Efficiency assessment for a small heliostat solar concentration plant

Summary In this paper, a small non-imaging focusing heliostat is presented, and an analytical model for assessing its performance is described. The main novelty of the system lies in the tracking mechanism and the mirror mount, which are based on off-the-shelf components and allow a good trade-off between accuracy and costs. The concentrator mirrors are moved by this two-axis tracking machinery to reflect the sun's rays onto a fixed target, the dimensions of which can be varied to suit the user's needs. A prototype plant to be located in central Italy was designed and simulated with a ray-tracing algorithm, and it comprises 90 heliostats for a total reflective area of 7.5 m2. The reflected solar rays are tracked taking the mechanical positioning errors of the tracking system into account. The total flux of radiation energy hitting the target was determined, and intensity distribution maps were drawn. Simulations showed that the system's optical efficiency can exceed 90% in summer, despite the tracking errors, mainly because of the smaller distance between the heliostats and the receiver. The solar concentration ratio over a receiver of 250 mm in diameter reached 80 suns with a very good uniformity. Over a 400-mm receiver, the concentrated radiation was less uniform, and the solar concentration ratio reached 50 suns, with a higher optical efficiency and collected solar radiation. The present concentration ratio is still suitable for many applications ranging from the electric power production, industrial process heat, and solar cooling. Copyright © 2014 John Wiley & Sons, Ltd

A Remote Monitoring System to Optimize the Home Management of Oral Anticancer Therapies (ONCO-TreC): Prospective Training-Validation Trial

Background: A platform designed to support the home management of oral anticancer treatments and provide a secure web-based patient–health care professional communication modality, ONCO-TreC, was tested in 3 cancer centers in Italy. Objective: The overall aims of the trial are to customize the platform; assess the system’s ability to facilitate the shared management of oral anticancer therapies by patients and health professionals; and evaluate system usability and acceptability by patients, caregivers, and health care professionals. Methods: Patients aged ≥18 years who were candidates for oral anticancer treatment as monotherapy with an Eastern Cooperative Oncology Group performance status score of 0 to 1 and a sufficient level of familiarity with mobile devices were eligible. ONCO-TreC consisted of a mobile app for patients and a web-based dashboard for health care professionals. Adherence to treatment (pill count) and toxicities reported by patients through the app were compared with those reported by physicians in medical records. Usability and acceptability were evaluated using questionnaires. Results: A total of 40 patients were enrolled, 38 (95%) of whom were evaluable for adherence to treatment. The ability of the system to measure adherence to treatment was high, with a concordance of 97.3% (95% CI 86.1%-99.9%) between the investigator and system pill count. Only 60% (3/5) of grade 3, 54% (13/24) of grade 2, and 19% (7/36) of grade 1 adverse events reported by physicians in the case report forms were also reported in the app directly by patients. In total, 94% (33/35) of patients had ≥1 app launch each week, and the median number of daily accesses per patient was 2. Approximately 71% (27/38) and 68% (26/38) of patients used the app for messages and vital sign entering, respectively, at least once during the study period. Conclusions: ONCO-TreC is an important tool for measuring and monitoring adherence to oral anticancer drugs. System usability and acceptability were very high, whereas its reliability in registering toxicity could be improved

A double-blind, randomized, multicenter, Italian study of frovatriptan versus almotriptan for the acute treatment of migraine

