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In this study, the effect of different carbon sources on the carbothermal reduction of low-grade phosphate ore were examined using FactSage7.2 calculations and vacuum reduction experiments. The thermodynamic calculations showed that the trend of the effect for three types of reducing agents was generally consistent under 1 Pa pressure and 14% carbon dosage. The reduction effect was maximum when graphite was used as the reducing agent, and a maximum mass of P was obtained at 1250 ?C. The vacuum experiment results showed that the reduction and volatilization ratios of phosphate rock increased with temperature for different carbon sources. Maximum reduction ratio was obtained using graphite in the temperature range 1250-1300 ?C. The reduction effect of pulverized coal was optimal at 1350 ?C, when SiO2, Al2O3, and MgO in the pulverized coal ash were exposed to form low-melting eutectics with CaO due to the increased degree of reaction, and the heat and mass transfer rates were increased. At this time, a maximum reduction ratio of 51.77% of the sample and a maximum volatilization ratio of 82.44% of P were achieved. Considering the cost effectiveness, pulverized coal was the optimum carbon source for the treatment of low-grade phosphate rock using vacuum carbothermal reduction.

Reducing CO2 into fuels via photochemical reactions relies on highly efficient photocatalytic systems. Herein, we report a new and efficient photocatalytic system for CO2 reduction. Driven by electrostatic attraction, an anionic metal-organic framework Cu-HHTP (HHTP = 2,3,6,7,10,11-hexahydroxytriphenylene) as host and a cationic photosensitizer [Ru(phen)3]2+ (phen = 1,10-phenanthroline) as guest were self-assembled into a photocatalytic system Ru@Cu-HHTP, which showed high activity for photocatalytic CO2 reduction under laboratory light source (CO production rate of 130(5) mmol g-1 h-1, selectivity of 92.9%) or natural sunlight (CO production rate of 69.5 mmol g-1 h-1, selectivity of 91.3%), representing the remarkable photocatalytic CO2 reduction performance. More importantly, the photosensitizer [Ru(phen)3]2+ in Ru@Cu-HHTP is only about 1/500 in quantity reported in the literature. Theoretical calculations and control experiments suggested that the assembly of the catalysts and photosensitizers via electrostatic attraction interactions can provide a better charge transfer efficiency, resulting in high performance for photocatalytic CO2 reduction.

A novel N-doped graphene-like carbon nanosheets (CNs) and carbon nanotubes (CNTs)-encapsulated Co-Co3O4 nanoparticles (NPs) (CN@Co-Co3O4/CNTs) were synthesized successfully by a simple hydrothermal and annealing method with graphite carbon nitride (g-C3N4) as self-template. By annealing Co2+/g-C3N4 under N2 atmosphere, g-C3N4 was transformed into CN/CNTs, and Co2+ was reduced into CoNPs which were embedded in CNs. Further annealing in air, a shell of Co3O4 was formed around CoNPs. The amount of CNs, CNTs, and CoNPs can be adjusted by changing the ratio of Co2+ in Co2+/g-C3N4. The graphene-like CNs provided a large number of active sites and a large specific surface area for loading lots of small CoNPs uniformly. The CNTs with a diameter of 100 nm could not only improve the conductivity but also provide a buffer space for the aggregation and volume expansion of Co3O4. CNTs also enlarged the interlayer distance of CNs, which prevented the re-stacking of CNs and provided great convince for the intercalation and de-intercalation of Li+. When applied for anode material of lithium-ion batteries, CN@Co-Co3O4/CNTs exhibited a high discharge capacity of 460.0 mAh g−1 at 5000 mA g−1 after 300 cycles with a Coulombic efficiency of 98% and excellent higher-rate capacity (401.0 mAh g−1 at 2000 mA g−1 and 329.0 mAh g−1 at 5000 mA g−1).

Conversion from CO2 to C2H4 is important for the development of energy and the environment, but the high energy barrier of hydrogenation of the *CO intermediate and C-C coupling step tend to result in C1 compounds as the main product and thus restrict the generation of C2H4. Here, we report a metal-organic framework (denoted as PcCu-Cu-O), composed of 2,3,9,10,16,17,23,24-octahydroxyphthalo-cyaninato)copper(II) (PcCu-(OH)8) ligands and the square-planar CuO4 nodes, as the electrocatalyst for CO2 to C2H4. Compared with the discrete molecular copper-phthalocyanine (Faradaic efficiency (FE) of C2H4 = 25%), PcCu-Cu-O exhibits much higher performance for electrocatalytic reduction of CO2 to C2H4 with a FE of 50(1)% and a current density of 7.3 mA cm-2 at the potential of -1.2 V vs RHE in 0.1 M KHCO3 solution, representing the best performance reported to date. In-situ infrared spectroscopy and control experiments suggested that the enhanced electrochemical performance may be ascribed to the synergistic effect between the CuPc unit and the CuO4 unit, namely the CO on the CO-producing site (CuO4 site) can efficiently migrate and dimerize with the *CO intermediate adsorbed on the C2H4-producing site (CuPc), giving a lower C-C dimerization energy barrier.

A new and general strategy for the rapid construction of pyrrolotropones via a domino process involving 1,6-nucleophilic addition, isonitrile insertion, azacyclopropylidene-annulated cyclohexenone to tropone rearrangement, and subsequent aromatization, from the reaction of para-quinone methides (p-QMs) with p-toluenesulfonylmethyl isocyanide (TosMIC) has been proposed. The reaction does not require transition metals or stoichiometric oxidants and can be performed through one-step operation promoted by a base. This method uses easy-to-synthesize p-QMs and commercially abundant TosMIC and shows excellent scalability and broad substrate scope. Furthermore, the screening of these pyrrolotropone compounds in several human cancer cell lines shows excellent anticancer activity, which validates the feasibility of this protocol for generating bioactive compounds.

Chemical vapor synthesis was used to prepare Nb nanopowders with NbCl5 vapor as a raw material and Na vapor as a reductant. Thermodynamic analysis indicated that Na had a strong ability to reduce NbCl5. X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) with energy dispersive spectrometry (EDS), and transmission electron microscopy (TEM) were used to analyze and characterize the product powders. These powders contained two phases: Nb and NaCl. Pure-phase Nb powders were synthesized by vacuum evaporation. The spherical Nb particles had an average size of 30 to 120 nm. In addition, the effects of operating conditions, such as the evaporation temperature, the reaction temperature, and the argon flow rate, on the Nb particle size were investigated.

