Recent studies have used the Ba/Ca ratio of planktic foraminifer shells as a proxy for river run-off at oceanic sites near estuaries. Such studies assume that the Ba/Ca ratio in planktic foraminifer shells is primarily controlled by the Ba/Ca concentration of seawater and that other parameters such as salinity, temperature and pH do not compromise the primary Ba concentration relationship. Here we provide new insights from culture experiments and review published studies to confirm that environmental parameters including pH, temperature, salinity, and symbiont photosynthesis do not affect Ba substitution into planktic foraminiferal calcite. The partition coefficient for Ba in spinose planktic foraminifers is estimated as DBa=0.15±0.05 (95% confidence limits). The same factor also seems applicable to the non-spinose genus Neogloboquadrina but not to specimens of the non-spinose genus Globorotalia.
This study investigated how achievement goals are combined to affect students’ learning. We used a multiple goals perspective, based on mastery (i.e., mastery approach) and performance (including both approach and avoidance components) goals, to examine the achievement goal patterns of 1697 Singapore Secondary 3 students in their math study. Four types of goal clusters emerged from latent class cluster analyses: Diffuse (moderate multiple), Moderate Mastery (moderate mastery/low performance approach and avoidance), Success Oriented (moderate mastery/high performance approach and avoidance), and Approach (high mastery and performance approach/low performance avoidance). Analyses of covariance were conducted to compare these four clusters on eleven cognitive, behavioral, and affective learning outcomes. In general, students in the Success Oriented and Approach groups were higher on self-efficacy, subjective task values, class engagement, homework engagement, time management, and meta-cognitive self-regulation than those in the other two groups. In addition, students in the Approach and Moderate Mastery groups were more likely to make effort when encountering difficulties in learning math, showed lower test anxiety, lower negative affect, and achieved higher scores in math than students in the other two groups. These findings suggest that the goal profile with high mastery and performance approach goals combined with low performance avoidance goals is most beneficial for learning, whereas high performance approach goals, when associated with performance avoidance goals, have some negative effects on affective outcomes. The patterns help to refine distinctions in performance goals, and are discussed in the context of academic achievement in Singapore.
In this paper, we examine why some Big Four alumni more than others choose to benefit their former firm (post-employment citizenship). Grounded in social exchange theory, we find that organizational fairness predicts perceived organizational support, which in turn predicts organizational commitment. Organizational commitment predicts post-employment citizenship, and perceived organizational support and organizational commitment partially mediate the positive relationship between organizational fairness and post-employment citizenship. The contributions, limitations, and practical implications of these findings are discussed.
Ice slurries are phase change materials extensively used in refrigeration technology. This work describes an experimental study and empirical modeling that was carried out to characterize the rheological behavior of ice-in-oil slurries. Decane and crushed ice were mixed to prepare test samples with ice volume percentages ranging from 3.5 to 17.7%. The size of the particles was 0.27±0.13mm. The viscosity measurements are performed at −2.5, −5.0, and −10.0°C using a rotational viscometer with a three-bladed impeller. The maximum relative velocity was ∼3.1 for 17.7% vol. concentration. A Bingham viscoplastic model was used to predict the rheological behavior of ice-in-oil slurries. The fractal dimension, packing limit, size of ice particles, and inter-particle cohesive forces were all considered in rheological calculations to make the model extensively applicable. The model accuracy is then examined using third-party experiments and experimental findings from the current study. The model appears to be a viable tool for predicting the viscosity of ice-in-oil slurries.
This paper tests the static tradeoff theory against the pecking order theory. We focus on an important difference in prediction: the static tradeoff theory argues that a firm increases leverage until it reaches its target debt ratio, while the pecking order yields debt issuance until the debt capacity is reached. For a sample of U.S. firms in the period 1985-2005, we find that the pecking order theory is a better descriptor of firms’ issue decisions than the static tradeoff theory. In contrast, when we focus on repurchase decisions we find that the static tradeoff theory is a stronger predictor of firms’ capital structure decisions.
