Nonparametric two-sample tests of high dimensional mean vectors via random integration.

Testing the equality of the means in two samples is a fundamental statistical inferential problem. Most of the existing methods are based on the sum-of-squares or supremum statistics. They are possibly powerful in some situations, but not in others, and they do not work in a unified way. Using random integration of the difference, we develop a framework that includes and extends many existing methods, especially in high-dimensional settings, without restricting the same covariance matrices or sparsity. Under a general multivariate model, we can derive the asymptotic properties of the proposed test statistic without specifying a relationship between the data dimension and sample size explicitly. Specifically, the new framework allows us to better understand the test's properties and select a powerful procedure accordingly. For example, we prove that our proposed test can achieve the power of 1 when nonzero signals in the true mean differences are weakly dense with nearly the same sign. In addition, we delineate the conditions under which the asymptotic relative Pitman efficiency of our proposed test to its competitor is greater than or equal to 1. Extensive numerical studies and a real data example demonstrate the potential of our proposed test.

[Research progress on strontium isotope-traced plant remains production areas and implications for traceability of Dao-di herbs in Forbidden City of the Qing Dynasty].

Strontium isotope(~(87)S/~(86)Sr) tracing technology has been widely used in animal remains and origin of modern food origin sources. However, due to the problems of sample contamination and cleaning, this technology has been applied less frequently in the tracing of plant remains. The Palace Museum preserves more than 1 000 relics of medicinal materials from the Forbidden City of the Qing Dynasty, which are rare precious materials for the study of Dao-di herbs. The well-preserved environment of these medicinal materials in the Forbidden City of the Qing Dynasty helps avoid external strontium contamination, making it possible to introduce strontium isotope technology in their tracing research. On this basis, this study discussed the principle of strontium isotope tracing technology and summarized the current research progress on tracing plant remains using strontium isotope. In addition, this study discussed three key problems and their respective solutions encountered when applying strontium isotope technology to the tracing research on medicinal materials from the Forbidden City of the Qing Dynasty: creating strontium isotope ratio maps, dealing with the wide range of traceable results, and addressing the sample contamination and cleaning challenges. The literature and historical materials of the Qing Dynasty are the important basis for understanding the distribution and application of Dao-di herbs in the Qing Dynasty. Based on literature research, the use of strontium isotope to trace the producing area of medicinal materials in the Forbidden City of the Qing Dynasty can provide physical evidence for relevant research. The combined evidence of historical materials and medicinal relics is expected to provide a new perspective for the study of Dao-di herbs in the Qing Dynasty and also provide a reference for the study of the revolution of Dao-di herbs producing areas.

Fuling production areas in China: climate and distribution changes (A.D. 618-2100).

Through a meticulous analysis of ancient Chinese literature, this study comprehensively documents the geographical distribution of Fuling, a traditional Chinese medicinal material, during the Tang, Song, Ming, and Qing dynasties spanning from the seventh to the twentieth century in China. Based on the contemporary distribution information of Fuling, we utilized the maximum entropy (MaxEnt) model to simulate the suitable distribution areas of Fuling under both present-day conditions and in the future (2081~2100). The findings reveal that climate change has influenced the distribution of Fuling production areas. The shifts in Fuling's origin during different periods in ancient and modern times align with climate fluctuations and concurrent societal development. During the Tang and Song dynasties, Fuling primarily originated in northern China. However, it migrated southward during the Little Ice Age (LIA) and has recently shown a slight northward shift, in line with the climate fluctuations of the LIA and contemporary global warming trends. This study offers a comprehensive analysis of the changes in the distribution and production areas of Fuling over a 1500-year period, encompassing ancient, modern, and future periods. The results provide critical insights for adjusting Fuling cultivation areas in response to climate change and for further exploration of the mechanisms through which climate impacts the growth of Fuling.

Use of random integration to test equality of high dimensional covariance matrices.

