17 research outputs found
Interplay of coarsening, aging, and stress hardening impacting the creep behavior of a colloidal gel
We explore the dynamical and mechanical characteristics of an evolving gel in diffusing wave spectroscopy (DWS) and rheometry, aiming to assess how the gel evolution impacts the creep response of the system. Our gel is formed by inducing the aggregation of thermosensitive colloids by a variation in temperature. We find experimental evidence that the long time evolution of this gel is due to two distinct processes: A coarsening process that involves the incorporation of mobile particles into the network structure and an aging process that triggers intermittent rearrangement events. While coarsening is the main process governing the evolution of the elastic properties of the gel, aging is the process determining structural relaxation. The combination of both processes in addition to stress hardening governs the creep behavior of the gel, a creep behavior that is determined by three distinct contributions: an instantaneous elastic, a delayed elastic, and a loss contribution. The systematic investigation of these contributions in recovery experiments provides evidence that losses and delayed elastic storage have a common origin, both being due to intermittent local structural relaxation events
Revealing the fast atomic motion of network glasses
Still very little is known on the relaxation dynamics of glasses at the microscopic level due to the lack of experiments and theories. It is commonly believed that glasses are in a dynamical arrested state, with relaxation times too large to be observed on human time scales. Here we provide the experimental evidence that glasses display fast atomic rearrangements within a few minutes, even in the deep glassy state. Following the evolution of the structural relaxation in a sodium silicate glass, we find that this fast dynamics is accompanied by the absence of any detectable aging, suggesting a decoupling of the relaxation time and the viscosity in the glass. The relaxation time is strongly affected by the network structure with a marked increase at the mesoscopic scale associated with the ion-conducting pathways. Our results modify the conception of the glassy state and asks for a new microscopic theory
The effect of race on survival after local therapy in metastatic prostate cancer patients.
INTRODUCTION: Local therapy (LT) may offer a survival advantage in highly select, newly diagnosed metastatic prostate cancer (mPCa) patients. However, it is unknown whether the benefits vary in Caucasian vs. African American (AA) patients.
METHODS: Within the Surveillance Epidemiology and End Results (SEER) database (2004-2014), we focused on Caucasians and AA patients with newly diagnosed mPCa treated with LT: radical prostatectomy (RP) and brachytherapy (RT). Endpoints consisted of cancer-specific mortality (CSM) and overall mortality (OM). Kaplan-Meier analyses and multivariable Cox regression models tested for racial difference in CSM and OM.
RESULTS: Between 2004 and 2014, we identified 408 (77.2%) Caucasians and 121 (22.8%) AAs with newly diagnosed mPCa treated with LT: RP (n=357) or RT (n=172). According to race, when LT is defined as RP, Caucasian patients had a significantly longer survival vs. AA patients: CSM-free survival 123 vs. 63 months (p=0.004) and OM-free survival 108 vs. 46 months (p=0.002). The CSM and OM benefits were confirmed in multivariable analyses (hazard ratio [HR] 0.56, p=0.01 for CSM; HR 0.60, p=0.01 for OM). However, no differences in CSM or OM were recorded according to race when LT consisted of RT.
CONCLUSIONS: Our results indicate that race is not associated with difference in survival after LT in mPCa patients. However, when focusing on RP-treated patients, Caucasian race is associated with higher CSM and OM rates relative to AA race. This racial difference does not apply to RT. Our findings should be considered in future prospective trials for the purpose of preplanned stratification according to race
Survival effect of perioperative systemic chemotherapy on overall mortality in locally advanced and/or positive regional lymph node non-metastatic urothelial carcinoma of the upper urinary tract
Nephroureterectomy with or without Bladder Cuff Excision for Localized Urothelial Carcinoma of the Renal Pelvis.
BACKGROUND: Few studies examined the rates of guideline implementation and the survival effect of bladder cuff excision (BCE) at nephroureterectomy (NU).
OBJECTIVE: To assess the rates of guideline implementation regarding NU with BCE relative to NU without BCE in patients with upper tract urothelial carcinoma (UTUC) and to test the effect of BCE on cancer-specific (CSM) and other-cause mortality (OCM).
DESIGN, SETTING, AND PARTICIPANTS: We relied on Surveillance, Epidemiology, and End Results database (2004-2014) for UTUC of the renal pelvis patients (T1-T3, N0, M0) treated with NU with or without BCE.
OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Cumulative incidence plots relying on competing-risks methodology illustrated 5-yr CSM and OCM rates. Multivariable competing-risks regression (MCRR) models tested the effect of BCE versus no BCE at NU.
