Molecular Descriptor Subset Selection in Theoretical Peptide Quantitative Structure–Retention Relationship Model Development Using Nature-Inspired Optimization Algorithms

Ž,uvela, Petar,Liu, J. Jay,Macur, Katarzyna,Bą,czek, Tomasz American Chemical Society 2015 ANALYTICAL CHEMISTRY - Vol.87 No.19

<P>In this work, performance of five nature-inspired optimization algorithms, genetic algorithm (GA), particle swarm optimization (PSO), artificial bee colony (ABC), firefly algorithm (FA), and flower pollination algorithm (EPA), was compared in molecular descriptor selection for development of quantitative structure retention relationship (QSRR) models for 83 peptides that originate from eight model proteins. The matrix with 423 descriptors was used as input, and QSRR models based on selected descriptors were built using partial least squares (PLS), whereas root mean square error of prediction (RMSEP) was used as a fitness function for their selection. Three performance criteria, prediction accuracy, computational cost, and the number of selected descriptors, were used to evaluate the developed QSRR models. The results show that all five variable selection methods outperform interval PLS (iPLS), sparse PLS (sPLS), and the full PLS model, whereas GA is superior because of its lowest computational cost and higher accuracy (RMSEP of 5.534%) with a smaller number of variables (nine descriptors). The GA-QSRR model was validated initially through Y-randomization. In addition, it was successfully validated with an external testing set out of 102 peptides originating from Bacillus subtilis proteomes (RMSEP of 22.030%). Its applicability domain was defined, from which it was evident that the developed GA-QSRR exhibited strong robustness. All the sources of the model's error were identified, thus allowing for further application of the developed methodology in proteomics.</P>

Microstructural Stability and Creep Performance of a Novel Low-Cost Single Crystal Superalloy

Z. H. Tan,X. G. Wang,Y. L. Du,Y. M. Li,Y. H. Yang,J. L. Liu,J. D. Liu,J. G. Li,Y. Z. Zhou,X. F. Sun 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.7

The increasing pursuit of advanced aero-engines with lower ratio between the cost and performance has greatly promotedthe demanding of single crystal superalloys characterized by low cost and outstanding temperature capability. In this study,a novel low-cost single crystal superalloy was designed and the creep tests as well as micro-characterization were carried outon the experimental alloy. The results illustrated that the novel single crystal alloy exhibited an ideal microstructural stabilitywithout precipitating TCP phases, after long-term thermal exposure at the ultimate service temperature of third generationsingle crystal superalloys. Moreover, the experimental alloy with only 3 wt% Re addition demonstrated remarkable creepresistance and maintained a very low minimum creep rate at 1100 °C/137 MPa and 1120 °C/137 MPa, while the accumulationand coalescence of micro-pores had eventually led to the alloy fracture. Apart from that, the compact interfacial dislocationnetworks the 2nd γ′ phase were observed after high-temperature creep rupture, and the typical a < 010 > superdislocationswith relatively poor mobility was found at 1120 °C. At 760 °C/800 MPa, both the minimum creep velocity and entire creepstain was increased evidently, however, the ultimate creep rupture life of the alloy had still reached 200 h. The correspondingdeformation mechanism was identified as the combination of superdislocation pairs shearing and a/3 < 121 > partial dislocationcutting the γ′ phase with a SISF being generated. In general, the novel single crystal alloy characterized by remarkablemechanical properties and cost reduction possesses a great potential for future application in the advanced aircraft engines.

A nonNMDA antagonist, GYKI 52466 improves microscopic O₂balance in the cortex during focal cerebral ischemia

Chi, Oak Z.,Chang, Qiang,Wang, Guolin,Liu, Xia,Harvey R. Weiss 경희대학교 동서의학연구소 1999 INTERNATIONAL SYMPOSIUM ON EAST-WEST MEDICINE Vol.1999 No.1

