Projection Stereolithography 3D Printing High-Conductive Hydrogel for Flexible Passive Wireless Sensing.

Hydrogel-based electronics have inherent similarities to biological tissues and hold potential for wearable applications. However, low conductivity, poor stretchability, nonpersonalizability, and uncontrollable dehydration during use limit their further development. In this study, projection stereolithography 3D printing high-conductive hydrogel for flexible passive wireless sensing is reported. The prepared photocurable silver-based hydrogel is rapidly planarized into antenna shapes on substrates using surface projection stereolithography. After partial dehydration, silver flakes within the circuits form sufficient conductive pathways to achieve high conductivity (387 S cm-1). By sealing the circuits to prevent further dehydration, the resistance remains stable when tensile strain is less than 100% for at least 30 days. Besides, the sealing materials provide versatile functionalities, such as stretchability and shape memory property. Customized flexible radio frequency identification tags are fabricated by integrating with commercial chips to complete the accurate recognition of eye movement, realizing passive wireless sensing.

A 4D Printed Adhesive, Thermo-Contractile, and Degradable Hydrogel for Diabetic Wound Healing.

Chronic wound healing remains a substantial clinical challenge. Current treatments are often either prohibitively expensive or insufficient in meeting the various requirements needed for effective diabetic wound healing. A 4D printing multifunctional hydrogel dressing is reported here, which aligns perfectly with wounds owning various complex shapes and depths, promoting both wound closure and tissue regeneration. The hydrogel is prepared via digital light process (DLP) 3D printing of the mixture containing N-isopropylacrylamide (NIPAm), curcumin-loaded Pluronic F127 micelles (Cur-PF127), and poly(ethylene glycol) diacrylate-dopamine (PEGDA575-Do), a degradable crosslinker. The use of PEGDA575-Do ensures tissue adhesion and degradability, and cur-PF127 serves as an antibacterial agent. Moreover, the thermo-responsive mainchains (i.e., polymerized NIPAm) enables the activation of wound contraction by body temperature. The features of the prepared hydrogel, including robust tissue adhesion, temperature-responsive contraction, effective hemostasis, spectral antibacterial, biocompatibility, biodegradability, and inflammation regulation, contribute to accelerating diabetic wound healing in Methicillin-resistant Staphylococcus aureus (MRSA)-infected full-thickness skin defect diabetic rat models and liver injury mouse models, highlighting the potential of this customizable, mechanobiological, and inflammation-regulatory dressing to expedite wound healing in various clinical settings.

Repeatedly Recyclable 3D Printing Catalyst-Free Dynamic Thermosetting Photopolymers.

Photo-curing 3D printing technology has promoted the advanced manufacturing in various fields, but has exacerbated the environmental crisis by the demand for the chemically cross-linked thermosetting photopolymers. Here, the authors report a generic strategy to develop catalyst-free dynamic thermosetting photopolymers, based on photopolymerization and transesterification, that can enable users to realize repeatable 3D printing, providing a practical solution to the environmental challenges. That the ß-carbonyl group adjacent to the ester group greatly accelerates the rate of transesterification is demonstrated. The generated resins from the immobilization of the catalyst-free reversible bonds into the photopolymers leads to a dynamic covalently crosslinked network structure upon UV based 3D printing, which exhibit controllable mechanical properties with elastomeric behaviors to thermadapt shape memory polymers. Furthermore, the resulting network can be reverted into an acrylate-functioned photopolymer that is suitable for 3D printing again, presenting an on-demand, repeatedly recyclable thermosetting photopolymer platform for sustainable 3D printing.

Solid-state Fluorescence from Carbon Dots Widely Tunable from Blue to Deep Red through Surface Ligand Modulation.

