Photoacoustic Spectroscopy Gas Detection Technology Research Progress.

Photoacoustic spectroscopy (PAS) can be utilized as an ultrasensitive gas detection method. The basic principles of gas detection using PAS are discussed in this paper. First, the basic instrumentation for a PAS gas detection system is introduced focusing on the photoacoustic cell. The discussion includes non-resonant photoacoustic cells and the different types of resonant photoacoustic cells, including the longitudinal photoacoustic cell, the Helmholtz photoacoustic cell, the T-type photoacoustic cell, and the high-frequency resonant photoacoustic cell. The basic working principles of each of these, cells as well as the advantages and disadvantages of photoacoustic cells are discussed, and the development of newer types of photoacoustic cells in recent years is outlined in detail. This review provides detailed reference information and guidance for interested researchers who would like to design and build advanced photoacoustic cells for gas detection.

Low Dimensional Nanostructure-Assisted Long-Range Surface Plasmon Resonance Sensors With High Figure of Merit.

Long-range surface plasmon resonance (LRSPR) sensors have been extensively studied by virtue of their extremely narrow full width at half maxima (FWHM) characteristics, but their low sensitivity remains an important factor limiting the figure of merit (FOM), making the sensors have difficulties in detecting small refractive index changes accurately. To address this problem, this paper proposes and demonstrates a low dimensional nanostructure (Au nanospheres, WS2) assisted LRSPR sensor to achieve an effective enhancement of the sensor interfaced electric field and thus improve the sensitivity. The performance parameters of the two sensors are compared with the LRSPR sensor by finite element method analysis, and the results showed that the assistance of the low dimensional nanostructure has a positive effect on the sensor. The first refractive index sensing experiment of the WS2-assisted LRSPR sensor was realized with a 25.47% increase in sensitivity and a 7.13% increase in FOM simultaneously, and the Au nanospheres-assisted LRSPR sensor with a 29.23% increase in sensitivity and a 15.95% increase in FOM simultaneously. The introduction of low dimensional nanostructures provides a flexible and effective means of sensitization for LRSPR sensors, making the plasmon resonance sensors combine high sensitivity, narrow FWHM and high FOM, which have promising applications in biochemical sensing.

Study on the Mechanism of Sancao Tiaowei Decoction in the Treatment of MNNG-Induced Precancerous Lesions of Gastric Carcinoma Through Hedgehog Signaling Pathway.

Sancao Tiaowei Decoction (SCTWD), a traditional Chinese medicine created by Professor Chen Weijian, has been used in the prevention and treatment of precancerous lesions of gastric carcinoma (PLGC). However, its mechanism has not been made clear. This study aimed to evaluate the therapeutic effect of SCTWD on 1-methyl-3-nitro-1-nitrosoguanidine-induced PLGC in rats and the mechanism of this effect. We found that SCTWD effectively repaired gastric mucosal injury, reversed the process of PLGC, and inhibited the occurrence of gastric cancer to some extent. In the results of hematoxylin-eosin (HE) staining, the number and arrangement of mucosal glands and the number of mononuclear cells in the lamina propria were improved in varying degrees; the enzyme-linked immunosorbent assay (ELISA) showed that the PG I and PGR of the medication treatment group were significantly higher; a Reverse Transcription-Polymerase Chain Reaction (RT-PCR) test showed that SCTWD could significantly upregulate the expression levels of Shh, Ptch, and Gli-1 in the gastric tissue of rats. The immunohistochemical method showed that SCTWD could significantly upregulate the protein expressions of Shh, Gli-1, Smo, cyclin D1, CDKN2A/p16INK4a, and NF-κBP65 and could reduce the expression of Ptch at the same time. Through the preliminary analysis of 75 compounds screened by UPLC-Q-TOF-MS, the main components, such as organic acids, esters and anhydrides, flavonoids, phenols, tanshinones, and so on, have anti-inflammatory and anti-tumor pharmacological effects. The results of KEGG enrichment analysis showed that 5 signaling pathways related to this project were found, and 33 differential genes were presented to construct the interaction network. These results suggested that SCTWD had a good regulatory effect on PLGC and thus may have a multi-targeted effect; SCTWD can not only significantly improve the pathological changes of gastric mucosa in rats with PLGC but also exert a strong effect of the regulation of the hedgehog signaling pathway.

Expression and prognostic significance of EPAS-1 in renal clear cell carcinoma.

OBJECTIVE: predict the relationship between EPAS-1 in the occurrence and development of renal cell carcinoma and its effect on prognosis. METHODS: The immunohistochemical EnVision two-step method was used to detect the expression of EPAS-1 protein in 145 cases of renal cell carcinoma and adjacent tissues to verify the correlation between EPAS-1 expression and clinicopathological characteristics and its effect on survival. RESULTS: The expression of EPAS-1 protein in renal cell carcinoma and adjacent tissues was 75.9% and 15.9%, respectively. Univariate analysis showed that positive expression of EPAS-1, PT staging, lymphatic metastasis, distant metastasis, and ISUP grade were associated with poor prognosis of renal cell carcinoma (P <0.05); Multivariate analysis results showed that EPAS-1 protein and ISUP classification are independent prognostic factors for renal cell carcinoma. Kaplan-Mier survival analysis showed that the survival rate of renal cell carcinoma patients increased with the expression of EPAS-1 protein decreased significantly (P <0.05). CONCLUSION: The expression of EPAS-1 protein is related to the PT stage, lymphatic metastasis, distant metastasis, and ISUP classification of renal cell carcinoma. EPAS-1 can be used as a potential prognostic marker or Treatment target. KEY WORDS: EPAS-1 prognosis, Immunohistochemistry, Molecular markers, Renal neoplasms, Renal clear cell carcinoma.

