bluuebunny/crossref_metadata_2025_split huggingface dataset:
A simple method to identify supramolecules in action: Hill coefficients for exergonic self‐assembly
Authors: Bhosale Sheshanath , Matile Stefan 
Published: September 2006

AbstractPrecise supramolecular architecture is often essential for significant function. Simple methods to reliably and rapidly demonstrate the existence of such supramolecular structure and function at relevant concentrations in complex systems are badly needed. Hill plots, describing the dependence of a signal on the n‐th power of the monomer concentration, are compatible only with the identification of supramolecules that do not really exist, that is, endergonic self‐assembly (Litvinchuk et al., J Am Chem Soc 2004;126:10067). Here, we show that the artificial increase in monomer concentration by chemical denaturation restores compatibility of Hill plots with exergonic self‐assembly and affords Hill coefficients n > 1 for stable supramolecules. Recent rigid‐rod π‐stack architecture with photosynthetic and ion channel activity is used as timely example, circular dichroism (CD) spectroscopy as method of choice for both sensitive and selective detection under relevant conditions. Chirality, 2006. © 2006 Wiley‐Liss, Inc.
Colchicine delays the development of hepatocellular carcinoma in patients with hepatitis virus‐related liver cirrhosis
Authors: Arrieta Oscar , Rodriguez‐Diaz Jose Luis , Rosas‐Camargo Vanessa , Morales‐Espinosa Daniela , de Leon Sergio Ponce , Kershenobich David , Leon‐Rodriguez Eucario 
Published: September 2006

AbstractBACKGROUNDHepatocellular carcinoma (HCC) is a malignant neoplasm associated with liver cirrhosis, with an annual incidence of 3% to 9%, which is one of the main causes of death in patients with cirrhosis. Viral hepatitis is associated with an increased risk of HCC, probably due to an inflammatory reaction. Colchicine is an antiinflammatory agent that inhibits the formation of intracellular microtubules, affecting mitosis and fibrogenesis. Diverse clinical studies have failed to demonstrate the benefit of colchicine over the progression of fibrosis in patients with liver cirrhosis; nevertheless, to the authors' knowledge there are no studies that evaluate its effect in the development of HCC.METHODSThe effect of the administration of colchicine on the development of HCC was evaluated in 186 patients with hepatitis virus‐related liver cirrhosis in a retrospective cohort study. The minimum follow‐up time was 3 years (median, 84 months ± 2.8 months). One hundred sixteen patients received treatment with colchicine. The characteristics of both groups were similar.RESULTSThe percentage of patients who developed HCC was significantly smaller in the colchicine group when compared with the noncolchicine group (9% vs. 29%; P = .001). On multivariate analysis, an α‐fetoprotein level ≥5 ng/dL (P = .03), a platelet count <100,000 at diagnosis (P = .05), alanine aminotransferase ≥52 IU (P = .006), and a lack of treatment with colchicine (P = .0001) were found to be associated with an earlier development of HCC. The average time for the development of HCC was 222 months ± 15 months and 150 months ± 12 months in the patients who received and who did not receive colchicine, respectively. CONCLUSIONSThe results suggest that treatment with colchicine prevents and delays the development of HCC in patients with hepatitis virus‐related cirrhosis. The protective mechanisms of colchicine over the development of HCC could be related to antiinflammatory properties and inhibition of mitosis. Prospective studies to confirm this observation with a greater number of patients and long‐term follow‐up may be indicated. Cancer 2006. © 2006 American Cancer Society.
Health profiles of younger and older breast cancer survivors
Authors: Stava Charles J. , Lopez Adriana , Vassilopoulou‐Sellin Rena 
Published: September 2006

