bluuebunny/crossref_metadata_2025 huggingface dataset:
Prognostic factors and predictive model in patients with advanced biliary tract adenocarcinoma receiving first‐line palliative chemotherapy
Authors: Park Inkeun , Lee Jae‐Lyun , Ryu Min‐Hee , Kim Tae‐Won , Sook Lee Sung , Hyun Park Do , Soo Lee Sang , Wan Seo Dong , Koo Lee Sung , Kim Myung‐Hwan
Published: June 2009

BACKGROUND:

Advanced biliary tract adenocarcinoma (BTA) has been a rare but fatal cancer. If unresectable, palliative chemotherapy improved the quality and length of life, but to the authors' knowledge, prognostic factors in such patients have not been well established to date. In the current study, prognostic factors were investigated in patients with advanced BTA receiving first‐line palliative chemotherapy.

METHODS:

Data from 213 patients with advanced BTA who were in prospective phase 2 or retrospective studies from September 2000 through October 2007 were used.

RESULTS:

With a median follow‐up duration of 29.7 months, the median overall survival (OS) was 7.3 months (95% confidence interval [95% CI], 6.3 months‐8.3 months). A Cox proportional hazards model indicated that metastatic disease (hazards ratio [HR], 1.521; P = .011), intrahepatic cholangiocellular carcinoma (HR, 1.368; P = .045), liver metastasis (HR, 1.845; P < .001), Eastern Cooperative Oncology Group performance status (HR, 1.707; P < .001), and alkaline phosphatase level (IU/L) (HR, 1.001; P < .001) were statistically significant independent predictors of poor prognosis. Patients were classified into 3 risk groups based on the prognostic index (PI), which was constructed using the regression coefficients of each variable. The median OS was 11.5 months (95% CI, 9.6 months‐13.5 months) for the low‐risk group (PI ≤ 1.5; n = 67), 7.3 months (95% CI, 5.7 months‐8.9 months) for the intermediate‐risk group (PI > 1.5 but ≤ 2.2; n = 75), and 3.6 months (95% CI, 2.9 months‐4.1 months) for the high‐risk group (PI > 2.2; n = 70 [P < .001]).

CONCLUSIONS:

Five prognostic factors in patients with advanced BTA were identified. The predictive model based on PI appears to be promising and may be used for the management of individual patients and to guide the design of future clinical trials, although external validation is needed. Cancer 2009. © 2009 American Cancer Society.
Randomized phase 2/3 trial of CpG oligodeoxynucleotide PF‐3512676 alone or with dacarbazine for patients with unresectable stage III and IV melanoma
Authors: Weber Jeffrey S. , Zarour Hassan , Redman Bruce , Trefzer Uwe , O'Day Steven , van den Eertwegh Alfons J. M. , Marshall Ernest , Wagner Stefan
Published: June 2009

BACKGROUND:

The primary objective of this phase 2 study was to assess the objective response rate (complete response [CR] + partial responses [PR]), by Response Evaluation Criteria in Solid Tumors, of PF‐3512676, a CpG oligodeoxynucleotide, alone in 2 doses or in combination with dacarbazine (DTIC) in patients with unresectable stage IIIB/C or stage IV malignant melanoma, with the aim of selecting an arm to take forward to a phase 3 portion of the study.

METHODS:

A total of 184 patients were randomized to 1 of 4 treatments: PF‐3512676 10 mg (low dose), at 40 mg (high dose), 40 mg plus DTIC (850 mg/m2), or DTIC (850 mg/m2) alone. Patients received PF‐3512676 subcutaneously weekly in a 3‐week cycle and received DTIC intravenously on the first week of the cycle.

RESULTS:

The objective response rate (PR or CR, confirmed or unconfirmed) in the 40 mg + DTIC arm was 16% (7 patients) compared with 8% (3 patients) with DTIC alone. One (2%) patient in the 10‐mg and 0 patients in the 40‐mg arms achieved an objective response. Best response of CR or PR or stable disease (SD), with no minimum duration defined for SD, was achieved by 15 (33%) patients in the 40 mg + DTIC arm, 15 (38%) patients in the DTIC‐only arm, 8 (17%) patients in the 10‐mg arm, and 9 (20%) patients in the 40‐mg arm. The most frequently reported adverse events were classified as local injection site reactions or systemic flu‐like symptoms, specifically fatigue, rigors, and pyrexia.

CONCLUSIONS:

PF‐3512676 at the doses used was generally well tolerated. The modest objective response rates observed in all arms did not warrant continuation to the phase 3 portion of the study. Cancer 2009. © 2009 American Cancer Society.
Predictors of avascular necrosis of bone in long‐term survivors of hematopoietic cell transplantation
Authors: Campbell Stephanie , Sun Can‐Lan , Kurian Seira , Francisco Liton , Carter Andrea , Kulkarni Sameer , Parker Pablo , Karanes Chatchada , Forman Stephen J. , Bhatia Smita
Published: June 2009

BACKGROUND:

Avascular necrosis (AVN) is a debilitating condition reported after chronic steroid use. The purpose of this study was to describe the magnitude of risk in individuals who survived ≥1 years after hematopoietic cell transplantation (HCT), and to investigate the role of immunosuppressive agents such as prednisone, tacrolimus (FK506), mycophenolate mofetil (MMF), and cyclosporine (CSA) in the development of AVN after HCT.

METHODS:

Using a retrospective study design, the authors followed 1346 eligible patients for the development of AVN. Cumulative incidence was calculated taking into consideration competing risk from death and disease recurrence. Cox proportional regression techniques were used to identify associated risk factors.