SREBP1 site 1 protease inhibitor PF-429242 suppresses renal cell carcinoma cell growth.

Renal cell carcinoma (RCC) cells have increased lipogenesis and cholesterol synthesis. Sterol regulatory element-binding protein-1 (SREBP1) is cleaved by site 1 protease (S1P) to release the transcriptionally active amino-terminal domain. PF-429242 is a potent and competitive S1P inhibitor. We here tested its activity in RCC cells. In established and primary human RCC cells, PF-429242 potently inhibited cell proliferation, migration, and invasion. The S1P inhibitor provoked apoptosis activation in RCC cells. Furthermore, shRNA-mediated S1P silencing or CRISPR/Cas9-induced S1P knockout led to RCC cell growth inhibition and apoptosis activation. Conversely, ectopic overexpression of SREBP1 or S1P augmented RCC cell proliferation and migration. Daily i.v. injection of a single dose of PF-429242 robustly inhibited RCC xenograft growth in severe combined immunodeficiency mice. Additionally, intratumoral injection of S1P shRNA lentivirus inhibited RCC xenograft growth in mice. SREBP1, S1P, and its target gene low density lipoprotein receptor (LDLR) were significantly elevated in human RCC tissues. These results suggest that targeting S1P by PF-429242 inhibited RCC cell growth in vitro and in vivo.

Downregulation of MiR-1297 predicts poor prognosis and enhances gastric cancer cell growth by targeting CREB1.

Dysregulation of mircoRNAs (miRs) that act as tumor suppressors or oncogenes is participated in tumorigenesis and progression. The aim of the study is to investigate the role and mechanism of miR-1297 in gastric cancer (GC). Here, we demonstrated that miR-1297 expression was significantly lower in GC tissue samples compared to adjacent normal tissue samples in 62 cases GC patients. Lower miR-1297 expression positively associated with larger tumor size, lymph node metastasis, advanced TNM stage and poor survival time of patients. Upregulation of miR-1297 significantly inhibited cell proliferation and cell colony forming abilities in vitro. However, downregulation of miR-1297 can cause the reverse biological function changes. In vivo, miR-1297 overexpression suppressed tumor growth. Luciferase reporter assay showed that CREB1 was a direct target of miR-1297 in GC. MiR-1297 inhibited the expression of CREB1 by targeting the 3'UTR of CREB1. Additionally, we demonstrated that CREB1 overexpression rescued the effects on GC cell growth induced by miR-1297. Therefore, these results indicated that miR-1297 might be a prognostic predictor for GC and potential target of GC treatment.

Arsenic trioxide-enhanced, matrine-induced apoptosis in multiple myeloma cell lines.

Matrine and arsenic trioxide are monomers used in traditional Chinese medicine possessing anti-myeloma activities. In this study, we evaluated the effects and mechanisms of matrine, arsenic trioxide, and their combination therapy on the proliferation and apoptosis of the myeloma cell lines RPMI8226 and U266. The effects of growth inhibition were measured by MTT, and apoptotic cells were analyzed by Hoechst 33258 staining and flow cytometry. The levels of caspase-3, poly (ADP-ribose) polymerase (a DNA repair enzyme), Bcl-2 and survivin (antiapoptotic signaling proteins), Bim (a proapoptotic signaling protein), total AKT, and phosphorylated AKT were evaluated by Western blot. Matrine significantly inhibited proliferation of RPMI8226 and U266 cell lines in a dose- and time-dependent manner with an IC50 at 24 h of 2.25 g/L and 2.18 g/L, and at 48 h of 1.64 g/L and 1.58 g/L, respectively. Arsenic trioxide also displayed a dose- and time-dependent inhibition of growth of multiple myeloma cell lines, and synergistic effects occurred when the two were combined. Matrine (0.5, 1.0 g/L) and arsenic trioxide (2, 4 ug/mL) induced the apoptosis of myeloma cells; more early-stage apoptotic cells were seen with the combination therapy (matrine 0.5 g/L plus arsenic trioxide 2 ug/mL and matrine 1.0 g/L plus arsenic trioxide 4 ug/mL). Activation of caspase-3 and poly (ADP-ribose) polymerase, upregulation of Bim expression, downregulation of Bcl-2, survivin expression, as well as inhibition of phosphorylated AKT related to matrine (0, 0.25, 0.5, 1.0, and 2.0 g/L)-mediated apoptosis, and the effects were enhanced when arsenic trioxide (8 ug/mL) was combined with matrine (1.0 g/L). In conclusion, matrine displayed anti-myeloma effects through apoptotic induction, and arsenic trioxide had synergistic effects with matrine enhancing matrine-induced apoptosis.