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Nonspecific activation of murine spleen cells in vitro by a synthetic immunoadjuvant (N-acetyl-muramyl-L-alanyl-D-isoglutamine) 总被引:12,自引:0,他引:12
We reported previously that synthetic N-acetyl-muramyl-l-alanyl-d-isoglutamine (MDP) displayed marked adjuvant activity but was devoid of mitogenicity in vitro. The data reported here establish that, under different cultural conditions, thymidine uptake and blast cells can be increased by MDP in spleen cells of DBA/2 and Balb/c mouse strains. Optimal responses were obtained on culture in a serum-free medium supplemented with 2-mercaptoethanol for 4 or 5 days. This effect was also obtained with spleen cells of Balb/c nude mice. When the synthetic MDP was compared to a natural water-soluble adjuvant (neo-WSA), extracted from Mycobacterium smegmatis cells, both were found to stimulate [3H] thymidine incorporation by mouse spleen cells. However, with the neo-WSA, the effect peaked on Day 2 and was weak or absent on Days 4 and 5. When the cells were cultured in a medium containing fetal calf serum, neo-WSA activation was completely abolished, while MDP-mediated stimulation was decreased. 相似文献
203.
《L'Anthropologie》2022,126(5):103098
The cobble industry in southern Chinese provinces was for a long time called large and simple “chopper-chopping tool tradition,” which persisted from the Early Pleistocene to the Middle Holocene. This recognition is 50% true and 50% false because it does not reflect the entire archaeological reality. On the one hand, the so-called “chopper-chopping tool” category often characterizes or dominates the lithic assemblages; on the other hand, a “chopper” from site A could be different from another “chopper” in site B. This distinction is important since the typological names lost their validity when conducting comparative studies inter- and intra-sites. The cobble tool industry of the Zengpiyan cave site (Guilin City, Guangxi Zhuang Autonomous Region, China) is an excellent example of this terminological dilemma, which presents some extent of both simplicity and complexity, underestimated in its production strategies. We could also find substantial flexibility between the two ends (simplicity and complexity) during the selection and exploitation of the cobble/pebble blanks. Although chopper-chopping tools are predominant at the site, the variability of their morpho-structures and techno-functional organization indicate that they are not just simple chopper-chopping tools sensu stricto but have their specific characteristics which could not be found in their typological names. In this context, we need to re-evaluate the previously so-called “choppers” in south China with a techno-functional approach before comparing different lithic assemblages. Compared with other contemporary sites, the Zengpiyan technical system is not far from those found in South China and mainland Southeast Asia. For example, it has similarities with the Sonvian phenomenon in northern Vietnam and some other sites in southern China. While very different from the Hoabinhian technocomplex, the Zengpiyan assemblage raises questions about the kinship with other Late Pleistocene lithic facies. Further technological studies on a larger number of sites in these regions are still needed to understand better the prehistoric techno-cultural relationships between the industrial assemblages of southern China and those bordering the Far East. 相似文献
204.
《L'Anthropologie》2022,126(1):102976
New occurrences of early artefacts ascribed to the Oldowan tradition come from localities at high level within the caldera of the extinct Kilombe volcano, located in the central rift valley of Kenya. The trachyte cone and caldera of Kilombe volcano formed at ca. 2.5 Ma, and the record of >130 m of sediment-fill indicates that the caldera subsequently held a lake for long periods during the Early Pleistocene. The Oldowan artefact localities, dated by 40Ar/39Ar and palaeomagnetism to ~1.78 Ma, lie east of the centre of the caldera, on the west side of an ancient small lake, which later drained away as a gorge formed on the east side of the mountain. The artefacts are dominantly made of Kilombe trachyte, and are associated with a fauna of large animals including Hippopotamus gorgops. These are the first Oldowan localities to be discovered in a new area of the Kenyan rift valley in the last thirty years, and their presence at high level in rugged landscape indicates that the associated hominins were exploiting a full range of environments. 相似文献
205.
《L'Anthropologie》2022,126(3):103028
The Lower-to-Middle Paleolithic transition of the Levant has attracted much attention, particularly because the early Middle Paleolithic is the period when the earliest anatomically modern humans fossils known to date in Eurasia have been attested in that part of Asia . The associated lithic assemblages are a significant source of information for investigating the cultural landscape of this important transition. This paper presents a new dataset from the 2003–2009 excavations at Dederiyeh Cave, northwest of Syria. A techno-typological analysis of the lithic industry reveals a common practice of blade blank production, which corroborates the other known early Middle Paleolithic assemblages of the Levant. However, its strong emphasis on Levallois core reduction and sidescraper manufacturing is noteworthy. The significance of this finding deserves further research from multiple viewpoints, including the functional and spatio-temporal variability of hominin activities in this period. It will be also important to interpret the techno-typological diagnostics of the early Middle Paleolithic assemblage of Dederiyeh considering its geographic location at the northern end of the Levant, distant from the previously known sites in the central and southern Levant. 相似文献
206.
Marine Cazenave Anna Oettlé John Francis Thackeray Masato Nakatsukasa Frikkie de Beer Jakobus Hoffman Roberto Macchiarelli 《Comptes Rendus Palevol》2019,18(2):223-235
SKX 1084 is an isolated partial patella from Swartkrans Member 2, South Africa, attributed to a small-bodied Paranthropus robustus. This study provides complementary information on its outer conformation and, for the first time for a fossil hominin patella, documents its inner structure in the perspective of adding biomechanically-related evidence to clarify its identity. We used X-ray micro-tomography to investigate SKX 1084 and to extract homologous information from a sample of 12 recent human, one Neanderthal, and two adult Pan, patellae. We used geometric morphometrics to compare the outer equatorial contours. In SKX 1084, we identified two cancellous bony spots suitable for textural assessment (trabecular bone volume fraction, trabecular thickness, degree of anisotropy), and two related virtual slices for measuring the maximum cortico-trabecular thickness (CTT) of the articular surface. SKX 1084 shows a more complex articular shape than that for Pan, but still simpler than typical in Homo sapiens. At all sites, its CTT is thinner compared to Pan and approaches the condition in humans. This is also true for the expanded volume of the cancellous network. However, at both investigated spots, SKX 1084 is systematically intermediate between Homo and Pan for trabecular bone volume fraction and trabecular thickness, a pattern already shown in previous analyses on other Paranthropus postcranial remains. In the absence of any structural signal from patellae unambiguously sampling Paranthropus, as well as of comparable evidence extracted from specimens representing early Homo, our results do not allow rejection of the original taxonomic attribution of SKX 1084. 相似文献
207.
208.
A gas chromatographic procedure for the analysis of nicotine in plasma, which uses quinoline as an internal standard, is reported. The nicotine is extracted with diethyl ether, concentrated without any evaporation, thus avoiding losses, and analyzed without derivatization. The recovery is 83.2 +/- 6.1% (n = 6). Although the analysis is carried out with a classical flame ionization detector, the detection limit is 0.1 ng/ml. Linearity is observed up to 100 ng/ml. The results of the precision analysis performed in the working range indicate a good reproducibility: a coefficient of variation of 5.2% is obtained for within-run analysis and 10.5 to 4.5% for nicotine values from 2.9 to 19.1 ng/ml for day analysis. Since a single run (the limitative step) lasts less than 15 min this improved procedure allows a great number of samples to be processed per day. 相似文献
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210.