RESULTS:

The median age at HCT was 34 years (range, 7 months‐69 years), and median length of follow‐up for those surviving was 8.2 years. Seventy‐five patients developed AVN of 160 joints. The cumulative incidence of AVN at 10 years was 2.9% after autologous HCT, 5.4% after allogeneic matched related donor HCT, and 15% after unrelated donor HCT (P< .001 compared with autologous HCT recipients). For allogeneic transplant recipients, male sex (relative risk [RR], 2.1; 95% confidence interval [95% CI], 1.1‐4.0); presence of chronic graft‐versus‐host disease (RR, 2.2); and exposure to CSA, FK506, prednisone, and MMF rendered patients at increased risk, especially in patients with a history of exposure to ≥3 drugs (RR, 9.2; 95% CI, 2.42‐35.24).

CONCLUSIONS:

Future studies examining the pathogenetic mechanism underlying AVN should help develop targeted interventions to prevent this chronic debilitating condition. Cancer 2009. © 2009 American Cancer Society.
Chronic lymphocytic leukemia
Authors: Motta Marina , Wierda William G. , Ferrajoli Alessandra
Published: June 2009

Patients with purine analogue–refractory chronic lymphocytic leukemia (CLL) have short survival and limited treatment options. Defining the best salvage strategies for this population is challenging, because limited data are available from clinical trials, and because studies have enrolled mixed populations (patients with recurrent and refractory disease or patients with refractory disease and Richter transformation). Moreover, patients with refractory CLL have a high incidence of unfavorable molecular and clinical features, such as high‐risk genomic profiles, unmutated immunoglobulin heavy‐chain genes, expression of zeta‐chain–associated protein kinase 70, and bulky lymphadenopathies. These patients are also severely immunosuppressed because of the underlying disease and the treatments received, and experience a high rate of infectious complications that pose an additional difficulty in selecting treatment. Despite these challenges, in parallel with better characterizations of the biologic features of refractory CLL, the number of available treatment modalities for this population has increased. Several chemoimmunotherapy combinations have been developed, and novel agents with a different mechanism of action are being investigated in clinical trials. Furthermore, allogeneic stem cell transplantation with nonmyeloablative conditioning regimens is a therapeutic strategy that is increasingly offered to patients with refractory CLL. Cancer 2009. © 2009 American Cancer Society.
Race does not impact outcome for advanced ovarian cancer patients treated with cisplatin/paclitaxel
Authors: Farley John H. , Tian Chunqiao , Rose G. Scott , Brown Carol L. , Birrer Michael , Larry Maxwell G.
Published: June 2009

BACKGROUND:

The objectives of this study were to confirm whether racial disparity exists with regard to outcome between black women and white women with ovarian cancer and to identify factors associated with the administration of adjuvant treatment that had an impact on survival.

METHODS:

A retrospective review of 97 black women and 1392 white women with International Federation of Gynecology and Obstetrics stage III/IV ovarian carcinoma was performed. All patients received paclitaxel combined with cisplatin while participating in 1 of 7 Gynecologic Oncology Group clinical trials. The treatment parameters that were reviewed included relative dose, relative time, and relative dose intensity. The treatment parameters and outcomes were compared between black patients and white patients.

RESULTS:

There were no differences in relative dose (0.90 vs 0.89), relative time (1.02 vs 0.99), or relative dose intensity (0.90 vs 0.91) received between black patients and white patients. Black women had less grade 3 and 4 leukopenia (53% vs 63%; P < .05) and gastrointestinal toxicity (10% vs 19%; P < .05) than white women. Performance status >0, age ≥70 years, and mucinous histology were associated with not completing treatment (P < .001). The median progression‐free survival was 16.2 months for black patients and 16.1 months for white patients, and the median overall survival was 37.9 months and 39.7 months, respectively (P > .05 for all).

CONCLUSIONS:

When they received similar treatment, there was no difference in clinical outcome between black women and white women with advanced stage epithelial ovarian cancer when they received similar treatment as participants in Gynecologic Oncology Group clinical trials. Black patients may experience less severe gastrointestinal toxicity or leukopenia compared with whites when treated with platinum‐based chemotherapy. Cancer 2009. Published 2009 by the American Cancer Society.
Dasatinib or high‐dose imatinib for chronic‐phase chronic myeloid leukemia resistant to imatinib at a dose of 400 to 600 milligrams daily
Authors: Kantarjian Hagop , Pasquini Ricardo , Lévy Vincent , Jootar Saengsuree , Holowiecki Jerzy , Hamerschlak Nelson , Hughes Timothy , Bleickardt Eric , Dejardin David , Cortes Jorge , Shah Neil P.
Published: June 2009

BACKGROUND:

In patients with chronic‐phase chronic myeloid leukemia (CP‐CML), imatinib resistance is of increasing importance. Imatinib dose escalation was the main treatment option before dasatinib, which has 325‐fold more potent inhibition than imatinib against unmutated Bcr‐Abl in vitro. Data with a minimum of 2 years of follow‐up were available for the current study of dasatinib and high‐dose imatinib in CP‐CML resistant to imatinib at daily doses from 400 mg to 600 mg.

METHODS:

A phase 2, open‐label study was initiated of 150 patients with imatinib‐resistant CP‐CML who were randomized (2:1) to receive either dasatinib 70 mg twice daily (n = 101) or high‐dose imatinib 800 mg (400 mg twice daily; n = 49).

RESULTS:

At a minimum follow‐up of 2 years, dasatinib demonstrated higher rates of complete hematologic response (93% vs 82%; P = .034), major cytogenetic response (MCyR) (53% vs 33%; P = .017), and complete cytogenetic response (44% vs 18%; P = .0025). At 18 months, the MCyR was maintained in 90% of patients on the dasatinib arm and in 74% of patients on the high‐dose imatinib arm. Major molecular response rates also were more frequent with dasatinib than with high‐dose imatinib (29% vs 12%; P = .028). The estimated progression‐free survival also favored dasatinib (unstratified log‐rank test; P = .0012).

