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PA
Kinds of PA Terms modified by PA Selected AbstractsBalloon Debanding the Pulmonary Artery: In Vitro Studies and Early Clinical ExperienceCONGENITAL HEART DISEASE, Issue 4 2009Gareth J. Morgan MPhil ABSTRACT Despite increasing corrective procedures for children with congenital heart disease, there remains a place for surgical banding of the main pulmonary artery (PA). In the vast majority of cases, these bands eventually need to be removed. We examined three cases of percutaneous disruption of PA bands using balloon catheters at our institution. We also performed an in vitro study of PA band disruption mechanism and disruption pressure. Our in vitro study suggested a predictable burst pressure for PA bands over the range of diameters routinely used in pediatric practice. Of three patients who underwent interventional debanding, two patients had successful disruption of their PA bands with no reintervention at 19 months and 23 months follow up. Balloon disruption of surgical PA bands may offer a less invasive alternative to surgical band removal. In vitro analysis suggests that the burst pressure required and mechanism of disruption are predictable. [source] The involvement of phospholipases C and D in the asymmetric division of subsidiary cell mother cells of Zea maysCYTOSKELETON, Issue 11 2008Panagiotis Apostolakos Abstract In the present study, the involvement of phospholipase C and D (PLC and PLD) pathways in the asymmetric divisions that produce the stomatal complexes of Zea mays was investigated. In particular, the polar organization of microtubules (MTs) and actin filaments (AFs) and the process of asymmetric division were studied in subsidiary cell mother cells (SMCs) treated with PLC and PLD modulators. In SMCs treated with butanol-1 (but-1), which blocks phosphatidic acid (PA) production via PLDs, AF-patch formation laterally to the inducing guard cell mother cell (GMC) and the subsequent asymmetric division were inhibited. In these SMCs, cell division plane determination, as expressed by MT preprophase band (MT-PPB) formation, was not disturbed. Exogenously applied PA partially relieved the but-1 effects on SMCs. In contrast to SMCs, but-1 did not affect the symmetric GMC division. Inhibition of the PLC catalytic activity by neomycin or U73122 resulted in inhibition of asymmetric SMC division, while AF-patch and MT-PPB were organized as in control SMCs. These data show that the PLC and PLD signaling pathways are involved in the transduction and/or perception of the inductive stimulus that is emitted by the GMCs and induces the polar AF organization and asymmetric SMC division. In contrast, division plane determination in SMCs, as expressed by MT-PPB formation, does not depend on PLC and PLD signaling pathways. Cell Motil. Cytoskeleton 2008. © 2008 Wiley-Liss, Inc. [source] 5-Hydroxytryptamine-induced microvascular pressure transients in lungs of anaesthetized rabbitsACTA PHYSIOLOGICA, Issue 2 2001N. Sen We determined lung microvascular pressure transients induced by 5-hydroxytryptamine (5HT), by the micropuncture technique. We mechanically ventilated anaesthetized (halothane 0.8%), open-chested rabbits, in which we recorded pulmonary artery (PA), left atrial (LA) and carotid artery pressures and cardiac output. For 4-min periods of stopped ventilation, we constantly inflated the lung with airway pressure of 7 cmH2O, then micropunctured the lung to determine pressures in arterioles and venules of 20,25 ,m diameter. An intravenous bolus infusion of 5HT (100 ,g), increased total pulmonary vascular resistance by 59%. Prior to 5HT infusion, the arterial, microvascular and venous segments comprised 30, 50 and 19% of the total pulmonary vascular pressure drop, respectively. However 14 s after 5HT infusion, the PA-arteriole pressure difference (arterial pressure drop) increased 46%, while the venule-LA pressure difference (venous pressure drop) increased >100%. The arteriole,venule pressure difference (microvascular pressure drop) was abolished. The increase in the arterial pressure drop was maintained for 4.8 min, whereas the increased venous pressure drop reverted to baseline in <1 min. We conclude that in the rabbit lung in situ, a 5HT bolus causes sustained arterial constriction and a strong but transient venous constriction. [source] Panic and suicidal ideation and suicide attempts: results from the National Comorbidity SurveyDEPRESSION AND ANXIETY, Issue 3 2006M.P.H., Renee D. Goodwin Ph.D. Abstract Our objective was to determine the association between panic attacks (PAs) and panic disorder (PD), and suicidal ideation (SI) and suicide attempts (SAs) in a nationally representative sample of adults in the community. Data were drawn from the National Comorbidity Survey (n=5,877), a representative household sample of adults ages 15,54 in the United States. Multiple logistic regression analyses were used to examine the relationship between current and lifetime PA and PD and SI and SA, adjusting for differences in demographic characteristics, comorbid mental disorders (major depression, alcohol dependence, and substance dependence), childhood trauma (physical and sexual abuse), and number of lifetime mental disorders. Past-year and lifetime PA and PD were associated with increased SI (both past year and lifetime), and persisted after adjusting for comorbidity and early trauma. Associations between PA and SA were no longer statistically significant after adjusting for comorbidity. Past-year and lifetime PD were associated with lifetime SA, but these associations were no longer statistically significant after adjusting for comorbidity. Past-year and lifetime PD were associated with past-year SA, and this association persisted after adjusting for demographics, comorbidity, and number of lifetime mental disorders. These findings are consistent with previous results, and further help to clarify the relationships between panic and suicide behavior by identifying potential methodological reasons for inconsistencies in results from previous studies. Depression and Anxiety 23:124,132, 2006. © 2006 Wiley-Liss, Inc. [source] Impact of substance use on the physical health of patients with bipolar disorderACTA PSYCHIATRICA SCANDINAVICA, Issue 6 2010M. P. Garcia-Portilla Garcia-Portilla MP, Saiz PA, Benabarre A, Florez G, Bascaran MT, Díaz