bluuebunny/crossref_metadata_2025 huggingface dataset:
Nitric oxide, lipid peroxidation and total thiol levels in acute appendicitis
Authors: Yilmaz Fatma Meriç , Yilmaz Gülsen , Erol Mehmet Fatih , Köklü Seyfettin , Yücel Dogˇan
Published: March 2010

Background: The mechanisms involved in the pathology of acute appendicitis (AA) and the factors affecting the progression have still been investigated. Oxidative stress is one of the factors of interest. Nitric oxide (NO) and its role in AA has not been studied previously.Methods: Thirty‐four patients who underwent operation with a perioperative diagnosis of AA and 16 age and sex‐matched controls were included in the study. Serum thiobarbituric acid reactive substances (TBARS), thiol groups (SH), NO metabolites (NOx), and conventional inflammation markers were determined.Results: NOx, TBARS, C‐reactive protein (CRP) levels, white blood cell (WBC) count, and erythrocyte sedimentation rate (ESR) were significantly higher, and total SH was significantly lower in AA than in control group. NOx, TBARS, and SH levels were comparable in acute phlegmonous appendicitis and advanced appendicitis. There was a significant positive correlation between NOxand TBARS, CRP, ESR, WBC and a significant negative correlation between NOxand SH.Conclusions:Serum NOxlevels and oxidative stress elevate in AA independent from the extent of the lesion. Increased NO may play a role in the increased oxidative stress in AA. J. Clin. Lab. Anal. 24:63–66, 2010. © 2010 Wiley‐Liss, Inc.
SWI/SNF chromatin remodeling enzyme ATPases promote cell proliferation in normal mammary epithelial cells
Authors: Cohet Nathalie , Stewart Kathleen M. , Mudhasani Rajini , Asirvatham Ananthi J. , Mallappa Chandrashekara , Imbalzano Karen M. , Weaver Valerie M. , Imbalzano Anthony N. , Nickerson Jeffrey A.
Published: March 2010

The ATPase subunits of the SWI/SNF chromatin remodeling enzymes, Brahma (BRM) and Brahma‐related gene 1 (BRG1), can induce cell cycle arrest in BRM and BRG1 deficient tumor cell lines, and mice heterozygous for Brg1 are pre‐disposed to breast tumors, implicating loss of BRG1 as a mechanism for unregulated cell proliferation. To test the hypothesis that loss of BRG1 can contribute to breast cancer, we utilized RNA interference to reduce the amounts of BRM or BRG1 protein in the nonmalignant mammary epithelial cell line, MCF‐10A. When grown in reconstituted basement membrane (rBM), these cells develop into acini that resemble the lobes of normal breast tissue. Contrary to expectations, knockdown of either BRM or BRG1 resulted in an inhibition of cell proliferation in monolayer cultures. This inhibition was strikingly enhanced in three‐dimensional rBM culture, although some BRM‐depleted cells were later able to resume proliferation. Cells did not arrest in any specific stage of the cell cycle; instead, the cell cycle length increased by approximately 50%. Thus, SWI/SNF ATPases promote cell cycle progression in nonmalignant mammary epithelial cells. J. Cell. Physiol. 223:667–678, 2010. © 2010 Wiley‐Liss, Inc.
Role of voltage‐gated potassium channels in the fate determination of embryonic stem cells
Authors: Ng Sze‐Ying , Chin Chi‐Hou , Lau Yuen‐Ting , Luo Jialie , Wong Chun‐Kit , Bian Zhao‐Xiang , Tsang Suk‐Ying
Published: March 2010

Embryonic stem cells (ESCs) possess two unique characteristics: self‐renewal and pluripotency. In this study, roles of voltage‐gated potassium channels (Kv) in maintaining mouse (m) ESC characteristics were investigated. Tetraethylammonium (TEA+), a Kv blocker, attenuated cell proliferation in a concentration‐dependent manner. Possible reasons for this attenuation, including cytotoxicity, cell cycle arrest and differentiation, were examined. Blocking Kv did not change the viability of mESCs. Interestingly, Kv inhibition increased the proportion of cells in G0/G1 phase and decreased that in S phase. This change in cell cycle distribution can be attributed to cell cycle arrest or differentiation. Loss of pluripotency as determined at both molecular and functional levels was detected in mESCs with Kv blockade, indicating that Kv inhibition in undifferentiated mESCs directs cells to differentiate instead of to self‐renew and progress through the cell cycle. Membrane potential measurement revealed that Kv blockade led to depolarization, consistent with the role of Kv as the key determinant of membrane potential. The present results suggest that membrane potential changes may act as a “switch” for ESCs to decide whether to proliferate or to differentiate: hyperpolarization at G1 phase would favor ESCs to enter S phase while depolarization would favor ESCs to differentiate. Consistent with this notion, S‐phase‐synchronized mESCs were found to be more hyperpolarized than G0/G1‐phase‐synchronized mESCs. Moreover, when mESCs differentiated, the differentiation derivatives depolarized at the initial stage of differentiation. This investigation is the first study to provide evidence that Kv and membrane potential affect the fate determination of ESCs. J. Cell. Physiol. 224:165–177, 2010 © 2010 Wiley‐Liss, Inc.
LPLI inhibits apoptosis upstream of Bax translocation via a GSK‐3β‐inactivation mechanism
Authors: Zhang Lingling , Zhang Yingjie , Xing Da
Published: March 2010

