Low-molecular-weight heparin ameliorates intestinal barrier dysfunction in aged male rats via protection of tight junction proteins.

The intestinal barrier weakens and chronic gut inflammation occurs in old age, causing age-related illnesses. Recent research shows that low-molecular-weight heparin (LMWH), besides anticoagulation, also has anti-inflammatory and anti-apoptotic effects, protecting the intestinal barrier. This study aims to analyze the effect of LMWH on the intestinal barrier of old male rodents. This study assigned Sprague-Dawley male rats to four groups: young (3 months), young + LMWH, old (20 months), and old + LMWH. The LMWH groups received 1 mg/kg LMWH via subcutaneous injection for 7 days. Optical and transmission electron microscopy (TEM) were used to examine morphological changes in intestinal mucosa due to aging. Intestinal permeability was measured using fluorescein isothiocyanate (FITC)-dextran. ELISA kits were used to measure serum levels of IL-6 and IL-1ß, while Quantitative RT-PCR detected their mRNA levels in intestinal tissues. Western blotting and immunohistochemistry (IHC) evaluated the tight junction (TJ) protein levels such as occludin, zonula occludens-1 (ZO-1), and claudin-2. Western blotting assessed the expression of the apoptosis marker cleaved caspase 3, while IHC was used to detect LGR5+ intestinal stem cells. The intestinal permeability of aged rats was significantly higher than that of young rats, indicating significant differences. With age, the protein levels of occludin and ZO-1 decreased significantly, while the level of claudin-2 increased significantly. Meanwhile, our study found that the levels of IL-1ß and IL-6 increased significantly with age. LMWH intervention effectively alleviated age-related intestinal barrier dysfunction. In aged rats treated with LMWH, the expression of occludin and ZO-1 proteins in the intestine increased, while the expression of claudin-2 decreased. Furthermore, LMWH administration in aged rats resulted in a decrease in IL-1ß and IL-6 levels. LMWH also reduced age-related cleaved caspase3 expression, but IHC showed no difference in LGR5+ intestinal stem cells between groups. Research suggests that LMWH could potentially be a favorable therapeutic choice for age-related diseases associated with intestinal barrier dysfunction, by protecting TJ proteins, reducing inflammation, and apoptosis.

ZNF283, a Krüppel-associated box zinc finger protein, inhibits RNA synthesis of porcine reproductive and respiratory syndrome virus by interacting with Nsp9 and Nsp10.

Porcine reproductive and respiratory syndrome virus (PRRSV) is a viral pathogen with substantial economic implications for the global swine industry. The existing vaccination strategies and antiviral drugs offer limited protection. Replication of the viral RNA genome encompasses a complex series of steps, wherein a replication complex is assembled from various components derived from both viral and cellular sources, as well as from the viral genomic RNA template. In this study, we found that ZNF283, a Krüppel-associated box (KRAB) containing zinc finger protein, was upregulated in PRRSV-infected Marc-145 cells and porcine alveolar macrophages and that ZNF283 inhibited PRRSV replication and RNA synthesis. We also found that ZNF283 interacts with the viral proteins Nsp9, an RNA-dependent RNA polymerase, and Nsp10, a helicase. The main regions involved in the interaction between ZNF283 and Nsp9 were determined to be the KRAB domain of ZNF283 and amino acids 178-449 of Nsp9. The KRAB domain of ZNF283 plays a role in facilitating Nsp10 binding. In addition, ZNF283 may have an affinity for the 3' untranslated region of PRRSV. These findings suggest that ZNF283 is an antiviral factor that inhibits PRRSV infection and extend our understanding of the interactions between KRAB-containing zinc finger proteins and viruses.

Dual Control of Enhanced Quasi-Bound States in the Continuum Emission from Resonant c-Si Metasurfaces.