EM, Bousoño M, Bobes J. Impact of substance use on the physical health of patients with bipolar disorder. Objective:, To describe the impact of tobacco, alcohol and cannabis on metabolic profile and cardiovascular risk in bipolar patients. Method:, Naturalistic, cross-sectional, multicenter Spanish study. Current use of tobacco, alcohol and cannabis was determined based on patient self-reports. Metabolic syndrome was defined using the National Health and Nutrition Examination Survey 1999,2000 and the American Heart Association/National Heart, Lung and Blood Institute criteria, and cardiovascular risk using the Framingham and the Systematic Coronary Risk Evaluation functions. Results:, Mean age was 46.6 years, 49% were male. Substance use: 51% tobacco, 13% alcohol and 12.5% cannabis. Patients who reported consuming any substance were significantly younger and a higher proportion was male. After controlling for confounding factors, tobacco was a risk factor for coronary heart disease (CHD) (unstandardized linear regression coefficient 3.47, 95% confidence interval 1.85,5.10). Conclusion:, Substance use, mainly tobacco, was common in bipolar patients. Tobacco use negatively impacted CHD risk. [source] A pilot examination of social context and everyday physical activity among adults receiving Community Mental Health ServicesACTA PSYCHIATRICA SCANDINAVICA, Issue 3 2009B. P. McCormick Objective:, Community mental health center (CMHC) clients include a variety of people with moderate to severe mental illnesses who also report a number of physical health problems. Physical activity (PA) has been identified as one intervention to improve health among this population; however, little is known about the role of social context in PA. The purpose of this study was to examine the role of social context in everyday PA among CMHC clients. Method:, Data were collected from CMHC clients in two cultures using accelerometery and experience sampling methods. Data were analyzed using hierarchical linear modeling. Results:, Independence in housing nor culture was significantly associated with levels of PA. Being alone was significantly negatively related to PA level. Conclusion:, Social isolation appears to be negatively related to PA at the level of everyday life. Physical activity interventions with this population should consider including social components as a part of PA. [source] Pleomorphic adenoma: Cytologic variations and potential diagnostic pitfallsDIAGNOSTIC CYTOPATHOLOGY, Issue 1 2009Uma Handa M.D. Abstract The diverse morphological features encountered in pleomorphic adenoma (PA) may cause diagnostic errors in fine needle aspiration cytology (FNAC). The present study was performed to evaluate the variations in the cytological features of pleomorphic adenoma and to assess the efficacy of FNAC in its diagnosis. Fifty cases diagnosed as PA on FNAC were retrieved from the records of the Pathology Department. Cytologic smears and sections were reviewed and the cytologic diagnoses were compared with the definitive histologic diagnoses. In cases correctly diagnosed on aspiration, morphological variables like patterns of the epithelial component, type and extent of the mesenchymal matrix, metaplastic cells, hyaline globules, cystic change, giant cells, crystalline deposits, nuclear inclusions/grooves, and nuclear atypia were evaluated. The extreme diversity in morphologic features seen in histologic sections was reflected in the smears of PA. Metaplastic changes were observed more frequently in sections, while nuclear changes like inclusions/grooves were more commonly seen in smears. Other morphological features like cylindromatous pattern, giant cells and crystalline deposits were observed with equal frequency in smears and sections. Cytohistologic agreement was present in 45 of the 50 cases (90%). In 5 cases diagnosed as pleomorphic adenoma on FNAC, the histology revealed 1 case each of schwannoma, perineurioma, ectomesenchymal chondromyxoid tumor of tongue, adenoid cystic carcinoma and mucoepidermoid carcinoma. FNAC is a fairly accurate pre-operative procedure for the diagnosis of PA. The cytopathologist needs to be aware of the cytologic variations in pleomorphic adenoma so as to avoid diagnostic errors. Diagn. Cytopathol. 2009. © 2008 Wiley-Liss, Inc. [source] The diagnostic utility of D2-40 for malignant mesothelioma versus pulmonary carcinoma with pleural involvementDIAGNOSTIC CYTOPATHOLOGY, Issue 12 2006Ph.D., Reda S. Saad M.D. Abstract Differentiating malignant mesothelioma (MM) from pulmonary carcinoma in pleural fluid cytology can be challenging. Recent studies have suggested that D2-40, a novel lymphatic marker, may be a useful marker for mesothelial differentiation in surgical specimens. However, there are no available data regarding its utility in effusion cytology specimens. We investigated the utility of D2-40 in pleural fluid cytology in differentiating MM from pulmonary carcinomas. Twenty cases of pleural effusion smears of surgically confirmed MM with their corresponding cell blocks were retrieved from the database of the hospital computer system. We also included 10 cases of metastatic pulmonary adenocarcinoma (PA) and 10 cases metastatic pulmonary squamous cell carcinoma (PSCC) involving the pleural fluid. Cell blocks were formalin-fixed, paraffin embedded, and immunostained for TTF1, p63, calretinin, CK5/6, WT-1, and D2-40. Cases were scored as negative (<5% positivity) or positive (>5% moderate/strong positivity). The positive rates for TTF1, p63, calretinin, CK5/6, WT-1, and D2-40 were as follows: MM (0/20), (0/20), (17/20), (18/20), (19/20), (17/20), for PA (8/10), (0/10), (3/10), (0/10), (0/10), (0/10), and for PSCC (1/10), (10/10), (6/10), (10/10), (0/15), (0/10). The staining pattern for D2-40 was characterized by thick membranous staining. Diffuse cytoplasmic staining by D2-40 was seen in 2 cases of pulmonary carcinoma, counted as negative. Our study showed that in differentiating MM from PA, CK5/6, WT-1, and D2-40 have high specificity and sensitivity for MM. Although calretinin is a sensitive IHC marker for MM, it is not specific since it stained 30% of PA. Conversely, to differentiate between MM and PSCC, p63 and WT-1 are the best available markers. We recommend a panel of CK5/6, p63, D2-40, and WT-1 to differentiate MM from pulmonary carcinomas in effusion cytology specimens. Diagn. Cytopathol. 