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Rapid and accurate realization of in situ analysis of deep-sea dissolved gases imperative to the study of ecological geology, oil and gas resource exploration, and global climate change. Herein, we report for the first time the deep-sea dissolved methane (CH4) in situ sensor based on quartz-enhanced photoacoustic and light-induced thermoelastic spectroscopy. The developed sensor system has a volume of φ120 mm × 430 mm and a power consumption of 7.6 W. The sensor, in the manner of frequency division multiplexing, is able to simultaneously measure the photoacoustic signals and light-induced thermoelastic signals, which can accurately correct laser-intensity induced influence on concentration. The spectral response of CH4 concentration varying from 0.01 to 5% is calibrated in detail based on the pressure and temperature in the application environment. The trend of the photoacoustic signal of CH4 at different water molecule (H2O) concentrations is investigated. An Allan variance analysis of several hours demonstrates a minimum detection limit of 0.21 ppm for the CH4 spectrometer. The sensor combined with the gas-liquid separation and enrichment unit is integrated into a compact marine standalone system. Since the specifically designed photoacoustic cell has a volume of only 1.2 mL, the time response for dissolved CH4 detection is reduced to 4 min. Furthermore, the sensor is successfully deployed in the vicinity of the "HaiMa" cold seeps at 1380 m underwater in the South China Sea, completing three consecutive days of measurements of dissolved CH4.
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Previously, we reported a cohort of Japanese encephalitis (JE) patients with Guillain-Barré syndrome. However, the evidence linking Japanese encephalitis virus (JEV) infection and peripheral nerve injury (PNI) remains limited, especially the epidemiology, clinical presentation, diagnosis, treatment, and outcome significantly differ from traditional JE. We performed a retrospective and multicenter study of 1626 patients with JE recorded in the surveillance system of the Chinese Center for Disease Control and Prevention, spanning the years 2016-2020. Cases were classified into type 1 and type 2 JE based on whether the JE was combined with PNI or not. A comparative analysis was conducted on demographic characteristics, clinical manifestations, imaging findings, electromyography data, laboratory results, and treatment outcomes. Among 1626 laboratory confirmed JE patients, 230 (14%) were type 2 mainly located along the Yellow River in northwest China. In addition to fever, headache, and disturbance of consciousness, type 2 patients experienced acute flaccid paralysis of the limbs, as well as severe respiratory muscle paralysis. These patients presented a greater mean length of stay in hospital (children, 22 years [range, 1-34]; adults, 25 years [range, 0-183]) and intensive care unit (children, 16 years [range, 1-30]; adults, 17 years [range, 0-102]). The mortality rate was higher in type 2 patients (36/230 [16%]) compared to type 1 (67/1396 [5%]). The clinical classification of the diagnosis of JE may play a crucial role in developing a rational treatment strategy, thereby mitigating the severity of the disease and potentially reducing disability and mortality rates among patients.
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Gene loss is common and influences genome evolution trajectories. Multiple adaptive strategies to compensate for gene loss have been observed, including copy number gain of paralogous genes and mutations in genes of the same pathway. By using the Ubl-specific protease 2 (ULP2) eviction model, we identify compensatory mutations in the homologous gene ULP1 by laboratory evolution and find that these mutations are capable of rescuing defects caused by the loss of ULP2. Furthermore, bioinformatics analysis of genomes of yeast gene knockout library and natural yeast isolate datasets suggests that point mutations of a homologous gene might be an additional mechanism to compensate for gene loss.
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Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Mutação Puntual/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Mutação , Endopeptidases/genética , Endopeptidases/metabolismoRESUMO
We developed a cavity ringdown spectrometer by utilizing a step-scanning and dithering method for matching laser wavelengths to optical resonances of an optical cavity. Our approach is capable of working with two and more lasers for quasi-simultaneous measurements of multiple gas species. The developed system was tested with two lasers operating around 1654 nm and 1658 nm for spectral detections of 12CH4 and its isotope 13CH4 in air, respectively. The ringdown time of the empty cavity was about 340 µs. The achieved high detection sensitivity of a noise-equivalent absorption coefficient was 2.8 × 10-11 cm-1 Hz-1/2 or 1 × 10-11 cm-1 by averaging for 30 s. The uncertainty of the high precision determination of δ13CH4 in air is about 1.3. Such a system will be useful for future applications such as environmental monitoring.