Low‐power laser irradiation (LPLI), a non‐damage physical therapy, which has been used clinically for decades of years, is shown to promote cell proliferation and prevent apoptosis. However, the underlying mechanisms that LPLI prevents cell apoptosis remain undefined. In this study, based on real‐time single‐cell analysis, we demonstrated for the first time that LPLI inhibits staurosporine (STS)‐induced cell apoptosis by inactivating the GSK‐3β/Bax pathway. LPLI could inhibit the activation of GSK‐3β, Bax, and caspase‐3 induced by STS. In the searching for the mechanism, we found that, LPLI can activate Akt, which was consistence with our former research, even in the presence of STS. In this anti‐apoptotic process, the interaction between Akt and GSK‐3β increased gradually, indicating Akt interacts with and inactivates GSK‐3β directly. Conversely, LPLI decreased the interaction between GSK‐3β and Bax, with the suppression of Bax translocation to mitochondria, suggesting LPLI inhibits Bax translocation through inactivating GSK‐3β. These results were further confirmed by the experiments of co‐immunoprecipitation. Wortmannin, an inhibitor of phosphatidylinositol 3′‐OH kinase (PI3K), potently suppressed the activation of Akt and subsequent anti‐apoptotic processes induced by LPLI. Taken together, we conclude that LPLI protects against STS‐induced apoptosis upstream of Bax translocation via the PI3K/Akt/GSK‐3β pathway. These findings raise the possibility of LPLI as a promising therapy for neuron‐degeneration disease induced by GSK‐3β. J. Cell. Physiol. 224:218–228, 2010 © 2010 Wiley‐Liss, Inc.
TNF‐α induces matrix metalloproteinase‐9 expression in A549 cells: Role of TNFR1/TRAF2/PKCα‐dependent signaling pathways
Authors: Lee I‐Ta , Lin Chih‐Chung , Wu Yang‐Chang , Yang Chuen‐Mao
Published: March 2010

Matrix metalloproteinases (MMPs), in particular MMP‐9, have been shown to be induced by cytokines, including TNF‐α and contributes to airway inflammation. However, the mechanisms underlying TNF‐α‐induced MMP‐9 expression in human A549 cells remain unclear. Here, we report that TNF‐α‐induced MMP‐9 gene expression was mediated through the TNFR1/TRAF2/PKCα‐dependent signaling pathways in A549 cells, determined by zymographic, RT‐PCR, and Western blotting analyses. TNF‐α‐induced MMP‐9 expression was reduced by pretreatment with a TNFR Ab. Furthermore, TNF‐α‐induced TNFR1 and TRAF2 complex formation was revealed by immunoprecipitation using an anti‐TNFR1 Ab followed by Western blot analysis against an anti‐TRAF2 or anti‐TNFR1 Ab. In addition, TNF‐α‐induced MMP‐9 expression was also reduced by pretreatment with the inhibitor of PKCα (Gö6983), c‐Src (PP1), EGFR (AG1478), or PI3K (LY294002) or transfection with siRNAs of PKCα, Src, EGFR, Akt, p65, p300, and c‐Jun. On the other hand, TNF‐α stimulated the phosphorylation of c‐Src, EGFR, Akt, JNK1/2, and c‐Jun, which were inhibited by pretreatment with Gö6983. We also showed that TNF‐α induced Akt translocation and the formation of an Akt/p65/p300 complex. Pretreatment with the inhibitor of JNK1/2 (SP600125) but not the inhibitor of MEK1/2 (U0126), p38 MAPK (SB202190), or PI3K (LY294002), markedly inhibited TNF‐α‐induced c‐Jun mRNA levels. Taken together, these data suggest that in A549 cells, TNF‐α induces MMP‐9 expression via the TNFR1/TRAF2/PKCα‐dependent JNK1/2/c‐Jun and c‐Src/EGFR/PI3K/Akt pathways. J. Cell. Physiol. 454–464, 2010. © 2010 Wiley‐Liss, Inc.
Semi‐specific biosensors for measuring BOD in dairy wastewater
Authors: Raud Merlin , Linde Evelin , Kibena Elo , Velling Siiri , Tenno Toomas , Talpsep Ene , Kikas Timo
Published: March 2010

BACKGROUND: Semi‐specific microbial biochemical oxygen demand (BOD) biosensors were constructed using living cells of Escherichia coli R17.1.3 (E. coli) and Raoultella terrigena P74.3 (R. terrigena) immobilized in agarose gel matrix. The research involved comparison with the Pseudomonas fluorescens P75 (P. fluorescens) biosensor that had no specificity in decomposing lactose and milk derivates. The constructed BOD biosensors were calibrated with OECD synthetic wastewater and tested with different wastewater samples.

RESULTS: The linear range of the calibration curve was 5–200 mg L−1 BOD7 for R. terrigena and P. fluorescens based biosensors and 150 mg L−1 BOD7 for the E. coli based biosensor. Service life was 60 days for E. coli and P. fluorescens based biosensors and 40 days for R. terrigena based biosensors. BOD values for dairy industry wastewater obtained with current semi‐specific biosensors considerably overestimate BOD7, while universal biosensors underestimate BOD7 obtained by the conventional 7‐day BOD test.

