Chinese Journal of Analytical Chemistry最新文献

The electrochemical sensor has been considered an efficient and portable platform for the rapid quantification of nitrate ions in industrial wastewater and natural water bodies. Albeit of the high sensitivity to NO₃⁻, the electron-deficient copper sites (Cu^δ+) were unstable under the negative working potentials for detection (Cu^δ+ was readily reduced to Cu⁰). Herein, the Schiff base was grafted on MIL-125 (Ti) via covalent binding to stabilize the Cu^δ+, leading to a composite Cu^δ+/Schiff base/MIL-125 (Ti) material (abbreviated as CuSM) for NO₃⁻ sensing. Moreover, the unique porous structure of CuSM can speed up the diffusion rate of NO₃⁻ from the bulk solution to the surface of the modified electrode, enhancing the sensitivity of NO₃⁻ assay. As a result, the CuSM-based sensor not only exhibited a wide linear range from 1.18 μM to 58.8 mM and a low detection limit (S/N = 3) of 0.253 μM but also possesses high specificity, excellent reproducibility (the RSD of the five inter-batch sensors was 1.138%) and the ability to detect real water samples.

Objective

To investigate the effects of water extract of the spleen-brain-related mineral drug Shehanshi on mouse sleep.

Methods

Shehanshi water extract was subjected to component analysis via X-ray photoelectron spectroscopy. Then, the effects of low-dose (50 mg kg^-1) and high-dose (100 mg kg^-1) Shehanshi water extract on mouse sleep were evaluated through behavioral tests such as pentobarbital sodium subthreshold and above-threshold sleep experiments and autonomic activity experiments. Furthermore, transcriptome sequencing and nontarget metabolomics analysis were performed on the spleen and brain tissues of the mice.

Results

The Shehanshi water extract contains a total of 30 elements and can reduce sleep latency, increase sleep time, and increase the sleep rate of mice. In the open field experiment, the movement distance of the mice decreased, and the central residence time and rest time increased. Immunoinfiltration analysis and immunohistochemical verification of spleen tissue showed that compared with those in the control group, the immune abundance of neutrophils in the administration groups increased (P < 0.05). Transcriptome data analysis revealed that the Atp1b2 gene was located at the intersection of the spleen and brain and was positively correlated with neutrophil expression but negatively correlated with the expression of the metabolite oleic acid in brain tissue. Immunohistochemical results showed that Atp2a3 protein expression decreased and Plcg1 protein expression increased in the high-dose group, and the difference was statistically significant (P < 0.05). The Atp1b2 protein level in the spleen tissue was positively correlated with that in the brain tissue of the mice (R = 0.829, P = 0.038). Western blotting revealed that Atp1b2 protein levels in the brain and spleen increased significantly in the high-dose group (P < 0.05).

Conclusion

The mechanism by which Shehanshi water extract influences sleep may be associated with the expression of genes related to the spleen-brain axis and calcium signaling pathways in brain tissues.

In graph theory, topological indices are numerical metrics that give information about a graph’s structural traits. The face index is one such topological index that describes planar networks. Since the discovery of graphene, the genealogy of two-dimensional 2D crystals has expanded and currently contains a large variety that has all logical electrical properties required for nano electronics. Nanotechnology benefits from the use of materials that resemble Dirac, such as silicon, graphite, semiconductors, and germanene, as well as TMDC (phosporene), a transition metal dichalcogenide. In contrast with standard topological descriptors, which are numerical values utilised to characterise molecular structures, the face index presents a potentially more comprehensive method for obtaining structural details. In investigations involving quantitative structure-property relationships (QSPR), this may result in more precise predictions. We calculated the recently created face index of Germanium Phosphide (GeP) and its many shapes, including triangle, rhombus, hourglass, and concentric circles.

