Hsa_circ_0087862 contributes to the progression of colorectal cancer through regulating miR-512-3p/HK2 axis.

BACKGROUND: Colorectal cancer (CRC) theratened thousands of people every year. Emerging evidences suggested that circular RNAs (circRNAs) were involved in CRC malignancies. However, the underlying mechanisms have yet not been revealed. METHODS: Quantitative real-time PCR (qRT-PCR) was used to determine the expression of circ_0087862 and microRNA-512-3p (miR-512-3p). Western blot was performed to measure the protein expression of hexokinase 2 (HK2), B-cell lymphoma-2 (Bcl-2), BCL2-associated X (Bax) and BCL2 antagonist/killer 1 (Bak). Moreover, 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2-H-tetrazolium bromide (MTT) assay, colony formation and 5-ethynyl-2'-deoxyuridine (EdU) assay were employed to assess CRC cell proliferation. Also, migration/invasion abilities and apoptosis rates were investigated by transwell assay and flow cytometry. Glucose consumption, lactate production and ATP production were detected using the corresponding kits. Dual-luciferase reporter analysis and RNA immunoprecipitation (RIP) experiments were utilized to analyze the target association of miR-512-3p and circ_0087862 or HK2. Finally, xenograft assay was carried out to analyze the function of circ_0087862 in tumor growth in vivo. RESULTS: Circ_0087862 expression was elevated in CRC tissues and cells. Circ_0087862 silencing repressed cell viabilities, proliferation, migration/invasion and glycolysis, and reinforced cell apoptosis. However, HK2 could weaken these impacts. Additionally, miR-512-3p targeted HK2, and circ_0087862 could regulate HK2 expression by miR-512-3p. Furthermore, circ_0087862 silencing decreased CRC cell xenograft tumor growth. CONCLUSION: Collectively, our data suggested that circ_0087862 knockdown impeded cell viabilities, proliferation, and glycolysis, and contributed to cell apoptosis in CRC, indicating circ_0087862 as a promising tumor promoter.

[Ba4X][In19S32] (X = Cl, Br): two quaternary metal chalcohalides exhibiting remarkable photocurrent responses.

Inorganic metal chalcohalides, as significant semiconductor materials, have emerged as promising candidates for photoelectric applications. Herein, a new type of quaternary chalcohalide, [Ba4X][In19S32] (X = Cl, Br), has been discovered using the high-temperature halide salt flux method. Single-crystal X-ray diffraction analysis reveals that they are isostructural and crystallize in the tetragonal space group I41/amd (no. 141) featuring the octahedral hole formed by six [InS4]5- tetrahedra filled with a [ClBa4]7+ polycation, surrounded by a three-dimensional covalent framework formed by interconnecting [InS6]9- octahedra through corner-sharing and edge-sharing. Moreover, [Ba4Cl][In19S32] and [Ba4Br][In19S32] exhibit wide optical bandgaps of 2.70 eV and 2.46 eV, respectively, and moderate birefringences (0.044 @ 2100 nm and 0.042 @ 2100 nm, respectively). Specifically, [Ba4X][In19S32] (X = Cl, Br) display remarkable photocurrent responses under simulated solar-light illumination, implying their potential for photocatalytic applications. Theoretical calculations were employed to understand the interrelationship between the optical properties and electronic structure. The study on the synthesis and structure-property relationship analysis of inorganic metal chalcohalides provides new insight into the exploration of promising photoelectric materials.

Efficient and polarization insensitive edge coupler based on cascaded vertical waveguide tapers.

We propose an efficient and polarization-insensitive edge coupler (EC) constructed principally with two cascaded vertical waveguide tapers. The proposed edge coupler only requires ordinary 365 nm (i-line) ultraviolet source for lithography process. We experimentally demonstrate the proposed EC on two kinds of photonic integrated circuit (PIC) platforms: silicon nitride (Si3N4) and lithium niobate thin film. Both achieve polarization-insensitive fiber chip coupling efficiency of >70% in the C-band. Our proposed EC have the advantages of efficient, cost-saving, and easy to implement and could serve as an effective solution to facilitate low-loss chip-fiber coupling.

