|
| ||
|
|
||
AC
Terms modified by AC Selected AbstractsRiparian Forest Restoration: Increasing Success by Reducing Plant Competition and HerbivoryRESTORATION ECOLOGY, Issue 2 2002Bernard W. Sweeney Abstract The reestablishment of riparian forest is often viewed as "best management practice" for restoring stream ecosystems to a quasi-natural state and preventing non-point source contaminants from entering them. We experimentally assessed seedling survivorship and growth of Quercus palustris (pin oak), Q. rubra (red oak), Q. alba (white oak), Betula nigra (river birch), and Acer rubrum (red maple) in response to root-stock type (bare root vs. containerized), herbivore protection (tree shelters), and weed control (herbicide, mowing, tree mats) over a 4-year period at two riparian sites near the Chester River in Maryland, U.S.A. We started with tree-stocking densities of 988/ha (400/ac) in the experimental plots and considered 50% survivorship (i.e., a density of 494/ha [200/ac] at crown closure) to be an "acceptable or minimum" target for riparian restoration. Results after four growing seasons show no significant difference in survivorship and growth between bare-root and containerized seedlings when averaged across all species and treatments. Overall survivorship and growth was significantly higher for sheltered versus unsheltered seedlings (49% and 77.6 cm vs. 12.1% and 3.6 cm, respectively) when averaged across all species and weed control treatments. Each of the five test species exhibited significantly higher 4-year growth with shelter protection when averaged across all other treatments, and all species but river birch had significantly higher survivorship in shelters during the period. Seedlings protected from weeds by herbicide exhibited significantly higher survivorship and growth than seedlings in all other weed-control treatments when averaged across all species and shelter treatments. The highest 4-year levels of survivorship/growth, when averaged across all species, was associated with seedlings protected by shelters and herbicide (88.8%/125.7cm) and by shelters and weed mats (57.5%/73.5 cm). Thus, only plots where seedlings were assisted by a combination of tree shelters and either herbicide or tree mats exhibited an "acceptable or minimum" rate of survivorship (i.e.,>50%) for riparian forest restoration in the region. Moreover, the combined growth and survivorship data suggest that crown closure over most small streams in need of restoration in the region can be achieved most rapidly (i.e., 15 years or less) by protecting seedlings with tree shelters and controlling competing vegetation with herbicides. [source] Review: A systematic review of prospective studies on attention problems and academic achievementACTA PSYCHIATRICA SCANDINAVICA, Issue 4 2010T. J. C. Polderman Polderman TJC, Boomsma DI, Bartels M, Verhulst FC, Huizink AC. A systematic review of prospective studies on attention problems and academic achievement. Objective:, Our aim was to provide an overview of prospective studies that have addressed the association between attention problems (AP, i.e. symptoms of hyperactivity and inattentiveness) and academic achievement (AA). Method:, We conducted a systematic search in the literature. Normal population studies and clinical studies were included. The methodological quality of each study was evaluated by objective criteria. A best evidence synthesis was used to determine the strengths of the association. Results:, Sixteen studies were included. We found convincing evidence for a negative association between AP and AA. After controlling for intelligence, comorbidity, and socioeconomic status (SES), the association between the hyperactive symptoms of AP and AA was non-significant in two studies. Conclusion:, Children with AP are at risk for lower AA and subsequent adverse outcomes later in life. Interventions in affected children should focus on their behavioural and educational development. [source] Efficacy and safety of two treatment algorithms in bipolar depression consisting of a combination of lithium, lamotrigine or placebo and paroxetineACTA PSYCHIATRICA SCANDINAVICA, Issue 3 2010M. L. M. Van Der Loos van der Loos MLM, Mulder P, Hartong EGThM, Blom MBJ, Vergouwen AC, van Noorden MS, Timmermans MA, Vieta E, Nolen WA, for the LamLit Study Group. Efficacy and safety of two treatment algorithms in bipolar depression consisting of a combination of lithium, lamotrigine or placebo and paroxetine. Objective:, In a previous paper, we reported about the efficacy of the addition of lamotrigine to lithium in patients with bipolar depression. In the second phase of this study paroxetine was added to ongoing treatment in non-responders. Method:, Bipolar depressed patients (n = 124) treated with lithium were randomized to addition of lamotrigine or placebo. In non-responders after 8 weeks, paroxetine 20 mg was added for another 8 weeks to ongoing treatment. Results:, After 8 weeks the improvement in patients treated with lamotrigine vs. patients treated with placebo was significant. After addition of paroxetine this difference disappeared as a result of greater further improvement in the non-responders to placebo. Conclusion:, Addition of lamotrigine to lithium was found effective in bipolar depressed patients. Further addition of paroxetine in non-responders to lithium plus lamotrigine did not appear to provide additional benefit, while it appeared to do so in non-responders to lithium plus placebo. [source] Interactions between bipolar disorder and antisocial personality disorder in trait impulsivity and severity of illnessACTA PSYCHIATRICA SCANDINAVICA, Issue 6 2010A. C. Swann Swann AC, Lijffijt M, Lane SD, Steinberg JL, Moeller FG. Interactions between bipolar disorder and antisocial personality disorder in trait impulsivity and severity of illness. Objective:, We investigated trait impulsivity in bipolar disorder and antisocial personality disorder (ASPD) with respect to severity and course of illness. Method:, Subjects included 78 controls, 34 