Drug repurposing for COVID-19: could vitamin C combined with glycyrrhizic acid be at play by the findings of Li et al.'s database-based network pharmacology analysis?

The outbreak and pandemic of SARS-CoV-2 in 2019 has caused a severe public health burden and will challenge global health for the future. The discovery and mechanistic investigation of drugs against Coronavirus disease 2019 (COVID-19) is in deadly demand. The paper published by Li and colleagues proposed the hypothesis that vitamin C combined with glycyrrhizic acid in treating COVID-19 and its mechanistic investigation was performed by a database-based network pharmacology. In this letter, we present critical comments on the limitations and insufficiencies involved, from both the perspective of network pharmacology and current evidence on COVID-19.

The relationship between activity level and cognitive function in Chinese community-dwelling elderly.

To study the relationship between daily activity level and cognitive function in community-dwelling elderly. We collected demographic features, cognitive function, activity level and self-rating depression scale scores in 53 community-dwelling olderly aged 60 years or above. The activity level and moderate-to-vigorous physical activity (MVPA) time were assessed by using the accelerometer for 7 consecutive days. We compared activity level, MVPA time and depression scores between cognitive impaired and normal groups. Cognitive functions were compared in groups with different MVPA level, and the correlation between cognitive function and MVPA time was analysed. Of the 53 subjects, 27 had varying degrees of cognitive impairment. Individuals with cognitive impairment shown significantly shorter MVPA time and higher depression score compared to the cognitive normal group (P < 0.05). After controlling for confounding factors (age, BMI), MVPA time was associated with cognitive function (r = 0.358, P = 0.009). The memory factor score correlated with MVPA time (r = 0.357, P = 0.012) and mean activity level (r = 0.287, P = 0.046). Moderate-to-vigorous physical activity in the elderly was positively related to their cognitive function. Strengthening daily activities may beneficial for the elderly to maintain better cognitive function.

Quantitative evaluation of Danqi tablet by ultra-performance liquid chromatography coupled with triple quadrupole mass spectrometry integrated with bioassay.

Danqi tablet composed of the dried roots of Salvia miltiorrhiza and Panax notoginseng is a well-known Chinese patent medicine commonly used for the treatment of cardio-cerebrovascular diseases such as coronary heart disease and myocardial ischemia. Numerous chemical constituents belonging to S. miltiorrhiza and P. notoginseng were detectable in Danqi tablet. Here, we established and validated a rapid and sensitive ultra-performance liquid chromatography coupled with triple quadrupole mass spectrometry method for simultaneous quantification of 23 components in Danqi tablet and then successfully applied to assay 12 batches of samples from ten manufacturers. Our results demonstrated that the contents of 23 components in 12 batches of Danqi tablets varied significantly and their quality indeed existed differently based on the principal component analysis. According to the quantitative data and the loading plot of principal component analysis, five abundant compounds in Danqi tablet were selected as characteristic chemical markers possibly responsible for the quality assessment. Among them, salvianolic acid B and ginsenoside Rg1 were further chosen to be combined at 2:5 ratio to evaluate the anti-thrombotic activity on phenylhydrazine-induced zebrafish heart thrombosis model. Expectedly, this component combination increased the heart red blood cells intensity compared with the model group and the median effective concentration was 123.4 µg/mL, suggestive of its well anti-thrombotic effect. This study contributed to the quantitative evaluation of Danqi tablet and indicated the combination of salvianolic acid B and ginsenoside Rg1 may be capable of reflecting the effect of Danqi tablet, thereby providing a reference for further investigations on the improvement of quality control and clinical application of Danqi tablet.

[Research progress on processing history evolution as well as effect on chemical compositions and traditional pharmacological effects of Rhei Radix et Rhizoma].

Rhei Radix et Rhizoma(RRR) is a commonly used traditional Chinese medicine, with extensive pharmacological effects and clinical applications. This paper summarized processing history evolution of RRR and its effect on chemical compositions and pharmacological effects, and provided feasible insights for further studies on the chemical compositions and pharmacological effects of RRR before and after processing. Relevant information demonstrated that RRR has a long history of processing and various methods. At pre-sent, Chinese Pharmacopoeia mainly records four processing methods: cleaning(raw RRR), wine processing(RRR stir-fried with wine), steaming processing(RRR wine steaming), fried charcoal(RRR charring). RRR has a good effect in clearing heat effect, hemostatic effect and blood promoting effect, and its main chemical components are anthraquinone/anthrones, stilbene, phenylbutanone, chromogens, flavonoids and tannin compounds. This paper reviewed the history evolution of RRR and its effect on chemical composition and pharmacological changes, and put forward further study ideas, with the aim to provide a basic reference for processing mechanism, effective material basis and clinical application of RRR.

