瑞芬太尼靶控输注对宫颈癌根治术患者麻醉苏醒质量、应激反应及Th1/Th2免疫平衡的影响

摘要 目的：观察瑞芬太尼靶控输注对宫颈癌根治术患者麻醉苏醒质量、应激反应及辅助T细胞（Th）1/Th2免疫平衡的影响。方法：按照随机数字表法将2023年1月到2023年6月期间我院接受的120例宫颈癌根治术患者分为舒芬太尼组（n=60,舒芬太尼麻醉）和瑞芬太尼组（n=60,瑞芬太尼麻醉）。对比两组的麻醉苏醒质量、应激反应指标[皮质醇（Cor）、去甲肾上腺素（NE）、血管紧张素1（Ang-1）、血管紧张素2（Ang-2）]、Th1/Th2免疫平衡指标[包括Th1、Th2及调节性T细胞（Treg）、Th1/Th2比值],术后记录不良反应发生情况。结果：与舒芬太尼组相比,瑞芬太尼组的应激呼吸恢复时间、睁眼时间、拔管时间更短（P<0.05）。术后1 d,两组Cor、NE、Ang-1、Ang-2升高,但瑞芬太尼组低于舒芬太尼组（P<0.05）。术后1 d,两组Th1、Treg、Th1/Th2升高,但瑞芬太尼组低于舒芬太尼组;Th2下降,但瑞芬太尼组高于舒芬太尼组（P<0.05）。两组不良反应发生率组间对比未见差异（P>0.05）。结论：瑞芬太尼靶控输注用于宫颈癌根治术患者,可改善麻醉苏醒质量,减轻应激反应,调节Th1/Th2免疫平衡,且不增加不良反应的发生率,效果较好。     

限制能量平衡膳食联合运动干预对肥胖儿童身体成分、脂质代谢及肠道菌群的影响

摘要 目的：观察限制能量平衡膳食联合运动干预对肥胖儿童身体成分、脂质代谢及肠道菌群的影响。方法：选取2020年4月至2022年10月期间浙江大学医学院附属儿童医院收治的肥胖儿童104例作为研究对象。按照随机数字表法将肥胖儿童分为对照组（n=52,限制能量平衡膳食）和观察组（n=52,限制能量平衡膳食联合运动干预）。对比两组身体成分、脂质代谢及肠道菌群变化情况。结果：观察组干预2个月后体重、体质量指数（BMI）、去脂体重、脂肪量、体脂率低于对照组（P<0.05）。观察组干预2个月后总胆固醇（TC）、甘油三酯（TG）、低密度脂蛋白胆固醇（LDL-C）低于对照组;高密度脂蛋白胆固醇（HDL-C）高于对照组（P<0.05）。观察组干预2个月后肠球菌、大肠杆菌低于对照组;乳杆菌、双歧杆菌高于对照组（P<0.05）。结论：限制能量平衡膳食联合运动干预可有效改善肥胖儿童身体成分,调节脂质代谢及肠道菌群平衡。     

Phosphorus limitation of forest leaf area and net primary production on a highly weathered soil

We tested the hypothesis that P was the nutrient limiting net primary production of a nativeMetrosideros polymorpha forest on a highly weathered montane tropical soil in Hawaii. A factorial experiment used all combinations of three fertilizer treatments: nitrogen (N), phosphorus (P) and a mix of other essential nutrients (OE), consisting primarily of mineral derived cations and excluding N and P. P addition, but not N or OE, increased leaf area index within 12 months, foliar P concentration measured at 18 months, and stem diameter increment within 18 months. Stem growth at 18 months was even greater when trees fertilized with P also received the OE treatment. N and P additions increased leaf litterfall and N and P in combination further increased litterfall. The sequence of responses suggests that increased available P promoted an increase in photosynthetic area which led to increased wood production. P was the essential element most limiting to primary production on old volcanic soil in contrast to the N limitation found on young volcanic soils.     

Effects of grass species and grass growth on atmospheric nitrogen deposition to a bog ecosystem surrounded by intensive agricultural land use

We applied a ¹⁵N dilution technique called “Integrated Total Nitrogen Input” (ITNI) to quantify annual atmospheric N input into a peatland surrounded by intensive agricultural practices over a 2-year period. Grass species and grass growth effects on atmospheric N deposition were investigated using Lolium multiflorum and Eriophorum vaginatum and different levels of added N resulting in increased biomass production. Plant biomass production was positively correlated with atmospheric N uptake (up to 102.7 mg N pot⁻¹) when using Lolium multiflorum. In contrast, atmospheric N deposition to Eriophorum vaginatum did not show a clear dependency to produced biomass and ranged from 81.9 to 138.2 mg N pot⁻¹. Both species revealed a relationship between atmospheric N input and total biomass N contents. Airborne N deposition varied from about 24 to 55 kg N ha⁻¹ yr⁻¹. Partitioning of airborne N within the monitor system differed such that most of the deposited N was found in roots of Eriophorum vaginatum while the highest share was allocated in aboveground biomass of Lolium multiflorum. Compared to other approaches determining atmospheric N deposition, ITNI showed highest airborne N input and an up to fivefold exceedance of the ecosystem-specific critical load of 5–10 kg N ha⁻¹ yr⁻¹.     