CONCLUSIONS:

After 2 years of follow‐up, dasatinib demonstrated durable responses and improved response and progression‐free survival rates relative to high‐dose imatinib. Cancer 2009. © 2009 American Cancer Society.
Series solution for a delay differential equation arising in electrodynamics
Authors: Koçak Hüseyin , Yıldırım Ahmet
Published: June 2009

In this study, the pantograph equation is investigated using the homotopy perturbation and variational iteration methods. The pantograph equation is a delay differential equation that arises in quite different fields of pure and applied mathematics, such as number theory, dynamical systems, probability, mechanics and electrodynamics. The procedure of present methods are based on the search for a solution in the form of a series with easily computed components. Application of these techniques to this problem shows the rapid convergence of the sequence constructed by these methods to the exact solution. Moreover, this technique reduces the volume of calculations by not requiring discretization of the variables, linearization or small perturbations. Copyright © 2009 John Wiley & Sons, Ltd.
How to construct efficient on‐line/off‐line threshold signature schemes through the simulation approach
Authors: Gao Chong‐zhi , Wei Baodian , Xie Dongqing , Tang Chunming
Published: June 2009

An on‐line/off‐line threshold signature (𝒪𝒯𝒮) scheme is a distributed cryptosystem in which a group of players jointly generate a signature for a message and use the on‐line/off‐line technique to improve the efficiency of signing. An
𝒪𝒯𝒮 scheme can be applied to large‐scaled distributed data storage systems and can highly improve the efficiency of writing files. There are two approaches to construct an ordinary threshold signature scheme: the direct approach and the simulation approach. Owing to its simplicity, people tend to use the simulation approach, in which the security of a threshold signature scheme is reduced to the security of its underlying (and simpler) signature scheme. The security proof in this approach is based on a theorem that guarantees the validity of the security reduction—we call this theorem the simulation theorem. However, the simulation theorem (and thus the simulation approach) for an ordinary threshold signature scheme cannot be applied to the on‐line/off‐line cases, because partial signature exposure problems might occur in these cases. This paper presents a simulation theorem for the on‐line/off‐line cases, where the security of an 𝒪𝒯𝒮 scheme is reduced to the security of a so‐called divisible on‐line/off‐line signature scheme. This provides a theoretical basis for constructing an 𝒪𝒯𝒮 scheme through the simulation approach. Furthermore, through this approach, we present a concrete 𝒪𝒯𝒮 scheme, which is efficient and its security proof is simple. Copyright © 2009 John Wiley & Sons, Ltd.
Water Splitting on Semiconductor Catalysts under Visible‐Light Irradiation
Authors: Navarro Yerga Rufino M. , Álvarez Galván M. Consuelo , del Valle F. , Villoria de la Mano José A. , Fierro José L. G.
Published: June 2009

Splitting image: Sustainable hydrogen production is a key target for the development of alternative, future energy systems that will provide a clean and affordable energy supply. This Minireview focuses on the development of semiconductor catalysts that enable hydrogen production via water splitting upon visible‐light irradiation.

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Sustainable hydrogen production is a key target for the development of alternative, future energy systems that will provide a clean and affordable energy supply. The Sun is a source of silent and precious energy that is distributed fairly all over the Earth daily. However, its tremendous potential as a clean, safe, and economical energy source cannot be exploited unless the energy is accumulated or converted into more useful forms. The conversion of solar energy into hydrogen via the water‐splitting process, assisted by photo‐semiconductor catalysts, is one of the most promising technologies for the future because large quantities of hydrogen can potentially be generated in a clean and sustainable manner. This Minireview provides an overview of the principles, approaches, and research progress on solar hydrogen production via the water‐splitting reaction on photo‐semiconductor catalysts. It presents a survey of the advances made over the last decades in the development of catalysts for photochemical water splitting under visible‐light irradiation. The Minireview also analyzes the energy requirements and main factors that determine the activity of photocatalysts in the conversion of water into hydrogen and oxygen using sunlight. Remarkable progress has been made since the pioneering work by Fujishima and Honda in 1972, but he development of photocatalysts with improved efficiencies for hydrogen production from water using solar energy still faces major challenges. Research strategies and approaches adopted in the search for active and efficient photocatalysts, for example through new materials and synthesis methods, are presented and analyzed.
Targeted disruption of Sonic Hedgehog in the mouse adrenal leads to adrenocortical hypoplasia
Authors: Ching Saunders , Vilain Eric
Published: June 2009

Development of the mammalian adrenal gland is regulated by a diverse network of growth and transcription factors. Disruptions in these pathways often result in adrenal insufficiency because of adrenal hypoplasia. Several lines of evidence have suggested that the Hedgehog signaling pathway, which controls many aspects of tissue and organ patterning, may play a direct role in adrenal morphogenesis as well. Therefore, we examined the role of Sonic Hedgehog (Shh), a member of the Hedgehog family, in mouse adrenal development. We show that Shh and its downstream effectors Gli1, Gli2, and Gli3 are expressed in the adrenal cortex throughout development, and that Shh is required for normal adrenal organogenesis. Conditional inactivation of Shh in the adrenal cortex using a Cre‐loxP system resulted in severe hypoplasia and disorganization of the cortex. In mice carrying the targeted mutation (Shhfl/fl;SF‐1/Cre+), adrenal mass was significantly reduced and the cortex failed to encapsulate the adrenal medulla. Taken together, these results establish a direct role for Shh signaling in normal adrenal development. genesis 47:628–637, 2009. © 2009 Wiley‐Liss, Inc.
Functional dissection of Timekeeper (Tik) implicates opposite roles for CK2 and PP2A during Drosophila neurogenesis
Authors: Kunttas‐Tatli Ezgi , Bose Anasua , Kahali Bhaskar , Bishop Clifton P. , Bidwai Ashok P.
Published: June 2009

