Biomedical subjects

Lin Wang

Publications and source records attributed to Lin Wang.

At least 253 records · Page 14Linked to original sources

PubMed2003

Estimating normal optic nerve axon numbers in non-human primate eyes.

PURPOSE: The goal of the present study is to develop a semi-automated method to estimate accurately, with minimum variance, the total number of axons by counting a subset of the axons within a primate optic nerve. METHODS: Using an imaging analysis system, axons in 50% of the area of cross-sections of the retrobulbar optic nerve from five adult Rhesus monkeys were counted and extrapolated as an estimate of total axon number of the optic nerves. Both neural and non-neural areas were sampled. With the coordinates of the counts topographically registered, axon numbers within areas ranging from 1 to 50% were resampled. A Monte Carlo and theoretical estimate of the standard deviation of the total axon count for each sampled area was computed. RESULTS: The mean cross-sectional area of the five optic nerves counted was 7.26 +/- 0.6 mm2, and the mean total axon count of the optic nerve area was 1,304,8168 +/- 89,112. When sampling less than 8% of the optic nerve, the standard deviation within the individual of the total estimated axon number increased sharply. CONCLUSION: With this technique, the variance within each individual increased only slightly when the counting area was reduced from 50 to 8%, but increased sharply when the counted area became less than 8%. While counting less than 8% of the optic nerve area gives a good estimation of total axon count, the effect of a substantial increase in the standard deviation on the statistical power needed to differentiate group differences will depend on the study design.

Anatomy, Cross-Sectional↗

PubMed2003

Epigenetic regulation of ARHI in breast and ovarian cancer cells.

ARHI (Ras homologue member I) encodes a 26-kDa GTPase with 50-60% amino acid homology to Ras and Rap. ARHI and Ras share similar GTP/GDP binding domains, but exert opposite functions. ARHI is one of the first reported tumor suppressors in the ras superfamily. ARHI is expressed consistently in normal breast and ovarian epithelial cells, but not in breast or ovarian cancers. The loss of ARHI can be related to tumor progression. Reexpression of ARHI induces apoptosis of breast and ovarian cancer cells by a caspase-independent, calpain-dependent pathway. ARHI is consistently expressed in normal breast and ovarian epithelial cells but is dramatically downregulated in more then 70% of breast and ovarian cancers. ARHI is maternally imprinted with methylation of the three CpG islands in the maternal allele of normal cells. ARHI is expressed only from the paternal allele whose three CpG islands are not methylated. Loss of ARHI expression can occur through a genetic event, with loss of heterozygosity observed in 40% of breast, ovarian, and pancreatic cancers; but it can also occur through epigenetic mechanisms, including DNA methylation, histone deacetylation, histone methylation, and transcriptional regulation. Our data suggest that acetylation and methylation of chromatin associated with the ARHI promoter leads to loss of both ARHI expression and the ability to suppress tumor growth. Changes in chromatin that silence ARHI may be driven by methylation-dependent and -independent pathways. Reactivation of both the silenced paternal and imprinted maternal alleles can be achieved by demethylation and inhibition of histone deacetylation.

Acetylation↗

PubMed2003

Varicosities of intraretinal ganglion cell axons in human and nonhuman primates.

PURPOSE: To describe varicosities of intraretinal ganglion cell axons in the nerve fiber layer of human and nonhuman primate retinas. METHODS: Intraretinal ganglion cell axons of seven human donors (1-85 years old) and two nonhuman primates (Macaca mulatta, 15 and 17 years old) were immunohistochemically stained with an antibody of neurofilament on flatmounted retinas and examined with light microscopy. In addition, the axons within the retinal nerve fiber layer were examined with transmission electron microscopy in one human and one nonhuman retina. The variations of diameters of single axons were measured on transverse- and parallel-cut sections, and the frequency distributions of the diameters were statistically evaluated. RESULTS: Varicosities of the intraretinal ganglion cell axons were found throughout the retinas in both nonhuman primate and human eyes of all ages examined. The varicosities were rich in mitochondria and had desmosome- and hemidesmosome-like junctions with other axons and retinal glial cells. Measured on parallel-cut axons, the mean diameter (+/-SD) of varicosities was 2.7 +/- 0.9 micro m, whereas the mean diameter of intervaricosity regions was 0.7 +/- 0.3 micro m. The diameter distribution for transverse-cut axons was also bimodal, but the two peaks were much closer because the peak of the larger-diameter group decreased. CONCLUSIONS: The results demonstrated that intraretinal ganglion cell axons are predominantly varicose fibers in both human and nonhuman primates. Size variations exist within a single axon's diameter and thereby affect the patterns of diameter distribution seen in transverse-cut preparations. The mitochondria-rich varicosities and the presence of intercellular junctions suggest that the varicosities may be functional sites that serve local high-energy demands of unmyelinated fibers and signal transmission.

