Some Properties of the Spin-Polarized Attractive Hubbard Model

The influence of a Zeeman magnetic field on the superconducting characteristics of the attractive Hubbard model was investigated. The ground state and temperature phase diagrams were obtained for a fixed number of particles. Two critical magnetic fields were found for the first order phase transition from the superconducting to the normal state for $n\neq 1$. For some range of parameters a reentrant transition was found and gapless superconductivity was obtained. The significance of the Hartree term was also analyzed.Comment: Minor changes. 5 pages, 2 figures, presented at The European Conference Physics of Magnetism 2008, June 24-27, Poznan, Polan

On the Phase Diagram of Spin-Polarized Attractive Hubbard Model: Weak Coupling Limit

The superfluid properties of the attractive Hubbard model in a Zeeman magnetic field, and in the weak coupling regime have been investigated. The temperature and magnetic field dependencies of the order parameter have been analyzed. Furthermore, the temperature vs. magnetic field and temperature vs. spin polarization phase diagrams for the 2D and 3D lattices have been obtained. For some parameters a reentrant transition has been found.Comment: 9 pages, 4 figures, Proceedings of the XIII National School Superconductivity, Spin And Charge Ordering, Ladek-Zdroj, November 6-10, 200

System komunikacji alternatywnej i wspomagającej wraz ze stosowanymi znakami oraz wykorzystanie urządzenia sterowanego za pomocą oczu w Polsce

Patients who do not communicate verbally or speak in an understandable way are a serious problem in providing appropriate care to patients due to a lack of understanding of their needs. Therefore, it is important that nursing staff have the knowledge and skills of alternative and assistive communication to communicate with patients with speech disorders. The purpose of article is to present the current state of knowledge of the alternative and augmentative communication with special consideration the signs used in Poland with a practicular emphasis laid to the revelant description of the eye tracking device. The literature has been reviewed, including also in this relation topics: alternative and augmentative communication, examples of signs used in alternative communication in Poland and communication and eye tracking. Not everyone has the ability to communicate verbally with the environment. In relation to this problem the solution is the alternative and augmentative communication which uses signs and devices to enable the patient to communicate with other people. (JNNN 2020;9(1):39–45)Pacjenci nie komunikujący się werbalnie lub mówiący w sposób niezrozumiały stanowią istotny problem w zapewnieniu właściwej opieki chorych w wyniku braku zrozumienia ich potrzeb. Z tego względu istotne jest posiadanie przez personel pielęgniarski wiedzy i umiejętności w zakresie komunikacji alternatywnej i wspomagającej by porozumieć się z pacjentami z zaburzeniami mowy. Celem pracy jest przedstawienie dotychczasowego stanu wiedzy na temat systemu komunikacji alternatywnej i wspomagającej ze szczególnym uwzgędnieniem wykorzystywanych znaków w Polsce oraz opis urządzenia sterowanego za pomocą oczu. Dokonano przeglądu literatury w zakresie tematów: komunikacja alternatywna i wspomagająca, przykłady znaków stosowanych w komunikacji alternatywnej w Polsce oraz komunikacja za pomocą oczu. Nie każdy człowiek posiada zdolność do komunikowania się werbalnie z otoczeniem. W odniesieniu do tego problemu rozwiązaniem jest komunikacja alternatywna i wspomagająca, która stosuje między innymi znaki oraz urządzenia, dające pacjentowi możliwość komunikowania się z ludźmi. (PNN 2020;9(1):39–45

Simple and efficient expression of Agaricus meleagris pyranose dehydrogenase in Pichia pastoris

Pyranose dehydrogenase (PDH) is a fungal flavin-dependent sugar oxidoreductase that is highly interesting for applications in organic synthesis or electrochemistry. The low expression levels of the filamentous fungus Agaricus meleagris as well as the demand for engineered PDH make heterologous expression necessary. Recently, Aspergillus species were described to efficiently secrete recombinant PDH. Here, we evaluate recombinant protein production with expression hosts more suitable for genetic engineering. Expression in Escherichia coli resulted in no soluble or active PDH. Heterologous expression in the methylotrophic yeast Pichia pastoris was investigated using two different signal sequences as well as a codon-optimized sequence. A 96-well plate activity screening for transformants of all constructs was established and the best expressing clone was used for large-scale production in 50-L scale, which gave a volumetric yield of 223 mg L−1 PDH or 1,330 U L−1 d−1 in space–time yield. Purification yielded 13.4 g of pure enzyme representing 95.8% of the initial activity. The hyperglycosylated recombinant enzyme had a 20% lower specific activity than the native enzyme; however, the kinetic properties were essentially identical. This study demonstrates the successful expression of PDH in the eukaryotic host organism P. pastoris paving the way for protein engineering. Additionally, the feasibility of large-scale production of the enzyme with this expression system together with a simplified purification scheme for easy high-yield purification is shown

Artificial Reproduction of Blue Bream (Ballerus ballerus L.) as a Conservative Method under Controlled Conditions

The blue bream Ballerus ballerus (L.) is one of two species of the Ballerus genus occurring in Europe. The biotechnology for its reproduction under controlled conditions needs to be developed to conserve its local populations. Therefore, a range of experiments were performed to obtain valuable gametes from blue bream following hormonal stimulation with carp pituitary homogenate (CPH), Ovopel and Ovaprim. CPH and Ovopel were injected twice and Ovaprim—once, under a pectoral fin. The spawners were inspected 12 h after the last injection, and the gametes were collected. Eggs were collected from spawning females and fertilized with sperm from three males. The smallest number of ovulating blue bream (four females) was obtained from individuals stimulated with Ovaprim. There were six to nine ovulating females in the other groups, accounting for 60–90% of the females in the respective groups. The latency period was the shortest in the spawners stimulated with Ovopel. The fish in this group ovulated 14 h after the hormonal injection. Spawning was synchronized and all females spawned simultaneously. The highest average weight of eggs per fish (75.4 g) was obtained from the females stimulated with Ovopel, whereas the individuals stimulated with Ovaprim provided the smallest average amount of eggs (49.5 g). The study showed that blue bream spawners are not very sensitive to reproduction-related handling under controlled conditions