Vibrations

induced cyclical, low-amplitude stepping-in-place movements that mimicked alternate walking movements with both legs, with 1 s and 2 s cycle durations, in one nondisabled participant and one participant with American Spinal Injury Association Impairment Scale B spinal cord injury standing, relaxed, with body-weight support. Electromechanical vibrators can deliver www.selleckchem.com/products/ipi-145-ink1197.html complex cyclical vibrations and trigger gait-like lower-limb movements. These results warrant the application of these vibration patterns on individuals with sensorimotor impairments to test their potential in gait rehabilitation.”
“Biophysical studies of the interaction of peptides with model membranes provide a simple yet effective approach to understand the transport of peptides and peptide based drug carriers across the cell membrane. Herein, the authors discuss the use of self-assembled monolayers fabricated from the full membrane-spanning thiol (FMST) 3-((14-((40-((5-methyl-1-phenyl-35-(phytanyl) oxy6,9,12,15,18,21,24,27,30,33,37- Batimastat inhibitor undecaoxa-2,3-dithiahenpentacontan-51-yl) oxy)-[1,10-biphenyl]-4yl) oxy) tetradecyl) oxy)-2-(phytanyl) oxy glycerol for ultrahigh vacuum (UHV) based experiments. UHV-based methods such as electron spectroscopy and

mass spectrometry can provide important information about how peptides bind and interact with membranes, especially with the hydrophobic core of a lipid bilayer. Near-edge x-ray absorption fine structure spectra and x-ray photoelectron spectroscopy (XPS) data showed that FMST forms UHV-stable and ordered films on gold. XPS and time of flight secondary ion mass spectrometry depth profiles indicated that a proline-rich amphipathic cell-penetrating peptide, known as sweet arrow peptide is located at the outer perimeter of the model membrane. (C) 2015 American Vacuum Society.”
“Cholangiocarcinoma is the second most common malignant Autophagy Compound Library tumor of the liver. We analyzed, immunohistochemically, the significance of cell cycle- and apoptosis-related markers in 128 cholangiocarcinomas (42 intrahepatic, 70 extrahepatic, and 16 gallbladder carcinomas) combined

in a tissue microarray. Follow-up was available for 57 patients (44.5%).\n\nIn comparison with normal tissue (29 specimens), cholangiocarcinomas expressed significantly more frequently p53, bcl-2, bax, and COX-2 (P < .05). Intrahepatic tumors were significantly more frequently bcl-2+ and p16+, whereas extrahepatic tumors were more often p53+ (P < .05). Loss of p16 expression was associated with reduced survival of patients.\n\nOur data show that p53, bcl-2, bax, and COX-2 have an important role in the pathogenesis of cholangiocarcinomas. The differential expression of p16, bcl-2, and p53 between intrahepatic and extrahepatic tumors demonstrates that there are location-related differences in the phenotype and the genetic profiles of these tumors. Moreover, p16 was identified as an important prognostic marker in cholangiocarcinomas.

“
“Objective The aim of this article is to evaluate the accuracy, precision, and safety of transcutaneous carbon dioxide tension (TcPCO2) monitoring at different electrode temperatures in preterm infants in the early postnatal period. Study Design A total of 26 neonates with a median birth weight of 974 g (432-1,694 g) and gestational age of 28.0 weeks (26.1-31.3 weeks) were studied in the first 5 days of life. A total of 252 simultaneous pairs (TcPCO2 and arterial carbon dioxide tension [PaCO2]) were analyzed at 38, 39, and 40 degrees C at 26 and 27 weeks, and at 38, 39, 40, and 42 degrees C at 28 to 31 weeks. Results The mean difference

of TcPCO2 and PaCO2 (bias) increased from 3.93 mm Hg at 42 degrees C to 5.64 mm Hg at 40 degrees C, 6.58 mm Hg at 39 degrees C, and