To understand the origins of racial disparities in breast cancer outcomes, the relative importance of race must be examined in the context of molecular subtype. We assessed racial differences in progression-free survival (PFS) and overall survival (OS) in relation to molecular subtype in a diverse cohort of stage II-III breast cancer patients treated in a uniform manner. We reviewed the records of 582 consecutively treated patients receiving post-mastectomy radiation (PMRT) between 1/1999 and 12/2009 and used the log-rank test and Cox proportional hazards models to evaluate the effect of demographic, tumor, and treatment characteristics on PFS and OS. Median follow-up was 44.7 months. Patient characteristics: 24% African descent (AD), 76% white, 61% Hispanic, median age 50, 55% pre/peri-menopausal. Disease characteristics: stage II 30%, stage III 70%. Treatment: all had mastectomy and PMRT to the chest wall (CW) +/- regional nodes (median CW dose 60.4 Gy including boost); 98% had chemotherapy (62% anthracycline/taxane +/- platinum, 20% trastuzumab-based, 16% other); 2% had no chemotherapy due to co-morbidity or patient refusal. All ER+ patients received endocrine therapy. AD and non-AD patients were similar with respect to age, menopause status, stage, and completion of trimodality therapy. AD patients were more likely to be ER- (56% vs 38%, p = 0.0001), PR- (69% vs 54%, p = 0.002), and triple negative (TN) (46% vs 24%, p < 0.0001). Among ER+, there were no significant differences in menopause or PR status depending on race. Overall, AD patients had worse PFS (60.6% vs 78.3%, p = .001) and OS (72.8% vs 87.7%, p < 0.0001). Although AD patients were more commonly ER- or TN, there was no difference in PFS (p = 0.229 and 0.273 respectively) or OS (p = 0.113 and 0.097 respectively) among AD vs non-AD patients in these categories. Among ER+, AD patients had worse PFS (55% vs 81%, p < 0.001) and OS (73% vs 91%, p < 0.0001). The difference in PFS was maintained in the ER+/PR+/HER2- ("luminal A") subgroup (p = 0.002) but not the ER+/PR-/HER2- ("luminal B") subgroup (p = 0.129), and in the post-menopausal ER+/HER2- subgroup (p = 0.004) but not the pre/perimenopausal ER+/HER2- subgroup (p = 0.150). On multivariate analysis, racial differences in PFS (HR 2.75, p = 0.055) and OS (HR 4.63; p = 0.052) were maintained in the luminal A subgroup. In this cohort of stage II-III breast cancer patients managed with trimodality therapy the survival disparity between AD and non-AD patients was driven by 1) a higher proportion of ER- and TN status in the AD population and 2) the worse outcome of similarly treated post-menopausal AD women with luminal A breast cancer. It is imperative that the effect of adjuvant hormonal therapy be examined in the setting of racial diversity.
Effects of reducing agents on the textural properties and bulk/surface phase compositions of a precipitated iron-manganese catalyst were investigated by N2-physisorption, X-ray photoelectron spectroscopy (XRD), Mössbauer effect spectroscopy (MES), X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy (LRS). Fischer–Tropsch synthesis (FTS) was performed in a slurry-phase continuously stirred tank reactor. The characterization results indicated that the hematite in the fresh catalyst was converted mainly to magnetite in H2 atmosphere without the formation of intermediate metallic iron. Large amounts of Fe3O4 and small amounts of ε′-Fe2.2C and χ-Fe2.5C were formed after syngas pretreatment. In contrast, CO activation led to the formation of large amounts of χ-Fe2.5C and carbonaceous species on the surface of magnetite. In the FTS reaction, the CO-activated catalyst presented the highest initial activity compared to the H2 and syngas-reduced catalysts, and remained unchanged in the activity following the transformation of iron carbides to Fe3O4. Furthermore, the FTS activity of the H2-reduced catalyst increased gradually accompanied with the conversion of magnetite to iron carbides. All of the results suggested that the formation of iron carbides (especially for χ-Fe2.5C) on the surface layers provides probably the active sites for FTS, whereas the Fe3O4 formed plays a negligible role in the FTS activity.
In this study, a kind of shape-stabilized phase change material (PCM) was adopted for constructing heat storage condensers. And a novel household refrigerator equipped with the heat storage condensers was setup based on an ordinary double-door three-star compartment refrigerator. The experimental investigation on the characteristics of the novel refrigerator and an ordinary refrigerator was carried out under the ISO standard test conditions. For the novel refrigerator, part of the condensation heat was stored in the shape-stabilized PCM during the on-time and discharged to the environment while the compressor was off. Therefore, the heat dissipation of the novel refrigerator was continuous during a complete cycle (including a successive on-time and off-time period), different from the intermittent heat dissipation of the ordinary setup. Thus, the overall heat-transfer performances of the condensers could be significantly improved, which resulted in a lower condensation temperature, a higher evaporation temperature and a much larger subcooling degree at the condenser outlet. Compared to the ordinary refrigerator, the total cycle time and the ratio of on-time to the total cycle time of the novel refrigerator were much smaller, which led to more frequent starts of the compressor but lower energy consumption. Experiments demonstrated that the novel refrigerator could increase the energy efficiency by about 12% with only little increase of the cost.