Gut microbiota modulation with traditional Chinese medicine: A system biology-driven approach.

With the development of system biology, traditional Chinese medicine (TCM) is drawing more and more attention nowadays. However, there are still many enigmas behind this ancient medical system because of the arcane theory and complex mechanism of actions. In recent decades, advancements in genome sequencing technologies, bioinformatics and culturomics have led to the groundbreaking characterization of the gut microbiota, a 'forgotten organ', and its role in host health and disease. Notably, gut microbiota has been emerging as a new avenue to understanding TCM. In this review, we will focus on the structure, composition, functionality and metabolites of gut microbiota affected by TCM so as to conversely understand its theory and mechanisms. We will also discuss the potential areas of gut microbiota for exploring Chinese material medica waste, Chinese marine material medica, add-on therapy and personalized precise medication of TCM. The review will conclude with future perspectives and challenges of gut microbiota in TCM intervention.

Scanning Tunneling Microscopy of the π Magnetism of a Single Carbon Vacancy in Graphene.

Pristine graphene is strongly diamagnetic. However, graphene with single carbon atom defects could exhibit paramagnetism. Theoretically, the π magnetism induced by the monovacancy in graphene is characteristic of two spin-split density-of-states (DOS) peaks close to the Dirac point. Since its prediction, many experiments have attempted to study this π magnetism in graphene, whereas only a notable resonance peak has been observed around the atomic defects, leaving the π magnetism experimentally elusive. Here, we report direct experimental evidence of π magnetism by using a scanning tunneling microscope. We demonstrate that the localized state of the atomic defects is split into two DOS peaks with energy separations of several tens of meV. Strong magnetic fields further increase the energy separations of the two spin-polarized peaks and lead to a Zeeman-like splitting. Unexpectedly, the effective g factor around the atomic defect is measured to be about 40, which is about 20 times larger than the g factor for electron spins.

[Filtration of active fractions with function of expelling water retention with drastic purgative from Kansui Radix stir-baked with vinegar].

To study the function of expelling water retention with drastic purgative of different polarities of Kansui Radix stir-baked with vinegar on the cancerous ascites model rats, the furosemide was taken as positive control drug, and the cancerous ascites model rats were respectively orally administered with different polarities of Kansui Radix stir-baked with vinegar for 7 d. The amount of urine and ascites, the level of urinary sodium, potassium, chloride ion and pH, and the content of PRL1, AII, ALD in serum were investigated. Compared with model groups, ethyl acetate extract group showed a decreasing trend in ascites; the amount of urine of showed a significant increase (P < 0.05); the level of urinary sodium, potassium, chloride ion (P < 0.05, P < 0.01), pH (P < 0.05), and the content of PRL1, AII, ALD in serum all showed a significant decrease (P < 0.01). The effects of petroleum ether extract and n-butanol extract were weaker than that of ethyl acetate extract. The water exact was the weakest. The results showed that ethyl acetate extract is the active part of Kansui Radix stir-baked with vinegar on the function of expelling water retention with drastic purgative on the cancerous ascites model rats, alleviating the water-electrolyte disorder and body fluid acid-base imbalance, regulating the renin angiotensin aldosterone system.

[Study on toxicity of vinegar-processed Kansui Radix on basis of symptom-based prescription theory].