Testing the equality of two covariance matrices is a fundamental problem in statistics, and especially challenging when the data are high-dimensional. Through a novel use of random integration, we can test the equality of high-dimensional covariance matrices without assuming parametric distributions for the two underlying populations, even if the dimension is much larger than the sample size. The asymptotic properties of our test for arbitrary number of covariates and sample size are studied in depth under a general multivariate model. The finite-sample performance of our test is evaluated through numerical studies. The empirical results demonstrate that our test is highly competitive with existing tests in a wide range of settings. In particular, our proposed test is distinctly powerful under different settings when there exist a few large or many small diagonal disturbances between the two covariance matrices.

The regulatory effects of the apelin/APJ system on depression: A prospective therapeutic target.

Depression is a debilitating neuropsychological disorder characterized by high incidence, high recurrence, high suicide, and high disability rates, which poses serious threats to human health and imposes heavy psychological and economic burdens on family and society. The pathogenesis of depression is extremely complex, and its etiology is multifactorial. Mounting evidence suggests that apelin and apelin receptor APJ, which compose the apelin/APJ system, are related to the development of depression. However, the specific mechanism is still unclear, and research in this area in human is still insufficient. Acceleration of research into the regulatory effects and underlying mechanisms of the apelin/APJ system in depression may identify attractive therapeutic targets and contribute to the development of novel intervention strategies against this devastating psychological disorder. In this review, we mainly discuss the regulatory effects of apelin/APJ system on depression and its potential therapeutic applications.

Heterodimerization of apelin and opioid receptor-like 1 receptors mediates apelin-13-induced G protein biased signaling.

The apelin receptor (APJ) and the opioid-related nociceptin receptor 1 (ORL1) are family A G protein-coupled receptors that participate in a variety of physiological processes. The distribution and function of APJ and ORL1 in the nervous system and peripheral tissues are similar; however, the detailed mechanism of how these two receptors modulate signaling and physiological effects remains unclear. Here, we examined whether APJ and ORL1 form dimers, and investigated signal transduction pathways. The endogenous co-expression of APJ and ORL1 in SH-SY5Y cells was confirmed by western blotting and RT-PCR. Bioluminescence and fluorescence resonance energy transfer assays, as well as a proximity ligation assay and co-immunoprecipitation experiments, demonstrated that APJ and ORL1 heterodimerize in HEK293 cells. We found that the APJ-ORL1 heterodimer is selectively activated by apelin-13, which causes the dimer to couple to Gαi proteins and reduce the recruitment of GRKs and ß-arrestins to the dimer. We showed that the APJ-ORL1 dimer exhibits biased signaling, in which G protein-dependent signaling pathways override ß-arrestin-dependent signaling pathways. Our results demonstrate that the structural interface of the APJ-ORL1 dimer switches from transmembrane domain TM1/TM2 in the inactive state to TM5 in the active state. We used mutational analysis and BRET assays to identify key residues in TM5 (APJ L2185.55, APJ I2245.61, and ORL1 L2295.52) responsible for the receptor-receptor interaction. These results provide important information on the APJ-ORL1 heterodimer and may assist the design of new drugs targeting biased signaling pathways for treatment of pain and cardiovascular and metabolic diseases.

Study on the Evolution and Optimization of the Spatial Structure of the Oasis in the Arid Area: A Case Study of the Aksu River Basin in China.

To achieve high-quality sustainable development in arid areas based on the concept of ecological civilization, it is necessary to deeply study the territorial spatial structure characteristics. Taking the Aksu River Basin, an important ecological security barrier in northwest China, as an example, this paper follows the research idea of "feature analysis-suitability evaluation-conflict identification analysis-optimization" and constructs a comprehensive model based on the AHP-entropy weight comprehensive evaluation method, ArcGIS spatial identification analysis, variance coefficient-TOPSIS method, and NRCA. A comprehensive model based on the AHP-entropy power integrated evaluation method, ArcGIS spatial identification analysis, variance coefficient-TOPSIS method, and NRCA was constructed to guide the optimization of the territorial spatial layout by exploring the characteristics of territorial spatial pattern, the suitability of territorial spatial development, the identification of territorial spatial conflicts, and the efficiency and functional advantage of territorial spatial utilization in the study area. The results show that: (1) The spatial type of territorial space in the Aksu River Basin from 2000 to 2020 is dominated by ecological space, agricultural space, and urban space, and the three spatial boundaries are irregularly interlaced. (2) The spatial utilization conflict pattern of the Aksu River Basin has formed, and the general conflict area is overgrowing. (3) The overall efficiency of territorial utilization in the Aksu River Basin is low, with significant differences among county administrative units. (4) After optimization, the three types of space in the watershed are adjusted and refined into six functional areas: basic farmland protection area, rural development area, ecological protection red line area, ecological control area, urban development area, and industrial supporting construction area.