In this study, a test system for spray cooling, in which the heating surface temperatures were simultaneously measured by thermocouples and an infrared imager, was set up. A mathematical model of spray cooling heat transfer characteristics was presented based on the fundamentals of dynamics and heat transfer. The temperature distribution on the heating surface was investigated by the experimental and theoretical methods, the surface temperature non-uniformity and its influencing factors were analyzed. The predictions by the model coincided with the experimental results well, and a comparison was demonstrated with a deviation below 10%. It can be concluded that the surface temperature non-uniformity is influenced by the spray characteristics, nozzle-to-surface distance, inlet pressure, heat flux, spray angle and the system pressure. In the case of the same heat flux, the surface temperature non-uniformity can be reduced by the small spray angle, low system pressure, low nozzle-to-surface distance, and the high inlet pressure.
The simulation of viscoelastic fluids is a challenging task from the theoretical and numerical points of view. This class of fluids has been extensively studied with the help of classical numerical methods. In this paper we propose a new approach based on the lattice Boltzmann method in order to simulate linear and non-linear viscoelastic fluids and in particular those described by the Oldroyd-B and FENE-P constitutive equations. We study the accuracy and stability of our model on three different benchmarks: the 3D Taylor-Green vortex decay, the simplified 2D four-rolls mill, and the 2D Poiseuille flow. To our knowledge, the methodology described in this work is a first attempt for the simulation of non-trivial flows of viscoelastic fluids using the lattice Boltzmann method to discretize the constitutive and conservation equations. (C) 2010 Elsevier B.V. All rights reserved.
Purpose/Objective(s)Induction chemotherapy (IC), in conjunction with chemoradiotherapy (CRT) and conventional once daily RT, decreases time to failure in unresectable head and neck carcinoma (HNC) patients. We sought to determine the impact of IC on outcomes in advanced HNC patients treated with CRT and hyperfractionated RT (HFRT).Materials/Methods311 patients with Stage IVA-B HNC treated on 4 prospective phase II studies with definitive CRT consisting of alternating weeks of paclitaxel, continuous 5-FU, hydroxyurea and concurrent HFRT (1.5 Gy bid) from 1995-2002 were analyzed retrospectively for this study. IC consisted of 2 cycles of carboplatin and paclitaxel. Age, PS (0-1 vs. 2), median RT dose, T-stage (T1-2 vs. 3-4), N-stage (≤N2b vs. ≥N2c) were tested on univariate analysis; significant covariates (p < 0.05) were tested on multivariate analysis (MVA).ResultsMedian age was 58 yrs. Primary sites were oral cavity (16%), oropharynx (47%), glottic/supraglottic larynx (24%) and hypopharynx (13%). 251 patients (81%) had T3-4 disease; 102 patients (33%) and 112 patients (36%) had N2b and N2c-N3 disease, respectively. 276 patients (81%) had ECOG performance status (PS) 0-1. Median RT dose was 73.5 Gy. 165 patients (53%) received IC. Median follow-up was 49 months. There were no differences in age, N-stage (≤N2b vs. ≥N2c), primary site, or follow-up time between IC and no IC cohorts. T3-4 (87% vs. 76%, p = 0.0117), PS 2 (16% vs. 6%, p = 0.0033), and RT dose > 73.5 Gy (74% vs. 42%, p < 0.0001) were more common in patients not receiving IC. 4-yr locoregional control (LRC), freedom from distant failure (FFDF), disease free survival (DFS) and overall survival (OS) for the entire cohort was 85%, 80%, 54%, and 55%, respectively. IC was associated with an improvement in 4-yr FFDF (88% vs. 72%, p = 0.0036) and DFS (61% vs. 46%, p = 0.0333), while it showed a non-statistically significant benefit in LRC (90% vs. 80%, p = 0.0918) and OS (62% vs. 48%, p = 0.0552). Improved 4-yr FFDF with IC was seen in patients with ≥ N2c disease (80% vs. 59%, p = 0.0483), while a trend towards significance was observed in N2b patients (92% vs. 76%, p = 0.0848) but not in ≤ N2a patients (93% vs. 83%, p = 