951 research outputs found
Dynamic Policy-Driven Adaptive Multi-Instance Learning for Whole Slide Image Classification
Multi-Instance Learning (MIL) has shown impressive performance for
histopathology whole slide image (WSI) analysis using bags or pseudo-bags. It
involves instance sampling, feature representation, and decision-making.
However, existing MIL-based technologies at least suffer from one or more of
the following problems: 1) requiring high storage and intensive pre-processing
for numerous instances (sampling); 2) potential over-fitting with limited
knowledge to predict bag labels (feature representation); 3) pseudo-bag counts
and prior biases affect model robustness and generalizability
(decision-making). Inspired by clinical diagnostics, using the past sampling
instances can facilitate the final WSI analysis, but it is barely explored in
prior technologies. To break free these limitations, we integrate the dynamic
instance sampling and reinforcement learning into a unified framework to
improve the instance selection and feature aggregation, forming a novel Dynamic
Policy Instance Selection (DPIS) scheme for better and more credible
decision-making. Specifically, the measurement of feature distance and reward
function are employed to boost continuous instance sampling. To alleviate the
over-fitting, we explore the latent global relations among instances for more
robust and discriminative feature representation while establishing reward and
punishment mechanisms to correct biases in pseudo-bags using contrastive
learning. These strategies form the final Dynamic Policy-Driven Adaptive
Multi-Instance Learning (PAMIL) method for WSI tasks. Extensive experiments
reveal that our PAMIL method outperforms the state-of-the-art by 3.8\% on
CAMELYON16 and 4.4\% on TCGA lung cancer datasets.Comment: Accepted by CVPR2024;Project
page:https://vilab.hit.edu.cn/projects/pami
Efficacy and prognostic factors of concurrent chemoradiotherapy in patients with stage Ib3 and IIa2 cervical cancer
Objectives: We investigated the efficacy, side effects, and prognostic factors of concurrent chemoradiotherapy for patientswith stage Ib3-IIa2 cervical cancer.Material and methods: We conducted a retrospective analysis of clinicopathologic data from 73 patients with stageIb3-IIa2 cervical cancer who received concurrent chemoradiotherapy from January 2008 to December 2013 in our hospital.Overall response and disease control rates were used to evaluate short-term outcomes; the 3-year and 5-year disease-freesurvival and overall survival were used to evaluate long-term efficacy. Toxicity reactions and prognostic factors were recorded.Results: With concurrent chemoradiotherapy, overall response and disease control rates were 91.78% and 97.26%, respectively.The 3-year disease-free and overall survival were 80.82% and 83.56%; the 5-year disease-free and overall survival were 75.34%and 79.45%, respectively. All side effects were tolerated and potentially alleviated by symptomatic treatment. Tumor pathologicaltype, differentiated degree, primary tumor size and squamous cell carcinoma antigen levels before and after treatment wereclosely related to survival (univariate analysis; p < 0.05). Pathological type, primary tumor size and squamous cell carcinomaantigen levels one month after treatment were independent prognostic factors for long-term outcome (multivariate analysis).Conclusions: Short- and long-term efficacy of concurrent chemoradiotherapy for stage Ib3-IIa2 cervical cancer is well-determinedand tolerable. Patients with adenocarcinomas, tumor diameter ≥ 5 cm and squamous cell carcinoma antigenlevels ≥ 1.5 ng/mL (one month after treatment) had poor prognosis and should be assessed further
2-(2,3-Dioxoindolin-1-yl)ethyl 4-(4-nitrophenyl)piperazine-1-carbodithioate
In the title compound, C21H20N4O4S2, the piperazine ring adopts a chair conformation. The 1-ethylindoline-2,3-dione system links to one N atom of the piperazine ring via a carbodithioate group. The indoline-2,3-dione ring and the nitrobenzene ring subtend adihedral angle of 37.27 (7)°. In the crystal structure, weak C—H⋯O and π–π stacking interactions [centroid–centroid distances = 3.534 (5) and 3.797 (5) Å] may help to establish the packing
Effects of China's Collective Forestland Tenure Reform Policies on Forest Product Firm Values