Repression by E(spl)M8 during inhibitory Notch (N) signaling (lateral inhibition) is regulated, in part, by protein kinase CK2, but the involvement of a phosphatase has been unclear. The studies we report here employ Tik, a unique dominant‐negative (DN) mutation in the catalytic subunit of CK2, in a Gal4‐UAS based assay for impaired lateral inhibition. Specifically, overexpression of Tik elicits ectopic bristles in N+ flies and suppresses the retinal defects of the gain‐of‐function allele Nspl. Functional dissection of the two substitutions in Tik (M161K and E165D), suggests that both mutations contribute to its DN effects. While the former replacement compromises CK2 activity by impairing ATP‐binding, the latter affects a conserved motif implicated in binding the phosphatase PP2A. Accordingly, overexpression of microtubule star (mts), the PP2A catalytic subunit closely mimics the phenotypic effects of loss of CK2 functions in N+ or Nspl flies, and elicits notched wings, a characteristic of N mutations. Our findings suggest antagonistic roles for CK2 and PP2A during inhibitory N signaling. genesis 47:647–658, 2009. © 2009 Wiley‐Liss, Inc.
Eating disorders in older women: Does late onset anorexia nervosa exist?
Authors: Scholtz Samantha , Hill Laura S. , Lacey Hubert
Published: June 2009

Objective:

The objective of this study is to determine whether eating disorders can present for the first time in older people.

Method:

This is a descriptive study of patients above the age of 50 years who have presented to a national eating disorder center within the last 10 years.

Results:

Thirty‐two patients were identified; data were available for 26 of these patients and 11 agreed for further interview and questionnaire completion. There were no cases where the eating disorder had its onset late in life. Of the 11 interviewed, six participants retained a diagnosis of anorexia nervosa, four had Eating Disorder Not Otherwise Specified and only one was recovered. Comorbid depression was universal in those still suffering with an eating disorder diagnosis, and their level of social functioning was impaired.

Discussion:

Anorexia nervosa is a chronic and enduring mental illness that, although rare, can be found in older people. In our sample, we found no evidence of late‐onset disorders; all described cases were lifelong. © 2009 by Wiley Periodicals, Inc. Int J Eat Disord 2010
Trait‐defined eating‐disorder subtypes and history of childhood abuse
Authors: Steiger Howard , Richardson Jodie , Schmitz Norbert , Israel Mimi , Bruce Kenneth R. , Gauvin Lise
Published: June 2009

Objective:

In participants with eating disorders (EDs), prior physical or sexual abuse has been associated with increased likelihood of impulsivity and affective instability. However, previous studies among participants with eating disorders have not systematically explored relationships between empirically derived, personality‐trait‐based classes, on the one hand, and likelihood of exposure to either childhood sexual or physical abuse, on the other.

Method:

We assessed multiple psychopathological traits, eating symptoms, and history of abuse in 185 women with an ED and 93 with no ED.

Results:

A latent class analysis, conducted using psychopathological‐trait measures, yielded latent classes of participants with eating disorders fitting the descriptors “dissocial/impulsive,” “inhibited/compulsive,” and “low psychopathology.” ED was generally associated with increased risk of childhood sexual abuse, but the dissocial/impulsive characteristic corresponded with a unique likelihood of physical abuse and especially high rates of sexual abuse.

Discussion:

Observed associations between different forms of childhood abuse and trait‐defined ED variants help inform models on the development of eating disorders and of psychopathological traits that often accompany them. © 2009 by Wiley Periodicals, Inc. Int J Eat Disord 2010
Assessment of HRQoL in patients with eating disorders by the beta‐binomial regression approach
Authors: Arostegui Inmaculada , Padierna Angel , Quintana Jose M.
Published: June 2009

Objective:

To study the influence of clinical variables on health‐related quality of life (HRQoL) among women with eating disorder (ED) using beta‐binomial regression (BBR) to analyze scores on the Short‐Form 36 (SF‐36) as dependent variable.

Method:

Female patients diagnosed with ED completed the SF‐36 at the beginning of the study and after 2 years of treatment. Sociodemographic and clinical information was recorded. For the multivariate analysis, we used BBR models to identify factors that influence SF‐36.

Results:

Questionnaires were completed by 193 women at baseline and 158 (82%) after 2 years of treatment. Anxiety, depression, and the severity of ED, explained scores in most domains of the SF‐36 at baseline. The main predictor of HRQoL after 2 years of follow‐up was the HRQoL in the same domain at baseline. However, depression, anxiety, and duration of symptoms at baseline also significantly influenced HRQoL after 2 years of treatment in some domains. Higher levels of anxiety or depression, longer duration of symptoms, and poorer SF‐36 scores at baseline were associated with worse HRQoL after 2 years of treatment and follow‐up.

