206 research outputs found
Development and validation of machine-learning models for the difficulty of retroperitoneal laparoscopic adrenalectomy based on radiomics
ObjectiveThe aim is to construct machine learning (ML) prediction models for the difficulty of retroperitoneal laparoscopic adrenalectomy (RPLA) based on clinical and radiomic characteristics and to validate the models.MethodsPatients who had undergone RPLA at Shanxi Bethune Hospital between August 2014 and December 2020 were retrospectively gathered. They were then randomly split into a training set and a validation set, maintaining a ratio of 7:3. The model was constructed using the training set and validated using the validation set. Furthermore, a total of 117 patients were gathered between January and December 2021 to form a prospective set for validation. Radiomic features were extracted by drawing the region of interest using the 3D slicer image computing platform and Python. Key features were selected through LASSO, and the radiomics score (Rad-score) was calculated. Various ML models were constructed by combining Rad-score with clinical characteristics. The optimal models were selected based on precision, recall, the area under the curve, F1 score, calibration curve, receiver operating characteristic curve, and decision curve analysis in the training, validation, and prospective sets. Shapley Additive exPlanations (SHAP) was used to demonstrate the impact of each variable in the respective models.ResultsAfter comparing the performance of 7 ML models in the training, validation, and prospective sets, it was found that the RF model had a more stable predictive performance, while xGBoost can significantly benefit patients. According to SHAP, the variable importance of the two models is similar, and both can reflect that the Rad-score has the most significant impact. At the same time, clinical characteristics such as hemoglobin, age, body mass index, gender, and diabetes mellitus also influenced the difficulty.ConclusionThis study constructed ML models for predicting the difficulty of RPLA by combining clinical and radiomic characteristics. The models can help surgeons evaluate surgical difficulty, reduce risks, and improve patient benefits
Role of microphysical parameterizations with droplet relative dispersion in IAP AGCM 4.1
Previous studies have shown that accurate descriptions of the cloud droplet effective radius (R (e)) and the autoconversion process of cloud droplets to raindrops (A (r)) can effectively improve simulated clouds and surface precipitation, and reduce the uncertainty of aerosol indirect effects in GCMs. In this paper, we implement cloud microphysical schemes including two-moment A (r) and R (e) considering relative dispersion of the cloud droplet size distribution into version 4.1 of the Institute of Atmospheric Physics's atmospheric GCM (IAP AGCM 4.1), which is the atmospheric component of the Chinese Academy of Sciences' Earth System Model. Analysis of the effects of different schemes shows that the newly implemented schemes can improve both the simulated shortwave and longwave cloud radiative forcings, as compared to the standard scheme, in IAP AGCM 4.1. The new schemes also effectively enhance the large-scale precipitation, especially over low latitudes, although the influences of total precipitation are insignificant for different schemes. Further studies show that similar results can be found with the Community Atmosphere Model, version 5.1
Observation of the superconducting proximity effect in the surface state of SmB6 thin films
The proximity effect at the interface between a topological insulator (TI)
and a superconductor is predicted to give rise to chiral topological
superconductivity and Majorana fermion excitations. In most TIs studied to
date, however, the conducting bulk states have overwhelmed the transport
properties and precluded the investigation of the interplay of the topological
surface state and Cooper pairs. Here, we demonstrate the superconducting
proximity effect in the surface state of SmB6 thin films which display bulk
insulation at low temperatures. The Fermi velocity in the surface state deduced
from the proximity effect is found to be as large as 10^5 m/s, in good
agreement with the value obtained from a separate transport measurement. We
show that high transparency between the TI and a superconductor is crucial for
the proximity effect. The finding here opens the door to investigation of
exotic quantum phenomena using all-thin-film multilayers with high-transparency
interfaces
Analysis of Pollution in Dianchi Lake and Consideration of Its Application in Crop Planting
AbstractAfter investigating the distribution and composition of N-cycle-related bacteria of different sites and different depth of Dianchi sediment, we analyzed the longitudinal distribution, lateral distribution of N, its transportation and transformation in Dianchi sediment, as well as the involvement of these bacteria in nitrogen cycle. Conclusion was drawn as follows, (1) Azotobateria could be effectively used as indicative strains to track the changes of Dianchi pollution because the distribution of Azotobateria can not only indicate N contamination but also P enrichment, (2) ammoniate and nitrite is mainly existed in top sediment of Dianchi Lake while other forms of nitrogen mainly in deeper sediment, (3) due to the fact that Dianchi is rich in P, together with the mutual promotion between N pollution and P pollution, the pollution of south part will worsen rapidly, (4) if the south part is also polluted badly, the pollution distribution will appear as peaking at both ends (north and south), and the pollution will definitely extend toward the middle, and finally Dianchi Lake will totally be seriously polluted. Combining with the fact that 40% of Dianchi pollution was caused by abusive use of chemical fertilizer, we put forward the idea of āchanging pollutants into things of valueā, which could be specified as āusing the sediment as agricultural fertilizerā. Such method can solve the problem of internal pollution, and what's more, it can develop agriculture, while cut down the use of chemical fertilizer and thus reduce relative pollution source
Synthesizing Physically Plausible Human Motions in 3D Scenes
Synthesizing physically plausible human motions in 3D scenes is a challenging
problem. Kinematics-based methods cannot avoid inherent artifacts (e.g.,
penetration and foot skating) due to the lack of physical constraints.