China's collective forestland tenure reform has dramatically affected the business environment of domestic forest product firms. This study examines the impact of the said reform on the expected values of these firms, via the reaction of investors (as seen on the stock markets) towards the issuance of related policies. Based on signaling theory and the assumption that the Chinese stock markets are efficient in terms of work form, this study adopts an event study method and examines five policies during the 2003-2009 period. The numbers of forest product firms used in the examinations herein differ among the policies and range from 21 to 29. This study found that the policies have differentially affected the expected values of forest product firms and that the impact on firms lacking forestland holdings is generally more significant than that on firms that hold forestland. The findings of this study enhance our understanding of the effect of collective forestland tenure reform on the value of forest product firms; they also have implications on forest product firms as they work to adapt to the reform
3,3-Dichloro-1-(chloromethyl)indolin-2-one
In the title compound, C9H6Cl3NO, the pyrrole ring is almost coplanar with the benzene ring [dihedral angle = 1.90 (9)°], while the Cl—C—N—C torsion angle is 98.78 (17)°. In the crystal, pairs of molecules are interconnected by pairs of Cl⋯Cl interactions [3.564 (5) Å], forming dimers, which are further peripherally connected through intermolecular C—H⋯O=C and π–π interactions [centroid–centroid distances = 4.134 (7), 4.134 (6) and 4.238 (7) Å], forming a two-dimensional network
Size Distribution and Fractal Characteristics of Coal Pores through Nuclear Magnetic Resonance Cryoporometry
This research was funded by the National Natural Science Foundation of China (Grant no. 41602170), the Research Program for Excellent Doctoral Dissertation Supervisor of Beijing (grant no. YB20101141501), the Key Project of Coal-based Science and Technology in Shanxi Province-CBM accumulation model and reservoir evaluation in Shanxi province (grant no. MQ2014-01) and the Fundamental Research Funds for Central Universities (grant no. 35832015136).Peer reviewedPostprin
Polarization splitter rotator on thin film lithium niobate based on multimode interference
Polarization splitter-rotators (PSRs) are the key elements to realize on-chip
polarization manipulation. Current PSRs on thin film lithium niobate (TFLN)
rely on sub-micron gaps to realize modes separation, which increase the
difficulties of lithography and etching. In this paper, a polarization
splitter-rotator on TFLN based on multimode interference (MMI) is demonstrated.
Mode division is achieved by an MMI-based mode demultiplexer. The feature size
of the PSR is 1.5 {\mu}m, which can be fabricated with low priced i-line
contact aligners. Experimental results show a polarization extinction ratio
(PER) > 20 dB and insertion loss (IL) <1.5 dB are achieved in a wavelength
range of 1542-1600 nm for TE-polarized light. And a PER > 9.5 dB and an IL <3.0
dB are achieved in a wavelength range of 1561-1600 nm for TM-polarized light.
This PSR could find application in the low-cost fabrication of
dual-polarization TFLN integrated photonic devices
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High-resolution and high-accuracy topographic and transcriptional maps of the nucleosome barrier.
Nucleosomes represent mechanical and energetic barriers that RNA Polymerase II (Pol II) must overcome during transcription. A high-resolution description of the barrier topography, its modulation by epigenetic modifications, and their effects on Pol II nucleosome crossing dynamics, is still missing. Here, we obtain topographic and transcriptional (Pol II residence time) maps of canonical, H2A.Z, and monoubiquitinated H2B (uH2B) nucleosomes at near base-pair resolution and accuracy. Pol II crossing dynamics are complex, displaying pauses at specific loci, backtracking, and nucleosome hopping between wrapped states. While H2A.Z widens the barrier, uH2B heightens it, and both modifications greatly lengthen Pol II crossing time. Using the dwell times of Pol II at each nucleosomal position we extract the energetics of the barrier. The orthogonal barrier modifications of H2A.Z and uH2B, and their effects on Pol II dynamics rationalize their observed enrichment in +1 nucleosomes and suggest a mechanism for selective control of gene expression
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