Pressure in isochoric systems containing aqueous solutions at subzero Centigrade temperatures.

ObjectivePreservation of biological materials at subzero Centigrade temperatures, cryopreservation, is important for the field of tissue engineering and organ transplantation. Our group is studying the use of isochoric (constant volume) systems of aqueous solution for cryopreservation. Previous studies measured the pressure-temperature relations in aqueous isochoric systems in the temperature range from 0°C to - 20°C. The goal of this study is to expand the pressure-temperature measurement beyond the range reported in previous publications.Materials and methodsTo expand the pressure-temperature measurements beyond the previous range, we have developed a new isochoric device capable of withstanding liquid nitrogen temperatures and pressures of up to 413 MPa. The device is instrumented with a pressure transducer than can monitor and record the pressures in the isochoric chamber in real time. Measurements were made in a temperature range from - 5°C to liquid nitrogen temperatures for various solutions of pure water and Me2SO (a chemical additive used for protection of biological materials in a frozen state and for vitrification (glass formation) of biological matter). Undissolved gaseous are is carefully removed from the system.ResultsTemperature-pressure data from - 5°C to liquid nitrogen temperature for pure water and other solutions are presented in this study. Following are examples of some, temperature-pressure values, that were measured in an isochoric system containing pure water: (- 20°C, 187 MPa); (-25°C, 216 MPa); (- 30°C, 242.3 MPa); (-180°C, 124 MPa). The data is consistent with the literature, which reports that the pressure and temperature at the triple point, between ice I, ice III and water is, - 21.993°C and 209.9 MPa, respectively. It was surprising to find that the pressure in the isochoric system increases at temperatures below the triple point and remains high to liquid nitrogen temperatures. Measurements of pressure-temperature relations in solutions of pure water and Me2SO in different concentrations show that, for concentrations in which vitrification is predicted, no increase in pressure was measured during rapid cooling to liquid nitrogen temperatures. However, ice formation either during cooling or warming to and from liquid nitrogen temperatures produced an increase in pressure.ConclusionsThe data obtained in this study can be used to aid in the design of isochoric cryopreservation protocols. The results suggest that the pressure measurement is important in the design of "constant volume" systems and can provide a simple means to gain information on the occurrence of vitrification and devitrification during cryopreservation processes of aqueous solutions in an isochoric system

The Directions and Socio-Economic Effects of the External Migration from the Romanian Countryside

Against the backdrop of socio-economic phenomena in the post-communist era, as a risk management strategy, a true culture of migration toward the developed West has emerged in Romania. This study will explore the particularities of external migration in the rural areas. The main objective is to find what are the most important socio-economic phenomena that shaped the Romanian rural society. The methodology includes a vast documentary, quantitative, and statistical research. The rural areas have a very low quality of life: 5 in 10 people work in agriculture, which only contributes 4% to the GDP. The main beneficiary countries are Italy and Spain. Temporary migration provides a context for social learning. The most worrying effects are physicians’ exodus, family abandonment and breakdown, forced modernization of rural areas, dropout rate, and youth exodus. There is a trend toward feminization of migration, due to a lack of opportunities home. Few migrants return home; 4 out of 10 people want to emigrate and 9 out of 10 know somebody abroad, half have relatives there. Authorities need to take measures at the macro, mezzo, and micro levels to slow down the emigration rate (organization of (re)qualification courses, investments in infrastructure, education and health, supporting medium-sized farms, and cooperatives)

THE NATIONALITY OF THE ARBITRAL SENTENCE IN INTERNATIONAL ARBITRATION

In the case of international disputes resolved by means of arbitration, the cross-border effects of the awards are essential for the parties. At first glance, these awards are assimilated to the national court judgements of the state where they were pronounced and are considered foreign court judgements in any other state. Nevertheless, in some cases, the links between the arbitral procedures and the place of pronouncement of the awards are weak or even non-existent, which raises serios doubts over the ability of this specific place to determine the nationality of the arbitral award. The described circumstance is the premise of the present scientific approach, which aims to deepen the analysis of the criteria for determining the nationality of an arbitral award (by a Romanian court), with implications on its cross-border effects, as well as on the procedures that could lead to its dissolution. From a methodological point of view, the research aims, successively, to inventory the applicable legal instruments, to delineate the solutions offered by them, in order to, finally, by overlapping them, provide a comprehensive theory on the determination of the nationality of an arbitral award

Prosthetic Reconstruction of the Upper Digestive Tract

In cases of locally advanced cancers involving the junction between the hypopharynx and cervical oesophagus, the curative surgical treatment is total circular laryngo-pharyngectomy with resection of the upper cervical oesophagus, coupled with modified radical neck dissection. Techniques used to re-establish the continuity of the digestive tract have been pectoral transposition flap, gastric pull-up, jejunum or colon transposition and free pedicled fascial-cutaneous flap reconstruction. Prosthetic reconstruction was thought of and used only as a temporary solution. In our clinic, we adapted the Montgomery oesophageal prosthesis as more than just a temporary solution and used it in 63 patients operated from 2004 to 2014 with advanced (stages III and IV) cancer involving most of the hypopharynx or extending towards the upper cervical oesophagus. Following total circular laryngo-pharyngectomy with bilateral modified radical neck dissection, prosthetic reconstruction was performed using the Montgomery oesophageal tube. Patients were followed up on, and their status was monitored. Favourable results encouraged the authors to further develop a new active prosthesis, with advanced design and materials that better mimic the anatomy and physiology of the replaced segment. Prosthetic reconstruction of the upper digestive tract following radical oncologic surgery is a viable option, with advantages compared to other laborious plastic techniques. The new active model is under development, hopefully offering soon a safe and more cost-effective alternative to the other techniques

