TMEM158 functions as an oncogene and promotes lung adenocarcinoma progression through the PI3K/AKT pathway via interaction with TWIST1.

Lung adenocarcinoma (LUAD) is a common and deadly form of lung cancer, with high rates of metastasis and unsatisfactory clinical outcomes. Herein, we examined the influence of TMEM158 on the LUAD progression. A combination of bioinformatic analyses was used to assess the TMEM158 expression pattern, prognostic implications, and potential function in LUAD. The levels of TMEM158 and TWIST1 were evaluated in clinical samples from LUAD patients using Western blot analysis and qRT-PCR. To discover the function and underlying molecular pathways of TMEM158 in LUAD, we employed a combination of experimental approaches in vitro, such as flow cytometry analysis and colony formation, Co-IP, CCK-8, Transwell, and wound-healing assays. Elevated expression of TMEM158 in LUAD is associated with increased cancer aggressiveness and a poor prognosis. In vitro experiments demonstrated that high levels of TMEM158 promote cell proliferation, progression through the cell cycle, migration, and invasion while suppressing apoptosis. Knockdown of TMEM158 produced opposite effects. The underlying mechanism involves TMEM158 and TWIST1 directly interacting, stimulating the PI3K/AKT signaling pathway in LUAD cells. This investigation emphasizes the molecular functions of TMEM158 in LUAD progression and proposes targeting it as a promising treatment approach for managing LUAD.

Effect of Thermo- and pH-Sensitive Block Copolymer Structure and Composition on the Synthesis and Stabilization of Gold Nanoparticles.

Homopolymers of poly[N-(2-(diethylamino)ethyl) acrylamide] exhibit the ability to adsorb onto the surface of preformed or growing gold nanoparticles. The resulting hybrid materials possess a pH and thermo-sensitive nature. Consequently, their optical properties can be modulated by manipulating either the temperature or the pH. Moreover, introducing monomers based on poly(N-isopropyl acrylamide) into block or random statistical polymers enables further modulation of the thermosensitive properties. These copolymers, employed for the in-situ synthesis and/or stabilization of gold nanoparticles, lead to hybrid materials whose properties and/or particle size depend on the polymer composition and microstructure: statistical polymers emerge as superior stabilizing agents compared to their block counterparts at a constant composition.

tRF3-IleAAT reduced extracellular matrix synthesis in diabetic kidney disease mice by targeting ZNF281 and inhibiting ferroptosis.

It is well established that the synthesis of extracellular matrix (ECM) in mesangial cells is a major determinant of diabetic kidney disease (DKD). Elucidating the major players in ECM synthesis may be helpful to provide promising candidates for protecting against DKD progression. tRF3-IleAAT is a tRNA-derived fragment (tRF) produced by nucleases at tRNA-specific sites, which is differentially expressed in the sera of patients with diabetes mellitus and DKD. In this study we investigated the potential roles of tRFs in DKD. Db/db mice at 12 weeks were adapted as a DKD model. The mice displayed marked renal dysfunction accompanied by significantly reduced expression of tRF3-IleAAT and increased ferroptosis and ECM synthesis in the kidney tissues. The reduced expression of tRF3-IleAAT was also observed in high glucose-treated mouse glomerular mesangial cells. We administered ferrostatin-1 (1 mg/kg, once every two days, i.p.) to the mice from the age of 12 weeks for 8 weeks, and found that inhibition of the onset of ferroptosis significantly improved renal function, attenuated renal fibrosis and reduced collagen deposition. Overexpression of tRF3-IleAAT by a single injection of AAV carrying tRF3-IleAAT via caudal vein significantly inhibited ferroptosis and ECM synthesis in DKD model mice. Furthermore, we found that the expression of zinc finger protein 281 (ZNF281), a downstream target gene of tRF3-IleAAT, was significantly elevated in DKD models but negatively regulated by tRF3-IleAAT. In high glucose-treated mesangial cells, knockdown of ZNF281 exerted an inhibitory effect on ferroptosis and ECM synthesis. We demonstrated the targeted binding of tRF3-IleAAT to the 3'UTR of ZNF281. In conclusion, tRF3-IleAAT inhibits ferroptosis by targeting ZNF281, resulting in the mitigation of ECM synthesis in DKD models, suggesting that tRF3-IleAAT may be an attractive therapeutic target for DKD.

