Hole array enhanced dual-band infrared photodetection.

Photonic structures have been attracting more attention due to their ability to capture, concentrate and propagate optical energy. In this work, we propose a photon-trapping hole-array structure integrated in a nip InAsSb-GaSb heterostructure for the enhancement of the photoresponse in both near- and mid-infrared regions. The proposed symmetrical hole array can increase the photon lifetime inside the absorption layer and reduce reflection without polarization dependence. Significant enhancements in absorption and photoelectric conversion efficiency are demonstrated in dual bands for unpolarized incidence. The enhancement factors of responsivity at room temperature under zero-bias are 1.12 and 1.33 for the near- and mid-infrared, respectively, and they are increased to 1.71 and 1.79 when temperature drops to the thermoelectric cooling temperature of 220 K. Besides, such an integrated hole array also slightly improves working frequency bandwidth and response speed. This work provides a promising way for high-efficiency polarization-independent photoelectric conversion in different electromagnetic wave ranges.

Rotated fourfold U-shape metasurface for polarization-insensitive strong enhancement of mid-infrared photodetection.

Metasurface with thin planar resonant elements offers great capability in manipulating electromagnetic waves and their interaction with semiconductors. Split-ring resonator (SRR), as the basic building block, has been extensively investigated for myriad applications owing to its multiple electric and magnetic resonant modes. In this work, we report a rotated fourfold U-shape SRR metasurface for polarization-insensitive strong enhancement of mid-infrared photodetection. The integrated photodetector consists of a rotated fourfold SRR array and an InAsSb based heterojunction photodiode. A photosensitivity enhancement factor as high as 11 has been achieved by adoption of superimposed high order magnetic and electric resonant modes in the SRR metasurface. This work provides a promising pathway for exploring high performance polarization-insensitive photodetection in different electromagnetic wave ranges.

Indium antimonide uncooled photodetector with dual band photoresponse in the infrared and millimeter wave range.

All-InSb film-based and spiral antenna-assisted Au-InSb-Au metal-semiconductor-metal detector is reported with dual-band photoresponse in the infrared (IR) and millimeter wave range. At IR, the detector exhibits a long wavelength 100% cut-off at 7.3 µm. Under an applied bias of 5 mA, the uncooled blackbody responsivity and specific detectivity are 3.5 A/W and 1×108 Jones, respectively. The f-3dB value measured at 2.94 µm is 75 KHz, corresponding to a detector rise speed of 4.7 µs. At millimeter wave range, the detector shows a narrowband response determined by the coupling of the antenna. A voltage responsivity of 25 V/W is achieved at 167 GHz (1.796 mm) under an applied bias of 25 mA, and the corresponding noise equivalent power (NEP) is 1.0×10-10 WHz-1/2, which can be improved to 1.8×10-12 WHz-1/2 if normalized to the real active semiconductor area. A f-3dB value of 17.5 KHz, corresponding to a detector rise speed of 20 µs is achieved in this range. A proof of principle for IR-modulated photoresponse for millimeter wave is achieved with a maximum modulation depth of 47.5%. This All-InSb film-based detector and the modulation are promising for future novel optoelectronic devices in IR and millimeter waves.

[Study of mycelial polysaccharide from Paraisaria dubia of Ophiocordyceps gracilis asexual].

In order to provide a foundation for the development and application of Ophiocordyceps gracilis and increase the new resources of cordyceps,an asexual Paraisaria dubia was isolated from an O. gracilis fruit body. After 10 days of liquid fermentation,white globular mycelium and clear transparent fermentation were produced. The mycelium was extracted by hot water and precipitated with ethanol to obtain intracellular crude polysaccharide. The protein was deproteinized to obtain deproteinized polysaccharide. The intracellular pure polysaccharide was purified by Sepharose 4 B column chromatography and were analyzed by UV,IR,1 H-NMR,and13 CNMR data,as well as GC and HPLC. The results showed that the intracellular polysaccharide of P. dubia was composed of glucose,galactose and mannose with a molar ratio of 25. 54 ∶2 ∶1. It was a ß-configuration glycosylic bond,containing pyranoside. The initial connection of polysaccharide was ß(1→2)(1→4)(1→6) connection. This experiment provides a theoretical basis for the development and application of P. dubia.

