2,578 research outputs found
Correction: Lone pair driven anisotropy in antimony chalcogenide semiconductors
No full textCorrection for 'Lone pair driven anisotropy in antimony chalcogenide semiconductors' by Xinwei Wang et al., Phys. Chem. Chem. Phys., 2022, 24, 7195-7202, https://doi.org/10.1039/D1CP05373F
sj-png-1-onc-10.1177_11795549231175715 – Supplemental material for VEGF Mediates Tumor Growth and Metastasis by Affecting the Expression of E-Cadherin and N-Cadherin Promoting Epithelial to Mesenchymal Transition in Gastric Cancer
No full textSupplemental material, sj-png-1-onc-10.1177_11795549231175715 for VEGF Mediates Tumor Growth and Metastasis by Affecting the Expression of E-Cadherin and N-Cadherin Promoting Epithelial to Mesenchymal Transition in Gastric Cancer by Yue Zhang, Yanyan Wang, Menglin Zhao, Xinwei Li, Huiyuan Li, Mingyue Tang, Zhijun Geng, Lugen Zuo, Xue Song, Zishu Wang, Qiang Wang and Fang Su in Clinical Medicine Insights: Oncology</p
A value-focused approach for establishing requirements specification of commercial aircraft
No full textAlthough systems engineering processes and standards are widely used in aircraft development programs, traditional requirements’ engineering practice for commercial aircraft does not explicitly address value perceptions and associated information. In this paper, a value-focused approach is proposed to promote a better understanding of customer-value perceptions and their derivation among different levels for value-based requirements engineering of commercial aircraft. The approach is a four-step process starting from initial customer statements to a customer-value model and leading to a system-value model with associated component-value models. A set of theories and methods are introduced in order to resolve different aspects of the approach regarding the appropriate understanding of customer-value perceptions and the establishment of the value-based requirements’ specification. A case study is used to demonstrate the transformation of airlines’ initial expectation statements into three types of value models. There are two significant benefits of this approach: (a) perceived customer value can be explicitly modeled, simulated, and derived into different levels of the system development and (b) the value model can be subsequently utilized reactively for design evaluations and proactively for design optimization to generate creative design alternatives
DS_DISC844566 – Supplemental material for Confirmation of Selected Synergistic Cancer Drug Combinations Identified in an HTS Campaign and Exploration of Drug Efflux Transporter Contributions to the Mode of Synergy
No full textSupplemental material, DS_DISC844566 for Confirmation of Selected Synergistic Cancer Drug Combinations Identified in an HTS Campaign and Exploration of Drug Efflux Transporter Contributions to the Mode of Synergy by Stanton J. Kochanek, David A. Close, Allen Xinwei Wang, Tongying Shun, Philip E. Empey, Julie L. Eiseman and Paul A. Johnston in SLAS Discovery</p
Towards avoiding the hidden traps in QFD during requirements establishment
No full textThe Quality Function Deployment (QFD) is a useful, widely used and representative methodology to transform customer needs into different level of requirements in a system hierarchy. Simplifications that are based on assumptions are ubiquitous in the QFD, but these underlying assumptions possibly do not hold true, which renders the simplifications unjustified. Additionally, these assumptions are usually not verified within the context of the application domain. This paper identifies and illustrates nine hidden traps in QFD during the process of establishing the requirements, where the assumptions, and therefore, the simplifications made are not reasonable. These traps are implicit in the understanding of customer needs, establishment of system requirements and the flow down of these requirements to lower levels of the system hierarchy. Suggestions are given to help avoid these hidden traps, thereby eliminating or alleviating their potentially detrimental effects. The intent of the paper is to make readers aware of these traps when applying QFD for the establishment of requirements, so that they may use QFD in better knowledge of its limitations and thereby may develop higher quality specification
Micro-embossing formability of a superlight dual-phase Mg-Li alloy processed by high-pressure torsion
