Unveiling the Roles of Alloyed Boron in Hexavalent Chromium Removal Using Borohydride-Synthesized Nanoscale Zerovalent Iron: Electron Donor and Antipassivator.

Nanoscale zerovalent iron synthesized using borohydride (B-NZVI) has been widely applied in environmental remediation in recent decades. However, the contribution of boron in enhancing the inherent reactivity of B-NZVI and its effectiveness in removing hexavalent chromium [Cr(VI)] have not been well recognized and quantified. To the best of our knowledge, herein, a core-shell structure of B-NZVI featuring an Fe-B alloy shell beneath the iron oxide shell is demonstrated for the first time. Alloyed boron can reduce H+, contributing to more than 35.6% of H2 generation during acid digestion of B-NZVIs. In addition, alloyed B provides electrons for Fe3+ reduction during Cr(VI) removal, preventing in situ passivation of the reactive particle surface. Meanwhile, the amorphous oxide shell of B-NZVI exhibits an increased defect density, promoting the release of Fe2+ outside the shell to reduce Cr(VI), forming layer-structured precipitates and intense Fe-O bonds. Consequently, the surface-area-normalized capacity and surface reaction rate of B-NZVI are 6.5 and 6.9 times higher than those of crystalline NZVI, respectively. This study reveals the importance of alloyed B in Cr(VI) removal using B-NZVI and presents a comprehensive approach for investigating electron pathways and mechanisms involved in B-NZVIs for contaminant removal.

In Situ Visualization of Concentration Polarization during Membrane Ultrafiltration Using Microscopic Laser-Induced Fluorescence.

A novel noninvasive technique-microscopic laser-induced fluorescence (micro-LIF)-has been applied to achieve in situ visualization of concentration polarization (CP) of nanoparticles during cross-flow ultrafiltration at high resolutions. The reversible, highly dynamic nature of CP and its sensitive response to the filtration conditions were investigated and validated by direct visualization of the CP layer and the well depicted concentration profile near the membrane surface. Using micro-LIF, the formation of a CP layer during filtration and its back-diffusion after the filtration ceased can be directly observed. The dynamic variation of the CP layer with the cross-flow velocity and transmembrane pressure (TMP) change has also been demonstrated. The results showed that CP reached the steady state approximately 1 min after the filtration condition change. A higher cross-flow velocity and/or a lower TMP decrease the CP concentration and thickness. Further quantitative analysis of the filtration test results using the film theory model helps to obtain the particle concentration at the membrane surface and the thickness of the CP layer (30-50 µm). Accordingly, the nature of CP dynamics was characterized and the deficiency of the traditional CP model was explored.

Effectiveness and Mechanisms of Defluorination of Perfluorinated Alkyl Substances by Calcium Compounds during Waste Thermal Treatment.

The mineralization of perfluorinated alkyl substances (PFASs) by calcium compounds during the waste thermal treatment was systemically studied. Different calcium compounds showed different mineralization efficiencies of PFASs during the thermal process, owing to the different reaction mechanisms. Calcium hydroxide was recommended as the most effective Ca reagent for PFAS defluorination because the carbon-fluorine bonds in PFASs can be converted to carbon-hydrogen bonds via the hydrodefluorination reaction. PFASs with different chain lengths and functional groups were further investigated for their potentially different mineralization behavior. The results showed that the chain length of PFASs had an insignificant effect on the mineralization efficiency by calcium hydroxide. The thermogravimetric analysis-differential thermal analysis (TGA-DTA) also revealed that perfluorooctanesulfonate (PFOS) and perfluorohexanesulfonate (PFHxS) (with different chain lengths) had a similar thermal behavior. However, PFASs with different functional groups showed different mineralization behavior with calcium hydroxide in relation to their different thermal decomposition temperatures. Finally, the mineralization ratio of polytetrafluoroethylene (PTFE) particles by calcium hydroxide could reach 80% or higher when the temperature was above 400 °C. The gas chromatography/mass spectrometry (GC/MS) results demonstrated much reduced production of gaseous fluorocarbon fragments during PTFE decomposition when coexisting with calcium hydroxide.

