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•Epiphytic bryophyte-cyanobacteria associations was crucial to natural forest ecosystems.•Water availability regulated physiological activities of poikilohydric bryophytes.•Nitrogen ...fixation-water relation was a unimodal curve, and water surpluses and shortages both inhibited N fixation activity.•Long-period drought would decrease cyanobacteria colonization and then inhibit nitrogen fixation.
Water changes are predicted to regulate physiological activities of bryophytes characterized by poikilohydric gametophytes. In montane forest ecosystems, nitrogen(N)–fixing bryophyte–cyanobacteria associations are main N resources. The aim of this study was to assess how bryophyte–associated microbiomes and their nitrogenase activity response to instant or long-term water content changes. We investigated the cyanobacterial colonization and nitrogenase activity of four epiphytic bryophyte species in a subtropical montane cloud forest during the dry and rainy seasons in Ailao Mountains, Yunnan, southwestern China. We also evaluated the nitrogenase activity of bryophyte–cyanobacteria associations in response to different water contents in laboratory experiment. The degree of cyanobacterial colonization was evaluated using ultraviolet fluorescence microscopy, and nitrogenase activity of bryophyte–cyanobacteria associations were measured using the acetylene reduction assay (ARA). Cyanobacteria showed an association with all four bryophyte species, with 1.04–3.37% area colonized of the shoot and 10.16–20.21 nmol C2H4·g−1·h−1 average nitrogenase activity. Nitrogenase activity was positively related to cyanobacterial colonization (R = 0.742; P = 0.0349). The relationship between water content and nitrogenase activity was unimodal, and both water surplus and shortage inhibited N fixation. Furthermore, long–term drought conditions reduced the degree of cyanobacteria colonization on bryophyte shoots, resulting in decreased nitrogenase activity in the dry season. These results indicate that different response strategies of N fixation operate in bryophyte–cyanobacteria associations to cope with instant and long–term changes in water availability. Our data suggest that both extreme precipitation and drought have a negative impact on N fixation of cyanobacteria–bryophyte associations.
Abstract Background Beta-amyloid (Aβ) deposition in the brain parenchyma is a crucial initiating step in the amyloid cascade hypothesis of Alzheimer’s disease (AD) pathology. Furthermore, dysfunction ...of plaque-associated microglia, also known as disease-associated microglia (DAM) has been reported to accelerate Aβ deposition and cognitive impairment. Our previous research demonstrated that intermittent hypoxia training (IHT) improved AD pathology by upregulating autophagy in DAM, thereby enhancing oligomeric Aβ (oAβ) clearance. Considering that oAβ internalization is the initial stage of oAβ clearance, this study focused on the IHT mechanism involved in upregulating Aβ uptake by DAM. Methods IHT was administered to 8-month-old APP/PS1 mice or 6-month-old microglial vacuolar protein sorting 35 (VPS35) knockout mice in APP/PS1 background (MG VPS35 KO: APP/PS1) for 28 days. After the IHT, the spatial learning-memory capacity of the mice was assessed. Additionally, AD pathology was determined by estimating the nerve fiber and synapse density, Aβ plaque deposition, and Aβ load in the brain. A model of Aβ-exposed microglia was constructed and treated with IHT to explore the related mechanism. Finally, triggering receptor expressed on myeloid cells 2 (TREM2) intracellular recycling and Aβ internalization were measured using a fluorescence tracing technique. Results Our results showed that IHT ameliorated cognitive function and Aβ pathology. In particular, IHT enhanced Aβ endocytosis by augmenting the intracellular transport function of microglial TREM2, thereby contributing to Aβ clearance. Furthermore, IHT specifically upregulated VPS35 in DAM, the primary cause for the enhanced intracellular recycling of TREM2. IHT lost ameliorative effect on Aβ pathology in MG VPS35 KO: APP/PS1 mice brain. Lastly, the IHT mechanism of VPS35 upregulation in DAM was mediated by the transcriptional regulation of VPS35 by transcription factor EB (TFEB). Conclusion IHT enhances Aβ endocytosis in DAM by upregulating VPS35-dependent TREM2 recycling, thereby facilitating oAβ clearance and mitigation of Aβ pathology. Moreover, the transcriptional regulation of VPS35 by TFEB demonstrates a close link between endocytosis and autophagy in microglia. Our study further elucidates the IHT mechanism in improving AD pathology and provides evidence supporting the potential application of IHT as a complementary therapy for AD. Graphical abstract
The study of exploring the internal connection between rail transit and land use is of great significance for the coordinated development of urban space and rail transit construction, and it is also ...important for the intensive use of land affected by rail transit stations. The land use structure and population density surrounding the stations of Line 1.2.3 of Xi’an Rail Transit were clustered by SPSS for identifying the rail transit stations with high population density. Subsequently, We have established an indicator system of urban land use and rail transit operation capabilities based on multivariate data, and explored the coordinated relationship between rail transit and land use through data envelopment analysis (DEA) evaluation methods at high population density stations. Besides, the coupling degree of land use in rail transit stations with high population density was evaluated, and the key indicators affecting the coupling degree were further analyzed in Xi’an. In conclusion, this study finds that the relationship between rail transit capacity and land use of high population density rail transit stations is unbalanced. Hence, to promote the sustainable development of rail transit capacity and surrounding land, it is suggested that we should confine the development of land use intensity around the station, improve the service functions of small-scale living areas, and optimize the travel environment intended for short-distance travel. For residents, they are encouraged to choose the mode of rail transit for their long-distance travel. At the same time, the peak passenger flow at the stations should be evacuated accordingly.