Cigarette smoke contains various harmful substances, including heavy metals, that pose significant health risks. Tobacco smoking is the leading cause of lung cancer, accounting for approximately 90 % of lung cancer-related deaths worldwide. However, limited information is available on the health hazards posed by heavy metals in cigarettes commonly consumed in Tanzania. This study aims to assess the potential health risks associated with heavy metal exposure from eight most commonly consumed cigarette products in Tanzania using atomic absorption spectrometry. The concentrations (mg kg⁻¹) of copper (Cu), zinc (Zn), cadmium (Cd), chromium (Cr), and nickel (Ni) ranged from 6.94 to 16.31, 0.6–1.93, 0.4–0.66, 0.69–2.86, and 0.11–2.69, respectively, with mean concentrations of 9.35, 0.92, 0.52, 1.82, and 1.24 mg kg⁻¹. The mean concentrations of Cu and Zn are within the permissible limits set by FAO/WHO while Cd, Cr, and Ni exceeded these limits, raising concerns. A high positive correlation is observed between Cu and Zn ($r=0.988$, $p=0.01$). The non-carcinogenic hazard quotient (HQ) for ingestion is below 1, indicating minimal risk, whereas HQ for inhalation is above 1, indicating considerable health risk. The carcinogenic risk assessment for ingestion is within acceptable limits for all metals. However, Cd, Cr, and Ni present higher risks than the acceptable limit set by USEPA (1E-06 to 1E-04), suggesting significant cancer risk associated with these metals. This study highlights the need for stringent regulation and monitoring of heavy metal content in cigarettes to mitigate health risks.

Halogenated polycyclic aromatic hydrocarbons (H-PAHs) are the emerging organic pollutants in environment, which are ubiquitous in the atmosphere, soil and water. Some H-PAH congeners have been proven to have dioxin-like toxicity. However, the research on the human internal exposure of H-PAHs is still limited. A simple and efficient analytical method is essential for the study of human internal exposure, so a method for the rapid and simultaneous determination of 16 polycyclic aromatic hydrocarbons (PAHs) and 33 H-PAHs in human serum was established in this study. After 1.0 mL serum was extracted with ethyl acetate/acetonitrile (1:4) solution containing 1 % formic acid, samples were purified by Captiva EMR-Lipid solid phase extraction column, and then determined by gas chromatography tandem triple quadrupole mass spectrometer (GC-MS/MS). The results showed that the recoveries of PAHs and H-PAHs ranged from 71.2 % to 119 % and 68.8 % to 121 %, respectively. When 1.0 mL of serum sample is used, the method detection limit of PAHs and H-PAHs is 0.001–0.314 ng/mL. The method is simple and efficient, and suitable for the simultaneous determination of trace PAHs and H-PAHs in human serum. High concentrations of chlorinated polycyclic aromatic hydrocarbons were detected in pooled serum, of which 1,5-dichloranthracene was the main contributor congener, with a concentration of 204–328 ng/g lipid, which deserved more attention.

In this work, the process of forming PF4/heparin complex was described based on their sizes measured with PCS. PF4/heparin complexes formed when a small amount of heparin was added to PF4, and they grew to bigger particles when more heparin was added, but they started to decompose after a certain amount of heparin was added. The larger the molecular weight of heparin has, the less amount of heparin is required to form the complex with PF4. This process was verified by the results of the complex surface charge. This method was used to compare the immunogenicity among the different batches of nadroparin after its specificity and stability were validated.

In this study, we have constructed a novel voltammetric sensor based on montmorillonite clay (MMT) incorporated with CeO₂ nanoparticles using a composite graphite paste electrode as a cross linker (MMT-CeO₂NPs/GPG-PE) for the trace determination of tadalafil (TAD) drug. The characterization of CeO₂ nanoparticles has been conducted using various analytical techniques, including X-ray diffraction, transmission electron microscopy, and high-resolution transmission electron microscopy. The morphology of the composite of CPG and MMT-CeO₂NPs/CPG was elucidated through scanning electron microscopy (SEM). The newly developed sensor (MMT-CeO₂NPs/CPG-PE) exhibited remarkable efficiency towards TAD oxidation using adsorptive stripping square-wave voltammetry (AdS-SWV) in Mcllvaine buffer solution (pH 8.0). A highly selective and sensitive method for TAD detection has been successfully applied based on MMT-CeO₂NPs/CPG-PE, showing two different linear concentration ranges of 0.005−0.1 and 0.1–9.9 µM. The LOD and LOQ were determined to be 1.97 × 10⁻¹⁰ and 6.57 × 10⁻¹⁰ M, respectively, with a sensitivity of 3916 µA µM⁻¹ cm⁻². Interestingly, the sensing electrode exhibited excellent reproducibility, reusability, and stability even after 30 days. Moreover, the newly developed nano-sensor (MMT-CeO₂NPs/CPG-PE) has been effectively utilized for the accurate detection of TAD in pharmaceutical formulations and spiked human blood serum and urine samples, demonstrating no interference from other substances.