Synthesis of magnetic molecularly imprinted polymers for the selective separation and determination of metronidazole in cosmetic samples.

In this study, novel magnetic molecularly imprinted polymers (MMIPs) were developed as a sorbent for solid-phase extraction (SPE) and used for the selective separation of metronidazole (MNZ) in cosmetics; MNZ was detected by high-performance liquid chromatography (HPLC). First, magnetic Fe3O4 nanoparticles (NPs) were prepared by the co-precipitation of Fe(2+)and Fe(3+) ions in an ammonia solution; then oleic acid (OA) was modified onto the surface of Fe3O4NPs. Finally, the MMIP was prepared by aqueous suspension polymerization, involving the copolymerization of Fe3O4NPs@OA with MNZ as the template molecule, methacrylic acid (MAA) as the functional monomer, ethylene glycol maleic rosinate acrylate (EGMRA) as the cross-linking agent, and 2,2-azobisisobutyronitrile (AIBN) as the initiator. The MMIP materials showed high selective adsorption capacity and fast binding kinetics for MNZ; the maximum adsorption amount of the MMIP to MNZ was 46.7 mg/g. The assay showed a linear range from 0.1 to 20.0 µg/mL for MNZ with the correlation coefficient 0.999. The relative standard deviations (RSD) of intra- and inter-day ranging from 0.71 to 2.45% and from 1.06 to 5.20% were obtained. The MMIP can be applied to the enrichment and determination of MNZ in cosmetic products with the recoveries of spiked toner, powder, and cream cosmetic samples ranging from 90.6 to 104.2, 84.1 to 91.4, and 90.3 to 100.4%, respectively, and the RSD was <3.54%.

Polyethyleneglycol diacrylate microspheres: a novel carrier for laccase immobilisation.

Laccase was immobilised on polyethyleneglycol diacrylate (PEGDA) microspheres. The optimal preparation conditions of PEGDA microspheres were as follows: 3.0% (w/v) 2,2-azobisisobutyro-nitrite (AIBN), 4.0-5.0% (w/v) polyvinylpyrrolidone (PVP), 5.0-8.0% (w/v) glucose and 4.0% (w/v) PEGDA in glucose solution. The volume ratio of PEGDA solution, glucose/PVP solution and AIBN solution was 25: 100: 1. Microspheres obtained exhibited good characteristics with small sizes (1-4 µm). The immobilised laccase showed a higher stability in a wide pH range. Thermal stability and storage stability of immobilised laccase were enhanced. The activity of immobilised laccase was 45.0% after six cycles uses. Only 62.7% of the activity remained for free laccase while there was a 60.4% increased for immobilised laccase with storage at 4 °C for 25 d. The Km value of laccase increased from 21.9 to 114.0 µmol/l after immobilisation.

Concurrent photocatalytic hydrogen production and organic degradation by a composite catalyst film in a two-chamber photo-reactor.

A novel visible light-driven photocatalyst film, MoS2/Ag/TiO2, was synthesized on a glass-fiber membrane. The composite catalyst film had a multi-layer structure with Ag as nanoconjunctions between the MoS2 and TiO2 layers. The catalyst film performed well for both photocatalytic hydrogen production and organic degradation in a two-chamber photo-reactor under either solar or visible light. Hydrogen was produced in the cathode side chamber while the model organic was decomposed in the anode side chamber. The specific hydrogen production rate went through a maximum of 85 mmol/m²-h with an energy conversion efficiency of 0.85%, while the maximum specific organic carbon removal for formic acid under solar light reached 1,520 mg/m²-h. It is apparent that Ag between the TiO2 and MoS2 layers allowed the transfer of photo-excited electrons via TiO2 → Ag → MoS2 for organic degradation and H⁺ reduction (e.g. hydrogen evolution) in two different chambers.