Featuring complex and fractured terrain, the Loess hilly and gully regions suffer poor grain production capacity. The behavior of farmers, the major users of agricultural production space, ...significantly influences the agricultural production space. Hence, it is essential to explore the evolution rules of the agricultural production space under the influence of farmer behavior and reveal the influencing mechanism of agricultural production space change, which will facilitate the promotion of ecological protection and high-quality development of the Yellow River Basin. Relying on six-stage remote sensing images of the Yanhe River Basin from 1995 to 2018, this study utilized a land use dynamic index, transfer matrix and landscape pattern index to analyze the spatial pattern evolution of agricultural production in the Yanhe River Basin. Furthermore, the geographic detector model was applied to quantitatively analyze the influencing factors of the spatial pattern evolution of agricultural production. The results demonstrated the following: (1) From 1995 to 2018, the overall area of cultivated land in the Yanhe River Basin decreased by 927.02 km2, with a change degree of 21.07%. The spatial structure of agricultural production changed, mainly transferring the cultivated land to woodland and grassland. (2) The spatial form of agricultural production has changed from fragmentation to regularity, and the complexity of the production space shows a trend of first increasing and then decreasing. (3) The evolution of the spatial pattern of agricultural production was affected by multiple factors of farmer behavior, where significant interactive enhancement effects existed. Specifically, labor input was the dominant factor affecting the overall scale of the production space, with an influence value of 0.202; fertilization input and cultivated land transfer were the key factors affecting the spatial distribution of production, with influence values of 0.264 and 0.242, respectively; income level and social interaction were the base factors affecting the spatial form of production, with influence values of 0.558 and 0.438, respectively. The research results provide scientific support for the improvement of agricultural production quality and the spatial evolution mechanism of agricultural production in the Yanhe River Basin.
Aquimarina megaterium sp. nov., isolated from seawater Yu, Tong; Zhang, Zenghu; Fan, Xiaoyang ...
International journal of systematic and evolutionary microbiology,
2014, 2014-Jan, Letnik:
64, Številka:
Pt 1
Journal Article
Recenzirano
A novel Gram-stain-negative, rod-shaped, non-flagellated, strictly aerobic strain with gliding motility, designated XH134T, was isolated from surface seawater of the South Pacific Gyre (45° 58′ S ...163° 11′ W) during the Integrated Ocean Drilling Program Expedition 329. The major respiratory quinone of strain XH134T was MK-6. The dominant fatty acids of strain XH134T were iso-C15 : 0, iso-C15 : 1 G, C16 : 1ω6c and/or C16 : 1ω7c, iso-C17 : 0 3-OH, iso-C15 : 0 3-OH and 10-methyl C16 : 0 and/or iso-C17 : 1ω9c. The polar lipids of strain XH134T comprised phosphatidylethanolamine, one unknown aminolipid and three unknown polar lipids. The DNA G+C content of strain XH134T was 32.4 mol%. Phylogenetic analyses based on 16S rRNA gene sequences showed that the novel strain was related most closely to Aquimarina macrocephali JAMB N27T with 96.9 % sequence similarity. A number of phenotypic characteristics distinguished strain XH134T from described members of the genus Aquimarina. On the basis of combined phenotypic and phylogenetic analyses, strain XH134T represents a novel species of the genus Aquimarina, for which the name Aquimarina megaterium sp. nov. is proposed. The type strain is XH134T ( = CGMCC 1.12186T = JCM 18215T).
