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Age-associated increase in ectopic fat degeneration and fibrosis in the skeletal muscle contribute to muscle degradation and weakness. Quercetin is a bioactive flavonoid with anti-inflammatory and anti-obesity effects. Thus, we aimed to investigate the effects of quercetin on adipogenesis and fibrosis in the human skeletal muscle, which have not yet been elucidated. Human muscle-derived PDGFRα

Intestinal epithelial cells (IECs) are crucial for the digestive process and nutrient absorption. The intestinal epithelium is composed of the different cell types of the small intestine (mainly, enterocytes, goblet cells, Paneth cells, enteroendocrine cells, and tuft cells). The small intestine is characterized by the presence of crypt-villus units that are in a state of homeostatic cell turnover. Organoid technology enables an efficient expansion of intestinal epithelial tissue in vitro. Thus, organoids hold great promise for use in medical research and in the development of new treatments. At present, the cholinergic system involved in IECs and intestinal stem cells (ISCs) are attracting a great deal of attention. Thus, understanding the biological processes triggered by epithelial cholinergic activation by acetylcholine (ACh), which is produced and released from neuronal and/or non-neuronal tissue, is of key importance. Cholinergic signaling via ACh receptors plays a pivotal role in IEC growth and differentiation. Here, we discuss current views on neuronal innervation and non-neuronal control of the small intestinal crypts and their impact on ISC proliferation, differentiation, and maintenance. Since technology using intestinal organoid culture systems is advancing, we also outline an organoid-based organ replacement approach for intestinal diseases.

In gastropods, the function of neuropeptides has been studied primarily in the peripheral motor systems. Their functional roles in the central nervous system have received less attention. The procerebrum, the secondary olfactory center of the terrestrial slug Limax, consists of several hundred thousand interneurons, and plays a pivotal role in olfactory learning and memory. In the present study, we found that enterin, known as a myoactive peptide functioning in the enteric and vascular system of Aplysia, is expressed in the procerebrum of Limax. These enterin-expressing neurons primarily make projections within the cell mass layer of the procerebrum. The oscillatory frequency of the local field potential in the procerebrum was reduced by an exogenous application of enterin. The local field potential oscillation in the tentacular ganglion, the primary olfactory center, was also modulated by enterin. Whole-cell patch-clamp recordings revealed that the modulatory effect in the procerebrum was due to the inhibitory effect of enterin on the bursting neurons, which function as the kernels determining the oscillatory activity of the procerebrum. Our results revealed the novel role of the myoactive neuropeptide enterin in the higher olfactory function in terrestrial gastropods.

A signaling cascade composing M3, EphB/ephrin-B, and MEK synergizes to guide the homeostasis of intestinal epithelial cell growth and differentiation following modifications of the cholinergic intestinal niche., Acetylcholine (ACh) signaling through activation of nicotinic and muscarinic ACh receptors regulates expression of specific genes that mediate and sustain proliferation, differentiation, and homeostasis in the intestinal crypts. This signaling plays a pivotal role in the regulation of intestinal stem cell function, but the details have not been clarified. Here, we performed experiments using type 3 muscarinic acetylcholine receptor (M3) knockout mice and their intestinal organoids and report that endogenous ACh affects the size of the intestinal stem niche via M3 signaling. RNA sequencing of crypts identified up-regulation of the EphB/ephrin-B signaling pathway. Furthermore, using an MEK inhibitor (U0126), we found that mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK) signaling, which is downstream of EphB/ephrin-B signaling, is activated in M3-deficient crypts. Collectively, M3, EphB/ephrin-B, and the MAPK/ERK signaling cascade work together to maintain the homeostasis of intestinal epithelial cell growth and differentiation following modifications of the cholinergic intestinal niche.

Hybrid bonding (or Cu-Cu direct bonding) is one of the most important interconnect technologies for next generation 3D-packaging. Because it is an enabler for fine pad pitch interconnection between chips such as $ and for lower conductivity at joints. However it needs very high temperature such as 300–350 degC for Cu diffusion to perform robust joint. Therefore, not only process equipments but also process materials are required to have thermal resistance during the high temperature bonding process. In this paper, a Temporary Bonding De-Bonding (TBDB) tape having over 300 degC thermal resistance is introduced for hybrid bonding. The adhesive is composed of a resin which has higher thermal resistance than conventional resins so that the tape can support thin wafer on glass carrier without delamination at the high temperature. Also it can be removed without any residue on the wafer after the thermal process. Many studies have been done to lower bonding temperature for metal diffusion of hybrid bonding, but it is indicated that over 300 degC for bonding process would be available bonding condition by using this TBDB tape for 3DIC applications.