No full textMicro‐embossing tests are performed on a coarse‐grained (CG) and an ultrafine‐grained (UFG) dual‐phase Mg–Li alloy processed by high‐pressure torsion (HPT) using different widths of the female die at ambient temperature under a force of 9 kN. The surface topography, rib profiles, and microstructures of the cross‐sections are measured by scanning electron microscopy, confocal scanning laser microscopy, and optical microscopy, respectively. The interactive effects of the cavity widths of the female die and dual phases on the formability of micro‐embossing are analyzed. Numerical simulations are performed to study the effects of the dual‐phases on the filling behavior of the CG and UFG alloys. The results show that a UFG Mg–Li alloy reduces the adverse effects of dual phases on the formability of micro‐embossing. Micro‐channel arrays with channel widths ranging from 50 to 200 µm are fabricated with good geometrical accuracy using a UFG dual‐phase alloy at ambient temperature, thereby establishing the excellent potential for using UFG dual‐phase Mg–Li alloys processed by HPT for applications in micro‐forming
Raman-based study of micro/nanoscale structure and thermal transport
No full textNanoparticles, two-dimensional (2D) materials, and carbon fibers are widely used in nano electronic devices, aerospace structures due to their extraordinary properties. Among these properties, the surface morphology and the thermal transport are two important properties. The Raman scanning technique is used to characterize the surface morphology. But, the various asymmetries of Raman scattering due to structure variation in space are not considered. The optothermal method based on Raman spectroscopy is widely used to study the thermal transport of these materials. However, a significant drawback of this method is that both temperature and power dependent Raman study should be done to extract the thermal conductivity of the sample. The laser absorption is also subject to very large errors induced by unknown sample-to-sample optical property variation. In addition, for measuring the thermal conductivity of carbon fibers, it is very important to verify whether the thermal conductivities in axial and radial directions are isotropic.
In this work, a Raman scanning technique is developed to explore the asymmetry of Raman scattering signal caused by structure variation in space. A nanosecond energy transport state-resolved Raman (ns ET-Raman) technique is developed to measure the thermal conductivity of suspended 2D atomic-layer molybdenum disulfide (MoS2) and molybdenum diselenide (MoSe2). And a novel method by combining the frequency domain energy transport state-resolved Raman (FET-Raman) technique and the transient electrothermal (TET) technique is developed to measure the anisotropic thermal conductivities of lignin-based microscale carbon fibers. The Raman scanning technique combines the confocal Raman system with a three-dimensional (3D) scanning stage. Silica microparticles, glass micro fibers, and MoSe2 nanosheet are used in the experiments. Three asymmetry types of Raman scattering signal due to physical structure variation in space are discovered, which indicates this technique could be used to study the surface morphology of the sample. In the ns ET-Raman technique, two energy transport states in time domain are constructed to eliminate the need of temperature calibration and laser absorption measurement. The ratio of temperature rise under the two energy transport states is determined by the in-plane thermal conductivity of 2D atomic-layer materials. As a result, the in-plane thermal conductivity could be determined accurately without doing Raman temperature calibration and knowing the laser absorption. Four suspended MoS2 (45 – 115 nm thick) and four suspended MoSe2 (45 – 140 nm thick) samples are characterized using ns ET-Raman. With the increased sample thickness, the measured thermal conductivity increases from 40.0 ± 2.2 to 74.3 ± 3.2 W·m-1·K-1 for MoS2, and from 11.1 ± 0.4 to 20.3 ± 0.9 W·m-1·K-1 for MoSe¬2. This is attributed to the decreased significance of surface phonon scattering in thicker samples. To measure the thermal conductivities in the two directions of carbon fibers, the TET technique is used to measure the axial thermal conductivity of carbon fibers, and the FET-Raman technique is then used to determine the radial thermal conductivity with the measured axial thermal conductivity. Four lignin-based microscale carbon fibers are characterized. The temperature effect on the thermal conductivities in the two directions is also explored. Detailed Raman study of the axial and radial structures uncovers very strong structure anisotropy and explains the observed anisotropic thermal conductivities. The future work about the energy coupling between optical and acoustic phonons under photon excitation is also discussed at the end of this work.</p
Effects of Xinwei granule on expression levels of cyclin D1 and its upstream genes in gastric intraepithelial neoplasia tissues
No full textPurpose: To explore the effects of Xinwei granule (XWG) on low-grade gastric intraepithelial neoplasia (LGIN) and the underlying mechanisms.
