Using random forest to classify T-cell epitopes based on amino acid properties and molecular features

T-lymphocyte (T-cell) is a very important component in human immune system. T-cell epitopes can be used for the accurately monitoring the immune responses which activation by major histocompatibility complex (MHC), and rationally designing vaccines. Therefore, accurate prediction of T-cell epitopes is crucial for vaccine development and clinical immunology. In current study, two types peptide features, i.e., amino acid properties and chemical molecular features were used for the T-cell epitopes peptide representation. Based on these features, random forest (RF) algorithm, a powerful machine learning algorithm, was used to classify T-cell epitopes and non-T-cell epitopes. The classification accuracy, sensitivity, specificity, Matthews correlation coefficient (MCC), and area under the curve (AUC) values for proposed method are 97.54%, 97.22%, 97.60%, 0.9193, and 0.9868, respectively. These results indicate that current method based on the combined features and RF is effective for T-cell epitopes prediction.     

Conversion of Thiols to Disulfides Using a Hexamethylenetetramine-Bromine Complex

Hexamethylenetetramine-bromine complex, a yellow-orange, very stable homogeneous solid, affects a mild and fairly general conversion of thiols to disulfides.     

Polystyrene‐supported Pd(II) complex‐catalysed carboacylation of 2‐arylpyridines with alcohols via C─H bond activation under solvent‐free conditions

Polystyrene‐supported N ,N ‐dimethylethylenediamine Pd(II) complex C was used as an efficient catalyst for the synthesis of aromatic ketones via ortho ‐acylation of sp² C─H bonds of 2‐arylpyridines with alcohols as effective coupling partners. The alcohols were oxidized with tert ‐butyl hydroperoxide to their corresponding aldehydes in situ and efficiently coupled with 2‐arylpyridines to form aryl ketones under solvent‐free conditions. Furthermore, catalyst C could be easily recovered by simple filtration and reused for five cycles without any significant decrease in its activity.     

Characterization of a Novel Dioxomolybdenum Complex by Cyclic Voltammetry

Metalloenzymes that carry a pterin-based molybdenum cofactor in their center catalyze numerous reactions in the human body and play a crucial role in its metabolism. Specifically, these enzymes promote redox reactions and oxygen transport in the body. Their absence may cause many problems leading to disability or even death in early childhood. Therefore, model compounds need to be synthesized and analyzed to investigate the reactivity, redox potential, and geometry of these cofactors. This study focused on electrode processes and determined the redox potentials of the new bis-(4-mercapto-5-(p-tolyl)-3H-1,2-dithiole-3-thione)-dioxomolybdenum complex by cyclic voltammetry. The 4-mercapto-5-(p-tolyl)-3H-1,2-dithiole-3-thione ligand underwent irreversible oxidation and reduction at thiol and thione functional groups. The new dioxomolybdenum complex showed a quasi-reversible two-stage electrode process.     

A Kinetic Method For The Determination Of A Nanogram Amount Of Mercury(ii) By Its Catalytic Effect On The Complex Formation Reaction Of Manganese(11) With α, β, γ δ-Tetraphenylporphinesulfonate

Abstract

Mercury(II) ion accelerates the complex formation reaction of manganese(II) with α, β, γ δ-tetraphenylporohinesulfonate (TPPS). Mercury(II) concentrations as low as 10^?8 mol dm^?3 can be determined from the decrease in absorbance at 413 nm (Λ_max of TPPS) at a fixed time after the initiation of the reaction of rnanganese(II) with TPPS. Sandell's sensitivity calculated from the calibration curve at 30 min after the start of the reaction is 3.8 × 10^?2 ng cm^?2. After the separation of metallic mercury by distillation at room temperature, the method is highly selective and is free from interference of most substances usually encountered.     

Syntheses,structures, and properties of Ni(II) complexes with 5,5′-bis(4-halogenphenyl)diazo-dipyrromethane

Ni(II) complexes with 5,5′-bis(4-halogenphenyl)diazo-dipyrromethane have been synthesized and characterized by X-ray crystallography. All the complexes have similar crystal structures in which Ni(II) is square-planar by coordinating to two pyrrole and two azo nitrogen atoms. The azo-pyrroles of the ligands can be converted to the hydrazone tautomer after complexing nickel. Moreover, the C–H?···?Ni interaction played an important role in directing self-assembly of the complexes. The UV-Vis spectra of the complexes showed great difference with the metal complexes of pyrrol-2-imine.     