Exogenous nerve growth factor promotes the repair of cardiac sympathetic heterogeneity and electrophysiological instability in diabetic rats.

OBJECTIVES: Diabetic cardiac autonomic neuropathy can lead to an increased incidence of ventricular arrhythmias (VAs). However, few data are available regarding the pathogenesis and therapy of the VAs accompanying diabetic cardiac autonomic neuropathy. We aimed to explore whether or not exogenous nerve growth factor (NGF) can reduce the sympathetic heterogeneity and the incidence of VAs in diabetes mellitus (DM). METHODS: Male Wistar rats were randomly divided into 3 groups: controls, rats with DM with saline infused into the left stellate ganglion (LSG), i.e. the DS group and rats with DM with NGF infused into the LSG, i.e. the DN group. After 28 weeks, all rats were subjected to electrophysiological experiments. Sympathetic innervations and NGF were studied by immunostaining, RT-PCR or Western blot analysis. RESULTS: The incidence of inducible VAs was significantly higher in the DS group than in the control group, but was markedly decreased in the DN group. In the DS group, the tyrosine hydroxylase (TH) and NGF expression were significantly lower than in the other groups, and significant proximal-distal heterogeneities existed regarding the TH and NGF expression in the left ventricle, but were markedly repaired in the DN group. CONCLUSIONS: NGF intervention in the LSG can reduce the heterogeneity of cardiac sympathetic innervations and the incidence of VAs in diabetic rats.

[Identification and antibacterial effect research of a Tolypocladium strain isolated from sclerotium of Ophiocordyceps gracilis in Xinjiang].

OBJECTIVE: To promote development and utilization of Ophiocordyceps gracilis in xinjiang and provide basic data for researching and sustainable developing medicine fungus related to O. gracilis. METHOD: A white strain SFYT002 isolated from the sclerotium of O. gracilis in Xinjiang was researched by morphological observation, ITS and 18SrDNA sequencing. The ITS and 18SrDNA sequences of the strain were determined, BLAST was compared with the other sequences of Tolypocladium in GenBank. The phylogenetic trees of ITS and 18SrDNA sequences were analyzed in Tolypocladium. In addition, the filter paper method was used to study the antibacterial effects. RESULT: The main morphological characters of this strain were white cotton-like colonies, phialide with inflated base, drastically sharping with partially bending tips, small and transparent budding spores with being always assemble to spearhead and globular, subglobular or ellipse conidiospores. The phylogenetic trees of ITS and 18SrDNA sequences were constructed and analyzed in Tolypocladium. It was resulted that Tolypocladium was confirmed to be monophyletic, and the strain SFYT002 was the same as the systematic position of others of T. inflatum. Meanwhile, the antibacterial test was performed against the 4 common pathogenic bacteria. It was showed that both fermentation and its extracts of different polar from this strain possessed good anti-bacteria capacities. CONCLUSION: The strain SFYT02 was identified as T. inflatum, and inhibited effectively growth of bacteria.

Metoprolol-mediated amelioration of sympathetic nerve sprouting after myocardial infarction.

OBJECTIVES: Systemic or local inflammation causes cardiac nerve sprouting and consequent arrhythmia. Metoprolol can prevent sympathetic nerve remodeling after myocardial infarction (MI), but the underlying mechanism is unclear. In this study, we evaluated the role of metoprolol in ameliorating sympathetic sprouting. METHODS: Rabbits underwent ligation of the coronary artery for MI. MI rabbits received metoprolol or saline for 7 days. Immunohistochemistry was used to measure cardiac nerve sprouting and sympathetic innervations. Nuclear factor-κB (NF-κB) DNA binding activity was analyzed by electrophoretic mobility shift assay. The protein levels of NF-κB p65, inhibitor κBα (IκBα) and nerve growth factor (NGF) were detected by Western blot analysis. The mRNA levels of NGF, interleukin-1ß (IL-1ß) and tumor necrosis factor-α (TNF-α) were examined by quantitative real-time PCR. RESULTS: MI rabbits showed nerve sprouting and sympathetic hyperinnervation. In MI rabbits, as compared with saline treatment, metoprolol reduced NF-κB DNA binding activity and NF-κB p65 level, and increased IκBα level. Moreover, metoprolol downregulated IL-1ß, TNF-α and NGF levels, and reduced the density of sympathetic nerve fibers. CONCLUSIONS: Metoprolol ameliorates sympathetic nerve sprouting in rabbits after MI and is associated in part with inhibiting NF-κB activity.