Oak Z.Chi,Qiang Chang, Guolin Wang*, Xia Liu, Harvey R. Weiss□.Deprtments of Anesthesai, Departments of Physiology and Biophysics, University of Medicne and Dentisrty of New Jersey,Robert Wood Johnson Medical School, New Brunswick, New Jersey, USA and*Department of Anesthesia, Medical University, Tianjing, People's Republic of China. A non-NMDA antagonist, GYKI 52466 improves microscopic O² balance in the cortex during focal cerebral ischemia. Proceedings of International Symposium on East-West Medicine, Seoul. 172-182, 1999.-This study was performed to test whether GYKI 52466, a non-NMDA receptor antagonist, would improve microregional oxygen supply and consumption balance in the focal cerebral ischemic area. Rats were anesthetized with 1.4% isoflurance. For the GYKI Group (n=8), 19 min before middle cerebral artery (MCA) occlusion, a bolus of 5mg/kg of GYKI 52466 iv was administered and was followed by an infusion of 5mg/kg/hr. For the control Group(n=8), the same volume of the vehicle was administered. One hour after MCA occlusion, regional cerebral blood flow (rCBF) was measured using the 14C-iodoantipyrine autoradiographic technique. Microscopic arterial and venous oxygen saturations were determined using microspectrophotometry. In the cortex contralateral to MCA occlusion, the average rCBF and the average O² consumption were lower in the GYKI Group than in the Control Group (rCBF:GYKI 65.5±24.1, Control 97.7 33.4ml/100g/min;O² consumption: GYKI3.9±1.2, Control 6.2±2.5ml O²/100g/min) without a significant difference in the number of veins with SvO²<50%. In the ischemic cortex, the number of veins with SvO²<50% was significantly smaller in the GYKI Group (21 veins out of 63)than in the Control Group(45 out of 59)without a significant difference in the average rCBF(GYKI44.9±17.7, Control 29.7±10.4) or regional O² consumption between these two groups (GYKI 3.3±1.4,Control 27.7±1.2). Our data demonstrated that GYKI 52466 was effective in improving microscopic O² balance in the focal ischemic cortical area of the brain and it decreased O² consumption in the non-ischemic cortex. [Neurological Research 1999;21:299-304]

Genetic Variability of mtDNA Sequences in Chinese Native Chicken Breeds

Liu, Z.G.,Lei, C.Z.,Luo, J.,Ding, C.,Chen, G.H.,Chang, H.,Wang, K.H.,Liu, X.X.,Zhang, X.Y.,Xiao, X.J.,Wu, S.L. Asian Australasian Association of Animal Productio 2004 Animal Bioscience Vol.17 No.7

The variability of mtDNA hypervariable segment I (HVS I) sequences was investigated in a total of 48 birds belonging to 12 Chinese native chicken breeds. Sixteen haplotypes were identified from 35 polymorphic nucleotide sites which accounted for 6.4% of a sequenced 544 bp fragment. Diversity analysis of the haplotypes showed that Tibetan, Langshan and Henan cockfight chicken had only one haplotype, while ancient haplotypes existed in Taihe silky and Chahua chicken. Phylogenetic analysis of the haplotypes suggested that Chinese native chicken breeds shared 5 maternal lineages and some breeds would share the same maternal lineage, regardless of their external features and ecological types. Both divergent and phylogenetic analysis of the haplotypes indicated the close genetic relationships between the Chinese native chicken breeds and G. g. gallus and G. g. spadiceus from different areas, which implied that G. g. gallus and G. g. spadiceus were the original ancestors of the Chinese native chicken breeds.

Epitaxial Growth and Optimization of ZnO Films by Pulsed Laser Deposition

Z. F. Liu,Yun-Sik Yu 한국물리학회 2004 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.44 No.52

ZnO lms have been grown on sapphire (0001) substrates by using the pulsed laser deposition technique with a KrF excimer laser ( = 248 nm) ablating the target. X-Ray diraction, photoluminescence, and spectroscopic ellipsometry were applied to characterize the structural and optical properties of the lms. High-quality epitaxial ZnO lms were obtained at the optimized conditions of 500 C and 200 mTorr. The X-Ray diraction /2 scan and the in-plane -scan revealed an epitaxial relationship between the ZnO lm and the sapphire substrate of (0001)ZnO // (0001)sapphire and [1010]ZnO==[1120]sapphire. The photoluminescence of ZnO lms was found to depend strongly on the growth temperature. Intensive ultraviolet emissions were observed from ZnO lms as the fabrication temperature was increased from 100 C to 500 C. The refractive indices and the extinction coecients were obtained by tting the spectroscopic ellipsometry data, and , using the Forouhi-Bloomer dispersion relation.

