Low-Temperature Resistant Stretchable Micro-Supercapacitor Based on 3D Printed Octet-Truss Design.

Recently, stretchable micro-supercapacitors (MSCs) that can be easily integrated into electronic devices have attracted research and industrial attentions. In this work, three-dimensional (3D) stretchable MSCs with an octet-truss electrode (OTE) design have been demonstrated by a rapid digital light processing (DLP) process. The 3D-printed electrode structure is beneficial for electrode-electrolyte interface formation and consequently increases the number of ions adsorbed on the electrode surface. The designed MSCs can achieve a high capacitance as ≈74.76 mF cm-3 under 1 mA cm-3 at room temperature even under a high mechanical deformation, and can achieve 19.53 mF cm-3 under 0.1 mA cm-3 at a low temperature (-30 °C). Moreover, finite element analysis (FEA) reveals the OTE structure provides 8 times more contact area per unit volume at the electrode-electrolyte interface compared to the traditional interdigital electrode (IDE). This work combines structural design and 3D printing techniques, which provides new insights into highly stretchable MSCs for next-generation electronic devices.

Multimaterial Three-Dimensional Printing of Ultraviolet-Curable Ionic Conductive Elastomers with Diverse Polymers for Multifunctional Flexible Electronics.

Ionic conductive elastomers (ICEs) are emerging stretchable and ionic conductive materials that are solvent-free and thus demonstrate excellent thermal stability. Three-dimensional (3D) printing that creates complex 3D structures in free forms is considered as an ideal approach to manufacture sophisticated ICE-based devices. However, the current technologies constrain 3D printed ICE structures in a single material, which greatly limits functionality and performance of ICE-based devices and machines. Here, we report a digital light processing (DLP)-based multimaterial 3D printing capability to seemly integrate ultraviolet-curable ICE (UV-ICE) with nonconductive materials to create ionic flexible electronic devices in 3D forms with enhanced performance. This unique capability allows us to readily manufacture various 3D flexible electronic devices. To demonstrate this, we printed UV-ICE circuits into polymer substrates with different mechanical properties to create resistive strain and force sensors; we printed flexible capacitive sensors with high sensitivity (2 kPa-1) and a wide range of measured pressures (from 5 Pa to 550 kPa) by creating a complex microstructure in the dielectric layer; we even realized ionic conductor-activated four-dimensional (4D) printing by printing a UV-ICE circuit into a shape memory polymer substrate. The proposed approach paves a new efficient way to realize multifunctional flexible devices and machines by bonding ICEs with other polymers in 3D forms.

How to select the quantitative magnetic resonance technique for subjects with fatty liver: A systematic review.

BACKGROUND: Early quantitative assessment of liver fat content is essential for patients with fatty liver disease. Mounting evidence has shown that magnetic resonance (MR) technique has high accuracy in the quantitative analysis of fatty liver, and is suitable for monitoring the therapeutic effect on fatty liver. However, many packaging methods and postprocessing functions have puzzled radiologists in clinical applications. Therefore, selecting a quantitative MR imaging technique for patients with fatty liver disease remains challenging. AIM: To provide information for the proper selection of commonly used quantitative MR techniques to quantify fatty liver. METHODS: We completed a systematic literature review of quantitative MR techniques for detecting fatty liver, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses protocol. Studies were retrieved from PubMed, Embase, and Cochrane Library databases, and their quality was assessed using the Quality Assessment of Diagnostic Studies criteria. The Reference Citation Analysis database (https:// www.referencecitationanalysis.com) was used to analyze citation of articles which were included in this review. RESULTS: Forty studies were included for spectroscopy, two-point Dixon imaging, and multiple-point Dixon imaging comparing liver biopsy to other imaging methods. The advantages and disadvantages of each of the three techniques and their clinical diagnostic performances were analyzed. CONCLUSION: The proton density fat fraction derived from multiple-point Dixon imaging is a noninvasive method for accurate quantitative measurement of hepatic fat content in the diagnosis and monitoring of fatty liver progression.

Directly Printed Embedded Metal Mesh for Flexible Transparent Electrode via Liquid Substrate Electric-Field-Driven Jet.