0.2268). On MVA, use of IC (p = 0.0079) and N-stage (p = 0.0012), but not PS (p = 0.1101), were significant for FFDF. Age (p = 0.0021), T-stage (p = 0.0144), N-stage (p = 0.0071) were significant for DFS, while use of IC showed a trend (p = 0.0707) toward significance.ConclusionsInduction chemotherapy may improve treatment outcomes in locoregionally advanced HNC patients treated with CRT and HFRT, particularly in those with advanced nodal stage. The results of completed phase III randomized studies are eagerly anticipated. Purpose/Objective(s)Induction chemotherapy (IC), in conjunction with chemoradiotherapy (CRT) and conventional once daily RT, decreases time to failure in unresectable head and neck carcinoma (HNC) patients. We sought to determine the impact of IC on outcomes in advanced HNC patients treated with CRT and hyperfractionated RT (HFRT). Induction chemotherapy (IC), in conjunction with chemoradiotherapy (CRT) and conventional once daily RT, decreases time to failure in unresectable head and neck carcinoma (HNC) patients. We sought to determine the impact of IC on outcomes in advanced HNC patients treated with CRT and hyperfractionated RT (HFRT). Materials/Methods311 patients with Stage IVA-B HNC treated on 4 prospective phase II studies with definitive CRT consisting of alternating weeks of paclitaxel, continuous 5-FU, hydroxyurea and concurrent HFRT (1.5 Gy bid) from 1995-2002 were analyzed retrospectively for this study. IC consisted of 2 cycles of carboplatin and paclitaxel. Age, PS (0-1 vs. 2), median RT dose, T-stage (T1-2 vs. 3-4), N-stage (≤N2b vs. ≥N2c) were tested on univariate analysis; significant covariates (p < 0.05) were tested on multivariate analysis (MVA). 311 patients with Stage IVA-B HNC treated on 4 prospective phase II studies with definitive CRT consisting of alternating weeks of paclitaxel, continuous 5-FU, hydroxyurea and concurrent HFRT (1.5 Gy bid) from 1995-2002 were analyzed retrospectively for this study. IC consisted of 2 cycles of carboplatin and paclitaxel. Age, PS (0-1 vs. 2), median RT dose, T-stage (T1-2 vs. 3-4), N-stage (≤N2b vs. ≥N2c) were tested on univariate analysis; significant covariates (p < 0.05) were tested on multivariate analysis (MVA). ResultsMedian age was 58 yrs. Primary sites were oral cavity (16%), oropharynx (47%), glottic/supraglottic larynx (24%) and hypopharynx (13%). 251 patients (81%) had T3-4 disease; 102 patients (33%) and 112 patients (36%) had N2b and N2c-N3 disease, respectively. 276 patients (81%) had ECOG performance status (PS) 0-1. Median RT dose was 73.5 Gy. 165 patients (53%) received IC. Median follow-up was 49 months. There were no differences in age, N-stage (≤N2b vs. ≥N2c), primary site, or follow-up time between IC and no IC cohorts. T3-4 (87% vs. 76%, p = 0.0117), PS 2 (16% vs. 6%, p = 0.0033), and RT dose > 73.5 Gy (74% vs. 42%, p < 0.0001) were more common in patients not receiving IC. 4-yr locoregional control (LRC), freedom from distant failure (FFDF), disease free survival (DFS) and overall survival (OS) for the entire cohort was 85%, 80%, 54%, and 55%, respectively. IC was associated with an improvement in 4-yr FFDF (88% vs. 72%, p = 0.0036) and DFS (61% vs. 46%, p = 0.0333), while it showed a non-statistically significant benefit in LRC (90% vs. 80%, p = 0.0918) and OS (62% vs. 48%, p = 0.0552). Improved 4-yr FFDF with IC was seen in patients with ≥ N2c disease (80% vs. 59%, p = 0.0483), while a trend towards significance was observed in N2b patients (92% vs. 76%, p = 0.0848) but not in ≤ N2a patients (93% vs. 83%, p = 0.2268). On MVA, use of IC (p = 0.0079) and N-stage (p = 0.0012), but not PS (p = 0.1101), were significant for FFDF. Age (p = 0.0021), T-stage (p = 0.0144), N-stage (p = 0.0071) were significant for DFS, while use of IC showed a trend (p = 0.0707) toward significance. Median age was 58 yrs. Primary sites were oral cavity (16%), oropharynx (47%), glottic/supraglottic larynx (24%) and hypopharynx (13%). 251 patients (81%) had T3-4 disease; 102 patients (33%) and 112 patients (36%) had N2b and N2c-N3 disease, respectively. 