Strong Eulerian triples

We prove that there exist infinitely many rationals a, b and c with the property that a^2-1, b^2-1, c^2-1, ab-1, ac-1 and bc-1 are all perfect squares. This provides a solution to a variant of the problem studied by Diophantus and Euler.Comment: 8 page

Cytotoxic activity of supercritical CO2 extract of old man's beard in L929 fibrosarcoma cell line

Old man’s beard (Usnea barbata) is one of the most investigated lichens which biological properties (such as antimicrobial, anti-inflammatory and cytotoxic activities) have been proven in several scien- tific studies. Stated properties of old man’s beard have been attributed mainly to its major secondary metabolite - a dibenzofuran derivative, usnic acid. The aim of the current study was to examine cyto- toxic activity of the quantified supercritical CO2 extract and pure usnic acid in parallel against L929 fibrosarcoma cells. Our results indicated the tested extract to be more toxic towards the investigated cell line compared to usnic acid per se, despite the high amount of this compound (81.41% (w/w)) revealed in the extract using HPLC. Such result may be connected to the unidentified compounds present in the supercritical CO2 extract that could be responsible for apoptosis and oxidative stress in the exerted cytotoxicity of the investigated extract, but not usnic acid. Our study supports further in- vestigations of supercritical CO2 extract of U. barbata as a prospective therapeutic agent with potential relevance in the treatment of sarcoma

Endoscopic Ultrasound in Solid Pancreatic Masses – Current State and Review of the Literature

Some 25 years ago endoscopic ultrasound (EUS) was introduced in clinical practice for better visualization of pancreas. At the time of introduction EUS was superior to other methods in detection of pancreatic masses allowing tissue diagnosis by later introduced EUS-guided fine needle aspiration (FNA). During the time EUS was improved, electronic probes replaced mechanical probes adding ability of color Doppler, power Doppler, contrast enhanced endosonography as well as EUS elastography analysis. Meanwhile, CT technology has also experienced significant improvements raising the question whether EUS has lost ground in diagnostics of solid pancreatic masses. The aim of this review was to discuss the current evidence of clinical impact of EUS and EUS-FNA in evaluation of solid pancreatic masses with special emphasis on differentiation between benign and malignant pancreatic lesions. According to the literature, the detection of small pancreatic tumors, preoperative localization of pancreatic endocrine tumors and tissue sampling by fine-needle aspiration of pancreatic masses in cases with therapeutic consequences are considered firm indications for EUS. Cytological tissue analysis remains undisputed in differentiation benign from malignant lesions, but the question when FNA is needed is discussed. Color Doppler, power Doppler, contrast enhanced endosonography and especially elastography are also discussed as tools that are bringing additional information in evaluation of pancreatic masses, however insufficient for definitive judgment of the lesion’s nature. Pancreatic cancer staging as indication for EUS is discussed controversially, inconsistent results and conflicting evidence in literature making adequate conclusion impossible. However, this indicates that at least the role of EUS is no longer undisputed in this matter. Resuming the role of EUS we can state that despite some controversies EUS is very valuable method in evaluation of solid pancreatic masses and with EUS guided FNA is nowadays by far the best method for obtaining tissue diagnosis

Evaluation of Anticancer and Antioxidant Activity of a Commercially Available CO2 Supercritical Extract of Old Man's Beard (Usnea barbata)

There is a worldwide ongoing investigation for novel natural constituents with cytotoxic and antioxidant properties. The aim of this study was to investigate chemical profile and stated biological activities of the supercritical CO2 extract (SCE) of old man's beard compared to the extracts obtained using the conventional techniques (Soxhlet extracts and macerate). The most abundant compound identified was usnic acid, which content was inversely proportional to the polarity of the solvent used and was the highest in the SCE, which was the sample revealing the highest cytotoxic activity in tested tumor cell lines (B16 mouse melanoma and C6 rat glioma), with lower IC50 values compared to pure usnic acid. Further investigations suggested both SCE and usnic acid to induce apoptosis and/ or autophagy in B16 and C6, indicating higher cytotoxicity of SCE to be related to the higher degree of ROS production. A good correlation of usnic acid content in the extracts and their antioxidant capacity was established, extricating SCE as the most active one. Presented results support further investigations of SCE of old man's beard as a prospective therapeutic agent with potential relevance in the treatment of cancer and/ or in oxidative stress-mediated conditions

