Three-Dimensional Simulation of the Shrinkage Behavior of Injection-Molded Poly Lactic Acid (PLA): Effects of Temperature, Shear Rate and Part Thickness

The effects of injection temperature, shear and part thickness on the linear shrinkage of injection-molded poly (lactic acid) (PLA) were intensively analyzed using the Autodesk Moldflow software. The obtained results showed that both melt temperature and shear rate had obvious effects on the linear shrinkage of PLA, i.e., the linear shrinkage of PLA increases significantly with the increase of melt temperature and shear rate. In addition, the shrinkage of high-crystallinity PLA was remarkably larger than that of low-crystallinity PLA, and thin-walled parts was larger than thick-walled ones in shrinkage

A Compact Dual-Polarized Filtering Antenna with Steep Cut-Off for Base-Station Applications

© 2022 IEEE - All rights reserved. This is the accepted manuscript version of an article which has been published in final form at https://doi.org/10.1109/TAP.2022.3161280 ​​​​​​​A dual-polarized filtering antenna with steep cut-off and compact size is developed for base station applications. In this design, four controllable radiation nulls are obtained by utilizing split rings, slotted T-shaped branches, a single-stub tuner, and a parasitic loop. Split rings are firstly used as the dipole arms to obtain the 1st radiation null at upper out-of-band. Four T-shaped branches working as DGS are printed under the crossed dipoles to achieve the 2nd radiation null. The connected outer conductors of the differential feed structure acting as a single-stub tuner can provide the 3rd radiation null to further enhance the upper-band rejection. Finally, a parasitic loop is incorporated around the split rings, and the out-of-band rejection of the lower-band is further enhanced by the 4th radiation null. More importantly, the impedance bandwidth of the antenna can be expended with two newly introduced resonant modes. As a result, a compact filtering antenna with a wide operational bandwidth of 1.7- 3.01 GHz (56%) is realized for |Sdd11| < -15 dB with the isolation higher than 38 dB. The out-of-band suppression is higher than 18.4 dB in 3.1-4.5 GHz and more than 47 dB in 0.8-1.1 GHz.Peer reviewedFinal Accepted Versio

Notch1 Pathway Protects against Burn-Induced Myocardial Injury by Repressing Reactive Oxygen Species Production through JAK2/STAT3 Signaling

Oxidative stress plays an important role in burn-induced myocardial injury, but the cellular mechanisms that control reactive oxygen species (ROS) production and scavenging are not fully understood. This study demonstrated that blockade of Notch signaling via knockout of the transcription factor RBP-J or a pharmacological inhibitor aggravated postburn myocardial injury, which manifested as deteriorated serum CK, CK-MB, and LDH levels and increased apoptosis in vitro and in vivo. Interruption of Notch signaling increased intracellular ROS production, and a ROS scavenger reversed the exacerbated myocardial injury after Notch signaling blockade. These results suggest that Notch signaling deficiency aggravated postburn myocardial injury through increased ROS levels. Notch signaling blockade also decreased MnSOD expression in vitro and in vivo. Notably, Notch signaling blockade downregulated p-JAK2 and p-STAT3 expression. Inhibition of JAK2/STAT3 signaling with AG490 markedly decreased MnSOD expression, increased ROS production, and aggravated myocardial injury. AG490 plus GSI exerted no additional effects. These results demonstrate that Notch signaling protects against burn-induced myocardial injury through JAK2/STAT3 signaling, which activates the expression of MnSOD and leads to decreased ROS levels

Differentially Fed Dual-Band Base Station Antenna with Multimode Resonance and High Selectivity for 5G Applications