Optical bound states in the continuum (BICs) offer strong interactions with quantum emitters and have been extensively studied for manipulating spontaneous emission, lasing, and polariton Bose-Einstein condensation. However, the out-coupling efficiency of quasi-BIC emission, crucial for practical light-emitting devices, has received less attention. Here, we report an adaptable approach for enhancing quasi-BIC emission from a resonant monocrystalline silicon (c-Si) metasurface through lattice and multipolar engineering. We identify dual-BICs originating from electric quadrupoles (EQ) and out-of-plane magnetic dipoles, with EQ quasi-BICs exhibiting concentrated near-fields near the c-Si nanodisks. The enhanced fractional radiative local density of states of EQ quasi-BICs overlaps spatially with the emitters, promoting efficient out-coupling. Furthermore, coupling the EQ quasi-BICs with Rayleigh anomalies enhances directional emission intensity, and we observe inherent opposite topological charges in the multipolarly controlled dual-BICs. These findings provide valuable insights for developing efficient nanophotonic devices based on quasi-BICs.

Effect of Imaging Selection Paradigms on Endovascular Thrombectomy Outcomes in Patients With Acute Ischemic Stroke.

BACKGROUND: The effect of imaging selection paradigms on endovascular thrombectomy outcomes in patients with acute ischemic stroke with large vessel occlusion remains uncertain. The study aimed to assess the effect of basic imaging (noncontrast computed tomography with or without computed tomographic angiography) versus advanced imaging (magnetic resonance imaging or computed tomography perfusion) on clinical outcomes following thrombectomy in patients with stroke with large vessel occlusion in the early and extended windows using a pooled analysis of patient-level data from 2 pivotal randomized clinical trials done in China. METHODS: This post hoc analysis used data from 1182 patients included in 2 multicenter, randomized controlled trials in China that evaluated adjunct therapies to endovascular treatment for acute ischemic stroke (Direct Endovascular Treatment for Large Artery Anterior Circulation Stroke performed from May 20, 2018, through May 2, 2020, and Intravenous Tirofiban Before Endovascular Treatment in Stroke from October 10, 2018, through October 31, 2021). Patients with occlusion of the intracranial internal carotid artery or proximal middle cerebral artery (M1/M2 segments) were categorized according to baseline imaging modality (basic versus advanced) as well as treatment time window (early, 0-6 hours versus extended, 6-24 hours from last known well to puncture). The primary outcome was the proportion of patients with functional independence (modified Rankin Scale score of 0-2) at 90 days. Multivariable Poisson regression analysis was performed to determine the association between imaging selection modality and outcomes after endovascular treatment at each time windows. RESULTS: A total of 1182 patients were included in this cohort analysis, with 648 in the early (471 with basic imaging versus 177 advanced imaging) and 534 in the extended (222 basic imaging versus 312 advanced imaging) time window. There were no differences in 90-day functional independence between the advanced and basic imaging groups in either time windows (early window: adjusted relative risk, 0.99 [95% CI, 0.84-1.16]; P=0.91; extended window: adjusted relative risk, 1.00 [95% CI, 0.84-1.20]; P=0.97). CONCLUSIONS: In this post hoc analysis of 2 randomized clinical trial pooled data involving patients with large vessel occlusion stroke, an association between imaging selection modality and clinical or safety outcomes for patients undergoing thrombectomy in either the early or extended windows was not detected. Our study adds to the growing body of literature on simpler imaging paradigms to assess thrombectomy eligibility across both the early and extended time windows. REGISTRATION: URL: http://www.chictr.org.cn; Unique identifiers: ChiCTR-IOR-17013568 and ChiCTR-INR-17014167.

Precisely constructing hybrid nanogap arrays via wet-transfer of dielectric metasurfaces onto a plasmonic mirror.