Discussion:

BBR models provide understandable results for clinicians and can be used in multivariate models with HRQoL dependent variables. © 2009 by Wiley Periodicals, Inc. Int J Eat Disord 2010
Towards a spatial understanding of water use of several land‐cover classes: an examination of relationships amongst pre‐dawn leaf water potential, vegetation water use, aridity and MODIS LAI
Authors: Palmer Anthony R. , Fuentes Sigfredo , Taylor Daniel , Macinnis‐Ng Cate , Zeppel Melanie , Yunusa Isa , Eamus Derek
Published: June 2009

Leaf area index (LAI) is a key physical variable which controls the exchange of water and CO2 between the earth and the atmosphere. Recent improvements in the quality of satellite‐derived estimates of LAI, specifically the MODIS LAI product, have led to increased confidence in their operational use. In this study, we examined the relationship amongst MODIS LAI (Collection 5), pre‐dawn leaf water potential (Ψpd) (a surrogate for plant water availability), vegetation water use (ET) and pan evaporation (E0) in forest, evergreen woodland, open shrubland and savanna in Australia. We present three models which demonstrate how the MODIS LAI product can be used to make spatially explicit predictions of the state of three key physical variables, namely Ψpd, the aridity index and vegetation water use. The LAI‐Ψpd model explains how plant available soil moisture can be predicted at a continental scale for intact forests, woodlands and savannas. In a similar manner, the aridity index (mean annual rainfall/E0) shows a powerful relationship with the MODIS LAI values. Using vegetation water use data from 16 field campaigns and published studies, we developed a MODIS LAI‐ET model that provides the ability to predict both site and catchment‐scale annual evapotranspiration. We test the model against independent estimates of site and catchment‐scale vegetation water use. Copyright © 2009 John Wiley & Sons, Ltd.
A Synthetic and X‐ray Crystallographic Study of Zinc and Platinum Complexes of 4,5‐Diazafluoren‐9‐one (Dafone) and Dicobalt Hexacarbonyl Derivatives of 9‐Phenylethynyl‐4,5‐Diazafluoren‐9‐ol: Chelation versus Monocoordination
Authors: Maguire Linda , Seward Corey M. , Baljak Sladjana , Reumann Thea , Ortin Yannick , Banide Emilie , Nikitin Kirill , Müller‐Bunz Helge , McGlinchey Michael J.
Published: June 2009

Reaction of 4,5‐diazafluoren‐9‐one (dafone, 6) and zinc dichloride yields [(dafone)ZnCl2(H2O)] (11) in which the ZnCl2 moiety is coordinated to a single nitrogen atom and also to a molecule of water. Hydrogen bonding, not only to the uncomplexed nitrogen atom of dafone but also to the ketonic oxygen atom of a neighbouring molecule, leads to a zigzag chain structure. In contrast, reaction with anhydrous zinc iodide forms cis‐(dafone)2ZnI2 (12) in which the metal–nitrogen distances – 2.170(5) and 2.456(5) Å – are significantly different. Dafone, in the presence of dimethyl sulfoxide, reacts with K2PtCl4 to produce square‐planar (dafone)PtCl2(dmso) (13), whereas with K2PtBr6 the octahedral complex (dafone)PtBr4 (14) is formed in which the ligand chelates in a symmetrical fashion. Treatment of dafone with phenylethynyllithium furnishes 9‐phenylethynyl‐4,5‐diazafluoren‐9‐ol (7), which forms a square‐planar nitrogen‐bonded PtCl2 complex, 15. Reaction of 7 with Co2(CO)8 yields the (μ‐alkyne)hexacarbonyldicobalt cluster 17, which undergoes protonation at the nitrogen atom to form 20 rather than at the alcohol to form a cobalt‐complexed propargyl cation. Alkynol 7 also reacts with HBr by addition across the triple bond to form Z‐9‐[(2‐bromo‐2‐phenyl)ethenyl]‐4,5‐diazafluoren‐9‐ol (10). X‐ray crystal structures are reported for 6, 7, 10–15, 17 and 20, and their differing hydrogen‐bonding motifs are discussed. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Unconventional Spin Crossover in Dinuclear and Trinuclear Iron(III) Complexes with Cyanido and Metallacyanido Bridges
Authors: Šalitroš Ivan , Boča Roman , Dlháň L'ubor , Gembický Milan , Kožíšek Jozef , Linares Jorge , Moncol' Ján , Nemec Ivan , Perašínová Lucia , Renz Franz , Svoboda Ingrid , Fuess Hartmut
Published: June 2009

A nonsymmetrical triamine, 1,6‐diamino‐4‐azahexane, was Schiff‐condensed with (X‐substituted) o‐salicylaldehyde to yield pentadentate ligands X‐L5: salpet and MeBu‐salpet. These ligands form mononuclear, dinuclear, and trinuclear FeIII complexes, whose structures were determined by single‐crystal X‐ray analysis. Of the mononuclear complexes, [FeIII(salpet)Cl] and [FeIII(MeBu‐salpet)Cl] are high spin (S = 5/2), whereas [FeIII(salpet)CN]·MeOH is low spin (S = 1/2). The dinuclear and trinuclear complexes show a kind ofthermally induced spin crossover. The dinuclear complex [L5FeIII(CN)FeIIIL5](ClO4)·2H2O (L5 = salpet) is a mixed‐spin assembly: the C‐coordinated FeIII center is low spin (L) and the N‐coordinated FeIII center is high spin (H) at low temperature; an antiferromagnetic interaction occurs between them. This LH reference state is mixed with the LL one. Upon heating, the system shows an increasing content of the HH state. Also, the dinuclear complex [L5FeIII(CN)FeIIIL5](BPh4)·2MeCN (L5 = MeBu‐salpet) exhibits a spin transition between LH and HH spin pairs. The mixed‐valence trinuclear complex [L5FeIII{FeII(CN)5(NO)}FeIIIL5]·0.5MeOH·3.75H2O (L5 = salpet) shows spin crossover with a residual high‐spin fraction at liquid He temperature owing to the LL + LH ground state. The metallacyanido‐bridged complex [L5FeIII{Ni(CN)4}FeIIIL5]·2MeOH (L5 = MeBu‐salpet) contains a high‐spin pair, HH, over the whole temperature interval with a ferromagnetic exchange interaction. A theoretical model was outlined that allows simultaneous fitting of all available experimental data (magnetic susceptibility, magnetization, high‐spin mole fraction obtained from the Mössbauer spectra) on a common set of parameters. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Pyridine‐Functionalised (Vinylenedithio)tetrathiafulvalene (VDT–TTF) Derivatives and Their Dithiolene Analogues
Authors: Brooks Andrew C. , Day Peter , Dias Sandra I. G. , Rabaça Sandra , Santos Isabel C. , Henriques Rui T. , Wallis John D. , Almeida Manuel
Published: June 2009