Photoelectrochemical Detection of Calcium Ions Based on Hematite Nanorod Sensors.

α-Fe2O3 (hematite) thin films have been shown to be a robust sensor substrate for photoelectrochemical imaging with good stability and high spatial resolution. Herein, one-dimensional (1D) hematite nanorods (NRs) synthesized via a simple hydrothermal method are proposed as a substrate which provides nanostructured surfaces with enhanced photocurrent responses compared to previously described hematite films, good stability, and excellent spatial resolution for potential imaging applications. The photoelectrochemical sensing capability of hematite NRs was demonstrated by a high pH sensitivity without modification. The modification of the hematite NRs with a thin poly(vinyl chloride) (PVC)-based ion-selective film allowed highly reversible amperometric detection of calcium ions with sensor materials traditionally employed in potentiometric devices.

Efficacy and safety of Xuefu Zhuyu Granules combined with western medicine in the treatment of angina pectoris of coronary heart disease: A study protocol of a randomized, double-blind, placebo-controlled clinical trial.

BACKGROUND: Despite advances in treatment strategies for coronary heart disease, angina pectoris remains a major cardiovascular disease causing death worldwide. For patients with angina pectoris of coronary heart disease, new or adjuvant treatment regimens are needed. The available evidence suggests that Xuefu Zhuyu Granules combined with Western medicine has advantages in the treatment of angina pectoris of coronary heart disease, but whether its efficacy has a placebo effect and whether it can be used as an adjuvant regimen for the treatment of angina pectoris of coronary heart disease remains controversial. METHODS: This is a prospective, randomized, double-blind, placebo-controlled trial to study the efficacy and safety of Xuefu Zhuyu Granules combined with Western medicine in the treatment of angina pectoris of coronary heart disease. Participants will be randomly divided into a treatment group or a control group, and all patients will receive Western medicine treatment based on guideline recommendations. On this basis, the treatment group orally takes Xuefu Zhuyu Granules and the control group orally takes Xuefu Zhuyu Granules mimic, and are followed up for 24 weeks after 12 weeks of continuous treatment. The observation indexes include: cardiac function parameters (left ventricular end-diastolic diameter; left ventricular end-systolic diameter; left ventricular ejection fraction, blood lipid levels (total cholesterol; triacylglycerol; low-density lipoprotein cholesterol; high-density lipoprotein cholesterol), the number of angina attacks per week, total amount of nitroglycerin tablets taken, and adverse reactions. Finally, SPSS22.0 (IBM Company, New York, NY) software will be used for statistical analysis of the data. DISCUSSION: This study will evaluate the efficacy and safety of Xuefu Zhuyu Granules combined with Western medicine in the treatment of angina pectoris of coronary heart disease. The results of this study will verify whether the efficacy of Xuefu Zhuyu Granules in the treatment of angina pectoris of coronary heart disease belongs to the placebo effect, which will also provide a reference for the clinical use of Xuefu Zhuyu Granules as a supplementary scheme for the treatment of angina pectoris of coronary heart disease.

Molecular Plasmonics with Metamaterials.