Cobalt exists widely in nature and is one of the essential functional elements in human body, performing in organic or inorganic forms. The lackness of adequate bone integration is a main issue to limit the biomedical substitute materials using widely in clinic. However, introducing cobalt element onto the surface of the materials can significantly change the biological behavior of the implants, which is a good way to solve the above problem. In this paper, the effects of doped cobalt ions on the biological properties of different materials were reviewed, and the development trend of cobalt ion doped biomedical device was prospected.

Chemoselective sulfonylation and isonitrilation reactions for the divergent synthesis of valuable diarylmethyl sulfones and isonitrile diarylmethanes starting from easy-to-synthesize para-quinone methides (p-QMs) and commercially abundant p-toluenesulfonylmethyl isocyanide (TosMIC) by using respectively zinc iodide and 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) as catalysts were developed. The distinguishing feature of this method is that TosMIC plays a dual role from the same substrates in the reaction: as a sulfonyl source or as an isonitrile source. The synthetic utility of this protocol was also demonstrated in the synthesis of difluoroalkylated diarylmethane 5 and diarylmethane ketone derivatives 6 and 7, which are important core structures in natural products and medicines.

BackgroundHepatocellular carcinoma (HCC) is characterized by inflammation and immunopathogenesis. Accumulating evidence has shown that the cystathionine β-synthase/hydrogen sulfide (CBS/H2S) axis is involved in the regulation of inflammation. However, roles of CBS in HCC development and immune evasion have not been systematically investigated, and their underlying mechanisms remain elusive. Here, we investigated the roles of CBS in tumor cells and tumor microenvironment of HCC.Methods236 HCC samples were collected to detect the expression of CBS, cleaved Caspase-3 and paired related homeobox 2 (PRRX2) and the number of immune cells. HCC cell lines were employed to examine the effects of CBS on cellular viability, apoptosis and signaling in vitro. Cbs heterozygous knockout mice, C57BL/6 mice, nude mice and non-obese diabetic severe combined immunodeficiency mice were used to investigate the in vivo functions of CBS.ResultsDownregulation of CBS was observed in HCC, and low expression of CBS predicted poor prognosis in HCC patients. CBS overexpression dramatically promoted cellular apoptosis in vitro and inhibited tumor growth in vivo. Activation of the Cbs/H2S axis also reduced the abundance of tumor-infiltrating Tregs, while Cbs deficiency promoted Tregs-mediated immune evasion and boosted tumor growth in Cbs heterozygous knockout mice. Mechanistically, CBS facilitated the expression cleaved Caspase-3 in tumor cells, and on the other hand, suppressed Foxp3 expression in Tregs via inactivating IL-6/STAT3 pathway. As a transcription factor of IL-6, PRRX2 was reduced by CBS. Additionally, miR-24-3p was proven to be an upstream suppressor of CBS in HCC.ConclusionsOur results indicate the antitumor function of CBS in HCC by inactivation of the PRRX2/IL-6/STAT3 pathway, which may serve as a potential target for HCC clinical immunotherapy.

The non-isothermal reduction kinetics and volatilisation behaviour of iron (Fe), silicon (Si), and magnesium (Mg) during the vacuum carbothermal reduction of ilmenite concentrate were investigated ...

To improve the osseointegration of titanium based implants, we herein modified Ti-25Nb-3Mo-2Sn-3Zr, a β-type titanium alloy by means of surface mechanical attrition treatment (SMAT). X-ray diffraction and transmission electron microscope results jointly indicate that SMAT process refined the average grain size of β phase in the surface layer of the alloy from about 110 μm to 26 nm. Besides, the surface properties and in-vitro cell culture tests of the SMAT-processed samples were investigated compared to those on the non-treated samples. Atomic force microscope and hydrophilicity tests revealed that the SMAT-processed surface was much rougher and hydrophilic than the non-treated surface. In vitro experimental results showed that SMAT-processed surface promoted adsorption of total protein as well as anchoring proteins such as vitronectin and fibronectin on its surface from cell culture medium, furthermore, significant improvements of osteoblast adhesion, proliferation, differentiation and extracellular mineralization were also found on the SMAT-processed surface compared to the non-treated surface. This could be attributed to the grain refinement as well as increased surface hydrophilicity and roughness after SMAT process. Our study provides a promising means of surface modification for future use in biomedical application.

Ketamine cystitis (KC) is a chronic bladder inflammation leading to urinary urgency, frequency, and pain. The pathogenesis of KC is complicated and involves multiple tissue injuries in the bladder. Recent studies indicated that urothelium disruption, lamina propria fibrosis and inflammation, microvascular injury, neuropathological alterations, and bladder smooth muscle (BSM) abnormalities all contribute to the pathogenesis of KC. Ketamine has been shown to induce these tissue injuries by regulating different signaling pathways. Ketamine can stimulate antiproliferative factor, adenosine triphosphate, and oxidative stress to disrupt urothelium. Lamina propria fibrosis and inflammation are associated with the activation of cyclooxygenase-2, nitric oxide synthase, immunoglobulin E, and transforming growth factor β1. Ketamine contributes to microvascular injury via the N-methyl-D aspartic receptor (NMDAR), and multiple inflammatory and angiogenic factors such as tumor necrosis factor α and vascular endothelial growth factor. For BSM abnormalities, ketamine can depress the protein kinase B, extracellular signal-regulated kinase, Cav1.2, and muscarinic receptor signaling. Elevated purinergic signaling also plays a role in BSM abnormalities. In addition, ketamine affects neuropathological alterations in the bladder by regulating NMDAR- and brain-derived neurotrophic factor-dependent signaling. Inflammatory cells also contribute to neuropathological changes via the secretion of chemical mediators. Clarifying the role and function of these signaling underlying tissue injuries in the bladder with KC can contribute to a better understanding of the pathophysiology of this disease and to the design of effective treatments for KC.

Reactive oxygen species (ROS) play a dual role in the initiation, development, suppression, and treatment of cancer. Excess ROS can induce nuclear DNA, leading to cancer initiation. Not only that, but ROS also inhibit T cells and natural killer cells and promote the recruitment and M2 polarization of macrophages; consequently, cancer cells escape immune surveillance and immune defense. Furthermore, ROS promote tumor invasion and metastasis by triggering epithelial-mesenchymal transition in tumor cells. Interestingly, massive accumulation of ROS inhibits tumor growth in two ways: (1) by blocking cancer cell proliferation by suppressing the proliferation signaling pathway, cell cycle, and the biosynthesis of nucleotides and ATP and (2) by inducing cancer cell death via activating endoplasmic reticulum stress-, mitochondrial-, and P53- apoptotic pathways and the ferroptosis pathway. Unfortunately, cancer cells can adapt to ROS via a self-adaption system. This review highlighted the bidirectional regulation of ROS in cancer. The study further discussed the application of massively accumulated ROS in cancer treatment. Of note, the dual role of ROS in cancer and the self-adaptive ability of cancer cells should be taken into consideration for cancer prevention.