Adolescent↗

PubMed2003

Local ganglion cell contributions to the macaque electroretinogram revealed by experimental nerve fiber layer bundle defect.

PURPOSE: To assess the structural and functional consequences of local ganglion cell (GC) loss in an experimental model of a retinal nerve fiber layer (NFL) bundle defect. To evaluate and compare three commonly used multifocal electroretinogram (mfERG) stimuli, as well as the standard transient pattern-reversal ERG (pERG) and the photopic full-field ERG, for detection of local GC damage. METHODS: Intraretinal axotomy was achieved by multiple treatments with a diode laser adapted to a slit lamp biomicroscope. Retinal laser burns were applied along an arc, subtending approximately 60 degrees, about one disc diameter superotemporal to the optic nerve. Functional measures were acquired before laser application and at numerous time points thereafter. These included mfERGs for three different stimuli: a standard fast m-sequence flicker, a global-field flash paradigm (MOFO), and a slowed m-sequence (with seven dark frames inserted to each m-step [7F]). pERGs were measured for a 24 degrees x 32 degrees checkerboard stimulus (0.56 cyc/deg, 90% contrast, 75 cd/m(2), 5 reversals/s). Photopic full-field ERGs were measured for red flashes (0.42 log photopic cd-s/m(2)) on a blue rod-saturating background (30 scotopic cd/m(2)). Retinal photography, fluorescein angiography and postmortem histologic evaluation of the optic nerve, NFL, and retinal tissues were performed. RESULTS: After six laser sessions, the NFL bundle defect appeared to be complete and contiguous and was visible both proximal to and distal to the site of the photoablation by clinical examination of the fundus and stereoscopic photographs. Histologic evaluation demonstrated localized loss of GC axons, confirmed at the level of the retrobulbar optic nerve. Retinal cross sections in the temporal retina (distal to the axotomy) showed loss of GC soma and NFL degeneration, whereas all other layers appeared intact. mfERGs showed loss of high-frequency components (HFCs) for responses located within the arcuate region corresponding to the NFL defect. Local GC damage was most easily detected using the slowed 7F m-sequence stimulus. This stimulus elicited relatively large HFCs that were significantly reduced from local responses after axotomy and that were tetrodotoxin (TTX)-sensitive in a control experiment. Low-frequency component loss with the 7F stimulus did not reach statistical significance. The photopic full-field ERG was not significantly affected. pERG amplitudes declined significantly from baseline but remained within normal limits. CONCLUSIONS: Focal loss of GC function in the macaque retina is most easily detected using the slowed-sequence mfERG. Local 7F HFCs depend on intact GC function.

Animals↗

PubMed2003

Interaction between hepatitis C virus core protein and translin protein--a possible molecular mechanism for hepatocellular carcinoma and lymphoma caused by hepatitis C virus.

AIM: To investigate the interaction between hepatitis C virus core protein and translin protein and its role in the pathogenensis of hepatocellular carcinoma and lymphoma. METHODS: With the components of the yeast two hybrid system 3, "bait" plasmids of HCV core the gene was constructed. After proving that hepatitis C virus core protein could be firmly expressed in AH109 yeast strains, yeast two- hybrid screening was performed by mating AH109 with Y187 that transformed with liver cDNA library plasmids-pACT2 and then plated on quadruple dropout (QDO) medium and then assayed for alpha-gal activity. Sequencing analysis of the genes of library plasmids in yeast colonies that could grow on QDO with alpha-gal activity was performed. The interaction between HCV core protein and the protein we obtained from positive colony was further confirmed by repeating yeast two - hybrid analysis and coimmunoprecipitation in vitro. RESULTS: A gene from a positive colony was the gene of translin, a recombination hotspot binding protein. The interaction between HCV core protein and translin protein could be proved not only in yeast, but also in vitro. CONCLUSION: The core protein of HCV can interact with translin protein. This can partly explain the molecular mechanism for hepatocellular carcinoma and lymphoma caused by HCV.

