Pharmacokinetic Comparison of 20(R)- and 20(S)-Ginsenoside Rh1 and 20(R)- and 20(S)-Ginsenoside Rg3 in Rat Plasma following Oral Administration of Radix Ginseng Rubra and Sheng-Mai-San Extracts

Ginsenosides Rh1 and Rg3, as the main bioactive components from Ginseng, are effective for prevention and treatment of cardiovascular diseases. Sheng-Mai-San (SMS), a classical complex prescription of traditional Chinese medicines, is composed of Radix Ginseng Rubra, Fructus Schisandrae, and Radix Ophiopogonis. In this research, a sensitive and specific liquid chromatography-mass spectrometric method was developed and validated for stereoselective determination and pharmacokinetic studies of 20(R)- and 20(S)-ginsenoside Rh1 and 20(R)- and 20(S)-ginsenoside Rg3 epimers in rat plasma after oral administration of Radix Ginseng Rubra or SMS extracts. The main pharmacokinetic parameters including Tmax, Cmax, t1/2, and AUC were calculated by noncompartment model. Compared with Radix Ginseng Rubra, SMS could significantly increase the content of ginsenosides Rh1 and Rg3 in the decocting process. Ginsenosides Rh1 and Rg3 following SMS treatment displayed higher Cmax, AUC(0–t), and AUC0–∞ and longer t1/2 and tmax except for 20(R)-Rh1 in rat plasma. The results indicated SMS compound compatibility could influence the dissolution in vitro and the pharmacokinetic behaviors in vivo of ginsenosides Rh1 and Rg3, suggesting pharmacokinetic drug-drug interactions between ginsenosides Rh1 and Rg3 and other ingredients from Fructus Schisandrae and Radix Ophiopogonis. This study would provide valuable information for drug development and clinical application of SMS

Scalable expansion of human pluripotent stem cells under suspension culture condition with human platelet lysate supplementation

The large-scale production of human pluripotent stem cells (hPSCs), including both embryonic stem cells (hESCs) and induced pluripotent stem cells (hiPSCs), shows potential for advancing the translational realization of hPSC technology. Among multiple cell culture methods, suspension culture, also known as three-dimensional (3D) culture, stands out as a promising method to fulfill the large-scale production requirements. Under this 3D culture condition, cell expansion and the preservation of pluripotency and identity during long-term culture heavily relies on the culture medium. However, the xenogeneic supplements in culture medium remains an obstacle for the translation of cell and gene therapy applications from bench to bedside. Here, we tested human platelet lysate (hPL), a xeno-free and serum-free biological material, as a supplement in the 3D culture of hPSCs. We observed reduced intercellular variability and enhanced proliferation in both hESC and hiPSC lines. These cells, after extended culture in the hPL-supplemented system, maintained pluripotency marker expression, the capacity to differentiate into cells of all three germ layers, and normal karyotype, confirming the practicability and safety of hPL supplementation. Furthermore, through RNA-sequencing analysis, we found an upregulation of genes associated with cell cycle regulations in hPL-treated cells, consistent with the improved cellular division efficiency. Taken together, our findings underscore the potential of hPL as a xeno-free and serum-free supplement for the large-scale production of hPSCs, which holds promise for advancing clinical applications of these cells

Three Capsular Polysaccharide Synthesis-Related Glucosyltransferases, GT-1, GT-2 and WcaJ, Are Associated With Virulence and Phage Sensitivity of Klebsiella pneumoniae

Klebsiella pneumoniae (K. pneumoniae) spp. are important nosocomial and community-acquired opportunistic pathogens, which cause various infections. We observed that K. pneumoniae strain K7 abruptly mutates to rough-type phage-resistant phenotype upon treatment with phage GH-K3. In the present study, the rough-type phage-resistant mutant named K7RR showed much lower virulence than K7. Liquid chromatography-tandem mass spectrometry (LC-MS-MS) analysis indicated that WcaJ and two undefined glycosyltransferases (GTs)- named GT-1, GT-2- were found to be down-regulated drastically in K7RR as compared to K7 strain. GT-1, GT-2, and wcaJ are all located in the gene cluster of capsular polysaccharide (CPS). Upon deletion, even of single component, of GT-1, GT-2, and wcaJ resulted clearly in significant decline of CPS synthesis with concomitant development of GH-K3 resistance and decline of virulence of K. pneumoniae, indicating that all these three GTs are more likely involved in maintenance of phage sensitivity and bacterial virulence. Additionally, K7RR and GT-deficient strains were found sensitive to endocytosis of macrophages. Mitogen-activated protein kinase (MAPK) signaling pathway of macrophages was significantly activated by K7RR and GT-deficient strains comparing with that of K7. Interestingly, in the presence of macromolecular CPS residues (>250 KD), K7(ΔGT-1) and K7(ΔwcaJ) could still be bounded by GH-K3, though with a modest adsorption efficiency, and showed minor virulence, suggesting that the CPS residues accumulated upon deletion of GT-1 or wcaJ did retain phage binding sites as well maintain mild virulence. In brief, our study defines, for the first time, the potential roles of GT-1, GT-2, and WcaJ in K. pneumoniae in bacterial virulence and generation of rough-type mutation under the pressure of bacteriophage