Quaternary alkaline-earth metal thiophosphate SrAgPS4: syntheses, structures, and optical properties.

Metal thiophosphates have outstanding properties for the generation of mid-infrared coherent light and are an emerging nonlinear optical material system. In this study, a new non-centrosymmetric (NCS) quaternary alkaline-earth metal thiophosphate, SrAgPS4, was obtained via a high-temperature solid-state method. The new compound crystallizes in the NCS Ama2 (No. 40) space group and features two-dimensional [AgPS4]2- layers consisting of alternately connected [PS4] and [AgS4] tetrahedra. SrAgPS4 exhibits a strong phase-matched second harmonic generation response (1.10 × AgGaS2 at 2100 nm) and a large band gap (2.97 eV). In addition, theoretical calculations reveal the intrinsic relationship between the electronic structure and optical properties. This work enriches and greatly promotes the research on infrared nonlinear optical materials based on thiophosphates.

Engineering of metal-organic framework nanomaterials on long-period fiber grating for acetone vapor sensing.

Metal-organic framework (MOF) material is one of the most promising porous nanomaterials for volatile organic compound (VOC) adsorption and sensing. The large surface area and the high porosity of MOF contribute to the high sensitivity of MOF-based VOC sensors. In this study, we engineer the coating of the zeolitic imidazolate framework material ZIF-8 grown on the surface of a long-period fiber grating (LPFG) for acetone vapor sensing. Being a periodic structure formed in a single-mode optical fiber, an LPFG is designed to couple light from the core to the cladding of the fiber at a specific resonance wavelength. Adsorption of acetone vapor molecules in the framework of the ZIF-8 coating can change the refractive index of the coating and cause a shift in the resonance wavelength of the LPFG. The sensitivity of the resonance shift of the LPFG to the acetone vapor concentration depends strongly on the thickness of the ZIF-8 coating. To create a dense ZIF-8 coating, at least five growth cycles of ZIF-8 (30 min growth for one cycle) are required, and nine growth cycles can create a 500 nm thick coating. The LPFG coated with nine growth cycles of ZIF-8 provides a high sensitivity of 21.9 nm ppm-1, a low detection limit of 1.4 ppm, and a wide detection range of about 1500 ppm. Our results can facilitate the development of high-performance optical fiber sensors based on MOF for VOC detection.

Thin-film lithium-niobate modulator with a combined passive bias and thermo-optic bias.

It is essential to bias a thin-film lithium-niobate Mach-Zehnder electro-optic (EO) modulator at the desired operation condition to ensure optimal performance of the modulator. While thermo-optic (TO) control can solve the problem of bias drift, it consumes significant electric power. In this paper, we propose a technique to largely reduce bias power consumption by combining passive bias and TO bias. In our design, waveguide sections with different widths are introduced in the two arms of the MZ modulator to produce a desired phase difference of π/2 rad (the desired operation condition), and local heating with electrode heaters placed on the waveguides is employed to provide compensation for any phase drift caused by fabrication errors and other effects. As the TO control only serves to compensate for small errors, the electric power required is low and the response is fast. To demonstrate our technique experimentally, we fabricate several modulators of the same design on the same chip. Our experimental modulators can operate up to ∼40 GHz with a half-wave voltage of ∼2.0 V over a wide optical bandwidth, and the performances are insensitive to ambient temperature variations. The TO bias powers required range from 1 mW to 15 mW, and the thermal rise and fall times are 47 µs and 14 µs, respectively. Our technique can facilitate the development of practical high-speed EO modulators on the lithium-niobate-on-insulator platform.

SrAgAsS4: A Noncentrosymmetric Sulfide with Good Infrared Nonlinear Optical Performance Induced by Aliovalent Substitution from Centrosymmetric SrGa2S4.