Independent Monte Carlo dose calculation identifies single isocenter multi-target radiosurgery targets most likely to fail pre-treatment measurement.

PURPOSE: For individual targets of single isocenter multi-target (SIMT) Stereotactic radiosurgery (SRS), we assess dose difference between the treatment planning system (TPS) and independent Monte Carlo (MC), and demonstrate persistence into the pre-treatment Quality Assurance (QA) measurement. METHODS: Treatment plans from 31 SIMT SRS patients were recalculated in a series of scenarios designed to investigate sources of discrepancy between TPS and independent MC. Targets with > 5% discrepancy in DMean[Gy] after progressing through all scenarios were measured with SRS MapCHECK. A matched pair analysis was performed comparing SRS MapCHECK results for these targets with matched targets having similar characteristics (volume & distance from isocenter) but no such MC dose discrepancy. RESULTS: Of 217 targets analyzed, individual target mean dose (DMean[Gy]) fell outside a 5% threshold for 28 and 24 targets before and after removing tissue heterogeneity effects, respectively, while only 5 exceeded the threshold after removing effect of patient geometry (via calculation on StereoPHAN geometry). Significant factors affecting agreement between the TPS and MC included target distance from isocenter (0.83% decrease in DMean[Gy] per 2 cm), volume (0.15% increase per cc), and degree of plan modulation (0.37% increase per 0.01 increase in modulation complexity score). SRS MapCHECK measurement had better agreement with MC than with TPS (2%/1 mm / 10% threshold gamma pass rate (GPR) = 99.4 ± 1.9% vs. 93.1 ± 13.9%, respectively). In the matched pair analysis, targets exceeding 5% for MC versus TPS also had larger discrepancies between TPS and measurement with no GPR (2%/1 mm / 10% threshold) exceeding 90% (71.5% ± 16.1%); whereas GPR was high for matched targets with no such MC versus TPS difference (96.5% ± 3.3%, p = 0.01). CONCLUSIONS: Independent MC complements pre-treatment QA measurement for SIMT SRS by identifying problematic individual targets prior to pre-treatment measurement, thus enabling plan modifications earlier in the planning process and guiding selection of targets for pre-treatment QA measurement.

[Microtubule-associated tumor suppressor 1 inhibits hemin-induced apoptosis of vascular endothelial cells via hemeoxygenase 1].

This study aimed to investigate the effects of microtubule associated tumor suppressor 1 (MTUS1) on hemeoxygenase 1 (HMOX1) expression and hemin-induced apoptosis of vascular endothelial cells and its regulatory mechanism. RNA sequencing, RT-qPCR and Western blot were used to assess altered genes of hemin binding proteins, the expression of cAMP response element-binding protein (CREB) and nuclear respiratory factor 2 (NRF2), hemin-induced HMOX1 expression in MTUS1 knockdown human umbilical vein endothelial cells (HUVEC), and the effect of overexpression of CREB and NRF2 on HMOX1 expression in MTUS1 knockdown 293T cells. The effect of MTUS1 or HMOX1 knockdown on hemin-induced apoptosis in HUVEC, and the overexpression of NRF2 on hemin-induced apoptosis in MTUS1 knockdown 293T cells were assayed with CCK8 and Western blot. The results showed that MTUS1 was knocked down significantly in HUVEC by siRNA (P < 0.01), accompanied by decreased HMOX1 expression (P < 0.01). The increased HMOX1 expression induced by hemin was also inhibited by MTUS1 knockdown (P < 0.01). And the apoptosis of HUVEC induced by hemin was amplified by MTUS1 or HMOX1 knockdown (P < 0.01). Moreover the expression of CREB and NRF2 were both inhibited by MTUS1 knockdown in HUVEC (P < 0.01). The decreased HMOX1 regulated by MTUS1 knockdown could be rescued partly by overexpression of NRF2 (P < 0.01), however, not by overexpression of CREB. And the MTUS1 knockdown mediated decreased 293T cells viability induced by hemin could be partly rescued by NRF2 overexpression (P < 0.01). These results suggest that MTUS1 can inhibit hemin-induced apoptosis of HUVEC, and the mechanism maybe related to MTUS1/NRF2/HMOX1 pathway.

