Method and apparatus for supercooling and solidifying substances

An enclosure provides a containerless environment in which a sample specimen is positioned. The specimen is heated in the containerless environment, and the specimen melt is dropped through the tube in which it cools by radiation. The tube is alternatively backfilled with an inert gas whereby the specimen melt cools by both radiation and convection during its free fall. During the free fall, the sample is in a containerless, low-gravity environment which enhances supercooling in the sample and prevents sedimentation and thermal convection influences. The sample continues to supercool until nucleation occurs which is detected by silicon photovoltaic detectors. The sample solidifies after nucleation and becomes completely solid before entering the detachable catcher. The amount of supercooling of the specimen can be measured by knowing the cooling ratio and determining the time for nucleation to occur

Comparison of two independent systematic reviews of trials of recombinant human bone morphogenetic protein-2 (rhBMP-2) : The Yale Open Data Access Medtronic Project

Background: It is uncertain whether the replication of systematic reviews, particularly those with the same objectives and resources, would employ similar methods and/or arrive at identical findings. We compared the results and conclusions of two concurrent systematic reviews undertaken by two independent research teams provided with the same objectives, resources, and individual participant-level data. Methods: Two centers in the USA and UK were each provided with participant-level data on 17 multi-site clinical trials of recombinant human bone morphogenetic protein-2 (rhBMP-2). The teams were blinded to each other's methods and findings until after publication. We conducted a retrospective structured comparison of the results of the two systematic reviews. The main outcome measures included (1) trial inclusion criteria; (2) statistical methods; (3) summary efficacy and risk estimates; and (4) conclusions. Results: The two research teams' meta-analyses inclusion criteria were broadly similar but differed slightly in trial inclusion and research methodology. They obtained similar results in summary estimates of most clinical outcomes and adverse events. Center A incorporated all trials into summary estimates of efficacy and harms, while Center B concentrated on analyses stratified by surgical approach. Center A found a statistically significant, but small, benefit whereas Center B reported no advantage. In the analysis of harms, neither showed an increased cancer risk at 48 months, although Center B reported a significant increase at 24 months. Conclusions reflected these differences in summary estimates of benefit balanced with small but potentially important risk of harm. Conclusions: Two independent groups given the same research objectives, data, resources, funding, and time produced broad general agreement but differed in several areas. These differences, the importance of which is debatable, indicate the value of the availability of data to allow for more than a single approach and a single interpretation of the data. Systematic review registration: PROSPERO CRD42012002040and CRD42012001907

Should patients with low-risk renal cell carcinoma be followed differently after nephron-sparing surgery vs radical nephrectomy?

Objective: To investigate whether pT1 renal cell carcinoma (RCC) should be followed differently after partial (PN) or radical nephrectomy (RN) based on a retrospective analysis of a multicentre database (RECUR). Subjects: A retrospective study was conducted in 3380 patients treated for nonmetastatic RCC between January 2006 and December 2011 across 15 centres from 10 countries, as part of the RECUR database project. For patients with pT1 clear-cell RCC, patterns of recurrence were compared between RN and PN according to recurrence site. Univariate and multivariate models were used to evaluate the association between surgical approach and recurrence-free survival (RFS) and cancer-specific mortality (CSM). Results: From the database 1995 patients were identified as low-risk patients (pT1, pN0, pNx), of whom 1055 (52.9%) underwent PN. On multivariate analysis, features associated with worse RFS included tumour size (hazard ratio [HR] 1.32, 95% confidence interval [CI] 1.14–1.39; P < 0.001), nuclear grade (HR 2.31, 95% CI 1.73–3.08; P < 0.001), tumour necrosis (HR 1.5, 95% CI 1.03–2.3; P = 0.037), vascular invasion (HR 2.4, 95% CI 1.3–4.4; P = 0.005) and positive surgical margins (HR 4.4, 95% CI 2.3–8.5; P < 0.001). Kaplan–Meier analysis of CSM revealed that the survival of patients with recurrence after PN was significantly better than those with recurrence after RN (P = 0.02). While the above-mentioned risk factors were associated with prognosis, type of surgery alone was not an independent prognostic variable for RFS nor CSM. Limitations include the retrospective nature of the study. Conclusion: Our results showed that follow-up protocols should not rely solely on stage and type of primary surgery. An optimized regimen should also include validated risk factors rather than type of surgery alone to select the best imaging method and to avoid unnecessary imaging. A follow-up of more than 3 years should be considered in patients with pT1 tumours after RN. A novel follow-up strategy is proposed

Recurrence pattern in localized RCC : results from a European multicenter database (RECUR)

Introduction: The impact of open versus minimally invasive surgery on recurrence pattern in the management of localized renal cell carcinoma (RCC) remains uncertain. We thus aimed to determine the impact of surgical approach on survival and recurrence pattern. Material and methods: This is a multi-institutional, matched cohort study on patients with pT1-3aN0M0 RCC from the RECUR database. After propensity score matching between open and minimally invasive surgery, disease-free (DFS) survival and risk of first recurrence according to recurrence site, namely local recurrence, abdominal/retroperitoneal, thoracic/mediastinal or uncommon site metastases were investigated with Cox regression analysis. Overall (OS) and Cancer Specific Survival (CSS) were also assessed. Results: After matching, 1,019 patients who underwent open and 1,019 who underwent minimally invasive surgery were included (of which 70 robot-assisted). At 5.2 years of median follow-up, 130 patients in open and 125 in minimally invasive group experienced disease progression. A higher risk of local recurrence (HR 2.06; 95% CI 1.18–3.58, P-value = 0.01) and uncommon site metastases (HR 1.09; 95% CI 1.01–1.16; P-value = .04) was found for minimally invasive surgery relative to open surgery, while no difference was found in terms of DFS (HR 0.83; 95% CI 0.64–1.06; P-value = .14). No differences were found in terms of OS and CSS. Main limitation is the retrospective nature of the study. Conclusions: The risk for local recurrence and uncommon site metastases was higher for minimally invasive surgery compared to open surgery, although no differences were found for OS, CSS, and DFS

Rivals without a cause? Relative performance feedback creates destructive competition despite aligned incentives

Whether people compete or cooperate with each other has consequences for their own performance and that of organizations. To explain why people compete or cooperate, previous research has focused on two main factors: situational outcome structures and personality types. Here, we propose that—above and beyond these two factors—situational cues, such as the format in which people receive feedback, strongly affect whether they act competitively, cooperatively, or individualistically. Results of a laboratory experiment support our theorizing: After receiving ranking feedback, both students and experienced managers treated group situations with cooperative outcome structures as competitive and were in consequence willing to forgo guaranteed financial gains to pursue a—financially irrelevant—better rank. Conversely, in dilemma situations, feedback based on the joint group outcome led to more cooperation than ranking feedback. Our study contributes to research on competition, cooperation, interdependence theory, forced ranking, and the design of information environments