Physiological responses of Porphyra haitanesis to different copper and zinc concentrations

No presente estudo foram investigadas as respostas fisiológicas da alga vermelha Porphyra haitanesis às elevadas concentrações de cobre (acima de 50 μM) e de zinco (acima de 100 μM). Os resultados mostram que os efeitos de Cu2+ e Zn2+ sobre o crescimento, pigmentos fotossintéticos (clorofilas e carotenóides), ficobiliproteína e metabolismo (o espectro de emissão de fluorescência e as atividades do fotossistema) não seguem o mesmo padrão. A taxa de crescimento relativo foi inibida por diferentes concentrações de Cu2+ e, em presença de Zn2+, aumentou ligeiramente em baixas concentrações (abaixo de 10 μM) e foi inibida em altas concentrações. Por outro lado, os teores de ficoeritrina apresentaram leve aumento em concentrações relativamente baixas de Cu2+ e Zn2+ (até 1 μM Cu2+ e até 20 μM Zn2+, respectivamente) e foram inibidas por altas concentrações. Além disso, tanto a fotossíntese quanto a respiração mostraram aumento nas trocas de oxigênio em resposta às concentrações relativamente baixas de Cu2+ (até 1 μM) e de Zn2+ (até 10 μM), além da redução em concentrações relativamente altas desses metais. Adicionalmente, as atividades fotoredutoras e as emissões de fluorescência do fotossistema II (PSII) foram incrementadas em baixas concentrações de Cu2+ (até 0,1 μM) e de Zn2+ (até 10 μM) e inibidas por altas concentrações. Desta forma, a intensidade da fluorescência da clorofila-a e dos centros de reação ativa PSII seguiram um padrão semelhante em resposta às elevadas concentrações de Cu2+ e Zn2+. Esses resultados sugerem que baixas concentrações de Cu2+ e Zn2+ afetam o metabolismo de P. haitanesis, que se torna inibido por altas concentrações desses metais.In the present study, several physiological responses of the red marine alga Porphyra haitanesis to elevated concentrations of copper (up to 50 μM) and zinc (up to 100 μM) were investigated. Our results showed that the effects of Cu2+ and Zn2+ on growth, photosynthetic pigments (chlorophylls and carotenoids), phycobiliprotein and metabolism (the fluorescence emission spectra and the activities of photosystemII) did not follow the same pattern. The relative growth rate was inhibited by different concentrations of Cu2+, and was slightly increased at lower concentrations (up to 10 μM) and inhibited at higher Zn2+concentrations. On the other hand, the phycoerythrin contents were slightly increased at relatively low concentrations (up to 1 μM Cu2+ or 20 μM Zn2+) and inhibited by high Cu2+ and Zn2+ concentrations. Moreover, photosynthesis and respiration showed an increase in the amount of oxygen exchange in response to relatively low Cu2+ (up to 1 μM) and Zn2+ concentrations (up to 10 μM), and a reduction to relatively high Cu2+ and Zn2+ concentrations. Oxygen evolution was more sensitive than oxygen uptake to Cu2+ and Zn2+. In addition, the photoreductive activities and fluorescence emission of photosystem II (PS II) were enhanced by lower concentrations of Cu2+ (up to 0.1 μM) and Zn2+ (up to 10 μM) and inhibited by higher concentrations. Furthermore, the intensity of chlorophyll a fluorescence and the active PSII reaction centers followed a similar pattern in response to elevated concentrations of Cu2+ and Zn2+. These results suggest that lower concentrations of Cu2+ and Zn2+ affected the metabolism of P. haitanesis, which was inhibited by higher concentrations of these metals

Establish real-time monitoring models of cotton aphid quantity based on different leaf positions in cotton seedlings

