Utjecaj onečišćenja zraka na ventilacijsku funkciju pluća nepušačica

This study investigated disorders of ventilatory function in unemployed nonsmoking women living in areas with different air pollution. Subjects from Bakar and Krasica had lived in areas with large industrial plants in the vicinity. Continuous air quality measurements showed that SO2 concentrations exceeded the recommended values. The control group had lived in the Viškovo area where measurements showed the air to be clean. Ventilatory functions were measured on two occasions, in 1986 and in 1990. FVC, FEV1, Tiffeneau index, and FMF25–75 were taken and expressed as absolute and relative values. In both 1986 and 1990 measurements, women of Viškovo manifested significantly better values of ventilatory function than the women living in Bakar, save for the Tiffeneau index. The same stands for the 1986 comparison between Viškovo and Krasica women, whereas the second, 1990 measurement showed no difference between the two groups. Decreased ventilatory function in the Bakar women over both measurements and in the Krasica women at the first measurement may be associated with a long-term exposure to an increased air pollution with respect to the Viškovo area. Direct effect of smoking or profession were excluded from the study design.Istraživan je poremećaj ventilacijskih funkcija pluća u nezaposlenih nepušačica, nastanjenih na područjima različitim po onečišćenju zraka. Skupine ispitanica iz Bakra i Krasice nastanjene su u područjima u čijoj su blizini izgrađena velika industrijska postrojenja. Kontinuirano mjerenje kakvoće zraka pokazalo je da koncentracije SO2 prelaze preporučene vrijednosti kakvoće zraka. Kontrolna skupina ispitanica nastanjena je u Viškovu, području gdje su mjerenja pokazala da je zrak čist. Mjerenje ventilacijskih funkcija pluća učinjeno je u dva navrata, 1986. i 1990. godine. Tražene su vrijednosti FVC, FEV1, Tiffeneauov indeks i FMF25–75 te izražene kao apsolutne i relativne vrijednosti. Prilikom obaju mjerenja nađene su značajno više vrijednosti ventilacijskih funkcija pluća, osim Tiffeneauova indeksa, u žena Viškova nego u žena nastanjenih u Bakru. Pri usporedbi mjerenih ventilacijskih funkcija pluća između žena s područja Viškova i žena s područja Krasice, sve vrijednosti osim Tiffeneauova indeksa bile su pri prvom mjerenju bolje u žena iz Viškova nego u žena iz Krasice. Pri drugom mjerenju razlike nisu utvrđene. Na temelju dobivenih rezultata može se pretpostaviti da su lošije vrijednosti ventilacijskih funkcija pluća u ispitanica iz Bakra nego u ispitanica iz Viškova u obim mjerenjima, a ispitanica iz Krasice u prvom mjerenju posljedica dugotrajne izloženosti većem onečišćenju zraka budući da je isključen izravan utjecaj pušenja odnosno radnog mjesta

Usporedba mikrostrukturnih karakteristika biomedicinskih Ti (70,80 AT.%)-Cr-Mo i Ti(70,80 AT.%)-Nb-Zr legura

This paper shows comparison of microstructural characteristics of Ti-Cr-Mo and Ti-Nb-Zr alloys. Purpose of this investigation was to examine the microstructure and hardness of these alloys with potential for biomedical use. Three samples of each alloy type with different composition were laboratory prepared by an arc melting method. Their microstructure was examined by light and scanning electron microscope with EDS. Hardness was determined by Vickers method. Results show that Ti-Cr-Mo alloys have two-phases microstructure containing β and L or L” phase, while Ti-Nb-Zr alloys were nearly β single-phase with traces of L-phase. EDS analysis indicates that L and β have similar chemical composition. Vickers hardness of Ti-Cr-Mo alloys increases with molybdenum content, while those for Ti-Nb-Zr alloys increases with niobium content. According to the closely single-phase microstructure and lower hardness, Ti-Nb-Zr alloys have adventage as potential biomedical materials.Ovaj rad prikazuje usporedbu mikrostrukturnih karakteristika Ti-Cr-Mo i Ti-Nb-Zr legura. Svrha rada bila je ispitati mikrostrukturu i tvrdoću navedenih legura za potencijalnu primjenu u biomedicini. Od svake skupine legura laboratorijski su pripremljena po tri uzorka različitog sastava u lučnoj peći. Njihova mikrostruktura je ispitana svjetlosnim i skenirajućim elektronskim mikroskopom s energijsko-disperzivnim spektrometrom. Tvrdoća je određena Vickersovom metodom. Rezultati pokazuju da su Ti-Cr-Mo legure dvofazne, odnosno da sadrže β i L ili L“ fazu, dok su Ti-Nb-Zr legure uglavnom β-jednofazne s L-fazom u tragovima. EDS analiza je pokazala da L (L“) i β faze imaju vrlo sličan kemijski sastav. Tvrdoća prema Vickersu Ti-Cr-Mo legura povećava se s udjelom molibdena u leguri, dok se ona za Ti-Nb-Zr legure povećava s udjelom niobija. Zbog skoro β-jednofazne mikrostrukture i niže tvrdoće u odnosu na Ti-Cr-Mo legure, Ti-Nb-Zr legure imaju veći potencijal za primjenu kao biomedicinski materijali

