Dual crosslinking silk fibroin/pectin-based bioink development and the application on neural stem/progenitor cells spheroid laden 3D bioprinting.

The human nervous system is an incredibly intricate physiological network, and neural cells lack the ability to repair and regenerate after a brain injury. 3-dimensional (3D) bioprinting technology offers a promising strategy for constructing biomimetic organ constructs and in vitro brain/disease models. The bioink serves as a pivotal component that emulates the microenvironment of biomimetic construct and exerts a profound influence on cellular behaviors. In this study, a series of mechanically adjustable and dual crosslinking bioinks were developed using photocrosslinkable methacrylated silk fibroin (SilMA) in combination with the ionic crosslinking material, pectin, or pectin methacryloyl (PecMA) with silk fibroin (SF) supplementation. SilMA/pectin exhibited superior properties, with SilMA providing biocompatibility and adjustable mechanical properties, while the addition of pectin enhanced printability. The porous structure supported neural cell growth, and 15 % SilMA/0.5 % pectin bioinks displayed excellent printability and shape fidelity. Neural stem/progenitor cells (NSPCs)-loaded bioinks were used to construct a 3D brain model, demonstrating sustained vitality and high neuronal differentiation without the need for growth factors. The SilMA/pectin bioinks demonstrated adjustable mechanical properties, favorable biocompatibility, and an environment highly conducive to neural induction, offering an alternative approach for neural tissue engineering applications or in vitro brain models.

A Printable Magnetic-Responsive Iron Oxide Nanoparticle (ION)-Gelatin Methacryloyl (GelMA) Ink for Soft Bioactuator/Robot Applications.

The features or actuation behaviors of nature's creatures provide concepts for the development of biomimetic soft bioactuators/robots with stimuli-responsive capabilities, design convenience, and environmental adaptivity in various fields. Mimosa pudica is a mechanically responsive plant that can convert pressure to the motion of leaves. When the leaves receive pressure, the occurrence of asymmetric turgor in the extensor and flexor sides of the pulvinus from redistributing the water in the pulvinus causes the bending of the pulvinus. Inspired by the actuation of Mimosa pudica, designing soft bioactuators can convert external stimulations to driving forces for the actuation of constructs which has been receiving increased attention and has potential applications in many fields. 4D printing technology has emerged as a new strategy for creating versatile soft bioactuators/robots by integrating printing technologies with stimuli-responsive materials. In this study, we developed a hybrid ink by combining gelatin methacryloyl (GelMA) polymers with iron oxide nanoparticles (IONs). This hybrid ION-GelMA ink exhibits tunable rheology, controllable mechanical properties, magnetic-responsive behaviors, and printability by integrating the internal metal ion-polymeric chain interactions and photo-crosslinking chemistries. This design offers the inks a dual crosslink mechanism combining the advantages of photocrosslinking and ionic crosslinking to rapidly form the construct within 60 s of UV exposure time. In addition, the magnetic-responsive actuation of ION-GelMA constructs can be regulated by different ION concentrations (0-10%). Furthermore, we used the ION-GelMA inks to fabricate a Mimosa pudica-like soft bioactuator through a mold casting method and a direct-ink-writing (DIW) printing technology. Obviously, the pinnule leaf structure of printed constructs presents a continuous reversible shape transformation in an air phase without any liquid as a medium, which can mimic the motion characteristics of natural creatures. At the same time, compared to the model casting process, the DIW printed bioactuators show a more refined and biomimetic transformation shape that closely resembles the movement of the pinnule leaf of Mimosa pudica in response to stimulation. Overall, this study indicates the proof of concept and the potential prospect of magnetic-responsive ION-GelMA inks for the rapid prototyping of biomimetic soft bioactuators/robots with untethered non-contact magneto-actuations.

Red Light-Emitting Diodes with All-Inorganic CsPbI3/TOPO Composite Nanowires Color Conversion Films.

This work presents a method for obtaining a color-converted red light source through a combination of a blue GaN light-emitting diode and a red fluorescent color conversion film of a perovskite CsPbI3/TOPO composite. High-quality CsPbI3 quantum dots (QDs) were prepared using the hot-injection method. The colloidal QD solutions were mixed with different ratios of trioctylphosphine oxide (TOPO) to form nanowires. The color conversion films prepared by the mixed ultraviolet resin and colloidal solutions were coated on blue LEDs. The optical and electrical properties of the devices were measured and analyzed at an injection current of 50 mA; it was observed that the strongest red light intensity was 93.1 cd/m2 and the external quantum efficiency was 5.7% at a wavelength of approximately 708 nm when CsPbI3/TOPO was 1:0.35.