OBJECTIVE: To study the differences in the toxicity of vinegar-processed Kansui Radix on normal and cancerous ascites model rats. METHOD: Normal and cancerous ascites model rats were taken as the research objects and orally administered with different doses of vinegar-processed Kansui Radix for 7 d. Pathological sections were prepared to observe the damages in liver, stomach, intestinal tissues in rats and detect the impacts on serum, liver, stomach and intestinal tissues and the oxidative damage index. RESULT: Compared with the blank group, all of normal administration groups and model groups showed significant damages in liver, stomach and intestinal tissues. Compared with the model groups, all of normal administration groups revealed notable alleviation in damages. Compared with the blank group, the model groups showed significant increases in AST, ALT and MDA in serum and liver (P < 0.01) and a significant decrease in GSH in serum and liver, stomach, intestinal tissues (P < 0.01). Compared with the blank group, the results showed significant decreases in ALT, AST in serum and ALT in liver in model low, medium and high dose groups and AST activity in liver tissues in the normal high dose group (P < 0.05, P < 0.01); significant decreases in GSH in serum and stomach tissues in normal low, medium and high dose groups and GSH content in liver and intestinal tissues in normal medium and high dose groups (P < 0.05, P < 0.01); notable rises in MDA in liver tissues in normal low, medium and high dose groups and MDA content in serum and stomach and intestinal tissues in normal medium and high dose groups (P < 0.05, P < 0.01). Compared with model groups, data revealed significant decreases in ALT, AST in serum in model low, medium and high dose groups, AST in liver tissues of model medium and high dose groups and ALT activity in liver in the model high dose group (P < 0.05, P < 0.01); significant increases in GSH content in serum and stomach tissues of model low, medium and high dose groups, GSH in liver tissues in model medium and high dose groups and GSH in intestinal tissues in the high dose groups (P < 0.05, P < 0.01); and notable declines in MDA content in serum in model low, medium and high dose groups, MDA in liver tissues of model medium and high dose groups and MDA in stomach and intestinal tissues the high dose group (P < 0.05, P < 0.01). CONCLUSION: According to the study, vinegar-processed Kansui Radix showed a significant lower toxicity liver, stomach, and intestines of cancerous ascites model rats, which provided a basis for clinical safe application of vinegar-processed Kansui Radix based on symptom-based prescription theory.

Exploring the effective compounds and potential mechanisms of Shengxian Decoction against coronary heart disease by UPLC-Q-TOF/MS and network pharmacology analysis.

As a well-known classical Chinese medicine prescription, Shengxian Decoction (SXD) has been applied for a century to treat cardiovascular diseases, especially coronary heart disease (CHD), but the potentially effective compounds and underlying mechanisms remain unclear. With ultra-performance liquid chromatography-quadrupole-time of flight-mass spectrometry (UPLC-Q-TOF/MS) and network pharmacology analysis, the potential effective compounds of SXD and their pharmacological mechanisms against CHD were identified and revealed. 57 effective compounds with favorable pharmacokinetic characteristics and biological activities were screened through UPLC-Q-TOF/MS analysis, database and literature mining, interacting with 96 CHD-related targets to support potential synergistic therapeutic actions. Systematic analysis of the PPI network and microarray data further revealed six core targets, including TNF, IL-1ß, IL-6, TP53, VEGFA and PTGS2, which were mainly involved in fluid shear stress and atherosclerosis, lipid and atherosclerosis, PI3K-Akt signaling pathway et al. Moreover, the proposed contribution indexes of effective compounds indicated these compounds, including isoferulic acid, quercetin, calycosin, ferulic acid, kaempferol, calycosin 7-O-glycoside, formononetin, astragaloside IV and saikosaponin D, as the core compounds of SXD. The molecular docking results confirmed that those core compound-target pairs exhibited strong binding energy. Furthermore, we validated that SXD significantly alleviated myocardial tissue injury in CHD rats and reversed H/R-induced decreases in H9c2 cell viability by attenuating the production of TNF, IL-6 and IL-1ß, and reducing cardiomyocyte apoptosis via down-regulating the TP53, caspase3 and cytochrome C mRNA expression levels as well as caspase3, caspase9 and cytochrome C protein expression levels according to RT-qPCR and Western blot results. Our findings explained the pharmacological mechanisms underlying the effectiveness of SXD in the treatment of CHD, and laid a foundation for future basic and clinical research of SXD.

The identification of metabolites from gut microbiota in coronary heart disease via network pharmacology.

Although the gut microbial metabolites exhibit potential effects on coronary heart disease (CHD), the underlying mechanism remains unclear. In this study, the active gut microbial metabolites acting on CHD and their potential mechanisms of action were explored through a network pharmacological approach. We collected a total of 208 metabolites from the gutMgene database and 726 overlapping targets from the similarity ensemble approach (SEA) and SwissTargetPrediction (STP) database, and ultimately identified 610 targets relevant to CHD. In conjunction with the gutMGene database, we identified 12 key targets. The targets of exogenous substances were removed, and 10 core targets involved in CHD were eventually retained. The microbiota-metabolites-targets-signalling pathways network analysis revealed that C-type lectin receptor signalling pathway, Lachnospiraceae, Escherichia, mitogen-activated protein kinase 1, prostaglandin-endoperoxidase synthase 2, phenylacetylglutamine and alcoholic acid are notable components of CHD and play important roles in the development of CHD. The results of molecular docking experiments demonstrated that AKT1-glycocholic acid and PTGS2-phenylacetylglutamine complexes may act on C-type lectin receptor signalling pathways. In this study, the key substances and potential mechanisms of gut microbial metabolites were analysed via network pharmacological methods, and a scientific basis and comprehensive idea were provided for the effects of gut microbial metabolites on CHD.