Molecular plasmonics, the area which deals with the interactions between surface plasmons and molecules, has received enormous interest in fundamental research and found numerous technological applications. Plasmonic metamaterials, which offer rich opportunities to control the light intensity, field polarization, and local density of electromagnetic states on subwavelength scales, provide a versatile platform to enhance and tune light-molecule interactions. A variety of applications, including spontaneous emission enhancement, optical modulation, optical sensing, and photoactuated nanochemistry, have been reported by exploiting molecular interactions with plasmonic metamaterials. In this paper, we provide a comprehensive overview of the developments of molecular plasmonics with metamaterials. After a brief introduction to the optical properties of plasmonic metamaterials and relevant fabrication approaches, we discuss light-molecule interactions in plasmonic metamaterials in both weak and strong coupling regimes. We then highlight the exploitation of molecules in metamaterials for applications ranging from emission control and optical modulation to optical sensing. The role of hot carriers generated in metamaterials for nanochemistry is also discussed. Perspectives on the future development of molecular plasmonics with metamaterials conclude the review. The use of molecules in combination with designer metamaterials provides a rich playground both to actively control metamaterials using molecular interactions and, in turn, to use metamaterials to control molecular processes.

A robust and efficient variable selection method for linear regression.

Variable selection is fundamental to high dimensional statistical modeling, and many approaches have been proposed. However, existing variable selection methods do not perform well in presence of outliers in response variable or/and covariates. In order to ensure a high probability of correct selection and efficient parameter estimation, we investigate a robust variable selection method based on a modified Huber's function with an exponential squared loss tail. We also prove that the proposed method has oracle properties. Furthermore, we carry out simulation studies to evaluate the performance of the proposed method for both pn. Our simulation results indicate that the proposed method is efficient and robust against outliers and heavy-tailed distributions. Finally, a real dataset from an air pollution mortality study is used to illustrate the proposed method.

Disruption of 5-hydroxytryptamine 1A receptor and orexin receptor 1 heterodimer formation affects novel G protein-dependent signaling pathways and has antidepressant effects in vivo.

G protein-coupled receptor (GPCR) heterodimers are new targets for the treatment of depression. Increasing evidence supports the importance of serotonergic and orexin-producing neurons in numerous physiological processes, possibly via a crucial interaction between 5-hydroxytryptamine 1A receptor (5-HT1AR) and orexin receptor 1 (OX1R). However, little is known about the function of 5-HT1AR/OX1R heterodimers. It is unclear how the transmembrane domains (TMs) of the dimer affect its function and whether its modulation mediates antidepressant-like effects. Here, we examined the mechanism of 5-HT1AR/OX1R dimerization and downstream G protein-dependent signaling. We found that 5-HT1AR and OX1R form constitutive heterodimers that induce novel G protein-dependent signaling, and that this heterodimerization does not affect recruitment of ß-arrestins to the complex. In addition, we found that the structural interface of the active 5-HT1AR/OX1R dimer transforms from TM4/TM5 in the basal state to TM6 in the active conformation. We also used mutation analyses to identify key residues at the interface (5-HT1AR R1514.40, 5-HT1AR Y1985.41, and OX1R L2305.54). Injection of chronic unpredictable mild stress (CUMS) rats with TM4/TM5 peptides improved their depression-like emotional status and decreased the number of endogenous 5-HT1AR/OX1R heterodimers in the rat brain. These antidepressant effects may be mediated by upregulation of BDNF levels and enhanced phosphorylation and activation of CREB in the hippocampus and medial prefrontal cortex. This study provides evidence that 5-HT1AR/OX1R heterodimers are involved in the pathological process of depression. Peptides including TMs of the 5-HT1AR/OX1R heterodimer interface are candidates for the development of compounds with fast-acting antidepressant-like effects.

Prophylactically injection of Nicorandil to reduce no-reflow phenomenon during PCI in acute STEMI patients: Protocol of a double-blinded, randomized, placebo-controlled trial.

