Radial growth responses of three coniferous species to climate change on the southern slope of Funiu Mountains, China.

Funiu Mountains are located in a transition region between warm temperate zone and northern subtropical region, where a variety of plant species are distributed with sensitive response to climate change. Their response characteristics to climate change are still unclear. We developed the basal area increment (BAI) index chronologies of Pinus tabuliformis, P. armandii, and P. massoniana in the Funiu Mountains to examine their growth trend and their sensitivity to climatic change. The results showed that the BAI chronologies gave a clue that the three conife-rous species had similar radial growth rate. The large Gleichlufigkeit (GLK) indices among the three BAI chronologies also indicated that the three species had a similar growth trend. Results of correlation analysis showed that the three species also had similar response to climatic change to a certain extent. Radial growth of all the three species was significantly positively correlated with the total monthly precipitation in December of previous year and June of the current year, but negatively correlated with the precipitation in September and the mean monthly temperature in June of the current year. There were some differences in the responses of the three coniferous to climate change. P. massoniana had a significant negative correlation with the mean temperature in March, and a significant positive correlation with the precipitation in March, while P. armandii and P. massoniana were affected negatively by the maximum temperature in August. Results of the moving correlation analysis showed that the three coniferous species had some similar sensitivity to climate change. Their positive responses to precipitation in previous December consistently increased, as well as the negative correlation with precipitation in current September. As to P. masso-niana, they had a relatively stronger climatic sensitivity and higher stability than the other two species. It would be more suitable for P. massoniana trees on the southern slope of the Funiu Mountains under global warming.

Antireflection of optical anisotropic dielectric metasurfaces.

We propose a hetero-nano-fin structure to further improve the efficiency of Pancharatnam-Berry phase metasurfaces. Two hetero-nano-fin types, MgF2/GaN and MgF2/Nb2O5, were investigated. The overall polarization conversion efficiency (PCE) improved from 52.7 to 54% for the MgF2/GaN nano-fin compared with the bare GaN nano-fin. The overall PCE of the Nb2O5 nano-fin was 1.7 times higher than that of the GaN nano-fin. The overall PCE improved from 92.4% up to 96% after the application of MgF2 antireflection. Moreover, the antireflection improves efficiency by an average of 4.3% in wavelengths from 450 to 700 nm. Although the increment of energy seems minimal, antireflection is crucial for a metasurface, not only enhancing efficiency but also reducing background signal of a meta-device.

Blockade of adenosine A2A receptor alleviates cognitive dysfunction after chronic exposure to intermittent hypoxia in mice.

Obstructive sleep apnea-hypopnea syndrome (OSAHS) is widely known for its multiple systems damage, especially neurocognitive deficits in children. Since their discovery, adenosine A2A receptors (A2ARs) have been considered as key elements in signaling pathways mediating neurodegenerative diseases such as Huntington's and Alzheimer's, as well as cognitive function regulation. Herein, we investigated A2AR role in cognitive impairment induced by chronic intermittent hypoxia (CIH). Mice were exposed to CIH 7 h every day for 4 weeks, and intraperitoneally injected with A2AR agonist CGS21680 or A2AR antagonist SCH58261 half an hour before IH exposure daily. The 8-arm radial arm maze was utilized to assess spatial memory after CIH exposures.To validate findings using pharmacology, the impact of intermittent hypoxia was investigated in A2AR knockout mice. CIH-induced memory dysfunction was manifested by increased error rates in the radial arm maze test. The behavioral changes were associated with hippocampal pathology, neuronal apoptosis, and synaptic plasticity impairment. The stimulation of adenosine A2AR exacerbated memory impairment with more serious neuropathological damage, attenuated long-term potentiation (LTP), syntaxin down-regulation, and increased BDNF protein. Moreover, apoptosis-promoting protein cleaved caspase-3 was upregulated while anti-apoptotic protein Bcl-2 was downregulated. Consistent with these findings, A2AR inhibition with SCH58261 and A2AR deletion exhibited the opposite result. Overall, these findings suggest that A2AR plays a critical role in CIH-induced impairment of learning and memory by accelerating hippocampal neuronal apoptosis and reducing synaptic plasticity. Blockade of adenosine A2A receptor alleviates cognitive dysfunction after chronic exposure to intermittent hypoxia in mice.

Scattering Analysis and Efficiency Optimization of Dielectric Pancharatnam-Berry-Phase Metasurfaces.

In this study, the phase modulation ability of a dielectric Pancharatnam-Berry (PB) phase metasurface, consisting of nanofins, is theoretically analyzed. It is generally considered that the optical thickness of the unit cell of a PB-phase metasurface is λ/2, i.e., a half-waveplate for polarization conversion. It is found that the λ/2 is not essential for achieving a full 2π modulation. Nevertheless, a λ/2 thickness is still needed for a high polarization conversion efficiency. Moreover, a gradient phase metasurface is designed. With the help of the particle swarm optimization (PSO) method, the wavefront errors of the gradient phase metasurface are reduced by fine-tuning the rotation angle of the nanofins. The diffraction efficiency of the gradient phase metasurface is thus improved from 73.4% to 87.3%. This design rule can be utilized to optimize the efficiency of phase-type meta-devices, such as meta-deflectors and metalenses.