ASPD, 61 bipolar disorder without Axis II disorder, and 24 bipolar disorder with ASPD, by Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) (SCID-I and -II). Data were analyzed using general linear model and probit analysis. Results:, Barratt Impulsiveness Scale (BIS-11) scores were higher in ASPD (effect sizes 0.5,0.8) or bipolar disorder (effect size 1.45) than in controls. Subjects with both had more suicide attempts and previous episodes than bipolar disorder alone, and more substance-use disorders and suicide attempts than ASPD alone. BIS-11 scores were not related to severity of crimes. Conclusion:, Impulsivity was higher in bipolar disorder with or without ASPD than in ASPD alone, and higher in ASPD than in controls. Adverse effects of bipolar disorder in ASPD, but not of ASPD in bipolar disorder, were accounted for by increased impulsivity. [source] Activation of ADF/cofilin mediates attractive growth cone turning toward nerve growth factor and netrin-1DEVELOPMENTAL NEUROBIOLOGY, Issue 8 2010Bonnie M. Marsick Abstract Proper neural circuitry requires that growth cones, motile tips of extending axons, respond to molecular guidance cues expressed in the developing organism. However, it is unclear how guidance cues modify the cytoskeleton to guide growth cone pathfinding. Here, we show acute treatment with two attractive guidance cues, nerve growth factor (NGF) and netrin-1, for embryonic dorsal root ganglion and temporal retinal neurons, respectively, results in increased growth cone membrane protrusion, actin polymerization, and filamentous actin (F-actin). ADF/cofilin (AC) family proteins facilitate F-actin dynamics, and we found the inactive phosphorylated form of AC is decreased in NGF- or netrin-1-treated growth cones. Directly increasing AC activity mimics addition of NGF or netrin-1 to increase growth cone protrusion and F-actin levels. Extracellular gradients of NGF, netrin-1, and a cell-permeable AC elicit attractive growth cone turning and increased F-actin barbed ends, F-actin accumulation, and active AC in growth cone regions proximal to the gradient source. Reducing AC activity blunts turning responses to NGF and netrin. Our results suggest that gradients of NGF and netrin-1 locally activate AC to promote actin polymerization and subsequent growth cone turning toward the side containing higher AC activity. © 2010 Wiley Periodicals, Inc. Develop Neurobiol 70: 565,588, 2010 [source] Does ethnic origin have an independent impact on hypertension and diabetic complications?DIABETES OBESITY & METABOLISM, Issue 2 2006V. Baskar Aim:, The morbidity and mortality from cardiovascular complications in diabetes reputedly differ with ethnicity. We have evaluated the prevalence of hypertension and vascular complications amongst Afro-Caribbean (AC), Caucasian (C) and Indo-Asian (IA) ethnic subgroups of a district's diabetes population to estimate the impact of ethnic origin as an independent risk variable. Methods:, Of the 6485 registered adult individuals, 6047 had ethnic data available and belonged to one of the three ethnic groups described (AC 9%, C 70% and IA 21%). Statistical analyses were performed using spss version 11.5. Results:, Results are presented as mean ± s.d. or percentage. IAs were younger (AC 63 ± 13, C 61 ± 15 and IA 57 ± 13 years), were less obese (body mass index 30 ± 8, 29 ± 9, 28 ± 6 kg/cm2) and had lower systolic blood pressure (155 ± 25, 149 ± 24, 147 ± 24 mmHg) and lower prevalence of hypertension (82%, 74% and 68%) compared with C, who had lower values than AC (all p < 0.01). Relative to C group, the AC group had higher prevalence of hypertension and microvascular complications but lower macrovascular disease burden, while the IA group had lower hypertension and macrovascular complications but with comparable microvascular disease burden [microvascular (51%, 44% and 46%; p < 0.01) and macrovascular (33%, 40% and 32%; p < 0.001)]. On logistic regression, this effect of ethnic origin on diabetic complications was found to be significant and independent of other risk variables. Conclusion:, Hypertension and diabetic complication rates were different amongst ethnic subgroups. On logistic regression, it was found that the difference in distribution of age and diabetes duration largely accounted for this difference, although ethnic origin remained an independent risk factor. [source] Association of aldose reductase gene Z+2 polymorphism with reduced susceptibility to diabetic nephropathy in Caucasian Type 1 diabetic patientsDIABETIC MEDICINE, Issue 8 2004M. Lajer Abstract Aims The Z,2 allele of the (AC)n polymorphism in the aldose reductase gene (ALR2) confers increased risk of microvascular diabetic complications, whereas the Z+2 allele has been proposed to be a marker of protection. However data are conflicting. Therefore, we investigated whether this polymorphism is associated with diabetic nephropathy and retinopathy in Type 1 diabetes mellitus in a large case,control study and a family-based analysis. Methods A total of 431 Type 1 diabetic patients with diabetic nephropathy and 468 patients with longstanding Type 1 diabetes and persistent normoalbuminuria were genotyped for the case,control study. In addition, 102 case trios and 98 control trios were genotyped for a family-based study. Results Thirteen different alleles were identified. In the case,control study, the Z+2 allele frequency was significantly higher in the normoalbuminuric diabetic than in patients with diabetic nephropathy (0.17 vs. 0.11, P = 0.008), suggesting a protective function of the Z+2 allele. No significant increase in the frequency of the putative risk allele Z,2 was found in patients with diabetic nephropathy vs. controls (0.39 vs. 0.36). No association with diabetic retinopathy was found. Although the results of the transmission of the Z,2 and Z+2 alleles in the independent family-based study were consistent with the association study, the number of informative families was limited and thus differences were not statistically significant. Conclusions The Z+2 