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Some ancient Chinese paper artifacts dyed with amur cork tree bark extracts are currently preserved to different extents in museums and libraries worldwide. As traditional natural plant dyes, the long-term performance of the amur cork tree bark extract-dyed handmade paper has been questioned under a preserved environment. The photodegradation process of the extract-dyed papers was examined under accelerating artificial UVA irradiation conditions according to China national standard-paper and board- accelerated aging (exposure to light). Changes during aging were analyzed by optical observation and scanning electron microscopy (SEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA), Fourier transform infrared spectrometry (FTIR), pH, and tensile strength and folding endurance tests. The results showed that the main components from extracted dyes played an important role in affecting the photodegradation properties of dyed paper. The changes in surface color, pH, morphology and mechanical properties after the artificial UVA accelerated degradation tests revealed that a suitable concentration of the extract dyes for maintaining the long-term irradiation stability of the paper is important. [ABSTRACT FROM AUTHOR]

The term "economic statecraft" is increasingly employed to describe China's use of economic resources to pursue objectives spanning the political, economic, and strategic spheres. One recent study suggests that "China's sophisticated use of economics in its foreign policy is still a fairly recent phenomenon." Yet close scrutiny of how since at least the early 1900s Chinese leaders sought to use economic leverage as a foreign policy instrument suggests that the antecedents of contemporary Chinese economic statecraft date back to the founding of the People's Republic of China and even before. This special issue represents an effort to explore in some depth in what ways post-Cold War Chinese economic statecraft does indeed represent a novel phenomenon, as opposed to the simple continuation of earlier trends; to identify its most important features and follow its evolution over time; and to investigate in detail several specific recent case studies. [ABSTRACT FROM AUTHOR]

Quercus variabilis (Chinese cork oak) has a substantial cork in the periderm that regenerates if removed, allowing a potential sustainable production. Samples of virgin and reproduction cork of Q. variabilis from China were characterized and compared with Q. suber cork. Virgin and reproduction cork are chemically very similar: on average 0.9% ash, 9.2% extractives, 37.8% suberin, and 28.5% lignin. The suberin composition of Q. variabilis cork is reported for the first time. It is composed mostly by saturated ω-hydroxyacids and substituted ω-hydroxyacids, including mainly 22-hydroxydocosanoic acid (20–23% of the total compounds) and 18-hydroxy-9-octadecenoic acid (17–22%). Comparison with Q. suber cork shows differences, stressing that suberin composition is species specific. The lipophilic extractives include mainly triterpenes (48.6–56.9%) especially friedelin and betulinic acid. Q. variabilis cork has the typical cellular characteristics of cork tissues with radially aligned cells without intercellular voids. Cell wall undulations were conspicuous, especially in virgin cork. Q. variabilis cork may be a complementary raw-material to Q. suber cork for agglomerated products. Despite similarities with the commercial cork, Q. variabilis cork has differences that impact unfavourably on properties e.g. higher density and compressive strength. [ABSTRACT FROM AUTHOR]

'Akituki' (Pyrus pyrifolia Nakai.) is a very popular and profitable pear cultivar in China. However, its high susceptibility to cork spot disorder has limited its expansion of cultivated area. The mechanisms of cork spot disorder have been discussed extensively, focusing on Ca2+ deficiency, yet no consensus has been made. In this study, we applied nitrendipine (NI) as a Ca2+ uptake inhibitor to explore the role of calcium in cork spot disorder occurrence. Results showed that NI treatment on the fruit remarkably increased the incidence of cork spot disorder; alteration of mineral contents happened at the early developmental stage of the fruit, especially on the outer flesh and the peel of the fruit; and this gap was filled gradually along with the expansion of the fruit. Significant differences in the expression levels of Ca2+ transport-related genes were found in the inner flesh, outer flesh and peel during the fruit growth period. The observation of free Ca2+ localization indicated the intracellular imbalance of Ca2+ in the NI-treated fruit. In conclusion, NI treatment reduced the calcium content in the fruit at an early developmental stage, altered the related expression of genes and influenced the cellular Ca2+ balance in the fruit, which prompted the occurrence of cork spot disorder. Measures for the prevention and control of cork spot disorder should be taken at the early stage of the fruit development in the field. [ABSTRACT FROM AUTHOR]

• Performance of X-ray CT in characterizing cork spot of pear fruit. • Larger pores formation closely correlates with the disorder of cork spot. • Pore network influences the cork spot disorder. • The feasibility of STL format 3D image analysis in the internal observation of cork spot disorder. Healthy and disordered fruit of Chinese 'Chili' (Pyrus bretschneideri Rehd.), a well-known pear cultivar in China, are used to investigate the cork spot disorder by non-destructive X-ray computed microtomography (μCT) scanning technology, with pixel resolution of 67-70 μm and scanning time of 60 min on intact fruit. The results suggested that X-ray μCT could clearly and accurately distinguish the internal organization, size and location of cork spot in the pear fruit. CT images showed that the spots mostly locate in the pulp tissue between the calyx end and the equator of disordered fruit, and usually within 14 mm below the pericarp. STL format 3D images had great potential to distinguish cork spotted fruit core from healthy one. In addition, total number of pores is strongly decreased while larger pores bigger than 900 μm are considerably increased in disordered fruit as compared to healthy fruit, which indicates that larger pores maybe formed by the extension and interconnection with adjacent pores of some small pores. Further analysis in pore skeleton-network shows that extremely higher porosity and highly branched, more connected and thicker pores are observed in cork spotted fruit than those in healthy fruit. In addition, the average length of the healthy pore throat is 160.08 μm, which is significantly smaller than that of disordered fruit (277.91 μm). Moreover, the coordination number of pores in cork spotted fruit is 2, while it is 0 in healthy fruit. All the above results indicate that X-ray μCT provides a new perspective to the non-destructive visualization, quantification and knowledge of the 3D image structure of pear fruit with cork spot, and it is highly essential for early diagnosis and further study of the pathogenic mechanism of this disorder. [ABSTRACT FROM AUTHOR]

Metasequoia glyptostroboides (Cupressaceae) is a rare deciduous conifer which grows successfully in both aquatic and terrestrial environments. This tree has a narrow natural distribution in central China but is cultivated worldwide. Using histochemical staining and microscopy (both brightfield and epifluorescent), we investigated whether the phenotypic anatomical and histochemical plasticity in the fine adventitious roots of M. glyptostroboides has promoted the adaptation of this plant to aquatic and terrestrial environments. The fine root development and cortex sloughing of M. glyptostroboides occurs later in aquatic habitats than in terrestrial habitats. Anatomical and histochemical analyses have revealed that the apoplastic barriers in the primary growth of the fine roots consist of the endodermis and exodermis with Casparian bands, suberin lamellae, and secondarily lignified cell walls. There were also lignified phi (Φ) thickenings in the cortex. In both aquatic and terrestrial roots, secondary growth was observed in the vascular cambium, which produced secondary xylem and phloem, as well as in the phellogen, which produced cork. As compared to terrestrial adventitious roots, aquatic adventitious roots had multiple lignified Φ thickenings throughout the cortex, larger air spaces, dilated parenchyma, and dense suberin and lignin depositions in the exodermis. Our results thus indicate that phenotypic plasticity in the anatomical features of the fine adventitious roots, including apoplastic barriers, air spaces, and lignified Φ thickenings, might support the adaptation of M. glyptostroboides to both aquatic and terrestrial environments. [ABSTRACT FROM AUTHOR]