A new artificial intelligence system for both stomach and small-bowel capsule endoscopy.

BACKGROUND AND AIMS: Despite the benefits of artificial intelligence in small-bowel (SB) capsule endoscopy (CE) image reading, information on its application in the stomach and SB CE is lacking. METHODS: In this multicenter, retrospective diagnostic study, gastric imaging data were added to the deep learning-based SmartScan (SS), which has been described previously. A total of 1069 magnetically controlled GI CE examinations (comprising 2,672,542 gastric images) were used in the training phase for recognizing gastric pathologies, producing a new artificial intelligence algorithm named SS Plus. A total of 342 fully automated, magnetically controlled CE examinations were included in the validation phase. The performance of both senior and junior endoscopists with both the SS Plus-assisted reading (SSP-AR) and conventional reading (CR) modes was assessed. RESULTS: SS Plus was designed to recognize 5 types of gastric lesions and 17 types of SB lesions. SS Plus reduced the number of CE images required for review to 873.90 (median, 1000; interquartile range [IQR], 814.50-1000) versus 44,322.73 (median, 42,393; IQR, 31,722.75-54,971.25) for CR. Furthermore, with SSP-AR, endoscopists took 9.54 minutes (median, 8.51; IQR, 6.05-13.13) to complete the CE video reading. In the 342 CE videos, SS Plus identified 411 gastric and 422 SB lesions, whereas 400 gastric and 368 intestinal lesions were detected with CR. Moreover, junior endoscopists remarkably improved their CE image reading ability with SSP-AR. CONCLUSIONS: Our study shows that the newly upgraded deep learning-based algorithm SS Plus can detect GI lesions and help improve the diagnostic performance of junior endoscopists in interpreting CE videos.

Effects of initial corncob particle size on the short-term composting for preparation of cultivation substrates for Pleurotus ostreatus.

The short-term composting based on corncob for preparing Pleurotus ostreatus cultivation medium originated from agricultural production practices and so lacked systematic investigation. In this study, the influences of a Dafen (15 mm, DFT) and Xiaofen (5 mm, XFT) initial particle size (IPS) of corncob on the microbial succession and compost quality were examined. Results demonstrated that XFT compost was better suited for mushroom cultivation due to its high biological efficiency of 70 % and the absence of contamination. The composting microbes differed significantly between the DFT and XFT composts. During composting, the genera of Bacillus, Acinetobacter, Lactobacillus, Streptomyces, and Paenibacillus were majorly found in the DFT compost, while Acinetobacter, Lactobacillus, Puccinia, Bacteroides, and Bacillus genera dominated the XFT compost. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that throughout the thermophilic phase, XFT compost had much greater relative abundances of sequences relevant to energy, carbohydrate, and amino acid metabolism than DFT compost. Analysis of network correlations and Mantel tests indicated that IPS reduction could increase microbial interactions. Overall, adjusting the IPS of corncob to 5 mm increased microbial interactions, improved compost quality, and thereby boosted the P. ostreatus yield. These findings will be pertinent in optimizing the composting process of cultivation medium for P. ostreatus.

[Isolation and functional characterization of (iso)eugenol O-methyltransferase (IEMT) gene in Asarum sieboldii].