AbstractBACKGROUND.Over the past several decades, the incidence of prolonged survival after a diagnosis of cancer has increased; however, little is known regarding the long‐term health profiles of cancer survivors in general and of breast cancer survivors in particular. To obtain more information concerning the consequences of surviving breast cancer, the authors conducted a large‐scale health survey of patients who had been treated for the disease at their institution.METHODS.A descriptive analysis of information was provided by cancer survivors. Of the breast cancer survivors who were studied, 695 women were age <45 years, 580 women were between ages 46 years and 54 years, and 655 women were age > 55 years at the time of diagnosis. Their medical and psychosocial responses were analyzed and compared with those of age‐matched responders in a national survey.RESULTS.Younger breast cancer survivors received chemotherapy more often than older survivors and were more likely to report memory loss and that cancer had affected their overall health adversely. Several other differences in physiologic and psychosocial characteristics, such as interpersonal relationships, also emerged.CONCLUSIONS.Physiologic and psychosocial differences distinguished younger breast cancer survivors from older breast cancer survivors. The findings of this study suggested that a systematic analysis of cancer survivors is needed to understand their unique health profiles and needs. Cancer 2006. © 2006 American Cancer Society.
Treatment of acute myelogenous leukemia with outpatient azacitidine
Authors: Sudan Nimit , Rossetti James M. , Shadduck Richard K. , Latsko Joan , Lech John A. , Kaplan Robert B. , Kennedy Margaret , Gryn Jeffrey F. , Faroun Yacoub , Lister John 
Published: September 2006

AbstractBACKGROUNDPatients older than 55 years of age with acute myelogenous leukemia (AML) are less likely to achieve complete remission and more likely to experience toxicity with conventional induction chemotherapy than younger patients. Azacitidine administered in the outpatient setting is well tolerated and can induce complete hematological remission in patients with myelodysplastic syndromes (MDS). At higher doses, azacitidine has activity in AML.METHODSTwenty patients were retrospectively identified who had been treated with azacitidine with bone marrow blast counts between 21 and 38%. Patients with blast counts up to 29% were initially treated as MDS, but by WHO now meet criteria for AML. Patients with blast counts over 29% were treated with azacitidine after being deemed poor candidates for induction chemotherapy. Azacitidine 75 mg/m2/day was administered subcutaneously for 7 days every 4 weeks, which was defined as 1 cycle.RESULTSThe overall response rate was 60% (12/20): complete response (CR; n = 4; 20%); partial response (PR; n = 5; 25%); hematologic improvement (HI; n = 3; 15%). The median survival of responders was 15+ months compared with 2.5 months for nonresponders (P = .009). During therapy, responders had an Eastern Cooperative Oncology Group (ECOG) performance status of 1 or 0. The most common toxic event was infection (n = 8). Four patients were hospitalized during the first cycle of treatment.CONCLUSIONSAzacitidine administered in the outpatient setting can induce remission in AML. The therapy is well tolerated and might be an alternative for patients unlikely to tolerate standard induction chemotherapy. Cancer 2006. © 2006 American Cancer Society.
Growth of cadmium zinc telluride by liquid phase electroepitaxy
Authors: Armour N. , Sheibani H. , Dost S. 
Published: September 2006

AbstractThis study was undertaken to examine the feasibility of growing CdZnTe by liquid phase electroepitaxy. Based on our successful LPEE system of GaInAs, a new crucible to grow CdZnTe was developed. The development presented numerous difficulties. The physical properties of CdZnTe make this material very difficult to grow. All components of the system were investigated. Electromigration of the solute across the solution carries species towards the growth interface. In liquid Cd‐Zn‐Te, the CdTe and ZnTe species remain associated, contrary to the GaInAs system. Experiments showed that LPEE growth of CdZnTe is possible and the electromigration mechanism functions well in the CdZnTe solution. Despite this, other problems remained with the new LPEE system. The preparation of the solution proved difficult without pressurizing the LPEE crucible. Control of the reaction required the use of pre‐compounded CdTe and ZnTe. Proper control of the solution saturation is imperative to ensure minimal dissolution of the seed prior to growth initiation and a reasonable growth rate during growth. The solution remained an issue during the duration of growth due to the high vapor pressures of the constituents. Tellurium evaporation during growth could lower solution volume until electrical contact across the solution is broken. Careful preparation of appropriate solution volume was imperative for successful growth. In LPEE, a uniform electric current passage across the growth interface is necessary for uniform and stable growth interface. This requires the design of a uniform contact zone between the bottom graphite electrode and the seed crystal. The contact zone issue was not adequately resolved in this study. However, a number of successful growth runs were achieved despite the electrical contact problems. Results show that the LPEE of growth CdZnTe is feasible. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Growth, structure and thermal properties of CuAlxGa1‐xSe2 alloys
Authors: Castro J. , Naranjo J. , Durán L. , Meléndez L. , Fermin J. R. , Cendros J. , Rincón C. A. Durante 
Published: September 2006

