Self-Emergent Protocells Generated in an Aqueous Solution with Binary Macromolecules through Liquid-Liquid Phase Separation

Recently, liquid–liquid phase separation (LLPS) has attracted considerable attention among researchers in the life sciences as a plausible mechanism for the generation of microstructures inside cells. LLPS occurs through multiple nonspecific interactions and does not always require a lock-and-key interaction with a binary macromolecular solution. The remarkable features of LLPS include the non-uniform localization and concentration of solutes, resulting in the ability to isolate certain chemical systems and thereby parallelize multiple chemical reactions within the limited space of a living cell. We report that, by using the macromolecules, poly(ethylene glycol) (PEG) and dextran, that exhibit LLPS in an aqueous solution, cell-sized liposomes are spontaneously formed therein in the presence of phospholipids. In this system, LLPS is generated through the depletion effect of macromolecules. The results showed that cell-like microdroplets entrapping DNA wrapped by a phospholipid layer emerge in a self-organized manner.     

Effect of Decontamination Treatment on Vitamin C and Potassium Attributes of Fresh-Cut Bell Pepper at Post-Washing Stage

To investigate the effect of decontamination treatment on the nutritional attributes of fresh-cut produce, fresh-cut slices of immature bell peppers were soaked in sodium hypochlorite solutions or slightly acidic electrolyzed water with varying concentrations of effective free chlorine. Changes in the residual ratios of the water-soluble nutrients, vitamin C (L-ascorbic acid, L-AsA) and potassium, were measured, as well as aerobic plate counts (APCs), after decontamination. The L-AsA ratios of the samples that were decontaminated with the sodium hypochlorite solutions exhibited a gradual decrease when higher concentrations of detergent and longer soaking times were employed. In contrast, the potassium ratio remained mostly constant around 50% after 1 min of soaking. A decrease in the L-AsA ratio to 80% was observed within 5 min of a soak in deionized water (a 0 ppm solution). Soakings in the slightly acidic electrolyzed water also resulted in a decrease in L-AsA ratios, yet the trend was not similar to that associated with the sodium hypochlorite solutions. These results indicate that water-soluble nutrient contents of fresh-cut produce decrease during a decontamination process that uses chlorine-based solutions according to the free chlorine concentration and the soaking time. Moreover, the reduction in nutrient content varied depending on the disinfectant used, even if the free chlorine concentration was the same for the different disinfectants.     

Secreted Signaling Molecules at the Neuromuscular Junction in Physiology and Pathology

Signal transduction at the neuromuscular junction (NMJ) is affected in many human diseases, including congenital myasthenic syndromes (CMS), myasthenia gravis, Lambert–Eaton myasthenic syndrome, Isaacs’ syndrome, Schwartz–Jampel syndrome, Fukuyama-type congenital muscular dystrophy, amyotrophic lateral sclerosis, and sarcopenia. The NMJ is a prototypic cholinergic synapse between the motor neuron and the skeletal muscle. Synaptogenesis of the NMJ has been extensively studied, which has also been extrapolated to further understand synapse formation in the central nervous system. Studies of genetically engineered mice have disclosed crucial roles of secreted molecules in the development and maintenance of the NMJ. In this review, we focus on the secreted signaling molecules which regulate the clustering of acetylcholine receptors (AChRs) at the NMJ. We first discuss the signaling pathway comprised of neural agrin and its receptors, low-density lipoprotein receptor-related protein 4 (Lrp4) and muscle-specific receptor tyrosine kinase (MuSK). This pathway drives the clustering of acetylcholine receptors (AChRs) to ensure efficient signal transduction at the NMJ. We also discuss three secreted molecules (Rspo2, Fgf18, and connective tissue growth factor (Ctgf)) that we recently identified in the Wnt/β-catenin and fibroblast growth factors (FGF) signaling pathways. The three secreted molecules facilitate the clustering of AChRs by enhancing the agrin-Lrp4-MuSK signaling pathway.     