allele of the ALR2 promoter polymorphism is associated with a reduced susceptibility to diabetic nephropathy in Danish Type 1 diabetic patients, suggesting a minor role for the polyol pathway in the pathogenesis of diabetic kidney disease. No association of the ALR2 polymorphism with diabetic retinopathy was found. [source] The high post-test probability of a cytological examination renders further investigations to establish a diagnosis of epithelial malignant pleural mesothelioma redundantDIAGNOSTIC CYTOPATHOLOGY, Issue 8 2006J.G.J.V. Aerts M.D., Ph.D. Abstract The aim of the study was to establish in a prospective and blinded manner the diagnostic yield of morphology, immunocytochemistry (ICH) and electron microscopy (EM) in the cytological analysis of malignant pleural mesothelioma (MPM). Pleural fluid from consecutive patients, 14 with a histologically proven MPM, 12 with a malignant pleuritis due to adenocarcinoma (AC), and 13 with a reactive pleural effusion (RM), was separately analyzed. Smears were incubated with monoclonal antibodies (Tag72, Ber-Ep4, anti-CEA, EMA). These were considered suggestive for MPM when only EMA stained positive, for AC when three out of four markers stained positive, and for RM when no marker stained positive. The post-test probability of the morphological, ICH, and EM analysis were 92, 100, 92% or MPM, 91, 100, 86% for AC, and 88, 88, 90% for RM, respectively. We concluded that the high post-test probability of a combined morphological and ICH diagnosis of MPM warrants to cease further diagnostic procedures in these patients. Electron microscopy did not add to accuracy of diagnosis. Diagn. Cytopathol. 2006;34:523,527. © 2006 Wiley-Liss, Inc. [source] INTRADUCTAL ULTRASONOGRAPHY OF THE GALLBLADDER IN APPLICATION OF THE ENDOSCOPIC NASO-GALLBLADDER DRAINAGEDIGESTIVE ENDOSCOPY, Issue 1 2007Daisuke Masuda Background:, Although endoscopic naso-gallbladder drainage (ENGBD) for gallbladder disease is useful, the procedure is difficult and investigations involving many cases are lacking. Furthermore, reports on transpapillary intraductal ultrasonography (IDUS) of the gallbladder using a miniature probe are rare. Methods:, A total of 150 patients (119 suspected of having gallbladder carcinoma, 24 with acute cholecystitis (AC), and seven with Mirizzi's syndrome (MS)) were the subject. (i) ENGBD: We attempted to put ENGBD tube into the GB. (ii) IDUS of the gallbladder: Using the previous ENGBD tube, we attempted to insert the miniature probe into the gallbladder and perform transpapillary IDUS of the gallbladder. In five patients, we attempted three-dimensional intraductal ultrasonography (3D-IDUS). Results:, (i) ENGBD: Overall success rate was 74.7% (112/150); the rate for the patients suspected of having gallbladder carcinoma was 75.6% (90/119), and was 71.0% (22/31) for the AC and MS patients. Inflammation and jaundice improved in 20/22 successful patients with AC and MS. Success rate was higher when cystic duct branching was from the lower and middle parts of the common bile duct than from the upper part, and was higher when branching was upwards than downwards. (ii) IDUS of the gallbladder: Success rate for miniature probe insertion into the gallbladder was 96.4% (54/56). Lesions could be visualized in 50/54 patients (92.6%). Of these, detailed evaluation of the locus could be performed in 41. In five patients attempted 3D-IDUS, the relationship between the lesion and its location was readily grasped. Conclusion:, IDUS of the gallbladder is superior for diagnosing minute images. Improvement on the device will further increase its usefulness. [source] International survey on esophageal cancer: part II staging and neoadjuvant therapyDISEASES OF THE ESOPHAGUS, Issue 3 2009J. Boone SUMMARY The outcome of esophagectomy could be improved by optimal diagnostic strategies leading to adequate preoperative patient selection. Neoadjuvant therapy could improve outcome by increasing the number of radical resections and by controlling metastatic disease. The purposes of this study were to gain insight into the current worldwide practice of staging modalities and neoadjuvant therapy in esophageal cancer, and to detect intercontinental differences. Surgeons with particular interest in esophageal surgery, including members of the International Society for Diseases of the Esophagus, the European Society of Esophagology , Group d'Etude Européen des Maladies de l'Oesophage, and the OESO, were invited to participate in an online questionnaire. Questions were asked regarding staging modalities, neoadjuvant therapy, and response evaluation applied in esophageal cancer patients. Of 567 invited surgeons, 269 participated resulting in a response rate of 47%. The responders currently performing esophagectomies (n= 250; 44%) represented 41 countries across the six continents. Esophagogastroscopy with biopsy and computed tomography (CT) scanning were routinely performed by 98% of responders for diagnosing and staging esophageal cancer, while endoscopic ultrasound (EUS) and barium esophagography were routinely applied by 58% and 51%, respectively. Neoadjuvant therapy is routinely administered by 33% and occasionally by 63% of responders. Of the responders that administer identical neoadjuvant regimens to esophageal adenocarcinoma (AC) and squamous cell carcinoma, 54% favor chemoradiotherapy. For AC, chemotherapy is preferred by 31% of the responders that administer neoadjuvant therapy, whereas for squamous cell carcinoma, the majority of responders (38%) prefer chemoradiotherapy. Response to neoadjuvant therapy is predominantly assessed by CT scanning of the chest and abdomen (86%). Barium esophagography, EUS, and combined CT/PET scan are requested for response monitoring in equal frequency (25%). Substantial differences in applied staging modalities and neoadjuvant regimens were detected between surgeons from different continents. In conclusion, currently the most commonly applied diagnostic modalities for staging and restaging esophageal cancer are CT scanning of