Cotton aphids, Aphis gossypii glover, are major pest threats to cotton plants, leading to quality and yield loss of cotton. Rapid and accurate evaluation on the occurrence and quantity of cotton aphids can help precision management and treatment of cotton aphids. The occurrence rules of cotton aphids on different leaf positions in cotton seedling stage for two cultivars of cotton were studied. The quantity of cotton aphids in the whole cotton seedlings were predicted based on the single leaf cotton aphid quantity. The correlation analysis results showed that cotton aphids of single leaf were significantly and positively correlated with the infected time, the all leaves of the whole plant, the whole plant contained all leaves and branches. The variance analysis results showed that cotton aphids of single leaf were significant difference with the extension of infected time. Based on different leaf positions, monitoring models were constructed respectively. The modelling set’s determination coefficient of ‘Xinluzao-45’ was greater than 0.8, while ‘Lumainyan-24’ was greater than 0.6. The best monitoring leaf position was the third for ‘Xinluzao-45’, the sixth for ‘Lumianyan-24’. From the data analysis, we can realize that it is feasible to construct a monitoring model based on the occurrence of cotton aphid in one leaf in cotton seedling, and different cotton varieties have different leaf positions. This will greatly reduce the investment of manpower and time

Classification of a Complexly Mixed Magnetic Mineral Assemblage in Pacific Ocean Surface Sediment by Electron Microscopy and Supervised Magnetic Unmixing

Unambiguous magnetic mineral identification in sediments is a prerequisite for reconstructing paleomagnetic and paleoenvironmental information from environmental magnetic parameters. We studied a deep-sea surface sediment sample from the Clarion Fracture Zone region, central Pacific Ocean, by combining magnetic measurements and scanning and transmission electron microscopic analyses. Eight titanomagnetite and magnetite particle types are recognized based on comprehensive documentation of crystal morphology, size, spatial arrangements, and compositions, which are indicative of their corresponding origins. Type-1 particles are detrital titanomagnetites with micron- and submicron sizes and irregular and angular shapes. Type-2 and -3 particles are well-defined octahedral titanomagnetites with submicron and nanometer sizes, respectively, which are likely related to local hydrothermal and volcanic activity. Type-4 particles are nanometer-sized titanomagnetites hosted within silicates, while type-5 particles are typical dendrite-like titanomagnetites that likely resulted from exsolution within host silicates. Type-6 particles are single domain magnetite magnetofossils related to local magnetotactic bacterial activity. Type-7 particles are superparamagnetic magnetite aggregates, while Type-8 particles are defect-rich single crystals composed of many small regions. Electron microscopy and supervised magnetic unmixing reveal that type-1 to -5 titanomagnetite and magnetite particles are the dominant magnetic minerals. In contrast, the magnetic contribution of magnetite magnetofossils appears to be small. Our work demonstrates that incorporating electron microscopic data removes much of the ambiguity associated with magnetic mineralogical interpretations in traditional rock magnetic measurements.This study was supported financially by the National Natural Science Foundation of China (Grant Nos. 41920104009, 41890843, and 41621004), The Senior User Project of RVKEXUE2019GZ06 (Center for Ocean Mega-Science, Chinese Academy of Sciences)

An Optical AC Voltage Sensor Based on the Transverse Pockels Effect

This paper introduces an optical AC voltage sensor based on the transverse Pockels effect. The sensor utilizes a bulk Bi4Ge3O12 (BGO) crystal as the sensing element. The measurement principle has been described and prototype of the sensor has been constructed and evaluated. Good linearity and accuracy performance was obtained for AC voltage measurement. The proposed sensor can be thus applied to high AC voltage measurements in the electric power industry

Atomic quantum state transferring and swapping via quantum Zeno dynamics

In this paper, we first demonstrate how to realize quantum state transferring (QST) from one atom to another based on quantum Zeno dynamics. Then, the QST protocol is generalized to realize the quantum state swapping (QSS) between two arbitrary atoms with the help of a third one. Furthermore, we also consider the QSS within a quantum network. The influence of decoherence is analyzed by numerical calculation. The results demonstrate that the protocols are robust against cavity decay.Comment: To appear in J. Opt. Soc. Am. B (JOSAB

Association of hematological parameters with metabolic syndrome in Beijing adult population: a longitudinal study