Angular-insensitive optical filtering based on meta-GMR.

In this study, the optical properties of a meta-GMR consisting of a metasurface stacked on a planar dielectric slab waveguide were theoretically investigated. Two different metasurfaces, namely chiral split-ring resonator dimer arrays with/without a rod-shaped antenna, were investigated and compared. Conventional GMR filters utilize gratings to couple the free-space electromagnetic field to the waveguide. The highly dispersive nature of grating leads to low angular tolerance. Here, the grating is replaced by metasurfaces. The metasurface unit cell can be regarded as a polarizable dipole that couples the free-space electromagnetic field to the waveguide and decouples the waveguide mode to the radiation modes. Based on the localized nature of the resonant metasurfaces, the metasurface/GMR hybrid mode exhibits a superior angular tolerance as compared with a conventional GMR filter. This study can open a new avenue to tailor the optical properties of GMR-based devices.

Activating adenosine A1 receptor accelerates PC12 cell injury via ADORA1/PKC/KATP pathway after intermittent hypoxia exposure.

Obstructive sleep apnea hypopnea syndrome (OSAHS) is associated with the neurocognitive deficits as a result of the neuronal cell injury. Previous studies have shown that adenosine A1 receptor (ADORA1) played an important role against hypoxia exposure, such as controlling the metabolic recovery in rat hippocampal slices and increasing the resistance in the combined effects of hypoxia and hypercapnia. However, little is known about whether ADORA1 takes part in the course of neuronal cell injury after intermittent hypoxia exposure which was the main pathological characteristic of OSAHS. The present study is performed to explore the underlying mechanism of neuronal cell injury which was induced by intermittent hypoxia exposure in PC12 cells. In our research, we find that the stimulation of the ADORA1 by CCPA accelerated the injury of PC12 cells as well as upregulated the expression of PKC, inwardly rectifying potassium channel 6.2(Kir6.2) and sulfonylurea receptor 1(SUR1) while inhibition of the ADORA1 by DPCPX alleviated the injury of PC12 cells as well as downregulated the expression of PKC, Kir6.2, and SUR1. Moreover, inhibition of the PKC by CHE, also mitigated the injury of PC12 cells, suppressed the Kir6.2 and SUR1 expressions induced by PKC. Taken together, our findings indicate that ADORA1 accelerated PC12 cells injury after intermittent hypoxia exposure via ADORA1/PKC/KATP signaling pathway.

Chronic intermittent hypoxia exposure induces kidney injury in growing rats.

OBJECTIVE: The objectives of this paper are to examine the effect of chronic intermittent hypoxia (CIH) on the morphological changes in the kidney of growing rats and to explore the mechanisms underlying the CIH-induced renal damage. METHODS: Forty Sprague-Dawley rats were randomly divided into two groups: 2 and 4 weeks CIH groups (2IH, 4IH), and in the control group 2 and 4 weeks air-stimulated groups (2C, 4C), with 10 rats in each group. Pathological changes of renal tissue were observed by HE staining, PAS staining, and Masson staining. Real-time PCR method was used to detect the mRNA expression of HIF-1α, CuZnSOD/ZnSOD, and MnSOD in renal tissue. RESULTS: (1) Intermittent hypoxia (IH) caused morphological damage in the kidney. Hypertrophy of epithelial cells in the kidney tubules and dilation in the glomeruli were observed under light microscope in HE and PAS stain, especially in 4IH group. Masson staining showed no significant fibrotic response in the IH groups. (2) Compared with the corresponding control groups, the levels of serum SOD were significantly lower in CIH groups, and especially in 4IH group. The mRNA expression of Cu/ZnSOD and MnSOD in CIH groups decreased significantly as compared to control groups. The mRNA levels of HIF-1α in the kidney were significantly higher in CIH groups than those in the corresponding control groups. CONCLUSION: Oxidative stress played a critical role in renal damage by up-regulating HIF-1α transcription and down-regulating Cu/ZnSOD and MnSOD transcription after chronic intermittent hypoxia exposure in growing rats.

Multiple system morbidities associated with children with snore symptom.