Methyleugenol is one of the main active constituents in the volatile oil of the traditional Chinese medicine Asari Radix et Rhizoma. It possesses various pharmacological effects such as analgesic, anesthetic, and anti-inflammatory properties. In biosynthesis, the initial precursor phenylalanine is finally converted into methyleugenol through a series of intermediate compounds including coniferyl acid, courmaryl acid, caffeic acid, ferulic acid/ferulic-CoA, coniferyl aldehyde, conferyl alcohol, cnfiferyl acetate, and eugenol/isoeugenol, which are produced through catalysis of a large number of enzymes. Eugenol O-methyltransferase(EOMT) is one of the key enzymes in the biosynthesis pathway, capable of methylating eugenol on the para-site hydroxyl group of the benzene ring, thereby generating methyleugenol. Here, an(iso)eugenol O-methyltransferase(IEMT) gene was cloned for the first time from Asarum siebo-ldii, holding an open reading frame that consisted of 1 113 bp and encoded a protein containing 370 amino acid residues. Bioinformatics analysis results showed that this protein was equipped with the characteristic structural domains of methyltransferases such as S-adenosylmethionine(SAM) binding sites and dimerization domains. The prokaryotic expression recombinant plasmid pET28a(+)-AsIEMT was constructed, and the candidate protein was induced and purified. In vitro enzyme assays confirmed that AsIEMT had dual functions. The enzyme could catalyze the production either of methyleugenol from eugenol or of methylisoeugenol from isoeugenol, although the latter was more prevalent. When isoeugenol was used as the substrate, the kinetics parameters K_m and V_(max) of catalytic reaction were(0.90±0.06) mmol·L~(-1) and(1.32±0.04)nmol·s~(-1)·mg~(-1), respectively. This study expanded our understandings of critical enzyme genes involved in phenylpropanoid metabolic pathways, and would facilitate the elucidation of quality formation mechanisms of the TCM Asari Radix et Rhizoma.

Forensic Identification and Evaluation of 25 Obstetric Brachial Plexus Palsy Medical Damage Cases.

OBJECTIVES: To analyze the high risk factors of obstetric brachial plexus palsy (OBPP), and to explore how to evaluate the relationship between fault medical behavior and OBPP in the process of medical damage forensic identification. METHODS: A retrospective analysis was carried out on 25 cases of medical damage liability disputes related to OBPP from 2017 to 2021 in Beijing Fayuan Judicial Science Evidence Appraisal Center. The shortcomings of hospitals in birth weight assessment, delivery mode selection, labor process observation and shoulder dystocia management, and the causal relationship between them and the damage consequences of the children were summarized. RESULTS: Fault medical behavior was assessed as the primary cause in 2 cases, equal cause in 10 cases, secondary cause in 8 cases, minor cause in 1 case, no causal relationship in 1 case, and unclear causal force in 3 cases. CONCLUSIONS: In the process of forensic identification of OBPP, whether medical behaviors fulfill diagnosis and treatment obligations should be objectively analyzed from the aspects of prenatal evaluation, delivery mode notification, standardized use of oxytocin, standard operation of shoulder dystocia, etc. Meanwhile, it is necessary to fully consider the objective risk of different risk factors and the difficulty of injury prevention, and comprehensively evaluate the causal force of fault medical behavior in the damage consequences.

Molecular Editing of Pyrroles to Benzenes/Naphthalenes by N2O Deletion.

A molecular editing reaction for converting pyrrole rings into benzene rings through a sequential pathway of Diels-Alder and cheletropic reactions was developed. The nitrogen atom in a N-bridged intermediate is eliminated in the form of N2O by a strain-releasing pathway, ultimately leading to the formation of substituted benzene and naphthalene derivatives.

Tafenoquine and its derivatives as inhibitors for the severe acute respiratory syndrome coronavirus 2.

The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has severely affected human lives around the world as well as the global economy. Therefore, effective treatments against COVID-19 are urgently needed. Here, we screened a library containing Food and Drug Administration (FDA)-approved compounds to identify drugs that could target the SARS-CoV-2 main protease (Mpro), which is indispensable for viral protein maturation and regard as an important therapeutic target. We identified antimalarial drug tafenoquine (TFQ), which is approved for radical cure of Plasmodium vivax and malaria prophylaxis, as a top candidate to inhibit Mpro protease activity. The crystal structure of SARS-CoV-2 Mpro in complex with TFQ revealed that TFQ noncovalently bound to and reshaped the substrate-binding pocket of Mpro by altering the loop region (residues 139-144) near the catalytic Cys145, which could block the catalysis of its peptide substrates. We also found that TFQ inhibited human transmembrane protease serine 2 (TMPRSS2). Furthermore, one TFQ derivative, compound 7, showed a better therapeutic index than TFQ on TMPRSS2 and may therefore inhibit the infectibility of SARS-CoV-2, including that of several mutant variants. These results suggest new potential strategies to block infection of SARS-CoV-2 and rising variants.

