bluuebunny/crossref_metadata_2025_split huggingface dataset:
Photobleaching‐based flow measurement in a commercial capillary electrophoresis chip instrument
Authors: Wang Guiren R. , Sas Ian , Jiang Hong , Janzen William P. , Hodge C. Nicholas 
Published: February 2008

AbstractFor microfluidic analytical instruments, a facile, fast, and accurate instrument test is highly demanded. The test includes the quantitative verification of the relationship between pressure drop and flow velocity for the hydrodynamic pump, between the electric voltage and electroosmotic flow (EOF) for the high‐voltage supply, and the chip quality. The key point for the test is the measurement of the flow velocity. However, most currently available velocimetries cannot be directly used without any instrumental modification or adding extra instruments. We applied a recently developed Laser Induced Fluorescence Photobleaching Anemometer (LIFPA) for the instrument test through measuring fluid flow velocity in a microfluidic instrument with optical measurement without any modification and extra instrument. We have successfully used the method to test Caliper HTS 250 System from Caliper Life Sciences (Hopkinton, MA) with its own light source and detector. The experimental result demonstrates that this single‐point method of measuring flow velocity can be easily used for accurate test of a microfluidic instrument in less than 10 min at extremely low cost without any modification and extra instrument.
Two New Steroidal Alkaloids from Veratrum nigrum L.
Authors: Wang Bin , Zhang Wei‐Dong , Shen Yun‐Heng , Tang Jian , Zhang Chuan , Liu Run‐hui , Lin Min , Li Hui‐Liang 
Published: February 2008

AbstractPhytochemical studies on Veratrum nigrum L., collected in Shanxi, P. R. China, resulted in the isolation of two new steroidal alkaloids, 23‐methoxycyclopamine (1) and 15‐O‐(2‐methylbutanoyl)‐3‐O‐veratroylprotoverine (2). The structures of the two new compounds were established by means of extensive NMR spectroscopic studies.
Enantioselective Synthesis of β‐Blockers via Hydrolytic Kinetic Resolution of Terminal Oxiranes by Using Bimetallic Chiral {{2,2′‐[Cyclohexane‐1,2‐diylbis(nitrilomethylidyne)]bis[phenolato]}(2−)}cobalt ([Co(salen)])‐Type Complexes
Authors: Kawthekar Rahul B. , Kim Geon‐Joong 
Published: February 2008

AbstractThe synthesis of chirally pure β‐blockers was successfully achieved via hydrolytic kinetic resolution of butyl (±)‐4‐(oxiran‐2‐ylmethoxy)benzeneacetate ((±)‐1) and (±)‐4‐(oxiran‐2‐ylmethoxy)benzeneacetonitrile ((±)‐2) in the presence of bimetallic chiral [Co(salen)]‐type complexes. The newly synthesized bimetallic chiral [Co(salen)]‐type complexes exhibited excellent enantioselectivities of up to >98% ee in good yields (Tables 1–3).
Two Novel abeo‐Dammaranes with a Six‐Membered Acetal Moiety from Aglaia perviridisHiern
Authors: Yang Shu‐Min , Tan Chang‐Heng , Luo Hong‐Feng , Wang Dong‐Xiao , Zhu Da‐Yuan 
Published: February 2008

AbstractTwo novel triterpenoids, named (20S,24S)‐20,24‐epoxy‐24‐methoxy‐23(24→25)abeo‐dammaran‐3‐one (=(20S,25S)‐20,25‐epoxy‐25‐methoxy‐24,24‐dimethyl‐26,27‐dinordammaran‐3‐one; 1), (3α,20S,24S)‐ 20,24‐epoxy‐24‐methoxy‐23(24→25)abeo‐dammaran‐3‐ol‐acetate (=(3α,20S,25S)‐20,25‐epoxy‐25‐methoxy‐24,24‐dimethyl‐26,27‐dinordammaran‐3‐ol acetate; 2), together with six known dammaranes, were isolated from the EtOH extract of the twigs of Aglaia perviridis by chromatographic methods. The structures of 1 and 2 were elucidated on the basis of spectral data.
Human papillomavirus and mutated H‐ras oncogene in cervical carcinomas and pathological negative pelvic lymph nodes: A retrospective follow‐up
Authors: Landro María Eulalia , Dalbert Delia , Picconi María Alejandra , Cúneo Nicasio , González Joaquín , Vornetti Silvia , Bazán Graciela , Mural Juan , Basiletti Jorge , Teyssié Angélica Rita , Alonio Lidia Virginia 
Published: February 2008