P450-Modified Ribosomally Synthesized Peptides with Aromatic Cross-Links.

Cyclization of linear peptides is an effective strategy to convert flexible molecules into rigid compounds, which is of great significance for enhancing the peptide stability and bioactivity. Despite significant advances in the past few decades, Nature and chemists' ability to macrocyclize linear peptides is still quite limited. P450 enzymes have been reported to catalyze macrocyclization of peptides through cross-linkers between aromatic amino acids with only three examples. Herein, we developed an efficient workflow for the identification of P450-modified RiPPs in bacterial genomes, resulting in the discovery of a large number of P450-modified RiPP gene clusters. Combined with subsequent expression and structural characterization of the products, we have identified 11 novel P450-modified RiPPs with different cross-linking patterns from four distinct classes. Our results greatly expand the structural diversity of P450-modified RiPPs and provide new insights and enzymatic tools for the production of cyclic peptides.

Fluorescence sensing and glycosidase inhibition effect of multivalent glycosidase inhibitors based on Naphthalimide-deoxynojirimycin conjugates.

Synthetic glycoconjugates as chemical probes have been widely developed for the detection of glycosidase enzymes. However, the binding interactions between iminosugar derivatives and glycosidases were limited, especially for the binding interactions between multivalent glycosidase inhibitors and α-glycosidases. In this paper, three naphthalimide-DNJ conjugates were synthesized. Furthermore, the binding interactions and glycosidase inhibition effects of them were investigated. It was found that the strong binding interactions of multivalent glycosidase inhibitors with enzymes were related to the efficient inhibitory activity against glycosidase. Moreover, the lengths of the chain between DNJ moieties and the triazole ring for the naphthalimide-DNJ conjugates influenced the self-assembly properties, binding interactions and glycosidase inhibition activities with multisource glycosidases. Compound 13 with six carbons between the DNJ moiety and triazole ring showed the stronger binding interactions and better glycosidase inhibition activities against α-mannosidase (jack bean) and α-glucosidase (aspergillus niger). In addition, compound 13 showed an effective PBG inhibition effect in mice with 51.18 % decrease in blood glucose at 30 min. This result opens a way for detection of multivalent glycosidase inhibition effect by a fluorescent sensing method.

Comparable long-term survival outcomes of endoscopic therapy versus surgical therapy for T1-2N0M0 duodenal neuroendocrine tumors.