Positive Solutions and Mann Iterations of a Fourth Order Nonlinear Neutral Delay Differential Equation

Liu, Z.,Zhu, J.,Ume, J.S.,Kang, S.M. MANCORP PUBLISHING 2014 Abstract and applied analysis Vol.2014 No.10

Electrochemical characteristics of cathode materials NiS2 and Fe-doped NiS2 synthesized by mechanical alloying for lithium-ion batteries

Liu, X.J.,Xu, Z.Z.,Ahn, H.J.,Lyu, S.K.,Ahn, I.S. Elsevier 2012 Powder technology Vol.229 No.-

INFLUENCE OF RAIL PRESSURE ON A TWO-STAGE TURBOCHARGED HEAVY-DUTY DIESEL ENGINE UNDER TRANSIENT OPERATION

Z. C. LIU,K. B. YU,J. TIAN,Y. Q. HAN,S. L. QI,P. K. TENG 한국자동차공학회 2017 International journal of automotive technology Vol.18 No.1

The demand for continually improving the transient performance of diesel engines requires higher rail pressure and more efficient turbocharger. Before the test, a two-stage turbocharger with a turbine by-pass valve (TBV) had been matched reasonably with the base engine. In order to reduce smoke emission under the typical 5-second transient process of constant speed and increasing torque, the influence of rail pressure on combustion, emissions and performance characteristics was experimentally investigated. The results showed that the two-stage turbocharger was helpful in improving transient performance. Moreover, the full-stage rail pressure (FSRP) strategies (increasing rail pressure during the whole transient process) could reduce smoke emission when the TBV was closed. However, smoke deteriorated once TBV opening got larger. Then the sectional-stage rail pressure (SSRP) strategies (increasing rail pressure from a pre-set load to 100 % load) were presented under small TBV opening to improve in-cylinder thermal condition. Hence, the air-fuel mixing process was improved at medium and large loads. Then the maximum decline of smoke opacity peak was 56.3 %, which happened under 10 % TBV opening. In addition, fuel consumption of FSRP strategies got worse under larger TBV opening. However, this deterioration situation could be effectively restrained by the utilization of SSRP strategies.

Electrospun Sn-doped LiTi2(PO4)3/C nanofibers for ultra-fast charging and discharging

Liu, L.,Song, T.,Han, H.,Park, H.,Xiang, J.,Liu, Z.,Feng, Y.,Paik, U. Royal Society of Chemistry 2015 Journal of Materials Chemistry A Vol.3 No.19

<P>Sn-doped LiTi2(PO4)(3)/C composite nanofibers are synthesized by a facile electrospinning process. The unique one dimensional nanostructure combined with a uniform electrically conductive carbon matrix allows high-rate transportation of lithium ions and electrons. Besides, Sn-doping could further decrease the electrochemical resistance. Sn-doped LiTi2(PO4)(3)/C composite nanofibers exhibit excellent electrochemical performance, especially ultra-fast charging/discharge capability. At a charging rate of about 600 C (64 A g(-1), 6 s), 66.2% capacity (68.9 mA h g(-1)) could be obtained when matched with a Li metal counter electrode. They also exhibit excellent electrochemical properties as an anode material for aqueous rechargeable lithium batteries. Sn-doped LiTi2(PO4)(3)/C composite nanofibers are promising electrode materials for both nonaqueous and aqueous lithium ion batteries.</P>

Indoor positioning and life detection by using asynchronous multiple frequency shift keying radar

Liu, Z.,Kim, Y.,Bien, F. IET 2015 Electronics letters Vol.51 No.22

<P>Indoor positioning and life detection using radio frequency has been widely researched; however, to achieve both indoor positioning and life detection has been a very challenging task until now. By careful design of the waveform and a novel detection algorithm, asynchronous multiple frequency shift keying (A-MFSK) is proposed to solve this task for the first time, which can operate between an MFSK mode and a single tone continuous wave mode, providing a possibility of A-MFSK for this task. Detailed explanation about the detection algorithm is given. Simulations and measurements results of both modes demonstrate that A-MFSK has the capability of indoor positioning and life detection.</P>