bluuebunny/crossref_metadata_2025 huggingface dataset:
Spectral analysis for a semi‐active–passive net‐zero base‐shear design concept
Authors: Rodgers G. W. , Chase J. G. , Roland T. , MacRae G. A.
Published: October 2011

Passive high force‐to‐volume (HF2V) dampers offer significant displacement reduction and energy dissipation, but cannot customise overall response. Semi‐active resettable devices offer adaptive, custom hysteresis loops that reduce displacement and base shear, but have limited dissipation. This paper presents a new, combined concept to maximise displacement reduction without increasing base shear – a net‐zero base‐shear concept.

HF2V devices, up to a maximum of 10% structural weight, are combined with fixed stiffness resettable devices. Spectral analyses are run for the three SAC ground motion suites that iteratively size the HF2V device at each structural period to achieve maximum displacement reductions without increasing median base shear. HF2V velocity dependence and the need to scale HF2V capacity to spectral velocity are examined in terms of their impact on the results of these analyses.

The net‐zero approach reduces base shear by up to 50% and displacements by 30–70% over all ground motions, exceeding reductions obtained by either device separately by 30–50% (relative). The net‐zero condition is not reached within the device limits defined, except at relatively long periods (>3.5 s) because of a virtuous circle of reduced displacement from the resettable and HF2V devices outweighing the increased base shear from the HF2V devices alone. These results are independent of HF2V device scaling, design and velocity dependence. The overall net‐zero concept offers a significant advantage in a combination that cannot be achieved by passive or semi‐active solutions alone. Copyright © 2011 John Wiley & Sons, Ltd.
Clinical and sociodemographic factors in a sample of older subjects experiencing depressive symptoms
Authors: Barcelos‐Ferreira Ricardo , Lopes Marcos A. , Nakano Eduardo Yoshio , Steffens David C. , Bottino Cássio M. C.
Published: October 2011

Objectives

This study aims to determine the frequency of clinically significant depressive symptoms (CSDS) in a community sample of older Brazilians and to examine their relationship with sociodemographic factors, cognitive and functional impairment (CFI), and medical illness.

Methods

A total of 1145 subjects aged 60 years or older living in the City of Ribeirao Preto, State of Sao Paulo, Brazil, were interviewed. The following instruments were used: a 10‐item scale for screening of depressive symptoms in older people, the mini mental state examination, the Fuld Object Memory Evaluation, the Informant Questionnaire on Cognitive Decline in the Elderly, the Bayer Activities of Daily Living Scale, and a sociodemographic and clinical questionnaire.

Results

The frequency of CSDS was 15.7%. Logistic regression analysis indicated that being previously depressed, having CFI, having lower level of education, using psychotropics, and not engaging in physical exercise were related to CSDS. On the other hand, being a woman, older, medically ill, employed, or married was not associated with CSDS.

Conclusions

Consistent with previous reports, lower education, lack of physical activity, and CFI were significantly associated with higher frequencies of CSDS. Further investigations are necessary to clarify the occurrence of depression and possible modifiable factors in developing countries such as Brazil. Copyright © 2011 John Wiley & Sons, Ltd.
Optical imaging of oral squamous cell carcinoma and cervical lymph node metastasis
Authors: Keereweer Stijn , Kerrebijn Jeroen D. F. , Mol Isabel M. , Mieog J. Sven D. , Van Driel Pieter B. A. A. , Baatenburg de Jong Robert J. , Vahrmeijer Alexander L. , Löwik Clemens W. G. M.
Published: October 2011

Background

In oral cancer surgery, intraoperative optical imaging could help the surgeon to determine adequate tumor‐free margins.

Methods

Tumor‐specific near‐infrared fluorescence agents targeting epidermal growth factor receptor (CW800 EGF) or glucose transporter system (CW800 2‐DG) were administered to mice with tongue carcinoma and cervical lymph node metastases. Tumor growth was followed by bioluminescence imaging. Fluorescence signals were compared with a control group of healthy animals.

Results

Significantly higher fluorescence was found in tongue tumors and cervical lymph node metastases compared with that in control animals. Fluorescence correlated with histopathology. Tumor‐to‐background ratio of CW800 EGF in the tongue was 13.8 (SD = 6.1) and in the lymph nodes 15.7 (SD = 8.8). For CW800 2‐DG, the tumor‐to‐background ratio in the tongue was 4.6 (SD = 2.1) and in the lymph nodes 33.9 (SD = 18.4).

Conclusions

Optical imaging can be used to detect oral cancer and cervical lymph node metastases and could potentially improve complete surgical resection by real‐time image‐guided surgery. © 2011 Wiley Periodicals, Inc. Head Neck, 2012
Upper Limits of Normal for Alanine Aminotransferase Activity in the United States Population
Authors: Ruhl Constance E. , Everhart James E.
Published: October 2011

Alanine aminotransferase (ALT) is an important test for liver disease, yet there is no generally accepted upper limit of normal (ULN) in the United States. Furthermore, the ability of ALT to differentiate persons with and without liver disease is uncertain. We examined cut-offs for ALT for their ability to discriminate between persons with positive hepatitis C virus (HCV) RNA and those at low risk for liver injury in the U.S. population. Among adult participants in the 1999-2008 U.S. National Health and Nutrition Examination Survey, 259 were positive for serum HCV RNA and 3,747 were at low risk for liver injury (i.e., negative HCV RNA and hepatitis B surface antigen, low alcohol consumption, no evidence of diabetes, and normal body mass index and waist circumference). Serum ALT activity was measured centrally. Maximum correct classification was achieved at ALT = 29 IU/L for men (88% sensitivity, 83% specificity) and 22 IU/L (89% sensitivity, 82% specificity) for women. The cut-off for 95% sensitivity was an ALT = 24 IU/L (70% specificity) for men and 18 IU/L (63% specificity) for women. The cut-off for 95% specificity was ALT = 44 IU/L (64% sensitivity) for men and 32 IU/L (59% sensitivity) for women. The area under the curve was 0.929 for men and 0.915 for women. If the cut-offs with the best correct classification were applied to the entire population, 36.4% of men and 28.3% of women would have had abnormal ALT.