BACKGROUND AND STUDY AIMS: The optimal treatment modality for T1-2N0M0 duodenal neuroendocrine tumors (DNETs) is still controversial. In this study, long-term survival outcomes were compared between the endoscopic therapy and surgical therapy for T1-2N0M0 DNETs using the Surveillance, Epidemiology, and End Results (SEER) database. PATIENTS AND METHODS: Patients with DNETs from the SEER database were selected from 2004 to 2015. We used the Kaplan-Meier method and log-rank test to compare long-term survival results between the endoscopic therapy and surgical therapy. An analysis of the multivariable Cox proportional hazards model was performed to identify risk factors for patient prognoses. The 1:1 propensity score matching (PSM) was performed to balance baseline data. RESULTS: A total of 816 patients with DNETs were included, of which 578 patients (70.8%) received endoscopic therapy and 238 patients (29.2%) received surgical therapy. Before the PSM, there was no difference between the two groups of patients with DNETs on long-term survival [5-year OS (86.1% vs. 87.9%, P = 0.45), 10-year OS (72.5% vs. 72.3%, P = 0.45)]. After adjusting covariates, we found endoscopic therapy and surgical therapy groups had comparable risks of overall survival (HR 0.86, 95% CI 0.60-1.23, P = 0.409) and cancer-specific survival (HR 1.68, 95% CI 0.74-3.83, P = 0.214). In the post-PSM analysis, there was no discernible difference between the endoscopic therapy and surgical therapy group. CONCLUSIONS: Our study found that for T1-2N0M0 DNETs patients, whose long-term OS and CSS results were similar for the endoscopic and surgical therapy groups. For these patients, endoscopic resection might be an optimal therapy modality.

Focus on Radiation Protection Improves Both Correct Behavior and Procedural Performance During Simulation-Based Training - A Randomized Comparison.

BACKGROUND: To explore whether simulation-based endovascular training with focus on radiation safety could improve correct behavior without jeopardizing the learning of procedural skills. METHODS: Twenty-four residents without previous endovascular experience completed 10 clinical scenarios on a virtual-reality endovascular simulator with software for peripheral endovascular interventions. Participants were randomized to receive feedback (n = 12) or not (n = 12) on radiation protection (RP) performance after each case. Expert assessments were done at the first, second, fourth, seventh, and 10th case on RP and endovascular skills (ES). Automatic simulator metrics on procedure time, contrast dose, handling errors, and estimated radiation exposure to patient and operator were registered. Outcome metrics were analyzed by two-way mixed analysis of variance pairwise comparisons with independent t-tests. Correlations were explored using Pearson's r for internal consistency reliability. RESULTS: The RP performance was similar in both groups at their first attempt (P = 0.61), but the feedback group significantly outperformed the control group over time (P < 0.001 for all comparisons). The feedback group was however slower to learn the ES at start (P = 0.047 at second performance), but after 7 attempts no difference was shown (P = 0.59). The feedback group used more time (19.5 vs. 15.3 min; P = 0.007) but less contrast (60 vs. 100 mL; P < 0.001). The number of errors was the same in both groups, but all metrics regarding radiation exposure favored the feedback group (P-values from 0.001 to 0.008). CONCLUSIONS: Simulation-based training (SBT) is effective to acquire basic endovascular intervention skills and concurrently learn RP behavior when feedback on radiation culture is provided.

Risk assessment of honeybee larvae exposure to pyrethroid insecticides in beebread and honey.

Honeybee is an essential pollinator to crops, evaluation to the risk assessment of honeybee larvae exposure to pesticides residue in the bee bread and honey is an important strategy to protect the bee colony due to the mixture of these two matrices is main food for 3-day-old honeybee larvae. In this study, a continuous survey to the residue of five pyrethroid insecticides in bee bread and honey between 2018 and 2020 from 17 major cultivation provinces which can be determined as Northeast, Northwest, Eastern, Central, Southwest, and Southern of China, there was at least one type II pyrethroid insecticide was detected in 54.7 % of the bee bread samples and 43.4 % of the honey. Then, we assayed the acute toxicity of type II pyrethroid insecticides based on the detection results, the LD50 value was 0.2201 µg/larva (beta-cyhalothrin), 0.4507 µg/larva (bifenthrin), 2.0840 µg/larva (fenvalerate), 0.0530 µg/larva (deltamethrin), and 0.1640 µg/larva (beta-cypermethrin), respectively. Finally, the hazard quotient was calculated as larval oral ranged from 0.046 × 10-3 to 2.128 × 10-3. Together, these empirical findings provide further insight into the accurate contamination of honey bee colonies caused by chemical pesticides, which can be used as a valuable guidance for the beekeeping industry and pesticide regulation.