We propose a new method for fabricating hybrid metasurfaces by combining Mie and plasmonic resonances. Our approach involves obtaining an ultrasmooth gold film and separately structuring monocrystalline silicon (c-Si) nanoantenna arrays, which are then wet-transferred and finally immobilized onto the gold film. The experimental and simulation analysis reveals the importance of the native oxide layer of Si and demonstrates fascinating dispersion curves with nanogap resonances and bound states in the continuum. The localized field enhancements in the nanogap cavities result from the coupling between multipolar Mie resonances and their mirror images in the gold film. This effective method improves our understanding of hybrid modes and offers opportunities for developing active metasurfaces, such as depositing c-Si nanoantenna arrays onto stretchable polydimethylsiloxane substrates or electro-optic and piezoelectric sensitive lithium niobate films for potential applications in MEMS, LiDAR, and beyond.

NetGO 2.0: improving large-scale protein function prediction with massive sequence, text, domain, family and network information.

With the explosive growth of protein sequences, large-scale automated protein function prediction (AFP) is becoming challenging. A protein is usually associated with dozens of gene ontology (GO) terms. Therefore, AFP is regarded as a problem of large-scale multi-label classification. Under the learning to rank (LTR) framework, our previous NetGO tool integrated massive networks and multi-type information about protein sequences to achieve good performance by dealing with all possible GO terms (>44 000). In this work, we propose the updated version as NetGO 2.0, which further improves the performance of large-scale AFP. NetGO 2.0 also incorporates literature information by logistic regression and deep sequence information by recurrent neural network (RNN) into the framework. We generate datasets following the critical assessment of functional annotation (CAFA) protocol. Experiment results show that NetGO 2.0 outperformed NetGO significantly in biological process ontology (BPO) and cellular component ontology (CCO). In particular, NetGO 2.0 achieved a 12.6% improvement over NetGO in terms of area under precision-recall curve (AUPR) in BPO and around 2.6% in terms of $\mathbf {F_{max}}$ in CCO. These results demonstrate the benefits of incorporating text and deep sequence information for the functional annotation of BPO and CCO. The NetGO 2.0 web server is freely available at http://issubmission.sjtu.edu.cn/ng2/.

Agrimoniin is a dual inhibitor of AKT and ERK pathways that inhibit pancreatic cancer cell proliferation.

Molecular-targeted therapy has shown its effectiveness in pancreatic cancer, while single-targeted drug often cannot provide long-term benefit because of drug resistance. Fortunately, multitarget combination therapy can reverse drug resistance and achieve better efficacy. The typical treatment characteristics of traditional Chinese medicine monomer on tumor are multiple targets, with small side effects, low toxicity, and so forth. Agrimoniin has been reported to be effective on some cancers, while the mechanism still needs to be clarified. In this study, we used 5-ethynyl-2'-deoxyuridine, cell counting kit-8, flow cytometry, and western blot experiments to confirm that agrimoniin can significantly inhibit the proliferation of pancreatic cancer cell PANC-1 by inducing apoptosis and cell cycle arrest. In addition, by using SC79, LY294002 (the agonist or inhibitor of AKT pathway), and U0126 (the inhibitor of ERK pathway), we found that agrimoniin inhibited cell proliferation by simultaneously inhibiting AKT and ERK pathways. Moreover, agrimoniin could significantly increase the inhibitory effect of LY294002 and U0126 on pancreatic cancer cells. Meanwhile, in vivo experiments also supported the above results. In general, agrimoniin is a double-target inhibitor of AKT and ERK pathways in pancreatic cancer cells; it is expected to be used as a resistance reversal agent of targeted drugs or a synergistic drug of the inhibitor of AKT pathway or ERK pathway.

Circ_0004104 participates in the regulation of ox-LDL-induced endothelial cells injury via miR-942-5p/ROCK2 axis.

