Search

Quantitative data of biological systems provide valuable baseline information for understanding pathology, experimental perturbations, and computational modeling. In mouse colon, calcitonin gene-related peptide (CGRP) is expressed by myenteric neurons with multiaxonal (Dogiel type II) morphology, characteristic of intrinsic primary afferent neurons (IPANs). Analogous neurons in other species and gut regions represent 5-35% of myenteric neurons. We aimed to quantify proportions of CGRP-immunopositive (CGRP+) myenteric neurons. Colchicine-treated wholemount preparations of proximal, mid, and distal colon were labeled for HuC/D, CGRP, nitric oxide synthase (NOS), and peripherin (Per). The pan-neuronal markers (Hu+/Per+) co-labeled 94% of neurons. Hu+/Per- neurons comprised ∼6%, but Hu-/Per+ cells were rare. Thus, quantification was based on Hu+ myenteric neurons (8576 total; 1225 ± 239 per animal, n = 7). CGRP+ cell bodies were significantly larger than the average of all Hu+ neurons (329 ± 13 vs. 261 ± 12 μm

Notably, the Pd–CuO/rGO sensor exhibits the highest response compared to the other three sensors (including the CuO, Pd–CuO and CuO/rGO sensors).

GaN-based Micro-LED has been widely regarded as the most promising candidate for next generation of revolutionary display technology due to its advantages of high efficiency, high brightness and high stability. However, the typical micro-fabrication process would leave a great number of damages on the sidewalls of LED pixels, especially for Micro-LEDs, thus reducing the light emitting efficiency. In this paper, sidewall passivation methods were optimized by using acid-base wet etching and SiO2 layer passivation. The optical and electrical characteristics of optimized Micro-LEDs were measured and analyzed. The internal quantum efficiency (IQE) of Micro-LED was increased to 85.4%, and the reverse leakage current was reduced down to 10−13 A at −5 V. Optimized sidewall passivation can significantly reduce the non-radiative recombination centers, improving the device performance and supporting the development of high-resolution Micro-LED display.

In the past few years, there has been extraordinary interest in how the gut communicates with the brain. This is because substantial and gathering data has emerged to suggest that sensory nerve pathways between the gut and brain may contribute much more widely in heath and disease, than was originally presumed. In the skin, the different types of sensory nerve endings have been thoroughly characterized, including the morphology of different nerve endings and the sensory modalities they encode. This knowledge is lacking for most types of visceral afferents, particularly spinal afferents that innervate abdominal organs, like the gut. In fact, only recently have the nerve endings of spinal afferents in any visceral organ been identified. What is clear is that spinal afferents play the major role in pain perception from the gut to the brain. Perhaps surprisingly, the majority of spinal afferent nerve endings in the gut express the ion channel TRPV1, which is often considered to be a marker of “nociceptive” neurons. And, a majority of gut-projecting spinal afferent neurons expressing TRPV1 are activated at low thresholds, in the “normal” physiological range, well below the normal threshold for detection of painful sensations. This introduces a major conundrum regarding visceral nociception. How should we define a “nociceptor” in the gut? We discuss the notion that nociception from the gut wall maybe a process encrypted into multiple different morphological types of spinal afferent nerve ending, rather than a single class of sensory ending, like free-endings, suggested to underlie nociception in skin.

This work investigates the impacts of structural parameters on the performances of p-GaN/AlGaN/GaN HEMT-based ultraviolet (UV) phototransistors (PTs) using Silvaco Atlas. The simulation results show that a larger Al content or greater thickness for the AlGaN barrier layer can induce a higher two-dimensional electron gas (2DEG) density and produce a larger photocurrent. However, they may also lead to a larger dark current due to the incomplete depletion of the GaN channel layer. The depletion conditions with various Al contents and thicknesses of the AlGaN layer are investigated in detail, and a borderline between full depletion and incomplete depletion was drawn. An optimized structure with an Al content of 0.23 and a thickness of 14 nm is achieved for UV-PT, which exhibits a high photocurrent density of 92.11 mA/mm, a low dark current density of 7.68 × 10−10 mA/mm, and a large photo-to-dark-current ratio of over 1011 at a drain voltage of 5 V. In addition, the effects of other structural parameters, such as the thickness and hole concentration of the p-GaN layer as well as the thickness of the GaN channel layer, on the performances of the UV-PTs are also studied in this work.