A new noncentrosymmetric (NCS) quaternary sulfide, SrAgAsS4, was obtained via the strategy of aliovalent substitution based on centrosymmetric (CS) SrGa2S4. The new compound features two-dimensional [AgAsS4]2- layers, which are composed of alternately connected [AsS4] tetrahedra and [AgS4] tetrahedra. Importantly, SrAgAsS4 exhibits a strong phase-matched second-harmonic generation response (1.35 × AgGaS2 at 2100 nm) and has a suitable birefringence (0.15@2100 nm) and moderate band gap (2.31 eV). The first-principles calculations revealed the significant contribution of [AsS4] and [AgS4] tetrahedra to its optical properties. This work will promote the application of the aliovalent substitution strategy in the design of NCS-structure-based functional materials.

The synthesis and structure-property relation analysis of metal chalcohalide crystals Cs2InPS4X2 (X = Cl, Br) with mixed anions.

Inorganic metal chalcohalides are significant semiconductive materials for photovoltaics, photodetetion and infrared optics. Thus it is considerably rewarding to develop a new synthetic strategy to provide more degrees of freedom for atomic coordination to tune the optical and electronic properties of metal chalcohalides. In this work, the mixed-anion strategy is performed to synthesize two new metal chalcohalides Cs2InPS4X2 (X = Cl, Br) with mixed-anion structure by the reaction of InPS4 and CsX. Single-crystal X-ray diffraction analysis shows that they are isostructural and crystallize in the centrosymmetric space group P21/n, consisting of zero-dimensional structure [In2P2S8X4]4- (X = Cl, Br) built from tetrahedral [PS4]3- and octahedral [InS4X2]7- (X = Cl, Br) through edge-sharing, with Cs cations filling in intervening voids. The UV-vis-NIR diffuse reflectance spectroscopy measurement reveals that Cs2InPS4Cl2 and Cs2InPS4Br2 exhibit large optical bandgaps of 3.21 eV and 3.12 eV, respectively. The electronic structure calculations show that the bandgap mainly originates from the [InS4X2]7- (X = Cl, Br) mixed-anion groups. First-principles calculations indicate that the birefringence of Cs2InPS4Cl2 and Cs2InPS4Br2 is ∼0.08 and ∼0.05 at 2090 nm, respectively. Furthermore, thermal analysis reveals that the Cs2InPS4X2 (X = Cl, Br) are thermostable up to 400 °C. This discovery enriches the structural diversity of inorganic chalcohalides and provides an insight for the exploration of new semiconductive materials.

Investigation into Structural Variation from 3D to 1D and Strong Second Harmonic Generation of the AHgPS4 (A+ = Na+, K+, Rb+, Cs+) Family.

The continuous exploration of multinary chalcogenide semiconductors has provided a variety of new functional materials. In this paper, four new quaternary chalcogenides AHgPS4 (A+ = Na+, K+, Rb+, Cs+) have been prepared by solid-state syntheses. These findings complement the lack of research on this quaternary system. Influenced by the size effect of cations and the coordination mode of Hg, the four compounds crystallize in four different space groups [NaHgPS4, P4̅n2; KHgPS4, Pnn2; RbHgPS4, P21/n; CsHgPS4, P212121] and show an interesting evolution from a 3D framework structure to a 1D chain structure. Moreover, all of these compounds feature noncentrosymmetric (NCS) structures except for RbHgPS4. The materials exhibit wide band gaps of 2.7 eV < Eg < 3.0 eV. The NCS- related second-harmonic-generation (SHG) property of NaHgPS4 and KHgPS4 was also studied. They display strong powder SHG responses (3.14 × AgGaS2 for NaHgPS4; 4.15 × AgGaS2 for KHgPS4), which indicate their intriguing potential as IR nonlinear-optical materials. Moreover, first-principles theoretical calculations were performed to understand the structure-property relationships of these materials.

Planar light-wave circuit-based switchable LP11a-LP11b mode rotator.