Conclusion :

ALT discriminates persons infected with HCV from those at low risk of liver disease, but would be considered elevated in a large proportion of the U.S. population. (Hepatology 2012)
Prospective Biopsy-Controlled Evaluation of Cell Death Biomarkers for Prediction of Liver Fibrosis and Nonalcoholic Steatohepatitis
Authors: Joka Diana , Wahl Kristin , Moeller Sarah , Schlue Jerome , Vaske Bernhard , Bahr Matthias J. , Manns Michael P. , Schulze-Osthoff Klaus , Bantel Heike
Published: October 2011

Fibrosis and steatosis are major histopathological alterations in chronic liver diseases. Despite various shortcomings, disease severity is generally determined by liver biopsy, emphasizing the need for simple noninvasive methods for assessing disease activity. Because hepatocyte cell death is considered a crucial pathogenic factor, we prospectively evaluated the utility of serum biomarkers of cell death to predict different stages of fibrosis and steatosis in 121 patients with chronic liver disease. We compared the M30 enzyme-linked immunosorbent assay (ELISA), which detects a caspase-cleaved cytokeratin-18 (CK-18) fragment and thereby apoptotic cell death, with the M65 ELISA, which detects both caspase-cleaved and uncleaved CK-18 and thereby overall cell death. Both biomarkers significantly discriminated patients with different fibrosis stages from healthy controls. However, whereas both markers differentiated low or moderate from advanced fibrosis, only the M65 antigen could discriminate even lower stages of fibrosis. The M65 assay also performed better in distinguishing low (≤10%) and higher (>10%) grades of steatosis. In a subgroup of patients, we evaluated the biomarkers for their power to predict nonalcoholic steatohepatitis (NASH). Importantly, both markers accurately differentiated healthy controls or simple steatosis from NASH. However, only serum levels of M65 antigen could differentiate simple steatosis from healthy controls.

Conclusion:

Cell death biomarkers are potentially useful to predict fibrosis, steatosis, or NASH. Compared with the widely used apoptosis marker M30, the M65 assay had a better diagnostic performance and even differentiated between lower fibrosis stages as well as between healthy individuals and patients with simple steatosis. (Hepatology 2012)
CD133+ liver tumor-initiating cells promote tumor angiogenesis, growth, and self-renewal through neurotensin/interleukin-8/CXCL1 signaling
Authors: Tang Kwan Ho , Ma Stephanie , Lee Terence K. , Chan Yuen Piu , Kwan Pak Shing , Tong Carol M. , Ng Irene O. , Man Kwan , To Ka-Fai , Lai Paul B. , Lo Chung-Mau , Guan Xin-Yuan , Chan Kwok Wah
Published: October 2011

A novel theory in the field of tumor biology postulates that cancer growth is driven by a population of stem-like cells, called tumor-initiating cells (TICs). We previously identified a TIC population derived from hepatocellular carcinoma (HCC) that is characterized by membrane expression of CD133. Here, we describe a novel mechanism by which these cells mediate tumor growth and angiogenesis by systematic comparison of the gene expression profiles between sorted CD133 liver subpopulations through genome-wide microarray analysis. A significantly dysregulated interleukin-8 (IL-8) signaling network was identified in CD133+ liver TICs obtained from HCC clinical samples and cell lines. IL-8 was found to be overexpressed at both the genomic and proteomic levels in CD133+ cells isolated from HCC cell lines or clinical samples. Functional studies found enhanced IL-8 secretion in CD133+ liver TICs to exhibit a greater ability to self-renew, induce tumor angiogenesis, and initiate tumors. In further support of these observations, IL-8 repression in CD133+ liver TICs by knockdown or neutralizing antibody abolished these effects. Subsequent studies of the IL-8 functional network identified neurotensin (NTS) and CXCL1 to be preferentially expressed in CD133+ liver TICs. Addition of exogenous NTS resulted in concomitant up-regulation of IL-8 and CXCL1 with simultaneous activation of p-ERK1/2 and RAF-1, both key components of the mitogen-activated protein kinase (MAPK) pathway. Enhanced IL-8 secretion by CD133+ liver TICs can in turn activate an IL-8-dependent feedback loop that signals through the MAPK pathway. Further, in its role as a liver TIC marker CD133 also plays a functional part in regulating tumorigenesis of liver TICs by way of regulating NTS, IL-8, CXCL1, and MAPK signaling.

Conclusion :

CD133+ liver TICs promote angiogenesis, tumorigenesis, and self-renewal through NTS-induced activation of the IL-8 signaling cascade.
Dickkopf 4 positively regulated by the thyroid hormone receptor suppresses cell invasion in human hepatoma cells
Authors: Liao Chen-Hsin , Yeh Chau-Ting , Huang Ya-Hui , Wu Sheng-Ming , Chi Hsiang-Cheng , Tsai Ming-Ming , Tsai Chung-Ying , Liao Chia-Jung , Tseng Yi-Hsin , Lin Yang-Hsiang , Chen Cheng-Yi , Chung I-Hsiao , Cheng Wan-Li , Chen Wei-Jan , Lin Kwang-Huei
Published: October 2011

Thyroid hormone (T3) mediates cellular growth, development, and differentiation by binding to the nuclear thyroid hormone receptor (TR). Recent studies suggest that long-term hypothyroidism is associated with human hepatocellular carcinoma (HCC) independent from other major HCC risk factors. Dickkopf (DKK) 4, a secreted protein, antagonizes the Wnt signal pathway. In this study, we demonstrate that T3 may play a suppressor role by inducing DKK4 expression in HCC cells at both the messenger RNA (mRNA) and protein levels. DKK4 was down-regulated in 67.5% of HCC cancerous tissues. The decrease in DKK4 levels was accompanied by a concomitant decrease in TR protein levels in the matched cancerous tissues in 31% of tissues compared by immunoblotting with the adjacent noncancerous tissues. Further, TR and DKK4 expression levels were positively correlated in both normal and cancerous specimens by tissue array analysis. In function assays, stable