2006; 34:801,806. © 2006 Wiley-Liss, Inc. [source] Ecological niche modelling as a technique for assessing threats and setting conservation priorities for Asian slow lorises (Primates: Nycticebus)DIVERSITY AND DISTRIBUTIONS, Issue 2 2009J. S. Thorn ABSTRACT Aim, Data on geographical ranges are essential when defining the conservation status of a species, and in evaluating levels of human disturbance. Where locality data are deficient, presence-only ecological niche modelling (ENM) can provide insights into a species' potential distribution, and can aid in conservation planning. Presence-only ENM is especially important for rare, cryptic and nocturnal species, where absence is difficult to define. Here we applied ENM to carry out an anthropogenic risk assessment and set conservation priorities for three threatened species of Asian slow loris (Primates: Nycticebus). Location, Borneo, Java and Sumatra, Southeast Asia. Methods, Distribution models were built using maximum entropy (MaxEnt) ENM. We input 20 environmental variables comprising temperature, precipitation and altitude, along with species locality data. We clipped predicted distributions to forest cover and altitudinal data to generate remnant distributions. These were then applied to protected area (PA) and human land-use data, using specific criteria to define low-, medium- or high-risk areas. These data were analysed to pinpoint priority study sites, suitable reintroduction zones and protected area extensions. Results, A jackknife validation method indicated highly significant models for all three species with small sample sizes (n = 10 to 23 occurrences). The distribution models represented high habitat suitability within each species' geographical range. High-risk areas were most prevalent for the Javan slow loris (Nycticebus javanicus) on Java, with the highest proportion of low-risk areas for the Bornean slow loris (N. menagensis) on Borneo. Eighteen PA extensions and 23 priority survey sites were identified across the study region. Main conclusions, Discriminating areas of high habitat suitability lays the foundations for planning field studies and conservation initiatives. This study highlights potential reintroduction zones that will minimize anthropogenic threats to animals that are released. These data reiterate the conclusion of previous research, showing MaxEnt is a viable technique for modelling species distributions with small sample sizes. [source] Impact of Scribes on Performance Indicators in the Emergency DepartmentACADEMIC EMERGENCY MEDICINE, Issue 5 2010Rajiv Arya MD Abstract Objectives:, The objective was to quantify the effect of scribes on three measures of emergency physician (EP) productivity in an adult emergency department (ED). Methods:, For this retrospective study, 243 clinical shifts (of either 10 or 12 hours) worked by 13 EPs during an 18-month period were selected for evaluation. Payroll data sheets were examined to determine whether these shifts were covered, uncovered, or partially covered (for less than 4 hours) by a scribe; partially covered shifts were grouped with uncovered shifts for analysis. Covered shifts were compared to uncovered shifts in a clustered design, by physician. Hierarchical linear models were used to study the association between percentage of patients with which a scribe was used during a shift and EP productivity as measured by patients per hour, relative value units (RVUs) per hour, and turnaround time (TAT) to discharge. Results:, RVUs per hour increased by 0.24 units (95% confidence interval [CI] = 0.10 to 0.38, p = 0.0011) for every 10% increment in scribe usage during a shift. The number of patients per hour increased by 0.08 (95% CI = 0.04 to 0.12, p = 0.0024) for every 10% increment of scribe usage during a shift. TAT was not significantly associated with scribe use. These associations did not lose significance after accounting for physician assistant (PA) use. Conclusions:, In this retrospective study, EP use of a scribe was associated with improved overall productivity as measured by patients treated per hour (Pt/hr) and RVU generated per hour by EPs, but not as measured by TAT to discharge. ACADEMIC EMERGENCY MEDICINE 2010; 17:490,494 © 2010 by the Society for Academic Emergency Medicine [source] Reliability of Intraoperative Transesophageal Echocardiography During Tetralogy of Fallot RepairECHOCARDIOGRAPHY, Issue 4 2000JAMES J. JOYCE M.D. There is limited information available concerning the accuracy of intraoperative transesophageal echocardiography (TEE) in predicting the extent of residual abnormalities after recovery from surgical repair of tetralogy of Fallot. Therefore, we investigated differences between the results of final postbypass TEE and those of postrecovery (mean, 6 days after surgery) transthoracic echocardiography in a total of 28 consecutive pediatric patients who underwent repair of tetralogy of Fallot with biplane or multiplane TEE. Both postbypass and postrecovery echocardiographic examinations included measurements of the right ventricle (RV)-main pulmonary artery (PA) and the main PA-branch PA peak instantaneous gradients, the degree of pulmonary valvar insufficiency, and color Doppler interrogation of the ventricular septum for residual defects. The RV-main PA gradient did not change significantly: 15 ± 13 vs 18 ± 14 mmHg (postbypass versus postrecovery, mean ± SD). None of the patients had a decrease of , 10 mmHg; and only one patient had an increase of ,: 15 mmHg. There also was no change in the degree of pulmonary insufficiency (3.0 ±1.2 versus 3.1 ± 1.1, using a scale of 0 to 4). Only one of the seven very small (, 2 mm) residual ventricular septal defects was not discovered during postbypass TEE. However, postrecovery transthoracic echocardiography detected significant branch PA stenosis (peak gradient, , 15 mmHg) in five patients (18%) that was not detected during postbypass TEE (P < 0.03). Of the branch PA stenoses that were not detected during TEE, four were left and one was right. Conclusions: Postbypass TEE after tetralogy of Fallot repair reliably predicts residual postrecovery hemodynamic abnormalities, except for branch PA stenosis. [source] Evaluating the contribution of soil properties to modifying lead phytoavailability and phytotoxicity,ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 