Kaempferia parviflora Extract Alleviated Rat Arthritis,Exerted Chondroprotective Properties In Vitro,and Reduced Expression of Genes Associated with Inflammatory Arthritis

Kaempferia parviflora Wall. ex Baker (KP) has been reported to attenuate cartilage destruction in rat model of osteoarthritis. Previously, we demonstrated that KP rhizome extract and its active components effectively suppressed mechanisms associated with RA in SW982 cells. Here, we further evaluated the anti-arthritis potential of KP extract by using multi-level models, including a complete Freund’s adjuvant-induced arthritis and a cartilage explant culture model, and to investigate the effects of KP extract and its major components on related gene expressions and underlying mechanisms within cells. In arthritis rats, the KP extract reduced arthritis indexes, with no significant changes in biological parameters. In the cartilage explant model, the KP extract exerted chondroprotective potential by suppressing sulfated glycosaminoglycans release while preserving high accumulation of proteoglycans. In human chondrocyte cell line, a mixture of the major components equal to their amounts in KP extract showed strong suppression the expression of genes-associated inflammatory joint disease similar to that of the extract. Additionally, KP extract significantly suppressed NF-κB and MAPK signaling pathways. The suppressing expression of necroptosis genes and promoted anti-apoptosis were also found. Collectively, these results provided supportive evidence of the anti-arthritis properties of KP extract, which are associated with its three major components.     

A correlation to predict heat-transfer rates of a miniature loop thermosyphon

This research is aimed at enhancing the traditional thermosyphon by preventing flooding and drying out from the opposite directions of the vapor and liquid. A miniature loop thermosyphon (MLT) consists of three sections, namely, the evaporator, the adiabatic and condenser sections. The return liquid channel is connected between the condenser and the evaporator to convey the condensed liquid. The MLT has a ratio of internal diameter of the condenser section to internal diameter of the evaporator section (Idc/Ide), which is 1.4. The MLT was made from a copper tube of 15-mm, 19-mm, and 22-mm ID. The filling ratios of the working fluid were 30%, 50%, and 80% of evaporator volume with an inclination angle of 90°. The operating temperatures were 70°C, 80°C, and 90°C with ratios of Ide/Idr of 3, 3.8, and 4.4. The research reports the effect of dimensionless parameters on heat-transfer characteristics, namely, Bo, Pr, We, Fr, Ja, Ku, ρ _υ /ρ _l, and Ide/Idr. It was found that the Bo, Pr, Ja, Ku, ρ _υ /ρ _l, and Ide/Idr have no effect on heattransfer characteristics. The We, Fr, and Ku have an effect on the heat-transfer characteristics as with increasing We, Fr, and Ku, the heat-transfer characteristics decrease. The research established another modified Kutateladze number, which can also be used to predict MLT in the vertical position.     

Simplified and Rapid Determination of Primaquine and 5,6-Orthoquinone Primaquine by UHPLC-MS/MS: Its Application to a Pharmacokinetic Study

The method for the determination of primaquine (PQ) and 5,6-orthoquinone primaquine (5,6-PQ), the representative marker for PQ active metabolites, via CYP2D6 in human plasma and urine has been validated. All samples were extracted using acetonitrile for protein precipitation and analyzed using the ultra-high-performance liquid chromatography–tandem mass spectrometry (UHPLC-MS/MS) system. Chromatography separation was carried out using a Hypersil GOLD^TM aQ C₁₈ column (100 × 2.1 mm, particle size 1.9 μm) with a C₁₈ guard column (4 × 3 mm) flowed with an isocratic mode of methanol, water, and acetonitrile in an optimal ratio at 0.4 mL/min. The retention times of 5,6-PQ and PQ in plasma and urine were 0.8 and 1.6 min, respectively. The method was validated according to the guideline. The linearity of the analytes was in the range of 25–1500 ng/mL. The matrix effect of PQ and 5,6-PQ ranged from 100% to 116% and from 87% to 104% for plasma, and from 87% to 89% and from 86% to 87% for urine, respectively. The recovery of PQ and 5,6-PQ ranged from 78% to 95% and form 80% to 98% for plasma, and from 102% to from 112% to 97% to 109% for urine, respectively. The accuracy and precision of PQ and 5,6-PQ in plasma and urine were within the acceptance criteria. The samples should be kept in the freezer (−80 °C) and analyzed within 7 days due to the metabolite stability. This validated UHPLC-MS/MS method was beneficial for a pharmacokinetic study in subjects receiving PQ.     