6.07 mm Hg at 38 degrees C. Standard deviation (SD) of the bias increased from 4.17 MK-2206 cell line mm Hg at 42 degrees C to 4.76 mm Hg at 40 degrees C, 5.29 mm Hg at 39 degrees C, and 5.07 mm Hg at 38 degrees C. Adverse skin lesions selleckchem were not observed. Conclusion TcPCO2 measurements are the most accurate and precise at an electrode temperature of 42 degrees C. However, in premature babies, monitoring at 38, 39, and 40 degrees C is possible provided a bias correction of 6 mm Hg and SD of 5 mm Hg are applied.”
“AimTo determine the cost effectiveness of increasing nurse staffing or changing the nursing skill mix in adult medical and/or surgical patients? BackgroundResearch has demonstrated that nurse staffing levels and skill mix are associated with patient outcomes in acute care settings. If increased nurse staffing levels or richer skill mix can be shown to be cost-effective hospitals may be more likely to consider these aspects when making staffing decisions. DesignA systematic review of the literature

on economic evaluations of nurse staffing and patient outcomes was conducted to see KPT-8602 solubility dmso whether there is consensus that increasing nursing hours/skill mix is a cost-effective way of improving patient outcomes. We used the Cochrane Collaboration systematic review method incorporating economic evidence. Data sourcesThe MEDLINE, CINAHL, SPORTDiscus and PsychINFO databases were searched in 2013 for published and unpublished studies in English with no date limits. Review methodsThe review focused on full economic evaluations where costs of increasing nursing hours or changing the skill mix were included and where consequences included nursing sensitive outcomes. ResultsFour-cost benefit and five-cost effectiveness analyses were identified. There were no cost-minimization or cost-utility studies identified in the review. A variety of methods to conceptualize and measure costs and consequences were used across the studies making it difficult to compare results.

0 diopters (D) to 30.0 D. The AFM analysis was performed in contact mode using a V-shaped silicon nitride cantilever with a pyramidal tip curvature of 15 nm and a nominal spring constant of 0.2 N/m. Detailed surface characterization of the IOL optic was obtained using 6 quantitative parameters provided by the AFM software.\n\nRESULTS: Five of 6 roughness parameters indicated statistically significant differences (P<.05) between IOLs with different dioptric powers, with the 100 D IOL

in both models providing the smoothest optic surface. Between models Momelotinib research buy with the same dioptric power, the SN60AT model had lower values of each surface roughness parameter than the SA30AL model.\n\nCONCLUSIONS: Atomic force microscopy was an accurate tool for assessing the surface properties of IOL optics. Manufacturing processes were responsible Entinostat mw for introducing detectable differences in the topography of IOL biomaterials with identical copolymer constituents but different dioptric powers Nanometric analysis may assist IOL manufacturers in developing IOLs with optimal surface characteristics. Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned.\n\nJ Cataract Refract Surg 2010; 36.1573-1578 (C) 2010 ASCRS and ESCRS”
“Objective: To investigate whether there is a relationship between gastroesophageal reflux disease (GERD) and recurrent acute otitis media (RAOM)

in infants and children. Possible risk factors are also explored.\n\nMaterial and methods: 221 consecutive children who had symptoms and signs associated with GERD and had undergone a prolonged ambulatory 24-h esophageal pH-monitoring. Thirty-four children were excluded from the study due to age, neurological deficits, congenital abnormalities, immunodeficiency syndromes

or other chronic systemic disorders. The remaining 187 children (96 boys and 91 girls), aged between 40 days and 33 months (mean age of 18.3 months) were assigned into three groups according NU7441 manufacturer to their Reflux Index (RI%). Group A: 49 children (26.2%) without GERD (control group); Group B: 78 children (41.7%) with low to moderate RI; and Group C: 60 children (32.1%) with severe GERD. Parental interviews and personal medical files of the National Health System were used for data collection. However, episodes of acute otitis media were taken into account only if they were diagnosed by a physician. The follow-up period ranged from 6 to 8 years in order to cover the peaks of otitis media incidence in childhood.\n\nResults: The results revealed that 6 children from Group A (12.24%), 11 from Group B (14.1%) and 19 from Group C (31.67%) presented episodes of RAOM. The difference was statistically significant (p = 0.01). Furthermore, in children who received anti-reflux treatment, the incidence of RAOM substantially decreased and eventually became approximate to that of the control Group A (12.32%).