DKK4

transfected into J7 or HepG2 cells decreased cell invasion

in vitro

. Conversely, knocking down DKK4 restores cell invasiveness. DKK4-expressing J7 clones showed increased degradation of β-catenin, but down-regulation of CD44, cyclin D1, and c-Jun. To investigate the effect of DKK4 and TR on tumor growth

in vivo

, we established a xenograft of J7 cells in nude mice. J7-DKK4 and J7-TRα1 overexpressing mice, which displayed growth arrest, lower lung colony formation index, and smaller tumor size than in control mice, supporting an inhibitory role of DKK4 in tumor progression.

Conclusion :

Taken together, these data suggest that the TR/DKK4/Wnt/β-catenin cascade influences the proliferation and migration of hepatoma cells during the metastasis process and support a tumor suppressor role of the TR.
Induced hyperammonemia may compromise the ability to generate restful sleep in patients with cirrhosis
Authors: Bersagliere Alessia , Raduazzo Iolanda D. , Nardi Mariateresa , Schiff Sami , Gatta Angelo , Amodio Piero , Achermann Peter , Montagnese Sara
Published: October 2011

In patients with cirrhosis, hyperammonemia and hepatic encephalopathy are common after gastrointestinal bleeding and can be simulated by an amino acid challenge (AAC), or the administration of a mixture of amino acids mimicking the composition of hemoglobin. The aim of this study was to investigate the clinical, psychometric, and wake-/sleep-electroencephalogram (EEG) correlates of induced hyperammonemia. Ten patients with cirrhosis and 10 matched healthy volunteers underwent: (1) 8-day sleep quality/timing monitoring; (2) neuropsychiatric assessment at baseline/after AAC; (3) hourly ammonia/subjective sleepiness assessment for 8 hours after AAC; (4) sleep EEG recordings (nap opportunity: 17:00-19:00) at baseline/after AAC. Neuropsychiatric performance was scored according to age-/education-adjusted Italian norms. Sleep stages were scored visually for 20-second epochs; power density spectra were calculated for consecutive 20-second epochs and average spectra determined for consolidated episodes of non-rapid eye movement (non-REM) sleep of minimal common length. The AAC resulted in: (i) an increase in ammonia concentrations/subjective sleepiness in both patients and healthy volunteers; (ii) a worsening of neuropsychiatric performance (wake EEG slowing) in two (20%) patients and none of the healthy volunteers; (iii) an increase in the length of non-REM sleep in healthy volunteers [49.3 (26.6) versus 30.4 (15.6) min;

P

= 0.08]; (iv) a decrease in the sleep EEG beta power (fast activity) in the healthy volunteers; (v) a decrease in the sleep EEG delta power in patients.

Conclusion :

AAC led to a significant increase in daytime subjective sleepiness and changes in the EEG architecture of a subsequent sleep episode in patients with cirrhosis, pointing to a reduced ability to produce restorative sleep.
Mortality and the Risk of Malignancy in Autoimmune Liver Diseases: A Population-Based Study in Canterbury, New Zealand
Authors: Ngu Jing Hieng , Gearry Richard Blair , Frampton Chris Miles , Malcolm Stedman Catherine Ann
Published: October 2011

Population-based quantitative data on the mortality and cancer incidence of autoimmune hepatitis (AIH), primary biliary cirrhosis (PBC), and primary sclerosing cholangitis (PSC) are scarce. Our aim was to systematically investigate the survival and risk of malignancy on population-based cohorts of AIH, PBC, and PSC in Canterbury, New Zealand. Multiple case-finding methods were employed, including searches of all public and private, adult and pediatric outpatient clinics, hospital notes, laboratory, radiology, and pathology reports. Cases that fulfilled standardized diagnostic criteria were included. Kaplan-Meier survival estimates, standardized mortality ratios (SMR), and standard incidence ratios (SIR) for malignancy were calculated. A total of 130 AIH, 70 PBC, and 81 PSC patients were included contributing to 1,156, 625, and 613 person-years at risk, respectively. For AIH, PBC, and PSC cohorts, SMRs for all-cause mortality were 2.1 (95% confidence interval [CI] 1.4-3.1), 2.7 (95% CI 1.7-4.0), and 4.1 (95% CI 2.6-6.3), SMRs for hepatobiliary mortality were 42.3 (95% CI 20.3-77.9), 71.2 (95% CI 30.7-140.3), and 116.9 (95% CI 66.8-189.8), SIRs for all cancers were 3.0 (95% CI 2.0-4.3), 1.6 (95% CI 0.8-2.9), and 5.2 (95% CI 3.3-7.8), and SIRs for extrahepatic malignancy were 2.7 (95% CI 1.8-3.9), 1.6 (95% CI 0.8-2.9), and 3.0 (95% CI 1.6-5.1), respectively.