Meanwhile, existing physics-based methods cannot generalize to multi-object
scenarios since the policy trained with reinforcement learning has limited
modeling capacity. In this work, we present a framework that enables physically
simulated characters to perform long-term interaction tasks in diverse,
cluttered, and unseen scenes. The key idea is to decompose human-scene
interactions into two fundamental processes, Interacting and Navigating, which
motivates us to construct two reusable Controller, i.e., InterCon and NavCon.
Specifically, InterCon contains two complementary policies that enable
characters to enter and leave the interacting state (e.g., sitting on a chair
and getting up). To generate interaction with objects at different places, we
further design NavCon, a trajectory following policy, to keep characters'
locomotion in the free space of 3D scenes. Benefiting from the divide and
conquer strategy, we can train the policies in simple environments and
generalize to complex multi-object scenes. Experimental results demonstrate
that our framework can synthesize physically plausible long-term human motions
in complex 3D scenes. Code will be publicly released at
https://github.com/liangpan99/InterScene
Gauge Field Induced Chiral Zero Mode in Five-dimensional Yang Monopole Metamaterials
Owing to the chirality of Weyl nodes characterized by the first Chern number,
a Weyl system supports one-way chiral zero modes under a magnetic field, which
underlies the celebrated chiral anomaly. As a generalization of Weyl nodes from
three-dimensional to five-dimensional physical systems, Yang monopoles are
topological singularities carrying nonzero second-order Chern numbers c2 = +1
or -1. Here, we couple a Yang monopole with an external gauge field using an
inhomogeneous Yang monopole metamaterial, and experimentally demonstrate the
existence of a gapless chiral zero mode, where the judiciously designed
metallic helical structures and the corresponding effective antisymmetric
bianisotropic terms provide the means for controlling gauge fields in a
synthetic five-dimensional space. This zeroth mode is found to originate from
the coupling between the second Chern singularity and a generalized 4-form
gauge field - the wedge product of the magnetic field with itself. This
generalization reveals intrinsic connections between physical systems of
different dimensions, while a higher dimensional system exhibits much richer
supersymmetric structures in Landau level degeneracy due to the internal
degrees of freedom. Our study offers the possibility of controlling
electromagnetic waves by leveraging the concept of higher-order and
higher-dimensional topological phenomena.Comment: 64 pages including supplementary material, to appear in Physical
Review Letter
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Downregulating Notch counteracts KrasG12D-induced ERK activation and oxidative phosphorylation in myeloproliferative neoplasm.
The Notch signaling pathway contributes to the pathogenesis of a wide spectrum of human cancers, including hematopoietic malignancies. Its functions are highly dependent on the specific cellular context. Gain-of-function NOTCH1 mutations are prevalent in human T-cell leukemia, while loss of Notch signaling is reported in myeloid leukemias. Here, we report a novel oncogenic function of Notch signaling in oncogenic Kras-induced myeloproliferative neoplasm (MPN). We find that downregulation of Notch signaling in hematopoietic cells via DNMAML expression or Pofut1 deletion significantly blocks MPN development in KrasG12D mice in a cell-autonomous manner. Further mechanistic studies indicate that inhibition of Notch signaling upregulates Dusp1, a dual phosphatase that inactivates p-ERK, and downregulates cytokine-evoked ERK activation in KrasG12D cells. Moreover, mitochondrial metabolism is greatly enhanced in KrasG12D cells but significantly reprogrammed by DNMAML close to that in control cells. Consequently, cell proliferation and expanded myeloid compartment in KrasG12D mice are significantly reduced. Consistent with these findings, combined inhibition of the MEK/ERK pathway and mitochondrial oxidative phosphorylation effectively inhibited the growth of human and mouse leukemia cells in vitro. Our study provides a strong rational to target both ERK signaling and aberrant metabolism in oncogenic Ras-driven myeloid leukemia
Transesterification Kinetics of Jatropha Methyl Ester and Trimethylol propane for Biolubricant Synthesis Using Paphiaundulata Shell Waste
Indium tin oxide (ITO) thin films of 150 nm thickness were deposited on quartz glass substrates by RF sputtering technique, followed by thermal annealing treatment. In this technique, the samples have been annealed at different temperature, 300į“¼C, 400į“¼C, 500į“¼C respectively in
Argon gas flow. Structural and surface morphological properties were analyzed by X-ray diffraction (XRD) and Atomic Force Microscopy (AFM) after annealing. The XRD showed a polycrystalline structure of ITO film with maximum peak intensity at 2Īø= 30.54, orientation without any
change in the cubic structure. Continuous and homogeneous films obtained by the AFM after annealing treatment. The visible spectrum from the spectrophotometer showed high transparency between 81% and 95% in the. Increasing the annealing temperature yields evenly distributed pyramidal peaks shaped particles with low roughness. Resistance of ITO thin film was significantly improved from 8.75 kā¦ to 1.96 kā¦ after 10 minute from 300į“¼C to 500į“¼C annealing temperatures respectively under Argon gas flow. ITO films physical properties would be well improved by this
method which is highly suitable for cost effective photonic devices
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