Reason and control strategy for denitrification and anammox sludge flotation in nitrogen removal process: Mechanisms, strategies and perspectives.

Anaerobic biological treatment technology, especially denitrification and anaerobic ammonia oxidation (anammox) technology as mainstream process, played dominant role in the field of biological wastewater treatment. However, the above process was prone to sludge floating during high load operation and thereby affecting the efficient and stable operation of the system. Excessive production of extracellular polymeric substance (EPS) was considered to be the main reason for anaerobic granular sludge flotation, but the summaries in this area were not comprehensive enough. In this review, the potential mechanisms of denitrification and anammox sludge floatation were discussed from the perspective of granular sludge structural characteristics, nutrient transfer, and microbial flora change respectively, and the corresponding control strategies were also summarized. Finally, this paper indicated that future research on sludge flotation should focus on reducing the negative effects of EPS in sludge particles.

Chiral Skeletons of Mesoporous Silica Nanospheres to Mitigate Alzheimer's ß-Amyloid Aggregation.

Chiral mesoporous silica (mSiO2) nanomaterials have gained significant attention during the past two decades. Most of them show a topologically characteristic helix; however, little attention has been paid to the molecular-scale chirality of mSiO2 frameworks. Herein, we report a chiral amide-gel-directed synthesis strategy for the fabrication of chiral mSiO2 nanospheres with molecular-scale-like chirality in the silicate skeletons. The functionalization of micelles with the chiral amide gels via electrostatic interactions realizes the growth of molecular configuration chiral silica sols. Subsequent modular self-assembly results in the formation of dendritic large mesoporous silica nanospheres with molecular chirality of the silica frameworks. As a result, the resultant chiral mSiO2 nanospheres show abundant large mesopores (∼10.1 nm), high pore volumes (∼1.8 cm3·g-1), high surface areas (∼525 m2·g-1), and evident CD activity. The successful transfer of the chirality from the chiral amide gels to composited micelles and further to asymmetric silica polymeric frameworks based on modular self-assembly leads to the presence of molecular chirality in the final products. The chiral mSiO2 frameworks display a good chiral stability after a high-temperature calcination (even up to 1000 °C). The chiral mSiO2 can impart a notable decline in ß-amyloid protein (Aß42) aggregation formation up to 79%, leading to significant mitigation of Aß42-induced cytotoxicity on the human neuroblastoma line SH-ST5Y cells in vitro. This finding opens a new avenue to construct the molecular chirality configuration in nanomaterials for optical and biomedical applications.

Robot Assisted Laparoscopy Combined with Thoracoscopy in the Treatment of Hepatocellular Carcinoma with Inferior Vena Cava Tumor Thrombus.

