Halogenated aliphatic and phenolic disinfection byproducts in chlorinated and chloraminated dairy wastewater: Occurrence and ecological risk evaluation.

The increasing demand for dairy products has led to the production of a large amount of wastewater in dairy plants, and disinfection is an essential treatment process before wastewater discharge. Disinfection byproducts (DBPs) in disinfected dairy wastewater may negatively influence the aquatic organisms in receiving water. During chlorine and chloramine disinfection of dairy wastewater, the concentrations of aliphatic DBPs increased from below the detection limits to 485.1 µg/L and 26.6 µg/L, respectively. Brominated and iodinated phenolic DBPs produced during chlor(am)ination could further react with chlorine/chloramine to be transformed. High level of bromide in dairy wastewater (12.9 mg/L) could be oxidized to active bromine species by chlorine/chloramine, promoting the formation of highly toxic brominated DBPs (Br-DBPs), and they accounted for 80.3% and 71.1% of the total content of DBPs in chlorinated and chloraminated dairy wastewater, respectively. Moreover, Br-DBPs contributed 49.9-75.9% and 34.2-96.4% to the cumulative risk quotient of DBPs in chlorinated and chloraminated wastewater, respectively. The cumulative risk quotient of DBPs on green algae, daphnid, and fish in chlorinated wastewater was 2.8-11.4 times higher than that in chloraminated wastewater. Shortening disinfection time or adopting chloramine disinfection can reduce the ecological risks of DBPs.

High efficiency removal of organic and inorganic iodine with ferrate[Fe(VI)] through oxidation and adsorption.

I- is a halogen species existing in natural waters, and the transformation of organic and inorganic iodine in natural and artificial processes would impact the quality of drinking water. Herein, it was found that Fe(VI) could oxidize organic and inorganic iodine to IO3-and simultaneously remove the resulted IO3- through Fe(III) particles. For the river water, wastewater treatment plant (WWTP) effluent, and shale gas wastewater treated by 5 mg/L of Fe(VI) (as Fe), around 63 %, 55 % and 71 % of total iodine (total-I) had been removed within 10 min, respectively. Fe(VI) was superior to coagulants in removing organic and inorganic iodine from the source water. Adsorption kinetic analysis suggested that the equilibrium adsorption amount of I- and IO3- were 11 and 10.1 µg/mg, respectively, and the maximum adsorption capacity of IO3- by Fe(VI) resulted Fe(III) particles was as high as 514.7 µg/mg. The heterogeneous transformation of Fe(VI) into Fe(III) effectively improved the interaction probability of IO3- with iron species. Density functional theory (DFT) calculation suggested that the IO3- was mainly adsorbed in the cavity (between the γ-FeOOH shell and γ-Fe2O3 core) of Fe(III) particles through electrostatic adsorption, van der Waals force and hydrogen bond. Fe(VI) treatment is effective for inhibiting the formation of iodinated disinfection by-products in chlor(am)inated source water.

Anthracite Releases Aromatic Carbons and Reacts with Chlorine to Form Disinfection Byproducts in Drinking Water Production.

Anthracite is globally used as a filter material for water purification. Herein, it was found that up to 15 disinfection byproducts (DBPs) were formed in the chlorination of anthracite-filtered pure water, while the levels of DBPs were below the detection limit in the chlorination of zeolite-, quartz sand-, and porcelain sandstone-filtered pure water. In new-anthracite-filtered water, the levels of dissolved organic carbon (DOC), dissolved organic nitrogen (DON), and ammonia nitrogen (NH3-N) ranged from 266.3 to 305.4 µg/L, 37 to 61 µg/L, and 8.6 to 17.1 µg/L, respectively. In aged anthracite (collected from a filter at a DWTP after one year of operation) filtered water, the levels of the above substances ranged from 475.1 to 597.5 µg/L, 62.1 to 125.6 µg/L, and 14 to 28.9 µg/L, respectively. Anthracite would release dissolved substances into filtered water, and aged anthracite releases more substances than new anthracite. The released organics were partly (around 5%) composed by the µg/L level of toxic and carcinogenic aromatic carbons including pyridine, paraxylene, benzene, naphthalene, and phenanthrene, while over 95% of the released organics could not be identified. Organic carbon may be torn off from the carbon skeleton structure of anthracite due to hydrodynamic force in the water filtration process.