A Joint Acoustic Emission Source Localization Method for Composite Materials.

Damage localization methods for composite materials are a popular research topic at present. The time-difference-blind localization method and beamforming localization method are often individually utilized in the localization of the acoustic emission sources of composite materials. Based on the performances of the two methods, a joint localization method for the acoustic emission sources of composite materials is proposed in this paper. Firstly, the performance of the time-difference-blind localization method and the beamforming localization method were analyzed. Then, with the advantages and disadvantages of these two methods in mind, a joint localization method was proposed. Finally, the performance of the joint localization method was verified using simulations and experiments. The results show that the joint localization method can reduce the localization time by half compared with the beamforming localization method. At the same time, compared with the time-difference-blind localization method, the localization accuracy can be improved.

Performance evaluation of rural water environment governance based on AHP: a case study of the Beitang River Basin.

Rural water environment governance in China still lacks a systematic and comprehensive assessment protocol to help analyze and improve such governance performance. The Analytic Hierarchy Process (AHP) method was employed in this study to build a governance assessment system that integrates ecological conditions, water pollution control, and public satisfaction. To cover these topics, the assessment system is composed of an indicator layer that is customized to rural water environment governance in China. The Beitang River, located in the rural region of Hangzhou, Zhejiang, China, was presented as a case study. Field investigation provided raw data for this assessment. A questionnaire survey was conducted to interview local residents on the governance performance. An additional survey with executives who played major roles in the governance was performed to reconstruct a water environment assessment on the Beitang River prior to the governance, in order to highlight the effects of the governance through contrast. The results showed consistency in the questionnaire survey and the assessment system. The AHP assessment system was able to reflect the improvement in the water quality, river ecology, and residential welfare after the governance, and suggested limits and future directions in the following upgrade programs for the river basin.

Study on the treatment of corn alcohol wastewater by the internal circulation anaerobic reactor.

To comprehensively assess the efficacy of employing the internal circulation (IC) anaerobic reactor for corn alcohol wastewater treatment and investigate its feasibility, this study focused on anaerobic digestion parameters, energy balance, and the composition of the prokaryotic microbial community. During the operation of the reactor, the hydraulic retention time was progressively reduced from 4.8 to 1.6 days while achieving an average organic loading rate of 12.46 kg chemical oxygen demand (COD)/(m3·d). Moreover, the removal rate of COD exceeded 98%, and the energy balance (ΔE) reached 10.29 kJ/g fed COD. The initial manifestation of organic acidosis in the reactor was a decline in gas production, which is primarily caused by propionic acid accumulation. The subsequent analysis revealed a high diversity of prokaryotes in granular sludge, with the predominant archaea primarily involved in methane production through the acetic acid pathway. The IC anaerobic reactor shows exceptional performance in treating corn alcohol wastewater by optimizing its operating conditions. Energy balance analysis confirmed the feasibility of the process. The findings of this study may offer valuable insights for optimizing control strategies and engineering applications.

100 Gb/s NRZ OOK signal regeneration using four-wave mixing in a silicon waveguide with reverse-biased p-i-n junction.

A silicon waveguide with reverse-biased p-i-n junction is used to experimentally demonstrate all-optical regeneration of non-return-to-zero (NRZ) on-off keying (OOK) signal based on four-wave mixing. The silicon waveguide allows a high conversion efficiency of -12 dB. The 0.22 dB (1.1 dB) quality (Q) factor and 0.74 dB (6.3 dB) extinction ratio (ER) improvements on average are achieved for 100 Gb/s (50 Gb/s) NRZ OOK signal regeneration at different receiving powers via the optimal match between the input signal optical power and input-output transfer curve. To the best of our knowledge, this silicon-based all-optical regenerator exhibits superior regeneration performance, including large ER and Q factor improvements, and the highest regeneration speed of NRZ OOK signal, and it has wide applications in 5 G/6 G networks.

