Phosphorus removal from wastewater using Ca-modified attapulgite: Fixed-bed column performance and breakthrough curves analysis.

The adsorbent calcium-modified attapulgite (Ca-GAT) prepared by calcium chloride modification and high temperature treatment (700 °C) has proved to remove phosphorus in low-concentration phosphorus wastewater in batch adsorption experiments. Dynamic adsorption performance and industrial application potential still need further determination. This study explored the effects of various parameters on the dynamic phosphorus adsorption, including initial phosphate concentration (2-10 mg/L), flow rate (1-3 mL/min) and adsorption bed height (2-6 cm). Phosphorus adsorption ability improved and the breakthrough time increased with the increase of bed height, flow rate, and a decrease in initial phosphorus concentration. Breakthrough curves fitted four models, the Adams-Bohart, Thomas, Yoon-Nelson and Bed depth service time (BDST). The maximum adsorption amount determined by the Thomas model obtained 13.477 mg/g. The saturated fixed-bed column were regenerated with NaOH, NaOH + NaCl and HCl, among which 0.5 mol/L NaOH had the best regeneration effect. During the utilization of a large fixed-bed to treat the actual membrane bioreactor (MBR) effluent, the breakthrough point (0.5 mg/L) was obtained after 177 h. These results implied that Ca-GAT had an application potential for the treatment of low-concentration phosphorus wastewater (2 mg/L).

Calcium-modified granular attapulgite removed phosphorus from synthetic wastewater containing low-strength phosphorus.

Traditional biological processes combined with chemical precipitation methods can effectively reduce phosphate concentration in wastewater. However, discharge standards required additional advanced treatment technologies, and the removal of low phosphorus concentration is complicated and expensive. This study proposes application of a simple and recyclable adsorbent to remove low-concentration phosphorus from water. The removal efficiency of phosphorus from low-strength synthetic wastewater was investigated and the adsorption mechanism was analyzed. When the initial phosphorus concentration was 2.0 mg/L, the phosphorus adsorption capacity of Ca-GAT increased to 0.891 mg/g from 0.074 mg/g for GAT at 298 K and pH of 7. Phosphorus adsorption on Ca-GAT performs well when the solution pH is in the range of 5-10, and it is not conducive to the adsorption reaction when the solution pH exceeds 11. The competing anions (such as NO3-, SO42-, HCO3- and F-) existed, Ca-GAT still performed better in removing phosphorus. Then, the saturated absorbents could be effectively regenerated with a 0.5 mos/L NaOH solution, while desorption efficiency was reduced from 97.11% to 33.06% after fifth regeneration cycle. Finally, Scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS), Fourier-transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS) analysis demonstrated that the Ca2+ content on the Ca-GAT surface played an important role in capturing phosphate ions from wastewater. Phosphorus was mainly removed via the formation of Ca-phosphorus precipitation. To some extent, ligand exchanges of CO32- and OH- with HPO42- and H2PO4- were also beneficial for phosphorus removal. The present work shows that attapulgite has sustainable and beneficial potential in the removal of low-strength phosphorous in wastewater, and the phosphorus loaded adsorbent can be used in the agriculture as slow-release fertilizer.

Discovery of novel Staphylococcus aureus penicillin binding protein 2a inhibitors by multistep virtual screening and biological evaluation.