CONCLUSION: In spite of extensive overestimation of BOD7 the semi‐specific biosensors enabled better estimation of BOD in dairy industry wastewater than a reference P. fluorescens biosensor. The best result, in terms of service life, stability, sensitivity and reproducibility was accomplished with semi‐specific E.coli biosensor. Copyright © 2010 Society of Chemical Industry
Millennial precipitation reconstruction for the Jemez Mountains, New Mexico, reveals changingb drought signal
Authors: Touchan Ramzi , Woodhouse Connie A. , Meko David M. , Allen Craig
Published: March 2010

Drought is a recurring phenomenon in the American Southwest. Since the frequency and severity of hydrologic droughts and other hydroclimatic events are of critical importance to the ecology and rapidly growing human population of this region, knowledge of long‐term natural hydroclimatic variability is valuable for resource managers and policy‐makers. An October–June precipitation reconstruction for the period AD 824–2007 was developed from multi‐century tree‐ring records of Pseudotsuga menziesii (Douglas‐fir), Pinus strobiformis (Southwestern white pine) and Pinus ponderosa (Ponderosa pine) for the Jemez Mountains in Northern New Mexico. Calibration and verification statistics for the period 1896–2007 show a high level of skill, and account for a significant portion of the observed variance (>50%) irrespective of which period is used to develop or verify the regression model. Split‐sample validation supports our use of a reconstruction model based on the full period of reliable observational data (1896–2007). A recent segment of the reconstruction (2000–2006) emerges as the driest 7‐year period sensed by the trees in the entire record. That this period was only moderately dry in precipitation anomaly likely indicates accentuated stress from other factors, such as warmer temperatures. Correlation field maps of actual and reconstructed October–June total precipitation, sea surface temperatures and 500‐mb geopotential heights show characteristics that are similar to those indicative of El Niño–Southern Oscillation patterns, particularly with regard to ocean and atmospheric conditions in the equatorial and north Pacific. Our 1184‐year reconstruction of hydroclimatic variability provides long‐term perspective on current and 20th century wet and dry events in Northern New Mexico, is useful to guide expectations of future variability, aids sustainable water management, provides scenarios for drought planning and as inputs for hydrologic models under a broader range of conditions than those provided by historical climate records. Copyright © 2010 Royal Meteorological Society
Statistical analysis of observed and simulated hourly surface wind in the vicinity of the Panama Canal
Authors: Cheng Fang‐Yi , Georgakakos Konstantine P.
Published: March 2010

Surface wind patterns at the Panama Canal vicinity are identified on the basis of 6 years of observed hourly surface wind data and with the use of high‐resolution numerical model simulations. Statistical analysis of the observed wind at various stations in the Panama Canal is presented, together with the analysis of simulated surface wind fields that are obtained from the MM5 mesoscale meteorological model using surface wind assimilation and forced by North American regional reanalysis data. The performance analysis indicates that the 2‐km‐resolution MM5 model surface wind simulations have skill when compared with the observations at the measurement sites. The analysis of the wind fields for the period 2002–2007 shows that the dry season (January to April) is more spatially and temporally coherent than the wet season in the region. The simulated wind shows that the average wind speed reaches up to 7–8 m s−1and the frequency of exceeding 5 m s−1reaches up to 0.7–0.8 in Lake Gatun, the entrance/exit of the Canal in the Caribbean and Pacific coasts, and at high elevations. The dry season exhibits higher climatological wind speeds and exceedence frequencies than the wet season but the wet season shows greater spatial variability. For both seasons, the morning hours have lower average winds than the evening hours. The analysis underlines the significant influence of convection, sea breeze and local conditions (elevation gradients and land surface cover) in the observed and simulated surface wind patterns.

The information presented herein, particularly as regards the Canal centerline results, may be useful for identifying the effects of air pollution from sources aboard transiting cargo ships on large communities in the Canal vicinity (e.g. Panama City). Information presented is also relevant to regional wind energy studies and fog formation analyses. Copyright © 2010 Royal Meteorological Society
A new objective procedure for classifying New Zealand synoptic weather types during 1958–2008
Authors: Jiang Ningbo
Published: March 2010

A set of 12 daily weather types has been obtained for the New Zealand region from the 51‐year NCAR/NCEP dataset by using a two‐stage classification procedure (rotated T‐mode principal component analysis followed by convergent K‐means clustering). Analysis of this classification confirms previous studies and provides further insight into the variation features of the regional synoptic weather on the seasonal, interannual and longer‐time scales.

There are seasonal variations in both intensity and frequency of synoptic weather types. For example, southern highs are more frequent in summer and autumn, while troughs and lows occur more often in winter and secondarily spring. The high and low centres of weather types tend to be more intense in winter than summer.

The frequency and lifetime of synoptic weather types fluctuate on the interannual and decadal scales; there exist significant correlations between frequencies of individual weather types and Southern Oscillation Index (SOI). In all seasons, the frequencies of weather types can change with phases of SOI. The most significant changes in weather type frequencies during the negative SOI phase occur in spring, and characterized by more frequent occurrence of weather types which provide prevailing southwesterly to westerly winds and reduced prominence of anticyclonic situations. The most significant changes in type frequencies during the positive SOI phase occur in summer, with more frequent anticyclonic types but less frequent cyclonic types. The frequency change in winter seems different from other seasons, although consistent with previous studies. In addition, the probability of extremely frequent occurrence or lack of occurrence of certain weather types during a month also varies significantly with SOI phases and with seasons, indicating that the chance for extreme weather conditions to occur is conditional on SOI.

The results can be useful for climate forecasts, studies of climate extremes, air pollution, climatic impacts on human health and other environmental problems. Copyright © 2010 Royal Meteorological Society
Physiological and quality responses of Chinese ‘Suli’ pear (Pyrus bretschneideri Rehd) to 1‐MCP vacuum infiltration treatment
Authors: Chen Shoujiang , Zhang Min , Wang Shaojin
Published: March 2010

BACKGROUND: 1‐Methylcyclopropene (1‐MCP) is a potent inhibitor of ethylene action and can maintain the quality and extend the shelf life of fresh produce. But the effectiveness of application of 1‐MCP may depend upon its capacity to diffuse into the flesh tissue. However, to our knowledge, no study has been performed on the quality maintenance of pear fruit treated with 1‐MCP vacuum infiltration. The objectives of this study were to examine the effect of 1‐MCP vacuum‐infiltration treatment on post‐harvest quality and physiology of ‘Suli’ pears (Pyrus bretschneideri Rehd).