3 2006Elizabeth A. Dayton Abstract Soil properties affect Pb bioavailability to human and ecological receptors and should be considered during ecological risk assessment of contaminated soil. We used path analysis (PA) to determine the relative contribution of soil properties (pH, organic C [OC], amorphous Fe and Al oxides [FEAL], and cation-exchange capacity [CEC]) in modifying Pb bioavailability. The response of biological endpoints (bioaccumulation and dry matter growth [DMG]) of lettuce (Lactuca sativa) grown on 21 Pb-spiked (2,000 mg/kg) soils were determined. Lettuce tissue Pb ranged from 3.22 to 233 mg/kg, and relative DMG ranged from 2.5 to 88.5% of their respective controls. Simple correlation showed strong relationships between CEC and OC (p < 0.01) and weaker relationships between pH and FEAL (p < 0.05) and Pb bioaccumulation. Results of PA suggest that soil pH increased the negative surface charge of organic matter and clay, thereby increasing CEC and decreasing Pb bioaccumulation. Also, the direct effect of OC on tissue Pb can be attributed to formation of surface Pb complexes by organic matter functional group ligands. Increased OC and/or CEC reduced Pb solubility and bioavailability in the 21 soils in the present study. The relative importance of soil properties likely will vary between studies employing different soils. Soil properties should be considered during the ecological risk assessment of metal in contaminated soils. Path analysis is useful for ecological studies involving soils with a wide range of physicochemical properties and can assist in site risk assessment of metals and remediation decisions on contaminated sites. [source] Biomimetic solid-phase microextraction to predict body residues and toxicity of chemicals that act by narcosisENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 2 2002Heather A. Leslie Abstract A biomimetic extraction technique using solid-phase microextraction (SPME) fibers has been developed for the risk assessment of contaminants with a narcotic mode of action. Our goal is to apply this technique in the future for the prediction of total baseline toxicity of environmental water and effluent samples. Validation of this method requires establishing the relationship between contaminant accumulation and toxicity in biota and accumulation in the surrogate solid phase (the SPME fiber coating). For this purpose, we determined the median lethal concentration (LC50) values for Chironomus riparius midge larvae exposed to two halogenated aromatic compounds separately and measured body residues in the exposed larvae. Solid-phase microextraction fibers with an 85-,m polyacrylate (PA) coating served as the surrogate hydrophobic phase, mimicking the uptake of the compounds by midge larvae. The toxicant concentrations in SPME fibers measured directly by gas chromatography/mass spectrometry (GCMS) or calculated from the SPME fiber,water partition coefficient, KSPME, were related to the toxicant concentrations found in midge larvae. Our results demonstrated that the biomimetic SPME method enables the estimation of body residues in biota and prediction of the degree of baseline toxicity of a water medium. [source] Interobserver Reliability of Video Recording in the Diagnosis of Nocturnal Frontal Lobe SeizuresEPILEPSIA, Issue 8 2007Luca Vignatelli Summary:,Background: Nocturnal frontal lobe seizures (NFLS) show one or all of the following semeiological patterns: (1) paroxysmal arousals (PA: brief and sudden recurrent motor paroxysmal behavior); (2) hyperkinetic seizures (HS: motor attacks with complex dyskinetic features); (3) asymmetric bilateral tonic seizures (ATS: motor attacks with dystonic features); (4) epileptic nocturnal wanderings (ENW: stereotyped, prolonged ambulatory behavior). Objective: To estimate the interobserver reliability (IR) of video-recording diagnosis in patients with suspected NFLS among sleep medicine experts, epileptologists, and trainees in sleep medicine. Methods: Sixty-six patients with suspected NFLS were included. All underwent nocturnal video-polysomnographic recording. Six doctors (three experts and three trainees) independently classified each case as "NFLS ascertained" (according to the above specified subtypes: PA, HS, ATS, ENW) or "NFLS excluded". IR was calculated by means of Kappa statistics, and interpreted according to the standard classification (0.0,0.20 = slight agreement; 0.21,0.40 = fair; 0.41,0.60 = moderate; 0.61,0.80 = substantial; 0.81,1.00 = almost perfect). Results: The observed raw agreement ranged from 63% to 79% between each pair of raters; the IR ranged from "moderate" (kappa = 0.50) to "substantial" (kappa = 0.72). A major source of variance was the disagreement in distinguishing between PA and nonepileptic arousals, without differences in the level of agreement between experts and trainees. Conclusions: Among sleep experts and trainees, IR of diagnosis of NFLS, based on videotaped observation of sleep phenomena, is not satisfactory. Explicit video-polysomnographic criteria for the classification of paroxysmal sleep motor phenomena are needed. [source] Phonology and Geographic Song Discrimination in Song SparrowsETHOLOGY, Issue 1 2003William A. Searcy We investigated whether song sparrows discriminate foreign from local songs using specific phonologic markers, a mechanism of geographic discrimination previously described for some other songbirds. Song sparrows from Linesville, Pennsylvania (PA) respond more strongly to local songs than to songs from Millbrook, New York (NY). We identify 61 note categories in PA and NY songs, of which 13 are unique to PA, 17 are unique to NY, and 31 are shared. The most common note category in PA song, ,buzz BO5', is present in 89% of PA songs and only in 8% of NY songs; this difference in percentage representation is the largest we found for any note category. Substituting this potential PA marker into NY songs, however, did not make those songs more salient to PA sparrows; instead, PA males tested with territorial playback responded significantly less aggressively to NY/PA hybrid songs than to NY songs. A series of control experiments showed that song sparrows do not detect substitution of PA notes into PA songs or of NY notes into NY songs. The results weigh against the hypothesis that geographic discrimination in song sparrows is