Matrix metalloproteinases (MMPs) are the major proteinases that process or degrade numerous extracellular matrix (ECM) components and are evolutionarily conserved from nematodes to humans. During molting in insects, the old cuticle is removed and replaced by a new counterpart. Although the regulatory mechanisms of hormones and nutrients in molting have been well studied, very little is known about the roles of ECM-modifying enzymes in this process. Here, we found that MMPs are necessary for imaginal molting of the American cockroach, Periplaneta americana. Inhibition of Mmp activity via inhibitor treatment led to the failure of eclosion and wing expansion. Five Mmps genes were identified from the P. americana genome, and PaMmp2 played the dominant roles during molting. Further microscopic investigations showed that newly formed adult cuticles were attenuated and that then chitin content was reduced upon Mmp inhibition. Transcriptomic analysis of the integument demonstrated that multiple signaling and metabolic pathways were changed. Microscopic investigation of the wings showed that epithelial cells were restrained together because they were incapable of degrading the ECM upon Mmp inhibition. Transcriptomic analysis of the wing identified dozens of possible genes functioned in wing expansion. This is the first study to show the essential roles of Mmps in the nymph-adult transition of hemimetabolous insects.

Paddy soil contamination by cadmium (Cd) and arsenic (As) is a great concern. Field experiments were conducted to study the effects of steel slag (SS, 2.0 and 4.0 t ha−1) on the solubility of Cd and As in soil and their accumulation by rice plants grown in a historically co-contaminated paddy field with Cd and As. The results showed that SS amendment (4.0 t ha−1) significantly decreased soluble concentrations of Cd in pore-water but increased that of As, related to markedly elevated soil pH and soluble silicon, phosphorus of pore-water in rice rhizosphere at both heading and mature stages. The amendments also evidently decreased Cd but enhanced As in iron plaque on root surfaces, while the formation of iron plaque was not significantly increased. Further, SS amendment (4.0 t ha−1) markedly reduced Cd concentrations in rice tissues (roots, straw, and brown rice) by 48–78% at both stages, though increased As by 13–38%. Cadmium translocation from roots to aerial parts decreased significantly after the amendments, but not for As. Besides, SS application increased the biomass of roots, straw and grains, and root antioxidant enzyme activities. Collectively, steel slag decreased Cd accumulation in rice tissues and in iron plaque but increased those of As, likely due to steel slag decreasing soluble Cd and enhancing soluble As in pore-water, related to soil pH and soluble nutrients (Si, P), and restraining Cd translocation within rice. Our results indicate that steel slag represents a favorable potential for Cd-contaminated paddy soils, though it seems undesirable for Cd and As co-contamination.

The exploration of new catalysts or co-catalysts to promoting the circulation efficiency between Fe3+ and Fe2+ in photo-Fenton system is of great significance for sewage treatment. Herein, metallic sulfides (ZnxCd1-xS) with different molar ratio of Zn/Cd were constructed by a facile solvothermal technology and applied to photo-Fenton system as both catalyst and co-catalyst for the first time. The catalytic activity of photo-Fenton systems could be enhanced by adding any as-prepared samples. Moreover, photo-Fenton system containing ZCS-3 (molar ratio of Zn:Cd = 3:7) presented the highest degradation rate for Rhodamine B (RhB, 93.5%), which showed significant improvement compared with that of photo-system without ZCS-3(43.7%). The excellent performance of this photo-Fenton system was mainly ascribed to the synergistic effect between photocatalytic and co-catalytic of ZCS-3. EPR and XPS results confirmed that the Zn2+ in the ZCS-3 would be reduced to Zn+ by the •O2–, which generated under visible light irradiation in photo-Fenton system. Thereby, more Zn+/Zn2+ exposed on the ZCS-3 surface during this photo-Fenton reaction, ensuring the acceleration of conversion between Fe2+ and Fe3+. The catalytic mechanism revealed that the formation of stable double recycles of Zn2+/Zn+ and Fe2+/Fe3+ in catalytic process displayed prominent enhancement for the catalytic properties of the photo-Fenton system.

Fusarium graminearum is the major causal agent of Fusarium head blight (FHB) disease in cereal crops worldwide. Infection with this fungal phytopathogen can regularly cause severe yield and quality losses and mycotoxin contamination in grains. In previous other studies, one research group reported that pyrrolnitrin had an ability to suppress of mycelial growth of F. graminearum. Other groups revealed that phenazine-1-carboxamide, a derivative of phenazine-1-carboxylic acid, could also inhibit the growth of F. graminearum and showed great potentials in the bioprotection of crops from FHB disease. In our recent work with Pseudomonas chlororaphis strain G05, however, we found that although the phz operon (phenazine biosynthetic gene cluster) was knocked out, the phenazine-deficient mutant G05Δphz still exhibited effective inhibition of the mycelial growth of some fungal phytopathogens in pathogen inhibition assay, especially including F. graminearum, Colletotrichum gloeosporioides, Botrytis cinerea. With our further investigations, including deletion and complementation of the prn operon (pyrrolnitrin biosynthetic gene cluster), purification and identification of fungal compounds, we first verified that not phenazines but pyrrolnitrin biosynthesized in P. chlororaphis G05 plays an essential role in growth suppression of F. graminearum and the bioprotection of cereal crops against FHB disease.