Cytotoxic activity of supercritical CO2 extract of old man’s beard in L929 fibrosarcoma cell line

Usnea barbata (old man’s beard) is one of the most investigated lichens which biological properties (such as antimicrobial, anti-inflammatory and cytotoxic activities) have been proven in several scientific studies. Stated properties of old man’s beard have been attributed mainly to its major secondary metabolite - a dibenzofuran derivative, usnic acid. The aim of the current study was to examine cytotoxic activity of the quantified supercritical CO2 extract and pure usnic acid in parallel against L929 fibrosarcoma cells. Our results indicated the tested extract to be more toxic towards the investigated cell line compared to usnic acid per se, despite the high amount of this compound (81.41 (% (w/w)) revealed in the extract using HPLC. Such result may be connected to the unidentified compound(s) present in the supercritical CO2 extract that could be responsible for apoptosis and oxidative stress in the exerted cytotoxicity of the investigated extract, but not usnic acid. Our study supports further investigations of supercritical CO2 extract of U. barbata as a prospective therapeutic agent with potential relevance in the treatment of sarcoma

Technology of maritime transportation of liqueifiedgas

U ovom radu istražit će se načini i protokoli prijevoza ukapljenih plinova morem, kao i osnovna kemijska i fizikalna svojstva ukapljenih plinova te njihove najvažnije značajke s obzirom na proizvodnju, uporabu, skladištenje i rukovanje s teretom. Ukapljeni plin transportiran je putem cjevovoda ili ukapljen u spremnicima brodova za prijevoz ukapljenih prirodnih ili naftnih plinova. Obzirom na povećanje potražnje za ukapljenim prirodnim plinom potrebno je usavršavati brojne trenutno postojeće tehnologije prijevoza te ukoliko je moguće, uvesti nove tehnologije da bi se prekrcaj i prijevoz ukapljenog prirodnog plina mogao odvijati sukladno načelima točnosti i učinkovitosti. U najvećem broju slučajeva se na prvo mjesto postavlja ukapljeni plin, prema današnjim procjenama i shvaćanjima smatra se jednim od najznačajnijih energenata u ovom stoljeću zbog jednostavne dostupnosti, jednostavnog prerađivanja i upotrebe te velikih zaliha diljem svijeta.In this act it will be investigated the transportation methods and protocols of liquefied gases by sea, as well as basic checmical and physical properties of liqueified gases and their most important features considering the production, use, storage and handling the cargo. Liquefiedgas is transported with pipelines or liquefied in ship tanks for transport of liquefied natural and oil gases. Considering the increase of transportation demands for liquefied gases, it is needed to perfect numerous currently existing technologies and, if it is possible, to bring in new technologies in order to make the transportation and transhipment of liquefied gases could take place accordingly to the accuracy and efficiency principles. In most cases liquiefied gases are set on the first place, according to today’s estimates and perceptions it is considered to be one of the most significant fuels in this century because of easy availability, easy processing and use and large amounts around the world

Cooperative urban traffic systems

Kooperativni sustavi u urbanom prometu predstavljaju napredne tehnološke pristupe koji povezuju vozila, prometnu infrastrukturu i informacijske tehnologije radi poboljšanja mobilnosti, sigurnosti i učinkovitosti u urbanim sredinama kako bi se unaprijedila protočnost prometa, smanjile gužve, poboljšala sigurnost i potaknula održivost u gradskim okruženjima. Kooperativni sustavi također podržavaju održive opcije prijevoza, kao što su dijeljenje vožnji i javni prijevoz, smanjujući emisije i potrebu za osobnim automobilima. Integracija autonomnih vozila i tehnologije interneta stvari (IoT) otvara put prema prometnoj revoluciji, pružajući priliku za stvaranje pametnih i učinkovitih gradova budućnosti. Ključni elementi uključuju razmjenu informacija o brzinama, gužvama, prometnim signalima i drugim prometnim uvjetima. Kooperativni sustavi predstavljaju ključni korak prema pametnim i održivim urbanim prometnim rješenjima, poboljšavajući mobilnost, smanjujući zagađenje i potičući razvoj inovativnih tehnologija.Cooperative systems in urban transport represent advanced technological approaches that connect vehicles, transport infrastructure and information technologies to improve mobility, safety and efficiency in urban environments to improve traffic flow, reduce traffic jams, improve safety and promote sustainability in urban environments. Cooperative systems also support sustainable transportation options, such as ride-sharing and public transportation, reducing emissions and the need for personal cars. The integration of autonomous vehicles and Internet of Things (IoT) technology is paving the way for a transportation revolution, providing an opportunity to create smart and efficient cities of the future. Key elements include sharing information about speeds, jams, traffic signals and other traffic conditions. Cooperative systems represent a key step towards smart and sustainable urban transport solutions, improving mobility, reducing pollution and encouraging the development of innovative technologies

