无稀释气立式氧碘化学激光器的设计与实验

分析了氧碘化学激光器（COIL）在无稀释气条件下工作所带来的一系列问题和对其性能的影响,并提出了相应的解决方法,进而对COIL结构和相关参数进行了有针对性的设计和实验研究。在氯气流量为117.6 mmol/s时,平均输出功率2.25 kW,化学效率达到21.1%,比功率0.22 J/g;分别以氦气和氮气为稀释气,对COIL进行了参数和实验数据比较。     

Nephroprotective Effects of Alhagi camelorum against Cisplatin-Induced Nephrotoxicity in Albino Wistar Rats

Alhagi camelorum (AC) is an old plant with a significant therapeutic value throughout Africa, Asia, and Latin America. The overuse of cisplatin (Cis > 50 mg/m²) is associated with observed nephrotoxicity, ototoxicity, gastrotoxicity, myelosuppression, and allergic reactions. Remedial measures are needed for the protection of nephrotoxicity against cisplatin. Thus, we investigated the nephroprotective effects of AC plant extract to prevent cisplatin-induced nephrotoxicity in albino Wistar rats. The presence of polyphenols, phenolic compounds, tannins, and saponins was revealed during phytochemical investigation, and a significantly intense antioxidant activity was recorded. There were no toxicological symptoms in the treated rats, and no anatomical, physiological, or histological abnormalities were found compared to the control rats. The results of correcting cisplatin-induced nephrotoxicity revealed that the extract has a significant ability to treat kidney damage, with most parameters returning to normal after only three weeks of therapy. It is concluded that co-administration of cisplatin with AC extract showed exceptional nephroprotective effects at a dose of 600 mg/kg for Cis-induced nephrotoxicity.     

Biological Risk Assessment of Three Dental Composite Materials following Gas Plasma Exposure

Gas plasma is an approved technology that generates a plethora of reactive oxygen species, which are actively applied for chronic wound healing. Its particular antimicrobial action has spurred interest in other medical fields, such as periodontitis in dentistry. Recent work has indicated the possibility of performing gas plasma-mediated biofilm removal on teeth. Teeth frequently contain restoration materials for filling cavities, e.g., resin-based composites. However, it is unknown if such materials are altered upon gas plasma exposure. To this end, we generated a new in-house workflow for three commonly used resin-based composites following gas plasma treatment and incubated the material with human HaCaT keratinocytes in vitro. Cytotoxicity was investigated by metabolic activity analysis, flow cytometry, and quantitative high-content fluorescence imaging. The inflammatory consequences were assessed using quantitative analysis of 13 different chemokines and cytokines in the culture supernatants. Hydrogen peroxide served as the control condition. A modest but significant cytotoxic effect was observed in the metabolic activity and viability after plasma treatment for all three composites. This was only partially treatment time-dependent and the composites alone affected the cells to some extent, as evident by differential secretion profiles of VEGF, for example. Gas plasma composite modification markedly elevated the secretion of IL6, IL8, IL18, and CCL2, with the latter showing the highest correlation with treatment time (Pearson’s r > 0.95). Cell culture media incubated with gas plasma-treated composite chips and added to cells thereafter could not replicate the effects, pointing to the potential that surface modifications elicited the findings. In conclusion, our data suggest that gas plasma treatment modifies composite material surfaces to a certain extent, leading to measurable but overall modest biological effects.     

Kinetics and mechanism of catalytic oxidation of alcohols to carbonyl compounds with dioxygen in the Pd-containing aqua system

The oxidation of lower aliphatic alcohols C₁–C₄ with dioxygen to form the corresponding carbonyl compounds in the presence of the PdII tetraaqua complexes and Fe^II-Fe^III aqua ions in an aqueous medium was studied at 40–80 °C. The introduction of an aromatic compound (acetophenone, benzonitrile, phenylacetonitrile, o-cyanotoluene, nitrobenzene) and Fe^II aqua ion instead of the Fe^III aqua ion into the reaction system increases substantially the catalytic activity and the yield of the carbonyl compound. The key role of the Pd species in the intermediate oxidation state stabilized by the aromatic additive in the catalytic cycle of alcohol oxidation with dioxygen to the carbonyl compound was shown. An increase in the kinetic isotope effect with an increase in the temperature of methanol oxidation indicates a change in the rate-determining step of alcohol oxidation with dioxygen in the presence of Pd^II-Fe^II-Fe^III and the aromatic compound. At temperatures below 60 °C, the catalytically active palladium species are mainly formed upon the reduction of the Pd^II tetraaqua complex with the Fe^II aqua ion, whereas at higher temperatures the reaction between the alcohol and Pd^II predominates. The mechanism and kinetic equation of the process were proposed. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 842–848, May, 2007.     

