Interaction Between Air Plasma-Produced Aqueous 1O2 and the Spin Trap DMPO in Electron Spin Resonance

A series of electron spin resonance (ESR) experiments is done to quantitatively measure the concentrations of aqueous 1O2 and OH produced by a surface micro-discharge air plasma device. 1O2 is tested to be existed in the plasma treated solution by using the spin trap of TEMP. However, the unexpected DMPOX spectrum is observed in measuringOH by the spin trap of 5,5-Dimethyl-1-Pyrroline-N-Oxide (DMPO). With more chemical scavenger experiments, it is found that removal of aqueous 1O2 leads to the disappearance of DMPOX in ESR. Therefore, the generation of DMPOX is directly related to the oxidation of DMPO by plasma-produced aqueous 1O2. This oxidation process and interactions between DMPO and chemical scavengers used in experiments can all be well explained by a proposed reaction mechanism. The revelation of interactions between aqueous 1O2 and the spin trap DMPO shows that the observation of spectra of DMPOX in the ESR measurement can be regarded as a marker of high concentrations of plasma-produced 1O2 in liquid. These results also prove the existence of interactions between spin traps and non-targeted plasma-produced reactive species in ESR experiments. Also, these results have offered a better understanding of the use of spin traps such as DMPO in the plasma-induced highly oxidative aqueous environment. Published by AIP Publishing

Antimicrobial Efficacy and Safety of a Novel Gas Plasma-Activated Catheter Lock Solution

Antimicrobial lock solutions are important for prevention of microbial colonization and infection of long-term central venous catheters. We investigated the efficacy and safety of a novel antibiotic-free lock solution formed from gas plasma-activated disinfectant (PAD). Using a luminal biofilm model, viable cells of methicillin-resistant Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa, and Candida albicans in mature biofilms were reduced by 6 to 8 orders of magnitude with a PAD lock for 60 min. Subsequent 24-h incubation of PAD-treated samples resulted in no detectable regrowth of viable bacteria or fungi. As a comparison, the use of a minocycline-EDTA-ethanol lock solution for 60 min led to regrowth of bacteria and fungi, up to 10(7) to 10(9) CFU/ml, in 24 h. The PAD lock solution had minimal impact on human umbilical vein endothelial cell viability, whereas the minocycline-EDTA-ethanol solution elicited cell death in nearly half of human endothelial cells. Additionally, PAD treatment caused little topological change to catheter materials. In conclusion, PAD represents a novel antibiotic-free, noncytotoxic lock solution that elicits rapid and broad-spectrum eradication of biofilm-laden microbes and shows promise for the prevention and treatment of intravascular catheter infections

Effect of He Plasma Jet Versus Surface Plasma on the Metabolites of Acute Myeloid Leukemia Cells

Cold atmospheric plasma, including plasma jet and surface plasma, can promote the apoptosis of cancer cells without causing significant damage to surrounding normal cells, which was hopeful to be applied to the clinical cancer therapy. However, experimental plasma devices used directly to clinical experiments has challenges in technology and methods, especially the difference in killing tumor cells efficiency of these two common plasma sources. Therefore, it is great necessity to explore the differences in treating tumors between different plasma sources. This paper achieved good killing efficiency by using two kinds of cold atmospheric plasma generating devices, namely plasma jet and surface plasma treatment along acute myeloid leukemia (AML). The results showed that the He plasma jet kills leukemia cells more efficiently than surface plasma with the same voltage and frequency and the same time. By GC-TOFMS and metabolomics analysis, this paper compared the differential metabolites of leukemia cells treated by two plasma devices and the key metabolic pathways closely related to differential metabolites. Simultaneously, we found alanine, aspartate and glutamate metabolism was most correlated with a key differential metabolite, glutamine. It was found that the glutaminase activity of He plasma jet group was lower than that of surface plasma group, which might be a reason for He plasma jet group to kill tumor cells better. It was also worth noting that relative quantity of glucose metabolites of plasma jet treatment group was lower than that of surface plasma treatment group. This study provides the basis for clinical trials for future

Fringe Visibility Enhanced Extrinsic Fabry-Perot Interferometer using a Graded Index Fiber Collimator

We report a fringe visibility-enhanced extrinsic Fabry-Perot interferometer (EFPI) by fusion splicing a quarter-pitch length of a graded-index fiber (GIF) to the lead-in single mode fiber (SMF). The performance of the GIF collimator is theoretically analyzed using a ray matrix model and experimentally verified through beam divergence angle measurements. The fringe visibility of the GIF-collimated EFPI is measured as a function of the cavity length and compared with that of a regular SMF-EFPI. At the cavity length of 500 μm, the fringe visibility of the GIF-EFPI is 0.8, while that of the SMF-EFPI is only 0.2. The visibility-enhanced GIF-EFPI may provide a better signal-to-noise ratio (SNR) for applications where a large dynamic range is desired