Binding dynamics of cavity solitons in a Kerr resonator with high order dispersion.

Cavity solitons are persistent light pulses arising from the externally driven Kerr resonators. Thanks to the passive parametric gain, cavity soliton has been endowed with the natural advantage of the chip-scaled integration since it was first experimentally generated in the fiber-based platform. Deterministic single soliton with smooth spectrum is a preferred state for numerous applications. However, multiple solitons are more common in the resonators with anomalous dispersion. In this condition, adjacent solitons are easily perturbed to attract and collide with each other. Some experimental observations deviated from the aforementioned description have recorded the stable soliton intervals that can last for a long time scale. This phenomenon is known as soliton binding and is attributed to the presence of narrow resonant sidebands in the spectrum. While the stationary configuration of two binding solitons has been investigated, the dynamical evolution remains an area for further exploration. In this paper, we discuss the binding dynamics of the cavity solitons in the presence of high-order dispersion. The proposed theoretical predictions match well with the numerical results, encompassing both the stationary stable intervals and dynamic trajectories. Our research will provide a comprehensive insight into the soliton motion induced by the internal perturbations.

Light-Driven Electron Uptake from Nonfermentative Organic Matter to Expedite Nitrogen Dissimilation by Chemolithotrophic Anammox Consortia.

Nonphotosynthetic microorganisms are typically unable to directly utilize light energy, but light might change the metabolic pathway of these bacteria indirectly by forming intermediates such as reactive oxygen species (ROS). This work investigated the role of light on nitrogen conversion by anaerobic ammonium oxidation (anammox) consortia. The results showed that high intensity light (>20000 lx) caused ca. 50% inhibition of anammox activity, and total ROS reached 167% at 60,000 lx. Surprisingly, 200 lx light was found to induce unexpected promotion of the nitrogen conversion rate, and ultraviolet light (<420 nm) was identified as the main contributor. Metagenomic and metatranscriptomic analyses revealed that the gene encoding cytochrome c peroxidase was highly expressed only under 200 lx light. 15N isotope tracing, gene abundance quantification, and external H2O2 addition experiments showed that photoinduced trace H2O2 triggered cytochrome c peroxidase expression to take up electrons from extracellular nonfermentative organics to synthesize NADH and ATP, thereby expediting nitrogen dissimulation of anammox consortia. External supplying reduced humic acid into a low-intensity light exposure system would result in a maximal 1.7-fold increase in the nitrogen conversion rate. These interesting findings may provide insight into the niche differentiation and widespread nature of anammox bacteria in natural ecotopes.

Spatial Transcriptomics of Aging Rat Ovaries Reveals Unexplored Cell Subpopulations with Reduced Antioxidative Defense.

INTRODUCTION: Ovarian aging is characterized by a gradual decline in quantity and quality of oocytes and lower chance of fertility. Better understanding the genetic modulation during ovarian aging can further address available treatment options for aging-related ovarian diseases and fertility preservation. METHODS: A novel technique spatial transcriptomics (ST) was used to investigate the spatial transcriptome features of rat ovaries. Transcriptomes from ST spots in the young and aged ovaries were clustered using differentially expressed genes. These data were analyzed to determine the spatial organization of age-induced heterogeneity and potential mechanisms underlying ovarian aging. RESULTS: In this study, ST technology was applied to profile the comprehensive spatial imaging in young and aged rat ovary. Fifteen ovarian cell clusters with distinct gene-expression signatures were identified. The gene expression dynamics of granulosa cell clusters revealed three sub-types with sequential developmental stages. Aged ovary showed a significant decrease in the number of granulosa cells from the antral follicle. Besides, a remarkable rearrangement of interstitial gland cells was detected in aging ovary. Further analysis of aging-associated transcriptional changes revealed that the disturbance of oxidative pathway was a crucial factor in ovarian aging. CONCLUSIONS: This study firstly described an aging-related spatial transcriptome changes in ovary and identified the potential targets for prevention of ovarian aging. These data may provide the basis for further investigations of the diagnosis and treatment of aging-related ovarian disorders.

