Particle Swarm Optimisation for Protein Motif Discovery

In this paper, a modified particle swarm optimisation algorithm is proposed for protein sequence motif discovery. Protein sequences are represented as a chain of symbols and a protein sequence motif is a short sequence that exists in most of the protein sequence families. Protein sequence symbols are converted into numbers using a one to one amino acid translation table. The simulation uses EGF protein and C2H2 Zinc Finger protein families obtained from the PROSITE database. Simulation results show that the modified particle swarm optimisation algorithm is effective in obtaining global optimum sequence patterns, achieving 96.9 and 99.5 classification accuracy respectively in EGF and C2H2 Zinc Finger protein families. A better true positive hit result is achieved when compared to the motifs published in PROSITE database.     

Inflammation,high ferritin,and erythropoietin resistance in indigenous maintenance hemodialysis patients from the Top End of Northern Australia

Use of erythropoiesis‐stimulating agents (ESAs) has improved the management of anemia in patients on maintenance hemodialysis (MHD). Iron deficiency and inflammation cause ESAs resistance and are both common among indigenous people of Northern Australia. As part of quality assurance in our Renal Anaemia Management program, we observed that there was use of higher doses of ESAs and adjuvant iron therapy in our MHD patients. This study aimed to explore the relationship among iron studies, inflammation, ESA responsiveness, and ESAs and iron requirements in indigenous patients on MHD from the Top End of Northern Australia. We performed a retrospective cohort analysis of anemia management in a cohort of our patients on MHD. We extracted data for 178 indigenous and 19 non‐indigenous patients from 1 March 2009 to 28 February 2010 from the Renal Anaemia Management database, which collects data prospectively in MHD patients. Ninety‐nine percent of the whole sample had a ferritin level above the international guidelines threshold of >500 µg/L. Indigenous patients had higher ferritin (1534 ± 245.5 µg/L vs. 1013 ± 323.3 µg/L, P = 0.002). C‐reactive protein (CRP) was high in 56.9% of the total cohort. One hundred percent of those with normal CRP had high ferritin (>500 µg/L). C‐reactive protein was higher in indigenous than in non‐indigenous patients. Erythropoiesis‐stimulating agents hyporesponsiveness was higher in indigenous patients (P < 0.0001). There was no significant difference in ESAs hyporesponsiveness among different levels of CRP (P = 0.116), ferritin (P = 0.408), and transferrin saturation (P = 0.503). Indigenous patients required higher total iron dose (2820.30 [2000–4350] vs. 2336.12 [1912–2900], P = 0.02). There was no significant relationship between the high ferritin and CRP. In indigenous dialysis patients, iron therapy and ESAs use are higher. The high iron use is due to a lack of published evidence to guide the administration of iron in patients with high ferritin. The high ferritin and ESAs resistance could not be fully explained by inflammation and need further evaluation. Further studies are required to determine the safe use of iron and management of ESAs resistance in our hemodialysis population.     

Characterization of solution processed,p-doped films using hole-only devices and organic field-effect transistors

We report a solution processed, p-doped film consisting of the organic materials 4,4′,4″-tris(3-methylphenylphenylamino)triphenylamine (MTDATA) as the electron donor and 2-(3-(adamantan-1-yl)propyl)-3,5,6-trifluorotetracyanoquinodimethane (F3TCNQ-Adl) as the electron acceptor. UV–vis–NIR absorption spectra identified the presence of a charge transfer complex between the donor and acceptor in the doped films. Field-effect transistors were used to characterize charge transport properties of the films, yielding mobility values. Upon doping, mobility increased and then slightly decreased while carrier concentration increased by two orders of magnitude, which in tandem leads to conductivity increasing from 4 × 10^?10 S/cm when undoped to 2 × 10^?7 S/cm at 30 mol% F3TCNQ-Adl. The hole density was calculated based on mobility values extracted from OFET data and conductivity values extracted from bulk I–V data for the MTDATA: x mol% F3TCNQ-Sdl films. These films were then shown to function as the hole injection/hole transport layer in a phosphorescent blue OLED.     