RESULTS: 1‐MCP treatment led to decreased losses in flesh firmness and titratable acidity (TA), delayed change in skin colour and reduced polyphenol oxidase (PPO) activity and accumulation of malondialdehyde (MDA) during cold storage. It also inhibited flesh browning and maintained a higher taste score after shelf life. These effects were higher when fruits were vacuum‐infiltrated with 1‐MCP. However, 1‐MCP had little effect on total soluble solids (TSSs) and respiration rate of pear.

CONCLUSION: Overall, our results indicated that 1‐MCP vacuum infiltration treatment was effective in controlling fruit ripening changes. Copyright © 2010 Society of Chemical Industry
In vitro study of the soft tissue effects of microsecond‐pulsed CO2 laser parameters during soft tissue incision and sulcular debridement
Authors: Vaderhobli Ram M. , White Joel M. , Le Christine , Ho Sunita , Jordan Richard
Published: March 2010

Background and Objectives

Carbon dioxide (CO2) lasers are an important part of dental treatment. Advances in laser technology have produced microsecond pulse durations and small beam sizes. The histological effects of porcine intraoral soft tissue with a range of microsecond‐pulsed CO2 laser parameters used for incision and sulcular debridement were evaluated in vitro and compared with historical histologic data.

Study Design/Materials and Methods

Fresh pig mandibles were used to perform incision and sulcular debridement using a microsecond‐pulsed CO2 laser. λ = 10,600 nm, articulated arm delivered non‐contact with spot size 200 µm, 500 µm, and 1 mm, and focal distance of 1 mm. For sulcular debridement, epithelium within periodontal pocket (6 mm×6 mm) was removed. Laser parameters for incision were from 30 Hz, 350 microseconds, 28 mJ and energy density of 143 J/cm2 to 90 Hz, 1,000 microseconds, 60 mJ, and 1,911 J/cm2. Width and depth of tissue removed, as well as coagulation effects of the tissue treated were measured. These were compared to historical histologic database. Laser‐treated surfaces were observed qualitatively using scanning electron microscopy (SEM).

Results

All laser parameters studied were able to reach the defined simulation objectives in reasonable amounts of time, less than a minute for incision and <20 seconds for sulcular debridement. The depth of the cut was significantly greater than the historical 95% confidence interval, but equivalent for width, lateral, and deep coagulation to the historical database. Sulcular debridement was achieved with minimal coagulation, <100 µm. SEM analysis did not identify any alteration to enamel, dentin, or bone during sulcular debridement.

Conclusion

The treatment objectives of incision and sulcular debridement were achieved with minimal lateral and deep coagulation in reasonable amount of time. Microsecond‐pulsed CO2 lasers can be safely and effectively used for incision and sulcular debridement. Lasers Surg. Med. 42:257–263, 2010. © 2010 Wiley‐Liss, Inc.
Detection of melanoma cells in vitro using an optical detector of photoacoustic waves
Authors: Gutierrez‐Juarez Gerardo , Gupta Sagar K. , Al‐Shaer Mays , Polo‐Parada Luis , Dale Paul S. , Papageorgio Chris , Viator John A.
Published: March 2010

Background and Objective

Circulating tumor cells have been shown to correlate positively with metastatic disease state in patients with advanced cancer. We have demonstrated the ability to detect melanoma cells in a flow system by generating and detecting photoacoustic waves in melanoma cells. This method is similar to flow cytometry, although using photoacoustics rather than fluorescence. Previously, we used piezoelectric films as our acoustic sensors. However, such films have indicated false‐positive signals due to unwanted direct interactions between photons from the high laser fluence in the flow system and the film itself. We have adapted an optical detection scheme that obviates the need for piezoelectric films.

Study Design/Materials and Methods

Our photoacoustic system comprised a tunable laser system with an output of 410–710 nm with a pulse duration of 5 nanoseconds. The light was delivered by optical fiber to a glass microcuvette that contained saline buffer suspensions of melanoma and white blood cells. We used a continuous HeNe laser to provide a probe beam that reflected off of a glass and water interface in close proximity to the microcuvette. The beam was detected by a high‐speed photodiode. When a photoacoustic wave was generated in the microcuvette, the wave propagated and changed the reflectance of the beam due to index of refraction change in the water. This perturbation was used to detect the presence of melanoma cells.

Results

We determined a detection threshold of about one individual melanoma cell with no pyroelectric noise indicated in the signals.

Conclusions

The optical reflectance method provides sensitivity to detect small numbers of melanoma cells without created false‐positive signals from pyroelectric interference, showing promise as a means to perform tests for circulating melanoma cells in blood samples. Lasers Surg. Med. 42:274–281, 2010. © 2010 Wiley‐Liss, Inc.
Semiautomated intraocular laser surgery using handheld instruments
Authors: Becker Brian C. , MacLachlan Robert A. , Lobes Louis A. , Riviere Cameron N.
Published: March 2010

Background and Objective

In laser retinal photocoagulation, hundreds of dot‐like burns are applied. We introduce a robot‐assisted technique to enhance the accuracy and reduce the tedium of the procedure.