In this paper, an L-shaped tunneling field effect transistor (LTFET) with ferroelectric gate oxide layer (Si: HfO
) is proposed. The electric characteristic of NC-LTFET is analyzed using Synopsys ...Sentaurus TCAD. Compared with the conventional LTFET, a steeper subthreshold swing (SS = 18.4 mV/dec) of NC-LTFET is obtained by the mechanism of line tunneling at low gate voltage instead of diagonal tunneling, which is caused by the non-uniform voltage across the gate oxide layer. In addition, we report the polarization gradient effect in a negative capacitance TFET for the first time. It is noted that the polarization gradient effect should not be ignored in TFET. When the polarization gradient parameter g grows larger, the dominant tunneling mechanism that affects the SS is the diagonal tunneling. The on-state current (I
) and SS of NC-LTFET become worse.
Neoadjuvant chemotherapy (NAC) remains the cornerstone of the treatment for triple negative breast cancer (TNBC), with the goal of complete eradication of disease. However, for patients with residual ...disease after NAC, recurrence and mortality rates are high and the identification of novel therapeutic targets is urgently needed. We quantified tyrosine phosphorylation (pTyr)-mediated signaling networks in chemotherapy sensitive (CS) and resistant (CR) TNBC patient-derived xenografts (PDX), to gain novel therapeutic insights. The antitumor activity of SFK inhibition was examined in vivo. Treated tumors were further subjected to phosphoproteomic and RNAseq analysis, to identify the mechanism of actions of the drug. We identified Src Family Kinases (SFKs) as potential therapeutic targets in CR TNBC PDXs. Treatment with dasatinib, an FDA approved SFK inhibitor, led to inhibition of tumor growth in vivo. Further analysis of post-treatment PDXs revealed multiple mechanisms of actions of the drug, confirming the multi-target inhibition of dasatinib. Analysis of pTyr in tumor specimens suggested a low prevalence of SFK-driven tumors, which may provide insight into prior clinical trial results demonstrating a lack of dasatinib antitumor activity in unselected breast cancer patients. Taken together, these results underscore the importance of pTyr characterization of tumors, in identifying new targets, as well as stratifying patients based on their activated signaling networks for therapeutic options. Our data provide a strong rationale for studying SFK inhibitors in biomarker-selected SFK-driven TNBC.
A moderate Mn(Ⅶ) oxidation-in situ Fe(Ⅲ) coagulation (Mn(Ⅶ)-Fe(Ⅱ)) conditioning strategy was proposed to improve sludge filterability and release the water bound in extracellular polymeric substances ...(EPS). During Mn(Ⅶ)-Fe(Ⅱ) conditioning, flocs disintegration and cell disruption, macro and micro physicochemical properties of activated sludge, especially of EPS, were investigated. Relationships between protein molecular structures in EPS fractions of three layers and sludge dewaterability were also determined. Besides, factor analysis was used to explain the variances of “functional” protein secondary structures, which may have an important effect on sludge dewaterability. Results showed that sludge filterability (CST0/CST) increased by 2.40 times and partial bound water was released at 2 min oxidation of 120 mg/g KMnO4 with subsequent FeCl2 termination at equivalent molar ratio of 1:3. During this strategy, EPS wrapping on cells surface was disintegrated, and a limited influence occurred on cells. It was also found that CST and bound water content were strongly correlated with aggregated strands, random coil and β-turn percentages in slime (R2 >−0.82, p < 0.05). Moreover, the dewaterability also presented strong negative correlations with aggregated strands, β-sheet and β-turn in TB-EPS (R2 >−0.78, p < 0.05). This suggested that unfolding and despiralization of slime protein and moderate weakening rigidity of tightly bound EPS (TB-EPS) protein were beneficial for improvement of sludge dewaterability. In addition, the strong correlation between percentages of “functional” protein secondary structures and factor 1 score (R2 > 0.85, p < 0.05) demonstrated that EPS migration, rather than only EPS disintegration, may have a key impact on the formation of some protein secondary structures in slime and TB-EPS. The observed protein secondary structures, which may affect sludge dewaterability, were probably derived from inner EPS.