Expression, purification, and characterization of the histidine kinase CarS from Fusobacterium nucleatum / 生物工程学报

Fusobacterium nucleatum is an opportunistic pathogenic bacterium that can be enriched in colorectal cancer tissues, affecting multiple stages of colorectal cancer development. The two-component system plays an important role in the regulation and expression of genes related to pathogenic resistance and pathogenicity. In this paper, we focused on the CarRS two-component system of F. nucleatum, and the histidine kinase protein CarS was recombinantly expressed and characterized. Several online software such as SMART, CCTOP and AlphaFold2 were used to predict the secondary and tertiary structure of the CarS protein. The results showed that CarS is a membrane protein with two transmembrane helices and contains 9 α-helices and 12 β-folds. CarS protein is composed of two domains, one is the N-terminal transmembrane domain (amino acids 1-170), the other is the C-terminal intracellular domain. The latter is composed of a signal receiving domain (histidine kinases, adenylyl cyclases, methyl-accepting proteins, prokaryotic signaling proteins, HAMP), a phosphate receptor domain (histidine kinase domain, HisKA), and a histidine kinase catalytic domain (histidine kinase-like ATPase catalytic domain, HATPase_c). Since the full-length CarS protein could not be expressed in host cells, a fusion expression vector pET-28a(+)-MBP-TEV-CarScyto was constructed based on the characteristics of secondary and tertiary structures, and overexpressed in Escherichia coli BL21-Codonplus(DE3)RIL. CarScyto-MBP protein was purified by affinity chromatography, ion-exchange chromatography, and gel filtration chromatography with a final concentration of 20 mg/ml. CarScyto-MBP protein showed both protein kinase and phosphotransferase activities, and the MBP tag had no effect on the function of CarScyto protein. The above results provide a basis for in-depth analysis of the biological function of the CarRS two-component system in F. nucleatum.

A Health Education Program for Home Emergency Management of Acute Complications of Diabetes in the Elderly / 中国医学科学院学报

Objective To establish a health education program for home emergency management of acute complications of diabetes in the elderly.Methods The program was drafted by literature review and panel discussion.The final draft was formed after two rounds of correspondence from 13 experts.Results The recovery rate of the two rounds of expert correspondence was 100%,and the expert authority coefficient was 0.98.The Kendall's harmony coefficients of the two rounds of correspondence were 0.263 and 0.212 respectively(both P<0.001).The established health education program included indicators of three categories:early stage of acute complications of diabetes at home(understanding the inducing factors),emergency warning(quick and early identification in case of emergency),and emergency treatment at home.Conclusion The contents of the health education program are systematic and reliable and meet the needs of health education for home emergency management of the elderly with diabetes.

Occurrence of Iodophenols in Aquatic Environments and the Deiodination of Organic Iodine with Ferrate(VI).

Toxic and odorous iodophenols are commonly identified as disinfection by-products (DBPs) in drinking water. Herein, ng/L levels of iodophenols were identified in river water, wastewater treatment plant effluent, and medical wastewater, with the simultaneous identification of µg/L to mg/L levels of iodide (I-) and total organic iodine (TOI). Oxidation experiment suggested that the I-, TOI, and iodophenols could be oxidized by ferrate [Fe(VI)], and more than 97% of TOI had been transformed into stable and nontoxic IO3-. Fe(VI) initially cleaved the C-I bond of iodophenols and led to the deiodination of iodophenols. The resulted I- was swiftly oxidized into HOI and IO3-, with the intermediate phenolic products be further oxidized into lower molecular weight products. The Gibbs free energy change (ΔG) of the overall reaction was negative, indicating that the deiodination of iodophenols by Fe(VI) was spontaneous. In the disinfection of iodine-containing river water, ng/L levels of iodophenols and chloro-iodophenols formed in the reaction with NaClO/NH2Cl, while Fe(VI) preoxidation was effective for inhibiting the formation of iodinated DBPs. Fe(VI) exhibited multiple functions for oxidizing organic iodine, abating their acute toxicity/cytotoxicity and controlling the formation of iodinated DBPs for the treatment of iodide/organic iodine-containing waters.