Naproxen (NPX) is a common PPCPs in wastewater treatment plants which is influenced by the coexistence on its photodegradation. Most research on reasons for NPX photodegradation has focused on the soluble substances in water mainly, and the adsorption effect of solid particles is less. The effects of initial concentration, temperature, and pH on the adsorption of NPX on γ-FeOOH were studied. It was found that the equilibrium time of γ-FeOOH adsorbed NPX was 240 min. The increase of initial concentration and temperature were favorable for the adsorption. The optimal adsorption pH was 7.0, and the adsorption capacity attained 28.05 mg·g−1. It was learned, through model fitting, that the adsorption reaction was in accordance with the Laggenren quasi-second-order kinetic model; the internal diffusion process was the control step, where the adsorption was close to the Langmuir isothermal adsorption model. The thermodynamic calculation showed that ΔG

Co3O4 nanomaterials and their composites are replacing carbon as anode materials of lithium-ion batteries (LIBs) because of their large theoretical capacity, low cost and high abundance. However, the volume expansion in the process of charging/discharging leads to the destruction of Co3O4 nanomaterials and thus results in poor cyclic stability, which limits their practical application seriously. Herein, a novel N-doped carbon nanobubble film (CNBF) with hollow Co3O4 nanomaterials (H–Co3O4) composites (H–Co3O4@CNBF) was prepared by proposing covalent-organic framework (COF) as template and carrier of Co2+. Using in-situ anchoring H–Co3O4 strategy, a two-step calcination method was employed to prepare H–Co3O4@CNBF. The obtained H–Co3O4@CNBF exhibited a good lithium storage ability originated from anchored H–Co3O4 nanomaterials and high cycle performance as the anode of LIBs came from the buffering of CNBF. The as-prepared H–Co3O4@CNBF showed excellent capacity of 808.0 mA h g−1 after 100 cycles at 0.2 A g−1 and outstanding cycle stability of 540.0 mA h g−1 after 200 cycles at 2 A g−1. The combination of CNBF derived from COFs with H–Co3O4 is a good strategy, which provides a new guide for the preparation of novel metal oxides and carbon composites.

The co-catalyst plays an important role for improving the catalysis efficiency in Fenton system. In this paper, a new co-catalyst, CuS-Cu9S8 micro-flower was successfully prepared by a facilely hydrothermal method. The effect of co-catalysis for CuS-Cu9S8 micro-flower was evaluated by degradation of Rhodamine B (RhB) in Fenton system, and the RhB solution could be degraded 90% in 15 min in the CuS-Cu9S8 co-catalytic Fenton system under optimal condition, which is apparently better than that of the conventional Fenton system (59%). And EPR result shows that the unsaturated S atoms on the surface of CuS-Cu9S8 can capture protons to form H2S and expose more Cu+/Cu2+ active sites on the surface of CuS-Cu9S8 flower. The high co-catalytic activity of CuS-Cu9S8 on pollutant degradation can be attributed to the acceleration for the rate-limiting Fe2+/Fe3+conversion by the exposed Cu+ /Cu2+ redox pairs. The cycle experiments show that CuS-Cu9S8 has excellent chemical stability and reusability.

SETD7 is a methyltransferase that specifically catalyzes the monomethylation of lysine 4 on histone H3. A variety of studies has revealed the role of SETD7 in posttranslational modifications of non-histone proteins. However, the prognostic value of SETD7 on breast cancer and the ability of SETD7 of regulating intrinsic redox homeostasis has never been investigated. In this study, using The Cancer Genome Atlas (TCGA) database, we revealed that SETD7 was a potential prognostic marker of breast cancer. Median survival time of patients with low SETD7 expression (18.1 years) was twice than that of SETD7 low-expressed patients (9.5 years). We demonstrated that SETD7 promoted tumor cell proliferation and prevented cell apoptosis and that SETD7 delicately maintained the redox homeostasis through regulating the levels of GSH/GSSG and ROS. Further studies indicated that SETD7 was a positive activator of KEAP1-NRF2 pathway. Using dual luciferase assay, we revealed the role of SETD7 as a transcriptional activator of antioxidant enzymes. Downregulation of SETD7 in MCF7 and MDA-MB-231 cells impaired the expression of antioxidant enzymes and induces imbalance of redox status. Together, we proposed SETD7 as a prognostic marker of breast cancer and a novel antioxidant promoter under oxidative stress in breast cancer.

Glaucoma damages the retinal nerve fiber layer (RNFL). Both RNFL thickness and retardance can be used to assess the damage, but birefringence, the ratio of retardance to thickness, is a property of the tissue itself. This study investigated the relationship between axonal cytoskeleton and RNFL birefringence in retinas with hypertensive damage.High intraocular pressure (IOP) was induced unilaterally in rat eyes. RNFL retardance in isolated retinas was measured. Cytostructural organization and bundle thickness were evaluated by confocal imaging of immunohistochemical staining of the cytoskeletal components: microtubules (MTs), F-actin, and neurofilaments. Bundles with different appearances of MT stain were studied, and their birefringence was calculated at different radii from the optic nerve head (ONH) center.Forty bundles in eight normal retinas and 37 bundles in 10 treated retinas were examined. In normal retinas, the stain of axonal cytoskeleton was approximately uniform within bundles, and RNFL birefringence did not change along bundles. In treated retinas, elevation of IOP caused non-uniform alteration of axonal cytoskeleton across the retina, and distortion of axonal MTs was associated with decreased birefringence. The study further demonstrated that change of RNFL birefringence profiles along bundles can imply altered axonal cytoskeleton, suggesting that ultrastructural change of the RNFL can be inferred from clinical measurements of RNFL birefringence. The study also demonstrated that measuring RNFL birefringence profiles along bundles, instead of at a single location, may provide a more sensitive way to detect axonal ultrastructural change.Measurement of RNFL birefringence along bundles can provide estimation of cytoskeleton alteration and sensitive detection of glaucomatous damage.

We present a hybrid electromagnetic generator (EMG) and leaf-shaped polytetrafluoroethylene (PTFE) triboelectric nanogenerator (TENG) with an arc-shaped brace structure for mechanical energy harvesting. The pick-up coil is incorporated into a carbon black (CB) and silicone rubber mixture film at the bottom of the separation component as the EMG, and the TENG is carefully designed with two opposite arc-shaped braces for the contact and separation. It has been demonstrated that the leaf-shaped PTFE film could greatly enhance the collection efficiency of the mechanical energy due to both the leaf-shaped surface and the high voltage corona charge in the TENG. The EMG and TENG can achieve an instantaneous power output of 80 µW cm−2 and 675 µW cm−2 by calculation, respectively. Moreover, a random finger tap test revealed that a high electrical performance is achieved, with a voltage output of 0.25 V and 24 V from the EMG and TENG, respectively.