The correlation of two bone turnover markers with bone mineral density: a population-based cross-sectional study.

OBJECTIVE: Exploring the correlation between bone turnover marks (BTMs) with lumbar BMD in middle-aged populations. METHODS: The cross-sectional analysis fetched data came from NHANES. The level of serum bone alkaline phosphatase (sBAP) and urinary N-telopeptide (uNTx) were regarded as representative of bone turnover. Lumbar BMD was the outcome of the study. Multivariable linear regression models were utilized to detect the correlation of sBAP and uNTx with Lumbar BMD. RESULTS: The level of sBAP and uNTx was negatively correlated with lumbar BMD in every multivariable linear regression. For sBAP, this inverse correlation was stable in both men and women (P < 0.01). uNTx indicated a negative association after all relevant covariables were adjusted (P < 0.01). The men group remained the negative correlation in gender subgroup analysis (P < 0.01). CONCLUSION: This study indicated that the increased level of sBAP and uNTx associated with lumbar BMD decreased among middle-aged adults. This correlation could prompt researchers to explore further the relationship between bone turnover rate and BMD, which may provide information for the early detection of BMD loss and provide a new strategy for clinical practice.

Osteal Tissue Macrophages Are Involved in Endplate Osteosclerosis through the OSM-STAT3/YAP1 Signaling Axis in Modic Changes.

Modic changes (MCs) are radiographic manifestations of lumbar degenerative diseases. Various types of MCs are often associated with endplate osteosclerosis. Osteal tissue macrophages (Osteomacs) were reported to be crucial for bone homeostasis and bone repair, but whether osteomacs participate in the endplate osteosclerosis in MCs remained unclear. In this study, we tried to explore the critical role of osteomacs in regulating osteogenesis in MCs. We collected MCs from patient samples and developed a Propionibacterium acnes-induced rat MCs model, using microcomputed tomography and immunohistochemistry to detect the endplate bone mass and distribution of osteomacs. In patients' MCs, osteomacs increased in endplate subchondral bone, especially in Modic type II. Endplate in Modic type III presented a stable osteosclerosis. In rat MCs model, osteomacs increased in the bone hyperplasia area but not in the inflammation area of the endplate region, whereas the distribution of osteomacs was consistent with the area of osteosclerosis. To further explore the functions of osteomacs in vitro, we isolated osteomacs using MACS technology and found osteomacs secreted oncostatin M (OSM) and strongly promoted osteoblast differentiation rather than osteoclast through the mechanism of OSM-mediated tyrosine phosphorylation and interaction of STAT3 and Yes-associated protein 1 (YAP1). STAT3 phosphorylation inhibition or YAP1 knockdown attenuated OSM-mediated osteoblast differentiation. Finally, we confirmed that blockade of OSM in vivo using anti-OSM-neutralizing Ab prevented endplate osteosclerosis in rat MCs model. Taken together, these findings confirmed that endplate osteosclerosis in MCs was accompanied by an increased number of osteomacs, which regulated osteogenesis via the OSM-STAT3/YAP1 signaling axis.

[Characteristics and Evolutionary Advantages of Coronavirus].

Coronaviruses are a major source of emerging infectious diseases in recent years.With a variety of family members,wide host spectrum,and diverse mutant strains,coronaviruses have demonstrated unique advantages in evolution.This paper reviews the research progress of coronaviruses from genome characteristics,host animals,distribution of receptorsand gene mutations,summarizes the advantages of coronaviruses in evolution and transmission,aiming to draw attention to the prevention and control of such viruses.

Damage to the human lumbar cartilage endplate and its clinical implications.

