Resolving the Stellar-Collapse and Hierarchical-Merger Origins of the Coalescing Black Holes.

Spin and mass properties provide essential clues in distinguishing the origins of coalescing black holes (BHs). With a dedicated semiparametric population model for the coalescing binary black holes (BBHs), we identify two distinct categories of BHs among the GWTC-3 events, which is favored over the one population scenario by a logarithmic Bayes factor (lnB) of 7.5. One category, with a mass ranging from ∼25M_{⊙} to ∼80M_{⊙}, is distinguished by the high spin magnitudes (∼0.75) and consistent with the hierarchical merger origin. The other category, characterized by low spins, has a sharp mass cutoff at ∼40M_{⊙}, which is natural for the stellar-collapse origin and in particular the pair-instability explosion of massive stars. We infer the local hierarchical merger rate density as 0.46_{-0.24}^{+0.61} Gpc^{-3} yr^{-1}. Additionally, we find that a fraction of the BBHs has a cosine-spin-tilt-angle distribution concentrated preferentially around 1, and the fully isotropic distribution for spin orientation is disfavored by a lnB of -6.3, suggesting that the isolated field evolution channels are contributing to the total population.

Detection and Utilization of Reflections in LiDAR Scans through Plane Optimization and Plane SLAM.

In LiDAR sensing, glass, mirrors and other materials often cause inconsistent data readings from reflections. This causes problems in robotics and 3D reconstruction, especially with respect to localization, mapping and, thus, navigation. Extending our previous work, we construct a global, optimized map of reflective planes, in order to then classify all LiDAR readings at the end. For this, we optimize the reflective plane parameters of the plane detection of multiple scans. In a further method, we apply the reflective plane estimation in a plane SLAM algorithm, highlighting the applicability of our method for robotics. As our experiments will show, this approach provides superior classification accuracy compared to the single scan approach. The code and data for this work are available as open source online.

Protein kinase C is involved in the neuroprotective effect of berberine against intrastriatal injection of quinolinic acid-induced biochemical alteration in mice.

Protein kinase C (PKC) shows a neuronal protection effect in neurodegenerative diseases. In this study, we test whether berberine has a positive effect on the activity of PKC in quinolinic acid (QA)-induced neuronal cell death. We used intrastriatal injections of QA mice model to test the effect of berberine on motor and cognitive deficits, and the PKC signalling pathway. Treatment with 50 mg/kg b.w of berberine for 2 weeks significantly prevented QA-induced motor and cognitive impairment and related pathologic changes in the brain. QA inhibited the phosphorylation of PKC and its downstream molecules, GSK-3ß, ERK and CREB, enhanced the glutamate level and release of neuroinflammatory cytokines; these effects were attenuated by berberine. We used in vivo infusion of Go6983, a PKC inhibitor to disturb PKC activity in mice brain, and found that the effect of berberine to reverse motor and cognitive deficits was significantly reduced. Moreover, inhibition of PKC also blocked the anti-excitotoxicity effect of berberine, which is induced by glutamate in PC12 cells and BV2 cells, as well as anti-neuroinflammatory effect in LPS-stimulated BV2 cells. Above all, berberine showed neuroprotective effect against QA-induced acute neurotoxicity by activating PKC and its downstream molecules.

Tolfenamic Acid Attenuates 3-Nitropropionic Acid-Induced Biochemical Alteration in Mice.

Tolfenamic acid (TA), a nonsteroidal anti-inflammatory drug, shows neuroprotective effects and alleviates cognitive deficits in transgenic mouse models of Alzheimer's disease. However, whether TA can prevent the biochemical alterations induced by intraperitoneal injection of 3-nitropropionic acid (3-NP) in mice is still unknown. In this study, the striatal lesion area was measured by 2,3,5-triphenyltetrazolium chloride staining. Glutamate, SDH and ATP levels were tested using colorimetric assay kits. The neuroinflammatory cytokine levels were tested by ELISA kits. The expression of synaptic proteins and the subtypes of the NMDA receptor were tested by western blotting. TA was orally administered 10 days before 3-NP injection (pretreatment) or on the same day as 3-NP injection (co-treatment). TA pretreatment showed the strongest neuroprotective effects: pretreatment significantly attenuated the 3-NP-induced muscular weakness in the forelimb and alterations in glutamate level, mitochondrial function, and pro-inflammatory cytokine release in the brains of mice. These results suggest that TA has preventive and protective effects on 3-NP-induced neurotoxicity.