Oncogenic potential of Nrf2 and its principal target protein heme oxygenase-1

Nuclear factor erythroid 2-related factor 2 (Nrf2) is an essential component of cellular defense against a vast variety of endogenous and exogenous insults, including oxidative stress. Nrf2 acts as a master switch in the circuits upregulating the expression of various stress-response proteins, especially heme oxygenase-1 (HO-1). Paradoxically, however, recent studies have demonstrated oncogenic functions of Nrf2 and its major target protein HO-1. Levels of Nrf2 and HO-1 are elevated in many different types of human malignancies, which may facilitate the remodeling of the tumor microenvironment making it advantageous for the autonomic growth of cancer cells, metastasis, angiogenesis, and tolerance to chemotherapeutic agents and radiation and photodynamic therapy. In this context, the cellular stress response or cytoprotective signaling mediated via the Nrf2–HO-1 axis is hijacked by cancer cells for their growth advantage and survival of anticancer treatment. Therefore, Nrf2 and HO-1 may represent potential therapeutic targets in the management of cancer. This review highlights the roles of Nrf2 and HO-1 in proliferation of cancer cells, their tolerance/resistance to anticancer treatments, and metastasis or angiogenesis in tumor progression.     

Photosynthesis–nitrogen relationships in species at different altitudes on Mount Kinabalu, Malaysia

In situ photosynthetic nitrogen-use efficiency (PNUE, photosynthetic capacity per unit leaf nitrogen) was investigated in species that commonly distributed at different altitudes (600–3700m above sea level) on Mount Kinabalu. Photosynthetic nitrogen-use efficiency was lower in species at higher altitudes, with a mean PNUE at 3700m being one-third as large as that at 600m. This difference in PNUE was larger than that explained by the biochemical response to lower air pressures only. Across altitudes a negative correlation between ¹³C abundance (¹³C) and PNUE was found. Species at higher altitudes tended to have higher ¹³C, suggesting that they had a lower conductance for CO₂ diffusion from the air to chloroplasts. The lower conductance might be responsible for the lower PNUE in species at higher altitudes. Although leaf nitrogen content per unit area tended to be higher at higher altitudes, it did not seem to contribute to increasing photosynthetic rates. Thus, the idea that a higher nitrogen content at higher altitudes is a compensation for a lower PNUE was not supported. In contrast to the large difference in PNUE among altitudes, PNUE tended to converge within a narrow range among species growing at the same altitude.     

Variation in performance of two co‐occurring mosquito species across diverse resource environments: insights from nutrient and stable isotope analyses

1. Inputs of animal and plant detritus are the main energy sources for food webs in a number of isolated container systems, including discarded automobile tyres and tree holes. Containers are dominated by mosquitoes in the genera Culex and Aedes, which among other differences often engage in different foraging behaviours. We hypothesised that because Aedes feed more by browsing surfaces, whereas Culex often filter the water column, these mosquitoes would show variation in performance and differentially affect detritus. Effects of different ratios of animal and plant detritus on survival, mass, and development time for two common container mosquito species, Culex restuans L. and Aedes albopictus Skuse, were examined. We also quantified detrital contribution to biomass via isotopic and nutrient analysis and the effect of larvae on detrital decay. 2. Adult male and female mass of both species was highest with some animal detritus and lowest in only leaf detritus. Aedes albopictus survival was higher than C. restuans across most detritus ratios. 3. Aedes albopictus had higher values of ¹⁵N and in some cases ¹³C across all detritus ratios compared with C. restuans; A. albopictus had lower nitrogen in tissue. Aedes albopictus appeared to be more efficient at obtaining potentially limiting nutrients and had a greater overall effect on detrital decay – a possible consequence of greater foraging effort. 4. Findings further support the view that mosquito performance can be influenced by detritus type, and provide a more precise hypothesis (i.e. lower need for nitrogen) that may explain the superior competitive ability of A. albopictus over other container mosquitoes.     

Deepwater sediments and trophic conditions in Florida lakes

Sediment cores were taken from near maximum depth in 15 Florida lakes representing a wide range of trophic conditions. Chemical analyses of surface sediments showed Al, Fe, and Ca to be the most abundant elements in all samples, and the ratio of Al to Ca to be smaller for eutrophic lakes. Sediment organic matter increased with trophic state, as did the degree to which it was enriched in nitrogen. Corresponding sediment C/N ratios decreased with increasing lake trophic state and showed significant negative correlation with chlorophylla, total N, and total P in the water column. Concentrations of sedimentary chlorophyll derivatives showed some relation to trophic state but differences in basin morphometry hinder its use as an inter-lake index of chlorophyll production.     

Ecosystem responses to changes in plant functional type composition: An example from the Patagonian steppe

Abstract. Grass cover along a grazing intensity gradient in Patagonia decreases, whereas bare soil and shrub cover increases. Our objective was to study the effect of a change in the dominant plant functional type on soil water balance, primary production, herbivore biomass, roughness, and albedo. Using a soil water balance model, we found increases in evaporation and deep drainage, and a decrease in total transpiration along the grazing intensity gradient. Above-ground primary production, estimated from transpiration, decreased along the grazing intensity gradient because shrubs did not fully compensate for the decrease in grass production. Using a statistical model, we calculated herbivore biomass from estimates of above-ground primary production. Estimated herbivore biomass was lowest in the shrub-dominated extreme of the grazing gradient. Roughness increased from the grass-dominated to the shrub-dominated community. Albedo had a maximum at an intermediate position along the gradient. Our results suggest that changes in plant functional type composition, independent of changes in biomass, affect ecosystem functioning and the exchange of energy and material with the atmosphere. Grasses and shrubs proved to be appropriate plant functional types to link structure and function of ecosystems.