The purposes of the study were to estimate the incidence of metabolic syndrome (MetS) and to systematically evaluate the relationship between hematological parameters and MetS in a 5-year follow-up of Beijing adult population. The longitudinal study included 3,180 adults, aged 20–65 years, who attended health check-ups in Beijing Tongren Hospital in 2007 and 2012. Multivariate logistic regression was conducted to explore the associations between hematological parameters and MetS. The 5-year cumulative incidence of MetS in this sample was 10.82 % (14.22 % for males and 7.59 % for females). Among all the hematological parameters, white blood cell count (WBC) was positively associated with MetS for 20–35-year-old (male OR 1.482, 95 % CI 1.169–2.974; female OR 1.398, 95 % CI 1.145–3.011), and 36–50-year-old (male OR 2.012, 95 % CI 1.290–4.010; female OR 3.400, 95 % CI 1.818–4.528) male and female subjects. Alanine aminotransferase (ALT) was significantly associated with the incidence of MetS for males (20–35-year-old OR 2.080, 95 % CI 1.371–3.159; 36–50-year-old OR 2.421, 95 % CI 1.335–3.412; 51–65-year-old OR 4.267, 95 % CI 1.161–6.781). Low-density lipoprotein cholesterol (LDL-C) was positively associated with MetS for 51–65-year-old (male OR 3.078, 95 % CI 2.468–5.131; female OR 2.140, 95 %CI 1.524–4.359) for male and female subjects. WBC is positively associated with MetS for young adults, while LDL-C is positively associated with MetS for elderly people. ALT is positively associated with MetS for males. Our findings provide further evidence in support of using hematological markers for early detection of individuals at risk for MetS

Continuous and low-energy 125I seed irradiation changes DNA methyltransferases expression patterns and inhibits pancreatic cancer tumor growth

<p>Abstract</p> <p>Background</p> <p>Iodine 125 (¹²⁵I) seed irradiation is an effective treatment for unresectable pancreatic cancers. However, the radiobiological mechanisms underlying brachytherapy remain unclear. Therefore, we investigated the influence of continuous and low-energy ¹²⁵I irradiation on apoptosis, expression of DNA methyltransferases (DNMTs) and cell growth in pancreatic cancers.</p> <p>Materials and methods</p> <p>For <it>in vitro </it>¹²⁵I seed irradiation, SW-1990 cells were divided into three groups: control (0 Gy), 2 Gy, and 4 Gy. To create an animal model of pancreatic cancer, the SW 1990 cells were surgically implanted into the mouse pancreas. At 10 d post-implantation, the 30 mice with pancreatic cancer underwent ¹²⁵I seed implantation and were separated into three groups: 0 Gy, 2 Gy, and 4 Gy group. At 48 or 72 h after irradiation, apoptosis was detected by flow cytometry; changes in DNMTs mRNA and protein expression were assessed by real-time PCR and western blotting analysis, respectively. At 28 d after ¹²⁵I seed implantation, <it>in vivo </it>apoptosis was evaluated with TUNEL staining, while DNMTs protein expression was detected with immunohistochemical staining. The tumor volume was measured 0 and 28 d after ¹²⁵I seed implantation.</p> <p>Results</p> <p>¹²⁵I seed irradiation induced significant apoptosis, especially at 4 Gy. DNMT1 and DNMT3b mRNA and protein expression were substantially higher in the 2 Gy group than in the control group. Conversely, the 4 Gy cell group exhibited significantly decreased DNMT3b mRNA and protein expression relative to the control group. There were substantially more TUNEL positive in the ¹²⁵I seed implantation treatment group than in the control group, especially at 4 Gy. The 4 Gy seed implantation group showed weaker staining for DNMT1 and DNMT3b protein relative to the control group. Consequently, ¹²⁵I seed implantation inhibited cancer growth and reduced cancer volume.</p> <p>Conclusion</p> <p>¹²⁵I seed implantation kills pancreatic cancer cells, especially at 4 Gy. ¹²⁵I-induced apoptosis and changes in DNMT1 and DNMT3b expression suggest potential mechanisms underlying effective brachytherapy.</p