β-Ga2O3 thin films have been successfully prepared on (0001) sapphire substrate by simple and effective sol-gel spin-coating method with post-annealing process (SSP). The effects of different preheating temperatures on the crystal quality and surface morphology of β-Ga2O3 films have been systematically investigated. The β-Ga2O3 thin films exhibit good crystallinity with ( $$\bar 2$$ 01) preferred orientation and smooth surface morphology. The results showed that β-Ga2O3 thin films directly grown on (0001) sapphire by SSP method have comparable or better crystal quality compared with other epitaxial methods. The β-Ga2O3 thin films annealed at 1000 °C with the preheating temperature of 300 °C and above have smooth and crack-free surface morphology. The single-domain-growth mode of β-Ga2O3 thin film prepared on ~7° off-angled (0001) sapphire substrate toward plane has been confirmed by SSP method, and the porous GaN layers have been obtained by the nitridation of the Sol-Gel grown β-Ga2O3 thin films for future applications in high-quality free-standing GaN substrates.

Flexible conductive hydrogel has been driven by scientific breakthroughs and offers a wide variety of applications, including sensors, electronic skins, biomedicine, energy storage, etc. Based on the mixed-ion crosslinking method, gelatin and sodium alginate (Gel-Alg) composite hydrogels were successfully prepared using Ca

Itch sensation provokes the scratch reflex to protect us from harmful stimuli in the skin. Although scratching transiently relieves acute itch through activation of mechanoreceptors, it propagates the vicious itch-scratch cycle in chronic itch by further aggravating itch over time. Although well recognized clinically, the peripheral mechanisms underlying the itch-scratch cycle remain poorly understood. Here, we show that mechanical stimulation of the skin results in activation of the Piezo2 channels on Merkel cells that pathologically promotes spontaneous itch in experimental dry skin. Three-dimensional reconstruction and immunoelectron microscopy revealed structural alteration of MRGPRA3 + pruriceptor nerve endings directed toward Merkel cells in the setting of dry skin. Our results uncover a functional miswiring mechanism under pathologic conditions, resulting in touch receptors triggering the firing of pruriceptors in the skin to drive the itch-scratch cycle.

As a burgeoning wide-band gap semiconductor material, Al

To improve the stability and sensitivity of pH sensors based on AlGaN/GaN high electron mobility transistors (HEMTs), we proposed a modified sensing structure by integrating a reference HEMT device. This structural pH sensor exhibits a typical Nernstian behavior with a sensitivity of 54.38 mV/pH, which is higher than the value of 49.43mV/pH derived from the AlGaN/GaN HEMT-based sensor without integrating the reference HEMTs device. Furthermore, the stability of the new structural sensor is enhanced by approximately 19.2% in comparison with that of its traditional counterpart. The improved performances are analyzed using an electrical double-layer model together with an equivalent circuit model, and we find that the new sensor structure has a larger capacitor and exhibits a better rectification effect, hence decreasing the electrical noise and enhancing the stability of the testing signal. Meanwhile, the new sensor structure displays a smaller equivalent resistance and results in a larger available output current, hence exhibiting a higher sensitivity.

A two-dimensional hole gas (2DHG) induced by polarization charges at the GaN/AlGaN hetero-interface is attracting much attention because of its potential to develop p-channel transistors required for GaN complementary logic integrated circuits. This platform is compatible with commercial AlGaN/GaN n-channel electronics, but the performance of GaN p-channel transistors has been far behind. In this work, 2DHGs in GaN/AlGaN/GaN heterostructures grown by plasma-assisted molecular beam epitaxy have been investigated. The Al composition of the AlGaN barrier has been pushed as high as possible without obvious strain relaxation, and the record high 2DHG sheet density and conductivity on the GaN/AlGaN/GaN platform have been obtained. By adopting a parallel conduction model, a dependent relationship of the 2DHG density on temperature has been extracted. The temperature dependent Hall-effect results have demonstrated that the 2DHG density boosts by 75 times and 46 times at room temperature and 77 K, respectively, when the Al composition is pushed from 0.18 to 0.45 for the AlGaN barriers. The 2DHG sheet density reaches 3.6 × 1013 and 2.1 × 1013 cm−2 at room temperature and 77 K, respectively, and the lowest sheet resistance is 8.9 kΩ/□ at 77 K. Such a 2DHG is beneficial for fabrication of p-channel GaN transistors with lower on-resistance on the already-industrialized platform.

