111 research outputs found
A Macroscopic Perspective on Lithic Technology and Human Behavior during Pleistocene in Zhejiang Province, Southeastern China
Paleolithic archeological remains were not reported from Zhejiang until 2002. Up to now, over 70 Paleolithic sites and/or localities have been recovered through a series of surveys mainly in the north part of Zhejiang. An overview of the Paleolithic record and archeological sequence in this region during the Early to Late Pleistocene are present from a macroscopic perspective in this article, as well as the brief introduction of lithic technology and human adaptation in south China. In general, the lithic assemblages in Zhejiang represent the features of Pebble Industry in south China and show a trend of reduction on the size of stone artifacts since the Late Paleolithic. It is presumed that prehistoric humankind has shown the behavioral strategies as followed: a) exploited local raw material; b) the utilization of core and the degree of proficiency in knapping have been improved gradually; c) the retouching focused on the areas of edges; and d) preferred to use sharp edges of tools
A negatively charged region of the skeletal muscle ryanodine receptor is involved in Ca2+-dependent regulation of the Ca2+ release channel
AbstractThe ryanodine receptor/Ca2+ release channels from skeletal (RyR1) and cardiac (RyR2) muscle cells exhibit different inactivation profiles by cytosolic Ca2+. D3 is one of the divergent regions between RyR1 (amino acids (aa) 1872ā1923) and RyR2 (aa 1852ā1890) and may contain putative binding site(s) for Ca2+-dependent inactivation of RyR. To test this possibility, we have deleted the D3 region from RyR1 (ĪD3-RyR1), residues 1038ā3355 from RyR2 (Ī(1038ā3355)-RyR2) and inserted the skeletal D3 into Ī(1038ā3355)-RyR2 to generate sD3-RyR2. The channels formed by ĪD3-RyR1 and Ī(1038ā3355)-RyR2 are resistant to inactivation by mM [Ca2+], whereas the chimeric sD3-RyR2 channel exhibits significant inactivation at mM [Ca2+]. The ĪD3-RyR1 channel retains its sensitivity to activation by caffeine, but is resistant to inactivation by Mg2+. The data suggest that the skeletal D3 region is involved in the Ca2+-dependent regulation of the RyR1 channel
Chinese ālow-tarā cigarettes do not deliver lower levels of nicotine and carcinogens
BackgroundLow-tar cigarette smoking is gaining popularity in China. The China National Tobacco Corporation (CNTC) promotes low-tar cigarettes as safer than regular cigarettes.MethodsA total of 543 male smokers smoking cigarettes with different tar yields (15 mg, regular cigarettes, 10-13 mg low-tar cigarettes and < 10 mg low-tar cigarettes) were recruited in Shanghai, China, who then completed a questionnaire on smoking behaviour and provided a urine sample for analysis of the nicotine metabolites cotinine and trans-3'-hydroxycotinine. A total of 177 urine samples were selected at random for the analysis of the carcinogens polycyclic aromatic hydrocarbon metabolites (PAHs) (1-hydroxypyrene, naphthols, hydroxyfluorenes and hydroxyphenanthrenes) and the tobacco specific nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-butanone (NNK) metabolites, 4-(methylnitrosamino)-1-(3-pyridyl)-butanol (NNAL) and NNAL-glucuronide. Values were normalised by creatinine to correct for possible distortions introduced by dilution or concentration of the urine.ResultsSmokers of low-tar cigarettes smoked fewer cigarettes per day (p=0.001) compared to smokers of regular cigarettes. Despite this lower reported consumption, levels of cotinine, trans-3'-hydroxycotinine and PAHs in urine of people smoking low-tar cigarettes were not correlated with nominal tar delivery of the cigarettes they smoked. Urine concentrations of NNAL were higher in smokers of lower tar than higher tar cigarettes.ConclusionsChinese low-tar cigarettes do not deliver lower doses of nicotine and carcinogens than regular cigarettes, therefore it is unlikely that there would be any reduction in harm. CNTC's promotion of low-tar cigarettes as 'less harmful' is a violation of the World Health Organization Framework Convention on Tobacco Control, which China ratified in 2005
Association of the Porcine Cluster of Differentiation 4 Gene with T Lymphocyte Subpopulations and Its Expression in Immune Tissues