A simple planar light-wave circuit-based switchable LP11a-LP11b mode rotator for reconfigurable mode division multiplexing is proposed, which consists of a polymer waveguide and an electrode heater located on the waveguide. Because of the asymmetric refractive index distribution in the horizontal and vertical directions, induced by the thermo-optic effect, mode rotation between the LP11a and LP11b modes can be achieved when the heater is ON but there can be no mode rotation when the heater is OFF. Numerical simulations show that our well-designed mode rotator with optical polymer materials, which has a length of 2750 µm, can achieve a mode conversion efficiency (MCE) larger than 84% over the entire C+L band (1530-1610 nm) and a maximum MCE of 96% at 1550 nm. The switching electric power is 161.5 mW. The calculated temperature within the waveguide core is from 186°C (close to the heater) to 86°C (away from the heater).

High-efficiency unidirectional vertical emitter achieved by an aperture-coupling nanoslot antenna array.

Coupling light from in-plane guided light into free space or optical fibers is crucial for many photonic integrated circuits and vice versa. However, traditional grating couplers or waveguide grating antennas suffer from low upward coupling efficiency due to the light radiating in both upward and downward directions simultaneously. In this paper, a compact aperture-coupling nanoslot antenna array is proposed for high-efficiency unidirectional radiation, where a two-dimensional high-contrast grating (HCG) is employed as a mirror to reflect the undesired downward radiation. Upon the HCG separated by a low-index spacing layer, a thin silver layer is deposited. Finally, a series of H-shaped slots are patterned on the silver thin film to arrange the aperture fields and radiate the in-plane guided light into free space. The proposed nanoslot antenna array features a front-to-back ratio (F/B) over 10 dB within the wavelength range of 1500 ∼ 1600 nm. At the same time, a high radiation efficiency of over 75% and a maximum radiation efficiency of 87.6% are achieved within the 100 nm bandwidth. The high-efficiency unidirectional antenna array is promising for the integrated photonic applications including wireless optical communications, light detection and ranging, and fiber input/output couplers.

On-chip integration of a metal-organic framework nanomaterial on a SiO2 waveguide for sensitive VOC sensing.

In silicon photonic waveguides, the on-chip integration of high-performance nanomaterials is considerably important to enable the waveguide sensing function. Herein, the in situ self-assembly of the low refractive index (RI) metal-organic framework nanomaterial ZIF-8 with a large surface area and high porosity on the surface of a designated SiO2 waveguide for evanescent wave sensing is demonstrated. The surface morphology and transmission loss of the nano-functionalized waveguide are investigated. The specific design and fabrication of asymmetric Mach-Zehnder interferometers (AMZIs) are performed based on the optical properties of ZIF-8. Such efforts in waveguide engineering result in an output interfering spectrum of nano-functionalized AMZI with an ultra-high extinction ratio (28.6 dB), low insertion loss (∼13 dB) and suitable free spectral range (∼30 nm). More significantly, the outstanding sensing features of ZIF-8 are successfully realized on the SiO2 waveguide chip. The results of ethanol detection show that the AMZI sensor has a large detection range (0 to 1000 ppm), high sensitivity (19 pm ppm-1 from 0 to 50 ppm or 41 pm ppm-1 from 600 to 1000 ppm) and low detection limit (1.6 ppm or 740 ppb). This combination of nanotechnology and optical waveguide technology is promising to push forward lab-on-waveguide technology for volatile organic compound (VOC) detection.

Livestock exclusion reduces the spillover effects of pastoral agriculture on soil bacterial communities in adjacent forest fragments.

Forest-to-pasture conversion is known to cause global losses in plant and animal diversity, yet impacts of livestock management after such conversion on vital microbial communities in adjoining natural ecosystems remain poorly understood. We examined how pastoral land management practices impact soil microorganisms in adjacent native forest fragments, by comparing bacterial communities sampled along 21 transects bisecting pasture-forest boundaries. Our results revealed greater bacterial taxon richness in grazed pasture soils and the reduced dispersal of pasture-associated taxa into adjacent forest soils when land uses were separated by a boundary fence. Relative abundance distributions of forest-associated taxa (i.e., Proteobacteria and Nitrospirae) and a pasture-associated taxon (i.e., Firmicutes) also suggest a greater impact of pastoral land uses on forest fragment soil bacterial communities when no fence is present. Bacterial community richness and composition were most related to changes in soil physicochemical variables commonly associated with agricultural fertilization, including concentrations of Olsen P, total P, total Cd, delta 15 N and the ratio of C:P and N:P. Overall, our findings demonstrate clear, and potentially detrimental effects of agricultural disturbance on bacterial communities in forest soils adjacent to pastoral land. We provide evidence that simple land management decisions, such as livestock exclusion, can mitigate the effects of agriculture on adjacent soil microbial communities.