Hydra has a single body axis, and new structures align themselves along this axis. When the head and foot are removed, a new head is always produced at the end where the original head was present and a foot at the opposite end. This phenomenon is referred to as “polarity of regeneration.” In order to explain polarity of regeneration, a reaction–diffusion model has been proposed. Schaller and co-workers identified the factors involved by purifying head activator, a undecapeptide, from the sea anemone Anthopleura elegantissima. Head activator has been identified in Hydra, as well as in the hypothalamus and intestine of rats and humans, where the peptide appears to have a role in neuronal differentiation. Since head activator increases the rate of head regeneration and bud formation, and increases the number of regenerated tentacles, the peptide was initially labeled a morphogen. Head activator also functions as a mitogen and an inducer of neuron differentiation.

Stem cells have extensive proliferative potential and the ability to differentiate into one or more mature cell types. The mechanisms by which stem cells accomplish self-renewal provide fundamental insight into the origin and design of multicellular organisms. These pathways allow the repair of damage and extend organismal life beyond that of component cells, and they probably preceded the evolution of complex metazoans. Understanding the true nature of stem cells can only come from discovering how they are regulated. The concept that stem cells are controlled by particular microenvironments, also known as niches, has been widely accepted. Technical advances now allow characterization of the zones that maintain and control stem cell activity in several organs, including the brain, skin, and gut. Cholinergic neurons release acetylcholine (ACh) that mediates chemical transmission via ACh receptors such as nicotinic and muscarinic receptors. Although the cholinergic system is composed of organized nerve cells, the system is also involved in mammalian non-neuronal cells, including stem cells, embryonic stem cells, epithelial cells, and endothelial cells. Thus, cholinergic signaling plays a pivotal role in controlling their behaviors. Studies regarding this signal are beginning to unify our understanding of stem cell regulation at the cellular and molecular levels, and they are expected to advance efforts to control stem cells therapeutically. The present article reviews recent findings about cholinergic signaling that is essential to control stem cell function in a cholinergic niche.

A wide variety of organs are in a dynamic state, continuously undergoing renewal as a result of constant growth and differentiation. Stem cells are required during these dynamic events for continuous tissue maintenance within the organs. In a steady state of production and loss of cells within these tissues, new cells are constantly formed by differentiation from stem cells. Today, organoids derived from either adult stem cells or pluripotent stem cells can be grown to resemble various organs. As they are similar to their original organs, organoids hold great promise for use in medical research and the development of new treatments. Furthermore, they have already been utilized in the clinic, enabling personalized medicine for inflammatory bowel disease. In this review, I provide an update on current organoid technology and summarize the application of organoids in basic research, disease modeling, drug development, personalized treatment, and regenerative medicine.

Pentacene, one of the most studied organic semiconductors, crystallizes in different structures depending on the growth conditions. The structure is usually classified into one of the three polymorphs, the so-called single crystal phase, bulk phase, and thin film phase. In this report, we show that epitaxial crystalline pentacene thin films on Bi(0001), which have been believed to be the bulk phase, have a distinct molecular orientation in the same crystal lattice as the bulk phase. The calculated band structures are clearly different from those of the bulk phase and show an excellent agreement with the experimental data for the bandwidth.(21) A tight-binding model indicates that one of the two main intermolecular interactions is almost identical to that of the single crystal phase, while the other one is almost identical to that of the bulk phase. The results implies that polymorphs in the same crystal lattice can be formed by a molecular-substrate interaction.

The structure of the Si(111)- 21 × 21 -(Ag + Au) surface is studied using surface X-ray diffraction and fluorescence yield measurements. The fluorescence measurements indicate that there are three gold atoms in the unit cell. From the analysis of the diffraction data, it is shown that the gold atoms form a trimer with an interatomic distance of 2.8 A and that the sides of the trimer are almost parallel to the Si(111)-1 × 1 fundamental vectors, similar to that in the Si(111)- 3 × 3 -Au structure.

