A 60-year record of 129I in Taal Lake sediments (Philippines): Influenceof human nuclear activities at low latitude region

The influence of human nuclear activities on environmental radioactivity is not well known at low latitude regions that are distant from nuclear test sites and nuclear facilities. A sediment core collected from Taal Lake in the central Philippines was analyzed for 129I and 127I to investigate this influence in a low-latitude terrestrial system. A baseline of 129I/127I atomic ratios was established at (2.04e5.14) * 10-12&nbsp;in the pre-nuclear era in this region. Controlled by the northeasterly equatorial trade winds, increased 129I/127I ratios of (20.1e69.3) * 10-12 suggest that atmospheric nuclear weapons tests at the Pacific Proving Grounds in the central Pacific Ocean was the major source of 129I in the sediment during 1956-1962. The 129I/127I ratios, up to 157.5*10-12 after 1964, indicate a strong influence by European nuclear fuel reprocessing plants. The East Asian Winter Monsoon is found to be the dominant driving force in the atmospheric dispersion of radioactive iodine (129I) from the European nuclear fuel reprocessing plants to Southeast Asia, which is also important for dispersion of other airborne pollutants from the middle-high to low latitude regions. A significant 129I/127I peak at 42.8 cm in the Taal Lake core appears to be the signal of the Chernobyl accident in 1986. In addition, volcanic activities are reflected in the iodine isotope profiles in the sediment core, suggesting the potential of using iodine isotopes as an indicator of volcanic eruptions.<br style="line-height: normal; text-align: -webkit-auto; text-size-adjust: auto;" /

Molecular characterisation of canine parvovirus strains circulating in China

Canine parvovirus (CPV) was first isolated at 1978 in the USA. Analysis of CPV isolates by monoclonal antibodies and restriction enzymes have shown that after the first emergence of CPV (CPV-2) it evolved to give rise to new antigenic types, which were designated CPV types 2a, 2b and 2c. These new types have replaced the original CPV type 2, although the proportions of each of the new antigenic types vary in different countries. In China, CPV infections were first observed in 1982, however, there has been no information concerning the antigenic types of CPV prevailing in China now. In this study, we designed a PCR assay to type canine parvovirus strains in fecal samples collected from symptomatic dogs from 2006 to 2009. Our data showed that the CPV prevalent strain is mostly 2b, the proportion of CPV-2a is very low, no CPV-2c and CPV-2 were observed

International collaboration and innovation: Evidence from a leading Chinese multinational enterprise

Copyright © 2022 The Authors. This paper investigates the impact of international collaboration and its characteristics on the quality of the innovation of multinational enterprises (MNEs) in emerging markets. Using a unique dataset of 1428 international and comparable domestic collaboration projects over the 2010–2016 period, it finds that while international innovation collaborations are associated with high innovation quality, cultural distance has a negative effect on collaboration outcomes. Moreover, proximity to the focal firm's overseas R&D centres and the size of expenditure budgets play significant moderating roles in overcoming cultural barriers. Based on the RBV and dynamic capabilities theory, we investigate how firms from emerging markets can acquire these two crucial requisites for innovation. The characteristics of partners and intellectual property (IP) arrangements are also found to have a significant impact on the quality of innovations.Chinese Academy of Medical Sciences for financial support, Grant/Award Number: 2018-I2M-2-002

Magnetic field effects on the electroluminescence of organic light emitting devices: A tool to indicate the carrier mobility

The magnetoelectroluminescence (MEL) of organic light emitting devices with a N, N′ -bis(l-naphthyl)- N, N′ -diphenyl- 1, l′ -biphentl- 4, 4′ -diamine:tris-(8-hydroxyquinoline) aluminum (NPB: Alq 3) mixed emission layer (EML) has been investigated. We find that MEL is maximized when the volume ratio of NPB of the mixed EML reaches 30% and the EML thickness is 40 nm. The features of MEL under various magnetic field strengths are insensitive to the change in EML thickness and mixing ratio. Meanwhile, MEL has a close relationship with the carrier mobility. We have conducted a theoretical study to further verify the relationship. Our experimental and theoretical results confirm that MEL can function as a tool to indicate the mobility. © 2010 American Institute of Physics.published_or_final_versio

Dietary behavior and knowledge of dental erosion among Chinese adults

<p>Abstract</p> <p>Objectives</p> <p>To study the dietary behavior and knowledge about dental erosion and self-reported symptoms that can be related to dental erosion among Chinese adults in Hong Kong.</p> <p>Methods</p> <p>Chinese adults aged 25-45 years were randomly selected from a list of registered telephone numbers generated by computer. A telephone survey was administered to obtain information on demographic characteristics, dietary habits, dental visits, and knowledge of and presence of self-reported symptoms that can be related to dental erosion.</p> <p>Results</p> <p>A total of 520 participants were interviewed (response rate, 75%; sampling error, ± 4.4%) and their mean age was 37. Most respondents (79%) had ever had caries, and about two thirds (64%) attended dental check-ups at least once a year. Respondents had a mean of 5.4 meals per day and 36% had at least 6 meals per day. Fruit (89%) and lemon tea/water (41%) were the most commonly consumed acidic food and beverage. When asked if they ever noticed changes in their teeth, most respondents (92%) said they had experienced change that can be related to erosion. However, many (71%) had never heard about dental erosion and 53% mixed up dental erosion with dental caries.</p> <p>Conclusion</p> <p>Hong Kong Chinese adults have frequent intake of food and many have experienced symptoms that can be related to dental erosion. Their level of awareness of and knowledge about dental erosion is generally low, despite most of them have regular dental check-ups. Dental health education is essential to help the public understand dental erosion and its damaging effects.</p