CST1 promotes the proliferation and migration of PDGF-BB-treated airway smooth muscle cells via the PI3K/AKT signaling pathway.

Typically, airway remodeling caused by migration and proliferation of airway smooth muscle cells (ASMCs) plays a crucial role in the pathophysiological characteristics of asthma development. Cystatin 1 (CST1), a protein-coding gene referred to as Cystatin SN, is highly expressed in asthma patients. However, the role of CST1 and related molecular mechanisms in the development of asthma remains to be explored. This study aims to investigate the role of CST1 in asthma progression and present related molecular mechanisms. To explore these aspects, human ASMCs with platelet-derived growth factor BB (PDGF-BB) are initially stimulated and applied as a cellular model of asthma. Further, CST1 is knocked down with small interfering ribose nucleic acid (siRNA) overexpressed with plasmids. Then, 5-ethynyl-2'-deoxyuridine (EdU) and Cell Count Kit (CCK)-8 assays are applied to assess the cell proliferation rates. Further, Transwell and Western blot analyses for migration of cells and expression of MMP1 and MMP9 proteins are assessed, respectively. Under PDGF-BB stimulation, human ASMCs showed an increased CST1 expression, enhanced proliferation, and migration abilities, as well as up-regulated PI3K/AKT signaling pathway. Further, knockdown or overexpression of CST1 presented the declined or enhanced proliferation, migration, and up-regulation of the PI3K/AKT signaling pathway of human ASMCs. Inhibiting PI3K/AKT signaling pathway displayed the reduced migration and proliferation of human ASMCs. In summary, these findings indicated that CST1 played an essential role in the progression of asthma by activating the PI3K/AKT signaling pathway and promoting the migration and proliferation abilities of human ASMCs treated with PDGF-BB.

Anti-obesity and Gut Microbiota Modulation Effect of Astragalus Polysaccharides Combined with Berberine on High-Fat Diet-Fed Obese Mice.

OBJECTIVE: To investigate whether astragalus polysaccharides (APS) combined with berberine (BBR) can reduce high-fat diet (HFD)-induced obesity in mice. METHODS: Except for normal mice, 32 HFD-induced obese mice were randomized into HFD, APS (1,000 mg/kg APS), BBR (200 mg/kg BBR), and APS plus BBR (1,000 mg/kg APS plus 200 mg/kg BBR) groups, respectively. After 6-week treatment (once daily by gavage), the obesity phenotype and pharmacodynamic effects were evaluated by histopathological examination of epididymal fat, liver, and colon using hematoxylin-eosin staining and serum biochemical analyses by an automated chemistry analyzer. The feces were collected at the 12 th week, and taxonomic and functional profiles of gut microbiota were analyzed by 16S ribosomal ribonucleic acid (16S rRNA) sequencing. RESULTS: Compared with HFD group, the average body weight of APS plus BBR group was decreased (P<0.01), accompanied with the reduced fat accumulation, enhanced colonic integrity, insulin sensitivity and glucose homeostasis (P<0.05 or P<0.01). Importantly, APS combined with BBR treatment was more effective than APS or BBR alone in improving HFD-induced insulin resistance (P<0.05 or P<0.01). 16S rRNA sequence-based analysis of fecal samples demonstrated that APS combined with BBR treatment exhibited a better impact on HFD-induced gut microbiota dysbiosis, exclusively via the enriched abundances of Bacteroides, which corresponded to the large increase of predicted bacterial genes involved in carbohydrate metabolism. CONCLUSION: APS combined with BBR may synergistically reduce obesity and modulate the gut microbiota in HFD-fed mice.

Differential regulation of hair cell actin cytoskeleton mediated by SRF and MRTFB.