Materials and Methods

Laser burn locations are overlaid on preoperative retinal images using common patterns such as grids. A stereo camera/monitor setup registers and displays the planned burn locations overlaid on real‐time video. Using an active handheld micromanipulator, a 7 × 7 grid of burns spaced 650 µm apart is applied to both paper slides and porcine retina in vitro using 30 millisecomds laser pulses at 532 nm. Two scenarios were tested: unaided, in which the micromanipulator is inert and the laser fires at a fixed frequency, and aided, in which the micromanipulator actively targets burn locations and the laser fires automatically upon target acquisition. Error is defined as the distance from the center of the observed burn mark to the preoperatively selected target location.

Results

An experienced retinal surgeon performed trials with and without robotic assistance, on both paper slides and porcine retina in vitro. In the paper slide experiments at an unaided laser repeat rate of 0.5 Hz, error was 125±62 µm with robotic assistance and 149±76 µm without (P < 0.005), and trial duration was 70±8 seconds with robotic assistance and 97±7 seconds without (P < 0.005). At a repeat rate of 1.0 Hz, error was 129±69 µm with robotic assistance and 166±91 µm without (P < 0.005), and trial duration was 26±4 seconds with robotic assistance and 47±1 seconds without (P < 0.005). At a repeat rate of 2.0 Hz on porcine retinal tissue, error was 123±69 µm with robotic assistance and 203±104 µm without (P < 0.005).

Conclusion

Robotic assistance can increase the accuracy of laser photocoagulation while reducing the duration of the operation. Lasers Surg. Med. 42:264–273, 2010. © 2010 Wiley‐Liss, Inc.
In vitro antioxidant activity of tocopherols and tocotrienols and comparison of vitamin E concentration and lipophilic antioxidant capacity in human plasma
Authors: Müller Lars , Theile Kathleen , Böhm Volker
Published: March 2010

A comparative study investigated four tocopherols, four tocotrienols, and α‐tocopheryl acetate on their antioxidative activities in five different popular assays, which were adapted to non‐polar antioxidants. α‐Tocopherol, used as calibration standard, showed the highest ferric reducing antioxidant power. Greater ring methyl substitution not only led to an increase of scavenging activity against the stable 2,2‐diphenyl‐1‐picrylhydrazyl radical, but also to a decrease in oxygen radical absorbance capacity. Regarding α‐tocopherol equivalent antioxidant capacity no significant differences in the antioxidant activity of all vitamin E isoforms were found. In contrast, a significantly lower peroxyl radical‐scavenging activity of α‐tocochromanols was determined in a chemiluminescence assay. Except oxygen radical absorbance capacity, no significant differences of the antioxidant activity related to the side chain could be detected. The data show that the reducing ability and radical chain‐breaking activity of the several vitamin E forms depends on the circumstances under which the assays are performed. In our opinion, the used lipophilic methods can be useful for estimating the antioxidant activity of strong non‐polar antioxidants, e.g. carotenoids, too. Furthermore, we could show a significant correlation between the total tocopherol content in human plasma and the lipophilic antioxidant capacity measured by α‐tocopherol equivalent antioxidant capacity and 2,2‐diphenyl‐1‐picrylhydrazyl.
Consumption of plant sterols reduces plasma and hepatic triglycerides and modulates the expression of lipid regulatory genes and de novo lipogenesis in C57BL/6J mice
Authors: Rideout Todd C. , Harding Scott V. , Jones Peter J. H.
Published: March 2010

To investigate emerging clinical data suggesting a triglyceride (TAG)‐lowering response to plant sterol (PS) therapy, we characterized changes in TAG metabolism in 16 C57BL/6J mice fed a basal control diet (CON) or the CON diet supplemented with 2% PS for 6 wk. PS consumption reduced (p<0.05) plasma (−28%) and hepatic (−30%) TAG concentrations compared with CON mice. PS consumption increased (p<0.05) hepatic lipogenic gene expression (sterol‐regulatory‐element‐binding protein 1c, 2.4‐fold of CON; fatty acid synthase, 6.5‐fold of CON) and de novo lipogenesis (4.51±0.72 versus 2.82±0.61%/day) compared with CON. PS consumption increased (p<0.05) fecal palmitate and stearate excretion and reduced body weight gain compared with CON mice. Although no change in the transcription of intestinal fatty acid absorptive genes was observed, peroxisome proliferator‐activated receptor α mRNA was reduced (p<0.05, 2.0‐fold of CON) in the PS‐fed mice. In conclusion, PS‐fed C57BL/6J mice showed pronounced reductions in plasma and hepatic TAG concentrations despite increases in hepatic lipogenic gene expression and de novo lipogenesis. Interference with intestinal fatty acid/TAG metabolism as suggested by increased fecal fatty acid loss and reduced weight gain may be associated with the TAG‐lowering response to PS consumption.
Analysis for temperature and pressure fields in process of hydrate dissociation by depressurization
Authors: Zhao Zhenwei , Shang Xinchun
Published: March 2010

An improved axisymmetric mathematic modeling is proposed for the process of hydrate dissociation by depressurization around vertical well. To reckon in the effect of latent heat of gas hydrate at the decomposition front, the energy balance equation is employed. The semi‐analytic solutions for temperature and pressure fields are obtained by using Boltzmann‐transformation. The location of decomposition front is determined by solving initial value problem for system of ordinary differential equations. The distributions of pressure and temperature along horizontal radiate in the reservoir are calculated. The numeric results indicate that the moving speed of decomposition front is sensitively dependent on the well pressure and the sediment permeability. Copyright © 2010 John Wiley & Sons, Ltd.
A three‐point time discretization technique for parabolic partial differential equations
Authors: Khoshghalb A. , Khalili N. , Selvadurai A. P. S.
Published: March 2010