A Novel Variant in the Desmoplakin Gene in One Case of the Rare Carvajal Syndrome with Dilated Cardiomyopathy: A Case Report and Literature Review.

Carvajal syndrome is a rare hereditary cardiocutaneous syndrome caused by the variants of the desmoplakin (DSP) gene. In this study, we report a patient of Carvajal syndrome with a novel homozygous missense variant of DSP gene. We diagnosed a 7-year-old female patient with Carvajal syndrome characterized by dilated cardiomyopathy, palmoplantar keratoderma, woolly hair, and dental dysplasia, who disclosed a novel homozygous missense variant c.4597C > T (p.Q1533X) in exon 6 of the DSP gene found for the first time. Both her parents were heterozygous for the identified nonsense variant c.4597C > T (p.Q1533X) in DSP gene but neither showed evidence of Carvajal syndrome, indicating that this novel variant causes the disease in an autosomal recessive manner. Genotypes of Carvajal syndrome are even broader than so far anticipated. When patients with dilated cardiomyopathy, palmoplantar keratoderma, woolly hair, and dental dysplasia are found in clinical practice, Carvajal syndrome should be highly suspected, and family gene sequencing should be actively carried out.

Transforming growth factor-ß: An early predictor of a functional cure in chronic hepatitis B treated with interferon.

BACKGROUND: The relationship between the serum transforming growth factor (TGF)-ß level and HBsAg loss has not been clearly elaborated in patients with chronic hepatitis B (CHB). METHODS: Two cohorts of patients with CHB were studied. Cohort A: A total of 207 hepatitis B e antigen (HBeAg)-negative CHB patients who finished ≥1 year nucleos(t)ide analogue monotherapy and sequentially received PEGylated interferon treatment for less than 96 weeks were included. Cohort B: Forty HBeAg-positive patients who initially received entecavir therapy for at least 96 weeks were included. Their viral markers and serum TGF-ß levels were measured at different time points during therapy. RESULTS: The levels of serum TGF-ß and HBsAg (0-24 W) were significantly lower in the patients who had HBsAg< 0.05 IU/mL at 48 weeks than in patients who did not in cohort A. We got the same results when we further divided the patients into subgroups according to the initial HBsAg cut-off values (1000 IU/mL, 100 IU/mL, 50 IU/mL) in cohort A. However, HBeAg seroconversion did not lead to the downregulation of TGF-ß levels. The levels of serum TGF-ß were significantly correlated with HBsAg quantitation in cohort A (12-24 W) but not in cohort B (0-48 W). The levels of TGF-ß at week 12 could be used as an early index to predict a functional cure (AUC=0.818) as well as the levels of HBsAg itself (AUC=0.882) in HBeAg-negative chronic hepatitis B patients treated with PEGylated interferon. CONCLUSIONS: The levels of serum TGF-ß were significantly associated with HBsAg loss but not with HBeAg seroconversion and could be used as an early index to predict a functional cure in CHB patients treated with PEGylated interferon.

[Effect of enamel matrix protein on osteogenic and adipogenic differentiation of dental pulp stem cells of deciduous teeth through miR-32].

