Characterizing Retinal Sensitivity and Structure in Congenital Stationary Night Blindness: A Combined Microperimetry and OCT Study.

Purpose: To investigate the characteristics of microperimetry and optical coherence tomography (OCT) in congenital stationary night blindness (CSNB), as well as their structure-function association. Methods: This cross-sectional study included 32 eyes from 32 participants with CSNB, comprising 18 with complete CSNB and 14 with incomplete CSNB, along with 36 eyes from 36 CSNB-unaffected controls matched for age, sex, and spherical equivalent. Using MP-3 microperimetry, central retinal sensitivity was assessed within a 20° field, distributed across six concentric rings (0°, 2°, 4°, 6°, 8°, and 10°). OCT was used to analyze retinal and choroidal thickness. The study aimed to assess the overall and ring-wise retinal sensitivity, as well as choroidal and retinal thickness in CSNB and CSNB-unaffected controls, with a secondary focus on the relationship between retinal sensitivity and microstructural features on OCT. Results: In comparison with CSNB-unaffected subjects, the overall and ring-wise retinal sensitivity as well as choroidal thickness were reduced in patients with CSNB (P < 0.001). Moreover, the central sensitivity in incomplete CSNB group was lower than in complete CSNB group (25.72 ± 3.93 dB vs. 21.92 ± 4.10 dB; P < 0.001). The retinal thickness in the CSNB group was thinner outside the fovea compared with the CSNB-unaffected group. Multiple mixed regression analyses revealed that point-to-point retinal sensitivity was significantly correlated with BCVA (P = 0.002) and the corresponding retinal thickness (P = 0.004). Conclusions: Examination of retinal sensitivity and OCT revealed different spatial distribution profiles in CSNB and its subtypes. In CSNB eyes, retinal sensitivity on microperimetry was associated with retinal thickness on OCT.

Roles of NRF2 in Fibrotic Diseases: From Mechanisms to Therapeutic Approaches.

Fibrosis is a persistent inflammatory response that causes scarring and tissue sclerosis by stimulating myofibroblasts to create significant quantities of extracellular matrix protein deposits in the tissue. Oxidative stress has also been linked to the development of fibrosis in several studies. The nuclear erythroid 2-related factor 2 (NRF2) transcription factor controls the expression of several detoxification and antioxidant genes. By binding to antioxidant response elements, NRF2 is activated by oxidative or electrophilic stress and promotes its target genes, resulting in a protective effect on cells. NRF2 is essential for cell survival under oxidative stress conditions. This review describes Kelch-like epichlorohydrin-associated protein 1 (KEAP1)/NRF2 signaling mechanisms and presents recent research advances regarding NRF2 and its involvement in primary fibrotic lesions such as pulmonary fibrosis, hepatic fibrosis, myocardial fibrosis, and renal fibrosis. The related antioxidant substances and drugs are described, along with the mechanisms by which KEAP1/NRF2 regulation positively affects the therapeutic response. Finally, the therapeutic prospects and potential value of NRF2 in fibrosis are summarized. Further studies on NRF2 may provide novel therapeutic approaches for fibrosis.

Growth and lipid accumulation by different nutrients in the microalga Chlamydomonas reinhardtii.

BACKGROUND: Individual nutrient depletion is widely used to induce lipid accumulation in microalgae, which also causes cell growth inhibition and decreases the total biomass. Thus, improving the lipid accumulation without biomass loss in the nutrient deficiency cells becomes a potential cost-effective treatment for cheaper biofuels. METHODS: In this study, the effects of different nutritional conditions on the growth and contents of lipids in Chlamydomonas reinhardtii were compared, and the metabolic profiles under different nutritional conditions were also investigated. RESULTS: We showed that similar to other microalgae, nitrogen or phosphorus deficiency inhibited the growth of Chlamydomonas and combined nutrition deficiency reduced biomass by up to 31.7%, though lipid contents in cells (g/g dry weight [DW]) were significantly increased. The addition of sodium acetate countered this growth inhibition that resulted from nitrogen and phosphorus deficiency, with significantly increased biomass. Furthermore, the combination of 4 g/L sodium acetate supplementation with nitrogen and phosphorous deficiency increased total fatty acid yield (mg/L) by 93.0 and 150.1% compared to nutrient-depleted and normal culture conditions, respectively. Metabolite content was affected by the different nutritional conditions, especially metabolites that are involved in lipid metabolism, amino acid metabolism and metabolism of external substances. CONCLUSION: Further research into these metabolites could shed light onto the relationship between cell growth inhibition and fatty acid accumulation in Chlamydomonas.

Fatty acid and metabolomic profiling approaches differentiate heterotrophic and mixotrophic culture conditions in a microalgal food supplement 'Euglena'.

BACKGROUND: Microalgae have been recognized as a good food source of natural biologically active ingredients. Among them, the green microalga Euglena is a very promising food and nutritional supplements, providing high value-added poly-unsaturated fatty acids, paramylon and proteins. Different culture conditions could affect the chemical composition and food quality of microalgal cells. However, little information is available for distinguishing the different cellular changes especially the active ingredients including poly-saturated fatty acids and other metabolites under different culture conditions, such as light and dark. RESULTS: In this study, together with fatty acid profiling, we applied a gas chromatography-mass spectrometry (GC-MS)-based metabolomics to differentiate hetrotrophic and mixotrophic culture conditions. CONCLUSIONS: This study suggests metabolomics can shed light on understanding metabolomic changes under different culture conditions and provides a theoretical basis for industrial applications of microalgae, as food with better high-quality active ingredients.

