Improvement of size-based particle separation throughput in slanted spiral microchannel by modifying outlet geometry

The inertial microfluidic technique, as a powerful new tool for accurate cell/particle separation based on the hydrodynamic phenomenon, has drawn considerable interest in recent years. Despite numerous microfluidic techniques of particle separation, there are few articles in the literature on separation techniques addressing external outlet geometry to increase the throughput efficiency and purity. In this work, we report on a spiral inertial microfluidic device with high efficiency (>98%). Herein, we demonstrate how changing the outlet geometry can improve the particle separation throughput. We present a complete separation of 4 and 6 μm from 10 μm particles potentially applicable to separate microalgae (Tetraselmis suecica from Phaeodactylum tricornutum). Two spiral microchannels with the same cross section dimension but different outlet geometry were considered and tested to investigate the particle focusing behavior and separation efficiency. As compared with particle focusing observed in channels with a simple outlet, the particle focusing in a modified outlet geometry appears in a more successful focusing manner with complete separation. This simple approach of particle separation makes it attractive for lab-on-a-chip devices for continuous extraction and filtration of a wide range of cell/particle sizes.     

Synthesis of chalcone precursor via Cu(I) catalyzed 1,3-dipolar reaction of functionalized acetylene and pyrazole embedded dipole

A new class of functionalized pyrazole bearing 1,2,3-triazole has been synthesized via Cu(I) mediated 1,3-dipolar cycloaddition of pyrazole bearing azide with various aromatic/heteroaromatic bearing terminal dipolarophile (acetylene). Structures of the newly synthesized compounds were explicated by analytical and spectral analysis. All the newly synthesized compounds were evaluated for their in-vitro antibacterial and antioxidant activity. Among the synthesized compound, triazole bearing 2,5-thiazolidinone 5b (20 ± 0.70) and triazole bearing thiocarboamide 5e (19 ± 0.70) showed good antibacterial activity against Escherichia coli and Pseudomonas aeruginosa, respectively. The newly synthesized compounds further tested for their ability to bleach DPPH radical using DPPH scavenging assay. Among the synthesized compounds 1,2,3-triazole bearing 2,5-thiazolidinone 5b (58.81%) exhibited good DPPH scavenging activity compared to the rest of the compounds. From the X-ray and Hirshfield analysis, it was observed that compound 3 , crystallizes in a triclinic crystal system with a P-1 space group. The major intercontacts present in these molecules are H…H (39.7%), C…H (23.9%), N…H (20.3%).     

Overexpression,Purification and Validation of Antigenic Salmonella enterica Serovar Typhi Proteins Identified from LC-MS/MS

In our earlier study, an immunoblot analysis using sera from febrile patients revealed that a 50-kDa band from an outer membrane protein fraction of Salmonella enterica serovar Typhi was specifically recognized only by typhoid sera and not sera from other febrile illnesses. Here, we investigated the identities of the proteins contained in the immunogenic 50-kDa band to pinpoint antigens responsible for its immunogenicity. We first used LC-MS/MS for protein identification, then used the online tool ANTIGENpro for antigenicity prediction and produced recombinant proteins of the lead antigens for validation in an enzyme-linked immunosorbent assay (ELISA). We found that proteins TolC, GlpK and SucB were specific to typhoid sera but react to antibodies differently under native and denatured conditions. This difference suggests the presence of linear and conformational epitopes on these proteins.     

Synthesis of KIT-5 decorated by Bi2S3-Fe3O4 photocatalyst for degradation of parathion pesticide in aqueous media: Offering a degradation model and optimization using response surface methodology (RSM)

In this research, a novel KIT-5/Bi₂S₃-Fe₃O₄ nanocomposite was prepared. The structure and morphology properties of the nanocomposite were well characterized by XRD, FESEM-EDS-mapping, TEM, and N₂ adsorption–desorption. Benefiting from the visible light, the as-prepared KIT-5/Bi₂S₃-Fe₃O₄ nanocomposite exhibit significantly improved photocatalytic performance for the degradation of parathion. The optimum photocatalytic efficiency of KIT-5/Bi₂S₃-Fe₃O₄ nanocomposite was investigated with the central composite design using Design Expert software. The four critical variables affecting parathion degradation such as the concentration of parathion, pH, irradiation time, and amount of KIT-5/Bi₂S₃-Fe₃O₄ nanocatalyst. A polynomial function corresponding to degradation percent was obtained for the experimental data. The results showed that this catalyst has a good performance for the degradation of parathion.     