Utjecaj sastava na strukturu i svojstva Ti-Co-Cr legura

The present work is a study of six as-cast Ti-Co-Cr alloys in the Ti-rich region with the purpose of examining the possibility of obtaining a new β-type Ti-alloys. Two experimental alloys Ti80Co10Cr10 and Ti70Co10Cr20 are nearly single-phases and are identified as bcc β-Ti phase. They also display the lowest hardness values and the best corrosion properties. The present study indicates that the region of biomedically-acceptable ternary Ti-rich alloys is situated within lower concentrations of alloying elements, i.e. about 10 at.% Co and 20 at. % Cr.Istraživanje šest lijevanih Ti-Co-Cr legura u području bogatom s titanom provedeno je s ciljem da se ustanovi mogućnost dobivanja novih β-Ti legura. Dvije eksperimentalne legure Ti80Co10Cr10 i Ti70Co10Cr20 pokazuju skoro jedno-faznu mikrostrukturu, koja je identificirana kao bcc β-Ti faza. One također imaju najniže vrijednosti tvrdoća i najbolja korozijska svojstva. Ovo istraživanje pokazuje, da se područje biomedicinski prihvatljivih ternarnih, titanom bogatih legura nalazi unutar nižih koncentracija legirnih elemenata tj. oko 10 at.% Co i 20 at. % Cr

Utjecaj sastava na strukturu i svojstva Ti-Co-Cr legura

The present work is a study of six as-cast Ti-Co-Cr alloys in the Ti-rich region with the purpose of examining the possibility of obtaining a new β-type Ti-alloys. Two experimental alloys Ti80Co10Cr10 and Ti70Co10Cr20 are nearly single-phases and are identified as bcc β-Ti phase. They also display the lowest hardness values and the best corrosion properties. The present study indicates that the region of biomedically-acceptable ternary Ti-rich alloys is situated within lower concentrations of alloying elements, i.e. about 10 at.% Co and 20 at. % Cr.Istraživanje šest lijevanih Ti-Co-Cr legura u području bogatom s titanom provedeno je s ciljem da se ustanovi mogućnost dobivanja novih β-Ti legura. Dvije eksperimentalne legure Ti80Co10Cr10 i Ti70Co10Cr20 pokazuju skoro jedno-faznu mikrostrukturu, koja je identificirana kao bcc β-Ti faza. One također imaju najniže vrijednosti tvrdoća i najbolja korozijska svojstva. Ovo istraživanje pokazuje, da se područje biomedicinski prihvatljivih ternarnih, titanom bogatih legura nalazi unutar nižih koncentracija legirnih elemenata tj. oko 10 at.% Co i 20 at. % Cr

Pension System in Serbia in the Light of Crisis

Mjere koje se u Srbiji provode kao odgovor na krizu ne podrazumijevaju preispitivanje sustava u cjelini, već se donose kao odraz nužnosti na rashodnoj strani. Pojedine mjere obrazlažu se različitim načelima pa postaje uočljivo da nije jasno definiran model kome se teži. Pod pritiskom krize postaje posebno vidljivo da se javni mirovinski sustav sve više pomjera u pravcu koji će omogućavati samo smanjenje siromaštva u starosti i to u apsolutnom smislu, a ne i održanje standarda nakon umirovljenja. Ovakvo opredjeljenje, ukoliko bi se prihvatilo i na duži rok zadržalo, zahtijeva i određeno redizajniranje postojećeg sustava, kako ne bi došlo do urušavanja njegove unutrašnje logike. Nejasno je, međutim, nastaje li ova suštinska konceptualna promjena kao rezultat strateške i utemeljene odluke ili slučajno. Naposljetku, sve veće oslanjanje na budžetsko financiranje pokreće i pitanje opravdanosti osiguravanja mirovina samo za stare koji su uplaćivali mirovinsko osiguranje i potrebu da se sustav preispita i s tog aspekta.The measures implemented in Serbia in answer to the crisis do not imply re-evaluation of the system as a whole, but are taken as a result of the necessity on the side of expenditure. Individual measures are explained by different principles, so it is becoming visible that the desired model has not been clearly defined. Under the pressure of the crisis it is becoming particularly visible that the public pension system is increasingly shifting towards the direction that would enable only a reduction of poverty in the old age, in the absolute sense, but not the maintenance of standard of living after retirement. Such an orientation, if accepted and maintained in the long run, demands a certain redesigning of the existing system in order to prevent the implosion of its internal logic. However, it remains unclear whether this substantial conceptual change appears a result of a strategic and well-founded decision or randomly. Finally, increasing reliance on budgetary financing raises the question of the justifiability of ensuring pensions only for those who have been paying their pension contributions and creates the need to re-examine the system from that aspect as well