Growth and nitrogen uptake characteristics reveal outbreak mechanism of the opportunistic macroalga Gracilaria tenuistipitata.

Macroalgae has bloomed in the brackish lake of Shenzhen Bay, China continuously from 2010 to 2014. Gracilaria tenuistipitata was identified as the causative macroalgal species. The aim of this study was to explore the outbreak mechanism of G. tenuistipitata, by studying the effects of salinity and nitrogen sources on growth, and the different nitrogen sources uptake characteristic. Our experimental design was based on environmental conditions observed in the bloom areas, and these main factors were simulated in the laboratory. Results showed that salinity 12 to 20 ‰ was suitable for G. tenuistipitata growth. When the nitrogen sources' (NH4+, NO3-) concentrations reached 40 µM or above, the growth rate of G. tenuistipitata was significantly higher. Algal biomass was higher (approximately 1.4 times) when cultured with NH4+ than that with NO3- addition. Coincidentally, macroalgal bloom formed during times of moderate salinity (∼12 ‰) and high nitrogen conditions. The NH4+ and NO3- uptake characteristic was studied to understand the potential mechanism of G. tenuistipitata bloom. NH4+ uptake was best described by a linear, rate-unsaturated response, with the slope decreasing with time intervals. In contrast, NO3- uptake followed a rate-saturating mechanism best described by the Michaelis-Menten model, with kinetic parameters Vmax = 37.2 µM g-1 DM h-1 and Ks = 61.5 µM. Further, based on the isotope 15N tracer method, we found that 15N from NH4+ accumulated faster and reached an atom% twice than that of 15N from NO3-, suggesting when both NH4+ and NO3- were available, NH4+ was assimilated more rapidly. The results of the present study indicate that in the estuarine environment, the combination of moderate salinity with high ammonium may stimulate bloom formation.

Vertical velocity distribution in open-channel flow with rigid vegetation.

In order to experimentally investigate the effects of rigid vegetation on the characteristics of flow, the vegetations were modeled by rigid cylindrical rod. Flow field is measured under the conditions of submerged rigid rod in flume with single layer and double layer vegetations. Experiments were performed for various spacings of the rigid rods. The vegetation models were aligned with the approaching flow in a rectangular channel. Vertical distributions of time-averaged velocity at various streamwise distances were evaluated using an acoustic Doppler velocimeter (ADV). The results indicate that, in submerged conditions, it is difficult to described velocity distribution along the entire depth using unified function. The characteristic of vertical distribution of longitudinal velocity is the presence of inflection. Under the inflection, the line is convex and groove above inflection. The interaction of high and low momentum fluids causes the flow to fold and creates strong vortices within each mixing layer. Understanding the flow phenomena in the area surrounding the tall vegetation, especially in the downstream region, is very important when modeling or studying the riparian environment. ADV measures of rigid vegetation distribution of the flow velocity field can give people a new understanding.

Reduction of waste water in Erhai Lake based on MIKE21 hydrodynamic and water quality model.

In order to study the ecological water environment in Erhai Lake, different monitoring sections were set to research the change of hydrodynamics and water quality. According to the measured data, MIKE21 Ecolab, the water quality simulation software developed by DHI, is applied to simulate the water quality in Erhai Lake. The hydrodynamics model coupled with water quality is established by MIKE21FM software to simulate the current situation of Erhai Lake. Then through the comparison with the monitoring data, the model parameters are calibrated and the simulation results are verified. Based on this, water quality is simulated by the two-dimensional hydrodynamics and water quality coupled model. The results indicate that the level of water quality in the north and south of lake is level III, while in the center of lake, the water quality is level II. Finally, the water environment capacity and total emmision reduction of pollutants are filtered to give some guidance for the water resources management and effective utilization in the Erhai Lake.

A photoelectrochemical sensor based on nickel hydroxyl-oxide modified n-silicon electrode for hydrogen peroxide detection in an alkaline solution.

A novel photoelectrochemical hydrogen peroxide (H2O2) sensor was constructed with platinum (Pt) and nickel hydroxyl-oxide (NiOOH) double layers modified n-silicon electrode (NiOOH/Pt/n-n(+)-Si). About 40nm Pt layer and about 100nm Ni layer were successively coated on the front surface of n-n(+)-Si (111) wafers by vacuum evaporating. A stable layer of NiOOH was formed through oxidation of the Ni layer on the coated silicon wafer by the electrochemical method. The surface of modified electrode was characterized by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The NiOOH/Pt/n-n(+)-Si electrode has been used for determination of H2O2 with a two-electrode cell in the absence of reference electrode by photocurrent measurement at a zero bias. The photoelectrochemical sensor showed a good linear response to H2O2 concentrations in a range from 1.0×10(-5) to 6×10(-5)M with a determination limit (S/N=3) of 2.2µM. The NiOOH/Pt/n-n(+)-Si electrode exhibited excellent reproducibility and stability. Particularly, the facile measurement requirements made this novel modified electrode promising for the development of outdoor H2O2 sensors.