酚醛树脂对高软化点沥青的发泡行为及生物挂膜性能的影响

以高软化点沥青为原料,采用自发泡法制备泡沫炭,将其用作生物污水处理固菌载体材料,并通过添加适量的酚醛树脂以提高泡沫炭的开孔率,进而提高其生物挂膜量。研究结果表明：当在高软化点沥青中添加酚醛树脂的质量分数为30%时,所制泡沫炭的开孔率高达100%,生物挂膜量（质量分数）达5.4%;当酚醛树脂的添加质量分数为40%时,所制泡沫炭的压缩强度达5.2 MPa,但其开孔率较低,孔结构的均一性较差。     

不同发芽阶段对黄芩种苗生物量及活性成分含量变化的研究

该文主要研究从萌发到移栽5个不同发芽阶段对黄芩种苗生物量及活性成分含量的影响。采集不同发芽阶段的黄芩种苗,测定其根长、芽长、根径及根重,利用HPLC测定根中的黄芩苷、野黄芩苷、汉黄芩苷、黄芩素、汉黄芩素的含量。结果表明,随着黄芩种苗的萌发,黄芩的各个生物学指标均升高,但根部折干率从32.90%下降至27.96%。野黄芩苷和黄芩素的含量均呈现先增加后减少的趋势,在芽/根值为0.35时达到最大,质量分数分别为3.22,3.89 mg·g~(-1),黄芩苷含量在芽/根值为0.23时最高,质量分数为107.39 mg·g~(-1),汉黄芩苷在芽/根值为0.06时含量最高,质量分数为16.11 mg·g~(-1),汉黄芩素则呈现逐渐增加的趋势,在芽/根值为0.50时达到最大值,质量分数为0.88 mg·g~(-1)。当芽/根值为0.35时,黄芩种苗中的野黄芩苷、黄芩苷、汉黄芩苷、黄芩素和汉黄芩素的含量达到或接近发芽阶段的最大值,可用芽/根值作为黄芩种苗活性成分的判定指标。     

Total quantification and extraction of shikimic acid from star anise (llicium verum) using solid-state NMR and cellulose-dissolving aqueous hydroxide solutions

Many pharmaceutically relevant molecules are still extracted directly from lignocellulosic biomass sources. As this can be a bottleneck in supply, total quantification followed by total extraction are desirable processes to ensure as much as possible is obtained, at the optimal time in the growth cycle. Herein we report the application of solid-state ¹³C nuclear magnetic resonance (NMR) spectroscopy to quantify shikimic acid present inside Chinese star anise (or star aniseed, llicium verum). Subsequently, methanol soxhlet extraction is compared with conventional aqueous hydroxides (i.e. sodium hydroxide) and cellulose-dissolving aqueous hydroxides (i.e. tetraethylammonium and tetrabutylammonium hydroxide) for shikimic acid isolation. Methanol extraction isolated ca. 6.6±0.1 wt% (wt%) shikimic acid (post-purification), and solid-state NMR confirmed extraction was incomplete even after 72 h. Conversely, dissolution of the star anise at room temperature in tetrabutylammonium hydroxide ([N₄₄₄₄]OH) allowed isolation of ca. 14.0±0.6 wt% shikimic acid (post-purification). Solid state NMR confirmed the star anise initially contained 19±3 wt% shikimic acid, which was quantitatively extracted after dissolution in the aqueous hydroxide solution. The solubility of the star anise and the kinetics of the shikimic acid extraction were also briefly evaluated.     