INTRODUCTION: An acute ST-elevation myocardial infarction (STEMI) is a very serious type of heart attack and a profoundly life-threatening medical emergency, and percutaneous coronary intervention (PCI) is the preferred strategy. However, in patients undergoing primary PCI, 30% to 40% may suffer the no-reflow phenomenon (NRP), and it could expand the myocardial infarction area and accompanied with high rehospitalization rate and fatality rate. In this study, we try to conduct a double blinded, randomized, placebo-controlled trial to observe whether the prophylactically intracoronary administration of Nicorandil could reduce the occurrence of NRP in STEMI patients undergoing PCI. METHODS: Simple randomization in a 1:1 ratio will be made in blocks of variable size according to a random numbers generated by Excel 2010 to divide the patients to treatment group (Nicorandil) and control group (Saline). The outcomes are the occurrence of NRP, levels of interleukin-6 and HS-CRP, cTnT, and CK-MB before, and every 4 hours following PCI, and major adverse cardiovascular events at day 30. SPSS 23.0 (IBM, Chicago, IL) will be used, and P-value < .05 will be considered statistically significant. CONCLUSIONS: The findings will determine the efficacy of prophylactically intracoronary administration of Nicorandil to reduce the occurrence of NRP during PCI in acute STEMI patients. TRIAL REGISTRATION: OSF Registration number: DOI 10.17605/OSF.IO/QPF3V.

The Effects of Apelin and Elabela Ligands on Apelin Receptor Distinct Signaling Profiles.

Apelin and Elabela are endogenous peptide ligands for Apelin receptor (APJ), a widely expressed G protein-coupled receptor. They constitute a spatiotemporal dual ligand system to control APJ signal transduction and function. We investigated the effects of Apelin-13, pGlu1-apelin-13, Apelin-17, Apelin-36, Elabela-21 and Elabela-32 peptides on APJ signal transduction. Whether different ligands are biased to different APJ mediated signal transduction pathways was studied. We observed the different changes of G protein dependent and ß-arrestin dependent signaling pathways after APJ was activated by six peptide ligands. We demonstrated that stimulation with APJ ligands resulted in dose-dependent increases in both G protein dependent [cyclic AMP (cAMP), Ca2+ mobilization, and the early phase extracellular related kinase (ERK) activation] and ß-arrestin dependent [GRKs, ß-arrestin 1, ß-arrestin 2, and ß2 subunit of the clathrin adaptor AP2] signaling pathways. However, the ligands exhibited distinct signaling profiles. Elabela-32 showed a >1000-fold bias to the ß-statin-dependent signaling pathway. These data provide that Apelin-17 was biased toward ß-arrestin dependent signaling. Eabela-21 and pGlu1-Apelin-13 exhibited very distinct activities on the G protein dependent pathway. The activity profiles of these ligands could be valuable for the development of drugs with high selectivity for specific APJ downstream signaling pathways.

Outlier detection and robust variable selection via the penalized weighted LAD-LASSO method.

This paper studies the outlier detection and robust variable selection problem in the linear regression model. The penalized weighted least absolute deviation (PWLAD) regression estimation method and the adaptive least absolute shrinkage and selection operator (LASSO) are combined to simultaneously achieve outlier detection, and robust variable selection. An iterative algorithm is proposed to solve the proposed optimization problem. Monte Carlo studies are evaluated the finite-sample performance of the proposed methods. The results indicate that the finite sample performance of the proposed methods performs better than that of the existing methods when there are leverage points or outliers in the response variable or explanatory variables. Finally, we apply the proposed methodology to analyze two real datasets.

Individual phosphorylation sites at the C-terminus of the apelin receptor play different roles in signal transduction.