Conclusion :

This is the first population-based study to examine and compare the survival and cancer incidence in AIH, PBC, and PSC in the same population. The mortality for all three cohorts was significantly increased due to liver-related death, demonstrating the inadequacy of current management strategies. The risk of hepatic and extrahepatic malignancy was significantly increased in AIH and PSC patients. (Hepatology 2012)
Deregulated LAP2α expression in cervical cancer associates with aberrant E2F and p53 activities
Authors: Ward Michelle C. , van der Watt Pauline J. , Tzoneva Gannie , Leaner Virna D.
Published: October 2011

Lamina‐associated polypeptide 2 alpha (LAP2α) plays a role in maintaining nuclear structure, in nuclear assembly/disassembly, and in transcriptional regulation. Elevated LAP2α mRNA expression has been previously reported to associate with certain cancer types. The aim of this study was to investigate LAP2α expression in cervical cancer and transformed cells and to identify factors that associate with its differential expression. LAP2α expression was found to be elevated in cervical cancer tissue by microarray, qRT‐PCR, and immunofluorescence analyses. LAP2α also showed elevated expression in cervical cancer cell lines and in transformed fibroblasts compared with normal cells. To determine factors associated with elevated LAP2α in cervical cancer, the effect of inhibiting HPV E7 and E6 oncoproteins was investigated. E7 inhibition resulted in a decrease in phosphorylated Rb and an associated decrease in LAP2α, suggesting a role for E2F in regulating LAP2α expression. This finding was confirmed by inhibiting DP1, a co‐activator of E2F, which resulted in decreased LAP2α levels. Inhibition of E6 resulted in elevated p53 and an associated decrease in LAP2α, suggesting that p53 associates with the negative regulation of LAP2α expression. This hypothesis was tested by inhibiting p53 in normal cells, and a resultant increase in LAP2α expression was observed. In conclusion, this study provides evidence for elevated LAP2α expression in cervical cancer and suggests that E2F and p53 activities associate with the positive and negative regulation of LAP2α expression, respectively. © 2011 IUBMB IUBMB Life, 63(11): 1018–1026, 2011
Synthesis, Reactivity and Crystal Structures of the Palladium(II) Complexes with the Pyrimidine Containing Ligand: Crystal Structures of [Pd(PPh3)(η1‐C4H3N2)(η2‐S2CNC4H8)] and [Pd(PPh3)(η1‐C4H3N2)(η2‐Tp)]
Authors: Wang Hsiao‐Fen , Yih Kuang‐Hway , Lee Gene‐Hsiang , Huang Shou‐Ling
Published: October 2011

Treatment of Pd(PPh3)4 with 5‐bromo‐pyrimidine [C4H3N2Br] in dichloromethane at ambient temperature cause the oxidative addition reaction to produce the palladium complex [Pd(PPh3)2(η1‐C4H3N2)(Br)], 1, by substituting two triphenylphosphine ligands. In acetonitrile solution of 1 in refluxing temperature for 1 day, it do not undergo displacement of the triphenylphosphine ligand to form the dipalladium complex [Pd(PPh3)Br]2{μ,η2‐(η1‐C4H3N2)}2, or bromide ligand to form chelating pyrimidine complex [Pd(PPh3)2(η2‐C4H3N2)]Br. Complex 1 reacted with bidentate ligand, NH4S2CNC4H8, and tridentate ligand, KTp {Tp = tris(pyrazoyl‐1‐yl)borate}, to obtain the η2‐dithiocarbamate η1‐pyrimidine complex [Pd(PPh3)(η1‐C4H3N2)(η2‐S2CNC4H8)], 4 and η2‐Tp η1‐pyrimidine complex [Pd(PPh3)(η1‐C4H3N2)(η2‐Tp)], 5, respectively. Complexes 4 and 5 are characterized by X‐ray diffraction analyses.
Facile Assembly of Dispersed ZrMCM‐41 Nanoparticles Promoted in‐situ by Zirconium Salt
Authors: Zhai Shang‐Ru , Wei Zhi‐Ping , An Qing‐Da , Wub Dong , Sun Yu‐Han
Published: October 2011

Mesoporous ZrMCM‐41 nanoparticles were synthesized by a usual way where tetraethyl‐orthosilicate (TEOS) and zirconium nitrate were used as the inorganic precursors. The obtained nanoscale ZrMCM‐41 was characterized by X‐ray diffraction, N2 physis‐sorption, scanning electron microscopy and transmission electron microscopy. Characterization results revealed that zirconium salt added in the synthesis had a crucial effect on the assembly of nanoscale ZrMCM‐41 with relatively uniform particle size, which was rarely observed in reported studies for ZrMCM‐41 synthesized using the similar method. Meanwhile, the possible mechanism behind the synthesis was discussed based on the character of hydrolysis and condensation of TEOS and the mild acidic environment induced by the hydrolysable zirconium salt under aqueous conditions. Thus obtained nanoscale ZrMCM‐41 with developed pore structures may be advantageous to general applications in catalysis or adsorption host‐guest chemistry in terms of efficient mass transport of guest molecules.
Seaweed Chlorophyll on the Light‐electron Efficiency of DSSC
Authors: Kuo Chin‐Guo , Sheen Bee‐Jeng
Published: October 2011

Four different seaweed extracts were employed as the dyes of dye sensitized solar cells (DSSCs) to investigate the light‐electron efficiency. The sensitizers, extracted from Nannochloropsis spp., Tetraselmis spp., Gracilaria spp., and Ulvales spp., showed their light‐electronic transfer ability in different light intensities. Among them, Ulvales output a higher light‐voltage, about 0.4 V. The output voltage increased when light intensity increased. Gracilaria extract produced a higher output voltage at 35 Lux, but its output voltage decreased over 500 Lux. The sensitizers extracted from these seaweeds had monochromatic incident photon‐to‐electron conversion efficiencies (IPCE) between 23‐61% in 220‐260 nm wavelengths. Among them, Ulvales output higher IPCE than Tetraselmis and Nannochloropsis. SEM analysis of DSSC surfaces revealed that the efficiency of seaweed DSSCs was governed by chlorophyll size. The chlorophyll particle size of Ulvales spp. was the largest. The chlorophyll particle size of Gracilaria spp. was the smallest and yielded the lowest IPCE.
Effects of Immobilized Metal Ion on Retention Behaviors of Proteins in Metal Chelate Affinity Chromatography
Authors: Li Rong , Wang Yan , Chen Guo‐Liang , Mei‐Shi  , Wang Xiao‐Gang , Zheng Jian‐Bin , Chen Bin
Published: October 2011