The effectiveness of high-resolution ultrasound in the assessment of the carotid intima-media thickness for postirradiated neck.

OBJECTIVE: The carotid intimal-medial thickness (CIMT) is a strong predictor of future cardiovascular events. We assessed the mean CIMT and evaluated associated factors in head and neck cancer (HNC) patients. MATERIALS AND METHODS: Between January 2016 and March 2018, 70 volunteers underwent automatic ultrasound measurement of the common carotid artery CIMT. A mean CIMT ≥ 1.0 mm was regarded as an elevated risk for cardiovascular disease (CVD). We aimed to investigate the risk factors for an increased mean CIMT. RESULTS: We recruited 20 HNC survivors and 50 noncancer control individuals. Multiple linear regression analysis showed that old age (ß = 0.006, 95% confidence interval, CI 0.004-0.008), increased weight (ß = 0.003, 95% CI 0.001-0.005), hypertension (ß = 0.10, 95% CI 0.03-0.17), and prior irradiation (ß = 0.13, 95% CI 0.08-0.19) were positively correlated with the mean CIMT. From logistic regression analysis, it was shown that patients who underwent radiotherapy (OR 13.5, 95% CI 1.48-122.8) and who had higher bodyweight (OR 1.09, 95% CI 1.01-1.18) had a significantly higher risk of developing CVD. CONCLUSION: Measurement of the mean CIMT using ultrasound could be useful for assessing CVD risk in HNC survivors after neck irradiation.

Simultaneous determination of p-phenylenediamines and aminophenols in hair dye products: interlaboratory study.

An isocratic HPLC method routinely used in the National Laboratory for Food and Drug Analysis of Taiwan was validated for the simultaneous determination of six aminophenols and phenylenediamines in commercial hair dyes. After extraction of the commercial hair dye product, the dye intermediates were determined by HPLC. Recoveries from the extraction were between 91.6 and 96.5%. The method was then evaluated in an interlaboratory collaborative study according to AOAC guidelines. Five laboratories in Taiwan participated in the study that analyzed the test product, which was preanalyzed by two laboratories to ensure acceptable homogeneity. The RSD(r) and RSD(R) values of the measurements obtained for the dye intermediates in the product were < or = 3.75 and < or = 5.95%, respectively. The method demonstrated acceptable reproducibility, as evidenced by HorRat values of 0.82- 0.97. The applicability of the method to the determination of oxidative hair dye components was further demonstrated in analyses of two different products. The method is thus proposed to be used by manufacturers and laboratories to evaluate the quality of commercial hair dyes containing the six aminophenols and phenylenediamines.

Helicobacter pylori colonization of the human gastric epithelium: a bug's first step is a novel target for us.

After Helicobacter pylori enters the stomach, three steps are vital for infection: (i) establishing colonization; (ii) evading host immunity; and (iii) invading gastric mucosa; the last step is what is associated with diverse outcomes. Urease activity and motility mediated by the flagella of H. pylori are important in harboring colonies beneath the gastric mucus in niches adjacent to the epithelium. Several putative adhesins attach the organism to the gastric epithelium and prompt the succeeding processes for evading host immunity and invading the mucosa. Successful colonization is thus the leading and critical step. From another point of view, this can be a novel target to control this common and important infection. This review summarizes the putative adhesins that influence the evasion of host immunity, and how these could determine different clinico-pathologic outcomes. The putative adhesins include the interplay between bacterial and host Lewis antigens (type I: Le(a) and Le(b); type II: Le(x) and Le(y)), the dominant pathway between BabA and Le(b), the SabA adhesin binding to sialylated Le(x) that is upregulated in inflamed gastric tissue or those with weak-Le(b), the CagL apparatus to adapt with the alpha5beta1 integrin to mediate a type IV secretory system for CagA translocation into the epithelium; and other outer membrane proteins as HopZ, AlpA/AlpB, or OipA, without known corresponding receptors. This review implicates the adhesins vital for bugs that could be alternatively provided as novel targets for us to overcome the colonization.

Gender differences in relationships of actual and virtual social support to Internet addiction mediated through depressive symptoms among college students in Taiwan.

This study examined gender differences in the relationships of actual and virtual social support to Internet addiction mediated through depressive symptoms among college students in Taiwan. Results revealed that in females, both actual and virtual social support directly predicted Internet addiction or were mediated through depressive symptoms. However, in males, while Internet addiction was predicted by virtual social support directly or indirectly mediated through depressive symptoms, the link of actual social support to Internet addiction was only mediated through depressive symptoms. Furthermore, in both genders, lower actual social support and higher virtual social support were associated with higher depressive symptoms.