Complete two-dimensional photonic bandgap in refractive-index ratio 2.1 photonic crystals due to high-order bands.

We find that in a suitably designed photonic crystal (PC) certain high-order photonic bands are less affected by the refractive-index ratio (RIR) than low-order bands, enabling the realization of a robust and complete two-dimensional (2D) photonic bandgap in a moderate refractive-index-ratio PC. A detailed theoretical investigation of low- and high-order bandgaps in a series of PCs with different configurations is performed that shows that high-order bands may favor substantial complete photonic bandgaps (CPBGs) for systems with a moderate RIR. Furthermore, the importance of the geometry and structural parameters on achieving a high-order CPBG is found. Specifically, a hexagonal lattice PC of annular-hole-peripheral connecting rods is proposed, which can support a CPBG with a refractive-index ratio (RIR) as low as nhigh:nlow=2.1; to the best of our knowledge, this is the lowest RIR used to obtain a 2D CPBG in a PC.

A high-quality spin and valley beam splitter in WSe2 tunnelling junction through the Goos-Hänchen shift.

We have theoretically studied the Goos-Hänchen shift of spin and valley electron in single and double barrier WSe2 tunnelling junctions. For single barrier structure, it has shown that a two-fold degenerate lateral shift induced by the spin-valley locking occurs at Fabry-Perot resonance width. By introducing the ferromagnetic exchange field, one spin and valley dependent lateral shift can be further obtained. Different from single barrier structure, the double barrier structure exhibits two series of Fabry-Perot interferences with lateral shifts exceeding thousands of Fermi wavelengths due to the effect of localized states, and more important, these interferences generated between two potential barriers are even higher than the shift formed inside of two potential barriers. In addition, for a specified Fermi energy, one can modulate the desired spatial separation of spin and valley beam by controlling the incident angle or potential barrier. Our results demonstrate that the proposed WSe2 double barrier structure is a fascinating candidate for designing high-quality spin and valley beam splitter.

Effect of Red Light-Emitting Diodes Irradiation on Hemoglobin for Potential Hypertension Treatment Based on Confocal Micro-Raman Spectroscopy.

Red light-emitting diodes (LED) were used to irradiate the isolated hypertension hemoglobin (Hb) and Raman spectra difference was recorded using confocal micro-Raman spectroscopy. Differences were observed between the controlled and irradiated Hb by comparing the spectra records. The Raman spectrum at the 1399 cm-1 band decreased following prolonged LED irradiation. The intensity of the 1639 cm-1 band decreased dramatically in the first five minutes and then gradually increased in a time-dependent manner. This observation indicated that LED irradiation increased the ability of oxygen binding in Hb. The appearance of the heme aggregation band at 1399 cm-1, in addition to the oxygen marker band at 1639 cm-1, indicated that, in our study, 30 min of irradiation with 15.0 mW was suitable for inhibiting heme aggregation and enhancing the oxygen-carrying capacity of Hb. Principal component analysis showed a one-to-one relationship between irradiated Hb at different time points and the corresponding Raman spectra. Our approach could be used to analyze the hemoglobin from patients with confocal micro-Raman spectroscopy and is helpful for developing new nondrug hypertension therapy.

Development of graphene oxide-wrapped gold nanorods as robust nanoplatform for ultrafast near-infrared SERS bioimaging.

The rapid development of near-infrared surface-enhanced Raman scattering (NIR SERS) imaging technology has attracted strong interest from scientists and clinicians due to its narrow spectral bandwidth, low background interference, and deep imaging depth. In this report, the graphene oxide (GO)-wrapped gold nanorods (GO@GNRs) were developed as a smart and robust nanoplatform for ultrafast NIR SERS bioimaging. The fabricated GO@ GNRs could efficiently load various NIR probes, and the in vitro evaluation indicated that the nanoplatform could exhibit a higher NIR SERS activity in comparison with traditional gold nanostructures. The GOs were prepared by directly pyrolyzing citric acid for greater convenience, and GO@GNRs were fabricated via a facile synthesis strategy. Higher NIR SERS activity, facile synthesis method, excellent biocompatibility, and superb stability make the GO@GNRs/probe complex promising nanoprobes for NIR SERS-based bioimaging applications.

Single NMR image super-resolution based on extreme learning machine.