Flexible transparent electrodes (FTEs) with embedded metal meshes play an indispensable role in many optoelectronic devices due to their excellent mechanical stability and environmental adaptability. However, low-cost, simple, efficient, and environmental friendly integrated manufacturing of high-performance embedded metal meshes remains a huge challenge. Here, a facile and novel fabrication method is proposed for FTEs with an embedded metal mesh via liquid substrateelectric-field-driven microscale 3D printing process. This direct printing strategy avoids tedious processes and offers low-cost and high-volume production, enabling the fabrication of high-resolution, high-aspect ratio embedded metal meshes without sacrificing transparency. The final manufactured FTEs with 80 mm × 80 mm embedded metal mesh offers excellent optoelectronic performance with a sheet resistance (Rs ) of 6 Ω sq-1 and a transmittance (T) of 85.79%. The embedded metal structure still has excellent mechanical stability and good environmental suitability under different harsh working conditions. The practical feasibility of the FTEs is successfully demonstrated with a thermally driven 4D printing structure and a resistive transparent strain sensor. This method can be used to manufacture large areas with facile, high-efficiency, low-cost, and high-performance FTEs.

3D Printed High Performance Silver Mesh for Transparent Glass Heaters through Liquid Sacrificial Substrate Electric-Field-Driven Jet.

Transparent glass with metal mesh is considered a promising strategy for high performance transparent glass heaters (TGHs). However, the realization of simple, low-cost manufacture of high performance TGHs still faces great challenges. Here, a technique for the fabrication of high performance TGHs is proposed using liquid sacrificial substrate electric-field-driven (LS-EFD) microscale 3D printing of thick film silver paste. The liquid sacrificial substrate not only significantly improves the aspect ratio (AR) of silver mesh, but also plays a positive role in printing stability. The fabricated TGHs with a line width of 35 µm, thickness of 12.3 µm, and pitch of 1000 µm exhibit a desirable optoelectronic performance with sheet resistance (Rs ) of 0.195 Ω sq-1 and transmittance (T) of 88.97%. A successful deicing test showcases the feasibility and practicality of the manufactured TGHs. Moreover, an interface evaporator is developed for the coordination of photothermal and electrothermal systems based on the high performance TGHs. The vapor generation rate of the device reaches 10.69 kg m-2 h-1 with a voltage of 2 V. The proposed technique is a promising strategy for the cost-effective and simple fabrication of high performance TGHs.

Clinical efficacy of immunotherapy combined with chemotherapy in patients with advanced gastric cancer, its effect on nutritional status and Changes of peripheral blood T lymphocyte subsets.

OBJECTIVES: To evaluate the clinical efficacy of immunotherapy combined with chemotherapy in patients with advanced gastric cancer and its effect on nutritional status and changes of peripheral blood T lymphocyte subsets. METHODS: Sixty patients with locally advanced gastric cancer who were admitted by Affiliated Hospital of Hebei University from March 2020 to February 2021 were enrolled and randomly divided into two groups, with 30 cases in each group. The control group was treated with FOLFOX4 chemotherapy, while the experimental group was additively treated with cindilizumab on the basis of control group. The incidence of adverse reactions, clinical efficacy, improvement of nutritional and physical status, and changes in the levels of T lymphocyte subgroups in the two groups were compared and analyzed. RESULTS: The total effective rate was 70% in the experimental group, which was better than 43.3% of the control group (p=0.04). The improvement rate of performance status (ECOG) score and nutritional indicators in the experimental group was significantly better than that in the control group (p<0.05). Moreover, the indicators of CD3+, CD4+, CD4+/CD8+ in the experimental group were significantly higher than those in the control group after treatment, with statistically significant differences (CD3+, p=0.01; CD4 +, p= 0.02; CD4+/CD8+, p=0.01). CONCLUSION: Immunotherapy combined with chemotherapy has a significant effect on locally advanced gastric cancer patients, with significant improvement in physical strength and nutritional status, significant improvement in T lymphocyte function, and no obvious adverse reactions. It is worth promoting in clinical application.

3D Printing of a PDMS Cylindrical Microlens Array with 100% Fill-Factor.

Cylindrical microlens arrays (CMLAs) play a key role in many optoelectronic devices, and 100% fill-factor CMLAs also have the advantage of improving the signal-to-noise ratio and avoiding stray-light effects. However, the existing preparation technologies are complicated and costly, which are not suitable for mass production. Herein, we propose a simple, efficient, and low-cost manufacturing method for CMLAs with a high fill-factor via the electric-field-driven (EFD) microscale 3D printing of polydimethylsiloxane (PDMS). By adjusting the printing parameters, the profile and the fill-factor of the CMLAs can be controlled to improve their optical performance. The optical performance test results show that the printed PDMS CMLAs have good image-projecting and light-diffraction properties. Using the two printing modes of this EFD microscale 3D-printing technology, a cylindrical dual-microlens array with a double-focusing function is simply prepared. At the same time, we print a series of specially shaped microlenses, proving the flexible manufacturing capabilities of this technology. The results show that the prepared CMLAs have good morphology and optical properties. The proposed method may provide a viable route for manufacturing large-area CMLAs with 100% fill-factor in a very simple, efficient, and low-cost manner.