AbstractThe metastasis status of pelvic lymph nodes (PLNs) seems to be a predictive factor of survival. It was suggested that the presence of HPV DNA and other biological markers in PLN may indicate a sub clinical early metastasis. The aim was to describe the prevalence and distribution patterns of HPV DNA and H‐ras mutations in intra operatively obtained cervical tumors and PLN. Thirty‐seven cervical tumors and 61 lymph node biopsies from 37 patients with cervical cancer were selected. HPV typing and location were performed by PCR/dot blot and in situ hybridization (ISH) respectively. PCR/RFLP was used to scan for mutations in H‐ras. Hundred percent of the cervical cancers and 85% of the PLN were HPV positive; co‐infection with more than one type was 27%. HPV 16 was detected alone or co‐infecting with other types in 84% of tumors and 46% of PLN; the second most frequent viral type was HPV 18 (tumor: 27%; PLN: 20%). In PLN, HPV was located in nuclei or/and cytoplasm of lymphocytes, macrophages, endothelial, and /or stromal cells. H‐ras mutations were identified in 5/24 (21%) of patients with cervical tumors showing poor or moderated differentiation. HPV DNA in histological tumor‐free PLN not necessary indicate metastasis, but it may be associated to an active immune reaction. Mutated H‐ras is probably involved in cervical carcinogenesis and its detection in tumor and metastasis free PLN may be related to early metastasis or recurrence in at least a subset of poorly differentiated cervical tumors. J. Med. Virol. 80:694–701, 2008. © 2008 Wiley‐Liss, Inc.
Genetic characterization of RS‐12 (S‐12), an Iranian isolate of mumps virus, by sequence analysis and comparative genomics of F, SH, and HN genes
Authors: Alirezaie Behnam , Aghaiypour Khosrow , Shafyi Abbas 
Published: February 2008

AbstractRS‐12 mumps virus strain was isolated in 1986, in monkey kidney cells, from the throat‐washing of an Iranian patient and developed to RS‐12 vaccine by serial passage of the pathogen in MRC‐5 cells. During the present study, an early passage RS‐12 containing its virulent pathogenic phenotype, was characterized genetically. Its F, SH and HN genes were isolated by RT‐PCR amplification and sequenced. It is quite evident that RS‐12 belongs to genotype H, closely related to European strains but distinguishable from Asian strains. The deduced amino acid sequences of HN and F proteins that comprise immunogenic epitopes, were compared to other vaccine and wild strains. The multiple sequence alignment revealed that the RS‐12 has isoleucine and aspartic acid at positions 269 and 523 of its F and HN proteins, respectively, which could differentiate RS‐12 from other available sequences. This isolate has trivial variations in the major antigenic sites of HN protein. The frequency and pattern of F and HN glycosylation sites seems to be similar to most other strains. It seems that the mumps regional outbreak during 1986 in Iran was caused by genotype H and this strain has been spreading in countries surrounding the Caspian sea for over 17 years. These data support the previous results that RS‐12 could be an efficient vaccine, especially in the Middle East. This is the first genotype report from Iranian isolates and provides strong data on the molecular epidemiology of mumps in Iran, the Middle East, Central Asia, Russia and other countries of this region. J. Med. Virol. 80:702–710, 2008. © 2008 Wiley‐Liss, Inc.
High prevalence of genotype 4 among hepatitis C virus‐infected intravenous drug users in North‐Eastern Poland
Authors: Chlabicz S. , Flisiak R. , Kowalczuk O. , Wiercińska‐Drapalo A. , Pytel‐Krolczuk B. , Prokopowicz D. , Chyczewski L. 
Published: February 2008

AbstractThe aim of this study was to describe the distribution of hepatitis C genotypes among intravenous drug users in north‐eastern Poland. The study group included intravenous drug users recruited at a drug treatment center and a clinic for HIV‐infected patients. HCV infection was confirmed by qualitative nested RT‐PCR to test for the presence of HCV RNA. Genotypes were determined by 5′UTR sequencing and comparing the results with known genotype sequences. Among 111 HCV‐infected and HCV–RNA‐positive intravenous drug users, the most prevalent genotypes were 1 (38.7%), 3 (37.8%), and 4 (23.4%). Most infections with genotype 4 (88.5%) were found among HCV–HIV‐coinfected drug users. The study demonstrated a high prevalence of genotype 4 (23.4%) among HCV‐infected Polish drug users. J. Med. Virol. 80:615–618, 2008. © 2008 Wiley‐Liss, Inc.
Is serum uric acid a predictive factor of response to IFN‐treatment in patients with chronic hepatitis C infection?
Authors: Pellicano Rinaldo , Puglisi Giovanni , Ciancio Alessia , Balzola Federico , Saracco Giorgio , Ciccone Giovannino , Baldi Ileana , Abate Maria Lorena , Smedile Antonina , Rizzetto Mario 
Published: February 2008