PURPOSE: To explore the effect of enamel matrix proteins(EMPs) on osteogenesis and adipogenesis of stem cells from human exfoliated deciduous teeth SHED), and explore its molecular mechanism. METHODS: SHEDs were used to detect the expression of its surface antigens CD73, CD146, CD34 and CD45 by flow cytometry. SHED was induced by OB osteogenic induction liquid, and then the osteogenic differentiation ability was measured by alizarin red staining. SHEDs were divided into 4 groups, NC group had invalid sequence shRNA interfered with SHED, EMPs group had invalid sequence shRNA interfered with SHED. Then 100 µg/L EMPs was used to interfere with SHED. In miR-32 inhibitor group, miR-32 shRNA plasmid was used to interfere with SHED; while in EMPs+miR-32 inhibitor group, 100 µg/L EMP was used to intervene SHED after silencing miR-32. QPCR was used to detect the expression of miR-32, dentin sialophosphoprotein (DSPP), dentin matrix protein 1, DMP-1, peroxisome proliferators-activated receptor γ (PPARγ) and CCAAT enhancer binding protein α (C/EBPα) gene expression; Western blot was used to detect the expression of DSPP, DMP-1, PPARγ and C/EBPα protein expression; Alizarin red staining was used to detect SHED osteogenic capacity; Oil red O staining was used to detect adipogenetic capacity of SHED. RESULTS: The results of flow cytometry showed that SHED had positive expression of CD146 and CD73, and negative expression of CD34 and CD45, which was consistent with the characteristics of stem cell surface markers. Alizarin red staining and oil red O staining showed mineralized nodules and oil droplets increased significantly, consistent with the multi-directional differentiation characteristics of stem cells. Compared with NC group, the expression of miR-32 gene in EMPs group was significantly increased(P<0.05), and the expression of miR-32 in miR-32 inhibitor group and EMPs+miR-32 inhibitor group was significantly decreased(P<0.05). Compared with NC group, the expression of DSPP and DMP-1, the number of mineralized nodules in EMPs group were significantly increased(P<0.05), the expression of PPARγ and C/EBPa and the number of lipid droplets were significantly decreased (P<0.05), while the result of miR-32 inhibitor group was the opposite (P<0.05). Compared with miR-32 inhibitor group, there was no significant difference in the expression of DSPP, DMP-1, PPARγ and C/EBPα, number of mineralized nodules and oil droplets in EMPs+miR-32 inhibitor group(P>0.05). Compared with EMPs group, the expression of DSPP and DMP-1 and the number of mineralized nodules in EMPs+miR-32 inhibitor group were significantly reduced(P<0.05), while the expression of PPARγ and C/EBPα and the number of lipid droplets were significantly increased(P<0.05). CONCLUSIONS: EMPs can regulate osteogenic and adipogenic differentiation of SHED by promoting the expression of miR-32.

Fabrication of conductive ceramic membranes for electrically assisted fouling control during membrane filtration for wastewater treatment.

Membrane technology is widely used in water and wastewater treatment. However, membrane fouling remains one of the biggest challenges for membrane applications. In this study, an electrically assisted technique was developed for the control of fouling on flat-sheet ceramic membranes. The novel conductive membrane was fabricated by coating dopamine and carbon nanotubes (CNTs) onto the surface of an α-alumina membrane support to form a conductive CNT coating. The resulting flat-sheet conductive ceramic membrane (FSCCM) exhibited excellent electric conductivity and stability, which performed well in filtration of the synthetic wastewater containing inorganic matter (kaolin solution) or organic pollutants (oil emulsion). By applying a negative charge on the FSCCM with a DC voltage of 2.0 V, the membrane fouling rate was reduced by approximately 50%. The energy consumption rate for the electrically assisted membrane fouling control was only 22.2 × 10-3 kWh/m3 in paused-charge mode, with a pause duration of 15 s. A fouling-layer analysis indicted that the imposed electric field greatly reduced the amount of strongly attached foulants on the membrane surface and in the membrane pores. It is believed that the electric field exerted an electrostatic force on the negatively charged pollutants, such as particles and oil droplets, which prevented the foulants from attaching to the membrane surface. This FSCCM-based method provides a clean, effective, and energy-efficient technique for membrane fouling control, thereby enabling high-rate membrane filtration.

[Orofacial myofunctional therapy improves facial morphology of children with obstructive sleep apnea after adenotonsillectomy].

