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To understand the effect of the hydroxyl group and processing temperatures on dielectric losses of flame retardants and flame-retardant polymers, the performance difference between 6-methyldibenzo[c,e][1,2]oxaphosphinine 6-oxide (DOPO-Me) and 6-(hydroxymethyl)dibenzo[c,e][1,2]oxaphosphinine 6-oxide (DOPO-HM) has been investigated, respectively, in non-polar and polar polymers at 7–20 GHz. DOPO-HM and DOPO-Me differ by only one OH group. The former demonstrates a lower dissipation factor (Df) than the latter, owing to hydrogen bonds. In polystyrene and crosslinked polyphenylene oxide, both flame retardants increase a dielectric loss of flame-retardant polymers, with DOPO-HM being less detrimental because of its higher crystallizability and lower plasticization. In polar poly(methyl methacrylate) (PMMA), conformational changes in PMMA main chains caused by flame retardants and high processing temperatures lead to an early Df drop of PMMA at low loadings of the flame retardants. At high loadings, a change in the physical form of flame retardants from a primitive crystalline state to an amorphous state increases a dielectric loss of flame retardant PMMA, with DOPO-HM resulting in a slightly higher dielectric loss than DOPO-Me. These results prove that the effect of a hydroxyl group in organophosphorus structures on the dielectric loss of flame-retardant polymers is crucially dependent on its interaction with the polymer matrix.

Numerous research studies have examined carbon emissions generated from tourism activities. However, the environmental impact of anthropogenic heat release has not attracted researchers’ attention. We apply the tourism heat footprint method to assess the environmental impact of China’s tourism activities. The results indicate that (1) China’s tourism heat footprint increased from 0.99 × 10 3 w/km 2 in 1994 to 7.53 × 10 3 w/km 2 in 2018, with an average annual growth rate of 8.82%. (2) Particularly during high seasons, the tourism heat footprint increases sharply; tourism transportation accounts for the highest proportion of the tourism heat footprint, ranging from 36.50 to 69.07% from 1994 to 2018. (3) The rapid growth in arrivals and transportation-related changes have contributed to the rapid growth of the tourism heat footprint. Advances in science and technology, laws and regulations, environmental pollution constraints, and national macroeconomic policy have helped reduce the tourism heat footprint. Generally, tourism activities caused by a significant increase in income are the root cause of tourism heat footprint growth. (4) Finally, some suggestions, including cultivating a low-energy tourism culture, improving energy efficiency, implementing low-energy policies, and performing spatial-temporal monitoring, are proposed. This paper expands sustainable tourism’s analytical research and enriches the tourism footprint family evaluation process.

Background Postmastectomy radiation therapy (PMRT) can influence the outcome of implant-based breast reconstruction (IBBR). This study aims to investigate the complications and patient-reported outcomes (PROs) following PMRT between direct-to-implant (DTI) and tissue expander-to-implant (TEI) reconstruction. Methods The retrospective study included breast cancer patients undergoing IBBR and PMRT. Patients were divided into a permanent implant group (PI-PMRT) and a tissue expander group (TE-PMRT). Complications, reconstruction failure, and reoperation were compared between the two groups. PROs were assessed using the BREAST-Q scale. Results A total of 203 patients were included: 99 in the PI-PMRT group and 104 in the TE-PMRT group. The incidence of severe capsular contracture was significantly higher in the PI-PMRT group compared to the TE-PMRT group (37.4% vs. 24.0%, p  = 0.039). The PI-PMRT group had a significantly lower rate of reconstruction failure (9.1% vs. 19.2%, p  = 0.039) and reoperation (13.1% vs. 24.0%, p  = 0.046). Multivariate analysis revealed that the absence of mesh (OR = 2.177, p  = 0.040) and DTI reconstruction (OR = 1.922, p  = 0.046) were independent predictors of severe capsular contracture; the absence of mesh (OR = 4.699, p  = 0.015) and TEI reconstruction (OR = 2.429, p  = 0.043) were independent predictors of reconstruction failure. BREAST-Q scores indicated greater breast satisfaction in the PI-PMRT group ( p  = 0.031). Conclusions Although DTI reconstruction resulted in a higher risk of severe capsular contracture, the higher risk of reconstruction failure and reoperation in patients undergoing TEI reconstruction was even more concerning. Furthermore, patients were more likely to report greater breast satisfaction with DTI reconstruction. Therefore, DTI reconstruction may be a more appropriate option for patients anticipating PMRT.