The synthesis and characterisation of a group of vinylenedithio–TTFs bearing two or four 2‐ or 4‐pyridyl groups are described, along with related nickel and gold bidithiolene, as potential substrates for preparing multifunctional materials. In spite of the pyridyl groups not being coplanar with the vinylenedithio–TTF cores and the significant chair‐type distortions of the cores, because of the flexing of the dithiin rings, these substituted donors preserve the stacking ability of the unsubstituted donors in the solid state. The pyridyl substitution does not significantly change the redox potentials of these donors. Electrocrystallisation of a bis(2‐pyridyl) donor with perrhenate gave a dicationic salt in which the donor is both protonated and oxidized, and the pyridinium group makes a hydrogen bond to a perrhenate ion. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
A New Trigonal‐Bipyramidal [CuII(pytBuN3)Cl2] Complex: Synthesis, Structure and Ligand Substitution Behaviour
Authors: Shaban Shaban Y. , Heinemann Frank W. , van Eldik Rudi
Published: June 2009

The synthesis, structure and ligand substitution mechanism of a new five‐coordinate copper(II) complex with a sterically constrained pytBuN3 chelate ligand [pytBuN3 = 2,6‐bis(3,5‐di‐tert‐butylphenyliminomethyl)pyridine] are reported. In the crystal structure of the complex the [Cu(pytBuN3)Cl2] chromophore possesses a distorted trigonal‐bipyramidal coordination geometry. The kinetics and mechanism of chloride substitution by thiourea (TU) and N,N,N′,N′‐tetramethylthiourea (TMTU) were studied in detail as a function of nucleophile concentration, temperature and pressure in methanol as solvent. The kinetics showed that the substitution reaction of [Cu(pytBuN3)Cl2] is a biphasic process that involves the subsequent displacement of both chloride ligands. The substitution of the first chloride by TU, k1296 = 918 ± 30 M–1 s–1, is 570 times faster than the substitution of the second chloride, k2296 = 1.62 ± 0.06 M–1 s–1. Substitution of chloride by TU is characterized by the activation parameters: ΔH# = 42 ± 2 and 58 ± 2 kJ mol–1, ΔS# = –46 ± 7 and –47 ± 6 J K–1 mol–1, and ΔV# = –6.5 ± 0.2 and –5.3 ± 0.7 cm3 mol–1, for the first and second substitution reactions, respectively. It is concluded from the activation parameters that both reactions follow an associative interchange (Ia) mechanism. When the substitution reaction was carried out with the sterically hindered nucleophile TMTU, the rate constant for the displacement of the first chloride, k2296 = 6.9 ± 0.5 M–1 s–1, was more than 133 times slower than for the reaction with TU, which further supports the Ia nature of the substitution mechanism.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Chemistry and Physical Properties of the Phosphide Telluride Zr2PTe2
Authors: Tschulik Kristina , Ruck Michael , Binnewies Michael , Milke Edgar , Hoffmann Stefan , Schnelle Walter , Fokwa Boniface P. T. , Gilleßen Michael , Schmidt Peer
Published: June 2009

The synthesis of the phosphide telluride Zr2PTe2 by solid‐state reaction from the elements at 850 °C or by thermite‐type reaction of Zr and Te8O10(PO4)4 was accomplished. Crystals were grown by chemical vapour transport by using iodine from 800 °C in the direction of higher temperatures up to 900 °C. The chemical bonding in Zr2PTe2 was investigated by the linear muffin‐tin orbital (LMTO) method. The non‐vanishing DOS of zirconium and tellurium states at the Fermi level (EF) complies with the metallic conductivity (ρ ≈ 40 μΩ cm at 300 K) and temperature‐independent Pauli paramagnetism.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
BINBAM – A New Motif for Strong and Chiral Brønsted Acids
Authors: Treskow Marcel , Neudörfl Jörg , Giernoth Ralf
Published: June 2009

We are reporting the first synthesis of the new chiral Brønsted acid BINBAM [(R)‐1,1′‐binaphthyl‐2,2′‐bis(sulfon)amide, 2], which can be obtained in four steps from commercially available BINOL (5). The compound is expected to be an alternative for established catalysts like phosphoric acids of BINOL 4 or TRIP and to show stronger Brønsted acidity. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Single and multigrain quartz‐luminescence dating of irrigation‐channel features in Santa Fe, New Mexico
Authors: Berger Glenn W. , Post Stephen , Wenker Chris
Published: June 2009

Acequias (irrigation channels and ditches) were used by Spanish settlers, their descendants, and Native Americans in New Mexico. Several such features were recently excavated in Santa Fe, but material for numeric dating was difficult to find. Therefore, for this high‐energy‐deposition irrigation‐feature setting we applied optically stimulated luminescence (OSL) sediment dating methods to determine the timing of last filling of some of these acequias. We report multigrain single‐aliquot quartz (MGSAQ) OSL dating results and the first single‐grain quartz (SGQ) OSL dating results for irrigation features. One sample yielded an average age of 96 ± 13 yr, consistent with the maximum expected age of 127 yr (before 2007). An OSL age of 175 ± 15 yr for another sample delimits a sedimentation event since the first construction of that feature ca. 300 yr ago. A sample known to be younger than 400–450 yr but predating the mid‐19th century gave an SGQ age of 376 ±31 yr. These results indicate that: (1) Regional quartz in New Mexico is highly favorable to OSL dating; (2) in this setting, SGQ OSL dating is preferred to MGSAQ dating; and (3) for the last 500–600 yr, SGQ OSL dating in such settings is preferred to14C dating because OSL dating lacks those ambiguities inherent in converting14C ages to calendar years. © 2009 Wiley Periodicals, Inc.
Soil properties and stable carbon isotope analysis of landscape features in the Petexbatún region of Guatemala
Authors: Wright David R. , Terry Richard E. , Eberl Markus
Published: June 2009