BACKGROUND: Facing the 0.7-22% incidence rate of hepatocellular carcinoma (HCC) with inferior vena cava tumor thrombus (IVCTT), there are usually no obvious symptoms and signs when the tumor thrombus completely blocks the IVCTT in the early stage.1.J Gastroenterol. 29:41-46;2.Hepatogastroenterology. 41:154-157;3.Clin Cardiol. 19:211-213; Once diagnosed, it is the end-stage manifestation without unified treatment for HCC with IVCTT, bringing poor prognosis. Without active treatment, the median survival time is only 3 months. Previous scholars believed that patients with IVCTT should not adopt active surgical treatment. With the advance of technology, active surgical treatment has significantly lengthened the survival time with IVCTT.4.Ann Surg Oncol. 20:914-22;5.World J Surg Oncol. 11:259;6.Hepatogastroenterology. 58:1694-1699; However, for patients with HCC and IVCTT, open surgery was always selected in the past by opening the diaphragm through the combined thoracoabdominal incision to block the superior and subhepatic vena cava, leading long incision and huge trauma. With the development of minimally invasive techniques, laparoscopy thoracoscopy has showed great advantages in the treatment of HCC with IVCTT. A patient underwent laparoscopic with thoracoscopic resection of tumor and cancer thrombectomy after neoadjuvant therapy and then survived after follow-up.7.Ann Surg Oncol. 29:5548-5549 Therefore, it used as a first reported case of robot-assisted laparoscopic with thoracoscopic treatment of HCC complicated inferior vena cava cancer thrombectomy. METHODS: A 41-year-old man had a liver space-occupying lesion discovered during his medical examination 2 months ago. The diagnosis of HCC with IVCTT was confirmed by enhanced CT and biopsy specimen in the first hospitalization. A combination of TACE, targeted therapy, and immunotherapy plan was applied for the patient after multidisciplinary treatment (MDT). Specifically, Lenvatinib was taken orally 8 mg daily and 160 mg of toripalimab was given intravenously every 3 weeks. His reexamination CT showed that the tumor was more advanced after 2 months of treatment. The surgical operation was performed based on comprehensive consideration. The patient was placed in the left lateral decubitus position, and a thoracoscopic prefabricated the inferior vena cava above diaphragm blocking device was pulled out of the incision. The patient was switched to a supine position with the head of the bed raised 30 degrees. The gallbladder was removed first after entering the abdominal cavity, then prefabricated first hilar blocking band. Sterile rubber glove edges and hemo-lock were used to fabricate the blocking device. The novel hepatic inflow occlusion device is a safe, reliable, and convenient technique that is associated with favorable perioperative outcomes and low risk of conversion.8.Surg Endosc. 34:2807-2813 The liver along the middle hepatic vein was cut to expose the anterior wall of the inferior vena cava, then prefabricated posterior inferior vena cava blocking belt and right hepatic vein blocking belt. Finally, the first portal of liver, right hepatic vein, retrohepatic inferior vena cava, and inferior vena cava above diaphragm were blocked in sequence, so that accomplishing tumor resection and thrombectomy of inferior vena cava. It should be emphasized that before the inferior vena cava is completely sutured, the retrohepatic inferior vena cava blocking device should be released to allow blood flow to flush the inferior vena cava. Moreover, transesophageal ultrasound is required to real-time monitor inferior vena cava blood flow and IVCTT. Some images of the operation are shown in Fig. 1. Fig. 1 (a) Layout of the trocar. ①Make a 3cm small incision between the right anterior axillary line and the midaxillary line, parallel to the fourth and fifth intercostal spaces; a puncture hole in the next intercostal space for endoscope; ②2cm above the intersection of umbilicus horizontal line and axillary front line; ③Intersection of right clavicular midline and umbilical horizontal line; ④Superior margin of umbilicus; ⑤The midpoint of '④ & ⑥'; ⑥2cm below the intersection of left clavicular midline and left costal margin. (b) Prefabricated the inferior vena cava blocking device above diaphragm by thoracoscopic. (c) The smooth tumor thrombus protruding into the inferior vena cava RESULTS: It took 475 min to finish the operation, and the loss of blood was estimated as 300 ml. The patient was discharged from hospital 8 days after the operation without postoperative complication. HCC was confirmed by postoperative pathology. CONCLUSIONS: Robot surgical system reduces the limitations of laparoscopic surgery by offering a stable three-dimensional view, 10-times-enlarged image, restored eye-hand axis, and excellent dexterity with the endowristed instruments, which has several advantages over open operation such as diminished blood loss, reduced morbidity, and shorter hospital stay.9.Chirurg. 88:7-11;10.BMC Surg. 11:2;11.Minerva Chir. 64:135-146; Furthermore, it could favor the operative feasibility of difficult resections reducing the conversion rate and playing a role to extend the indications of liver resection to minimally invasive approaches. It may provide new curative options in patients deemed inoperable with conventional surgery, such as HCC with IVCTT.12.Biosci Trends. 16:178-188;13.J Hepatobiliary Pancreat Sci. 29:1108-1123.