PURPOSE: This study investigated the effectiveness of orofacial myofunctional therapy(OMT) in improving facial morphology of children with obstructive sleep apnea (OSA) after adenotonsillectomy (AT). METHODS: Ten children aged from 4-7 years with persistent oral breathing for more than 1 month after adenotonsillectomy were chosen to receive orofacial myofunctional therapy. The patients were required to take photos before and after orofacial myofunctional therapy. In order to compare the soft changes before and after OMT treatment, twelve representative mark points were selected and used for proportion and angle measurements. Graphpad Prism 8 statistical software was used for statistical analysis, to compare the differences in facial morphology of patients before and after treatment. RESULTS: Compared with before OMT, a significant difference was found in the proportion of Sn-Ls/Sn-Stms(P=0.0002), Sn-Stms/Sn-Me'(P<0.05), as well as in the angle of Gs-Sn-Pos (P<0.05), nasolabial angle(P=0.0005), mentolabial angle (P=0.0026) after OMT treatment. CONCLUSIONS: Orofacial myofunctional therapy can be considered as an effective complementary treatment for OSA patients with oral breathing after adenotonsillectomy.

A three-year clinical investigation of a Chinese child with craniometaphyseal dysplasia caused by a mutated ANKH gene.

BACKGROUND: Craniometaphyseal dysplasia (CMD) is a rare genetic disorder. Autosomal dominant CMD (AD-CMD) is caused by mutations in the ANKH gene. Affected individuals typically have distinctive facial features including progressive thickening of the craniofacial bones. Treatment for AD-CMD primarily consists of surgical intervention to release compression of the cranial nerves and the brain stem/spinal cord. To alleviate progression of the clinical course and improve the quality of life in children waiting to undergo the necessary surgery, we investigated clinical changes in a diagnosed patient with AD-CMD over three years. CASE SUMMARY: A 17-mo-old boy presented with progressive nasal obstruction, snoring and hearing loss symptoms. Physical examination showed enlargement of the head circumference and clinical features such as wide nasal bridge, paranasal bossing, widely spaced eyes with an increased bizygomatic width, and a prominent mandible. The patient underwent otolaryngological examination, endoscopy, hearing test, laboratory examination of phosphorus and bone metabolism, cranial and femoral computed tomography, X-ray and next-generation sequencing. The patient was diagnosed with AD-CMD due to p.Phe377 deletion (c.1129_1131del) on exon 9 of the ANKH gene. After adherence to a prescribed low-calcium diet, the boy's alkaline phosphatase (ALP) levels continuously decreased to within the normal range. However, after 14 mo of dietary intervention, his parents altered his diet to an intermittent low-calcium diet to include milk and eggs. The patient's ALP was slightly higher than normal after the dietary change but remained close to the normal range. His serum osteocalcin changed to within normal levels after dietary regulation for 33 mo. His serum combined beta C-terminal telopeptide of type I collagen also continuously decreased after the nutritional intervention, although still slightly higher than normal levels. Despite fluctuating blood test results, the boy's nasal symptoms were markedly relieved and steadily improved after dietary intervention. No significant changes were found in the craniofacial bones by cranial radiography. Close monitoring of clinical features is still ongoing. Calcitriol treatment is currently under consideration and a surgical procedure is planned as necessary in the future. CONCLUSION: We herein report the first Chinese case of AD-CMD with heterozygous mutation of p.Phe377 deletion (c.1129_1131del) on the ANKH gene. Biochemical alterations were significantly improved after dietary intervention indicating that a low-calcium diet may be applied in pediatric AD-CMD patients with ANKH mutations to help alleviate phenotypic manifestations and improve the quality of life before surgical intervention. Further large scale studies are needed to replicate these findings and to establish the appropriate timing for nutritional and surgical interventions.

Injectable hydrogel helps bone marrow-derived mononuclear cells restore infarcted myocardium.