To enhance corrosion resistance and osseointegration of Mg-based endosseous implants, novel coatings with self-healing and osteoimmunomodulation functions were fabricated on Mg. The coatings exhibited similar three-layered structure, comprising an inner layer of MgO, an interlayer of poly-L-lactide containing curcumin loaded F-encapsulated mesoporous silica nanocontainers (cFMSNs) and an outer layer of dicalcium phosphate dehydrate, while the amounts of cFMSNs contained in the interlayers were different (thus namely 5FMSN, 10FMSN, 20FMSN). Localized-electrochemical impedance spectroscopy, electrochemical and immersion tests were used to investigate self-healing property and corrosion resistance of the coatings, moreover, curcumin release, immunomodulation effects and osseointegration of these coatings were also assayed, together with cFMSNs-free coating (0FMSN). Due to the cFMSNs functioning as corrosion inhibitor, cFMSNs-contained coatings exhibited obvious self-healing property to enhance protection to Mg in vitro and in vivo compared to 0FMSN, and the enhancements were more pronounced with cFMSNs increase. cFMSNs-contained coatings sustainably released curcumin, and the accumulative curcumin concentration of the 20FMSN immersed physiological saline (PS) was 1.51 μM after 10 days of immersion, which was higher than those of the PS immersing 10FMSN (1.02 μM) and 5FMSN (0.31 μM). Owing to the released curcumin, cFMSNs-contained coatings significantly modulated the immune microenvironment towards favoring osteo-differentiation and extracellular matrix mineralization of bone marrow stem cells, consequently exhibited better osseointegration compared to 0FMSN. 20FMSN exhibited higher immunomodulatory efficiency compared to 10FMSN and 5FMSN, and thus achieved the best osseointegration in vivo. Our work paves an alternative way to design coatings on Mg for realizing improved clinical performance.

Mercury (Hg) accumulation records spanning the last 16,000 years before present (yr BP, relative to AD 1950) were derived from a peat core collected from Dajiuhu mire, central China. The natural Hg concentration and accumulation rate (free from anthropogenic influence) were 135.5 ± 53.9 ng g −1 and 6.5 ± 4.5 μg m −2 yr −1 , respectively. The increase in Hg flux that started from a core depth of 96.5 cm (3358 cal yr BP) is independent of soil erosion and organic matter content. We attribute this to an increase in atmospheric Hg deposition derived from regional anthropogenic activities. Anthropogenic Hg accumulation rates (Hg-AR A ) in the pre-industrial period peaked during the Ming and the early Qing dynasties (582–100 cal yr BP), with Hg-AR A of 9.9–24.6 and 10.7–24.4 μg m −2 yr −1 , respectively. In the industrial interval (post∼1850 AD), Hg-AR A increased progressively and reached 32.7 μg m −2 yr −1 at the top of the core. Our results indicate the existence of regional atmospheric Hg pollution spanning the past ∼3400 years, and place recent Hg enrichment in central China in a broader historical context.

Here, free-standing lithium-ion batteries (LIBs) anodes were fabricated through using flexible N-doped carbon foam (NCF) derived from melamine foam as substrate and current collector based on triethylamine (TEA)-assisted burning of Co(CO3)0·5OH/NCF in air. The burning not only achieved the simple transformation from Co(CO3)0·5OH to porous Co3O4 nanorods which were arrayed on NCFs evenly, but also maintained the flexibility and integrity of NCF. The as-obtained NCF/Co3O4 composites had a robust three-dimensional framework and porous structure, which improved the electron/ion transfer, enhanced contact area with electrolyte and prevented the volume inflation in discharging/charging process. In the combusting process, TEA was transformed into N and carbon atom coating on NCF and Co3O4 nanorods, and eventually formed cross-linked NCF frame helpful to stabilize Co3O4 nanorods. When the NCF/Co3O4 composites were applied directly as free-standing LIBs’ anode, it had a higher loading mass of ∼2.5 mg cm−2 compared to traditional anode. In addition, the low charge transfer impedance and easy separation caused by the addition of traditional inactive materials were eliminated. Therefore, the flexible porous NCF/Co3O4 anode without any conductive additives and binders showed the discharge capacity of 576 mAh g−1 at 1 A g−1 after 300 cycles and excellent rate capability.

Prostate cancer (PCa) is one of the most common male malignancies in the world. It was aimed to investigate differential expression of inflammatory and related factors in benign prostatic hyperplasia (BPH), prostate cancer (PCa), histological prostatitis (HP) and explore the role of Inducible nitric oxide synthase (iNOS), (VEGF) Vascular endothelial growth factor, androgen receptor (AR) and IL-2, IL-8 and TNF-α in the occurrence and development of prostate cancer. RT-PCR was used to detect the mRNA expression level of iNOS, VEGF, AR and IL-2, IL-8 and TNF-α in BPH, PCa and BPH+HP. Western blotting and immunohistochemical staining were used to detect the protein levels of various proteins in three diseases. The results showed the mRNA and protein levels of iNOS, VEGF and IL-2, IL-8 and TNF-α were significantly increased in PCa and BPH+HP groups compared with BPH group (p .05), while the AR was significantly lower than those in PCa and BPH+HP groups (p .05). There was no significant difference in the mRNA and protein levels of iNOS, VEGF, AR and IL-2, IL-8 and TNF-α between PCa and BPH+HP groups (p .05). iNOS, VEGF, AR and IL-2, IL-8 and TNF-α are involved in the malignant transformation of prostate tissue and play an important role in the development and progression of Prostate cancer (PCa).

Important role of flowering genes in enhancing grain productivity in rice has become well recognized for a number of key genes regulating the florigen production, but little has been known for the two florigen genes themselves. In this study, pleiotropism of Rice Flowering Locus T 1 (RFT1), one of the two florigen genes in rice, was firstly evaluated using near isogenic lines (NILs) carrying RFT1 alleles from the indica rice cultivars Zhenshan 97 (ZS97) and Milyang 46, respectively, and then determined by transformation of the RFT1ZS97 allele into a japonica rice variety, Zhonghua 11. The RFT1ZS97 allele was shown to delay heading and increase plant height, grain weight, grain number and grain yield, indicating that RFT1 plays an important role in the growth and development of rice. This study has also validated the potential of using a new type of genetic resource, sequential residual heterozygotes (SeqRHs), for QTL fine-mapping. A step-by-step approach was employed for SeqRHs identification, NIL development and QTL fine-mapping. The heterozygous segments and candidate QTL regions were gradually narrowed down. Eventually, the QTL region was delimited to a 1.7 kb region containing a single gene.

Apatite is the raw material, which is mainly used in phosphate fertilizer, and part are used in yellow phosphorus, red phosphorus, and phosphoric acid in the industry. With the decrease of the high grade phosphorite lump, the agglomeration process is necessary for the phosphorite concentrate after beneficiation process. The decomposition behavior and the phase transformation are of vital importance for the agglomeration process of phosphorite. In this study, the thermal kinetic analysis method was used to study the kinetics of the decomposition of phosphorite concentrate. The phosphorite concentrate was heated under various heating rate, and the phases in the sample heated were examined by the X-ray diffraction method. It was found that the main phases in the phosphorite are fluorapatiteCa5(PO4)3F, quartz SiO2,and dolomite CaMg(CO3)2.The endothermic DSC peak corresponding to the mass loss caused by the decomposition of dolomite covers from 600?C to 850?C. The activation energy of the decomposition of dolomite, which increases with the increase in the extent of conversion, is about 71.6~123.6kJ/mol. The mechanism equation for the decomposition of dolomite agrees with the Valensi equation and G-B equation.