Carbon dots (CDs) find widespread attention due to their remarkable fluorescent and electronic properties. However, aggregation-caused quenching currently limits the application of CDs in colored displays. The construction of CDs with color-tunable solid-state fluorescence (SSF) is rarely reported, since the preparation of SSF CDs is technically challenging. Herein, through surface ligand modulation, SSF CDs with an emission-color span of almost 300 nm (from blue to deep red) were obtained. In-depth structure-property studies reveal that intra- and inter-molecular hydrogen-bonding inside SSF CDs provokes the emission properties in the aggregated state. Photodynamic characterizations demonstrate emission wavelengths can be switched smoothly by deliberately altering conjugation ability between substituent ligands and CDs core. Three-dimensional printing patterning is used to create a range of emissive objects, demonstrating the commercial potential for use in optical lamps.

Construction of Photoresponsive 3D Structures Based on Triphenylethylene Photochromic Building Blocks.

Photoresponsive materials have been widely used in sensing, bioimaging, molecular switches, information storage, and encryption nowadays. Although a large amount of photoresponsive materials have been reported, the construction of these smart materials into precisely prescribed complex 3D geometries is rarely studied. Here we designed a novel photoresponsive material methyl methacrylate containing triphenylethylene (TrPEF2-MA) that can be directly used for digital light processing (DLP) 3D printing. Based on TrPEF2-MA, a series of photoresponsive 3D structures with reversible color switching under ultraviolet/visible light irradiations were fabricated. These complex photoresponsive 3D structures show high resolutions (50 µm), excellent repeatability (25 cycles without fatigue), and tunable saturate color degrees. Multicomponent DLP 3D printing processes were also carried out to demonstrate their great properties in information hiding and information-carrying properties. This design strategy for constructing photoresponsive 3D structures is attractive in the area of adaptive camouflage, information hiding, information storage, and flexible electronics.

Construction of the waaF Subunit and DNA Vaccine Against Escherichia coli in Cow Mastitis and Preliminary Study on Their Immunogenicity.

Escherichia coli (E. coli) is one of the major pathogenic bacteria in bovine mastitis, which usually triggers systemic symptoms by releasing lipopolysaccharide (LPS). waaF is the core in LPS pathogenicity. In this study, a new waaF vaccine candidate was identified, constructed with the pcDNA3.1 (+)HisB-waaF plasmid to create to a DNA vaccine (pcwaaF), and transfected into MCF-7 cells to produce recombinant waaF subunit vaccine (rwaaF). After that, the safety of the two vaccine candidates was evaluated in mouse model. Immunogenicity and mortality of challenged mice were compared in 20 and 40 µg per dose, respectively. The results showed that rwaaF and pcwaaF were successfully constructed and the complete blood count and serum biochemical indicated that both of the vaccine candidates were safe (p > 0.05). In addition, histopathological staining showed no obvious pathological changes. The immune response induced by rwaaF was significantly higher than that of pcwaaF (p < 0.01), indicated by levels of serum concentration of IgG IL-2, IL-4, and IFN-γ, and feces concentration of sIgA. Survival rates of mice in rwaaF groups (both 80%) were also higher than in the pcwaaF groups (40 and 50%, respectively). Comparing the safety, immunogenicity, and E. coli challenge of two vaccine candidates, rwaaF had the better effect and 20 µg rwaaF was more economical. In conclusion, this study demonstrates the utility of a new E. coli vaccine and provides a rationale for further investigation of bovine mastitis therapy and management.

Multimode Grasping Soft Gripper Achieved by Layer Jamming Structure and Tendon-Driven Mechanism.

Robotic grasping has become increasingly important in many application areas such as industrial manufacturing and logistics. Because of the diversity and uncertainty of objects and environments, common grippers with one single grasping mode face difficulties to fulfill all the tasks. Hence, we proposed a soft gripper with multiple grasping modes in this study. The gripper consists of four modular soft fingers integrated with layer jamming structure and tendon-driven mechanism. Each finger's rotating shaft of the base uses a torsional spring to decouple the bending deformation and relative rotation. An octopus-mimicking vacuum sucker is installed in the fingertip to generate suction. The effectiveness of the bending deformation and variable stiffness of the design were proved by finite element simulation. Thus, the control model of the finger was built, and the control strategy of multimode grasping of the gripper was proposed. Three control modes were designed to realize the four anthropomorphic grasping modes, including wrap, pinch, hook, and suck. Furthermore, the grasping performance was evaluated to show the abilities. The experiments indicated the superior performance of the proposed gripper and the multimode grasping ability that satisfies various grasping tasks.