To improve the performance of optoelectronic devices, a high performance wide angle SiO2/Ti3O5 Distributed Bragg Reflector (DBR) mirror was designed and fabricated on double polished sapphire substrate. 17-pairs gradually varied DBR structure was applied in order to acquire a broad stopband reflectivity over 95% from 400 nm to 800 nm, covering the whole visible light region. The DBR mirrors deposited at the backside of optoelectronics devices are also demonstrated to remain a high reflectivity at wide incident angles, which improves the emission efficiency of LEDs and light absorption efficiency of InGaN/GaN photoelectrochemical cell (PEC).

In this letter, we demonstrate high-performance lateral AlGaN/GaN Schottky barrier diodes (SBD) on Si substrate with a recessed-anode structure. The optimized rapid etch process provides results in improving etching quality with a ~ 0.3 nm roughness of the ${5}\times {5}\,\,\mu \text{m}^{{{2}}}$ anode recessed surface. Supported by the flat anode recess surface and optimized anode field plate design. When the anode-to-cathode spacing is 30 $\mu \text{m}$ , the physical breakdown voltage ( ${V}_{\textit {BK}}{)}$ can reach 3.4 kV, with a specific on-resistance ( ${R}_{\textit {on},\textit {sp}}{)}$ of 3.7 $\text{m}\Omega \cdot $ cm2, the power figure of merit ( ${V}_{\textit {BK}}^{{2}}/{R}_{\textit {on},\textit {sp}}{)}$ can be as high as 3.1 GW/cm2, demonstrating its great potential for the application in power electronics.

Pain emanating from the female reproductive tract is notoriously difficult to treat, and the prevalence of transient pelvic pain has been placed as high as 70%-80% in women surveyed. Although sex hormones, especially estrogen, are thought to underlie enhanced pain perception in females, the underlying molecular and cellular mechanisms are not completely understood. Here, we showed that the pain-initiating TRPA1 channel was required for pain-related behaviors in a mouse model of estrogen-induced uterine pain in ovariectomized female mice. Surprisingly, 2- and 4-hydroxylated estrogen metabolites (2- and 4-HEMs) in the estrogen hydroxylation pathway, but not estrone, estradiol, or 16-HEMs, directly increased nociceptor hyperactivity through TRPA1 and TRPV1 channels, and picomolar concentrations of 2- and 4-hydroxylation estrone (2- or 4-OHE1) could sensitize TRPA1 channel function. Moreover, both TRPA1 and TRPV1 were expressed in uterine-innervating primary nociceptors, and their expression was increased in the estrogen-induced uterine pain model. Importantly, pretreatment with 2- or 4-OHE1 recapitulated estrogen-induced uterine pain-like behaviors, and intraplantar injections of 2- and 4-OHE1 directly produced a TRPA1-dependent mechanical hypersensitivity. Our findings demonstrated that TRPA1 is critically involved in estrogen-induced uterine pain-like behaviors, which may provide a potential drug target for treating female reproductive tract pain.

Methotrexate (MTX) has been widely used for the treatment of many types of autoimmune diseases, such as rheumatoid arthritis, psoriasis and dermatomyositis. However, its pharmacological mechanism is still unclear completely. In this study, we found that MTX is a potent and selective inhibitor of the Kv1.3 channel, a class of potassium channels highly associated with autoimmune diseases. Electrophysiological experiments showed that MTX inhibited human Kv1.3 channel with an IC50 of 41.5 ± 24.9 nM, and 1 μM MTX inhibited 32.6 ± 1.3% and 25.6 ± 2.2% of human Kv1.1 and Kv1.2 channel currents, respectively. These data implied the unique selectivity of MTX towards the Kv1.3 channel. Excitingly, using channel activation and chimeric experiments, we found that MTX bound to the outer pore region of Kv1.3 channel. Mutagenesis experiments in the Kv.3 channel extracellular pore region further showed that the Dsp371, Thr373 and His399 residues of outer pore region of Kv1.3 channel played important roles in MTX inhibiting activities. In conclusion, MTX inhibited Kv1.3 channel by targeting extracellular pore region, which is different form all the report small molecules, such as PAP-1 and 4-AP, but similar with many natural animal toxin peptides, such as ChTX, ShK and BmKTX. To the best of our knowledge, MTX is the first small molecular scaffold targeting the Kv1.3 channel extracellular pore region, suggesting its potential applications for designing novel Kv1.3 lead drugs and treating Kv1.3 channel-associated autoimmune diseases.