Determining the atomic structure across electrolyte–electrode interfaces with a sufficient temporal resolution is crucial to understanding how electrochemical reactions proceed. Surface X-ray diffraction is a well-established method for determining interface structures at the atomic scale. However, existing measurement methods are often incapable of quantifying time-dependent structural changes during electrochemical processes because acquiring a diffraction rod profile sufficient for structure determination usually takes a longer time than the rate of the structural changes. This report demonstrates that the wavelength-dispersive method, which can acquire a range of the diffraction rod profile at once, is capable of the time-resolved analysis of electrochemical dynamics on a time scale of seconds and less, using electrochemical reactions on Pt(111) electrode surface as examples. In the case of the electrochemical oxidation of methanol, the quantitative analysis of the transient vertical displacement of t...

The ability of stem cells to divide and differentiate is necessary for tissue repair and homeostasis. Appropriate spatial and temporal mechanisms are needed. Local intercellular signaling increases expression of specific genes that mediate and maintain differentiation. Diffusible signaling molecules provide concentration-dependent induction of specific patterns of cell types or regions. Differentiation of adjacent cells, on the other hand, requires cell−cell contact and subsequent signaling. These two types of signals work together to allow stem cells to provide what organisms require. The ability to grow organoids has increased our understanding of the cellular and molecular features of small “niches” that modulate stem cell function in various organs, including the small intestine.

Backgrounds Recent studies have shown that various mammalian non-neuronal cells synthesize acetylcholine (ACh) in situ and operate cholinergic signaling via nicotinic and muscarinic ACh receptors (nAChRs and mAChRs). Understanding the mechanisms that control intestinal stem cell (ISC) function through activation of nAChR signaling is critical for developing therapeutic interventions for diseases such as inflammatory bowel disease (IBD). Previously, by conducting RNA sequencing (RNA-Seq) analysis using crypt-villus organoid cultures, we found that the Hippo signaling pathway, a stem cell regulating network, is upregulated in ISCs after treatment with nicotine. Here, we explored the roles of nAChR signaling through activation of the Hippo signaling pathway. Methods RNA-Seq data were validated by quantitative reverse transcription polymerase chain reaction (qRT-PCR) analysis. β4-knock-in mice were generated, and experiments using the knock-in mice and their intestinal organoids were carried out. Results RNA-Seq and qRT-PCR analyses demonstrated that the expression of YAP1/TAZ and Notch1/Dll1 was upregulated after treatment with nicotine. However, a nAChR antagonist, mecamylamine, strongly inhibited the expression of these genes. Notably, we found that in β4-knock-in mouse small intestines, expression of YAP1 and Notch1 was significantly reduced, but not that of TAZ and Dll1, suggesting that Hippo and Notch signaling pathways are putative targets for nAChR signaling. Furthermore, fluorescent signals were detected in Paneth cells that interact with ISCs at the crypt bottom, indicating an interaction between Paneth cells and ISCs via nAChR signaling through the activation of Hippo and Notch signaling pathways. Conclusion Our results indicate that upregulated nAChR signaling contributes to the maintenance of ISC activity and balances differentiation through activation of Hippo and Notch signaling pathways.

Nicotinic acetylcholine receptors (nAChRs) are ligand-gated ion channels that signal using endogenous acetylcholine (ACh) and the agonist, nicotine. The nAChR signaling pathway is a central regulator of physiological homeostasis in the central and peripheral nervous systems. The receptors are expressed not only in the nervous system, but also play a pivotal role in regulation of epithelial cell growth, migration, differentiation, and inflammation processes in various mammalian non-neuronal cells. In the intestine, the Wnt signaling pathway plays a central role in the epithelium and is a principal regulator of intestinal stem cell (ISC) identity and proliferation. Since Wnt signaling was first described more than 40 years ago in ISCs, large amounts of scientific evidence have demonstrated remarkable long-term self-renewal capacity of ISCs. Intestinal organoids are commonly used for studying ISC biology and intestinal pathophysiology. The contribution of non-neuronal nAChR signaling to Wnt signaling in the intestine has received less attention. Experiments using cultured intestinal organoids that lack nerve and immune cells were performed. Endogenous ACh is synthesized in the intestinal epithelium and drives organoid growth and differentiation through activation of nAChR signaling. Furthermore, nAChR signaling is coordinated with Wnt signaling for regulation of ISC function. Elucidating the mechanism of the coordinated activities of nAChR and Wnt signaling in the intestine provides new insight into epithelial homeostasis, and may be of particular relevance in inflammatory bowel diseases such as ulcerative colitis and Crohn's disease.