Occludin facilitates tumour angiogenesis in bladder cancer by regulating IL8/STAT3 through STAT4.

Bladder cancer (BLCA) is a common genitourinary cancer in patients, and tumour angiogenesis is indispensable for its occurrence and development. However, the indepth mechanism of tumour angiogenesis in BLCA remains elusive. According to recent studies, the tight junction protein family member occludin (OCLN) is expressed at high levels in BLCA tissues and correlates with a poor prognosis. Downregulation of OCLN inhibits tumour angiogenesis in BLCA cells and murine xenografts, whereas OCLN overexpression exerts the opposite effect. Mechanistically, the RT-qPCR analysis and Western blotting results showed that OCLN increased interleukin-8 (IL8) and p-signal transducer and activator of transcription 3 (STAT3) levels to promote BLCA angiogenesis. RNA sequencing analysis and dual-luciferase reporter assays indicated that OCLN regulated IL8 transcriptional activity via the transcription factor STAT4. In summary, our results provide new perspectives on OCLN, as this protein participates in the development of BLCA angiogenesis by activating the IL8/STAT3 pathway via STAT4 and may serve as a novel and unique therapeutic target.

Establishment of an animal model of Sparganum mansoni infection and study on therapeutic methods II Establishment of a mouse model of sparganosis mansoni via oral administration of procercoids / 中国血吸虫病防治杂志

Objective To establish an animal model of sparganosis mansoni through oral administration of Cyclops infected with procercoids. Methods Domestic cats were infected with Sparganum mansoni under laboratory conditions, and fresh cat stool samples were collected, washed in dechlorinated water, and filtered. Spirometra mansoni eggs were collected and prepared into suspensions. Twenty C57BL/6j mice were randomly divided into the experimental group (n = 15) and the control group (n = 5). Wild Cyclops were infected with Spirometra mansoni coracidia to allow 3 to 5 procercoids in each Cyclop. Then, each mouse in the experimental group was given 15 Cyclops infected with procercoids by gavage, while mice in the control group were orally administered with the same volume of dechlorinated water. All mice were sacrificed after 5 months, and dissected, and suspicious Sparganum mansoni worms were collected. The serum specific IgG antibody against Sparganum mansoni was measured in mice using enzyme-linked immunosorbent assay (ELISA). Genomic DNA was isolated from suspicious Sparganum mansoni worms, and the specific Sparganum mansoni cytochrome oxidase I (COI) gene was amplified using PCR assay. Results Among the 15 mice in the experimental group, six were positive for the serum specific IgG antibody against Sparganum mansoni, and milky white worms were found and collected from the subcutaneous regions of 4 out of 6 mice. Only one worm was detected in each mouse, and the worm morphology was similar to Sparganum mansoni. Capillary electrophoresis of the PCR amplification products of COI gene presented a specific band with 151 bp in size, and sequencing analysis revealed 100% homology with Sparganum mansoni. Conclusions A mouse model of sparganosis mansoni is successfully created through oral administration of Cyclops infected with Spirometra mansoni procercoids.

Haze removal with channel-wise scattering coefficient awareness based on grey pixels.

Before being captured by observers, the information carried by light may be attenuated by the transmission medium. According to the atmospheric scattering model, this attenuation is wavelength-dependent and increases with distance. However, most existing haze removal methods ignore this wavelength dependency and therefore cannot handle well the color distortions caused by it. To solve this problem, we propose a scattering coefficient awareness method based on the image formation model. The proposed method first makes an initial transmission estimation by the dark channel prior and then calculates the scattering coefficient ratios based on the initial transmission map and the grey pixels in the image. After that, fine transmission maps in RGB channels are calculated from these ratios and compensated for in sky areas. A global correction is also applied to eliminate the color bias induced by the light source before the final output. Qualitatively and quantitatively compared on synthetic and real images against state-of-the-art methods, the proposed method provides better results for the scenes with either white fog or colorized haze.