The Crank–Nicolson scheme has second‐order accuracy, but often leads to oscillations affecting numerical stability. On the other hand, the implicit scheme is free from oscillation, but it has only first‐order accuracy. In this work, a three‐point discretization scheme with variable time step is presented for the time marching of parabolic partial differential equations. The method proposed has second‐order accuracy, is unconditionally stable and dampens spurious oscillations of the numerical results. The application and effectiveness of the new method are demonstrated through several numerical examples. It is shown that, unlike the Crank–Nicolson method, the approach proposed produces no oscillatory response irrespective of the time step adopted. Copyright © 2010 John Wiley & Sons, Ltd.
Hydromechanical behavior of Tournemire argillites: Measurement of the poroelastic parameters and estimation of the intrinsic permeability by œdometric tests
Authors: Noiret A. , Giot R. , Bemer E. , Giraud A. , Homand F.
Published: March 2010

Knowledge of shale poromechanical behavior is proven to be essential for various environmental issues such as deep geological storage of CO2, high level radioactive waste storage, oil field abandonment and so forth… This paper sets out the key points of shale experimental characterization within the framework of Biot's mechanics of fluid saturated porous solids. Shales are well known to present a more or less transverse isotropy. This paper describes a full methodology for
œdometric tests on such sensitive and weakly permeable material. To illustrate this methodology, measurements carried out on Tournemire argillite are proposed. A transverse isotropic poroelastic model is also used to give a more in depth understanding of the hydromechanical coupling. Copyright © 2010 John Wiley & Sons, Ltd.
eXtended Stochastic Finite Element Method for the numerical simulation of heterogeneous materials with random material interfaces
Authors: Nouy A. , Clément A.
Published: March 2010

An eXtended Stochastic Finite Element Method has been recently proposed for the numerical solution of partial differential equations defined on random domains. This method is based on a marriage between the eXtended Finite Element Method and spectral stochastic methods. In this article, we propose an extension of this method for the numerical simulation of random multi‐phased materials. The random geometry of material interfaces is described implicitly by using random level set functions. A fixed deterministic finite element mesh, which is not conforming to the random interfaces, is then introduced in order to approximate the geometry and the solution. Classical spectral stochastic finite element approximation spaces are not able to capture the irregularities of the solution field with respect to spatial and stochastic variables, which leads to a deterioration of the accuracy and convergence properties of the approximate solution. In order to recover optimal convergence properties of the approximation, we propose an extension of the partition of unity method to the spectral stochastic framework. This technique allows the enrichment of approximation spaces with suitable functions based on an a priori knowledge of the irregularities in the solution. Numerical examples illustrate the efficiency of the proposed method and demonstrate the relevance of the enrichment procedure. Copyright © 2010 John Wiley & Sons, Ltd.
Environmental quality versus economic performance: A dynamic game approach
Authors: Boucekkine Raouf , Krawczyk Jacek B. , Vallée Thomas
Published: March 2010

We study a trade‐off between economic and environmental benefits using a two‐stage optimal control setting where the player can switch to a cleaner technology that is environmentally ‘efficient’ but economically less productive. We provide an analytical characterization of the solution paths for the case where the considered utility functions are increasing and strictly concave with respect to consumption and decreasing linearly with respect to the pollution stock. We establish that in this context, an isolated player will either immediately start using the cleaner technology or for ever continue applying the old ‘dirty’ technology. In a two‐player dynamic game (between two neighboring countries) where the pollution results from a sum of two consumptions, we prove existence of a Nash (open‐loop) equilibrium, in which each player chooses the technology selfishly, i.e., without considering the choice made by the other player. A Stackelberg game solution displays the same properties. Under cooperation, the country reluctant to adopt the clean technology under autarky will adopt the cleaner technology provided it benefits from some ‘transfer’ from the more environment‐friendly partner. Copyright © 2010 John Wiley & Sons, Ltd.
Rapid method for simultaneous determination of 20 components in Isodon nervosa by high‐performance liquid chromatography–electrospray ionisation tandem mass spectrometry
Authors: Du Yingfeng , Jin Yiran , Liu Pengwei , Zhang Xiaowei , Sheng Xiaona , Shi Xiaowei , Wang Qiao , Zhang Lantong
Published: March 2010

Introduction – Isodon nervosa is a commonly used traditional Chinese medicine including diterpenoids, phenolic acids, triterpenoids and volatile oil. Qualitative and quantitative analysis of multi‐components is important for its quality control.

Objective – To establish a liquid chromatography–electrospray ionisation–mass spectrometry method for simultaneous analysis of 20 bioactive constituents of Isodon nervosa in different places of China and different parts of this herb.

Methodology – The optimal chromatographic conditions were achieved on a C18 column (250 × 4.6 mm, 5 µm) with with linear gradient elution with 0.1% aqueous formic acid : methanol containing 0.1% formic acid at a flow‐rate of 0.7 mL/min in 15 min. The identification and quantification of those analytes were achieved on a hybrid quadrupole linear ion trap mass spectrometer. Multiple‐reaction monitoring scanning was employed for quantification with switching electrospray ion source polarity between positive and negative modes in a single run. Full validation of the method was carried out (linearity, precision, accuracy, limit of detection and limit of quantification).

Results – The results indicated that the method was simple, rapid, specific and reliable. The proposed method was successfully applied for the qualitative and quantitative analysis of 20 chemical compositions in Isodon nervosa samples.