BACKGROUND: Cardiovascular disease was the most common disease among the elderly with high morbidity and mortality. Circ_0004104 was demonstrated to be involved in the regulation of atherosclerosis. METHODS: Quantitative real-time polymerase chain reaction was employed to measure the expression of circ_0004104, miR-942-5p and Rho associated coiled-coil containing protein kinase 2 (ROCK2). Cell proliferation was tested by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay. Cell apoptosis was measured by flow cytometry, and tube formation assay was used to detect the angiogenesis ability of cells. Western blot assay was performed to assess protein levels. Enzyme­linked immunosorbent assay was used to detect the release of IL-1ß and TNF-α. The relationship between miR-942-5p and circ_0004104 or ROCK2 was identified by dual-luciferase reporter assay, RNA immunoprecipitation (RIP) assay, and RNA pull-down assay. RESULTS: Oxidized low-density lipoprotein (ox-LDL) inhibited the proliferation of human umbilical vein endothelial cells (HUVECs) and promoted apoptosis in a dose-dependent manner. Circ_0004104 was increased in serum of atherosclerosis patients and ox-LDL-treated HUVECs, and silence of circ_0004104 promoted the proliferation of ox-LDL-exposed HUVECs and inhibited cell apoptosis. MiR-942-5p downregulation reversed si-circ_0004104-mediated influences in HUVECs upon ox-LDL exposure. ROCK2 was the target of miR-942-5p and circ_0004104 regulated the expression of ROCK2 through sponging miR-942-5p. ROCK2 abated the influences of miR-942-5p in ox-LDL-stimulated HUVECs. Circ_0004104 was increased in the exosomes derived from ox-LDL-exposed HUVECs, and the expression of circ_0004104 was promoted in HUVECs after stimulation with ox-LDL-treated HUVECs cells-derived exosomes. CONCLUSION: Circ_0004104 downregulation receded ox-LDL-induced injury in HUVECs through miR-942-5p and ROCK2.

[Effect of a delay mode of a ventricular assist device on hemodynamics of the cardiovascular system].

The implantation of biventricular assist device (BiVAD) is more challenging than that of left ventricular assist device for the interaction in the process of multiple input and output. Besides, ventricular assist device (VAD) often runs in constant speed (CS) mode in clinical use and thus BiVAD also faces the problems of low pulsation and imbalance of blood volume between systemic circulation and pulmonary circulation. In this paper, a delay assist mode for a VAD by shortening the support time of VAD was put forward. Then, the effect of the delay mode on cardiac output, pulsation and the function of the aortic valve was observed by numerical method and the rules of hemodynamics were revealed. The research showed that compared with VAD supported in CS mode, the VAD using delay mode in systolic and diastolic period proposed in this paper could meet the demand of cardiac output perfusion and restore the function of the arterial valves. The open ratio of aortic valve (AV) and pulmonary valve (PV) increased with the time set in delay mode, and the blood through the AV/PV helped to balance the left and the right cardiac volume. Besides, delay mode also improved the pulsation index of arterial blood flow, which is conducive to the recovery of the ventricular pulse function of patients.

Correlated Exciton Fluctuations in a Two-Dimensional Semiconductor on a Metal.

Excitons in nanoscale materials can exhibit fluorescence fluctuations. Intermittency is pervasive in zero-dimensional emitters such as single molecules and quantum dots. In contrast, two-dimensional semiconductors are generally regarded as stable light sources. Noise contains, however, valuable information about a material. Here, we demonstrate fluorescence fluctuations in a monolayer semiconductor due to sensitivity to its nanoscopic environment focusing on the case of a metal film. The fluctuations are spatially correlated over tens of micrometers and follow power-law statistics, with simultaneous changes in emission intensity and lifetime. At low temperatures, an additional spectral contribution from interface trap states emerges with fluctuations that are correlated with neutral excitons and anticorrelated with trions. Mastering exciton fluctuations has implications for light-emitting devices such as single-photon sources and could lead to novel excitonic sensors. The quantification of fluorescence fluctuations, including imaging, unlocks a set of promising tools to characterize and exploit two-dimensional semiconductors and their interfaces.

Polarization sensitive microstructures fabricated on lithium niobate surfaces by using femtosecond laser pulses.

