Study on mitigating membrane fouling based on precursor and flocculant Alb matching in EC/O-UF system.

One of the effective ways to remove halogenated disinfection by-products (DBPs) from drinking water is the application of ultrafiltration technology. However, membrane fouling is an important factor affecting the service life and treatment effect. In this study, the electrocoagulation/oxidation-ultrafiltration (EC/O-UF) process was used to remove the precursor substance that produced DBPs, i.e. dissolved organic matters (DOMs). Operating parameters were optimized from the matching of different flocculant morphology to low concentration DOM. The degree of membrane fouling was characterized by analyzing DOMs concentration and membrane flux. The results showed that the optimal conditions for the production of Alb were: current density 10 A/m2, hydraulic retention time 10 min, and initial pH 5.0-7.0. Under these conditions, the production of flocculant Alb could reach 58-61%, 94-97% DOMs were removed by EC/O-UF.

Two novel pathogenic variants in the TCOF1 found in two Chinese cases of Treacher Collins syndrome.

BACKGROUND: Treacher Collins Ι syndrome (TCS1, OMIM:154500) is an autosomal dominant disease with a series of clinical manifestations such as craniofacial dysplasia including eye and ear abnormalities, small jaw deformity, cleft lip, as well as repeated respiratory tract infection and conductive hearing loss. Two cases of Treacher Collins syndrome with TCOF1(OMIM:606847) gene variations were reported in the article, with clinical characteristics, gene variants and the etiology. METHODS: The clinical data of two patients with Treacher Collins syndrome caused by TCOF1 gene variation were retrospectively analyzed. The whole exome sequencing (WES) was performed to detect the pathogenic variants of TCOF1 gene in the patients, and the verification of variants were confirmed by Sanger sequencing. RESULTS: Proband 1 presented with bilateral craniofacial deformities, conductive hearing loss and recurrent respiratory tract infection. Proband 2 showed bilateral craniofacial malformations with cleft palate, which harbored similar manifestations in her family. She died soon after birth due to dyspnea and feeding difficulties. WES identified two novel pathogenic variants of TCOF1 gene in two probands, each with one variant. According to the American College of Medical Genetics and Genomics, the heterozygous variation NM_001371623.1: c.877del (p. Ala293Profs*34) of TCOF1 gene was detected in Proband 1, which was evaluated as a likely pathogenic (LP) and de novo variant. Another variant found in Proband 2 was NM_001135243.1: c.1660_1661del (p. D554Qfs*3) heterozygous variation, which was evaluated as a pathogenic variation and the variant inherited from the mother. To date, the two variants have not been reported before. CONCLUSION: Our study found two novel pathogenic variants of TCOF1 gene and clarified the etiology of Treacher Collins syndrome. We also enriched the phenotypic spectrum of Treacher Collins syndrome and TCOF1 gene variation spectrum in the Chinese population, and provided the basis for clinical diagnosis, treatment and genetic counseling.

Removal of intraocular foreign body in anterior chamber angle with prism contact lens and 23-gauge foreign body forceps.

AIM: To introduce a novel approach in removal of anterior chamber angle foreign body (ACFB) using a prism contact lens and 23-gauge foreign body forceps. METHODS: Data of 42 eyes of 42 patients who had undergone removal of ACFB using a prism contact lens and 23-gauge foreign body forceps from January 2008 to October 2013 were collected and analyzed. Twenty eyes in group A received the conventional approach by using toothed forceps through corneal limbus incision, and 22 eyes in group B underwent the novel method through the opposite corneal limbus incision. RESULTS: The success rate of ACFB once removal was 75% (15/20) in group A, and 100% (22/22) in group B. The average operation time of group A was significantly longer compared with group B (34.9±9.88min vs 22.13±8.85min; P<0.05). The average size of corneal limbus incision in group A was significantly larger than that of group B (4.85±1.89 mm vs 3.95±1.17 mm; P<0.05). The corneal limbus incision suturing were conducted in all eyes in group A, and only 5 eyes in group B. CONCLUSION: Removal of ACFB using a prism contact lens and 23-gauge foreign body forceps is a safer, more effective, and convenient technique compared with the conventional approach.

Removal of fluorescent dissolved organic matter in biologically treated textile effluents by NDMP anion exchange process: efficiency and mechanism.