BACKGROUNDS: Experimental and clinical studies have suggested that cell implantation could improve cardiac function after myocardial infarction (MI). However, this technique was limited by decreased engraftment and survival of transplanted cells within the ischemic tissue. The present study was performed to investigate whether implantation of bone marrow-derived mononuclear cells (BMMNCs) encapsulated in hydrogel could increase cell engraftment and help to restore cardiac function of MI rabbits. METHODS: MI was induced in rabbits by coronary artery ligation. One week later, cell culture medium, Dex-PCL-HEMA/PNIPAAm hydrogel, BMMNCs in medium or BMMNCs in hydrogel were injected into the infarcted area of the left ventricle (LV). RESULTS: Increased cell engraftment was observed 48 h after injection when cells were encapsulated in hydrogel; 30 days after treatment, echocardiographic studies showed that injection of BMMNCs in hydrogel preserved LV ejection fraction and attenuated LV dilatation compared with other groups. Histological analysis indicated that injection of BMMNCs in hydrogel enhanced neovascular formation and prevented scar expansion compared with the other groups. CONCLUSION: Injection of hydrogel-encapsulated BMMNCs increased cell engraftment and improved LV function; this technique may serve as an effective approach to restore infarcted myocardium.

Novel thermosensitive hydrogel injection inhibits post-infarct ventricle remodelling.

AIMS: Myocardial infarction (MI) remains the commonest cause of cardiac-related death throughout the world. Adverse cardiac remodelling and progressive heart failure after MI are associated with excessive and continuous damage of the extracellular matrix (ECM). In this study, we hypothesized that implantation of hydrogel into infarcted myocardium could replace the damaged ECM, thicken the infarcted wall, and inhibit cardiac remodelling. METHODS AND RESULTS: MI was induced in rabbits by coronary artery ligation; 4 days later, 200 microL Dex-PCL-HEMA/PNIPAAm gel solution was injected into the infarcted myocardium. Injection of phosphate-buffered saline served as control. Thirty days after treatment, histological analysis indicated that injection of the biomaterial prevented scar expansion and wall thinning compared with controls. Echocardiography studies showed that injection of hydrogel increased left ventricular ejection fraction and attenuated left ventricular systolic and diastolic dilatation. Haemodynamic analysis demonstrated improved cardiac function following implantation of the hydrogel. CONCLUSION: These results suggest that injection of thermosensitive Dex-PCL-HEMA/PNIPAAm hydrogel is an effective strategy that prevents adverse cardiac remodelling and dysfunction in MI rabbits.

[Effect of a novel injectable hydrogel implant on ventricular remodeling in rabbits with experimental myocardial infarction].

OBJECTIVE: To observe whether injectable hydrogel implantation could prevent adverse cardiac remodeling and preserve cardiac function in rabbits with myocardial infarction (MI). METHODS: A novel injectable hydrogel, the copolymer MPM/alpha-CD, which self-assembled between alpha-cyclodextrin and methoxy polyethylene glycol-poly (caprolactone)-(dodecanedioic acid)-poly (caprolactone)-methoxypolyethylene glycol triblock polymer, was synthesized by chemical crosslinking and characterized by biocompatibility and biodegradability. Experimental MI was induced in male rabbits by coronary artery ligation. The MI rabbits were randomly divided into hydrogel group (200 microl MPM/alpha-CD were injected into the infarcted myocardium 7 days after MI) and control group (equal volume phosphate buffered saline myocardial injection, n = 8 each). Four weeks after MPM/alpha-CD implantation, echocardiography, histochemistry and immunohistochemistry were performed. RESULTS: Left ventricle ejection fraction was significantly improved in the hydrogel-treated group (56.1% +/- 8.4%) than that in the control group (37.3% +/- 6.4%, P < 0.05). Histological analysis indicated that hydrogel degraded 4 weeks after hydrogel injection, and prevented scar expansion and wall thinning [(3.08 +/- 0.32) mm vs. (2.18 +/- 0.46) mm in control group, P < 0.05]. Neovasculature formation was similar between the hydrogel group [(100.8 +/- 2.4)/mm(2)] and the control [(98.5 +/- 2.9)/mm(2), P > 0.05]. CONCLUSION: MPM/alpha-CD could serve as an excellent injectable biomaterial for improves cardiac function and attenuating scar expansion and left ventricular dilation in MI rabbits.