INTRODUCTION: The performance limitation of MRI equipment and higher resolution demand of NMR images from radiologists have formed a strong contrast. Therefore, it is important to study the super resolution algorithm suitable for NMR images, using low costs software to replace the expensive equipment-updating. METHODS AND MATERIALS: Firstly, a series of NMR images are obtained from original NMR images with original noise to the lowest resolution images with the highest noise. Then, based on extreme learning machine, the mapping relation model is constructed from lower resolution NMR images with higher noise to higher resolution NMR images with lower noise in each pair of adjacent images in the obtained image sequence. Finally, the optimal mapping model is established by the ensemble way to reconstruct the higher resolution NMR images with lower noise on the basis of original resolution NMR images with original noise. Experiments are carried out by 990111 NMR brain images in datasets NITRC, REMBRANDT, RIDER NEURO MRI, TCGA-GBM and TCGA-LGG. RESULTS: The performance of proposed method is compared with three approaches through 7 indexes, and the experimental results show that our proposed method has a significant improvement. DISCUSSION: Since our method considers the influence of the noise, it has 20% higher in Peak-Signal-to-Noise-Ratio comparison. As our method is sensitive to details, and has a better characteristic retention, it has higher image quality upgrade of 15% in the additional evaluation. Finally, since extreme learning machine has a celerity learning speed, our method is 46.1% faster.

Fabrication of Graphene and AuNP Core Polyaniline Shell Nanocomposites as Multifunctional Theranostic Platforms for SERS Real-time Monitoring and Chemo-photothermal Therapy.

In this work, novel theranostic platforms based on graphene oxide and AuNP core polyaniline shell (GO-Au@PANI) nanocomposites are fabricated for simultaneous SERS imaging and chemo-photothermal therapy. PANI, a new NIR photothermal therapy agent with strong NIR absorption, outstanding stability and low cytotoxicity is decorated on AuNPs by one-pot oxidative polymerization, then the Au@PANI core-shell nanoparticles are attached to the graphene oxide (GO) sheet via π-π stacking and electrostatic interaction. The obtained GO-Au@PANI nanohybirds exhibit excellent NIR photothermal transduction efficiency and ultrahigh drug-loading capacity. The nanocomposites can also serve as novel NIR SERS probes utilizing the intense SERS signals of PANI. Rapid SERS imaging of cancer cells is achieved using this ultrasensitive nanoprobe. GO-Au@PANI also reveals good capability of drug delivery with the DOX-loading efficiency of 189.2% and sensitive NIR/pH-responsive DOX release. The intracellular real-time drug release dynamics from the nanocomposites is monitored by SERS-fluorescence dual mode imaging. Finally, chemo-photothermal ablation of cancer cells is carried out in vitro and in vivo using GO-Au@PANI as high-performance chemo-photothermal therapeutic nanoagent. The theranostic applications of GO-Au@PANI endow it with great potential for personalized and precise cancer medicine.

In vitro and in vivo brain-targeting chemo-photothermal therapy using graphene oxide conjugated with transferrin for Gliomas.

Current therapies for treating malignant glioma exhibit low therapeutic efficiency because of strong systemic side effects and poor transport across the blood brain barrier (BBB). Herein, we combined targeted chemo-photothermal glioma therapy with a novel multifunctional drug delivery system to overcome these issues. Drug carrier transferrin-conjugated PEGylated nanoscale graphene oxide (TPG) was successfully synthesized and characterized. When loaded on the proposed TPG-based drug delivery (TPGD) system, the anticancer drug doxorubicin could pass through the BBB and improve drug accumulation both in vitro and in vivo. TPGD was found to perform dual functions in chemotherapy and photothermal therapy. Targeted TPGD combination therapy showed higher rates of glioma cell death and prolonged survival of glioma-bearing rats compared with single doxorubicin or PGD therapy. In conclusion, we developed a potential nanoscale drug delivery system for combined therapy of glioma that can effectively decrease side effects and improve therapeutic effects.

Simplified HIV Testing and Treatment in China: Analysis of Mortality Rates Before and After a Structural Intervention.

