3,235 research outputs found
ONLINE AUCTION EFFECTIVENESS: OPTIMAL SELLING STRATEGIES FOR ONLINE AUCTION MARKET
The introduction of internet auction has significantly widened the pool of consumers who participate in auctions and increased the number of companies attempting to sell their products in an auction format. Previous empirical research on auctions has focused almost exclusively on the behavior of professional bidders. In this study, we collect data on a large number of internet auctions to explore the outcome of the auction in a real marketplace. In particular, we focus on the characteristic of seller, auction parameter and the effect of supply and demand, and examine these impacts on auction effectiveness
The Role of Molecular Imaging in the Diagnosis and Management of Neuropsychiatric Disorders
Neuropsychiatric disorders are becoming a major socioeconomic burden to modern society. In recent years, a dramatic expansion of tools has facilitated the study of the molecular basis of neuropsychiatric disorders. Molecular imaging has enabled the noninvasive characterization and quantification of biological processes at the cellular, tissue, and organism levels in intact living subjects. This technology has revolutionized the practice of medicine and has become critical to quality health care. New advances in research on molecular imaging hold promise for personalized medicine in neuropsychiatric disorders, with adjusted therapeutic doses, predictable responses, reduced adverse drug reactions, early diagnosis, and personal health planning. In this paper, we discuss the development of radiotracers for imaging dopaminergic, serotonergic, and noradrenergic systems and β-amyloid plaques. We will underline the role of molecular imaging technologies in various neuropsychiatric disorders, describe their unique strengths and limitations, and suggest future directions in the diagnosis and management of neuropsychiatric disorders
Tunable magnetism and electron correlation in Titanium-based Kagome metals RETi3Bi4 (RE = Yb, Pr, and Nd) by rare-earth engineering
Rare-earth engineering is an effective way to introduce and tune the
magnetism in topological Kagome magnets, which has been acting as a fertile
platform to investigate the quantum interactions between geometry, topology,
spin, and correlation. Here we report the structure and properties of three
newly discovered Titanium-based Kagome metals RETi3Bi4 (RE = Yb, Pr, and Nd)
with various magnetic states. They crystalize in the orthogonal space group
Fmmm (No.69), where slightly distorted Ti Kagome lattice, RE triangular
lattice, Bi honeycomb and triangular lattices stack along the a axis. By
changing the rare earth atoms on RE zag-zig chains, the magnetism can be tuned
from nonmagnetic YbTi3Bi4 to short-range ordered PrTi3Bi4 (Tanomaly ~ 8.2 K),
and finally to ferromagnetic NdTi3Bi4 (Tc ~ 8.5 K). The measurements of
resistivity and specific heat capacity demonstrate an evolution of electron
correlation and density of states near the Fermi level with different rare
earth atoms. In-situ resistance measurements of NdTi3Bi4 under high pressure
further reveal a potential relationship between the electron correlation and
ferromagnetic ordering temperature. These results highlight RETi3Bi4 as another
family of topological Kagome magnets to explore nontrivial band topology and
exotic phases in Kagome materials.Comment: Manuscript:17 pages, 5 figures; Supporting information:11 pages, 11
tables and 10 figure
Establishment of OPG Transgenic Mice and the Effect of OPG on Bone Microarchitecture
Osteoprotegerin (OPG) plays a determinant role in regulating bone metabolism, but the effect of OPG on bone microarchitecture needs to be further elucidated. We attempted to construct pCI-hOPGp-mOPG vector containing human OPG promoter and FLAG tag and to microinject vector into fertilized zygotes from C57BL/6J × CBA mice to prepare transgenic mice. The OPG transgenic positive mice were identified by PCR and western blotting. Twelve-week-old OPG transgenic mice (OPG-Tg mice) and wild-type mice (WT mice) were utilized in the study of bone microarchitecture. Microcomputed tomography (micro-CT) data showed that compared with WT mice, the tibia of OPG-Tg mice showed an increased volumetric BMD (vBMD), tissue BMD (tBMD), trabecular thickness (Tb.Th), and trabecular number (Tb.N), and a decreased trabecular separation (Th.Sp) (P<0.05) . The cortical bone microarchitecture parameters, such as cortical area (Ct.Ar), cortical thickness (Ct.Th), cortical BMD (Ct.BMD), cortical BMC (Ct.BMC), BMD, and BMC of femur, were increased, and the inner perimeter (In.Pm) was decreased, in OPG-Tg mice, compared to those in WT mice (P<0.05). The established OPG transgenic mouse model could be valuable for further studying the biological significance and gene regulation of OPG in vivo
