1,101 research outputs found
Influence of Abiotic Drivers on 1-Year Seedling Survival of Six Mangrove Species in Southeast Asia
Establishment and survival of plant species in systems with dominant environmental drivers (i.e. factors that exert disproportionate control over species establishment and survival) is often thought to be dominated by one master variable. In forested wetlands such as mangroves, hydrology is typically considered the dominant limiting driver. At the same time, light is a major driver of plant community dynamics, with some of the best understood plant life-history tradeoffs related to fast growth under high-light conditions versus survival under low-light conditions. Yet light is given relatively limited consideration in mangrove research compared to other drivers. Understanding the relative importance of abiotic drivers for seedling survival is crucial for effective management and restoration of mangrove ecosystems. Despite increasing global efforts to plant mangrove propagules at elevations appropriate for the hydrologic conditions needed at early life history stages, restoration efforts report low survival of planted propagules. Although many studies have made considerable progress to characterize the abiotic limitations of mangrove propagule establishment, fewer studies have addressed multiple abiotic drivers that limit the survival of the established seedling stage. We characterized the light and inundation conditions of more than 900 naturally established mangrove seedlings and monitored the survival of more than 2,800 seedlings (including 16 species) located on a species-rich island in tropical Southeast Asia for 1 year. Our findings suggest that light has a stronger effect than hydrology on survival following seedling establishment. We provide a conceptual visualization of shifts in the drivers of mangrove survival/loss throughout ontogeny
(4Z)-4-[(2-Chloroanilino)(phenyl)methylidene]-3-methyl-1-phenyl-1H-pyrazol-5(4H)-one
The title compound, C23H18ClN3O, exists in an enamine–keto form with the amino group involved in an intramolecular N—H⋯O hydrogen bond. The five-membered ring is nearly planar, the largest deviation being 0.0004 (7) Å, and makes dihedral angles of 16.62 (6), 41.89 (5) and 71.27 (4)° with the phenyl rings. In the crystal, weak C—H⋯O hydrogen bonds link the molecules into supramolecular chains along the b axis
Tetraaquabis(2-methylbenzimidazolium-1,3-diacetato-κO)zinc(II) tetrahydrate
The asymmetric unit of the title compound, [Zn(C12H11N2O4)2(H2O)4]·4H2O, contains one-half of the complex molecule and two uncoordinated water molecules. The four water O atoms in the equatorial plane around the ZnII centre ( symmetry) form a distorted square-planar arrangement, while the distorted octahedral coordination geometry is completed by the O atoms of the zwitterionic 2-methylbenzimidazolium-1,3-diacetate ligands in the axial positions. The benzimidazole ring system is planar, with a maximum deviation of 0.041 (3) Å. Intramolecular O—H⋯O hydrogen bonding results in the formation of a non-planar six-membered ring. In the crystal structure, strong intra- and intermolecular O—H⋯O hydrogen bonds link the molecules into a three-dimensional network. π–π contacts between benzimidazole rings [centroid–centroid distance = 3.899 (1) Å] may further stabilize the structure
[μ-N,N,N′,N′-Tetrakis(diphenylphosphinomethyl)benzene-1,4-diamine-κ4 P,P′:P′′,P′′′]bis[bis(nitrato-κO)palladium(II)]
The asymmetric unit of the title complex, [Pd2(NO3)4(C58H52N2P4)], contains one half-molecule, in which the central benzene ring is located on a crystallographic centre of inversion. The Pd atom has a distorted square-planar coordination consisting of two P and two O atoms. In the crystal structure, intermolecular C—H⋯O interactions link the molecules into chains, and π–π contacts between the phenyl rings [centroid–centroid distance = 3.928 (3) Å] may further stabilize the structure
4-[(Z)-(2-Furyl)(2-naphthylamino)methylene)]-3-methyl-1-phenyl-1H-pyrazol-5(4H)-one
The title compound, C25H19N3O2, crystallizes as discrete molecules which are well ordered through one intramolecular N—H⋯O hydrogen bond. Structural analysis indicates that the molecules exist as the amine–one form
