Vacuum Impregnation Process Optimization for Tilapia with Biopreservatives at Ice Temperature.

The vacuum impregnation (VI) process was used to pretreat tilapia fillets with biopreservatives at -2 °C. Response surface methodology (RSM) was utilised to optimize processing conditions, including vacuum pressure (pv), vacuum maintenance time (t1), and atmospheric pressure recovery time (t2), which were determined to be 67.73 kPa, 23.66 min, and 8.87 min, respectively. The anticipated values for the aerobic plate count (APC), total volatile basic nitrogen (TVB-N), and comprehensive score (CS) were 5.17 lg CFU/g, 14.04 mg/100 g, and 0.98, respectively. Verification experiments were conducted, and the experimental results for APC and TVB-N deviated from the predicted values by 0.19% and 0.64%, respectively. After 30 days of storage following VI and atmosphere impregnation (AI) pretreatment, the water-holding capacity (WHC), APC, TVB-N, hardness, and whiteness were determined. On the 30th day, the results for VI pretreatment were 63.38%, 6.27 lg CFU/g, 17.41 mg/100 g, 3.11 N, and 47.73, respectively. Compared with AI pretreatment, WHC, hardness, and whiteness increased by 14.8%, 18.6%, and 6.3%, respectively, whereas APC and TVB-N decreased by 11.3% and 29.6%, respectively. This study demonstrates that when biopreservatives are applied during the pretreatment process, VI technology can be utilised to facilitate their penetration into the interior of tilapia, hence significantly enhancing the effect of ice-temperature preservation.

Assessing effects of Ca2+ addition on membrane bioreactor performance and macro-floc sludge characteristics.

Calcium ions (Ca2+) can trigger coagulation-flocculation process to form macro-flocculated sludge (MFS). Thus, dosing Ca2+-containing reagents into membrane bioreactors (MBRs) is considered as a promising approach to mitigate membrane biofouling. However, a mechanistic understanding of Ca2+ addition to MBR performance remains elucidated, such as physicochemical characteristics of MFS and their functionality variations. Consequently, this study was sought to understand the interplays of Ca2+ addition and MBR performance with a focus on characterizing MFS in detail. Three parallel MBRs were amended with 82, 208 and 410 mg-Ca2+/L final concentrations. Particle size analyses revealed that MFS formation was overall enhanced by the Ca2+ addition and granular sludge with diameters of up to 900 µm was formed in the 410 mg-Ca2+/L scenario. We believed that cationic bridges facilitated by elevated Ca2+ concentrations in conjunction with coagulation-flocculation were primary mechanisms of the formation of large flocs. Moreover, significant portions of soluble proteins and polysaccharides were flocculated and precipitated by Ca2+, which demonstrated a negative correlation between extracellular polymeric substances (EPS) concentrations and the formation of MFS. Furthermore, the population abundancies of Thiotrichaceae, Sphingomonadales and Hyphomicrobiaceae decreased in the sludge with Ca2+ addition resulted in profound changes of the microbial communities in the MBRs. But MBR performance, such as chemical oxygen demand removal (over 90%), showed no variation during the MBR operation. On the contrary, total nitrogen removal was inhibited in the MBRs. It was because the enlarging MFS formed diffusion barriers to prevent organic component from entering into the sludge flocs to be consumed.

Controllable scattering of a single photon inside a one-dimensional coupled resonator waveguide with second-order nonlinearity.

We note that most of the studies of the single photon scattering inside a one-dimensional coupled resonator waveguide are based on the waveguide coupling with the atom systems. In this paper, we will study the single photon scattering enabled by another system, i.e., the second-order nonlinearity, which can act as a single photon switch to control the single photon transmission and reflection inside the one-dimensional coupled resonator waveguide. The transmission rate is calculated to analyze the single-photon scattering properties. In addition, a more complicated second-order nonlinear form, i.e., three-wave mixing, is discussed to control single photon transmission inside the one-dimensional coupled resonator waveguide.

Diverting colostomy is an effective and reversible option for severe hemorrhagic radiation proctopathy.

