694 research outputs found
Wild Soybeans: An Opportunistic Resource for Soybean Improvement
Reduced genetic diversity in cultivated soybean coupled with changing dietary expectations, climate change, and increase in population demands expansion of current gene pool. Wild soybeans are an opportunistic resource and a rational choice to discover novel genes and gene families for alternative crop production systems and to improve soybean. Multiple agronomic traits, lineage-specific genes, and domestication-related traits have been studied in wild soybeans in contrast to cultivated soybeans, and it has been proved that wild soybeans are an essential genomic resource containing unique and useful genetic resources that have been lost during domestication to expand the gene pool in order to improve soybean. Wild soybean is very often a plant of disturbed habitats of Southeast Asia. The vulnerability of these habitats to agriculture systems and urban expansion causes a reduction in the area of distribution and hence the diversity. To capture the wild soybean genetic diversity in its main distribution areas, a unique and comprehensive germplasm collection, characterization, and conservation platform is direly needed. Chung’s Wild Legume Germplasm Collection is preserving and maintaining a representative wild soybean germplasm collection guided by the principles of conservation genetics. These wild legumes and particularly wild soybean is a promising genetic resource for soybean breeders
Robust Kernel-based Feature Representation for 3D Point Cloud Analysis via Circular Graph Convolutional Network
Feature descriptors of point clouds are used in several applications, such as
registration and part segmentation of 3D point clouds. Learning discriminative
representations of local geometric features is unquestionably the most
important task for accurate point cloud analyses. However, it is challenging to
develop rotation or scale-invariant descriptors. Most previous studies have
either ignored rotations or empirically studied optimal scale parameters, which
hinders the applicability of the methods for real-world datasets. In this
paper, we present a new local feature description method that is robust to
rotation, density, and scale variations. Moreover, to improve representations
of the local descriptors, we propose a global aggregation method. First, we
place kernels aligned around each point in the normal direction. To avoid the
sign problem of the normal vector, we use a symmetric kernel point distribution
in the tangential plane. From each kernel point, we first projected the points
from the spatial space to the feature space, which is robust to multiple scales
and rotation, based on angles and distances. Subsequently, we perform graph
convolutions by considering local kernel point structures and long-range global
context, obtained by a global aggregation method. We experimented with our
proposed descriptors on benchmark datasets (i.e., ModelNet40 and ShapeNetPart)
to evaluate the performance of registration, classification, and part
segmentation on 3D point clouds. Our method showed superior performances when
compared to the state-of-the-art methods by reducing 70 of the rotation and
translation errors in the registration task. Our method also showed comparable
performance in the classification and part-segmentation tasks with simple and
low-dimensional architectures.Comment: 10 pages, 9 figure
Multi-kilowatt single-mode ytterbium-doped large-core fiber laser
We have demonstrated a highly efficient cladding-pumped ytterbium-doped fiber laser, generating >2.1 kW of continuous-wave output power at 1.1 µm with 74% slope efficiency with respect to launched pump power. The beam quality factor (M2) was better than 1.2. The maximum output power was only limited by available pump power, showing no evidence of roll-over even at the highest output power. We present data on how the beam quality depends on the fiber parameter, based on our current and past fiber laser developments. We also discuss the ultimate power-capability of our fiber in terms of thermal management, Raman nonlinear scattering, and material damage, and estimate it to 10 k
Association Study of FOS-Like Antigen-2 Promoter Polymorphisms With Papillary Thyroid Cancer in Korean Population
ObjectivesFOS-like antigen-2 (FOSL-2), a member of the FOS gene family, encode leucine zipper proteins that can heterodimerize with proteins of Jun family. Thus, activating protein (AP)-1 transcription factor is formed, has a crucial role in proliferation, differentiation and apoptosis of normal tissue as well as oncogenic transformation and progression. We performed an association study of single nucleotide polymorphisms (SNPs) in the FOSL-2 with papillary thyroid cancer (PTC). We also estimated the relationships between the SNPs and the clinicopathologic characteristics of PTC.MethodsOne promoter SNPs (rs925255) of FOSL-2 gene were genotyped with direct sequencing method in 94 PTC and 213 controls. PTC patients were dichotomized and compared with respect to clinical parameters of PTC. Genetic data were analyzed using Helixtree, SNPAnalyzer, SNPStats. Multivariate logistic regression analysis was fulfilled to evaluate the genetic effect with adjustment for age and sex.ResultsSNP (rs925255) in FOSL-2 showed a significant association (codominant 1 model [G/G vs. A/G]: odds ratio [OR], 0.531, 95% confidence interval [CI], 0.293 to 0.96, P=0.036; dominant model: OR, 0.50, 95% CI, 0.28 to 0.89, P=0.015) with PTC. The frequency of allele G in rs925255 was also significantly associated with PTC (OR, 0.59; 95% CI, 0.34 to 0.91; P=0.02). But we fail to prove significant association between this polymorphism (rs925255) and clinico-pathological parameters.ConclusionOur findings suggest that the rs925255 SNP and its allele G show significant association with the PTC in Korean population