Distributed quantum computing over 7.0 km
Distributed quantum computing provides a viable approach towards scalable
quantum computation, which relies on nonlocal quantum gates to connect distant
quantum nodes, to overcome the limitation of a single device. However, such an
approach has only been realized within single nodes or between nodes separated
by a few tens of meters, preventing the target of harnessing computing
resources in large-scale quantum networks. Here, we demonstrate distributed
quantum computing between two nodes spatially separated by 7.0 km, using
stationary qubits based on multiplexed quantum memories, flying qubits at
telecom wavelengths, and active feedforward control based on field-deployed
fiber. Specifically, we illustrate quantum parallelism by implementing
Deutsch-Jozsa algorithm and quantum phase estimation algorithm between the two
remote nodes. These results represent the first demonstration of distributed
quantum computing over metropolitan-scale distances and lay the foundation for
the construction of large-scale quantum computing networks relying on existing
fiber channels.Comment: 6 pages, 3 figure
Retrospective study on MGMT methylation status and its clinical significance in gliomas
Background and purpose: Glioma is a common malignant tumor of central nervous system with poor prognosis. Postoperative concurrent chemoradiotherapy with temozolomide (TMZ) is the main treatment for glioma. The methylation status of the O6-methylguanine-DNA methyltransferase (MGMT) promoter can predict the sensitivity of glioma patients to TMZ treatment, however its relationship with clinical pathology and how to better predict treatment and prognosis still need further research. The purpose of this study was to analyze the status of MGMT promoter methylation (MGMTmet) in gliomas and its correlation with clinical pathological features and other common molecular abnormalities, and to explore the value of combined analysis of MGMTmet and other molecular abnormalities in predicting the prognosis of glioma and the efficacy of TMZ treatment. Methods: We retrospectively collected clinical and pathological data from 205 glioma patients diagnosed by the Department of Pathology, Fudan University Shanghai Cancer Center from July 2019 to September 2022. Real-time fluorescence quantitative polymerase chain reaction (RTFQ-PCR) was used to detect MGMTmet status. Sanger sequencing was used to detect the mutation of isocitrate dehydrogenase 1 and 2 (IDH1/2) and telomerase reverse transcriptase (TERT) genes. Fluorescence in situ hybridization (FISH) was used to detect the deletion of the short arm of chromosome 1 and the long arm of chromosome 19 (1p19q). Results: Among 205 patients, the incidence of MGMTmet was higher in female patients than in male patients. Compared to glioblastoma (47.3%), astrocytoma (74.1%) and oligodendroglioma (100.0%) were more prone to methylation of the MGMT gene promoter (P<0.05). In MGMTmet group, IDH1 mutation rate and 1p19q co-deletion rate were significantly increased, and methylation of MGMT promoter was correlated with IDH1 mutation and 1p19q co-deletion (P<0.05). Patients with MGMTmet, age less than 55 years, oligodendroglioma, and World Health Organization (WHO) grade 1-3 all showed longer overall survival (OS), and the difference is statistically significant (P<0.05). Compared with individual influencing factors, dual/triple gene combination analysis (MGMTmet/IDH1 mutation or MGMTmet/1p19q co-deletion or MGMTmet/IDH1 mutation/1p19q co-deletion) had better effect for predicting the patient prognosis (P<0.05), with the latter two being independent prognostic factors. Among TMZ treated patients, MGMTmet (MGMTmet/TMZ+) patients had a better prognosis than other groups. If the patients had combined IDH1 mutations, the prognosis of the patients was further improved (P<0.05). Conclusion: MGMTmet is more common in women and patients with oligodendroglioma. It is positively correlated with IDH1 mutation and 1p19q co-deletion. Patients with MGMTmet are associated with better TMZ treatment efficacy and prognosis, and MGMTmet combined with IDH mutations and 1p19q co-deletion analysis have better TMZ treatment efficacy and prognostic implications
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