Sidewall Corrugation-Modulated Phase-Apodized Silicon Grating Filter.

In this work, phase-apodized silicon grating filters with varying sidewall corrugation width and location were investigated, while the resonance wavelength, extinction ratio, and rejection bandwidth were tuned flexibly. The grating filters with a waveguide width of 500 nm and grating period of 400 nm were fabricated and characterized as a proof of concept. The resonance wavelength of the device can be shifted by 4.54 nm by varying the sidewall corrugation width from 150 to 250 nm. The corresponding rejection bandwidth can be changed from 1.19 to 2.03 nm by applying a sidewall corrugation location offset from 50 to 200 nm. The experimental performances coincide well with the simulation results. The presented sidewall corrugation-modulated apodized grating can be expected to have great application prospects for optical communications and semiconductor lasers.

1D/2D Heterostructured WS2@PANI Composite for Highly Sensitive, Flexible, and Room Temperature Ammonia Gas Sensor.

Flexible and room-temperature (RT) ammonia gas sensors are needed for exhaled breath detection and recognition. Two-dimensional transition metal disulfides are potential materials for RT gas sensing because of their low band gap and a large number of edge-exposed sites that can provide strong binding to gas molecules. In this work, a 1D/2D heterostructured composite material of 2D tungsten disulfide (WS2) modified with 1D polyaniline (PANI) was proposed. The fibrous PANI adsorbed on the edges and inserted in the interlayers of the laminated WS2 provide more diffusion channels for the ammonia gas and act as sensing sites. The WS2@PANI-based sensor shows high selectivity for ammonia with satisfying reproducibility and long-term stability. A response of 216.3% and a short response/recovery time of 25 s/39 s were achieved for 100 ppm ammonia gas. The sensing mechanism was investigated in detail via complex impedance spectra and in situ FT-IR, which was attributed to the synergistic effect of WS2 and PANI. The excellent sensing performance coupled with its resistance to thermal and humidity interference endows the WS2@PANI-based sensor with potential for human exhaled detection and wearable electronics.

Expression of four cancer-testis antigens in TNBC indicating potential universal immunotherapeutic targets.

OBJECTIVE: Immunotherapy is an attractive treatment for breast cancer. Cancer-testis antigens (CTAs) are potential targets for immunotherapy for their restricted expression. Here, we investigate the expression of CTAs in breast cancer and their value for prognosis. So as to hunt for a potential panel of CTAs for universal immunotherapeutic targets. MATERIAL AND METHODS: A total of 137 breast cancer tissue specimens including 51 triple-negative breast cancer (TNBC) were assessed for MAGE-A4, MAGEA1, NY-ESO-1, KK-LC-1 and PRAME expression by immunohistochemistry. The expression of PD-L1 and TILs was also calculated and correlated with the five CTAs. Clinical data were collected to evaluate the CTA's value for prognosis. Data from the K-M plotter were used as a validation cohort. RESULTS: The expression of MAGE-A4, NY-ESO-1 and KK-LC-1 in TNBC was significantly higher than in non-TNBC (P = 0.012, P = 0.005, P < 0.001 respectively). 76.47% of TNBC expressed at least one of the five CTAs. Patients with positive expression of either MAGE-A4 or PRAME had a significantly extended disease-free survival (DFS). Data from the Kaplan-Meier plotter confirm our findings. CONCLUSIONS: MAGE-A4, NY-ESO-1, PRAME and KK-LC-1 are overexpressed in breast cancer, especially in TNBC. Positive expression of MAGE-A4 or PARME may be associated with prolonged DFS. A panel of CTAs is attractive universal targets for immunotherapy.

Flexible Humidity Sensor with High Sensitivity and Durability for Respiratory Monitoring Using Near-Field Electrohydrodynamic Direct-Writing Method.

The humidity of breath can serve as an important health indicator, providing crucial clinical information about human physiology. Significant progress had been made in the development of flexible humidity sensors. However, improving its humidity sensing performance (sensitivity and durability) is still facing many challenges. In this work, near-field electrohydrodynamic direct writing (NFEDW) was proposed to fabricate humidity sensors with high sensitivity and durability for respiration monitoring. Due to the applied electric field, dense carbon nanotube/cellulose nanofiber (CNT/CNF) networks formed during the printing process that enhance the sensitivity of the sensor. The prepared sensor showed excellent humidity responses, with a maximum response value of 61.5% (ΔR/R0) at 95% relative humidity (RH). Additionally, the sensitivity film prepared by the NFEDW method closely fits the poly(ethylene terephthalate) (PET) substrate, endowing the sensor with outstanding bending (with a maximum curvature of 4.7 cm-1) and folding durability (up to 50 times). The sensitivity of the prepared sensor under different simulated conditions, namely, nose breathing, mouth breathing, coughing, yawning, breath holding, and speaking, was excellent, demonstrating the potential of the sensor for the real-time monitoring of human breath humidity. Thus, the high-performance flexible humidity sensor is suitable for human respiration and health monitoring.