The objective of this study was to evaluate patients’ satisfaction with acute treatment of migraine with frovatriptan or almotriptan by preference questionnaire. One hundred and thirty three subjects with a history of migraine with or without aura (IHS 2004 criteria), with at least one migraine attack in the preceding 6 months, were enrolled and randomized to frovatriptan 2.5 mg or almotriptan 12.5 mg, treating 1–3 attacks. The study had a multicenter, randomized, double blind, cross-over design, with treatment periods lasting <3 months. At study end patients assigned preference to one of the treatments using a questionnaire with a score from 0 to 5 (primary endpoint). Secondary endpoints were pain free and pain relief episodes at 2 and 4 h, and recurrent and sustained pain free episodes within 48 h. Of the 133 patients (86%, intention-to-treat population) 114 of them expressed a preference for a triptan. The average preference score was not significantly different between frovatriptan (3.1 ± 1.3) and almotriptan (3.4 ± 1.3). The rates of pain free (30% frovatriptan vs. 32% almotriptan) and pain relief (54% vs. 56%) episodes at 2 h did not significantly differ between treatments. This was the case also at 4 h (pain free: 56% vs. 59%; pain relief: 75% vs. 72%). Recurrent episodes were significantly (P < 0.05) less frequent under frovatriptan (30% vs. 44%), also for the attacks treated within 30 min. No significant differences were observed in sustained pain free episodes (21% vs. 18%). The tolerability profile was similar between the two drugs. In conclusion, our study suggests that frovatriptan has a similar efficacy of almotriptan in the short-term, while some advantages are observed during long-term treatment

Colorectal Cancer Stage at Diagnosis Before vs During the COVID-19 Pandemic in Italy

IMPORTANCE Delays in screening programs and the reluctance of patients to seek medical attention because of the outbreak of SARS-CoV-2 could be associated with the risk of more advanced colorectal cancers at diagnosis. OBJECTIVE To evaluate whether the SARS-CoV-2 pandemic was associated with more advanced oncologic stage and change in clinical presentation for patients with colorectal cancer. DESIGN, SETTING, AND PARTICIPANTS This retrospective, multicenter cohort study included all 17 938 adult patients who underwent surgery for colorectal cancer from March 1, 2020, to December 31, 2021 (pandemic period), and from January 1, 2018, to February 29, 2020 (prepandemic period), in 81 participating centers in Italy, including tertiary centers and community hospitals. Follow-up was 30 days from surgery. EXPOSURES Any type of surgical procedure for colorectal cancer, including explorative surgery, palliative procedures, and atypical or segmental resections. MAIN OUTCOMES AND MEASURES The primary outcome was advanced stage of colorectal cancer at diagnosis. Secondary outcomes were distant metastasis, T4 stage, aggressive biology (defined as cancer with at least 1 of the following characteristics: signet ring cells, mucinous tumor, budding, lymphovascular invasion, perineural invasion, and lymphangitis), stenotic lesion, emergency surgery, and palliative surgery. The independent association between the pandemic period and the outcomes was assessed using multivariate random-effects logistic regression, with hospital as the cluster variable. RESULTS A total of 17 938 patients (10 007 men [55.8%]; mean [SD] age, 70.6 [12.2] years) underwent surgery for colorectal cancer: 7796 (43.5%) during the pandemic period and 10 142 (56.5%) during the prepandemic period. Logistic regression indicated that the pandemic period was significantly associated with an increased rate of advanced-stage colorectal cancer (odds ratio [OR], 1.07; 95%CI, 1.01-1.13; P = .03), aggressive biology (OR, 1.32; 95%CI, 1.15-1.53; P &lt; .001), and stenotic lesions (OR, 1.15; 95%CI, 1.01-1.31; P = .03). CONCLUSIONS AND RELEVANCE This cohort study suggests a significant association between the SARS-CoV-2 pandemic and the risk of a more advanced oncologic stage at diagnosis among patients undergoing surgery for colorectal cancer and might indicate a potential reduction of survival for these patients

Entry and Exit Strategies in Migration Dynamics

This work is devoted to study the role of combined entry and exit strategies in the migration process. We develop a real option model in which the community of immigrants in the host country is described as a club and the immigrants benefits is a U-shaped function, depending on the dimension of the district. There exist two threshold levels: the first one triggers the migration choice, while the second triggers the return to the country of origin. The theoretical results show that the phenomenon of hysteresis is amplified by the existence of a community both in the entry case and in the exit case. Furthermore, the community can reduce the minimum wage level required to trigger both exit and entry: this fact could explain why in some cases we observe migration inflows with a low wage differential and also with underunemployment. We show also some possible further extensions of the model: in one case we introduce a possible way to select the entrants skills and in another case we show some theoretical implementations to include possible policy shocks in the migrants choice