the chest and abdomen, gastroscopy, barium esophagography and EUS. Neoadjuvant therapy is routinely applied by one third of the responders. Intercontinental differences have been detected in the diagnostic modalities applied in esophageal cancer staging and in the administration of neoadjuvant therapy. The results of this survey provide baseline data for future research and for the development of international guidelines. [source] Estrogen and progesterone receptors in esophageal carcinomaDISEASES OF THE ESOPHAGUS, Issue 4 2008R. Kalayarasan SUMMARY., Information is sparse and contradictory in the literature regarding the role of estrogen receptor (ER) and progesterone receptor (PR) in esophageal carcinoma. This study was conducted over a period of 18 months from September 2004 with the primary aim of determining the PR, ER alpha (ER,) and ER beta (ER,) status of esophageal carcinoma and normal esophageal mucosa (NEM). The receptor status was correlated with tumor type, tumor differentiation and tumor stage. A total of 45 patients with histologically proven squamous cell carcinoma (SCC) (n = 30) and adenocarcinoma (AC) (n = 15) were studied. Receptor status was detected by immunohistochemistry (IHC) and semiquantitative assessment was done by quick score method of endoscopic biopsy specimens. The mean age for SCC and AC were not significantly different. The gender ratio in favor of males was 3 : 2 for SCC and 4 : 1 for AC. None of the specimens from SCC or AC showed positivity for PR both in NEM and tumor tissue. Likewise none of the specimens were positive for ER, by IHC. The mean ER, score for AC was significantly higher than SCC. For SCC it was seen that ER, positivity in tumor cells increases with dedifferentiation and increasing tumor stage. This trend was seen for AC as well. ER, is over-expressed in poorly differentiated SCC and AC compared to NEM. Thus ER, may be a marker for poor biological behavior, that is dedifferentiation or higher stage of disease. In view of these findings we propose a large-scale prospective, longitudinal interventional study using selective estrogen modulators. [source] Effects of Antrodia camphorata on viability, apoptosis, [Ca2+]i, and MAPKs phosphorylation in MG63 human osteosarcoma cellsDRUG DEVELOPMENT RESEARCH, Issue 2 2007Yih-Chau Lu Abstract The present study explored the effect of Antrodia camphorata (AC) on viability, apoptosis, mitogen-activated protein kinases (MAPKs) phosphorylation, and Ca2+ regulation in MG63 human osteosarcoma cells. AC (25,50,µg/ml) did not affect cell viability, but at 100,200,µg/ml decreased viability and induced apoptosis in a concentration-dependent manner. AC at concentrations of 25,200,µg/ml did not alter basal [Ca2+]i, but at 25,µg/ml decreased [Ca2+]i increases induced by ATP, bradykinin, histamine, and thapsigargin. ATP, bradykinin, and histamine increased cell viability while thapsigargin decreased it. AC (25,µg/ml) pretreatment failed to alter bradykinin- and thapsigargin-induced effects on viability, but potentiated ATP- and histamine-induced increases in viability. Immunoblotting showed that MG63 cells did not have background phospho-JNK and phospho-p38 mitogen-activated protein kinases (MAPKs); and AC did not induce the phosphorylation of these two MAPKs. Conversely, the cells had significant background phospho-ERK MAPK that was inhibited by 200,µg/ml AC. The ERK-specific inhibitor PD98059 also induced cell death. Collectively, in MG63 cells, AC exerted multiple effects on viability and [Ca2+]i, caused apoptosis probably via inhibition of ERK MAPK phosphorylation. Drug Dev Res 68:71,78, 2007. © 2007 Wiley-Liss, Inc. [source] Echo-Tracking Assessment of Carotid Artery Stiffness in Patients with Aortic Valve StenosisECHOCARDIOGRAPHY, Issue 7 2009Francesco Antonini-Canterin M.D. Background: There is little information about mechanical properties of large arteries in patients (pts) with aortic stenosis (AS). Methods: Nineteen patients with AS (aortic valve area: 0.88 ± 0.29 cm2) and 24 control subjects without AS but with a similar distribution of risk factors were recruited. , index, pressure-strain elastic modulus (Ep), arterial compliance (AC), augmentation index (AIx), and local pulse-wave velocity (PWV) were obtained at the level of right common carotid artery (CCA) by a real time echo-tracking system. Time to dominant peak of carotid diameter change waveform, corrected for heart rate (tDPc), and maximum rate of rise of carotid diameter (dD/dt) were measured. Systemic arterial compliance (SAC) was also calculated. Parameters of AS severity (mean gradient, valve area, stroke work loss [SWL]) were determined. Results: tDPc was higher in patients with AS than in controls (7.9 ± 0.6 vs. 6.6 ± 0.7, P < 0.0001) while dD/dt was lower (5.3 ± 3.6 mm/s vs. 7.8 ± 2.8 mm/s, P = 0.01). AIx was significantly higher in AS group (32.5 ± 13.6% vs. 20.6 ± 12.2%, P = 0.005) and had a linear correlation both with tDPc (r = 0.63, P < 0.0001) and with dD/dt (r =,0.38, P = 0.01). There was a significant correlation between carotid AC and SAC (r = 0.49, P = 0.03), but only carotid AC was related to SWL (r = 0.51, P = 0.02), while SAC was not (P = 0.26).Conclusions: AIx was the only parameter of arterial rigidity found to be higher in patients with AS than in controls. Carotid AC showed a significant correlation with SAC and it seemed to be more closely related to AS severity than to SAC. [source] The Effect of Angiotensin II Type-1 Receptor Gene Polymorphisms on Doppler Blood Flow Parameters of Carotid and Brachial Arteries in Patients with Myocardial InfarctionECHOCARDIOGRAPHY, Issue 7 2006Onder Ozturk M.D. Background: Genetic influence on Doppler blood flow parameters of carotid and brachial arteries (BA) is uncertain. We investigated the relationship between the angiotensin II type-1 receptor (AT1R) gene polymorphism and the blood flow characteristics of common carotid arteries (CCA) and BA by color Doppler ultrasound (CDUS) in patients with a first anterior acute myocardial infarction (AMI). Methods and