BACKGROUND: Severe chronic radiation proctopathy (CRP) is difficult to treat. AIM: To evaluate the efficacy of colostomy and stoma reversal for CRP. METHODS: To assess the efficacy of colostomy in CRP, patients with severe hemorrhagic CRP who underwent colostomy or conservative treatment were enrolled. Patients with tumor recurrence, rectal-vaginal fistula or other types of rectal fistulas, or who were lost to follow-up were excluded. Rectal bleeding, hemoglobin (Hb), endoscopic features, endo-ultrasound, rectal manometry, and magnetic resonance imaging findings were recorded. Quality of life before stoma and after closure reversal was scored with questionnaires. Anorectal functions were assessed using the CRP symptom scale, which contains the following items: Watery stool, urgency, perianal pain, tenesmus, rectal bleeding, and fecal/gas incontinence. RESULTS: A total of 738 continual CRP patients were screened. After exclusion, 14 patients in the colostomy group and 25 in the conservative group were included in the final analysis. Preoperative Hb was only 63 g/L ± 17.8 g/L in the colostomy group compared to 88.2 g/L ± 19.3 g/L (P < 0.001) in the conservative group. All 14 patients in the former group achieved complete remission of bleeding, and the colostomy was successfully reversed in 13 of 14 (93%), excepting one very old patient. The median duration of stoma was 16 (range: 9-53) mo. The Hb level increased gradually from 75 g/L at 3 mo, 99 g/L at 6 mo, and 107 g/L at 9 mo to 111 g/L at 1 year and 117 g/L at 2 years after the stoma, but no bleeding cessation or significant increase in Hb levels was observed in the conservative group. Endoscopic telangiectasia and bleeding were greatly improved. Endo-ultrasound showed decreased vascularity, and magnetic resonance imaging revealed an increasing presarcal space and thickened rectal wall. Anorectal functions and quality of life were significantly improved after stoma reversal, when compared to those before stoma creation. CONCLUSION: Diverting colostomy is a very effective method in the remission of refractory hemorrhagic CRP. Stoma can be reversed, and anorectal functions can be recovered after reversal.

Assessment of membrane bioreactor fouling with the addition of suspended aluminum nitride nanoparticles.

In this study, we assessed fouling in a membrane bioreactor (MBR) with the addition of suspended aluminum nitride (AlN) nanoparticles (NPs). Three parallel laboratory-scale submerged MBRs were operated with 0, 10, and 50 mg AlN NPs/L for over 70 days. The results showed that the addition of suspended AlN NPs did not significantly affect pollutant biodegradation; there was only a slight decrease in NH4+-N removal. Furthermore, the membrane's permeability was increased with effective fouling mitigation by the addition of a high amount of suspended AlN NPs. This was because the suspended AlN NPs decreased the content of polysaccharides in both the extracellular polymeric substances and soluble microbial products, and decreased the sludge floc size. However, the AlN NPs also promoted pore-blocking, particularly standard blocking, which enhanced irreversible fouling. Additionally, owing to the larger ionic radius and higher electronegativity, the AlN NPs inhibited the accumulation of framework components (SiO2). Therefore, suspended AlN NPs resulted in a thinner cake layer.

Structural characteristics of cake layer in membrane bioreactor with chromate exposure.

Chromate (CrO42-) exposure, especially high concentration (mg/L), still probably occurs in the industrial and mining area due to industrial accidents or even illegal discharge, though CrO42- has been restricted to be discharged into wastewater treatment system (WWTS). Therefore, this study was applied to better understand the structural characteristics of cake layer in membrane bioreactor (MBR), which is one of best alternative for WWTS of industrial or mining area, with CrO42- exposure. Three submerged MBRs with CrO42- exposure (10 mg/L was normal high concentration CrO42-; 50 mg/L as extreme level for better identification; 0 mg/L as control condition) were applied in this study. Results showed that CrO42- exposure caused an obvious variation of cake layer structure. Because of organic component variation, cake layer structure with CrO42- exposure was re-constructed into loose and porous with biomicromolecules, and resulted in the rapid cake layer thickness increase, finally leading to severe membrane biofouling. Additionally, CrO42- distributed evenly along the cross-sectional cake layer. CrO42- only induced the inorganic structure variations of cake layer, but without any obvious effects on the other inorganic elements structure. CrO42- exposure induced the bacterial community structure variation and led to tolerated-CrO42- microorganisms as the majority in cake layer community, but had no obvious effects on the population diversity.

Assessing membrane biofouling and its gel layer of anoxic/oxic membrane bioreactor for megacity municipal wastewater treatment during plum rain season in Yangtze River Delta, China.

This study assessed membrane biofouling and its gel layer of anoxic/oxic membrane bioreactor (A/O-MBR) for megacity municipal wastewater treatment during plum rain season, which was continuous rainy weather, in Yangtze River Delta, China. A laboratory-scale A/O-MBR was operated to treat the municipal wastewater from Quyang wastewater treatment plant, which located at the typical megacity of Shanghai in Yangtze River Delta, from April to July accompanying with plum rain season. As reactor performance showed, CODCr, NH4+-N, TN, TP of the influent gradually decreased during plum rain season, and inhibited pollutant removal due to organic carbon shortage. However, dissolve inorganic carbon and inorganic components in mixed liquid had an obvious increase under rainy weather. Membrane filtration results indicated that plum rain season enhanced pore blocking behavior, further leading to the serious membrane biofouling but inhibiting gel layer formation. Additionally, gel layer analysis predicted that plum rain season led to plenty of inorganic components and precipitate flew into A/O-MBR reactor. Inorganic components with elements of Ca, Mg Ba, Fe, Al and Si seriously blocked membrane pores. Those components also accumulated into gel layer in the form of SiO2, CaCO3, CaSiO3, MgNH4PO4, BaCO3, AlPO4, etc. Consequently, plum rain season enhanced pore blocking behavior and led to severe membrane biofouling but with the inhibition of gel layer formation.