Electro-optic reconfigurable two-mode (de)multiplexer on thin-film lithium niobate.

We propose and demonstrate a compact electro-optic reconfigurable two-mode (de)multiplexer using the configuration of cascaded Mach-Zehnder interferometers formed on thin-film X-cut lithium niobate on silica. Our fabricated device, which is 9.5-mm long, can spatially switch between the two transverse-electric modes with an efficiency higher than 98% from 1530-1560 nm and beyond at an applied voltage of 6.5 V. The switching speed is faster than 30 ns. Our proposed mode switch could find applications in fiber-based and on-chip mode-division-multiplexing systems.

Electro-optic mode-selective switch based on cascaded three-dimensional lithium-niobate waveguide directional couplers.

We propose an electro-optic mode-selective switch based on cascaded three-dimensional lithium-niobate waveguide directional couplers fabricated with a single-step annealed proton-exchange process. To compensate for discrepancies due to uncertainties in the fabrication process, we develop a post-tuning technique to improve the performance of the coupler by means of depositing a layer of titanium oxide (TiO2) onto one of the waveguides of the coupler. By integrating two cascaded dissimilar directional couplers, we experimentally demonstrate switchable (de)multiplexing of the LP01, LP11a, and LP11b modes, where the LP11a mode can be switched at an efficiency over 75% from 1530 nm to 1612 nm with an applied voltage varying between -9 V and +30 V, and the LP11b mode can be switched at an efficiency higher than 90% from 1534 nm to 1577 nm with an applied voltage varying between -21 V to 0 V. The switching times are 230-300 ns. Our proposed waveguide platform could be employed to develop advanced switches for applications in areas where high-speed switching of spatial modes is required, such as reconfigurable mode-division-multiplexing communication.

EuHgGeSe4 and EuHgSnS4: Two Quaternary Eu-Based Infrared Nonlinear Optical Materials with Strong Second-Harmonic-Generation Responses.

Metal chalcogenides play a critical role in the infrared (IR) nonlinear optical (NLO) field. However, Eu-based chalcogenide-type IR NLO materials are still scarce up to now. In this paper, two new quaternary Eu-based chalcogenides, EuHgGeSe4 and EuHgSnS4, containing the "NLO active groups" [HgQ4]6- (Q = S, Se) and [GeSe4]4-/[SnS4]4- were synthesized through traditional high-temperature solid-state reactions. They possess noncentrosymmetric structures, crystallizing in the Ama2 space group, and exhibit strong phase-matchable second-harmonic-generation (SHG) responses (3.1× and 1.77× that of AgGaS2 for EuHgGeSe4 and EuHgSnS4, respectively). Meanwhile, the optical band gaps of EuHgGeSe4 (1.97 eV) and EuHgSnS4 (2.14 eV) were determined from UV-vis-NIR diffuse reflectance spectra. Differential scanning calorimetry (DSC) analyses reveal the congruent-melting behavior of EuHgGeSe4. Furthermore, structural analysis and theoretical calculations verify the critical driving effects of [HgQ4]6- tetrahedra on the strong SHG activity. The overall results demonstrate that EuHgGeSe4 and EuHgSnS4 are potential IR NLO materials.

Grating lobe suppression in optical phased arrays by loading near-wavelength grating.

Optical phased arrays based on optical waveguides are compelling components enabling efficient and accurate beam steering. However, to avoid crosstalk between the waveguides, the element pitch is typically larger than one wavelength, which gives rise to grating lobes in real space. In this Letter, we report that near-wavelength gratings can be employed to suppress the grating lobes by utilizing the angular low-pass-filter characteristics. The properly designed near-wavelength grating acts as an angle-sensitive transmission structure. Nearly 100% transmissivity can be realized at small incident angles. However, it quickly declines to a low level when the incident angle is over the critical one. Then, a simple line current array is utilized to demonstrate the grating lobe suppression effect with the grating designed for TE-polarized incidence. Finally, we demonstrate that by loading the proposed grating designed for TM-polarized incidence upon a waveguide grating array with a 2.4 µm pitch, a grating lobe suppression of 10 dB can be achieved when scanning up to ±14∘.