Improved Efficiency in Blue Phosphorescent Organic Light‐Emitting Devices Using Host Materials of Lower Triplet Energy than the Phosphorescent Blue Emitter

Data from a series of phosphorescent blue organic light‐emitting devices with emissive layers consisting of either 4,4′‐bis(N‐carbazolyl)‐2,2′‐biphenyl (CBP):6% bis[(4,6‐difluorophenyl)pyridinato‐N,C²](picolinato)iridium(III) (FIrpic) or bis(9‐carbazolyl)benzene (mCP):6% FIrpic show that the triplet energy of the hole and electron transport layers can have a larger influence on the external quantum efficiency of an operating device than the triplet energy of the host material. A maximum external quantum efficiency of 14% was obtained for CBP:6% FIrpic devices which is nearly double all other published CBP:6% FIrpic results. A new host material, 4‐(diphenylphosphoryl)‐N,N‐di‐p‐tolylaniline (DHM‐A2), which has a triplet energy lower than that of FIrpic is also reported. Devices fabricated using DHM‐A2 show improved performance (lower drive voltage and higher external quantum efficiency) over devices using 4‐(diphenylphosphoryl)‐N,N‐diphenylaniline (HM‐A1), a high performance ambipolar DHM‐A2 analogue with a triplet energy greater than FIrpic. Nearly 18% external quantum efficiency was obtained for the DHM‐A2:5% FIrpic devices. The results suggest modified design rules for the development of high performance host materials: more focus can be placed on molecular structures that provide good charge transport (ambipolarity for charge balance) and good molecular stability (for long lifetimes) rather than first focusing on the triplet energy of the host material.     

Hole‐rich host materials for blue‐phosphorescent OLEDs

Abstract— Stable and efficient organic light‐emitting devices (OLEDs) are an integral part of the future of lighting and displays. The hole accumulation at the hole‐transport/emissive‐layer interface in such devices is considered to be a major pathway for degradation and efficiency loss. Here, the design and synthesis of two charge‐transporting host materials, based on the phosphine oxide (PO) moiety, engineered to improve hole transport of the emissive layer, will be reported. The compounds are an extension of a molecular design strategy which incorporates a hole‐transporting moiety and an electron‐transporting moiety. These materials were designed with two hole‐transport moieties (HTms) to further improve hole transport, compared to the first‐generation host materials that were designed with one hole‐transport functional group. The triplet exciton energy was maintained at a level greater than that of FIrpic (2.7 eV) to prevent exciton quenching. The EHOMO and ELUMO of the two classes of molecules (i.e., 1 HTm vs. 2 HTms) were similar; however, their device performance varied greatly. Emission zone experiments were conducted to further characterize the difference in charge transport between the molecules.     

An improved multi-objective identification of Johnson–Cook material parameters

A weighted multi-objective identification strategy is presented for estimating Johnson–Cook material parameters often used in general purpose finite element models. The method is shown through illustrative examples for two different materials (Nitronic 33 super alloy and Ti–6Al–4V) using sets of data from quasi-static and split Hopkinson pressure bar (SHPB) compression experiments with varying temperature and strain rates. Results indicate an improved Johnson–Cook model predictability as compared to using conventional ad hoc methods. A sensitivity analysis is performed to reveal the variation of a normalized response rate with respect to the parameters. It is shown that the overall effect of some parameters in the model changes with the range of strain/rate/temperature employed in experiments. An interaction analysis is discussed and signifies the likelihood of high parameter interactions in the Johnson–Cook model owing to its multiplicative form. Using the proposed framework, it is possible to (a) reduce the number of experiments necessary for the identification of model parameters, particularly with respect to the strain rate hardening and thermal softening parameters, (b) consider all possible interactions among material parameters simultaneously, (c) account for variability in the regression degree-of-freedom in different tests by means of a proposed weighting scheme, and (d) arrive at a more generalized set of parameters. The performance of the multi-objective method is also checked with a modified constitutive relation where the number of parameters is increased.     

Hermetic storage of pearl millet, Pennisetum americanum (L.) Leeke; laboratory studies

The effect of airtight storage of pearl millet, Pennisetum americanum (L.) Leeke, on intergranular atmosphere, insects, mold infection, grain viability and moisture content (m.c.) was investigated in the laboratory. Six hermetically sealed 19-1 cans were used to store millet of three moisture contents (9.9, 12.8 and 15.6%) for 76 days at 27 ± 1°C. One can of grain of each m.c. was infested with 150 adult Sitophilus oryzae L./kg; the others remained uninfested. Carbon dioxide concentrations increased and oxygen concentrations decreased in all cans infested with insects, and in uninfested grain of 15.6% m.c. The changes in atmospheric concentrations were slower in the uninfested grain than in the infested 15.6% m.c. grain. No live insects were found in any treatment, percentages of mold-infested kernels were not significantly different among treatments, and m.c. did not change due to treatment or time. Kernel viability decreased significantly only in the 15.6% m.c. gram. All grain appeared normal; but the 15.6% m.c. grain had a slightly sour odor.