The MRTF-SRF pathway has been extensively studied for its crucial role in driving the expression of a large number of genes involved in actin cytoskeleton of various cell types. However, the specific contribution of MRTF-SRF in hair cells remains unknown. In this study, we showed that hair cell-specific deletion of Srf or Mrtfb, but not Mrtfa, leads to similar defects in the development of stereocilia dimensions and the maintenance of cuticular plate integrity. We used fluorescence-activated cell sorting-based hair cell RNA-Seq analysis to investigate the mechanistic underpinnings of the changes observed in Srf and Mrtfb mutants, respectively. Interestingly, the transcriptome analysis revealed distinct profiles of genes regulated by Srf and Mrtfb, suggesting different transcriptional regulation mechanisms of actin cytoskeleton activities mediated by Srf and Mrtfb. Exogenous delivery of calponin 2 using Adeno-associated virus transduction in Srf mutants partially rescued the impairments of stereocilia dimensions and the F-actin intensity of cuticular plate, suggesting the involvement of Cnn2, as an Srf downstream target, in regulating the hair bundle morphology and cuticular plate actin cytoskeleton organization. Our study uncovers, for the first time, the unexpected differential transcriptional regulation of actin cytoskeleton mediated by Srf and Mrtfb in hair cells, and also demonstrates the critical role of SRF-CNN2 in modulating actin dynamics of the stereocilia and cuticular plate, providing new insights into the molecular mechanism underlying hair cell development and maintenance.

Intensive vs non-intensive statin pretreatment before percutaneous coronary intervention in Chinese patients: A meta-analysis of randomized controlled trials.

BACKGROUND: The results of intensive statin pretreatment before percutaneous coronary intervention (PCI) is inconsistent between Chinese and Western populations, and there are no corresponding meta-analyses involving hard clinical endpoints in the available published literature. AIM: To evaluate the efficacy and safety of high-dose statin loading before PCI in Chinese patients through a meta-analysis. METHODS: Relevant studies were identified by searching the electronic databases of PubMed, Embase and Cochrane's Library to December 2019. The outcomes included an assessment of major adverse cardiovascular event (MACE), non-fatal myocardial infarction (MI), cardiac death, target vessel revascularization (TVR), myalgia /myasthenia and abnormal alanine aminotransferase (ALT) in all enrolled patients. Random effect model and fixed effect model were applied to combine the data, which were further analyzed by χ 2 test and I 2 test. The main outcomes were then analyzed through the use of relative risks (RR) and its 95% confidence interval (95%CI). RESULTS: Eleven studies involving 3123 individuals were included. Compared with patients receiving placebo or no statin treatment before surgery, intensive statin treatment was associated with a clear reduction of risk of MACE (RR = 0.44, 95%CI: 0.31-0.61, P < 0.00001). However, compared with the patients receiving moderate-intensity statin before surgery, no advantage to intensive statin treatment was seen (RR = 1.04, 95%CI: 0.82-1.31, P = 0.74). In addition, no significant difference was observed between intensive statin therapy and non-intensive statin therapy on the incidence of TVR (RR = 0.43, 95%CI: 0.18-1.02, P = 0.06) , myalgia /myasthenia (RR = 1.35, 95%CI: 0.30-5.95, P = 0.69) and abnormal alanine aminotransferase (RR = 1.47, 95%CI: 0.54-4.02, P = 0.45) except non-fatal MI (RR = 0.54, 95%CI: 0.33-0.88, P = 0.01). CONCLUSION: Compared with placebo or no statin pretreatment, intensive statin before PCI displayed reduced incidence of MACE. However, there was no significant benefit between high and moderate-intensity statin. In addition, no significant difference was observed between intensive statin therapy and non-intensive statin therapy on the incidence of TVR, myalgia/myasthenia and abnormal alanine aminotransferase except non-fatal MI.

New Alloy of an Al-Chalcogen System: AlSe Surface Alloys on Al(111).

Metal chalcogenides are a promising material for novel physical research and nanoelectronic device applications. Here, we systematically investigate the crystal structure and electronic properties of AlSe alloys on Al(111) using scanning tunneling microscopy, angle-resolved photoelectron spectrometry, and first-principle calculations. We reveal that the AlSe surface alloy possesses a closed-packed atomic structure. The AlSe surface alloy comprises two atomic sublayers (Se sublayer and Al sublayer) with a height difference of 1.16 Å. Our results indicate that the AlSe alloy hosts two hole-like bands, which are mainly derived from the in-plane orbital of AlSe (p x and p y ). These two bands located at about -2.22 ±0.01 eV around the Gamma point, far below the Fermi level, distinguished from other metal chalcogenides and binary alloys. AlSe alloys have the advantages of large-scale atomic flat terraces and a wide band gap, appropriate to serve as an interface layer for two-dimensional materials. Meanwhile, our results provide implications for related Al-chalcogen interfaces.

Methodology of network pharmacology for research on Chinese herbal medicine against COVID-19: A review.