The apelin and Elabela proteins constitute a spatiotemporal double-ligand system that controls apelin receptor (APJ) signal transduction. Phosphorylation of multiple sites within the C-terminus of APJ is essential for the recruitment of ß-arrestins. We sought to determine the precise mechanisms by which apelin and Elabela promote APJ phosphorylation, and to elucidate the influence of ß-arrestin phosphorylation on G-protein-coupled receptor (GPCR)/ß-arrestin-dependent signaling. We used techniques including mass spectrometry (MS), mutation analysis, and bioluminescence resonance energy transfer (BRET) to evaluate the role of phosphorylation sites in APJ-mediated G-protein-dependent and ß-dependent signaling. Phosphorylation of APJ occurred at five serine residues in the C-terminal region (Ser335, Ser339, Ser345, Ser348 and Ser369). We also identified two phosphorylation sites in ß-arrestin1 and three in ß-arrestin2, including three previously identified residues (Ser412, Ser361, and Thr383) and two new sites, Tyr47 in ß-arrestin1 and Tyr48 in ß-arrestin2. APJ mutations did not affect the phosphorylation of ß-arrestins, but it affects the ß-arrestin signaling pathway, specifically Ser335 and Ser339. Mutation of Ser335 decreased the ability of the receptor to interact with ß-arrestin1/2 and AP2, indicating that APJ affects the ß-arrestin signaling pathway by stimulating Elabela. Mutation of Ser339 abolished the capability of the receptor to interact with GRK2 and ß-arrestin1/2 upon stimulation with apelin-36, and disrupted receptor internalization and ß-arrestin-dependent ERK1/2 activation. Five peptides act on distinct phosphorylation sites at the APJ C-terminus, differentially regulating APJ signal transduction and causing different biological effects. These findings may facilitate screening for drugs to treat cardiovascular and metabolic diseases.

The Protective Effects and Mechanisms of Apelin/APJ System on Ischemic Stroke: A Promising Therapeutic Target.

The orphan receptor APJ and its endogenous ligand apelin, which are expressed in the brain, are the major components of the apelin/APJ system. Growing evidence shows that the apelin/APJ system plays a vital role in the pathophysiology of cerebral ischemic injury. Targeting the apelin/APJ system may have protective effects on cerebral ischemic injury. In this review, we sum up the latest research progress relating to the actions and therapeutic potential of the apelin/APJ system in ischemic stroke. An in-depth knowledge of the pathophysiological effects of the apelin/APJ system and the underlying mechanisms will help to develop novel therapeutic interventions for ischemic stroke.

Apelin-36 mediates neuroprotective effects by regulating oxidative stress, autophagy and apoptosis in MPTP-induced Parkinson's disease model mice.

Parkinson's disease (PD), a common human neurodegenerative disorder, is characterized by the presence of intraneuronal Lewy bodies composed principally of abnormal aggregated and post-translationally modified α-synuclein. In our previous research, we have demonstrated the neuroprotective effect of Apelin-36, a neuroendocrine peptide in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridin (MPTP)-lesioned PD model mice. Therefore, this study was designed to evaluate the neuroprotective mechanism of Apelin-36 against MPTP-induced neurotoxicity in mice. The results showed that MPTP-induced the depletion of dopamine in the striatum (STR) was partially reversed by Apelin-36. Apelin-36 also improved the activity of antioxidant system including superoxide dismutase (SOD) and glutathione (GSH), and decreased the overproduction of malondialdehyde (MDA) in the substantia nigra pars compacta (SNpc) and STR of MPTP-treated mice. Moreover, Apelin-36 downregulated inducible nitric oxide synthase (iNOS) and nitrated α-synuclein expression. Furthermore, Apelin-36 significantly promoted autophagy indicated by the up-regulation of LC3-II and Beclin1 and inhibition of p62 expression in the SNpc and STR of MPTP-treated mice. The protective effect of Apelin-36 was also associated with the inhibition of the apoptosis signal-regulating kinase 1 (ASK1)/c-Jun N-terminal kinase (JNK) signaling pathway and inactivation of caspase-3. Taken together, our findings demonstrated that the neuroprotective mechanism of Apelin-36 against MPTP-induced neurotoxicity in mice might be related to decreasing the aggregation of nitrated α-synuclein and alleviating oxidative stress as well as promoting autophagy and inhibiting ASK1/JNK/caspase-3 apoptotic pathway, which provides a novel strategy for PD treatment.

Plasmonic Metamaterials for Nanochemistry and Sensing.