276 patients (81%) had ECOG performance status (PS) 0-1. Median RT dose was 73.5 Gy. 165 patients (53%) received IC. Median follow-up was 49 months. There were no differences in age, N-stage (≤N2b vs. ≥N2c), primary site, or follow-up time between IC and no IC cohorts. T3-4 (87% vs. 76%, p = 0.0117), PS 2 (16% vs. 6%, p = 0.0033), and RT dose > 73.5 Gy (74% vs. 42%, p < 0.0001) were more common in patients not receiving IC. 4-yr locoregional control (LRC), freedom from distant failure (FFDF), disease free survival (DFS) and overall survival (OS) for the entire cohort was 85%, 80%, 54%, and 55%, respectively. IC was associated with an improvement in 4-yr FFDF (88% vs. 72%, p = 0.0036) and DFS (61% vs. 46%, p = 0.0333), while it showed a non-statistically significant benefit in LRC (90% vs. 80%, p = 0.0918) and OS (62% vs. 48%, p = 0.0552). Improved 4-yr FFDF with IC was seen in patients with ≥ N2c disease (80% vs. 59%, p = 0.0483), while a trend towards significance was observed in N2b patients (92% vs. 76%, p = 0.0848) but not in ≤ N2a patients (93% vs. 83%, p = 0.2268). On MVA, use of IC (p = 0.0079) and N-stage (p = 0.0012), but not PS (p = 0.1101), were significant for FFDF. Age (p = 0.0021), T-stage (p = 0.0144), N-stage (p = 0.0071) were significant for DFS, while use of IC showed a trend (p = 0.0707) toward significance. ConclusionsInduction chemotherapy may improve treatment outcomes in locoregionally advanced HNC patients treated with CRT and HFRT, particularly in those with advanced nodal stage. The results of completed phase III randomized studies are eagerly anticipated. Induction chemotherapy may improve treatment outcomes in locoregionally advanced HNC patients treated with CRT and HFRT, particularly in those with advanced nodal stage. The results of completed phase III randomized studies are eagerly anticipated.
Purpose/Objective(s)Human papillomavirus (HPV) positivity in head and neck squamous cell carcinoma (HNSCC) results in higher survival rates after treatment with induction chemotherapy or concurrent cisplatin-based chemoradiotherapy. We assess tumor HPV status and report outcomes in patients with locally advanced HNSCC treated with concurrent cetuximab (C) and radiation therapy (RT).Materials/MethodsTumors from sequential HNSCC patients treated with C and intensity-modulated radiation therapy were analyzed for HPV status using PCR for the E6/E7 gene sequence unique to HPV 16 or 18. Differences in overall survival (OS) and progression-free survival (PFS) were assessed by HPV status, stage, tumor (T) and nodal (N) status, primary site, and duration of RT using the log rank test.ResultsBetween 1/07 and 11/09, 20 patients were treated with concurrent C (400 mg/m2 load; 250 mg/m2 weekly) and RT. Primary sites included oral cavity (1), oropharynx (12), hypopharynx (1), larynx (5), and unknown (1). Six patients had Stage III disease and 14 had IVa disease. The median age was 63 yrs (range, 31 - 78). The median RT dose was 72.0 Gy (range, 70.0 - 75.6 Gy) and the median duration of RT was 59 days (range, 49-73). C was given for a median of 7 cycles (range, 4 - 8). Six patients were HPV+, all of which were HPV 16 and oropharynx primaries; the median age was 64 yrs. After a median follow-up among survivors of 25.7 mos., 4 patients have died and 13 patients had disease progression. One-year and 2-year PFS rates were 100% vs. 31% and 60% vs. 23%, respectively (p = 0.05). One-year and 2-year rates OS rates were 100% vs. 83% and 100% vs. 71% for HPV+ vs. HPV- tumors, respectively (p = 0.12). No statistically significant association was found between OS or PFS and stage, T or N status, primary site, or RT duration.ConclusionsHPV positive HNSCC was associated with improved PFS and a trend toward improved OS in patients treated with concurrent C + RT. These findings are consistent with previous reports that HPV+ disease has a better prognosis irrespective of the treatment modality. Future clinical research will involve optimizing therapy based on HPV status. Purpose/Objective(s)Human papillomavirus (HPV) positivity in head and neck squamous cell carcinoma (HNSCC) results in higher survival rates after treatment with