Conclusion – Twenty chemical compositions in 21 batches of wild and cultivated Isodon nervosa samples from different sources had great variation in the contents. Copyright © 2010 John Wiley & Sons, Ltd.
Comparative quantitative analysis of artemisinin by chromatography and qNMR
Authors: Liu Ning Qing , Choi Young Hae , Verpoorte Robert , van der Kooy Frank
Published: March 2010

Introduction – Since the discovery of artemisinin in the 1970s, many techniques based on diverse chromatography techniques have been developed to detect and quantify this important antiplasmodial compound. The accurate quantification of this compound in the Artemisia annua plant material is mainly needed for breeding purposes in order to cultivate higher yielding varieties. It is also important for the quality control of herbal preparations containing A. annua plant material.

Objective – To evaluate the most common validated quantification techniques (LC‐MS, HPLC‐ELSD and TLC) and compare the results to quantitative nuclear magnetic resonance spectroscopy (qNMR) in eight different A. annua samples collected from around the world.

Methodology – The leaf material were extracted according to standard procedures and analysed with the validated quantification techniques. For the qNMR analysis we did not employ a standard curve but instead used an internal standard (maleid acid) which is not chemically related to artemisinin.

Results – We found a significant difference between the results in this study. Compared with the qNMR results the HPLC‐ELSD corresponded closely, followed by LC‐MS. Quantitation with TLC led to an estimation range of −0.5 to +3.2 mg artemisinin/g of A. annua.

Conclusion – These results imply that qNMR, with the addition of an internal standard, can be used to quantify artemisinin in A. annua samples in a rapid and reproducible manner. Copyright © 2010 John Wiley & Sons, Ltd.
Direct MS measurement of the extract of Ligularia virgaurea collected in Yunnan and Sichuan provinces of China
Authors: Okamoto Yasuko , Saito Yoshinori , Kuroda Chiaki , Hanai Ryo , Gong Xun , Tori Motoo
Published: March 2010

Introduction – There are numerous Ligularia species in the eastern Qinghai–Tibet Plateau and adjacent areas. L. virgaurea has been used as a traditional folk medicine for the treatment of stomachache and nausea.

Objective – To analyse chemical constituents of L. virgaurea, grown in Yunnan and Sichuan provinces of China.

Methodology – The direct MS measurement of the crude extract of plant samples was used for grouping of this species. As the main compounds were available in pure form, the main peaks were analysed by LCMS.

Results – An easy and speedy method of analysis using MS spectra was developed. On the basis of the findings, L. virgaurea could be divided into two groups. The genetic studies also supported this grouping. Type 1 mainly includes virgaurenones and virgaurenolides. The MS of type 2 is quite different because it includes mainly ligularol and its congeners. Both MS were easily distinguished.

Conclusion – The crude extracts of 11 L. virgaurea samples already collected in recent years were analysed and it was possible to identify them as type 1 or 2. This method was applied to three samples collected in 2009 to successfully classify them as either type 1 or 2. Copyright © 2010 John Wiley & Sons, Ltd.
Chromatographic analysis of simple phenols in some species from the genus Salix
Authors: Pobłocka‐Olech Loretta , Krauze‐Baranowska Mirosława , Głód Daniel , Kawiak Anna , Łojkowska Ewa
Published: March 2010

Introduction – Salicis Cortex, made from willow bark is a herbal remedy, which is standardised based on the content of salicin, a compound with analgesic and antiphlogistic properties. However, clinical trials suggest that other compounds also present in Salicis Cortex can contribute to the pharmacological effects.

Objective – To characterise the composition of phenolic acids in the barks of different species and clones from the genus Salix by use of chromatographic methods—HPTLC and HPLC.

Methodology – The phenolic acid composition was analysed by MGD (multiple gradient development)–HPTLC technique. The separation was performed on HPTLC Diol plates with gradient elution using a mixture of chloroform:hexane:ethyl acetate with increasing concentration of ethyl acetate from 10 to 25%. Derivatisation with thymol reagent was employed for the first time for specific detection of phenolic acids containing methoxyl groups.

Results – The presence of all phenolic acids previously reported in the genus Salix was confirmed, namely p‐hydroxybenzoic, vanillic, cinnamic, p‐coumaric, ferulic and caffeic acids. Furthermore, pyrocatechol as a constituent of willow bark was revealed. The highest concentration of this compound was observed in the S. purpurea bark (2.25 mg/g).

Conclusion – The presence of a relatively high content of pyrocatechol in Salix species may raise doubts about the safe application of this herbal medicine. Copyright © 2010 John Wiley & Sons, Ltd.
Miscibility enhancement of supramolecular polymer blends through complementary multiple hydrogen bonding interactions
Authors: Kuo Shiao‐Wei , Hsu Cheng‐Huo
Published: March 2010

We have investigated the miscibility behavior and specific interactions of supramolecular poly[vinylbenzylthymine‐co‐(butyl methacrylate)] (T‐PBMA) and poly[(2‐vinyl‐4,6‐diamino‐1,3,5‐triazine)‐co‐styrene] (VDAT‐PS) blends with respect to their vinylbenzylthymine (VBT) and 2‐vinyl‐4,6‐diamino‐1,3,5‐triazine (VDAT) contents. Fourier transform infrared spectroscopy revealed that multiple hydrogen bonding interactions occurred exclusively between the VDAT and VBT units, which were stronger than adenine and thymine interactions. A miscibility window occurred in the VDAT‐PS/T‐PBMA blend system when the VBT and VDAT fractions in the copolymers were greater than 7 mol%, as predicted using the Painter–Coleman association model. Copyright © 2010 Society of Chemical Industry
Physiotherapists' participation in peer review in New Zealand: Implications for the profession
Authors: Rolland Ta‐Mera , Hocking Clare , Jones Marion
Published: March 2010