Many equine behavior and welfare scientists remain in agreement that management of crib-biting horses should focus on addressing the suspected influential factors prior to attempts at physical prevention of the behavior. The findings of several survey and experimental selleck chemicals studies

are reviewed, with emphasis on research conducted since the late 1990s, in an effort to provide the reader with a relatively comprehensive look into that which is known about crib-biting behavior in horses. Knowledge deficiencies and areas for future research are identified. (C) 2010 Elsevier B.V. All rights reserved.”
“An 86-year-old woman was found dead lying on her back on the floor of an unkempt kitchen. She had last been seen four days before. Her dress was pulled up and she was not wearing underpants. The house was noted to be in “disarray” with papers covering most surfaces and the floor. Rubbish was piled up against one of the doors. At autopsy the major findings were of a fractured left neck of femur, fresh pressure areas over her right buttock, Wischnewski spots of the stomach and foci of pancreatic necrosis, in keeping with hypothermia. No significant underlying organic diseases were identified and there was no other evidence of trauma. Death was due to hypothermia complicating

immobility from a fractured neck of femur. This case confirms the vulnerability of frail, elderly and socially-isolated individuals to death from hypothermia if a significant illness or injury occurs. Additional risk factors for hypothermia selleck compound are also illustrated in this case that involve inadequate housing construction with absent insulation and window double glazing. The approach to hypothermic deaths should, therefore, include checking for these features as well as measuring room and environmental temperatures, evaluating the type and quality of heating and the nature of the floor and its coverings, Given the ageing population in many Western countries, increasing social isolation of

the elderly, cost of fuel and electricity, and lack of energy efficient housing, this type of death may become an increasingly witnessed occurrence during the colder months of the BEZ235 in vitro year. (c) 2012 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.”
“Paraneoplastic pemphigus (PNP) is an autoimmune blistering disease associated with neoplasms, typically lymphoproliferative disorders. PNP is characterized clinically by painful erosive stomatitis and polymorphous skin lesions. Histopathological findings are also very varied, and include lichen planus-like and pemphigus-like changes. These polymorphic clinicopathological findings are probably due to the complex pathogenic mechanism, in which both cellular and humoral immunity are implicated. Eosinophilic spongiosis, although infrequent, can be found with pemphigus herpetiformis and bullous pemphigoid, although this association has not been established in PNP.

\n\nResults from this study need to be replicated in an appropriate animal model

Entinostat mouse before testing this adenoviral vector in a human trial.\n\nEffective targeting of gene therapy to leiomyoma cells enhances its potential as a non-invasive treatment of uterine fibroids.\n\nThis work was supported by a grant from the National Institute of Child Health and Human Development, National Institutes of Health [R01 HD046228]. None of the authors has any conflict of interest to declare.”
“The present study reports the characterization of forced degradation products of bosentan and a validated stability-indicating HPLC method for the stability testing of bosentan tablets. The

forced degradation was carried out under the conditions of hydrolysis, oxidation, dry heat and photolysis. The drug was found unstable in acid, alkali and oxidative media whereas stable to the hydrolysis in water, to dry heat and to photolysis. In total, six degradation products were formed in all conditions which were resolved TPCA-1 datasheet in a single run on a C-18 column with gradient elution using ammonium acetate buffer (pH 4.5, 5.0 mM), methanol and acetonitrile. Structures of all the degradation products were characterized through +ESI-MSn and LC-ESI-MS spectral data of bosentan as well as LC-ESI-MS spectral data of the products. The products II-VI were characterized as 6-amino-[2,2']bipyrimidinyl-4,5-diol, 6-amino-5-(2-methoxyphenoxy)-[2,2']-bipyrimidinyl-4-ol, BTSA1 inhibitor 2-[6-amino-5-(2-methoxyphenoxy)-[2,2']-bipyrimidinyl-4-yloxyl-ethanol, 4-tert-butyl-N-[6-(1-methoxyethoxy)-5-(2-methoxyphenoxy)-[2,2']-bipyrimidinyl-4-yl]-benzenesulfonamide and 4-tert-butyl-N-[6-hydroxy-5-(2-methoxyphenoxy)-[2,2']bipyrimidinyl-4-yl]-benzenesulfonamide,

respectively. The peak of the product I was found to be due to two secondary degradation products which co-eluted and were characterized as beta-hydroxyethyl p-tert-butylphenylsulfonate (Ia) and 2[2-(2-hydroxyethoxy)-phenoxy]-ethanol (Ib). These products were formed due to hydrolysis of sulfonamide and alkylaryl ether and the diaryl ether linkages as well as dehydration of the primary alcohol group. The most probable degradation mechanisms were proposed. The HPLC method was found to be stability-indicating, linear (2-100 mu g ml(-1)), accurate, precise, sensitive, specific, rugged and robust for quantitation of the drug. The method was applied to the stability testing of the commercially available bosentan tablets successfully. (C) 2012 Elsevier B.V. All rights reserved.”
“Aim To determine whether expression of a cyanobacterial flavodoxin in soil bacteria of agronomic interest confers protection against the widely used herbicides paraquat and atrazine.

