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Exogenous ghrelin reduces glucose-stimulated insulin secretion and endogenous ghrelin protects against hypoglycemia during starvation. Islet ε-cells produce ghrelin and δ-cells express growth hormone secretagogue receptor (GHSR), suggesting the possibility of a paracrine mechanism for islet ghrelin to reach high local concentrations and affect insulin secretion. GHSR has high constitutive activity and may act independently of ghrelin. The objective in this study was to determine whether an intraislet ghrelin-GHSR axis modulates insulin secretion and glucose metabolism using mouse models lacking ghrelin (Ghrl-/- ) or GHSR (Ghsr-/- ). Ghsr-/- and Ghsr+/+ mice had comparable islet ghrelin concentrations. Exogenous ghrelin decreased insulin secretion in perifused isolated islets in a GHSR-dependent manner. Islets isolated from Ghrl-/- or Ghsr-/- mice did not differ from controls in glucose-, alanine-, or GLP-1-stimulated insulin secretion during perifusion. Consistent with this finding, Ghrl-/- and Ghsr-/- male mice studied after either 6 or 16 h of fasting had blood glucose concentrations comparable with those of controls following intraperitoneal glucose, or insulin tolerance tests, or after mixed nutrient meals. Collectively, our data provide strong evidence against a paracrine ghrelin-GHSR axis mediating insulin secretion or glucose tolerance in lean, chow-fed adult mice. [ABSTRACT FROM AUTHOR]

One of the characteristics of topological materials is their nontrivial Berry phase. Experimental determination of this phase largely relies on a phase analysis of quantum oscillations. We study the angular dependence of the oscillations in a Dirac material ZrTe5 and observe a striking spin-zero effect (i.e., vanishing oscillations accompanied with a phase inversion). This indicates that the Berry phase in ZrTe5 remains nontrivial for arbitrary field direction, in contrast with previous reports. The Zeeman splitting is found to be proportional to the magnetic field based on the condition for the spin-zero effect in a Dirac band. Moreover, it is suggested that the Dirac band in ZrTe5 is likely transformed into a line node other than Weyl points for the field directions at which the spin zero occurs. The results underline a largely overlooked spin factor when determining the Berry phase from quantum oscillations. [ABSTRACT FROM AUTHOR]

Bariatric surgeries, including vertical sleeve gastrectomy (VSG), resolve diabetes in 40-50% of patients. Studies examining the molecular mechanisms underlying this effect have centered on the role of the insulinotropic glucagon-like peptide 1 (GLP-1), in great part because of the ∼10-fold rise in its circulating levels after surgery. However, there is currently debate over the role of direct β-cell signaling by GLP-1 to mediate improved glucose tolerance following surgery. In order to assess the importance of β-cell GLP-1 receptor (GLP-1R) for improving glucose control after VSG, a mouse model of this procedure was developed and combined with a genetically modified mouse line allowing an inducible, β-cell-specific Glp1r knockdown (Glp1rβ-cell-ko). Mice with VSG lost ∼20% of body weight over 30 days compared with sham-operated controls and had a ∼60% improvement in glucose tolerance. Isolated islets from VSG mice had significantly greater insulin responses to glucose than controls. Glp1r knockdown in β-cells caused glucose intolerance in diet-induced obese mice compared with obese controls, but VSG improved glycemic profiles to similar levels during oral and intraperitoneal glucose challenges in Glp1rβ-cell-ko and Glp1rWT mice. Therefore, even though the β-cell GLP-1R seems to be important for maintaining glucose tolerance in obese mice, in these experiments it is dispensable for the improvement in glucose tolerance after VSG. Moreover, the metabolic physiology activated by VSG can overcome the deficits in glucose regulation caused by lack of β-cell GLP-1 signaling in obesity. [ABSTRACT FROM AUTHOR]