Starfish are suitable animals for the study of hormonal regulatory mechanism of oocyte maturation and ovulation. Although contraction of the gonadal walls is essential for the shedding gametes, little was known about the mechanism. When ovaries of starfish Patiria pectinifera were incubated in Ca

An X-ray reflectometer, using a laboratory X-ray source, that can measure the specular X-ray reflectivity curve with a time resolution of 10 s or less was developed. Low reflectivities can be measured accurately because the background can be subtracted from the signal., An X-ray reflectometer using a laboratory X-ray source for quick measurements of the specular X-ray reflectivity curve is presented. It uses a bent–twisted crystal to monochromatize and focus the diverging X-rays (Cu Kα1) from a laboratory point source onto the sample. The reflected X-rays are recorded with a two-dimensional detector. Reflectivity curves can be measured without rotating the sample, detector or X-ray source during measurements. The instrument can separate the specularly reflected X-rays from the diffuse scattering background, so low reflectivities can be measured accurately. For a gold thin film on silicon, the reflectivity down to the order of 10−6 was obtained with a measurement time of 100 s and that down to 10−5 with a measurement time of 10 s. Reflectivity curves of a silicon wafer and a liquid ethylene glycol surface are shown as well. Time-resolved measurements of a TiO2 surface during UV irradiation are also reported.

The surface structural change of the rutile–TiO2(110) during the UV-light-induced wettability conversion was studied with atomic resolution using the X-ray crystal truncation rod (CTR) scattering method. We confirmed that an atomic-scale surface structural change occurs during the UV-light irradiation by using time-resolved CTR profile measurements. Quantitative structural analysis on static CTR data, which were measured before and after the conversion, shows that on the hydrophobic (nonphotoirradiated) surface the five-coordinated Ti atom is covered with an O atom likely in a form of water molecule, for which the bridging O atom is not likely hydroxylated, and that large atomic positional fluctuations occur on the hydrophilic (photoirradiated) surface possibly due to the photoinduced proton transfer from the intact water molecule to the bridging oxygen atom. The resulting surface OH groups might be active sites for water adsorption to make the surface superhydrophilic.

We have investigated the atomic structure of the “multilayer silicene” grown on the Ag(111) single crystal surface by using low energy electron diffraction (LEED) and scanning tunneling microscopy (STM). We measured the intensity of the LEED spot as a function of the incident electron energy (I–V curve) and analyzed the I–V curve using a dynamical LEED theory. We have found that the Si(111)( 3 × 3 )-Ag model well reproduces the I–V curve whereas the models consisting of the honeycomb structure of Si do not. The bias dependence of the STM image of multilayer silicene agrees with that of the Si(111)( 3 × 3 )-Ag reconstructed surface. Consequently, we have concluded that the multilayer silicene grown on Ag(111) is identical to the Si(111)( 3 × 3 )-Ag reconstructed structure.

Starfish are suitable animals for the study of hormonal regulatory mechanism of oocyte maturation and ovulation. Although contraction of the gonadal walls is essential for the shedding gametes, little was known about the mechanism. When ovaries of starfish Patiria pectinifera were incubated in Ca2+-free seawater in the presence of 1-methyladenine (1-MeAde), the germinal vesicles in oocytes broke down, but no ovulation occurred. Verapamil, a potent inhibitor of voltage-dependent Ca2+ channels, inhibited 1-MeAde-induced ovulation. These results suggest that extracellular Ca2+ and its influx are indispensable for gamete shedding. Furthermore, acetylcholine (ACh) was involved in extracellular Ca2+-dependent contractions of gonadal walls. Although 1-MeAde failed to induce contraction of the gonadal walls in normal seawater containing L-glutamic acid, application of ACh or carbachol, an agonist for ACh receptor, could bring about shedding of mature oocytes. Atropine, a competitive antagonist of the muscarinic ACh receptor, inhibited 1-MeAde-induced ovulation, but a nicotinic ACh receptor antagonist mecamylamine had no effect. Furthermore, ACh was detected in the ovaries and testes in P. pectinifera. These findings suggest that ACh acts on muscarinic ACh receptors in gonadal walls to induce peristaltic contractions caused by Ca2+ influx via Ca2+ channels in the gonadal wall muscle for gamete shedding. The present study also provides new insight into the regulatory mechanism that 1-MeAde acts on secretion of ACh in ovaries and testes.