General One-Pot Method for Preparing Highly Water-Soluble and Biocompatible Photoinitiators for Digital Light Processing-Based 3D Printing of Hydrogels.

We report a facile but general method to prepare highly water-soluble and biocompatible photoinitiators for digital light processing (DLP)-based 3D printing of high-resolution hydrogel structures. Through a simple and straightforward one-pot procedure, we can synthesize a metal-phenyl(2,4,6-trimethylbenzoyl)phosphinates (M-TMPP)-based photoinitiator with excellent water solubility (up to ∼50 g/L), which is much higher than that of previously reported water-soluble photoinitiators. The M-TMPP aqueous solutions show excellent biocompatibility, which meets the prerequisite for biomedical applications. Moreover, we used M-TMPP to prepare visible light (405 nm)-curable hydrogel precursor solutions for 3D printing hydrogel structures with a high water content (80 wt %), high resolution (∼7 µm), high deformability (more than 80% compression), and complex geometry. The printed hydrogel structures demonstrate great potential in flexible electronic sensors due to the fast mechanical response and high stability under cyclic loadings.

Author Correction: Elastic pseudospin transport for integratable topological phononic circuits.

The original version of this Article contained errors in the second sentence in the legend of Fig. 1, which incorrectly read 'These two elastic insulators are identical in lattice constant a (3a0), plate thickness (0.4a0), and radius of perforated holes r (0.18a0) but different hole-center distance characterized by b.' The correct version states 'plate thickness (√3 × 0.4a0)' in place of 'plate thickness (0.4a0)' and 'radius of perforated holes r (√3 × 0.18a0)' rather than 'radius of perforated holes r (0.18a0)'.The first sentence of the 'Sample preparation' section of the Methods originally incorrectly read 'Our samples are prepared exclusively on polished stainless-steel plates (Type 201, mass density 7803 kg m-3) with a fixed plate thickness 7.82 mm.' In the corrected version, 'mass density 7903 kg m-3' replaces 'mass density 7803 kg m-3'.The second sentence in the legend of Supplementary Fig. 3, originally incorrectly read 'The symmetry of the phononic crystal remains unchanged as C6ν, and thickness of the substrates H (equals to 0.4a0), lattice constant a (equals to 3a0) and radius of perforated holes r (equals to 0.18 a0) maintain constant.' The correct version states '√3 × 0.4a0' in place of '0.4a0' and '√3 × 0.18a0' rather than '0.18a0'.This has been corrected in both the PDF and HTML versions of the Article.

Elastic pseudospin transport for integratable topological phononic circuits.

Precise control of solid-state elastic waves' mode content and coherence is of great use nowadays in reinforcing mechanical energy harvesting/storage, nondestructive material testing, wave-matter interaction, high sensitivity sensing, and information processing, etc. Its efficacy is highly dependent on having elastic transmission channels with lower loss and higher degree of freedom. Here, we demonstrate experimentally an elastic analog of the quantum spin Hall effects in a monolithically scalable configuration, which opens up a route in manipulating elastic waves represented by elastic pseudospins with spin-momentum locking. Their unique features including robustness and negligible propagation loss may enhance elastic planar-integrated circuit-level and system-level performance. Our approach promotes topological materials that can interact with solid-state phonons in both static and time-dependent regimes. It thus can be immediately applied to multifarious chip-scale topological phononic devices, such as path-arbitrary elastic wave-guiding, elastic splitters and elastic resonators with high-quality factors.

Effects of a liquid high-fat meal on postprandial lipid metabolism in type 2 diabetic patients with abdominal obesity.

