Intra-articular Histone Deacetylase Inhibitor Microcarrier Delivery to Reduce Osteoarthritis.

The histone deacetylase inhibitor (HDACi) was a milestone in the treatment of refractory T-cell lymphoma. However, the beneficial effects of HDACi have not been appreciated in osteoarthritis (OA). Herein, we implemented a microcarrier system because of the outstanding advantages of controlled and sustained release, biodegradability, and biocompatibility. The poly(d,l-lactide-co-glycolide) (PLGA) microcapsules have a regulated and sustained release profile with a reduced initial burst release, which can improve the encapsulation efficiency of the Chidamide. The emulsion solvent evaporation strategy was used to encapsulate Chidamide in PLGA microcapsules. The encapsulation of Chidamide was established by UV-vis spectra and scanning electron microscopy. Additionally, the inhibition of Tnnt3 and immune stimulation by Chidamide helped to inhibit cartilage destruction and prevent articular cartilage degeneration. Based on the results, the Chidamide in PLGA microcapsules provides a transformative therapeutic strategy for the treatment of osteoarthritis patients to relieve symptoms and protect against cartilage degeneration.

Tibial Tubercle Osteotomy May Not Provide Additional Benefit in Treating Patellar Dislocation With Increased Tibial Tuberosity-Trochlear Groove Distance: A Systematic Review.

PURPOSE: To examine the indications and outcomes of medial patellofemoral ligament reconstruction (MPFLR) with or without tibial tubercle osteotomy (TTO) in treating recurrent or habitual patellar dislocation with an increased tibial tuberosity-trochlear groove (TT-TG) distance. METHODS: We performed a literature search of the established medical databases Cochrane Central, PubMed-MEDLINE, EMBASE, and Web of Science. The inclusion criteria were as follows: skeletally mature patients with recurrent or habitual patellar dislocation and an increased TT-TG distance, treatment with MPFLR combined with a TTO procedure or isolated MPFLR, and reporting of clinical outcomes and complications. Each study was assessed for quality and the level of evidence. The general characteristics, indications, surgical techniques, TT-TG distance, clinical results, imaging evaluation findings, and complications of each study were recorded. RESULTS: Nine studies consisting of 288 knees met the inclusion criteria. The average Coleman score was 71.56 (range, 55-83). The threshold for an increased TT-TG distance ranged from 16 to 20 mm in the included studies. Similar good postoperative outcomes were reported in patients with an increased TT-TG distance treated with MPFLR with versus without a TTO procedure. The mean postoperative Lysholm score ranged from 75.0 to 94.7 (I2 = 87.6%) in the isolated MPFLR group and from 85.0 to 87.6 (I2 = 16.3%) in the TTO-with-MPFLR group. Similar postoperative congruence angles were reported in both groups. The postoperative redislocation rate ranged from 0% to 4.2% in the TTO-with-MPFLR group, and no redislocation was found in the isolated MPFLR group. The postoperative apprehension sign was only reported in isolated MPFLR patients. CONCLUSIONS: The outcomes of MPFLR with or without TTO to treat recurrent or habitual patellar dislocation with an increased TT-TG distance appeared similar. However, this study was limited by the considerable heterogeneity, variety of techniques, variety of TT-TG distances, and variability in patella alta and trochlear dysplasia among the included studies. LEVEL OF EVIDENCE: Level IV, systematic review of Level II to IV studies.

Synthesis and Antitumor Activity of Novel Arylpiperazine Derivatives Containing the Saccharin Moiety.

Prostate cancer is a major public health problem worldwide. For the development of potential anti-prostate cancer agents, a series of novel arylpiperazine derivatives containing the saccharin moiety based on previous studies was designed, synthesized, and evaluated in prostate (PC-3, LNCaP, and DU145) cancer cell lines for their anticancer activities. The majority of the compounds exhibited excellent selective activity for the tested cancer cells. Compounds 4 and 12 exhibited strong cytotoxic activities against DU145 cells (half maximal inhibitory concentration (IC50) < 2 µM). The structure-activity relationship (SAR) of these arylpiperazine derivatives was also discussed based on the obtained experimental data. This work provides a potential lead compound for anticancer agent development focusing on prostate cancer therapy.