accomplished simply by recognition of a small number of phonologic markers. [source] Prokineticin 2 depolarizes paraventricular nucleus magnocellular and parvocellular neuronsEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 2 2007Erik A. Yuill Abstract Blind whole-cell patch-clamp techniques were used to examine the effects of prokineticin 2 (PK2) on the excitability of magnocellular (MNC), parvocellular preautonomic (PA), and parvocellular neuroendocrine (NE) neurons within the hypothalamic paraventricular nucleus (PVN) of the rat. The majority of MNC neurons (76%) depolarized in response to 10 nm PK2, effects that were eliminated in the presence of tetrodotoxin (TTX). PK2 also caused an increase in excitatory postsynaptic potential (EPSP) frequency, a finding that was confirmed by voltage clamp recordings demonstrating increases in excitatory postsynaptic current (EPSC) frequency. The depolarizing effects of PK2 on MNC neurons were also abolished by kynurenic acid (KA), supporting the conclusion that the effects of PK2 are mediated by the activation of glutamate interneurons within the hypothalamic slice. PA (68%) and NE (67%) parvocellular neurons also depolarized in response to 10 nm PK2. However, in contrast to MNC neurons, these effects were maintained in TTX, indicating that PK2 directly affects PA and NE neurons. PK2-induced depolarizations observed in PA and NE neurons were found to be concentration-related and receptor mediated, as experiments performed in the presence of A1MPK1 (a PK2 receptor antagonist) abolished the effects of PK2 on these subpopulations of neurons. The depolarizing effects of PK2 on PA and NE neurons were also shown to be abolished by PD 98059 (a mitogen activated protein kinase (MAPK) inhibitor) suggesting that PK2 depolarizes PVN parvocellular neurons through a MAPK signalling mechanism. In combination, these studies have identified separate cellular mechanisms through which PK2 influences the excitability of different subpopulations of PVN neurons. [source] Effects of additional and extended acid etching on bonding to caries-affected dentineEUROPEAN JOURNAL OF ORAL SCIENCES, Issue 5 2004César Augusto Galvão Arrais This study evaluated the effects of additional and extended acid etching on microtensile bond strength (µTBS) of two adhesive systems to sound (SD) and caries-affected dentine (CAD). Flat surfaces of CAD surrounded by SD of 36 extracted carious third molars were assigned to four treatments (i): self-etching adhesive system (Clearfil SE Bond) applied to dentine surfaces following manufacturer's instructions (MI); (ii) after additional etching for 15 s (35% phosphoric acid, PA); (iii) total-etch one-bottle adhesive (Single Bond) applied to dentine surfaces following MI; or (iv), after etching for 45 s with PA. Composite ,blocks' were built on bonded surfaces and restored teeth were vertically sectioned to obtain bonded slices of 0.7 mm thick. Slices were trimmed to create hourglass-shaped specimens (cross-sectional area of 1 mm2), which were tested under tension in a universal testing machine. Additional CAD and SD samples were prepared for scanning electron microscopy observations. Additional and extended etching significantly increased µTBS to CAD; however, µTBS of both adhesives to CAD were significantly lower than to SD. Additional and extended etching can improve bonding to CAD; however, adhesives applied on SD showed the best results for bonding. [source] Theoretical Description of Substituent Effects in Electrophilic Aromatic Substitution ReactionsEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 35 2008Tobias Schwabe Abstract The ability of the current Kohn,Sham density functional theory (DFT) to compute the change of the proton affinity (PA) of phenol derivatives due to substitution is investigated. These systems can be used as models to predict reactivities in electrophilic aromatic substitution reactions. The complexity of the problem is increased systematically by introducing successively up to four substituents in five typical cases (methyl, cyano, fluorine, chlorine, and bromine). Our investigation can be regarded as representative for an important class of problems consistently encountered in the DFT modeling of organic reactions. High-level theoretical reference data from CCSD(T) and SCS-MP2 wave-function calculations are presented, and the PAs are compared to those obtained by a series of density functionals (DFs). It is shown that not all DFs are capable of quantitatively reproducing the substituent effects. These can be simply linear in the number of substituents or show more complicated patterns. Especially for halogens, some DFs even fail completely. In these cases, linearly increasing errors with the number of groups are observed. Reliable results are obtained with hybrid DFs or the even more accurate double-hybrid DF approach. The errors are attributed to the common self-interaction (over-delocalization) error in part of the DFs. Comparison with Hartree,Fock results shows that a reliable account of electron correlation is necessary to compute the PA of unsaturated and highly substituted molecules with chemical accuracy.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) [source] The Acidity of Brønsted CH Acids in DMSO , The Extreme Acidity of NonacyanocyclononatetraeneEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 24 2004Robert Vianello Abstract The gas-phase (GP) acidity of a large variety of CH organic acids is studied by a carefully selected B3LYP/6-311+G(2d,p)//B3LYP/6-31G(d) theoretical model. Acidities are mirrored by the proton affinities of the corresponding conjugate bases. A very good agreement with available experimental data is achieved. It is concluded that the model applied has a high predictive value and that theoretical PA(anion)GP values can be used instead of measured data in cases where experiments are not feasible or not performed. It is shown, employing the isodensity polarized continuum model (IPCM), that there is a good linear relationship between the enthalpies of the proton-transfer reactions in DMSO and the observed pKa(DMSO) values. This relation can be used in predicting the acidity of strong, neutral organic superacids. As an illustrative case, the acidity of cyclononatetraene-1,2,3,4,5,6,7,8,9-nonacarbonitrile ("nonacyanocyclononatetraene") is considered. It is conclusively shown that this compound should be a very potent superacid, as evidenced by its PA(anion)GP (260.0 kcal·mol,1) and pKa (,14.8). The origin of high acidity is identified as a very strong anionic resonance effect in the resulting conjugate base. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004) [source] DOES EVOLUTION OF ITEROPAROUS AND SEMELPAROUS REPRODUCTION CALL FOR SPATIALLY STRUCTURED SYSTEMS?EVOLUTION, Issue 1 2000Esa Ranta Abstract., A persistent question in the evolution of life histories is the fitness trade-off between reproducing only once (semelparity) in a lifetime or reproducing repeated times in different seasons (iteroparity). The problem can be formulated into a research agenda by assuming that one reproductive strategy is resident (has already evolved) and by asking whether invasion (evolution) of an alternative reproductive strategy is possible. For a spatially nonstructured system, Bulmer (1994) derived the relationship v + PA < 1 (PA is adult survival; vbs and bs are offspring numbers for iteroparous and semelparous breeding strategies, respectively) at which semelparous population cannot be invaded by an iteroparous mutant. When the inequality is changed to v + PA > 1, invasion of a semelparous mutant is not possible. From the inequalities, it is easy to see that possibilities for evolutionary establishment of a novel reproductive strategy are rather narrow. We extended the evolutionary scenario into a spatially structured system with dispersal linkage among the subunits. In this domain, a rare reproductive strategy can easily invade a population dominated by a resident reproductive strategy. The parameter space enabling invasion is far more generous with spatially structured evolutionary scenarios than in a spatially nonstructured system. [source] Short-term dynamics of bacterial communities in a tidally affected coastal ecosystemFEMS MICROBIOLOGY ECOLOGY, Issue 2 2008Beate Rink Abstract Tidal effects on the composition of free-living (FL) and particle-associated (PA) bacterial communities were studied in a tidal flat ecosystem in the southern North Sea. Denaturing gradient gel electrophoresis targeting the 16S rRNA gene and the 16S rRNA of Bacteria, Bacteroidetes, Alphaproteobacteria and the Roseobacter clade was applied. Despite strong tidal variations in the quantity and, depending on the season, also the quality of suspended matter as well as variations in bacterial activity, the bacterial community composition remained rather stable. FISH showed some variations of the community composition, but these were not related to typical tidal situations. Variations were higher during tidal cycles in May and July compared with November. Bacteroidetes, Alpha - and Gammaproteobacteria constituted the majority of the bacterial communities but relative proportions of the different groups varied considerably. On particles, Betaproteobacteria were also detected to substantial proportions. The Roseobacter clade constituted up to 90% of FL but only 30% of PA Alphaproteobacteria. Banding patterns of the Bacteroidetes -specific amplicons, and in particular those targeting the 16S rRNA, revealed tidally induced effects, as several bands appeared or disappeared at distinct events such as slack water or resuspension. Sequencing of prominent bands revealed predominantly phylotypes reported previously from this ecosystem. [source] Übersicht über die Sporenassoziationen (lepidophyta - bis pusilla -Zone) aus dem Unterkarbon der Bohrung Neuenkirchen 2/1973 (Insel Rügen, NE-Deutschland)FOSSIL RECORD-MITTEILUNGEN AUS DEM MUSEUM FUER NATURKUNDE, Issue 1 2001Gusti Burmann Abstract Es wird die Sporenzonierung für das Tournai (einschließlich der Grenzschichten) der Bohrung Neuenkirchen 2/73 auf der Insel Rügen (NE-Deutschland) vorgelegt - von der lepidophyta -Zone var. minor -Subzone des Tnla des obersten Devons bis zur pusilla -Zone des tieferen Visé. Das Profit wird verglichen mit der Zonenabfolge aus der Bohrung Wiek 4/70 (Burmann 1975). Zur lepidophyta -Zone liegen vergleichbare Daten aus dem Harz vor (Burmann 1976). Die untersuchte Abfolge von Sporenzonen umfasst die lepidophyta -Zone mit der var. minor -Subzone (höheres Tnla); PA (pusillites-asperitis; Tn1b); NRH (nitidus-rarituberculatus-hederatus; Tn1b-Tn2); ND (nitidus-distinctus; Tn2); RM (rarituber-culatus-minutissimus; tieferes Tn3); CM (claviger-macra; höheres Tn3); Pu (pusilla; V1a+V1b; Obergrenze der Pu-Zone nicht erfasst). Die stratigraphische Einbindung der Sporenzonen erfolgte durch makrofaunistische Datierungen. Die Pu-Zone ist in beiden Bohrungen untergliederbar durch einen Horizont mit Gloeocapsamorpha. Lower Carboniferous spore assemblages (lepidophyta zone to pusilla zone) in the Neuenkirchen 2/1973 borehole of Rügen Island, NE Germany A spore zonation is given for the Tournaisian sequence of the Neuenkirchen 2/73 borehole on the island of Rügen (NE Germany). The deposits range from the lepidophyta zone var. minor subzone of the uppermost Famennian (Tnla) to the pusilla zone of the basal Viséan. The results are compared with the miospore zonation of the borehole Wiek 4 (Burmann 1975), and comparable dates for the lepidophyta zone from the Harz mountains (Burmann 1976). In ascending order the miospore zones examined are: lepidophyta zone with var. minor subzone (upper part of Tnla); PA (pusillites-asperitis; Tnlb); NRH (nitidus-rarituberculatus-hederatus; Tnlb-Tn2): ND (nitidus-distinctus; Tn2); RM (rarituber-culatus-minutissimus; lower part of Tn3): CM (claviger-macra; upper part of Tn3); Pu (pusilla; V1a+V1b; the upper boundary of the Pu zone is not determined). The stratigraphy of the spore zones is also compared with the macrofaunal data. The Pu zone in both boreholes is divided into two parts by a horizon with Gloeocapsamorpha. [source] Growth and population size of crayfish in headwater streams: individual- and higher-level consequences of acidificationFRESHWATER BIOLOGY, Issue 7 2004Steven M. Seiler Summary 1. Environmental stress may have indirect positive effects on population size through modification of food-web interactions, despite having negative effects on individuals. Here we evaluate the individual- and population-level effects of acidification on crayfish (Cambarus bartonii) in headwater streams of the Allegheny Plateau (PA, U.S.A.) with field experiments and survey data. Median baseflow pH of 24 study reaches in nine streams varied from 4.4 to 7.4, with substantial variation found both among and within streams. 