Our results provide the first evidence of a reverberating input-output buffer system in the dorsal

stream underlying speech sensorimotor integration, consistent with recent phonological loop, competitive queuing, and speech-motor control models. These findings also shed new light on potential sources of speech dysfunction in aphasia and neuropsychiatric disorders, identifying anatomically and behaviorally dissociable activation time windows critical for successful speech reproduction.”
“A two-year-old male German shepherd dog was admitted to Shahid Bahonar Veterinary Hospital with clinical signs that included lethargy, anorexia, vomiting, abdominal pain and dehydration. Physical examination revealed nothing significant. Routine paraclinical tests only revealed a stress leukogram. Radiography revealed a mass in the stomach. Whilst performing a laparotomy, the surgeon observed an unusual mass Selleckchem Ulixertinib in the subserosal layer of the proximal part of the jejunum. The histopathology of the mass revealed some scattered sebaceous and sweat glands associated with the cyst wall that confirmed the diagnosis of a dermoid cyst. Intestinal dermoid cysts are very rare and to our knowledge this is the first report of an intestinal dermoid cyst in a dog.”
“Background Computer- and selleckchem robot-assisted technologies are capable of improving the accuracy of planar cutting in orthopaedic surgery.

This study is a first step toward formulating and validating NSC23766 chemical structure a new evaluation methodology for planar bone cutting, based on the standards from the international Organization for Standardization.\n\nMethods our

experimental test bed consisted of a purely geometrical model of the cutting process around a simulated bone. Cuts were performed at three levels of surgical assistance: unassisted, computer-assisted and robot-assisted. We measured three parameters of the standard ISO1101 : 2004: flatness, parallelism and location of the cut plane.\n\nResults The location was the most relevant parameter for assessing cutting errors, The three levels of assistance were easily distinguished using the location parameter.\n\nConclusions Our ISO methodology employs the location to obtain all information about translational and rotational cutting errors. Location may be used on any osseous structure to compare the performance of existing assistance technologies. Copyright (C) 2009 John Wiley & Sons, Ltd.”
“Importance: More than 90% of thermal injury-related deaths occur in low-resource settings. While baseline assessment of burn management capabilities is necessary to guide capacity building strategies, limited data exist from low and middle-income countries (LMICs). Objective: The objective of our review is to assess burn management capacity in LMICs. Evidence review: A PubMed literature review was performed based on studies assessing baseline surgical capacity in individual LMICs.

These human histologic data are extremely valuable to validate and confirm those obtained from studies performed on animal models. Moreover, immediate loading of the implants did not compromise soft tissue integration. (Int J Periodontics Restorative Dent 2012;32;323-328.)”
“The ontogeny of Belosaepia ungula Gabb, 1860 from the Crockett Formation (Bartonian stage, Eocene) of Texas is documented for growth from embryo to old age. During the last stage of life, much skeletal resorption occurred,

resulting in a major change in form of the skeleton. The animal produced a large skeleton (to 180 mm in length and 50 mm in diameter) with endogastric coiling, oblique septa and a very large siphuncle. The skeleton has a guard with a solid posterior prong, a posteroventral corona plate and a noded dorsal shield. The ventral margin of the skeleton consists of a thin flattened deck containing strongly recurved selleck screening library septa, conotheca and a secondary prismatic shell layer. New terms are defined for features of the skeleton not previously described. The microstructure of the ventral deck and the presence of a rod structure between the prong and callus are described for the first time. Chamberlets similar to those

in living Sepia cuttlebones are present between closely spaced septa and they vary from walled units on lateral margins to pillar form in mid-ventor. The siphuncle is secondarily thickened within Dibutyryl-cAMP solubility dmso the dorsal interior, producing a siphuncle band. The skeleton was produced by a deep-bodied animal of demersal life habits.

