Optical confinement in the nanocoax: coupling to the fundamental TEM-like mode.

The nanoscale coaxial cable (nanocoax) has demonstrated optical confinement in the visible and the near infrared. We report on a novel nanofabrication process which yields optically addressable, sub-µm diameter, and high aspect ratio metal-insulator-metal nanocoaxes made by atomic layer deposition of Pt and Al2O3. We observe sub-diffraction-limited optical transmission via the fundamental, TEM-like mode by excitation with a radially polarized optical vortex beam. Our experimental results are based on interrogation with a polarimetric imager. Finite element method numerical simulations support these results, and their uniaxial symmetry was exploited to model taper geometries with both an electrically large volume, (15λ)3, and a nanoscopic exit aperture, (λ/200)2.

Comparison of land surface and air temperatures for quantifying summer and winter urban heat island in a snow climate city.

The urban heat island (UHI) effect is an increasingly consequential problem that confronts cities. The accurate characterization and quantification of UHI are crucial for sustainable urban development. Few UHI studies, however, compare data source, spatio-temporal variations, and indicators for the same city in parallel. This study uses Changchun, a snow climate city in China, as an example and compares five different indicators of the UHI based on land surface temperature (LST) derived from Landsat 8 TIRS and hourly air temperature (AT) collected from 41 meteorological weather stations to conduct a more comprehensive comparative study of the UHI. The results show the following. (1) The relationships between LST and AT are all statistically significant, and the surface urban heat island (SUHI) intensity characterized by the LST is considerably stronger than that of AT both in summer and winter. (2) The SUHI intensity is significantly stronger in summer (6.83 °C) than in winter (1.55 °C) based on the morning LST, whereas the UHI intensity (0.27 °C in summer and 0.40 °C in winter) that is simultaneously quantified by the AT has an opposite result. The mean whole-day and daytime UHI intensity difference, which is quantified hourly by the AT between summer and winter, is not significant. The difference between nighttime and daytime UHI intensities is evident in both summer (1.26 °C) and winter (0.76 °C). Additionally, the high temperatures for both LST and AT have a more concentrated distribution in winter than in summer. (3) The values of UHI/SUHI intensity considerably vary based on different indicators. The different choices among land covers to represent "urban" and "rural" areas would significantly affect the values of UHI/SUHI intensity. The selection of appropriate indicators and data sources to quantify the UHI remains a problem that has to be resolved in future studies.

[Method for determining concentration of dichlorvos in serum by gas chromatography].

OBJECTIVE: To develop a method for determining the concentration of dichlorvos in serum by gas chromatography and to provide a basis for clinical diagnosis and monitoring of dichlorvos poisoning. METHODS: The serum (0.5 ml)collected from patients with dichlorvos poisoning was mixed with ethyl acetate (2.0 ml) and underwent shaking/extraction; the obtained liquid was subjected to standing (5 min) and centrifuging (4000 rpm); the obtained supernatant was collected and blow-dried with nitrogen and was then dissolved in ethanol (50 µl); 1.0 µl of the obtained liquid was collected and loaded into a glass-packed column; gas chromatography was performed using a nitrogen-phosphorus detector. RESULTS: A linear relationship was found when the concentration of dichlorvos in serum was 5.0 ∼ 50.0 µg/ml, with a regression equation of y = 804.13x-691.8 (r = 0.9992). The minimum detectable concentration was 2.0 µg/ml, the recovery rate was 86.8% ∼ 94.5%, the relative standard deviation (RSD) was 4.6% ∼ 5.5%, with an intra-day RSD of 4.52% ∼ 5.21% and an inter-day RSD of 3.56% ∼ 5.52%. CONCLUSION: This determination method is easy to operate, efficient, and accurate, and can be used for quickly diagnosing dichlorvos poisoning and quantitatively evaluating treatment outcome.

[Functional analysis on sucrose transporters in sweet potato].