induction chemotherapy or concurrent cisplatin-based chemoradiotherapy. We assess tumor HPV status and report outcomes in patients with locally advanced HNSCC treated with concurrent cetuximab (C) and radiation therapy (RT). Human papillomavirus (HPV) positivity in head and neck squamous cell carcinoma (HNSCC) results in higher survival rates after treatment with induction chemotherapy or concurrent cisplatin-based chemoradiotherapy. We assess tumor HPV status and report outcomes in patients with locally advanced HNSCC treated with concurrent cetuximab (C) and radiation therapy (RT). Materials/MethodsTumors from sequential HNSCC patients treated with C and intensity-modulated radiation therapy were analyzed for HPV status using PCR for the E6/E7 gene sequence unique to HPV 16 or 18. Differences in overall survival (OS) and progression-free survival (PFS) were assessed by HPV status, stage, tumor (T) and nodal (N) status, primary site, and duration of RT using the log rank test. Tumors from sequential HNSCC patients treated with C and intensity-modulated radiation therapy were analyzed for HPV status using PCR for the E6/E7 gene sequence unique to HPV 16 or 18. Differences in overall survival (OS) and progression-free survival (PFS) were assessed by HPV status, stage, tumor (T) and nodal (N) status, primary site, and duration of RT using the log rank test. ResultsBetween 1/07 and 11/09, 20 patients were treated with concurrent C (400 mg/m2 load; 250 mg/m2 weekly) and RT. Primary sites included oral cavity (1), oropharynx (12), hypopharynx (1), larynx (5), and unknown (1). Six patients had Stage III disease and 14 had IVa disease. The median age was 63 yrs (range, 31 - 78). The median RT dose was 72.0 Gy (range, 70.0 - 75.6 Gy) and the median duration of RT was 59 days (range, 49-73). C was given for a median of 7 cycles (range, 4 - 8). Six patients were HPV+, all of which were HPV 16 and oropharynx primaries; the median age was 64 yrs. After a median follow-up among survivors of 25.7 mos., 4 patients have died and 13 patients had disease progression. One-year and 2-year PFS rates were 100% vs. 31% and 60% vs. 23%, respectively (p = 0.05). One-year and 2-year rates OS rates were 100% vs. 83% and 100% vs. 71% for HPV+ vs. HPV- tumors, respectively (p = 0.12). No statistically significant association was found between OS or PFS and stage, T or N status, primary site, or RT duration. Between 1/07 and 11/09, 20 patients were treated with concurrent C (400 mg/m2 load; 250 mg/m2 weekly) and RT. Primary sites included oral cavity (1), oropharynx (12), hypopharynx (1), larynx (5), and unknown (1). Six patients had Stage III disease and 14 had IVa disease. The median age was 63 yrs (range, 31 - 78). The median RT dose was 72.0 Gy (range, 70.0 - 75.6 Gy) and the median duration of RT was 59 days (range, 49-73). C was given for a median of 7 cycles (range, 4 - 8). Six patients were HPV+, all of which were HPV 16 and oropharynx primaries; the median age was 64 yrs. After a median follow-up among survivors of 25.7 mos., 4 patients have died and 13 patients had disease progression. One-year and 2-year PFS rates were 100% vs. 31% and 60% vs. 23%, respectively (p = 0.05). One-year and 2-year rates OS rates were 100% vs. 83% and 100% vs. 71% for HPV+ vs. HPV- tumors, respectively (p = 0.12). No statistically significant association was found between OS or PFS and stage, T or N status, primary site, or RT duration. ConclusionsHPV positive HNSCC was associated with improved PFS and a trend toward improved OS in patients treated with concurrent C + RT. These findings are consistent with previous reports that HPV+ disease has a better prognosis irrespective of the treatment modality. Future clinical research will involve optimizing therapy based on HPV status. HPV positive HNSCC was associated with improved PFS and a trend toward improved OS in patients treated with concurrent C + RT. These findings are consistent with previous reports that HPV+ disease has a better prognosis irrespective of the treatment modality. Future clinical research will involve optimizing therapy based on HPV status.