Safety of early cumulus cell removal combined with early rescue ICSI in the prevention of fertilization failure.

RESEARCH QUESTION: What are the clinical outcomes and safety implications of early cumulus cell removal after short-term insemination combined with early rescue intracytoplasmic sperm injection (ICSI) in preventing fertilization failure? DESIGN: In this retrospective study, a total of 14,360 cycles were divided into four groups based on insemination method and fertilization ability: conventional IVF group (n = 5519); early cumulus cell removal group (n = 4107); conventional ICSI group (n = 4215); and early rescue ICSI group (where failed or low fertilization was predicted, n = 519). Fertilization outcomes, pregnancy outcomes, neonatal outcomes and birth defects were analysed by comparing the early cumulus cell removal group with the conventional IVF group, and the early rescue ICSI group with the conventional ICSI group. RESULTS: There were no significant differences in the outcomes of fertilization, pregnancy, neonates or birth defects between the conventional IVF group and the early cumulus cell removal group (P > 0.05). When compared with the conventional ICSI group, the early rescue ICSI group had similar rates of two pronuclei (2PN) at fertilization, clinical pregnancy, miscarriage, ectopic pregnancy, live birth, sex, mean gestational age, very low birthweight, macrosomia and birth defects (P > 0.05) but a higher polyploidy rate, lower high-quality embryo rate (both P < 0.001), lower twin pregnancy rate (P < 0.01), lower rate of low birthweight, and a higher rate of normal birthweight (both P = 0.024). CONCLUSIONS: Early cumulus cell removal combined with early rescue ICSI led to good pregnancy and neonatal outcomes without an increase in birth defects. This approach could therefore be an effective and safe method for patients with fertilization failure in conventional IVF.

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.

Concentrations, seasonal trends, sources, health risk and subchronic toxicity to the respiratory and immune system of PAHs in PM2.5 in Xi'an.

PM2.5-bound polycyclic aromatic hydrocarbons (PAHs) have been proved to be hazardous to health. Previous studies have focused on the distribution and sources of PAHs, whereas there is little knowledge of the damage to organs. Here we sought to investigate the pollution level and seasonal variation characteristics of PAHs in PM2.5 in Xi'an and assess the health risk, to establish a PAHs exposure model, and investigate the toxicological effects of PAHs on the respiratory and immune functions. A sub-chronic exposure model of PAHs was established by inhalation. The pathological changes of lung tissues were observed with a light microscope. Inflammatory reactions in alveolar lavage fluid were determined using the corresponding kit. The levels of interleukin-6 (IL-6) and interleukin-8 (IL-8) were detected with enzyme linked immunosorbent assay (ELISA) kit; the proliferation of lymphocytes in spleen was detected with methyl tetrazolium (MTT); DNA immune damage was determined with DNA gel electrophoresis. The results showed that (1) the total concentration of 16 PAHs ranged from 41.1 to 387 ng/m3, with a mean value of 170 ng/m3, and the concentration of PAHs in PM2.5 was higher in winter than in other seasons. (2) The sources of PAHs in the atmosphere of Xi'an urban area were mainly coal combustion, and the equivalent carcinogenic concentration of PAHs in PM2.5 was 3.9 ng/m3. (3) Foreign body granuloma formation and inflammatory cell damage were observed in the lungs of rats infected with toxin; the levels of reactive oxygen species (ROS) and mobile device assistant (MDA) increased while nitric oxide synthase (NOS) decreased with the increase of dose; the expression levels of IL-6 and IL-8 elevated with the increase of toxin dose, showing an obvious dose-effect relationship; the level of PAHs damage to cells showed a dose-effect relationship. Sub-chronic exposure to PAHs could cause sustained inflammatory injury to the organism. Measures should be taken to counter the problems of PAHs in PM2.5 in Xi'an and relevant health promotion strategies should be developed.

Inhibition of AMPK/PFKFB3 mediated glycolysis synergizes with penfluridol to suppress gallbladder cancer growth.