Cancer Cell Membrane-Coated Gambogic Acid Nanoparticles for Effective Anticancer Vaccination by Activating Dendritic Cells.

Purpose: Recent studies have shown that traditional Chinese medicine (TCM), such as gambogic acid (GA), is involved in the regulation of tumor immune microenvironment and can be combined with other anti-tumor treatment strategies. Here, we used GA as an adjuvant to construct a nano-vaccine to improve the anti-tumor immune response of colorectal cancer (CRC). Materials and Methods: We used a previously reported two-step emulsification method to obtain poly (lactic-co-glycolic acid) /GA nanoparticles (PLGA/GA NPs), and then CT26 colon cancer cell membrane (CCM) was used to obtain CCM-PLGA/GA NPs. This novel nano-vaccine, CCM-PLGA/GA NPs, was co-synthesized with GA as an adjuvant and neoantigen provided by CT26 CCM. We further confirmed the stability, tumor targeting, and cytotoxicity of CCM-PLGA/GA NPs. The regulatory effect on the tumor immune microenvironment, the anti-tumor efficacy, and the combined anti-tumor efficacy with anti-PD-1 monoclonal Antibodies (mAbs) of this novel nano-vaccine was also detected in vivo. Results: We successfully constructed the CCM-PLGA/GA NPs. In vitro and in vivo tests showed low biological toxicity, as well as the high tumor-targeting ability of the CCM-PLGA/GA NPs. Besides, we revealed a remarkable effect of CCM-PLGA/GA NPs to activate the maturation of dendritic cells (DCs) and the formation of a positive anti-tumor immune microenvironment. Conclusion: This novel nano-vaccine constructed with GA as the adjuvant and CCM providing the tumor antigen can not only directly kill tumors by enhancing the ability of GA to target tumors, but also indirectly kill tumors by regulating tumor immune microenvironment, providing a new strategy for immunotherapy of CRC.

High-Performance Flexible Piezoresistive Pressure Sensor Printed with 3D Microstructures.

Flexible pressure sensors have been widely used in health detection, robot sensing, and shape recognition. The micro-engineered design of the intermediate dielectric layer (IDL) has proven to be an effective way to optimize the performance of flexible pressure sensors. Nevertheless, the performance development of flexible pressure sensors is limited due to cost and process difficulty, prepared by inverted mold lithography. In this work, microstructured arrays printed by aerosol printing act as the IDL of the sensor. It is a facile way to prepare flexible pressure sensors with high performance, simplified processes, and reduced cost. Simultaneously, the effects of microstructure size, PDMS/MWCNTs film, microstructure height, and distance between the microstructures on the sensitivity and response time of the sensor are studied. When the microstructure size, height, and distance are 250 µm, 50 µm, and 400 µm, respectively, the sensor shows a sensitivity of 0.172 kPa-1 with a response time of 98.2 ms and a relaxation time of 111.4 ms. Studies have proven that the microstructured dielectric layer printed by aerosol printing could replace the inverted mold technology. Additionally, applications of the designed sensor are tested, such as the finger pressing test, elbow bending test, and human squatting test, which show good performance.

Electrospun PA66/Graphene Fiber Films and Application on Flexible Triboelectric Nanogenerators.

Triboelectric nanogenerators (TENGs) are considered to be the most promising energy supply equipment for wearable devices, due to their excellent portability and good mechanical properties. Nevertheless, low power generation efficiency, high fabrication difficulty, and poor wearability hinder their application in the wearable field. In this work, PA66/graphene fiber films with 0, 1 wt%, 1.5 wt%, 2 wt%, 2.5 wt% graphene and PVDF films were prepared by electrospinning. Meanwhile, TENGs were prepared with PA66/graphene fiber films, PVDF films and plain weave conductive cloth, which were used as the positive friction layer, negative friction layer and the flexible substrate, respectively. The results demonstrated that TENGs prepared by PA66/graphene fiber films with 2 wt% grapheme showed the best performance, and that the maximum open circuit voltage and short circuit current of TENGs could reach 180 V and 7.8 µA, respectively, and that the power density was 2.67 W/m2 when the external load was 113 MΩ. This is why the PA66/graphene film produced a more subtle secondary network with the addition of graphene, used as a charge capture site to increase its surface charge. Additionally, all the layered structures of TENGs were composed of breathable electrospun films and plain conductive cloth, with water vapor transmittance (WVT) of 9.6 Kgm-2d-1, reflecting excellent wearing comfort. The study showed that TENGs, based on all electrospinning, have great potential in the field of wearable energy supply devices.