HPV-Positive Oral Squamous Cell Carcinoma

Head and neck malignancies represent the sixth most frequent type of cancer currently in worldwide statistics. Of these, oral and pharyngeal cancers have steadily increased, being linked with the increase in HPV infection pandemic. This rise is not due to one cause, but rather multiple factors such as lifestyle and sexual behavior pattern changes and globalization. Because of the anatomy of the oral cavity and oropharynx, the proper diagnosis is easily delayed, and patients present with advanced stage disease, which requires aggressive and extensive surgery along with neck dissection and chemoradiotherapy. Patients with advanced stage disease have a high recurrence risk with a low 5-year survival rate. Preventing the HPV infection is of course desirable, but right now, for adults which already are infected and have a higher risk of developing HPV-related neoplasias, as well as for our head and neck cancer patients, alternative treatment algorithms are necessary

Factors of sustainable competitiveness at company level: a comparison of four global economic sectors

Built on the premise that a company’s competitiveness is given by its robust financial performance and the strength of its position on the market, but only under conditions of sustainability, this study aims to investigate the key factors of company competitiveness while considering sustainability issues. The two research objectives were: (1) to identify and analyze the key factors of sustainable competitiveness at company level (2) to find sector-related discrepancies regarding the identified factors. To achieve them, a horizontal analysis covering ten financial years (2012–2021) was performed on a sample of 1,449 companies from four global economic sectors (Consumer Cyclicals, Energy, Health Care, and Technology) – using Exploratory factor analysis (EFA) and ANOVA. Nine factors (both financial and non-financial) were found: liquidity, profitability, revenue efficiency, inventory management efficiency, ESG performance, receivables management efficiency, R&D efficiency, book value, and market value. Of them, ESG performance has emerged as an independent factor based on non-financial variables, its introduction into the research model being one of the study’s novelties. Significant mean differences were found between the nine factors, depending on the sector, which allowed the ranking of sectors in terms of sustainable competitiveness, in descending order: Health Care, Technology, Consumer Cyclicals, and Energy

Prototype isochoric preservation device for large organs

This paper presents the design and prototype of a constant volume (isochoric) vessel that can be used for the preservation of large organs in a supercooled state. This prototype is a preliminary version of a more advanced design. The device consists of a cooling bath operated by a mechanical vapor compression refrigeration unit and an isochoric chamber made of stainless steel. The preservation of organs using supercooling technology in an isochoric chamber requires a continuous temperature and pressure monitoring. While the device was initially designed for pig liver experiments, its innovative design and preservation capabilities suggest potential applications for preserving other organs as well. The isochoric reactor may be used to accommodate a variety of organ types, opening the door for further research into its multi-organ preservation capabilities. All the design details are presented in this study with the purpose of encouraging researchers in the field to build their own devices, and by this to improve the design. We chose to design the device for isochoric supercooling as the method of preservation to avoid the ice formation

Pharyngocutaneous Fistulas Following Total Laryngectomy

Total laryngectomy is still the final therapeutic solution in cases of locally advanced laryngeal cancer, as well as in cases of therapeutic failure of organ-sparing surgery or radiation therapy. Following excision of the larynx, the remaining pharynx is reconstructed to obtain continuity of the upper digestive tract. One of the most common complications in these patients, despite constant refinement of the procedure, is the development of a pharyngo-cutaneous fistula. These fistulas prolong hospital stay and often require a second surgical procedure, increasing morbidity and cost for the patient, while diminishing his quality of life. Some risk-factors have been identified, but only some may be corrected before surgery to lower this risk. Managing the fistula once present depends on multiple factors, essential being the size of the fistula as well as the position and concomitant factors, with options ranging from conservative measures to aggressive reconstructive surgery with local miocutaneous flaps. Modern vocal rehabilitation with T.E.P. (tracheo-esophageal puncture) and vocal prosthesis placement presents a new challenge – because of the risk of developing a tracheo-esophageal fistula, with an even higher risk for the patient because of tracheal aspiration. Understanding healing mechanisms of these structures is key to proper management of this complication

Pharynx Reconstruction and Quality of Life

Patients who are diagnosed with squamous cell carcinoma of the pharynx have a first delayed presentation, with advanced stages of the disease. Therefore, they frequently require a multimodal approach—by surgery, radio, and chemotherapy. Due to anatomic spatial limits and particularities, therapy can imply large organ resection with difficulties in reconstruction. Nowadays, there is a paradigm shift in the management of this pathology, with significant first referral to oncology departments and initiation as the first line of treatment of radio/radio-chemotherapy. As a consequence, salvage surgery may be mandatory in some selected cases. The proposed chapter will address the oncological particularities of the pharynx, with a focus on the oro- and hypopharynx, ways of reconstruction after oncological ablative surgery of these segments, and impact on quality of life (QoL) index. Speech, respiratory, and deglutition rehabilitation of these patients is essential and will be a distinct topic. This paper will have the structure of a literature review with clinical examples of reconstruction from ENT and Head and Neck Surgery Department of Coltea Clinical Hospital, Bucharest. Reconstruction methods used in our clinic are regional flaps and biocompatible prostheses in advanced stages. QoL index in our clinic is assessed with questionnaires developed by the European Organization for Research and Treatment of Cancer – EORTC QLQ C30