Carcinoma, Hepatocellular↗

PubMed2003

[Screening of the genes of hepatitis B virus PreS2 interacting proteins].

OBJECTIVE: To screen and clone the genes of proteins in hepatocytes interacting with hepatitis B virus (HBV) PreS2 by yeast-two hybridization technique. METHODS: The HBV PreS2 gene was amplified by polymerase chain reaction (PCR) and HBV PreS2 bait plasmid was constructed by using yeast-two hybridization system 3, then transformed into yeast AH109, followed by mating with yeast Y187 containing liver cDNA library plasmid in 2 YPDA medium. Diploid yeast was plated on synthetic dropout nutrient medium (SD/-Trp-Leu-Ade-His) and synthetic dropout nutrient medium (SD/-Trp-Leu-Ade-His) containing X-alpha-gal for selecting positive blue clones, then amplified by PCR, sequenced, and performed bioinformatics analysis. RESULTS: HBV PreS2 gene was cloned successfully and expressed in yeast AH109.Twenty-six positive colonies were selected, among them, twelve containing metallothionein 2A, one cytochrome C oxidase II, two cytochrome P450 subfamily IV4F, two cytochrome c oxidase subunit 4 isoform 1, three albumin (ALB), one Na(+)K(+) transporting ATPase beta-1 polypeptide, two prealbumin, one lectin galactoside-binding subunit, and Two new genes with unknown function. CONCLUSION: Genes of HBV PreS2 interacting proteins have been successfully cloned, which brings some new clues for studying the biological functions of HBV PreS2 and related proteins.

Cloning, Molecular↗

PubMed2003

Mycoplasma pneumoniae-associated Stevens-Johnson syndrome exhibits lymphopenia and redistribution of CD4+ T cells.

Erythema multiforme (EM) is an immune-mediated disease categorized into EM minor and EM major, also called Stevens-Johnson syndrome. The presence of mucosal involvement differentiates erythema multiforme major from erythema multiforme minor. Many drugs and agents can induce Stevens-Johnson syndrome. We report a case of Stevens-Johnson syndrome associated with Mycoplasma pneumoniae infection. Lymphopenia with a significant decrease of CD4+ T cells in the blood and predominant CD4+ T cells in the skin vesicular fluid was found. The improvement of lymphopenia was associated with disease recovery. In a retrospective chart review of patients treated in our hospital over the past 3 years, we found that 5 patients with Stevens-Johnson syndrome all had lymphopenia (< 1.50 x 10(9)/L; average 0.99 x 10(9)/L), whereas 13 other patients with erythema multiforme minor demonstrated normal lymphocyte counts (average 3.13 x 10(9)/L), with the exception of one patient with herpes infection showing lymphopenia. These results suggested that an immunopathogenesis involving redistribution of CD4+ T cells might contribute to the development of Stevens-Johnson syndrome. Further studies to investigate the involvement of CD4+ T cells in Stevens-Johnson syndrome may implicate a specific strategy to prevent fatal Stevens-Johnson syndrome.

CD4 Lymphocyte Count↗

PubMed2003

[Changes in interleukin-1beta in serum and bronchoalveolar lavage fluid in the patient with acute respiratory distress syndrome].

OBJECTIVE: To study the role of interleukin-1beta (IL-1beta) in the pathogenesis of acute respiratory distress syndrome (ARDS). METHODS: The bronchoalveolar lavage fluid (BALF) and serum in 13 patients with ARDS and 9 healthy controls were collected. The contents of IL-1beta were measured by enzyme-linked immunoadsorbent assay(ELISA). RESULTS: The levels of IL-1beta in BALF [(144.67+/-80.79)ng/L] and serum [(45.71+/-7.09)ng/L] in patients with ARDS were significantly higher than those in the control groups [(20.39+/-1.87)ng/L, P=0.000; (35.06+/-5.46)ng/L, P=0.001, respectively], and the levels of IL-1beta in BALF were also significantly higher than those of the serum in the patients with ARDS (P=0.000). CONCLUSION: The results indicate that IL-1beta is involved in the pathogenesis of ARDS. Early determination of IL-1beta level in BALF may be more valuable in the evaluation of disease process of ARDS.

Adult↗

PubMed2003

[Random control trial of the efficacy of cardio pump on pre-hospital cardiac arrest].

