Humic acid protein complexation

Interactions of purified Aldrich humic acid (PAHA) with lysozyme (LSZ) are investigated. In solution LSZ is moderately positively and PAHA negatively charged at the investigated pH values. The proton binding of PAHA and of LSZ is determined by potentiometric proton titrations at various KCl concentrations. It is also measured for two mixtures of PAHA¿LSZ and compared with theoretically calculated proton binding assuming no mutual interaction. The charge adaptation due to PAHA¿LSZ interaction is relatively small and only significant at low and high pH. Next to the proton binding, the mass ratio PAHA/LSZ at the iso-electric point (IEP) of the complex at given solution conditions is measured together with the pH using the Mütek particle charge detector. From the pH changes the charge adaptation due to the interaction can be found. Also these measurements show that the net charge adaptation is weak for PAHA¿LSZ complexes at their IEP. PAHA/LSZ mass ratios in the complexes at the IEP are measured at pH 5 and 7. At pH 5 and 50 mmol/L KCl the charge of the complex is compensated for 30¿40% by K+; at pH 7, where LSZ has a rather low positive charge, this is 45¿55%. At pH 5 and 5 mmol/L KCl the PAHA/LSZ mass ratio at the IEP of the complex depends on the order of addition. When LSZ is added to PAHA about 25% K+ is included in the complex, but no K+ is incorporated when PAHA is added to LSZ. The flocculation behavior of the complexes is also different. After LSZ addition to PAHA slow precipitation occurs (6¿24 h) in the IEP, but after addition of PAHA to LSZ no precipitation can be seen after 12 h. Clearly, PAHA/LSZ complexation and the colloidal stability of PAHA¿LSZ aggregates depend on the order of addition. Some implications of the observed behavior are discussed

Genetic and bioinformatic analyses of the expression and function of PI3K regulatory subunit PIK3R3 in an Asian patient gastric cancer library

10.1186/1755-8794-5-34BMC Medical Genomics5

Atenuasi ultrasonik dan modulus ricih pada suhu genting superkonduktor terdop sederhana (Tl0.8Bi0.2)Sr2 (Ca0.9Cr0.1)Cu2 O7

Modulus ricih dan atenuasi ultrasonik superkonduktor suhu tinggi terdop sederhana (Tl0.8Bi0.2)Sr2 (Ca0.9Cr0.1)Cu2 O7 (Tl-1212) dengan suhu genting (Tc ) 98 K telah dikaji. Modulus ricih, G meningkat apabila suhu diturunkan daripada 240 K ke 80 K yang menunjukkan pengerasan kekisi. Walau bagaimanapun, pada suhu antara 160 K hingga 190 K modulus ricih menunjukkan anomali menandakan kecenderungan untuk kekisi melembut. Berhampiran suhu genting modulus ricih menunjukkan pelembutan kekisi iaitu ketakselanjaran pada cerun (dG/dT) dan ini sejajar dengan ciri peralihan fasa termodinamik tertib ke dua. Peratus perubahan modulus ricih antara 240 K dan 80 K ialah 5.5%. Atenuasi ultrasonik menunjukkan penurunan mendadak daripada 240 K ke 210 K diikuti dengan profil yang hampir mendatar sehingga 140 K. Puncak atenuasi dicerap berhampiran suhu genting dan ini menunjukkan penyerapan tenaga akustik meningkat apabila bahan memasuki fasa mensuperkonduksi. Anomali modulus ricih dan atenuasi ultrasonik ini dijelaskan melalui peralihan fasa tertib kedua dan tertiban oksigen jarak dekat dalam satah Cu-O unit sel bahan superkonduktor ini

Preliminary Studies of Porous GaNbased Dye-Sensitized Solar Cells

This work presents the preliminary studies of porous gallium nitride (GaN) based dye-sensitized solar cells (DSSC). Porous GaN was fabricated using photo-assisted electrochemical etching (PEC), then characterized in terms of its morphological, structural, optical and vibrational aspects. Next, the sample underwent sensitization through immersing in N719 ruthenium based dye for one day. For the DSSC assembly, the dyed porous GaN would serve as anode while platinum (Pt) coated fluorinedoped tin oxide (FTO) glass being the cathode. A thin glass spacer separates the anode/cathode, while triiodide/iodide redox electrolyte would fill the gap between them. Current density-voltage (J-V) curves was obtained under light illumination and used to determine the essential electrical parameters of the DSSC. The open circuit potential <Voc). short-circuit current density (Jsc). and efficiency (TJ) for the aforementioned were 638.8 mV, 0.81 mA/cm2 , and 0.2% respectively. Aside from that, similar works have been repeated here for as-grown GaN, however, the resultant efficiency was ten times lower than that of porous GaN