Background and Purpose. Peer review is increasingly used for professional development and to monitor physiotherapists' competence to practice. This study set out to describe the experience of participating in peer review. Method. Qualitative descriptive methods were employed to elicit and analyze interview data from physiotherapists with experience as reviewers and having their practice reviewed. Results. Reviewers managed the process to provide an appropriate level of challenge to junior and senior therapists, and to avoid disrupting professional relationships. Those being reviewed reduced anxiety about the process and risk of negative feedback by putting their best practice on show, and where they could, by carefully choosing the reviewer and patient interaction to be reviewed. Conclusion. When peer review has competing purposes it is neither an effective professional development tool nor an accurate measure of competence. Power and interpersonal relationships need to be acknowledged if peer review is used to assess practitioner competence. Copyright © 2010 John Wiley & Sons, Ltd.
Extremal black hole flows and duality invariants
Authors: Ceresole A.
Published: March 2010

Extremal black holes in Maxwell‐Einstein supergravities with scalar fields can be obtained as solutions of first order flow equations even when they are not supersymmetric, provided one identifies a suitable superpotential W entering the effective potential, and driving the evolution of the scalar fields. We briefly review the main ideas for the construction of W in terms of duality invariants of N = 2 special geometry and we comment on its properties in wider contexts.
Growth and characterization of ZnMgTe/ZnTe layered structures grown by molecular beam epitaxy
Authors: Imada S. , Baba T. , Sakurasawa S. , Kobayashi M.
Published: March 2010

ZnMgTe/ZnTe layered structures were grown on ZnTe substrates by molecular beam epitaxy, and the crystal structures were characterized using X‐ray diffraction methods. This structure would be the waveguide for various optoelectronic devices. Therefore, the crystal quality of this layered structure would be very crucial for the realization of high performance devices. ZnMgTe is lattice mismatched to ZnTe, and the increase of the ZnMgTe layer thickness or Mg mole fraction ratio would result in the crystal quality deterioration of the layered structure. The critical layer thickness (CLT) was theoretically derived, and various structures with various ZnMgTe layer thickness and Mg mole fraction were grown. The lattice mismatch strain relief and crystal quality of those samples were investigated by means of X‐ray reciprocal space mapping (RSM) and cross sectional transmission electron microscopy (TEM). The dislocation formation and the lattice mismatch relaxation were confirmed for various samples and it was revealed that the calculated CLT values could be used as an appropriate guideline to design the dislocation free and high performance device structures (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effect of annealing on nitrogen‐doped ZnO grown by MOVPE with a high‐speed rotating disk reactor
Authors: Nishimoto Naoki , Matsuo Yuki , Fujita Yasuhisa
Published: March 2010

Nitrogen‐doped ZnO thin films were grown by metalorganic vapor phase epitaxy; growth was carried out using a vertical‐type reactor having a high speed rotating disk. Diisopropylzinc, tertiary‐butanol and tertiary‐butylamine were used as the zinc source, the oxygen source and the nitrogen source, respectively. The growth temperature was 350 °C, and VI/II ratio was ranged between 1 and 5. The thin‐film properties were evaluated by Hall‐effect, Raman scattering measurements, and secondary ion mass spectroscopy analyses. The as‐grown film at VI/II = 2 had a nitrogen concentration of 1.42 × 1019 cm‐3, while the residual electron concentration and mobility were 1.12 × 1018 cm‐3 and 60.8 cm2/Vs, respectively. It is demonstrated that a nitrogen concentration of around 2.0 × 1019 cm‐3 represents the solubility limit for this growth condition. Post‐annealing led to a decrease in the residual electron concentration to 8.46 × 1015 cm‐3 while maintaining the comparatively high mobility. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Perturbation growth at the convective scale for CSIP IOP18
Authors: Leoncini G. , Plant R. S. , Gray S. L. , Clark P. A.
Published: March 2010

The Met Office Unified Model is run for a case observed during Intensive Observation Period 18 (IOP18) of the Convective Storms Initiation Project (CSIP). The aims are to identify the physical processes that lead to perturbation growth at the convective scale in response to model‐state perturbations and to determine their sensitivity to the character of the perturbations. The case is strongly upper‐level forced but with detailed mesoscale/convective‐scale evolution that is dependent on smaller‐scale processes. Potential temperature is perturbed within the boundary layer. The effects on perturbation growth of both the amplitude and typical scale length of the perturbations are investigated, and perturbations are applied either sequentially (every 30 minutes throughout the simulation) or at specific times.

The direct effects (within one time step) of the perturbations are to generate propagating Lamb and acoustic waves and produce generally small changes in cloud parameters and convective instability. In exceptional cases a perturbation at a specific grid point leads to switching of the diagnosed boundary‐layer type or discontinuous changes in convective instability, through the generation or removal of a lid. The indirect effects (during the entire simulation) are changes in the intensity and location of precipitation and in the cloud‐size distribution. Qualitatively different behaviour is found for strong (1 K amplitude) and weak (0.01 K amplitude) perturbations, with faster growth after sunrise found only for the weaker perturbations. However, the overall perturbation growth (as measured by the root‐mean‐square error of accumulated precipitation) reaches similar values at saturation, regardless of the perturbation characterization. Copyright © 2010 Royal Meteorological Society and Crown Copyright.