Mesenchymal stem cell therapy improves diabetic cardiac autonomic neuropathy and decreases the inducibility of ventricular arrhythmias.

BACKGROUND: Diabetic cardiac autonomic neuropathy (DCAN) may cause fatal ventricular arrhythmias and increase mortality in diabetics. Mesenchymal stem cells (MSCs) can secrete various cytokines and growth factors exerting neurosupportive effects. In this study, we investigated the effect of MSC on DCAN in diabetic rats. METHODS: Forty rats were divided into normal control, diabetes mellitus (DM) control, MSC treatment (6 × 10(6) MSCs via direct myocardial injection) and MSC-conditioned medium group (100 µl via direct myocardial injection). Immunohistochemistry was used to measure choline acetyltransferase (ChAT, a marker for parasympathetic nerves) and tyrosine hydroxylase (TH, a marker for sympathetic nerves) positive nerve fibres in the ventricular myocardium. Heart rate variability and programmed electrical stimulation was used to assess the inducibility of ventricular arrhythmias in the animals. RESULTS: Two weeks after MSC treatment, the density of ChAT- and TH-positive nerve fibres in MSCs and MSC-conditioned medium group was higher than in DM control group (P < 0.05 or P < 0.01). The ChAT/TH ratio in MSC group was higher than in DM control group (0.37 ± 0.014 vs. 0.27 ± 0.020, P < 0.01). The standard deviation of normal-to-normal R-R intervals in MSCs (5.13 ± 0.69) and MSC-conditioned medium group (4.30 ± 0.56) was higher than in DM control group (3.45 ± 0.60, P < 0.05). The inducibility of VAs in the MSC group was lower than in the DM control group. CONCLUSIONS: MSC therapy may promote cardiac nerve sprouting and increase the ratio of parasympathetic to sympathetic nerve fibres. It may also suppress the inducibility of ventricular arrhythmias in the diabetic rats.

Risk of ventricular arrhythmias after myocardial infarction with diabetes associated with sympathetic neural remodeling in rabbits.

BACKGROUND: Abnormal sympathetic innervation underlies both long-term hyperglycemia and myocardial infarction (MI). The incidence of ventricular arrhythmias (VAs) after MI is higher in diabetic than in nondiabetic patients. However, the exact mechanism remains unclear. In this study, we aimed to explore sympathetic neural remodeling after MI in diabetic rabbits and its relationship with VAs. METHODS: Rabbits were randomly assigned to 4 groups: control, diabetes mellitus (DM), MI and diabetic myocardial infarction (DI). After electrophysiological experiments in vivo, immunohistochemistry and real-time RT-PCR were used to measure sympathetic innervations. To test the function of sympathetic nerve fibers, norepinephrine levels were measured by high-performance liquid chromatography. RESULTS: The corrected QT interval and QT dispersion were significantly more prolonged with DI than other conditions. The density of tyrosine hydroxylase-positive fibers and corresponding mRNA abundance was significantly higher with DI than with DM and under control conditions, but was lower than with the MI group. Moreover, the distribution and structure of regenerated nerve was heterogeneous in DI rabbits. Norepinephrine content was higher in the DI group, and accompanied by an increased quantity of tyrosine hydroxylase-positive fibers. CONCLUSION: MI results in sympathetic neural remodeling in diabetic rabbits, which may be responsible in part for the increased occurrence of VAs.

Eosinophilia complicated with venous thromboembolism: A case report.