Monolithic quantum-dot distributed feedback laser array on silicon
Electrically-pumped lasers directly grown on silicon are key devices
interfacing silicon microelectronics and photonics. We report here, for the
first time, an electrically-pumped, room-temperature, continuous-wave (CW) and
single-mode distributed feedback (DFB) laser array fabricated in InAs/GaAs
quantum-dot (QD) gain material epitaxially grown on silicon. CW threshold
currents as low as 12 mA and single-mode side mode suppression ratios (SMSRs)
as high as 50 dB have been achieved from individual devices in the array. The
laser array, compatible with state-of-the-art coarse wavelength division
multiplexing (CWDM) systems, has a well-aligned channel spacing of 20 0.2 nm
and exhibits a record wavelength coverage range of 100 nm, the full span of the
O-band. These results indicate that, for the first time, the performance of
lasers epitaxially grown on silicon is elevated to a point approaching
real-world CWDM applications, demonstrating the great potential of this
technology
CSE1L/CAS, the cellular apoptosis susceptibility protein, enhances invasion and metastasis but not proliferation of cancer cells
<p>Abstract</p> <p>Background</p> <p>The cellular apoptosis susceptibility (CAS) protein is regarded as a proliferation-associated protein that associates with tumour proliferation as it associates with microtubule and functions in the mitotic spindle checkpoint. However, there is no any actual experimental study showing CAS (or CSE1 and CSE1L) can increase the proliferation of cancer cells. Previous pathological study has reported that CAS was strongly positive stained in all of the metastasis melanoma that be examined. Thus, CAS may regulate the invasion and metastasis of cancers. CAS is highly expressed in cancers; if CAS is associated with cancer proliferation, then increased CAS expression should be able to increase the proliferation of cancer cells. We studied whether increased CAS expression can increase cancer cell proliferation and whether CAS regulates the invasion of cancer cells.</p> <p>Methods</p> <p>We enhanced or reduced CAS expression by transfecting CAS or anti-CAS expression vectors into human MCF-7 breast cancer cells. The proliferations of cells were determined by trypan blue exclusion assay and flow cytometry analysis. Invasion of cancer cells were determined by matrigel-based invasion assay.</p> <p>Results</p> <p>Our studies showed that increased CAS expression was unable to enhance cancer cell proliferation. Immunofluorescence showed CAS was distributed in cytoplasm areas near cell membrane and cell protrusions. CAS was localized in cytoplasmic vesicle and immunogold electronmicroscopy showed CAS was located in vesicle membrane. CAS overexpression enhanced matrix metalloproteinase-2 (MMP-2) secretion and cancer cell invasion. Animal experiments showed CAS reduction inhibited the metastasis of B16-F10 melanoma cells by 56% in C57BL/6 mice.</p> <p>Conclusion</p> <p>Our results indicate that CAS increases the invasion but not the proliferation of cancer cells. Thus, CAS plus ECM-degradation proteinases may be used as the markers for predicting the advance of tumour metastasis.</p
The effect of adjuvant chemotherapy on survival in node negative colorectal cancer with or without perineural invasion: a systematic review and meta-analysis
PurposeIt was aimed at assessing the benefits of adjuvant chemotherapy (ACT) for patients with node-negative colorectal cancer (CRC) either with or without perineural invasion (PNI).MethodsWe systematically searched PubMed, Cochrane Library, Embase, and Web of Science from database inception through October 1, 2023. Survival outcomes were analyzed using hazard ratios (HRs) and corresponding 95% confidence intervals (CIs). The methodological quality of included studies was assessed using the Newcastle-Ottawa Scale (NOS). Heterogeneity for the descriptive meta-analyses was quantified using the I2 statistic.ResultsTen studies included in this review. ACT improved overall survival (OS) (HR 0.52, 95% CI 0.40–0.69) and disease-free survival (DFS) (HR 0.53, 95% CI 0.35–0.82) in PNI + patients but did not affect DFS (HR 1.13, 95% CI 0.72–1.77) in PNI- patients. A disease-specific survival (DSS) benefit with chemotherapy was observed in PNI + (HR 0.76, 95% CI 0.58–0.99) and PNI- patients (HR 0.76, 95% CI 0.57–1.00). And PNI decreased DFS (HR 1.94, 95% CI 1.52–2.47) and OS (HR 1.75, 95% CI 0.96–3.17) in node-negative CRC.ConclusionsIn conclusion, chemotherapy appears most beneficial for survival outcomes in node-negative patients with PNI, but may also confer some advantage in those without PNI.Systematic Review RegistrationIdentifier INPLASY2021120103
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