1,022 research outputs found
Primary intrathoracic liposarcoma: a clinicopathologic study and prognostic analysis of 23 cases
BACKGROUND: Primary intrathoracic liposarcoma is an extremely rare malignancy as well as a rare histologic subtype of intrathoracic sarcoma. Relatively few reports appear in the world literatures. We explored the clinicopathologic features and prognostic factors of this tumor in this study. METHODS: We retrospectively analyzed the clinicopathological data of 23 patients with primary intrathoracic liposarcoma who were treated in Shanghai chest Hospital affiliated to Jiao Tong University, from January 2003 to March 2013. These patients were classified into three groups according to the distinct tumor locations, including mediastinum, pleura and lung liposarcoma. Also, these patients could be divided into four types, including well-differentiated, myxoid, dedifferentiated and pleomorphic liposarcoma. The influences of age, sex, tumor size, tumor location, tumor histologic type and therapy on the prognosis of the patients were analyzed. RESULTS: There were no significant difference for survival among distinct liposarcoma locations. However, significant difference for survival among distinct liposarcoma types were observed. Poor disease-free survival (DFS) was observed in the myxoid, pleomorphic and dedifferentiated types as compared to well-differentiated type (P = 0.038). Inferior overall-survival (OS) was observed in dedifferentiated, pleomorphic and myxoid types relative to well-differentiated type (P = 0.027). The radical surgery was a favorable prognostic factor for OS, as demonstrated by the better OS of the radical surgery group as compared to that of the non-radical surgery group ( P = 0.029). Notably, there were no significant differences for DFS and OS in other clinical parameters including tumor size, gender and age. In addition, radiotherapy and/or chemotherapy could not improve the prognosis of the patients receiving non-radical surgery or suffering from relapse. CONCLUSIONS: The histological type and the radical surgery are the factors that influence the behavior and prognosis of liposarcoma. In general, radiotherapy and chemotherapy are believed to be ineffective therapeutic modalities for survival. So it is essential to completely resect the primary intrathoracic liposarcoma as radical cure of the disease
Spectroscopic Study of Globular Clusters in the Halo of M31 with Xinglong 2.16m Telescope II: Dynamics, Metallicity and Age
(Abridged) We performed the spectroscopic observations of 11 confirmed GCs in
M31 with the Xinglong 2.16m telescope and we mainly focus on the fits method
and the metallicity gradient for the M31 GC sample. We analyzed and discussed
more about the dynamics, metallicity and age, and their distributions as well
as the relationships between these parameters. Eight more confirmed GCs in the
halo of M31 were observed, most of which lack the spectroscopic information
before. These star clusters are located far from the galactic center at a
projected radius of ~14 to ~117 kpc. The Lick absorption-line indices and the
radial velocities have been measured and ages, metallicities [Fe/H] and
alpha-element [alpha/Fe] have also been fitted by comparing the observed
spectral feature indices and Thomas et al.SSP model. Our results show that most
of the star clusters of our sample are older than 10 Gyr except B290 ~5.5 Gyr,
and most of them are metal-poor with the metallicity [Fe/H]<-1, suggesting that
these clusters were born at the early stage of the galaxy's formation. We find
that the metallicity gradient for the outer halo clusters with r_p>25 kpc may
not exist with a slope of -0.005+-0.005 dex kpc^-1. We also find that the
metallicity is not a function of age for the GCs with age < 7 Gyr while for the
old GCs with age >7 Gyr there seems to be a trend that the older ones have
lower metallicity. Besides, We plot metallicity distributions with the largest
sample of M31 GCs so far and it shows the bimodality is not significant and the
number of the metal-poor and metal-rich groups becomes comparable. The spatial
distributions shows that the metal-rich group is more centrally concentrated
while the metal-poor group is occupy a more extended halo and the young
population is centrally concentrated while the old population is more extended
spatially to the outer halo.Comment: 17 pages, 10 figures and 6 tables. Accepted for publication in RA
Polytypism and Unexpected Strong Interlayer Coupling of two-Dimensional Layered ReS2
The anisotropic two-dimensional (2D) van der Waals (vdW) layered materials,
with both scientific interest and potential application, have one more
dimension to tune the properties than the isotropic 2D materials. The
interlayer vdW coupling determines the properties of 2D multi-layer materials
by varying stacking orders. As an important representative anisotropic 2D
materials, multilayer rhenium disulfide (ReS2) was expected to be random
stacking and lack of interlayer coupling. Here, we demonstrate two stable
stacking orders (aa and a-b) of N layer (NL, N>1) ReS2 from ultralow-frequency
and high-frequency Raman spectroscopy, photoluminescence spectroscopy and
first-principles density functional theory calculation. Two interlayer shear