Multiwavelength Studies of Young OB Associations

We discuss how contemporary multiwavelength observations of young OB-dominated clusters address long-standing astrophysical questions: Do clusters form rapidly or slowly with an age spread? When do clusters expand and disperse to constitute the field star population? Do rich clusters form by amalgamation of smaller subclusters? What is the pattern and duration of cluster formation in massive star forming regions (MSFRs)? Past observational difficulties in obtaining good stellar censuses of MSFRs have been alleviated in recent studies that combine X-ray and infrared surveys to obtain rich, though still incomplete, censuses of young stars in MSFRs. We describe here one of these efforts, the MYStIX project, that produced a catalog of 31,784 probable members of 20 MSFRs. We find that age spread within clusters are real in the sense that the stars in the core formed after the cluster halo. Cluster expansion is seen in the ensemble of (sub)clusters, and older dispersing populations are found across MSFRs. Direct evidence for subcluster merging is still unconvincing. Long-lived, asynchronous star formation is pervasive across MSFRs.Comment: 22 pages, 9 figures. To appear in "The Origin of Stellar Clusters", edited by Steven Stahler, Springer, 2017, in pres

The energy spectrum of all-particle cosmic rays around the knee region observed with the Tibet-III air-shower array

We have already reported the first result on the all-particle spectrum around the knee region based on data from 2000 November to 2001 October observed by the Tibet-III air-shower array. In this paper, we present an updated result using data set collected in the period from 2000 November through 2004 October in a wide range over 3 decades between $10^{14}$ eV and $10^{17}$ eV, in which the position of the knee is clearly seen at around 4 PeV. The spectral index is -2.68 $\pm$ 0.02(stat.) below 1PeV, while it is -3.12 $\pm$ 0.01(stat.) above 4 PeV in the case of QGSJET+HD model, and various systematic errors are under study now.Comment: 12 pages, 7 figures, accepted by Advances in space researc

Moon Shadow by Cosmic Rays under the Influence of Geomagnetic Field and Search for Antiprotons at Multi-TeV Energies

We have observed the shadowing of galactic cosmic ray flux in the direction of the moon, the so-called moon shadow, using the Tibet-III air shower array operating at Yangbajing (4300 m a.s.l.) in Tibet since 1999. Almost all cosmic rays are positively charged; for that reason, they are bent by the geomagnetic field, thereby shifting the moon shadow westward. The cosmic rays will also produce an additional shadow in the eastward direction of the moon if cosmic rays contain negatively charged particles, such as antiprotons, with some fraction. We selected 1.5 x10^{10} air shower events with energy beyond about 3 TeV from the dataset observed by the Tibet-III air shower array and detected the moon shadow at $\sim 40 \sigma$ level. The center of the moon was detected in the direction away from the apparent center of the moon by 0.23$^\circ$ to the west. Based on these data and a full Monte Carlo simulation, we searched for the existence of the shadow produced by antiprotons at the multi-TeV energy region. No evidence of the existence of antiprotons was found in this energy region. We obtained the 90% confidence level upper limit of the flux ratio of antiprotons to protons as 7% at multi-TeV energies.Comment: 13pages,4figures; Accepted for publication in Astroparticle Physic

d-alpha Correlation functions and collective motion in Xe+Au collisions at E/A=50 MeV

The interplay of the effects of geometry and collective motion on d-$\alpha$ correlation functions is investigated for central Xe+Au collisions at E/A=50 MeV. The data cannot be explained without collective motion, which could be partly along the beam axis. A semi-quantitative description of the data can be obtained using a Monte-Carlo model, where thermal emission is superimposed on collective motion. Both the emission volume and the competition between the thermal and collective motion influence significantly the shape of the correlation function, motivating new strategies for extending intensity interferometry studies to massive particles.Comment: Accepted for publication on Physics Letters