264 research outputs found
Doubly Robust Proximal Synthetic Controls
To infer the treatment effect for a single treated unit using panel data,
synthetic control methods construct a linear combination of control units'
outcomes that mimics the treated unit's pre-treatment outcome trajectory. This
linear combination is subsequently used to impute the counterfactual outcomes
of the treated unit had it not been treated in the post-treatment period, and
used to estimate the treatment effect. Existing synthetic control methods rely
on correctly modeling certain aspects of the counterfactual outcome generating
mechanism and may require near-perfect matching of the pre-treatment
trajectory. Inspired by proximal causal inference, we obtain two novel
nonparametric identifying formulas for the average treatment effect for the
treated unit: one is based on weighting, and the other combines models for the
counterfactual outcome and the weighting function. We introduce the concept of
covariate shift to synthetic controls to obtain these identification results
conditional on the treatment assignment. We also develop two treatment effect
estimators based on these two formulas and the generalized method of moments.
One new estimator is doubly robust: it is consistent and asymptotically normal
if at least one of the outcome and weighting models is correctly specified. We
demonstrate the performance of the methods via simulations and apply them to
evaluate the effectiveness of a Pneumococcal conjugate vaccine on the risk of
all-cause pneumonia in Brazil
Curcumin suppresses leukemia cell proliferation by downregulation of P13K/AKT/mTOR signalling pathway
Purpose: To investigate the effect of curcumin ester on the proliferation of leukemia cell lines in vitro.
Methods: Changes in WEHI-3 and THP 1 cell viabilities were measured using Cell Counting Kit 8 (CCK 8). Analysis of cell cycle and determination of apoptosis were carried out using propidium iodide and Annexin V fluorescein isothiocyanate staining. Transmission electron microscopy was used for observing the presence of apoptotic features in cells.
Results: Treatment with curcumin ester for 72 h caused significant reduction in the proliferation of WEHI-3 and THP 1 cells. Curcumin ester, at a dose of 50 µM, decreased the proliferations of WEHI-3 and THP 1 cells to 28 and 32 %, respectively. On exposure to curcumin ester for 72 h, cell cycle in WEHI-3 cells was arrested in G1/G0 phase. Curcumin ester at doses of 25, 30 and 50 µM enhanced apoptosis in WEHI-3 cells to 46, 58 and 64 %, respectively. Curcumin ester suppressed the levels of phosphoinositide 3 kinase (PI3K), protein kinase B (AKT) and mechanistic target of rapamycin (mTOR) protein and mRNA in WEHI-3 cells. In curcumin ester-treated WEHI-3 cells, the presence of apop¬totic bodies increased significantly and concentration-dependently.
Conclusion: These results demonstrate that curcumin ester inhibits leukemia cell proliferation by inducing apoptosis and arresting cell cycle in G1/G0 phase, probably via suppression of PI3K, AKT and mTOR, and promotion of PTEN. Thus, curcumin ester has potentials for use in the development of an effective treatment strategy for leukemia
Exciton photoluminescence of CsPbBr3@SiO2 quantum dots and its application as a phosphor material in light-emitting devices
A Hyper-network Based End-to-end Visual Servoing with Arbitrary Desired Poses
Recently, several works achieve end-to-end visual servoing (VS) for robotic
manipulation by replacing traditional controller with differentiable neural
networks, but lose the ability to servo arbitrary desired poses. This letter
proposes a differentiable architecture for arbitrary pose servoing: a
hyper-network based neural controller (HPN-NC). To achieve this, HPN-NC
consists of a hyper net and a low-level controller, where the hyper net learns
to generate the parameters of the low-level controller and the controller uses
the 2D keypoints error for control like traditional image-based visual servoing
(IBVS). HPN-NC can complete 6 degree of freedom visual servoing with large
initial offset. Taking advantage of the fully differentiable nature of HPN-NC,
we provide a three-stage training procedure to servo real world objects. With
self-supervised end-to-end training, the performance of the integrated model
can be further improved in unseen scenes and the amount of manual annotations
can be significantly reduced
Surface plasmon polaritons assisted diffraction in periodic subwavelength holes of metal films with reduced interplane coupling
Metal films grown on Si wafer perforated with a periodic array of
subwavelength holes have been fabricated and anomalous enhanced transmission in
the mid-infrared regime has been observed. High order transmission peaks up to
Si(2,2) are clearly revealed due to the large dielectric constant contrast of
the dielectrics at the opposite interfaces. Si(1,1) peak splits at oblique
incidence both in TE and TM polarization, which confirms that anomalous
enhanced transmission is a surface plasmon polaritons (SPPs) assisted
diffraction phenomenon. Theoretical transmission spectra agree excellently with
the experimental results and confirm the role of SPPs diffraction by the
lattice.Comment: 4 pages, 5 figures, 26 reference
Soybean C2H2-Type Zinc Finger Protein GmZFP3 with Conserved QALGGH Motif Negatively Regulates Drought Responses in Transgenic Arabidopsis
The Evolutionary Relationship between Microbial Rhodopsins and Metazoan Rhodopsins
Rhodopsins are photoreceptive proteins with seven-transmembrane alpha-helices and a covalently bound retinal. Based on their protein sequences, rhodopsins can be classified into microbial rhodopsins and metazoan rhodopsins. Because there is no clearly detectable sequence identity between these two groups, their evolutionary relationship was difficult to decide. Through ancestral state inference, we found that microbial rhodopsins and metazoan rhodopsins are divergently related in their seven-transmembrane domains. Our result proposes that they are homologous proteins and metazoan rhodopsins originated from microbial rhodopsins. Structure alignment shows that microbial rhodopsins and metazoan rhodopsins share a remarkable structural homology while the position of retinal-binding lysine is different between them. It suggests that the function of photoreception was once lost during the evolution of rhodopsin genes. This result explains why there is no clearly detectable sequence similarity between the two rhodopsin groups: after losing the photoreception function, rhodopsin gene was freed from the functional constraint and the process of divergence could quickly change its original sequence beyond recognition
Depositing Molecular Graphene Nanoribbons on Ag(111) by Electrospray Controlled Ion Beam Deposition: Self-Assembly and On-Surface Transformations
The chemical processing of low-dimensional carbon nanostructures is crucial for their integration in future devices. Here we apply a new methodology in atomically precise engineering by combining multistep solution synthesis of N-doped molecular graphene nanoribbons (GNRs) with mass-selected ultra-high vacuum electrospray controlled ion beam deposition on surfaces and real-space visualisation by scanning tunnelling microscopy. We demonstrate how this method yields solely a controllable amount of single, otherwise unsublimable, GNRs of 2.9 nm length on a planar Ag(111) surface. This methodology allows for further processing by employing on-surface synthesis protocols and exploiting the reactivity of the substrate. Following multiple chemical transformations, the GNRs provide reactive building blocks to form extended, metal-organic coordination polymers.This project has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreements No. 946223 and No. 899895. Financial support was provided by the German Research Foundation (DFG) through the TUM International Graduate School of Science and Engineering (IGSSE), Excellence Cluster e-conversion, and the priority programme 1928 COORNETs, the China Scholarship Council (CSC) and the European Research Council (ERC) (no. 722951). This project has received funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (Grant Agreement No. 722951). This work was carried out with support from the Basque Foundation for Science (Ikerbasque), POLYMAT, the University of the Basque Country, Gobierno Vasco (BERC programme). Technical and human support provided by SGIker of UPV/EHU and European funding (ERDF and ESF) is acknowledged. Open Access funding enabled and organized by Projekt DEAL
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