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Monitoramento Ambiental , Lasers , Análise EspectralRESUMO
BACKGROUND: Recently, many studies utilizing next generation sequencing have investigated plant evolution and domestication in annual crops. Peach, Prunus persica, is a typical perennial fruit crop that has ornamental and edible varieties. Unlike other fruit crops, cultivated peach includes a large number of phenotypes but few polymorphisms. In this study, we explore the genetic basis of domestication in peach and the influence of humans on its evolution. RESULTS: We perform large-scale resequencing of 10 wild and 74 cultivated peach varieties, including 9 ornamental, 23 breeding, and 42 landrace lines. We identify 4.6 million SNPs, a large number of which could explain the phenotypic variation in cultivated peach. Population analysis shows a single domestication event, the speciation of P. persica from wild peach. Ornamental and edible peach both belong to P. persica, along with another geographically separated subgroup, Prunus ferganensis. CONCLUSIONS: Our analyses enhance our knowledge of the domestication history of perennial fruit crops, and the dataset we generated could be useful for future research on comparative population genomics.
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Produtos Agrícolas/classificação , Genoma de Planta , Metagenômica/métodos , Prunus/classificação , Produtos Agrícolas/genética , Evolução Molecular , Variação Genética , Homozigoto , Humanos , Desequilíbrio de Ligação , Dados de Sequência Molecular , Filogenia , Polimorfismo de Nucleotídeo Único , Prunus/genética , Seleção Genética , Análise de Sequência de DNARESUMO
This paper studied the source-sink characters and grain-filling traits of six genotype summer maize varieties under 2 years (from 2007 to 2008) application of low dosage (105 kg x hm(-2)) and normal dosage (337.5 kg x hm(-2)) fertilizer nitrogen. Under low nitrogen stress, the population yield, leaf area index (LAI), source-sink characters, and grain-filling traits of test varieties differed significantly. The varieties tolerant to low nitrogen, e.g., Xianyu 335 and Zhengdan 958, had longer active grain-filling stage, higher maximum filling rate, longer duration of maximum LAI, and more harmonious sink-source relation; while less tolerant species, e.g., Shaandan 902 and Yuyu 22, had shorter active grain-filling hours, lower maximum filling rate, lower mass increment and LAI under maximum grain-filling rate after silking, and significantly decreased source supply capacity. Low nitrogen stress increased the yield difference among the test varieties significantly.
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Grão Comestível/crescimento & desenvolvimento , Fertilizantes , Nitrogênio/análise , Zea mays/crescimento & desenvolvimento , Zea mays/genética , Biomassa , China , Genótipo , Estações do Ano , Estresse FisiológicoRESUMO
BACKGROUND AND OBJECTIVE: Cancer is one of the most primary causes of death for children. The study was to analyze the cancer incidence and mortality of children in urban districts of Guangzhou between 2000 and 2004, to explore the incidence regularity of pediatric cancers and to provide a reference for prevention and treatment of pediatric cancers. METHODS: The data of cancer incidence and mortality of children during 2000-2004 were collected from Guangzhou Population-based Cancer Registry, and were calculated and analyzed. RESULTS: The cancer incidence of children between 2000 and 2004 in Guangzhou was 17.91 per 100,000 (18.92 per 100,000 in males, 16.70 per 100,000 in females); the cancer mortality was 4.73 per 100,000 (4.65 per 100,000 in males, 4.83 per 100,000 in females). The incidence of lymphoid leukemia ranked first followed by cancer of central nervous system and non-Hodgkin's lymphoma. Cancer incidence was 77.52 per 100 000 in children of less than one year old, 21.49 per 100,000 in 1-4 years, 9.66 per 100,000 in 5-9 years and 17.11 per 100 000 in 10-14 years, with significant difference among the four groups (Chi(2) = 307.602, P < 0.001). CONCLUSION: Lymphoid leukemia, cancer of central nervous system and non-Hodgkin's lymphoma are the most common cancers in children. The children of 0-4 years old are the population with high cancer incidence.