Development and evaluation of a hydrophilic interaction liquid chromatography-MS/MS method to quantify 19 nucleobases and nucleosides in rat plasma.

As essential endogenous compounds, nucleobases and nucleosides fulfill various functions in living organisms. This study presents the development and validation of a new hydrophilic interaction liquid chromatography tandem mass spectrometry method for simultaneous quantification of 19 nucleobases and nucleosides in rat plasma. For the sample preparation, 15 kinds of protein precipitants were evaluated according to the chromatographic profile and ion response of analytes. The optimization of chromatographic separation was respectively performed using reversed-phase liquid chromatography and hydrophilic interaction liquid chromatography mode; each separation mode included two test columns with different stationary phases. The chromatographic profile and parameters such as half-width (W1/2 ), capacity factor (K') and tailing factor (ft ) were used to evaluate the separation efficiencies. Furthermore, the adopted composition of two mobile phase systems and the concentrations of the additives in the optimum buffer system were also investigated. The developed method was fully validated and successfully applied quantitatively to determine 19 nucleobases and nucleosides in plasma from normal and diabetic nephropathy (DN) rats. Significant differences between normal and DN rats were found in plasma levels of cytosine, xanthine, thymidine, adenosine, guanosine, inosine and 8-hydroxy-2'-deoxyguanosine. This information may provide a useful reference for the discovery of potential biomarkers of DN.

Urinary Macrophage Migration Inhibitory Factor as a Noninvasive Biomarker in Pediatric Henoch-Schönlein Purpura Nephritis.

PURPOSES: The aims of this study were to investigate urinary macrophage migration inhibitory factor (MIF) levels and their clinical significance in Henoch-Schönlein purpura (HSP) children with or without nephritis (N) and to assess the influence of steroid treatment on the urine MIF levels of HSPN patients. METHODS: Group I comprised 35 children with HSPN who were examined twice (A before treatment and B after steroid treatment). Group II comprised 41 children with HSP. The control group included 32 healthy children. Urinary MIF levels were measured via enzyme linked immunosorbent assay. The levels of serum creatinine, blood urea nitrogen, urinary microalbumin (mAlb), and 24-hour proteinuria were performed to determine their associations with MIF levels. RESULTS: Urinary MIF levels were significantly higher in group I compared with group II and the control group (P < 0.01); however, no significant difference was found between group II and the control group (P > 0.05). Upon examination, albeit urinary MIF concentration was significantly lower in group IB compared with group IA (P < 0.05), these concentrations were statistically higher than that of group II (P < 0.05). In addition, in the HSPN patients, the urinary MIF was positively associated with urinary microalbumin and 24-hour proteinuria but no association with serum creatinine and blood urea nitrogen. CONCLUSIONS: Elevated urinary MIF levels were found to be correlated with proteinuria in pediatric HSPN. An obvious decrease in urinary MIF concentrations among the children with HSPN was associated with steroid treatment. Urinary MIF can be used as a noninvasive biomarker in pediatric HSPN.

Evaluation of sample preparation and chromatographic separation for the parallel determination of taurine and edaravone in rat tissues using HILIC-MS/MS.

The quantitative analysis of taurine and edaravone in biological sample is critical in pharmaceutical studies. Although each of them can be individually analyzed by different approaches, concurrent quantification is still a highly challenging task with respect to their great polarity variation and the complex composition of tissue sample. In the present study, to simultaneously determine taurine and edaravone in rat tissue, the sample preparation and chromatographic separation conditions were evaluated and discussed in detail. As for the sample preparation, four kinds of solvent and the volume ratio of the optimal solvent to biological sample were both tested and evaluated based on the chromatographic profile, extraction recovery, and matrix effect (ME). The chromatographic separation was performed in a reverse phase (RP) and two hydrophilic interaction liquid chromatography (HILIC) modes, and the corresponding separation efficiencies were assessed using chromatographic parameters like half-width (W 1/2 ), tailing factor (f t), theoretical plates number (N), and ME. Furthermore, adopted composition of two mobile phase systems and the concentrations of the additives in the optimum buffer system were also investigated on an Atlantis HILIC silica column according to the resultant chromatographic profiles and peak areas of the analytes. The optimal results were obtained when the biological samples were deproteined by 4-fold volume of methanol/acetonitrile (1:3, v/v) and separated on a HILIC column with a gradient elution of acetonitrile/water containing 0.2 % formic acid and 10 mM ammonium formate. The proposed approach was validated and successfully applied to the parallel determination of the tissue distribution of edaravone and taurine in rat tissues.

