an individual presented with right upper extremity radicular symptoms consistent with a clinical diagnosis of cervical radiculopathy. EMG studies revealed that the lesion could be more specifically isolated to the T1 nerve root and, furthermore, provided evidence that the abductor pollicis brevis receives predominantly T1 innervation.
Using Theoretical Correction Factors for Quantitative Analysis of Sterols and Sterol Concentrates
Authors: Costin Colin D. , Hansen Steven L. , Chambers Daniel P.
Published: December 2008

A common detector for the analysis of sterols and sterol concentrates by gas chromatography is the flame ionization detector (FID). The detector measures the response of ions from a molecule as it is pyrolyzed in a hydrogen flame. The response is relative to the number of hydrogen and carbon atoms in a molecule and it gives different responses for the same amounts of different analytes. Theoretical correction factors (TCF) can be used to account for these differences during data analysis and are based upon the number of active carbons in a molecule and can be calculated from known structures. TCF have been used to provide a more reproducible approach to the analysis of sterol concentrates in raw materials. Use of empirical correction factors (ECF) requires determination of relative responses for each analyte and also a high purity standard (and determination of that purity), which can be expensive or difficult to obtain for the more uncommon sterols. Experiments have been conducted to determine ECF for Ergost‐5‐en‐3‐ol, (3β,24R), commonly known as campesterol, Stigmasta‐5,22‐dien‐3‐ol, (3β,22E), commonly known as stigmasterol, and Stigmast‐5‐en‐3‐ol, (3β), commonly known as β‐sitosterol and compared to the calculated TCF for these same sterols. The experiments evaluated differences in concentration, standard purity, and injection technique and found that all three factors had an effect on the determination of ECF. It was also found that cool on column injections gave more accurate ECF values and are preferable for quantitative analysis of sterols.
Docetaxel/zoledronic acid combination triggers apoptosis synergistically through downregulating antiapoptotic Bcl‐2 protein level in hormone‐refractory prostate cancer cells
Authors: Karabulut B. , Erten C. , Gul M.K. , Cengiz E. , Karaca B. , Kucukzeybek Y. , Gorumlu G. , Atmaca H. , Uzunoglu S. , Sanli U.A. , Baran Y. , Uslu R.
Published: December 2008

Docetaxel, a semi‐synthetic taxane analogue, is used effectively in the treatment of metastatic prostate cancer. Zoledronic acid, the most potent member of bisphosphonates, has shown pleiotropic anti‐tumoral effects on prostate cancer cells. We have explored the possible additive/synergistic effects and the apoptotic pathways induced by combination treatment of docetaxel and zoledronic acid in hormone and drug refractory, PC‐3 and DU‐145 prostate cancer cells. Combination of docetaxel and zoledronic acid synergistically inhibits cell growth in PC‐3 and DU‐145 cells. Moreover, this effect was due to downregulation of antiapoptotic protein Bcl‐2 in PC‐3 and DU‐145 cells. In conclusion, docetaxel/zoledronic acid combination is potentially a novel and effective approach for the treatment of prostate cancer.
Effects of lactoferrin on the differentiation of pluripotent mesenchymal cells
Authors: Yagi Motohiko , Suzuki Naoto , Takayama Tadahiro , Arisue Masatoshi , Kodama Takuya , Yoda Yasushi , Otsuka Kichibee , Ito Koichi
Published: December 2008

Lactoferrin accelerates bone formation, but the precise cellular mechanism behind this is still unclear. We examined the effect of lactoferrin on the differentiation of pluripotent mesenchymal cells using a typical pluripotent mesenchymal cell line, C2C12. Cells were cultured in low‐mitogen differentiation medium to induce cell differentiation, with or without the addition of lactoferrin. The cell lineage was determined by alkaline phosphatase (ALPase) activity, mRNA expression of cellular phenotype‐specific markers using real‐time polymerase chain reaction (PCR), and protein synthesis using Western blotting. The expression of low‐density lipoprotein lipase receptor‐related proteins (LRPs) 1 and 2, both lactoferrin receptors, was determined by reverse transcription‐PCR. ALPase activity increased after the addition of lactoferrin. The mRNA expression of Runx2, osteocalcin, and Sox9 increased markedly as a result of lactoferrin treatment, whereas the expression of MyoD, desmin, and PPARγ decreased significantly. Western blots showed that lactoferrin stimulation increased Runx2 and Sox9 proteins, whereas it decreased MyoD and PPARγ synthesis. C2C12 cells expressed the LRP1 lactoferrin receptor. These results indicate that lactoferrin treatment converts the differentiation pathway of C2C12 cells into the osteoblastic and chondroblastic lineage.
Pax3 and Pax7 expression during myoblast differentiation in vitro and fast and slow muscle regeneration in vivo
Authors: Brzóska Edyta , Przewoźniak Marta , Grabowska Iwona , Jańczyk‐Ilach Katarzyna , Moraczewski Jerzy
Published: December 2008