AbstractIngots of the CuAlxGa1‐xSe2 (0 ≤ x ≤ 1) alloys system were prepared by direct fusion of the stoichiometric mixture of the elements. The analysis of X‐ray Powder Diffraction data showed the presence of one single phase with chalcopyrite tetragonal structure at room temperature for all the studied compositions. The lattice parameters, a and c, and the bond lengths were calculated. The phase transition temperatures were obtained by the onset method from Differential Thermal Analysis measurements performed on samples sealed in evacuated quartz ampoules. Fusion or transition enthalpies were determined from the area of the corresponding DTA peak. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Crystal growth and structure of KBi(WO4)2 single crystals
Authors: Xie Huidong , Shen Dezhong , Xie Chengzhi , Wang Xiaoqing , Shen Guangqiu 
Published: September 2006

AbstractPotassium bismuth tungstate [KBi(WO4)2] single crystals have been grown by the top‐seeded solution growth technique. Bulk crystal with dimensions up to several centimeters is obtained for the first time. Several self‐flux systems have been used for the growth from the solution and the experiments using K2W2O7 as a solvent are detailed. Powder and single crystal X‐ray diffraction of this crystal are reported. The structure refinement shows that KBi(WO4)2 crystallizes in the monoclinic space group C2/c, with a=10.837(3), b=10.586(3), c=7.622(2)Å, β=130.860(3)°, V=661.4(3)Å3, and Z=4. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Crystallization and characterization of nonlinear optical l‐histidinium dihydrogen orthophosphate orthophosporic acid single crystal
Authors: Madhavan J. , Aruna S. , Ambujam K. , Arul Pragasam A. Joseph , Ravikumar S. M. , Gulam Mohamed M. , Sagayaraj P. 
Published: September 2006

AbstractL‐histidinium dihydrogen orthophosphate orthophosporic acid (abbreviated as LHP) with molecular formula C6H10N3O2+·H2PO4‐·H3PO4 was successfully grown by slow evaporation technique from aqueous solution. The crystal was characterized by X‐ray diffractometry (XRD), UV‐Vis‐NIR, TGA, DTA, microhardness and solubility studies. The dielectric constant and dielectric loss of the crystal were studied as function of frequency. Photoconductivity studies were also carried out on the sample. The SHG efficiency of the crystal is studied using the Kurtz and Perry technique. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Formation of boride layers on steel substrates
Authors: Stergioudis G. 
Published: September 2006

AbstractBoronizing coatings were prepared by means of pack cementation technique. It was found that using the appropriate substrate and controlling parameters of the boribing process such as boron activity of the mixture, temperature and time of treatment, it is possible to obtain a structure predominantly consisting of the Fe2B phase. In the present study low alloy ferritic steels were chosen as substrates. Changing the boron carbide concentration in the mixture and the temperature and time of boronizing process the conditions of the boronizing were altered. As a result the formation of the Fe2B phase is enhanced. Characterization of the as‐borided steels is discussed based on X‐ray diffraction and Curie temperature measurements. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Influence of cationic substitution on lattice constants and optical characterization in solution grown mixed crystals of potassium‐ ammonium zinc chloride
Authors: Abu El‐Fadl A. , Soltan A. S. , Shaalan N. M. 
Published: September 2006

AbstractMixed crystals of potassium‐ammonium zinc chloride in different concentrations were grown from aqueous solution employing the techniques of slow cooling and controlled evaporation. Powder x‐ray diffraction studies were carried out on the grown crystals. The comparison between lattice parameters a, b and c are experimentally determined and calculated by Vegad's law. The concentration of K+ ions in the crystals was measured by the atomic absorption technique. The crystal morphology changed considerably by increasing K+ concentration. The optical absorption coefficient (α) indicated strong influence changing concentration. The optical energy gap was found to decrease with increasing K+ concentration. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Positive magnetoresistance in TixW1‐xSe2 (x = 0, 0.03) platelet crystals
Authors: Kunjachan Sunil 
Published: September 2006

AbstractLayered transition metal dichalcogenide crystal, WSe2, has been grown by direct vapour transport technique. Titanium is used as a dopant in to the 2H type MX2 matrix. These crystals show positive magnetoresistance and a switching behaviour is observed at room temperature in the titanium‐intercalated sample. The relative resistance change due to magnetic field for the doped sample is found to switch from 23.6% to 39.6% when the sample is rotated through 0° to 90°. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Realization of log‐domain high‐order transfer functions using first‐order building blocks and complementary operators
Authors: Psychalinos Costas 
Published: September 2006