Sweet potato is an important food crop that can also be used as an industrial raw material. Sucrose is the main form of long-distance carbohydrate transport in plants, and sucrose transporter (SUT) regulates the transmembrane transport and distribution of sucrose during plant growth and metabolism. Moreover, SUT plays a key role in phloem mediated source-to-sink sucrose transport and physiological activities, supplying sucrose for the sink tissues. In this study, the full-length cDNA sequences of IbSUT62788 and IbSUT81616 were obtained by rapid amplification of cDNA ends (RACE) cloning according to the transcripts of the two SUT coding genes which were differentially expressed in sweet potato storage roots with different starch properties. Phylogenetic analysis was performed to clarify the classification of IbSUT62788 and IbSUT81616. The subcellular localization of IbSUT62788 and IbSUT81616 was determined by transient expression in Nicotiana benthamiana. The function of IbSUT62788 and IbSUT81616 in sucrose and hexose absorption and transport was identified using yeast functional complementarity system. The expression pattern of IbSUT62788 and IbSUT81616 in sweet potato organs were analyzed by real-time fluorescence quantitative PCR (RT-qPCR). Arabidopsis plants heterologous expressing IbSUT62788 and IbSUT81616 genes were obtained using floral dip method. The differences in starch and sugar contents between transgenic and wild-type Arabidopsis were compared. The results showed IbSUT62788 and IbSUT81616 encoded SUT proteins with a length of 505 and 521 amino acids, respectively, and both proteins belonged to the SUT1 subfamily. IbSUT62788 and IbSUT81616 were located in the cell membrane and were able to transport sucrose, glucose and fructose in the yeast system. In addition, IbSUT62788 was also able to transport mannose. The expression of IbSUT62788 was higher in leaves, lateral branches and main stems, and the expression of IbSUT81616 was higher in lateral branches, stems and storage roots. After IbSUT62788 and IbSUT81616 were heterologously expressed in Arabidopsis, the plants grew normally, but the biomass increased. The heterologous expression of IbSUT62788 increased the soluble sugar content, leaf size and 1 000-seed weight of Arabidopsis plants. Heterologous expression of IbSUT81616 increased starch accumulation in leaves and root tips and 1 000-seed weight of seeds, but decreased soluble sugar content. The results obtained in this study showed that IbSUT62788 and IbSUT81616 might be important genes regulating sucrose and sugar content traits in sweet potato. They might carry out physiological functions on cell membrane, such as transmembrane transport of sucrose, sucrose into and out of sink tissue, as well as transport and unloading of sucrose into phloem. The changes in traits result from their heterologous expression in Arabidopsis indicates their potential in improving the yield of other plants or crops. The results obtained in this study provide important information for revealing the functions of IbSUT62788 and IbSUT81616 in starch and glucose metabolism and formation mechanism of important quality traits in sweet potato.

IbInvInh2, a novel invertase inhibitor in sweet potato, regulates starch content through post-translational regulation of vacuolar invertase IbßFRUCT2.

As a key enzyme in the starch and sugar metabolic pathways in sweet potato (Ipomoea batatas (L.) Lam.), the vacuolar invertase (EC 3.2.1.26) IbßFRUCT2 is involved in partitioning and modulating the starch and sugar components of the storage root. However, the post-translational regulation of its invertase activity remains unclear. In this study, we identified three invertase inhibitors, IbInvInh1, IbInvInh2, and IbInvInh3, as potential interaction partners of IbßFRUCT2. All were found to act as vacuolar invertase inhibitors (VIFs) and belonged to the plant invertase/pectin methyl esterase inhibitor superfamily. Among the three VIFs, IbInvInh2 is a novel VIF in sweet potato and was confirmed to be an inhibitor of IbßFRUCT2. The N-terminal domain of IbßFRUCT2 and the Thr39 and Leu198 sites of IbInvInh2 were predicted to be engaged in their interactions. The transgenic expression of IbInvInh2 in Arabidopsis thaliana plants reduced the starch content of leaves, while its expression in the Ibßfruct2-expressing Arabidopsis plants increased the starch content of leaves, suggesting that the post-translational inhibition of IbßFRUCT2 activity by IbInvInh2 contributes to the regulation of the plant starch content. Taken together, our findings reveal a novel VIF in sweet potato and provide insights into the potential regulatory roles of the VIFs and invertase-VIF interaction in starch metabolism. These insights lay the foundation for using VIFs to improve the starch properties of crops.

