12064 research outputs found
Sort by
Measurements of long-range two-particle correlation over a wide pseudorapidity range in p–Pb collisions at √sNN = 5.02 TeV
No full textCorrelations in azimuthal angle extending over a long range in pseudorapidity between particles, usually called the“ridge”phenomenon, were discovered in heavy-ion collisions, and later found in pp and p–Pb collisions. In large systems, they are thought to arise from the expansion (collective flow) of the produced particles. Extending these measurements over a wider range in pseudorapidity and final-state particle multiplicity is important to understand better the origin of these long-range correlations in small collision systems. In this Letter, measurements of the long-range correlations in p–Pb collisions at √sNN = 5.02TeV are extended to a pseudorapidity gap of Δη ∼ 8 between particles using the ALICE forward multiplicity detectors. After suppressing non-flow correlations, e.g., from jet and resonance decays, the ridge structure is observed to persist up to a very large gap of Δη ∼ 8 for the first time in p–Pb collisions. This shows that the collective flow-like correlations extend over an extensive pseudorapidity range also in small collision systems such as p–Pb collisions. The pseudorapidity dependence of the second-order anisotropic flow coefficient, v2(η), is extracted from the long-range correlations. The v2(η) results are presented for a wide pseudorapidity range of −3.1 < η < 4.8 in various centrality classes in p–Pb collisions. To gain a comprehensive understanding of the source of anisotropic flow in small collision systems, the v2(η) measurements are compared with hydrodynamic and transport model calculations. The comparison suggests that the final-state interactions play a dominant role in developing the anisotropic flow in small collision systems
Search for the Chiral Magnetic Effect with charge-dependent azimuthal correlations in Xe–Xe collisions at √NN = 5.44 TeV
No full textCharge-dependent two- and three-particle correlations measured in Xe–Xe collisions at √NN = 5.44 TeV are presented. Results are obtained for charged particles in the pseudorapidity range || < 0.8 and transverse momentum interval 0.2 ≤ T < 5.0 GeV/ for different collision centralities. The three-particle correlator ≡ ⟨cos( + − 2Ψ2)⟩, calculated for different combinations of charge sign and , is expected to be sensitive to the presence of the Chiral Magnetic Effect (CME). Its magnitude is similar to the one observed in Pb–Pb collisions in contrast to a smaller CME signal in Xe–Xe collisions than in Pb–Pb collisions predicted by Monte Carlo (MC) calculations including a magnetic field induced by the spectator protons. These observations point to a large nonCME contribution to the correlator. Furthermore, the charge dependence of can be described by a blast wave model calculation that incorporates background effects and by the Anomalous Viscous Fluid Dynamics model with values of the CME signal consistent with zero. The Xe–Xe and Pb–Pb results are combined with the expected CME signal dependence on the system size from the MC calculations including a magnetic field to obtain the fraction of CME contribution in , CME. The CME fraction is compatible with zero for the 30% most central events in both systems and then becomes positive. This yields an upper limit of 2% (3%) and 25% (32%) at 95% (99.7%) confidence level for the CME signal contribution to in the 0–70% Xe–Xe and Pb–Pb collisions, respectively
Light‐Controlled Electric Stimulation with Organic Electrolytic Photocapacitors Achieves Complex Neuronal Network Activation: Semi‐Chronic Study in Cortical Cell Culture and Rat Model
No full textNeurostimulation employing photoactive organic semiconductors offers an appealing alternative to conventional techniques, enabling targeted action and wireless control through light. In this study, organic electrolytic photocapacitors (OEPC) are employed to investigate the effects of light‐controlled electric stimulation on neuronal networks in vitro and in vivo. The interactions between the devices and biological systems are characterized. Stimulation of primary rat cortical neurons results in an elevated expression of c‐Fos within a mature neuronal network. OEPC implantation for three weeks and subsequent stimulation of the somatosensory cortex leads to an increase of c‐Fos in neurons at the stimulation site and in connected brain regions (entorhinal cortex, hippocampus), both in the ipsi‐ and contralateral hemispheres. Reactivity of glial and immune cells after semi‐chronic implantation of OEPC in the rat brain is comparable to that of surgical controls, indicating minimal foreign body response. Device functionality is further substantiated through retained charging dynamics following explantation. OEPC‐based, light‐controlled electric stimulation has a significant impact on neural responsiveness. The absence of detrimental effects on both the brain and device encourages further use of OEPC as cortical implants. These findings highlight its potential as a novel mode of neurostimulation and instigate further exploration into applications in fundamental neuroscience