Vertically aligned nanowire arrays, with high surface-to-volume ratio and efficient light-trapping absorption, have attracted much attention for photoelectric devices. In this paper, vertical β-Ga2O3 nanowire arrays with an average diameter/height of 110/450 nm have been fabricated by the inductively coupled plasma etching technique. Then a metal-semiconductor-metal structured solar-blind photodetector (PD) has been fabricated by depositing interdigital Ti/Au electrodes on the nanowire arrays. The fabricated β-Ga2O3 nanowire PD exhibits ∼10 times higher photocurrent and responsivity than the corresponding film PD. Moreover, it also possesses a high photocurrent to dark current ratio (I light/I dark) of ∼104 and a ultraviolet/visible rejection ratio (R 260 nm/R 400 nm) of 3.5 × 103 along with millisecond-level photoresponse times.

The transient receptor potential cation channel subfamily V member 3 (TRPV3) channel plays a critical role in skin physiology, and mutations in TRPV3 result in the development of a congenital skin disorder, Olmsted syndrome. Here we describe multiple cryo-electron microscopy structures of human TRPV3 reconstituted into lipid nanodiscs, representing distinct functional states during the gating cycle. The ligand-free, closed conformation reveals well-ordered lipids interacting with the channel and two physical constrictions along the ion-conduction pore involving both the extracellular selectivity filter and intracellular helix bundle crossing. Both the selectivity filter and bundle crossing expand upon activation, accompanied by substantial structural rearrangements at the cytoplasmic intersubunit interface. Transition to the inactivated state involves a secondary structure change of the pore-lining helix, which contains a π-helical segment in the closed and open conformations, but becomes entirely α-helical upon inactivation. Together with electrophysiological characterization, structures of TRPV3 in a lipid membrane environment provide unique insights into channel activation and inactivation mechanisms. Cryo-EM structures of TRPV3 in nanodiscs reveal lipids bound to the channel and unprecedented conformations of the selectivity filter and of the pore-lining helix S6, underscoring the importance of lipids for the channel structure.

Semi-polar micro-LEDs have gain increasing interests due to the advantages of polarization control and quantum efficiency improvement. In this work, a novel semi-polar (20–21)-plane micro-LEDs array has been designed and manufactured. In comparison with c-plane micro-LEDs, semi-polar micro-LEDs indicate better electrical and optical performance. The relative EQE of semi-polar micro-LEDs remains at 62% under the injected current density of 775.6 A/cm2, which indicates a reduced efficiency droop due to less polarization in MQWs. It has been further proved by a significant reduction of 55% in emission peak blue-shift under the injected current density from 11.1 A/cm2 to 775.6 A/cm2. In addition, the carrier recombination dynamics and spatial light distribution of semi-polar micro-LEDs with different pixel sizes have been studied. Fast recombination lifetime in smaller size semi-polar micro-LEDs indicates a promising way to be used as a high modulation bandwidth light source. Stable and uniform light distribution in a wider range of spatial azimuths further supports for the semi-polar micro-LEDs as a strong candidate for the applications of high-resolution display and high-speed visible light communication.

In this paper, we demonstrate high-performance quasi-vertical GaN-on-Sapphire Schottky barrier diodes (SBD) with a reverse GaN p-n junction termination (RPN). The SBD has a current output of 1 kA/cm2 at $V_{F}=2.5$ V, a low $V_{on}$ of 0.66 V ± 0.017 V, a low $R_{on,sp}$ of 1.4 $\text{m}\Omega \cdot $ cm2, current ON/OFF ratio of over $10^{9}$ (−3 V~3 V). By introducing the RPN, the breakdown voltage can boost from 459 V to 1419 V, and power figure-of-merit (FOM) can reach 1438 MV/cm2. It is shown that the presence of the RPN with a suitable anode recess depth can generate an electric field (EF) opposite to the built-in EF at the center of the second top p-n junction, which can decrease the EF peak intensity and make the electric field more uniformly distributed inside the device. Finally, the leakage current of the SBD is inhibited and the breakdown voltage is increased.

Mounting evidence indicates that gastrointestinal (GI) homeostasis hinges on communications among many cellular networks including the intestinal epithelium, the immune system, and both intrinsic and extrinsic nerves innervating the gut. The GI tract, especially the colon, is the home base for gut microbiome which dynamically regulates immune function. The gut’s immune system also provides an effective defense against harmful pathogens entering the GI tract while maintaining immune homeostasis to avoid exaggerated immune reaction to innocuous food and commensal antigens which are important causes of inflammatory disorders such as coeliac disease and inflammatory bowel diseases (IBD). Various ion channels have been detected in multiple cell types throughout the GI tract. By regulating membrane properties and intracellular biochemical signaling, ion channels play a critical role in synchronized signaling among diverse cellular components in the gut that orchestrates the GI immune response. This work focuses on the role of ion channels in immune cells, non-immune resident cells, and neuroimmune interactions in the gut at the steady state and pathological conditions. Understanding the cellular and molecular basis of ion channel signaling in these immune-related pathways and initial testing of pharmacological intervention will facilitate the development of ion channel–based therapeutic approaches for the treatment of intestinal inflammation.

