Laser-induced breakdown spectroscopy has become a very attractive technique in the field of chemical analysis.The technique utilizes a laser focused on a small spot to create a micro-plasma on the sample surface.In recent years, laser-induced breakdown spectroscopy (LIBS) is a frontier analysis technique in spectrometric analysis, with the advantages such as real-time, online and non-contact analysis.The research and development of various instruments based on this technology has attracted great attention of researchers.In the article, we reviewed the research progress of LIBS instrument from the components and field equipment in recent years, mainly including portable LIBS, handheld LIBS and remote LIBS.

A novel method for the determination of metallic elements in environmental samples was developed based on the matrix-assisted plasma surface sampling atomic emission spectrometry ( AES system) . A piece of filter paper was used as sample substrate. By direct interaction of the plasma tail plume with the filter paper surface, the filter paper absorbed energy from the plasma source and released combustion heating to the analytes originally present on its surface, thus to promote the atomization and excitation process. Surface sampling was performed in both cases of liquid and solid state analytes. Therefore, no flow injection system was required and sample pretreatment process was simplified. The proposed method provides several advantages, including fast analysis speed ( about 240 samples/h ) , little sample consumption (μL or μg level) , simplicity in instrument design, and also ease of system operation. These advantages made it attractive as a potential miniaturized AES system for in situ and high-throughput elemental analyses. Quantitative analysis of metal ions were achieved in this study for elements Ag, Au, Ba, Cd, Cr, Cu, Eu, La, Mn, Ni, Pb, Sr and Y. Under optimal conditions, the LOD values of the 13 elements ranged from 1. 0 to 88 μg/L. The repeatability, expressed as relative standard deviation ( RSD) from 10 replicates, ranged from 2. 3% to 6. 8%. To validate the proposed method, the system was employed to determine metal elements in standard reference materials of environmental samples. The content of each element was well in agreement with the certified values.

To investigate the role of mitochondria in neuronal apoptosis, ischemia-reperfusion mediated neuronal cell injury model was established by depriving of glucose, serum and oxygen in media. DNA fragmentation, cell viability, cytochrome C releasing, caspase3 activity and mitochondrial transmembrane potential were observed after N2a cells suffered the insults. The results showed that N2a cells in ischemic territory exhibited survival damage, classical cell apoptosis change, DNA ladder and activation of caspase3. Apoptosis-related alterations in mitochondrial functions, including release of cytochrome C and depression of mitochondrial transmembrane potential (deltapsim) were testified in N2a cells after mimic ischemia-reperfusion. Moreover, activation of caspase3 occurred following the release of cytochrome C. However, the inhibitor of caspase3, Ac-DEVD-CHO, couldn't completely rescue N2a cells from apoptosis. Administration of cyclosporine A, an inhibitor of mitochondria permeability transition pore only partly inhibited caspase3 activity and reduced DNA damage. Interestingly, treatment of Z-IETD-FMK, an inhibitor of caspase8 could completely reverse DNA fragmentation, but can't completely inhibit caspase3 activity. It was concluded that there were caspase3 dependent and independent cellular apoptosis pathways in N2a cells suffering ischemia-reperfusion insults. Mitochondria dysfunction may early trigger apoptosis and amplify apoptosis signal.
Animals ; Apoptosis ; physiology ; Caspase 3 ; Caspases ; biosynthesis ; Cytochromes c ; biosynthesis ; Mice ; Mitochondria ; physiology ; Neuroblastoma ; pathology ; Neurons ; pathology ; Reperfusion Injury ; metabolism ; pathology ; Tumor Cells, Cultured

Objective    To investigate the predictive value of volatile organic compounds (VOCs) on pulmonary nodules in people aged less than 50 years. Methods    The 147 patients with pulmonary nodules and aged less than 50 years who were treated in the Department of Thoracic Surgery of Sichuan Cancer Hospital from August 1, 2019 to January 15, 2020 were divided into a lung cancer group and a lung benign disease group. The lung cancer group included 36 males and 68 females, with the age of 27-49 (43.54±5.73) years. The benign lung disease group included 23 males and 20 females, with the age of 22-49 (42.49±6.83) years. Clinical data and exhaled breath samples were collected prospectively from the two groups. Exhaled breath VOCs were analyzed by gas chromatography mass spectrometry. Binary logistic regression analysis was used to select variables and establish a prediction model. The sensitivity, specificity, and area under the receiver operating characteristic (ROC) curve of the prediction model were calculated. Results    There were statistically significant differences in sex (P=0.034), smoking history (P=0.047), cyclopentane (P=0.002), 3-methyl pentane (P=0.043) and ethylbenzene (P=0.009) between the two groups. The sensitivity, specificity and area under the ROC curve of the prediction model with gender, cyclopentane, 3-methyl pentane, ethylbenzene and N,N-dimethylformamide as variables were 80.8%, 60.5% and 0.781, respectively. Conclusion    The combination of VOCs and clinical characteristics has a certain predictive value for the benign and malignant pulmonary nodules in people aged less than 50 years.

Sodium-glucose cotransporter 2 (SGLT2) inhibitors have been reapproved for heart failure (HF) therapy in patients with and without diabetes. However, the initial glucose-lowering indication of SGLT2i has impeded their uses in cardiovascular clinical practice. A challenge of SGLT2i then becomes how to separate their anti-HF activity from glucose-lowering side-effect. To address this issue, we conducted structural repurposing of EMPA, a representative SGLT2 inhibitor, to strengthen anti-HF activity and reduce the SGLT2-inhibitory activity according to structural basis of inhibition of SGLT2. Compared to EMPA, the optimal derivative JX01, which was produced by methylation of C2-OH of the glucose ring, exhibited weaker SGLT2-inhibitory activity (IC₅₀ > 100 nmol/L), and lower glycosuria and glucose-lowering side-effect, better NHE1-inhibitory activity and cardioprotective effect in HF mice. Furthermore, JX01 showed good safety profiles in respect of single-dose/repeat-dose toxicity and hERG activity, and good pharmacokinetic properties in both mouse and rat species. Collectively, the present study provided a paradigm of drug repurposing to discover novel anti-HF drugs, and indirectly demonstrated that SGLT2-independent molecular mechanisms play an important role in cardioprotective effects of SGLT2 inhibitors.