Results: Sixty-seven patients (15 women and 52 men), aged 25,77 years, with anterior AMI were studied. The AT1R genotypes were established. Based on the polymorphism of the AT1R, they were classified into three groups: AT1R AA genotype (Group1, n = 42 patients), AT1R AC genotype (Group 2, n = 17 patients), and AT1R CC genotype (Group 3, n = 8 patients). Peak-systolic velocity (PSV) and end-diastolic velocity (EDV) of right and left CCA, PSV of right BA, and intimal-medial thickness (IMT) of both CCA were measured by CDUS. All results evaluated statistically. The AT1R genotypes were distributed as follows: 63% AA, 25% AC, and 12% CC. PSV of BA and both CCA were higher in patients with CC and AC than AA (P < 0.05). Also, IMT of both CCA were also higher in the same groups (P < 0.05). Conclusions: Our results suggest that AT1R gene polymorphism influences Doppler blood flow parameters of both BA and CCA, and IMT of CCA. Although further studies are required. [source] Hydrological connectivity in coastal inland systems: lessons from a Neotropical fish metacommunityECOLOGY OF FRESHWATER FISH, Issue 1 2010P. H. M. De Macedo-Soares de Macedo-Soares PHM, Petry AC, Farjalla VF, Caramaschi EP. Hydrological connectivity in coastal inland systems: lessons from a Neotropical fish metacommunity. Ecology of Freshwater Fish 2010: 19: 7,18. © 2009 John Wiley & Sons A/S Abstract,,, We assessed the influence of hydrological connectivity in structuring fish communities through seasonal samplings of environmental variables and fishes in a coastal lagoon and associated pools in the Restinga de Jurubatiba National Park, Brazil. Community structure attributes such as species richness, numerical density and biomass, Shannon,Wiener diversity index and evenness were compared between periods of the lowest and highest hydrological connectivity, while the environmental gradient and fish zonation were explored through ordination techniques. The greater hydrological connectivity established in the rainy season promoted the homogenisation of most environmental variables and fish species, which differed markedly from the arrangement observed in the dry season. Despite variation in fish species composition, community attributes showed non-significant differences between the dry and rainy seasons. The patterns of composition and numerical density in pools were strongly influenced by local factors, especially salinity, dissolved oxygen, total phosphorous concentration and water colour in the dry season, in addition to total nitrogen concentration and depth in the rainy season. Comparable to the role played by flood pulses in river-floodplain systems, the hydrological connectivity in these tropical coastal waterbodies seems to strongly influence fish community structure, and, therefore to determine regional biodiversity. [source] Effects of output power fluctuation on short-circuit current of induction-type wind power generatorsELECTRICAL ENGINEERING IN JAPAN, Issue 3 2009Teruhisa Kumano Abstract Effects of the fluctuation inherent in wind speed are studied by a probabilistic method. The random variation in wind speed is responsible for random behavior in output power and internal voltage of a wind power generator. In case of fault occurrence at the instant of high internal voltage, the resultant short-circuit current will be big, and vice versa. The DC component is also affected. According to the study, 2.4% and 1.3% increase of short-circuit current in AC and DC components are observed respectively in a large variation case. This implies that the wind speed variation should be considered for accurate short-circuit study. © 2008 Wiley Periodicals, Inc. Electr Eng Jpn, 166(3): 27,36, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20721 [source] Study of corrosion resistance improvement by metallic coating for overhead transmission line conductorELECTRICAL ENGINEERING IN JAPAN, Issue 1 2008Masanori Isozaki Abstract Applying anticorrosion grease and aluminum-clad steel (AC) wires to ACSR have been adopted as general methods to protect overhead transmission line conductors and/or wires from corrosion. However, in some cases those means have been found to be ineffective on some transmission lines passing through acid atmosphere in the vicinity of a factory exhausting acid smoke. The corrosion caused by acid atmosphere is characterized by a higher speed in its progress as is well known. As means against such acid corrosion, application of high-purity aluminum, selective removal of intermetallic compound in aluminum, and plastic coating wires have been reported before, and each has both advantages and disadvantages. In a former report, we found that a new type of anticorrosion grease shows an excellent property against acid atmosphere as well as in a salty condition. Here we present a new type of anticorrosion technology of applying high-corrosion-resistance aluminum alloy or zinc coatings on each component wire of a conductor that we succeeded in developing through a serial study of anticorrosion methods on overhead transmission lines. © 2008 Wiley Periodicals, Inc. Electr Eng Jpn, 163(1): 41,47, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20365 [source] Spatial Imaging of Cu2+ -Ion Release by Combining Alternating Current and Underpotential Stripping Mode Scanning Electrochemical MicroscopyELECTROANALYSIS, Issue 2-3 2007Dirk Ruhlig Abstract Anodic underpotential stripping voltammetry was integrated into SECM in order to characterize local corrosion of metallic copper deposits on metal surfaces as a model for copper containing alloys. Primarily, the alternating current mode of SECM was applied in an electrolyte of low ionic strength for localizing possible corrosion sites without any perturbation of the corroding surface, e.g., by the presence of any redox mediator. Sequentially, the release of Cu2+ -ions was confirmed and locally visualized at the previously detected electrochemically active sites by means of spatially resolved anodic underpotential stripping voltammetry performed during SECM