In this paper, the behavior of exciton radiative recombination in a GaN-based triangular-like ridge cavity is studied at room-temperature. The triangular-like ridge cavity is fabricated on a standard-blue-LED epitaxial wafer grown on a sapphire substrate. Through the photoluminescence (PL) and time-resolved photoluminescence (TR-PL) measurements, a clear modulation of the original spontaneous emission is found in the microcavity, a new transition channel is observed, and the effect is angle-dependent. Furthermore, by changing the tilt angle during angle-resolution photoluminescence (AR-PL), it is found that the coupling between excitons and photons in the cavity is the strongest when tilted at 10°. By simulation, the strong localization of photons in the top of the cavity can be confirmed. The PL, TR-PL, and AR-PL results showed the sign of the exciton-photon coupling in the triangular-like ridge cavity.

Paeonol (PAE) is a hydrophobic drug. In this study, we encapsulated paeonol in a lipid bilayer of liposomes (PAE-L), which delayed drug release and increased drug solubility. When PAE-L was dispersed in gels (PAE-L-G) based on a poloxamer matrix material for local transdermal delivery, we observed amphiphilicity, reversible thermal responsiveness, and micellar self-assembly behavior. These gels can be used for atopic dermatitis (AD), an inflammatory skin disease, to change the surface temperature of the skin. In this study, we prepared PAE-L-G at an appropriate temperature for the treatment of AD. We then assessed the gel’s relevant physicochemical properties, in vitro cumulative drug release, and antioxidant properties. We found that PAE-loaded liposomes could be designed to increase the drug effect of thermoreversible gels. At 32 °C, PAE-L-G could change from solution state to gelatinous state at 31.70 ± 0.42 s, while the viscosity was 136.98 ± 0.78 MPa.S and the free radical scavenging rates on DPPH and H2O2 were 92.24 ± 5.57% and 92.12 ± 2.71%, respectively. Drug release across the extracorporeal dialysis membrane reached 41.76 ± 3.78%. In AD-like mice, PAE-L-G could also relieve skin damage by the 12th day. In summary, PAE-L-G could play an antioxidant role and relieve inflammation caused by oxidative stress in AD.

Inflammatory and functional gastrointestinal disorders such as irritable bowel syndrome (IBS) and obstructive bowel disorder (OBD) underlie the most prevalent forms of visceral pain. Although visceral pain can be generally provoked by mechanical distension/stretch, the mechanisms that underlie visceral mechanosensitivity in colon-innervating visceral afferents remain elusive. Here, we show that virally mediated ablation of colon-innervating TRPV1-expressing nociceptors markedly reduces colorectal distention (CRD)-evoked visceromotor response (VMR) in mice. Selective ablation of the stretch-activated Piezo2 channels from TRPV1 lineage neurons substantially reduces mechanically evoked visceral afferent action potential firing and CRD-induced VMR under physiological conditions, as well as in mouse models of zymosan-induced IBS and partial colon obstruction (PCO). Collectively, our results demonstrate that mechanosensitive Piezo2 channels expressed by TRPV1-lineage nociceptors powerfully contribute to visceral mechanosensitivity and nociception under physiological conditions and visceral hypersensitivity under pathological conditions in mice, uncovering potential therapeutic targets for the treatment of visceral pain.

Immunometabolism contributes to inflammation, but how activated macrophages acquire extracellular nutrients to fuel inflammation is largely unknown. Here, we show that the plasma membrane potential (Vm) of macrophages mediated by Kir2.1, an inwardly-rectifying K+ channel, is an important determinant of nutrient acquisition and subsequent metabolic reprogramming promoting inflammation. In the absence of Kir2.1 activity, depolarized macrophage Vm lead to a caloric restriction state by limiting nutrient uptake and concomitant adaptations in nutrient conservation inducing autophagy, AMPK (Adenosine 5‘-monophosphate-activated protein kinase), and GCN2 (General control nonderepressible 2), which subsequently depletes epigenetic substrates feeding histone methylation at loci of a cluster of metabolism-responsive inflammatory genes, thereby suppressing their transcription. Kir2.1-mediated Vm supports nutrient uptake by facilitating cell-surface retention of nutrient transporters such as 4F2hc and GLUT1 by its modulation of plasma membrane phospholipid dynamics. Pharmacological targeting of Kir2.1 alleviated inflammation triggered by LPS or bacterial infection in a sepsis model and sterile inflammation in human samples. These findings identify an ionic control of macrophage activation and advance our understanding of the immunomodulatory properties of Vm that links nutrient inputs to inflammatory diseases.