Polarization sensitive microstructures with different morphologies were induced by irradiating dual lithium niobate crystals with femtosecond laser pulses. An upper lithium niobate crystal served as a mask plate to tailor light field, which led to the formation of crater and arc-shaped structures on the surface of a lower lithium niobate crystal. In single-shot irradiation, the orientation and morphology of resultant microstructures can be tailored by controlling the focusing position, because focus splitting took place when a focused laser light propagated through dual lithium niobate crystals. In scanning, the width and morphology of laser scan lines can be governed using various combinations of focusing position and scanning direction. Furthermore, large-area micro/nanostructures with different topography features were successfully fabricated on the crystal surface and their absorption spectra indicated that the absorptance in the visible wavelength range was strongly dependent on fabricated micro/nanostructures. This new type of structured lithium niobate surfaces can be potentially applied in optical and photonic devices.

Potential methods for improving the efficacy of mesenchymal stem cells in the treatment of inflammatory bowel diseases.

Inflammatory bowel diseases (IBD) are a group of chronic recurrent gastrointestinal inflammatory diseases, including ulcerative colitis (UC), Crohn's disease (CD) and IBD unclassified. The pathogenesis may be related to the mucosal immune dysfunction in genetically susceptible hosts affected by environmental factors. Current therapeutic agents mainly include aminosalicylates, corticosteroids, immunosuppressive drugs and novel biological agents. The purpose of treatment is to suppress inflammation and prevent irreversible structural damage. However, long-term application of these drugs may lead to multiple adverse effects and is not always effective. Mesenchymal stem cells (MSCs) are multipotent progenitors with low immunogenicity, which can be obtained and expanded easily. They play an important role in regulating immune responses and repairing damaged tissues in vivo. Therefore, MSCs are considered to be a promising option for the treatment of IBD. Nonetheless, there are many factors that can reduce the efficacy of MSCs, such as gradual deterioration of functional stem cells with age, low recruitment and persistence in vivo and different routes of administration. In recent years, researchers have been able to improve the efficacy of MSCs by pretreatment, genetic modification or co-application with other substances, as well as using different tissue-derived cells, administration methods or doses. This article reviews these methods to provide references for more effective application of MSCs in the treatment of IBD in the future.

Controllable formation of laser-induced periodic surface structures on ZnO film by temporally shaped femtosecond laser scanning.

We achieved the controllable formation of laser-induced periodic surface structures (LIPSSs) on ZnO films deposited on fused silica induced by modulated temporally shaped femtosecond (fs) laser pulses (800 nm, 50 fs, 1 kHz) through the laser scanning technique. Two-dimensional (2D) high spatial frequency LIPSSs (HSFLs) with a period from 100 to 200 nm could be flexibly modulated based on the preprocessed nanostructures with appropriate fs laser irradiation conditions (fluence, scanning speed, and pulse delay). The finite-difference time-domain (FDTD) method combined with the Drude model was employed to calculate the redistributions of electric fields, which suggested the origin of HSFL formation.

Ultrafast Dynamics of Nonequilibrium Organic Exciton-Polariton Condensates.

Exciton-polariton condensation in organic materials, arising from the coupling of Frenkel excitons to the electromagnetic field in cavities, is a phenomenon resulting in low-threshold coherent light emission among other fascinating properties. The exact mechanisms leading to the thermalization of organic exciton-polaritons toward condensation are not yet understood, partly due to the complexity of organic molecules and partly to the canonical microcavities used in condensation studies, which limit broadband studies. Here, we exploit an entirely different cavity design, i.e., an array of plasmonic nanoparticles strongly coupled to organic molecules, to successfully measure the broadband ultrafast dynamics of the strongly coupled system. Sharp features emerge in the transient spectrum originating from the formation of a condensate with a well-defined molecular vibrational composition. These measurements represent the first direct experimental evidence that molecular vibrations drive condensation in organic systems and provide a benchmark for modeling the dynamics of organic-based exciton-polariton condensates.

Effect of long-term exercise training on static postural control in older adults: a cross-sectional study.