Chlorination decreases acute toxicity of iodophenols through the formation of iodate and chlorinated aliphatic disinfection byproducts.

Highly toxic iodinated phenolic by-products were frequently detected in the oxidative treatment and disinfection of iodine-containing water. Herein, it was found that three model iodinated phenolic disinfection byproducts (DBPs), 2-iodophenol, 4-iodophenol and 2,4,6-triiodophenol, were reactive with HOCl, and the reaction rate constants (at pH 7.0 and 25℃) were 1.86 ×102, 1.62 ×102 and 7.5 ×101 M-1s-1, respectively. When HOCl was in excess (HOCl/iodophenol = 40/1, [iodophenol]0 = 20 µM), acute toxicity of water sample containing iodophenols could be largely eliminated (> 85%), with the conversion of iodophenols into stable and non-toxic iodate (IO3-) and iodinated and chlorinated aliphatic DBPs. Besides IO3-, seven kinds of aromatic intermediate products including iodophenols, chloroiodophenols, iodoquinones, chloroiodoquinones, chloroquinones, chlorophenols, and coupling products were detected. C-I bond of iodophenols was cleaved in the reaction and the resulted aromatic products were further transformed into chlorinated aliphatic DBPs [trichloromethane (TCM), trichloroacetic acid (TCAA), dichloroacetic acid (DCAA), and chloral hydrate (CH)] (mg/L level) and iodinated trihalomethanes (µg/L level). HOCl was effective for converting iodophenols into IO3- and less toxic chlorinated aliphatic DBPs. Considering that chlorine was widely used as disinfectant, transformation and toxicity alteration of emerging DBPs during chlorination/booster chlorination warrant further investigations.

Correction: Neuroinflammatory inhibitors from Gardneria nutans Siebold & Zuccarini.

[This corrects the article DOI: 10.1039/D1RA05204G.].

Neuroinflammatory inhibitors from Gardneria nutans Siebold & Zuccarini.

Two new monoterpene indole alkaloid glycosides nutanoside A-B (1-2), two new phenolic glycoside esters nutanester A-B (6-7), together with five known compounds (3-5, 8-9) were isolated from the ethanol extract of Gardneria nutans Siebold & Zuccarini. Their structures were established on the basis of extensive spectroscopic analysis and TDDFT/ECD calculations. Compounds 1 and 2 are two rare monoterpene indole alkaloids with the glucosyl moiety located at C-12 and represent the first two examples of enantiomer of ajmaline type monoterpene indole alkaloids. Compounds 3, 4 and 6 displayed significant inhibitory effects on NO production in over-activated BV2 microglial cells, with the IC50 values of 2.29, 6.36, and 8.78 µM, respectively. Compounds 1, 5, 7 could significantly inhibit the mRNA expression of inflammatory factors TNF-α and IL-6 induced by LPS in BV2 microglial cells at the effective concentration. Moreover, compound 3 exhibited stronger cytotoxicities against U87 and HCT116 cell lines than taxol with IC50 values of 10.58 and 14.60 µM, respectively.