Solar-blind ultraviolet (UV) photodetectors (PDs) have attracted tremendous attention in the environmental, industrial, military, and biological fields. As a representative III-nitride material, AlGaN alloys have broad development prospects in the field of solar-blind detection due to their superior properties, such as tunable wide bandgaps for intrinsic UV detection. In recent decades, a variety of AlGaN-based PDs have been developed to achieve high-precision solar-blind UV detection. As integrated optoelectronic technology advances, AlGaN-based focal plane arrays (FPAs) are manufactured and exhibit outstanding solar-blind imaging capability. Considering the rapid development of AlGaN detection techniques, this paper comprehensively reviews the progress on AlGaN-based solar-blind UV PDs and FPAs. First, the basic physical properties of AlGaN are presented. The epitaxy and p-type doping problems of AlGaN alloys are then discussed. Diverse PDs, including photoconductors and Schottky, metal-semiconductor-metal (MSM), p-i-n, and avalanche photodiodes (APDs), are demonstrated, and the physical mechanisms are analyzed to improve device performance. Additionally, this paper summarizes imaging technologies used with AlGaN FPAs in recent years. Benefiting from the development of AlGaN materials and optoelectronic devices, solar-blind UV detection technology is greeted with significant revolutions. Summarizing recent advances in the processing and properties of AlGaN-based solar-blind UV PDs and FPAs as well as AlGaN growth and doping techniques.

How the enteric nervous system determines the pacing and propagation direction of neurogenic contractions along the colon remains largely unknown. We used a chemogenetic strategy to ablate enteric neurons expressing calretinin (CAL). Mice expressing human diphtheria toxin receptor (DTR) in CAL neurons were generated by crossing CAL-ires-Cre mice with Cre-dependent ROSA26-DTR mice. Immunohistochemical analysis revealed treatment with diphtheria toxin incurred a 42% reduction in counts of Hu-expressing colonic myenteric neurons (P = 0.036), and 57% loss of CAL neurons (comprising ∼25% of all Hu neurons; P = 0.004) compared to control. As proportions of Hu-expressing neurons, CAL neurons that contained nitric oxide synthase (NOS) were relatively spared (control: 15 ± 2%, CAL-DTR: 13 ± 1%; P = 0.145), while calretinin neurons lacking NOS were significantly reduced (control: 26 ± 2%, CAL-DTR: 18 ± 5%; P = 0.010). Colonic length and pellet sizes were significantly reduced without overt inflammation or changes in ganglionic density. Interestingly, colonic motor complexes (CMCs) persisted with increased frequency (mid-colon interval 111 ± 19 vs. 189 ± 24 s, CAL-DTR vs. control, respectively, P < 0.001), decreased contraction size (mid-colon AUC 26 ± 24 vs. 59 ± 13 gram/seconds, CAL-DTR vs. control, respectively, P < 0.001), and lacked preferential anterograde migration (P < 0.001). The functional effects of modest calretinin neuron ablation, particularly increased neurogenic motor activity frequencies, differ from models that incur general enteric neuron loss, and suggest calretinin neurons may contribute to pacing, force, and polarity of CMCs in the large bowel.

In this paper, based on the different etching characteristics between GaN and Ga2O3, large-scale and vertically aligned β-Ga2O3 nanotube (NT) and microtube (MT) arrays were fabricated on the GaN template by a facile and feasible selective etching method. GaN micro-/nanowire arrays were prepared first by inductively coupled plasma (ICP) etching using self-organized or patterning nickel masks as the etching masks, and then the Ga2O3 shell layer converted from GaN was formed by thermal oxidation, resulting in GaN@Ga2O3 micro-/nanowire arrays. After the GaN core of GaN@Ga2O3 micro-/nanowire arrays was removed by ICP etching, hollow Ga2O3 tubes were obtained successfully. The micro-/nanotubes have uniform morphology and controllable size, and the wall thickness can also be controlled with the thermal oxidation conditions. These vertical β-Ga2O3 micro-/nanotube arrays could be used as new materials for novel optoelectronic devices.