Essential versus accessory aspects of cell death: recommendations of the NCCD 2015

Cells exposed to extreme physicochemical or mechanical stimuli die in an uncontrollable manner, as a result of their immediate structural breakdown. Such an unavoidable variant of cellular demise is generally referred to as ‘accidental cell death’ (ACD). In most settings, however, cell death is initiated by a genetically encoded apparatus, correlating with the fact that its course can be altered by pharmacologic or genetic interventions. ‘Regulated cell death’ (RCD) can occur as part of physiologic programs or can be activated once adaptive responses to perturbations of the extracellular or intracellular microenvironment fail. The biochemical phenomena that accompany RCD may be harnessed to classify it into a few subtypes, which often (but not always) exhibit stereotyped morphologic features. Nonetheless, efficiently inhibiting the processes that are commonly thought to cause RCD, such as the activation of executioner caspases in the course of apoptosis, does not exert true cytoprotective effects in the mammalian system, but simply alters the kinetics of cellular demise as it shifts its morphologic and biochemical correlates. Conversely, bona fide cytoprotection can be achieved by inhibiting the transduction of lethal signals in the early phases of the process, when adaptive responses are still operational. Thus, the mechanisms that truly execute RCD may be less understood, less inhibitable and perhaps more homogeneous than previously thought. Here, the Nomenclature Committee on Cell Death formulates a set of recommendations to help scientists and researchers to discriminate between essential and accessory aspects of cell death

Tire Defect Detection Based on Faster R-CNN

The tire defect detection method can help the rehabilitation robot to achieve autonomous positioning function and improve the accuracy of the robot system behavior. Defects such as foreign matter sidewall, foreign matter tread, and sidewall bubbles will appear in the process of tire production, which will directly or indirectly affect the service life of the tire. Therefore, a novel and efficient tire defect detection method was proposed based on Faster R-CNN. At preprocessing stage, the Laplace operator and the homomorphic filter were used to sharpen and enhance the data set, the gray values of the image target and the background were significantly different, which improved the detection accuracy. Moreover, data expansion was used to increase the number of images and improve the robustness of the algorithm. To promote the accuracy of the position detection and identification, the proposed method combined the convolution features of the third layer and the convolution features of the fifth layer in the ZF network (a kind of convolution neural network). Then, the improved ZF network was used to extract deep characteristics as inputs for Faster R-CNN. From the experiment, the proposed faster R-CNN defect detection method can accurately classify and locate the tire X-ray image defects, and the average test recognition rate is up to 95.4%. Moreover, if there are additional types of defects that need to be detected, then a new detection model can be obtained by fine-tuning the network

Influence of Dll4 via HIF-1α-VEGF Signaling on the Angiogenesis of Choroidal Neovascularization under Hypoxic Conditions

Choroidal neovascularization (CNV) is the common pathological basis of irreversible visual impairment encountered in a variety of chorioretinal diseases; the pathogenesis of its development is complicated and still imperfectly understood. Recent studies indicated that delta-like ligand 4 (Dll4), one of the Notch family ligands might participate in the HIF-1α-VEGF pathway to regulate CNV angiogenesis. But little is known about the influence and potential mechanism of Dll4/Notch signals on CNV angiogenesis. Real-time RT-PCR, Western blotting were used to analyze the expression alteration of Dll4, VEGF and HIF-1α in hypoxic RF/6A cells. Immunofluorescence staining, a laser-induced rat CNV model and intravitreal injection techniques were used to confirm the relationships among these molecules in vitro and in vivo. RPE-RF/6A cell co-culture systems were used to investigate the effects of Dll4/Notch signals on CNV angiogenesis. We found that the Dll4 was involved in hypoxia signaling in CNV angiogenesis. Results from the co-culture system showed that the enhancement of Dll4 expression in RF/6A cells led to the significantly faster proliferation and stronger tube forming ability, but inhibited cells migration and invasion across a monolayer of RPE cells in hypoxic environment, while siRNA-mediated Dll4 silencing caused the opposite effects. Pharmacological disruption of Notch signaling using gamma-secretase inhibitor (GSI) produced similar, but not identical effects, to that caused by the Dll4 siRNA. In addition, the expression of several key molecules involved in the angiogenesis of CNV was altered in RF/6A cells showing constitutively active Dll4 expression. These results suggest that Dll4 play an important role in CNV angiogenesis, which appears to be regulated by HIF-1α and VEGF during the progression of CNV under hypoxic conditions. Targeting Dll4/Notch signaling may facilitate further understanding of the mechanisms that underlie CNV angiogenesis