Cluster of differentiation 4 (CD4) is mainly expressed on CD4+ T cells, which plays an important role in immune response. The aim of this study was to detect the association between polymorphisms of the CD4 gene and T lymphocyte subpopulations in pigs, and to investigate the effects of genetic variation on the CD4 gene expression level in immune tissues. Five missense mutations in the CD4 gene were identified using DNA pooling sequencing assays, and two main haplotypes (CCTCC and AGCTG) in strong linkage disequilibrium (with frequencies of 50.26% and 46.34%, respectively) were detected in the population of Large White pigs. Our results indicated that the five SNPs and the two haplotypes were significantly associated with the proportions of CD4āCD8ā, CD4+CD8+, CD4+CD8ā, CD4+ and CD4+/CD8+ in peripheral blood (p0.05). These results indicate that the CD4 gene may influence T lymphocyte subpopulations and can be considered as a candidate gene affecting immunity in pigs
Geochemical source analysis of rock cuttings based on major elemental geochemistry
In recent years, shale logging has played a crucial role in the grouting reinforcement engineering of the floor limestone strata in āNorth China-typeācoalfields. However, existing shale logging techniques are limited to the recognition of physical indicators such as color, particle size, and morphology. This limitation makes an accurate stratification challenging, and the āalong-stratum rateā in borehole design is difficult to be ensured. These constraints hinder the effectiveness of water damage control in the floor limestone strata areas. This study, based on the elemental geochemical differences in the Carboniferous Taiyuan Formation thin-layered limestone and its clastic interlayers, selected the Taoyuan Coal Mine in the Huaibei Coalfield as the research area. Some vertical core samples were obtained from drill holes in the upper part of the Taiyuan Formation, including L1 limestone to L4 limestone (with L3 limestone as the grouting control target layer). Using the X-ray fluorescence spectrometry (XRF), the major elemental background values of thin-layered limestone and its interlayers were quantitatively determined. Also, a major elemental geochemical identification model was established for thin-layered limestone using mathematical statistical methods such as cluster analysis and factor analysis. Simultaneously, major elemental testing was conducted on shale samples from directional drilling horizontal branch holes. The identification pattern validation was completed through shale stratigraphic source analysis based on the established geochemical identification model. The results showed that high CaO content and Loss on Ignition (LOI) value could serve as characteristic indicators for the target layer L3 limestone in grouting and reinforcement. Abundances of MgO (0.5%Ā±), MnO (0.03%Ā±), and P2O5 (0.08%Ā±) could be used as recognition indicators for the overlying marker layer J3. The cluster analysis identification model effectively distinguished the Taiyuan Formation L1 to L3 limestone. The model established using element factor scores effectively differentiated clastic interlayers from thin-layered limestone in the Taiyuan Formation. The Fisher discriminant equation obtained by running the model with rock geochemical background values achieved an accuracy rate of 100% in the source analysis of cuttings from grouting target layer L3 limestone. Based on the above findings, the feasibility of applying the elemental geochemical source analysis method, aimed at ensuring the āin-layer rateā in horizontal branch hole cuttings, was demonstrated. This, in turn, led to the proposal of a ground directional drilling āin-layer rateā control technology scheme. This study, grounded in elemental geochemical theory, identified the target layer stratification through characteristic geochemical information carried by cuttings from directional drilling. With the support of on-site rapid quantitative testing techniques, the technology offers new insights into addressing the challenge of grouting and modification at bottom limestone water hazard areas in the North China-type coalfields
Altered intrinsic functional brain architecture in patients with functional constipation: a surface-based network study