Mechanically Robust and UV-Curable Shape-Memory Polymers for Digital Light Processing Based 4D Printing.

4D printing is an emerging fabrication technology that enables 3D printed structures to change configuration over "time" in response to an environmental stimulus. Compared with other soft active materials used for 4D printing, shape-memory polymers (SMPs) have higher stiffness, and are compatible with various 3D printing technologies. Among them, ultraviolet (UV)-curable SMPs are compatible with Digital Light Processing (DLP)-based 3D printing to fabricate SMP-based structures with complex geometry and high-resolution. However, UV-curable SMPs have limitations in terms of mechanical performance, which significantly constrains their application ranges. Here, a mechanically robust and UV-curable SMP system is reported, which is highly deformable, fatigue resistant, and compatible with DLP-based 3D printing, to fabricate high-resolution (up to 2 µm), highly complex 3D structures that exhibit large shape change (up to 1240%) upon heating. More importantly, the developed SMP system exhibits excellent fatigue resistance and can be repeatedly loaded more than 10 000 times. The development of the mechanically robust and UV-curable SMPs significantly improves the mechanical performance of the SMP-based 4D printing structures, which allows them to be applied to engineering applications such as aerospace, smart furniture, and soft robots.

Templateless, Plating-Free Fabrication of Flexible Transparent Electrodes with Embedded Silver Mesh by Electric-Field-Driven Microscale 3D Printing and Hybrid Hot Embossing.

Flexible transparent electrodes (FTEs) with an embedded metal mesh are considered a promising alternative to traditional indium tin oxide (ITO) due to their excellent photoelectric performance, surface roughness, and mechanical and environmental stability. However, great challenges remain for achieving simple, cost-effective, and environmentally friendly manufacturing of high-performance FTEs with embedded metal mesh. Herein, a maskless, templateless, and plating-free fabrication technique is proposed for FTEs with embedded silver mesh by combining an electric-field-driven (EFD) microscale 3D printing technique and a newly developed hybrid hot-embossing process. The final fabricated FTE exhibits superior optoelectronic properties with a transmittance of 85.79%, a sheet resistance of 0.75 Ω sq-1 , a smooth surface of silver mesh (Ra  ≈ 18.8 nm) without any polishing treatment, and remarkable mechanical stability and environmental adaptability with a negligible increase in sheet resistance under diverse cyclic tests and harsh working conditions (1000 bending cycles, 80 adhesion tests, 120 scratch tests, 100 min ultrasonic test, and 72 h chemical attack). The practical viability of this FTE is successfully demonstrated with a flexible transparent heater applied to deicing. The technique proposed offers a promising fabrication strategy with a cost-effective and environmentally friendly process for high-performance FTE.

Fractal-Based Stretchable Circuits via Electric-Field-Driven Microscale 3D Printing for Localized Heating of Shape Memory Polymers in 4D Printing.

Thermally responsive shape memory polymers (SMPs) used in 4D printing are often reported to be activated by external heat sources or embedded stiff heaters. However, such heating strategies impede the practical application of 4D printing due to the lack of precise control over heating or the limited ability to accommodate the stretching during shape programming. Herein, we propose a novel 4D printing paradigm by fabricating stretchable heating circuits with fractal motifs via electric-field-driven microscale 3D printing of conductive paste for seamless integration into 3D printed structures with SMP components. By regulating the fractal order and printing/processing parameters, the overall electrical resistance and areal coverage of the circuits can be tuned to produce an efficient and uniform heating performance. Compared with serpentine structures, the resistance of fractal-based circuits remains relatively stable under both uniaxial and biaxial stretching. In practice, steady-state and transient heating modes can be respectively used during the shape programming and actuation phases. We demonstrate that this approach is suitable for 4D printed structures with shape programming by either uniaxial or biaxial stretching. Notably, the biaxial stretchability of fractal-based heating circuits enables the shape change between a planar structure and a 3D one with double curvature. The proposed strategy would offer more freedom in designing 4D printed structures and enable the manipulation of the latter in a controlled and selective manner.

3D printing of highly stretchable hydrogel with diverse UV curable polymers.

