Modulating the Activity of Enzyme in Metal-Organic Frameworks Using the Photothermal Effect of Ti3C2 Nanosheets.

Enzymes are versatile catalysts with high potential in various applications, and much attention has been paid to the stability improvement of native enzymes and activity modulation. Encapsulation in metal-organic frameworks (MOFs) as an efficient strategy for protecting fragile native enzymes while modulating the activity of enzymes remotely, which is practically demanded, has rarely been explored in MOF-encapsulated enzymes. Herein, Ti3C2 nanosheets exhibiting photothermal effect and biocompatibility were encapsulated in Cyt c-embedded ZIF-8 to tailor the enzymatic activity remotely by near-infrared (NIR) irradiation for the first time. By exposure to NIR light, the temperature of an aqueous solution containing Ti3C2/Cyt c@ZIF-8 increases obviously (up to 15 °C), while that of Cyt c@ZIF-8 shows no change. The enzymatic activity in the composites with a certain amount of nanosheets increases, which is attributed to the created defect and transformed microenvironment caused by the introduction of nanosheets. Importantly, the enzymatic activity in ZIF-8 can be further enhanced up to 150% under NIR light irradiation, and this enhancement can be modulated flexibly by varying laser power density. Our investigations indicate that Ti3C2 nanosheets are promising candidates for modulating the activity of encapsulated enzymes remotely.

Ancient DNA and multimethod dating confirm the late arrival of anatomically modern humans in southern China.

The expansion of anatomically modern humans (AMHs) from Africa around 65,000 to 45,000 y ago (ca. 65 to 45 ka) led to the establishment of present-day non-African populations. Some paleoanthropologists have argued that fossil discoveries from Huanglong, Zhiren, Luna, and Fuyan caves in southern China indicate one or more prior dispersals, perhaps as early as ca. 120 ka. We investigated the age of the human remains from three of these localities and two additional early AMH sites (Yangjiapo and Sanyou caves, Hubei) by combining ancient DNA (aDNA) analysis with a multimethod geological dating strategy. Although U-Th dating of capping flowstones suggested they lie within the range ca. 168 to 70 ka, analyses of aDNA and direct AMS 14C dating on human teeth from Fuyan and Yangjiapo caves showed they derive from the Holocene. OSL dating of sediments and AMS 14C analysis of mammal teeth and charcoal also demonstrated major discrepancies from the flowstone ages; the difference between them being an order of magnitude or more at most of these localities. Our work highlights the surprisingly complex depositional history recorded at these subtropical caves which involved one or more episodes of erosion and redeposition or intrusion as recently as the late Holocene. In light of our findings, the first appearance datum for AMHs in southern China should probably lie within the timeframe set by molecular data of ca. 50 to 45 ka.

Uniparental Genetic Analyses Reveal the Major Origin of Fujian Tanka from Ancient Indigenous Daic Populations.

The Fujian Tanka people are officially classified as a southern Han ethnic group, whereas they have customs similar to Daic and Austronesion people. Whether they originated in Han or Daic people, there is no consensus. Three hypotheses have been proposed to explain the origin of this group: (1) the Han Chinese origin, (2) the ancient Daic origin, (3) and the admixture between Daic and Han. This study addressed this issue by analyzing the paternal Y chromosome and maternal mtDNA variation of 62 Fujian Tanka and 25 neighboring Han in Fujian. The southern East Asian predominant haplogroups (e.g., Y-chromosome O1a1a-P203 and O1b1a1a-M95, and mtDNA F2a, M7c1, and F1a1) had relatively high frequencies in Tanka. The interpopulation comparison revealed that the Tanka have a closer affinity with Daic populations than with Han Chinese in paternal lineages but are closely clustered with southern Han populations such as Hakka and Chaoshanese in maternal lineages. Network and haplotype-sharing analyses also support the admixture hypothesis. The Fujian Tanka mainly originate from the ancient indigenous Daic people and have only limited gene flows from Han Chinese populations. Notably, the divergence time inferred by the Tanka-specific haplotypes indicates that the formation of Fujian Tanka was a least 1033.8-1050.6 years before present (the early Northern Song dynasty), indicating that they are an indigenous population, not late Daic migrants from southwestern China.

Molecular genealogy of Tusi Lu's family reveals their paternal relationship with Jochi, Genghis Khan's eldest son.

Genghis Khan's lineage has attracted both academic and general interest because of its mystery and large influence. However, the truth behind the mystery is complicated and continues to confound the scientific study. In this study, we surveyed the molecular genealogy of Northwestern China's Lu clan who claim to be the descendants of the sixth son of Genghis Khan, Toghan. We also investigated living members of the Huo and Tuo clans, who, according to oral tradition, were close male relatives of Lu clan. Using network analysis, we found that the Y-chromosomal haplotypes of Lu clan mainly belong to haplogroup C2b1a1b1-F1756, widely prevalent in Altaic-speaking populations, and are closely related to the Tore clan from Kazakhstan, who claim to be the descendants of the first son of Genghis Khan, Jochi. The most recent common ancestor of the special haplotype cluster that includes the Lu clan and Tore clan lived about 1000 years ago (YA), while the Huo and Tuo clans do not share any Y lineages with the Lu clan. In addition to the reported lineages, such as C3*-Star Cluster, R1b-M343, and Q, our results indicate that haplogroup C2b1a1b1-F1756 might be another candidate of the true Y lineage of Genghis Khan.