The chromatographic behaviors of proteins on iminodiacetic acid (IDA) column with and without immobilized metal ion were examined in detail. Comparing the effects of pI, solution pH, and salt concentration on retention of proteins in cation‐exchange chromatography (CEC) and metal chelate affinity chromatography (MCAC), the retention mechanism of proteins was investigated in MCAC. By aid of observing the retention characteristics of proteins on naked IDA and metal chelate columns in high concentration salt‐out salt solution, the hydrophobic interaction in MCAC and the influence of metal ion on it were proved. In terms of the comparison of the thermodynamics of proteins in CEC and MCAC, the thermostability, the conformational change entropy Δ(ΔS0) and enthalpy Δ(ΔH0), compensation temperature β, the driving force and caloritic effect of proteins in MCAC were discussed. The identity of retention mechanism at protein thermal denaturation in CEC and MCAC was demonstrated by using the compensation relationship between ΔH0 and ΔS0.
A Simple and Efficient Electrochemical Sensor for Electrocatalytic Reduction of Nitrite Based on Poly(4‐aminoacetanilide) Film Using Carbon Paste Electrode
Authors: Ojani Reza , Raoof Jahan‐Bakhsh , Rahemi Vanoushe
Published: October 2011

In this study, the electrochemical reduction of nitrite was investigated on poly(4‐aminoacetanilide) (PPAA) forming by cyclic voltammetry at the surface of carbon paste electrode. The electrochemical properties of the modified electrode have been studied by cyclic voltammetry and double potential step chronoamperometry. Results showed that in the optimum condition (pH = 0.00) the reduction of nitrite occurred at a potential about 667 mV more positive than that unmodified carbon paste electrode. This amount of electrocatalytic ability is high compared with other electrocatalysts. Using a chronoamperometric method, the catalytic rate constant (k) was calculated 8.4 × 104 cm3 mol‐1 s‐1. Also, the electrocatalytic reduction peak currents was found to be linear with the nitrite concentration in the ranges of 5 × 10‐4 M to 2.5 × 10‐2 M and 2 × 10‐5 M to 7 × 10‐3 M with detection limits (2σ) were determined as 4.5 × 10‐4 M and 1 × 10‐5 M by cyclic voltammetry (CV) and hydrodynamic amperometry methods respectively. Recovery experiments exhibit the satisfactory results.
Thiourea: An Efficient and Inexpensive Catalyst for the Knoevenagel Condensation of Pyrazole Derivates
Authors: Li Jian‐Ping , Qiu Ji‐Kuan , Li Hui‐Juan , Zhang Gui‐Sheng
Published: October 2011

Thiourea is an inexpensive, efficient and mild catalyst for the synthesis of Knoevenagel condensation of pyrozoles derivate. In the presence of 10 mol% of thiourea, pyrazole aldehyde react with active methylene compound under microwave‐assisted solvent‐free conditions at 300 W for 2‐5 min to give corresponding products in good yields.
New Validated Potentiometric Determination of Vasodilator Pentoxifylline in its Pharmaceutical Formulations and Biological Fluids
Authors: Alarfaj Nawal , El‐Tohamy Maha
Published: October 2011

The construction and performance characteristics of pentoxifylline selective electrodes were developed. Two types of electrodes: plastic membrane I and coated wire II were constructed based on the incorporation of pentoxifylline with phosphotungstic acid (PTA). The influence of membrane composition, kind of plasticizer, pH of the test solution, soaking time, and foreign ions on the electrodes was investigated. The electrodes showed a Nernstain response with a mean calibration graph slope of 56.77 ± 0.19 and 55.76 ± 0.71 mV decade‐1 at 25 °C for electrode I and II respectively, over pentoxifylline concentration range from 1.0 × 10‐5‐1.0 × 10‐2 and 9.0 × 10‐6‐1.0 × 10‐2 mol L‐1, with detection limits 4.89 × 10‐6 and 3.90 × 10‐6 mol L‐1 for electrode I and II, respectively. The pH range of the constructed electrodes was 4‐6. Interferences from common cations, alkaloids, sugars, amino acids and drug excipients were reported. The results obtained by the proposed electrodes were also applied successfully to the determination of the drug in its pharmaceutical preparations and biological fluids.
An UPLC‐MS3 Method for Rapid Separation and Determination of Four Tobacco‐specific Nitrosamines in Mainstream Cigarette Smoke
Authors: Ding Yu , Yang Jun , Zhu Wen‐Jing , Wang Cheng‐Hui , Zhu Dong‐Liang , Su Qing‐De
Published: October 2011

An ultra‐high‐pressure liquid chromatography/MS3 (UPLC‐MS3) method has been developed and validated for the quantitative determination of four major TSNAs in mainstream cigarette smoke using MS3 scan mode on a hybrid triple quadrupole‐linear ion trap mass spectrometer. The new method combining the UPLC with MS3 scan mode offers decreased sample analysis time and good selectivity. After mainstream cigarette smoke was collected on a Cambridge filter pad, the particulate matter was extracted with ammonium acetate solution and analyzed by UPLC‐MS3 using isotopically labeled analogues as internal standards. Four TSNAs were completely separated on an Agilent XDB‐C18 UPLC column using isocratic elution during a 6 min LC run time. Excellent linearity was obtained over the concentration range of 1.0‐150.0 ng/mL for all TSNAs with values for correlation coefficient (r) between 0.9985‐0.9994. Limits of detection (LOD) of each TSNA varied from 0.023 to 0.067 ng/mL, and lower limits of quantification (LLOQ) varied from 0.077 to 0.223 ng/mL, respctively. The recovery of each TSNA was from 89.2 to 106.8%. The method achieved excellent reproducibility with RSD 2.1‐6.8% for intra‐assay and 3.4‐9.1% for inter‐assay. This method can be used as an effective approach to significantly improve the detection capability for TSNAs in complex matrices.
Synthesis and antimicrobial activity of substituted [(pyrazol‐4‐yl)methylene]hydrazono‐2,3‐dihydrothiazoles and their sugar derivatives
Authors: Abdel‐Rahman Adel A.‐H. , El‐Sayed Wael A. , Zaki El‐Sayed G. , Mohamed Asem A. , Fadda Ahmed A.
Published: October 2011

