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Branched titanium dioxide nanorods (B-TiO2 NRs) grown on fluorine-doped tin oxide glass (FTO) were developed, which can be used as a solid-phase extractant for preconcentration and determination of trace Pb(II) combined with inductively coupled plasma optical emission spectrometry (ICP-OES). The B-TiO2 NR-based glass substrate displayed excellent adsorptive selectivity and capacity for Pb(II); the maximum adsorption capacity was found to be 168.4 mg⋅g−1 PB(II) at pH = 5.0. It proved that the primary extraction mechanism was attributed to soft acid/soft base interactions to form complexes for chemisorption. Investigating the adsorption kinetics and isotherms indicated that the pseudo-second-order and Langmuir models can better describe Pb(II) adsorption on the B-TiO2 NRs. The proposed method presented good linearity from 0.01 to 5 mg⋅L−1 with a correlation coefficient (R2) of 0.9989 and a low limit of detection (LOD) of 2.2 μg⋅L−1 for Pb(II) under optimal conditions. The method was successfully applied to Pb(II) determination in foodstuffs with desirable recoveries from 93.18 to 108.1% and good precision with an RSD of less than 12.2%. This work provides a new strategy for selective extraction and determination of Pb(II) in complicated matrix samples. [ABSTRACT FROM AUTHOR]

Background. Vascular occlusion or thrombosis was often attributed to uncontrolled platelet activation. Influence of sugarcane policosanol extract on platelet was reported but little was known of rice bran policosanol, particularly its mechanisms of actions on platelet activities. Objective. Antiplatelet mechanisms of rice bran policosanol extract (RBE) were studied using hyperlipidemic Sprague Dawley rats. Ex vivo platelet aggregation, platelet count (PC), bleeding time (BT), and coagulation time were assayed. Serum eicosanoids and other aggregation-related metabolites levels were quantified. Design. Rats were divided into 6 groups for comparisons (vehicle control Tween 20/H2O, high dose policosanol 500 mg/kg, middle dose policosanol 250 mg/kg, low dose policosanol 100 mg/kg, and positive control aspirin 30 mg/kg). Results. Low dose 100 mg/kg of RBE inhibited aggregation by 42.32±4.31% and this was comparable with the effect of 30 mg/kg aspirin, 43.91±5.27%. Results showed that there were no significant differences in PC, BT, and coagulation time among various groups after RBE treatment. Serum thromboxane A2 was attenuated while prostacyclin level increased upon RBE treatment. Conclusions. RBE reduced ex vivo ADP-induced platelet aggregation without giving adverse effects. No changes in full blood count suggested that rice bran policosanol did not disturb biological blood cell production and destruction yet it reduced aggregation through different mechanisms. [ABSTRACT FROM AUTHOR]

Instrumental analysis is an important professional course for many chemistry majors. Its teaching content is rich, diverse and is closely related to daily life. Moreover, this course contains a large number of ideological and political resources. This study investigates chromatography technology in instrumental analysis as an example, focusing on aspects such as chromatography knowledge, solution preparation, standard operations, and guided experiments, to deeply explore the elements of ideological and political education and organically integrate them into the teaching of instrumental analysis courses. Academic teaching of professional knowledge increases the diversity and richness of the teaching content and enhances the innovative skills of the students. In addition, this teaching method can inspire students to establish life goals and great ideals, with the aim of ultimately cultivating moral people.

Cholesterol is a vital component of the central nervous system and tissues, and understanding its spatial distribution is crucial for biology, pathophysiology, and diagnostics. However, direct imaging of cholesterol using matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) remains challenging and time-consuming due to the difficulty in ionizing the sterol molecule. To tackle this issue, a MALDI-MSI method is established for direct and rapid analysis of the spatial distribution of cholesterol in Alzheimer's disease (AD), different cancer tissues and organs via MALDI-MSI. This excellent imaging performance depends on the study and systemic optimization of various conditions that affect the imaging of MALDI-MSI. In this case, we report the distribution and levels of cholesterol across specific structures of the AD mouse brain and different tumor tissue and organs. According to the results, the content of cholesterol in the AD mouse cerebellum, especially in the arborvitae, was significantly higher than that in the wild type (WT) model. Furthermore, we successfully visualize the distribution of cholesterol in other organs, such as the heart, liver, spleen, kidney, pancreas, as well as tumor tissues parenchyma and interstitium using MALDI-MSI. Notably, the attribution of cholesterol MS/MS hydrocarbon fragments was systematically investigated. Our presented optimization strategy and established MALDI-MSI method can be easily generalized for different animal tissues or live samples, thereby facilitating the potential for applications of MALDI-MSI in clinical, medical and biological research.

Aim: To investigate hepatitis B surface antigen (HBsAg) levels in patients with HBeAg-positive chronic hepatitis B (CHB) and different immune conditions., Methods: HBeAg-positive CHB patients with different immune conditions were enrolled in this cross-sectional study. These patients were grouped according to the following criteria: immune-tolerant patients, IT group; patients with a mild immune response in the immune clearance phase, IC-Mild group; and patients with a dramatic immune response in the immune clearance phase and exhibiting acute on chronic liver failure (ACLF), ACLF group. All these patients had not previously received antiviral therapy and were enrolled at a pre-settled ratio of 2:2:1. Serum HBsAg levels and the correlation between serum HBsAg level and serum hepatitis B virus (HBV) DNA level were evaluated in these groups., Results: In total, 180 HBeAg-positive CHB patients [IT group (n = 72), IC-Mild group (n = 72), and ACLF group (n = 36)] were enrolled in this study. The median serum HBsAg levels varied among the groups (P < 0.001): IT, 4.86 log10 IU/mL; IC-Mild, 3.97 log10 IU/mL; and ACLF, 3.57 log10 IU/mL. Serum HBsAg level showed a moderate positive correlation with serum HBV-DNA level in the IC-Mild group (r = 0.60, P < 0.001), but exhibited a weaker correlation in the IT (r = 0.52, P < 0.001) and ACLF groups (r = 0.51, P = 0.001). The ratio of HBsAg/HBV DNA did not differ significantly among the IT, IC-Mild, and ACLF groups (medians: 0.56, 0.55, and 0.56, respectively; P = 0.179)., Conclusion: Serum HBsAg levels varied significantly in HBeAg-positive patients with different immune conditions. These findings may have important implications for understanding the immune clearance of HBV in HBeAg-positive CHB patients.