Vital Members in the More Dysbiotic Oropharyngeal Microbiotas in H7N9-Infected Patients.

The dysbiosis of oropharyngeal (OP) microbiota is associated with multiple diseases, including H7N9 infection. Different OP microbial colonization states may reflect different severities or stages of disease and affect the effectiveness of the treatments. Current study aims to determine the vital bacteria that could possibly drive the OP microbiota in the H7N9 patients to more severe microbial dysbiosis state. The OP microbiotas of 42 H7N9 patients and 30 healthy subjects were analyzed by a series of bioinformatics and statistical analyses. Two clusters of OP microbiotas in H7N9 patients, i.e., Cluster_1_Diseased and Cluster_2_Diseased, were determined at two microbial colonization states by Partition Around Medoids (PAM) clustering analysis, each characterized by distinct operational taxonomic units (OTUs) and functional metabolites. Cluster_1_Diseased was determined at more severe dysbiosis status compared with Cluster_2_Diseased, while OTU143_Capnocytophaga and OTU269_Treponema acted as gatekeepers for both of the two clustered microbiotas. Nine OTUs assigned to seven taxa, i.e., Alloprevotella, Atopobium, Megasphaera, Oribacterium, Prevotella, Stomatobaculum, and Veillonella, were associated with both H7N9 patients with and without secondary bacterial lung infection in Cluster_1. In addition, two groups of healthy cohorts may have potential different susceptibilities to H7N9 infection. These findings suggest that two OP microbial colonization states of H7N9 patients were at different dysbiosis states, which may help determine the health status of H7N9 patients, as well as the susceptibility of healthy subjects to H7N9 infection.

Characteristics of three microbial colonization states in the duodenum of the cirrhotic patients.

Aim: Investigation of characteristics of different duodenal microbial colonization states in patients with liver cirrhosis (LC). Materials & methods: Deep-sequencing analyses of the 16S rRNA gene V1-V3 regions were performed. Results: Both bacterial compositions and richness were different between the three-clustered LC microbiotas, in other words, Cluster_1_LC, Cluster_2_LC and Cluster_3_LC. Cluster_1_LC were more likely at severe dysbiosis status due to its lowest modified cirrhosis dysbiosis ratio. OTU12_Prevotella and OTU10_Comamonas were most associated with Cluster_1_LC and Cluster_3_LC, respectively, while OTU38_Alloprevotella was vital in Cluster_2_LC. Pyruvate-ferredoxin/flavodoxin oxidoreductase, dihydroorotate dehydrogenase and branched-chain amino acid transport system substrate-binding protein were most associated with Cluster_1_LC, Cluster_2_LC and Cluster_3_LC, respectively. Conclusion: The three duodenal microbial colonization states had distinct representative characteristics, which might reflect the health status of cirrhotic patients.

Graphene electrodes for electric poling of electro-optic polymer films.

We propose electric poling of electro-optic (EO) polymer films with graphene electrodes. The use of graphene electrodes can waive the use of buffer layers and minimize the poling voltage. To demonstrate the idea, we prepared EO polymer thin-film waveguides for poling with traditional Au/ITO electrodes and graphene electrodes, where the EO polymer is a guest-host system formed by doping 15 wt% of dipolar polyene chromophore AJLZ53 into the random copolymer P(S-co-MMA). Our experiments confirm that the use of graphene electrodes can significantly reduce the poling voltage. For a 3.8-µm-thick EO polymer film, we achieve high EO coefficients of 82 pm/V at 1541 nm and 110 pm/V at 1300 nm with a poling voltage of 420 V. In addition, the use of graphene electrodes allows more flexible waveguide designs and can potentially simplify the fabrication of devices based on EO polymer.