Design, synthesis and biological evaluation of novel arylpiperazine derivatives on human prostate cancer cell lines.

A series of novel arylpiperazine derivatives was synthesized. The in vitro cytotoxic activities of all synthesized compounds against three human prostate cancer cell lines (PC-3, LNCaP, and DU145) were evaluated by a CCK-8 assay. Compounds 10, 24 and 29 exhibited strong cytotoxic activities against LNCaP cells (IC50 <3µM). In addition, these compounds exhibited weak cytotoxic effects on human epithelial prostate normal cells RWPE-1. The structure-activity relationship (SAR) of these arylpiperazine derivatives was also discussed based on the obtained experimental data.

[Chemical Constitutes from Seeds of Plantago asiatica].

OBJECTIVE: To study the chemical constituents of Plantago asiatica seeds. METHODS: The constituents were isolated from the seeds of Plantago asiatica by column chromatography over silica gel, MCI gel, macroporous resin HP-20, Sephadex LH-20, Polyamide and by preparative HPLC. Their structures were elucidated by analysis of physical and chemical properties and spectral data. RESULTS: Five compounds were isolated and their structures were identified as acteoside (1), isoacteoside (2), decaffeoylacteoside (3), tetradecanoic acid (4), and bis (2-ethythexyl) benzene-1,2-dicarboxylate (5). CONCLUSION: Compound 5 is isolated from Plantaginaceae for the first time. Compounds 3 and 4 are firstly characterized in Plantago asiatica.

Arene-Arene Coupled Disulfamethazines (or Sulfadiazine)-Phenanthroline-Metal(II) Complexes were Synthesized by In Situ Reactions and Inhibited the Growth and Development of Triple-Negative Breast Cancer through the Synergistic Effect of Antiangiogenesis, Anti-Inflammation, Pro-Apoptosis, and Cuproptosis.

The novel metal(II)-based complexes HA-Cu, HA-Co, and HA-Ni with phenanthroline, sulfamethazine, and aromatic-aromatic coupled disulfamethazines as ligands were synthesized and characterized. HA-Cu, HA-Co, and HA-Ni all showed a broad spectrum of cytotoxicity and antiangiogenesis. HA-Cu was superior to HA-Co and HA-Ni, and even superior to DDP, showing significant inhibitory effect on the growth and development of tripe-negative breast cancer in vivo and in vitro. HA-Cu exhibited observable synergistic effects of antiproliferation, antiangiogenesis, anti-inflammatory, pro-apoptosis, and cuproptosis to effectively inhibited tumor survival and development. The molecular mechanism was confirmed that HA-Cu could downregulate the expression of key proteins in the VEGF/VEGFR2 signaling pathway and the expression of inflammatory cytokines, enhance the advantage of pro-apoptotic protein Bax, and enforce cuproptosis by weakening the expression of FDX1 and enhancing the expression of HSP70. Our research will provide a theoretical and practical reference for the development of metal-sulfamethazine and its derivatives as chemotherapy drugs for cancer treatment.

The meniscotibial ligament does exist: An anatomic and histological description.