PURPOSE Experimental evidence suggests that anticoagulants (ACs) may inhibit cancer growth and metastasis, but clinical data have been limited. We investigated whether use of ACs was associated with the risk of death from prostate cancer. PATIENTS AND METHODS This study comprised 5,955 men in the Cancer of the Prostate Strategic Urologic Research Endeavor database with localized adenocarcinoma of the prostate treated with radical prostatectomy (RP) or radiotherapy (RT). Of them, 2,175 (37%) were receiving ACs (warfarin, clopidogrel, enoxaparin, and/or aspirin). The risk of prostate cancer-specific mortality (PCSM) was compared between the AC and non-AC groups. RESULTS After a median follow-up of 70 months, risk of PCSM was significantly lower in the AC group compared with the non-AC group (3% v 8% at 10 years; P < .01). The risks of disease recurrence and bone metastasis were also significantly lower. In a subgroup analysis by clinical risk category, the reduction in PCSM was most prominent in patients with high-risk disease (4% v 19% at 10 years; P < .01). The benefit from AC was present across treatment modalities (RT or RP). Analysis by type of AC medication suggested that the PCSM reduction was primarily associated with aspirin. Multivariable analysis indicated that aspirin use was independently associated with a lower risk of PCSM (adjusted hazard ratio, 0.43; 95% CI, 0.21 to 0.87; P = .02). CONCLUSION AC therapy, particularly aspirin, was associated with a reduced risk of PCSM in men treated with RT or RP for prostate cancer. The association was most prominent in patients with high-risk disease.
Polyurethanes (PU) are polymers made with diisocyanates such as MDI (4,4'-methylene diphenyl diisocyanate) and TDI (2,4-toluene diisocyanate and 2,6-toluene diisocyanate). Investigations have been undertaken with MDI and TDI to assess dermal uptake and resulting systemic exposure. Absorption, distribution and excretion of MDI was studied in rats using a single dermal administration of C-14-MDI dissolved in acetone at nominal 165 mg/kg body weight and 15 mg/kg bw (4.0 and 0.4 mg/cm(2)) and intradermal injection of 14C-MDI dissolved in corn oil at nominal 1.4 mg/kg bw. Dermal absorption of 14C-MDI (at both doses) was low; at or below 1% of the applied dose. Considerable amounts of the applied radioactivity were found at the application site which could not be washed off. By intradermal administration of 14C-MDI approximately 66% of applied radioactivity remained at the application site with approximately 26% recovered in excreta, cage wash, tissues and carcass. The absorption, distribution and excretion of 2,4-TDI was studied in rats following a single dermal administration of radiolabelled C-14-2.4-TDI at nominal 350 mg/kg body weight (12 mg/cm2). Dermal absorption of C-14-2,4-TDI was at or below 1% of the applied dose. Considerable amounts of the applied radioactivity were found at the application site which could not be washed off. In summary the results show that dermal uptake of MDI and TDI is very low. Due to the chemical reactivity of isocyanates it can be expected that small amounts which might be absorbed will react with tissue constituents directly at the exposed skin area, or will be converted to adducts with biomacromolecules or to biologically inactive oligoureas. Overall it is concluded that, following dermal exposure to MDI and TDI, systemic exposures and resulting toxicity, other than the known sensitization, can be expected to be very low.In addition studies were performed with dermal application of unlabelled 2,4 and 2,6 TDI to check the availability and fate of this chemical on rat skin surface and to assess possible tissue damage. These experiments showed that unchanged test material can be detected on rat skin for up to 8 h if not washed off. Dermal treatment with 2,4 or 2,6 TDI was associated with irritation with increased severity over a 48 h period after washing with a decontaminant solution. (C) 2010 Elsevier Ireland Ltd. All rights reserved.
Non-extensive thermodynamics is one of the most intriguing physics new frontiers. A large number of researchers have been successfully finding connections between the new concepts introduced by this new field and other complex systems already presented. In particular, Borland [Phys. Rev. E 57 (1998) 6634–6642] has introduced a very interesting relation between the entropic index q that arises in the non-extensive entropy and the well-known Hurst exponent H used to measure long-range dependence in complex systems. In this paper, we provide statistical support to Borland results and test the validity of these results in real financial data.
A series of world-traded coal samples has been tested using the Imperial College high temperature wire mesh apparatus (HTWM) in order to assess the relationship between high temperature (1600 degrees C) char nitrogen content and NOx formation in Hemweg Power Station (in the Netherlands) using deep furnace air staging. A linear relationship between high temperature char nitrogen and NOx formation has been confirmed. These results suggest that high temperature char N content is the main factor limiting NOx emissions with deep air-staged combustion.Char N and (hence apparently deep air-staged NOx) can be predicted with an accuracy of approximately +/- 20% for most coals from the coal proximate and ultimate analysis-but this might not be sufficient for stations operating close to their emission limits. Measuring high temperature char N directly reduces the likely uncertainty in deep air-staged NO, emissions for coals (and most blends) to approximately +/- 10%. Its use should be considered on a routine basis for coal selection on plants employing this technology. (c) 2005 Elsevier Ltd. All rights reserved.