New Heteroleptic Cobalt Precursors for Deposition of Cobalt-Based Thin Films
A new series of heteroleptic complexes of cobalt were synthesized using aminoalkoxide and ??-diketonate ligands. The complexes, [Co(dmamp)(acac)]2 (3), [Co(dmamp)(tfac)]2 (4), [Co(dmamp)(hfac)]2 (5), [Co(dmamp)(tmhd)]2 (6), and [Co(dmamb)(tmhd)]2 (7), were prepared by two-step substitution reactions and studied using Fourier transform infrared spectroscopy, mass spectrometry, elemental analysis, and thermogravimetric analysis (TGA). Complexes 3-7 displayed dimeric molecular structures for all of the complexes with cobalt metal centers interconnected by ??2-O bonding by the alkoxy oxygen atom. TGA and a thermal study of the complexes displayed high volatilities and stabilities for complexes 6 and 7, with sublimation temperatures of 120 ??C/0.5 Torr and 130 ??C/0.5 Torr, respectively
Doxorubicin-incorporated polymeric micelles composed of dextran-b-poly(DL-lactide-co-glycolide) copolymer
Young-Il Jeong1,*, Do Hyung Kim1,2,*, Chung-Wook Chung1, Jin-Ju Yoo1, Kyung Ha Choi1, Cy Hyun Kim1,2, Seung Hee Ha1, Dae Hwan Kang1,2 1National Research and Development Center for Hepatobiliary Cancer, Pusan National University Yangsan Hospital, Yangsan, Republic of Korea, Research Institute for Convergence of Biomedical Science and Technology, 2School of Medicine, Pusan National University, Yangsan, Republic of Korea*These authors contributed equally to this work.Background: Polymeric micelles using amphiphilic macromolecules are promising vehicles for antitumor targeting. In this study, we prepared anticancer agent-incorporated polymeric micelles using novel block copolymer.Methods: We synthesized a block copolymer composed of dextran and poly (DL-lactide-co-glycolide) (DexbLG) for antitumor drug delivery. Doxorubicin was selected as the anticancer drug, and was incorporated into polymeric micelles by dialysis. Polymeric micelles were observed by transmission electron microscopy to be spherical and smaller than 100 nm, with a narrow size distribution. The particle size of doxorubicin-incorporated polymeric micelles increased with increasing drug content. Higher initial drug feeding also increased the drug content. Results: During the drug-release study, an initial burst release of doxorubicin was observed for 10 hours, and doxorubicin was continuously released over 4 days. To investigate the in vitro anticancer effects of the polymeric micelles, doxorubicin-resistant HuCC-T1 cells were treated with a very high concentration of doxorubicin. In an antiproliferation study, the polymeric micelles showed higher cytotoxicity to doxorubicin-resistant HuCC-T1 cells than free doxorubicin, indicating that the polymeric micelles were effectively engulfed by tumor cells, while free doxorubicin hardly penetrated the tumor cell membrane. On confocal laser scanning microscopy, free doxorubicin expressed very weak fluorescence intensity, while the polymeric micelles expressed strong red fluorescence. Furthermore, in flow cytometric analysis, fluorescence intensity of polymeric micelles was almost twice as high than with free doxorubicin.Conclusion: DexbLG polymeric micelles incorporating doxorubicin are promising vehicles for antitumor drug targeting.Keywords: dextran, polymeric micelle, block copolymer, poly(DL-lactide-co-glycolide
Recurred pneumocephalus in a head trauma patient following positive pressure mask ventilation during induction of anesthesia -A case report-
Pneumocephalus is a condition which usually results from head trauma. It has been known that iatrogenic pneumocephalus can occur as a complication of positive pressure mask ventilation during induction of anesthesia or ventilatory care for head trauma patients. We report a case of mask ventilation during anesthesia induction in a 50-year-old male patient with head trauma. Initial pneumocephalus associated with cerebrospinal fluid leakage was diagnosed immediate following head injury involving facial sinuses. He was managed with emergent lumbar drainage and supportive care. Pneumocephalus recurred following positive pressure mask ventilation (PPMV) during anesthesia induction for surgery on the right arm. Recurred pneumocephalus was managed with high flow oxygen and supportive care. Anesthesiologists should be aware of pneumocephalus as a potential complication of PPMV in head trauma patients, even after resolution of previous pneumocephalus
Antitumor activity of sorafenib-incorporated nanoparticles of dextran/poly(dl-lactide-co-glycolide) block copolymer
Sorafenib-incoporated nanoparticles were prepared using a block copolymer that is composed of dextran and poly(DL-lactide-co-glycolide) [DexbLG] for antitumor drug delivery. Sorafenib-incorporated nanoparticles were prepared by a nanoprecipitation-dialysis method. Sorafenib-incorporated DexbLG nanoparticles were uniformly distributed in an aqueous solution regardless of the content of sorafenib. Transmission electron microscopy of the sorafenib-incorporated DexbLG nanoparticles revealed a spherical shape with a diameter < 300 nm. Sorafenib-incorporated DexbLG nanoparticles at a polymer/drug weight ratio of 40:5 showed a relatively uniform size and morphology. Higher initial drug feeding was associated with increased drug content in nanoparticles and in nanoparticle size. A drug release study revealed a decreased drug release rate with increasing drug content. In an in vitro anti-proliferation assay using human cholangiocarcinoma cells, sorafenib-incorporated DexbLG nanoparticles showed a similar antitumor activity as sorafenib. Sorafenib-incorporated DexbLG nanoparticles are promising candidates as vehicles for antitumor drug targeting
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