To probe the possibility of thiophenolate as an origin of dibenzothiophenes (DBTs) and establish the detailed chemical transformations from thiophenolate to DBTs, the thermal degradation of thiophenolate has been carried out at various temperatures. The characterizations of both gaseous products and solid residues indicate that DBTs together with benzene, diphenyl sulfide, and diphenyl disulfide are the major degradation products. The presence of benzene supports that the thermal degradation of thiophenolate begins with the homolysis of Ar‒H bonds. The subsequent hydroarylation followed by the elimination and cyclization reactions facilely generates DBTs. The transformation of thiophenolate to DBTs is chemically simple and highly geochemically feasible. It readily unifies the chemical pathways involved in the generation of DBTs from thiophenolate and that of dibenzofurans from phenolate in nature.

Background & objectives The introduction of traditional Chinese medicine to the treatment of breast cancer increases the risk of adverse herb-herb interactions. Both nobiletin and tetrahydrocurcumin (THC) have been demonstrated to inhibit breast cancer progression, which makes them easily co-prescribed. This study evaluated the co-administration of nobiletin and THC, aiming to assess their synergistic effect in inhibiting breast cancer and reveal the potential mechanism. Materials & methods A single dosage of nobiletin and its co-administration with THC were performed in rats. The pharmacokinetic profiling of nobiletin was analyzed under the two administration strategies. Rat liver microsomes were employed for evaluating the metabolic stability of nobiletin and the activity of CYP1A1 with the probe-substance assay. The cytotoxicity of nobiletin and its combination with THC was evaluated in MCF-7 cells with the help of the CCK8 assay. Results Co-administration strategy significantly changed the pharmacokinetics of nobiletin with the increasing Cmax (187.00 ± 9.27 vs. 145.87 ± 8.16 mg/L), prolonging t 1/2 (22.01 ± 5.46 vs. 12.16 ± 1.20 h), and decreasing clearance rate (0.039 ± 0.01 vs. 0.062 ± 0.01 L/h/kg). THC increased the metabolic stability of nobiletin and enhanced its inhibitory effect on breast cancer cell growth. Additionally, THC also improved the cytotoxicity of nobiletin to MCF-7 cells, with the IC 50 value decreased from 27.38 to 6.52 µM. Significant inhibition of CYP1A1 was observed under the treatment of THC. Conclusion Co-administration of nobiletin with THC increased its systemic exposure and enhanced its cytotoxicity to breast cancer. The inhibited activity of CYP1A1 was considered the underlying mechanism of their interaction.

Glaciers are distributed in the Nyainqntanglha Mountains, Himalayas, Tanggula Mountains, Gangdise Mountains and Hengduan Mountains in Southwestern China. Daily temperature and precipitation data from 111 stations, together with the records of glacier changes, indicate that temperature patterns during 1961–2008 were consistent with warming at a statistically significant level. Seasonal warming was greatest in autumn and winter. Temperature rise showed a significant relationship with sea surface temperature in the Western Pacific, net longwave radiation flux, altitude, sunshine hours, strengthening anticyclonic circulations in summer and anomalous cyclonic circulation in winter. The increase was more apparent in higher altitude areas than in lower ones. Precipitation variations were less marked than those of temperature, generally showing weak decreasing trends during 1961–2008. Increasing trends were apparent only in spring and winter, when regional trends of precipitation increases with altitude also were evident. The strengthening Western Pacific Subtropical Highs were related to precipitation variation. Against the background of increasing temperature, especially the increasing warming with altitude, the fronts of 32 glaciers and areas of 13 glacial basins have retreated, mass losses of 10 glaciers have been considerable, glacial lakes in six regions have expanded and melt water discharge of four basins has also increased, but these glaciers and basins in our study are only a fraction of the retreating glaciers over southwestern China.