Methods: To establish LGIN model, Wistar rats were treated with N-methyl-N'-nitrosoguanidine for 3 months. LGIN model rats were randomly grouped into five groups (n = 15), viz, negative control (NC), normal saline (NS) group, Xinwei granule (XWG) group, Weifuchun tablet (WFCT) group, and vatacoenayme tablet (VT) group. Normal rats (n = 17) served as negative control. Histological evaluation of gastric mucosa was undertaken using hematoxylin and eosin staining. Quantitative realtime polymerase chain reaction (qRT-PCR), western blot, and immunohistochemical assays were performed to determine mRNA expressions, protein expression, and the distribution of cyclin D1, kruppel-like factor 4 (KLF4), and p21-WAF1-CIP1, respectively.
Results: Compared with LGIN group, the body weight of the rats increased in XWG, WFCT, and VT groups. The pathological characteristics of LGIN group were alleviated by XWG, WFCT and VT treatments. The positive expression of cyclin D1 was enhanced in LGIN group, but reduced in XWG, WFCT and VT groups. The expression levels of KLF4 and p21-WAF1-CIP1, upstream regulators of cyclin D1 reduced in LGIN groups. However, administration of XWG, WFCT and VT strengthened the expressions of KLF4 and p21-WAF1-CIP1. More importantly, the protective effects of XWG against LGIN were superior to those of WFCT and VT.
Conclusion: Xinwei granules alleviate LGIN in vivo by inhibiting cyclin D1 expression and enhancing KLF4 and p21-WAF1-CIP1 expression
Multi-pulse time delay integration method for flexible 3D super-resolution range-gated imaging
No full textThermal characterization of nm-thick black phosphorus based on Raman spectroscopy
No full textAs a new two-dimensional material, black phosphorus has attracted worldwide attention due to its extraordinary electronic and optoelectronic properties. Despite its importance for the performance of electronic devices, thermal properties of black phosphorus are still not well studied, which leads to incomplete understanding on phonon transport and interaction in black phosphorus. This is related to difficulties for preparing black phosphorus samples since black phosphorus is easily oxidized in air and the difficulty in characterizing this nm-thin material. In this work, black phosphorus is studied systematically with techniques developed based on Raman spectroscopy. Our study on black phosphorus involves identifying its crystalline orientation and measuring its interface thermal conductance and anisotropic in-plane thermal conductivity.
In this work, the crystalline orientation of black phosphorus is identified with a newly developed technique, optothermal Raman spectroscopy. This technique utilizes the anisotropic heating effect of a linear polarized laser for crystalline orientation identification. It can distinguish the armchair direction and zigzag direction precisely regardless of excitation wavelength and sample thickness. This in-situ and nondestructive technique is required to identify the crystalline orientation of black phosphorus samples before their interface thermal conductance and anisotropic in-plane thermal conductivity are measured. Interface thermal conductance between black phosphorus and Si is measured with micro-Raman spectroscopy. It is found there is large interface thermal conductance between black phosphorus and its adjacent Si, which suggests black phosphorus can be used as new interface material for future devices. Also, interface thermal conductance shows a strong negative correlation to temperature, while no correlation to thickness. These results lead to the discovery of the temperature-related morphological variation of supported black phosphorus on Si. Frequency-resolved Raman spectroscopy is developed to measure the anisotropic in-plane thermal conductivity of black phosphorus. This technique is first used to measure thermal diffusivity of a c-Si cantilever, which has a reference value of thermal diffusivity. The validity of this technique is sufficiently verified since our measured thermal diffusivity is very close to its reference value. Our measurements on black phosphorus with thickness between 99.8 and 157.6 nm show the armchair thermal conductivity is 13.5~22 W m-1 K-1, and the zigzag thermal conductivity is 39.8~62.7 W m-1 K-1. These studies significantly advance our fundamental understanding of phonon transport and interaction in black phosphorus, which can further benefit the development of new-generation devices.</p
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