The cartilaginous endplate (CEP) is a thin layer of hyaline cartilage, and plays an important role in the diffusion of nutrients into the intervertebral discs. Its damage may seriously affect the disc degeneration, and result in low back pain (LBP). However, the structural features of damaged CEPs have not been well characterized, and this hinders our understanding of the etiology of disc degeneration and pain. To present the structural features of micro-damaged CEPs in patients with disc degeneration and LBP that might even be regarded as an initial factor for disc degeneration, we performed a histological study of micro-damaged CEPs harvested from human lumbar intervertebral discs and analyzed its clinical implications. Human lumbar CEPs were excised from 35 patients (mean age 60.91 years) who had disc degeneration and LBP. Control tissue was obtained from 15 patients (mean age 54.67 years) with lumbar vertebral burst fractures. LBP and disability were assessed clinically, and all patients underwent anterior vertebral body fusion surgery. CEPs together with some adjacent nucleus pulposus (NP) were sectioned at 4 µm, and stained using H&E, Safranin O/Fast Green, and Alcian Blue. Immunostaining and PCR were used to identify various markers of degeneration, innervation, and inflammation. Histology demonstrated physical micro-damage in 14/35 CEPs from the disc degeneration group. Six major types of damage could be distinguished: fissure, traumatic nodes, vascular mimicry, incorporation of NP tissue within the CEP, incorporation of bone within the CEP, and incorporation of NP and bone within the CEP. Pain and disability scores (ODI: p = 0.0190; JOA: p = 0.0205; JOABPEQ: p = 0.0034) were significantly higher in those with micro-damaged CEPs (N = 14) than in those with non-damaged CEPs (N = 21). CEP damage was significantly associated with elevated MMP3 (p = 0.043), MMP13 (p = 0.0191), ADAMTS5 (p = 0.0253), TNF-α (p = 0.0011), and Substance P (p = 0.0028), and with reduced Sox9 (p = 0.0212), aggrecan (p = 0.0127), and type II collagen (p = 0.0139). In conclusion, we presented a new classification of human lumbar micro-damaged CEPs. Furthermore, we verify disc degeneration, innervation, and discogenic pain in micro-damaged CEPs.

Dioscin ameliorates murine ulcerative colitis by regulating macrophage polarization.

Restoring immune balance by targeting macrophage polarization is a potentially valuable therapeutic strategy for ulcerative colitis (UC). Dioscin is a steroidal saponin with potent anti-inflammatory, immunoregulatory, and hypolipidemic effects. This study examined the protective effect of Dioscin on UC in mice and explored the underlying mechanisms. Mice were induced colitis by dextran sulfate sodium (DSS) and concurrently treated with Dioscin oral administration. RAW264.7 cells were skewed to M1 macrophage polarization by lipopolysaccharide (LPS) and interferon-γ (INF-γ) in vitro, and received Dioscin treatment. The results showed that Dioscin ameliorated colitis in mice, reduced macrophage M1 polarization, but markedly promoted M2 polarization in mice colon. Dioscin inhibited mammalian target rapamycin complex 1 (mTORC1)/hypoxia-inducible factor-1α (HIF-1α) signaling and restrained glycolysis in RAW264.7; however, it activated mammalian target rapamycin complex 2 (mTORC2)/peroxisome proliferator-activated receptor-γ (PPAR-γ) signal and facilitated fatty acid oxidation (FAO). The modulation of mTORs signaling may inhibit M1, but promote M2 polarization. Furthermore, the effect of Dioscin on M2 polarization was neutralized by the FAO inhibitor Etomoxir and the mTORC2 inhibitor JR-AB2-011. In parallel, the inhibitory effect of Dioscin on M1 polarization was mitigated by the mTORC1 agonist L-leucine. Both JR-AB2-011 and L-leucine blocked the therapeutic effect of Dioscin in mice with UC. Therefore, Dioscin ameliorated UC in mice, possibly by restraining M1, while skewing M2 polarization of macrophages. Regulation of mTORC1/HIF-1α and mTORC2/PPAR-γ signals is a possible mechanism by which Dioscin inhibited aerobic glycolysis and promoted FAO of macrophages. In summary, Dioscin protected mice against DSS-induced UC by regulating mTOR signaling, thereby adjusting macrophage metabolism and polarization.

Molecular Insight into the Binding Property and Mechanism of Sulfamethoxazole to Extracellular Proteins of Anammox Sludge.