As induced by the loss of prologues or irrelevant parts added in sequences, gene duplicates affect evolution. Following fish specific genome duplication (FSGD), gene duplicates undergo divergent pathways in gene evolution. Our aim is to map the evolution process of DNAH9 duplication in Paralichthys olivaceus (P. olivaceus) after FSGD to gain an insight into the evolution pathway in teleostes. In this study, two duplicates (DNAH9A and DNAH9B) and two transcripts (dnah9a and dnah9b) were identified in P. olivaceus. A comparison of each genomic duplicate with each transcript DNAH9B could transcribe a complete transcript, dnah9b, but DNAH9A was necessary to co-transcribe DNAH9B with dnah9a. From phylogenetic trees, the DNAH9 type of P. olivaceus shared the same cluster with all ray-finned fishes. However, DNAH9 duplicates only occurred in P. olivaceus and Cynoglossus semilaevis. In conclusion, the duplication of P. olivaceus DNAH9 occurred during FSGD, and the duplicates showed a divergent evolution path, undergoing a period of duplication-degeneration-complementation and then obtaining a new function. [ABSTRACT FROM AUTHOR]

Impurity doping plays a pivotal role in semiconductor electronics. We study the doping effect in a two-dimensional semiconductor, gapped bilayer graphene. By employing in situ deposition of calcium on the bilayer graphene, dopants are controllably introduced. Low temperature transport results show a variable range hopping conduction near the charge neutrality point persisting up to 50 K, providing evidence for the impurity levels inside the gap. Our experiment confirms a predicted peculiar effect in the gapped bilayer graphene, i.e., formation of in-gap states even if the bare impurity level lies in the conduction band. The result provides perspective on the effect of doping and impurity levels in semiconducting bilayer graphene. [ABSTRACT FROM AUTHOR]

The Nodal signaling pathway downstream transcription target pitx2 has been found to be involved in determination of left-right (L-R) asymmetry in the mouse, chick and Xenopus embryos. However, the genetic characteristic and evolution of pitx2 has rarely been reported in marine fish. In our study, we cloned and analyzed the structure of pitx2 in tongue sole (Cynoglossus semilaevis) (Cs-pitx2) and stone flounder (Kareius bicoloratus) (Kbpitx2). Phylogenetic and sequences analysis showed that Cs-pitx2 and Kb-pitx2 had high identity, and homologous to the pitx2 of other vertebrates. A low Ka/Ks ratio showed that pitx2 evolving was under purifying selection. There are several basal core promoter elements and transcription factor binding sites in the promoter region of Cs-pitx2. Quantitative RT-PCR analysis showed that the expression of pitx2 increased during the developmental stages. Interestingly, the expression of pitx2 in sinistral tongue sole was much higher than in dextral flatfish stone flounder during metamorphosis, which might be one of the reasons of different deflecting direction of them. These data provide the evidence that pitx2 was a crucial Nodal signaling pathway gene that might mediate L-R asymmetry in flatfish. [ABSTRACT FROM AUTHOR]

Objective To investigate the clinical and electroencephalographic (EEG) features of children with eating-induced reflex epilepsy. Methods A retrospective analysis was performed for the clinical features, EEG findings, treatment, and prognosis of three children with eating-induced reflex epilepsy who attended Department of Pediatrics in our hospital from 2014 to 2024. Results There were two boys among the three children. Two children had normal intellectual development before the onset of the disease, while one was diagnosed with intellectual disability. All three children had normal cranial MRI results, and whole-exome genetic testing and copy number variation testing were performed for two children and their families, which yielded negative results. In case 1, the child had focal seizures and later developed into focal secondary bilateral tonic-clonic seizures, and EEG monitoring showed bilateral Rolandic discharges in the interictal period, but without eating-induced seizures. In case 2, the child had focal epileptic spasms during wakefulness and generalized myoclonic seizures during sleep, and EEG monitoring showed the coexistence of multifocal discharges and generalized discharges in the interictal period, drinking water induced three clusters of predominantly right-sided generalized multiphase slow waves with epileptic spasms, as well as several spontaneous generalized myo-clonic seizures during sleep. In case 3, the child had coexistence of focal epileptic spasms and generalized tonic seizures, and EEG monitoring showed the coexistence of multifocal discharges and generalized discharges, eating induced a cluster of predominantly left posterior multiphase slow waves with epileptic spasms. All three children received more than two anti-seizure medications (ASMs) and failed to achieve the control of seizures, and they presented with varying degrees of intellectual disability after disease onset. Conclusion Eating-induced reflex epilepsy is slightly more common in boys and is often accompanied by intellectual disability after disease onset. The coexistence of spontaneous seizures and induced seizures is often observed in this disease, with epileptic spasms being the more common type of eating-induced seizures. EEG manifestations in the interictal period include focal discharges, generalized discharges, or the coexistence of both types of discharges. ASMs have a poor therapeutic effect on this disease.

