Oscillatory pressure-driven rarefied binary gas mixture flow between parallel plates

The rarefied, oscillatory, pressure-driven binary gas mixture flow between parallel plates is computationally investigated in terms of the mixture molar fraction and molecular mass ratio of the species, in a wide range of gas rarefaction and oscillation frequency. Modeling is based on the McCormack kinetic model. The output quantities are in dimensionless form and include the flow rate, wall shear stress and pumping power of the mixture, as well as the velocity and shear stress distributions and flow rates of the species. The presented results are for He-Xe and Ne-Ar. The heavier species are affected more drastically than the lighter ones from the inertial forces, resulting to large differences between the flow rate amplitudes of the species, which are increased as the flow becomes less rarefied, provided that the oscillation frequency is adequately high. At very high frequencies the ratio of the flow rate amplitudes of the light over the heavy species tends to the inverse of their molecular mass ratio in the whole range of gas rarefaction. The velocity overshooting effect becomes more pronounced as the molecular mass is increased. The mixture flow rate amplitude is larger, while its phase angle is smaller, than the corresponding ones of single gas, and they both vary nonmonotonically with the molar fraction. The effect of the mixture composition on the wall shear stress and pumping power is small. The present work may be useful in the design of gas separation devices, operating at moderate and high frequencies in rarefied and dense atmospheres. © 2021 American Physical Society

The Role of Endobronchial Ultrasound in Lung Cancer Diagnosis and Staging: A Comprehensive Review

Endobronchial ultrasound (EBUS) technology is a relatively new bronchoscopic method of visualizing the tracheobronchial tree, the surrounding pulmonary parenchyma, and the mediastinal structures, with a particular role in lung cancer diagnosis, staging, and treatment. There are 2 types of probes used in EBUS: the peripheral or radial probe (RP) and the linear or convex probe (CP) EBUS, which have technical differences and distinct diagnostic abilities. Both are used for EBUS-guided biopsies and transbronchial needle aspirations (TBNA), which increases the diagnostic yield over conventional bronchoscopic techniques, thus providing advanced information on staging, diagnosis, and treatment. Complications of EBUS are rare, and they are usually related to the underlying biopsy procedure and the operator’s experience. EBUS examination duration is usually short, and it can be performed as an outpatient procedure. Interestingly, EBUS combinations with other current and evolving techniques, eg, electromagnetic navigation, are feasible and have a role in therapeutic interventions and molecular diagnostics. In conclusion, EBUS is a safe and accurate technique that is comparable with current criterion standard procedures, eg, mediastinoscopy. More training is required for the vast majority of respiratory physicians, and precise diagnostic algorithms are needed so that more patients benefit from this development

Metastin is not involved in metastatic potential of non-small cell lung cancer

Metastin, the product of the KISS-1 gene, seems to represent a strong suppressant of metastasis for some types of cancer. The aim of this study is to explore whether circulating levels of metastin could be used as a marker for the metastatic potential of non-small cell lung cancer (NSCLC) as well as a diagnostic marker in NSCLC patients. The possible correlation between metastin and leptin circulating levels was also evaluated. Fasting serum levels of metastin and leptin were determined in 96 NSCLC patients at diagnosis (76 with metastatic disease and 21 with locally advanced disease) and 49 healthy volunteers using commercial available ELISA. Serum metastin levels presented no differences between NSCLC patients and healthy volunteers (1.18 ± 0.98 vs. 1.17 ± 0.39 ng/ml, P = 0.979) as well as between patients with metastatic and locally advanced disease (1.17 ± 1.05 vs. 1.21 ± 0.64 ng/ml, P = 0.872). There was no statistically significant correlation between circulating metastin and leptin levels in NSCLC patients and patients with locally advanced and metastatic disease. This study shows a lack of direct involvement of metastin in the diagnosis and metastatic potential of NSCLC. © 2010 Springer Science+Business Media, LLC

Investigation of energy and financial performance of a novel CO2 supercritical solar-biomass trigeneration system for operation in the climate of Athens

The ever-growing increase of the energy demand required to satisfy the needs of society has aroused considerable interest regarding the investigation of polygeneration systems that employ renewable energy sources. In the present work, the concept of installing a supercritical CO2 trigeneration system to cover the needs of a refrigerated warehouse in Athens with simultaneous production of power and heating is studied in terms of energy performance, and its financial benefits compared to the solution of an ejector refrigeration-only system are analyzed and assessed. The trigeneration system utilizes solar energy in parabolic trough collectors and biomass energy as the supplementary source, in order to increase the temperature of high-pressure CO2 and produce power in the turbine which is coupled to a generator. Regarding the collectors, the installation of zero up to four solar modules that exploit the solar power is examined, while the rest energy input needed in order to achieve the selected operating conditions is supplied by a biomass boiler. Since all the trigeneration cases require the same amount of energy input to reach the desired conditions, the trigeneration system for every combination of solar modules is found to produce 185.59 MWh annually, while the refrigeration-only system is found to consume 172.94 MWh during a year. The power production efficiency, the combined power and refrigeration production efficiency and the total trigeneration efficiency for the selected nominal conditions are calculated 11.77 %, 66.09 % and 163.70 % respectively. The case of a trigeneration system with four solar collectors displays a payback period of 4.0 years compared to the refrigeration-only case, providing financial savings equal to 542 k€ for the duration of the project lifetime. The same case compared to that of trigeneration system using only biomass boiler and no solar collectors exhibits payback period of 13.5 years, achieving financial savings of 22.9 k€ for the considered lifetime of the project. © 2021 Elsevier Lt