Purpose: To describe the anatomical and histological characteristics of the human MTL (meniscotibial ligament) that keeps the meniscus stable and are rarely discussed. Study design: Descriptive laboratory study. Methods: In total, six fresh-frozen adult cadaver knees were dissected, and the dissection protocol were designed by two experienced anatomy professors. The anatomical morphology of MTL was observed. The main anatomical specimens included meniscus, tibial plateau, MTL. The osteotome was used to excise the portion of the tibial plateau, which could obtain the complex including partial meniscus, MTL, and a tibial fragment. A histopathologic study was performed by two experienced pathologists. Results: Macroscopically, the MTL could be divided into two parts: medial meniscotibial ligament (MMTL)and lateral meniscotibial ligament (LMTL). The MMTL is distributed continuously, whereas the LMTL is discontinuous on the tibial plateau. The average length from the tibial attachment of the LMTL to the articular surface was 19 ± 1.0mm (mean ± SD). The average length from the tibial attachment of the MMTL to the articular surface was 10 ± 1.2 mm (mean ± SD). Microscopy of the MTL showed that the MTL is a ligamentous tissue, composed of a network of oriented collagenous fibers. Conclusions: In all knees, the MTL was inserted on the outer edge of the meniscus, attaching to the tibia below the level of articular cartilage, which was key to maintaining the rotational stability of knee and the meniscus in the physiological position on the tibial plateau. Histological analysis of this ligament demonstrated that the MTL is a veritable ligamentous structure, which is made up of collagen type I-expressing fibroblasts. Clinical relevance: This article contributes to the understanding of the anatomical and histological characteristics of the MTL. It is beneficial to promote the development of relevant surgical techniques for the MTL lesion.

Syntheses, crystal structures of copper (II)-based complexes of sulfonamide derivatives and their anticancer effects through the synergistic effect of anti-angiogenesis, anti-inflammation, pro-apoptosis and cuproptosis.

Three novel copper(II)-based complexes Cu-1, Cu-2, and Cu-3 containing sulfamethoxazole or sulfamethazine ligand were obtained, and their single structures were characterized. Both Cu-1 and Cu-3 show a broad spectrum of cytotoxicity than Cu-2, and Cu-1 is more cytotoxic than Cu-3. What's interesting is that Cu-1 can exhibit obvious inhibitory effect on the growth of human triple-negative breast cancer in vivo and vitro through anti-proliferative, anti-angiogenic, anti-inflammatory, pro-apoptotic and cuproptotic synergistic effects. Though Cu-3 shows no significant cytotoxicity against MDA-MB-231 cells, it can significantly inhibit the growth of SKOV3 cells in vitro by down-regulating the expression of some key proteins in the VEGF/VEGFR2 signaling pathway and the expression of some pro-inflammatory cytokines, and by disrupting the balance of intracellular reactive oxygen species levels.

A novel chiral oxazoline copper(II)-based complex inhibits ovarian cancer growth in vitro and in vivo by regulating VEGF/VEGFR2 downstream signaling pathways and apoptosis factors.

A novel chiral oxazoline copper(II)-based complex {[Cu(C13H14NO3S)2]}2 (Cu-A) was synthesized by an in situ reaction using L-methioninol, 4-hydroxyisophthalaldehyde, sodium hydroxide and copper(II) nitrate trihydrate as reactants. Its crystal structure was characterized. In vitro, Cu-A was superior to cis-dichlorodiammineplatinum (DDP) in cytotoxicity and angiogenesis inhibition. Cu-A significantly induced apoptosis of ovarian cancer cells (SKOV3) and human umbilical vein endothelial cells (HUVECs), showing significant anti-ovarian cancer and anti-angiogenesis effects. Notably, Cu-A significantly inhibits the growth of ovarian cancer in nude mice xenografted with SKOV3 cells, and it is less renal toxic than DDP. The molecular mechanism of anti-ovarian cancer and anti-angiogenesis is possibly that it down-regulates the expression of the proteins ERK1/2, AKT, FAK, and VEGFR2 and their phosphorylated proteins p-ERK1/2, p-AKT, p-FAK, and p-VEGFR2 in the VEGF/VEGFR2 signal transduction pathway to inhibit SKOV3 cell and HUVEC proliferation, induce apoptosis, suppress migration and metastasis, and inhibit angiogenesis. What's more, Cu-A significantly inhibits ovarian tumor growth in vivo by inhibiting tumor cells from inducing vascular endothelial cells to form their own vasculature and by inhibiting the expression of the anti-apoptotic protein Bcl-2 and up-regulating the expression of the pro-apoptotic proteins Caspase-9 and Bax to induce apoptosis of tumor cells.

