91 research outputs found

    Holocene lake response to glacier and catchment changes on the eastern Tibetan Plateau from quantitative conductivity reconstructions based on sedaDNA-derived macrophyte records

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    Understanding the response of long-term aquatic environmental changes in lakes to ongoing climate change and human activities is key to forecasting future lake conditions. In this study, we infer the Holocene limnological changes in Emu Co, a proglacial lake in Nianbaoyuze on the eastern Tibetan Plateau, from sedimentary ancient DNA (sedaDNA) data, and palynomorph, element, lithological, and grain-size analyses. We developed a transfer function based on Siberia and Tibet/China surface sedimentary DNA and applied it to Emu Co sedaDNA to trace lake conductivity changes. The results show that the conductivity of Emu Co was high during 12.6−9.7 cal ka BP, often surpassing 1000 μs cm−1, driven by elevated summer solar radiation. The freshwater influx from glacial meltwater and precipitation, however, reduced the lake's conductivity as the climate warmed and humidified. This led to a decrease in the abundance of taxa characterised by high conductivity. Freshwater pulses, triggered by climatic fluctuations, likely led to significant variations in conductivity within the overarching downward trend. By 8 cal. ka BP, lake recharge conditions stabilised and conductivity reached a lower level of ∼70 μs cm−1. The warm and humid mid-Holocene (8−5 cal. ka BP) provided suitable habitat conditions for many submerged freshwater taxa. After 5 cal. ka BP, the growth of submerged taxa was restricted, as indicated by a shift from asexual to sexual reproduction in macrophytes, likely in response to suboptimal conditions of a colder and drier climate. Since 1 cal. ka BP, human activities might have increased lake nutrient levels, with an enhanced richness of macrophytes. Our results indicate how millennial-scale hydrological changes in a lake are related to glacial retreat and catchment changes in the alpine region of the Tibetan Plateau, which is today facing climate change much greater than the global average

    Human activities have reduced plant diversity in eastern China over the last two millennia

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    Understanding the history and regional singularities of human impact on vegetation is key to developing strategies for sustainable ecosystem management. In this study, fossil and modern pollen datasets from China are employed to investigate temporal changes in pollen composition, analogue quality, and pollen diversity during the Holocene. Anthropogenic disturbance and vegetation's responses are also assessed. Results reveal that pollen assemblages from non-forest communities fail to provide evidence of human impact for the western part of China (annual precipitation less than 400 mm and/or elevation more than 3000 m.a.s.l.), as inferred from the stable quality of modern analogues, principal components, and diversity of species and communities throughout the Holocene. For the eastern part of China, the proportion of fossil pollen spectra with good modern analogues increases from ca. 50% to ca. 80% during the last 2 millennia, indicating an enhanced intensity of anthropogenic disturbance on vegetation. This disturbance has caused the pollen spectra to become taxonomically less diverse over space (reduced abundances of arboreal taxa and increased abundances of herbaceous taxa), highlighting a reduced south–north differentiation and divergence from past vegetation between regions in the eastern part of China. We recommend that care is taken in eastern China when basing the development of ecosystem management strategies on vegetation changes in the region during the last 2000 years, since humans have significantly disturbed the vegetation during this period

    Correlation Between C-MYC, BCL-2, and BCL-6 Protein Expression and Gene Translocation as Biomarkers in Diagnosis and Prognosis of Diffuse Large B-cell Lymphoma

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    This study investigates the protein expression of C-MYC, BCL-2, and BCL-6 in diffuse large B-cell lymphoma (DLBCL) and their relationship with genetic abnormalities. A retrospective study of 42 cases on paraffin-embedded tissue specimens diagnosed with DLBCL was performed using immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH). The expression of C-MYC, BCL-2, BCL-6 protein, and gene abnormalities in these tissue samples was analyzed. The relationship in genetic abnormalities and Ki-67, Hans classification, gender, and age was also evaluated. It was found that the positive rate of C-MYC expression was 47.6% (20/42), the rate of C-MYC gene abnormality was 26.2% (11/42), in which gene translocation accounted for 23.8% (10/42) and gene amplification 2.4% (1/42); C-MYC protein expression was positively correlated with C-MYC gene translocation (χ2 = 11.813; P = 0.001); C-MYC gene translocation was mainly found in germinal center B cell type (χ2 = 4.029; P = 0.045). The positive rate of BCL-2 protein expression was 85.71% (36/42), the positive rate of translocation was 42.86% (18/42) and the amplification rate was 26.19% (11/42); the overexpression of BCL-2 protein was correlated with the BCL-2 translocation (χ2 = 3.407; P = 0.029). The positive rate of BCL-6 protein expression was 45.24% (19/42), the positive rate of BCL-6 translocation was 14.29% (6/42) and the positive rate of BCL-6 amplification was 7.14% (3/42); the overexpression of BCL-6 protein was significantly correlated with BCL-6 translocation (χ2 = 6.091; P = 0.014). The Ki-67 index was significantly higher in C-MYC translocation cases than in non-C-MYC translocation cases (χ2 = 4.492; P = 0.034). Taken together, our results suggest that the protein expression of C-MYC, BCL-2, and BCL-6 are positively correlated with their gene translocation. Overexpression of C-MYC, BCL-2, BCL-6 protein suggests the possibility of translocation. Therefore, immunohistochemical detection of C-MYC, BCL-2, and BCL-6 are useful in diagnosis and prognosis of DLBCL

