Thermodynamic Analysis of ORC for Energy Production from Geothermal Resources

Abstract This study concerns a thermodynamic analysis of Organic Rankine Cycles for energy conversion from geothermal resources. A numerical flow-chart tool based on a lumped parameters approach is adopted to compute values of thermodynamic variables during each transformation composing the cycle. The equation of state is expressed by the Peng-Robinson formulation. The different plant components are outlined by single blocks, linked each other by connections through balance equations. Analyses are carried-out considering two working fluids (isopentane and isobutane). Results are obtained for several sets of operating parameters, such as the evaporation and condensation pressure for the working fluid, the mass flow rate of the geothermal fluid and the cooling water temperature. From results, thermodynamic cycles are built-up in the T-s plan, allowing to quantify effectiveness and energy benefit related to the investigated functional scenarios

Sensitivity analysis for room thermal response

The sensitivity theory is a suitable approach for assessing the room thermal response. It results in the 'sensitivity coefficients' (SCs) which, as derived here, evaluate the variation of the thermal load due to a fluctuation in a given design parameter around its nominal value. In this paper the general method is presented and a number of SCs are derived to evaluate the sensitivity of the building energy demand to the window surface area, to the overall transmittance and mass thermal capacity of a given wall, and to other structural data

Assessment of thermal discomfortin non-uniformly heated enclosures: Two indices in the time-space domain

In this paper two indices are proposed to assess the thermal discomfort in not-uniformly heated enclosures in the time-space domain. The discussion of some meaningful cases reveals that living spaces are subject to significant non-uniform radiant heat fields, resulting in thermal discomfort. In order to quantify such effects, the concept of 'uniform equivalent temperature' is invoked. This allows two indices i+ and i− to be developed for assessing the thermal discomfort in intensity and duration. Such indices have a clear physical meaning and therefore may provide substantial help in detecting causes and/or locations of thermal unpleasantness. On this basis a necessary but not sufficient condition for thermal comfort is stated in the form: i+ = i− = 0, to be sought everywhere within the room. Further examples illustrate the value of the procedure in thermal comfort conscious design

Breast cancer cells treated with proton beam: Immunological features and gene signatures

The breast cancer (BC) disease is characterized by a wide heterogeneity at both clinical and molecular level, showing distinct subtypes with different clinical outcomes. Thus, the choice of the therapeutic plan, such as the type of radiotherapy (RT) need to take into account this complexity. Indeed, the proton therapy (PT) shows a medical benefit compared to conventional X-ray RT, as regards the localized delivery of the radiation dose sparing health tissues, but few data regarding proton-induced molecular changes are currently available. The aim of this study was therefore to investigate the production of immunological molecules and gene expression profiles induced by proton irradiation on BC cell lines. Clonogenic survival assay, luminex assay and cDNA microarray gene expression analyses were performed both in the non-tumorigenic MCF10A cell line and in two tumorigenic MCF7 and MDA-MB-231 cell lines, following irradiation with 0.5, 2 and 9 Gy of clinical proton beams. We found that proton irradiation induced gene expression changes useful to define a cell line and dose-dependent gene signatures. The lack of molecular data in the literature can be filled by data here presented that could represent a useful tool to better understand the molecular mechanisms elicited by protons predicting the treatment outcome

Preliminary study of novel SRC tyrosine kinase inhibitor and proton therapy combined effect on glioblastoma multiforme cell line: In vitro evaluation of target therapy for the enhancement of protons effectiveness

The aim of this work was to evaluate proton therapy effectiveness in combination with a molecule SRC protein inhibitor for glioblastoma multiforme treatment. The role of this novel compound, Si306, is to interfere with glioblastoma carcinogenesis and progression, creating a radiosensitivity condition. The experiments were performed on U87 human glioblastoma multiforme cell line. Molecule concentrations of 10 μM and 20μM were tested in combination with proton irradiation doses of 2, 4, 10 and 21Gy. Cell survival evaluation was performed by clonogenic assay. The results showed that Si306 increases the efficacy of proton therapy reducing the surviving cells fraction significantly compared to treatment with protons only. These studies will support the preclinical phase realization, in order to evaluate proton therapy effects and molecularly targeted drug combined treatments

Proton-irradiated breast cells: molecular points of view

Breast cancer (BC) is the most common cancer in women, highly heterogeneous at both the clinical and molecular level. Radiation therapy (RT) represents an efficient modality to treat localized tumor in BC care, although the choice of a unique treatment plan for all BC patients, including RT, may not be the best option. Technological advances in RT are evolving with the use of charged particle beams (i.e. protons) which, due to a more localized delivery of the radiation dose, reduce the dose administered to the heart compared with conventional RT. However, few data regarding proton-induced molecular changes are currently available. The aim of this study was to investigate and describe the production of immunological molecules and gene expression profiles induced by proton irradiation. We performed Luminex assay and cDNA microarray analyses to study the biological processes activated following irradiation with proton beams, both in the non-tumorigenic MCF10A cell line and in two tumorigenic BC cell lines, MCF7 and MDA-MB-231. The immunological signatures were dose dependent in MCF10A and MCF7 cell lines, whereas MDA-MB-231 cells show a strong pro-inflammatory profile regardless of the dose delivered. Clonogenic assay revealed different surviving fractions according to the breast cell lines analyzed. We found the involvement of genes related to cell response to proton irradiation and reported specific cell line- and dose-dependent gene signatures, able to drive cell fate after radiation exposure. Our data could represent a useful tool to better understand the molecular mechanisms elicited by proton irradiation and to predict treatment outcome