Effects of Three-Dimensional Circular Truncated Cone Microstructures on the Performance of Flexible Pressure Sensors.

Three-dimensional microstructures play a key role in the fabrication of flexible electronic products. However, the development of flexible electronics is limited in further applications due to low positioning accuracy, the complex process, and low production efficiency. In this study, a novel method for fabricating three-dimensional circular truncated cone microstructures via low-frequency ultrasonic resonance printing is proposed. Simultaneously, to simplify the manufacturing process of flexible sensors, the microstructure and printed interdigital electrodes were fabricated into an integrated structure, and a flexible pressure sensor with microstructures was fabricated. Additionally, the effects of flexible pressure sensors with and without microstructures on performance were studied. The results show that the overall performance of the designed sensor with microstructures could be effectively improved by 69%. Moreover, the sensitivity of the flexible pressure sensor with microstructures was 0.042 kPa-1 in the working range of pressure from 2.5 to 10 kPa, and the sensitivity was as low as 0.013 kPa-1 within the pressure range of 10 to 30 kPa. Meanwhile, the sensor showed a fast response time, which was 112 ms. The stability remained good after the 100 cycles of testing. The performance was better than that of the flexible sensor fabricated by the traditional inverted mold method. This lays a foundation for the development of flexible electronic technology in the future.

Flexible pressure sensors via engineering microstructures for wearable human-machine interaction and health monitoring applications.

Flexible pressure sensors capable of transducing pressure stimuli into electrical signals have drawn extensive attention owing to their potential applications for human-machine interaction and healthcare monitoring. To meet these application demands, engineering microstructures in the pressure sensors are an efficient way to improve key sensing performances, such as sensitivity, linear sensing range, response time, hysteresis, and durability. In this review, we provide an overview of the recent advances in the fabrication and application of high-performance flexible pressure sensors via engineering microstructures. The implementation mechanisms and fabrication strategies of microstructures including micropatterned, porous, fiber-network, and multiple microstructures are systematically summarized. The applications of flexible pressure sensors with microstructures in the fields of wearable human-machine interaction, and ex vivo and in vivo healthcare monitoring are comprehensively discussed. Finally, the outlook and challenges in the future improvement of flexible pressure sensors toward practical applications are presented.

Preparation of Bimodal Silver Nanoparticle Ink Based on Liquid Phase Reduction Method.

Improving the conductivity of metal particle inks is a hot topic of scientific research. In this paper, a method for preparing metal-filled particles was proposed. By adding filled particles to the ink, the size distribution of particles could be changed to form a bimodal distribution structure in accordance with Horsfield's stacking model. The filling particles had small volume and good fluidity, which could fill the gaps between the particles after printing and improve its electrical conductivity without significantly changing the metal solid content in the ink. Experimental results show that the silver content of the ink slightly increased from 15 wt% to 16.5 wt% after adding filled particles. However, the conductivity of the ink was significantly improved, and after sintering, the resistivity of the ink decreased from 70.2 µΩ∙cm to 31.2 µΩ∙cm. In addition, the filling particles prepared by this method is simple and has a high material utilization rate, which could be applied to the preparation of other kinds of metal particle inks.

Silicon Nanowire-Assisted High Uniform Arrayed Waveguide Grating.

Determining how to improve the non-uniformity of arrayed waveguide grating (AWG) is of great significance for dense wavelength division multiplexing (DWDM) systems. In this work, a silicon nanowire-assisted AWG structure is proposed, which can achieve high uniformity with a low insertion loss. The article compares the effect of nanowire number and shape on uniformity and insertion loss, finding that double nanowires provide the best performance. Double nanowires with a width of 230 nm and length of 3.5 µm can consist of a slot configuration between arrayed waveguides, both connecting to the star coupler and spacing 165 nm from the waveguides. Compared with conventional 8- and 16-channel AWGs with channel spacing of 200 GHz, the non-uniformity of the presented structure can be improved from 1.09 and 1.6 dB to 0.24 and 0.63 dB, respectively. The overall footprint of the device would remain identical, which is 276 × 299 or 258 × 303 µm2 for the 8- or 16-channel AWG. The present high uniformity design is simple and easy to fabricate without any additional insertion loss, which is expected to be widely applied in the highly integrated DWDM systems.

High performance polypyrrole/SWCNTs composite film as a promising organic thermoelectric material.