Study on feasibility of the partial meniscal allograft transplantation.

Since the meniscus is an important stabilizing structure of the knee joint and has a significant role in load-bearing and shock absorption, so the complete structural and functional reconstructions of the teared menisci should be done not only after partial meniscectomy but also post total meniscectomy. So far, animal experiments and good clinical practice have showed that TMAT after total meniscectomy has partially solved the problem of structural and functional reconstructions after total meniscectomy. However, partial meniscectomy will also lead to accelerated knee degeneration, and its proportion is much higher than that of patients with total meniscectomy. Herein, the feasibility of PMAT after partial meniscectomy was investigated for the first time by using the 40% posterior horn meniscectomy model of the medial meniscus in Beagle dogs, and also for the first time, TMAT group and the total meniscectomy group were used as control groups. Compared with the TMAT, the transcriptomics evaluation, scanning electron microscope observation, histological regeneration and structure, biomechanical property, inflammation environment, and the knee function post PMAT were more similar to that of normal meniscus was first reported. This study provides a PMAT scheme with clinical translational value for the complete structural and functional reconstruction of the patients with partial meniscectomy and fills the gap in the field of teared meniscus therapy on the basis of quite well clinical applications of the meniscus repair and the TMAT.

MicroRNA-210-3p Promotes Chondrogenic Differentiation and Inhibits Adipogenic Differentiation Correlated with HIF-3α Signalling in Bone Marrow Mesenchymal Stem Cells.

Cartilage injury of the knee joint is very common. Due to the limited self-healing ability of articular cartilage, osteoarthritis is very likely to occur if left untreated. Bone marrow mesenchymal stem cells (BMMSCs) are widely used in the study of cartilage injury due to their low immunity and good amplification ability, but they still have disadvantages, such as heterogeneous undifferentiated cells. MicroRNAs can regulate the chondrogenic differentiation ability of MSCs by inhibiting or promoting mRNA translation and degradation. In this research, we primarily investigated the effect of microRNA-210-3p (miR-210-3p) on chondrogenic and adipogenic differentiation of BMMSCs in vitro. Our results demonstrate that miR-210-3p promoted chondrogenic differentiation and inhibited adipogenic differentiation of rat BMMSCs, which was related to the HIF-3α signalling pathway. Additionally, miR-210-3p promotes mRNA and protein levels of the chondrogenic expression genes COLII and SOX9 and inhibits mRNA and protein levels of the adipogenic expression genes PPARγ and LPL. Thus, miR-210-3p combined with BMMSCs is a candidate for future clinical applications in cartilage regeneration and could represent a promising new therapeutic target for OA.

Advances in the Application of Supramolecular Hydrogels for Stem Cell Delivery and Cartilage Tissue Engineering.

Cartilage defects pose a great threat to the health of the aging population. Cartilage has limited self-regeneration ability because it lacks blood vessels, nerves and lymph. To achieve efficient cartilage regeneration, supramolecular hydrogels are used in medical applications and tissue engineering as they are tunable and reversible in nature. Moreover, they possess supramolecular interactions which allow the incorporation of cells. These hydrogels present great potential for tissue engineering-based therapies. This review presents advances in the development of stem cell-laden supramolecular hydrogels. We discuss new possibilities for stem cell therapy and their uses in cartilage tissue engineering. Gray areas and future perspectives are discussed.

The Use of Peripheral Blood-Derived Stem Cells for Cartilage Repair and Regeneration In Vivo: A Review.