RESULTS AND LIMITATIONS: Of 4266 assessable patients, 2913 (68.3%) underwent NU with BCE. Between 2004 and 2014, rates of BCE at NU increased from 63.0% to 74.5% (European Association for Palliative Care: 2%; p\u3c0.001). At 60 mo, CSM rates were 19.7% versus 23.5% (p=0.005) in NU with BCE versus NU without BCE patients, respectively. In MCRR models, no difference in CSM was recorded according to BCE at NU (hazard ratio [HR]: 0.88, confidence interval [CI]: 0.75-1.03, p=0.1). Finally, OCM was unaffected by BCE at NU (HR: 0.94, CI: 0.77-1.15, p=0.5). This study is retrospective.
CONCLUSIONS: According to guideline recommendation, the rates of NU with BCE increased over time. However, BCE status does not appear to affect CSM or OCM. Thus, our study was unable to examine the rates of urothelial cancer recurrence or metastatic progression according to BCE status.
PATIENT SUMMARY: Rates of bladder cuff excision (BCE) at nephroureterectomy (NU) are increasing. This observation confirms improved adherence to guidelines over time. However, BCE status does not appear to affect survival after NU for upper tract urothelial carcinoma
Comparison of Partial Versus Radical Nephrectomy Effect on Other-cause Mortality, Cancer-specific Mortality, and 30-day Mortality in Patients Older Than 75 Years.
BACKGROUND: Historically, partial nephrectomy (PN) showed no benefit on other-cause mortality (OCM) in elderly patients with small renal masses.
OBJECTIVE: To test the effect of PN versus radical nephrectomy (RN) on OCM, cancer-specific mortality (CSM), as well as 30-d mortality in patients with nonmetastatic T1a renal cell carcinoma (RCC), aged ≥75 yr old.
DESIGN, SETTING, AND PARTICIPANTS: Within the Surveillance, Epidemiology and End Results registry (2004-2014), we identified surgically treated patients with nonmetastatic pT1a RCC aged ≥75 yr.
OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: We relied on propensity score (PS) matching to reduce the effect of inherent differences between PN and RN. After PS matching, cumulative incidence, multivariable competing-risks regression (CRR) and logistic regression models were used. LOESS plots graphically depicted the relation between nephrectomy type and OCM after adjustment for all the covariates. Landmark analyses at 6 mo tested for immortal time bias.
RESULTS AND LIMITATIONS: Of all 4541 patients, 41.6% underwent PN. After 1:1 PS matching, 2826 patients remained. In multivariable CRR models, lower OCM rates were recorded in PN patients (hazard ratio [HR]: 0.67, confidence interval [CI]: 0.54-0.84; p\u3c0.001). LOESS plots showed lower OCM rates after PN across all examined ages. Lower CSM rates were also recorded in PN patients (HR: 0.64, CI=0.44-0.92; p=0.02). Landmark analyses rejected the hypothesis of immortal time bias. Finally, PN did not result in different 30-d mortality rates (odds ratio: 1.87; CI: 0.79-4.47; p=0.2) versus RN. Data are retrospective.
CONCLUSIONS: PN results in lower OCM in elderly patients with pT1a RCC. Moreover, PN does not contribute to higher CSM or 30-d mortality in patients aged ≥75 yr. In consequence, PN should be given strong consideration, even in elderly patients.
PATIENT SUMMARY: Partial nephrectomy (PN) may protect from renal insufficiency, hypertension, and other unfavorable health outcomes, even in elderly patients. This protective effect results in lower other-cause mortality. Moreover, PN benefits are not undermined by higher cancer-specific mortality or 30-d mortality
Nephroureterectomy with or without Bladder Cuff Excision for Localized Urothelial Carcinoma of the Renal Pelvis.
BACKGROUND: Few studies examined the rates of guideline implementation and the survival effect of bladder cuff excision (BCE) at nephroureterectomy (NU).
OBJECTIVE: To assess the rates of guideline implementation regarding NU with BCE relative to NU without BCE in patients with upper tract urothelial carcinoma (UTUC) and to test the effect of BCE on cancer-specific (CSM) and other-cause mortality (OCM).
DESIGN, SETTING, AND PARTICIPANTS: We relied on Surveillance, Epidemiology, and End Results database (2004-2014) for UTUC of the renal pelvis patients (T1-T3, N0, M0) treated with NU with or without BCE.
OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Cumulative incidence plots relying on competing-risks methodology illustrated 5-yr CSM and OCM rates. Multivariable competing-risks regression (MCRR) models tested the effect of BCE versus no BCE at NU.