Plasmonic nanostructures were initially developed for sensing and nanophotonic applications but, recently, have shown great promise in chemistry, optoelectronics, and nonlinear optics. While smooth plasmonic films, supporting surface plasmon polaritons, and individual nanostructures, featuring localized surface plasmons, are easy to fabricate and use, the assemblies of nanostructures in optical antennas and metamaterials provide many additional advantages related to the engineering of the mode structure (and thus, optical resonances in the given spectral range), field enhancement, and local density of optical states required to control electronic and photonic interactions. Focusing on two of the many applications of plasmonic metamaterials, in this Account, we review our work on the sensing and nanochemistry applications of metamaterials based on the assemblies of plasmonic nanorods under optical, as well as electronic interrogation. Sensors are widely employed in modern technology for the detection of events or changes in their local environment. Compared to their electronic counterparts, optical sensors offer a combination of high sensitivity, fast response, immunity to electromagnetic interference, and provide additional options for signal retrieval, such as optical intensity, spectrum, phase, and polarization. Owing to the ability to confine and enhance electromagnetic fields on subwavelength scales, plasmonics has been attracting increasing attention for the development of optical sensors with advantages including both nanometer-scale spatial resolution and single-molecule sensitivity. Inherent hot-electron generation in plasmonic nanostructures under illumination or during electron tunneling in the electrically biased nanostructures provides further opportunities for sensing and stimulation of chemical reactions, which would otherwise not be energetically possible. We first provide a brief introduction to a metamaterial sensing platform based on arrays of strongly coupled plasmonic nanorods. Several prototypical sensing examples based on this versatile metamaterial platform are presented. Record-high refractive index sensitivity of gold nanorod arrays in biosensing based on the functionalization of the nanorod surface for selective absorption arises because of the modification of the electromagnetic coupling between the nanorods in the array. The capabilities of nanorod metamaterials for ultrasound and hydrogen sensing were demonstrated by precision coating of the nanorods with functional materials to create core-shell nanostructures. The extension of this metamaterial platform to nanotube and nanocavity arrays, and metaparticles provides additional flexibility and removes restrictions on the illumination configurations for the optical interrogation. We then discuss a nanochemical platform based on the electrically driven metamaterials to stimulate and detect chemical reactions in the tunnel junctions constructed with the nanorods by exploiting elastic tunneling for the activation of chemical reactions via generated hot-electrons and inelastic tunneling for the excitation of plasmons facilitating optical monitoring of the process. This represents a new paradigm merging electronics, plasmonics, photonics and chemistry at the nanoscale, and creates opportunities for a variety of practical applications, such as hot-electron-driven nanoreactors and high-sensitivity sensors, as well as nanoscale light sources and modulators. With a combination of merits, such as the ability to simultaneously support both localized and propagating modes, nanoporous texture, rapid and facile functionalization, and low cost and scalability, plasmonic nanorod metamaterials provide an attractive and versatile platform for the development of optical sensors and nanochemical platforms using hot-electrons with high performance for applications in fundamental research and chemical and pharmaceutical industries.

Apelin-36 mitigates MPTP/MPP+-induced neurotoxicity: Involvement of α-synuclein and endoplasmic reticulum stress.

Parkinson's disease (PD) is characterized by the progressive loss of dopaminergic neurons within the substantia nigra compacta (SNpc) which leads to the behavioral dysfunction. In the present study, we investigated the effect of Apelin-36 on 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridin (MPTP)/1-methyl-4-phenylpyridinium (MPP+)-induced neurotoxicity. The treatment with Apelin-36 significantly alleviated the MPTP-induced the behavioral dysfunction and dopaminergic neurodegeneration in the SNpc of mice, and also remarkably decreased the MPP+-induced cell death of SH-SY5Y cells. Furthermore, Apelin-36 reversed the MPTP/MPP+-induced loss of TH expression and the induction of α-synuclein expression. Additionally, Apelin-36 significantly attenuated the endoplasmic reticulum stress (ERS) indicated by the inhibition of GRP78, CHOP and cleaved caspase-12 expression in MPTP/MPP+ treated mice and cells. Taken together, the results indicated that Apelin-36 attenuates MPTP/MPP+-induced neurotoxicity, and suggested that Apelin-36 could be a potential therapeutic strategy for the treatment of PD.