BACKGROUND: Eosinophilia is an increase of more than 0.5 × 109/L in the number of eosinophils; it is a systemic condition with an unknown etiology and is often accompanied by multiple impaired organ functions. The clinical manifestations of the disease are highly variable and diverse, rendering identification of the diagnosis challenging; hence, diagnosis and treatment are often delayed. Very few reports of this disease exist globally, especially with rare manifestations of cerebral venous sinus thrombosis and hemorrhage. CASE SUMMARY: A 32-year-old woman with eosinophilia presented to the hospital with bilateral lower-limb edema as the first clinical manifestation, followed by an extensive maculopapular rash throughout the body. She subsequently developed cerebral venous sinus thrombosis along with bilateral lower-limb deep vein thrombosis. Two weeks earlier, she had received a single course of antibiotics from a local hospital for a low-grade fever and sore throat. After various treatments were administered for anticoagulation, maintaining blood circulation, and relieving blood stasis, the lower extremity edema improved significantly; however, the patient's eosinophil count gradually increased. She experienced cerebral venous sinus thrombosis, cerebral hemorrhage, and deep vein thrombosis of the lower limbs before being declared brain dead. In this case report, we have elaborated the diagnosis and management of deep vein thrombosis manifested as eosinophilia, thrombocytopenia, and elevated D-dimer levels. CONCLUSION: Because proper diagnosis is challenging, clinical vigilance is required for patients with eosinophilia, as it can lead to thrombus formation.

Plasmonic semiconductor nanogroove array enhanced broad spectral band millimetre and terahertz wave detection.

High-performance uncooled millimetre and terahertz wave detectors are required as a building block for a wide range of applications. The state-of-the-art technologies, however, are plagued by low sensitivity, narrow spectral bandwidth, and complicated architecture. Here, we report semiconductor surface plasmon enhanced high-performance broadband millimetre and terahertz wave detectors which are based on nanogroove InSb array epitaxially grown on GaAs substrate for room temperature operation. By making a nanogroove array in the grown InSb layer, strong millimetre and terahertz wave surface plasmon polaritons can be generated at the InSb-air interfaces, which results in significant improvement in detecting performance. A noise equivalent power (NEP) of 2.2 × 10-14 W Hz-1/2 or a detectivity (D*) of 2.7 × 1012 cm Hz1/2 W-1 at 1.75 mm (0.171 THz) is achieved at room temperature. By lowering the temperature to the thermoelectric cooling available 200 K, the corresponding NEP and D* of the nanogroove device can be improved to 3.8 × 10-15 W Hz-1/2 and 1.6 × 1013 cm Hz1/2 W-1, respectively. In addition, such a single device can perform broad spectral band detection from 0.9 mm (0.330 THz) to 9.4 mm (0.032 THz). Fast responses of 3.5 µs and 780 ns are achieved at room temperature and 200 K, respectively. Such high-performance millimetre and terahertz wave photodetectors are useful for wide applications such as high capacity communications, walk-through security, biological diagnosis, spectroscopy, and remote sensing. In addition, the integration of plasmonic semiconductor nanostructures paves a way for realizing high performance and multifunctional long-wavelength optoelectrical devices.

The complete mitochondrial genome of Ophiocordyceps gracilis and its comparison with related species.

In this study, the complete mitochondrial genome of O. gracilis was sequenced and assembled before being compared with related species. As the second largest mitogenome reported in the family Ophiocordycipitaceae, the mitogenome of O. gracilis (voucher OG201301) is a circular DNA molecule of 134,288 bp that contains numerous introns and longer intergenomic regions. UCA was detected as anticodon in tRNA-Sec of O. gracilis, while comparative mitogenome analysis of nine Ophiocordycipitaceae fungi indicated that the order and contents of PCGs and rRNA genes were considerably conserved and could descend from a common ancestor in Ophiocordycipitaceae. In addition, the expansion of mitochondrial organization, introns, gene length, and order of O. gracilis were determined to be similar to those of O. sinensis, which indicated common mechanisms underlying adaptive evolution in O. gracilis and O. sinensis. Based on the mitochondrial gene dataset (15 PCGs and 2 RNA genes), a close genetic relationship between O. gracilis and O. sinensis was revealed through phylogenetic analysis. This study is the first to investigate the molecular evolution, phylogenetic pattern, and genetic structure characteristics of mitogenome in O. gracilis. Based on the obtained results, the mitogenome of O. gracilis can increase understanding of the genetic diversity and evolution of cordycipitoid fungi.

Altered profiles of fecal bile acids correlate with gut microbiota and inflammatory responses in patients with ulcerative colitis.

