In the developing hypothalamus, the fat‐derived hormone leptin stimulates the growth of axons from the arcuate nucleus of the hypothalamus (ARH) to other regions that control energy balance. These ...projections are significantly reduced in leptin deficient (Lepob/ob) mice and this phenotype is largely rescued by neonatal leptin treatments. However, treatment of mature Lepob/ob mice is ineffective, suggesting that the trophic action of leptin is limited to a developmental critical period. To temporally delineate closure of this critical period for leptin‐stimulated growth, we treated Lepob/ob mice with exogenous leptin during a variety of discrete time periods, and measured the density of Agouti‐Related Peptide (AgRP) containing projections from the ARH to the ventral part of the dorsomedial nucleus of the hypothalamus (DMHv), and to the medial parvocellular part of the paraventricular nucleus (PVHmp). The results indicate that leptin loses its neurotrophic potential at or near postnatal day 28. The duration of leptin exposure appears to be important, with 9‐ or 11‐day treatments found to be more effective than shorter (5‐day) treatments. Furthermore, leptin treatment for 9 days or more was sufficient to restore AgRP innervation to both the PVHmp and DMHv in Lepob/ob females, but only to the DMHv in Lepob/ob males. Together, these findings reveal that the trophic actions of leptin are contingent upon timing and duration of leptin exposure, display both target and sex specificity, and that modulation of leptin‐dependent circuit formation by each of these factors may carry enduring consequences for feeding behavior, metabolism, and obesity risk.
Leptin deficient (Lepob/ob) mice receiving exogenous leptin treatment during several discrete time periods were used to identify the closure of a critical period for leptin‐dependent growth of arcuate hypothalamic (ARH) projections. Anatomical, temporal, and sex‐specific differences in the ability of leptin to stimulate neurotrophic outgrowth of ARH projections are demonstrated.
Recently, perovskite (PV) oxides with ABO3 structures have attracted considerable interest from scientists owing to their functionality. In this study, CaFeOx is introduced to reveal the resistive ...switching properties and mechanism of oxygen vacancy transition in PV and brownmillerite (BM) structures. BM‐CaFeO2.5 is grown on an Nb‐STO conductive substrate epitaxially. CaFeOx exhibits excellent endurance and reliability. In addition, the CaFeOx also demonstrates an electroforming‐free characteristic and multilevel resistance properties. To construct the switching mechanism, high‐resolution transmission electron microscopy is used to observe the topotactic phase change in CaFeOx. In addition, scanning TEM and electron energy loss spectroscopy show the structural evolution and valence state variation of CaFeOx after the switching behavior. This study not only reveals the switching mechanism of CaFeOx, but also provides a PV oxide option for the dielectric material in resistive random‐access memory (RRAM) devices.
A complex oxide CaFeOx (CFO) is introduced as the dielectric layer in resistive random‐access memory (RRAM), demonstrating excellent RRAM properties, such as electroforming‐free and multilevel data storage. This study provides not only the switching mechanism of the CFO RRAM devices, but also the novel aspect for the RRAM dielectric materials.
The as-prepared cobalt oxide (assigned as CoO
x
) was fabricated by precipitation–oxidation from aqueous cobalt nitrate solution using sodium hydroxide and oxidation with hydrogen peroxide. Another ...series of pure cobalt oxides was refined by the decomposition of CoO
x
in a nitrogen environment at temperatures of 280, 450 and 950
°C (D-280, D-450 and D-950, respectively). Phase transformation, structural properties and red-ox properties were characterized by thermogravimetry-mass spectrometry (TG-MS), X-ray diffraction (XRD), infrared spectroscopy (IR), Raman spectroscopy and temperature-programmed decomposition/reduction (TPD/TPR). Analysis of the thermal behavior on CoO
x
revealed that a series of pure cobalt oxide with particle sizes of 10–20
nm could be obtained easily. The results demonstrated that the refined samples D-280, D-450 and D-950 were CoO(OH), Co
3O
4 and CoO, respectively.
This study aimed to develop an automated method to measure the gray-white matter ratio (GWR) from brain computed tomography (CT) scans of patients with out-of-hospital cardiac arrest (OHCA) and ...assess its significance in predicting early-stage neurological outcomes.
Patients with OHCA who underwent brain CT imaging within 12 h of return of spontaneous circulation were enrolled in this retrospective study. The primary outcome endpoint measure was a favorable neurological outcome, defined as cerebral performance category 1 or 2 at hospital discharge. We proposed an automated method comprising image registration, K-means segmentation, segmentation refinement, and GWR calculation to measure the GWR for each CT scan. The K-means segmentation and segmentation refinement was employed to refine the segmentations within regions of interest (ROIs), consequently enhancing GWR calculation accuracy through more precise segmentations.