AbstractSeveral factors, including metabolic profile, are predictive of response to standard antiviral therapy in patients with chronic hepatitis C. In a retrospective study, it was investigated whether uric acid, involved in metabolic syndrome, could be included. A total of 153 patients (56.2% males; mean age 45.7 ± 11.3 years) treated with pegylated‐interferon and ribavirin were included. Eighty‐five were infected with hepatitis C virus (HCV) genotype 1 or 4 and 68 with genotype 2 or 3. Viral load was >1,000,000 IU/ml in 101, ≤1,000,000 IU/ml in 35 and unknown in 17 patients. Ishak fibrosis score was ≤4 in 81, >4 in 15 and unknown in 57 patients. Mean serum uric acid was 5.05 ± 1.3 mg/dl. Sustained virological response (negative serum HCV‐RNA 6 months after treatment cessation) was achieved in 102 patients (67%). In the final logistic model, serum uric acid level ≥5.8 mg/dl (OR = 0.46; 95% CI: 0.30–0.62), viral load (OR = 0.29; 95% CI: 0.09–0.92) and HCV genotype (OR = 0.23; 95% CI: 0.09–0.60) were identified as the most important factors independently influencing clinical outcome. The prognostic role of serum uric acid was confirmed on the sub‐sample reporting Ishak fibrosis score (OR = 0.49; 95% CI: 0.28–0.85). Serum uric acid level ≥5.8 mg/dl is predictive of poor response to HCV treatment. Prospective studies are needed to clarify the issue. J. Med. Virol. 80:628–631, 2008. © 2008 Wiley‐Liss, Inc.
Study of the volatile profile characteristics of longan during storage by a combination sampling method coupled with GC/MS
Authors: Zhang Zhuomin , Zeng Dandan , Li Gongke 
Published: February 2008

AbstractBACKGROUND: Longan (Dimocarpus longan Lour.) is a kind of subtropical fruit, but it has a very short shelf life under normal ambient conditions. In this work, a combination sampling method, including headspace solid phase micro‐extraction (HSSPME), simultaneous distillation extraction (SDE) and steam distillation (SD), was used to study the volatile profile characteristics of longan at the fresh and deteriorated storage phases followed by gas chromatography–mass spectrometry (GC‐MS) detection. The study would provide a method for investigating the volatile profile characteristics of longan during storage and some helpful clues for quality discrimination.RESULTS: In total, 28 and 22 volatile compounds of fresh and deteriorated longan were identified. Alkenes and esters were the main volatile components of longan. β‐ocimene accumulated, whereas allo‐ocimene and 3,4‐dimethyl‐2,4,6‐octatriene decreased during storage. Different volatile profile characteristics at the fresh and deteriorated storage phases obtained by HSSPME were specified by principal component analysis (PCA). Typical volatile compounds were distilled by a common model strategy.CONCLUSION: The volatile profiles of longan during storage were studied using a combination of sampling methods followed by GC‐MS detection. Five typical volatiles contributing significantly to the difference in volatile profile characteristics of longan at the fresh and deteriorated storage phases were distilled using a common model strategy. These compounds are potential bio‐markers for longan degradation. Tentative results suggest that combining HSSPME with conventional volatile isolation methods would provided more representative data on changes in the volatile compounds of longan during storage and some helpful clues for quality discrimination. Copyright © 2008 Society of Chemical Industry
Electrokinetic separation of peptides and proteins using a polyvinylamine‐coated capillary with UV and ESI‐MS detection
Authors: Wu Yue , Xie Jun , Wang Fang , Chen Zilin 
Published: February 2008