Enzymatically Crosslinked Ulvan Hydrogels as Injectable Systems for Cell Delivery

The present study represents a challenging effort aiming at converting the waste algal biomass Ulva sp. into a source of high added value materials for biomedical applications by means of a clean and sustainable process. Ulvan, a sulphated polysaccharide extracted from Ulva sp., is investigated as in situ gelling material by using the enzyme horseradish peroxidase as catalyst and H₂O₂ as reagent. The polysaccharide is successfully modified with tyramine units in order to be susceptible to enzymatic recognition and crosslinking through oxidative coupling. The times of gelation of ulvan‐tyramine solutions are optimized by adjusting the amount of H₂O₂ used for ensuring their practical administration as injectable systems. The rheological properties of the polymeric solutions and the relevant hydrogels evaluated under operative conditions prove to be suitable as injectable in situ forming 3D‐hydrogels. The preliminary biological assays evidence the full cytocompatibility of the developed hydrogels and their feasibility for being used as 3D‐hydrogels for cell delivery.

     

From the Cover: Large contribution of biomass burning emissions to ozone throughout the global remote troposphere

Ozone is the third most important anthropogenic greenhouse gas after carbon dioxide and methane but has a larger uncertainty in its radiative forcing, in part because of uncertainty in the source characteristics of ozone precursors, nitrogen oxides, and volatile organic carbon that directly affect ozone formation chemistry. Tropospheric ozone also negatively affects human and ecosystem health. Biomass burning (BB) and urban emissions are significant but uncertain sources of ozone precursors. Here, we report global-scale, in situ airborne measurements of ozone and precursor source tracers from the NASA Atmospheric Tomography mission. Measurements from the remote troposphere showed that tropospheric ozone is regularly enhanced above background in polluted air masses in all regions of the globe. Ozone enhancements in air with high BB and urban emission tracers (2.1 to 23.8 ppbv [parts per billion by volume]) were generally similar to those in BB-influenced air (2.2 to 21.0 ppbv) but larger than those in urban-influenced air (−7.7 to 6.9 ppbv). Ozone attributed to BB was 2 to 10 times higher than that from urban sources in the Southern Hemisphere and the tropical Atlantic and roughly equal to that from urban sources in the Northern Hemisphere and the tropical Pacific. Three independent global chemical transport models systematically underpredict the observed influence of BB on tropospheric ozone. Potential reasons include uncertainties in modeled BB injection heights and emission inventories, export efficiency of BB emissions to the free troposphere, and chemical mechanisms of ozone production in smoke. Accurately accounting for intermittent but large and widespread BB emissions is required to understand the global tropospheric ozone burden.