Cooperative urban traffic systems

Kooperativni sustavi u urbanom prometu predstavljaju napredne tehnološke pristupe koji povezuju vozila, prometnu infrastrukturu i informacijske tehnologije radi poboljšanja mobilnosti, sigurnosti i učinkovitosti u urbanim sredinama kako bi se unaprijedila protočnost prometa, smanjile gužve, poboljšala sigurnost i potaknula održivost u gradskim okruženjima. Kooperativni sustavi također podržavaju održive opcije prijevoza, kao što su dijeljenje vožnji i javni prijevoz, smanjujući emisije i potrebu za osobnim automobilima. Integracija autonomnih vozila i tehnologije interneta stvari (IoT) otvara put prema prometnoj revoluciji, pružajući priliku za stvaranje pametnih i učinkovitih gradova budućnosti. Ključni elementi uključuju razmjenu informacija o brzinama, gužvama, prometnim signalima i drugim prometnim uvjetima. Kooperativni sustavi predstavljaju ključni korak prema pametnim i održivim urbanim prometnim rješenjima, poboljšavajući mobilnost, smanjujući zagađenje i potičući razvoj inovativnih tehnologija.Cooperative systems in urban transport represent advanced technological approaches that connect vehicles, transport infrastructure and information technologies to improve mobility, safety and efficiency in urban environments to improve traffic flow, reduce traffic jams, improve safety and promote sustainability in urban environments. Cooperative systems also support sustainable transportation options, such as ride-sharing and public transportation, reducing emissions and the need for personal cars. The integration of autonomous vehicles and Internet of Things (IoT) technology is paving the way for a transportation revolution, providing an opportunity to create smart and efficient cities of the future. Key elements include sharing information about speeds, jams, traffic signals and other traffic conditions. Cooperative systems represent a key step towards smart and sustainable urban transport solutions, improving mobility, reducing pollution and encouraging the development of innovative technologies

Technology of maritime transportation of liqueifiedgas

U ovom radu istražit će se načini i protokoli prijevoza ukapljenih plinova morem, kao i osnovna kemijska i fizikalna svojstva ukapljenih plinova te njihove najvažnije značajke s obzirom na proizvodnju, uporabu, skladištenje i rukovanje s teretom. Ukapljeni plin transportiran je putem cjevovoda ili ukapljen u spremnicima brodova za prijevoz ukapljenih prirodnih ili naftnih plinova. Obzirom na povećanje potražnje za ukapljenim prirodnim plinom potrebno je usavršavati brojne trenutno postojeće tehnologije prijevoza te ukoliko je moguće, uvesti nove tehnologije da bi se prekrcaj i prijevoz ukapljenog prirodnog plina mogao odvijati sukladno načelima točnosti i učinkovitosti. U najvećem broju slučajeva se na prvo mjesto postavlja ukapljeni plin, prema današnjim procjenama i shvaćanjima smatra se jednim od najznačajnijih energenata u ovom stoljeću zbog jednostavne dostupnosti, jednostavnog prerađivanja i upotrebe te velikih zaliha diljem svijeta.In this act it will be investigated the transportation methods and protocols of liquefied gases by sea, as well as basic checmical and physical properties of liqueified gases and their most important features considering the production, use, storage and handling the cargo. Liquefiedgas is transported with pipelines or liquefied in ship tanks for transport of liquefied natural and oil gases. Considering the increase of transportation demands for liquefied gases, it is needed to perfect numerous currently existing technologies and, if it is possible, to bring in new technologies in order to make the transportation and transhipment of liquefied gases could take place accordingly to the accuracy and efficiency principles. In most cases liquiefied gases are set on the first place, according to today’s estimates and perceptions it is considered to be one of the most significant fuels in this century because of easy availability, easy processing and use and large amounts around the world