2. Two bioassays were conducted to evaluate the relationship between stream pH and crayfish growth rates. Growth rates were always higher in circumneutral reaches than in acidic reaches. Crayfish originating in acidic water grew less when transplanted into neutral water than did crayfish originating in neutral water, providing some evidence for a cost of acclimation to acidity. 3. Stream surveys showed that fish were less abundant and crayfish more abundant in acidified streams than in circumneutral streams. Crayfish density was sixfold higher in reaches with the lowest pH relative to circumneutral reaches. Large crayfish made up a higher proportion of crayfish populations at sites with high fish biomass, consistent with the hypothesis that fish predation on small individuals may be limiting crayfish population size at these sites. 4. Although individual crayfish suffered lower growth in acidified streams, increased acidity appeared to cause an increase in crayfish population size and shifts in size structure, possibly by relieving predation pressure by fish. [source] Influenza virus RNA polymerase PA subunit is a novel serine protease with Ser624 at the active siteGENES TO CELLS, Issue 2 2001Koyu Hara Background Influenza virus RNA polymerase is a multifunctional enzyme that catalyses both transcription and replication of the RNA genome. The function of the influenza virus RNA polymerase PA subunit in viral replication is poorly understood, although the enzyme is known to be required for cRNA , vRNA synthesis. The protease related activity of PA has been discussed ever since protease-inducing activity was demonstrated in transfection experiments. Results PA protein was highly purified from insect cells infected with the recombinant baculovirus carrying PA cDNA, and a novel chymotrypsin-type serine protease activity was identified with the synthetic peptide, Suc-LLVY-MCA, in the PA protein. [3H]DFP was crosslinked with PA and a mutational analysis revealed that serine624 was as an active site for the protease activity. Conclusions These results constitute the demonstration of protease activity in PA subunit of the influenza virus RNA polymerase complexes. [source] A Surface-Based Approach to Measuring Spatial SegregationGEOGRAPHICAL ANALYSIS, Issue 2 2007David O'Sullivan Quantitative indices of residential segregation have been with us for half a century, but suffer significant limitations. While useful for comparison among regions, summary indices fail to reveal spatial aspects of segregation. Such measures generally consider only the population mix within zones, not between them. Zone boundaries are treated as impenetrable barriers to interaction between population subgroups, so that measurement of segregation is constrained by the zoning system, which bears no necessary relation to interaction among population subgroups. A segregation measurement approach less constrained by the chosen zoning system, which enables visualization of segregation levels at the local scale and accounts for the spatial dimension of segregation, is required. We propose a kernel density estimation approach to model spatial aspects of segregation. This provides an explicitly geographical framework for modeling and visualizing local spatial segregation. The density estimation approach lends itself to development of an index of spatial segregation with the advantage of functional compatibility with the most widely used index of segregation (the dissimilarity index D). We provide a short review of the literature on measuring segregation, briefly describe the kernel density estimation method, and illustrate how the method can be used for measuring segregation. Examples using a simulated landscape and two empirical cases in Washington, DC and Philadelphia, PA are presented. [source] Relationship between intensity of physical activity and health-related quality of life in Portuguese institutionalized elderlyGERIATRICS & GERONTOLOGY INTERNATIONAL, Issue 4 2008Alexandrina Lobo Aims: Health-related quality of life (HRQOL) is considered to be the key goal for health promotion in older people. This study explores the relationship between HRQOL and objectively measured intensity of physical activity (PA) in institutionalized older adults. The analysis of the PA patterns of the subjects in relation to recommended levels of PA was also performed. Methods: One hundred and eighty-five residents of long-term care homes aged 65 years or more, volunteered for this study. The Medical Outcome Study Short Form 36-Item health survey (MOS SF-36) questionnaires and the uni-axial MTI Actigraph were used to assess HRQOL and PA, respectively. Participants were classified as less active, reasonably active and more active by tertile of moderated physical activity (MPA). Results: (i) The men represented a greater number of counts/h and min of MPA in all the tertile groups; (ii) men from the less active group had a significantly higher body mass index; (iii) women came third and exhibited less total activity even though they used this time in more intense activities; (iv) there was a higher significant correlation between MPA, physical function and negative association with body pain in relation to the time of institutionalization in both sexes but was more strongly visible in men; and (v) only men presented a significant positive association with physical health, mental health and vitality. Conclusion: Any intensity of PA seems to be better than no activity for HRQOL, but MPA confers greater benefits for the perception of physical function and body pain in the case of institutionalized elderly persons. [source] Amplified Spontaneous Emission of Poly(ladder-type phenylene)s , The Influence of Photophysical Properties on ASE Thresholds,ADVANCED FUNCTIONAL MATERIALS, Issue 20 2008Frédéric Laquai Abstract Amplified spontaneous emission (ASE) of a series of blue-emitting poly(ladder-type phenylene)s (LPPP)s has been studied in thin film polymer waveguide structures. The chemically well-defined step-ladder polymers consist of an increasing number of bridged phenylene rings per monomer unit starting from fully arylated poly(ladder-type indenofluorene) up to poly(ladder-type pentaphenylene). The ASE characteristics