Direct filtration for the treatment of the coagulated domestic sewage using flat-sheet ceramic membranes.

Direct membrane filtration (DMF) is considered as a promising technology for municipal wastewater treatment. We utilized an innovative application of flat-sheet ceramic membranes (FSCM) for DMF for the rapid treatment of domestic sewage. Coagulation was applied before FSCM filtration to increase the pollutant removal and to mitigate membrane fouling. This coagulation-FSCM filtration can significantly reduce the pollutant load on the downstream treatment and concentrate organics and nutrients into sludge to facilitate resource recovery. Using polyaluminum chloride (PACl) based FSCM filtration, approximately 90.0% of the chemical oxygen demand (COD) and 99.0% of the phosphorus (P) were removed from the sewage influent and retained in the concentrated sludge, with less than 25.0 mg/L COD left in the effluent. Long-term operation of the PACl-based FSCM filtration stably maintained a high flux of 41.7 L/m2-h (LMH, or 1.0 m/d). The fouled membranes were cleaned chemically every 3-5 d, and the membrane permeability could almost be completely recovered using chemical backwash for only 10 min with a diluted acidic, alkaline, chlorine or H2O2 solution. The novel FSCM process will fundamentally advance wastewater treatment technology. It can be readily modularized and installed as simple add-on units to upgrade and retrofit existing wastewater treatment systems.

Accumulation of biopolymer clusters in a submerged membrane bioreactor and its effect on membrane fouling.

A laboratory-scale submerged membrane bioreactor (SMBR) with a hollow-fibre membrane module was used to investigate membrane fouling under various operational conditions. The results showed that the sludge supernatant inside the SMBR had a consistently higher organic content than the MBR effluent. Detailed analysis revealed a pool of organic substances, classified as biopolymer clusters (BPC), in the SMBR system that were larger in size than the soluble microbial products (SMP). The BPC content in the MBR sludge mixture ranged from 0.7 to 18.8 mg/L in terms of the total organic carbon (TOC), with an average of 5.6+/-3.5mg/L, which was about twice the SMP concentration in the suspension. Under a fluorescent microscope and using DAPI staining, the BPC in the sludge supernatant after centrifugation were found to be particulate organic substances that were independent of the sludge flocs and had a size distribution up to 50 microm. The findings of the experiment suggest that BPC are an important foulant and have a profound effect on membrane fouling. The fouling rate in the reactor, as indicated by the increase in trans-membrane pressure (TMP), correlates to a certain extent with the BPC concentration in the sludge suspension under various conditions. It is argued that BPC are a special form of organic substances that are formed by the adsorption and affinity clustering of mainly SMP within the sludge layer deposited on the membrane surface. The BPC can be detached with the sludge from the membrane and returned to the suspension. The accumulation of BPC in the SMBR sludge mixture would facilitate the formation of a sludge fouling layer on the membrane surface, thus causing a serious fouling problem.

[Long-term follow-up and prognostic analysis on the silicone oil-dependent eyes].