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•CST0/CST reached 2.40 at a 2min Mn(Ⅶ) oxidation-in situ Fe(Ⅲ) coagulation.•Aggregated strands, random coil, β-turn in slime correlated with dewaterability.•Aggregated strands, β-sheet and β-turn in TB-EPS correlated with dewaterability.•Moderate weakening TB-EPS rigidity was beneficial for dewaterability improvement.•Aggregated strands, β-turn in slime and TB-EPS correlated with EPS migration.
•Siderite/PMS conditioning coupled with PEOD reduced 91.76% bound water in AS.•Conditioning led to denser protein structure in TB-EPS and looser one in slime.•Dewatering stages led to more water flow ...outsider of slime than TB-EPS.•Ala / Lys-in slime and TB-EPS showed strong correlations with dewaterability.•Siderite/PMS conditioning caused increased contacts between Ala-and water in slime.
In this study, the siderite/PMS conditioning-pressurized vertical electro-osmotic dewatering (PEOD) process was used to reduce the volume of activated sludge (AS). The changes in water content, cell, extracellular polymeric substances (EPS) distribution, protein secondary structures and typical amino acids in EPS fractions of AS along siderite/PMS conditioning-PEOD process were investigated. Results showed that the final water content (WC) of dewatered AS was 58.02% under the RSM optimized conditioning conditions of 0.05 g/g TSS siderite dosage, 0.23 g/g TSS PMS dosage, 600 kPa mechanical pressure and 20 V voltage. At conditioning and PEOD stages, the bound water content(BWC) of AS decreased by 25.23% and 91.76%, respectively. The HO• and SO4−· generated from siderite activating PMS could lead to the disruption of cells. The ratio of Ala-to Lys (Ala/Lys) showed strong negative correlations with BWC or WC in slime (RBWC2=−0.803, p<0.01; RWC2=−0.771, p<0.01) and TB-EPS (RBWC2=−0.693, p<0.01; RWC2=−0.705, p<0.01), and could be considered as an indicator of AS dewaterability. Compared with raw AS, conditioning led to the occurrence of the denser protein structure in TB-EPS and the looser one in slime. The contact number between Ala-and water decreased in TB-EPS and increased in slime, which indicated that the migration of water adhered in TB-EPS to outer layer. At the DG, MC and EC process, while the looser protein structure in TB-EPS and the denser one in slime occurred, as well as higher contact number between Ala-and water in TB-EPS than that in slime, which indicated that more water flowed outsider of slime than TB-EPS. This implied that the variations of the compactness of protein secondary structures and the contact number between Ala-and water in EPS layers correlated with AS dewaterability.
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Porous biomass carbon materials were successfully synthesized from wheat straw by a citric-acid-crosslinking and KOH-activating method. Structural characterization results indicate that the ...as-obtained biomass carbon materials have hierarchical porous structure and high specific surface area. Electrochemical test demonstrates that the porous biomass carbon materials from wheat straw have the optimal super-capacitive properties when the quality of KOH is 5 times that of the carbonization product, i.e.: high specific capacitance of 294 F g−1, superior rate performances of 200 F g−1 at 10 A g−1 and excellent cycle stabilization (97.6% of capacitance retention after 5000 cycles). More importantly, porous biomass carbon from wheat straw with the optimal performance was assembled into flexible, all-solid-state, symmetric supercapacitors. The assembled symmetric supercapacitors reveal high energy density (14 Wh kg−1 at 440 W kg−1 power density) and excellent cycle stability (only 4.3% capacitance loss after 8000 cycles). Meanwhile, the present full-cell supercapacitors manifest the remarkable flexibility, low-temperature resistance, and commercial value. Hence one can see that all-solid-state supercapacitors based on porous biomass carbon derived from wheat straw have great potential prospect in the field of portable and wearable electronic devices.
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•Porous biomass carbon can be synthesized with wheat straw as the raw materials.•Biomass carbon obtained under certain condition has the optimal electrochemical properties.•Assembled flexible, all-solid-state symmetric devices have remarkable supercapacitor performance.•Porous biomass carbon derived from wheat straw has the potential applied prospect for energy storage.
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