Synergistic Effect of Ferulic Acid and Z-Ligustilide, Major Components of A. sinensis

Angelica sinensis has been used to attenuate cold-induced cutaneous vasospasm syndrome, such as Raynaud’s disease and frostbite, in China for many years. Ferulic acid (PubChem CID: 445858) and Z-ligustilide (PubChem CID: 529865), two major components extracted from Angelica sinensis, had been reported to inhibit vasoconstriction induced by vasoconstrictors. In this study, the pharmacological interaction in regulating cold-induced vascular smooth muscle cell contraction via cold-sensing protein TRPM8 and TRPA1 was analyzed between ferulic acid and Z-ligustilide. Pharmacological interaction on inhibiting [Ca2+]i influx evoked by TRPM8 agonist WS-12 or TRPA1 agonist ASP 7663 as well as cold-induced upregulation of TRPM8 was determined using isobolographic analysis. The isobolograms demonstrated that the combinations investigated in this study produced a synergistic interaction. Combination effect of two components in inhibiting RhoA activation and phosphorylation of MLC20 induced by WS-12 or ASP 7663 was also being quantified. These findings suggest that the therapeutic effect of Angelica sinensis on cold-induced vasospasm may be partially attributed to combinational effect, via TRPM8 and TPRA1 way, between ferulic acid and Z-ligustilide

The correlation between the plasma concentration of gemcitabine and short-term efficacy and adverse reactions in patients with advanced squamous cell carcinoma of the lung using liquid chromatography-mass spectrometry

AbstractBackground: Worldwide, non-small cell lung cancers have the highest incidence and mortality rates of all cancers. Gemcitabine (2’,2’-difluoro-2’-deoxycytidine or dFdC, C9H11F2N304) is widely used as the first-line chemo-reagent for lung cancer patients whose tumors have been diagnosed to be at an advanced stage and are therefore unresectable. Objective: The objective of this systematic study was to establish the correlation between the plasma concentration of gemcitabine and short-term clinical efficacy and adverse reactions in patients with advanced squamous cell carcinoma of the lung using liquid chromatography-mass spectrometry. Material and methods: In total, 53 patients were given the chemotherapy medications, gemcitabine and cisplatin, every 3 weeks. Plasma concentrations of gemcitabine were determined using liquid chromatography-mass spectrometry. A modified methodology of the liquid chromatography-mass spectrometry system was verified and performed to detect plasma concentrations of gemcitabine. The clinical endpoints – short-term clinical efficacy and adverse reactions – were evaluated after two cycles. Results: The plasma concentration range of gemcitabine in 53 patients was 1.58-28.70μg/ml (mean 14.37±8.63μg/ml), with 28 patients in the >15μg/ml group (mean 21.76±3.45μg/ml), and 25 patients in the ≤15μg/ml group (mean 6.09±3.57μg/ml). The clinical benefit rate (CBR) of the >15μg/ml group was significantly higher than that of the 15μg/ml group (p<0.05). The incidences of leukopenia and neutropenia, thrombocytopenia and grade III-IV gastrointestinal reactions in the >15μg/ml group were significantly higher than in the ≤15μg/ml group (p<0.05). There was no statistical difference between the two groups in terms of the incidences of reduced hemoglobin, liver and kidney function damage, allergic reaction and rash (p>0.05). The analysis of the plasma concentration of gemcitabine and the percentage of reduction in neutrophil count (NEUT) (r2 = 0.3212; p<0.05) and platelet (PLT) (r2 = 0.6439; p<0.05) showed a significant positive correlation. Conclusions: In patients with advanced non-small cell lung cancer, a high plasma concentration of gemcitabine can improve the short-term clinical efficacy of treatment, but increase the incidence of grade III-IV adverse reactions. [Ethiop. J. Health Dev. 2021; 35(1):72-82] Key words: Non-small cell lung cancer, gemcitabine, plasma concentration, short-term efficacy, adverse reaction

Thermomechanical property of rice kernels studied by DMA

The thermomechanical property of the rice kernels was investigated using a dynamic mechanical analyzer (DMA). The length change of rice kernels with a loaded constant force along the major axis direction was detected during temperature scanning. The thermomechanical transition occurred in rice kernels when heated. The transition temperatures were determined as 47°C, 50°C and 56°C for the medium-grain rice with the moisture contents of 18.1%, 16.0% and 12.5% (wet basis), respectively. Length change of the rice kernels increased with the increase of the temperature and moisture content. Among the four rice varieties investigated, the results showed that the thermomechanical property was not significantly affected by variety