A total of 12 indices of temperature extremes and 11 indices of precipitation extremes at 111 stations in southwestern China at altitudes of 285-4700 m were examined for the period 1961-2008. Significant correlations of temperature extremes and elevation included the trends of diurnal temperature range, frost days, ice days, cold night frequency and cold day frequency. Regional trends of growing season length, warm night frequency, coldest night and warmest night displayed a statistically significant positive correlation with altitude. These characteristics indicated the obvious warming with altitude. For precipitation extreme indices, only the trends of consecutive dry days, consecutive wet days, wet day precipitation and the number of heavy precipitation days had significant correlations with increasing altitude owing to the complex influence of atmospheric circulation. It also indicated the increased precipitation mainly at higher altitude areas, whereas the increase of extreme precipitation events mainly at lowers altitude. In addition, the clearly local influences are also crucial on climate extremes. The analysis revealed an enhanced sensitivity of climate extremes to elevation in southwestern China in the context of recent warming.

This study focused on the chemical compositions of the rivers around Yulong Mountain, one of the typical monsoonal temperate glacier regions in China. Water samples were collected from Baishui, Sanshu and Geji hydrological stations around Mt. Yulong during rainy season. The chemical analyses indicated that the river water around Mt. Yulong was characterized by high pH values (>8.0) and EC values varied from 36.4 to 71.7 μS/cm with an average of 52.6 μS/cm. Ca²⁺ and Mg²⁺ were the dominant cations, together accounting for about 90 % of the total cations. HCO₃ ⁻, followed by SO₄ ²⁻, was the dominant anion. Obvious variations had been perceived during the rainy season. River water chemistry in rainy season was mainly influenced by precipitation and rock weathering. The proportions of Na⁺, K⁺, Ca²⁺, Mg²⁺ and SO₄ ²⁻ from precipitation in river water were 23.44, 9.66, 3.10, 17.81 and 10.48 %, respectively. In addition, the ion characteristics of river water were mainly influenced by carbonate weathering. The human activities should not be ignored though its influence was little.

An extremely efficient flame retardant with low water solubility has been developed for bisphenol-A based polycarbonate. Potassium trimethylsilylbenzenesulfonate (KTSS) combining trimethylsilyl and sulfonate groups in its molecule is 7 times less water soluble and 5 times more effective in flame retardancy than potassium benzenesulfonylbenzenesulfonate (KSS), the commercial workhorse for polycarbonate (PC). At a loading of 0.02%, KTSS enables PC to achieve a solid UL-94 V0 rating and a limiting oxygen index (LOI) value of 34.4%, representing an increase of 8.5 units. The extremely high efficiency of KTSS stems from its great migration ability to the burning polymer surface facilitated by trimethylsilyl group, its timely release of active alkaline species that promote the charring process of PC, and the stabilization of char by silicon. In addition to the exceptional flame retardancy, PC/KTSS retains excellent physical properties of PC.

Objective To measure clusterin expression in pancreatic cancer tissues and cell lines and to evaluate whether clusterin confers resistance to gmcitabine in pancreatic cancer cells. Methods Immunohistochemistry for clusterin was performed on 50 primary pancreatic cancer tissues and 25 matched backgrounds, and clusterin expression in 5 pancreatic cancer cell lines was quantified by Western blot and PT-PCR. The correlation between clusterin expression level and gmcitabine IC50 in pancreatic cancer cell lines was evaluated. The effect of an antisense oligonucleotide (ASO) against clusterin(OGX-011) on gmcitabine resistance was evaluated by MTT assays. Xenograft model was used to demonstrate tumor growth. Results Pancreatic cancer tissues expressed significantly higher levels of clusterin than did normal pancreatic tissues ( P < 0.01). Clusterin expression levels were correlated with gmcitabine resistance in pancreatic cancer cell lines, and OGX-011 significantly decreased BxPc-3 cells resistance to gmcitabine ( P < 0.01). In vivo systemic administration of AS clusterin and gmcitabine significantly decreased the s.c. BxPC-3 tumor volume compared with mismatch control ODN plus gmcitabine. Conclusion Our finding that clusterin expression was significantly higher in pancreatic cancer than in normal pancreatic tissues suggests that clusterin may confer gmcitabine resistance in pancreatic cancer cells.