Online Detection of Hydrogen Fluoride under Corona Discharge in Gas-Insulated Switchgear Based on Photoacoustic Spectroscopy.

Internal discharge and overheating faults in sulfur hexafluoride (SF6) gas-insulated electrical equipment will generate a series of characteristic gas products. Hydrogen fluoride (HF) is one of the main decomposition gases under discharge failure. Because of its extremely corrosive nature, it can react with other materials in gas-insulated switchgear (GIS), resulting in a short existence time, so it needs to be detected online. Resonant gas photoacoustic spectroscopy has the advantage of high sensitivity, fast response, and no sample gas consumption, and can be used for the online detection of flowing gas. In this paper, a simulated GIS corona discharge experimental platform was built, and the HF generated in the discharge was detected online by gas photoacoustic spectroscopy. The absorption peak of HF molecule near 1312.59 nm was selected as the absorption spectral line, and a resonant photoacoustic cell was designed. To improve the detection sensitivity of HF, wavelength modulation and second-harmonic detection technology were used. The online monitoring of HF in the simulated GIS corona discharge fault was successfully realized. The experimental results show that the sensitivity of the designed photoacoustic spectroscopy detection system for HF is 0.445 µV/(µL/L), and the limit of detection (LOD) is 0.611 µL/L.

Siglec-15 on macrophages suppress the immune microenvironment in patients with PD-L1 negative non-metastasis lung adenocarcinoma.

Sialic acid-binding immunoglobulin-like lectin 15 (Siglec-15) is an immune checkpoint molecule with sequence homology to programmed cell death ligand 1 (PD-L1), which is mainly expressed on macrophages and tumor cells. However, whether Siglec-15-induced immunosuppression and poor prognosis are independent of PD-L1 remains unclear. In this study, we collected samples of 135 non-small cell lung cancers and found that Siglec-15 and PD-L1 expression were independent in non-small cell lung cancer by multiple immunofluorescence staining. Siglec-15 on macrophages (Mφ-Siglec-15) was significantly associated with DFS (p < 0.05) in PD-L1- patients with non-metastasis lung adenocarcinoma, not in PD-L1+ or lung squamous cell carcinoma patients. Moreover, stromal Siglec-15+ macrophages of Mφ-Siglec-15+PD-L1- patients were significantly more than those of Mφ-Siglec-15-PD-L1- patients (p = 0.002). We further found that Siglec-15+ macrophages polarized toward M2 and produced more IL-10, negatively associated with inflamed immunophenotype in PD-L1- patients and may inhibit CD8+T cells infiltration. In conclusion, PD-L1-independent Siglec-15+ macrophages contribute to the formation of an immunosuppressive microenvironment in non-metastasis lung adenocarcinoma patients, which may cause a higher risk of recurrence. Siglec-15 could be a potential target for normalizing cancer immunotherapy, benefiting patients who fail to respond to anti-PD-L1 therapy.

The influence on acoustic frequency characteristics of conductivity gradual-varying tissue in magnetoacoustic tomography (MAT).

BACKGROUND: As a functional imaging technology, magneto acoustic tomography (MAT) has broad application prospect in early tumor diagnosis and image monitoring during treatment. METHOD: The influence on the acoustic field characteristics of the gradual change in conductivity was studied in magneto-acoustic tomography with current injection (MAT-CI) in this article. RESULT: Theoretical analysis showed that the value of electro-acoustic conversion ratio (E-ACR) was different in different source frequencies under the same conductivity gradual-varying boundary. CONCLUSION: The frequency characteristics of the acoustic pressure tend to shift towards the low frequency region. This conclusion provides a theoretical foundation for the MA signal detection and processing system optimization in the area of conductivity gradual-varying.

Action of topical thyroid hormone analogues on glucocorticoid-induced skin atrophy in mice.

Previously we demonstrated the stimulation of collagen synthesis in triiodothyroacetic acid (TRIAC)-topically treated human and mice. In the present study, we have evaluated the dose response effect of thyroid hormone (TH) analogues and tretinoin on glucocorticoid-induced skin atrophy in a haired mouse model. For this investigation, we treated haired mice twice daily for 7 days with various topically administered doses of TRIAC, triiodothyronine-sodium salt (T(3)-Na), diiodothyroacetic acid (DIAC), 3,5-diiodothyropropionic acid (DITPA), and tretinoin with 0.2 mM betamethasone17-valerate (BM), or with the vehicle as a control group. We also investigated a combination of commercial betamethasone dipropionate (BD) 0.05% cream and various doses of TRIAC on mouse skin. TRIAC was able to reverse the skin atrophy by 25% in a daily dose of 1 nmol/cm(2) in the presence of 0.2 mM BM (p < 0.05). Neither other TH analogues nor TRIAC in lower and higher concentrations had a significant inhibitory effect on dermal atrophy (p > 0.05). A combination of 0.2 mM BM and 10 nmol/cm(2) TRIAC was able to prevent dermal atrophy by 18%. The addition of TRIAC to 0.05% BD cream in a final concentration of 0.1% was able partially to reverse the dermal atrophy by 15% (p < 0.05). TRIAC alone in a concentration of 1,000 nmol/cm(2) stimulated dermal proliferation by 34% (p < 0.05). Other TH analogues alone had no stimulatory effect on dermal proliferation. Tretinoin 0.8 mM was able to inhibit dermal atrophy by 20% (p < 0.05) and had an effect on dermal thickness of 85% (p < 0.05). However, severe side effects with edema, erythema, and scaling were commonly observed in all tretinoin-treated mouse skin, which could partly explain the increase in dermal thickness. In contrast, no skin side effects were observed after treatment with TRIAC. This study indicates that TRIAC may have a therapeutic effect on BM-induced dermal atrophy in mouse skin and a direct stimulatory effect on dermal proliferation when given alone.

Dose-response effects of tri-iodothyroacetic acid (Triac) and other thyroid hormone analogues on glucocorticoid-induced skin atrophy in the haired mouse.

Thyroid hormones have an influence on the connective tissue biology of the skin and, theoretically, topically applied thyroid hormones or hormone analogues could have a stimulatory effect on collagen synthesis. In this investigation the effect of topical tri-iodothyroacetic acid (Triac) and other thyroid hormone analogues were tested for their effect in preventing betamethasone-induced skin atrophy in the normal haired mouse. Triac, tri-iodoproprionic acid (Triprop) and the synthetically developed thyroid hormone analogue KB-026 and 2 different Triac cream formulations were applied along with betamethasone on shaved mouse skin. Triac in daily doses of 1 nmol/cm2 and higher was able to block the betamethasone-induced skin atrophy in mice skin. In high doses, Triprop and KB-026 also had a blocking effect. Triac alone had a stimulatory effect on dermal thickness. This study indicates that thyroid hormone analogues may be used to prevent corticosteroid-induced skin atrophy.