Antibiotics are widely found in nitrogen-containing wastewater, which may affect the operation stability of anaerobic ammonium oxidation (anammox)-based biological treatment systems. Extracellular polymeric substances (EPSs) of anammox sludge play a pivotal role in combining with antibiotics; however, the exact role and how the structure of the leading component of EPSs (i.e., extracellular proteins) changes under antibiotic stress remain to be elucidated. Here, the interaction between sulfamethoxazole and the extracellular proteins of anammox sludge was investigated via multiple spectra and molecular simulation. Results showed that sulfamethoxazole statically quenched the fluorescent components of EPSs, and the quenching constant of the aromatic proteins was the largest, with a value of 1.73 × 104 M-1. The overall binding was an enthalpy-driven process, with ΔH = -75.15 kJ mol-1, ΔS = -0.175 kJ mol-1 K-1, and ΔG = -21.10 kJ mol-1 at 35 °C. The O-P-O and C═O groups responded first under the disturbance of sulfamethoxazole. Excessive sulfamethoxazole (20 mg L-1) would decrease the ratio of α-helix/(ß-sheet + random coil) of extracellular proteins, resulting in a loose structure. Molecular docking and dynamic simulation revealed that extracellular proteins would provide abundant sites to bind with sulfamethoxazole, through hydrogen bond and Pi-Akyl hydrophobic interaction forces. Once sulfamethoxazole penetrates into the cell surface and combines with the transmembrane ammonium transport domain, it may inhibit the NH4+ transport. Our findings enhance the understanding on the interaction of extracellular proteins and sulfamethoxazole, which may be valuable for deciphering the response property of anammox sludge under the antibiotic stress.

Needle Adjustment Free (NAF) running suture technique (PAN suture) in laparoscopic partial nephrectomy.

BACKGROUND: It is proposed a new running suture technique called Needle Adjustment Free (NAF) technique, or PAN suture. The efficiency and the safety were evaluated in laparoscopic partial nephrectomy. METHODS: This new running suture technique avoids the Needle Adjustment method used in traditional techniques. The new continuous suture technique (11 patients) was compared with the traditional continuous suture method (33 patients) used in both transperitoneal and retroperitoneal laparoscopic partial nephrectomy (LPN) in terms of suture time (ST), warm ischemia time (WIT), blood loss (BL), open conversion rate and post-op discharge time, post-op bleeding, post-op DVT, ΔGFR (affected side, 3 months post-op). Differences were considered significant when P < 0.05. RESULTS: ST in the PAN suture group was 30.37 ± 16.39 min, which was significant shorter (P = 0.0011) than in the traditional technique group which was 13.68 ± 3.33 min. WIT in the traditional technique group was 28.73 ± 7.89 min, while in the PAN suture group was 20.64 ± 5.04 min, P = 0.0028. The BL in entirety in the traditional technique group was 141.56 ± 155.23 mL, and in the PAN suture group was 43.18 ± 31.17 mL (P = 0.0017). BL in patients without massive bleeding in the traditional technique group was significantly greater than in the PAN suture group at 101.03 ± 68.73 mL versus 43.18 ± 31.17 mL (P = 0.0008). The open conversion rate was 0 % in both groups. There was no significant difference between the two groups in postoperative discharge time, post-op bleeding, post-op DVT, ΔGFR (affected side, 3 months post-op). CONCLUSIONS: The NAF running suture technique, or PAN suture, leading to less ST, WIT and BL, which was shown to be more effective and safer than the traditional technique used for LPN. A further expanded research with larger sample size is needed.

Activating ß-catenin/Pax6 axis negatively regulates osteoclastogenesis by selectively inhibiting phosphorylation of p38/MAPK.

