The conventional wisdom has been challenged recently that microblades with handles are only tools for hunting and gathering in the Neolithic Age. Some scholars argued that microblades actually played an important part...The conventional wisdom has been challenged recently that microblades with handles are only tools for hunting and gathering in the Neolithic Age. Some scholars argued that microblades actually played an important part in the early agricultural development in the Neolithic. However, both of these opinions lacked direct evidence. Environmental scanning electron microscopy (ESEM) is used to analyze the residues of the bone-handled microblade excavated at the Shangzhai site in Pinggu, Beijing. The ESEM observation and EDX analysis show that at the edge of this bone-handled microblade are Ca, P, C, O or C, N, O, etc, which provide direct evidence for determining its function, namely that this microblade may have been dealt with animals. In addition, there was a layer of glue at the back of the microblade with barium and zinc salt distributed evenly in it, this new discovery sheds new light on adhesive technology in ancient China.展开更多
<strong>Background and Objective:</strong> The aesthetic products’ safety should not be neglected to the detriment of the market. This study aimed to evaluate the mutagenic potential of commercial inks. I...<strong>Background and Objective:</strong> The aesthetic products’ safety should not be neglected to the detriment of the market. This study aimed to evaluate the mutagenic potential of commercial inks. It was formulated with organic (P1) and inorganic (P2) pigments for eyebrows microblading using a validated method by regulatory agencies, the <em>Salmonella</em>/microsome assay, to assure the safety of use. <strong>Methods:</strong> The assay was carried out in three steps: preliminary toxicity, medium without (-S9), and presence (+S9) of metabolic activation. The strains, auxotrophic to histidine (His-) TA97a, TA98, TA100, and TA102, were exposed to both types of inks, in triplicate, compared to negative and positive controls. Data were statistically analyzed, and values with mutagenic index ≥ 2.0 were indicative of mutagenicity. <strong>Results:</strong> The inks with organic (P1) and inorganic (P2) pigments were not toxic to TA98 and TA100 S. <em>typhimurium</em> tester strains, even at concentrations applied in humans. Both inks were not mutagenic either in the absence or presence of metabolic activation in the tested concentrations, including that applied in humans. The assay showed that P1 and P2 were not direct (-S9) or indirect (+S9) mutagens as commercially formulated. <strong>Conclusions:</strong> These results indicate that applying these inks on organisms with microsomal enzymes, including humans, is safe since no compound in the inks became more toxic to induce the bacterial reverse mutation.展开更多
Lithic miniaturization is a key adaptive and technological feature of human populations and one of the key cultural hallmarks in the Late Pleistocene of Eastern Asia.In northern China this form of stone tool technolog...Lithic miniaturization is a key adaptive and technological feature of human populations and one of the key cultural hallmarks in the Late Pleistocene of Eastern Asia.In northern China this form of stone tool technology is well represented,including by microblade technology.Lithic miniaturization has been identified in South China,though this technological feature has received little research attention in comparison to the north.Here,we examine three miniaturized lithic assemblages in South China,ranging from the terminal Pleistocene to middle Holocene.To examine technological variations in lithic miniaturization,the three assemblages were subject to comparative quantitative analyses,including principal component analysis(PCA),K-means clustering and the Zingg system.The three sites were found to exhibit varied temporal and geographic patterns of lithic miniaturization across South China,potentially related to fluctuating climatic conditions and changes in population dynamics since the Late Pleistocene.展开更多
基金supported by National Social Science Foundation of China (Nos.08BKJ002 and 07KG001)Major Projects of the Humanities and Social Bases of Ministry of Education (Grant No.05JJD78002)+1 种基金"Eleventh Five-Year Plan" Project of the Philosophy and Social Sciences of Beijing Grant Grant (Grant No.06AALS002)Horizontal Project "East Lake stone disease investigation and countermeasures"
文摘The conventional wisdom has been challenged recently that microblades with handles are only tools for hunting and gathering in the Neolithic Age. Some scholars argued that microblades actually played an important part in the early agricultural development in the Neolithic. However, both of these opinions lacked direct evidence. Environmental scanning electron microscopy (ESEM) is used to analyze the residues of the bone-handled microblade excavated at the Shangzhai site in Pinggu, Beijing. The ESEM observation and EDX analysis show that at the edge of this bone-handled microblade are Ca, P, C, O or C, N, O, etc, which provide direct evidence for determining its function, namely that this microblade may have been dealt with animals. In addition, there was a layer of glue at the back of the microblade with barium and zinc salt distributed evenly in it, this new discovery sheds new light on adhesive technology in ancient China.
文摘<strong>Background and Objective:</strong> The aesthetic products’ safety should not be neglected to the detriment of the market. This study aimed to evaluate the mutagenic potential of commercial inks. It was formulated with organic (P1) and inorganic (P2) pigments for eyebrows microblading using a validated method by regulatory agencies, the <em>Salmonella</em>/microsome assay, to assure the safety of use. <strong>Methods:</strong> The assay was carried out in three steps: preliminary toxicity, medium without (-S9), and presence (+S9) of metabolic activation. The strains, auxotrophic to histidine (His-) TA97a, TA98, TA100, and TA102, were exposed to both types of inks, in triplicate, compared to negative and positive controls. Data were statistically analyzed, and values with mutagenic index ≥ 2.0 were indicative of mutagenicity. <strong>Results:</strong> The inks with organic (P1) and inorganic (P2) pigments were not toxic to TA98 and TA100 S. <em>typhimurium</em> tester strains, even at concentrations applied in humans. Both inks were not mutagenic either in the absence or presence of metabolic activation in the tested concentrations, including that applied in humans. The assay showed that P1 and P2 were not direct (-S9) or indirect (+S9) mutagens as commercially formulated. <strong>Conclusions:</strong> These results indicate that applying these inks on organisms with microsomal enzymes, including humans, is safe since no compound in the inks became more toxic to induce the bacterial reverse mutation.
基金National Natural Science Foundation of China,No.42177424,No.42488201Youth Innovation Promotion Association of the Chinese Academy of Sciences,No.2020074National Key Research and Development Projects,No.2022YFF0801502。
文摘Lithic miniaturization is a key adaptive and technological feature of human populations and one of the key cultural hallmarks in the Late Pleistocene of Eastern Asia.In northern China this form of stone tool technology is well represented,including by microblade technology.Lithic miniaturization has been identified in South China,though this technological feature has received little research attention in comparison to the north.Here,we examine three miniaturized lithic assemblages in South China,ranging from the terminal Pleistocene to middle Holocene.To examine technological variations in lithic miniaturization,the three assemblages were subject to comparative quantitative analyses,including principal component analysis(PCA),K-means clustering and the Zingg system.The three sites were found to exhibit varied temporal and geographic patterns of lithic miniaturization across South China,potentially related to fluctuating climatic conditions and changes in population dynamics since the Late Pleistocene.