A dual-polarized antenna with multimode resonance and high selectivity is proposed in this paper to cover the 5G sub-6 GHz bands. The proposed antenna achieves dual wide impedance bandwidth characteristics by incorporating a dual mode coupled patch and four planar coupled strips around the driven patch. Through the four resonant modes of these structures, the antenna effectively covers the two desired frequency bands. Moreover, the electric/magnetic coupling between the driven patch, dual mode coupled patch, and planar coupled strips enables the creation of three radiation nulls that suppress unwanted radiation. To further improve the out-of-band rejection level and half power beamwidth, four shorted strips are introduced around the radiator. The introduction of these strips results in a 4th radiation null at higher out-of-band frequencies and expands the antenna's half power beamwidth from 52° to 62°. To demonstrate the feasibility of the design, both the proposed antenna and its array were manufactured and tested. Measured results show that the filtering element was able to operate within frequency bands of 3.24-3.83 GHz (16.7%) and 4.74-5.30 GHz (11.2%) with a reference of |Sdd11| < -14 dB. The input ports exhibited a high level of isolation, measuring 40 dB. Furthermore, the four radiation nulls proved effective in suppressing out-of-band radiation

Differential Characterization of Two Kinds of Stem Cells Isolated from Rabbit Nucleus Pulposus and Annulus Fibrosus

Objective. Nucleus pulposus (NP) and annulus fibrosus (AF) are two main components of intervertebral disc (IVD). We aimed to figure out whether NP and AF also contain stem cells and whether these stem cells share common properties with chondrocytes and/or fibroblasts in their phenotypes or whether they are completely different types of cells with different characteristics. Design. The disk cells were isolated from AF and NP tissues of the same lumbar spine of the rabbits. The properties of these disk cells were characterized by their morphology, population doubling time (PDT), stem cell marker expression, and multidifferentiation potential using tissue culture techniques, immunocytochemistry, and RT-PCR. Results. Both disk cells formed colonies in culture and expressed stem cell markers, nucleostemin, Oct-4, SSEA-4, and Stro-1, at early passages. However, after 5 passages, AFSCs became elongated and NPSCs appeared senescent. Conclusion. This study indicated that IVD contains stem cells and the characteristics of AFSCs and NPSCs are intrinsically different. The findings of this study may provide basic scientific data for understanding the properties of IVD cells and the mechanisms of lower back pain

Numerical calculation method for wave loads of floating structures in shallow water

[Objectives] For figuring out the response of floating structures in the waves of shallow water, the main difficulty lies in the accurate solution and efficient calculation of Green's function and its partial derivative of the finite water depth.[Methods] Therefore, a method is proposed to accurately calculate the Green's function and its partial derivative by using the improved Gauss-Laguerre quadrature; then by combining this method with circulant matrix principle, one approach for dealing with symmetry problem and a simplified way of series for solving the formula are given. Finally, the numerical results of this method are compared with those of other commercial software.[Results] The analysis results show that the method proposed in this paper has high accuracy.[Conclusions] This proposed method can be used to accurately estimate motions and wave loads of the floating structures in shallow water

Detecting electronic structure evolution of semiconductor nanocrystals by magnetic circular dichroism spectroscopy

The evolution of electronic states of nanocrystals under shape variation is hardly detected by conventional optical and electronic instruments due to the condensed electronic levels of nanocrystals. Herein, we demonstrate that magnetic circular dichroism (MCD) spectroscopy is a high-resolution method to monitor this delicate progress on account of the sensitive Zeeman response to electronic states. In particular, the MCD intensity of the first excitonic transition exponentially decreases with the shape changing from quantum dots to quantum rods owing to the increased density of valence p(z) state with elongation in the z direction, which contributes much less to MCD intensity compared with p(+/-). This work provides a simple but effective strategy for understanding the electronic state evolution in various semiconductor nanomaterials