Overall, 443 patients were divided into derivation N=265, 60% and validation N=178, 40% sets, based on age and sex. The ROI Hounsfield unit values derived from the automated method showed a strong correlation with those obtained from the manual method. Regarding outcome prediction, the automated method significantly outperformed the manual method in GWR calculation (AUC 0.79 vs. 0.70) across the entire dataset. The automated method also demonstrated superior performance across sensitivity, specificity, and positive and negative predictive values using the cutoff value determined from the derivation set. Moreover, GWR was an independent predictor of outcomes in logistic regression analysis. Incorporating the GWR with other clinical and resuscitation variables significantly enhanced the performance of prediction models compared to those without the GWR.
Automated measurement of the GWR from non-contrast brain CT images offers valuable insights for predicting neurological outcomes during the early post-cardiac arrest period.
•Method of images is successfully adopted to predict the LVG vortex dynamics.•A mixed LVG configuration is suggested to enhance the heat transfer performance.•LVG aspect ratio and channel height are ...very critical to the LVG effectiveness.
This paper reports a numerical investigation of fluid flow and heat transfer in a rectangular channel with delta-shaped winglet longitudinal vortex generators (LVGs) under different configurations. In addition to the conventional common-flow-down configuration and the common-flow-up configuration, a unique mixed configuration is suggested. The “method of images” is successfully adopted to analyze the dynamics of the longitudinal vortices due to wall interference. The Nusselt number, friction factor and overall performance coefficient for the three configurations are compared at various Reynolds numbers (all less than 2200), LVG row numbers, channel heights, and LVG aspect ratios. It is found that the channel height and LVG aspect ratio are the two most critical factors influencing the effectiveness of the different LVG configurations, which may explain why inconsistent conclusions have been presented by previous studies comparing the performance of the common-flow-down and common-flow-up configurations. When the channel height is relatively small, the unique mixed configuration is found to be the most effective at enhancing fluid mixing (and therefore improving heat transfer) at streamwise cross sections. When the LVG aspect ratio becomes large, the common-flow-down configuration outperforms the common-flow-up configuration. This paper sheds some insight on how to design the optimal LVG configuration for enhancing heat transfer performance.
Obesity is a potential risk factor for cognitive deficits in the elder humans. Using a high-fat diet (HFD)–induced obese mouse model, we investigated the impacts of HFD on obesity, metabolic and ...stress hormones, learning performance, and hippocampal synaptic plasticity. Both male and female C57BL/6J mice fed with HFD (3 weeks to 9–12 months) gained significantly more weights than the sex-specific control groups. Compared with the obese female mice, the obese males had similar energy intake but developed more weight gains. The obese male mice developed hyperglycemia, hyperinsulinemia, hypercholesterolemia, and hyperleptinemia, but not hypertriglyceridemia. The obese females had less hyperinsulinemia and hypercholesterolemia than the obese males, and no hyperglycemia and hypertriglyceridemia. In the contextual fear conditioning and step-down passive avoidance tasks, the obese male, but not female, mice showed poorer learning performance than their normal counterparts. These learning deficits were not due to sensorimotor impairment as verified by the open-field and hot-plate tests. Although, basal synaptic transmission characteristics (input–output transfer and paired-pulse facilitation (PPF) ratio) were not significantly different between normal and HFD groups, the magnitudes of synaptic plasticity (long-term potentiation (LTP) and long-term depression (LTD)) were lower at the Schaffer collateral-CA1 synapses of the hippocampal slices isolated from the obese male, but not female, mice, as compared with their sex-specific controls. Our results suggest that male mice are more vulnerable than the females to the impacts of HFD on weight gains, metabolic alterations and deficits of learning, and hippocampal synaptic plasticity.
Photocatalytic membrane reactors (PMRs) have been widely used in wastewater treatment over the past few years. In this study, P-doped g-C3N4 (PCN), a metal-free, visible light (Vis)-driven ...photocatalyst, was prepared and coated on an Al2O3 substrate followed by integration with an inorganic Al2O3 hollow fiber membrane module for use as a PMR. The 10 wt % of PCN exhibited the highest degradation activity for methyl blue (MB) removal under Vis irradiation because the C sites and vacancies within the heptazine rings of the CN units were substituted with P to improve charge separation and reduce the number of unpaired electrons. The PMR exhibits higher efficiency and stability in the removal of MB, methyl orange, phenol solution, and a mixture of the three organic compounds than do individual hollow fiber membranes or photocatalysis systems. The TOC (total organic carbon) analysis revealed that more than 92% of the phenol was decomposed and mineralized in the PMR, which also had a MB removal efficiency of greater than 90% when repeatedly used for four times. These results indicate that the PMR developed in this study is highly active and stable, and can serve as a promising system for effective removal of organic pollutants in wastewater.
Photocatalytic membrane reactor integrated with P-doped g-C3N4 with Al2O3 hollow fiber membrane module exhibits excellent photocatalytic activity. Display omitted
•P replaces C in g-C3N4 structure to improve charge separation and photocatalysis.•P-doped g-C3N4 was fabricated and integrated with photocatalytic membrane reactor.•PMR can be used for wastewater treatment under irradiation of simulated sunlight.•PMR degrades MB under irradiation with light of wavelength larger than 400 nm.