Prevalence of Spirometra mansoni infections in hosts in Jiangsu Province / 中国血吸虫病防治杂志

Objective To investigate the prevalence of Spirometra mansoni infections in hosts in Jiangsu Province, so as to provide the scientific basis for the management of sparganosis mansoni. Methods From 2018 to 2019, nine counties (cities, districts) were randomly selected from Jiangsu Province as the survey sites, and 100 healthy individuals were randomly selected to perform the serological test of S. mansoni infections and the detection of S. mansoni eggs. The procercoids were detected in the intermediate host Cyclops, and the S. mansoni eggs were identified in the stool samples of the definitive hosts cats and dogs. Results The prevalence of S. mansoni human infections was 0 (0/900) in the 9 survey sites of Jiangsu Province, and the sero-prevalence of the specific IgG antibody against S. mansoni was 1.22% (11/900). The positive rate of procercoids was 0.33% (3/900) in Cyclops. In addition, the S. mansoni egg-positive rate was 1.48% (2/135) in cats and dogs. Conclusions Sparganosis mansoni is prevalent in Jiangsu Province. Health education pertaining to the damages of sparganosis mansoni and the route of S. mansoni infections should be improved.

Effects of Bilateral Arm Transcutaneous Electrical Acupoint Stimulation on Upper Limb Function for Subacute Stroke Hemiplegic Patients / 中国康复理论与实践

Objective:To explore the effects of bilateral arm transcutaneous electrical acupoint stimulation (TEAS) based on mirror therapy (MT) on upper limb function of subacute stroke hemiplegic patients. Methods:From September, 2017 to October, 2019, 48 subacute stroke hemiplegic patients were randomly divided into control group (n = 24) and experimental group (n = 24). All the patients accepted routine rehabilitation and MT, while the experimental group received bilateral arm TEAS and the control group received sham TEAS, for four weeks. They were assessed with Fugl-Meyer Assessment-Upper Extremity (FMA-UE), Action Research Arm Test (ARAT), Wolf Motor Function Test (WMFT) and modified Barthel Index (MBI) before and after treatment. Results:All the scores of FMA-UE, ARAT, WMFT and MBI improved in both groups after treatment (|t| > 11.870, P < 0.001), and improved more in the experimental group than in the control group (|t| > 2.678, P < 0.05). Conclusion:Bilateral arm TEAS based on MT can promote the upper limb function of subacute stroke hemiplegic patients.

Effects of NF-κB/NOX1 signaling pathway in TNF-α-induced apoptosis of A549 cells / 中国职业医学

OBJECTIVE: To investigate the effects of nuclear transcription factor-κB(NF-κB)/amide adenine dinucleotide phosphate oxidase 1(NOX1) signaling pathway in tumor necrosis factor-α(TNF-α) induced apoptosis of A549 cells. METHODS: i) A549 cells were stimulated with TNF-α at the concentrations of 0.00, 0.25, 0.50, and 1.00 nmol/L. CCK-8 assay was used to detect the cell viability to screen the optimal stimulating concentration of TNF-α. ii) A549 cells at logarithmic growth stage were randomly divided into four groups, the control group, the TNF-α group, the BAY11-7082(NF-κB inhibitor) group and the TNF-α+BAY11-7082 group. The cells in the control group were not treated. The TNF-α and BAY11-7082 groups were stimulated with 0.50 nmol/L TNF-α and 5 μmol/L BAY11-7082, respectively. The TNF-α+BAY11-7082 group was stimulated by both TNF-α and BAY11-7082. After 24 hours of culture, the cell survival rate was detected by CCK-8 assay. Flow cytometry was used to detect cell apoptotic rate, and Western blotting was used to detect the relative expression of NF-κB(p65) and NOX1 proteins. RESULTS: i) When A549 cells were stimulated with TNF-α at the concentration of 0.50 nmol/L, the cell proliferative activity was reduced and the cell apoptosis was promoted. This concentration was selected as the stimulation dose of TNF-α in subsequent experiments. ii) The survival rate of A549 cells in the TNF-α group decreased(P<0.05), the apoptotic rate and the protein expressions of NF-κB(p65) and NOX1 increased in TNF-α group(all P<0.05) compared with the control group. In BAY11-7082 group, the survival rate and the relative expression of NF-κB(p65) and NOX1 of A549 cells were decreased(all P<0.05), and the apoptotic rate of A549 cells was increased(P<0.05) compared with the control group. A549 cells in TNF-α+BAY11-7082 group changed from a long spindle shape to an irregular one. The cell survival rate increased(P<0.05), the apoptotic rate and the relative expression of NF-κB(p65) and NOX1 decreased(all P<0.05) compared with the TNF-α group. CONCLUSION: NF-κB/NOX1 signaling pathway is involved in A549 cells apoptosis induced by TNF-α.