We examined the effects of long-term exercise on age-related decline in static balance control through centre-of-pressure (CoP) measurements of four groups of participants: older controls, younger controls, older Tai Chi exercisers and older joggers. The participants stood quietly in a tandem stance on a force platform for 30 s with eyes open (EO) and eyes closed (EC). The older controls showed remarkably larger CoP and EC/EO ratios than younger controls and older Tai Chi exercisers. The EC/EO ratios of velocity in the mediolateral direction of older joggers were significantly smaller than those of older controls. Results suggest that the static balance of older controls showed a significant decline caused by age-related changes. Long-term Tai Chi and jogging, particularly the former, contributed to static balance control in older people. Older adults relied more on visual information in static postural control than young people. Tai Chi would be an ideal exercise for improving static balance in older people.

Syndecan-1 suppresses cell growth and migration via blocking JAK1/STAT3 and Ras/Raf/MEK/ERK pathways in human colorectal carcinoma cells.

BACKGROUND: Syndecan-1 (SDC-1) is a crucial membrane proteoglycan, which is confirmed to participate in several tumor cell biological processes. However, the biological significance of SDC-1 in colorectal carcinoma is not yet clear. An objective of this study was to investigate the role of SDC-1 in colorectal carcinoma cells. METHODS: Expression of SDC-1 in colorectal carcinoma tissues was evaluated by Reverse transcription-quantitative real-time PCR (RT-qPCR) and western blot. After transfection with pcDNA3.1 or pc-SDC-1, the transfection efficiency was measured. Next, SW480, SW620 and LOVO cell viability, apoptosis, migration and adhesion were assessed to explore the effects of exogenous overexpressed SDC-1 on colorectal carcinoma. In addition, the influences of aberrant expressed SDC-1 in Janus kinase 1 (JAK1)/signal transducer and activator of transcription 3 (STAT3) and rat sarcoma virus (Ras)/rapidly accelerated fibrosarcoma (Raf)/mitogen-activated protein kinase (MEK)/extracellular signal-regulated kinase (ERK) pathways were detected by western blot analysis. RESULTS: SDC-1 mRNA and protein levels were down-regulated in human colorectal carcinoma tissues. SDC-1 overexpression inhibited cell proliferation via suppressing CyclinD1 and c-Myc expression, meanwhile stimulated cell apoptosis via increasing the expression levels of B-cell lymphoma-2-associated x (Bax) and Cleaved-Caspase-3. Additionally, SDC-1 overexpression restrained cell migration via inhibiting the protein expression of matrix metallopeptidase 9 (MMP-9), and elicited cell adhesion through increasing intercellular cell adhesion molecule-1 (ICAM-1). Furthermore, SDC-1 overexpression suppressed JAK1/STAT3 and Ras/Raf/MEK/ERK-related protein levels. CONCLUSIONS: In general, the evidence from this study suggested that SDC-1 suppressed cell growth, migration through blocking JAK1/STAT3 and Ras/Raf/MEK/ERK pathways in human colorectal carcinoma cells.

High red blood cell distribution width is closely associated with in-stent restenosis in patients with unstable angina pectoris.