Synthesis and characterizations of bis(phenoxy)‐amine tin(II) complexes for ring‐opening polymerization of lactide

A series of tin(II) complexes supported by N₂O₂ bis(phenol)‐amine ligands were prepared from the reactions of the corresponding ligands with Sn[N(SiMe₃)₂]₂ in benzene at room temperature. The ligands were designed to have different substituted group at the ortho‐position on the aryl rings (R = ^tBu, CH₃) and N‐containing side arm (E = ? CH₂NEt₂ and pyridine) giving a variation of tin(II) complexes (R = ^tBu, E = CH₂NEt₂, 2a ; R = ^tBu, E = py, 2b ; R = CH₃, E = CH₂NEt₂, 2c ; R = CH₃, E = py, 2d ). All complexes were characterized by NMR spectroscopy and single‐crystal X‐ray analysis. The single‐crystal X‐ray crystallography revealed that all complexes have a monomeric four‐coordinate tin center with a distorted seesaw structure. All complexes are active for solvent‐free polymerization of l ‐lactide at 120 °C giving poly(l ‐lactide) with narrow to moderate dispersity (Ð = 1.12–1.56). In the presence of benzyl alcohol during the polymerization, the resulting polymer was found to be linear having benzyl alcohol as the end group while, in the absence of benzyl alcohol, the polymer was cyclic. The large ^tBu group at the ortho‐position was found to decrease polymerization activity while the more basic ? CH₂NEt₂ group was found to increase the polymerization activity. The polymerization of rac‐lactide under a similar condition gave PLA having a slight heterotactic bias for all catalysts. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 2104–2112     

Acrylamide–itaconic acid superabsorbent polymers and superabsorbent polymer/mica nanocomposites

Superabsorbent polymer acrylamide (AM)/itaconic acid (IA) and its nanocomposite were synthesized by redox polymerization in an aqueous solution of both monomers with mica used as an inorganic additive. The influences of IA concentration, mica content, and crosslinker concentration on the water absorption and physical properties of the superabsorbent polymer and its nanocomposite were examined. Water absorbency in artificial urine by the synthesized copolymers, and the gel strength of the superabsorbent copolymers and their nanocomposites, were tested with loads of 0.28 or 0.70 psi. Transmission electron micrographs and X‐ray diffraction confirmed that the polymer chains were successfully intercalated into the silicate layers in the mica. The water absorbency and the artificial urine absorbency of the composite with an AM‐to‐IA mole ratio of 95:5, 0.2% mol N‐MBA, and 5% w/w mica were 748 ± 5 and 76 ± 2 g g^?1, respectively, whilst the neat copolymer achieved only 640 ± 7 and 72 ± 2 g g^?1 in water and artificial urine, respectively. The viscoelastic behavior suggested that the swollen gel of the nanocomposites exhibited mechanical stability and elasticity. Copyright © 2009 John Wiley & Sons, Ltd.     

Prussian Blue Dispersed Sphere Catalytic Labels for Amplified Electronic Detection of DNA

A highly sensitive electrochemical DNA hybridization assay using Prussian blue (PB)-modified polymeric spheres as the oligonculeotide labeling tag is described. The sandwich assay relies on a secondary nucleic-acid probe functionalized with polystyrene beads loaded with numerous Prussian blue nanoparticles. The very strong catalytic activity of the captured PB 'artificial peroxidase' tag towards the reduction of hydrogen peroxide, along with the encapsulation of numerous catalytic particles onto polymeric beads, allows amperometric detection of the DNA target down to the 50 fM level (2.5 amol). Imaging and spectroscopic measurements are used to characterize the PB-tagged polystyrene beads. Such coupling of PB catalytic labels with polymeric carrier beads offers great promise for amplified transduction of different biomolecular interactions.     