Retina inspired tone mapping method for high dynamic range images.

The limited dynamic range of regular screens restricts the display of high dynamic range (HDR) images. Inspired by retinal processing mechanisms, we propose a tone mapping method to address this problem. In the retina, horizontal cells (HCs) adaptively adjust their receptive field (RF) size based on the local stimuli to regulate the visual signals absorbed by photoreceptors. Using this adaptive mechanism, the proposed method compresses the dynamic range locally in different regions, and has the capability of avoiding halo artifacts around the edges of high luminance contrast. Moreover, the proposed method introduces the center-surround antagonistic RF structure of bipolar cells (BCs) to enhance the local contrast and details. Extensive experiments show that the proposed method performs robustly well on a wide variety of images, providing competitive results against the state-of-the-art methods in terms of visual inspection, objective metrics and observer scores.

Ferrate Oxidation of Phenolic Compounds in Iodine-Containing Water: Control of Iodinated Aromatic Products.

Highly toxic iodinated products would form in oxidation and disinfection of iodine-containing water. Variation of iodinated aromatic products in ferrate [Fe(VI)] oxidation of phenolic compounds (phenol, bisphenol A (BPA), and p-hydroxybenzoic acid (p-HBA)) in iodine-containing water was investigated. At pH 5.0, oxidation of phenolic compounds was inhibited by competitive reaction of ferrate with I-, and no formation of iodinated aromatic products was detected. Almost all I- was converted into nontoxic IO3-. At pH 7.0, 8.0, and 9.0, HOI formed in ferrate oxidation of I- and further reacted with phenols, with the formation of iodinated aromatic products. Mass spectrometry analysis showed that both kinds and contents of iodinated aromatic products were raised with the increase in solution pH and the content of I-, and these iodinated aromatic products were further oxidized by ferrate. Ferrate deprived iodine from iodinated aromatic products and transferred highly toxic organic iodine into nontoxic IO3-. An electron-donating substituent (alkyl) increased the reactivity of phenol with ferrate and HOI and facilitated ferrate oxidation of iodinated phenols. An electron-drawing substituent (carboxyl) decreased the reactivity of phenol with ferrate and HOI and hindered the further oxidation of iodinated aromatic products. A kinetic model about the variation of phenol, BPA, and p-HBA in reaction with ferrate in iodine-containing water was developed, and the oxidation profile of phenolic compounds could be satisfactorily predicted at various iodide concentrations.

Analysis of vitamin A and E levels in children of different ages with different respiratory diseases / 中国医师杂志