Hydrogel-polymer hybrids have been widely used for various applications such as biomedical devices and flexible electronics. However, the current technologies constrain the geometries of hydrogel-polymer hybrid to laminates consisting of hydrogel with silicone rubbers. This greatly limits functionality and performance of hydrogel-polymer-based devices and machines. Here, we report a simple yet versatile multimaterial 3D printing approach to fabricate complex hybrid 3D structures consisting of highly stretchable and high-water content acrylamide-PEGDA (AP) hydrogels covalently bonded with diverse UV curable polymers. The hybrid structures are printed on a self-built DLP-based multimaterial 3D printer. We realize covalent bonding between AP hydrogel and other polymers through incomplete polymerization of AP hydrogel initiated by the water-soluble photoinitiator TPO nanoparticles. We demonstrate a few applications taking advantage of this approach. The proposed approach paves a new way to realize multifunctional soft devices and machines by bonding hydrogel with other polymers in 3D forms.

Structural multi-colour invisible inks with submicron 4D printing of shape memory polymers.

Four-dimensional (4D) printing of shape memory polymer (SMP) imparts time responsive properties to 3D structures. Here, we explore 4D printing of a SMP in the submicron length scale, extending its applications to nanophononics. We report a new SMP photoresist based on Vero Clear achieving print features at a resolution of ~300 nm half pitch using two-photon polymerization lithography (TPL). Prints consisting of grids with size-tunable multi-colours enabled the study of shape memory effects to achieve large visual shifts through nanoscale structure deformation. As the nanostructures are flattened, the colours and printed information become invisible. Remarkably, the shape memory effect recovers the original surface morphology of the nanostructures along with its structural colour within seconds of heating above its glass transition temperature. The high-resolution printing and excellent reversibility in both microtopography and optical properties promises a platform for temperature-sensitive labels, information hiding for anti-counterfeiting, and tunable photonic devices.

Design framework for mechanically tunable soft biomaterial composites enhanced by modified horseshoe lattice structures.

Soft biomaterials have a wide range of applications in many areas. However, one material can only cover a specific range of mechanical performance such as the elastic modulus and stretchability. In order to improve the mechanical performance of soft biomaterials, lattice structures are embedded to reinforce the biomaterials. In this paper, rectangular and triangular lattice structures formed by modified horseshoe microstructures are used because their mechanical properties are tunable and can be tailored precisely to match the desired properties by adjusting four geometrical parameters, the length L, radius R, width w and arc angle θ0. A theoretical design framework for the modified horseshoe lattice structures is developed to predict the dependence of the mechanical behaviors on geometrical parameters. Both experiments and finite element simulations on lattice structures are conducted to validate the theoretical models. Results show that a wide range of design space for the elastic modulus (a few kPa to hundreds of MPa), stretchability (strain up to 180%) and Poisson ratio (ranging from -0.5 to 1.2) can be achieved. Experiments on lattice-hydrogel composites are also conducted to verify the reinforcement effect of lattice structures on the hydrogel. This work provides a theoretical method to predict the mechanical behaviors of the lattice structures and aid the rational design of reinforced biomaterials, which has applications in tissue engineering, drug delivery and intraocular lenses.

Self-Healing Four-Dimensional Printing with an Ultraviolet Curable Double-Network Shape Memory Polymer System.

Four-dimensional (4D) printing that enables 3D printed structures to change configurations over time has gained great attention because of its exciting potential in various applications. Among all the 4D printing materials, shape memory polymers (SMPs) possess higher stiffness and faster response rate and therefore are considered as one of most promising materials for 4D printing. However, most of the SMP-based 4D printing materials are (meth)acrylate thermosets which have permanently cross-linked covalent networks and cannot be repaired if any damage occurs. To address the unrepairable nature of SMP-based 4D printing materials, this paper reports a double-network self-healing SMP (SH-SMP) system for high-resolution self-healing 4D printing. In the SH-SMP system, the semicrystalline linear polymer polycaprolactone (PCL) is incorporated into a methacrylate-based SMP system which has good compatibility with the digital light processing-based 3D printing technology and can be used to fabricate complex 4D printing structures with high resolution (up to 30 µm). The PCL linear polymer imparts the self-healing ability to the 4D printing structures, and the mechanical properties of a damaged structure can be recovered to more than 90% after adding more than 20 wt % of PCL into the SH-SMP system. We investigated the effects of PCL concentration on the thermomechanical behavior, viscosity, and the self-healing capability of the SH-SMP system and performed the computational fluid dynamics simulations to study the effect of SH-SMP solution's viscosity on the 3D printing process. Finally, we demonstrated the self-healing 4D printing application examples to show the merits of the SH-SMP system.

Expression of pigment epithelium-derived factor and tumor necrosis factor-α is correlated in bladder tumor and is related to tumor angiogenesis.