BACKGROUND: Penfluridol (PF) is an FDA-approved antipsychotic drug that has recently been shown to have anticancer activity. However, the anticancer effects and underlying mechanisms of PF are not well-established in gallbladder cancer (GBC). METHODS: The anticancer efficacy of PF on GBC was investigated via a series of cell functions experiments, including cell viability, colony formation, apoptosis assays, and so on. The corresponding signaling changes after PF treatment were explored by western blotting. Then, nude mice were utilized to study and test the anticancer activity of PF in vivo. Besides, glucose consumption and lactic production assays were used to detect the glycolysis alteration. RESULTS: In this study, we discovered that PF greatly inhibited the proliferation and invasion ability of GBC cells (GBCs). The glucose consumption and lactic generation ability of GBCs were dramatically elevated following PF treatment. Additionally, we discovered that inhibiting glycolysis could improve PF's anticancer efficacy. Further studies established that the activation of the AMPK/PFKFB3 signaling pathway medicated glycolysis after PF treatment. We proved mechanistically that inhibition of AMPK/PFKFB3 singling pathway mediated glycolysis was a potential synergetic strategy to improve the anticancer efficacy of PF on GBC. CONCLUSIONS: By inhibiting AMPK, the anticancer effects of PF on GBCs were amplified. As a result, our investigations shed new light on the possibility of repurposing PF as an anticancer drug for GBC, and AMPK inhibition in combination with PF may represent a novel therapeutic strategy for GBC. Video abstract.

Anammox sludge preservation: Preservative agents, temperature and substrate.

The difficulties of enrichment and preservation of anaerobic ammonium oxidation bacteria (AnAOB) greatly limit their application in practice. Herein, traditional and emerging preservative agents (e.g., EPS + N2H4, betaine, glycerol and trehalose) were evaluated for their preservation of AnAOB-dominant sludge at different temperatures (e.g., 4 °C and room temperature). In addition, the effects of substrates on preservation were also considered. The results showed that adding betaine or glycerol at 4 °C was the optimal strategy for preserving anammox granular sludge. The relative anammox activities (rAA) increased by 145.26% and 158.30% at the recovery phase, respectively. Moreover, the absolute abundances of functional gene hzsA increased by 339% and 46%, respectively. Although the granular properties and microbial community structures changed during the preservation, the general performance of anammox granules could effectively restored. Collectively, this study provides the optimal strategies for anammox sludge preservation at low temperatures.

Anlotinib combined with PD-1 blockade for the treatment of lung cancer: a real-world retrospective study in China.

BACKGROUND: This study evaluated the efficacy and safety of anlotinib combined with programmed cell death protein 1 (PD-1) blockade for the treatment of small-cell lung cancer (SCLC) and non-small-cell lung cancer (NSCLC). PATIENTS AND METHODS: SCLC (n = 28) and NSCLC (n = 177) patients who received treatment at Hunan Cancer Hospital between June 1, 2019, and July 1, 2020, were retrospectively analyzed. Progression-free survival (PFS) and treatment responses were compared among patients who received combination therapy of anlotinib plus PD-1 inhibitor, or monotherapy of either chemotherapy or PD-1 inhibitor. Independent prognostic factors were identified by Cox regression analysis. RESULTS: Patients with relapsed SCLC who received anlotinib plus PD-1 inhibitor as a ≥ second-line therapy (n = 14) had a significantly longer PFS than those who received PD-1 inhibitor alone (n = 14, 5.0 vs. 3.0 months; P = 0.005). For patients with previously untreated wild-type NSCLC, the combination therapy in the first-line setting (n = 6) provided a marginally longer PFS than mono-chemotherapy (n = 6, 8.0 vs. 3.0 months; P = 0.075). For patients with relapsed NSCLC, the combination therapy in the ≥ second-line setting (n = 62) resulted in significantly higher objective response rate (19.3 vs. 5.0 vs. 2.4%; P = 0.013) and longer PFS (8.0 vs. 2.0 vs. 2.0 months; P <0.001) as compared to monotherapy of either chemotherapy (n = 41) or PD-1 inhibitor (n = 62). Anlotinib and PD-1 blockade combination therapy was an independent predictive factor of longer PFS (P <0.001). CONCLUSION: The combination of anlotinib and PD-1 inhibitor has promising efficacy and manageable toxicity as a second- or later-line treatment of relapsed NSCLC and possibly for relapsed SCLC.