The efficiency and mechanism of anion exchange resin Nanda Magnetic Polymer (NDMP) for removal of fluorescent dissolved organic matter in biologically treated textile effluents were studied. The bench-scale experiments showed that as well as activated carbon, anion exchange resin could efficiently remove both aniline-like and humic-like fluorescent components, which can be up to 40 % of dissolved organic matter. The humic-like fluorescent component HS-Em460-Ex3 was more hydrophilic than HS-Em430-Ex2 and contained fewer alkyl chains but more acid groups. As a result, HS-Em460-Ex3 was eliminated more preferentially by NDMP anion exchange. However, compared with adsorption resins, the polarity of fluorescent components had a relatively small effect on the performance of anion exchange resin. The long-term pilot-scale experiments showed that the NDMP anion exchange process could remove approximately 30 % of the chemical oxygen demand and about 90 % of color from the biologically treated textile effluents. Once the issue of waste brine from resin desorption is solved, the NDMP anion exchange process could be a promising alternative for the advanced treatment of textile effluents.

[Calcification and biomechanics in vivo of ultra-microporous expanded polytetrafluoroethylene in rabbits].

OBJECTIVE: To study in vivo calcification and biomechanics of the ultra-microporous expanded polytetrafluo- roethylene (UePTFE) in rabbits in comparison with glutaral-treated bovine pericardium (BP), so as to assess the potential of UePTFE as a material for cardiac valve prosthesis. METHODS: Factorial analysis was adopted in the experiment. UePTFE and glutaral-treated BP of appropriate sizes were embedded beneath skin of young New Zealand rabbits, and at 0, 1, 3 and 6 months following the implantation, the materials were measured for the content of calcium and biomechanics properties. RESULTS: Lower level of calcification of the UePTFE occurred after the implantation, as compared with BP, and the biomechanics indices of the former UePTFE were obviously suprior to those of the latter. CONCLUSION: UePTFE is a better material than BP for cardiac valve prosthesis.

[Evaluation of ultramicroporous expanded polytetrafluoroethylene mitral valve under pulsatile flow condition in vitro].

OBJECTIVE: To test 25# and 27# ultramicroporous expanded polytetrafluo-roethylene mitral valve (UPMV) under pulsatile flow condition in vitro. METHODS: Six 25# and six 27#UPMV were tested using TH-1200 HV Prosthesis Pulsatile Flow Tester in vitro at the cycling rate of 70 cycle/min, with the systolic pressure maintained at about 16 kPa (120 mmHg), diastolic pressure at 10.7 kPa (80 mmHg), and the percentage of mean forward flow at 35%. The stimulant cardiac output was maintained at 2, 3, 4, 5 and 6 L/min, respectively, for the testing. RESULTS: The mean pressure difference for the 25#UPMV under stimulant cardiac output of 2, 3, 4, 5 and 6 L/min was 2.488-/+0.378, 4.427-/+0.240, 5.460-/+0.449, 6.776-/+0.391 and 8.327-/+0.490 mmHg, and its effective valvular orifice was 1.430-/+0.333, 1.993-/+0.208, 2.260-/+0.477, 3.204-/+0.174 and 3.652-/+0.158 cm(2), respectively. The regurgitant fraction of the 25#UPMV under each stimulant cardiac output was (5.731-/+0.643) %, (5.431-/+0.312) %, (5.059-/+0.708) %, (3.545-/+0.097) % and (2.615-/+0.125) %, respectively. The mean pressure difference of the 27#UPMV under each stimulant cardiac output was 1.618-/+0.497, 3.448-/+0.440, 4.825-/+0.434, 5.494-/+0.446 and 7.482-/+0.455 mmHg, effective valvular orifice was 1.773-/+0.364, 2.113-/+0.305, 2.409-/+0.295, 3.326-/+0.417 and 4.522-/+0.445 cm(2), and regurgitant fraction was (5.357-/+0.509) %, (5.407-/+0.110) %, (4.999-/+0.182) %, (4.010-/+0.254) % and (2.584-/+0.114)%, respectively. CONCLUSION: The mean pressure difference, effective valvular orifice and regurgitant fraction of the UPMVs can measure up to the national criteria for artificial heart valve prosthesis of China.

[Accelerated fatigue test in vitro of expanded polytetrafluoroethylene artificial heart valve].

OBJECTIVE: To study the durability of expanded polytetrafluoroethylene artificial heart valve (ePTFE AHV). METHODS: Six ePTFE AHVs were tested for 400 million times against accelerated fatigue using TH-2200 artificial heart valve exosomatic accelerated fatigue instrument. Hydromechanical parameters of fore-and-aft accelerated fatigue test of the 6 AHVs were obtained by TH-1200 artificial heart valve exosomatic pulsatile stream instrument. RESULTS AND CONCLUSION: The mean gradient pressure spanning the valve and the effective orific area of ePTFE AHVs did not undergo significant changes after fore-and-aft the fatigue test, but the regurgitation volume and regurgitation rate of ePTFE AHVs were reduced after the accelerated fatigue test, suggesting good durability of ePTFE AHV.