High-performance liquid chromatographic column packings with different particle sizes: chromatographic behavior for the quality analysis of HuanglianShangqing pill.

The chromatographic separation of traditional Chinese medicines is still a highly challenging task in analytical science with respect to its hundreds and thousands of chemical compounds, while increase of separation efficiency can greatly improve the separation power of chromatographic column for traditional Chinese medicine. In this study, 13 bioactive components in HuanglianShangqing pill were selected as an index to optimize the separation conditions and evaluate the system suitability of three commercially available columns packed with 1.8, 3.5, and 5.0 µm particles. The chromatographic separations were obtained by the most appropriate Eclipse Plus C18 column (100 × 2.1 mm, 3.5 µm) within 45 min using gradient elution with aqueous-ammonium acetate (10 mmol/L, pH 5.0) and acetonitrile, at a flow rate of 0.3 mL/min and an operating temperature of 30°C. The quality of HuanglianShangqing pill was assessed through combining simultaneous quantification of 13 compounds with fingerprint analysis. For the qualitative analysis, mass spectrometry was used to confirm the 13 compounds. All the validation data conformed to the acceptable requirements. For the fingerprint analysis, 32 peaks were selected as the common peaks at 254 nm to evaluate the similarities among HuanglianShangqing pills obtained from ten manufacturers.

Simultaneous determination of baicalin, oroxylin A-7-O-glucuronide and wogonoside in rat plasma by UPLC-DAD and its application in pharmacokinetics of pure baicalin, Radix Scutellariae and Yinhuang granule.

A novel UPLC-DAD method was developed and validated for the simultaneous determination of baicalin (baicalein-7-glucuronide, BG), oroxylin A-7-O-glucuronide (OAG) and wogonoside (WG) in rat plasma using rutin as the internal standard. Plasma samples were precipitated using acetonitrile containing 0.1% formic acid. Separation was performed on an Agilent Eclipse Plus C18 column (2.1 × 50 mm, 1.8 µm) using gradient acetonitrile and 0.2% formic acid water solution as mobile phase. The flow-rate was set at 0.4 mL/min and the eluate was detected at 275 nm. The method was linear over the ranges of 0.075-17.50, 0.050-12.60 and 0.056-14.10 µg/mL for BG, OAG and WG, respectively. The intra- and inter-day precisions were respectively <4.8% and 6.4%. All of the limits of detection of three analytes in rat plasma were 0.01 µg/mL, whereas the limits of quantification were, respectively, 0.035, 0.025 and, 0.025 µg/mL. This assay has been successfully applied to pharmacokinetics of BG, OAG and WG in rats after oral administration of Yinhuang granule (YHG) and comparative pharmacokinetics of BG in rats following oral administration of the pure BG, Radix Scutellariae (RS) or YHG. We speculate that some co-existing ingredients in RS or YHG may increase the absorption and elimination of BG in rat. This work may be helpful for the quality control of Yinhuang granule.

Study on the interaction of plasma protein binding rate between edaravone and taurine in human plasma based on HPLC analysis coupled with ultrafiltration technique.

In this work, two high-performance liquid chromatography (HPLC) assays were developed and validated for the independent determination of edaravone and taurine using 3-methyl-1-p-tolyl-5-pyrazolone and L-glutamine as internal standards. In in vitro experiments, human plasma was separately spiked with a mixture of edaravone and taurine, edaravone or taurine alone. Plasma was precipitated with acetonitrile containing 0.1% formic acid. Ultrafiltration was employed to obtain the unbound ingredients of the two drugs. The factors that might influence the ultrafiltration effiency were elaborately optimized. Plasma supernatant and ultrafiltrate containing taurine were derivated with o-phthalaldehyde and ethanethiol in the presence of 40 mmol/L sodium borate buffer (pH 10.2) at room temperature within 1 min. Chromatographic separations were achieved on an InertSustain C18 column (250 × 4.6 mm, 5 µm). Isocratic 50 mmol/L ammonium acetate-acetonitrile and gradient 50 mmol/L sodium acetate (pH 5.3)-methanol were respectively selected as the mobile phase for the determination of edaravone and taurine. All of the validation data including linearity, extraction recovery, precision, accuracy and stability conformed to the requirements. Results showed that there were no significant alterations in the plasma protein binding rate of taurine and edaravone, implying that the proposed combination therapy was pharmacologically feasible.