The crystalline structure and quality of ZnSnAs2:Mn films grown by molecular beam epitaxy (MBE) on InP substrates are two of the most important issues in preparing spintronic structures such as magnetic quantum wells and spin-based transistors. We conducted high-resolution X-ray diffraction (XRD) measurements to clarify the crystalline structure of ZnSnAs2:Mn thin films. The XRD measurements reveal with very high accuracy that the samples have a sphalerite structure with high epitaxial quality. These results, within the limits of measurement accuracy support the previous assumption that ZnSnAs2:Mn thin films are coherently clustered ferromagnetic semiconductors without breaking the continuity of the sphalerite structure, leading to ferromagnetism with a high Curie temperature close to that of zincblende MnAs.

BACKGROUND Cocoa contains biologically active ingredients that have broad-spectrum antimicrobial activity, which includes an inhibitory effect on influenza virus infection. RESULTS A cocoa extract (CE) was prepared by treating defatted cocoa powder with boiling water. The extract demonstrated dose-dependent inhibition of infection in Madin–Darby canine kidney (MDCK) cells infected with human influenza virus A (H1N1, H3N2), human influenza virus B and avian influenza viruses (H5N1, H5N9). CE inhibited viral adsorption to MDCK cells. Animal experiments showed that CE significantly improved survival in mice after intra-nasal administration of a lethal dose of influenza virus. In human intervention trials, participants were allocated to two groups, one in which the participants ingested cocoa for 3 weeks before and after vaccination against A(H1N1)pdm2009 influenza virus and another in which the participants did not ingest cocoa. Neutralizing antibody titers against A(H1N1)pdm2009 influenza virus increased significantly in both groups; however, the extent of the increase was not significantly different between the two groups. Although natural killer cell activity was also elevated in both groups, the increase was more substantial in the cocoa intake group. CONCLUSION Drinking cocoa activates natural immunity and enhances vaccination-induced immune response, providing stronger protection against influenza virus infection and disease onset. © 2015 Society of Chemical Industry

Cholinergic signaling, which modulates cell activities via nicotinic and muscarinic acetylcholine receptors (n- and mAChRs) in response to internal or external stimuli, has been demonstrated in mammalian non-neuronal cells that synthesize acetylcholine (ACh). One of the major pathways of excitatory transmission in the enteric nervous system (ENS) is mediated by cholinergic transmission, with the transmitter ACh producing excitatory potentials in postsynaptic effector cells. In addition to ACh-synthesizing and ACh-metabolizing elements in the ENS, the presence of non-neuronal ACh machinery has been reported in epithelial cells of the small and large intestines of rats and humans. However, little is known about how non-neuronal ACh controls physiological function in the intestine. Here, experiments using crypt-villus organoids that lack nerve and immune cells in culture suggest that endogenous ACh is synthesized in the intestinal epithelium to drive organoid growth and differentiation through activation of nAChRs. Treatment of organoids with nicotine enhanced cell growth and the expression of marker genes for stem and epithelial cells. On the other hand, the nAChR antagonist mecamylamine strongly inhibited the growth and differentiation of organoids, suggesting the involvement of nAChRs in the regulation of proliferation and differentiation of Lgr5-positive stem cells. More specifically, RNA sequencing analysis revealed that Wnt5a expression was dramatically upregulated after nicotine treatment, and Wnt5a rescued organoid growth and differentiation in response to mecamylamine. Taken together, our results indicate that coordinated activities of nAChR and Wnt signaling maintain Lgr5-positive stem cell activity and balanced differentiation. Furthermore, we could clearly separate the two groups, neuronal ACh in the ENS and non-neuronal ACh in the intestinal epithelium. Dysfunction of the non-neuronal cholinergic system is involved in the pathogenesis of disease. The data will increase our understanding of the cholinergic properties of non-neuronal cells and lead to optimization of drug therapy.