Torque magnetometry study of magnetically ordered state and spin reorientation in the quasi-one-dimensional S=1/2S=1/2 Heisenberg antiferromagnet CuSb2_2O6_6

We present an experimental study of macroscopic and microscopic magnetic anisotropy of a spin tetramer system \cso using torque magnetometry and ESR spectroscopy. Large rotation of macroscopic magnetic axes with temperature observed from torque magnetometry agrees reasonably well with the rotation of the $\mathbf{g}$ tensor above $T \gtrsim 50$~K. Below 50~K, the $\mathbf{g}$ tensor is temperature independent, while macroscopic magnetic axes continue to rotate. Additionally, the susceptibility anisotropy has a temperature dependence which cannot be reconciled with the isotropic Heisenberg model of interactions between spins. ESR linewidth analysis shows that anisotropic exchange interaction must be present in \csos. These findings strongly support the presence of anisotropic exchange interactions in the Hamiltonian of the studied system. Below $T_N=8$~K, the system enters a long - range antiferromagnetically ordered state with easy axis along the $^*$ direction. Small but significant rotation of magnetic axes is also observed in the antiferromagnetically ordered state suggesting strong spin-lattice coupling in this system.Comment: 10 pages, 10 figure

Proteins of intrinsically disordered structure and their interactions using p53 protein as an example

Intrinzično neuređeni proteini čine veliki dio proteoma stanice. Ovdje je opisan samo mali dio strukture, funkcije i interakcija jednog od mnoštva proteina s intrinzično neuređenim dijelovima koji imaju ključne uloge u životu stanice. Suvremena istraživanja daju nam realniji uvid u stanične procese na molekularnoj razini, te mijenjaju sliku proteinskih interakcija. Tek smo na početku i još mnogo posla čeka buduće strukturne biologe u karakterizaciji intrinzične neuređenosti. Naš koncept funkcionalnog proteina kao statičnog entiteta se mijenja u jedan vrlo dinamični i kompleksni. Također fleksibilnost neuređenih struktura zahtijeva razvoj novih eksperimentalnih pristupa za karakterizaciji ponašanja takvih konformacijskih sklopovina. Kao primjer u radu je poslužio protein p53, ali on ne predstavlja nikakvu iznimku. Isti koncepti se mogu primijeniti i na sve ostale intrinzično neuređene proteine s vrlo važnim ulogama u stanici i u patogenezi. Definitivno se polje strukturne biologije usmjerava na proučavanje intrinzične neuređenosti proteina, i gotovo je sigurno da će u bliskoj budućnosti nestrukturna biologija zauzeti većinski dio tematike u udžbenicima molekularne biologije i biokemije.Intrinsically unstructured proteins make up a large part of cell's proteome. Here is described only small part of structure, function and interactions of only one of many proteins with intrinsically unstructured segments that have crucial roles in the cells life. Modern discoveries give us insight into a more realistic picture of cell processes on molecular level and change the concept of protein-protein interactions. We are still at the beginning of the new era of structural biology and lot of work is ahead to fully characterize intrinsic disorder in proteins. Our concept of functional protein changes from a static entity to a very complex and dynamic ensemble. Also, flexibility of disordered structures demands development of new experimental approaches for further characterization of those ensembles. Here, p53 was an example, but it is not an exception. The same concepts are applicable on all the others proteins with unconstructed parts of structure that can be important participants in cell life and pathogenesis. Today, field of structural biology is directed to studying protein disorder, and it is almost certain that in the near future, nonstructural biology will occupy most of the subjects in molecular biology and biochemistry textbooks