Conducting polymer thermoelectric (TE) materials have received great attention due to their unique properties. In this work, polypyrrole (PPy)/single-walled carbon nanotubes (SWCNTs) composite films with improved TE performance have been prepared by chemical interfacial polymerization at the cyclohexane/water interface under a controlled temperature. Attributed to the smooth surface, higher conjugation length and more ordered molecular structure of the interfacial polymerized PPy film, the electrical conductivity can be as high as ∼500 S cm-1. To further enhance the TE properties of PPy, SWCNT was added to construct a PPy/SWCNTs composite. Due to the synergistic effect between the two phases and the energy filtering effect at the interfaces between PPy and SWCNTs, the Seebeck coefficient of the composite enhanced significantly with the increase SWCNTs content. The composite shows an optimal power factor of 37.6 ± 2.3 µW mK-2 when the content of SWCNTs is 0.8 mg. This value is one of the largest values among the reported PPy based composites fabricated by the chemical polymerization method. The results indicate that interfacial polymerization under a controlled temperature is a promising way to improve the TE performance of conducting polymer based composite materials.

Meta-Analysis of CTLA-4 +49 Gene Polymorphism and Susceptibility to Graves' Disease.

Cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) plays an important role in the initiation and development of Graves' disease (GD), especially CTLA-4 +49A/G polymorphism and genetic susceptibility to GD. However, the current conclusions are consistent. Therefore, this study adopted meta-analysis method to assess the exact correlation between this polymorphism and GD risk. METHODS: Literature searches were performed in PubMed, Embase, Web of Science, China National Knowledge Infrastructure, China Wanfang, and other databases for data on the correlation between polymorphisms of CTLA-4 +49A/G and GD risk. The end date for publications was May 2020. Stata 15.0 software was used for data analysis. RESULTS: A total of 33 papers were included, covering 8,555 cases and 9,533 controls. The results showed that the CTLA-4 +49 allele G compared to allele A, odds ratio (OR) = 1.62, 95% CI [1.56, 2.09]. In the dominant, recessive, homozygous, and heterozygous genetic models, comparing the GD group and the control group, the combined OR was 1.81, 95% CI [1.56, 2.09]; 1.91, 95% CI [1.66, 2.21]; 2.75, 95% CI, [2.21, 3.41]; and 1.49, 95% CI [1.29, 1.71], respectively. When it was analyzed by dividing genetic models into subgroups according to ethnicity and published year, the data the of genetic model in each subgroup were also statistically significant. CONCLUSION: The CTLA-4 +49A/G polymorphism was strongly associated with genetic susceptibility to GD. Allele G, genotypes GG, GG + GA, and GA are correlated with an increase in the risk of GD.

Transport of polymer-modified nanoparticles in nanochannels coated with polymers.

Using molecular dynamics simulations based on explicit-solvent model, we study migration of polymer-modified nanoparticles through nanochannels coated with polymers. The polymers densely grafted on the spherical nanoparticle and the channel surface form spherical polymer brush (SPB) and planar polymer brush (PPB), respectively. The migration of the neutral polymer-modified nanoparticle is driven by electroosmotic flow (EOF). The effects of the electric field strength and the SPB-PPB interaction on polymer conformations and transport dynamics of the SPB are explored. The migration velocity of the SPB reduces as the interaction between the SPB and the PPB increases. For strong SPB-PPB interaction, the directional migration of the SPB can be triggered only after the electric field strength exceeds a critical value. The high EOF velocity forces the center of mass of the spherical nanoparticle to keep near the central region of the channel due to high shear rate close to the brush-fluid interface. Unlike electrophoresis of charged polymer-grafted spherical particles, the SPB adopts a more extended conformation in the plane perpendicular to the EOF direction.

Ion-Specific Effects on the Elongation Dynamics of a Nanosized Water Droplet in Applied Electric Fields.

We report an all-atom molecular dynamics study of the structures and dynamics of salty water droplets on a silicon surface under the influence of applied electric field. Our simulation results support ion-specific effects on the elongation dynamics of salty nanodroplets, induced by the field. This feature has not been explored up to now in monovalent salts. Nevertheless, the importance of ion-specific effects is widely confirmed in biological and colloidal systems. In particular, the increase of salt concentration enhances the effect of the nature of ions on the wetting properties of droplets. In the presence of electric field (0.05 V Å-1), a complete spreading is implemented in a short time for different droplets at a concentration of 1 M, and the droplet morphology is stable, observed at long time scales. However, a higher salt concentration of 4 M considerably suppresses the spreading process owing to the increase of surface tension. It was found that the NaCl droplet shows deformation oscillations along the external field, but cannot fully wet the substrate surface. By contrast, the CsCl droplet reaches complete elongation rapidly and adopts a steady strip shape. The KCl droplet undergoes frequent transitions between breakup and connection. Additionally, the droplets can be elongated only when the electric field strength exceeds a threshold value. The dipole orientation of interfacial water and the ionic diffusion exhibit ion-specific dependences, but the hydrogen bond network is scarcely disturbed, excluding a concentration-dependent effect.