Modeling tumor growth
No full textTemeljna problematika koja se obrađuje u ovome radu je razvitak matematičkog modela koji bi, na zadovoljavajućoj razini, oponašao proces nastanka i razvitka tumora mozga. Konstrukcija modela sa željenim svojstvom pokazala se relativno zahtjevnom te je stoga bilo nužno dani problem particionirati na puno manjih potproblema. Strategija pristupa razvitku modela vrlo je intuitivna; krenuli smo od najjednostavnijeg slučaja. Konkretno, domenu smo podrazumijevali homogenom, pritom odabravši jednadžbu sačuvanja kao centralnu vodilju modela, uz pripadne početne i rubne uvjete koji simuliraju fizikalne i biološke značajke danog problema. Glavnina posla svela se na provedbu analize i integraciju prostorne heterogenosti u sami model te (numeričku) aproksimaciju nepoznatih parametara. Vrijednosti spomenutih parametara prikupljene su optimizacijskim metodama (poput metode najmanjih kvadrata), pri čemu je kao oslonac korištena prikupljena medicinska dokumentacija. Posljednje poglavlje posvećeno je prezentaciji ishoda dvaju istraživanja provedenih u Republici Hrvatskoj. Zajednička odrednica ovih istraživanja je proučavanje incidencije, odnosno mortaliteta na osnovi spola ispitanika. Dobiveni rezultati prikazani su tablično i grafički
Erratum to: NLO corrections to the deeply virtual meson production revisited: impact on the extraction of generalized parton distributions
No full textClimate change in physics teaching: thermal camera
No full textKlimatske promjene su jedan od najvećih izazova suvremenog društva. Da bismo razumjeli osnove ovih kompleksnih procesa, potrebno je naučiti temeljne fizikalne principe. Uvođenjem ove teme u nastavu fizike dajemo dodatni smisao učenju fizike povezujući fizikalne koncepte sa stvarnim pojavama na Zemlji. Interes učenika za učenje fizike može se dodatno pobuditi kroz pokuse i korištenje suvremenih tehnologija. Termokamera je mjerni instrument kojim se vizualiziraju termodinamički procesi koje je inače puno teže pratiti i predočiti. Termokamera se može uvesti u brojne pokuse koje već izvodimo u okviru nastave fizike, ali i za razvoj novih ideja kao što su u ovom slučaju proučavani fizikalni procesi vezani uz klimatske promjene.Climate change is one of the biggest challenges of modern society. In order to understand the basics of these complex processes, it is necessary to learn basic physical principles. By introducing this topic into physics classes, we give additional meaning to physics learning by connecting physical concepts with real phenomena on Earth. Students’ interest in learning physics can be further stimulated through experiments and the use of modern technologies. A thermal camera is a measuring instrument used to visualize thermodynamic processes that are otherwise much more difficult to monitor and visualize. The thermal camera can be introduced into numerous experiments that we already perform as part of the physics lessons, but also for the development of new ideas, such as in this case the physical processes related to climate change
Molecular typing of parvovirus B19 isolates from 2023. epidemic in Croatia
No full textParvovirus B19 jednolančani je DNA virus bez ovojnice iz porodice Parvoviridae, a jedini mu je domaćin čovjek. Primarno zaražava stanice prekursore eritrocita te se virusna replikacija odvija u jezgri zaražene stanice. Parvovirus B19 prenosi se kapljičnim putem, krvlju i krvnim derivatima te s majke na dijete, a uzrokuje bolest erythema infectiosum, koja se naziva još i „peta bolest“. Obolijevaju najčešće osobe pedijatrijske dobi koje razvijaju blage simptome, dok u trudnica, imunokompromitiranih pojedinaca i osoba s hematološkim poremećajima može izazvati težu kliničku sliku. Na temelju filogenetske analize regije NS1 virusnog genoma razlikujemo genotipove 1, 2 i 3. Genotipovi 1 i 3 dodatno su podijeljeni u podtipove A i B. Cilj ovog istraživanja bio je odrediti raspodjelu genotipova i podtipova parvovirusa B19 u Hrvatskoj. U istraživanje je bilo uključeno 107 ispitanika zaraženih parvovirusom B19 čiji su uzorci krvi