Electrochemistry on Paper‐based Analytical Devices: A Review

Even though they were introduced less than a decade ago, electrochemical paper‐based devices (ePADs) have attracted widespread attention because of their inherent advantages in many applications. ePADs combine the advantages of microfluidic paper‐based devices (low cost, ease of use, equipment free pumping, etc.) for sample handling and processing with the advantages of sensitive and selective detection provided by electrochemistry. As a result, ePADs provide simplicity, portability, reproducibility, low cost and high selectivity and sensitivity for analytical measurements in a variety of applications ranging from clinical diagnostics to environmental sensing. Herein, recent advances in ePAD development and application are reviewed, focusing on electrode fabrication techniques and examples of applications specially focused on environmental monitoring, biological applications and clinical assays. Finally, a summary and prospective directions for ePAD research are also provided.     

Online assay of bone specific alkaline phosphatase with a flow injection-bead injection system

Alkaline phosphatase (ALP) has been used as one of the biomarkers for bone resorption and liver diseases. Normally, total alkaline phosphatase is quantified along with other symptoms to determine the releasing source of the alkaline phosphatase. A semi-automated flow injection-bead injection system was proposed to conveniently and selectively assay bone alkaline phosphatase (BALP) based on its specific binding to wheat germ coated beads. Amount of BALP in serum was determined from the intensity of the yellow product produced from bound BALP on the retained beads and its substrate pNPP. The used beads were discarded and the fresh ones were introduced for the next analysis. The reaction cell was designed to be opened and closed using a computer controlled solenoid valve for a precise incubation time. The performance of the proposed system was evaluated by using it to assay BALP in human serum. The results were compared to those obtained by using a commercial ELISA kit. The system is proposed to be an easy and cost effective system for quantification of BALP as an alternative to batch wise wheat germ specific binding technique.     

Ultrasensitive and Simple Method for Determination of N‐Acetyl‐L‐Cysteine in Drug Formulations Using a Diamond Sensor

A boron‐doped diamond (BDD) electrode coupled to flow injection analysis (FIA) was firstly developed for determination of N‐acetyl‐L ‐cysteine (NAC) in drug formulations. The effects of experimental parameters including pH, applied potential and scan rate on the response were investigated. FIA amperometry was applied as an automatic method for the quantitative detection of trace amounts of NAC. A wide linear range of 0.5–50 µmol/L and a low detection limit of 10 nmol/L were obtained. The results of amperometric determinations show a very good reproducibility, and the RSD for the measurement based on 10 measurements was <3.7 % and <4.1 % for intra‐ and inter‐day, respectively. The benefits of the proposed method are fast, simple, sensitive and no requirement of complicated operational steps.     

A novel paper-based device coupled with a silver nanoparticle-modified boron-doped diamond electrode for cholesterol detection

A novel paper-based analytical device (PAD) coupled with a silver nanoparticle-modified boron-doped diamond (AgNP/BDD) electrode was first developed as a cholesterol sensor. The AgNP/BDD electrode was used as working electrode after modification by AgNPs using an electrodeposition method. Wax printing was used to define the hydrophilic and hydrophobic areas on filter paper, and then counter and reference electrodes were fabricated on the hydrophilic area by screen-printing in house. For the amperometric detection, cholesterol and cholesterol oxidase (ChOx) were directly drop-cast onto the hydrophilic area, and H₂O₂ produced from the enzymatic reaction was monitored. The fabricated device demonstrated a good linearity (0.39 mg dL⁻¹ to 270.69 mg dL⁻¹), low detection limit (0.25 mg dL⁻¹), and high sensitivity (49.61 μA mM⁻¹ cm⁻²). The precision value for ten replicates was 3.76% RSD for 1 mM H₂O₂. In addition, this biosensor exhibited very high selectivity for cholesterol detection and excellent recoveries for bovine serum analysis (in the range of 99.6–100.8%). The results showed that this new sensing platform will be an alternative tool for cholesterol detection in routine diagnosis and offers the advantages of low sample/reagent consumption, low cost, portability, and short analysis time.