BACKGROUND: Multistage stepwise HIV testing and treatment initiation procedures can result in lost opportunities to provide timely antiretroviral therapy (ART). Incomplete patient engagement along the continuum of HIV care translates into high levels of preventable mortality. We aimed to evaluate the ability of a simplified test and treat structural intervention to reduce mortality. METHODS AND FINDINGS: In the "pre-intervention 2010" (from January 2010 to December 2010) and "pre-intervention 2011" (from January 2011 to December 2011) phases, patients who screened HIV-positive at health care facilities in Zhongshan and Pubei counties in Guangxi, China, followed the standard-of-care process. In the "post-intervention 2012" (from July 2012 to June 2013) and "post-intervention 2013" (from July 2013 to June 2014) phases, patients who screened HIV-positive at the same facilities were offered a simplified test and treat intervention, i.e., concurrent HIV confirmatory and CD4 testing and immediate initiation of ART, irrespective of CD4 count. Participants were followed for 6-18 mo until the end of their study phase period. Mortality rates in the pre-intervention and post-intervention phases were compared for all HIV cases and for treatment-eligible HIV cases. A total of 1,034 HIV-positive participants (281 and 339 in the two pre-intervention phases respectively, and 215 and 199 in the two post-intervention phases respectively) were enrolled. Following the structural intervention, receipt of baseline CD4 testing within 30 d of HIV confirmation increased from 67%/61% (pre-intervention 2010/pre-intervention 2011) to 98%/97% (post-intervention 2012/post-intervention 2013) (all p < 0.001 [i.e., for all comparisons between a pre- and post-intervention phase]), and the time from HIV confirmation to ART initiation decreased from 53 d (interquartile range [IQR] 27-141)/43 d (IQR 15-113) to 5 d (IQR 2-12)/5 d (IQR 2-13) (all p < 0.001). Initiation of ART increased from 27%/49% to 91%/89% among all cases (all p < 0.001) and from 39%/62% to 94%/90% among individuals with CD4 count ≤ 350 cells/mm3 or AIDS (all p < 0.001). Mortality decreased from 27%/27% to 10%/10% for all cases (all p < 0.001) and from 40%/35% to 13%/13% for cases with CD4 count ≤ 350 cells/mm3 or AIDS (all p < 0.001). The simplified test and treat intervention was significantly associated with decreased mortality rates compared to pre-intervention 2011 (adjusted hazard ratio [aHR] 0.385 [95% CI 0.239-0.620] and 0.380 [95% CI 0.233-0.618] for the two post-intervention phases, respectively, for all newly diagnosed HIV cases [both p < 0.001], and aHR 0.369 [95% CI 0.226-0.603] and 0.361 [95% CI 0.221-0.590] for newly diagnosed treatment-eligible HIV cases [both p < 0.001]). The unit cost of an additional patient receiving ART attributable to the intervention was US$83.80. The unit cost of a death prevented because of the intervention was US$234.52. CONCLUSIONS: Our results demonstrate that the simplified HIV test and treat intervention promoted successful engagement in care and was associated with a 62% reduction in mortality. Our findings support the implementation of integrated HIV testing and immediate access to ART irrespective of CD4 count, in order to optimize the impact of ART.

Study of molecule variations in human xanthelasma skin based on confocal micro-raman spectroscopy.

Confocal micro-Raman spectroscopy was used to distinguish human xanthelasma skin (HXS) from the human normal skin (HNS). Results showed that intensive Raman peaks at 1,269, 1,336, 1,448, and 1,656 cm(-1) increased obviously. Both 1,269 and 1,656 cm(-1) peaks showed that the proteins in HXS were mostly in the anti-parallel ß sheet conformation. While the intensities of bands at 1,032, 1,087, 1,300, and 1,448 cm(-1) belonged to lipids were enhanced in HXS spectrum compared to those in HNS spectrum. There were main intercellular lipids alkyl chains with minor proteins contribution at 1,087 cm(-1) and phenylalanine at 1,032 cm(-1) . To quantitative analysis of the difference, the ratio of I852/I829 was calculated, which was 1:1.04 ± 0.04 and 1:1.11 ± 0.02 for HNS and HXS (p < 0.01), respectively. The data indicated that some tyrosine residues, which form a hydrogen bond with H2 O prior to aggregation, were captured by strong hydrogen-bond acceptors in the aggregate. The decreased ratio of I852/I829 indicated more hydrophobic in HXS than HNS. Principal component analysis showed a one-to-one relationship between human xanthelasma skin and the corresponding Raman spectra. It could be given useful help for the diagnostication of xanthelasma.