Synthesis,Characterization, Theoretical Studies,and Antimicrobial/Antitumor Potencies of Salen and Salen/Imidazole Complexes of Co (II), Ni (II), Cu (II), Cd (II), Al (III) and La (III)

Although salens and imidazoles are well-studied motifs among bioactive and therapeutic agents, their properties when combined in transition metal complexes are not well developed. To explore the structure/reactivity of this class of compounds, a salen-based ligand, namely (2,2′-{1,2-ethanediylbis[nitrilo(E)methylylidene]}diphenol, S), and its binary (MS) and ternary (MSI) complexes (I = imidazole; M = Co (II), Ni (II), Cu (II), Cd (II), Al (III), and La (III)) have been synthesized and fully characterized by standard physicochemical and theoretical methods. Evidence from structural analysis tools along with DFT modeling revealed an unusual monobasic tridentate salen binding mode, involving the phenolic oxygen, the nitrogen of the azomethine group, and NH group formed via phenol-to-cyclohexadienone tautomerization, giving rise to a general molecular formula of MSI complexes as [M(S)(I)₂(Cl)] for M (II) = Co, Ni, Cu and Cd or [M(S)(I)(Cl)₂] for M (III) = Al and La, respectively. The antimicrobial activities of S, MS, and MSI were screened against several bacterial and fungal strains. Of all tested complexes, CdS and CuSI were the most effective antimicrobials, giving larger inhibition zones than the reference antibiotics. The antimicrobial efficacy for the MS complexes follows the order: CdS > gentamicin > CuS > NiS > CoS > LaS > AlS > S, whereas MSI complex, potencies are ordered as CuSI > gentamicin > CdSI >NiSI > CoSI > LaSI > AlSI > S. In vitro cytotoxicity screening of MSI complexes disclosed that both CuSI and CdSI exhibited higher activity against human liver (Hep-G2) and breast (MDA-MB231) carcinoma cell lines than the reference (cisplatin) drug. The satisfactory bioactivities observed for several of these compounds supports the underlying design idea for combining important bioactive motifs for possible therapeutic benefit.     

Bioreducible cationic random copolymer for gene delivery

Cationic polymers have been widely investigated for gene delivery, although their low transfection efficiency and high cytotoxicity limit their application. We synthesized a bioreducible cationic random copolymer, poly(cystamine bisacylamide‐aminoethyl piperazine)‐co‐poly(cystamine bisacylamide‐histamine) (denoted as CBA‐AEP‐His) from N,N′‐cystamine bis acrylamide (CBA) with aminoethyl piperazine (AEP) and histamine (His). CBA‐AEP‐His copolymer possesses disulfide linkages that endow it with redox‐responsivity to the intracellular environment. This polymer efficiently condenses pZNF580 into complexes with the size of 160 ± 4 nm to 280 ± 5 nm and positive zeta potential of 20 ± 0.3 mV to 30 ± 0.4 mV. The gel‐retardation assay shows that CBA‐AEP‐His can retard pZNF580 even at a low mass ratio of 1/1. The gene complexes were triggered to release pZNF580 when exposed to the reducing environment of dithiothreitol (DTT). CBA‐AEP‐His random copolymer presented higher buffer capacity owing to its His moieties, which protected pZNF580 from DNase degradation. The gene transfection results reveal that CBA‐AEP‐His can efficiently deliver pZNF580 and transfect EA. Hy926 cells. The MTT assay indicates that CBA‐AEP‐His and its complexes exhibit lower cytotoxicity than PEI25KDa. These results illustrate that CBA‐AEP‐His had promising properties for gene delivery, which may provide a suitable platform for the development of a non‐viral gene carrier.     

Asymptotic Behavior of Eigenvalues of Variance-Covariance Matrix of a High-Dimensional Heavy-Tailed Lévy Process

Methodology and Computing in Applied Probability - In this paper, we study the limiting behavior of eigenvalues of the variance-covariance matrix of a random sample from a multivariate subordinator...     

Study of Optical Soliton Perturbation with Quadratic-Cubic Nonlinearity by Lie Symmetry and Group Invariance

Here, optical soliton perturbation with quadratic-cubic nonlinearity has been discussed by applying Lie symmetry and group invariants. The perturbation terms include third and fourth order dispersions in addition to self-steepening, intermodal dispersion and higher order dispersion effects. Using presented algorithms, Bright and dark soliton solutions are revealed.     

Synthesis and Serviceability of New Symmetric Bis-pyrazolone Metal Complex Acid Dyes

Russian Journal of General Chemistry - Synthesis of new symmetric bis-pyrazolone acid dye and its 3d transition metal complexes is studied. Bis-pyrazolone is synthesized from...     

Photocatalytic degradation of benzothiophene by a novel photocatalyst,removal of decomposition fragments by MCM-41 sorbent

Research on Chemical Intermediates - In this study, a catalyst was synthesized by introduction of ZnO onto the surface of FSM-16 catalyst support (ZnO/FSM-16). Impregnation of catalyst support by...