In this report, we focused on Pax3 and Pax7 expression in vitro during myoblast differentiation and in vivo during skeletal muscle regeneration. We showed that Pax3 and Pax7 were present in EDL (extensor digitorum longus) and Soleus muscle derived cells. These cells express in vitro a similar level of Pax3 mRNA, however, differ in the levels of mRNA encoding Pax7. Analysis of Pax3 and Pax7 proteins showed that Soleus and EDL satellite cells differ in the level of Pax3/7 proteins and also in the number of Pax3/7 positive cells. Moreover, Pax3/7 expression was restricted to undifferentiated cells, and both proteins were absent at further stages of myoblast differentiation, indicating that Pax3 and Pax7 are down‐regulated during myoblast differentiation. However, we noted that the population of undifferentiated Pax3/7 positive cells was constantly present in both in vitro cultured satellite cells of EDL and Soleus. In contrast, there was no significant difference in Pax3 and Pax7 during in vivo differentiation accompanying regeneration of EDL and Soleus muscle. We demonstrated that Pax3 and Pax7, both in vitro and in vivo, participated in the differentiation and regeneration events of muscle and detected differences in the Pax7 expression pattern during in vitro differentiation of myoblasts isolated from fast and slow muscles.
The factor structure and factorial invariance of the Pain‐Coping Questionnaire across age: Evidence from community‐based samples of children and adults
Authors: Huguet Anna , Miró Jordi , Nieto Rubén
Published: December 2008

The Pain‐Coping Questionnaire was developed for children to assess pain‐coping strategies. It was originally suggested as a second‐order factor measure: eight first‐order factors and three higher‐order factors. The main objective of this study was to investigate the psychometric properties of the PCQ when used with children and adults. Two samples of 702 children and 590 adults completed the measure. Confirmatory factor analytic procedures were used to examine the factor structure, and invariance across samples. The results provided good support for a second‐order structural model of seven subscales for children, for a first‐order structural model of seven subscales for adults, and for between‐group invariance first‐order structural model. These findings suggest that data obtained on the seven first‐order factors from children are directly comparable to scores from adults. The internal consistency, criterion validity and convergent validity were also confirmed in both children and adult samples. This work also reports some preliminary findings related to sex and age differences on the use of pain‐coping styles.
Effect of somatostatin analogue octreotide on pain relief after major abdominal surgery
Authors: Dahaba Ashraf A. , Mueller Gabriele , Mattiassich Georg , Rumpold‐Seitlinger Gudrun , Bornemann Helmar , Rehak Peter H. , Linck Guillermo , Mischinger Hans‐Joerg , Metzler Helfried
Published: December 2008

Background: Octreotide acetate is an 8‐amino‐acids synthetic octapeptide analogue of somatostatin with much‐enhanced duration of action and lower incidence of side effects. We assessed the utility of using intravenous octreotide as an adjuvant to opioid analgesia that might exert a post‐operative opioid‐sparing effect.

Methods: Forty‐four patients were randomly allocated, to receive either a placebo or intraoperative octreotide 0.33μgkg−1h−1 intravenous infusion that was maintained in the post‐operative period. Patients received for post‐operative analgesia an intravenous piritramide patient controlled analgesia (PCA), set to deliver a piritramide 0.02mgkg−1 dose.

Results: Two‐way ANOVA revealed significantly fewer (P=0.0003) mean±SD weighted piritramide dose requirements in the octreotide group (19.5±6.3μgkg−1h−1) than in the control group (35.7±8.2μgkg−1h−1). Dunnett's two‐sided multiple‐comparison post hoc test revealed a significant difference between the two groups during the first 22 post‐operative hours, following which there were no differences between the two groups. There were no significant differences over time in the mean arterial pressure (P=0.722), heart rate (P=0.579) and respiratory rate (P=0.823) between the octreotide group (80±10mm Hg, 74±12, 14±2) and the control group (82±9mm Hg, 76±11, 15±3), respectively.

Conclusion: We demonstrated that perioperative octreotide intravenous infusion could be an adjuvant to opioid analgesia as it exerted a piritramide opioid‐sparing effect. We encountered more systemic side effects such as nausea, abdominal discomfort, and diarrhea in the octreotide group than in the control group. Our findings could be beneficial to patients who cannot tolerate the adverse effects of opioids.