Herein, a monolithic micro-pixelated light-emitting diode ( μLED) display realized using ion-surface-treatment-based planar-geometry pixelation is reported. A high-resolution blue-emitting μLED array is fabricated by optimizing ion species of a near-surface selectively positioned isolation process. The μLED array exhibiting inhibited surface recombination and higher output power is achieved by using heavy ions, such as fluorine (F−), due to more stable opto-electrical isolation and better process reliability. Furthermore, the low forward voltage of F−-IST-based μLED pixels can effectively improve the wall-plug efficiency for the μLED array with a pixel diameter of 6 μm. Conversely, the poor thermal stability of light hydrogen (H+) ions limits its device applications. Analysis based on a rate equation model reveals that the luminescence mechanism of F−-IST-based μLEDs is dominated by radiative recombination, which will benefit the planar-geometry pixelation for realizing highly efficient full-color microdisplays.

Flexible conductive hydrogel has been driven by scientific breakthroughs and offers a wide variety of applications, including sensors, electronic skins, biomedicine, energy storage, etc. Based on the mixed-ion crosslinking method, gelatin and sodium alginate (Gel–Alg) composite hydrogels were successfully prepared using Ca2+ crosslinking. The migration behavior of berberine hydrochloride (BBH) in the matrix network structure of Gel–Alg hydrogel with a certain pore size under an electric field was studied, and the transdermal effect of berberine hydrochloride under an electric field was also studied. The experimental results show that Gel–Alg has good flexibility and conductivity, and electrical stimulation can enhance the transdermal effect of drugs. Gel–Alg composite hydrogel may be a new material with potential application value in future biomedical directions.

Long-term sunlight exposure will cause the accumulation of free radicals in the skin and lead to oxidative damage and aging, antioxidant drugs have gradually become the focus of research, but there is little research on antioxidant drugs for percutaneous treatment. The purpose of this study was to prepare ligustrazine hydrochloride (TMPZ)-loaded liposome–hydrogel (TMPZ-LG), evaluate its antioxidant properties, and apply it on the skin of mice to observe whether it had preventive and therapeutic effect on the irradiation under the ultraviolet rays, in an attempt to make it into a new kind of delivery through the skin. TMPZ-LG was prepared by the combination of film dispersion and sodium carboxymethylcellulose (2%, CMC-Na) natural swelling method. The release rates in vitro permeation across the dialysis membrane and ex vivo transdermal had both reached 40%; the scavenging effect of TMPZ-LG on 1,1-diphenyl-2-picrylhydrazyl (DPPH) and H2O2 were 65.57 ± 4.13% and 73.06 ± 5.65%; the inhibition rate of TMPZ-LG on malondialdehyde (MDA) production in liver homogenate and anti-low density lipoprotein (LDL) oxidation experiments ex vivo were 15.03 ± 0.9% and 21.57 ± 1.2%. Compared with untreated mice, the skin pathological symptoms of mice coated with TMPZ-LG were significantly reduced after ultraviolet irradiation, and there was statistical significance. The results showed TMPZ-LG could exert good antioxidant activity in vitro and ex vivo; therefore, it is feasible to prevent and treat skin oxidation.

Nociceptive pain is a hallmark of many chronic inflammatory conditions including inflammatory bowel diseases (IBDs); however, whether pain-sensing neurons influence intestinal inflammation remains poorly defined. Employing chemogenetic silencing, adenoviral-mediated colon-specific silencing, and pharmacological ablation of TRPV1

Current-voltage ( I-V ) characteristics of AlGaN ultraviolet light-emitting diodes (UV-LEDs) under the temperatures ranging from 50 K to 300 K are analyzed. The abnormal diode characteristics of UV-LEDs below the turn-on voltage indicate the existence of space-charge-limited (SCL) current transport in the presence of deep trap states, which induce a non-linear current leakage effect. The SCL current is gradually overwhelmed by Ohmic leakage as the temperature increases, which is mainly due to the thermally generated carrier concentration and traps deactivation. A modified three-diode circuit model is suggested with an additional series resistor and diode to emulate the forward-bias I-V characteristics of UV-LEDs. An excellent fit to the I-V curves of UV-LEDs is achieved, which illustrates the impact of deep trap states on the electrical characteristics of UV-LEDs.