Surface Modification of TiO2 Nanotubes Prepared by Porous Titanium Anodization via Hydrothermal Reaction: A Method for Synthesis High-Efficiency Adsorbents of Recovering Sr Ions.

The recycling of strontium ions (Sr2+) from sea water has been well known for its good cost-effectiveness and environment friendliness. Herein, we modified the surface of TiO2 nanotubes (TNTs) prepared by porous titanium anodization via hydrothermal (HT) reaction and synthesized a highly efficient adsorbent for the repeated recycling of Sr2+. TNTs with a high specific surface area were manufactured on porous titanium by internal anodic oxidation. The as-prepared TNTs were treated by HT method to synthesize adsorption materials with a tubular bottom and grass-type top structure loaded with Na+. The surface cracks were eliminated by annealing pretreatment, and the investigation found that the 6 h HT reaction most effectively increased the Na+ content in the adsorbent. The as-synthesized adsorbents (HT-6TNTs) were used to recover Sr2+, and the maximum adsorption efficiency (approximately 100%) and adsorption equilibrium were observed within 10 h. Meanwhile, three consecutive cycles of adsorption experiments proved the uniform behavior of the HT-6TNTs in the reproducible recycling of Sr2+. In addition, by increasing the anodization time of TNTs from 0.5 to 3 h, the maximum adsorption capacity can be increased from 4.68 to 36.15 mg·unit-1, approximately 7.7 times higher.

Screening high-risk population of persistent postpartum hypertension in women with preeclampsia using latent class cluster analysis.

BACKGROUND: A significant proportion of women with preeclampsia (PE) exhibit persistent postpartum hypertension (PHTN) at 3 months postpartum associated with cardiovascular morbidity. This study aimed to screen patients with PE to identify the high-risk population with persistent PHTN. METHODS: This retrospective cohort study enrolled 1,000 PE patients with complete parturient and postpartum blood pressure (BP) profiles at 3 months postpartum. The enrolled patients exhibited new-onset hypertension after 20 weeks of pregnancy, while those with PE superimposed upon chronic hypertension were excluded. Latent class cluster analysis (LCCA), a method of unsupervised learning in machine learning, was performed to ascertain maternal exposure clusters from eight variables and 35 subordinate risk factors. Logistic regression was applied to calculate odds ratios (OR) indicating the association between clusters and PHTN. RESULTS: The 1,000 participants were classified into three exposure clusters (subpopulations with similar characteristics) according to persistent PHTN development: high-risk cluster (31.2%), medium-risk cluster (36.8%), and low-risk cluster (32.0%). Among the 1,000 PE patients, a total of 134 (13.4%) were diagnosed with persistent PHTN, while the percentages of persistent PHTN were24.68%, 10.05%, and 6.25% in the high-, medium-, and low-risk clusters, respectively. Persistent PHTN in the high-risk cluster was nearly five times higher (OR, 4.915; 95% confidence interval (CI), 2.92-8.27) and three times (OR, 2.931; 95% CI, 1.91-4.49) than in the low- and medium-risk clusters, respectively. Persistent PHTN did not differ between the medium- and low-risk clusters. Subjects in the high-risk cluster were older and showed higher BP, poorer prenatal organ function, more adverse pregnancy events, and greater medication requirement than the other two groups. CONCLUSION: Patients with PE can be classified into high-, medium-, and low-risk clusters according to persistent PHTN severity; each cluster has cognizable clinical features. This study's findings stress the importance of controlling persistent PHTN to prevent future cardiovascular disease.

Gas-particle partitioning of polycyclic aromatic hydrocarbons from oil combustion involving condensate, diesel and heavy oil.