Limb-girdle muscular dystrophy (LGMD) is a genetically heterogeneous, hereditary disease characterized by limb-girdle weakness and histologically dystrophic changes. The prevalence of each subtype of ...LGMD varies among different ethnic populations. This study for the first time analyzed the phenotypes and genotypes in Taiwanese patients with LGMD in a referral center for neuromuscular diseases (NMDs). We enrolled 102 patients clinically suspected of having LGMD who underwent muscle biopsy with subsequent genetic analysis in the previous 10 years. On the basis of different pathological categories, we performed sequencing of target genes or panel for NMDs and then identified patients with type 1B, 1E, 2A, 2B, 2D, 2I, 2G, 2 N, and 2Q. The 1B patients with LMNA mutation presented with mild limb-girdle weakness but no conduction defect at the time. All 1E patients with DES mutation exhibited predominantly proximal weakness along with distal weakness. In our cohort, 2B and 2I were the most frequent forms of LGMD; several common or founder mutations were identified, including c.1097_1099delACA (p.Asn366del) in DES, homozygous c.101G > T (p.Arg34Leu) in SGCA, homozygous c.26_33dup (p.Glu12Argfs*20) in TCAP, c.545A > G (p.Tyr182Cys), and c.948delC (p.Cys317Alafs*111) in FKRP. Clinically, the prevalence of dilated cardiomyopathy in our patients with LGMD2I aged > 18 years was 100%, much higher than that in European cohorts. The only patient with LGMD2Q with PLEC mutation did not exhibit skin lesions or gastrointestinal abnormalities but had mild facial weakness. Muscle imaging of LGMD1E and 2G revealed a more uniform involvement than did other LGMD types. Our study revealed that detailed clinical manifestation together with muscle pathology and imaging remain critical in guiding further molecular analyses and are crucial for establishing genotype-phenotype correlations. We also determined the common mutations and prevalence for different subtypes of LGMD in our cohort, which could be useful when providing specific care and personalized therapy to patients with LGMD.
Abstract Objective Studies have shown the detrimental effect of hyperoxia in animals with return of spontaneous circulation (ROSC) after cardiac arrest. To maximize the value of existing clinical ...studies, we performed the systemic review and meta-analysis of human observational studies to examine the effect of hyperoxia on outcomes of post-ROSC patients. Methods We searched PubMed and Embase from the inception to October 2013. We selected adult observational studies that compared different levels of partial pressure of arterial oxygen (PaO2 ) in post-ROSC patients with mortality or neurological status at hospital discharge as outcome. Studies comparing hypoxia with normoxia only were excluded. Results Fourteen studies were identified from 2982 references. Odds ratio (OR) was used as effect estimate. OR was reconstructed if not provided in original articles. Hyperoxia was defined as a PaO2 >300 mmHg. Meta-analysis indicated that hyperoxia appeared to be correlated with increased in-hospital mortality (OR, 1.40; 95% CI, 1.02–1.93; I2 , 69.27%; 8 studies) but not worsened neurological outcome (OR, 1.62; 95% CI, 0.87–3.02; I2 , 55.61%; 2 studies). However, the results were inconsistent in subgroup and sensitivity analyses. Conclusions Hyperoxia appears to be correlated with increased in-hospital mortality of post-ROSC patients. This result should be interpreted cautiously because of the significant heterogeneity and limited number of studies analyzed. However, because exposure to hyperoxia had no obvious benefits, clinicians should monitor PaO2 closely and titrate oxygen administration cautiously.
The development of bilayer models is crucial for enhancing the performance and enabling multifunctionality of next-generation resistive random-access memory (RRAM). However, detailed switching ...information is still insufficient for multilayer RRAM, necessitating direct observation of the microstructural evolution to clarify its switching mechanism. In this study, the electrical properties of Pt/Nb2O5−x/Pt monolayer devices were improved by introducing a polycrystalline NiO layer, and the resulting Pt/NiO/Nb2O5−x/Pt bilayer devices exhibited a doubling of the endurance and a reduction of the set voltage. The bilayer device also exhibited a long retention time (>104 s) and high on/off ratio of 104. Transmission electron microscopy, X-ray photoelectron spectroscopy, and electron energy-loss spectroscopy revealed that the conductive filament (CF) contained oxygen vacancies. In addition, a funnel-shaped CF was observed in the Pt/NiO/Nb2O5−x/Pt system, with the neck at the NiO/Nb2O5−x interface. This study provides a distinctive viewpoint and an innovative strategy for improving RRAM devices and exploring new applications in electronics.
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•Introducing an oxygen reservoir layer enhances device performance and versatility.•The addition of a polycrystalline nickel oxide layer reduces device switching voltage.•The migration of holes and electrons forms funnel-shaped conductive filaments.•Electrical bias induces niobium oxide structural transformation, altering properties.
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