Penicillin-binding protein 2a (PBP2a) is an essential protein involved in the resistance to ß-lactam antibiotics acquired by methicillin-resistant Staphylococcus aureus (MRSA) and is a potential antibacterial target. In the current study, we employed a strategy that combined virtual screening with biological evaluation to discover novel inhibitors of PBP2a. In this investigation, a hybrid virtual screening method, consisting of drug-likeness evaluation (Lipinski's Rule of Five and ADMET) and rigid (LibDock) and semi-flexible (CDOCKER) docking-based virtual screenings, was used for retrieving novel PBP2a inhibitors from commercially available chemical databases. 11 compounds were selected from the final hits and subsequently shifted to experimental studies. Among them, Hit 2, Hit 3, and Hit 10 exhibited excellent anti-MRSA ATCC 33591 activity and weak toxicity in vitro. The affinity of the three compounds to bind to PBP2a was further confirmed by surface plasmon resonance (SPR) experiments and molecular dynamics (MD) simulation. An inter-complex interaction study showed that all hit compounds adapted well to the allosteric site of the PBP2a protein. In addition, Hit 2 (with best binding affinity to PBP2a, KD = 1.29 × 10-7 M) significantly inhibits proliferation of MRSA clinical isolates. Together, the 3 hit compounds, especially Hit 2, may be potential non-ß-lactam antibiotics against MRSA and the work will provide clues for the future development of specific compounds that block the interaction of PBP2a with their targets.

Microbiota-Derived Short-Chain Fatty Acids Promote LAMTOR2-Mediated Immune Responses in Macrophages.

ABSRTACTKlebsiella pneumoniae is a common cause of human-pneumonia-derived sepsis with high morbidity and mortality. The microbiota promotes and maintains host immune homeostasis. The mechanisms by which the gut microbiota affects the host defenses in the respiratory system systematically, however, remain poorly understood. Here, we show that gut microbiota depletion increases susceptibility to extracellular K. pneumoniae infections in terms of increased bacterial burdens in lung and decreased survival rates. Oral supplementation with gut microbiota-derived short-chain fatty acids (SCFAs), subsequently activating G protein-coupled receptor 43 (GPCR43), enhances a macrophage's capacity to phagocytose invading K. pneumoniae Furthermore, SCFAs and GPR43 increase macrophage bacterial clearance by upregulating LAMTOR2, which is further identified as an antibacterial effector and elucidated to facilitate phagosome-lysosome fusion and extracellular signal-regulated kinase (ERK) phosphorylation. Lastly, conditional ablation of Lamtor2 in macrophages decreases their antimicrobial activity, even though mice were pretreated with exogenous SCFA supplementation.IMPORTANCE These observations highlight that SCFAs promote macrophage elimination of K. pneumoniae via a LAMTOR2-dependent signal pathway and suggest that it is possible to intervene in K. pneumoniae pneumonia by targeting the gut microbiota.

Near-Infrared-Controlled Nanoplatform Exploiting Photothermal Promotion of Peroxidase-like and OXD-like Activities for Potent Antibacterial and Anti-biofilm Therapies.

Nanozymes that mimic peroxidase (POD) activity can convert H2O2 into bactericidal free radicals, which is referred to as chemodynamic therapy (CDT). High glutathione (GSH) levels in the infectious tissue severely limit the performance of CDT. Herein, we report a near-infrared-controlled antibacterial nanoplatform that is based on encapsulating tungsten sulfide quantum dots (WS2QDs) and the antibiotic vancomycin in a thermal-sensitive liposome. The system exploits the photothermal sensitivity of the WS2QDs to achieve selective liposome rupture for the targeted drug delivery. We determined that WS2QDs show a strong POD-like activity under physiological conditions and the oxidase-like activity, which can oxidate GSH to further improve the CDT efficacy. Moreover, we found that increased temperature promotes multiple enzyme-mimicking activities of WS2QDs. This platform exerts antibacterial effects against Gram-positive Mu50 (a vancomycin-intermediate Staphylococcus aureus reference strain) and Gram-negative Escherichia coli and disrupts biofilms for improved penetration of therapeutic agents inside biofilms. In vivo studies with mice bearing Mu50-caused skin abscess revealed that this platform confers potent antibacterial activity without obvious toxicity. Accordingly, our work illustrates that the photothermal and nanozyme properties of WS2QDs can be deployed alongside a conventional therapeutic to achieve synergistic chemodynamic/photothermal/pharmaco therapy for powerful antibacterial effects.

Effects of a formula with a probiotic Bifidobacterium lactis Supplement on the gut microbiota of low birth weight infants.

