bluuebunny/crossref_metadata_2025_split huggingface dataset:
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

AbstractThe 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

AbstractTwo 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

AbstractThe 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

AbstractUnderstanding 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

AbstractDwarf 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.
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

AbstractA 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

AbstractDocetaxel, 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

AbstractLactoferrin 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

AbstractIn 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

ABSTRACTThe 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

ABSTRACTBackground: 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.
Anticonvulsant drugs for pediatric migraine prevention: An evidence‐based review
Authors: Bakola Eleni , Skapinakis Petros , Tzoufi Meropi , Damigos Dimitris , Mavreas Venetsanos 
Published: December 2008

ABSTRACTBackground: The use of anticonvulsant drugs for the prevention of migraine in children and adolescents has been supported in the past.Aims: To evaluate the available evidence for the efficacy and safety of anticonvulsants drugs in the prevention of migraine attacks in children and adolescents.Methods: Studies were selected through a comprehensive literature search. We included all types of study designs (controlled and uncontrolled) due to the limited evidence. Monthly migraine frequency was used as the primary outcome measure in most of the studies. Studies were classified into levels of evidence according to their design.Results: Fourteen studies were included with a total of 939 patients. Topiramate (4 randomized controlled trials [RCT], two uncontrolled trials), sodium valproate/divalproex sodium (two RCTs, one uncontrolled trial, two retrospective chart reviews) levetiracetam and zonisamide (both only uncontrolled studies) are the anticonvulsants that have been reported in the literature. The findings show that valproate is not different from placebo and topiramate may not be different but further randomized trials are needed. All drugs were well tolerated in this age group with no serious events reported.Conclusions: The use of anticonvulsants in the prevention of migraine in children and adolescents is not adequately supported by methodologically sound RCTs. More research is needed in the future to establish the efficacy and safety of specific agents.
Cerebral expression of DNA repair protein, Ku70, and its association with cell proliferation following cerebral hypoxia–ischemia in neonatal rats
Authors: Meng Shuzhen , Lin Lily , Lama Sanju , Qiao Min , Tuor Ursula I. 
Published: December 2008

AbstractWe hypothesized that increased Ku70 expression could be involved in recovery following cerebral hypoxia–ischemia. We investigated the progression of cerebral alterations in Ku70 expression at different time points (24 h, 72 h, 1 week, 4 weeks and 8 weeks) after hypoxia–ischemia (right carotid artery occlusion plus 1.5 h of hypoxia) in neonatal rats. To determine whether in addition to its known role of DNA repair, Ku70 was associated with cell death or cell proliferation we performed double staining for Ku70 and DNA fragmentation or bromodeoxyuridine, respectively. The results show that Ku70 expression was increased in the infarct core and peri‐infarct regions at 24 h following hypoxia–ischemia. The increased Ku70 expression was transient in the infarct core with a loss of Ku70 positive cells over days. In contrast, in the peri‐infarct region the expression of Ku70 remained increased at chronic times 8 weeks following the insult. Cells positive for DNA fragmentation were not co‐localized with cells positive for Ku70 after an insult. However, most of the cells positive for bromodeoxyuridine indicative of cell proliferation were positive for Ku70 in the peri‐infarct region at 8 weeks after the insult. Considering the roles of Ku70 in DNA repair or inhibiting apoptosis and its co‐localization within cells that had undergone proliferation, Ku70 may be considered a potential novel target to enhance recovery following hypoxia–ischemia.
A comparison of the effects of soya isoflavonoids and fish oil on cell proliferation, apoptosis and the expression of oestrogen receptors α and β in the mammary gland and colon of the rat
Authors: Kramer Franziska , Johnson Ian T. , Doleman Joanne F. , Lund Elizabeth K. 
Published: December 2008

Isoflavonoids and fish oil may be protective against colorectal cancer, but the evidence in relation to breast cancer risk is ambiguous. In the present study, we have investigated the impact of soya-derived isoflavonoids andn-3 fatty acids from fish oil, both individually and in combination, on apoptosis, cell proliferation and oestrogen receptor (ER) expression in the colon and mammary gland of the rat. Female rats were fed diets high inn-3 fatty acids (80 g/kg diet) or soya protein (765 mg/kg diet isoflavones) for 2 weeks, and then killed before the removal of the colon and mammary glands. Cell proliferation and apoptosis were quantified morphologically in whole crypts and terminal end buds. The expressions ofERαandERβwere measured in colon tissue scrapes and the mammary gland. Fish oil significantly increased apoptosis and decreased mitosis in both tissues, an effect associated with a decrease in the expressions ofERα andERβ. Soya had no effect on apoptosis in either tissue, but reduced mitosis in the colon (P < 0·001) while increasing it in the mammary gland (P = 0·001). The changes in proliferation were associated with contrasting changes in theERexpression such that fish oil significantly decreased bothERβandERα, while soya increasedERαand decreasedERβ. The results may provide a novel mechanism by whichn-3 fatty acids could reduce cancer risk, but the interpretation of the results in relation to soya consumption and breast cancer risk requires further investigation.
Conditions that alter saccadic eye movement latencies and affect target choice to visual stimuli and to electrical stimulation of area V1 in the monkey
Authors: SCHILLER PETER H. , KENDALL GEOFFREY L. , SLOCUM WARREN M. , TEHOVNIK EDWARD J. 
Published: December 2008

AbstractIn this study, we examined procedures that alter saccadic latencies and target selection to visual stimuli and electrical stimulation of area V1 in the monkey. It has been shown that saccadic eye movement latencies to singly presented visual targets form a bimodal distribution when the fixation spot is turned off a number of milliseconds prior to the appearance of the target (the gap period); the first mode has been termed express saccades and the second regular saccades. When the termination of the fixation spot is coincident with the appearance of the target (0 ms gap), express saccades are rarely generated. We show here that a bimodal distribution of saccadic latencies can also be obtained when an array of visual stimuli is presented prior to the appearance of the visual target, provided the elements of the array overlap spatially with the visual target. The overall latency of the saccadic eye movements elicited by electrical stimulation of area V1 is significantly shortened both when a gap is introduced between the termination of the fixation spot and the stimulation and when an array is presented. However, under these conditions, the distribution of saccadic latencies is unimodal. When two visual targets are presented after the fixation spot, introducing a gap has no effect on which target is chosen. By contrast, when electrical stimulation is paired with a visual target, introducing a gap greatly increases the frequency with which the electrical stimulation site is chosen.