RESULTS AND LIMITATIONS: Of 4266 assessable patients, 2913 (68.3%) underwent NU with BCE. Between 2004 and 2014, rates of BCE at NU increased from 63.0% to 74.5% (European Association for Palliative Care: 2%; p
CONCLUSIONS: According to guideline recommendation, the rates of NU with BCE increased over time. However, BCE status does not appear to affect CSM or OCM. Thus, our study was unable to examine the rates of urothelial cancer recurrence or metastatic progression according to BCE status.
PATIENT SUMMARY: Rates of bladder cuff excision (BCE) at nephroureterectomy (NU) are increasing. This observation confirms improved adherence to guidelines over time. However, BCE status does not appear to affect survival after NU for upper tract urothelial carcinoma
The Effect of Institution Teaching Status on Perioperative Outcomes After Robotic Partial or Radical Nephrectomy
The Impact of Lymph Node Metastases Burden at Radical Prostatectomy.
BACKGROUND: We hypothesized that a cut-off in positive lymph node (LN) counts may discriminate between cancer-specific mortality (CSM) rates in clinically localized prostate cancer patients treated with radical prostatectomy (RP).
OBJECTIVE: To test this relationship, we relied on different LN count cut-offs, as well as the continuously coded number of positive LNs (NPN).
METHODS: Within the Surveillance, Epidemiology, and End Results database (2004-2014), we identified patients with D\u27Amico intermediate- or high-risk characteristics who underwent RP and pelvic LN dissection, regardless of pathologic LN stage. Kaplan-Meier analyses and multivariable Cox regression models tested the effect of LN invasion (LNI) on CSM, according to the NPN.
RESULTS: Of 30016 patients treated with RP, 6.2% (n=1869) exhibited LNI, with respectively higher rates of LNI in patients with D\u27Amico high- versus intermediate-risk characteristics (11.6% vs 3.4%). Overall, the median age was 63yr, median prostate-specific antigen value was 6.6ng/ml and the median number of removed LNs was six. At 60 mo after RP, CSM rates were, respectively, 6.0% versus 0.8% for patients with and without LNI: multivariable hazard ratio (HR) 4.4 (p
CONCLUSIONS: The NPN is an independent predictor of higher CSM rate. Specifically, patients with one to two positive LNs are at moderately higher risk of CSM than those without LNI, and CSM risk increases sharply in those with ≥3 positive LNs. Our contemporary findings corroborate the NPN cut-offs within previous studies.
PATIENT SUMMARY: Patients with three or more positive lymph nodes at radical prostatectomy have significantly higher cancer-specific mortality rates than those without or one to two positive lymph nodes. This stratification can be useful in considering adjuvant treatment options
Contemporary Trends and Survival Outcomes After Aborted Radical Prostatectomy in Lymph Node Metastatic Prostate Cancer Patients.
BACKGROUND: Aborted radical prostatectomy (aRP) in lymph node (LN) metastatic (pN1) prostate cancer (PCa) patients showed worse survival in European patients. Contemporary rates of aRP are unknown in North America.
OBJECTIVE: To examine the rate of aRP and its effect on cancer-specific mortality (CSM) in contemporary North American patients.
DESIGN, SETTING, AND PARTICIPANTS:
Within the Surveillance Epidemiology and End Results database (2004-2014), we identified 3719 pN1 PCa patients.
INTERVENTION: RP.
OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Incidence proportion and median survival of LN metastatic PCa patients who underwent aRP versus completed RP (cRP). Cumulative incidence plots and competing-risks regression (CRR) models tested CSM and other-cause mortality rates according to aRP versus cRP. The effect of selected variables on CSM rate was graphically depicted using LOESS methodology. All analyses were repeated after propensity score matching.
RESULTS AND LIMITATIONS: Between 2004 and 2014, the rate of aRP decreased from 20.4% to 5.6% (p\u3c0.001). Ten-year CSM rates were significantly higher after aRP (38.9% vs 21.6%) versus cRP (p\u3c0.001). In multivariable CRR models, aRP yielded higher CSM (hazard ratio [HR]: 1.99) than cRP. A higher 5-yr CSM rate was recorded after aRP through the entire range of baseline prostate-specific antigen (PSA) values and in patients with up to nine LN metastases. After propensity score matching, aRP resulted in overall higher CSM (HR: 1.72). Higher CSM was recorded after aRP for PSA values up to 50ng/ml and in patients with up to seven LN metastases. Results were limited by a selection bias that applies to aRP patients.
CONCLUSIONS: Of contemporary North American patients, 5% are affected by aRP. It confers a significant survival disadvantage that applies to patients with baseline PSA values up to 50ng/ml and in those with up to seven LN metastases.
PATIENT SUMMARY: Radical prostatectomy should not be aborted in pN1 prostate cancer individuals