A number of new [(pyrazol‐4‐yl)methylene]hydrazono‐2,3‐dihydrothiazole derivatives, their sugar hydrazones and N‐glycosides were synthesized. Furthermore, N‐substituted oxygenated alkyl and hydroxyl derivatives and 1,3,4,‐oxadiazoline acyclic nucleoside analogs were prepared. The newly synthesized compounds were tested for their antimicrobial activities and showed moderate to high inhibition activities. J. Heterocyclic Chem., (2012).
Synthesis of a highly potent leukocyte function‐associated antigen‐1 antagonist and its metabolite labeled with stable isotopes and carbon‐14, part 2
Authors: Latli Bachir , Hrapchak Matt , Xu Yibo , Qiu Fenghe , Krishnamurthy Dhileepkumar , Senanayake Chris H.
Published: October 2011

(S)‐2‐[(R)‐7‐(3,5‐Dichlorophenyl)‐5‐methyl‐6‐oxo‐5‐(4‐trifluoromethoxybenzyl)‐6,7‐dihydro‐5H‐imidazo[1,2‐a]imidazole‐3‐sulfonylamino]‐proprionamide (1), a potent lymphocyte function‐associated antigen‐1 antagonist and its sulfonamide metabolite (2) labeled with stable isotopes and carbon‐14 were prepared for Drug Metabolism and PharmacoKinetics and other studies. A long linear route was used to prepare [13C2, 2H3]‐(1) using [3,3,3‐2H]‐D‐alanine and [13C2]‐glycine in 15 steps and 2.5% overall yield. With the availability of [13C6]‐3,5‐dichloroaniline, the sulfonamide [13C6]‐(2) was prepared in 12 steps and in 5.6% overall yield. For the carbon‐14 synthesis, a six‐step synthesis gave both compounds [14C]‐(1) and [14C]‐(2) from the common sulfonyl chloride intermediate [14C]‐(15) in 18% and 4% radiochemical yields and specific activities of 44 and 40.5 mCi/mmol, respectively. Copyright © 2011 John Wiley & Sons, Ltd.
Regeneration of ciliary comb plates in the ctenophore Mnemiopsis leidyi. i. morphology
Authors: Tamm Sidney L.
Published: October 2011

Regeneration of missing body parts in model organisms provides information on the mechanisms underlying the regeneration process. The aim here is to use ctenophores to investigate regeneration of their giant ciliary swimming plates. When part of a row of comb plates on Mnemiopsis is excised, the wound closes and heals, greatly increasing the distance between comb plates near the former cut edges. Video differential interference contrast (DIC) microscopy of the regeneration of new comb plates between widely separated plates shows localized widenings of the interplate ciliated groove (ICG) first, followed by growth of two opposing groups of comb plate cilia on either side. The split parts of a new plate elongate as their bases extend laterally away from the ICG widening and continue ciliogenesis at both ends. The split parts of a new plate grow longer and move closer together into the ICG widening until they merge into a single plate that interrupts the ICG in a normal manner. Video DIC snapshots of dissected gap preparations 1.5–3‐day postoperation show that ICG widenings and/or new plates do not all appear at the same time or with uniform spacing within a gap: the lengths and distances between young plates in a gap are quite variable. Video stereo microscopy of intact animals 3–4 days after the operation show that all the new plates that will form in a gap are present, fairly evenly spaced and similar in length, but smaller and closer together than normal. Normal development of comb plates in embryos and growing animals is compared to the pattern of comb plate regeneration in adults. Comb plate regeneration differs in the cydippid Pleurobrachia that lacks ICGs and has a firmer mesoglea than Mnemiopsis. This study provides a morphological foundation for histological, cellular, and molecular analysis of ciliary regeneration in ctenophores. J. Morphol. 2011. © 2011 Wiley Periodicals, Inc.
Changes in knee cartilage T2 values over 24 months in subjects with and without risk factors for knee osteoarthritis and their association with focal knee lesions at baseline: Data from the osteoarthritis initiative
Authors: Baum Thomas , Stehling Christoph , Joseph Gabby B. , Carballido‐Gamio Julio , Schwaiger Benedikt J. , Müller‐Höcker Christina , Nevitt Michael C. , Lynch John , McCulloch Charles E. , Link Thomas M.
Published: October 2011

Purpose:

To examine the changes in knee cartilage T2 values over 24 months in subjects with and without risk factors for knee osteoarthritis (OA) and their association with focal knee lesions at baseline.

Materials and Methods:

Forty‐one subjects without and 101 subjects with OA risk factors (such as history of knee injury or surgery) were selected from the Osteoarthritis Initiative database (age: 45–55 years, no radiographic OA in the right knee). Baseline magnetic resonance imaging (MRI) of the right knee were assessed for prevalence and grade of focal knee lesions. Right knee cartilage T2 measurements were performed in five compartments (patella, medial/lateral femur/tibia) at baseline and at 24‐month follow‐up.

Results:

Compared to subjects without OA risk factors, those with OA risk factors showed no significant differences in baseline prevalence and grade of focal knee lesions (P > .05), but had significantly higher T2 values in the medial femur compartment at both timepoints (P < 0.05). T2 values averaged over all five compartments increased significantly over 24 months in both groups, but differences in T2 increase between the groups were not significant. Subjects with cartilage lesions showed significantly higher T2 values compared to subjects without cartilage lesions at both timepoints, but no accelerated T2 increase over 24 months (P > 0.05).