Balance of osteoclast formation is regulated by the receptor activator of NF-κB ligand and extracellular negative regulators such as IFN-γ and IFN-ß. However, very little is known about the intrinsic negative regulatory factors of osteoclast differentiation. Recently, the paired-box homeodomain transcription factor Pax6 was shown to negatively regulate receptor activator of NF-κB ligand-mediated osteoclast differentiation. However, the mechanism underlying this regulation is still unclear. In this study, we show that a p38 inhibitor (VX-745) up-regulates the expression of Pax6 during osteoclast differentiation. Subsequently, we found that ß-catenin could bind to the proximal region of Pax6 promoter to induce its expression, and this action could be impaired by p38-induced ubiquitin-mediated degradation of ß-catenin. Our results suggest that Pax6 is regulated by a novel p38/ß-catenin pathway. Pax6 can further regulate the nuclear translocation of NF of activated T cells, cytoplasmic 1. Our study indicates that this novel p38/ß-catenin/Pax6 axis contributes to negative regulation of osteoclastogenesis. In addition, our study proposes a novel approach to treat osteoclast-related diseases through the use of VX-745 complemented with the ß-catenin activator SKL2001.-Jie, Z., Shen, S., Zhao, X., Xu, W., Zhang, X., Huang, B., Tang, P., Qin, A., Fan, S., Xie, Z. Activating ß-catenin/Pax6 axis negatively regulates osteoclastogenesis by selectively inhibiting phosphorylation of p38/MAPK.

Anammox Granules Acclimatized to Mainstream Conditions Can Achieve a Volumetric Nitrogen Removal Rate Comparable to Sidestream Systems.

The implementation of mainstream anammox has gained increasing attention. In this study, the feasibility of using sidestream anammox granules to start up mainstream reactors was investigated by comparing two switching strategies. A maximum nitrogen removal potential of 3.6 ± 0.2 kg N m-3 d-1 was obtained for the reactor after direct switching to mainstream conditions (70 mg TN L-1, 15 °C). Nevertheless, the reactor preacclimatized to 25 °C (Ma) exhibited a higher nitrogen removal potential of 7.0 ± 0.3 kg N m-3 d-1 at 15 °C, which is the highest volumetric nitrogen removal rate of mainstream anammox reactors to date. Candidatus Kuenenia stuttgartiensis was identified as the dominant anammox bacterium, and its relative abundance in two reactors remained stable throughout the whole operation (200 days). Moreover, with the aid of acclimatization, the activation energy was reduced and the specific growth rate became higher. These results indicated that the physiological evolution of the dominant anammox bacterium instead of interspecies selection was the main reason for the high potential during the switch to mainstream conditions. Therefore, using sidestream anammox granules as seed sludge to start up mainstream reactors was demonstrated to be feasible, and a switching strategy of acclimatization at 25 °C was recommended.

Exploration of (3-benzyl-5-hydroxyphenyl)carbamates as new antibacterial agents against Gram-positive bacteria.

A series of (3-benzyl-5-hydroxyphenyl)carbamates were evaluated as new antibacterial agents. Several compounds showed potent inhibitory activity against sensitive and drug-resistant Gram-positive bacteria. The compounds are ineffective against all tested Gram-negative bacteria. The structure of the ester group exerted a profound effect on antibacterial activity. 4,4-Dimethylcyclohexanyl carbamate 6h exhibited the most potent inhibitory activity against the standard and clinically isolated Staphylococcus aureus, Staphylococcus epidermidis, and Enterococcus faecalis (minimum inhibitory concentration = 4-8 µg/ml) strains. The preliminary experimental evidence indicated that these carbamates target the bacterial cell wall and share a similar mechanism of action with vancomycin.

Deciphering the toxic effects of antibiotics on denitrification: Process performance, microbial community and antibiotic resistance genes.

The extensive application of antibiotics, and the occurrence and spread of antibiotic resistance genes (ARGs) shade health risks to human and animal. The long-term effects of sulfamethoxazole (SMX) and tetracycline (TC) on denitrification process were evaluated in this study, with the focus on nitrogen removal performance, microbial community and ARGs. Results showed that low-concentration SMX and TC (<0.2 mg L-1) initially caused a deterioration in nitrogen removal performance, while higher concentrations (0.4-20 mg L-1) of both antibiotics had no further inhibitory influences. The abundances of ARGs in both systems generally increased during the whole period, and most of them had significant correlations with intI1, especially efflux-pump genes. Castellaniella, which was the dominant genus under antibiotic pressure, might be potential resistant bacteria. These findings provide an insight into the toxic effects of different antibiotics on denitrification process, and guides future efforts to control antibiotics pollution in ecosystems.