Oceanic non-Kolmogorov optical turbulence and spherical wave propagation.

Light propagation in turbulent media is conventionally studied with the help of the spatio-temporal power spectra of the refractive index fluctuations. In particular, for natural water turbulence several models for the spatial power spectra have been developed based on the classic, Kolmogorov postulates. However, as currently widely accepted, non-Kolmogorov turbulent regime is also common in the stratified flow fields, as suggested by recent developments in atmospheric optics. Until now all the models developed for the non-Kolmogorov optical turbulence were pertinent to atmospheric research and, hence, involved only one advected scalar, e.g., temperature. We generalize the oceanic spatial power spectrum, based on two advected scalars, temperature and salinity concentration, to the non-Kolmogorov turbulence regime, with the help of the so-called "Upper-Bound Limitation" and by adopting the concept of spectral correlation of two advected scalars. The proposed power spectrum can handle general non-Kolmogorov, anisotropic turbulence but reduces to Kolmogorov, isotropic case if the power law exponents of temperature and salinity are set to 11/3 and anisotropy coefficient is set to unity. To show the application of the new spectrum, we derive the expression for the second-order mutual coherence function of a spherical wave and examine its coherence radius (in both scalar and vector forms) to characterize the turbulent disturbance. Our numerical calculations show that the statistics of the spherical wave vary substantially with temperature and salinity non-Kolmogorov power law exponents and temperature-salinity spectral correlation coefficient. The introduced spectrum is envisioned to become of significance for theoretical analysis and experimental measurements of non-classic natural water double-diffusion turbulent regimes.

Olaparib and enzalutamide synergistically suppress HCC progression via the AR-mediated miR-146a-5p/BRCA1 signaling.

Hepatocellular carcinoma (HCC) is one of most common cancers worldwide, however, the treatment for advanced HCC remains unsatisfactory. We focused on the function of the androgen receptor (AR) in HCC and tried to find new treatment strategy based on antiandrogen enzalutamide (Enz). Here, we found that olaparib, a FDA-approved PARP inhibitor, could enhance the cytotoxicity in HCC cells with a lower BRCA1 expression, and suppressing the AR with either Enz or AR-shRNA could further increase the olaparib sensitivity to better suppress the HCC cell growth via a synergistic mechanism that may involve suppressing the expression of BRCA1 and other DNA damage response (DDR) genes. Mechanism studies revealed that Enz/AR signaling might transcriptionally regulate the miR-146a-5p expression via binding to the Androgen Response Elements on its 5' promoter region, which could then lead to suppress the homologous recombination-related BRCA1 expression via direct binding to the mRNA 3'UTR. Preclinical studies using an in vivo mouse model also demonstrated that combining Enz plus olaparib led to better suppression of the HCC progression. Together, these in vitro/in vivo data suggest that combining Enz and olaparib may help in the development of a novel therapy to better suppress the HCC progression.

Study on risk factors, bacterial species, and drug resistance of acute pyelonephritis associated with ureteral stent after percutaneous nephrolithotomy.