scanning. Underpotential stripping voltammetry of Cu2+ -ions was performed at a specifically developed 15,,m gold-coated Pt microelectrode used as SECM tip with a detection limit of 0.15,nM Cu2+ (N=4, RSD=6%) for an accumulation of 45,s at ,0.4,V. SECM images of model samples such as copper coated microelectrodes and lacquered metallic copper workpieces demonstrated the feasibility and applicability of combining AC- and underpotential stripping mode of SECM for local visualization of Cu2+ -ion release from corroding surfaces. [source] Picoliter-volume aqueous droplets in oil: Electrochemical detection and yeast cell electroporationELECTROPHORESIS, Issue 10 2006Chunxiong Luo Abstract An electrochemical detection method was introduced for aqueous droplet analysis in oil phase of microfluidic devices. This method is based on the electrochemical signal difference between aqueous and oil. Applying a low alternating current,(AC) voltage to a couple of Au microelectrodes, this method can offer size information and ion concentration range from 0.02,mmol/L to 1,mol/L of tens of picoliter to nanoliter aqueous droplets. Alternatively, applying a relative high AC voltage (18,Vpp) at a frequency of 1,kHz leads to electroporation of yeast cells encapsulated into picoliter droplets. We believe that this simple technique is useful for a number of aqueous droplet-based chemical and biological analyses as well as cell electroporation. [source] Droplet fusion by alternating current (AC) field electrocoalescence in microchannelsELECTROPHORESIS, Issue 19 2005Max Chabert Abstract We present a system for the electrocoalescence of microfluidic droplets immersed in an immiscible solvent, where the undeformed droplet diameters are comparable to the channel diameter. The electrodes are not in direct contact with the carrier liquid or the droplets, thereby minimizing the risk of cross-contamination between different coalescence events. Results are presented for the coalescence of buffered aqueous droplets in both quiescent and flowing fluorocarbon streams, and on-flight coalescence is demonstrated. The capillary-based system presented here is readily amenable to further miniaturization to any lab-on-a-chip application where the conductivity of the droplets is much greater than the conductivity of the stream containing them, and should aid in the further application of droplet microreactors to biological analyses. [source] Cyclical electrical field flow fractionationELECTROPHORESIS, Issue 9 2005Bruce K. Gale Abstract Cyclical electrical field flow fractionation (Cy/ElFFF) is demonstrated in a standard electrical field flow fractionation (ElFFF) channel for the first time. Motivation for the use of alternating current (AC) fields in a traditionally direct current (DC) technique are discussed. The function of the system over a wide range of operating conditions is explored and challenges associated with various operating conditions reported. Retention of polystyrene nanoparticle standards is accomplished and the effect of varying parameters of the applied field, such as voltage and frequency, are explored. The first separations using this technique are demonstrated. The experimental results are compared to analytical models previously reported in the literature. The general trend of the experimental results is similar to those predicted in theoretical models and possible reasons for discrepancies are elucidated. Suggestions are made for improving the separation and analysis method, and possible applications explored. [source] Mercury binding on activated carbonENVIRONMENTAL PROGRESS & SUSTAINABLE ENERGY, Issue 4 2006Bihter Padak Abstract Density functional theory has been employed for the modeling of activated carbon (AC) using a fused-benzene ring cluster approach. Oxygen functional groups have been investigated for their promotion of effective elemental mercury binding on AC surface sites. Lactone and carbonyl functional groups yield the highest mercury binding energies. Further, the addition of halogen atoms has been considered to the modeled surface, and has been found to increase the AC's mercury adsorption capacity. The mercury binding energies increase with the addition of the following halogen atoms, F > Cl > Br > I, with the fluorine addition being the most promising halogen for increasing mercury adsorption. © 2006 American Institute of Chemical Engineers Environ Prog, 2006 [source] Bioaccumulation of native polycyclic aromatic hydrocarbons from sediment by a polychaete and a gastropod: Freely dissolved concentrations and activated carbon amendmentENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 9 2006Gerard Cornelissen Abstract The present paper describes a study on the bioaccumulation of native polycyclic aromatic hydrocarbons (PAHs) from three harbors in Norway using the polychaete Nereis diversicolor and the gastropod Hinia reticulata. First, biota,sediment accumulation factors (BSAFs) were measured in laboratory bioassays using the original sediments. Median BSAFs were 0.004 to 0.01 kg organic carbon/kg lipid (10 PAHs and 6 organism,sediment combinations), which was a factor of 89 to 240 below the theoretical BSAF based on total sediment contents (which is approximately one). However, if BSAFs were calculated on the basis of measured freely dissolved PAH concentrations in the pore water (measured with polyoxymethylene passive samplers), it appeared that these BSAFfree values agreed well with the measured BSAFs, within a factor of 1.7 to 4.3 (median values for 10 PAHs and six organism,sediment combinations). This means that for bioaccumulation, freely dissolved pore-water concentrations appear to be a much better measure than total sediment contents. Second, we tested the effect of 2% (of sediment dry wt) activated carbon (AC) amendments on BSAF. The BSAFs were significantly reduced by a factor of six to seven for N. diversicolor in two sediments (i.e., two of six organism,sediment combinations), whereas no significant reduction was observed for H. reticulata. This implies that