BACKGROUND: Peripheral blood (PB) is a potential source of chondrogenic progenitor cells that can be used for cartilage repair and regeneration. However, the cell types, isolation and implantation methods, seeding dosage, ultimate therapeutic effect, and in vivo safety remain unclear. METHODS: PubMed, Embase, and the Web of Science databases were systematically searched for relevant reports published from January 1990 to December 2019. Original articles that used PB as a source of stem cells to repair cartilage in vivo were selected for analysis. RESULTS: A total of 18 studies were included. Eight human studies used autologous nonculture-expanded PB-derived stem cells (PBSCs) as seed cells with the blood cell separation isolation method, and 10 animal studies used autologous, allogenic or xenogeneic culture-expanded PB-derived mesenchymal stem cells (PB-MSCs), or nonculture-expanded PBSCs as seed cells. Four human and three animal studies surgically implanted cells, while the remaining studies implanted cells by single or repeated intra-articular injections. 121 of 130 patients (in 8 human clinical studies), and 230 of 278 animals (in 6 veterinary clinical studies) using PBSCs for cartilage repair achieved significant clinical improvement. All reviewed articles indicated that using PB as a source of seed cells enhances cartilage repair in vivo without serious adverse events. CONCLUSION: Autologous nonculture-expanded PBSCs are currently the most commonly used cells among all stem cell types derived from PB. Allogeneic, autologous, and xenogeneic PB-MSCs are more widely used in animal studies and are potential seed cell types for future applications. Improving the mobilization and purification technology, and shortening the culture cycle of culture-expanded PB-MSCs will obviously promote the researchers' interest. The use of PBSCs for cartilage repair and regeneration in vivo are safe. PBSCs considerably warrant further investigations due to their superiority and safety in clinical settings and positive effects despite limited evidence in humans.

Low-Molecular-Weight Heparin-Functionalized Chitosan-Chondroitin Sulfate Hydrogels for Controlled Release of TGF-ß3 and in vitro Neocartilage Formation.

Repair of hyaline cartilage remains a huge challenge in clinic because of the avascular and aneural characteristics and the paucity of endogenous repair cells. Recently, tissue engineering technique, possessing unique capacity of repairing large tissue defects, avoiding donor complications and two-stage invasive surgical procedures, has been developed a promising therapeutic strategy for cartilage injury. In this study, we incorporated low-molecular-weight heparin (LMWH) into carboxymethyl chitosan-oxidized chondroitin sulfate (CMC-OCS) hydrogel for loading transforming growth factor-ß3 (TGF-ß3) as matrix of peripheral blood mesenchymal stem cells (PB-MSCs) to construct tissue-engineered cartilage. Meanwhile, three control hydrogels with or without LMWH and/or TGF-ß3 were also prepared. The gelling time, microstructures, mechanical properties, degradation rate, cytotoxicity, and the release of TGF-ß3 of different hydrogels were investigated. In vitro experiments evaluated the tri-lineage differentiation potential of PB-MSCs, combined with the proliferation, distribution, viability, morphology, and chondrogenic differentiation. Compared with non-LMWH-hydrogels, LMWH-hydrogels (LMWH-CMC-OCS-TGF-ß3) have shorter gelling time, higher mechanical strength, slower degradation rate and more stable and lasting release of TGF-ß3. After two weeks of culture in vitro, expression of cartilage-specific genes collagen type-2 (COL-2) and aggrecan (AGC), and secretion of glycosaminoglycan (GAG), and COL-2 proteins in LMWH-CMC-OCS-TGF-ß3 group were significantly higher than those in other groups. COL-2 immunofluorescence staining showed that the proportion of COL-2 positive cells and immunofluorescence intensity in LMWH-CMC-OCS-TGF-ß3 hydrogel were significantly higher than those in other groups. The LMWH-CMC-OCS-TGF-ß3 hydrogel can slowly release TGF-ß3 in a long term, and meanwhile the hydrogel can provide a biocompatible microenvironment for the growth and chondrogenic differentiation of PB-MSCs. Thus, LMWH functionalized CMC-OCS hydrogels proposed in this work will be beneficial for constructing functional scaffolds for tissue-engineered cartilage.

Kinetics and mechanism of degradation of p-chloronitrobenzene in water by ozonation.

