Urban development and sustainability challenges chronicled by a century of construction material flows and stocks in Tiexi,China

Construction materials are considerable forces of global environmental impacts, but their dynamics vis‐à‐vis urban development are poorly documented, in part because their long lifespans require elusive and sometimes nonexistent decade‐long high‐resolution data. This study analyzes the construction material flow and stock trends that shaped and were shaped by the development, decline, and renewal of the Tiexi district of Shenyang, a microcosm of China's urban transformations since the early 20th century. Chronicling building‐by‐building the material flows and stock accumulations involved in the buildup of this area, we shed light on the physical resource context of its socioeconomic history. We find that 42 million tonnes of construction materials were needed to develop the Tiexi district from 1910 to 2018, and 18 million tonnes of material outflows were generated by end‐of‐life building demolition. However, over 55% of inflows and 93% of outflows occurred since 2002 during a complete redevelopment of the district. Only small portions of end‐of‐life materials could have been reused or recycled because of temporal and typological mismatches of supply and demand and technical limitations. Our analysis reveals a dramatic decrease in median building lifetimes to as low as 6 years in the early 21st century. These findings contribute to the discussion of long‐term environmental efficiency and sustainability of societal development through construction and reflect on the challenges of urban renewal processes not only in China but also in other developing and developed countries that lost (or may lose) their traditional economic base and restructure their urban forms. This article met the requirements for a Silver/Silver JIE data openness badge described at http://jie.click/badges .     

S-PI对香菇酸性蛋白酶的抑制机理及其促进出菇的生化解释

S-PI对纯化的香菇酸性蛋白酶具有强烈的抑制作用,10μmol／L的S-PI可使酶活降低77％,这种抑制属于可逆竞争抛物线型抑制。经25μmol／L酸性蛋白酶水解6小时后,香菇胞外酸性磷酸酶的活性从24．6单位降低到20．8单位,同时C1酶和Cx酶的活性分别比对照降低了76％和58％,这表明香菇酸性蛋白酶不仅直接左右着香菇发育的氮代谢,同时也间接地影响着碳代谢及能量转换。     

Cloning,expression, and characterization of thermostable Manganese superoxide dismutase from <Emphasis Type="Italic">Thermoascus aurantiacus</Emphasis> var. <Emphasis Type="Italic">levisporus</Emphasis>

A superoxide dismutase (SOD) gene of Thermoascus aurantiacus var. levisporus, a thermophilic fungus, was cloned, sequenced, and expressed in Pichia pastoris and its gene product was characterized. The coding sequence predicted a 231 residues protein with a unique 35 amino acids extension at the N-terminus indicating a mitochondrial-targeting sequence. The content of Mn was 2.46 μg/mg of protein and Fe was not detected in the purified enzyme. The enzyme was found to be inhibited by NaN₃, but not by KCN or H₂O₂. These results suggested that the SOD in Thermoascus aurantiacus var. levisporus was the manganese superoxide dismutase type. In comparison with other MnSODs, all manganese-binding sites were also conserved in the sequence (H88, H136, D222, H226). The molecular mass of a single band of the enzyme was estimated to be 21.7 kDa. The protein was expressed in tetramer form with molecular weight of 68.0 kDa. The activity of purified protein was 2,324 U/mg. The optimum temperature of the enzyme was 55°C and it exhibited maximal activity at pH 7.5. The enzyme was thermostable at 50 and 60°C and the half-life at 80°C was approximately 40 min.     

水氮运筹对膜下滴灌棉花光合特性及产量形成的影响

以不同基因型棉花品种为材料,在土柱栽培条件下研究膜下滴灌条件下水氮运筹方式对新疆棉花光合性能和产量构成的影响.结果表明： 播前灌溉+盛花期前限量滴灌+盛花期后充分滴灌,并配合氮肥基施20%+追施80%的水氮运筹方式（W₄N₂）下,盛花期叶片叶绿素含量、气孔导度（g_s）、净光合速率（P_n）、PSⅡ实际光化学效率（Φ_PSⅡ）和光化学猝灭系数（q_P）均显著低于全生育期常规滴灌处理,非光化学猝灭系数（NPQ）增加,地上部干物质累积量受到限制;盛铃期至吐絮期叶绿素含量、g_s、P_n、Φ_PSⅡ、q_P均随水氮供应量的提高而增大,地上部干物质产生超补偿积累,且有利于光合产物向棉铃的运转与分配.在氮肥基施20%+追施80%的施氮方式下,新陆早13号以播前灌溉+全生育期常规滴灌（W₃）处理的籽棉产量较高,新陆早43号以播前灌溉+盛花期前限量滴灌+盛花期后充分滴灌（W₄）处理籽棉产量最高.因此,在播前灌溉条件下适当减少盛花期前、增加生育中后期水氮供应,可以延长冠层叶片光合功能期,促进光合物质优先向生殖器官分配,充分发挥膜下滴灌棉花的增产潜力.     

Human umbilical cord-derived MSC culture: the replacement of animal sera with human cord blood plasma

Human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) hold great potential for their therapeutic use in various clinical diseases. Many publications have reported on human blood-derived alternatives to animal serum for culturing mesenchymal stem cells, such as human serum, allogenic umbilical cord blood serum, and human platelet derivatives. However, it is not clear whether human umbilical cord blood plasma (UCBP), as the surplusage of umbilical cord blood mesenchymal stem cell extraction, could be used. In this study, in order to make the best of umbilical cord blood, the human UCBP was dialyzed to replace fetal bovine serum (FBS) in the culture medium. hUC-MSCs were cultured in the new medium. Cell growth rate, specific biomarkers, and differentiation properties were detected to characterize the cell proliferation and MSC-specific properties. The hUC-MSCs cultured in such derived medium were verified with proliferation rate, cluster differentiation markers, cell cycle, as well as differentiation capabilities. Such dialyzed human UCBP is fully comparable with, if not superior to, FBS in deriving and culturing hUC-MSCs.     