Synthesis,structure, and luminescence of rhenium(I) complexes with substituted bipyridines

Two new rhenium(I) complexes chelated by a substituted 2,2′-bipyridine with general formula Re(CO)₃LCl, where L?=?6?-(2″-methoxyphenyl)-2,2′-bipyridine (L₁ ) and 6?-(4″-diphenylaminophenyl)-2,2′-bipyridine (L₂ ), are synthesized and characterized by IR, NMR, and elemental analysis. Structure of 1 was determined by single-crystal X-ray crystallography, revealing that rhenium is six-coordinate octahedral. The electrochemical, photophysical, and thermal properties of the two rhenium(I) complexes were investigated. Electroluminescent devices were fabricated by doping 1 in polymer blend host of poly(vinylcarbazole) and 2-tert-butylphenyl-5-biphenyl-1,3,4-oxadiazole using simple solution spin-coating technique. The device exhibits a maximum current efficiency of 2.97?cd?A^?1 and peak brightness in excess of 2390?cd?m^?2.     

Synthesis,characterization, and biological studies of lanthanide complexes with 2,6-pyridine dicarboxylic acid and α-picolinic acid

Four new solid ternary complexes of lanthanide with 2,6-pyridine dicarboxylic acid and α-picolinic acid [Ln(DPA)(L^α)(H₂O)] · 2H₂O (Ln = La³⁺, Ce³⁺, Eu³⁺, or Gd³⁺; DPA = 2,6-pyridine dicarboxylic acid; HL^α = α-picolinic acid) have been synthesized and characterized by elemental analysis, molar conductance, FT-IR, UV–Vis, and TG–DTA. The antibacterial activities indicate that all the complexes exhibit antibacterial ability against Escherichia coli and Staphylococcus aureus with broad antimicrobial spectra. The anticancer activity of the La complex against K562 tumor cell in vitro is measured using methyl thiazolyl tetrazolium (MTT) colorimetry and flow cytometry. The La complex can induce K562 tumor cell apoptosis, presenting the best apoptosis effect by acting on the S period after inducing K562 tumor cell for 72 h.     

Syntheses and Crystal Structures of Two One-dimensional Cobalt(Ⅱ) Compounds with the Flexible Dipyridyl Ligan

Two one-dimensional cobalt(Ⅱ) compounds {[Co(Hbpma)(H2O)4 ] 2 ·3SO 4 ·4.5H2O} n1 and {[Co(Hbpma)(NCS) 3 (H2O)]·2.85H2O}n2 (bpma = N,N -bis(3-pyridylmethyl)amine) have been synthesized and structurally characterized by single-crystal X-ray diffraction. Complex 1 crystallizes in triclinic, space group P1 with a = 15.8780(5), b = 16.2187(5), c = 16.4858(5) , α = 91.0420(10), β = 94.5190(10), γ = 101.4360(10)°, V = 4145.7(2) 3 , C 24 H 53 Co 2 N 6 O 24.50 S 3 , M r = 1031.76, Z = 4, D c = 1.653 g/cm 3 , μ(MoKα) = 1.046 mm -1 , F(000) = 2148, S = 1.017, the final R = 0.0269 and wR = 0.0644 for 13032 observed reflections (I > 2σ(I)). For complex 2, it belongs to triclinic, space group P1 with a = 9.3761(11), b = 10.5814(13), c = 11.2972(14) , α = 85.472(2), β = 88.058(2), γ = 76.203(2)°, V = 1085.0(2) 3 , C 15 H 21.70 CoN 6 O 3.85 S 3 , M r = 502.79, Z = 2, D c = 1.539 g/cm 3 , μ(MoKα) = 1.112 mm -1 , F(000) = 519, S = 1.070, the final R = 0.0358 and wR = 0.0899 for 3466 observed reflections (I > 2σ(I)). Two complexes 1 and 2 are both found to be one-dimensional coordination polymers bridged by the protonated bpma ligands, which are assembled into three-dimensional supramolecular structures through the hydrogen bonding interactions and π-π packing interactions.