AbstractHigh‐order log‐domain filters could be easily designed by using the functional block diagram (FBD) representation of the corresponding linear prototype and a set of complementary operators. For this purpose, lossy and lossless integrator blocks have been already introduced in the literature. Novel first‐order log‐domain highpass and allpass filter configurations, which are fully compatible with the already published integrator blocks, are introduced in this paper. These are realized using integration and subtraction blocks or a novel differentiation configuration. As a result, a complete set of first‐order building blocks would be available for synthesizing any arbitrary high‐order transfer function. In order to verify the correct operation of the proposed structures, the performance of the introduced highpass filters was evaluated through simulation results. In addition, a fifth‐order log‐domain bandpass filter was designed and simulated using one of the introduced first‐order highpass filter configurations. Copyright © 2006 John Wiley & Sons, Ltd.
DIANANE‐CrIII‐salen Complexes as Highly Enantioselective Catalysts for Hetero‐Diels–Alder Reactions of Aldehydes with Dienes
Authors: Berkessel Albrecht , Vogl Nadine 
Published: September 2006

AbstractA new type of chromium‐salen complex bearing DIANANE (endo,endo‐2,5‐diaminonorbornane) as chiral backbone has been synthesized and applied to the hetero‐Diels–Alder reaction of Danishefsky’s diene with various aldehydes. The reactions afford the corresponding 2‐substituted 2,3‐dihydro‐4H‐pyran‐4‐ones in high yields and enantioselectivities (up to 96 % ee). The effect of different counteranions of the complex on reactivity as well as enantioselectivity has been investigated. Besides Danishefsky’s diene, reaction of the less reactive 1‐methoxybutadiene with benzaldehyde and ethyl glyoxylate can be effected by the chromium catalysts as well.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
A nonparametric analysis of the spatial distribution of Convolvulus arvensis in wheat‐sunflower rotations
Authors: Francisco‐Fernández Mario , Jurado‐Expósito Montserrat , Opsomer J. D. , López‐Granados Francisca 
Published: September 2006

AbstractThis article describes an application of nonparametric regression to study the spatial structure and identify persistent spatial patterns of the perennial weed Convolvulus arvensis L. in 4 years of wheat‐sunflower crop rotation in Southern Spain. The annual spatial distributions of weed patches over the study field are estimated using local linear regression. These are then used to delimit areas whose infestation is above an economic threshold. In order to identify the areas at the highest risk of weed infestation across years, a multi‐year index is developed and mapped. A parametric bootstrap is used to quantify the variability of the multi‐year map. In a precision agriculture environment, such maps can be a useful component of a long‐term weed management strategy. Copyright © 2006 John Wiley & Sons, Ltd.
Application of the beta‐binomial model for the detection of rare marine benthos using point intercept techniques
Authors: Ryan Daniel A. J. 
Published: September 2006

AbstractThe beta‐binomial distribution is used to provide estimates of the probability of detecting a rare species, the smallest proportion cover detectable with a stated confidence for a survey, and is a method for estimating the sample size required to detect a species with a stated presence at a stated level of confidence for independent clusters of binary data. The equations, while general, were derived in the context of marine benthic video transects and are useful for evaluating a wide range of existing surveys or designing new surveys. Application of the equations is demonstrated for a data set collected from three marine surveys on the Great Barrier Reef in Australia. Copyright © 2006 John Wiley & Sons, Ltd.
Average SEP for M‐ary CPSK with noisy phase reference in Nakagami fading and Gaussian noise
Authors: Kostić Ivo M. 
Published: September 2006

AbstractAnalytic expressions for the symbol‐error probabilities of M‐ary coherent phase shift keying (M‐CPSK) detection with an imperfect local carrier reference phase in Nakagami‐m fading and additive Gaussian noise are derived. Both the Tikhonov probability density function (PDF) and the uniform PDF of the carrier phase error are considered. We based our analyses on a newly derived expression for the Fourier coefficients of the PDF of the composite phase of the received signal impaired by Nakagami‐m fading and additive Gaussian noise. We present a comparison of the results based on the Tikhonov PDF with those based on the uniform PDF in order to show substantial performance differences between these two‐phase noise models. Copyright © 2006 AEIT
Classification of hydrological regimes of northern floodplain basins (Peace–Athabasca Delta, Canada) from analysis of stable isotopes (δ18O, δ2H) and water chemistry
Authors: Wolfe Brent B. , Karst‐Riddoch Tammy L. , Hall Roland I. , Edwards Thomas W. D. , English Michael C. , Palmini Roger , McGowan Suzanne , Leavitt Peter R. , Vardy Sheila R. 
Published: September 2006