u periodu od ožujka do rujna 2023. godine zaprimljeni u Kliniku za infektivne bolesti „Dr. Fran Mihaljević“. Sekvencije dobivene Sangerovom metodom sekvenciranja filogenetski su vrlo slične te pripadaju genotipu 1A. Nukleotidne supstitucije detektirane su u šest uzoraka, od čega pet istoznačnih i jedna zamjenska mutacija. Izrazita sličnost dobivenih sekvencija potvrđuje da je riječ o epidemiji, a ne o sporadičnim slučajevima zaraze.Parvovirus B19 is an uncoated single-stranded DNA virus from the Parvoviridae family. This human pathogen primarily infects erythroid progenitors while viral replication occurs in the nucleus of the infected cell. Parvovirus B19 is transmitted through respiratory secretions, blood and blood products as well as vertically, causing fifth disease or erythema infectiosum. Pediatric patients most commonly develop mild symptoms, while pregnant women, immunocompromised individuals and those with hematological disorders may experience more severe clinical manifestations. Based on phylogenetic analysis of the NS1 region of the viral genome, genotypes 1, 2, and 3 are distinguished. Genotypes 1 and 3 are further divided into subtypes A and B. The aim of this study was to determine the distribution of parvovirus B19 genotypes and subtypes in Croatia. The study included 107 participants infected with parvovirus B19, whose blood samples were analyzed at the University Hospital for Infectious Diseases "Dr. Fran Mihaljević" between March and September 2023. The sequences obtained by the Sanger sequencing method showed high phylogenetic similarity and all clustered to genotype 1A. Nucleotide substitutions were detected in six samples, five of which were samesense and one was a missense mutation. The results suggest a common source of infection during the epidemic
Geoecological evaluation of the Significant landscape of Zelenjak - Risvička and Cesarska gora
No full textZnačajni krajobraz Zelenjak – Risvička i Cesarska gora zaštićeno je područje u Krapinsko-zagorskoj županiji, u sastavu Grada Klanjca, Općine Kumrovec i Općine Tuhelj. Zaštićeno je zbog očuvanja biološke i krajobrazne raznolikosti, stoga je u ovome radu provedeno vrednovanje georaznolikosti kako bi se prikazala i njezina važnost u zaštiti prirode. Georaznolikost predstavlja abiotičku sastavnicu prirode, a dijeli se na geološku, geomorfološku i pedološku raznolikost. U radu su korištene kabinetske i terenske metode, koje uključuju metode analize i vizualizacije u GIS-u, terensko geomorfološko kartiranje i modificiranu metodu relativnog vrednovanja reljefa. Osim vrednovanja, izrađen je i idejni projekt nove poučne staze duljine 9,5 km, koja sadrži 16 interpretacijskih ploča na kojima su prikazana obilježja georaznolikosti i bioraznolikosti te kulturno-povijesne znamenitosti. Konačno, na temelju provedenih analiza dan je prijedlog proširenja granica značajnog krajobraza na istočnom i južnom dijelu Cesargradske gore.The Significant landscape of Zelenjak – Risvička and Cesarska gora is a protected area in Krapinsko-zagorska County, part of the City of Klanjec, the Municipality of Kumrovec and the Municipality of Tuhelj. It is protected due to the preservation of biological and landscape diversity, therefore, in this work, an evaluation of geodiversity was carried out in order to show its importance in nature conservation. Geodiversity represents the abiotic component of nature, and is divided into geological, geomorphological and pedological diversity. Cabinet and field methods were used in the work, which include methods of analysis and visualization in GIS, field geomorphological mapping and modified method of relative relief evaluation. In addition to the evaluation, a conceptual project of a new 9,5 km long educational trail was created, which contains 16 interpretive panels showing features of geodiversity and biodiversity, as well as cultural and historical sights. Finally, based on the conducted analyses, a proposal was made to expand the borders of the significant landscape on the eastern and southern part of Cesargradska gora
Genetic basis of bladder carcinoma