Regulatory and functional divergence among members of Ibßfruct2, a sweet potato vacuolar invertase gene controlling starch and glucose content.

Sweet potato [Ipomoea batatas (L.) Lam.] is an important food and industrial crop. Its storage root is rich in starch, which is present in the form of granules and represents the principal storage carbohydrate in plants. Starch content is an important trait of sweet potato controlling the quality and yield of industrial products. Vacuolar invertase encoding gene Ibßfruct2 was supposed to be a key regulator of starch content in sweet potato, but its function and regulation were unclear. In this study, three Ibßfruct2 gene members were detected. Their promoters displayed differences in sequence, activity, and cis-regulatory elements and might interact with different transcription factors, indicating that the three Ibßfruct2 family members are governed by different regulatory mechanisms at the transcription level. Among them, we found that only Ibßfruct2-1 show a high expression level and promoter activity, and encodes a protein with invertase activity, and the conserved domains and three conserved motifs NDPNG, RDP, and WEC are critical to this activity. Only two and six amino acid residue variations were detected in sequences of proteins encoded by Ibßfruct2-2 and Ibßfruct2-3, respectively, compared with Ibßfruct2-1; although not within key motifs, these variations affected protein structure and affinities for the catalytic substrate, resulting in functional deficiency and low activity. Heterologous expression of Ibßfruct2-1 in Arabidopsis decreased starch content but increased glucose content in leaves, indicating Ibßfruct2-1 was a negative regulator of starch content. These findings represent an important advance in understanding the regulatory and functional divergence among duplicated genes in sweet potato, and provide critical information for functional studies and utilization of these genes in genetic improvement.

[The impact of L-carnitine administration on the serum level of myocardium injury markers in patients with acute carbon monoxide poisoning].

OBJECTIVE: To examine the serum level of myocardial injury markers in patients with carbon monoxide (CO) poisoning, the correlation between these markers and the severity of the disease, and the therapeutic effects of L-carnitine administration. METHODS: 69 patients, chosen from 309 cases of acute carbon monoxide poisoning (ACOP) for abnormally high level of serum myocardial injury markers (myoglobin, Mb; MB isoenzyme of creatine kinase, CK-MB; cardiac troponin-I, cTnI) at the time of admission, were randomly divided into control group (n = 34) and observation group (n = 35). The patients in control group were given Xingnaojing (20 ml/d i.v. drip), and the observation group Xingnaojing (20 ml/d)+L-carnitine (2 g/d i.v. drip), in addition to the conventional oxygen supply and symptom-focused therapy. The plasma concentration of carboxyhemoglobin (HbCO, as index for CO poisoning severity), Mb, CK-MB, and cTnI in these patients were further examined 24 hours, 72 hours and 1 week after the treatment, for difference between the two groups, and the correlation between the serum level of HbCO and the myocardial injury markers. RESULTS: At the time of admission, the incidence of abnormal findings in myocardial injury markers were 2.5% (5/204), 46.8% (36/77) and 100.0% (28/28) in patients with mild (HbCO: 10% ~ 19%), moderate (20% ~ 39%) and severe (≥40%) CO poisoning, respectively. The incidence of abnormal findings in injury markers was significantly correlated to the HbCO concentration (x(2)=170.3549, P < 0.0001). Before the treatment, no significant difference was found in any of the indexes [HbCO: (31.1 ± 17.6)%, (32.3 ± 16.9)%, Mb (µg/L): 154.2 ± 51.8, 165.4 ± 48.6, CK-MB (µg/L): 8.7 ± 3.3, 9.6 ± 3.8), and cTnI (µg/L): 2.7 ± 1.2, 2.8 ± 1.5, all P > 0.05] between the control and observation group. However, it was found in: Mb (24 hours: 74.0 ± 36.5 vs. 97.1 ± 35.8, 72 hours: 40.1 ± 6.8 vs. 69.0 ± 11.2), cTnI (24 hours: 1.9 ± 0.5 vs. 2.3 ± 0.7, 72 hours: 1.2 ± 0.3 vs. 1.8 ± 0.4) both 24 hours and 72 hours after the treatment, and CK-MB, 24 hours after treatment (10.6 ± 4.1 vs. 13.0 ± 3.9) with the values in observation group significantly lower (P < 0.05 or P < 0.01); 1 week after the treatment, the concentration of all the injury markers returned to the normal levels with no significant difference between the two groups. Meanwhile, no significant difference was found between the two groups in HbCO concentration throughout the due-course of the therapy. CONCLUSIONS: The incidence of abnormal findings in serum myocardial injury markers was positively correlated with HbCO concentration after CO poisoning. L-carnitine may protect the myocardium and striated muscles against injury in patients with CO poisoning.