Soil properties and stable carbon isotope ratios contained in the soil organic matter (SOM) were used to investigate the change in vegetative history of land cleared anciently for maize (Zea maysL.) agriculture in the Petexbatún region of Guatemala. Maize and other C4plants associated with land clearance leave a carbon isotopic signature in the SOM different from the C3plants of native forest vegetation. Soil profiles were collected from various landscape features around the Classic Maya site of Aguateca: control locations (areas likely not used in ancient agriculture), defensible locations (areas near defensive walls),rejolladas(natural karst depressions), upland locations (well‐drained soils atop the Aguateca escarpment), andbajos(seasonal and perennial wetlands). The chemical and physical properties of the profiles were examined and the soils were taxonomically classified to the great group level. The changes in d13C with soil depth were determined and compared statistically. The13C enrichment of the SOM inbajoandrejolladaprofiles were similar and were significantly (p< 0.05) greater than the control, defensible, and upland soils. This isotopic signature of sustained C4vegetation was likely associated with forest clearance and ancient Maya agriculture. Both thebajoandrejolladalandscape features appear to have been valuable agricultural resources for ancient Maya. © 2009 Wiley Periodicals, Inc.
Sources of social capital: Effects of altruistic citizenship behavior and job involvement on advice network centrality
Authors: Zhang Mian , Zheng Wei , Wei Jun
Published: June 2009

Social capital has been receiving increasing attention in HRD research. However, the sources of social capital have received inadequate attention. Little has been done to reveal how people obtain their social capital in the workplace. This study investigated the effects of employees' altruistic citizenship behavior and job involvement on their advice network centrality. Advice network centrality was used as an indicator of social capital. The results suggest that altruistic citizenship behavior and job involvement are positively associated with employees' advice network centrality. Furthermore, our findings suggest that job involvement moderates the effect of altruistic citizenship behavior on advice network centrality. Theoretical and practical implications for HRD are discussed and future directions are drawn.
Stream nitrate levels in a small catchment in south west England over a period of 35 years (1970–2005)
Authors: Burt Tim P. , Worrall Fred
Published: June 2009

This study considers a 35‐year record of streamwater nitrate concentration in a small agricultural catchment in south west England (Slapton Wood). The study revisits earlier work to assess whether upward trends have been maintained and how the controls upon streamwater concentration have been altered. The study has shown that (1) the catchment has reached a new position of equilibrium and increases in nitrate concentration have lessened; (2) the occurrence of severe drought in the record means that records of less than a decade are misleading and only long‐term records can illustrate changes of state; (3) the change of state observed in the catchment is illustrated in the switching of long‐term memory effects from a negative to a positive annual memory and (4) several significant long‐term impulsivity relationships with rainfall that become insignificant over the course of the study period. The study shows the importance of long‐term records in understanding changes in state in catchments and understanding the time constants of a range of driving processes. Copyright © 2009 John Wiley & Sons, Ltd.
Spatial variation of snowmelt and sublimation in a high‐elevation semi‐desert basin of western Canada
Authors: Jackson Scott I. , Prowse Terry D.
Published: June 2009

The Okanagan Basin, a semi‐desert region of western Canada, is currently experiencing rapidly increasing pressure on its water resources from development and population increases, exacerbated by changes in climate. The major source of freshwater in the region originates from the melt of high‐elevation snowpacks, about which little is currently known, including the proportion of the peak snowpack lost to sublimation. To better understand the hydrologic regime of this snow resource, a detailed field program was conducted during the 2007 snowmelt season. Specifically, peak annual snow distribution, ablation‐season surface‐energy exchange and mass balance were measured in a forested high‐elevation catchment of the Okanagan Basin. During the snowmelt period, 1–4% of the peak annual snow‐water equivalent (SWE) was lost to sublimation in open sites—averaging 0·4 mm d−1. Melt and sublimation rates increased significantly with elevation, and were observed to be higher and more variable in the open sites than under forest canopies. The largest sublimation events (>0·25 mm d−1) were associated with low atmospheric vapour pressure, temperatures below 0 °C, and higher than average wind speeds. Condensation occurred under highly stable conditions in the boundary layer when sensible heat fluxes exceeded net radiative inputs to the snow surface. Melt rates were driven almost entirely by sensible heat fluxes and exceeded 30 mm d−1 during large‐scale advection events. The results from this study will allow water managers to better predict the amount of water available for ecological, agricultural and municipal needs. This work also provides the basis for assessing changes in snow surface energetics due to ongoing salvage cutting in forested areas affected by the current mountain pine‐beetle outbreak. Copyright © 2009 John Wiley & Sons, Ltd and Her Majesty the Queen in right of Canada.
The influence of spatial variability in snowmelt and active layer thaw on hillslope drainage for an alpine tundra hillslope
Authors: Quinton William L. , Bemrose Robert K. , Zhang Yinsuo , Carey Sean K.
Published: June 2009