This study investigated temporal change of retinal nerve fiber layer (RNFL) reflectance speckle in retinas with ocular hypertensive (OHT) damage and in control retinas from untreated eyes. Experimental OHT damage to rat retinas was induced by laser photocoagulation of the trabecular meshwork. A series of 660 nm reflectance images was collected from isolated retinas at 10-sec intervals. Areas containing speckled texture were selected on nerve fiber bundles. Correlation coefficients between images with different imaging delays were calculated and plotted as a function of delay. To evaluate the temporal change of speckles, decay of correlation coefficients with time was fitted with an exponential function characterized by a time constant τ. Reflectance per unit thickness (σ) of the areas was also measured and low σ was used as a surrogate of OHT damage. Speckle phenomena occurred in the control RNFL and the RNFL with reduced σ. In the control retinas, τ and σ were nearly constant along bundles but differed significantly among bundles in the same retinas. Among the control retinas, σ was similar, whereas τ varied significantly. In the retinas with OHT damage (low σ) τ could be within, greater or lower than the range in controls. The parameters τ and σ provide independent assessment of the RNFL with OHT damage. Measurements of temporal change of RNFL reflectance speckle may offer a method for detecting functional abnormality of the RNFL.

Nano- and ultrafine-grained β-Ti layers were fabricated on Ti-25Nb-3Mo-3Zr-2Sn alloy by surface mechanical attrition treatment (SMAT). After being ground and polished, the two layers exhibited the same chemical composition, similar surface roughness and topography features to the coarse-grained surface, however, higher hardness values were exhibited on the ultrafine- and nano-grained surfaces, especially on nano-grained surface compared to coarse-grained surface. Hydrophilicity test, evaluated by measuring water contact angles, showed that the nano-grained surface was much more hydrophilic than the ultrafine- and coarse-grained surfaces. The adsorption of total protein and anchoring proteins such as vitronectin and fibronectin on the different surfaces from DMEM medium containing 10% fetal bovine serum was also examined. Employing hFOB1.19 cells, the behaviors of osteoblasts on the three kinds of grain-scaled surfaces, including adhesion, proliferation and differentiation, were evaluated by examining the morphology, the number of adherent cells, actin cytoskeleton reorganization, vinculin signals, expressions of steogenesis-related genes, alkaline phosphatase activity, contents of intracellular specific proteins and collagen type I, extracellular collagen secretion as well as matrix mineralization. The significant enhancements of osteoblast adhesion, proliferation, maturation and mineralization are exhibited on the nano-grained surface, while little improvements are found on the ultrafine-grained surface compared to the conventional coarse-grained surface. The differences in the cellular response to the three kinds of grain-scaled surfaces are related to grain size and degree of hydrophilicity. The improved cell functions together with mechanical properties make SMAT-processed nanograined β-Ti a promising biomaterial for surgical implants.

Ilmenite produced from the Panxi area in China has high impurities such as Ca and Mg. High-grade titanium (Ti) slag can be obtained by the electric arc furnace process, a traditional method of treating ilmenite. Thus, Ti slag prepared from the Panxi ilmenite contains high CaO and MgO, exceeding 5 pct of the slag content. This high CaO and MgO content confers considerable difficulty in producing titania (TiO2) white using fluidizing chlorination. In this study, a new process named vacuum separation was found to produce high-grade TiO2 materials. The effects of separation temperature and time on the TiO2 grade were studied. The high-grade TiO2 slag, which has 93 pct TiO2

Oolitic hematite is widely distributed and counted about 10% of the total iron ore resources in China. The powders mixture of the oolitic hematite, the graphite, and the calcium hydroxide was extruded into the cylindrical pieces in the mold by a 10MPa pressure, and reduced in microwave at 1373K. The microstructure and the metallization rate of the sample were studied by optical microscope and chemical analysis. The result shows that the metallization rate increased either with the time extending from 2.0h to 3.5h, or with the C/O atomic ratio increasing from 1.0 to 1.3, or with the binary basicity increasing from 0.16 to 1.5, and the highest value was up to 94.7% on the condition that the atomic ratio C/O is 1.3, the basicity of the sample is 1.5, and the holding time is 3.5h.

Purpose To study the effects of acute optic nerve damage on the reflectance of the retinal nerve fiber layer (RNFL) and to compare the time courses of changes of RNFL reflectance and thickness. Methods A rat model of optic nerve crush (ONC) was compared with previously studied normal retinas. The reflectance and thickness of the RNFL were studied at 1 to 5 weeks after ONC. Reflectance spectra from 400 to 830 nm were measured for eyes with ONC, their contralateral untreated eyes, and eyes with sham surgery. Directional reflectance was studied by varying the angle of light incidence. RNFL thickness was measured by confocal microscopy. Results After ONC, the RNFL reflectance remained directional. At 1 week, RNFL reflectance decreased significantly at all wavelengths (P < 0.001), whereas there was no significant change in RNFL thickness (P = 0.739). At 2 weeks, both RNFL reflectance and thickness decreased significantly, and by 5 weeks they declined to approximately 40% and 30%, respectively, of the normal values. Although RNFL reflectance decreased at all wavelengths, there was a greater reduction at short wavelengths. Spectral shape at long wavelengths was similar to the normal. Some of these changes were also found in the contralateral untreated eyes, but none of these changes were found in eyes with sham surgery. Conclusions Decrease of RNFL reflectance after ONC occurs prior to thinning of the RNFL and the decrease is more prominent at short wavelengths. Direct measurement of RNFL reflectance, especially at short wavelengths, may provide early detection of axonal damage.

Halogen-containing flame retardants are not preferred for environmental reasons. Herein, a halogen-free intumescent flame-retardant ethylene-vinyl acetate copolymer (EVA/IFR) system containing organic montmorillonite (OMMT) and graphene nanosheets (GNSs) is fabricated with well dispersion structure, enhanced thermal-oxidative resistance at high temperature. Interestingly, the amount of residual chars from thermogravimetric analysis is increased to 12.7 wt % at 700 °C, the EVA/IFR composite containing both OMMT and GNSs exhibits the best flame retardancy with the lowest peak heat release rate value of 529.58 kW m−2, and the highest limited oxygen index value of 24.8%. The excellent flame retardancy is attributed to the formation of complete and compact protective char layer. Furthermore, the decreases of the mechanical properties caused by the addition of IFR are relieved and a high volume resistivity is maintained when combining OMMT and GNSs in the EVA/IFR system together. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46361.