PURPOSE: Low birth weight (LBW) infants have a less diverse gut microbiota, enriched in potential pathogens, which places them at high risk of systemic inflammation diseases. This study aimed to identify the differences in gut bacterial community structure between LBW infants who received probiotics and LBW infants who did not receive probiotics. METHODS: Forty-one infants were allocated to the non-probiotic group (N group) and 56 infants to the probiotic group (P group), according to whether the formula they received contained a probiotic Bifidobacterium lactis. Gut bacterial composition was identified with sequencing of the 16S rRNA gene in fecal samples collected at 14 days after birth. RESULTS: There was no significant difference between the alpha diversity of the two groups, while the beta diversity was significantly different (p < 0.05). Our results showed that Bifidobacterium and Lactobacillus (both p < 0.05) were enriched in the P group, while Veillonella, Dolosigranulum and Clostridium sensu stricto 1 (all p < 0.05) were enriched in the N group. Predicted metagenome function analysis revealed enhancement of fatty acids, peroxisome, starch, alanine, tyrosine and peroxisome pathways in the P group, and enhancement of plant pathogen, Salmonella and Helicobacter pylori infection pathways in the N group. CONCLUSIONS: Probiotic supplement in formula may affect the composition, stability and function of LBW infants' gut microbiota. LBW infants who receive probiotic intervention may benefit from gut microbiota that contains more beneficial bacteria.

Associations of blood metal exposure with thyroid hormones in Chinese pregnant women: A cross-sectional study.

BACKGROUND: Few epidemiological studies have investigated associations of exposure to multiple metals with thyroid hormone homeostasis, especially for the pregnant women. METHODS: Among all the 1644 participants enrolled in Hangzhou Birth Cohort Study (HBCS) at baseline, a total of 915 pregnant women with complete data of interest were analyzed. Eleven metals were measured in blood samples collected around 25 weeks gestation. Serum levels of thyroid hormones including free triiodothyronine (FT3), total triiodothyronine (TT3), free thyroxine (FT4), total thyroxine (TT4) and thyroid-stimulating hormone (TSH) were abstracted from the medical records. Relationships between tertiles of metal levels (setting the lowest tertile as the reference) and percent changes in thyroid hormones were estimated by multivariable adjusted linear regression models. RESULTS: Five metals [arsenic (As), selenium (Se), manganese (Mn), nickel (Ni), antimony (Sb)] were significantly linked to decreased levels of one or more thyroid hormones based on trend tests in the single-metal models. Percent changes [95% confidence intervals (CIs)] in thyroid hormones for the third tertiles of metals remained significant between FT3 and As [-3.53% (-5.48%, -1.54%)]; and between TT3 and As [-4.19% (-7.00%, -1.31%)]; and between FT4 and Mn [-2.05% (-3.49%, -0.58%)], Sb [-1.99% (-3.44%, -0.52%)] in the multiple-metal models. CONCLUSIONS: Thyroid hormone concentrations were reversely related to the levels of blood metals of As, Mn and Sb among Chinese pregnant women. Additional prospective studies are warranted to confirm the causality. Paper capsule: Exposure to multiple metals was reversely associated with one or more thyroid hormones in the Chinese pregnant women.

An unusual sesquiterpene coumarin from the seeds of Ferula sinkiangensis.

A sesquiterpene coumarin, sinkiangenorin E, consisting of a novel bicyclo[4.3.1]decane-type sesquiterpene system, was isolated from the seeds of Ferula sinkiangensis. The structure of sinkiangenorin E including the relative stereochemistry and the absolute configuration was elucidated on the basis of spectroscopic data. The new compound showed cytotoxic activity against AGS cells (IC50, 12.7 µM) and inhibiting effect against influenza A H1N1 (IC50, 4.0 µM), which provided important clues for the study on the bioactivities of this type of sesquiterpene coumarins.

[HPLC Fingerprint and Determination in the Root of Amorpha fruticosa].