OBJECTIVE: To exam the relationship between snoring and morbidities of multiple systems in children. STUDY DESIGN: Children with snoring were enrolled and divided into primary snorer (PS) group and obstructive sleep apnea hypopnea syndrome (OSAHS) group based on polysomnography. The healthy children served as the control group. The growth parameters, maxillofacial malformations, blood chemistry, electrocardiogram, and echocardiogram were recorded and intelligence testing was performed in the enrolled children who were ≥6 years old. RESULTS: The weight and height were similar in the control group (n = 60) and the PS group (n = 63), but lower in the OSAHS group (n = 89; P < 0.001). Occurrence of adenoidal face and dental malocclusion in the OSAHS and the PS group was significantly higher than that in the control group (P < 0.001). Compared with the control group, the OSAHS group had a lower serum high-density lipoprotein cholesterol level, higher low-density lipoprotein cholesterol level; and a possible higher pulmonary artery pressure based on the echocardiogram (P < 0.001). All the above parameters in the PS group were similar to those in the control group. Full-scale IQ and performance IQ of the OSAHS group was lower (P < 0.001), attention deficits were significantly higher in the OSAHS group (P < 0.001), but were similar in the PS group when compared to the control group. CONCLUSIONS: OSAHS in children is associated with delayed growth, maxillofacial malformations, impaired cognitive functions, abnormalities in lipid metabolism, and changes in pulmonary artery pressures. PS children also have higher incidence of maxillofacial malformations but have a normal growth and normal cognitive functions.

[Association of single nucleotide polymorphisms in the promoter region of the TLR9 gene with childhood atopic asthma].

OBJECTIVE: To investigate the distribution characteristics of the single nucleotide polymorphisms (SNPs) in the promoter region of the toll-like receptor 9 gene (TLR9) in Chinese Han children from Zhejiang province, and their associations with asthma susceptibility and phenotypes. METHODS: A case-control study was conducted. A total of 312 asthmatic children aged between 1.9 and 11.6 and 339 age matched healthy controls were enrolled in this study from April 2007 to November 2008. The -1486 C/T in rs187084 and -1237 C/T in rs5743836 loci of the TLR9 gene were genotyped by direct DNA sequencing of the PCR products. Serum levels of IFN gamma, IL-12 and IL-4 were detected by enzyme linked immunosorbent assay.Serum levels of total IgE were detected by chemiluminescence, and serum levels of antigen specific IgE antibodies were detected by fluoroenzymeimmunoassay. RESULTS: (1) The -1486 C/T polymorphism was identified in both groups. The genotype frequencies of TT, TC and CC at -1486 C/T were 41.0%, 44.3%, 14.7% in the healthy controls, and 38.8%, 48.4%, 12.8% in the asthmatic children. The -1237 C/T polymorphism was not detected in the population. (2) There were no statistically significant differences in the allele and genotype frequencies at the -1486 C/T locus between the two groups (P;>0.05). (3) Serum levels of IFN gamma and IL-4 differed significantly among the three genotypes at the -1486 C/T locus in asthmatic children (P<0.01). The CC genotype had the lowest levels of serum IFN gamma and the highest levels of serum IL-4 among the three genotypes. There were no significant differences in these cytokines among the healthy controls (P>0.05). No statistical differences of serum IL-12 were found among the three genotypes in the two groups (P>0.05). (4) There were no significant differences of total IgE (log-transformed) among the three genotypes in the asthmatic children (P>0.05). CONCLUSION: The -1237 C/T polymorphism of TLR9 gene was not detected in Chinese Han children in this study. The -1486 C/T polymorphism was associated with the levels of serum IFN gamma and IL-4 in children with asthma. However, there were no correlations between the -1486C/T polymorphism and serum IL-12 levels, total IgE levels or asthmatic susceptibility.

[The pathological effects of snoring on pregnant women].

OBJECTIVE: To discuss the pathological effect of snoring on pregnant women in Wenzhou area. METHODS: The study was performed between January 2006 and February 2008, 601 women with pregnancies being in clinic or the ward were surveyed about snoring occur, measuring physiological and biochemical parameters in the 13th, 28th week of pregnancy and before delivery, recording the complication and pregnancy outcome. According to their pregnancy and snoring occur, they were divided into the first, the second and the third trimester snoring group and non-snoring group. RESULT: Compared with the non-snoring group, The BMI, abdominal perimeter, the neck circumference and systolic blood pressure in snoring group of every trimester increased significantly (P<0.05). There were no significant differences about the hip circumference of snoring group in the first trimester (P>0.05), but they increased significantly in the second and the third trimester (P<0.05). There were no significant differences about the diastolic blood pressure of snoring group in the first and the second trimester (P>0.05), but they increased significantly in the third trimester (P<0.05). There were no significant differences about the snoring group's BMI, abdominal perimeter, the neck circumference, the hip circumference and blood pressure between the groups of every trimester (P>0.05). Compared with the non-snoring group, the incidence of snoring group's gestational hypertension, premature birth and abdominal delivery increased significantly every trimester of pregnancy (P<0.05). There were no significant differences Between the snoring groups of every trimester (P>0.05). CONCLUSION: The snore makes pregnant women physiological characteristics changed, the incidence of gestational hypertension, premature delivery and abdominal delivery increased. So we should pay more attentions to them in their perinatal stage.