Tropospheric ozone (O₃) has been the focus of decades of scientific research due to its central role in atmospheric chemistry (1), its adverse impact on human and ecosystem health (2, 3), and its role as a climate forcer (4, 5). Despite this focus, there remains considerable uncertainty in tropospheric O₃ production pathways, precursor sources, and long-term trends. Sources of tropospheric O₃ include downward transport from the stratosphere and photochemical production from a complex set of coupled reactions between nitrogen oxides (NO_x) and volatile organic compounds (VOCs), each of which is in turn emitted from both anthropogenic and natural sources (1, 6). The contribution of fossil fuel combustion to tropospheric O₃ has recently declined in the United States and in Europe, proportionally increasing the contribution from natural sources (7–10). However, the spatial distribution of anthropogenic O₃ precursor emissions have shifted to lower latitudes (11, 12), where they are still increasing (13). Additionally, globally averaged tropospheric O₃ has increased over the past five decades (14, 15). Understanding the sources of tropospheric O₃ is thus essential to explain this trend and to inform the development of effective mitigation strategies from regional to hemispheric scales.Biomass burning (BB) is an important source of O₃ precursors (16–19). A recent study based on observed O₃ to carbon monoxide (CO) enhancements in smoke plumes attributed 3.5% of the global tropospheric chemical O₃ production to BB emissions (19). Other studies have accounted for the numerous production and destruction pathways of O₃ in the troposphere using global chemical transport models (CTMs) to estimate the global budget of O₃ (20, 21). However, few studies separately quantify the contributions of fossil fuel combustion and BB emissions to global tropospheric O₃ (22). Global inventories attribute five times more NO_x (23, 24) but roughly equal VOC emissions (17, 25) to fossil fuel combustion (hereafter referred to as urban sources) compared with BB. However, precursor emissions do not necessarily determine tropospheric O₃ production close to the sources because of the nonlinearity of O₃ formation chemistry (26, 27). Additionally, global CTMs do not always agree on the tropospheric O₃ burden, suggesting possible deficiencies with emission inventories of O₃ precursors and/or an incomplete representation of O₃ chemistry (21, 28–30), although a recent model intercomparison study showed that the model ensemble reproduced well the salient spatial, seasonal, and decadal variability and trends of tropospheric O₃ (31).Large-scale in situ observational constraints commensurate with the grid resolution of current global CTMs are rare. Instead, modeling studies often rely on ozonesonde-derived climatologies and satellite-based remote sensing observations to constrain tropospheric O₃ distributions and precursor sources (20, 32, 33). The recent NASA Atmospheric Tomography (ATom) mission provides global-scale and seasonally resolved in situ measurements of O₃ and CO and a comprehensive suite of trace gases and aerosol parameters, including tracers of BB and urban emissions (34). ATom sampled the remote troposphere from the Arctic to the Antarctic over the Pacific and Atlantic Oceans using repeated vertical profiles from ∼0.2 to ∼13 km in altitude during four seasonal deployments between 2016 and 2018 (Fig. 1). Recently, the ubiquitous presence of dilute BB smoke in the remote troposphere and its significant contribution to aerosol mass loading was established using ATom observations (35). Here, we use ATom measurements to quantify the individual contributions of urban and BB emissions to O₃ in the remote global troposphere using tracers specific to each source. We compare this analysis with simulations from three global CTMs that alternatively set BB and urban emissions to zero to evaluate their impact on modeled tropospheric O₃.Open in a separate windowFig. 1.Map of ATom flight tracks from the four seasonal global circuits colored by tropospheric O₃ mixing ratios. Note that the color scale terminates at 70 ppbv of O₃, and higher values are shown in red. Measurements with a strong stratospheric influence were parsed out as indicated in Materials and Methods.     

Efficacy of Alkaline-Treated Soy Waste Biomass for the Removal of Heavy-Metal Ions and Opportunities for Their Recovery

In this study, soy waste biomass (SW) resulting from oil extraction was treated with alkaline solution, and the obtained material (Na-SW) was used as biosorbent for the removal of Pb(II), Cd(II), and Zn(II) ions from aqueous media. The performance of this biosorbent was examined in batch systems, at different initial metal ion concentrations and contact times (pH 3.4; 5 g of biosorbent/L). Isotherm and kinetic modeling was used to calculate the equilibrium and kinetics of the biosorption processes. The maximum biosorption capacity, calculated from the Langmuir isotherm model, followed the order Zn(II) (0.49 mmol/g) > Cd(II) (0.41 mmol/g) ≈ Pb(II) (0.40 mmol/g), while the kinetics of biosorption processes fit the pseudo-second-order model. Three cycles of biosorption/desorption were performed to estimate the reusability of Na-SW biosorbent, and the regeneration efficiency was higher than 97% in all cases. The practical applicability of Na-SW biosorbent in treating of wastewater contaminated with Pb(II), Cd(II), and Zn(II) ions was examined using simulated wastewater samples, and the main quality characteristics of the effluents obtained after treatment were evaluated. All these aspects highlight the potential applicability of Na-SW for large-scale wastewater treatment.     

Pulmonary hypertension associated with combined fibrosing mediastinitis and bronchial anthracofibrosis: A retrospective analysis in a single Chinese hospital

Introduction

Both fibrosing mediastinitis (FM) and bronchial anthracofibrosis (BAF) are unique diseases. The combined appearance of FM and BAF is extremely rare.

Objectives

The aim of this study was to investigate the clinical features of patients with coexisting FM and BAF.

Method

Between January 2003 and December 2015, a total of eight patients were diagnosed at the Peking Union Medical College Hospital as having combined FM and BAF. The clinical presentations, radiographic features and bronchoscopic findings of the eight patients were reviewed.