OBJECTIVE: To compare the efficacy of early resuscitation of active compression-decompression cardiopulmonary resuscitation (ACD-CPR) with standard CPR in pre-hospital cardiac arrest. METHODS: Ninety-two patients with cardiac arrest occurring out of hospital were allocated to ACD-CPR (cardio pump) or standard CPR randomly, then determine systolic blood pressure (SBP) of both groups at the 1st, 3rd, 5th, 10th, 15th, 30th minute after the beginning of resuscitation, and the proportion of resumption of spontaneous circulation (ROSC), as well as admission rate. RESULTS: The SBP and ROSC at 3rd, 5th, 10th, 15th minute were significantly higher in the group receiving ACD-CPR than in the group receiving standard CPR. On arriving the hospital, the survival rate was higher in the ACD-CPR group than in the control group, but of no statistical significance. CONCLUSION: ACD-CPR may improve the efficacy of early resuscitation in patients with pre-hospital cardiac arrest.

Adult↗

PubMed2003

[Synergetic transactivating effect of HCV core and HBV X proteins on SV40 early promoter/enhancer].

BACKGROUND: To investigate the synergetic transactivating effects of HCV core and HBV X proteins. METHODS: HCV core and HBV X protein-expressing plasmids were constructed with the vector pcDNA3.1(-). The plasmids were transfected into HepG2 cells and cotransfected Hep2 cells with reporter plasmid Psv-lacZ by lipofectamine plus reagents. The virus proteins produced in transient expression system were detected at the transcription and translation levels. The activity of b-galactosidase was detected, which reflected the transactivating function of the proteins. RESULTS: The expression of plasmids were detected in soluble protein cell extracts of transiently transfected HepG2 cells. HCV core protein activated the b-galactosidase expression at a value 4.9 times higher than the control, while HBV X protein activated at a value 3.5 times. It arrived at 9 times transfected with the plasmids simultaneously. The activating effect increased in relation to the amount of plasmids. CONCLUSIONS: The results suggested that the two kinds of virus proteins have transactivating effect on SV40 early promoter/enhancer, and they acted synergistically. These contribute to explain the mechanisms of liver injury or tumorigenesis induced by HCV or/and HBV infection.

Animals↗

PubMed2003

[TLR4 is involved in hepatic ischemia/reperfusion injury in mice].

OBJECTIVES: To explore the role of TLR4 in the mechanism of hepatic ischemia/reperfusion (I/R) injury in mice. METHODS: Wild-type (C3H/Heouj) mice and TLR4 deficient mice (C3H/Hej) were used to prepare the models of liver I/R injury. Partial hepatic ischemia was produced by inflow causing occlusion in the median and left lobes for 45 minutes. Blood was drawn to kill the mice at 1 hours and 3 hours after reperfusion. The blood was used to analyze aspartate aminotransferase (AST) and tumor necrosis factor-alpha (TNFalpha). TNF-alpha mRNA expression and myeloperoxidase (MPO) level in ischemic lobes was examined by northern blot and myeloperoxidase assay, respectively. RESULTS: AST levels were significantly lower in TLR4 deficient mice, compared with those in wild-type mice at both time points (661.83U/L+/-106.09U/L vs. 1215.5U/L+/- 174.03U/L, t=-6.65, P<0.01; 1145.17U/L+/-132.42U/L vs. 2958.17U/L+/-186.81U/L, t=-5.57, P<0.01). Serum TNF-alpha level was lower in TLR4 deficient mice at 3 hours after reperfusion compared with that in wild-type mice (152.39pg/ml+/-43.3 pg/ml vs. 249.12pg/ml+/-51.89pg/ml, t=-3.13, P<0.05). This difference appeared to be mediated at the gene level, since TNF-alpha mRNA expression had decreased in TLR4 deficient mice at 1 hours after reperfusion, compared with that in wild type mice (80.3+/-28.8 vs. 189.4+/-24.6, t=-3.25, P<0.05). MPO level in ischemic lobes in TLR4 deficient mice at 3 hours after reperfusion was significantly lower than that in wild type mice (F=33.49, P<0.01). CONCLUSIONS: I/R hepatic injury in TLR4 deficient mice is less than that in wild-type mice. TNF-alpha expression down-regulated at the mRNA level appears critical. These suggest that TLR4 be involved in the mechanism of hepatic ischemia/reperfusion injury in mice.

Alanine Transaminase↗

PubMed2003

[Study on the high-affinity IgE receptor beta gene polymorphism and its association with the susceptibility to allergic asthma in Han nationality of Hubei province].

