4,422 research outputs found
Video-Bench: A Comprehensive Benchmark and Toolkit for Evaluating Video-based Large Language Models
Video-based large language models (Video-LLMs) have been recently introduced,
targeting both fundamental improvements in perception and comprehension, and a
diverse range of user inquiries. In pursuit of the ultimate goal of achieving
artificial general intelligence, a truly intelligent Video-LLM model should not
only see and understand the surroundings, but also possess human-level
commonsense, and make well-informed decisions for the users. To guide the
development of such a model, the establishment of a robust and comprehensive
evaluation system becomes crucial. To this end, this paper proposes
\textit{Video-Bench}, a new comprehensive benchmark along with a toolkit
specifically designed for evaluating Video-LLMs. The benchmark comprises 10
meticulously crafted tasks, evaluating the capabilities of Video-LLMs across
three distinct levels: Video-exclusive Understanding, Prior Knowledge-based
Question-Answering, and Comprehension and Decision-making. In addition, we
introduce an automatic toolkit tailored to process model outputs for various
tasks, facilitating the calculation of metrics and generating convenient final
scores. We evaluate 8 representative Video-LLMs using \textit{Video-Bench}. The
findings reveal that current Video-LLMs still fall considerably short of
achieving human-like comprehension and analysis of real-world videos, offering
valuable insights for future research directions. The benchmark and toolkit are
available at: \url{https://github.com/PKU-YuanGroup/Video-Bench}.Comment: Benchmark is available at
https://github.com/PKU-YuanGroup/Video-Benc
Silicon nitride metalenses for unpolarized high-NA visible imaging
As one of nanoscale planar structures, metasurface has shown excellent
superiorities on manipulating light intensity, phase and/or polarization with
specially designed nanoposts pattern. It allows to miniature a bulky optical
lens into the chip-size metalens with wavelength-order thickness, playing an
unprecedented role in visible imaging systems (e.g. ultrawide-angle lens and
telephoto). However, a CMOS-compatible metalens has yet to be achieved in the
visible region due to the limitation on material properties such as
transmission and compatibility. Here, we experimentally demonstrate a divergent
metalens based on silicon nitride platform with large numerical aperture
(NA~0.98) and high transmission (~0.8) for unpolarized visible light,
fabricated by a 695-nm-thick hexagonal silicon nitride array with a minimum
space of 42 nm between adjacent nanoposts. Nearly diffraction-limit virtual
focus spots are achieved within the visible region. Such metalens enables to
shrink objects into a micro-scale size field of view as small as a single-mode
fiber core. Furthermore, a macroscopic metalens with 1-cm-diameter is also
realized including over half billion nanoposts, showing a potential application
of wide viewing-angle functionality. Thanks to the high-transmission and
CMOS-compatibility of silicon nitride, our findings may open a new door for the
miniaturization of optical lenses in the fields of optical fibers,
microendoscopes, smart phones, aerial cameras, beam shaping, and other
integrated on-chip devices.Comment: 16 pages, 7 figure
Relationship between Microstructure and Properties of Cu-Cr-Ag-(Ce) Alloy Using Microscopic Investigation
Microstructure, precipitation hardening response, and mechanical and physical properties of Cu-Cr-Ag alloy and Cu-Cr-Ag-Ce alloy have been investigated using transmission electron microscopy, scanning electron microscope, optical microscope, electrical conductivity analysis, and tensile test. The influence of element Ce on the matrix refinement, impurity removal, and precipitation in the Cu-Cr-Ag alloys has been analyzed. The experimental results show that the strength and electrical conductivity of Ce containing alloys are greater than those of Ce-free alloys after each processing step. Improvement of strength and electrical conductivity of the Cu-Cr-Ag alloy by adding Ce element is attributed to removing oxygen and sulfur from as-cast alloy
Benzo[a]fluoren-11-one
The molecule of the title compound, C17H10O, is nearly planar, the largest deviation from the mean plane being 0.06 Å. The crystal structure is governed by π–π interactions, with centroid–centroid distances ranging from .559 to 3.730 Å
Preoperative Imaging for Thoracic Branch of Supraclavicular Artery Flap A Comparative Study of Contrast-Enhanced Ultrasound With Three-Dimensional Reconstruction and Color Duplex Ultrasound
Objective: The thoracic branch of supraclavicular artery (TBSA) flap has been widely used to reconstruct face and neck defects. However, the branches of the supraclavicular artery (SCA) exhibit considerable anatomical variations. The aim of this study was to evaluate and compare the role of contrast-enhanced ultrasound (CEUS) with 3-dimensional (3D) reconstruction and regular color duplex ultrasonography (CDUS) in the preoperative assessment of TBSA flap. Methods: From May 2009 to October 2013, 20 patients (involving 26 flaps) receiving anterior chest flaps for lower face and neck reconstruction underwent both CDUS and CEUS with 3D reconstruction preoperatively for detecting the TBSAs. The number of TBSAs, their caliber, peak systolic velocity (PSV), and course were recorded. In case of an absent TBSA, the second and third perforators of the internal mammary artery were detected. The preoperative imaging data were compared with the intraoperative findings to evaluate the value of CDUS and CEUS with 3D reconstruction for planning and performing the TBSA flaps. All patients were followed up for more than 1 year. Results: A total of 37 TBSAs in 16 flaps were found by CDUS with a mean caliber of 0.6 +/- 0.1 mm and a mean PSV of 13.1 +/- 1.6 cm/s, whereas 48 TBSAs in 20 flaps were found by CEUS with a mean caliber of 0.8 +/- 0.2 mm and a mean PSVof 12.5 +/- 2.1 cm/sec. In 18 flaps with TBSA PSV above 10 cm/s, pedicled TBSA flaps were performed, whereas pedicled or free internal mammary artery flaps were chosen as alternative for the remaining 8 flaps. All 48 TBSAs were found intraoperatively and their origin from the SCA confirmed, indicating specificity and positive predictive value of both CDUS and CEUS were 100% in localizing TBSA preoperatively, whereas sensitivity and negative predictive value of CEUS were higher than using CDUS. Conclusions: The branches of SCA have marked anatomical variations. CEUS with 3D reconstruction has advantages over CDUS for the preoperative assessment of the donor-site vascular supply of TBSA flaps