The species B. uncinata, B. harrisi and B. alabamensis voltzi proposed by Palmer (1937) are synonymised with B. ungula. The species B. veatchii and B. saccaria of Palmer (1937) are considered to be valid species, but B. alabamensis proposed by Palmer (1937) is synonymised with B. veatchii. Descriptions of belosaepiid species must be based only on specimens of adult size that have not been affected by resorption.”
“Community acquired pneumonia (CAP) is a common reason for hospitalization and death in elderly people. Many predictors of in-hospital outcome have been studied in the general population with CAP. However, data are lacking on the prognostic significance of conditions unique to older patients, such as delirium and the coexistence of multiple comorbidities. The aim of GSK1904529A this study was to evaluate predictors of in-hospital outcome in elderly patients hospitalized for CAP. In this retrospective study, consecutive patients with CAP aged bigger than = 65 years were enrolled between January 2011 and June 2012 in two general wards. Clinical and laboratory characteristics were collected from electronic medical records. The end-point of the study was the occurrence of in-hospital death. 443 patients (mean age 81.8 +/- 7.5, range 65-99 years) were enrolled. More than 3 comorbidities were present in 31 % of patients.

Reaction of CN in vitro with the Cys(558)Cys(667) disulfide bond in HSA is specific, rapid, LDK378 and concentration dependent within a putative, physiologically relevant range. Data from various human sera demonstrate the potential usefulness of this adduct as a biomarker of CN

exposure.”
“We have developed a multi-target cell tracking program TADOR, which we applied to a series of fluorescence images. TADOR is based on an active contour model that is modified in order to be free of the problem of locally optimal solutions, and thus is resistant to signal fluctuation and morphological changes. Due to adoption of backward tracing and addition of user-interactive correction functions, TADOR is used in an off-line and semi-automated mode, but enables precise tracking of cell division. By applying TADOR to the analysis of cultured cells whose nuclei had been fluorescently labeled, we tracked cell division and cell-cycle progression on coverslips over an extended ABT-263 manufacturer period of time. (C) 2011 Elsevier Inc. All rights reserved.”
“The pro-inflammatory cytokine interleukin-1 (IL-1), whose levels are elevated in the brain in Alzheimer’s and other

neurodegenerative diseases, has been shown to have both detrimental and beneficial effects on disease progression. In this article, we demonstrate that incubation of mouse primary cortical neurons (mPCNs) with IL-1 increases the expression of the P2Y2 nucleotide receptor (P2Y2R) and that activation of the up-regulated receptor with UTP, a relatively selective agonist of the P2Y2R, increases neurite outgrowth. Consistent with the accepted Volasertib nmr role of

cofilin in the regulation of neurite extension, results indicate that incubation of IL-1-treated mPCNs with UTP increases the phosphorylation of cofilin, a response absent in PCNs isolated from P2Y2R-/- mice. Other findings indicate that function-blocking anti-v3/5 integrin antibodies prevent UTP-induced cofilin activation in IL-1-treated mPCNs, suggesting that established P2Y2R/v3/5 interactions that promote G12-dependent Rho activation lead to cofilin phosphorylation involved in neurite extension. Cofilin phosphorylation induced by UTP in IL-1-treated mPCNs is also decreased by inhibitors of Ca2+/calmodulin-dependent protein kinase II (CaMKII), suggesting a role for P2Y2R-mediated and Gq-dependent calcium mobilization in neurite outgrowth. Taken together, these studies indicate that up-regulation of P2Y2Rs in mPCNs under pro-inflammatory conditions can promote cofilin-dependent neurite outgrowth, a neuroprotective response that may be a novel pharmacological target in the treatment of neurodegenerative diseases.”
“We are presenting a case of catastrophic antiphospholipid syndrome in an adult female manifesting with abdominal thrombosis, pancytopenia, and alveolar hemorrhage.

Therefore, studies employing distinct body measurements to assess body condition are not comparable to each other. Using multiple structural size measurements in body condition analyses is better than the common practice of using only one size measurement. However, in the present study, results provided AZD5153 by both methods differ only slightly. A recommendation on the

use of terminology in studies on body condition is introduced.”
“Targets implemented at national or state levels have been employed in response to excessive numbers of adverse events (AEs) such as multiple antibiotic-resistant Staphylococcus aureus bacteraemias. Hospital resources are limited and setting such targets can result in resource diversion to dealing with the targeted AEs. There may be initial success as judged by decreasing counts but underlying problems are not necessarily addressed, and there is evidence that other non-targeted AEs may increase. Moreover, the values of individual observations can be greatly influenced by random variation. This can make it difficult using comparisons and targets to draw conclusions about the work of