The purpose of this study is to explore the risk factors, bacterial species, and drug resistance of acute pyelonephritis (AP) associated with ureteral stent after percutaneous nephrolithotomy (PCNL) and to provide reference for clinical intervention. The clinical data of 415 patients with indwelling ureteral stent after PCNL from December 2016 to May 2019 were analyzed retrospectively. The patients were divided into infection group (n = 54) and non-infection group (n = 361) according to whether patients had AP. Patients' clinical data, blood and urine bacterial culture, and drug sensitivity were collected and analyzed. The incidence of AP associated with ureteral stent after PCNL was 13.01% and diabetes mellitus (P = 0.001), postoperative stone residue (P = 0.002), urinary leucocytes ≥ 100/HP (P = 0.018), positive urine culture results (P = 0.001), ureteral stent retention time ≥ 8 weeks (P = 0.004), and high S.T.O.N.E. score (P = 0.014) are independent risk factors for it. Escherichia coli (40.54%, 47.82%), Klebsiella pneumoniae (16.21%, 15.21%), Pseudomonas aeruginosa (10.81%, 4.34%), Enterococcus faecalis (21.6%, 19.56%), and epidermis Staphylococci (10.81%, 13.33%) are the main pathogens in blood and urine. The main sensitive drugs of pathogenic bacteria are imipenem, meropenem, tigecycline, piperacillin/tazobactam, ceftazidime, linezolid, teicoplanin, levofloxacin, vancomycin, tigecycline, etc., while levofloxacin, norfloxacin, penicillin G, first, and second-generation cephalosporins showed a strong drug resistance rate (> 70%). This study found that diabetes, postoperative stone residuals, urinary leukocytes ≧ 100 cells/HP, positive urine culture results, ureteral stent indwelling time ≧ 8 weeks, and high S.T.O.N.E. score were independent of AP associated with ureteral stent after PCNL risk factors and Escherichia coli is the main pathogenic bacteria and shows drug resistance.

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.

Learning U-Net Based Multi-Scale Features in Encoding-Decoding for MR Image Brain Tissue Segmentation.

Accurate brain tissue segmentation of MRI is vital to diagnosis aiding, treatment planning, and neurologic condition monitoring. As an excellent convolutional neural network (CNN), U-Net is widely used in MR image segmentation as it usually generates high-precision features. However, the performance of U-Net is considerably restricted due to the variable shapes of the segmented targets in MRI and the information loss of down-sampling and up-sampling operations. Therefore, we propose a novel network by introducing spatial and channel dimensions-based multi-scale feature information extractors into its encoding-decoding framework, which is helpful in extracting rich multi-scale features while highlighting the details of higher-level features in the encoding part, and recovering the corresponding localization to a higher resolution layer in the decoding part. Concretely, we propose two information extractors, multi-branch pooling, called MP, in the encoding part, and multi-branch dense prediction, called MDP, in the decoding part, to extract multi-scale features. Additionally, we designed a new multi-branch output structure with MDP in the decoding part to form more accurate edge-preserving predicting maps by integrating the dense adjacent prediction features at different scales. Finally, the proposed method is tested on datasets MRbrainS13, IBSR18, and ISeg2017. We find that the proposed network performs higher accuracy in segmenting MRI brain tissues and it is better than the leading method of 2018 at the segmentation of GM and CSF. Therefore, it can be a useful tool for diagnostic applications, such as brain MRI segmentation and diagnosing.

How anammox responds to the emerging contaminants: Status and mechanisms.

Numerous researches have been carried out to study the effects of emerging contaminants in wastewater, such as antibiotics, nanomaterials, heavy metals, and microplastics, on the anammox process. However, they are fragmented and difficult to provide a comprehensive understanding of their effects on reactor performance and the metabolic mechanisms in anammox bacteria. Therefore, this paper overviews the effects on anammox processes by the introduced emerging contaminants in the past years to fulfill such knowledge gaps that affect our perception of the inhibitory mechanisms and limit the optimization of the anammox process. In detail, their effects on anammox processes from the aspects of reactor performance, microbial community, antibiotic resistance genes (ARGs), and functional genes related to anammox and nitrogen transformation in anammox consortia are summarized. Furthermore, the metabolic mechanisms causing the cell death of anammox bacteria, such as induction of reactive oxygen species, limitation of substrates diffusion, and membrane binding are proposed. By offering this review, the remaining research gaps are identified, and the potential metabolic mechanisms in anammox consortia are highlighted.