Energy and environmental investigation of R744 all-in-one configurations for refrigeration and heating/air conditioning needs of a supermarket

Refrigeration systems and heating/air conditioning units used in supermarkets are responsible for a great part of the annual electricity consumption of industrialized countries. Taking also into consideration the direct emissions of carbon dioxide to the environment due to leakage of refrigerants with high Global Warming Potential that are employed today for such applications, a step towards more environmentally friendly and less energy-consuming solutions should be made. In the current research, different topologies of an all-in-one R744 transcritical unit providing refrigeration, heating and air conditioning to a real Greek supermarket store (METRO S.A.) in Athens are studied, using the softwares Engineering Equation Solver and EnergyPlus. The different configurations include a state-of-the-art R744 system with parallel compression and multi-ejector block, the same system with the addition of a subcooling heat exchanger that utilizes available geothermal water, as well as the last described unit with the integration of adiabatic cooling configuration on the gas cooler. These solutions are investigated in terms of energy efficiency and environmental impact (total equivalent warming impact) and they are compared to an indirect arrangement employing R744 and R290, to conventional direct expansion solutions (with R448A or R404A) and to a heat pump employing R410A that covers the heating and air conditioning demands of the supermarket. The comparative energy analysis was separated into the refrigeration part, the heating and air conditioning part and the sum of them. The results indicated that for the climate of the store's location, the case including the subcooler and adiabatic cooling configuration, the case with only the subcooler and the case with neither the subcooler nor the adiabatic cooling configuration consume annually 20.9%, 17.6% and 8.7% less energy respectively than the combination of a refrigeration unit with R448A and a heat pump with R410A for the heating/cooling needs. © 2020 Elsevier Lt

Measurement of exhaled alveolar nitrogen oxide in patients with lung cancer: a friend from the past still precious today

Anastasios Kallianos,1 Sotirios Tsimpoukis,2 Paul Zarogoulidis,3 Kaid Darwiche,4 Andriani Charpidou,2 Ilias Tsioulis,3 Georgia Trakada,5 Konstantinos Porpodis,3 Dionysios Spyratos,3 Athanasios Panoutspoulos,5 Lemonia Veletza,5 Konstantinos Kostopoulos,5 Charalampos Kostopoulos,4 Ilias Karapantzos,6 Kosmas Tsakiridis,7 Wolfgang Hohenforst-Schmidt,8 Konstantinos Zarogoulidis,3 Aggeliki Rapti,1 Konstantinos Syrigos21Second Pulmonary Clinic, Sotiria Hospital, 2Oncology Unit, Sotiria Hospital, Athens, Greece; 3Oncology Unit, G Papanikolaou General Hospital, Thessaloniki, Greece; 4Interventional Unit, Ruhrland Clinic, Essen, Germany; 5Pulmonary Laboratory, Alexandra Hospital, Athens, Greece; 6Ear, Nose, and Throat Department, Saint Luke Private Hospital, 7Cardiothoracic Department, Saint Luke Private Hospital, Thessaloniki, Greece; 8II Medical Clinic, Hospital of Coburg, Coburg, GermanyAbstract: Nitric oxide (NO) is a marker of airway inflammation and indirectly a general indicator of inflammation and oxidative stress. NO is a contributing factor in lung cancer at an early stage and also after chemotherapy treatment of lung cancer. We studied whether exhaled NO levels were altered by three cycles of chemotherapy at diagnosis and after chemotherapy, and whether, directly or indirectly, these changes were related to the course of disease. Also, a correlation of NO levels with other markers of inflammation was performed. We studied 42 patients diagnosed early: 26 men and 16 women with lung cancer. We analyzed blood tests for control of inflammatory markers, functional pulmonary tests, and alveolar exhaled NO. We recorded a decrease in exhaled NO after three cycles of chemotherapy in all patients, regardless of histological type and stage: there were 42 patients with mean 9.8 NO after three cycles (average 7.7). Also, a strong correlation appeared between NO measurements before and after chemotherapy and C-reactive protein (P < 0.05, r = 0.42, before) and (P < 0.045, r = 0.64, after). NO alveolar measurement as an indicator of airway inflammation indicates response to chemotherapy in lung cancer. Also, the inflammatory process in lung cancer was confirmed and indicated response to chemotherapy through an index that is sensitive to inflammatory disease of the airways.Keywords: nitric oxide, lung cancer, inflammatio