In alpine tundra, hillslope drainage occurs predominantly below the ground surface, between the relatively impermeable frost table and the water table above it. The saturated hydraulic conductivity decreases by two to three orders of magnitude between the ground surface and the top of the mineral substrate at 0·2–0·3 m depth. Consequently, the rate of sub‐surface conveyance from hillslopes strongly depends on the degree of active layer thaw. In addition, although rarely examined, the volume and timing of hillslope drainage and streamflow in alpine tundra are strongly influenced by the spatial pattern of active layer thaw in the runoff‐contributing hillslopes. The spatial and temporal pattern of soil thaw was modelled on a 25 535 m2 area of interest (AOI) on a north‐facing alpine tundra hillslope in southern Yukon, Canada. Daily oblique photographs were used to pixilate the AOI and measure the snow cover depletion for the AOI. Transects of thaw depth through selected snow‐free patches within or adjacent to the AOI were used to provide spatial representation of thaw depth and saturated hydraulic conductivity. To compute thaw depth for each pixel within the AOI as it became snow‐free, a finite element geothermal model was driven from meteorological forcing and soil hydro‐thermal data. Daily maps of snow‐free area and thaw depth were generated for the AOI, which were then combined with information on flowpath tortuosity and depth‐integrated saturated hydraulic conductivity for snow‐free areas to provide a drainage rate for the AOI. This drainage rate varied with the spatial arrangement of the snowpack and soil thaw depth. At the beginning of melt, the lack of hydrological connectivity for the AOI inhibited drainage. The drainage rate was maximized during the mid‐melt period since sub‐surface connections among snow‐free patches were widespread, and the hydraulic conductivity of the sub‐surface flow zone was still relatively high, owing to shallow soil thaw depths. Drainage was low at the end of the melt period because the frost table was at a depth where the hydraulic conductivity was very low. The results of this study indicate that to accurately simulate runoff at the hillslope scale during snowmelt, both the spatial pattern of snowmelt and ground thaw should be considered. Copyright © 2009 John Wiley & Sons, Ltd.
MicroRNA‐10b is overexpressed in malignant glioma and associated with tumor invasive factors, uPAR and RhoC
Authors: Sasayama Takashi , Nishihara Masamitsu , Kondoh Takeshi , Hosoda Kohkichi , Kohmura Eiji
Published: June 2009

MicroRNAs (miRNAs) are effective post‐transcriptional regulators of gene expression and are important in many biological processes. Although the oncogenic and tumor suppressive functions of several miRNAs have been characterized, the role of miRNAs in mediating tumor invasion and migration remains largely unexplored. Recently, miR‐10b was identified as an miRNA highly expressed in metastatic breast cancer, promoting cell migration and invasion. Here, we performed real‐time reverse transcriptase polymerase chain reaction (RT‐PCR) assays on 43 glioma samples (17 glioblastoma, 6 anaplastic astrocytoma, 10 low‐grade astrocytoma, 6 oligodendroglioma and 4 ependymoma) and 6 glioma cell lines. We found that miR‐10b expression was upregulated in all glioma samples compared to non‐neoplastic brain tissues. The expression levels of miR‐10b were associated with higher grade glioma. In addition, mRNA expressions of RhoC and urokinase‐type plasminogen activator receptor (uPAR), which were thought to be regulated by miR‐10b via HOXD10, were statistically significantly correlated with the expression of miR‐10b (p < 0.001, p = 0.001, respectively). Also, protein expression levels of RhoC and uPAR were associated with expression levels of miR‐10b (p = 0.009, p = 0.014, respectively). Finally, multifocal lesions on enhanced MRI of 7 malignant gliomas were associated with higher expression levels of miR‐10b (p = 0.02). Our data indicated that miR‐10b might play some role in the invasion of glioma cells. © 2009 UICC
Identification of a chemokine receptor profile characteristic for mediastinal large B‐cell lymphoma
Authors: Rehm Armin , Anagnostopoulos Ioannis , Gerlach Kerstin , Broemer Meike , Scheidereit Claus , Jöhrens Korinna , Hübler Michael , Hetzer Roland , Stein Harald , Lipp Martin , Dörken Bernd , Höpken Uta E.
Published: June 2009

Mediastinal large B‐cell lymphomas (MLBCLs) are considered as a subtype of diffuse large B‐cell lymphoma; however, they exhibit completely different patterns of dissemination. Since they share a number of surface markers with thymic B cells, a close relationship was assumed. MLBCLs arise extranodally within the anterior mediastinum and have a low propensity to metastasize. To address the preferential positioning of MLBCL, we focused on homeostatic chemokines involved in B‐cell compartmental homing in secondary lymphoid organs, which are also capable of shaping lymphoid niches in ectopic sites. Here, we applied immunohistochemistry to assess chemokine receptor and ligand expression in situ. Flow cytometry was used to identify the chemokine receptor profile on an MLBCL‐derived cell line, Karpas1106 and on thymic B cells. Migration assays were performed to examine functionality of chemokine receptors. Electrophoretic mobility shift assay was applied to score for NF‐κB activity. Using immunohistochemistry, we obtained an unexpectedly low‐expression frequency for the chemokine receptors CXCR5 and CCR7 in primary lesions. Although the mature B‐cell marker CCR6 was absent in most cases, the lineage aberrant marker CCR9 emerged in the majority of MLBCL cases. Given the role of NF‐κB in the transcriptional activation of CCR7, we identified the involvement of the noncanonical activation pathway in MLBCLs. MLBCLs exhibit a diagnostic chemokine receptor profile that is instrumental in the discrimination from diffuse large B‐cell lymphoma not otherwise specified and classical Hodgkin lymphoma. Furthermore, we suggest that low‐abundance expression of CCR7 and CXCR5 may hinder lymphoma cells from nodal dissemination. © 2009 UICC