It is known that the commercialized white light-emitting diodes (WLEDs) depend on phosphor conversion, which is limited by the unbalanced carrier injection in multiple quantum wells (MQWs) and low down-conversion efficiency. To solve these problems, hybrid organic/inorganic III-nitride WLEDs were designed and fabricated based on Rubrene/(InGaN/GaN) MQWs p-n junction. In such new structure, Rubrene can act as yellow–red emitter and play an important role in hole transport layer owing to its high carrier mobility. By optimizing the hybrid LED structure, the charge balance and recombination zone in radiative region were significantly improved. In this work, the optimal hybrid WLED with color coordinates of (0.31, 0.33) shows a maximum current efficiency of 15.22 cd/A with excellent long lifetime stability. The hybrid WLEDs based on organic/inorganic p-n junction were demonstrated with a good performance, which provides an attractive route to achieve high performance phosphor-free WLED sources for microdisplay or large-area WLED applications.

We proposed an improved front-illuminated GaN/AlGaN separate absorption and multiplication (SAM) ultraviolet avalanche photodiode (APD) based on physical analysis and device simulations. By inserting an Al0.2Ga0.8N p-type layer into the p-i-p-i-n APD structure, a built-in electric field resulted from polarization effect will be introduced to facilitate the transport of electrons from absorption layer to multiplication region. The enhanced heterostructure APD presents significantly higher multiplication gain compared with the homogeneous one. Moreover, the doping concentration and thickness of the interlayer were optimized according to device performances, because the interlay has important effects on the electric field distribution and energy-band profile of the front-illuminated SAM APD.

We report here the preparation of porous single-crystal GaN films by direct top-down high temperature nitridation of β-Ga2O3. It is found that, although the crystallographic orientations of the original β-Ga2O3 samples are different, the GaN films converted from both bulk (200) β-Ga2O3 single crystal and (−201) β-Ga2O3 film have the same (0002) orientation and show no obvious stress. And we also found that the crystal quality of converted GaN strongly depends on the crystal quality of β-Ga2O3. In particular, we have successfully converted β-Ga2O3 film entirely to single-crystal GaN porous film on sapphire, and the self-separation happens naturally between the porous GaN film and sapphire.

Gallium nitride (GaN) films homo-epitaxially grown on GaN/sapphire templates and free standing GaN substrates by plasma-assisted molecular beam epitaxy (PA-MBE) have been investigated. After optimizations of growth temperature, the Ga/N flux ratio, surface preparation as well as initial growth process, the high quality MBE-GaN films were obtained. Combined with X-ray diffraction (XRD) and transmission electron microscopy (TEM) measurements, the TD densities were measured ∼4.2 × 108 cm−2 and ∼5 × 105 cm−2 for MBE-grown GaN films grown on GaN/sapphire templates and free standing GaN substrates, respectively. The observations of TEM prove the clear interface and well-arranged atomic lattice between substrates and as-grown layers. Besides, a flat and smooth surface with step-flow growth mode is observed by atomic force microscopy (AFM). Photoluminescence (PL) measurements exhibit that the linewidth for free excitons is as narrow as 4 meV at low temperature of 8 K and the deep level related yellow band emission ∼550 nm have been effectively suppressed at room temperature. The process optimization and obtained results give us wide latitude to fabricate high performance devices with lower tolerance to dislocation density.

We have successfully obtained a hexagonal single crystal GaN layer with (002) orientation by nitridating β-Ga2O3 film under NH3 flow despite structural mismatch between β-Ga2O3 and hexagonal GaN. The conversion process of β-Ga2O3 to GaN has also been systematically investigated. The nitridated GaN layer shows a network structure without significant stress, which makes it very suitable to be used as a template for the epitaxial growth of high-quality GaN films. The GaN/Ga2O3 heterostructure can also be used to obtain free-standing GaN (FS-GaN) films by self-separation or chemical lift-off (CLO) process due to the selective etching of β-Ga2O3. Further investigation demonstrates the feasibility of the in situ growth of low-stress FS-GaN substrates by halide vapor phase epitaxy (HVPE).

It is known that the commercialized white light-emitting diodes (WLEDs) depend on phosphor conversion, which is limited by the unbalanced carrier injection in multiple quantum wells (MQWs) and low down-conversion efficiency. To solve these problems, hybrid organic/inorganic III-nitride WLEDs were designed and fabricated based on Rubrene/(InGaN/GaN) MQWs p-n junction. In such new structure, Rubrene can act as yellow-red emitter and play an important role in hole transport layer owing to its high carrier mobility. By optimizing the hybrid LED structure, the charge balance and recombination zone in radiative region were significantly improved. In this work, the optimal hybrid WLED with color coordinates of (0.31, 0.33) shows a maximum current efficiency of 15.22 cd/A with excellent long lifetime stability. The hybrid WLEDs based on organic/inorganic p-n junction were demonstrated with a good performance, which provides an attractive route to achieve high performance phosphor-free WLED sources for microdisplay or large-area WLED applications.