175 research outputs found
GO-FEAP: Global Optimal UAV Planner Using Frontier-Omission-Aware Exploration and Altitude-Stratified Planning
Autonomous exploration is a fundamental problem for various applications of
unmanned aerial vehicles(UAVs). Existing methods, however, are demonstrated to
static local optima and two-dimensional exploration. To address these
challenges, this paper introduces GO-FEAP (Global Optimal UAV Planner Using
Frontier-Omission-Aware Exploration and Altitude-Stratified Planning), aiming
to achieve efficient and complete three-dimensional exploration.
Frontier-Omission-Aware Exploration module presented in this work takes into
account multiple pivotal factors, encompassing frontier distance, nearby
frontier count, frontier duration, and frontier categorization, for a
comprehensive assessment of frontier importance. Furthermore, to tackle
scenarios with substantial vertical variations, we introduce the
Altitude-Stratified Planning strategy, which stratifies the three-dimensional
space based on altitude, conducting global-local planning for each stratum. The
objective of global planning is to identify the most optimal frontier for
exploration, followed by viewpoint selection and local path optimization based
on frontier type, ultimately generating dynamically feasible three-dimensional
spatial exploration trajectories. We present extensive benchmark and real-world
tests, in which our method completes the exploration tasks with unprecedented
completeness compared to state-of-the-art approaches.Comment: 7 pages,29 figure
Graphene-analogues boron nitride nanosheets confining ionic liquids: a high-performance quasi-liquid solid electrolyte
Solid electrolytes are one of the most promising electrolyte systems for safe lithium batteries, but the low ionic conductivity of these electrolytes seriously hinders the development of efficient lithium batteries. Here, a novel class of graphene-analogues boron nitride (g-BN) nanosheets confining an ultrahigh concentration of ionic liquids (ILs) in an interlayer and out-of-layer chamber to give rise to a quasi-liquid solid electrolyte (QLSE) is reported. The electron-insulated g-BN nanosheet host with a large specific surface area can confine ILs as much as 10 times of the host's weight to afford high ionic conductivity (3.85 × 10−3 S cm−1 at 25 °C, even 2.32 × 10−4 S cm−1 at −20 °C), which is close to that of the corresponding bulk IL electrolytes. The high ionic conductivity of QLSE is attributed to the enormous absorption for ILs and the confining effect of g-BN to form the ordered lithium ion transport channels in an interlayer and out-of-layer of g-BN. Furthermore, the electrolyte displays outstanding electrochemical properties and battery performance. In principle, this work enables a wider tunability, further opening up a new field for the fabrication of the next-generation QLSE based on layered nanomaterials in energy conversion devices
Intakes of magnesium, calcium and risk of fatty liver disease and prediabetes
Objective
Obesity and insulin resistance play important roles in the pathogenesis of non-alcoholic fatty liver disease (NAFLD). Mg intake is linked to a reduced risk of metabolic syndrome and insulin resistance; people with NAFLD or alcoholic liver disease are at high risk of Mg deficiency. The present study aimed to investigate whether Mg and Ca intakes were associated with risk of fatty liver disease and prediabetes by alcohol drinking status.
Design
We analysed the association between Ca or Mg intake and fatty liver disease, prediabetes or both prediabetes and fatty liver disease in cross-sectional analyses.
Setting
Third National Health and Nutrition Examination Survey (NHANES III) follow-up cohort of US adults.
Subjects
Nationally representative sample of US adults in NHANES (n 13 489).
Results
After adjusting for potential confounders, Mg intake was associated with approximately 30 % reduced odds of fatty liver disease and prediabetes, comparing the highest intake quartile v. the lowest. Mg intake may only be related to reduced odds of fatty liver disease and prediabetes in those whose Ca intake is less than 1200 mg/d. Mg intake may also only be associated with reduced odds of fatty liver disease among alcohol drinkers.
Conclusions
The study suggests that high intake of Mg may be associated with reduced risks of fatty liver disease and prediabetes. Further large studies, particularly prospective cohort studies, are warranted to confirm the findings
Case report: Pathological complete response to perioperative treatment of radiotherapy combined with angiogenesis inhibitor in a patient with pleomorphic liposarcoma
BackgroundLiposarcomas (LPS) are mesenchymal malignancies with four principal subtypes presenting distinct molecular and clinical features. Pleomorphic liposarcoma (PLPS) is one of the rarest and most aggressive subtypes of LPS. Surgical resection is currently a preferred curative approach for localized PLPS. However, the prognosis of unresectable PLPS is extremely poor, and there is no standard treatment.Case presentationA 59-year-old Chinese woman was diagnosed with unresectable PLPS. The case was discussed and managed by specialists from a multidisciplinary team at Fudan Zhongshan Hospital. Preoperative radiotherapy (RT) of intensity-modulated radiation therapy (IMRT) at 50 Gy/25 Fx concurrently with the angiogenesis inhibitor anlotinib (8 mg, days 1–14, every 3 weeks) was prescribed to the patient. The dosage of anlotinib was increased to 10 mg after RT. After 6 months of treatment, the tumor had significantly shrunk and was successfully resected. Examination of the surgical specimens showed a pathological complete response (pCR). Until the latest follow-up (April 2022), no recurrence was observed, and disease-free survival has exceeded 14 months.ConclusionThis case sheds light on the probability that perioperative RT combined with an angiogenesis inhibitor can be effectively used in PLPS, which is resistant to chemotherapy and usually considered to have a poor prognosis. Further studies with randomized controlled clinical trials will improve our knowledge of this preoperative treatment strategy
Insight-HXMT observations of Swift J0243.6+6124 during its 2017-2018 outburst
The recently discovered neutron star transient Swift J0243.6+6124 has been
monitored by {\it the Hard X-ray Modulation Telescope} ({\it Insight-\rm HXMT).
Based on the obtained data, we investigate the broadband spectrum of the source
throughout the outburst. We estimate the broadband flux of the source and
search for possible cyclotron line in the broadband spectrum. No evidence of
line-like features is, however, found up to . In the absence of
any cyclotron line in its energy spectrum, we estimate the magnetic field of
the source based on the observed spin evolution of the neutron star by applying
two accretion torque models. In both cases, we get consistent results with
, and peak luminosity of which makes the source the first Galactic ultraluminous
X-ray source hosting a neutron star.Comment: publishe
- …