Surgery after combination therapy with a tyrosine kinase inhibitor and anti-PD-1 antibody in sarcomatoid hepatocellular carcinoma: case report and literature review
IntroductionAlthough surgery is the preferred treatment for sarcomatoid hepatocellular carcinoma (SHC), the prognosis remains considerably poor due to early postoperative recurrence and metastasis. Reports on surgery after combined treatment with a tyrosine kinase inhibitor and anti-programmed cell death (PD)-1 antibody are unavailable.Case presentationA 69-year-old male patient with SHC was admitted to our hospital for treatment of a liver tumor that was detected on ultrasonography. Abdominal computed tomography with triple-phase enhancement revealed a lesion in the right hepatic lobe that measured 86.0 mm × 75.0 mm × 71.0 mm. Biopsy revealed a pathological diagnosis of liver sarcoma or sarcomatoid carcinoma. The patient subsequently received transcatheter arterial chemo-embolization, as he did not consent to surgery. More than two months later, he received a combination of lenvatinib with camrelizumab, as computed tomography showed an increase in the lesion size (to 123.0 mm × 90.0 mm × 80.0 mm) and lateral growth posterior to the upper pole of the right kidney. Liver resection was performed after 6 months of systemic therapy; pathological examination confirmed a diagnosis of SHC and showed extensive necrosis of tumor cells. Combined treatment with lenvatinib and camrelizumab was continued for 6 months after surgery. The patient has survived for over 24 months after initial diagnosis and is currently tumor-free.ConclusionCombined systemic therapy with a tyrosine kinase inhibitor and anti-PD-1 antibody may represent a feasible treatment strategy for improving resectability in cases of unresectable SHC. The outcomes with this combination may also be explored in cases of resectable SHC that have a high-risk of recurrence; this may improve the therapeutic effect
Rethinking the Metric in Few-shot Learning: From an Adaptive Multi-Distance Perspective
Few-shot learning problem focuses on recognizing unseen classes given a few
labeled images. In recent effort, more attention is paid to fine-grained
feature embedding, ignoring the relationship among different distance metrics.
In this paper, for the first time, we investigate the contributions of
different distance metrics, and propose an adaptive fusion scheme, bringing
significant improvements in few-shot classification. We start from a naive
baseline of confidence summation and demonstrate the necessity of exploiting
the complementary property of different distance metrics. By finding the
competition problem among them, built upon the baseline, we propose an Adaptive
Metrics Module (AMM) to decouple metrics fusion into metric-prediction fusion
and metric-losses fusion. The former encourages mutual complementary, while the
latter alleviates metric competition via multi-task collaborative learning.
Based on AMM, we design a few-shot classification framework AMTNet, including
the AMM and the Global Adaptive Loss (GAL), to jointly optimize the few-shot
task and auxiliary self-supervised task, making the embedding features more
robust. In the experiment, the proposed AMM achieves 2% higher performance than
the naive metrics fusion module, and our AMTNet outperforms the
state-of-the-arts on multiple benchmark datasets
Whole-genome resequencing of Escherichia coli K-12 MG1655 undergoing short-term laboratory evolution in lactate minimal media reveals flexible selection of adaptive mutations
Background
Short-term laboratory evolution of bacteria followed by genomic sequencing provides insight into the mechanism of adaptive evolution, such as the number of mutations needed for adaptation, genotype-phenotype relationships, and the reproducibility of adaptive outcomes. Results
In the present study, we describe the genome sequencing of 11 endpoints of Escherichia coli that underwent 60-day laboratory adaptive evolution under growth rate selection pressure in lactate minimal media. Two to eight mutations were identified per endpoint. Generally, each endpoint acquired mutations to different genes. The most notable exception was an 82 base-pair deletion in the rph-pyrE operon that appeared in 7 of the 11 adapted strains. This mutation conferred an approximately 15% increase to the growth rate when experimentally introduced to the wild-type background and resulted in an approximately 30% increase to growth rate when introduced to a background already harboring two adaptive mutations. Additionally, most endpoints had a mutation in a regulatory gene (crp or relA, for example) or the RNA polymerase. Conclusions
The 82 base-pair deletion found in the rph-pyrE operon of many endpoints may function to relieve a pyrimidine biosynthesis defect present in MG1655. In contrast, a variety of regulators acquire mutations in the different endpoints, suggesting flexibility in overcoming regulatory challenges in the adaptation
3-Chloro-4-hydroxyfuran-2(5H)-one
In the title compound, C4H3ClO3, molecules are linked via O—H⋯O hydrogen bonds into an infinite chain with graph-set motif C(6) along the c axis
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