Conclusion:

Cartilage T2 values significantly increased over 24 months in subjects with and without OA risk factors, but neither the presence of OA risk factors nor the presence of cartilage lesions at baseline were associated with these T2 increases. J. Magn. Reson. Imaging 2012;370‐378. © 2011 Wiley Periodicals, Inc.
Antioxidant capacity and phenolic composition of fermented Centella asiatica herbal teas
Authors: Ariffin Fazilah , Heong Chew Shio , Bhupinder Kaur , Karim Alias A , Huda Nurul
Published: October 2011

BACKGROUND: C. asiatica was exposed to various fermentations: no fermentation (0 min), partial fermentation (120 min) and full fermentation (24 h). Total phenolic content (TPC) and ferric‐reducing antioxidant power (FRAP) of C. asiatica infusions were studied as a function of water temperature (60, 80 or 100 °C), the brewing stage (one, two or three) and the brewing time (1, 3, 5, 10, 15 or 20 min). The optimum brewing procedure was adopted to study the antioxidant properties and phenolic compounds in C. asiatica infusions.

RESULTS: The optimum extraction efficiency of C. asiatica infusions was achieved at 100 °C after a 10 min brewing time, and decreased substantially after applying multiple brewing steeps. However, no significant different was found between the second and third infusions. The non‐fermented C. asiatica (CANF) infusion had the highest antioxidant activity. Gallic acid, naringin, chlorogenic acid, catechin, rutin, rosmarinic acid and quercetin were identified to present. Luteolin and kaempferol were only found in 80% methanol extraction method.

CONCLUSION: C. asiatica herbal teas should be prepared at 100 °C for 10 min to obtain the optimum antioxidant capacity. Multiple brewing steps in C. asiatica herbal tea are encouraged due to the certain amount of antioxidant obtained. Copyright © 2011 Society of Chemical Industry
Restricted mineralization of fresh organic materials incorporated into a subtropical paddy soil
Authors: Wu Jinshui , Zhou Ping , Li Ling , Su Yirong , Yuan Hongzhao , Syers John Keith
Published: October 2011

BACKGROUND: Microbial activities involved in the dynamics of organic matter determine the potential for organic carbon (C) accumulation in soil. To understand this for paddy soil, an incubation experiment (25 °C, 45% water‐holding capacity) was established using 14C‐labelled glucose and rice straw (500 µg C g−1 soil) as substrates; an adjacent upland soil was used for comparison.

RESULTS: The amount of microbial biomass in the paddy soil was approximately 6 times larger and its turnover rate was 1.5–3 times faster than in the upland soil. These proportions of 14C‐labelled glucose and rice straw mineralized in the paddy soil were about 3% smaller (P < 0.01) than those in the upland soil. Also, there was no significant priming effect of fresh substrate additions on the mineralization of native organic C in the paddy soil, while the priming effect was significant in the upland soil.

CONCLUSION: Although the paddy soil contains a large amount of microbial biomass, which is also very active, the mineralization of fresh substrates is significantly restricted in this soil, along with a small priming effect. This favours the accumulation of organic C in paddy soils. Copyright © 2011 Society of Chemical Industry
Underground networking: the potential for improving yield and quality of pot‐grown herbs with mycorrhizas
Authors: Schroeder Viviane , Gange Alan C , Stead Anthony D
Published: October 2011

With constant pressure on herb growers to perform to a continuous high standard, finding new ways to improve herb quality and or quantity are gaining importance, with arbuscular mycorrhizal fungi (AMF) presenting one possible solution. Viviane Schroeder, Alan Gange and Anthony Stead discuss the introduction of AMF to the herb growth cycle and discuss the benefits and costs that their symbiosis with plants bring to modern agriculture. Copyright © 2011 Society of Chemical Industry
Laser projection imaging for measurement of pediatric voice
Authors: Patel Rita R. , Donohue Kevin D. , Johnson Weston C. , Archer Sanford M.
Published: October 2011

Objectives/Hypothesis:

The aim of the study was to present the development of a miniature laser projection endoscope and to quantify vocal fold length and vibratory amplitude of the pediatric glottis using high‐speed digital imaging coupled with the laser endoscope.

Study Design:

For this prospective study, absolute measurement of entire vocal fold length, membranous length of the vocal fold, and vibratory amplitude during phonation were obtained in one child (9 years old), one adult male (36 years old), and one adult female (20 years old) with the use of high‐speed digital imaging, coupled with a custom‐developed laser projection endoscope.

Methods:

The laser projection system consists of a module slip‐fit sleeve with two 3‐mW 650‐nm laser diodes in horizontal orientation separated by a distance of 5 mm. Calibration involved projecting the laser onto grid patterns at depths ranging from 6 to 10 cm and tilt angles of 15 to −5 degrees to obtain pixel‐to‐millimeter conversion templates. Measurements of vocal fold length and vibratory amplitude were extracted based on methods of image processing.

Results:

The system demonstrated a method for estimating vocal fold length and vibratory amplitude with a single laser point with high measurement precision. First measurements of vocal fold length (6.8 mm) and vibratory amplitude (0.25 mm) during phonation in a pediatric participant are reported.