BACKGROUND: Postprandial lipemia and lipoprotein lipase (LPL) activity play crucial roles in the pathogenesis of accelerated atherosclerosis. This study aimed to evaluate the postprandial lipid metabolism after the ingestion of a liquid high-fat meal in type 2 diabetic patients with abdominal obesity, and determine if the PvuII polymorphisms of LPL influence their postprandial lipid responses. METHODS: Serum glucose, insulin, triglycerides (TG), total cholesterol (TC) and high density lipoprotein cholesterol (HDL-C) were measured in fasting and postprandial state at 0.5, 1, 2, 4, 6 and 8 h after a liquid high-fat meal in 51 type 2 diabetic patients with abdominal obesity, 31 type 2 diabetic patients without abdominal obesity and 39 controls. Their PvuII polymorphisms of LPL were tested in fasting. RESULTS: Type 2 diabetic patients with abdominal obesity had significantly higher postprandial areas under the curve (AUC) of glucose [least square mean difference (LSMD) = 30.763, 95% confidence interval (CI) = 23.071-38.455, F = 37.346, P < 0.05] and TC (LSMD = 3.995, 95% CI = 1.043-6.947, F = 3.681, P < 0.05) than controls. Postprandial AUCs for insulin, homeostasis model assessment-insulin resistance (HOMA-IR) and TG were higher (LSMD = 86.987, 95% CI = 37.421-136.553, F = 16.739, P < 0.05; LSMD = 37.456, 95% CI = 16.312-58.600, F = 27.012, P < 0.05; LSMD = 4.684, 95% CI = 2.662-6.705, F = 26.158, P < 0.05), whereas HDL-C AUC was lower (LSMD = -1.652, 95% CI = -2.685 - -0.620, F = 8.190, P < 0.05) in type 2 diabetic subjects with abdominal obesity than those without abdominal obesity. In type 2 diabetic patients with abdominal obesity, postprandial TG AUC was lower in P-/- than in P+/- (LSMD = -4.393, 95% CI = -9.278 - -0.491, F = 4.476, P < 0.05) and P+/+ (LSMD = -7.180, 95% CI = -12.319 - -2.014, F = 4.476, P < 0.05) phenotypes. Postprandial AUCs for glucose, insulin, HOMA-IR, TC and HDL-C were not different according to PvuII phenotypes. CONCLUSIONS: Abdominal obesity exacerbates the postprandial lipid responses in type 2 diabetic patients, which partly explains the excess atherogenic risk in these patients. In addition, the presence of P+ allele could contribute to a greater postprandial TG increase in type 2 diabetic patients with abdominal obesity. TRIAL REGISTRATION: ChiCTR-IOR-16008435. Registered 8 May 2016.

Consumption of a liquid high-fat meal increases triglycerides but decreases high-density lipoprotein cholesterol in abdominally obese subjects with high postprandial insulin resistance.

Abdominal obesity is associated with an increased risk of insulin resistance, which may be a potential contributor to dyslipidemia. However, the relationship between postprandial insulin resistance and lipid metabolism in abdominally obese subjects remains unknown. We hypothesized that postprandial dyslipidemia would be exaggerated in abdominally obese subjects with high postprandial insulin resistance. To test this hypothesis, serum glucose, insulin, triglycerides, total cholesterol, high-density lipoprotein cholesterol, and apolipoprotein B were measured at baseline and postprandial state at 0.5, 1, 2, 4, 6, and 8 hours after a liquid high-fat meal in non-abdominally obese controls (n=44) and abdominally obese subjects with low (AO-LPIR, n=40), middle (n=40), and high postprandial insulin resistance (AO-HPIR, n=40) based on the tertiles ratio of the insulin to glucose areas under the curve (AUC). Their serum adipokines were tested at baseline only. Fasting serum leptin was higher (P<.05) in AO-HPIR than that in AO-LPIR and controls. Postprandial triglycerides AUC was higher (P<.05), whereas high-density lipoprotein cholesterol AUC was lower (P<.05), in AO-HPIR than those in AO-LPIR and controls. Postprandial AUCs for total cholesterol and apolipoprotein B were similar in abdominally obese subjects with different degrees of postprandial insulin resistance and controls. The present study indicated that the higher degree of postprandial insulin resistance, the more adverse lipid profiles in abdominally obese subjects, which provides insight into opportunity for screening in health.