Cnidarians are the most primitive animals to possess a nervous system. This phylum is composed of the classes Scyphozoa (jellyfish), Cubozoa (box jellyfish), and Hydrozoa (e.g., Hydra, Hydractinia), which make up the subphylum Medusozoa, as well as the class Anthozoa (sea anemones and corals). Neuropeptides have an early evolutionary origin and are already abundant in cnidarians. For example, from the cnidarian Hydra, a key model system for studying the peptides involved in developmental and physiological processes, we identified a wide variety of novel neuropeptides from Hydra magnipapillata (the Hydra Peptide Project). Most of these peptides act directly on muscle cells and induce contraction and relaxation. Some peptides are involved in cell differentiation and morphogenesis. In this review, we describe FMRFamide-like peptides (FLPs), GLWamide-family peptides, and the neuropeptide Hym-355; FPQSFLPRGamide. Several hundred FLPs have been isolated from invertebrate animals such as cnidarians. GLWamide-family peptides function as signaling molecules in muscle contraction, metamorphosis, and settlement in cnidarians. Hym-355; FPQSFLPRGamide enhances neuronal differentiation in Hydra. Recently, GLWamide-family peptides and Hym-355; FPQSFLPRGamide were shown to trigger oocyte maturation and subsequent spawning in the hydrozoan jellyfish Cytaeis uchidae. These findings suggest the importance of these neuropeptides in both developmental and physiological processes.

For the understanding of the neural regulation of homeostasis, reproduction and behaviors, elucidation of structure and function of neuropeptides is inevitable. A classical technique for peptide purification is the separation of peptidic extract from nervous tissue by the high-performance liquid chromatography, which was followed by screening of fractions with biological or immunological assays. Although this approach requires relatively large amount of tissues for extraction and the screening is time- consuming, we have identified more than 15 kinds of bioactive neuropeptides in the nervous tissue of a marine snail, Thais clavigera. The purified peptides include TEP (Thais excitatory peptide)-1/-2, FRFamide, WWamide and others. The molecular cloning of precursor for each neuropeptide demonstrated that structurally related peptides are aligned in tandem on most of the precursor proteins. To identify the peptides on the precursors, we conducted the de novo sequencing of peptides with the nanoLC-Orbitrap-MS/MS analysis. It identified most of the neuropeptides found on the precursor proteins in the extract from 50 of Thais ganglia. Thus, this technique is suitable for the comprehensive identification of peptides from relatively small amount of tissues. However, several peptides that had been identified by the classical technique, such as APGWamide and leucokinin, were not identified, suggesting the limitation of this brand-new technique.

Scedosporium prolificans (S. prolificans) is a type of mold, which rarely affects immunocompromised people. We treated a 71-year-old woman with acute myeloid leukemia (AML-M5a) with low-dose cytarabine, acralubicin, and filgrastim as the induction therapy. On day 7 after the initiation of chemotherapy, she became febrile and agranulocytic, and developed anal pain ; therefore, we discontinued the chemotherapy on day 8. Broad-spectrum antibiotics, micafungin, and then liposomal amphotericin B were ineffective. The serum concentration of β-D-glucan was 525 pg/mL. She died of multiple organ failure on day 17. S. prolificans was detected from the blood culture on day 13. Physicians should consider Scedosporium spp. infection when principal antifungal agents are ineffective and fungal infection is strongly suspected.

Sixty-five CTX-M-2/15/14 extended-spectrum-β-lactamase-producing Enterobacteriaceae were isolated from 258,888 mastitic milk samples from Japanese dairy farms between 2007 and 2011. CTX-M-2-producing Klebsiella pneumoniae and CTX-M-15-producing Escherichia coli were the predominant strains isolated. There was no predominant clonal type, and clonal diversity was found even in strains isolated from a single farm.

We have investigated the electrical and optical properties of p–i–n junction structures in which un-doped GaNAs/GaAs multiple quantum wells (MQWs) were sandwiched by p- and n-doped GaAs layers. The samples were formed on the GaAs (001) substrates by plasma assisted molecular beam epitaxy (RF-MBE) using the modulated N radical beam method. We have prepared several samples for various GaNAs MQW structures. The electroluminescence (EL) measurements showed slightly different spectra to those of photoluminescence (PL) and the EL intensities were almost proportional to the applied currents. The room temperature EL measurement revealed strong electron confinement of GaNAs/GaAs MQW.