Impact of carbon nanotube additives on carbide-derived carbon-based electroactive polymer actuators

The effects of single-walled carbon nanotubes (SWCNTs) on the properties of carbide-derived carbon (CDC)-based electroactive polymer (EAP) actuators were studied. SWCNTs were used as an additive to increase the mesoporosity and electrical conductivity of the electrodes, and also to support the CDC matrix. EAP actuators with various ratios of SWCNTs to CDC in the electrodes were fabricated and their electromechanical and electrochemical characteristics were examined. The addition of SWCNTs to CDC-based electrodes significantly increased the bending strain and stress (bending force) of the actuators. The actuator assembled with electrodes containing SWCNTs and CDC in the ratio 50/50 (wt.%/wt.%) showed the highest strain output among the samples at lower frequencies (<0.1 Hz). The increase in maximum strain was more than twice that of pure CDC-based EAPs (0.85% vs. 0.35% at an applied voltage of ±2 V). Also, the high frequency (5–50 Hz) response of the combined SWCNT/CDC-based actuators was considerably improved.     

Analysis of beam properties in the neighbourhood of a double-heterostructure laser source

Abstract

The power density distribution and beam characteristics of double-heterostructure lasers with very thin active layers in the neighbourhood of the light source are evaluated by using a plane wave spectrum approach and a second-moment order theory for diffracted scalar light beams. It is shown that the evanescent waves contribute to shape the power density when the distance is smaller than the emission wavelength λ or of the order of λ. It should be noted that the optical fields deeply penetrate into the cladding layers when the thickness of the active layer is much smaller than the emission wavelength λ.     

a-Si/mc-Si hybrid solar cell using silicon sheet substrate

A hybrid junction solar cell with amorphous silicon (a-Si) and multicrystalline silicon (mc-Si) was fabricated using a mc-Si sheet substrate, which is produced directly from molten silicon using a novel rotational solidification method. The efficiency of 11.6% was obtained for the hybrid junction cell, while 10.2% for the single junction cell made of a mc-Si sheet substrate, which confirmed that the hybrid structure is effective to improve the solar cell property made of a mc-Si substrate. With introducing light trapping structure, the efficiency was improved to be 12.0%. Moreover, the possibility of Jsc improvement was investigated using the advanced light trapping structure. Jsc of 15.6 mA/cm² was obtained and it was confirmed that the hybrid junction is a promising structure.     

Ultrasonographic appearance of orthotopic ureterocele in a dog

A three-year-old, intact male, Siberian husky was evaluated for a two day history of dysuria. Sonographically there was an anechoic cyst-like structure in the urinary bladder. The abnormality appeared to be a 'cyst within a cyst', which is a characteristic ultrasonographic feature of ureterocele in humans. Ultrasonography may be a useful means of establishing a diagnosis of ureterocele in dogs.     

Integrated-optic timing tuner for high-speed WDM signals

We demonstrate an integrated-optic timing tuner, which is used for the fine adjustment of wavelength-division-multiplexing (WDM) signal delays. This tuner can be utilized to compensate for the bit skew of high-speed WDM bit-parallel links in the next generation or to reduce nonlinear effects in WDM transmissions. The tuner consists of an arrayed-waveguide grating and variable delay lines comprising asymmetrical Mach-Zehnder interferometers with different arm lengths. We demonstrate experimentally that our device is capable of accurate delay tuning for 16 /spl times/ 10 to 40-Gb/s systems.     

A murine AP-endonuclease gene-targeted deficiency with post-implantation embryonic progression and ionizing radiation sensitivity

Much research has been directed toward finding the most prominent psychological factors affecting ratings of perceived exertion during physical exercise. The one most frequently mentioned, although rarely investigated empirically, is locus of control. Findings from non-sport-related research indicate that individuals with an internal locus of control (internals) are better at using the available information than individuals with an external locus of control (externals). That finding has been attributed to the inferior information-processing capacity of the latter group, a deficit that might also affect the processing of exertional cues during physical exercise. In the present study, a group of women categorized as internals were compared with a similar group of externals during both ergometer cycling and treadmill running. The results indicated significantly different ratings between the groups not only for overall perceived exertion but also for local (muscles and joints) and central (cardiopulmonary) exertion. The observed differences were greater during ergometer cycling than during treadmill running. It is possible that the more distinct cues available during cycling, stemming mainly from the working muscles (local factors), presented more information to process, a task that the internals were better at than the externals.