OBJECTIVE: To determine whether 2 polymorphism sites of the high-affinity IgE receptor beta (Fc epsilon RI beta) gene were associated with allergic asthma in Han nationality of Hubei province in China. METHODS: DNA and clinical data were obtained from allergic asthma patients and were compared with those from a group of healthy control subjects. The subjects were genotyped for the -109C/T and a coding variant Glu237Gly in Fc epsilon RI beta gene by polymerase chain reaction-restriction fragment length polymorphism. RESULTS: (1) The genotype frequencies were 0.403 for -109T/T, 0.491 for -109T/C and 0.106 for -109C/C in allergic asthma patients in a Chinese population. No significant difference in the distribution of -109C/T polymorphism was found between allergic asthma patients and healthy control subjects; however, a homozygosity for the -109T allele was associated with increased total plasma IgE levels in patients with allergic asthma (F=7.523, P<0.01). (2) The frequency of Gly237Gly genotype was 0.051 in patient group, and 0.020 in control group. The allele frequencies of Gly237 in the patients and control were 0.236 and 0.136 respectively. There was a significant association between Gly/Gly genotype and allergic asthma. Among allergic asthma patients Gly237Gly was significantly associated with high IgE. CONCLUSION: These data suggested that the Gly237Gly genotype of the Fc epsilon RI beta gene conferred genetic susceptibility to allergic asthma in Chinese, which affected the total plasma IgE levels in the allergic asthma patients. And a homozygosity for the -109T allele was associated with increased total plasma IgE.

Adolescent↗

PubMed2003

[Study on biodegraded characteristics of endocrine disruptor di-n-butyl phthalate].

The biodegraded Characteristics of di-n-butyl Phthalate (DBP), endocrine disruptor were studied. The activated sludge was acclimated using DBP as the only carbon in the culture medium. DBP concentration was increased progressively from 0.05 g/L to 0.5 g/L. The degradation tests were carried out on the constant temperature table using the acclimated sludge at different PH, temperature, DBP concentration and hydraulic residence time. The results showed that DBP could be rapidly degraded-nearly 90% in 48 hours. The appropriate condition for DBP degradation was pH 6.0-8.0, temperature 25 degrees C-35 degrees C, DBP concentration no more than 300 mg/L, and hydraulic residence time 12 h-24 h. The form of biodegradation of DBP can be described as the first-order reaction model.

Biodegradation, Environmental↗

PubMed2003

[Clinical evaluation of laparoscopic radical hysterectomy with pelvic and para-aortic lymphadenectomy in patients with cervical cancer].

OBJECTIVE: To evaluate the effective, results and complications in patients with cervical cancer who consented to undergo laparoscopic radical hysterectomy and retroperitoneal lymphadenectomy. METHODS: In 57 consecutive patients with stage Ia to IIb cervical cancer, laparoscopic radical hysterectomy and lymphadenectomy were performed. Forty-eight patients had squamous cell carcinomas, 7 patients had adenocarcinomas, and 2 patients had adenosquamous carcinomas of the cervix. RESULTS: All but 2 surgical procedures were completed laparoscopically. The average operative time was 186 min (150 - 320 min). The average blood loss was 168 ml (120 - 700 ml). Average numbers of pelvic and paraaortic lymph nodes removed were 18.6 (12 - 23) and 8.2 (6 - 12), respectively. Eight patients (14.0%) had positive lymph nodes. All surgical margins were macroscopically negative. Operative cystotomies occurred in 2 patients and one patient with venous injuries were repaired laparoscopically. Two other patients underwent laparotomy to control bleeding or repair ascending colon. After surgery, patients passed gas in 2.3 days and self-voided in 10.2 days on average. Follow-up has been provided every 3 months. There have been 3 cases of recurrences, one patient uncontrolled, and one patient ureteral constriction. Three patients have retention of urine. CONCLUSIONS: Laparoscopic radical hysterectomy and lymphadenectomy can be successfully completed in patients with cervical cancer with acceptable operation complications, a less injury and recovery time, and may become preferred for treating early cervical cancer.

Adult↗

PubMed2003

A novel approach to treat combined domestic wastewater and excess sludge in MBR.