The kinetics and mechanism of p-chloronitrobenzene (pCNB) degradation by ozone were investigated. With reference compounds, nitrobenzene (NB) and chlorobenzene (CB), reaction rate constants of pCNB with O3 and OH were measured by means of competition kinetics (mixtures of pCNB and NB, or pCNB and CB), with the rate constants being, 1.6 L mol(-1) s(-1), 2.6 x 10(9) L mol(-1) s(-1), respectively. During the ozonation process of pCNB, an increase of chloride and nitrate ions in the water sample solution was observed, which is consistent with the decrease in pCNB concentration. But the total organic carbon (TOC) removal rate is not consistent with the pCNB elimination rate indicating only part of pCNB was mineralized and thus presumably some intermediate products were formed. The pCNB degradation intermediate products were analyzed by gas chromatography-mass spectrometry (GC-MS), liquid chromatography-mass spectrometry (LC-MS), high performance liquid chromatography (HPLC) and ion chromatography (IC). The main intermediate products were phenol, p-chlorophenol, p-nitrophenol, 2-chloro-5-nitrophenol, 5-chloro-2-nitrophenol, 5-nitro-catechol, para-benzoquinone, 5-nitro-1,2,3-trihydroxy phenol, trihydroxy semiquinone, glycolic acid, oxalic acid, hydroxybutanoic acid, mesoxalic acid, tartrouic acid, malonic acid, maleic acid, hydroxymalonic acid, tartaric acid, malic acid, ketoglutaric acid and muconic acid. From the identified reaction products, a possible degradation pathway for the ozonation of pCNB has been proposed.

[Preparation of red mud loaded Co catalysts: optimization using response surface methodology (RSM) and activity evaluation].

The removal efficiency of catalytic ozonation of bezafibrate (BZF) by red mud loaded Co catalysts (Co/RM) was used as the index value in statistical experimental designs. The most important factors influencing BZF degradation (P < 0.05) in water were dipping mass of cobalt and calcination temperature. Under the conditions of 4.14% of dipping mass of cobalt and 389 degrees C of calcination temperature, the BZF removal efficiency was 71.29% as calculated by predictive value and a maximum removal efficiency of 70.74% was actually achieved. The experiment data was very close to the predictive value and the deviation was 1% (< 5%). The results indicated that the response surface methodology and mathematical model was reliable for experimental design. By comparing the differences of BZF degradation in RM and Co/RM processes, it was observed that Co/RM exhibited the greater catalytic activity. Furthermore, the surface structure and composition properties of the two catalysts were evaluated by N2 adsorption, XRD and UV-Vis analysis. It was found that the specific surface area and total pore volume had the same variation trend, RM < Co/RM, which was consistent with the trend of catalytic ozonation. It was also found that Co3O4, the active component formed on the surface of RM by the addition of cobalt into red mud, enhanced the catalytic activity. Moreover, the dissolved metal concentration in the solution for catalytic ozonation of BZF degradation by RM or Co/RM was determined by ICP-OES. The results showed that for both catalysts there was no leaching of catalytic active components into the solution, which could suggest that the two catalysts were safe and could have certain application prospect.

[Catalytic ozonation of nitrobenzene in water by acidification-activated red mud].

Red mud as one kind of aluminum industrial wastes was used as raw material for catalyst preparation. It was activated by acidification in order to enhance its catalytic activity in the system of catalytic ozonation. Furthermore, removal performance and reaction mechanism in degradation of organic pollutants were discussed. Results showed that acid modified red mud had more significant catalytic activity than the raw red mud. The removal efficiency of nitrobenzene by catalytic ozonation with acidified red mud (RM6.0) increased with the increasing ozone concentration. When the ozone concentration was increased from 0.4 mg x L(-1) to 1.7 mg x L(-1), the removal efficiency of nitrobenzene increased from 45% to 92%. There was a consistent effect of water pH on the removal efficiency and the ozone concentration variation. The variation of the removal efficiency depended on the initial water pH. This was because the concentration of OH(-) led to ozone decomposition to generate hydroxyl radicals. The higher water pH value led to the quenching of hydroxyl radicals, resulting in the reduction of catalytic activity of RM6.0. The experimental results of aqueous ozone concentration variation in the presence of RM6.0 and inhibition by hydroxyl radicals indicated that the main reaction mechanism was catalytic ozonation of NB. Firstly, aqueous ozone was absorbed onto the surface of RM6.0, and then the concentrated ozone oxidized NB in water which was with a combination of direct and indirect oxidation. In catalytic reaction, hydroxyl radicals were present, which were generated during the oxidation of NB on the surface of RM6.0.