BACKGROUND: In-stent restenosis remains an unresolved issue. Inflammation plays a pivotal role in the process of in-stent restenosis. Significant and positive associations were found between red blood cell distribution width (RDW) and inflammation. But whether there is a close relationship between higher RDW and in-stent restenosis is still not clarified. METHODS: This retrospective observational study investigated 214 consecutive patients with unstable angina pectoris who underwent successful percutaneous coronary interventions with drug-eluting stents. Patients were divided into three groups according to baseline RDW before percutaneous coronary interventions (low RDW group:≤12.5%; intermediate RDW group:> 12.5% and ≤ 13.5%; high RDW group:> 13.5%). The follow-up angiographies were routinely performed 9-12 months after the initial percutaneous coronary interventions. The multivariate logistic regression analysis was employed to determine the independent predictors of in-stent restenosis. RESULTS: The in-stent restenosis rate was significantly higher in group with higher baseline RDW value (12.3, 19.7, 47.7% in low, intermediate, and high RDW groups respectively, P < 0.001). The baseline RDWs were significantly higher in patients with in-stent restenosis compared with those in patients without in-stent restenosis (13.7 ± 0.8% vs. 13.0 ± 0.8%, P < 0.001). For prediction of in-stent restenosis, the ROC (receiver operating characteristic) curve analysis demonstrated the optimal RDW cutoff value was 13.37 (sensitivity: 65.5%, specificity: 73.6%); the diagnosis cutoff value was 13.89 (sensitivity: 40.0%, specificity: 91.8%); the screening cutoff value was 12.99 (sensitivity: 83.6%, specificity: 49.1%). By multivariate logistic analysis, higher baseline RDW (odds ratio [OR], 5.179; 95% confidence interval [CI], 2.568 to 10.446; P<0.001) together with lower baseline indirect bilirubin (OR, 0.413; 95% CI, 0.305 to 0.559; P<0.001) and diabetes (OR, 4.077; 95% CI, 1.654 to 10.054; P = 0.002) were closely associated with in-stent restenosis at followup (11.1 ± 5.8 months). CONCLUSIONS: The baseline RDW was closely associated with in-stent restenosis at follow-up. The patients with higher baseline RDW might have more chances to develop in-stent restenosis at followup.

Contribution of soil variables to bacterial community composition following land use change in Napahai plateau wetlands.

Land use changes have significant modifications on soil conditions, which is likely to induce alterations in the soil bacterial communities. Little is known about the respective contributions of soil variables to these changes in bacterial communities. For this study, high-throughput sequencing technology was applied to measure the change in bacterial community compositions under the effects of soil variables across three land-use types (i.e., reference, degraded, and agricultural wetlands) in the Napahai plateau. Compared with the reference wetland, a pronounced decrease (1.5-5.3 times) in soil water content, soil organic matter, and total and available nitrogen was observed in degraded and agricultural wetlands. However, a conspicuous increase (1.3-5.7 times) was found for the total and available phosphorus, and potassium. Land use also strongly affected the taxonomic composition of soil bacterial assemblages, changing the normalized ratio of Acidobacteria to Proteobacteia, or to δ-proteobacteia. Soil properties had different contributions to the variations in abundance composition of bacterial community. Soil available phosphorus and potassium were the best predictors for changes in bacterial community composition, explaining 80.9% and 82% of the variations, respectively. In contrast, soil organic matter, carbon/nitrogen, total phosphorus, and total and available nitrogen accounted for 58.7-72.7% of the variations in bacterial community composition. Soil pH (24.6%) and soil water content (40.4%) had a minor contribution. Our data suggested that the compositional alterations of microbial communities following land-use change were likely realized through modifications in the availability of primary soil nutrients in the Napahai plateau wetlands.

Femtosecond laser induced concentric semi-circular periodic surface structures on silicon based on the quasi-plasmonic annular nanostructure.

In this study, we report polarization-dependent concentric circular periodic surface structures on Si induced by a single shot femtosecond (fs) laser pulse based on pre-processed quasi-plasmonic annular-shaped nanostructure. An abnormal annular-shaped energy deposition of the fundamental fs laser pulse can be found by using dual-wavelength superposition of the fundamental frequency (ω) and the second-harmonic frequency (2ω) of an fs Ti:sapphire laser, which is confirmed by real beam shape detection. Based on the annular-shaped energy distribution of dual-wavelength fs laser, a concentric quasi-plasmonic corral nanostructure can be imprinted on the Au thin film. Surface plasmon polaritons (SPPs) excitations on the planar metallic nanostructures enable the manipulation of light on subwavelength scales. Thus, the pre-processed concentric quasi-plasmonic corral nanostructure can act as a precursor for the subsequent SPPs excitation and propagation by the fs laser irradiation. Using this technique, polarization-dependent semi-circular periodic surface structures on silicon can be found by the irradiation of fs laser pulse with only one shot. This research provides an additional freedom for the laser induced periodic surface structure (LIPSS) modulation based on the modulation of SPPs excitation and propagation, which plays an important role in the formation of LIPSS.