OBJECTIVE: Angiogenesis is a pivotal process on which solid tumor growth is substantially dependent. Pigment epithelium-derived factor (PEDF) is the most potent natural anti-angiogenic factor, which has seldom been studied in bladder tumor, and whose functioning pathway remains unclear. We have thus investigated PEDF expression in relation to tumor necrosis factor-α (TNF-α) and microvessel density (MVD) with immunohistochemistry. METHODS: Antibodies of PEDF and TNF-α were examined by Western blotting before immunohistochemistry. Sixty-four urothelial tumor sections and 23 normal controls were stained and expression of PEDF, TNF-α, and MVD were studied. RESULTS: Decreased PEDF expression and increased TNF-α expression was noticed in tumorous tissue compared with healthy urothelium. Lower PEDF expression was related to higher tumor grade but stage. Increased TNF-α expression was noticed in recurrent, larger tumors as well as in tumors with progression in grade and stage. Expression of PEDF and TNF-α was correlated in bladder tumor. PEDF or TNF-α was correlated with MVD negatively or positively, respectively, in cancerous tissue and tumorous grouping without correlation in papillary urothelial neoplasm of low malignant potential. CONCLUSION: Expressional change of PEDF and TNF-α is in relation to angiogenesis of bladder tumor, especially in bladder cancer development.

Pigment epithelium-derived factor expression is down-regulated in bladder tumors and correlates with vascular endothelial growth factor and matrix metalloproteinase-9.

Growth of solid tumor depends on angiogenesis, a process regulated by the balance of pro- and anti-angiogenic factors. We investigated the expression of anti-angiogenic factor pigment epithelium-derived factor (PEDF) and proangiogenic factors vascular endothelial growth factor (VEGF) and matrix metalloproteinase-9 (MMP-9) with immunohistochemistry in 64 bladder tumor samples and 23 normal controls. Compared with normal urothelium, we identified decreased PEDF expression (P = 0.000) whereas increased expression of VEGF (P = 0.000) and MMP-9 (P = 0.000) in tumorous tissue as well as in papillary urothelial neoplasm of low malignant potential (PUNLMP) (P = 0.009 and P = 0.000 accordingly) but MMP-9 (P = 0.704). Decreased PEDF expression was revealed with higher tumor grade (P = 0.014) but stage (P = 0.687). There was no age or gender preference in PEDF, VEGF or MMP-9 expression. Negative correlation of expression in tumorous and cancerous tissue regarding PEDF and VEGF (P = 0.000, r = -0.56, and P = 0.000, r = -0.50, respectively), PEDF and MMP-9 (P = 0.002, r = -0.39, and P = 0.032, r = -0.30, respectively) was identified. There was a negative correlation of expression between PEDF and VEGF (P = 0.016, r = -0.677) and no correlation between PEDF and MMP-9 (P = 0.147, r = -0.45) in PUNLMP. Decreased PEDF and increased VEGF and MMP-9 expression may play considerable roles in differentiation and invasion of bladder tumor.

Serum protein profiling to identify biomarkers for small renal cell carcinoma.

Diagnostic biomarkers for early detection of renal cell carcinoma (RCC) are in great need. In the present study, we compared the serum protein profiles of patients with small RCC to those of healthy individuals to identify the differentially expressed proteins with potential to serve as biomarkers. Serum samples were collected from 10 patients with small RCC and 10 healthy individuals. The serum protein expression profiles were analyzed by two-dimensional (2-D) gel electrophoresis. Twenty-seven proteins with differences in expression levels between RCC patients and healthy volunteers were identified. Of these, 19 were expressed at different levels and eight were expressed in serum from the RCC group, but not from the control group. Six differentially expressed proteins identified by using mass spectrometry included coagulation factor XIII B, complement C3 and its precursor, misato homolog 1 (isoform CRA_b), hemopexin, and alpha-1-B-glycoprotein. Some of these serum proteins are known regulators of tumor progression in human malignancies. In conclusion, we successfully applied 2-D gel electrophoresis and identified six serum proteins differentially expressed between patients with small RCC and healthy volunteers. These proteins may provide novel biomarkers for early detection and diagnosis of human RCC.

Application of SELDI-TOF-MS to identify serum biomarkers for renal cell carcinoma.

PURPOSE: Early diagnosis is critical for improving the outcome of patients with renal cell carcinoma (RCC). In this study, we applied a proteomic approach to identify serum biomarkers associated with different stages of renal tumor development. MATERIALS AND METHODS: The protein expression profiles in patient serum samples were analyzed using surface enhanced laser desorption/ionization time-of-flight mass spectroscopy (SELDI-TOF-MS). The subjects included 65 patients with renal cell carcinomas, 34 with benign renal tumors, and 69 normal controls. A diagnostic decision tree was developed and validated based on the differentially expressed proteins between the serum of patients with small (