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Background: Acute lung injury (ALI) is a complex disease with a high mortality. Src homology 2 (SH2)-containing protein tyrosine phosphatase 2 (SHP2) is a protein tyrosine phosphatase that participates in pathogenesis of multiple diseases. Nevertheless, the role of SHP2 in ALI remains unknown. Methods: The in vivo and in vitro lipopolysaccharide (LPS)-induced ALI models were successfully established. The histopathological changes were evaluated by hematoxylin and eosin staining. The vascular permeability of lungs was assessed by Evans blue assay. The expression of ACSL4 and SHP2 was detected by western blot and qRT-PCR assay. The lactate dehydrogenase (LDH) activity, malondialdehyde (MDA), iron, and glutathione (GSH) levels were mea-sured by commercial kits. Results: The SHP2 was upregulated in LPS-induced ALI mice and LPS-stimulated MLE-12 cells. In loss-of function experiment, the knockdown of SHP2 attenuated LPS-induced lung injury, microvessels damage, pulmonary edema, and increase of lung vascular permeability in vivo. Mechanically, shSHP2-rescued LPS induced increase in LDH activity, MDA, and iron levels, and decrease in GSH levels, as well as the accumulation of reactive oxygen species in vivo and in vitro, leading to an alleviation of LPS-induced ferroptosis. Notably, shSHP2 reduced the expression of Acyl-CoA synthetase long-chain 4 (ACSL4). In the rescued experiments, overexpression of ACSL4 abolished the shSHP2-induced reduction of LDH activity, MDA, and iron levels, and increase in GSH levels, thereby aggravating the LPS-induced ferroptosis. Conclusion: These findings concluded that the knockdown of SHP2 attenuated LPS-induced ferroptosis via downregulation of ACSL4 expression in ALI, providing a novel sight for ALI treatment.

Plasmon-induced transparency (PIT) is a key addition to mimicking the quantum phenomena of electromagnetically induced transparency (EIT) in atomic systems. So far, various metamaterial structures have been proposed to excite and manipulate the PIT effect. However, most of the reported works were based on 2-D metal structures, and consequently, the PIT phenomena often arise from their electric responses. Here, we propose a novel PIT metamaterial scheme based on three vertically placed split ring resonators (SRRs) working at terahertz frequencies. This stereo structure, with a typical EIT-like transmission, couples to both the electric and magnetic fields of the normally incident wave. We numerically demonstrate that the coupling between the radiative and subradiative elements can be modulated not only by their mutual separation but also by the vertical height of the SRRs. In addition, a classical Fano resonance model is applied to explain the coupling effects of EIT-like transmission spectra, which is in good accordance with the numerical results. Considering the higher design freedom of the stereo metamaterials, our work provides a promising way for PIT metamaterial and terahertz slow light device research.

Metasurfaces provide an alternative way to design three-dimensional arbitrary-shaped carpet cloaks with ultrathin thicknesses. Nevertheless, the previous metasurface carpet cloaks work only at a single frequency. To overcome this challenge, we here propose a macroscopic metasurface carpet cloak. The cloak is designed with a metasurface of a few layers that exhibit a special spatial distribution of the conductance and inductance in the unit cell; therefore, it can fully control the reflection phases at several independent frequencies simultaneously. Because of this, the present metasurface cloak can work at dual frequencies based on multi-resonance principle. The proposed design methodology will be very useful in future broadband macroscopic cloaks design with low profiles, light weights, and easy access.

A novel broadband and wide-angle 2-bit coding metasurface for radar cross section (RCS) reduction is proposed and characterized at terahertz (THz) frequencies. The ultrathin metasurface is composed of four digital elements based on a metallic double cross line structure. The reflection phase difference of neighboring elements is approximately 90° over a broadband THz frequency. The mechanism of RCS reduction is achieved by optimizing the coding element sequences, which redirects the electromagnetic energies to all directions in broad frequencies. An RCS reduction of less than −10 dB bandwidth from 0.7 THz to 1.3 THz is achieved in the experimental and numerical simulations. The simulation results also show that broadband RCS reduction can be achieved at an incident angle below 60° for TE and TM polarizations under flat and curve coding metasurfaces. These results open a new approach to flexibly control THz waves and may offer widespread applications for novel THz devices.

In this paper, we propose an automatic conversion and verification method based on AADL (Architecture Analysis and Design Language) scheduling model for Embedded Real-Time System using timed automata and the Eclipse plug-in development technology. Firstly, according to the proprieties of AADL scheduling models, the Non-preemptive and preemptive scheduler with periodic and aperiodic thread timed automata templates are designed to guide the transformation from components and properties of AADL models to timed automata. Then, the Eclipse plug-in is designed and integrated into OSATE providing an integrated development environment of modeling, conversion, verification and analysis with UPPAAL. Simulated experiments demonstrate that our proposed method can efficiently perform the conversion and verification of the original AADL scheduling model.