Mitochondrial fission factor promotes cisplatin resistance<?A3B2 ACK?>in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the most common primary liver tumor and one of the leading causes of cancer-related death worldwide. Chemotherapeutic agents/regimens such as cisplatin (DDP) are frequently used for advanced HCC treatment. However, drug resistance remains a major hindrance and the underline mechanisms are not fully understood. In this study, we investigated the expression pattern and function of mitochondrial fission factor (Mff) in cisplatin-resistant HCC. We found that Mff is highly expressed in cisplatin-resistant HCC tissues and cell lines. Knockdown of Mff suppresses cell proliferation and promotes cell apoptosis of HCC/DDP cells. In addition, knockdown of Mff sensitizes Huh-7/DDP cells to cisplatin treatment, inhibits cell proliferation, migration and invasion, and enhances cell apoptosis. Confocal imaging showed that knockdown of Mff inhibits the mitochondrial fission and downregulates the expression of GTPase dynamin-related protein 1 (Drp1) in cisplatin-resistant Huh-7/DDP cells. Moreover, xenograft tumor model revealed that knockdown of Mff sensitizes Huh-7/DDP xenograft tumor to cisplatin treatment in vivo. In summary, our findings suggest that Mff regulates mitochondrial Drp1 expression and promotes cisplatin resistance in HCC, which provides a potential therapeutic target for the treatment of cisplatin-resistant HCC

Autologous Scar-Related Tissue Combined with Skin Grafting for Reconstructing Large Area Burn Scar

Background This study introduced a novel method to reconstruct large areas of scarring caused by burns via combining autologous scar-related tissue with spit-thickness skin grafting (ASTCS). Methods 25 patients underwent reconstruction after scar resection surgeries around the joints were analyzed between Jan 2012 and Jan 2018. Patient demographics and clinical parameters were collected, autologous scar-related tissue was modified to meshed structure, and the split-thickness skin was acquired from the scalp. The scar was resected and punched by a meshing machine with a thickness of 0.3–0.5 mm at a ratio of 1:1. The secondary wounds were covered by the epidermis from a donor site. The surgical areas were bandaged for 7–10 days before the first dressing change. Results 25 patients (mean [SD] age, 26.4 [18.8] years; 16 [64%] men) underwent wounds reconstructive operations due to scar resection were reviewed. Wound location of 9 (22%), 8 (19.5%), 9 (22%), 7 (17.1%) and 8 (19.5%) cases were reconstructed in axillary, hand and wrist, popliteal fossa, elbow and neck, respectively. 39 sites of transplanted tissues survived well, and 2 sites were cured after two weeks of dressing changes. Except the analysis of injury causes, nutritional status, wound area and hospital days, patients with scar deformities in joint areas achieved satisfactory function by assessing the Vancouver Burn Skin Score and the Barthel Index Scale Scores after 12-month follow-up. Conclusions Combining autologous scar-related tissue with skin grafting provided a novel method for treating large areas of burn scars with better functional outcomes

ROS-Mediated NLRP3 Inflammasome Activity Is Essential for Burn-Induced Acute Lung Injury

The NLRP3 inflammasome is necessary for initiating acute sterile inflammation. However, its role in the pathogenesis of burn-induced acute lung injury (ALI) is unknown. This study aimed to determine the role of the NLRP3 inflammasome and the signaling pathways involved in burn-induced ALI. We observed that the rat lungs exhibited enhanced inflammasome activity after burn, as evidenced by increased levels of NLRP3 expression and Caspase-1 activity and augmented inflammatory cytokines. Inhibition of NLRP3 inflammasome by BAY11-7082 attenuated burn-induced ALI, as demonstrated by the concomitant remission of histopathologic changes and the reduction of myeloperoxidase (MPO) activity, inflammatory cytokines in rat lung tissue, and protein concentrations in the bronchoalveolar lavage fluid (BALF). In the in vitro experiments, we used AMs (alveolar macrophages) challenged with burn serum to mimic the postburn microenvironment and noted that the serum significantly upregulated NLRP3 inflammasome signaling and reactive oxygen species (ROS) production. The use of ROS scavenger N-acetylcysteine (NAC) partially reversed NLRP3 inflammasome activity in cells exposed to burn serum. These results indicate that the NLRP3 inflammasome plays an essential role in burn-induced ALI and that burn-induced NLRP3 inflammasome activity is a partly ROS-dependent process. Targeting this axis may represent a promising therapeutic strategy for the treatment of burn-induced ALI