Glaucoma damages the retinal nerve fiber layer (RNFL). The purpose of this study was to investigate the distribution in RNFL of axonal F-actin, a cytoskeletal component, under the development of glaucoma. Intraocular hypertension was induced in a rat model by translimbal laser photocoagulation of the trabecular meshwork. The retinas of control and treated eyes were obtained after different exposures to elevated IOP. Nerve fiber bundles were identified by fluorescent phalloidin staining of F-actin. Nuclei of cell bodies were identified by DAPI fluorescent counterstain. F-actin distribution in whole-mounted retinas was examined by confocal microscopy. En face and cross-sectional images of RNFL were collected around the optic nerve head (ONH). F-actin in normal RNFL was intensely and uniformly stained. In glaucomatous retina, F-actin staining was not uniform within bundles and total loss of F-actin staining was found in severely damaged areas. Altered F-actin often occurred near the ONH in bundles that appeared normal more peripherally. Both alteration and total loss of F-actin were found most often in dorsal retina. In normal RNFL, F-actin is rich and approximately uniformly distributed within nerve fiber bundles. Elevated IOP changes F-actin distribution in RNFL. Topographic features of F-actin alteration suggest that F-actin near the ONH is more sensitive to glaucomatous damage. The alteration pattern also suggests an ONH location for the glaucomatous insult in this rat model.

Purpose Glaucoma damages the retinal nerve fiber layer (RNFL). This study used precise multimodal image registration to investigate the changes of the RNFL reflectance spectrum and birefringence in nerve fiber bundles with different degrees of axonal damage. Methods The reflectance spectrum of individual nerve fiber bundles in normal rats and rats with experimental glaucoma was measured from 400 to 830 nm and their birefringence was measured at 500 nm. Optical measurements of the same bundles were made at different distances from the optic nerve head (ONH). After the optical measurements, the axonal cytoskeleton of the RNFL was evaluated by confocal microscopy to assess the severity of cytoskeletal change. Results For normal bundles, the shape of the RNFL reflectance spectrum and the value of RNFL birefringence did not change along bundles. In treated retinas, damage to the cytoskeleton varied within and across retinas. The damage in retinal sectors was subjectively graded from normal-looking to severe. Change of spectral shape occurred near the ONH in all sectors studied. This change became more prominent and occurred farther from the ONH with increased damage severity. In contrast, RNFL birefringence did not show change in normal-looking sectors, but decreased in sectors with mild and moderate damage. The birefringence of severely damaged sectors was either within or below the normal range. Conclusions Varying degrees of cytoskeletal damage affect the RNFL reflectance spectrum and birefringence differently, supporting differences in the ultrastructural basis for the two optical properties. Both properties, however, may provide a means to detect disease and to estimate ultrastructural damage of the RNFL in glaucoma.

Ye Z Spector,1,2 Qi Zhao,3 Xiaopeng Zhao,2 William J Feuer,2 Portia Lynn Maravich,2 Xiang-Run Huang1,2 1Department of Biomedical Engineering, College of Engineering, University of Miami, Miami, FL, USA; 2Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami, Leonard M Miller School of Medicine, Miami, FL, USA; 3Department of Ophthalmology, The Second Affiliated Hospital of Dalian Medical University, Dalian, Liaoning, People's Republic of China Background: Retinal ganglion cells are often classified into different subtypes according to their morphology or physiological functions. The axons of RGCs contain three major cytoskeletal components: actin filaments (F-actin); microtubules; and neurofilaments (NFs). The contents of these components vary among axons. Our objective was to classify axons into subtypes based on the contents of cytoskeletal components and study their distributions across the retina in normal rodent retinas. Methods: Whole-mounted retinas of female Wistar rats were stained with phalloidin to label F-actin, anti-β-tubulin monoclonal antibody to mark microtubules, and antineurofilament antibody to label NFs. A confocal laser scanning microscope was used to provide en face images of retinal nerve fiber bundles with a resolution of 0.24 µm/pixel. Staining intensity profiles across axons were obtained for each cytoskeletal component. Axonal subtypes were then determined from the relative contents, indicated by the staining intensity, of these components. Linear density was used to investigate topographical distribution of each subtype across the retina. Results: Normal axons could be classified into seven subtypes – FMN, FM, FN, and MN subtypes, (in which at least two or three cytoskeletal components were intensely stained), and F, M, and N subtypes, (in which only one cytoskeletal component was intensely stained within an axon). The FMN subtype was the most abundant subtype. There was no preferential distribution of subtypes around the optic nerve head. However, the densities of the axonal subtypes that contained NFs were found significantly different in the central and peripheral retinal regions. Axonal sizes were subtype-dependent. Conclusion: Axons of retinal ganglion cells can be classified into different subtypes, based on the contents of axonal cytoskeletal components. The classified subtypes will provide a new means to study selective damage of axonal ultrastructures in ocular neuropathic diseases. Keywords: retina, cytoskeletal components, F-actin, microtubules, neurofilaments

Glaucoma damages the retinal never fiber layer (RNFL). RNFL thickness, measured with optical coherence tomography (OCT), is often used in clinical assessment of the damage. In this study the relation between the RNFL reflectance and thickness at early stages of glaucoma was investigated.A rat model of glaucoma was used that involved laser photocoagulation of the trabecular meshwork. The reflectance of the RNFL in an isolated retina was measured, followed by immunohistochemical staining of the axonal cytoskeleton. RNFL thickness was measured by confocal fluorescence imaging. RNFL reflectance was calculated for bundle areas located at radii of 0.22, 0.33, and 0.44 mm from the optic nerve head (ONH) center. Linear regression was used to study the relation between reflectance and thickness. For glaucomatous eyes, only those bundles with no apparent structural damage were used.Bundles in 11 control retinas and 10 treated retinas were examined. Bundle thickness of both groups at each radius was similar (P = 0.89). The reflectance of the bundles at radii of 0.33 and 0.44 mm was found to be similar in both control and treated retinas (P0.5). However, the reflectance of the bundles at the 0.22-mm radius decreased significantly in the treated group (P = 0.005).Elevation of intraocular pressure causes decrease in RNFL reflectance for bundles near the ONH. Change in RNFL reflectance precedes thinning of the RNFL. The results suggest that a decrease in RNFL reflectance near the ONH is an early sign of glaucomatous damage.