Traditional Chinese medicine, as a complementary and alternative medicine, has been practiced for thousands of years in China and possesses remarkable clinical efficacy. Thus, systematic analysis and examination of the mechanistic links between Chinese herbal medicine (CHM) and the complex human body can benefit contemporary understandings by carrying out qualitative and quantitative analysis. With increasing attention, the approach of network pharmacology has begun to unveil the mystery of CHM by constructing the heterogeneous network relationship of "herb-compound-target-pathway," which corresponds to the holistic mechanisms of CHM. By integrating computational techniques into network pharmacology, the efficiency and accuracy of active compound screening and target fishing have been improved at an unprecedented pace. This review dissects the core innovations to the network pharmacology approach that were developed in the years since 2015 and highlights how this tool has been applied to understanding the coronavirus disease 2019 and refining the clinical use of CHM to combat it.

Network Pharmacology-Based Dissection of the Active Ingredients and Protective Mechanism of the Salvia Miltiorrhiza and Panax Notoginseng Herb Pair against Insulin Resistance.

The Salvia miltiorrhiza and Panax notoginseng herb pair (DQ) has been widely utilized in traditional Chinese medicine for the longevity and for preventing and treating cardio-cerebrovascular diseases. Often associated with cardio-cerebrovascular diseases are comorbidities such as insulin resistance. However, the protective mechanisms of DQ against insulin resistance remain not well understood. Through network pharmacology analysis, a total of 94 candidate active compounds selected from DQ (61 from S. miltiorrhiza Bunge and 33 from P. notoginseng (Burk.) F. H. Chen) interacted with 52 corresponding insulin resistance-related targets, which mainly involved insulin resistance and the AMPK signaling pathway. Furthermore, the contribution index calculation results indicated 25 compounds as the principal components of this herb pair against insulin resistance. Among them, ginsenoside F2, protocatechuic acid, and salvianolic acid B were selected and validated to promote glucose consumption through activating AMPK phosphorylation and upregulating GLUT4 in insulin-resistant cell model (HepG2/IR) cells. These findings indicated that DQ has the potential for repositioning in the treatment of insulin resistance mainly through the AMPK signaling pathway.

Therapeutic Potential of Hydroxysafflor Yellow A on Cardio-Cerebrovascular Diseases.

The incidence rate of cardio-cerebrovascular diseases (CCVDs) is increasing worldwide, causing an increasingly serious public health burden. The pursuit of new promising treatment options is thus becoming a pressing issue. Hydroxysafflor yellow A (HSYA) is one of the main active quinochalcone C-glycosides in the florets of Carthamus tinctorius L., a medical and edible dual-purpose plant. HSYA has attracted much interest for its pharmacological actions in treating and/or managing CCVDs, such as myocardial and cerebral ischemia, hypertension, atherosclerosis, vascular dementia, and traumatic brain injury, in massive preclinical studies. In this review, we briefly summarized the mode and mechanism of action of HSYA on CCVDs based on these preclinical studies. The therapeutic effects of HSYA against CCVDs were presumed to reside mostly in its antioxidant, anti-inflammatory, and neuroprotective roles by acting on complex signaling pathways.

[Partial Nitrification Fast Start-up and Stable Performance of 15℃ SBBR].

In this study, controlled C/N effects on fast start-up and stable performance of partial nitrification process at 15℃ in a Sequenced Batch Biofilm Reactor (SBBR) were investigated. The results showed that partial nitrification successfully fast initiated when C/N was 1.5 but failed when C/N was 0/3 during 60 cycles. Fluorescence in situ hybridization and confocal laser scanning microscope (FISH-CLSM) results showed that ammonia oxidizing bacteria (AOB) was found as the dominant bacteria population when C/N was 1.5. When C/N were 0/3, there were almost no existence of AOB and nitrite oxidative bacteria (NOB). Partial nitrification could be stably achieved without carbon source. However, the addition of an appropriate amount of carbon can effectively improve the nitrification performance, and it is better for the stable operation of partial nitrification. In this experiment, partial nitrification was successfully initiated at high dissolved oxygen (DO) (about 9 mg·L-1) conditions. The average DO was maintained at about 6.5 mg·L-1 during the stable operation, which successfully decoupled partial nitrification from low DO concentration. Excessive residual ammonium concentration in the reactors effectively repressed the growth of NOB and guaranteed the stable operation of partial nitrification. At 15℃, full nitritation was more suitable for sidestream wastewater, while mainstream wastewater was more suitable for partial nitritation.