an institution. Although Akt inhibitor counting AEs is essential, the key to avoiding episodes of patient harm is prevention. This requires the implementation of evidence-based systems. These are already available for many AEs in the form of ‘bundles’ and checklists. When these systems are properly implemented and sustained, AE rates tend to occur at minimum predictable levels. Unfortunately, in spite of widespread knowledge and aggressive promotion, high levels of compliance have often been difficult to achieve and sustain. Better understanding and implementation of methods to sustain evidence-based systems are needed. Checklists, used as part of an overall system involving leadership and empowerment, application of evidence, culture change and measurement, may help to overcome this problem. (C) 2010 The Hospital Infection

Society. Published by Elsevier AG-881 chemical structure Ltd. All rights reserved.”
“Objective: To compare the postural control of persons with a dysvascular transtibial amputation and traumatic transtibial amputation with able-bodied adults with and without a dysvascular condition in altered sensory testing conditions. Design: Cross-sectional study. Setting: University balance clinic. Participants: The study participants (N=35) included: participants with a dysvascular transtibial amputation (n=9), participants with a traumatic transtibial amputation (n=9), age-matched able-bodied adults without a dysvascular condition (n=9), and able-bodied adults with a dysvascular condition (n=8).

“
“Background Previous studies suggested that mechanical

intervention during early reperfusion, or ischemia postconditioning (IPo), could protect kidneys against renal ischemia reperfusion injury (RIRI). However, the mechanisms responsible for this protection remain unclear. This study therefore investigated the protection afforded by IPo in rat kidneys in vivo, and the roles of mitochondrial K(ATP) channels (mitoK(ATP)) and mitochondrial permeability transition pores (MPTPs), by inhibiting mitoK(ATP) with 5-hydroxydecanoate (5-HD), and by directly detecting open MPTPs using calcein-AM and CoCl(2).\n\nMethods Thirty-five male Sprague-Dawley rats were randomly assigned to sham-operation (S), ischemia-reperfusion (I/R), IPo, ischemia reperfusion with 5-HD (I/R+5-HD), or IPo with 5-HD (IPo +5-HD) groups. Rats in each group were Dibutyryl-cAMP molecular weight sacrificed after 6 hours of reperfusion by heart exsanguination or cervical dislocation under anesthesia. RIRI was assessed by determination of creatinine and blood urea nitrogen (BUN), and by examination of histologic sections. The roles of mitoK(ATP) and MPTP were investigated by analyzing fluorescence intensities of mitochondria, mitochondrial membrane potential, intracellular reactive oxygen species (ROS) and intracellular calcium, using

appropriate selleckchem fluorescent markers. The relationship between apoptosis and RIRI was assessed by determining the apoptotic index (Al) of kidney tubular epithelial cells.\n\nResults The RIRI model was shown to be successful. Significantly higher levels of creatinine and BUN, and abnormal pathology of histologic

sections, were observed in group I/R, compared with group S. 5-HD eliminated the renoprotective effects of IPo. Mitochondrial and mitochondrial membrane potential fluorescence intensities increased, and intracellular calcium, ROS fluorescence intensities and Al decreased in group IPo, compared with group I/R. However, mitochondrial and selleck products mitochondrial membrane potential fluorescence intensities decreased, and intracellular calcium and ROS fluorescence intensities and Al increased in group IPo+5-HD, compared with group IPo.\n\nConclusions mitoK(ATP) and MPTPs participated in IPo-induced renoprotective mechanisms in rat kidneys subjected to RIRI, possibly through decreased renal tubular epithelial cell apoptosis. Chin Med J 2011;124(14):2191-2195″
“In a continuous anaerobic-anoxic-aerobic (A(2)O) process treating domestic wastewater at ambient temperatures, nitritation was achieved through a combination of short aerobic actual hydraulic retention time (AHRT) and low dissolved oxygen (DO) levels (0.3-0.5 mg/L). The nitrite accumulation rate was about 90% and ammonia removal efficiency was over 95%. With respect to total nitrogen removal, nitritation-denitritation at low DO levels of 0.3-0.5 mg/L was essentially equal to the complete nitrification-denitrification at DO levels of 1.5-2.5 mg/L with the addition of external carbon sources.