Objective: To establish HPLC fingerprint in the root of Amorpha fruticosa, and simultaneously to determine the content of calycosin-7-O-ß-D-glucopyranoside, ononin, calycosin, formononetin. Methods: The analytical column was Diamonsil C18( 250 mm ×4. 6 mm,5 µm). The mobile phase was acetonitrile( A)-water( B)( containing 0. 2% phosphoric acid) in gradient elution, and the detection wavelength was set at 260 nm. "Chromatographic fingerprint similarity evaluation software "version( 2004A) was used to evaluate similarity for the ten batches medicinal materials,and SPSS software was used for cluster analysis. Results: The HPLC fingerprint of the root of Amorpha fruticosa was established with good separation, and four chemical compositions were determinated. 16 common peaks were defined in the HPLC fingerprint among the 10 batches of the root of Amorpa fruticosa. The similarity among them was more than0. 90. Conclusion: This analytical method has strong features,with a good repeatability and the method is simple, which can be used efficiently in the quality control in the root of Amorpha fruticosa.

Antiobesity activity of aqueous extracts of Rhizoma Dioscoreae Tokoronis on high-fat diet-induced obesity in mice.

We examined the effects of Rhizoma Dioscoreae Tokoronis extracts (RDTEs) on plasma lipids, body weight, and lipogenic enzymes. Mice were administered a standard chow diet, a 60% high-fat diet, or a high-fat diet with RDTE. Mice that were fed a high-fat diet containing RDTE were found to have lower increases in body and epididymal adipose tissue weights and a lessened occurrence of hepatic steatosis than mice that were fed a high-fat diet. The decreased adiposity that was induced by RDTE accounted for lower plasma levels of tumor necrosis factor-alpha, leptin, and glucose and a higher level of adiponectin. RDTE administration also resulted in a significant decrease in triglyceride, total plasma cholesterol, and low-density lipoprotein-cholesterol when compared to the high-fat group. To identify the mechanism by which RDTE induced its antiobesity effect, we investigated the sterol response element binding protein (SREBP) transcription system, which was induced in mice that were fed the high-fat diet. RDTE was found to suppress the expression of SREBP-1 as well as that of fatty acid synthase in adipose and liver tissues in mice provided the high-fat diet. These findings suggest that the antiobesity action of RDTE in mice that are fed a high-fat diet may occur in response to suppression of the SREBP-1-dependent lipogenic pathway.

Effect of Angelica gigas extract on melanogenesis in B16 melanoma cells.

During the screening of herbs for inhibition of melanogenesis, it was observed that ethanolic extract of Angelicae Gigantis Radix (AGE) effectively inhibited isobutylmethylxanthine-induced melanogenesis in B16 melanoma cells. The melanin content was significantly decreased by AGE in a dose-dependent manner, and no cytotoxicity was observed at the effective concentrations. Decreased melanin content was accompanied by reduced enzyme activity as well as reduced expression of tyrosinase protein and mRNA. The level of tyrosinase-related protein 1 and 2 mRNAs was also decreased by AGE. Additionally, AGE effectively inhibited alpha-melanocyte stimulating hormone- and forskolin-induced melanogenesis, and downregulated the mRNA expression of microphthalmia-associated transcription factor, a master transcriptional regulator of melanogenic genes. These results suggest that AGE acts as a putative hypopigmenting agent through downregulation of tyrosinase expression induced via a cAMP-dependent pathway.

Radix asari extract protects pancreatic beta cells against cytokine-induced toxicity: implication of the NF-kappaB-iNOS signaling cascade.