Practical Application of Antidiabetic Efficacy of Lycium barbarum Polysaccharide in Patients with Type 2 Diabetes.

Lycium barbarum polysaccharide (LBP) has traditionally been used in Chinese medicine as a chief ingredient of Lycium barbarum (wolf berry/goji berry) for the treatment of various diseases with the symptoms of frequent drinking and urination. This study was conducted as a randomized, controlled clinical trial. A total of 67 patients with type 2 diabetes (30 in control group and 37 in LBP group) were enrolled in this prospective, randomized, double-blind study (administration at 300 mg/day body weight). In order to observe the hypoglycemic and lipid-lowering activity of LBP in patients with type 2 diabetes after dinner, various tests were conducted between control and LBP intervention groups in 3 months. Although, the study had small sample size and short follow-up, significant findings were observed. The results of our study indicated a remarkable protective effect of LBP in patients with type 2 diabetes. Serum glucose was found to be significantly decreased and insulinogenic index increased during OMTT after 3 months administration of LBP. LBP also increased HDL levels in patients with type 2 diabetes. It showed more obvious hypoglycemic efficacy for those people who did not take any hypoglycemic medicine compared to patients taking hypoglycemic medicines. This study showed LBP to be a good potential treatment aided-agent for type 2 diabetes.

[The study on the relationship between serum folic acid and vitamin B2 levels and esophageal cancer].

OBJECTIVE: To study the relationship between serum folic acid and VB2 levels and esophageal cancer. METHOD: The enzyme-linked immunosorbent assay was used to observe the serum folic acid and vitamin B2 levels of the 1:1:1 paired of 106 groups, which include 106 cases of esophageal cancer, 106 cases of esophageal precancerous lesions and 106 cases of normal control group. RESULTS: The levels of folic acid and VB2 in serum of esophageal cancer group and esophageal precancerous lesions group were significantly lower than normal control group (P<0.05), the level of folic acid in serum of esophageal cancer group was significantly lower than esophageal precancerous lesions group (P<0.05), but the difference of the serum VB2 of esophageal cancer group and esophageal precancerous lesions group was not statistically significant (P>0.05). CONCLUSION: The folic acid and vitamin B2 deficiency has the relationship with the esophageal cancer occurrence and development.

Improving balance skills in patients who had stroke through virtual reality treadmill training.

OBJECTIVE: The aim of this study was to evaluate the effects of virtual reality (VR) treadmill training on the balance skills of patients who have had a stroke. DESIGN: A total of 14 patients with strokes were recruited and randomly assigned to receive VR treadmill or traditional treadmill training. The outcome measures that were included for the study were center of pressure (COP) sway excursion, COP maximum sway in anterior-posterior direction, COP maximum sway in medial-lateral direction, COP sway area, bilateral limb-loading symmetric index, the sway excursion values for the paretic foot (sway excursion/P), paretic limb stance time (stance time/P), number of steps of the paretic limb (number of steps/P), and contact area of the paretic foot (contact A/P) during quiet stance, sit-to-stand transfer, and level walking. RESULTS: There were no significant improvements in COP-related measures and symmetric index during the quiet stance, either in the VR treadmill or traditional treadmill training group (P > 0.05). However, the difference between groups after training in COP maximum sway in medial-lateral direction during the quiet stance was significant (P = 0.038). Traditional treadmill training failed to improve sit-to-stand performance, whereas VR treadmill training improved symmetric index (P = 0.028) and sway excursion (P = 0.046) significantly during sit-to-stand transfer. The changes of symmetric index between groups were markedly different (P = 0.045). Finally, both groups improved significantly in stance time/P, but only VR treadmill training increased contact A/P (P = 0.034) after training during level walking. The difference between groups during level walking was not significant. CONCLUSIONS: Neither traditional treadmill nor VR treadmill training had any effect on balance skill during quiet stance, but VR treadmill training improved balance skill in the medial-lateral direction better than traditional training did. VR treadmill training also improved balance skill during sit-to-stand transfers and the involvement of paretic limb in level walking more than the traditional one did.