modes are observed in aa-stacked NL-ReS2 while only one interlayer shear mode
appears in a-b-stacked NL-ReS2, suggesting anisotropic-like and isotropic-like
stacking orders in aa- and a-b-stacked NL-ReS2, respectively. The frequency of
the interlayer shear and breathing modes reveals unexpected strong interlayer
coupling in aa- and a-b-NL-ReS2, the force constants of which are 55-90% to
those of multilayer MoS2. The observation of strong interlayer coupling and
polytypism in multi-layer ReS2 stimulate future studies on the structure,
electronic and optical properties of other 2D anisotropic materials
Towards Few-shot Out-of-Distribution Detection
Out-of-distribution (OOD) detection is critical for ensuring the reliability
of open-world intelligent systems. Despite the notable advancements in existing
OOD detection methodologies, our study identifies a significant performance
drop under the scarcity of training samples. In this context, we introduce a
novel few-shot OOD detection benchmark, carefully constructed to address this
gap. Our empirical analysis reveals the superiority of ParameterEfficient
Fine-Tuning (PEFT) strategies, such as visual prompt tuning and visual adapter
tuning, over conventional techniques, including fully fine-tuning and linear
probing tuning in the few-shot OOD detection task. Recognizing some crucial
information from the pre-trained model, which is pivotal for OOD detection, may
be lost during the fine-tuning process, we propose a method termed
DomainSpecific and General Knowledge Fusion (DSGF). This approach is designed
to be compatible with diverse fine-tuning frameworks. Our experiments show that
the integration of DSGF significantly enhances the few-shot OOD detection
capabilities across various methods and fine-tuning methodologies, including
fully fine-tuning, visual adapter tuning, and visual prompt tuning. The code
will be released
Fabrication, Characterization, Properties, and Applications of Low-Dimensional BiFeO 3
Low-dimensional BiFeO3 nanostructures (e.g., nanocrystals, nanowires, nanotubes, and nanoislands) have received considerable attention due to their novel size-dependent properties and outstanding multiferroic properties at room temperature. In recent years, much progress has been made both in fabrications and (microstructural, electrical, and magnetic) in characterizations of BiFeO3 low-dimensional nanostructures. An overview of the state of art in BiFeO3 low-dimensional nanostructures is presented. First, we review the fabrications of high-quality BiFeO3 low-dimensional nanostructures via a variety of techniques, and then the structural characterizations and physical properties of the BiFeO3 low-dimensional nanostructures are summarized. Their potential applications in the next-generation magnetoelectric random access memories and photovoltaic devices are also discussed. Finally, we conclude this review by providing our perspectives to the future researches of BiFeO3 low-dimensional nanostructures and some key problems are also outlined
Exosomes from embryonic mesenchymal stem cells alleviate osteoarthritis through balancing synthesis and degradation of cartilage extracellular matrix
Abstract
Background
Mesenchymal stem cell therapy for osteoarthritis (OA) has been widely investigated, but the mechanisms are still unclear. Exosomes that serve as carriers of genetic information have been implicated in many diseases and are known to participate in many physiological processes. Here, we investigate the therapeutic potential of exosomes from human embryonic stem cell-induced mesenchymal stem cells (ESC-MSCs) in alleviating osteoarthritis (OA).
Methods
Exosomes were harvested from conditioned culture media of ESC-MSCs by a sequential centrifugation process. Primary mouse chondrocytes treated with interleukin 1 beta (IL-1β) were used as an in vitro model to evaluate the effects of the conditioned medium with or without exosomes and titrated doses of isolated exosomes for 48 hours, prior to immunocytochemistry or western blot analysis. Destabilization of the medial meniscus (DMM) surgery was performed on the knee joints of C57BL/6 J mice as an OA model. This was followed by intra-articular injection of either ESC-MSCs or their exosomes. Cartilage destruction and matrix degradation were evaluated with histological staining and OARSI scores at the post-surgery 8 weeks.
Results
We found that intra-articular injection of ESC-MSCs alleviated cartilage destruction and matrix degradation in the DMM model. Further in vitro studies illustrated that this effect was exerted through ESC-MSC-derived exosomes. These exosomes maintained the chondrocyte phenotype by increasing collagen type II synthesis and decreasing ADAMTS5 expression in the presence of IL-1β. Immunocytochemistry revealed colocalization of the exosomes and collagen type II-positive chondrocytes. Subsequent intra-articular injection of exosomes derived from ESC-MSCs successfully impeded cartilage destruction in the DMM model.
Conclusions
The exosomes from ESC-MSCs exert a beneficial therapeutic effect on OA by balancing the synthesis and degradation of chondrocyte extracellular matrix (ECM), which in turn provides a new target for OA drug and drug-delivery system development
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