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

Optimal Sensor Placement and Minimum Number Selection of Sensors for Health Monitoring of Transmission Towers

Transmission towers are structurally complex, which makes it challenging to choose the right place and number of sensors for health monitoring. In this paper, optimal sensor placement of a cat-head-type transmission tower is conducted by using the Effective Independent Method (EIM) and a method is proposed for calculating the minimum number of sensors for structural health monitoring by combining EIM and Modal Assurance Criterion (MAC). The method for calculating the number of sensors prescribed in this paper derives a curve that shows the relationship between MAC value and the number of sensors. It is found that the MAC value decreases with increase in the number of sensors. When the number of sensors reaches a certain threshold, the curve tends to stabilize. Then, the number of sensors corresponding to the minimum MAC is proposed as the minimum number of sensors. Through calculation, the minimum number of sensors of the cat-head-type transmission tower is obtained. Also, the optimal sensor placement results show that the position of a large number of sensors includes the position of a smaller number of sensors

Preparation and Characterization of Cellulose Membrane Modified with β-Cyclodextrin for Chiral Separation

In this study, it is first time to obtain a complete separation of using β-cyclodextrin (β-CD) modified cellulose microfiltration membrane. Commercially cellulose membrane with the pore diameter of 0.22μm was functionalized with β-cyclodextrin (β-CD) by aldolization at the solid–liquid interface. Filtration experiments were carried out using a dead-end filtration cell holding a flat sheet membrane with effective area of 36 mm2. Aqueous solution of racemic tryptophan (0.05g/L, 150 mL) was forced to permeate through the cellulose membrane immobilized by β-CD at a flow rate of 0.1 ml/min through the membrane microdevice. Chiral ligand exchange chromatography was used to determine the concentration and ratio of D- and L-tryptophan in the filtrate. A complete separation of racemic tryptophan can be obtained by using this novel composite membrane-based separation system. In addition, a multi-stage filtration separation was applied in order to obtain higher permselectivity. The objective of this study is to obtain an easy prepared chiral membrane with good reproducibility and can be applied to a variety of chiral separations

Forming Difficulty Evaluation for Curved Hull Plates Based on Grey Relational Analysis

To solve the problem that the lack of reference for hull plate division leads to the difficulty and low efficiency of curved plate forming, the forming difficulty evaluation of complex curved hull plates is researched. Considering the characteristics in curved plate forming process, the forming difficulty evaluation model of complex curved hull plates based on grey relational analysis is established. The evaluation process of forming difficulty for curved plates is designed. The influence law of parameters and forming parameters on the forming difficulty of curved plates are revealed. The weight coefficients of different influencing factors on the forming difficulty of curved plates are quantified. Taking the real hull plate of a container ship as an example, the evaluation results for the forming difficulty of curved plates are calculated based on the evaluation model. The rationality of the evaluation model is verified by comparing the evaluation results of curved plate forming and the process time data. The research can provide a reference for the reasonable division of hull plates and reduce the forming difficulty of curved plates

Interactions and Diffusion of Methane and Hydrogen in Microporous Structures: Nuclear Magnetic Resonance (NMR) Studies

Measurements of nuclear spin relaxation times over a wide temperature range have been used to determine the interaction energies and molecular dynamics of light molecular gases trapped in the cages of microporous structures. The experiments are designed so that, in the cases explored, the local excitations and the corresponding heat capacities determine the observed nuclear spin-lattice relaxation times. The results indicate well-defined excitation energies for low densities of methane and hydrogen deuteride in zeolite structures. The values obtained for methane are consistent with Monte Carlo calculations of A.V. Kumar et al. The results also confirm the high mobility and diffusivity of hydrogen deuteride in zeolite structures at low temperatures as observed by neutron scattering

Interactions and Diffusion of Methane and Hydrogen in Microporous Structures: Nuclear Magnetic Resonance (NMR) Studies

Measurements of nuclear spin relaxation times over a wide temperature range have been used to determine the interaction energies and molecular dynamics of light molecular gases trapped in the cages of microporous structures. The experiments are designed so that, in the cases explored, the local excitations and the corresponding heat capacities determine the observed nuclear spin-lattice relaxation times. The results indicate well-defined excitation energies for low densities of methane and hydrogen deuteride in zeolite structures. The values obtained for methane are consistent with Monte Carlo calculations of A.V. Kumar et al. The results also confirm the high mobility and diffusivity of hydrogen deuteride in zeolite structures at low temperatures as observed by neutron scattering