Glaucoma damages the retinal nerve fiber layer (RNFL). The purpose of this study was to investigate the distribution of major cytoskeleton components, F-actin, microtubules (MTs), and neurofilaments (NFs), in the RNFL during the development of glaucoma. methods: Intraocular hypertension was induced in a rat model by laser photocoagulation of the trabecular meshwork. Retinas were obtained after 2 to 3.5 weeks of treatment. Multiple fluorescent stains were used to identify F-actin, MTs, NFs, and nuclei simultaneously in the same tissue. Distribution of these components in a whole-mounted retina was examined by confocal microscopy. Fluorescent stain was quantitatively described.In normal RNFL F-actin, MTs, and NFs were intensely stained. Along the bundles, F-actin and MTs were strongly colocalized, but alternating strands of F-actin and NFs were apparent. Normal RNFL lacked nuclei. In glaucomatous retinas, irregular staining of F-actin, MTs, and NFs was found within the bundles. A strong network of F-actin appeared on the RNFL surface and between the bundles. In severely damaged retinal regions total loss of F-actin and MTs was found, whereas residual strands of NFs were evident. Before the decrease in RNFL thickness, irregularity of F-actin stain and density of nuclei in the RNFL significantly increased.The results suggest that F-actin, MTs, and NFs are rich and approximately uniformly distributed in the normal RNFL. Glaucoma causes alteration of the cytoskeleton in the RNFL. F-actin is the most sensitive component in its response to stress on the retina. An increase in the number of nuclei in the RNFL may be an early sign of glaucomatous damage.

Purpose The retinal nerve fiber layer (RNFL) exhibits birefringence that is due to the oriented cylindrical structure of the ganglion cell axons. Possible birefringent structures include axonal membranes, microtubules (MTs), and neurofilaments. MTs are generally assumed to be a major contributor, but this has not been demonstrated. In this study, the MT depolymerizing agent colchicine was used to evaluate the contribution of MTs to RNFL birefringence. Methods Retinal nerve fiber bundles of isolated rat retina were observed through an imaging polarimeter set near extinction. Images were taken over an extended period. During baseline, the tissue was perfused with a physiological solution. During a treatment period, the solution was switched either to a control solution identical with the baseline solution or to a similar solution containing colchicine. The contrast of nerve fiber bundles was used to follow change of RNFL birefringence over time. Results When imaged by the polarimeter, birefringent retinal nerve fiber bundles appeared as either bright or dark stripes. Bundles displayed as bright stripes were used to follow changes in retardance. The contrast of nerve fiber bundles was stable in control experiments. However, in treatment experiments, bundles were bright during the baseline period, but the contrast of bundles decreased rapidly when the colchicine solution was applied; bundles were barely visible after 30 minutes of treatment. After 70 minutes, the bundle contrast was close to zero at all wavelengths studied (440-780 nm). Conclusions MTs make a significant contribution to RNFL birefringence. The decrease of RNFL birefringence in glaucoma may indicate a loss of MTs.

Scanning laser polarimetry uses an anterior segment compensating device that assumes a fixed axis of corneal birefringence, which we call the corneal polarization axis. The purpose of this investigation was to establish the distribution of corneal polarization axes among a population of normal eyes and to evaluate the relationship between corneal polarization axis and posterior segment retardation.We constructed a noninvasive slit lamp-mounted device incorporating two crossed linear polarizers and an optical retarder in order to measure the slow axis of corneal birefringence. Normal subjects underwent corneal polarization axis measurement. A subset of eyes underwent scanning laser polarimetry of the peripapillary retinal nerve fiber layer (n = 32) and macula (n = 29), and retardation measurements were evaluated in each group.One hundred eighteen eyes of 63 normal subjects (35 female, 28 male) underwent corneal polarization axis measurement (mean age, 45.5 +/- 17.1 years). Six eyes (5.1%) demonstrated unmeasurable corneal polarization. In the remaining 112 eyes, the mode of the corneal polarization axis distribution was 10 to 20 degrees nasally downward (range, 90 degrees nasally downward to 54 degrees nasally upward). A significant (P.0001) correlation was observed between fellow eyes (R(2) =.52), with a mean difference of 11.2 +/- 10.5 degrees (range, 0-52 degrees). Corneal polarization axis was significantly associated (R(2) =.52-.84) with retinal nerve fiber layer and macula summary retardation parameters (average thickness, ellipse average, superior and inferior average, superior and total integral; P.0001 for all groups).The mean corneal polarization axis among normal corneas is nasally downward; however, considerable intraindividual and interindividual variability exists. The linear relationship between corneal polarization axis and posterior segment retardation parameters is responsible, in part, for the wide distribution of retinal nerve fiber layer thickness data generated by scanning laser polarimetry.

The polarization properties of the retinal nerve fiber layer (RNFL) were investigated with a multispectral imaging micropolarimeter. The RNFL exhibits birefringence, which may be due to form birefringence. The reflectance from the RNFL preserves polarization and exhibits weak diattenuation.

This study investigated the retinal nerve fiber layer (RNFL) reflectance speckle and tested the hypothesis that temporal change of RNFL speckle reveals axonal dynamic activity.RNFL reflectance speckle of isolated rat retinas was studied with monochromatic illumination. A series of reflectance images was collected every 5 seconds for approximately 15 minutes. Correlation coefficients (CC) of selected areas between a reference and subsequent images were calculated and plotted as a function of the time intervals between images. An exponential function fit to the time course was used to evaluate temporal change of speckle pattern. To relate temporal change of speckle to axonal activity, in vitro living retina perfused at a normal (34°C) and a lower (24°C) temperature, paraformaldehyde-fixed retina, and retina treated with microtubule depolymerization were used.RNFL reflectance was not uniform; rather nerve fiber bundles had a speckled texture that changed with time. In normally perfused retina, the time constant of the CC change was 0.56 ± 0.26 minutes. In retinas treated with lower temperature and microtubule depolymerization, the time constants increased by two to four times, indicating that the speckle pattern changed more slowly. The speckled texture in fixed retina was stationary.Fixation stops axonal activity; treatments with either lower temperature or microtubule depolymerization are known to decrease axonal transport. The results obtained in this study suggest that temporal change of RNFL speckle reveals structural change due to axonal activity. Assessment of RNFL reflectance speckle may offer a new means of evaluating axonal function.