Operationalizing mild cognitive impairment criteria in small vessel disease: The VMCI-Tuscany Study

Introduction Mild cognitive impairment (MCI) prodromic of vascular dementia is expected to have a multidomain profile. Methods In a sample of cerebral small vessel disease (SVD) patients, we assessed MCI subtypes distributions according to different operationalization of Winblad criteria and compared the neuroimaging features of single versus multidomain MCI. We applied three MCI diagnostic scenarios in which the cutoffs for objective impairment and the number of considered neuropsychological tests varied. Results Passing from a liberal to more conservative diagnostic scenarios, of 153 patients, 5% were no longer classified as MCI, amnestic multidomain frequency decreased, and nonamnestic single domain increased. Considering neuroimaging features, severe medial temporal lobe atrophy was more frequent in multidomain compared with single domain. Discussion Operationalizing MCI criteria changes the relative frequency of MCI subtypes. Nonamnestic single domain MCI may be a previously nonrecognized type of MCI associated with SVD

Sex difference and intra-operative tidal volume: Insights from the LAS VEGAS study

BACKGROUND: One key element of lung-protective ventilation is the use of a low tidal volume (VT). A sex difference in use of low tidal volume ventilation (LTVV) has been described in critically ill ICU patients.OBJECTIVES: The aim of this study was to determine whether a sex difference in use of LTVV also exists in operating room patients, and if present what factors drive this difference.DESIGN, PATIENTS AND SETTING: This is a posthoc analysis of LAS VEGAS, a 1-week worldwide observational study in adults requiring intra-operative ventilation during general anaesthesia for surgery in 146 hospitals in 29 countries.MAIN OUTCOME MEASURES: Women and men were compared with respect to use of LTVV, defined as VT of 8 ml kg-1 or less predicted bodyweight (PBW). A VT was deemed 'default' if the set VT was a round number. A mediation analysis assessed which factors may explain the sex difference in use of LTVV during intra-operative ventilation.RESULTS: This analysis includes 9864 patients, of whom 5425 (55%) were women. A default VT was often set, both in women and men; mode VT was 500 ml. Median [IQR] VT was higher in women than in men (8.6 [7.7 to 9.6] vs. 7.6 [6.8 to 8.4] ml kg-1 PBW, P &lt; 0.001). Compared with men, women were twice as likely not to receive LTVV [68.8 vs. 36.0%; relative risk ratio 2.1 (95% CI 1.9 to 2.1), P &lt; 0.001]. In the mediation analysis, patients' height and actual body weight (ABW) explained 81 and 18% of the sex difference in use of LTVV, respectively; it was not explained by the use of a default VT.CONCLUSION: In this worldwide cohort of patients receiving intra-operative ventilation during general anaesthesia for surgery, women received a higher VT than men during intra-operative ventilation. The risk for a female not to receive LTVV during surgery was double that of males. Height and ABW were the two mediators of the sex difference in use of LTVV.TRIAL REGISTRATION: The study was registered at Clinicaltrials.gov, NCT01601223

Outcomes from elective colorectal cancer surgery during the SARS-CoV-2 pandemic

This study aimed to describe the change in surgical practice and the impact of SARS-CoV-2 on mortality after surgical resection of colorectal cancer during the initial phases of the SARS-CoV-2 pandemic

Environmental Resources Depletion and Interplay Between Negative and Positive Externalities in a Growth Model

We analyse growth dynamics in an economy where the well-being of economic agents depends on three goods: leisure, a free access environmental good and a private good which can be produced by each agent through his own labour input. The private good can be consumed as a substitute for the environmental resource. The production process of the private good by each agent generates negative externalities on the other agents, by depleting the free access natural resource; but it also produces positive externalities by increasing the productivity of labour via a learning-by-doing mechanism of accumulation of knowledge [which is a pure public good]. In this context, we show that attracting steady states may exist which are Pareto-dominated by others where aggregate private consumption and labour productivity are lower. However, negative externalities can also be an engine of desirable growth: the deterioration of the environmental good can play the role of a coordination device leading economic agents to a wider exploitation of positive externalities