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Neoplasias/epidemiologia , Neoplasias/mortalidade , Adolescente , Neoplasias do Sistema Nervoso Central/epidemiologia , Neoplasias do Sistema Nervoso Central/mortalidade , Criança , Pré-Escolar , China/epidemiologia , Feminino , Humanos , Incidência , Lactente , Recém-Nascido , Leucemia Linfoide/epidemiologia , Leucemia Linfoide/mortalidade , Linfoma não Hodgkin/epidemiologia , Linfoma não Hodgkin/mortalidade , MasculinoRESUMO
BACKGROUND AND OBJECTIVE: The incidence of colorectal cancer is increasing with the change of the diet habit. This study was to analyze the incidence of colorectal cancer in Guangzhou City, thus to provide references and information for the prevention and treatment of this disease. METHODS: Data of colorectal cancer patients during 2000-2002 were collected from Guangzhou population-based cancer registry. Incidence and mortality of colorectal cancer were calculated and analyzed. RESULTS: The crude incidence and mortality of colon cancer in Guangzhou from 2000 to 2002 were 13.4 per 100000 (13.5 per 100000 in males, 13.3 per 100000 in females) and 7.1 per 100000 (7.3 per 100000 in males, 6.9 per 100000 in females), respectively. The crude incidence and mortality of rectal cancer in Guangzhou from 2000 to 2002 were 9.6 per 100000 (10.8 per 100000 in males, 8.2 per 100000 in females) and 5.0 per 100000 (5.5 per 100000 in males, 4.5 per 100000 in females), respectively. The incidence of colon cancer and rectal cancer ranked the fifth and seventh respectively among all cancers. The incidence of colorectal cancer was increased with age. CONCLUSIONS: The incidence rate of colorectal cancer is high in Guangzhou. Studies on prevention and treatment of colorectal cancer should be enhanced.
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Neoplasias do Colo/epidemiologia , Neoplasias Colorretais/epidemiologia , Neoplasias Retais/epidemiologia , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , China/epidemiologia , Neoplasias do Colo/mortalidade , Neoplasias Colorretais/mortalidade , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Neoplasias Retais/mortalidadeRESUMO
BACKGROUND & OBJECTIVE: Population-based cancer registration has never been carried out before in Guangzhou. This study was to analyze the cancer incidence and mortality in Guangzhou and to provide references for prevention and treatment of cancer. METHODS: Data of cancer incidence and mortality during 2000--2002 were collected from Guangzhou Population-based Cancer Registry. Cancer incidence and mortality were calculated and analyzed. RESULTS: The crude cancer incidence during 2000--2002 in Guangzhou was 227.7 per 100,000 (257.0 per 100,000 in males and 196.5 per 100,000 in females)û the crude cancer mortality was 147.9 per 100,000 (183.6 per 100,000 in males and 109.7 per 100,000 in females). The incidence of lung cancer ranked first followed by those of liver cancer, nasopharyngeal cancer, gastric cancer and colon cancer in males. Breast cancer was the leading cancer in females followed by those of lung cancer, liver cancer, colon cancer and nasopharyngeal cancer. The cancer incidence and mortality increased with age. CONCLUSION: Cancer incidence is high in Guangzhou, and the research for prevention and treatment of cancer should be enhanced.
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Neoplasias/epidemiologia , Neoplasias/mortalidade , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , China/epidemiologia , Feminino , Humanos , Incidência , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Fatores de TempoRESUMO
By using D-saturation optimum design and the methods of crop population physiology, this paper studied the effects of planting date and density on the population physiological indices of summer maize Shandan 8806 and its yield in central Shaanxi irrigation area. The results showed that in the period from 13 June to 22 July, the delay of planting had negative effects on grain yield, dry matter accumulation (DMA), maximum leaf area index (LAImax), net assimilation rate (NAR), leaf area duration (LAD) and crop growth rate (CGR), with larger effects on LAD and CGR than on LAImax and NAR. Within the range of 45 000-65 918 plants . hm (-2), planting density had positive effects on grain yield, DMA, LAImax, LAD and CGR but negative effect on NAR, with larger effects on LAImax, LAD and CGR than on NAR. The effects of planting date were more significant than those of planting density, and thus, Shandan 8806 should be sowed as early as possible. The regressive model based on the population physiological indices indicated that for the high yield of summer maize Shandan 8806, the optimum planting date was from 10 to 20 June, and the optimum planting density was from 57 767 to 71 706 plants . hm(-2).
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Agricultura/métodos , Biomassa , Zea mays/fisiologia , Fatores de Tempo , Zea mays/crescimento & desenvolvimentoRESUMO
Taken maize in two plant types of compact-type and flat-type as research object, the relationships between density-tolerance and light distribution in population, indices of productivity(LAI, NAR, and CGR), and population sink-source were studied synthetically by means of crop growth analysis method. The results showed that light distribution in population was the chief index to measure density-tolerance of different maize varieties. The kinetic rules of LAI, NAR, and CGR were the basic feature reflecting density-tolerance. The correspondent relationship in population sink-source was a comprehensive index to appraise density-tolerance of different maize varieties.