    Pre‐symptomatic transmission of novel coronavirus in community settings

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    We used contact tracing to document how COVID‐19 was transmitted across 5 generations involving 10 cases, starting with an individual who became ill on January 27. We calculated the incubation period of the cases as the interval between infection and development of symptoms. The median incubation period was 6.0 days (interquartile range, 3.5‐9.5 days). The last two generations were infected in public places, 3 and 4 days prior to the onset of illness in their infectors. Both had certain underlying conditions and comorbidity. Further identification of how individuals transmit prior to being symptomatic will have important consequences.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/163478/2/irv12773.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/163478/1/irv12773_am.pd

    The Association Between Diabetic Retinopathy and the Prevalence of Age-Related Macular Degeneration—The Kailuan Eye Study

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    This study aimed to investigate the prevalence of age-related macular degeneration (AMD) in patients with diabetes mellitus (DM) and diabetic retinopathy (DR) and analyze whether DR is a risk factor for AMD. This population-based epidemiological study included 14,440 people from the Kailuan Eye Study in 2016, of whom 1,618 were patients with type 2 DM aged over 50 years, and 409 had DM with DR. We analyzed whether there were differences in the prevalence of AMD between DM with DR and DM without DR, and conducted a hierarchical statistical analysis according to different stages of DR. Using variable regression analysis, we explored whether DR constituted a risk factor for AMD. In the DM population, the prevalence of wet AMD in patients with DM with and without DR was 0. 3 and 0.2%, respectively, with no significant difference (P = 0.607). Meanwhile, the prevalence of dry AMD in patients with DM with and without DR was 20.8 and 16.0%, respectively, with a significant difference. In the subgroup analysis of dry AMD, the prevalence of early, middle, and late dry AMD in DM with DR was 14.4, 5.9, and 0.5%, respectively. In DM without DR, the prevalence of early, middle, and late dry AMD was 10.5, 4.8, and 0.7%, respectively (P = 0.031). In the subgroup analysis of DR staging, statistical analysis could not be performed because of the limited number of patients with PDR. In the variable regression analysis of risk factors for dry AMD, after adjusting for age, sex, body mass index, hypertension, and dyslipidemia, DR constituted the risk factor for dry AMD. In conclusion, DM did not constitute a risk factor for AMD, and the prevalence of wet AMD and dry AMD in patients with DM and DR was higher than that in patients with DM without DR (among which dry AMD was statistically significant). Multivariate regression analysis confirmed that DR is an independent risk factor for dry AMD. Reasonable control of DM and slowing down the occurrence and development of DR may effectively reduce the prevalence of AMD in patients with DM

    Seizing the window of opportunity to mitigate the impact of climate change on the health of Chinese residents

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    The health threats posed by climate change in China are increasing rapidly. Each province faces different health risks. Without a timely and adequate response, climate change will impact lives and livelihoods at an accelerated rate and even prevent the achievement of the Healthy and Beautiful China initiatives. The 2021 China Report of the Lancet Countdown on Health and Climate Change is the first annual update of China’s Report of the Lancet Countdown. It comprehensively assesses the impact of climate change on the health of Chinese households and the measures China has taken. Invited by the Lancet committee, Tsinghua University led the writing of the report and cooperated with 25 relevant institutions in and outside of China. The report includes 25 indicators within five major areas (climate change impacts, exposures, and vulnerability; adaptation, planning, and resilience for health; mitigation actions and health co-benefits; economics and finance; and public and political engagement) and a policy brief. This 2021 China policy brief contains the most urgent and relevant indicators focusing on provincial data: The increasing health risks of climate change in China; mixed progress in responding to climate change. In 2020, the heatwave exposures per person in China increased by 4.51 d compared with the 1986–2005 average, resulting in an estimated 92% increase in heatwave-related deaths. The resulting economic cost of the estimated 14500 heatwave-related deaths in 2020 is US$176 million. Increased temperatures also caused a potential 31.5 billion h in lost work time in 2020, which is equivalent to 1.3% of the work hours of the total national workforce, with resulting economic losses estimated at 1.4% of China’s annual gross domestic product. For adaptation efforts, there has been steady progress in local adaptation planning and assessment in 2020, urban green space growth in 2020, and health emergency management in 2019. 12 of 30 provinces reported that they have completed, or were developing, provincial health adaptation plans. Urban green space, which is an important heat adaptation measure, has increased in 18 of 31 provinces in the past decade, and the capacity of China’s health emergency management increased in almost all provinces from 2018 to 2019. As a result of China’s persistent efforts to clean its energy structure and control air pollution, the premature deaths due to exposure to ambient particulate matter of 2.5 μm or less (PM2.5) and the resulting costs continue to decline. However, 98% of China’s cities still have annual average PM2.5 concentrations that are more than the WHO guideline standard of 10 μg/m3. It provides policymakers and the public with up-to-date information on China’s response to climate change and improvements in health outcomes and makes the following policy recommendations. (1) Promote systematic thinking in the related departments and strengthen multi-departmental cooperation. Sectors related to climate and development in China should incorporate health perspectives into their policymaking and actions, demonstrating WHO’s and President Xi Jinping’s so-called health-in-all-policies principle. (2) Include clear goals and timelines for climate-related health impact assessments and health adaptation plans at both the national and the regional levels in the National Climate Change Adaptation Strategy for 2035. (3) Strengthen China’s climate mitigation actions and ensure that health is included in China’s pathway to carbon neutrality. By promoting investments in zero-carbon technologies and reducing fossil fuel subsidies, the current rebounding trend in carbon emissions will be reversed and lead to a healthy, low-carbon future. (4) Increase awareness of the linkages between climate change and health at all levels. Health professionals, the academic community, and traditional and new media should raise the awareness of the public and policymakers on the important linkages between climate change and health.</p
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