BACKGROUND: Gut microbiota and its metabolites may be involved in the pathogenesis of inflammatory bowel disease. Several clinical studies have recently shown that patients with ulcerative colitis (UC) have altered profiles of fecal bile acids (BAs). It was observed that BA receptors Takeda G-protein-coupled receptor 5 (TGR5) and vitamin D receptor (VDR) participate in intestinal inflammatory responses by regulating NF-ĸB signaling. We hypothesized that altered profiles of fecal BAs might be correlated with gut microbiota and inflammatory responses in patients with UC. AIM: To investigate the changes in fecal BAs and analyze the relationship of BAs with gut microbiota and inflammation in patients with UC. METHODS: The present study used 16S rDNA sequencing technology to detect the differences in the intestinal flora between UC patients and healthy controls (HCs). Fecal BAs were measured by targeted metabolomics approaches. Mucosal TGR5 and VDR expression was analyzed using immunohistochemistry, and serum inflammatory cytokine levels were detected by ELISA. RESULTS: Thirty-two UC patients and twenty-three HCs were enrolled in this study. It was found that the diversity of gut microbiota in UC patients was reduced compared with that in HCs. Firmicutes, Clostridium IV, Butyricicoccus, Clostridium XlVa, Faecalibacterium, and Roseburia were significantly decreased in patients with UC (P = 3.75E-05, P = 8.28E-07, P = 0.0002, P = 0.003, P = 0.0003, and P = 0.0004, respectively). Proteobacteria, Escherichia, Enterococcus, Klebsiella, and Streptococcus were significantly enriched in the UC group (P = 2.99E-09, P = 3.63E-05, P = 8.59E-05, P = 0.003, and P = 0.016, respectively). The concentrations of fecal secondary BAs, such as lithocholic acid, deoxycholic acid, glycodeoxycholic acid, glycolithocholic acid, and taurolithocholate, in UC patients were significantly lower than those in HCs (P = 8.1E-08, P = 1.2E-07, P = 3.5E-04, P = 1.9E-03, and P = 1.8E-02, respectively) and were positively correlated with Butyricicoccus, Roseburia, Clostridium IV, Faecalibacterium, and Clostridium XlVb (P < 0.01). The concentrations of primary BAs, such as taurocholic acid, cholic acid, taurochenodeoxycholate, and glycochenodeoxycholate, in UC patients were significantly higher than those in HCs (P = 5.3E-03, P = 4E-02, P = 0.042, and P = 0.045, respectively) and were positively related to Enterococcus, Klebsiella, Streptococcus, Lactobacillus, and pro-inflammatory cytokines (P < 0.01). The expression of TGR5 was significantly elevated in UC patients (0.019 ± 0.013 vs 0.006 ± 0.003, P = 0.0003). VDR expression in colonic mucosal specimens was significantly decreased in UC patients (0.011 ± 0.007 vs 0.016 ± 0.004, P = 0.033). CONCLUSION: Fecal BA profiles are closely related to the gut microbiota and serum inflammatory cytokines. Dysregulation of the gut microbiota and altered constitution of fecal BAs may participate in regulating inflammatory responses via the BA receptors TGR5 and VDR.

High Order Magnetic and Electric Resonant Modes of Split Ring Resonator Metasurface Arrays for Strong Enhancement of Mid-Infrared Photodetection.

Integration of photonic nanostructures with optoelectrical semiconductors offers great potential of developing high sensitivity and multifunctional photodetectors enabled by enhanced light-matter interactions. Split ring resonator (SRR) array which resonates at different resonant modes, including fundamental magnetic mode (m0), high order magnetic mode (m1), and electric (e) mode has been investigated because of the high potential for different applications. In this work, we study photodetection enhancement of these resonant modes of U-shape SRR arrays in the mid-infrared (2-5 µm) range and report, for the first time, the strong enhancement of photodetection by superimposition of m1 and e modes in an integrated photodetector consisting of a U-shape SRR array and an InAsSb-based heterojunction photodiode. We observe that the m1 mode in the SRR array shows the strongest enhancement of photocurrent, sequentially followed by the e and m0 modes. Using superimposed m1 and e modes, about an order of enhancement in room temperature detectivity (to about 2.0 × 1010 Jones) is achieved under zero-power-supply without sacrificing the response speed. In addition, polarization-resolved photoresponse between m1 and e modes and tunable enhancement of photoresponse are also demonstrated. The remarkable enhancement makes mid-infrared photodetection possible to operate at room temperature.