Characterizing the Hourly Variation of Urban Heat Islands in a Snowy Climate City during Summer.

Temporal variation of urban heat island (UHI) intensity is one of the most important themes in UHI studies. However, fine-scale temporal variability of UHI with explicit spatial information is sparse in the literature. Based on the hourly air temperature from 195 meteorological stations during August 2015 in Changchun, China, hourly spatiotemporal patterns of UHI were mapped to explore the temporal variability and the effects of land use on the thermal environment using time series analysis, air temperature profiling, and spatial analysis. The results showed that: (1) high air temperature does not indicate strong UHI intensity. The nighttime UHI intensity (1.51 °C) was much stronger than that in the daytime (0.49 °C). (2) The urban area was the hottest during most of the day except the period from late morning to around 13:00 when there was about a 40% possibility for an "inverse UHI intensity" to appear. Paddy land was the coolest in the daytime, while woodland had the lowest temperature during the nighttime. (3) The rural area had higher warming and cooling rates than the urban area after sunrise and sunset. It appeared that 23 °C was the threshold at which the thermal characteristics of different land use types changed significantly.

Wireless communication system via nanoscale plasmonic antennas.

Present on-chip optical communication technology uses near-infrared light, but visible wavelengths would allow system miniaturization and higher energy confinement. Towards this end, we report a nanoscale wireless communication system that operates at visible wavelengths via in-plane information transmission. Here, plasmonic antenna radiation mediates a three-step conversion process (surface plasmon → photon → surface plasmon) with in-plane efficiency (plasmon → plasmon) of 38% for antenna separation 4λ0 (with λ0 the free-space excitation wavelength). Information transmission is demonstrated at bandwidths in the Hz and MHz ranges. This work opens the possibility of optical conveyance of information using plasmonic antennas for on-chip communication technology.

[Monitoring on spatial and temporal changes of snow cover in the Heilongjiang Basin based on remote sensing].

This paper extracted and verified the snow cover extent in Heilongjiang Basin from 2003 to 2012 based on MODIS Aqua and Terra data, and the seasonal and interannual variations of snow cover extent were analyzed. The result showed that the double-star composite data reduced the effects of clouds and the overall accuracy was more than 91%, which could meet the research requirements. There existed significant seasonal variation of snow cover extent. The snow cover area was almost zero in July and August while in January it expanded to the maximum, which accounted for more than 80% of the basin. According to the analysis on the interannual variability of snow cover, the maximum winter snow cover areas in 2003-2004 and 2009-2010 (>180 x 10(4) km2) were higher than that of 2011 (150 x 10(4) km2). Meanwhile, there were certain correlations between the interannual fluctuations of snow cover and the changes of average annual temperature and precipitation. The year with the low snow cover was corresponding to less annual rainfall and higher average temperature, and vice versa. The spring snow cover showed a decreasing trend from 2003 to 2012, which was closely linked with decreasing precipitation and increasing temperature.