AbstractIn order to accomplish the analysis of peptides and proteins by capillary electrophoresis, Lupamin, a high‐molecular‐weight linear polyvinylamine (PVAm) polymer, was introduced to modify the inner wall of fused‐silica capillaries by physical absorption. Thanks to the high density of positively charged amino groups in Lupamin under acidic conditions, not only is a strong reversed electroosmotic flow generated in the coated capillary but the adsorption of analytes on the inner wall of the capillary is also efficiently eliminated. It has been demonstrated that the Lupamin‐coated capillary can be used to advantage for the rapid analysis of amino acids, peptides, and proteins with good resolution and peak shape by capillary electrophoresis. In order to evaluate the basic feature of a Lupamin‐coated capillary, electroosmotic flows generated by a Lupamin coating layer under different conditions including pH, coating time, concentration, and the composition of electrolytes on Lupamin‐coated and uncoated capillaries were investigated. Furthermore, electrospray ionization‐mass spectrometry (ESI‐MS) detection was carried out for the analysis of amino acids and peptides.
Estimating failure time distribution and its parameters based on intermediate data from a Wiener degradation model
Authors: Tang Jen , Su Tsui‐Shu 
Published: February 2008

AbstractInstead of measuring a Wiener degradation or performance process at predetermined time points to track degradation or performance of a product for estimating its lifetime, we propose to obtain the first‐passage times of the process over certain nonfailure thresholds. Based on only these intermediate data, we obtain the uniformly minimum variance unbiased estimator and uniformly most accurate confidence interval for the mean lifetime. For estimating the lifetime distribution function, we propose a modified maximum likelihood estimator and a new estimator and prove that, by increasing the sample size of the intermediate data, these estimators and the above‐mentioned estimator of the mean lifetime can achieve the same levels of accuracy as the estimators assuming one has failure times. Thus, our method of using only intermediate data is useful for highly reliable products when their failure times are difficult to obtain. Furthermore, we show that the proposed new estimator of the lifetime distribution function is more accurate than the standard and modified maximum likelihood estimators. We also obtain approximate confidence intervals for the lifetime distribution function and its percentiles. Finally, we use light‐emitting diodes as an example to illustrate our method and demonstrate how to validate the Wiener assumption during the testing. © 2008 Wiley Periodicals, Inc. Naval Research Logistics, 2008
Growth morphologies and charge carrier mobilities of pentacene organic field effect transistors with rf sputtered aluminium oxide gate insulators on ITO glass
Authors: Voigt M. , Pflaum J. , Sokolowski M. 
Published: February 2008

AbstractOrganic field effect transistors of pentacene (Pc) were prepared on indium‐tin‐oxide (ITO) coated glass substrates with a thin layer of rf sputtered aluminium oxide (AlOx) on top of the ITO, serving as the gate insulator. The Pc films were grown by vapour deposition with a large variation of the substrate temperature (–17–93 °C). Source and drain contacts were obtained by Au deposition through a shadow mask. The morphology and the structure of the Pc films were investigated by X‐ray diffraction and atomic force microscopy. The Pc film growth starts with the substrate induced thin film phase, which changes to the bulk (Campbell) phase for thicker films. The nucleation of the bulk phase appears to be induced at structural defects in the underlying thin film phase, stemming from the Pc/AlOx interface. The field effect hole mobilities, determined from the saturation drain current as a function of the gate voltage, under vacuum conditions, are in the range of 0.005 cm2/Vs to 0.20 cm2/Vs at room temperature. The mobilities are strongly thermally activated, with activation energies from 44 meV to 108 meV, indicating a significant role of charge carrier traps. From a detailed analysis of the gate and drain voltage dependence of the mobilities, we find that three mechanisms are limiting the field effect mobilities: trapping of charge carriers at low charge densities (consistent with the multiple trapping and release model), scattering at structural defects between the Pc grains, and scattering/trapping at the AlOx/Pc interface of the charge carriers at higher charge densities. Relating this information with the structural information makes it plausible that the same structural defects which limit the mobilities by trapping of charge carriers also act as the nucleation centres for the bulk phase that grows on top of the thin film phase. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Modeling of complex surface structures for ARXPS
Authors: Oswald S. , Oswald F. 
Published: February 2008

AbstractAngle‐resolved X‐ray photoelectron spectroscopy (ARXPS) has a great potential for nondestructive depth profiling in the nanometer thickness range. A method using computer simulation of ARXPS measurements is presented, which allows systematic studies on surfaces with artificial spatial inhomogeneity in the nanometer‐range. Investigations of rough surfaces with varied structure sizes show that inhomogeneous structures can be increasingly better described by homogeneous smooth layers when lowering the typical length dimensions. In parallel, the obtained effective amount of overlayer material (or effective overlayer thickness), is systematically lower than the real one. Limitations of the ‘magic‐angle concept’ are derived. Possible improvement of the method is discussed by consideration of elastic scattering. Copyright © 2008 John Wiley & Sons, Ltd.
Enhanced myocardial vitamin C accumulation in left ventricular hypertrophy in rats is not attenuated with transition to heart failure
Authors: Rohrbach Susanne , Martin Antonio , Niemann Bernd , Cherubini Antonio 
Published: February 2008