The rise of graphene marks the advent of two-dimensional atomic crystals, which have exhibited a cornucopia of intriguing properties, such as the integer and fractional quantum Hall effects, valley Hall effect, charge density waves, and superconductivity, to name a few. Yet, magnetism, a property of extreme importance in both science and technology, remains elusive. There is a paramount need for magnetic two-dimensional crystals. With the availability of many magnetic materials consisting of van der Waals coupled two-dimensional layers, it thus boils down to the question of how the magnetic order will evolve with reducing thickness. Here we investigate the effect of thickness on the magnetic ordering in nanothick V5S8. We uncover an anomalous Hall effect, by which the magnetic ordering in V5S8 down to 3.2 nm is probed. With decreasing thickness, a breakdown of antiferromagnetism is evident, followed by a spin-glass-like state. For thinnest samples, a weak ferromagnetic ordering emerges. The results not only show an interesting effect of reducing thickness on the magnetic ordering in a potential candidate for magnetic two-dimensional crystals, but demonstrate the anomalous Hall effect as a useful characterization tool for magnetic orderings in two-dimensional systems. [ABSTRACT FROM AUTHOR]

ZrTe5 is a newly discovered topological material. Shortly after a single layer ZrTe5 had been predicted to be a two-dimensional topological insulator, a handful of experiments have been carried out on bulk ZrTe5 crystals, which however suggest that its bulk form may be a three-dimensional topological Dirac semimetal. We report a transport study on ultrathin ZrTe5 flakes down to 10 nm. A significant modulation of the characteristic resistivity maximum in the temperature dependence by thickness has been observed. Remarkably, the metallic behavior, occurring only below about 150 K in bulk, persists to over 320 K for flakes less than 20 nm thick. Furthermore, the resistivity maximum can be greatly tuned by ionic gating. Combined with the Hall resistance, we identify contributions from a semiconducting and a semimetallic band. The enhancement of the metallic state in thin flakes are a consequence of shifting of the energy bands. Our results suggest that the band structure sensitively depends on the film thickness, which may explain the divergent experimental observations on bulk materials. [ABSTRACT FROM AUTHOR]

Background: Internet-based interventions are more cost-effective than conventional interventions and can provide immediate, easy-to-access, and individually tailored support for behavior change. Waist circumference is a strong predictor of an increased risk for a host of diseases, such as hypertension, diabetes, and dyslipidemia, independent of body mass index. To date, no study has examined the effect of Internet-based lifestyle interventions on waist circumference change. [ABSTRACT FROM AUTHOR]

We study the intervalley scattering in defected graphene by low-temperature transport measurements. The scattering rate is strongly suppressed when defects are charged. This finding highlights "screening" of the short-range part of a potential by the long-range part. Experiments on calcium-adsorbed graphene confirm the role of a long-range Coulomb potential. This effect is applicable to other multivalley systems, provided that the charge state of a defect can be electrically tuned. Our result provides a means to electrically control valley relaxation and has important implications in valley dynamics in valleytronic materials. [ABSTRACT FROM AUTHOR]