Objective:To investigate the difference of vitamin A and E levels in children with different respiratory diseases at different ages.Methods:A total of 671 children in Hunan Children's Hospital from July 2017 to October 2019 were selected as the disease group, including 197 cases of pneumonia, 152 cases of recurrent respiratory tract infection, 91 cases of asthma, 88 cases of cough variant asthma and 143 cases of Mycoplasma pneumoniae pneumonia; At the same time, 245 healthy children were selected as the normal group. The serum vitamin A and vitamin E levels of the two groups were detected by high performance liquid chromatography (HPLC).Results:⑴ The vitamin A level [(0.31±0.09)mg/L] of the disease group was lower than the normal group [(0.35±0.25)mg/L], and the vitamin E level [(8.92±2.57)mg/L] was lower than the normal group [(9.62±2.79)mg/L], with statistically significant difference ( P<0.05); ⑵ The level of vitamin A in the disease group at the age of >1-3 years [(0.32±0.09)mg/L] was lower than that in the normal group of the same age group [(0.35±0.08)mg/L]; the level of vitamin A in the disease group at the age of >3-6 years old [(0.30±0.08)mg/L] was lower than that of the same age group [(0.32±0.07)mg/L], with statistically significant difference ( P<0.05); ⑶ The vitamin E level of the disease group at >1-3 years old [(9.23±2.56)mg/L], >3-6 [(8.02±1.86)mg/L] and >6-14 years old [(8.02±1.82)mg/L] were lower than that of the same age normal group [(9.76±2.81)mg/L, (9.67±2.87)mg/L, (9.19±2.58)mg/L], with statistically significant difference ( P<0.05); ⑷ There were significant differences in vitamin A levels among different age in disease group ( P<0.05). Among them, the children with high risk of subclinical deficiency accounted for the largest proportion (45.78%) in the 6-month-1-year-old group, and the proportion of children with normal vitamin A levels in other age groups was the largest; ⑸ There are significant differences in vitamin E levels in different age groups in the disease group ( P<0.05), the levels in the normal range accounts for the largest proportion of all ages; ⑹ The levels of vitamin A and vitamin E in mycoplasma pneumoniae infection group were increased compared with in recurrent respiratory infection group , asthma group, and cough variant asthma group, and the difference was statistically significant ( P<0.05). Compared with the pneumonia group, the level of vitamin E increased in the recurrent respiratory infection group, and the difference was statistically significant ( P<0.05); The vitamin E levels in the cough variant asthma group were reduced compared with the repeated respiratory infection group, asthma group and pneumonia group ( P<0.05). Conclusions:The Vitamin A and E levels of children suffering from respiratory diseases are lower than those of normal children. The Vitamin A and E levels of different respiratory diseases and different age groups are different. Vitamin A and E supplementation may be significantly targeted according to different ages and different respiratory diseases in clinical practice.

A Biological Vision Inspired Framework for Image Enhancement in Poor Visibility Conditions.

Image enhancement is an important pre-processing step for many computer vision applications especially regarding the scenes in poor visibility conditions. In this work, we develop a unified two-pathway model inspired by the biological vision, especially the early visual mechanisms, which contributes to image enhancement tasks including low dynamic range (LDR) image enhancement and high dynamic range (HDR) image tone mapping. Firstly, the input image is separated and sent into two visual pathways: structure-pathway and detail-pathway, corresponding to the M-and P-pathway in the early visual system, which code the low-and high-frequency visual information, respectively. In the structure-pathway, an extended biological normalization model is used to integrate the global and local luminance adaptation, which can handle the visual scenes with varying illuminations. On the other hand, the detail enhancement and local noise suppression are achieved in the detail-pathway based on local energy weighting. Finally, the outputs of structure-and detail-pathway are integrated to achieve the low-light image enhancement. In addition, the proposed model can also be used for tone mapping of HDR images with some fine-tuning steps. Extensive experiments on three datasets (two LDR image datasets and one HDR scene dataset) show that the proposed model can handle the visual enhancement tasks mentioned above efficiently and outperform the related state-of-the-art methods.

Underwater Image Enhancement Using Adaptive Retinal Mechanisms.

We propose an underwater image enhancement model inspired by the morphology and function of the teleost fish retina. We aim to solve the problems of underwater image degradation raised by the blurring and nonuniform color biasing. In particular, the feedback from color-sensitive horizontal cells to cones and a red channel compensation are used to correct the nonuniform color bias. The center-surround opponent mechanism of the bipolar cells and the feedback from amacrine cells to interplexiform cells then to horizontal cells serve to enhance the edges and contrasts of the output image. The ganglion cells with color-opponent mechanism are used for color enhancement and color correction. Finally, we adopt a luminance-based fusion strategy to reconstruct the enhanced image from the outputs of ON and OFF pathways of fish retina. Our model utilizes the global statistics (i.e., image contrast) to automatically guide the design of each low-level filter, which realizes the self-adaption of the main parameters. Extensive qualitative and quantitative evaluations on various underwater scenes validate the competitive performance of our technique. Our model also significantly improves the accuracy of transmission map estimation and local feature point matching using the underwater image. Our method is a single image approach that does not require the specialized prior about the underwater condition or scene structure.