Radionuclide therapy (RNT) stands out as a highly effective method for treating solid tumors. However, its therapeutic efficiency faces challenges due to the radioresistance of tumors, the limited penetration depth and intracellular deposition of rays in tumor tissue, which causes residue of living cancer cells. Herein, we report a novel approach by utilizing radionuclide ¹³¹I-labelled polydopamine encapsulated gold nanoparticle co-loaded with the classical anticancer drug gemcitabine within a hydrogel formed from oxidized glucan and chitosan hydrochloride, combining RNT with chemotherapy for cancer treatment. Au, as a high Z element, is able to interact with short-range β-rays to emit bremsstrahlung and secondary charged particles which in turn increase the dose deposited in tumor cells. Simultaneously, gemcitabine is able to affect cell cycle redistribution, resulting in an increase in the radiosensitive cellular component of the cycle, and gemcitabine also inhibits the repair of radioactive damage to cellular DNA, which has a radiosensitizing effect. In both in vivo and vitro experiments, the injectable hydrogel demonstrates excellent biosecurity, stability in radionuclide labeling, and capabilities for single-photon emission computed tomography (SPECT) imaging. Compared analysis with single RNT revealed that combination therapy markedly inhibits the growth of triple-negative breast cancer. This integrated therapeutic strategy establishes an efficient tumor synergistic treatment platform, offering new avenues for advancing radionuclide therapy in the clinical treatment of cancer.

African swine fever (ASF) is a highly contagious disease caused by the African swine fever virus (ASFV) infecting pigs, which has caused huge economic losses in countries around the world. Currently, there is no effective vaccine, and the prevention and control of ASF is mainly through rapid detection, so it is particularly important to carry identify and develop rapid detection methods for ASFV. In this study, recombinant plasmid PET-28a(+)-p30 was constructed, and the recombinant protein was obtained by inducing expression and Ni⁺ resin affinity column purification. Mice were immunized with recombinant p30 protein, and after three immunizations, ten strains of hybridoma cells that stably secreted monoclonal antibodies (mAbs) against p30 protein were obtained by cell fusion and subcloning. A colloidal gold immunochromatography assay (GICA) based on double antibody sandwich technology was established to screen the paired antibodies, and the trapping and detecting antibodies were mAb-11F11 and mAb-7A8, respectively, with a detection limit of 1 ng/mL, which laid an important material foundation for the early detection of ASF in the future.

Nowadays, people are highly conscious of the environment, leading to rapid growth and progress in research and innovation in eco-friendly natural fiber composites (NFCs), which are also cost-effective. The sustainable development of biodegradable NFCs obtained from renewable sources is paving the way for the replacement of synthetic fiber composites. Furthermore, researchers are focusing on enhancing the mechanical performance of NFCs for various applications. Some renewable sources, such as rice, wheat, and corn, have been used to produce polylactic acid-based NFCs. Due to their low greenhouse gas emissions and minimal energy consumption during production, NFCs are also suitable for 3D printing applications. However, they do have some drawbacks, and to overcome them, they are often blended with other NFCs. The purpose of this review article is to provide data on the physical, chemical, and mechanical properties of natural fiber-reinforced composites to assist new researchers. The central idea is that natural, biodegradable, and eco-friendly materials can replace plastics, enhancing their properties in terms of mechanical strength, thermal resistance, antimicrobial properties, water absorption, and degradability. The use of NFCs is flourishing in various fields. Every year, a substantial amount of agricultural waste with potential fibers is discarded. Some examples of waste products include fruit, including areca and tamarind. The reinforcement obtained from these materials is utilized in polymer composites for lightweight structures, the automotive industry, and domestic applications.