[Efficiency of photodecomposition of trace NDMA in water by UV irradiation].

Efficiency of photodecomposition of trace NDMA by UV irradiation was investigated with analyzing the initial concentration of NDMA, solution pH, irradiation area, irradiation intensity and water quality effect on NDMA photolysis. NDMA could be effectively photodegraded by UV irradiation. The removal efficiency of NDMA was 97.5% after 5 min of UV irradiation. Effect of initial NDMA concentration on photodecomposition of NDMA was not remarkable. With pH value ascending, the removal rate of NDMA photodecomposition decreased. The yields of photoquantum were more under lower solution pH than that under higher pH. NDMA had fastest reaction rate at solution pH = 2.2. Removal efficiency of NDMA increased with the available irradiation area ascending. Increscent ultraviolet irradiation intensity was good for NDMA degradation. Water quality affected the removal of NDMA slightly. The removal efficiency of NDMA in tap water and Songhua River raw water were 96.7% and 94.8%, respectively.

[Control on products of NDMA degradation by UV/O3].

Comparison experiments of two advanced oxidation processes, UV/O3 and UV/H2O2, were carried out to evaluate their degradation effect of N-nitrosodimethylamine (NDMA) and controlling effect of dimethylamine (DMA) formation. The results showed that UV/H2O2 could enhance NDMA degradation, but could not control on the formation of DMA. UV/O3 was not only effective for NDMA degradation, but also was good at controlling on DMA formation. Furthermore, factors affecting the formation of DMA during degradation of NDMA by UV/O3 were studied. The formation of DMA decreased with O3 dosage increasing and DMA was 0.98 mg x L(-1) with 7.7 mg x L(-1) NDMA and 6.64 mg x L(-1) O3 dose. Solution pH had obvious effect on controlling of DMA formation during degradation of NDMA by UV/O3 . The formation of DMA lightly increased with pH increasing from acid to neutral but dramatically decreased in basic aqueous solution. The formation of DMA was only 0.3 mg x L(-1) when the initial concentration of NDMA was 7.7 mg x L(-1) under pH = 11.0 condition. UV/O3 had better controlling of DMA formation with lesser initial concentration of NDMA.

[Gamma-Al2O3 catalyzed ozonation for removing taste and odor substance 2-methylisoborneol in drinking water].

gamma-Alumina was used as a catalyst in ozonation, and efficiency and influencing factors in degradation of taste and odor substance 2-methylisoborneol (MIB) in drinking water were studied. The result shown that gamma-alumina was activated in catalytic ozonation for degradation MIB not only in distilled water, but also in tap water. In distilled water condition, catalyzed ozonation could enhance 47% removal efficiency; in tap water condition, catalyzed ozonation could increase 40% removal efficiency. The concentration of ozone, gamma-alumina, MIB can affect the degradation of MIB observably. gamma-Alumina catalyzed ozonation for removing MIB did not depend on rigidity in water, but was affected by inorganic negative ions. By capturing the hydroxyl radicals produced by gamma-alumina catalyzed ozone decomposition, the bicarbonate/carbonate in natural water can restrain the effect of gamma-alumina catalyzed ozonation for degradation of MIB. Lower concentration of humic acid can promote the effect of oxidation of the MIB, but higher concentration of humic acid may reduce the efficiency. As pH values can affect the process of catalyzed ozonation and tert-butyl alcohol can inhibit the efficiency of catalyzed ozonation efficiency of MIB, the mechanism of gamma-alumina enhanced ozone oxidation of MIB can be identified as that gamma-alumina catalyzed ozone to decompose into hydroxyl radicals which further break up the molecule of MIB.