HIV-1 Tat Regulates Occludin and Aß Transfer Receptor Expression in Brain Endothelial Cells via Rho/ROCK Signaling Pathway.

HIV-1 transactivator protein (Tat) has been shown to play an important role in HIV-associated neurocognitive disorders. The aim of the present study was to evaluate the relationship between occludin and amyloid-beta (Aß) transfer receptors in human cerebral microvascular endothelial cells (hCMEC/D3) in the context of HIV-1-related pathology. The protein expressions of occludin, receptor for advanced glycation end products (RAGE), and low-density lipoprotein receptor-related protein 1 (LRP1) in hCMEC/D3 cells were examined using western blotting and immunofluorescent staining. The mRNA levels of occludin, RAGE, and LRP1 were measured using quantitative real-time polymerase chain reaction. HIV-1 Tat at 1 µg/mL and the Rho inhibitor hydroxyfasudil (HF) at 30 µmol/L, with 24 h exposure, had no significant effect on hCMEC/D3 cell viability. Treatment with HIV-1 Tat protein decreased mRNA and protein levels of occludin and LRP1 and upregulated the expression of RAGE; however, these effects were attenuated by HF. These data suggest that the Rho/ROCK signaling pathway is involved in HIV-1 Tat-mediated changes in occludin, RAGE, and LRP1 in hCMEC/D3 cells. HF may have a beneficial influence by protecting the integrity of the blood-brain barrier and the expression of Aß transfer receptors.

[Mutation analysis of presenilin 1 gene in a Chinese family affected with early-onset familial Alzheimer's disease].

OBJECTIVE: To explore the clinical phenotype and genotype in a Chinese family affected with early-onset familial Alzheimer's disease (EOFAD). METHODS: Potential mutation of beta-amyloid precursor protein (APP) gene, presenilin 1 (PSEN1) gene and apolipoprotein E (APOE) gene was detected with polymerase chain reaction (PCR) and direct sequencing. RESULTS: Homozygous APOE ε 2 allele and no gene mutation of APP gene were detected in the proband (III1). A 488A>G mutation (His163Arg) of the PSEN1 gene was found in the proband and other 4 family members (IV1, IV12, IV21, V2). CONCLUSION: A mutation (c.488A>G, p.His163Arg) of PSEN1 gene was found in a Chinese family affected with EOFAD.

Effects of suspended titanium dioxide nanoparticles on cake layer formation in submerged membrane bioreactor.

Effects of the suspended titanium dioxide nanoparticles (TiO2 NPs, 50 mg/L) on the cake layer formation in a submerged MBR were systematically investigated. With nanometer sizes, TiO2 NPs were found to aggravate membrane pore blocking but postpone cake layer fouling. TiO2 NPs showed obvious effects on the structure and the distribution of the organic and the inorganic compounds in cake layer. Concentrations of fatty acids and cholesterol in the cake layer increased due to the acute response of bacteria to the toxicity of TiO2 NPs. Line-analysis and dot map of energy-dispersive X-ray were also carried out. Since TiO2 NPs inhibited the interactions between the inorganic and the organic compounds, the inorganic compounds (especially SiO2) were prevented from depositing onto the membrane surface. Thus, the postponed cake layer fouling was due to the changing features of the complexes on the membrane surface caused by TiO2 NPs.

[Analysis of spectral features based on water content of desert vegetation].

By using HR-768 field-portable spectroradiometer made by the Spectra Vista Corporation (SVC) of America, the hyper-spectral data of nine types of desert plants were measured, and the water content of corresponding vegetation was determined by roasting in lab. The continuum of measured hyperspectral data was removed by using ENVI, and the relationship between the water content of vegetation and the reflectance spectrum was analyzed by using correlation coefficient method. The result shows that the correlation between the bands from 978 to 1030 nm and water content of vegetation is weak while it is better for the bands from 1133 to 1266 nm. The bands from 1374 to 1534 nm are the characteristic bands because of the correlation between them and water content is the best. By using cluster analysis and according to the water content, the vegetation could be marked off into three grades: high (>70%), medium (50%-70%) and low (<50%). The research reveals the relationship between water content of desert vegetation and hyperspectral data, and provides basis for the analysis of area in desert and the monitoring of desert vegetation by using remote sensing data.