AbstractIndirect observations are compatible with cardiac vitamin C deficiency as one contributory factor to oxidative stress in heart failure, but data on ventricular vitamin C content are lacking. Here, we used the well established model of aortic‐banded rats at the stage of compensated hypertrophy (6 weeks after banding) and at the transition to cardiac failure (22 weeks after banding) to analyze vitamin C, vitamin E, protein carbonyls and malondialdehyde tissue content together with the respective plasma concentrations. Furthermore, we investigated the expression of the vitamin C transporters SVCT1 and SVCT2 in the left ventricle (LV).Aortic‐banded rats, independently from their age, had higher malondialdehyde and protein carbonyl levels in plasma and LV tissue compared to sham‐operated animals indicating increased oxidative stress. Plasma vitamin C remained unaffected from cardiac overload, while LV vitamin C was elevated in both stages of hypertrophy together with an increased expression of the vitamin C transporter SVCT2 suggesting increased vitamin C uptake. The levels of antioxidants and lipid peroxides were similar 6 and 22 weeks after aortic banding. Therefore, the accumulation of vitamin C in compensated hypertrophy and in decompensated failure excludes cardiac vitamin C deficiency as a primary factor to oxidative stress in this model.
The corpus revolution revisited
Authors: Rundell Michael 
Published: February 2008

ABSTRACTStarts with an excerpt from Michael Rundell and Penny Stock, The Corpus revolution (ET30, 1992). An update on the rise and rise of electronic language corpora and their impact on dictionaries. How dramatically the world has changed since Penny Stock and I wrote about the ‘Corpus Revolution’ in 1992.At the time, it was not hard to predict that computer processing power and storage capacity would carry on doubling each year. It was already clear, too, that the arrival of the corpus would revolutionize the work of dictionary-makers – hence the title of our articles. These changes were well under way in 1992 and, sixteen years on, their effects are still being felt. In the process, dictionaries have got dramatically better – if by ‘better’ we mean that the description of language they provide corresponds more closely to the way people actually use words when they communicate with one another.
Tolerance of Cotton (Gossypium hirsutum) Seedlings to Preemergence and Postemergence Herbicides with Four Modes of Action
Authors: Kendig J. A. , Nichols R. L. , Ohmes G. A. 
Published: February 2008

The current dominant weed control program in cotton relies heavily on glyphosate. Typical glyphosate-based weed control programs require repeat applications. A residual herbicide might reduce the number of herbicide applications needed, and potentially reduce costs. Residual herbicides that can be used postemergence in cotton are limited in number, and there are few studies evaluating the response of cotton to over-the-top application of herbicides. A greenhouse study evaluated response of cotton to fluometuron, propazine, metolachlor, pyrithiobac, and glyphosate. Most of these herbicides caused minimal crop injury; however, fluometuron and propazine caused significant visual injury when applied over-the-top at the cotyledon and two-leaf stages, but less injury when applied preemergence. Accepted for publication 5 July 2007. Published 8 November 2007.
Sweet Potato Yield Reduction Caused by Reniform Nematode in the Mississippi Delta
Authors: Abel Craig A. , Adams Larry C. , Stetina Salliana R. 
Published: February 2008

A study was conducted to determine the effect of variable reniform nematode, Rotylenchulus reniformis Linford and Oliveira, population densities on sweet potato production. In 2003, post-harvest soil samples revealed that nematicide-treated plots had 1019 ± 257.2 reniform nematodes per 500 cm3 sample of soil compared to 2255 ± 383.3 for untreated plots. There were 1057 kg/ha more marketable sweet potato harvested from the nematicide-treated plots compared to the control. In 2004, there were fewer nematodes in the nematicide-treated plots at pre-planting, mid-season, and pre-harvest, with the most pronounced difference occurring at mid-season with 927 nematodes per 500 cm3 sample of soil in the nematicide untreated plots compared to 140 for the treated plots. The difference in nematode levels resulted in a 996-kg/ha increase in US #1 sweet potatoes harvested from nematicide-treated plots compared to the untreated plots. In 2005, two nematicides, K-PAM and Temik, were not different in their level of nematode control during the growing season, however, there was an increase in US #1 class sweet potatoes produced from the Temik-treated plots when compared to K-PAM. Both nematicide treatments produced more US #1 sweet potatoes when compared to a Lorsban control and an untreated control. Accepted for publication 13 September 2007. Published 15 November 2007.