Conclusions:

The proposed laser projection system can be used to obtain absolute length and vibratory measurements of the pediatric glottis. The projection system can be used with stroboscopy or high‐speed digital imaging systems with a 70‐degree rigid endoscope.
Modified transnasal endoscopic medial maxillectomy with medial shift of preserved inferior turbinate and nasolacrimal duct
Authors: Suzuki Motohiko , Nakamura Yoshihisa , Nakayama Meiho , Inagaki Akira , Murakami Shingo , Takemura Keiji , Yokota Makoto
Published: October 2011

Although transnasal endoscopic medial maxillectomy (TEMM) is effective for the treatment of inverted papilloma (IP) in maxillary sinus (MS), it involves resection of the inferior turbinate (IT). TEMM also involves resection of the nasolacrimal duct (ND) in many cases to gain better access. Therefore, we developed a novel procedure in which the preserved IT and ND are shifted medially for a complete resection of IP in the MS. Incision was made in the mucosa of the lateral wall along the anterior margin of the IT. After removal of the medial maxillary wall except the ND and the lateral nasal mucosa, the anterior lateral mucosa of the nose, including the IT and the ND, was shifted in the medial direction to allow wider access to the MS. The tumor was removed together with the attachment through the anterior side of the ND. This modified TEMM was performed in 10 patients with IP. The IT and ND were preserved in all patients. We have not observed epiphora after this surgery. The advantages of the novel approach presented herein include: 1) preservation of the IT, ND, and lateral nasal mucosa; 2) wide access to the MS by shifting the IT, ND, and lateral nasal mucosa in the medial direction; and 3) direct access to the MS through anterior space of the ND, resulting in easier operation with a straight endoscope and instruments. This approach is a safe and effective method to obtain wide and straight access to the MS and to resect IP in the MS.
Biocompatibility and Structural Stability of a Laminin Biopolymer
Authors: Freire Elisabete , Sant'Ana Barroso Madalena Martins , Klier Richard Norman , Coelho‐Sampaio Tatiana
Published: October 2011

Polylaminin (polyLM) is a polymerized form of the extracellular matrix protein laminin obtained upon pH acidification. Here microscopy and spectroscopic tools are used to study the cell compatibility and the structural stability of polyLM, aiming at establishing its robustness as a biopolymer for therapeutic use. PolyLM is cell compatible as judged by the efficiency of attachment and neuritogenesis. It is resistant to low temperature. Addition of urea or an increase in hydrostatic pressure leads to polymer disassembly. PolyLM biofilms remain stable for 48 h in contact with cell culture medium. The sedimented polymer recovered after centrifugation and adsorbed on a glass coverslip preserved its original structure and its biological properties.

magnified image
Corrosion at the urea injection in SCR‐system during component test
Authors: Nockert J. , Norell M.
Published: October 2011

The corrosion behaviour of the austenitic stainless steels 304L and 904L was investigated after component testing in diesel exhaust urea environment. Cross‐sectional analyses and depth profiling of corrosion products were performed with Auger electron spectroscopy (AES) and X‐ray photoelectron spectroscopy (XPS). The samples of both materials displayed high amounts of silicon oxide on their surfaces, though this did not appear to have an active role in the corrosion. The higher alloyed 904L exhibited only small signs of corrosion and the inner oxide below the silicon oxide was chromium rich. Substantial nitrogen uptake was detected, presumably due to the presence of NH3, cyanates and similar species. The lower alloyed 304L showed more severe corrosion. The oxide on the 304L samples mainly consisted of iron oxide apart from the silicon oxide present. The nitrogen uptake was less pronounced and possibly connected to presence of nitride precipitates. The most pronounced corrosion was detected at sites where deposits frequently form and decompose. Those deposits are a probable nitrogen source and may also form compounds enabling the breakdown of the oxide.
Spectral analysis of higher order differential operators with unbounded coefficients II
Authors: Behncke Horst , Oluoch Nyamwala Fredrick
Published: October 2011

Differential operators of higher order with unbounded coefficients are analyzed with respect to deficiency index and spectra. The eigenvalues fall into clusters of distinct size and each cluster contributes separately to the deficiency index and spectra.
Off‐resonance artifacts correction with convolution in k‐space (ORACLE)
Authors: Lin Wei , Huang Feng , Simonotto Enrico , Duensing George R. , Reykowski Arne
Published: October 2011

Off‐resonance artifacts hinder the wider applicability of echo‐planar imaging and non‐Cartesian MRI methods such as radial and spiral. In this work, a general and rapid method is proposed for off‐resonance artifacts correction based on data convolution in k‐space. The acquired k‐space is divided into multiple segments based on their acquisition times. Off‐resonance‐induced artifact within each segment is removed by applying a convolution kernel, which is the Fourier transform of an off‐resonance correcting spatial phase modulation term. The field map is determined from the inverse Fourier transform of a basis kernel, which is calibrated from data fitting in k‐space. The technique was demonstrated in phantom and in vivo studies for radial, spiral and echo‐planar imaging datasets. For radial acquisitions, the proposed method allows the self‐calibration of the field map from the imaging data, when an alternating view‐angle ordering scheme is used. An additional advantage for off‐resonance artifacts correction based on data convolution in k‐space is the reusability of convolution kernels to images acquired with the same sequence but different contrasts. Magn Reson Med, 2011. © 2011 Wiley Periodicals, Inc.
Stress‐enhanced clonal selection algorithm for structural topology optimization
Authors: Wu C. Y. , Ku C. C.
Published: October 2011

Recently, numerous modified versions of immune algorithms (IAs) have been adopted in both theoretical and practical applications. However, few have been proposed for solving structural topology optimization problems. In addition, the design connectivity handling and one‐node connected hinge prevention, which are vital in the application of population‐based methods with binary representation for structural topology optimization, have not been applied to IAs in the literature. A stress‐enhanced clonal selection algorithm (SECSA) incorporating an IA with a dominance‐based constraint‐handling technique and a new stress‐enhanced hypermutation operator is proposed to rectify those deficiencies. To demonstrate the high viability of the presented method, comparisons between the presented SECSA and genetic algorithm‐based methods were made on minimum compliance and minimum weight benchmark structural topology design problems in two‐dimensional, three‐dimensional, and multiloading cases. In each case, SECSA was shown to be competitive in terms of convergence speed and solution quality. The main goal of this study is not only to further explore the capabilities of IAs, but also to show that an IA with appropriate enhancements can lead to the development of attractive computational tools for global search in structural topology optimization. Copyright © 2011 John Wiley & Sons, Ltd.