OBJECTIVE: To study on the outcome of the eyes with silicone oil tamponade retrospectively, and to observe ocular complications and prognosis after long-term intraocular silicone oil tamponade. METHODS: Retrospective observational case series. 36 patients (37 eyes) with silicone oil tamponade for over 2 years without removal were analyzed from 1992 to 2005 in our hospital. The patients were 30 males (31 eyes) and 6 females (6 eyes); age ranged from one year and 2 months to 73 years old. The lasted time of silicone oil tamponade were from 2 to 13 years. 37 eyes were all open ocular trauma, including traumatic eyeball rupture 24 eyes, intraocular foreign body 5 eyes, ocular perforating injury 3 eyes and penetrating injury 5 eyes. Vitrectomy, retinotomy and retinectomy, retinal photocoagulation and silicone oil tamponade were performed in different patients. RESULTS: Complete retinal attachment was seen in 13 eyes (35.1%); partly retinal attachment was accomplished in 11 eyes; retinal detachment with silicone oil tamponade was revealed in 7 eyes. Visual acuity in 9 eyes was better than 0.01 (24.3%), the best vision acuity was 0.1 among all of patients. The complications in the long-term follow-up included: cornea band-shaped degeneration 13 eyes (35.1%); complete corneal opacity 6 eyes; silicone emulsification 17 eyes (45.9%); secondary glaucoma 2 eyes; cataract 4 eyes, without obvious complications 8 eyes (21.6%). CONCLUSIONS: Long-term intraocular silicone oil tamponade will be adaptive and rational in serious ocular trauma if no other better treatments can maintain retinal attachment and the appearance of eyeball.

A membrane bioreactor with iron dosing and acidogenic co-fermentation for enhanced phosphorus removal and recovery in wastewater treatment.

A novel phosphorous (P) removal and recovery process using a membrane bioreactor (MBR) with ferric iron dosing and acidogenic co-fermentation was developed for municipal wastewater treatment. The very different solubility of Fe(III)-P and Fe(II)-P complex and the microbial transformation of Fe(III) to Fe(II) were utilized for P removal and recovery. By means of Fe-induced precipitation, chemical P removal was effectively achieved by an MBR with a flat-plate ceramic membrane; however, the Fe(III)-P solids accumulated in the MBR that constituted a significant fraction of the activated sludge. Anaerobic co-fermentation of the MBR sludge and food waste in a side-stream allowed the extraction of P and Fe from the sludge into the supernatant. The P in the supernatant was recovered as a fertilizer resource, while the sludge was returned to the MBR tank. The experimental results show that by adding FeCl3 at 20 mg Fe/L into the influent of domestic wastewater, about 95.6% of total P could be removed by the MBR. One fifth (20%) of the sludge in the MBR was circulated daily through the side-stream fermenters for co-fermentation with cooked rice as the model food waste. The sludge underwent acidogenesis and dissimilatory iron reduction, resulting in a drop of the pH to below 5.0 and reduction of Fe(III) to Fe(II). Owing to the high solubility of the Fe(II)-P complex, P and Fe were then dissolved and released from the sludge into the supernatant. By simply adjusting the solution pH to 8.0, the P and Fe(II) in the supernatant readily re-precipitated to form vivianite for the P recovery. Using the iron dosing MBR and side-stream sludge fermentation, an overall P recovery efficiency of 62.1% from wastewater influent can be achieved, and the problem of inorganic build-up in the MBR is effectively alleviated.

[Establishment of pharyngeal 3-dimensional finite element model of patients with isolated cleft palate].

PURPOSE: The aim of this study was to provide basis for future design and selection of cleft palate surgery through establishing finite element model of pharyngeal cavity which was suitable for biomechanical analysis. METHODS: One patient with isolated cleft palate and 1 normal child underwent multilayer head CT examination. The scanned data of pharyngeal cavity were imported into Mimics software for a 3-D geometric model reconstruction. The model was divided into a grid, so it can be further processed for subsequent finite element analysis. RESULTS: After applying 5cm water column pressure load of 0.0005 MPa at the back edge of the soft palate in the two models respectively, the results showed that the maximum stress of the abnormal nasopharyngeal cavity model was 0.025 MPa, greater than the normal model (0.017 MPa). The same pressure loading was applied to different parts of the two models, the stress change area in the posterior margin of the soft palate and the middle of the palate was the same, and the stress in the front of the hard palate was smaller. CONCLUSIONS: Finite element model has good biomechanical characteristics and geometric similarity. It can be used in isolated cleft palate with preoperative biomechanical analysis, for repairing and functional reconstructive surgery to provide ideal biomechanical model predicts.