Plasmon-exciton systems with high quantum yield using deterministic aluminium nanostructures with rotational symmetries.

The abundance and corrosion-resistant properties of aluminium, coupled with its compatibility to silicon processing make aluminium an excellent plasmonic material for light-matter interaction in the ultraviolet-visible spectrum. We investigate the interplay of the excitation and emission enhancements of quantum dots coupled with ultra-small aluminium nanoantennae with varying rotational symmetries, where emission enhancements of ∼8 and ∼6 times have been directly measured for gammadion and star-shaped structures. We observed spontaneous emission modification in the Al antenna with a C6 symmetry and deduce a Purcell factor in the range of 68.01 < FP < 118.25 at plasmonic hotspots, corresponding to a modified quantum yield of >89% in the single antenna and near-unity quantum yield at the plasmonic hotspots. This finding brings us a step closer towards the realization of circularly polarized nanoemitters.

Targeted NGF siRNA delivery attenuates sympathetic nerve sprouting and deteriorates cardiac dysfunction in rats with myocardial infarction.

Nerve growth factor (NGF) is involved in nerve sprouting, hyper-innervation, angiogenesis, anti-apoptosis, and preservation of cardiac function after myocardial infarction (MI). Positively modulating NGF expression may represent a novel pharmacological strategy to improve post-infarction prognosis. In this study, lentivirus encoding NGF short interfering RNA (siRNA) was prepared, and MI was modeled in the rat using left anterior descending coronary artery ligation. Rats were randomly grouped to receive intramyocardial injection of lentiviral solution containing NGF-siRNA (n = 19, MI-SiNGF group), lentiviral solution containing empty vector (n = 18, MI-GFP group) or 0.9% NaCl solution (n = 18, MI-control group), or to receive thoracotomy and pericardiotomy (n = 17, sham-operated group). At 1, 2, 4, and 8 wk after transduction, rats in the MI-control group had higher levels of NGF mRNA and protein than those in the sham-operated group, rats in the MI-GFP group showed similar levels as the MI-control group, and rats in the MI-SiNGF group had lower levels compared to the MI-GFP group, indicating that MI model was successfully established and NGF siRNA effectively inhibited the expression of NGF. At 8 wk, echocardiographic and hemodynamic studies revealed a more severe cardiac dysfunction in the MI-siRNA group compared to the MI-GFP group. Moreover, rats in the MI-siRNA group had lower mRNA and protein expression levels of tyrosine hydroxylase (TH) and growth-associated protein 43-positive nerve fibers (GAP-43) at both the infarcted border and within the non-infarcted left ventricles (LV). NGF silencing also reduced the vascular endothelial growth factor (VEGF) expression and decreased the arteriolar and capillary densities at the infarcted border compared to the MI-GFP group. Histological analysis indicated a large infarcted size in the MI-SiNGF group. These findings suggested that endogenous NGF silencing attenuated sympathetic nerve sprouting and angiogenesis, enlarged the infarct size, aggravated cardiac dysfunction, and potentially contributed to an unfavorable prognosis after MI.

Myocardial infarction induces sympathetic hyperinnervation via a nuclear factor-κB-dependent pathway in rabbit hearts.

Cardiac sympathetic hyperinnervation after myocardial infarction (MI) is associated with a high incidence of lethal arrhythmia. However, the mechanisms of nerve sprouting induced by MI are unclear. In this study, we showed a nuclear factor-κB (NF-κB) signaling pathway involved in cardiac sympathetic hyperinnervation after MI in rabbit hearts. An MI model was induced by ligation of the coronary artery in rabbits, which were then euthanized after 7 days. Rabbits with MI showed sympathetic hyperinnervation, as revealed by immunohistochemical analysis of the density of nerve fibers positive for growth-associated protein 43 (GAP43) and tyrosine hydroxylase (TH). Using western blot and real-time RT-PCR techniques, we found that MI was associated with activation of NF-κB signaling and consequent upregulation of nerve growth factor. Intravenous administration with the NF-κB inhibitor pyrrolidine dithiocarbamate (100mg/kg/day) inhibited NF-κB activation and ameliorated sympathetic hyperinnervation after MI. These results suggest that cardiac nerve sprouting after MI is associated in part with NF-κB activation and may be one of the mechanisms responsible for sympathetic hyperinnervation induced by MI.