Dependence of calibration sensitivity of a polysulfone/Ru(II)-tris(4,7-diphenyl-1,10-phenanthroline)-based oxygen optical sensor on its structural parameters

The optimum performance of an optical oxygen sensor based on polysulfone (PSF)/[Ru(II)-Tris(4,7-diphenyl-1,10-phenanthroline)] octylsulfonate (Ru(dpp)OS) was checked by carefully tuning the parameters affecting the membrane preparation. In particular, membranes having thickness ranging between 0.2 and 8.0 μm with various luminophore concentrations were prepared by dip-coating and tested. The membrane thickness was controlled by tuning the solution viscosity, and was measured both by secondary ion mass spectrometry (SIMS) and by visible spectroscopy (Vis). Luminescence-quenching-based calibration was a single value of the Stern-Volmer constant (K^′SV) for membranes containing up to 20 mmol Ru(dpp) g⁻¹ PSF (1.35 μm average thickness). The K^′SV value decreased for larger concentration. The highest sensitivity was obtained with membrane thickness around 1.6 μm, having a response time close to 1 s. Thicker membranes exhibited an emission saturation effect and were characterized by longer response time. The K^′SV behavior was interpreted on the basis of a mathematical approach accounting for the contribution of luminescence lifetime (τ₀), oxygen diffusion coefficient (DO₂) and oxygen solubility inside the membrane (sO₂) establishing the role of all of them and allowing their experimental determination. Moreover, a simple experimental way to estimate K^′SV without needing calibration was proposed. It was based either on the light emission asymmetry or on the percent variation of light emission on passing from pure nitrogen to pure oxygen.     

Electrochemical impedance spectroscopy of poly{pyrrole-trans-[(RuCl2(pmp)4]} copolymer films deposited on platinum electrodes

The present study focuses on the electronic and electrochemical features of a copolymer electrochemically grown from pyrrole and trans-[RuCl₂(pmp)₄] monomers, where pmp = 3-(pyrrol-1-ylmethyl)pyridine. The results from electrochemical impedance spectroscopy analyses revealed the redox behavior of the poly{pyrrole-trans-[RuCl₂(pmp)₄]} compound as well as the non-homogeneous nature of the extremely thin polymeric layers. An equivalent circuit is proposed for an optimized film produced under the scope of the work. Received: 4 May 1998 / Accepted: 24 August 1998     

Evolution and Trade-Off Dynamics of Functional Load

Functional load (FL) quantifies the contributions by phonological contrasts to distinctions made across the lexicon. Previous research has linked particularly low values of FL to sound change. Here, we broaden the scope of enquiry into FL to its evolution at higher values also. We apply phylogenetic methods to examine the diachronic evolution of FL across 90 languages of the Pama–Nyungan (PN) family of Australia. We find a high degree of phylogenetic signal in FL, indicating that FL values covary closely with genealogical structure across the family. Though phylogenetic signals have been reported for phonological structures, such as phonotactics, their detection in measures of phonological function is novel. We also find a significant, negative correlation between the FL of vowel length and of the following consonant—that is, a time-depth historical trade-off dynamic, which we relate to known allophony in modern PN languages and compensatory sound changes in their past. The findings reveal a historical dynamic, similar to transphonologization, which we characterize as a flow of contrastiveness between subsystems of the phonology. Recurring across a language family that spans a whole continent and many millennia of time depth, our findings provide one of the most compelling examples yet of Sapir’s ‘drift’ hypothesis of non-accidental parallel development in historically related languages.     

A New Supramolecular Tetraruthenated Cobalt (II) Porphyrazine Displaying Outstanding Electrocatalytical Performance in Oxygen Evolution Reaction

A new supramolecular electrocatalyst for Oxygen Evolution Reaction (OER) was synthesized from a central multibridging cobalt tetrapyridylporphyrazine (CoTPyPz) species by attaching four [Ru(bpy)₂Cl]⁺ groups. Both CoTPyPz and the tetraruthenated cobalt porphyrazine species, TRuCoTPyPz, form very homogenous molecular films just by dropcasting their methanol solutions onto GCE electrodes. Such films exhibited low overpotentials for O₂ evolution, e.g., 560 e 340 mV, respectively, displaying high stability, typically exceeding 15 h. The kinetic parameters obtained from the Tafel plots showed that the peripheral complexes are very important for the electrocatalytic activity. Hyperspectral Raman images taken along the electrochemical process demonstrated that the cobalt center is the primary active catalyst site, but its performance is enhanced by the ruthenium complexes, which act as electron-donating groups, in the supramolecular system.     

逆Walsh序p值Walsh变换的演化生成及快速算法

本文利用二分演化思想和矩阵分解技术 ,重点讨论逆Walsh序三值Walsh变换的演化生成和快速算法 ,并将之推广至p值情形 .