AbstractWe used stable isotopes (δ18O and δ2H) and water chemistry to characterize the water balance and hydrolimnological relationships of 57 shallow aquatic basins in the Peace‐Athabasca Delta (PAD), northern Alberta, Canada, based on sampling at the end of the 2000 thaw season. Evaporation‐to‐inflow ratios (E/I) were estimated using an isotope mass‐balance model tailored to accommodate basin‐specific input water compositions, which provided an effective, first‐order, quantitative framework for identifying water balances and associated limnological characteristics spanning three main, previously identified drainage types. Open‐drainage basins (E/I < 0·4; n = 5), characterized by low alkalinity, low concentrations of nitrogen, dissolved organic carbon (DOC) and ions, and high minerogenic turbidity, include large, shallow basins that dominate the interior of the PAD and experience frequent or continuous river channel connection. Closed‐drainage basins (E/I ≥ 1·0; n = 16), in contrast, possess high alkalinity and high concentrations of nitrogen, DOC, and ions, and low minerogenic turbidity, and are located primarily in the relict and infrequently flooded landscape of the northern Peace sector of the delta. Several basins fall into the restricted‐drainage category (0·4 # E/I < 1·0; n = 26) with intermediate water chemistries and are predominant in the southern Athabasca sector, which is subject to active fluviodeltaic processes, including intermittent flooding from riverbank overflow. Integration of isotopic and limnological data also revealed evidence for a new fourth drainage type, mainly located near the large open‐drainage lakes that occupy the central portion of the delta but within the Athabasca sector (n = 10). These basins were very shallow (<50 cm deep) at the time of sampling and isotopically depleted, corresponding to E/I characteristic of restricted‐ and open‐drainage conditions. However, they are limnologically similar to closed‐drainage basins except for higher conductivity and higher concentrations of Ca2+ and Na+, and lower concentrations of SiO2 and chlorophyll c. These distinct features are due to the overriding influence of recent summer rainfall on the basin water balance and chemistry. The close relationships evident between water balances and limnological conditions suggest that past and future changes in hydrology are likely to be coupled with marked alterations in water chemistry and, hence, the ecology of aquatic environments in the PAD. Copyright © 2006 John Wiley & Sons, Ltd.
Changes in stream flow regime in headwater catchments of the Yellow River basin since the 1950s
Authors: Zheng Hongxing , Zhang Lu , Liu Changming , Shao Quanxi , Fukushima Yoshihiro 
Published: September 2006

AbstractThe headwater catchments of the Yellow River basin generate over 35% of the basin's total stream flow and play a vital role in meeting downstream water resources requirements. In recent years the Yellow River has experienced significant changes in its hydrological regime, including an increased number of zero‐flow days. These changes have serious implications for water security and basin management. We investigated changes in stream flow regime of four headwater catchments since the 1950s. The rank‐based non‐parametric Mann–Kendall test was used to detect trends in annual stream flow. The results showed no significant trend for the period 1956 to 2000. However, change‐point analysis showed that a significant change in annual stream flow occurred around 1990, and hence the stream‐flow data can be divided into two periods: 1956–1990 and 1991–2000. There was a considerable difference in average annual stream flow between the two periods, with a maximum reduction of 51%. Wet‐season rainfall appears to be the main factor responsible for the decreasing trend in annual stream flow. Reductions in annual stream flow were associated with decreased interannual variability in stream flow. Seasonal stream flow distribution changed from bimodal to unimodal between the two periods, with winter stream flow showing a greater reduction than other seasons. Daily stream flow regime represented by flow duration curves showed that all percentile flows were decreased in the second period. The high flow index (Q5/Q50) reduced by up to 28%, whereas the reduction in the low flow index (Q95/Q50) is more dramatic, with up to 100% reduction. Copyright © 2006 John Wiley & Sons, Ltd.