Molecular Investigation on a Triple Negative Breast Cancer Xenograft Model Exposed to Proton Beams

Specific breast cancer (BC) subtypes are associated with bad prognoses due to the absence of successful treatment plans. The triple-negative breast cancer (TNBC) subtype, with estrogen (ER), progesterone (PR) and human epidermal growth factor-2 (HER2) negative receptor status, is a clinical challenge for oncologists, because of its aggressiveness and the absence of effective therapies. In addition, proton therapy (PT) represents an effective treatment against both inaccessible area located or conventional radiotherapy (RT)-resistant cancers, becoming a promising therapeutic choice for TNBC. Our study aimed to analyze the in vivo molecular response to PT and its efficacy in a MDA-MB-231 TNBC xenograft model. TNBC xenograft models were irradiated with 2, 6 and 9 Gy of PT. Gene expression profile (GEP) analyses and immunohistochemical assay (IHC) were performed to highlight specific pathways and key molecules involved in cell response to the radiation. GEP analysis revealed in depth the molecular response to PT, showing a considerable immune response, cell cycle and stem cell process regulation. Only the dose of 9 Gy shifted the balance toward pro-death signaling as a dose escalation which can be easily performed using proton beams, which permit targeting tumors while avoiding damage to the surrounding healthy tissue

Radiobiological Outcomes, Microdosimetric Evaluations and Monte Carlo Predictions in Eye Proton Therapy

CATANA (Centro di AdroTerapia ed Applicazioni Nucleari Avanzate) was the first Italian protontherapy facility dedicated to the treatment of ocular neoplastic pathologies. It is in operation at the LNS Laboratories of the Italian Institute for Nuclear Physics (INFN-LNS) and to date, 500 patients have been successfully treated. Even though proton therapy has demonstrated success in clinical settings, there is still a need for more accurate models because they are crucial for the estimation of clinically relevant RBE values. Since RBE can vary depending on several physical and biological parameters, there is a clear need for more experimental data to generate predictions. Establishing a database of cell survival experiments is therefore useful to accurately predict the effects of irradiations on both cancerous and normal tissue. The main aim of this work was to compare RBE values obtained from in-vitro experimental data with predictions made by the LEM II (Local Effect Model), Monte Carlo approaches, and semi-empirical models based on LET experimental measurements. For this purpose, the 92.1 uveal melanoma and ARPE-19 cells derived from normal retinal pigmented epithelium were selected and irradiated in the middle of clinical SOBP of the CATANA proton therapy facility. The remarkable results show the potentiality of using microdosimetric spectrum, Monte Carlo simulations and LEM model to predict not only the RBE but also the survival curves

Fatality rate and predictors of mortality in an Italian cohort of hospitalized COVID-19 patients

Clinical features and natural history of coronavirus disease 2019 (COVID-19) differ widely among different countries and during different phases of the pandemia. Here, we aimed to evaluate the case fatality rate (CFR) and to identify predictors of mortality in a cohort of COVID-19 patients admitted to three hospitals of Northern Italy between March 1 and April 28, 2020. All these patients had a confirmed diagnosis of SARS-CoV-2 infection by molecular methods. During the study period 504/1697 patients died; thus, overall CFR was 29.7%. We looked for predictors of mortality in a subgroup of 486 patients (239 males, 59%; median age 71 years) for whom sufficient clinical data were available at data cut-off. Among the demographic and clinical variables considered, age, a diagnosis of cancer, obesity and current smoking independently predicted mortality. When laboratory data were added to the model in a further subgroup of patients, age, the diagnosis of cancer, and the baseline PaO2/FiO2 ratio were identified as independent predictors of mortality. In conclusion, the CFR of hospitalized patients in Northern Italy during the ascending phase of the COVID-19 pandemic approached 30%. The identification of mortality predictors might contribute to better stratification of individual patient risk

How future surgery will benefit from SARS-COV-2-related measures: a SPIGC survey conveying the perspective of Italian surgeons

COVID-19 negatively affected surgical activity, but the potential benefits resulting from adopted measures remain unclear. The aim of this study was to evaluate the change in surgical activity and potential benefit from COVID-19 measures in perspective of Italian surgeons on behalf of SPIGC. A nationwide online survey on surgical practice before, during, and after COVID-19 pandemic was conducted in March-April 2022 (NCT:05323851). Effects of COVID-19 hospital-related measures on surgical patients' management and personal professional development across surgical specialties were explored. Data on demographics, pre-operative/peri-operative/post-operative management, and professional development were collected. Outcomes were matched with the corresponding volume. Four hundred and seventy-three respondents were included in final analysis across 14 surgical specialties. Since SARS-CoV-2 pandemic, application of telematic consultations (4.1% vs. 21.6%; p < 0.0001) and diagnostic evaluations (16.4% vs. 42.2%; p < 0.0001) increased. Elective surgical activities significantly reduced and surgeons opted more frequently for conservative management with a possible indication for elective (26.3% vs. 35.7%; p < 0.0001) or urgent (20.4% vs. 38.5%; p < 0.0001) surgery. All new COVID-related measures are perceived to be maintained in the future. Surgeons' personal education online increased from 12.6% (pre-COVID) to 86.6% (post-COVID; p < 0.0001). Online educational activities are considered a beneficial effect from COVID pandemic (56.4%). COVID-19 had a great impact on surgical specialties, with significant reduction of operation volume. However, some forced changes turned out to be benefits. Isolation measures pushed the use of telemedicine and telemetric devices for outpatient practice and favored communication for educational purposes and surgeon-patient/family communication. From the Italian surgeons' perspective, COVID-related measures will continue to influence future surgical clinical practice