Response of anammox granules to the simultaneous exposure to macrolide and aminoglycoside antibiotics: Linking performance to mechanism.

Antibiotic pollution is becoming increasingly severe due to its extensive use. The potential application of the anaerobic ammonium oxidation (anammox) process in the treatment of wastewater containing antibiotics has attracted much attention. As common antibiotics, spiramycin (SPM) and streptomycin (STM) are widely used to treat human and animal diseases. However, their combined effects on the anammox process remain unknown. Therefore, this study systematically evaluated the response of the anammox process to both antibiotics. The half maximal inhibitory concentrations of SPM and STM were determined. The continuous-flow anammox system could adapt to SPM and STM at low concentrations, while antibiotics at high concentrations exhibited inhibitory effects. When the concentrations reached 5 mg L-1 SPM and 50 mg L-1 STM, the nitrogen removal efficiency dramatically decreased and then rapidly recovered within 8 days. Correspondingly, the abundances of dominant bacteria and genes also changed with antibiotic concentrations. In general, the anammox process showed a stable performance and a high resistance to SPM and STM, suggesting that acclimatization by elevating the concentrations was beneficial for the anammox process to obtain resistance to different antibiotics with high concentrations. This study provides guidance for the stable operation of anammox-based biological treatment of antibiotics containing wastewater.

Chirality Detection by Raman Spectroscopy: The Case of Enantioselective Interactions between Amino Acids and Polymer-Modified Chiral Silica.

In chirality research area, it is of interest to reveal the chiral feature of inorganic nanomaterials and their enantioselective interactions with biomolecules. Although common Raman spectroscopy is not regarded as a direct chirality analysis tool, it is in fact effective and sensitive to study the enantioselectivity phenomena, which is demonstrated by the enantio-discrimination of amino acid enantiomers using the polydopamine-modified intrinsically chiral SiO2 nanofibers in this work. The Raman scattering intensities of an enantiomer of cysteine are more than twice as high as those of the other enantiomer with opposite handedness. Similar results were also found in the cases of cystine, phenylalanine, and tryptophan enantiomers. In turn, these organic molecules could be used as chirality indicators for SiO2, which was clarified by the unique Raman spectra-derived mirror-image relationships. Thus, an indirect chirality detection method for inorganic nanomaterials was developed.

Chiral Plasmonic Nanoparticle Assisted Raman Enantioselective Recognition.

Au nanoparticles (NPs) labeled with the handedness tag of "d-" or "l-", which were detached from inorganic chiral silica, showed both intrinsic chirality and surface enhanced Raman scattering (SERS) activity. In the presence of these chiral Au substrates, it was found that the enantiomer of cystine with the same handedness tag of Au NPs would show stronger Raman scattering signal intensities than those of the enantiomer with the opposite tag, where the differences could be over three times. Consequently, this work afforded a novel enantioselective recognition method on ordinary Raman spectroscopy by using chiral plasmonic metallic nanomaterials.

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.

Spatial power spectrum of natural water turbulence with any average temperature, salinity concentration, and light wavelength.

The power spectrum of water optical turbulence is shown to vary with its average temperature ⟨T⟩ and average salinity concentration ⟨S⟩, as well as with light wavelength λ. This study explores such variations for ⟨T⟩∈[0∘C,30∘C], ⟨S⟩∈[0ppt,40ppt] covering most of the possible natural water conditions within the Earth's boundary layer and for visible electromagnetic spectrum, λ∈[400nm,700nm]. For illustration of the effects of these parameters on propagating light, we apply the developed power spectrum model for estimation of the scintillation index of a plane wave (the Rytov variance) and the threshold between weak and strong turbulence regimes.