Air emissions from surface coating operations result from the evaporation of the organic solvents in the coatings and consist primarily of volatile organic compounds (VOCs). These VOC emissions can occur in a number of places along the production line: during atomization and application of the coating, during initial air drying of the part after it leaves the spray paint booth, and, eventually, in the bake oven.The aim of this paper is to present an innovative and sustainable process based on VOC absorption. An absorption tower is fed on the top by oil, which efficiently absorbs at low temperature the VOCs contained by the off-gas that enters the tower at its bottom. The mass ratio between oil and gas is approximately 1, so that a tray configuration results more efficiently than an alternative packed column. Saturated oil from the column is then stripped at high temperature in a vacuum system that condenses VOCs at a temperature slightly below the ambient temperature. Stripped oil is then recycled to the absorption tower. Special utilities are foreseen to reduce the water content in the gas and for energy recovery all over the plant. An industrial site located in Italy works at 14,000 Nm(3)/h off-gas absorbed with slightly more than 10 m(3)/h of oil. VOCs content in the off-gas ranges daily from 1200 to 2500 ppm; an average efficiency of approx. 90% recovery is presently obtained. A further reduction to an expected value of about 95-98% will be achieved in the next months. (c) 2004 Published by Elsevier Ltd.
This paper analyses the potential biomass supply in the 15 EU countries (EU15), 8 new member states and 2 candidate countries (ACC10), plus Belarus and the Ukraine. The objective of this study is to make a more detailed assessment of the potential in Europe than previously undertaken. For this purpose five scenarios were designed to describe the short-, medium- and long-term potential of biomass for energy. The scenarios are based on assumptions regarding residue harvests, energy-crop yields and surplus agricultural land. Energy-crop yields are correlated with the national wheat yields, a methodology we have not seen used in biomass assessments before. Our assessments show that under certain restrictions on land availability, the potential supply of biomass energy amounts to up to 11.7EJy−1 in the EU15 and 5.5EJy−1 in the ACC10. For comparison, the overall energy supply in the EU15 totalled 62.6EJy−1 in 2001. Consequently, there are no important resource limitations in meeting the biomass target, 5.6EJy−1 in the EU15 by 2010, which was set by the European Commission in the 1997 White paper on renewable energy sources (RES). However, given the slow implementation of the RES policy it is very unlikely that the biomass targets will be met.
This study is devoted to a chemical reaction, carried out in a gaseous phase under isothermal conditions and without internal convective flow. Traditionally, in the mass-balance equations, the transport of reactants and products in a porous catalyst is introduced by the diffusion phenomenon in gaseous phase. The reaction rate then is written as a function of the reactant's and product's concentrations in gaseous phase [G.F. Froment, K.B. Bischoff, Chemical Reactor Analysis and Design, Wiley, New York, 1979]. However, in stationary conditions and with the hypothesis of the thermodynamic equilibrium between the gaseous and the adsorbed phase, the existence of a concentration gradient in the gaseous phase brings about a concentration gradient in the adsorbed phase. The diffusion process occurring in the adsorbed phase is usually neglected in the traditional modeling. The present work aims to investigate the influence of the considered diffusion processes on the evaluation of the performance of the catalyzed chemical reaction. The analysis is based on the study of a simple chemical reaction and consecutive reactions. The study shows that the flux of consumed reactant, evaluated by a traditional way could be different from the flux obtained with the diffusion in the adsorbed phase. Also, in these conditions the kinetic parameters obtained by the traditional modeling of the experimental results do not represent then the real kinetic parameters.
Project-based mechanisms for emissions reductions credits, like the Clean Development Mechanism, pose important challenges for policy design because of several inherent characteristics. Participation is voluntary, so it will not occur without sufficient credits. Evaluating reductions requires assigning an emissions baseline for a counterfactual that cannot be measured. Some investments have both economic and environmental benefits and might occur anyway. Uncertainty surrounds both emissions and investment returns, and parties to the project are likely to have more information than the certifying authority. The certifying agent is limited in its ability to design a contract that would reveal investment intentions. As a result, rules for benchmarking emissions may be systematically biased to overallocate, and they also risk creating inefficient investment incentives. This paper evaluates, in a situation with asymmetric information, the efficacy of the main baseline rules currently under consideration: historical emissions, an average industry emissions standard, and expected emissions.