肺癌组织中岩藻糖化糖链结构免疫组化研究

Lewis X(Le~x)、唾液酸化的Lewis X(Sialyl Lewis X,SLe~x)和唾液酸化的双岩藻糖Lewis X(Sialyl Dimeric Lewis X,SDLe~x)是细胞表面外侧带α1,3岩藻糖的糖链结构。本文用免疫组化ABC法研究了肺癌原发灶、转移灶和癌旁组织中这三种抗原结构的表达。结果发现这三种抗原在肺癌细胞表面及胞浆中均有不同程度的表达,而在肺癌癌旁组织及正常肺组织中未见表达。有转移的肺癌和(或)低分化肺癌中这三种抗原结构的表达要明显高于未发生转移和高、中分化肺癌中相同抗原结构的表达。其中以SLe~x的表达与肺癌细胞的转移能力和分化程度关系最为密切。另外,肺癌浸润转移的淋巴结中也有Le~x、SLe~x的明显表达和SDLe~x的少量表达,而未被肺癌浸润转移的淋巴结中就没有它们的表达。     

西双版纳原始热带湿性季节雨林生物量及净初级生产

应用生物量回归模型和生产力方程,研究了西双版纳原始热带湿性季节雨林生物量及净初级生产量（NPP）。雨林总生物量为692．590t·hm-2,总生物量分配为：乔木层占98．66％、灌木层占0．76％、木质藤本层占0．50％、草本层占0．09％,生物量主要集中于乔木层。雨林年平均NPP为25．764t·hm-2·a－1,其中各层次的NPP分别为（t·hm-2·a－1）：乔木层23．972（占总NPP的93．04％）、灌木层0．749（占2．91％）、木质藤本层0．431（占1．67％）和草本层0．612（占2．38％）。乔木层NPP分配为（t·hm－2·a-1）：凋落量11．566、叶虫食量0．694和生物量增量11．712。结果表明：西双版纳虽地处热带北缘,当地原始热带湿性季节雨林同样具有典型热带雨林一样高的生物量和NPP。     

刚毛柽柳S-腺苷甲硫氨酸合成酶(ThSAMS)基因的克隆及表达分析

通过对刚毛柽柳转录组分析,克隆获得了一条与S-腺苷甲硫氨酸合成酶(SAMS)基因同源性高的基因,命名为ThSAMS。序列分析结果表明:ThSASM基因全长cDNA为1185bp,编码394个氨基酸,编码蛋白相对分子质量为97.85kDa,理论等电点为5.02。通过生物信息学分析表明,ThSASM基因编码的氨基酸与其他物种SAMS基因编码的氨基酸具有很高的同源性,其中与枣的同源性最高,达95%。实时荧光定量PCR(quantitativereal-timePCR,qRT-PCR)分析表明,ThSASM表达受NaCl、聚乙二醇(PEG)和ABA处理做出应答,暗示ThSASM可能参与了刚毛柽柳对盐和干旱的胁迫应答,为进一步研究SAMS基因在植物胁迫应答中的功能及作用机制提供了参考依据。     

放线菌结瘤植物根与根瘤中有机氮化物的组分及其上运形式

杨梅、沙棘和赤杨三种放线菌结瘤植物根瘤、根部有机氮化物的组分中,都含有占总有机氮化物50％以上的尿囊酸,说明在它们的根瘤中合成了大量的酰脲;同时,三种植物结瘤植株的茎木质部提取物中也含有大量的尿囊酸,表明根瘤将其合成的酰脲向植物地上部位运送。三种植物的根瘤还将其合成的特定的氨基酸及酰胺向地上部位转运,其中杨梅根瘤将固定的氮素以Asn和Gln的形式输出,而根部则以Arg的形式向上转运;沙棘根瘤以Ash,Gln及Ser,赤杨根瘤以Cit的形式合成并转运固定的氮素;后两种植物的无根瘤植株,以NH_4~+为氮源时,在转运的氨基酸组分中Arg的比例明显提高。     

Aptamer selection for the detection of Escherichia coli K88

In this study, the first group of single-stranded DNA aptamers that are highly specific to enterotoxigenic Escherichia coli (ETEC) K88 was obtained from an enriched oligonucleotide pool by the SELEX (Systematic Evolution of Ligands by Exponential Enrichment) procedure, during which the K88 fimbriae protein was used as the target and bovine serum albumin as counter targets. These aptamers were applied successfully in the detection of ETEC K88. They were then grouped under different families based on the similarity of their secondary structure and the homology of their primary sequence. Four sequences from different families were deliberately chosen for further characterization by fluorescence analysis. Having the advantage of high sensitivity, fluorescence photometry was selected as single-stranded DNA quantification method during the SELEX process. Aptamers with the highest specificity and affinity were analyzed to evaluate binding ability with E. coli. Since ETEC K88 is the only type of bacterium that expressed abundant K88 fimbriae, the selected aptamers against the K88 fimbriae protein were able to specifically identify ETEC K88 among other bacteria. This method of detecting ETEC K88 by aptamers can also be applied to bacteria other than ETEC K88.