A large scale homogenous invisibility cloak functioning at terahertz frequencies is reported. The terahertz invisibility device features a large concealed volume, low loss, and broad bandwidth. In particular, it is capable of hiding objects with a dimension nearly an order of magnitude larger than that of its lithographic counterpart, but without involving complex and time-consuming cleanroom processing.

Based on a broadband time-domain terahertz radar system, we performed far-field radar cross section measurements of two metal scaled models at terahertz frequencies. The novel broadband radar can provide not only frequency-averaged RCS but also RCS distributions at arbitrary frequency. The measured terahertz RCS of the models can be scaled to that of the full-size real object at conventional radar frequencies. In addition, imaging of the scaled models based on filtered back projection algorithm has been proved to be helpful for finding the main scattering points.

Quasi-three-dimensional invisibility cloaks, comprised of either homogeneous or inhomogeneous media, are experimentally demonstrated in the terahertz regime. The inhomogeneous cloak was lithographically fabricated using a scalable Projection Microstereolithography process. The triangular cloaking structure has a total thickness of 4.4 mm, comprised of 220 layers of 20 μm thickness. The cloak operates at a broad frequency range between 0.3 and 0.6 THz, and is placed over an α-lactose monohydrate absorber with rectangular shape. Characterized using angular-resolved reflection terahertz time-domain spectroscopy, the results indicate that the terahertz invisibility cloak has successfully concealed both the geometrical and spectroscopic signatures of the absorber, making it undetectable to the observer. The homogeneous cloaking device made from birefringent crystalline sapphire features a large concealed volume, low loss, and broad bandwidth. It is capable of hiding objects with a dimension nearly an order of magnitude larger than that of its lithographic counterpart, but without involving complex and time-consuming cleanroom processing. The cloak device was made from two 20-mm-thick high-purity sapphire prisms. The cloaking region has a maximum height 1.75 mm with a volume of approximately 5% of the whole sample. The reflected TM beam from the cloak shows nearly the same profile as that reflected by a flat mirror.

Case-Based Reasoning (CBR) is a most promising direction in artificial intelligence field. To bring actual case reasoning tech into drilling fluid formula optimal design, and to join the actual course, it is the first time to adopt a mixed searching strategy that involves knowledge guided method, nearest neighbor method and improved range similarity match method. To be exact, first to find the similar drilling fluid type, then to modify its performance parameter value till maximum optimized and rematch, finally get the most optimal drilling fluid formula. Such design method can largely improve the efficiency and accuracy of drilling fluid formula.

Abstract In this paper, the effects of drilling fluids on shale strength have been tackled, and a case study has been presented to study the instability mechanism and the stability methodology in the shale formation. A program has been undertaken to develop a better understanding of the effects of the using polymer drilling fluid on the shale mechanical properties and how to modify its performance. Over 20 different drilling fluids were examined for their effects on shale strength. Emphasis here was on the mechanical properties of shale samples after exposed to different drilling fluids for 24 hours. All shale samples selected from similar depth and all tri-axial rock mechanic tests were performed under the conditions of 45MPa confining pressure. The mud which maintains high compressive strength of the shale is the optimum selection. The all shale samples exposed to using polymer drilling fluid exhibit the lowest strength, from the stress-strain curve, almost lost all strength. The use of KCl brine in drilling fluids is based on its shale-inhibition characteristics as it is thought that the k+ ion provides additional attraction among the clay platelets due to its size and charge. However, in Quka shale, the shale samples also lose most part of strength when exposed to the modified using polymer drilling muds only adding 5% KCl and 10% KCl respectively. The one of main possible reasons is Kaolinite in the shale. The shale samples will keep more original strength when exposed to the modified using polymer drilling muds with chemical agents with plugging ability to pore throat and micro-fracture. The all shale samples exposed to using polymer drilling fluid with 10%KCl and 3%A and B% exhibit the highest strength, then it was used to be a new system in drilling 2 new wells. The results show that the drilling fluid density has been decreased largely, and the wellbore stability has been improved remarkably while shale formation is stable. Introduction Wellbore instability is a serious drilling problem. It is reported that shale account for 75% of all formations1 drilled by the oil and gas industry, and 90% of wellbore stability problems1,2 occur in shale formations. The main factors that influence stability of shale formation are related to mechanical properties and physicochemical factors. Shale hydration is the main factor that causes instability problem3. All drilling fluids were found to cause instability problems due to water phase. Gas drilling fluid, oil based drilling fluid or all-oil drilling fluid can minimize the instability problem which is caused by shale hydration. However, we must be sure that there won't meet water zone in gas drilling process, and gas drilling isn't suitable to brittle shale formation, as well as the gas drilling equipment is expensive, so massive compatible analysis should be made in the drilling process. It is no doubt that oil based drilling fluid and all-oil drilling fluid will minimize the instability in shale formation. But oil based drilling fluid can't replace water based drilling fluid due to the environmental restrictions and expensive disposal costs4–6.