Results

The patients were five women and three men with a median age of 64 years (range 56‐86 years). Symptoms included dyspnea (eight patients), cough (seven patients), chest pain (two patients), hemoptysis (two patients) and so on. Chest CT of all eight patients showed mediastinal soft‐tissue lesions, with multiple narrowed or obliterated lobar or segmental bronchi and arteries. Bronchoscopy showed that all of the patients had multiple stenoses of lobar or segmental bronchi with anthracotic pigmentation on the mucosa. Echocardiography showed that all of the patients had elevated pulmonary arterial systolic pressure (median 81 mm Hg, range 51‐107 mm Hg). Each of the eight patients had a history of exposure to, or infection with, tuberculosis, although there was no evidence of active disease. All of the eight patients had long‐term exposure to indoor coal or biomass fuel smoke.

Conclusions

FM can coexist with BAF, characterized by prominent pulmonary hypertension. The possible etiological factors are tuberculosis and coal or biomass fuel exposure.     

红茶菌的研究概况

红茶菌是一种历史悠久的功能性饮料,检索国内外相关文献,主要从红茶菌的菌体组成、营养成分、培养方法、红茶菌中微生物的分离纯化、发酵机理、保健功能以及作用机理等方面进行了综述,展望了红茶菌开发利用的前景并提出了亟待解决的问题。     

若尔盖白河牧场地上生物量与遥感植被指数关系研究

目的：为探讨利用遥感影像进行草原地上生物量估测,更好服务于保护区内的植被生态建设。方法：本文采用TM影像研究若尔盖地区白河牧场地上生物量与遥感植被指数的关系,分别建立了7种植被指数（NDVI、RVI、DVI、SAVI、MSAVI、PVI、GVI）与地上生物量的线性和6种非线性（对数、反函数、二次多项式、三次多项式、复合、幂函数）回归模型。结果：植被指数MSAVI、NDVI、SAVI、RVI、GVI、DVI、PVI与白河牧场地上生物量模型表现出三次多项式回归模型最优,其次是二次多项式、反函数曲线模型、对数曲线模型、线性模型、幂函数曲线模型、复合曲线模型。结论：基于MSAVI的地上生物量的三次多项式模型的模拟效果最好,复相关系数R2=0.823005,精度检验结果表明该模型的平均误差为38.7%,拟合精度达到61.3%,能够满足中尺度地上生物量的估测。     

液相色谱-线性离子阱串联质谱法检测人正常晶状体水溶性蛋白质

目的检测和分析人正常晶状体水溶性蛋白质的组成和功能。方法通过聚丙烯酰胺凝胶和液相色谱分离晶状体中的水溶性蛋白质,应用线性离子阱串联质谱仪鉴定蛋白质。运用基因本体论(geneontology,GO)对鉴定出的蛋白质的表达功能进行富集和缺失分析。结果鉴定出人正常水溶性晶状体蛋白质242个,包括许多酶类等重要的功能性蛋白。鉴定出的晶状体水溶性蛋白质参与细胞组成显示富集结果有:眼晶状体结构组成、细胞质、细胞内、细胞内部件、细胞骨架;参与分子功能显示富集结果有:催化活性、结构分子活性、氧化还原酶活性、异构酶活性;参与生物过程显示富集结果有:糖酵解、戊糖磷酸旁路、细胞大分子分解代谢过程、NADP代谢过程、烟酰胺代谢过程、吡啶核苷酸代谢过程、NADPH再生、细胞成分结构和生物合成的调节、以微管为基础的过程。运用GO分析结果表明,鉴定出蛋白质的功能与晶状体正常的生理活动密切相关,进一步证实鉴定结果的可靠性。结论线性离子阱串联质谱仪在晶状体水溶性蛋白质鉴定方面显示独特的优势。采用基于GO的功能分析等生物信息学分析方法是对蛋白质组学研究的有益补充。