of the polymers including the onset threshold values for ASE, the gain and loss coefficients as well as the photoluminescence (PL) properties, i.e., the solid state fluorescence lifetimes, decay kinetics and solid state quantum efficiencies have been studied by time-resolved PL spectroscopy. A fully arylated polyfluorene has been synthesized and its photophysical properties were compared to the step-ladder polymers. Steady-state photoinduced absorption and ultrafast transient absorption spectroscopy have been used to study excited state absorption of singlet and triplet states and polarons present in the solid state. The results demonstrate a minimum regarding the onset threshold value of ASE for a fully arylated poly(ladder-type indenofluorene) and a successive increase of the ASE threshold for the step-ladder polymers with more bridged phenylene rings. In particular, carbazole-containing step-ladder LPPPs exhibit significantly increased ASE threshold values as compared to their carbazole-free analogues due to a pronounced overlap of stimulated emission (SE) and photoinduced absorption (PA). [source] Redox Processes and Water Quality of Selected Principal Aquifer SystemsGROUND WATER, Issue 2 2008P.B. McMahon Reduction/oxidation (redox) conditions in 15 principal aquifer (PA) systems of the United States, and their impact on several water quality issues, were assessed from a large data base collected by the National Water-Quality Assessment Program of the USGS. The logic of these assessments was based on the observed ecological succession of electron acceptors such as dissolved oxygen, nitrate, and sulfate and threshold concentrations of these substrates needed to support active microbial metabolism. Similarly, the utilization of solid-phase electron acceptors such as Mn(IV) and Fe(III) is indicated by the production of dissolved manganese and iron. An internally consistent set of threshold concentration criteria was developed and applied to a large data set of 1692 water samples from the PAs to assess ambient redox conditions. The indicated redox conditions then were related to the occurrence of selected natural (arsenic) and anthropogenic (nitrate and volatile organic compounds) contaminants in ground water. For the natural and anthropogenic contaminants assessed in this study, considering redox conditions as defined by this framework of redox indicator species and threshold concentrations explained many water quality trends observed at a regional scale. An important finding of this study was that samples indicating mixed redox processes provide information on redox heterogeneity that is useful for assessing common water quality issues. Given the interpretive power of the redox framework and given that it is relatively inexpensive and easy to measure the chemical parameters included in the framework, those parameters should be included in routine water quality monitoring programs whenever possible. [source] Palatal adhesion: The treatment of unilateral palatal paralysis after high vagus nerve injuryHEAD & NECK: JOURNAL FOR THE SCIENCES & SPECIALTIES OF THE HEAD AND NECK, Issue 8 2002James L. Netterville MD Abstract Background Resection of skull base tumors commonly necessitates intraoperative sacrifice of lower cranial nerves at the level of the jugular foramen. Sequelae of unilateral vagus nerve loss include ipsilateral laryngeal paralysis, ipsilateral palatal and pharyngeal paralysis, and velopharyngeal incompetence (VPI) marked by hypernasal speech and nasopharyngeal reflux of liquids during swallowing. Methods Palatal adhesion (PA), a procedure whereby the unilaterally paralyzed palate is attached to the posterior pharyngeal wall, decreases the size of the velopharyngeal port and minimizes the symptoms. This study assessed the outcome of PA in 31 patients with VPI secondary to proximal vagus nerve injury. Results PA decreased postoperative nasality in 96% of patients. Nasopharyngeal reflux was significantly improved in 83%. Three patients (11%) had minor wound breakdown postoperatively, all of which healed completely with conservative management. Conclusion PA offers a favorable result with minimal concomitant morbidity and is recommended for patients with VPI secondary to unilateral proximal vagus nerve paralysis. © 2002 Wiley Periodicals, Inc. Head Neck 24: 721,730, 2002 [source] Benefit-Cost Analysis of Addiction Treatment: Methodological Guidelines and Empirical Application Using the DATCAP and ASIHEALTH SERVICES RESEARCH, Issue 2 2002Michael T. French Objective. To provide detailed methodological guidelines for using the Drug Abuse Treatment Cost Analysis Program (DATCAP) and Addiction Severity Index (ASI) in a benefit-cost analysis of addiction treatment. Data Sources/Study Setting. A representative benefit-cost analysis of three outpatient programs was conducted to demonstrate the feasibility and value of the methodological guidelines. Study Design. Procedures are outlined for using resource use and cost data collected with the DATCAP. Techniques are described for converting outcome measures from the ASI to economic (dollar) benefits of treatment. Finally, principles are advanced for conducting a benefit-cost analysis and a sensitivity analysis of the estimates. Data Collection/Extraction Methods. The DATCAP was administered at three outpatient drug-free programs in Philadelphia, PA, for 2 consecutive fiscal years (1996 and 1997). The ASI was administered to a sample of 178 treatment clients at treatment entry and at 7-months postadmission. Principal Findings. The DATCAP and ASI appear to have significant potential for contributing to an economic evaluation of addiction treatment. The benefit-cost analysis and subsequent sensitivity analysis all showed that total economic benefit was greater than total economic cost at the three outpatient programs, but this representative application is meant to stimulate future economic research rather than justifying treatment per se. Conclusions. This study used previously validated, research-proven instruments and methods to perform a practical benefit-cost analysis of real-world treatment programs. The study demonstrates one way to combine economic and clinical data and offers a methodological foundation for future economic evaluations of addiction treatment. [source] | ||||||||||||||||||||||||||||||||||||||||||||||||||||