This study focuses on the gas-particle (G-P) partitioning of 16 polycyclic aromatic hydrocarbons (PAHs) from oil combustion, which is one of the important contributors of anthropogenic PAHs but has been rarely studied. The combustions of different types of oils involving ultra-light to heavy oils were investigated, and the PAH partitioning mechanism was determined by the widely used Junge-Pankow adsorption model, Koa absorption model, and dual sorption model, respectively. The results show that the source-specific diagnostic ratios of Ant/(Ant+Phe) are between 0.09 and 0.24, the estimated regression slopes of G-P partition coefficients (KP) of the total PAHs on their sub-cooled liquid vapor pressures (PLO) are in the range of - 0.34 to - 0.25, and the predicted fractions of PAHs in the particle phase (φ) by Koa absorption model are close to the measured values, while the log KPvalues of the LMW PAHs from the combustions of diesel and heavy oil are better represented by the dual sorption model. Our findings indicate that PAHs are derived from mixed sources that include the unburned original oil and combustion products, and the PAH partitioning mechanism is governed by the process of absorption into organic matter because of the unburned oil, but both adsorption and absorption exist simultaneously in the lighter PAHs from the combustions of heavier oils (i.e., diesel and heavy oil). Based on these findings, the understanding of the fate and transport of PAH emissions and the optimization of the emergency responses to accidents such as marine oil spills would be potentially improved.

A comparative study of death metaphors in Han and Tibetan ethnic groups.

We compared 385 Han participants and 302 Tibetan participants' death metaphors and investigated the associations between death metaphors and death attitudes. The results show that the death metaphor "Separation from loved ones" was the most common among both groups. Both groups scored highest in the Empty death metaphor subscale. Ethnicity had a significant effect on the Empty subscale and age had a significant effect on the Sorrowful death metaphor subscale. Death metaphor is significantly positively correlated with approaching acceptance and escape acceptance attitudes to death. Our comprehensive exploration of death metaphors enables a better understanding the Chinese concept of death.

A comparative study of death anxiety and death attitudes in Han and Tibetan ethnic groups.

This study compared the responses of 380 Han and 315 Tibetan respondents regarding their attitudes about death and factors influencing those attitudes using the Death Anxiety Scale and Death Attitude Profile-Revised. The results show that Tibetan respondents expressed more death anxiety, fear of death, death avoidance, and escape acceptance than the Han participants, while Han participants showed more neutral acceptance than the Tibetan participants. There was a significant interaction between age and gender around Approaching Death. In addition, the death attitudes of Han and Tibetan participants were influenced by religious beliefs, funeral experiences, and the way their families talked about death.

Influence of additional methanol on both pre- and post-denitrification processes in treating municipal wastewater.

Changes in functional properties of biological denitrification in the long-term use of methanol were explored in both pre- and post-denitrification processes. The two systems employed were sequencing batch reactor (SBR) using post-denitrification in temporal sequence, and Carrousel oxidation ditch, which was equipped with a separate pre-denitrification zone. In the SBR, stable nitrate reduction rates reached after 37 days elapsed with addition of methanol (TOC/N = 1.4-1.8) at the start of anoxic phase, and specific denitrification rate increased from 0.378 mgNOx-N·(gVSS·h)-1 to 2.406 mgNOx-N·(gVSS·h)-1. Besides, by means of nitrogen uptake rate (NUR) batch tests based on methanol-adapted sludge, the appropriate range of TOC/N ratios for complete denitrification was estimated to be 1.10-2.68. By comparison, the Carrousel oxidation ditch that was fed with methanol in the anaerobic zone took fewer days (29 days) to obtain a constant effluent nitrate. Moreover, the denitrification yield in ditch was elevated from an initial value of 0.082 mgTN/mgCOD to 0.123 mgTN/mgCOD, and the nitrogen removal efficiency reached up to a level of 68%. The focus on denitrification potential with external methanol is valuable to provide information for developing carbon dosage control, as well as predict the nitrate effluent quality of the plant.