BackgroundFunctional constipation (FCon) is a common functional gastrointestinal disorder (FGID). Studies have indicated a higher likelihood of psychiatric disorders, such as anxiety, depression, sleep disturbances, and impaired concentration, among patients with FCon. However, the underlying pathophysiological mechanisms responsible for these symptoms in FCon patients remain to be fully elucidated. The human brain is a complex network architecture with several fundamental organizational properties. Neurological interactions between gut symptoms and psychiatric issues may be closely associated with these complex networks.MethodsIn the present study, a total of 35 patients with FCon and 40 healthy controls (HC) were recruited for a series of clinical examinations and resting-state functional magnetic imaging (RS-fMRI). We employed the surface-based analysis (SBA) approach, utilizing the Schaefer cortical parcellation template and Tikhonov regularization. Graph theoretical analysis (GTA) and functional connectivity (FC) analysis of RS-fMRI were conducted to investigate the aberrant network alterations between the two groups. Additionally, correlation analyses were performed between the network indices and clinical variables in patients with FCon.ResultsAt the global level, we found altered topological properties and networks in patients with FCon, mainly including the significantly increased clustering coefficient (CP), local efficiency (Eloc), and shortest path length (LP), whereas the decreased global efficiency (Eglob) compared to HC. At the regional level, patients with FCon exhibited increased nodal efficiency in the frontoparietal network (FPN). Furthermore, FC analysis demonstrated several functional alterations within and between the Yeo 7 networks, particularly including visual network (VN), limbic network (LN), default mode network (DMN), and somatosensory-motor network (SMN) in sub-network and large-scale network analysis. Correlation analysis revealed that there were no significant associations between the network metrics and clinical variables in the present study.ConclusionThese results highlight the altered topological architecture of functional brain networks associated with visual perception abilities, emotion regulation, sensorimotor processing, and attentional control, which may contribute to effectively targeted treatment modalities for patients with FCon
UNIQUENESS AND DIFFERENTIAL POLYNOMIALS OF MEROMORPHIC FUNCTIONS SHARING ONE VALUE
Abstract In this paper, we study the uniqueness of differential polynomials of meromorphic functions sharing one value, and obtain some results, which improve and generalize the related results due to Fang, Zhang-Lin, and BhoosnurmathDyavanal, etc
Preparation of Monolayer Photonic Crystals from Ag Nanobulge-Deposited SiO2 Particles as Substrates for Reproducible SERS Assay of Trace Thiol Pesticide
Surface-enhanced Raman scattering (SERS) greatly increases the detection sensitivity of Raman scattering. However, its real applications are often degraded due to the unrepeatable preparation of SERS substrates. Herein presented is a very facile and cost-effective method to reproducibly produce a novel type of SERS substrate, a monolayer photonic crystal (PC). With a building block of laboratory-prepared monodisperse SiO2 particles deposited with space-tunable silver nanobulges (SiO2@nAg), a PC substrate was first assembled at the air–water interface through needle tip flowing, then transferred onto a silicon slide by a pulling technique. The transferred monolayer PCs were characterized by SEM and AFM to have a hexagonal close-packed lattice. They could increase Raman scattering intensity by up to 2.2 × 107-fold, as tested with p-aminothiophenol. The relative standard deviations were all below 5% among different substrates or among different locations on the same substrate. The excellent reproducibility was ascribed to the highly ordered structure of PCs, while the very high sensitivity was attributed to the strong hotspot effect caused by the appropriately high density of nanobulges deposited on SiO2 particles and by a closed lattice. The PC substrates were validated to be applicable to the SERS assay of trace thiol pesticides. Thiram pesticide is an example determined in apple juice samples at a concentration 102-fold lower than the food safety standard of China. This method is extendable to the analysis of other Raman-active thiol chemicals in different samples, and the substrate preparation approach can be modified for the fabrication of more PC substrates from other metallic nanobulge-deposited particles rather than silica only
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