No full textJedna od najučestalijih malignih bolesti na svijetu je karcinom mokraćnog mjehura. Kod muškaraca mlađih od 75 godina se javlja češće nego kod ženskog spola, s tim da je kod žena veća stopa smrtnosti. Disurija, povećana potreba za mokrenjem, ili nemogućnost mokrenja su najizraženiji simptomi bolesti. Dijagnoza se postavlja cistoskopijom s transuretalnom resekcijom nakon koje slijedi patološka analiza tumorskog tkiva kojom se doznaje je li riječ o mišićno-invazivnom ili mišićno-neinvazivnom karcinomu. Svjetska zdravstvena organizacija (WHO, od eng. World Health Organisation) i tumor-limfni čvor-metastaza (TMN, od eng. Tumor, Nodes and Metastasis) sustavi su najčešći klasifikacijski sustavi ove maligne bolesti. Stanice se krenu jako brzo i nekontrolirano dijeliti, najčešće kao rezultat međudjelovanja promijenjenih onkogena i gena za tumorske supresore. Najčešće mutacije su one u genima FGFR3, RB1, HRAS i TP5. Rizični faktori koji utječu na za razvoj karcinoma mokraćnog mjehura su pušenje duhana, konzumacija kave, vode za piće i parazitska trematoda Schistosomiasis haematobium. Za njegovo liječenje primjenjuje se ili kemoterapijsko ili imunoterapijsko liječenje, ali pozornost treba obratiti i na otpornost pacijenata na određene terapije.One of the most common malignant diseases in the world is bladder cancer. It occurs more often in men under the age of 75 than in women, with a higher mortality rate when diagnosed in women. Dysuria, increased need to urinate, or inability to urinate are the most common symptoms of the disease. The diagnosis is made by cystoscopy with transurethral resection, followed by a pathological analysis of tumor tissue to determine whether it is muscle-invasive or non-muscle-invasive cancer. World Health Organisation (WHO) and Tumor, Nodes, Metastasis (TNM) systems are the most common classification systems of this malignant disease. Cells begin to divide very quickly and uncontrollably, most often as a result of the interaction of changed oncogenes and tumor suppressor genes. Most often mutations are the one in genes FGFR3, RB1, HRAS and TP5. Risk factors that influence the development of bladder cancer include tobacco smoking, coffee consumption, drinking water, and the parasitic trematode Schistosomiasis haematobium. Chemotherapy or immunotherapy is used for treatment, but attention should also be paid to the patient's resistance to certain therapies
Impact of sirtuin 3 on the oxidative and metabolic state of kidney and brain tissue in male and female mouse
No full textSirtuin 3 (SIRT3) pripada obitelji proteina sirtuina i glavna je mitohondrijska NAD+ ovisna deacetilaza. Sudjeluje u regulaciji staničnog metabolizma, oksidativnog stresa i transkripcije. Njegova pojačana aktivacija, što suplementima, a što zbog polimorfizama prirodno prisutnih u populaciji, pokazala se efikasnom metodom produljenja životnog vijeka modelnih organizama i čovjeka. U ovom istraživanju analiziran je njegov utjecaj na oksidativno i metaboličko stanje u tkivu bubrega i mozga. Istraživanje je provedeno na osamnaest tjedana starim mužjacima i ženkama miševa divljeg tipa i miševa s nedostatkom proteina SIRT3, pri normalnoj prehrani. Analizirana je ekspresija proteina uključenih u antioksidativnu obranu i metabolizam metodom Western blot. Na uzorcima tkiva bubrega i mozga provedena je analiza oksidativnih oštećenja proteina analizom karbonilacije, odnosno oštećenja lipida lipidnom peroksidacijom. Dodatno je određena aktivnost antioksidativnih enzima katalaze i superoksid dismutaze. U analizi ekspresije uočen je utjecaj SIRT3 na količinu proteina SOD2 u bubregu i PPARγ u mozgu. Oksidativna oštećenja sugeriraju protektivno djelovanje na lipide u mozgu i proteine u bubregu, a aktivnost antioksidativnih enzima varira s obzirom na spol i tip organa.Sirtuin 3 (SIRT3) belongs to the sirtuin protein family and is a key mitochondrial NAD+-dependent deacetylase. It is involved in regulating cellular metabolism, oxidative stress, and transcription. Its increased activation, either through supplements or due to naturally occurring polymorphisms in the population, has proven to be an effective method for extending the lifespan of model organisms and humans. In this study, its impact on oxidative and metabolic states in kidney and brain tissues was analyzed. The research was conducted on 18-week-old male and female wild-type mice and mice lacking the SIRT3 protein, under normal dietery conditions. The expression of proteins involved in antioxidant defense and metabolism was analyzed using the Western blot method. Oxidative damage to proteins in kidney and brain tissue samples was determined by analyzing carbonylation, and lipid damage was assessed through lipid peroxidation. Additionally, the activity of antioxidant enzymes catalase and superoxide dismutase was measured. The analysis of protein expression showed an influence of SIRT3 on the amount of SOD2 protein in the kidney and PPARγ in the brain. Oxidative damage suggests a protective effect on lipids in the brain and proteins in the kidney, while the activity of antioxidant enzymes varies depending on the sex and type of organ