either site-specific evaluations of AC amendment are necessary, using several site-relevant benthic organisms, or that the physiology of H. reticulata caused artifactually high BSAF values in the presence of AC. [source] Natural killer cells become tolerogenic after interaction with apoptotic cellsEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 6 2010Wai Po Chong Abstract NK cells are effectors in innate immunity and also participate in immunoregulation through the release of TGF-,1 and lysis of activated/autoreactive T cells. Apoptotic cells (AC) have been shown to induce tolerogenic properties in innate immune cells, including macrophages and dendritic cells, but not NK cells. In this study, we demonstrated that after interaction with AC, NK cells released TGF-,1, which in turn suppressed the production of IFN-, by NK cells upon IL-12 and IgG activation. We further identified phosphatidylserine as a potential target on AC for the NK cells, as phosphatidylserine could stimulate NK cells to release TGF-,1, which in turn suppressed CD4+ T-cell proliferation and activation. Moreover, AC-treated NK cells displayed cytotoxicity against autologous-activated CD4+ T cells by upregulating NKp46. This lysis occurred in part through the NKp46-vimentin pathway, as activated CD4+ T cells expressed vimentin on the cell surface and blocking of vimentin or NKp46, but not other NK-cell receptors, significantly suppressed the NK-cell cytotoxicity. We report here a novel interaction between NK cells and AC, resulting in the tolerogenic properties of NK cells required for immune contraction. [source] Controllable Synthesis of Cu2O Microcrystals via a Complexant-Assisted Synthetic RouteEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 7 2010Wanqun Zhang Abstract A novel method using Cu(AC)2·H2O and dimethylglyoxime as reagents has been successfully developed for the controllable synthesis of Cu2O microcrystals with distinctive morphologies, including porous hollow microspheres, octahedral microcages, and microcrystals with truncated corners and edges and octahedral microcrystals. These structures can be fine-tuned by varying reaction temperature, reaction time, and concentration. The products were characterized by X-ray diffraction, field emission scanning electron microscopy, X-ray photoelectron spectra, and UV/Vis diffuse reflectance spectra. This is the first report of the preparation of the novel microcage structure of Cu2O through a simple solution-based route. By investigating the intermediate products which resemble the final crystal structures, a possible growth mechanism is proposed. Moreover, the investigations showed that the various 3D architectures of the as-made products exhibit different abilities to catalytically degrade rhodamine-B. Our work shows that octahedral Cu2O crystals with entirely {111} faces are photocatalytically more active than octahedral microcrystals with truncated corners and edges, suggesting the {111} faces of Cu2O nanostructures are catalytically more active than the {100} and {110} faces. Due to dual effect of the cavity structure and the {111} surfaces, the octahedral microcages with truncated corners and edges exhibit a higher extent of the photodecomposition reaction. As a result of very slow photocorrosion rate of the Cu2O microcrystal, it is expected that these microcrystals with different surfaces may find more applications in photocatalysis. [source] Hybrid Magnetic Materials Based on Nitroxide Free Radicals and Extended Oxalato-Bridged Bimetallic NetworksEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 2 2005Antonio Alberola Abstract A series of hybrid organic-inorganic magnets of formula p -rad[MIICr(ox)3] [M = Mn (1), Co (2), Ni (3), Zn (4)] and m -rad[MIICr(ox)3] [M = Mn (5), Co (6)], in which N -methylpyridinium cations bearing a nitronyl nitroxide moiety in positions 3 (m -rad) or 4 (p -rad) of the pyridine ring coexist with the 2D honeycomb-like oxalato-bridged bimetallic lattice, has been prepared and studied by AC and DC magnetic susceptibility measurements and EPR spectroscopy. In general, the physical properties of these magnets are not altered significantly by the insertion of the nitronyl nitroxide radicals although these paramagnetic molecules seem to interact weakly with the inorganic network as demonstrated by EPR spectroscopy. Some differences can also be observed between the p -rad and m -rad series, i.e. m -rad derivatives have smaller values for the critical temperatures and coercive fields. We also report on the X-ray crystal structures and magnetic properties of p -rad[Mn(H2O)Cr(ox)3]·2H2O (7) and m -rad[Mn(H2O)2Cr(ox)3]·2H2O (8), two extended oxalato-bridged compounds with new topologies. Compound 7 is antiferromagnetic and its structure is a 3D achiral lattice in which zigzag ferromagnetic MnCr chains (J/k = +0.8 K) are interconnected to form hellicoidal hexagonal channels with the cationic free radicals residing in the free space. Compound 8, however, exhibits a ladder-like structural pattern with competing magnetic interactions and paramagnetic behaviour down to low temperatures. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005) [source] Ferromagnetism in [Mn(Cp*)2]+ -Derived Complexes: the "Miraculous" Stacking in [Mn(Cp*)2][Ni(dmit)2]EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 15 2003Christophe Faulmann Abstract The synthesis and characterisation (X-ray structure and magnetism) of metal complexes (Ni, Au) with the [Mn(Cp*)2]+ cation and the dmit2, and dmid2, ligands are reported. [Mn(Cp*)2][Ni(dmit)2] (1) and [Mn(Cp*)2][Au(dmit)2] (2) exhibit the same structural arrangement, built on stacks of [Ni(dmit)2], pairs separated by two [Mn(Cp*)2]+ cations, showing a ···D+D+A,A,D+D+A,A,··· motif. On the contrary, the dmid2, derivative [Mn(Cp*)2][Ni(dmid)2]·CH3CN (3) exhibits a totally different structure, built on mixed layers composed of one [Ni(dmid)2], unit separated by two [Mn(Cp*)2]+ cations, showing a ···D+D+A,D+D+A,···motif. The layers are separated from each other by perpendicular [Ni(dmid)2], units and solvent molecules. Compound 2 exhibits antiferromagnetic interactions, whereas 1 and 3 exhibit ferromagnetic interactions at low temperature. Moreover, as confirmed by AC and DC magnetic susceptibility measurements, 1 is a ferrimagnet, the first ever derived from a 1,2-bis-dithiolene ligand. The ferromagnetic interactions in 1 and 3 are explained using the McConnell I mechanism. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003) [source] Antioxidant capacity of rapeseed meal and rapeseed oils enriched with meal extractEUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY, Issue 7 2010Aleksandra Szyd, owska-Czerniak Abstract Response surface methodology (RSM) was used to evaluate the quantitative effects of two independent variables: solvent polarity and temperature of the extraction process on the antioxidant capacity (AC) and total phenolics content (TPC) in meal rapeseed extracts. The mean AC and TPC results for meal ranged between 1181,9974,µmol TE/100,g and 73.8,814,mg sinapic acid/100,g of meal. The experimental results of AC and TPC were close to the predicted values calculated from the polynomial response surface models equations (R2,=,0.9758 and 0.9603, respectively). The effect of solvent polarity on AC and TPC in the examined extracts was about 3.6 and 2.6 times greater, respectively, than the effect of processing temperature. The predicted optimum solvent polarity of ,,=,78.3 and 63.8, and temperature of 89.4 and 74.2°C resulted in an AC of 10,014,µmol TE/100,g and TPC of 863,mg SAE/100,g meal, respectively. The phenolic profile of rapeseed meal was determined by an HPLC method. The main phenolics in rapeseed meal were sinapine and sinapic acid. Refined rapeseed oils were fortified with an extract , rich in polyphenols , obtained from rapeseed meal. The supplemented rapeseed oil had higher AC and TPC than the refined oil without addition of meal extracts. However, AC and TPC in the enriched oils decreased during storage. The TPC in the studied meal extracts and rapeseed oils correlated significantly (p<0.0000001) positively with their AC (R2,=,0.9387). Practical applications: Many bioactive compounds extracted from rapeseed meal provide health benefits and have antioxidative properties. Therefore, it seems worth to consider the application of antioxidants extracted from the rapeseed meal for the production of rapeseed oils with potent AC. Moreover, antioxidants extracted from the rapeseed meal were added to refined rapeseed oil in order to enhance its AC. AC was then tested by FRAP assay. FRAP method is based on the reduction of the ferric tripyridyltriazine (Fe3+ -TPTZ) complex to the ferrous tripyridyltriazine (Fe2+ -TPTZ), and it is simple, fast, low cost, and robust method. FRAP method does not require specialized equipment and can be performed using automated, semi-automatic, or manual methods. Therefore the proposed FRAP method can be employed by the fat industry laboratories to asses the AC of rapeseed oils and meal. [source] Optimization of activated carbon-based decontamination of fish oil by response surface methodologyEUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY, Issue 7 2007Åge Oterhals Abstract The effect of activated carbon (AC) adsorption on the reduction of persistent organic pollutants (POP) in fish oil was studied based on response surface methodology at a 5-g/kg AC inclusion level. Pretreatment of the oil by alkali refining and bleaching increased the POP levels. The tested process variables (contact time and temperature) affected the AC adsorption rate and significant first- and second-order response models could be established. Polychlorinated dibenzo- p -dioxins and dibenzofurans (PCDD/F) showed a very rapid adsorption behavior and the concentration and toxic equivalent (TEQ) level could be reduced by 99%. Adsorption of dioxin-like polychlorinated biphenyls (DL-PCB) was less effective and depended on ortho substitution, i.e. non- ortho PCB were adsorbed more effectively than mono- ortho PCB with a maximum of 87 and 21% reduction, respectively, corresponding to a DL-PCB-TEQ reduction of 73%. A common optimum for both PCDD/F and DL-PCB adsorption could not be identified. AC treatment had no effect on the level of polybrominated diphenyl ether flame retardants. The differences in adsorption patterns may be explained based on molecular conformation. No change in oil quality could be observed based on oxidation parameters. Compliance with present PCDD/F and DL-PCB legislation levels in fish oil can be achieved based on AC adsorption. [source] A pilot study on systemic thrombolysis followed by low molecular weight heparin in ischemic strokeEUROPEAN JOURNAL OF NEUROLOGY, Issue 10 2006R. Mikulík Low molecular weight heparin (LMWH) administered immediately after intravenous thrombolysis (IT) may reduce the risk of arterial re-occlusion. Its benefit, however, may not outweigh the risk of intracranial hemorrhage (ICH). We sought preliminary data regarding safety of this combined therapy in an open-label, non-randomized study. The patients received either a standard anticoagulation (AC) starting 24 h after IT (the standard AC group) or AC with 2850 IU of nadroparin, given every 12 h immediately after IT (the early AC group). Sixty patients received IT treatment: 25 in the standard AC group [mean age 66, median National Institutes of Health Stroke Scale (NIHSS) 13, 64% men] and 35 in the early AC group (mean age 68, median NIHSS 13, 69% men). Symptomatic ICH occurred in one patient (4%) in the standard AC group and three patients (8.6%) in the early AC group [odds ratio (OR) 1.8; 95%CI 0.2,12.8]. At 3 months, nine patients in the standard AC group (36%) and 16 patients in the early AC group (45.7%) achieved a modified Rankin scale 0 or 1 (OR 1.2; 95%CI 0.5,3.2). Our study suggests that treatment with LMWH could be associated with higher odds of ICH, although it may not necessarily lead to a worse outcome. This justifies larger clinical trials. [source] | |||||||||||||||||||||||||||||||||||||||||||||||||