In this study, we assessed the preventive effects of Radix asari extract (RAE) against cytokine-induced beta-cell destruction. Cytokines secreted by immune cells that have infiltrated pancreatic islets are crucial mediators of beta-cell destruction in insulin-dependent diabetes mellitus. Treatment of RINm5F (RIN) cells with interleukin (IL)-1beta and interferon (IFN)-gamma resulted in a reduction of cell viability and proliferation. However, treatment of RIN cells with RAE protected the IL-1beta and IFN-gamma- mediated viability and proliferation reduction in a concentration-dependent manner. Incubation with RAE also resulted in significant suppression of IL-1beta and IFN-gamma-induced nitric oxide (NO) production, and this reduction was correlated with reduced levels of mRNA and protein associated with the inducible form of NO synthase (iNOS). The molecular mechanism by which RAE inhibited iNOS gene expression appeared to involve the inhibition of NF-kappaB activation as a result of RAE's suppression of IL-1beta and IFN-gamma-induced IkappaBalpha degradation. The protective effects of RAE were verified via the observation of reduced NO generation and iNOS expression, as well as the observation of normal insulin-secretion responses to glucose in IL-1beta and IFN-gamma-treated rat islets. These results suggest that RAE protects beta cells from cytokine toxicity by suppression of NF-kappaB activation.

Coptidis rhizoma extract protects against cytokine-induced death of pancreatic beta-cells through suppression of NF-kappaB activation.

We demonstrated previously that Coptidis rhizoma extract (CRE) prevented S-nitroso-N-acetylpenicillamine-induced apoptotic cell death via the inhibition of mitochondrial membrane potential disruption and cytochrome c release in RINm5F (RIN) rat insulinoma cells. In this study, the preventive effects of CRE against cytokine-induced beta-cell death was assessed. Cytokines generated by immune cells infiltrating pancreatic islets are crucial mediators of beta-cell destruction in insulin-dependent diabetes mellitus. The treatment of RIN cells with IL-1beta and IFN-gamma resulted in a reduction of cell viability. CRE completely protected IL-1beta and IFN-gamma-mediated cell death in a concentration-dependent manner. Incubation with CRE induced a significant suppression of IL-1beta and IFN-gamma-induced nitric oxide (NO) production, a finding which correlated well with reduced levels of the iNOS mRNA and protein. The molecular mechanism by which CRE inhibited iNOS gene expression appeared to involve the inhibition of NF-kappaB activation. The IL-1beta and IFN-gamma-stimulated RIN cells showed increases in NF-kappaB binding activity and p65 subunit levels in nucleus, and IkappaB alpha degradation in cytosol compared to unstimulated cells. Furthermore, the protective effects of CRE were verified via the observation of reduced NO generation and iNOS expression, and normal insulin-secretion responses to glucose in IL-1beta and IFN-gamma-treated islets.

Inhibitory effect of Artemisia capillaris extract on cytokine-induced nitric oxide formation and cytotoxicity of RINm5F cells.

Cytokines produced by immune cells infiltrating pancreatic islets are important mediators of beta-cell destruction in insulin-dependent diabetes mellitus. Cytokines stimulate an inducible form of nitric oxide synthase (iNOS) expression and nitric oxide (NO) production, leading to insulin insufficiency. In the present study, the effects of Artemisia capillaris extract (ACE) on cytokine-induced beta-cell damage were examined. Treatment of RINm5F (RIN) rat insulinoma cells with interleukin-1beta (IL-1beta) and interferon-gamma (IFN-gamma) induced cell damage. ACE completely protected IL-1beta and IFN-gamma-mediated cytotoxicity in a concentration-dependent manner. Incubation with ACE resulted in a significant reduction in IL-1beta and IFN-gamma-induced NO production, a finding that correlated well with reduced levels of the iNOS mRNA and protein. The molecular mechanism by which ACE inhibited iNOS gene expression appeared to involve the inhibition of NF-kappaB activation. The IL-1beta and IFN-gamma-stimulated RIN cells showed increases in NF-kappaB binding activity and p65 subunit levels in the nucleus, and IkappaBalpha degradation in cytosol compared to unstimulated cells. Furthermore, ACE restored the cytokine-induced inhibition of insulin release from isolated islets. These results suggest that ACE protects beta-cells by suppressing NF-kappaB activation.