Domestic wastewater was treated by combined anaerobic biofilm-aerobic membrane bioreactor(MBR) process, and part biomass MBR was withdrawn to treat with ozone, then the ozonated sludge was returned to anaerobic inlet. In aerobic MBR, MISS and DO were controlled at 3000-3500 mg/L and 0.8 mg/L respectively. Comparing the experimental results of two stages, it was noticed that ozonation did not affect the removal efficiency for organics but had a significant influence on the removals of NH3-N and TN. During the ozonation period of two months, no excess sludge was wasted, and a zero sludge yield was obtained.

Anaerobiosis↗

PubMed2003

Screening of augmenter of liver regeneration-binding proteins by yeast-two hybrid technique.

OBJECTIVE: To investigate the biological function of augmenter of liver regeneration (ALR), we used yeast-two hybrid technique to detect proteins in hepatocytes interacting with ALR. METHODS: ALR bait plasmid was constructed by using yeast-two hybrid system 3, then transformed into yeast AH109. The transformed yeast was mated with yeast Y187 containing liver cDNA library plasmid in a 2XYPDA medium. Diploid yeast was plated on a synthetic dropout nutrient medium (SD/-Trp-Leu-His-Ade) containing x-alpha-gal for selection and screening. After extracting and sequencing of the plasmid from blue colonies. Analysis was performed by bioinformatics. RESULTS: Of 36 colonies sequenced, 14 are metallothionein, 12 albumin, and 3 selenoprotein P. One colony is a new gene with unknown function. CONCLUSION: The successful cloning of gene of ALR interacting protein has paved the way for studying the physiological function of ALR and associated proteins.

Animals↗

PubMed2003

The association analysis of FcepsilonRIbeta with allergic asthma in a Chinese population.

OBJECTIVE: To investigate the link between the polymorphism of -109 and Glu237 in the high-affinity IgE receptor beta (FcepsilonRIbeta) gene and susceptibility to allergic asthma in a Chinese population. METHOD: Blood samples from 216 allergic asthma patients and 198 age- and sex-matched controls were studied. A -109C/T and a coding variant Glu237Gly in FcepsilonRIbeta were detected with polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). RESULTS: The genotype frequencies were 0.403 for -109T/T, 0.491 for -109T/C and 0.106 for -109C/C in allergic asthma in a Chinese population. No significant difference in the distribution of -109C/T polymorphism was found between allergic asthma subjects and healthy controls, however, homozygosity for the -109T allele was associated with increased total plasma IgE levels in subjects with allergic asthma (F = 4.020, P < 0.05). The allele frequency of Gly237 in the patients and control was 0.236 and 0.136 respectively. There was a significant association between the Gly/Gly genotype and allergic asthma. Among allergic asthma patients Gly237 was significantly associated with high IgE levels. CONCLUSIONS: These results suggest that the Gly237 variant of the FcepsilonRIbeta gene is involved in the development of allergic asthma. The -109C/T and Glu237Gly polymorphisms are two of the genetic factor identified thus far, which affect total plasma IgE levels of allergic asthma patients in a Chinese population.

Adolescent↗

PubMed2003

Treating both wastewater and excess sludge with an innovative process.

The innovative process consists of biological unit for wastewater treatment and ozonation unit for excess sludge treatment. An aerobic membrane bioreactor (MBR) was used to remove organics and nitrogen, and an anaerobic reactor was added to the biological unit for the release of phosphorus contained at aerobic sludge to enhance the removal of phosphorus. For the excess sludge produced in the MBR, which was fed to ozone contact column and reacted with ozone, then the ozonated sludge was returned to the MBR for further biological treatment. Experimental results showed that this process could remove organics, nitrogen and phosphorus efficiently, and the removals for COD, NH3-N, TN and TP were 93.17%, 97.57%, 82.77% and 79.5%, respectively. Batch test indicated that the specific nitrification rate and specific denitrification rate of the MBR were 1.03 mg NH3-N/(gMLSS x h) and 0.56 mg NOx-N/(gMLSS x h), and denitrification seems to be the rate-limiting step. Under the test conditions, the sludge concentration in the MBR was kept at 5000-6000 mg/L, and the wasted sludge was ozonated at an ozone dosage of 0.10 kgO3/kgSS. During the experimental period of two months, no excess sludge was wasted, and a zero withdrawal of excess sludge was implemented. Through economic analysis, it was found that an additional ozonation operating cost for treatment of both wastewater and excess sludge was only 0.045 RMB Yuan (USD 0.0054)/m3 wastewater.

Bioreactors↗